1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * Generic hugetlb support. 46d49e352SNadia Yvette Chambers * (C) Nadia Yvette Chambers, April 2004 51da177e4SLinus Torvalds */ 61da177e4SLinus Torvalds #include <linux/list.h> 71da177e4SLinus Torvalds #include <linux/init.h> 81da177e4SLinus Torvalds #include <linux/mm.h> 9e1759c21SAlexey Dobriyan #include <linux/seq_file.h> 101da177e4SLinus Torvalds #include <linux/sysctl.h> 111da177e4SLinus Torvalds #include <linux/highmem.h> 12cddb8a5cSAndrea Arcangeli #include <linux/mmu_notifier.h> 131da177e4SLinus Torvalds #include <linux/nodemask.h> 1463551ae0SDavid Gibson #include <linux/pagemap.h> 155da7ca86SChristoph Lameter #include <linux/mempolicy.h> 163b32123dSGideon Israel Dsouza #include <linux/compiler.h> 17aea47ff3SChristoph Lameter #include <linux/cpuset.h> 183935baa9SDavid Gibson #include <linux/mutex.h> 1997ad1087SMike Rapoport #include <linux/memblock.h> 20a3437870SNishanth Aravamudan #include <linux/sysfs.h> 215a0e3ad6STejun Heo #include <linux/slab.h> 22bbe88753SJoonsoo Kim #include <linux/sched/mm.h> 2363489f8eSMike Kravetz #include <linux/mmdebug.h> 24174cd4b1SIngo Molnar #include <linux/sched/signal.h> 250fe6e20bSNaoya Horiguchi #include <linux/rmap.h> 26c6247f72SMatthew Wilcox #include <linux/string_helpers.h> 27fd6a03edSNaoya Horiguchi #include <linux/swap.h> 28fd6a03edSNaoya Horiguchi #include <linux/swapops.h> 298382d914SDavidlohr Bueso #include <linux/jhash.h> 3098fa15f3SAnshuman Khandual #include <linux/numa.h> 31c77c0a8aSWaiman Long #include <linux/llist.h> 32cf11e85fSRoman Gushchin #include <linux/cma.h> 338cc5fcbbSMina Almasry #include <linux/migrate.h> 34f9317f77SMike Kravetz #include <linux/nospec.h> 35662ce1dcSYang Yang #include <linux/delayacct.h> 36d6606683SLinus Torvalds 3763551ae0SDavid Gibson #include <asm/page.h> 38ca15ca40SMike Rapoport #include <asm/pgalloc.h> 3924669e58SAneesh Kumar K.V #include <asm/tlb.h> 4063551ae0SDavid Gibson 4124669e58SAneesh Kumar K.V #include <linux/io.h> 4263551ae0SDavid Gibson #include <linux/hugetlb.h> 439dd540e2SAneesh Kumar K.V #include <linux/hugetlb_cgroup.h> 449a305230SLee Schermerhorn #include <linux/node.h> 45ab5ac90aSMichal Hocko #include <linux/page_owner.h> 467835e98bSNick Piggin #include "internal.h" 47f41f2ed4SMuchun Song #include "hugetlb_vmemmap.h" 481da177e4SLinus Torvalds 49c3f38a38SAneesh Kumar K.V int hugetlb_max_hstate __read_mostly; 50e5ff2159SAndi Kleen unsigned int default_hstate_idx; 51e5ff2159SAndi Kleen struct hstate hstates[HUGE_MAX_HSTATE]; 52cf11e85fSRoman Gushchin 53dbda8feaSBarry Song #ifdef CONFIG_CMA 54cf11e85fSRoman Gushchin static struct cma *hugetlb_cma[MAX_NUMNODES]; 5538e719abSBaolin Wang static unsigned long hugetlb_cma_size_in_node[MAX_NUMNODES] __initdata; 56a01f4390SMike Kravetz static bool hugetlb_cma_page(struct page *page, unsigned int order) 57a01f4390SMike Kravetz { 58a01f4390SMike Kravetz return cma_pages_valid(hugetlb_cma[page_to_nid(page)], page, 59a01f4390SMike Kravetz 1 << order); 60a01f4390SMike Kravetz } 61a01f4390SMike Kravetz #else 62a01f4390SMike Kravetz static bool hugetlb_cma_page(struct page *page, unsigned int order) 63a01f4390SMike Kravetz { 64a01f4390SMike Kravetz return false; 65a01f4390SMike Kravetz } 66dbda8feaSBarry Song #endif 67dbda8feaSBarry Song static unsigned long hugetlb_cma_size __initdata; 68cf11e85fSRoman Gushchin 6953ba51d2SJon Tollefson __initdata LIST_HEAD(huge_boot_pages); 7053ba51d2SJon Tollefson 71e5ff2159SAndi Kleen /* for command line parsing */ 72e5ff2159SAndi Kleen static struct hstate * __initdata parsed_hstate; 73e5ff2159SAndi Kleen static unsigned long __initdata default_hstate_max_huge_pages; 749fee021dSVaishali Thakkar static bool __initdata parsed_valid_hugepagesz = true; 75282f4214SMike Kravetz static bool __initdata parsed_default_hugepagesz; 76b5389086SZhenguo Yao static unsigned int default_hugepages_in_node[MAX_NUMNODES] __initdata; 77e5ff2159SAndi Kleen 783935baa9SDavid Gibson /* 7931caf665SNaoya Horiguchi * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, 8031caf665SNaoya Horiguchi * free_huge_pages, and surplus_huge_pages. 813935baa9SDavid Gibson */ 82c3f38a38SAneesh Kumar K.V DEFINE_SPINLOCK(hugetlb_lock); 830bd0f9fbSEric Paris 848382d914SDavidlohr Bueso /* 858382d914SDavidlohr Bueso * Serializes faults on the same logical page. This is used to 868382d914SDavidlohr Bueso * prevent spurious OOMs when the hugepage pool is fully utilized. 878382d914SDavidlohr Bueso */ 888382d914SDavidlohr Bueso static int num_fault_mutexes; 89c672c7f2SMike Kravetz struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp; 908382d914SDavidlohr Bueso 917ca02d0aSMike Kravetz /* Forward declaration */ 927ca02d0aSMike Kravetz static int hugetlb_acct_memory(struct hstate *h, long delta); 937ca02d0aSMike Kravetz 941d88433bSMiaohe Lin static inline bool subpool_is_free(struct hugepage_subpool *spool) 951d88433bSMiaohe Lin { 961d88433bSMiaohe Lin if (spool->count) 971d88433bSMiaohe Lin return false; 981d88433bSMiaohe Lin if (spool->max_hpages != -1) 991d88433bSMiaohe Lin return spool->used_hpages == 0; 1001d88433bSMiaohe Lin if (spool->min_hpages != -1) 1011d88433bSMiaohe Lin return spool->rsv_hpages == spool->min_hpages; 1021d88433bSMiaohe Lin 1031d88433bSMiaohe Lin return true; 1041d88433bSMiaohe Lin } 1051d88433bSMiaohe Lin 106db71ef79SMike Kravetz static inline void unlock_or_release_subpool(struct hugepage_subpool *spool, 107db71ef79SMike Kravetz unsigned long irq_flags) 10890481622SDavid Gibson { 109db71ef79SMike Kravetz spin_unlock_irqrestore(&spool->lock, irq_flags); 11090481622SDavid Gibson 11190481622SDavid Gibson /* If no pages are used, and no other handles to the subpool 1127c8de358SEthon Paul * remain, give up any reservations based on minimum size and 1137ca02d0aSMike Kravetz * free the subpool */ 1141d88433bSMiaohe Lin if (subpool_is_free(spool)) { 1157ca02d0aSMike Kravetz if (spool->min_hpages != -1) 1167ca02d0aSMike Kravetz hugetlb_acct_memory(spool->hstate, 1177ca02d0aSMike Kravetz -spool->min_hpages); 11890481622SDavid Gibson kfree(spool); 11990481622SDavid Gibson } 1207ca02d0aSMike Kravetz } 12190481622SDavid Gibson 1227ca02d0aSMike Kravetz struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, 1237ca02d0aSMike Kravetz long min_hpages) 12490481622SDavid Gibson { 12590481622SDavid Gibson struct hugepage_subpool *spool; 12690481622SDavid Gibson 127c6a91820SMike Kravetz spool = kzalloc(sizeof(*spool), GFP_KERNEL); 12890481622SDavid Gibson if (!spool) 12990481622SDavid Gibson return NULL; 13090481622SDavid Gibson 13190481622SDavid Gibson spin_lock_init(&spool->lock); 13290481622SDavid Gibson spool->count = 1; 1337ca02d0aSMike Kravetz spool->max_hpages = max_hpages; 1347ca02d0aSMike Kravetz spool->hstate = h; 1357ca02d0aSMike Kravetz spool->min_hpages = min_hpages; 1367ca02d0aSMike Kravetz 1377ca02d0aSMike Kravetz if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { 1387ca02d0aSMike Kravetz kfree(spool); 1397ca02d0aSMike Kravetz return NULL; 1407ca02d0aSMike Kravetz } 1417ca02d0aSMike Kravetz spool->rsv_hpages = min_hpages; 14290481622SDavid Gibson 14390481622SDavid Gibson return spool; 14490481622SDavid Gibson } 14590481622SDavid Gibson 14690481622SDavid Gibson void hugepage_put_subpool(struct hugepage_subpool *spool) 14790481622SDavid Gibson { 148db71ef79SMike Kravetz unsigned long flags; 149db71ef79SMike Kravetz 150db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 15190481622SDavid Gibson BUG_ON(!spool->count); 15290481622SDavid Gibson spool->count--; 153db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 15490481622SDavid Gibson } 15590481622SDavid Gibson 1561c5ecae3SMike Kravetz /* 1571c5ecae3SMike Kravetz * Subpool accounting for allocating and reserving pages. 1581c5ecae3SMike Kravetz * Return -ENOMEM if there are not enough resources to satisfy the 1599e7ee400SRandy Dunlap * request. Otherwise, return the number of pages by which the 1601c5ecae3SMike Kravetz * global pools must be adjusted (upward). The returned value may 1611c5ecae3SMike Kravetz * only be different than the passed value (delta) in the case where 1627c8de358SEthon Paul * a subpool minimum size must be maintained. 1631c5ecae3SMike Kravetz */ 1641c5ecae3SMike Kravetz static long hugepage_subpool_get_pages(struct hugepage_subpool *spool, 16590481622SDavid Gibson long delta) 16690481622SDavid Gibson { 1671c5ecae3SMike Kravetz long ret = delta; 16890481622SDavid Gibson 16990481622SDavid Gibson if (!spool) 1701c5ecae3SMike Kravetz return ret; 17190481622SDavid Gibson 172db71ef79SMike Kravetz spin_lock_irq(&spool->lock); 17390481622SDavid Gibson 1741c5ecae3SMike Kravetz if (spool->max_hpages != -1) { /* maximum size accounting */ 1751c5ecae3SMike Kravetz if ((spool->used_hpages + delta) <= spool->max_hpages) 1761c5ecae3SMike Kravetz spool->used_hpages += delta; 1771c5ecae3SMike Kravetz else { 1781c5ecae3SMike Kravetz ret = -ENOMEM; 1791c5ecae3SMike Kravetz goto unlock_ret; 1801c5ecae3SMike Kravetz } 1811c5ecae3SMike Kravetz } 1821c5ecae3SMike Kravetz 18309a95e29SMike Kravetz /* minimum size accounting */ 18409a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->rsv_hpages) { 1851c5ecae3SMike Kravetz if (delta > spool->rsv_hpages) { 1861c5ecae3SMike Kravetz /* 1871c5ecae3SMike Kravetz * Asking for more reserves than those already taken on 1881c5ecae3SMike Kravetz * behalf of subpool. Return difference. 1891c5ecae3SMike Kravetz */ 1901c5ecae3SMike Kravetz ret = delta - spool->rsv_hpages; 1911c5ecae3SMike Kravetz spool->rsv_hpages = 0; 1921c5ecae3SMike Kravetz } else { 1931c5ecae3SMike Kravetz ret = 0; /* reserves already accounted for */ 1941c5ecae3SMike Kravetz spool->rsv_hpages -= delta; 1951c5ecae3SMike Kravetz } 1961c5ecae3SMike Kravetz } 1971c5ecae3SMike Kravetz 1981c5ecae3SMike Kravetz unlock_ret: 199db71ef79SMike Kravetz spin_unlock_irq(&spool->lock); 20090481622SDavid Gibson return ret; 20190481622SDavid Gibson } 20290481622SDavid Gibson 2031c5ecae3SMike Kravetz /* 2041c5ecae3SMike Kravetz * Subpool accounting for freeing and unreserving pages. 2051c5ecae3SMike Kravetz * Return the number of global page reservations that must be dropped. 2061c5ecae3SMike Kravetz * The return value may only be different than the passed value (delta) 2071c5ecae3SMike Kravetz * in the case where a subpool minimum size must be maintained. 2081c5ecae3SMike Kravetz */ 2091c5ecae3SMike Kravetz static long hugepage_subpool_put_pages(struct hugepage_subpool *spool, 21090481622SDavid Gibson long delta) 21190481622SDavid Gibson { 2121c5ecae3SMike Kravetz long ret = delta; 213db71ef79SMike Kravetz unsigned long flags; 2141c5ecae3SMike Kravetz 21590481622SDavid Gibson if (!spool) 2161c5ecae3SMike Kravetz return delta; 21790481622SDavid Gibson 218db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 2191c5ecae3SMike Kravetz 2201c5ecae3SMike Kravetz if (spool->max_hpages != -1) /* maximum size accounting */ 22190481622SDavid Gibson spool->used_hpages -= delta; 2221c5ecae3SMike Kravetz 22309a95e29SMike Kravetz /* minimum size accounting */ 22409a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { 2251c5ecae3SMike Kravetz if (spool->rsv_hpages + delta <= spool->min_hpages) 2261c5ecae3SMike Kravetz ret = 0; 2271c5ecae3SMike Kravetz else 2281c5ecae3SMike Kravetz ret = spool->rsv_hpages + delta - spool->min_hpages; 2291c5ecae3SMike Kravetz 2301c5ecae3SMike Kravetz spool->rsv_hpages += delta; 2311c5ecae3SMike Kravetz if (spool->rsv_hpages > spool->min_hpages) 2321c5ecae3SMike Kravetz spool->rsv_hpages = spool->min_hpages; 2331c5ecae3SMike Kravetz } 2341c5ecae3SMike Kravetz 2351c5ecae3SMike Kravetz /* 2361c5ecae3SMike Kravetz * If hugetlbfs_put_super couldn't free spool due to an outstanding 2371c5ecae3SMike Kravetz * quota reference, free it now. 2381c5ecae3SMike Kravetz */ 239db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 2401c5ecae3SMike Kravetz 2411c5ecae3SMike Kravetz return ret; 24290481622SDavid Gibson } 24390481622SDavid Gibson 24490481622SDavid Gibson static inline struct hugepage_subpool *subpool_inode(struct inode *inode) 24590481622SDavid Gibson { 24690481622SDavid Gibson return HUGETLBFS_SB(inode->i_sb)->spool; 24790481622SDavid Gibson } 24890481622SDavid Gibson 24990481622SDavid Gibson static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) 25090481622SDavid Gibson { 251496ad9aaSAl Viro return subpool_inode(file_inode(vma->vm_file)); 25290481622SDavid Gibson } 25390481622SDavid Gibson 2540db9d74eSMina Almasry /* Helper that removes a struct file_region from the resv_map cache and returns 2550db9d74eSMina Almasry * it for use. 2560db9d74eSMina Almasry */ 2570db9d74eSMina Almasry static struct file_region * 2580db9d74eSMina Almasry get_file_region_entry_from_cache(struct resv_map *resv, long from, long to) 2590db9d74eSMina Almasry { 2600db9d74eSMina Almasry struct file_region *nrg = NULL; 2610db9d74eSMina Almasry 2620db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count <= 0); 2630db9d74eSMina Almasry 2640db9d74eSMina Almasry resv->region_cache_count--; 2650db9d74eSMina Almasry nrg = list_first_entry(&resv->region_cache, struct file_region, link); 2660db9d74eSMina Almasry list_del(&nrg->link); 2670db9d74eSMina Almasry 2680db9d74eSMina Almasry nrg->from = from; 2690db9d74eSMina Almasry nrg->to = to; 2700db9d74eSMina Almasry 2710db9d74eSMina Almasry return nrg; 2720db9d74eSMina Almasry } 2730db9d74eSMina Almasry 274075a61d0SMina Almasry static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg, 275075a61d0SMina Almasry struct file_region *rg) 276075a61d0SMina Almasry { 277075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 278075a61d0SMina Almasry nrg->reservation_counter = rg->reservation_counter; 279075a61d0SMina Almasry nrg->css = rg->css; 280075a61d0SMina Almasry if (rg->css) 281075a61d0SMina Almasry css_get(rg->css); 282075a61d0SMina Almasry #endif 283075a61d0SMina Almasry } 284075a61d0SMina Almasry 285075a61d0SMina Almasry /* Helper that records hugetlb_cgroup uncharge info. */ 286075a61d0SMina Almasry static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg, 287075a61d0SMina Almasry struct hstate *h, 288075a61d0SMina Almasry struct resv_map *resv, 289075a61d0SMina Almasry struct file_region *nrg) 290075a61d0SMina Almasry { 291075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 292075a61d0SMina Almasry if (h_cg) { 293075a61d0SMina Almasry nrg->reservation_counter = 294075a61d0SMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 295075a61d0SMina Almasry nrg->css = &h_cg->css; 296d85aecf2SMiaohe Lin /* 297d85aecf2SMiaohe Lin * The caller will hold exactly one h_cg->css reference for the 298d85aecf2SMiaohe Lin * whole contiguous reservation region. But this area might be 299d85aecf2SMiaohe Lin * scattered when there are already some file_regions reside in 300d85aecf2SMiaohe Lin * it. As a result, many file_regions may share only one css 301d85aecf2SMiaohe Lin * reference. In order to ensure that one file_region must hold 302d85aecf2SMiaohe Lin * exactly one h_cg->css reference, we should do css_get for 303d85aecf2SMiaohe Lin * each file_region and leave the reference held by caller 304d85aecf2SMiaohe Lin * untouched. 305d85aecf2SMiaohe Lin */ 306d85aecf2SMiaohe Lin css_get(&h_cg->css); 307075a61d0SMina Almasry if (!resv->pages_per_hpage) 308075a61d0SMina Almasry resv->pages_per_hpage = pages_per_huge_page(h); 309075a61d0SMina Almasry /* pages_per_hpage should be the same for all entries in 310075a61d0SMina Almasry * a resv_map. 311075a61d0SMina Almasry */ 312075a61d0SMina Almasry VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h)); 313075a61d0SMina Almasry } else { 314075a61d0SMina Almasry nrg->reservation_counter = NULL; 315075a61d0SMina Almasry nrg->css = NULL; 316075a61d0SMina Almasry } 317075a61d0SMina Almasry #endif 318075a61d0SMina Almasry } 319075a61d0SMina Almasry 320d85aecf2SMiaohe Lin static void put_uncharge_info(struct file_region *rg) 321d85aecf2SMiaohe Lin { 322d85aecf2SMiaohe Lin #ifdef CONFIG_CGROUP_HUGETLB 323d85aecf2SMiaohe Lin if (rg->css) 324d85aecf2SMiaohe Lin css_put(rg->css); 325d85aecf2SMiaohe Lin #endif 326d85aecf2SMiaohe Lin } 327d85aecf2SMiaohe Lin 328a9b3f867SMina Almasry static bool has_same_uncharge_info(struct file_region *rg, 329a9b3f867SMina Almasry struct file_region *org) 330a9b3f867SMina Almasry { 331a9b3f867SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 3320739eb43SBaolin Wang return rg->reservation_counter == org->reservation_counter && 333a9b3f867SMina Almasry rg->css == org->css; 334a9b3f867SMina Almasry 335a9b3f867SMina Almasry #else 336a9b3f867SMina Almasry return true; 337a9b3f867SMina Almasry #endif 338a9b3f867SMina Almasry } 339a9b3f867SMina Almasry 340a9b3f867SMina Almasry static void coalesce_file_region(struct resv_map *resv, struct file_region *rg) 341a9b3f867SMina Almasry { 342a9b3f867SMina Almasry struct file_region *nrg = NULL, *prg = NULL; 343a9b3f867SMina Almasry 344a9b3f867SMina Almasry prg = list_prev_entry(rg, link); 345a9b3f867SMina Almasry if (&prg->link != &resv->regions && prg->to == rg->from && 346a9b3f867SMina Almasry has_same_uncharge_info(prg, rg)) { 347a9b3f867SMina Almasry prg->to = rg->to; 348a9b3f867SMina Almasry 349a9b3f867SMina Almasry list_del(&rg->link); 350d85aecf2SMiaohe Lin put_uncharge_info(rg); 351a9b3f867SMina Almasry kfree(rg); 352a9b3f867SMina Almasry 3537db5e7b6SWei Yang rg = prg; 354a9b3f867SMina Almasry } 355a9b3f867SMina Almasry 356a9b3f867SMina Almasry nrg = list_next_entry(rg, link); 357a9b3f867SMina Almasry if (&nrg->link != &resv->regions && nrg->from == rg->to && 358a9b3f867SMina Almasry has_same_uncharge_info(nrg, rg)) { 359a9b3f867SMina Almasry nrg->from = rg->from; 360a9b3f867SMina Almasry 361a9b3f867SMina Almasry list_del(&rg->link); 362d85aecf2SMiaohe Lin put_uncharge_info(rg); 363a9b3f867SMina Almasry kfree(rg); 364a9b3f867SMina Almasry } 365a9b3f867SMina Almasry } 366a9b3f867SMina Almasry 3672103cf9cSPeter Xu static inline long 36884448c8eSJakob Koschel hugetlb_resv_map_add(struct resv_map *map, struct list_head *rg, long from, 3692103cf9cSPeter Xu long to, struct hstate *h, struct hugetlb_cgroup *cg, 3702103cf9cSPeter Xu long *regions_needed) 3712103cf9cSPeter Xu { 3722103cf9cSPeter Xu struct file_region *nrg; 3732103cf9cSPeter Xu 3742103cf9cSPeter Xu if (!regions_needed) { 3752103cf9cSPeter Xu nrg = get_file_region_entry_from_cache(map, from, to); 3762103cf9cSPeter Xu record_hugetlb_cgroup_uncharge_info(cg, h, map, nrg); 37784448c8eSJakob Koschel list_add(&nrg->link, rg); 3782103cf9cSPeter Xu coalesce_file_region(map, nrg); 3792103cf9cSPeter Xu } else 3802103cf9cSPeter Xu *regions_needed += 1; 3812103cf9cSPeter Xu 3822103cf9cSPeter Xu return to - from; 3832103cf9cSPeter Xu } 3842103cf9cSPeter Xu 385972a3da3SWei Yang /* 386972a3da3SWei Yang * Must be called with resv->lock held. 387972a3da3SWei Yang * 388972a3da3SWei Yang * Calling this with regions_needed != NULL will count the number of pages 389972a3da3SWei Yang * to be added but will not modify the linked list. And regions_needed will 390972a3da3SWei Yang * indicate the number of file_regions needed in the cache to carry out to add 391972a3da3SWei Yang * the regions for this range. 392d75c6af9SMina Almasry */ 393d75c6af9SMina Almasry static long add_reservation_in_range(struct resv_map *resv, long f, long t, 394075a61d0SMina Almasry struct hugetlb_cgroup *h_cg, 395972a3da3SWei Yang struct hstate *h, long *regions_needed) 396d75c6af9SMina Almasry { 3970db9d74eSMina Almasry long add = 0; 398d75c6af9SMina Almasry struct list_head *head = &resv->regions; 3990db9d74eSMina Almasry long last_accounted_offset = f; 40084448c8eSJakob Koschel struct file_region *iter, *trg = NULL; 40184448c8eSJakob Koschel struct list_head *rg = NULL; 402d75c6af9SMina Almasry 4030db9d74eSMina Almasry if (regions_needed) 4040db9d74eSMina Almasry *regions_needed = 0; 405d75c6af9SMina Almasry 4060db9d74eSMina Almasry /* In this loop, we essentially handle an entry for the range 40784448c8eSJakob Koschel * [last_accounted_offset, iter->from), at every iteration, with some 4080db9d74eSMina Almasry * bounds checking. 4090db9d74eSMina Almasry */ 41084448c8eSJakob Koschel list_for_each_entry_safe(iter, trg, head, link) { 4110db9d74eSMina Almasry /* Skip irrelevant regions that start before our range. */ 41284448c8eSJakob Koschel if (iter->from < f) { 4130db9d74eSMina Almasry /* If this region ends after the last accounted offset, 4140db9d74eSMina Almasry * then we need to update last_accounted_offset. 4150db9d74eSMina Almasry */ 41684448c8eSJakob Koschel if (iter->to > last_accounted_offset) 41784448c8eSJakob Koschel last_accounted_offset = iter->to; 4180db9d74eSMina Almasry continue; 4190db9d74eSMina Almasry } 420d75c6af9SMina Almasry 4210db9d74eSMina Almasry /* When we find a region that starts beyond our range, we've 4220db9d74eSMina Almasry * finished. 4230db9d74eSMina Almasry */ 42484448c8eSJakob Koschel if (iter->from >= t) { 42584448c8eSJakob Koschel rg = iter->link.prev; 426d75c6af9SMina Almasry break; 42784448c8eSJakob Koschel } 428d75c6af9SMina Almasry 42984448c8eSJakob Koschel /* Add an entry for last_accounted_offset -> iter->from, and 4300db9d74eSMina Almasry * update last_accounted_offset. 431d75c6af9SMina Almasry */ 43284448c8eSJakob Koschel if (iter->from > last_accounted_offset) 43384448c8eSJakob Koschel add += hugetlb_resv_map_add(resv, iter->link.prev, 4342103cf9cSPeter Xu last_accounted_offset, 43584448c8eSJakob Koschel iter->from, h, h_cg, 4362103cf9cSPeter Xu regions_needed); 437d75c6af9SMina Almasry 43884448c8eSJakob Koschel last_accounted_offset = iter->to; 4390db9d74eSMina Almasry } 4400db9d74eSMina Almasry 4410db9d74eSMina Almasry /* Handle the case where our range extends beyond 4420db9d74eSMina Almasry * last_accounted_offset. 4430db9d74eSMina Almasry */ 44484448c8eSJakob Koschel if (!rg) 44584448c8eSJakob Koschel rg = head->prev; 4462103cf9cSPeter Xu if (last_accounted_offset < t) 4472103cf9cSPeter Xu add += hugetlb_resv_map_add(resv, rg, last_accounted_offset, 4482103cf9cSPeter Xu t, h, h_cg, regions_needed); 4490db9d74eSMina Almasry 4500db9d74eSMina Almasry return add; 4510db9d74eSMina Almasry } 4520db9d74eSMina Almasry 4530db9d74eSMina Almasry /* Must be called with resv->lock acquired. Will drop lock to allocate entries. 4540db9d74eSMina Almasry */ 4550db9d74eSMina Almasry static int allocate_file_region_entries(struct resv_map *resv, 4560db9d74eSMina Almasry int regions_needed) 4570db9d74eSMina Almasry __must_hold(&resv->lock) 4580db9d74eSMina Almasry { 4590db9d74eSMina Almasry struct list_head allocated_regions; 4600db9d74eSMina Almasry int to_allocate = 0, i = 0; 4610db9d74eSMina Almasry struct file_region *trg = NULL, *rg = NULL; 4620db9d74eSMina Almasry 4630db9d74eSMina Almasry VM_BUG_ON(regions_needed < 0); 4640db9d74eSMina Almasry 4650db9d74eSMina Almasry INIT_LIST_HEAD(&allocated_regions); 4660db9d74eSMina Almasry 4670db9d74eSMina Almasry /* 4680db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 4690db9d74eSMina Almasry * the number of in progress add operations plus regions_needed. 4700db9d74eSMina Almasry * 4710db9d74eSMina Almasry * This is a while loop because when we drop the lock, some other call 4720db9d74eSMina Almasry * to region_add or region_del may have consumed some region_entries, 4730db9d74eSMina Almasry * so we keep looping here until we finally have enough entries for 4740db9d74eSMina Almasry * (adds_in_progress + regions_needed). 4750db9d74eSMina Almasry */ 4760db9d74eSMina Almasry while (resv->region_cache_count < 4770db9d74eSMina Almasry (resv->adds_in_progress + regions_needed)) { 4780db9d74eSMina Almasry to_allocate = resv->adds_in_progress + regions_needed - 4790db9d74eSMina Almasry resv->region_cache_count; 4800db9d74eSMina Almasry 4810db9d74eSMina Almasry /* At this point, we should have enough entries in the cache 482f0953a1bSIngo Molnar * for all the existing adds_in_progress. We should only be 4830db9d74eSMina Almasry * needing to allocate for regions_needed. 4840db9d74eSMina Almasry */ 4850db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count < resv->adds_in_progress); 4860db9d74eSMina Almasry 4870db9d74eSMina Almasry spin_unlock(&resv->lock); 4880db9d74eSMina Almasry for (i = 0; i < to_allocate; i++) { 4890db9d74eSMina Almasry trg = kmalloc(sizeof(*trg), GFP_KERNEL); 4900db9d74eSMina Almasry if (!trg) 4910db9d74eSMina Almasry goto out_of_memory; 4920db9d74eSMina Almasry list_add(&trg->link, &allocated_regions); 4930db9d74eSMina Almasry } 4940db9d74eSMina Almasry 4950db9d74eSMina Almasry spin_lock(&resv->lock); 4960db9d74eSMina Almasry 497d3ec7b6eSWei Yang list_splice(&allocated_regions, &resv->region_cache); 498d3ec7b6eSWei Yang resv->region_cache_count += to_allocate; 4990db9d74eSMina Almasry } 5000db9d74eSMina Almasry 5010db9d74eSMina Almasry return 0; 5020db9d74eSMina Almasry 5030db9d74eSMina Almasry out_of_memory: 5040db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, &allocated_regions, link) { 505d75c6af9SMina Almasry list_del(&rg->link); 506d75c6af9SMina Almasry kfree(rg); 507d75c6af9SMina Almasry } 5080db9d74eSMina Almasry return -ENOMEM; 509d75c6af9SMina Almasry } 510d75c6af9SMina Almasry 5111dd308a7SMike Kravetz /* 5121dd308a7SMike Kravetz * Add the huge page range represented by [f, t) to the reserve 5130db9d74eSMina Almasry * map. Regions will be taken from the cache to fill in this range. 5140db9d74eSMina Almasry * Sufficient regions should exist in the cache due to the previous 5150db9d74eSMina Almasry * call to region_chg with the same range, but in some cases the cache will not 5160db9d74eSMina Almasry * have sufficient entries due to races with other code doing region_add or 5170db9d74eSMina Almasry * region_del. The extra needed entries will be allocated. 518cf3ad20bSMike Kravetz * 5190db9d74eSMina Almasry * regions_needed is the out value provided by a previous call to region_chg. 5200db9d74eSMina Almasry * 5210db9d74eSMina Almasry * Return the number of new huge pages added to the map. This number is greater 5220db9d74eSMina Almasry * than or equal to zero. If file_region entries needed to be allocated for 5237c8de358SEthon Paul * this operation and we were not able to allocate, it returns -ENOMEM. 5240db9d74eSMina Almasry * region_add of regions of length 1 never allocate file_regions and cannot 5250db9d74eSMina Almasry * fail; region_chg will always allocate at least 1 entry and a region_add for 5260db9d74eSMina Almasry * 1 page will only require at most 1 entry. 5271dd308a7SMike Kravetz */ 5280db9d74eSMina Almasry static long region_add(struct resv_map *resv, long f, long t, 529075a61d0SMina Almasry long in_regions_needed, struct hstate *h, 530075a61d0SMina Almasry struct hugetlb_cgroup *h_cg) 53196822904SAndy Whitcroft { 5320db9d74eSMina Almasry long add = 0, actual_regions_needed = 0; 53396822904SAndy Whitcroft 5347b24d861SDavidlohr Bueso spin_lock(&resv->lock); 5350db9d74eSMina Almasry retry: 5360db9d74eSMina Almasry 5370db9d74eSMina Almasry /* Count how many regions are actually needed to execute this add. */ 538972a3da3SWei Yang add_reservation_in_range(resv, f, t, NULL, NULL, 539972a3da3SWei Yang &actual_regions_needed); 54096822904SAndy Whitcroft 5415e911373SMike Kravetz /* 5420db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 5430db9d74eSMina Almasry * this add operation. Note that actual_regions_needed may be greater 5440db9d74eSMina Almasry * than in_regions_needed, as the resv_map may have been modified since 5450db9d74eSMina Almasry * the region_chg call. In this case, we need to make sure that we 5460db9d74eSMina Almasry * allocate extra entries, such that we have enough for all the 5470db9d74eSMina Almasry * existing adds_in_progress, plus the excess needed for this 5480db9d74eSMina Almasry * operation. 5495e911373SMike Kravetz */ 5500db9d74eSMina Almasry if (actual_regions_needed > in_regions_needed && 5510db9d74eSMina Almasry resv->region_cache_count < 5520db9d74eSMina Almasry resv->adds_in_progress + 5530db9d74eSMina Almasry (actual_regions_needed - in_regions_needed)) { 5540db9d74eSMina Almasry /* region_add operation of range 1 should never need to 5550db9d74eSMina Almasry * allocate file_region entries. 5560db9d74eSMina Almasry */ 5570db9d74eSMina Almasry VM_BUG_ON(t - f <= 1); 5585e911373SMike Kravetz 5590db9d74eSMina Almasry if (allocate_file_region_entries( 5600db9d74eSMina Almasry resv, actual_regions_needed - in_regions_needed)) { 5610db9d74eSMina Almasry return -ENOMEM; 5625e911373SMike Kravetz } 5635e911373SMike Kravetz 5640db9d74eSMina Almasry goto retry; 5650db9d74eSMina Almasry } 566cf3ad20bSMike Kravetz 567972a3da3SWei Yang add = add_reservation_in_range(resv, f, t, h_cg, h, NULL); 5680db9d74eSMina Almasry 5690db9d74eSMina Almasry resv->adds_in_progress -= in_regions_needed; 5700db9d74eSMina Almasry 5717b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 572cf3ad20bSMike Kravetz return add; 57396822904SAndy Whitcroft } 57496822904SAndy Whitcroft 5751dd308a7SMike Kravetz /* 5761dd308a7SMike Kravetz * Examine the existing reserve map and determine how many 5771dd308a7SMike Kravetz * huge pages in the specified range [f, t) are NOT currently 5781dd308a7SMike Kravetz * represented. This routine is called before a subsequent 5791dd308a7SMike Kravetz * call to region_add that will actually modify the reserve 5801dd308a7SMike Kravetz * map to add the specified range [f, t). region_chg does 5811dd308a7SMike Kravetz * not change the number of huge pages represented by the 5820db9d74eSMina Almasry * map. A number of new file_region structures is added to the cache as a 5830db9d74eSMina Almasry * placeholder, for the subsequent region_add call to use. At least 1 5840db9d74eSMina Almasry * file_region structure is added. 5850db9d74eSMina Almasry * 5860db9d74eSMina Almasry * out_regions_needed is the number of regions added to the 5870db9d74eSMina Almasry * resv->adds_in_progress. This value needs to be provided to a follow up call 5880db9d74eSMina Almasry * to region_add or region_abort for proper accounting. 5895e911373SMike Kravetz * 5905e911373SMike Kravetz * Returns the number of huge pages that need to be added to the existing 5915e911373SMike Kravetz * reservation map for the range [f, t). This number is greater or equal to 5925e911373SMike Kravetz * zero. -ENOMEM is returned if a new file_region structure or cache entry 5935e911373SMike Kravetz * is needed and can not be allocated. 5941dd308a7SMike Kravetz */ 5950db9d74eSMina Almasry static long region_chg(struct resv_map *resv, long f, long t, 5960db9d74eSMina Almasry long *out_regions_needed) 59796822904SAndy Whitcroft { 59896822904SAndy Whitcroft long chg = 0; 59996822904SAndy Whitcroft 6007b24d861SDavidlohr Bueso spin_lock(&resv->lock); 6015e911373SMike Kravetz 602972a3da3SWei Yang /* Count how many hugepages in this range are NOT represented. */ 603075a61d0SMina Almasry chg = add_reservation_in_range(resv, f, t, NULL, NULL, 604972a3da3SWei Yang out_regions_needed); 6055e911373SMike Kravetz 6060db9d74eSMina Almasry if (*out_regions_needed == 0) 6070db9d74eSMina Almasry *out_regions_needed = 1; 6085e911373SMike Kravetz 6090db9d74eSMina Almasry if (allocate_file_region_entries(resv, *out_regions_needed)) 6105e911373SMike Kravetz return -ENOMEM; 6115e911373SMike Kravetz 6120db9d74eSMina Almasry resv->adds_in_progress += *out_regions_needed; 61396822904SAndy Whitcroft 6147b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 61596822904SAndy Whitcroft return chg; 61696822904SAndy Whitcroft } 61796822904SAndy Whitcroft 6181dd308a7SMike Kravetz /* 6195e911373SMike Kravetz * Abort the in progress add operation. The adds_in_progress field 6205e911373SMike Kravetz * of the resv_map keeps track of the operations in progress between 6215e911373SMike Kravetz * calls to region_chg and region_add. Operations are sometimes 6225e911373SMike Kravetz * aborted after the call to region_chg. In such cases, region_abort 6230db9d74eSMina Almasry * is called to decrement the adds_in_progress counter. regions_needed 6240db9d74eSMina Almasry * is the value returned by the region_chg call, it is used to decrement 6250db9d74eSMina Almasry * the adds_in_progress counter. 6265e911373SMike Kravetz * 6275e911373SMike Kravetz * NOTE: The range arguments [f, t) are not needed or used in this 6285e911373SMike Kravetz * routine. They are kept to make reading the calling code easier as 6295e911373SMike Kravetz * arguments will match the associated region_chg call. 6305e911373SMike Kravetz */ 6310db9d74eSMina Almasry static void region_abort(struct resv_map *resv, long f, long t, 6320db9d74eSMina Almasry long regions_needed) 6335e911373SMike Kravetz { 6345e911373SMike Kravetz spin_lock(&resv->lock); 6355e911373SMike Kravetz VM_BUG_ON(!resv->region_cache_count); 6360db9d74eSMina Almasry resv->adds_in_progress -= regions_needed; 6375e911373SMike Kravetz spin_unlock(&resv->lock); 6385e911373SMike Kravetz } 6395e911373SMike Kravetz 6405e911373SMike Kravetz /* 641feba16e2SMike Kravetz * Delete the specified range [f, t) from the reserve map. If the 642feba16e2SMike Kravetz * t parameter is LONG_MAX, this indicates that ALL regions after f 643feba16e2SMike Kravetz * should be deleted. Locate the regions which intersect [f, t) 644feba16e2SMike Kravetz * and either trim, delete or split the existing regions. 645feba16e2SMike Kravetz * 646feba16e2SMike Kravetz * Returns the number of huge pages deleted from the reserve map. 647feba16e2SMike Kravetz * In the normal case, the return value is zero or more. In the 648feba16e2SMike Kravetz * case where a region must be split, a new region descriptor must 649feba16e2SMike Kravetz * be allocated. If the allocation fails, -ENOMEM will be returned. 650feba16e2SMike Kravetz * NOTE: If the parameter t == LONG_MAX, then we will never split 651feba16e2SMike Kravetz * a region and possibly return -ENOMEM. Callers specifying 652feba16e2SMike Kravetz * t == LONG_MAX do not need to check for -ENOMEM error. 6531dd308a7SMike Kravetz */ 654feba16e2SMike Kravetz static long region_del(struct resv_map *resv, long f, long t) 65596822904SAndy Whitcroft { 6561406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 65796822904SAndy Whitcroft struct file_region *rg, *trg; 658feba16e2SMike Kravetz struct file_region *nrg = NULL; 659feba16e2SMike Kravetz long del = 0; 66096822904SAndy Whitcroft 661feba16e2SMike Kravetz retry: 6627b24d861SDavidlohr Bueso spin_lock(&resv->lock); 663feba16e2SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 664dbe409e4SMike Kravetz /* 665dbe409e4SMike Kravetz * Skip regions before the range to be deleted. file_region 666dbe409e4SMike Kravetz * ranges are normally of the form [from, to). However, there 667dbe409e4SMike Kravetz * may be a "placeholder" entry in the map which is of the form 668dbe409e4SMike Kravetz * (from, to) with from == to. Check for placeholder entries 669dbe409e4SMike Kravetz * at the beginning of the range to be deleted. 670dbe409e4SMike Kravetz */ 671dbe409e4SMike Kravetz if (rg->to <= f && (rg->to != rg->from || rg->to != f)) 672feba16e2SMike Kravetz continue; 673dbe409e4SMike Kravetz 674feba16e2SMike Kravetz if (rg->from >= t) 67596822904SAndy Whitcroft break; 67696822904SAndy Whitcroft 677feba16e2SMike Kravetz if (f > rg->from && t < rg->to) { /* Must split region */ 678feba16e2SMike Kravetz /* 679feba16e2SMike Kravetz * Check for an entry in the cache before dropping 680feba16e2SMike Kravetz * lock and attempting allocation. 681feba16e2SMike Kravetz */ 682feba16e2SMike Kravetz if (!nrg && 683feba16e2SMike Kravetz resv->region_cache_count > resv->adds_in_progress) { 684feba16e2SMike Kravetz nrg = list_first_entry(&resv->region_cache, 685feba16e2SMike Kravetz struct file_region, 686feba16e2SMike Kravetz link); 687feba16e2SMike Kravetz list_del(&nrg->link); 688feba16e2SMike Kravetz resv->region_cache_count--; 68996822904SAndy Whitcroft } 69096822904SAndy Whitcroft 691feba16e2SMike Kravetz if (!nrg) { 692feba16e2SMike Kravetz spin_unlock(&resv->lock); 693feba16e2SMike Kravetz nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); 694feba16e2SMike Kravetz if (!nrg) 695feba16e2SMike Kravetz return -ENOMEM; 696feba16e2SMike Kravetz goto retry; 697feba16e2SMike Kravetz } 698feba16e2SMike Kravetz 699feba16e2SMike Kravetz del += t - f; 70079aa925bSMike Kravetz hugetlb_cgroup_uncharge_file_region( 701d85aecf2SMiaohe Lin resv, rg, t - f, false); 702feba16e2SMike Kravetz 703feba16e2SMike Kravetz /* New entry for end of split region */ 704feba16e2SMike Kravetz nrg->from = t; 705feba16e2SMike Kravetz nrg->to = rg->to; 706075a61d0SMina Almasry 707075a61d0SMina Almasry copy_hugetlb_cgroup_uncharge_info(nrg, rg); 708075a61d0SMina Almasry 709feba16e2SMike Kravetz INIT_LIST_HEAD(&nrg->link); 710feba16e2SMike Kravetz 711feba16e2SMike Kravetz /* Original entry is trimmed */ 712feba16e2SMike Kravetz rg->to = f; 713feba16e2SMike Kravetz 714feba16e2SMike Kravetz list_add(&nrg->link, &rg->link); 715feba16e2SMike Kravetz nrg = NULL; 71696822904SAndy Whitcroft break; 717feba16e2SMike Kravetz } 718feba16e2SMike Kravetz 719feba16e2SMike Kravetz if (f <= rg->from && t >= rg->to) { /* Remove entire region */ 720feba16e2SMike Kravetz del += rg->to - rg->from; 721075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 722d85aecf2SMiaohe Lin rg->to - rg->from, true); 72396822904SAndy Whitcroft list_del(&rg->link); 72496822904SAndy Whitcroft kfree(rg); 725feba16e2SMike Kravetz continue; 72696822904SAndy Whitcroft } 7277b24d861SDavidlohr Bueso 728feba16e2SMike Kravetz if (f <= rg->from) { /* Trim beginning of region */ 729075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 730d85aecf2SMiaohe Lin t - rg->from, false); 731075a61d0SMina Almasry 73279aa925bSMike Kravetz del += t - rg->from; 73379aa925bSMike Kravetz rg->from = t; 73479aa925bSMike Kravetz } else { /* Trim end of region */ 735075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 736d85aecf2SMiaohe Lin rg->to - f, false); 73779aa925bSMike Kravetz 73879aa925bSMike Kravetz del += rg->to - f; 73979aa925bSMike Kravetz rg->to = f; 740feba16e2SMike Kravetz } 741feba16e2SMike Kravetz } 742feba16e2SMike Kravetz 7437b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 744feba16e2SMike Kravetz kfree(nrg); 745feba16e2SMike Kravetz return del; 74696822904SAndy Whitcroft } 74796822904SAndy Whitcroft 7481dd308a7SMike Kravetz /* 749b5cec28dSMike Kravetz * A rare out of memory error was encountered which prevented removal of 750b5cec28dSMike Kravetz * the reserve map region for a page. The huge page itself was free'ed 751b5cec28dSMike Kravetz * and removed from the page cache. This routine will adjust the subpool 752b5cec28dSMike Kravetz * usage count, and the global reserve count if needed. By incrementing 753b5cec28dSMike Kravetz * these counts, the reserve map entry which could not be deleted will 754b5cec28dSMike Kravetz * appear as a "reserved" entry instead of simply dangling with incorrect 755b5cec28dSMike Kravetz * counts. 756b5cec28dSMike Kravetz */ 75772e2936cSzhong jiang void hugetlb_fix_reserve_counts(struct inode *inode) 758b5cec28dSMike Kravetz { 759b5cec28dSMike Kravetz struct hugepage_subpool *spool = subpool_inode(inode); 760b5cec28dSMike Kravetz long rsv_adjust; 761da56388cSMiaohe Lin bool reserved = false; 762b5cec28dSMike Kravetz 763b5cec28dSMike Kravetz rsv_adjust = hugepage_subpool_get_pages(spool, 1); 764da56388cSMiaohe Lin if (rsv_adjust > 0) { 765b5cec28dSMike Kravetz struct hstate *h = hstate_inode(inode); 766b5cec28dSMike Kravetz 767da56388cSMiaohe Lin if (!hugetlb_acct_memory(h, 1)) 768da56388cSMiaohe Lin reserved = true; 769da56388cSMiaohe Lin } else if (!rsv_adjust) { 770da56388cSMiaohe Lin reserved = true; 771b5cec28dSMike Kravetz } 772da56388cSMiaohe Lin 773da56388cSMiaohe Lin if (!reserved) 774da56388cSMiaohe Lin pr_warn("hugetlb: Huge Page Reserved count may go negative.\n"); 775b5cec28dSMike Kravetz } 776b5cec28dSMike Kravetz 777b5cec28dSMike Kravetz /* 7781dd308a7SMike Kravetz * Count and return the number of huge pages in the reserve map 7791dd308a7SMike Kravetz * that intersect with the range [f, t). 7801dd308a7SMike Kravetz */ 7811406ec9bSJoonsoo Kim static long region_count(struct resv_map *resv, long f, long t) 78284afd99bSAndy Whitcroft { 7831406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 78484afd99bSAndy Whitcroft struct file_region *rg; 78584afd99bSAndy Whitcroft long chg = 0; 78684afd99bSAndy Whitcroft 7877b24d861SDavidlohr Bueso spin_lock(&resv->lock); 78884afd99bSAndy Whitcroft /* Locate each segment we overlap with, and count that overlap. */ 78984afd99bSAndy Whitcroft list_for_each_entry(rg, head, link) { 790f2135a4aSWang Sheng-Hui long seg_from; 791f2135a4aSWang Sheng-Hui long seg_to; 79284afd99bSAndy Whitcroft 79384afd99bSAndy Whitcroft if (rg->to <= f) 79484afd99bSAndy Whitcroft continue; 79584afd99bSAndy Whitcroft if (rg->from >= t) 79684afd99bSAndy Whitcroft break; 79784afd99bSAndy Whitcroft 79884afd99bSAndy Whitcroft seg_from = max(rg->from, f); 79984afd99bSAndy Whitcroft seg_to = min(rg->to, t); 80084afd99bSAndy Whitcroft 80184afd99bSAndy Whitcroft chg += seg_to - seg_from; 80284afd99bSAndy Whitcroft } 8037b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 80484afd99bSAndy Whitcroft 80584afd99bSAndy Whitcroft return chg; 80684afd99bSAndy Whitcroft } 80784afd99bSAndy Whitcroft 80896822904SAndy Whitcroft /* 809e7c4b0bfSAndy Whitcroft * Convert the address within this vma to the page offset within 810e7c4b0bfSAndy Whitcroft * the mapping, in pagecache page units; huge pages here. 811e7c4b0bfSAndy Whitcroft */ 812a5516438SAndi Kleen static pgoff_t vma_hugecache_offset(struct hstate *h, 813a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 814e7c4b0bfSAndy Whitcroft { 815a5516438SAndi Kleen return ((address - vma->vm_start) >> huge_page_shift(h)) + 816a5516438SAndi Kleen (vma->vm_pgoff >> huge_page_order(h)); 817e7c4b0bfSAndy Whitcroft } 818e7c4b0bfSAndy Whitcroft 8190fe6e20bSNaoya Horiguchi pgoff_t linear_hugepage_index(struct vm_area_struct *vma, 8200fe6e20bSNaoya Horiguchi unsigned long address) 8210fe6e20bSNaoya Horiguchi { 8220fe6e20bSNaoya Horiguchi return vma_hugecache_offset(hstate_vma(vma), vma, address); 8230fe6e20bSNaoya Horiguchi } 824dee41079SDan Williams EXPORT_SYMBOL_GPL(linear_hugepage_index); 8250fe6e20bSNaoya Horiguchi 82684afd99bSAndy Whitcroft /* 82708fba699SMel Gorman * Return the size of the pages allocated when backing a VMA. In the majority 82808fba699SMel Gorman * cases this will be same size as used by the page table entries. 82908fba699SMel Gorman */ 83008fba699SMel Gorman unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) 83108fba699SMel Gorman { 83205ea8860SDan Williams if (vma->vm_ops && vma->vm_ops->pagesize) 83305ea8860SDan Williams return vma->vm_ops->pagesize(vma); 83408fba699SMel Gorman return PAGE_SIZE; 83508fba699SMel Gorman } 836f340ca0fSJoerg Roedel EXPORT_SYMBOL_GPL(vma_kernel_pagesize); 83708fba699SMel Gorman 83808fba699SMel Gorman /* 8393340289dSMel Gorman * Return the page size being used by the MMU to back a VMA. In the majority 8403340289dSMel Gorman * of cases, the page size used by the kernel matches the MMU size. On 84109135cc5SDan Williams * architectures where it differs, an architecture-specific 'strong' 84209135cc5SDan Williams * version of this symbol is required. 8433340289dSMel Gorman */ 84409135cc5SDan Williams __weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) 8453340289dSMel Gorman { 8463340289dSMel Gorman return vma_kernel_pagesize(vma); 8473340289dSMel Gorman } 8483340289dSMel Gorman 8493340289dSMel Gorman /* 85084afd99bSAndy Whitcroft * Flags for MAP_PRIVATE reservations. These are stored in the bottom 85184afd99bSAndy Whitcroft * bits of the reservation map pointer, which are always clear due to 85284afd99bSAndy Whitcroft * alignment. 85384afd99bSAndy Whitcroft */ 85484afd99bSAndy Whitcroft #define HPAGE_RESV_OWNER (1UL << 0) 85584afd99bSAndy Whitcroft #define HPAGE_RESV_UNMAPPED (1UL << 1) 85604f2cbe3SMel Gorman #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) 85784afd99bSAndy Whitcroft 858a1e78772SMel Gorman /* 859a1e78772SMel Gorman * These helpers are used to track how many pages are reserved for 860a1e78772SMel Gorman * faults in a MAP_PRIVATE mapping. Only the process that called mmap() 861a1e78772SMel Gorman * is guaranteed to have their future faults succeed. 862a1e78772SMel Gorman * 863a1e78772SMel Gorman * With the exception of reset_vma_resv_huge_pages() which is called at fork(), 864a1e78772SMel Gorman * the reserve counters are updated with the hugetlb_lock held. It is safe 865a1e78772SMel Gorman * to reset the VMA at fork() time as it is not in use yet and there is no 866a1e78772SMel Gorman * chance of the global counters getting corrupted as a result of the values. 86784afd99bSAndy Whitcroft * 86884afd99bSAndy Whitcroft * The private mapping reservation is represented in a subtly different 86984afd99bSAndy Whitcroft * manner to a shared mapping. A shared mapping has a region map associated 87084afd99bSAndy Whitcroft * with the underlying file, this region map represents the backing file 87184afd99bSAndy Whitcroft * pages which have ever had a reservation assigned which this persists even 87284afd99bSAndy Whitcroft * after the page is instantiated. A private mapping has a region map 87384afd99bSAndy Whitcroft * associated with the original mmap which is attached to all VMAs which 87484afd99bSAndy Whitcroft * reference it, this region map represents those offsets which have consumed 87584afd99bSAndy Whitcroft * reservation ie. where pages have been instantiated. 876a1e78772SMel Gorman */ 877e7c4b0bfSAndy Whitcroft static unsigned long get_vma_private_data(struct vm_area_struct *vma) 878e7c4b0bfSAndy Whitcroft { 879e7c4b0bfSAndy Whitcroft return (unsigned long)vma->vm_private_data; 880e7c4b0bfSAndy Whitcroft } 881e7c4b0bfSAndy Whitcroft 882e7c4b0bfSAndy Whitcroft static void set_vma_private_data(struct vm_area_struct *vma, 883e7c4b0bfSAndy Whitcroft unsigned long value) 884e7c4b0bfSAndy Whitcroft { 885e7c4b0bfSAndy Whitcroft vma->vm_private_data = (void *)value; 886e7c4b0bfSAndy Whitcroft } 887e7c4b0bfSAndy Whitcroft 888e9fe92aeSMina Almasry static void 889e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(struct resv_map *resv_map, 890e9fe92aeSMina Almasry struct hugetlb_cgroup *h_cg, 891e9fe92aeSMina Almasry struct hstate *h) 892e9fe92aeSMina Almasry { 893e9fe92aeSMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 894e9fe92aeSMina Almasry if (!h_cg || !h) { 895e9fe92aeSMina Almasry resv_map->reservation_counter = NULL; 896e9fe92aeSMina Almasry resv_map->pages_per_hpage = 0; 897e9fe92aeSMina Almasry resv_map->css = NULL; 898e9fe92aeSMina Almasry } else { 899e9fe92aeSMina Almasry resv_map->reservation_counter = 900e9fe92aeSMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 901e9fe92aeSMina Almasry resv_map->pages_per_hpage = pages_per_huge_page(h); 902e9fe92aeSMina Almasry resv_map->css = &h_cg->css; 903e9fe92aeSMina Almasry } 904e9fe92aeSMina Almasry #endif 905e9fe92aeSMina Almasry } 906e9fe92aeSMina Almasry 9079119a41eSJoonsoo Kim struct resv_map *resv_map_alloc(void) 90884afd99bSAndy Whitcroft { 90984afd99bSAndy Whitcroft struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); 9105e911373SMike Kravetz struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL); 9115e911373SMike Kravetz 9125e911373SMike Kravetz if (!resv_map || !rg) { 9135e911373SMike Kravetz kfree(resv_map); 9145e911373SMike Kravetz kfree(rg); 91584afd99bSAndy Whitcroft return NULL; 9165e911373SMike Kravetz } 91784afd99bSAndy Whitcroft 91884afd99bSAndy Whitcroft kref_init(&resv_map->refs); 9197b24d861SDavidlohr Bueso spin_lock_init(&resv_map->lock); 92084afd99bSAndy Whitcroft INIT_LIST_HEAD(&resv_map->regions); 92184afd99bSAndy Whitcroft 9225e911373SMike Kravetz resv_map->adds_in_progress = 0; 923e9fe92aeSMina Almasry /* 924e9fe92aeSMina Almasry * Initialize these to 0. On shared mappings, 0's here indicate these 925e9fe92aeSMina Almasry * fields don't do cgroup accounting. On private mappings, these will be 926e9fe92aeSMina Almasry * re-initialized to the proper values, to indicate that hugetlb cgroup 927e9fe92aeSMina Almasry * reservations are to be un-charged from here. 928e9fe92aeSMina Almasry */ 929e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, NULL, NULL); 9305e911373SMike Kravetz 9315e911373SMike Kravetz INIT_LIST_HEAD(&resv_map->region_cache); 9325e911373SMike Kravetz list_add(&rg->link, &resv_map->region_cache); 9335e911373SMike Kravetz resv_map->region_cache_count = 1; 9345e911373SMike Kravetz 93584afd99bSAndy Whitcroft return resv_map; 93684afd99bSAndy Whitcroft } 93784afd99bSAndy Whitcroft 9389119a41eSJoonsoo Kim void resv_map_release(struct kref *ref) 93984afd99bSAndy Whitcroft { 94084afd99bSAndy Whitcroft struct resv_map *resv_map = container_of(ref, struct resv_map, refs); 9415e911373SMike Kravetz struct list_head *head = &resv_map->region_cache; 9425e911373SMike Kravetz struct file_region *rg, *trg; 94384afd99bSAndy Whitcroft 94484afd99bSAndy Whitcroft /* Clear out any active regions before we release the map. */ 945feba16e2SMike Kravetz region_del(resv_map, 0, LONG_MAX); 9465e911373SMike Kravetz 9475e911373SMike Kravetz /* ... and any entries left in the cache */ 9485e911373SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 9495e911373SMike Kravetz list_del(&rg->link); 9505e911373SMike Kravetz kfree(rg); 9515e911373SMike Kravetz } 9525e911373SMike Kravetz 9535e911373SMike Kravetz VM_BUG_ON(resv_map->adds_in_progress); 9545e911373SMike Kravetz 95584afd99bSAndy Whitcroft kfree(resv_map); 95684afd99bSAndy Whitcroft } 95784afd99bSAndy Whitcroft 9584e35f483SJoonsoo Kim static inline struct resv_map *inode_resv_map(struct inode *inode) 9594e35f483SJoonsoo Kim { 960f27a5136SMike Kravetz /* 961f27a5136SMike Kravetz * At inode evict time, i_mapping may not point to the original 962f27a5136SMike Kravetz * address space within the inode. This original address space 963f27a5136SMike Kravetz * contains the pointer to the resv_map. So, always use the 964f27a5136SMike Kravetz * address space embedded within the inode. 965f27a5136SMike Kravetz * The VERY common case is inode->mapping == &inode->i_data but, 966f27a5136SMike Kravetz * this may not be true for device special inodes. 967f27a5136SMike Kravetz */ 968f27a5136SMike Kravetz return (struct resv_map *)(&inode->i_data)->private_data; 9694e35f483SJoonsoo Kim } 9704e35f483SJoonsoo Kim 97184afd99bSAndy Whitcroft static struct resv_map *vma_resv_map(struct vm_area_struct *vma) 972a1e78772SMel Gorman { 97381d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 9744e35f483SJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE) { 9754e35f483SJoonsoo Kim struct address_space *mapping = vma->vm_file->f_mapping; 9764e35f483SJoonsoo Kim struct inode *inode = mapping->host; 9774e35f483SJoonsoo Kim 9784e35f483SJoonsoo Kim return inode_resv_map(inode); 9794e35f483SJoonsoo Kim 9804e35f483SJoonsoo Kim } else { 98184afd99bSAndy Whitcroft return (struct resv_map *)(get_vma_private_data(vma) & 98284afd99bSAndy Whitcroft ~HPAGE_RESV_MASK); 9834e35f483SJoonsoo Kim } 984a1e78772SMel Gorman } 985a1e78772SMel Gorman 98684afd99bSAndy Whitcroft static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) 987a1e78772SMel Gorman { 98881d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 98981d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 990a1e78772SMel Gorman 99184afd99bSAndy Whitcroft set_vma_private_data(vma, (get_vma_private_data(vma) & 99284afd99bSAndy Whitcroft HPAGE_RESV_MASK) | (unsigned long)map); 99304f2cbe3SMel Gorman } 99404f2cbe3SMel Gorman 99504f2cbe3SMel Gorman static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) 99604f2cbe3SMel Gorman { 99781d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 99881d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 999e7c4b0bfSAndy Whitcroft 1000e7c4b0bfSAndy Whitcroft set_vma_private_data(vma, get_vma_private_data(vma) | flags); 100104f2cbe3SMel Gorman } 100204f2cbe3SMel Gorman 100304f2cbe3SMel Gorman static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) 100404f2cbe3SMel Gorman { 100581d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 1006e7c4b0bfSAndy Whitcroft 1007e7c4b0bfSAndy Whitcroft return (get_vma_private_data(vma) & flag) != 0; 1008a1e78772SMel Gorman } 1009a1e78772SMel Gorman 101004f2cbe3SMel Gorman /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ 1011a1e78772SMel Gorman void reset_vma_resv_huge_pages(struct vm_area_struct *vma) 1012a1e78772SMel Gorman { 101381d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 1014f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 1015a1e78772SMel Gorman vma->vm_private_data = (void *)0; 1016a1e78772SMel Gorman } 1017a1e78772SMel Gorman 1018550a7d60SMina Almasry /* 1019550a7d60SMina Almasry * Reset and decrement one ref on hugepage private reservation. 1020550a7d60SMina Almasry * Called with mm->mmap_sem writer semaphore held. 1021550a7d60SMina Almasry * This function should be only used by move_vma() and operate on 1022550a7d60SMina Almasry * same sized vma. It should never come here with last ref on the 1023550a7d60SMina Almasry * reservation. 1024550a7d60SMina Almasry */ 1025550a7d60SMina Almasry void clear_vma_resv_huge_pages(struct vm_area_struct *vma) 1026550a7d60SMina Almasry { 1027550a7d60SMina Almasry /* 1028550a7d60SMina Almasry * Clear the old hugetlb private page reservation. 1029550a7d60SMina Almasry * It has already been transferred to new_vma. 1030550a7d60SMina Almasry * 1031550a7d60SMina Almasry * During a mremap() operation of a hugetlb vma we call move_vma() 1032550a7d60SMina Almasry * which copies vma into new_vma and unmaps vma. After the copy 1033550a7d60SMina Almasry * operation both new_vma and vma share a reference to the resv_map 1034550a7d60SMina Almasry * struct, and at that point vma is about to be unmapped. We don't 1035550a7d60SMina Almasry * want to return the reservation to the pool at unmap of vma because 1036550a7d60SMina Almasry * the reservation still lives on in new_vma, so simply decrement the 1037550a7d60SMina Almasry * ref here and remove the resv_map reference from this vma. 1038550a7d60SMina Almasry */ 1039550a7d60SMina Almasry struct resv_map *reservations = vma_resv_map(vma); 1040550a7d60SMina Almasry 1041afe041c2SBui Quang Minh if (reservations && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 1042afe041c2SBui Quang Minh resv_map_put_hugetlb_cgroup_uncharge_info(reservations); 1043550a7d60SMina Almasry kref_put(&reservations->refs, resv_map_release); 1044afe041c2SBui Quang Minh } 1045550a7d60SMina Almasry 1046550a7d60SMina Almasry reset_vma_resv_huge_pages(vma); 1047550a7d60SMina Almasry } 1048550a7d60SMina Almasry 1049a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 1050559ec2f8SNicholas Krause static bool vma_has_reserves(struct vm_area_struct *vma, long chg) 1051a1e78772SMel Gorman { 1052af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_NORESERVE) { 1053af0ed73eSJoonsoo Kim /* 1054af0ed73eSJoonsoo Kim * This address is already reserved by other process(chg == 0), 1055af0ed73eSJoonsoo Kim * so, we should decrement reserved count. Without decrementing, 1056af0ed73eSJoonsoo Kim * reserve count remains after releasing inode, because this 1057af0ed73eSJoonsoo Kim * allocated page will go into page cache and is regarded as 1058af0ed73eSJoonsoo Kim * coming from reserved pool in releasing step. Currently, we 1059af0ed73eSJoonsoo Kim * don't have any other solution to deal with this situation 1060af0ed73eSJoonsoo Kim * properly, so add work-around here. 1061af0ed73eSJoonsoo Kim */ 1062af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE && chg == 0) 1063559ec2f8SNicholas Krause return true; 1064af0ed73eSJoonsoo Kim else 1065559ec2f8SNicholas Krause return false; 1066af0ed73eSJoonsoo Kim } 1067a63884e9SJoonsoo Kim 1068a63884e9SJoonsoo Kim /* Shared mappings always use reserves */ 10691fb1b0e9SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 10701fb1b0e9SMike Kravetz /* 10711fb1b0e9SMike Kravetz * We know VM_NORESERVE is not set. Therefore, there SHOULD 10721fb1b0e9SMike Kravetz * be a region map for all pages. The only situation where 10731fb1b0e9SMike Kravetz * there is no region map is if a hole was punched via 10747c8de358SEthon Paul * fallocate. In this case, there really are no reserves to 10751fb1b0e9SMike Kravetz * use. This situation is indicated if chg != 0. 10761fb1b0e9SMike Kravetz */ 10771fb1b0e9SMike Kravetz if (chg) 10781fb1b0e9SMike Kravetz return false; 10791fb1b0e9SMike Kravetz else 1080559ec2f8SNicholas Krause return true; 10811fb1b0e9SMike Kravetz } 1082a63884e9SJoonsoo Kim 1083a63884e9SJoonsoo Kim /* 1084a63884e9SJoonsoo Kim * Only the process that called mmap() has reserves for 1085a63884e9SJoonsoo Kim * private mappings. 1086a63884e9SJoonsoo Kim */ 108767961f9dSMike Kravetz if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 108867961f9dSMike Kravetz /* 108967961f9dSMike Kravetz * Like the shared case above, a hole punch or truncate 109067961f9dSMike Kravetz * could have been performed on the private mapping. 109167961f9dSMike Kravetz * Examine the value of chg to determine if reserves 109267961f9dSMike Kravetz * actually exist or were previously consumed. 109367961f9dSMike Kravetz * Very Subtle - The value of chg comes from a previous 109467961f9dSMike Kravetz * call to vma_needs_reserves(). The reserve map for 109567961f9dSMike Kravetz * private mappings has different (opposite) semantics 109667961f9dSMike Kravetz * than that of shared mappings. vma_needs_reserves() 109767961f9dSMike Kravetz * has already taken this difference in semantics into 109867961f9dSMike Kravetz * account. Therefore, the meaning of chg is the same 109967961f9dSMike Kravetz * as in the shared case above. Code could easily be 110067961f9dSMike Kravetz * combined, but keeping it separate draws attention to 110167961f9dSMike Kravetz * subtle differences. 110267961f9dSMike Kravetz */ 110367961f9dSMike Kravetz if (chg) 110467961f9dSMike Kravetz return false; 110567961f9dSMike Kravetz else 1106559ec2f8SNicholas Krause return true; 110767961f9dSMike Kravetz } 1108a63884e9SJoonsoo Kim 1109559ec2f8SNicholas Krause return false; 1110a1e78772SMel Gorman } 1111a1e78772SMel Gorman 1112a5516438SAndi Kleen static void enqueue_huge_page(struct hstate *h, struct page *page) 11131da177e4SLinus Torvalds { 11141da177e4SLinus Torvalds int nid = page_to_nid(page); 11159487ca60SMike Kravetz 11169487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1117b65a4edaSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1118b65a4edaSMike Kravetz 11190edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_freelists[nid]); 1120a5516438SAndi Kleen h->free_huge_pages++; 1121a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 11226c037149SMike Kravetz SetHPageFreed(page); 11231da177e4SLinus Torvalds } 11241da177e4SLinus Torvalds 112594310cbcSAnshuman Khandual static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) 1126bf50bab2SNaoya Horiguchi { 1127bf50bab2SNaoya Horiguchi struct page *page; 11281a08ae36SPavel Tatashin bool pin = !!(current->flags & PF_MEMALLOC_PIN); 1129bf50bab2SNaoya Horiguchi 11309487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1131bbe88753SJoonsoo Kim list_for_each_entry(page, &h->hugepage_freelists[nid], lru) { 11326077c943SAlex Sierra if (pin && !is_longterm_pinnable_page(page)) 1133bbe88753SJoonsoo Kim continue; 1134bbe88753SJoonsoo Kim 11356664bfc8SWei Yang if (PageHWPoison(page)) 11366664bfc8SWei Yang continue; 1137bbe88753SJoonsoo Kim 11380edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_activelist); 1139a9869b83SNaoya Horiguchi set_page_refcounted(page); 11406c037149SMike Kravetz ClearHPageFreed(page); 1141bf50bab2SNaoya Horiguchi h->free_huge_pages--; 1142bf50bab2SNaoya Horiguchi h->free_huge_pages_node[nid]--; 1143bf50bab2SNaoya Horiguchi return page; 1144bf50bab2SNaoya Horiguchi } 1145bf50bab2SNaoya Horiguchi 11466664bfc8SWei Yang return NULL; 11476664bfc8SWei Yang } 11486664bfc8SWei Yang 11493e59fcb0SMichal Hocko static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid, 11503e59fcb0SMichal Hocko nodemask_t *nmask) 115194310cbcSAnshuman Khandual { 11523e59fcb0SMichal Hocko unsigned int cpuset_mems_cookie; 11533e59fcb0SMichal Hocko struct zonelist *zonelist; 11543e59fcb0SMichal Hocko struct zone *zone; 11553e59fcb0SMichal Hocko struct zoneref *z; 115698fa15f3SAnshuman Khandual int node = NUMA_NO_NODE; 11573e59fcb0SMichal Hocko 11583e59fcb0SMichal Hocko zonelist = node_zonelist(nid, gfp_mask); 11593e59fcb0SMichal Hocko 11603e59fcb0SMichal Hocko retry_cpuset: 11613e59fcb0SMichal Hocko cpuset_mems_cookie = read_mems_allowed_begin(); 11623e59fcb0SMichal Hocko for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) { 116394310cbcSAnshuman Khandual struct page *page; 116494310cbcSAnshuman Khandual 11653e59fcb0SMichal Hocko if (!cpuset_zone_allowed(zone, gfp_mask)) 11663e59fcb0SMichal Hocko continue; 11673e59fcb0SMichal Hocko /* 11683e59fcb0SMichal Hocko * no need to ask again on the same node. Pool is node rather than 11693e59fcb0SMichal Hocko * zone aware 11703e59fcb0SMichal Hocko */ 11713e59fcb0SMichal Hocko if (zone_to_nid(zone) == node) 11723e59fcb0SMichal Hocko continue; 11733e59fcb0SMichal Hocko node = zone_to_nid(zone); 117494310cbcSAnshuman Khandual 117594310cbcSAnshuman Khandual page = dequeue_huge_page_node_exact(h, node); 117694310cbcSAnshuman Khandual if (page) 117794310cbcSAnshuman Khandual return page; 117894310cbcSAnshuman Khandual } 11793e59fcb0SMichal Hocko if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie))) 11803e59fcb0SMichal Hocko goto retry_cpuset; 11813e59fcb0SMichal Hocko 118294310cbcSAnshuman Khandual return NULL; 118394310cbcSAnshuman Khandual } 118494310cbcSAnshuman Khandual 1185a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 1186a5516438SAndi Kleen struct vm_area_struct *vma, 1187af0ed73eSJoonsoo Kim unsigned long address, int avoid_reserve, 1188af0ed73eSJoonsoo Kim long chg) 11891da177e4SLinus Torvalds { 1190cfcaa66fSBen Widawsky struct page *page = NULL; 1191480eccf9SLee Schermerhorn struct mempolicy *mpol; 119204ec6264SVlastimil Babka gfp_t gfp_mask; 11933e59fcb0SMichal Hocko nodemask_t *nodemask; 119404ec6264SVlastimil Babka int nid; 11951da177e4SLinus Torvalds 1196a1e78772SMel Gorman /* 1197a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 1198a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 1199a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 1200a1e78772SMel Gorman */ 1201af0ed73eSJoonsoo Kim if (!vma_has_reserves(vma, chg) && 1202a5516438SAndi Kleen h->free_huge_pages - h->resv_huge_pages == 0) 1203c0ff7453SMiao Xie goto err; 1204a1e78772SMel Gorman 120504f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 1206a5516438SAndi Kleen if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) 12076eab04a8SJustin P. Mattock goto err; 120804f2cbe3SMel Gorman 120904ec6264SVlastimil Babka gfp_mask = htlb_alloc_mask(h); 121004ec6264SVlastimil Babka nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 1211cfcaa66fSBen Widawsky 1212cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 12133e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1214cfcaa66fSBen Widawsky 1215cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 1216cfcaa66fSBen Widawsky nodemask = NULL; 1217cfcaa66fSBen Widawsky } 1218cfcaa66fSBen Widawsky 1219cfcaa66fSBen Widawsky if (!page) 1220cfcaa66fSBen Widawsky page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1221cfcaa66fSBen Widawsky 12223e59fcb0SMichal Hocko if (page && !avoid_reserve && vma_has_reserves(vma, chg)) { 1223d6995da3SMike Kravetz SetHPageRestoreReserve(page); 1224a63884e9SJoonsoo Kim h->resv_huge_pages--; 1225bf50bab2SNaoya Horiguchi } 1226cc9a6c87SMel Gorman 1227cc9a6c87SMel Gorman mpol_cond_put(mpol); 1228cc9a6c87SMel Gorman return page; 1229cc9a6c87SMel Gorman 1230c0ff7453SMiao Xie err: 1231cc9a6c87SMel Gorman return NULL; 12321da177e4SLinus Torvalds } 12331da177e4SLinus Torvalds 12341cac6f2cSLuiz Capitulino /* 12351cac6f2cSLuiz Capitulino * common helper functions for hstate_next_node_to_{alloc|free}. 12361cac6f2cSLuiz Capitulino * We may have allocated or freed a huge page based on a different 12371cac6f2cSLuiz Capitulino * nodes_allowed previously, so h->next_node_to_{alloc|free} might 12381cac6f2cSLuiz Capitulino * be outside of *nodes_allowed. Ensure that we use an allowed 12391cac6f2cSLuiz Capitulino * node for alloc or free. 12401cac6f2cSLuiz Capitulino */ 12411cac6f2cSLuiz Capitulino static int next_node_allowed(int nid, nodemask_t *nodes_allowed) 12421cac6f2cSLuiz Capitulino { 12430edaf86cSAndrew Morton nid = next_node_in(nid, *nodes_allowed); 12441cac6f2cSLuiz Capitulino VM_BUG_ON(nid >= MAX_NUMNODES); 12451cac6f2cSLuiz Capitulino 12461cac6f2cSLuiz Capitulino return nid; 12471cac6f2cSLuiz Capitulino } 12481cac6f2cSLuiz Capitulino 12491cac6f2cSLuiz Capitulino static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) 12501cac6f2cSLuiz Capitulino { 12511cac6f2cSLuiz Capitulino if (!node_isset(nid, *nodes_allowed)) 12521cac6f2cSLuiz Capitulino nid = next_node_allowed(nid, nodes_allowed); 12531cac6f2cSLuiz Capitulino return nid; 12541cac6f2cSLuiz Capitulino } 12551cac6f2cSLuiz Capitulino 12561cac6f2cSLuiz Capitulino /* 12571cac6f2cSLuiz Capitulino * returns the previously saved node ["this node"] from which to 12581cac6f2cSLuiz Capitulino * allocate a persistent huge page for the pool and advance the 12591cac6f2cSLuiz Capitulino * next node from which to allocate, handling wrap at end of node 12601cac6f2cSLuiz Capitulino * mask. 12611cac6f2cSLuiz Capitulino */ 12621cac6f2cSLuiz Capitulino static int hstate_next_node_to_alloc(struct hstate *h, 12631cac6f2cSLuiz Capitulino nodemask_t *nodes_allowed) 12641cac6f2cSLuiz Capitulino { 12651cac6f2cSLuiz Capitulino int nid; 12661cac6f2cSLuiz Capitulino 12671cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12681cac6f2cSLuiz Capitulino 12691cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); 12701cac6f2cSLuiz Capitulino h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); 12711cac6f2cSLuiz Capitulino 12721cac6f2cSLuiz Capitulino return nid; 12731cac6f2cSLuiz Capitulino } 12741cac6f2cSLuiz Capitulino 12751cac6f2cSLuiz Capitulino /* 127610c6ec49SMike Kravetz * helper for remove_pool_huge_page() - return the previously saved 12771cac6f2cSLuiz Capitulino * node ["this node"] from which to free a huge page. Advance the 12781cac6f2cSLuiz Capitulino * next node id whether or not we find a free huge page to free so 12791cac6f2cSLuiz Capitulino * that the next attempt to free addresses the next node. 12801cac6f2cSLuiz Capitulino */ 12811cac6f2cSLuiz Capitulino static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) 12821cac6f2cSLuiz Capitulino { 12831cac6f2cSLuiz Capitulino int nid; 12841cac6f2cSLuiz Capitulino 12851cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12861cac6f2cSLuiz Capitulino 12871cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); 12881cac6f2cSLuiz Capitulino h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); 12891cac6f2cSLuiz Capitulino 12901cac6f2cSLuiz Capitulino return nid; 12911cac6f2cSLuiz Capitulino } 12921cac6f2cSLuiz Capitulino 12931cac6f2cSLuiz Capitulino #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ 12941cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 12951cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 12961cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ 12971cac6f2cSLuiz Capitulino nr_nodes--) 12981cac6f2cSLuiz Capitulino 12991cac6f2cSLuiz Capitulino #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ 13001cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 13011cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 13021cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_free(hs, mask)) || 1); \ 13031cac6f2cSLuiz Capitulino nr_nodes--) 13041cac6f2cSLuiz Capitulino 13058531fc6fSMike Kravetz /* used to demote non-gigantic_huge pages as well */ 130634d9e35bSMike Kravetz static void __destroy_compound_gigantic_page(struct page *page, 130734d9e35bSMike Kravetz unsigned int order, bool demote) 1308944d9fecSLuiz Capitulino { 1309944d9fecSLuiz Capitulino int i; 1310944d9fecSLuiz Capitulino int nr_pages = 1 << order; 1311944d9fecSLuiz Capitulino struct page *p = page + 1; 1312944d9fecSLuiz Capitulino 1313c8cc708aSGerald Schaefer atomic_set(compound_mapcount_ptr(page), 0); 131447e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 131547e29d32SJohn Hubbard 1316944d9fecSLuiz Capitulino for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 1317a01f4390SMike Kravetz p->mapping = NULL; 13181d798ca3SKirill A. Shutemov clear_compound_head(p); 131934d9e35bSMike Kravetz if (!demote) 1320944d9fecSLuiz Capitulino set_page_refcounted(p); 1321944d9fecSLuiz Capitulino } 1322944d9fecSLuiz Capitulino 1323944d9fecSLuiz Capitulino set_compound_order(page, 0); 13245232c63fSMatthew Wilcox (Oracle) #ifdef CONFIG_64BIT 1325ba9c1201SGerald Schaefer page[1].compound_nr = 0; 13265232c63fSMatthew Wilcox (Oracle) #endif 1327944d9fecSLuiz Capitulino __ClearPageHead(page); 1328944d9fecSLuiz Capitulino } 1329944d9fecSLuiz Capitulino 13308531fc6fSMike Kravetz static void destroy_compound_hugetlb_page_for_demote(struct page *page, 13318531fc6fSMike Kravetz unsigned int order) 13328531fc6fSMike Kravetz { 13338531fc6fSMike Kravetz __destroy_compound_gigantic_page(page, order, true); 13348531fc6fSMike Kravetz } 13358531fc6fSMike Kravetz 13368531fc6fSMike Kravetz #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE 133734d9e35bSMike Kravetz static void destroy_compound_gigantic_page(struct page *page, 133834d9e35bSMike Kravetz unsigned int order) 133934d9e35bSMike Kravetz { 134034d9e35bSMike Kravetz __destroy_compound_gigantic_page(page, order, false); 134134d9e35bSMike Kravetz } 134234d9e35bSMike Kravetz 1343d00181b9SKirill A. Shutemov static void free_gigantic_page(struct page *page, unsigned int order) 1344944d9fecSLuiz Capitulino { 1345cf11e85fSRoman Gushchin /* 1346cf11e85fSRoman Gushchin * If the page isn't allocated using the cma allocator, 1347cf11e85fSRoman Gushchin * cma_release() returns false. 1348cf11e85fSRoman Gushchin */ 1349dbda8feaSBarry Song #ifdef CONFIG_CMA 1350dbda8feaSBarry Song if (cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order)) 1351cf11e85fSRoman Gushchin return; 1352dbda8feaSBarry Song #endif 1353cf11e85fSRoman Gushchin 1354944d9fecSLuiz Capitulino free_contig_range(page_to_pfn(page), 1 << order); 1355944d9fecSLuiz Capitulino } 1356944d9fecSLuiz Capitulino 13574eb0716eSAlexandre Ghiti #ifdef CONFIG_CONTIG_ALLOC 1358d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 1359d9cc948fSMichal Hocko int nid, nodemask_t *nodemask) 1360944d9fecSLuiz Capitulino { 136104adbc3fSMiaohe Lin unsigned long nr_pages = pages_per_huge_page(h); 1362953f064aSLi Xinhai if (nid == NUMA_NO_NODE) 1363953f064aSLi Xinhai nid = numa_mem_id(); 1364944d9fecSLuiz Capitulino 1365dbda8feaSBarry Song #ifdef CONFIG_CMA 1366dbda8feaSBarry Song { 1367cf11e85fSRoman Gushchin struct page *page; 1368cf11e85fSRoman Gushchin int node; 1369cf11e85fSRoman Gushchin 1370953f064aSLi Xinhai if (hugetlb_cma[nid]) { 1371953f064aSLi Xinhai page = cma_alloc(hugetlb_cma[nid], nr_pages, 1372953f064aSLi Xinhai huge_page_order(h), true); 1373953f064aSLi Xinhai if (page) 1374953f064aSLi Xinhai return page; 1375953f064aSLi Xinhai } 1376953f064aSLi Xinhai 1377953f064aSLi Xinhai if (!(gfp_mask & __GFP_THISNODE)) { 1378cf11e85fSRoman Gushchin for_each_node_mask(node, *nodemask) { 1379953f064aSLi Xinhai if (node == nid || !hugetlb_cma[node]) 1380cf11e85fSRoman Gushchin continue; 1381cf11e85fSRoman Gushchin 1382cf11e85fSRoman Gushchin page = cma_alloc(hugetlb_cma[node], nr_pages, 1383cf11e85fSRoman Gushchin huge_page_order(h), true); 1384cf11e85fSRoman Gushchin if (page) 1385cf11e85fSRoman Gushchin return page; 1386cf11e85fSRoman Gushchin } 1387cf11e85fSRoman Gushchin } 1388953f064aSLi Xinhai } 1389dbda8feaSBarry Song #endif 1390cf11e85fSRoman Gushchin 13915e27a2dfSAnshuman Khandual return alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask); 1392944d9fecSLuiz Capitulino } 1393944d9fecSLuiz Capitulino 13944eb0716eSAlexandre Ghiti #else /* !CONFIG_CONTIG_ALLOC */ 13954eb0716eSAlexandre Ghiti static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 13964eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 13974eb0716eSAlexandre Ghiti { 13984eb0716eSAlexandre Ghiti return NULL; 13994eb0716eSAlexandre Ghiti } 14004eb0716eSAlexandre Ghiti #endif /* CONFIG_CONTIG_ALLOC */ 1401944d9fecSLuiz Capitulino 1402e1073d1eSAneesh Kumar K.V #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ 1403d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 14044eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 14054eb0716eSAlexandre Ghiti { 14064eb0716eSAlexandre Ghiti return NULL; 14074eb0716eSAlexandre Ghiti } 1408d00181b9SKirill A. Shutemov static inline void free_gigantic_page(struct page *page, unsigned int order) { } 1409944d9fecSLuiz Capitulino static inline void destroy_compound_gigantic_page(struct page *page, 1410d00181b9SKirill A. Shutemov unsigned int order) { } 1411944d9fecSLuiz Capitulino #endif 1412944d9fecSLuiz Capitulino 14136eb4e88aSMike Kravetz /* 14146eb4e88aSMike Kravetz * Remove hugetlb page from lists, and update dtor so that page appears 141534d9e35bSMike Kravetz * as just a compound page. 141634d9e35bSMike Kravetz * 141734d9e35bSMike Kravetz * A reference is held on the page, except in the case of demote. 14186eb4e88aSMike Kravetz * 14196eb4e88aSMike Kravetz * Must be called with hugetlb lock held. 14206eb4e88aSMike Kravetz */ 142134d9e35bSMike Kravetz static void __remove_hugetlb_page(struct hstate *h, struct page *page, 142234d9e35bSMike Kravetz bool adjust_surplus, 142334d9e35bSMike Kravetz bool demote) 14246eb4e88aSMike Kravetz { 14256eb4e88aSMike Kravetz int nid = page_to_nid(page); 14266eb4e88aSMike Kravetz 14276eb4e88aSMike Kravetz VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); 14286eb4e88aSMike Kravetz VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); 14296eb4e88aSMike Kravetz 14309487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 14316eb4e88aSMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 14326eb4e88aSMike Kravetz return; 14336eb4e88aSMike Kravetz 14346eb4e88aSMike Kravetz list_del(&page->lru); 14356eb4e88aSMike Kravetz 14366eb4e88aSMike Kravetz if (HPageFreed(page)) { 14376eb4e88aSMike Kravetz h->free_huge_pages--; 14386eb4e88aSMike Kravetz h->free_huge_pages_node[nid]--; 14396eb4e88aSMike Kravetz } 14406eb4e88aSMike Kravetz if (adjust_surplus) { 14416eb4e88aSMike Kravetz h->surplus_huge_pages--; 14426eb4e88aSMike Kravetz h->surplus_huge_pages_node[nid]--; 14436eb4e88aSMike Kravetz } 14446eb4e88aSMike Kravetz 1445e32d20c0SMike Kravetz /* 1446e32d20c0SMike Kravetz * Very subtle 1447e32d20c0SMike Kravetz * 1448e32d20c0SMike Kravetz * For non-gigantic pages set the destructor to the normal compound 1449e32d20c0SMike Kravetz * page dtor. This is needed in case someone takes an additional 1450e32d20c0SMike Kravetz * temporary ref to the page, and freeing is delayed until they drop 1451e32d20c0SMike Kravetz * their reference. 1452e32d20c0SMike Kravetz * 1453e32d20c0SMike Kravetz * For gigantic pages set the destructor to the null dtor. This 1454e32d20c0SMike Kravetz * destructor will never be called. Before freeing the gigantic 1455e32d20c0SMike Kravetz * page destroy_compound_gigantic_page will turn the compound page 1456e32d20c0SMike Kravetz * into a simple group of pages. After this the destructor does not 1457e32d20c0SMike Kravetz * apply. 1458e32d20c0SMike Kravetz * 1459e32d20c0SMike Kravetz * This handles the case where more than one ref is held when and 1460e32d20c0SMike Kravetz * after update_and_free_page is called. 146134d9e35bSMike Kravetz * 146234d9e35bSMike Kravetz * In the case of demote we do not ref count the page as it will soon 146334d9e35bSMike Kravetz * be turned into a page of smaller size. 1464e32d20c0SMike Kravetz */ 146534d9e35bSMike Kravetz if (!demote) 14666eb4e88aSMike Kravetz set_page_refcounted(page); 1467e32d20c0SMike Kravetz if (hstate_is_gigantic(h)) 14686eb4e88aSMike Kravetz set_compound_page_dtor(page, NULL_COMPOUND_DTOR); 1469e32d20c0SMike Kravetz else 1470e32d20c0SMike Kravetz set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); 14716eb4e88aSMike Kravetz 14726eb4e88aSMike Kravetz h->nr_huge_pages--; 14736eb4e88aSMike Kravetz h->nr_huge_pages_node[nid]--; 14746eb4e88aSMike Kravetz } 14756eb4e88aSMike Kravetz 147634d9e35bSMike Kravetz static void remove_hugetlb_page(struct hstate *h, struct page *page, 147734d9e35bSMike Kravetz bool adjust_surplus) 147834d9e35bSMike Kravetz { 147934d9e35bSMike Kravetz __remove_hugetlb_page(h, page, adjust_surplus, false); 148034d9e35bSMike Kravetz } 148134d9e35bSMike Kravetz 14828531fc6fSMike Kravetz static void remove_hugetlb_page_for_demote(struct hstate *h, struct page *page, 14838531fc6fSMike Kravetz bool adjust_surplus) 14848531fc6fSMike Kravetz { 14858531fc6fSMike Kravetz __remove_hugetlb_page(h, page, adjust_surplus, true); 14868531fc6fSMike Kravetz } 14878531fc6fSMike Kravetz 1488ad2fa371SMuchun Song static void add_hugetlb_page(struct hstate *h, struct page *page, 1489ad2fa371SMuchun Song bool adjust_surplus) 1490ad2fa371SMuchun Song { 1491ad2fa371SMuchun Song int zeroed; 1492ad2fa371SMuchun Song int nid = page_to_nid(page); 1493ad2fa371SMuchun Song 1494ad2fa371SMuchun Song VM_BUG_ON_PAGE(!HPageVmemmapOptimized(page), page); 1495ad2fa371SMuchun Song 1496ad2fa371SMuchun Song lockdep_assert_held(&hugetlb_lock); 1497ad2fa371SMuchun Song 1498ad2fa371SMuchun Song INIT_LIST_HEAD(&page->lru); 1499ad2fa371SMuchun Song h->nr_huge_pages++; 1500ad2fa371SMuchun Song h->nr_huge_pages_node[nid]++; 1501ad2fa371SMuchun Song 1502ad2fa371SMuchun Song if (adjust_surplus) { 1503ad2fa371SMuchun Song h->surplus_huge_pages++; 1504ad2fa371SMuchun Song h->surplus_huge_pages_node[nid]++; 1505ad2fa371SMuchun Song } 1506ad2fa371SMuchun Song 1507ad2fa371SMuchun Song set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1508ad2fa371SMuchun Song set_page_private(page, 0); 1509ad2fa371SMuchun Song SetHPageVmemmapOptimized(page); 1510ad2fa371SMuchun Song 1511ad2fa371SMuchun Song /* 1512b65a4edaSMike Kravetz * This page is about to be managed by the hugetlb allocator and 1513b65a4edaSMike Kravetz * should have no users. Drop our reference, and check for others 1514b65a4edaSMike Kravetz * just in case. 1515ad2fa371SMuchun Song */ 1516ad2fa371SMuchun Song zeroed = put_page_testzero(page); 1517b65a4edaSMike Kravetz if (!zeroed) 1518b65a4edaSMike Kravetz /* 1519b65a4edaSMike Kravetz * It is VERY unlikely soneone else has taken a ref on 1520b65a4edaSMike Kravetz * the page. In this case, we simply return as the 1521b65a4edaSMike Kravetz * hugetlb destructor (free_huge_page) will be called 1522b65a4edaSMike Kravetz * when this other ref is dropped. 1523b65a4edaSMike Kravetz */ 1524b65a4edaSMike Kravetz return; 1525b65a4edaSMike Kravetz 1526ad2fa371SMuchun Song arch_clear_hugepage_flags(page); 1527ad2fa371SMuchun Song enqueue_huge_page(h, page); 1528ad2fa371SMuchun Song } 1529ad2fa371SMuchun Song 1530b65d4adbSMuchun Song static void __update_and_free_page(struct hstate *h, struct page *page) 15316af2acb6SAdam Litke { 15326af2acb6SAdam Litke int i; 1533dbfee5aeSMike Kravetz struct page *subpage = page; 1534a5516438SAndi Kleen 15354eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 1536944d9fecSLuiz Capitulino return; 153718229df5SAndy Whitcroft 15385981611dSMuchun Song if (hugetlb_vmemmap_alloc(h, page)) { 1539ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 1540ad2fa371SMuchun Song /* 1541ad2fa371SMuchun Song * If we cannot allocate vmemmap pages, just refuse to free the 1542ad2fa371SMuchun Song * page and put the page back on the hugetlb free list and treat 1543ad2fa371SMuchun Song * as a surplus page. 1544ad2fa371SMuchun Song */ 1545ad2fa371SMuchun Song add_hugetlb_page(h, page, true); 1546ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 1547ad2fa371SMuchun Song return; 1548ad2fa371SMuchun Song } 1549ad2fa371SMuchun Song 1550dbfee5aeSMike Kravetz for (i = 0; i < pages_per_huge_page(h); 1551dbfee5aeSMike Kravetz i++, subpage = mem_map_next(subpage, page, i)) { 1552dbfee5aeSMike Kravetz subpage->flags &= ~(1 << PG_locked | 1 << PG_error | 155332f84528SChris Forbes 1 << PG_referenced | 1 << PG_dirty | 1554a7407a27SLuiz Capitulino 1 << PG_active | 1 << PG_private | 1555a7407a27SLuiz Capitulino 1 << PG_writeback); 15566af2acb6SAdam Litke } 1557a01f4390SMike Kravetz 1558a01f4390SMike Kravetz /* 1559a01f4390SMike Kravetz * Non-gigantic pages demoted from CMA allocated gigantic pages 1560a01f4390SMike Kravetz * need to be given back to CMA in free_gigantic_page. 1561a01f4390SMike Kravetz */ 1562a01f4390SMike Kravetz if (hstate_is_gigantic(h) || 1563a01f4390SMike Kravetz hugetlb_cma_page(page, huge_page_order(h))) { 1564944d9fecSLuiz Capitulino destroy_compound_gigantic_page(page, huge_page_order(h)); 1565944d9fecSLuiz Capitulino free_gigantic_page(page, huge_page_order(h)); 1566944d9fecSLuiz Capitulino } else { 1567a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 15686af2acb6SAdam Litke } 1569944d9fecSLuiz Capitulino } 15706af2acb6SAdam Litke 1571b65d4adbSMuchun Song /* 1572b65d4adbSMuchun Song * As update_and_free_page() can be called under any context, so we cannot 1573b65d4adbSMuchun Song * use GFP_KERNEL to allocate vmemmap pages. However, we can defer the 1574b65d4adbSMuchun Song * actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate 1575b65d4adbSMuchun Song * the vmemmap pages. 1576b65d4adbSMuchun Song * 1577b65d4adbSMuchun Song * free_hpage_workfn() locklessly retrieves the linked list of pages to be 1578b65d4adbSMuchun Song * freed and frees them one-by-one. As the page->mapping pointer is going 1579b65d4adbSMuchun Song * to be cleared in free_hpage_workfn() anyway, it is reused as the llist_node 1580b65d4adbSMuchun Song * structure of a lockless linked list of huge pages to be freed. 1581b65d4adbSMuchun Song */ 1582b65d4adbSMuchun Song static LLIST_HEAD(hpage_freelist); 1583b65d4adbSMuchun Song 1584b65d4adbSMuchun Song static void free_hpage_workfn(struct work_struct *work) 1585b65d4adbSMuchun Song { 1586b65d4adbSMuchun Song struct llist_node *node; 1587b65d4adbSMuchun Song 1588b65d4adbSMuchun Song node = llist_del_all(&hpage_freelist); 1589b65d4adbSMuchun Song 1590b65d4adbSMuchun Song while (node) { 1591b65d4adbSMuchun Song struct page *page; 1592b65d4adbSMuchun Song struct hstate *h; 1593b65d4adbSMuchun Song 1594b65d4adbSMuchun Song page = container_of((struct address_space **)node, 1595b65d4adbSMuchun Song struct page, mapping); 1596b65d4adbSMuchun Song node = node->next; 1597b65d4adbSMuchun Song page->mapping = NULL; 1598b65d4adbSMuchun Song /* 1599b65d4adbSMuchun Song * The VM_BUG_ON_PAGE(!PageHuge(page), page) in page_hstate() 1600b65d4adbSMuchun Song * is going to trigger because a previous call to 1601b65d4adbSMuchun Song * remove_hugetlb_page() will set_compound_page_dtor(page, 1602b65d4adbSMuchun Song * NULL_COMPOUND_DTOR), so do not use page_hstate() directly. 1603b65d4adbSMuchun Song */ 1604b65d4adbSMuchun Song h = size_to_hstate(page_size(page)); 1605b65d4adbSMuchun Song 1606b65d4adbSMuchun Song __update_and_free_page(h, page); 1607b65d4adbSMuchun Song 1608b65d4adbSMuchun Song cond_resched(); 1609b65d4adbSMuchun Song } 1610b65d4adbSMuchun Song } 1611b65d4adbSMuchun Song static DECLARE_WORK(free_hpage_work, free_hpage_workfn); 1612b65d4adbSMuchun Song 1613b65d4adbSMuchun Song static inline void flush_free_hpage_work(struct hstate *h) 1614b65d4adbSMuchun Song { 16155981611dSMuchun Song if (hugetlb_optimize_vmemmap_pages(h)) 1616b65d4adbSMuchun Song flush_work(&free_hpage_work); 1617b65d4adbSMuchun Song } 1618b65d4adbSMuchun Song 1619b65d4adbSMuchun Song static void update_and_free_page(struct hstate *h, struct page *page, 1620b65d4adbSMuchun Song bool atomic) 1621b65d4adbSMuchun Song { 1622ad2fa371SMuchun Song if (!HPageVmemmapOptimized(page) || !atomic) { 1623b65d4adbSMuchun Song __update_and_free_page(h, page); 1624b65d4adbSMuchun Song return; 1625b65d4adbSMuchun Song } 1626b65d4adbSMuchun Song 1627b65d4adbSMuchun Song /* 1628b65d4adbSMuchun Song * Defer freeing to avoid using GFP_ATOMIC to allocate vmemmap pages. 1629b65d4adbSMuchun Song * 1630b65d4adbSMuchun Song * Only call schedule_work() if hpage_freelist is previously 1631b65d4adbSMuchun Song * empty. Otherwise, schedule_work() had been called but the workfn 1632b65d4adbSMuchun Song * hasn't retrieved the list yet. 1633b65d4adbSMuchun Song */ 1634b65d4adbSMuchun Song if (llist_add((struct llist_node *)&page->mapping, &hpage_freelist)) 1635b65d4adbSMuchun Song schedule_work(&free_hpage_work); 1636b65d4adbSMuchun Song } 1637b65d4adbSMuchun Song 163810c6ec49SMike Kravetz static void update_and_free_pages_bulk(struct hstate *h, struct list_head *list) 163910c6ec49SMike Kravetz { 164010c6ec49SMike Kravetz struct page *page, *t_page; 164110c6ec49SMike Kravetz 164210c6ec49SMike Kravetz list_for_each_entry_safe(page, t_page, list, lru) { 1643b65d4adbSMuchun Song update_and_free_page(h, page, false); 164410c6ec49SMike Kravetz cond_resched(); 164510c6ec49SMike Kravetz } 164610c6ec49SMike Kravetz } 164710c6ec49SMike Kravetz 1648e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 1649e5ff2159SAndi Kleen { 1650e5ff2159SAndi Kleen struct hstate *h; 1651e5ff2159SAndi Kleen 1652e5ff2159SAndi Kleen for_each_hstate(h) { 1653e5ff2159SAndi Kleen if (huge_page_size(h) == size) 1654e5ff2159SAndi Kleen return h; 1655e5ff2159SAndi Kleen } 1656e5ff2159SAndi Kleen return NULL; 1657e5ff2159SAndi Kleen } 1658e5ff2159SAndi Kleen 1659db71ef79SMike Kravetz void free_huge_page(struct page *page) 166027a85ef1SDavid Gibson { 1661a5516438SAndi Kleen /* 1662a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 1663a5516438SAndi Kleen * compound page destructor. 1664a5516438SAndi Kleen */ 1665e5ff2159SAndi Kleen struct hstate *h = page_hstate(page); 16667893d1d5SAdam Litke int nid = page_to_nid(page); 1667d6995da3SMike Kravetz struct hugepage_subpool *spool = hugetlb_page_subpool(page); 166807443a85SJoonsoo Kim bool restore_reserve; 1669db71ef79SMike Kravetz unsigned long flags; 167027a85ef1SDavid Gibson 1671b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1672b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_mapcount(page), page); 16738ace22bcSYongkai Wu 1674d6995da3SMike Kravetz hugetlb_set_page_subpool(page, NULL); 167578fbe906SDavid Hildenbrand if (PageAnon(page)) 167678fbe906SDavid Hildenbrand __ClearPageAnonExclusive(page); 16778ace22bcSYongkai Wu page->mapping = NULL; 1678d6995da3SMike Kravetz restore_reserve = HPageRestoreReserve(page); 1679d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 168027a85ef1SDavid Gibson 16811c5ecae3SMike Kravetz /* 1682d6995da3SMike Kravetz * If HPageRestoreReserve was set on page, page allocation consumed a 16830919e1b6SMike Kravetz * reservation. If the page was associated with a subpool, there 16840919e1b6SMike Kravetz * would have been a page reserved in the subpool before allocation 16850919e1b6SMike Kravetz * via hugepage_subpool_get_pages(). Since we are 'restoring' the 16866c26d310SMiaohe Lin * reservation, do not call hugepage_subpool_put_pages() as this will 16870919e1b6SMike Kravetz * remove the reserved page from the subpool. 16880919e1b6SMike Kravetz */ 16890919e1b6SMike Kravetz if (!restore_reserve) { 16900919e1b6SMike Kravetz /* 16910919e1b6SMike Kravetz * A return code of zero implies that the subpool will be 16920919e1b6SMike Kravetz * under its minimum size if the reservation is not restored 16930919e1b6SMike Kravetz * after page is free. Therefore, force restore_reserve 16940919e1b6SMike Kravetz * operation. 16951c5ecae3SMike Kravetz */ 16961c5ecae3SMike Kravetz if (hugepage_subpool_put_pages(spool, 1) == 0) 16971c5ecae3SMike Kravetz restore_reserve = true; 16980919e1b6SMike Kravetz } 16991c5ecae3SMike Kravetz 1700db71ef79SMike Kravetz spin_lock_irqsave(&hugetlb_lock, flags); 17018f251a3dSMike Kravetz ClearHPageMigratable(page); 17026d76dcf4SAneesh Kumar K.V hugetlb_cgroup_uncharge_page(hstate_index(h), 17036d76dcf4SAneesh Kumar K.V pages_per_huge_page(h), page); 170408cf9fafSMina Almasry hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 170508cf9fafSMina Almasry pages_per_huge_page(h), page); 170607443a85SJoonsoo Kim if (restore_reserve) 170707443a85SJoonsoo Kim h->resv_huge_pages++; 170807443a85SJoonsoo Kim 17099157c311SMike Kravetz if (HPageTemporary(page)) { 17106eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 1711db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1712b65d4adbSMuchun Song update_and_free_page(h, page, true); 1713ab5ac90aSMichal Hocko } else if (h->surplus_huge_pages_node[nid]) { 17140edaecfaSAneesh Kumar K.V /* remove the page from active list */ 17156eb4e88aSMike Kravetz remove_hugetlb_page(h, page, true); 1716db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1717b65d4adbSMuchun Song update_and_free_page(h, page, true); 17187893d1d5SAdam Litke } else { 17195d3a551cSWill Deacon arch_clear_hugepage_flags(page); 1720a5516438SAndi Kleen enqueue_huge_page(h, page); 1721db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 172227a85ef1SDavid Gibson } 17231121828aSMike Kravetz } 172427a85ef1SDavid Gibson 1725d3d99fccSOscar Salvador /* 1726d3d99fccSOscar Salvador * Must be called with the hugetlb lock held 1727d3d99fccSOscar Salvador */ 1728d3d99fccSOscar Salvador static void __prep_account_new_huge_page(struct hstate *h, int nid) 1729d3d99fccSOscar Salvador { 1730d3d99fccSOscar Salvador lockdep_assert_held(&hugetlb_lock); 1731d3d99fccSOscar Salvador h->nr_huge_pages++; 1732d3d99fccSOscar Salvador h->nr_huge_pages_node[nid]++; 1733d3d99fccSOscar Salvador } 1734d3d99fccSOscar Salvador 1735f41f2ed4SMuchun Song static void __prep_new_huge_page(struct hstate *h, struct page *page) 1736b7ba30c6SAndi Kleen { 17375981611dSMuchun Song hugetlb_vmemmap_free(h, page); 17380edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&page->lru); 1739f1e61557SKirill A. Shutemov set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1740ff546117SMike Kravetz hugetlb_set_page_subpool(page, NULL); 17419dd540e2SAneesh Kumar K.V set_hugetlb_cgroup(page, NULL); 17421adc4d41SMina Almasry set_hugetlb_cgroup_rsvd(page, NULL); 1743d3d99fccSOscar Salvador } 1744d3d99fccSOscar Salvador 1745d3d99fccSOscar Salvador static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) 1746d3d99fccSOscar Salvador { 1747f41f2ed4SMuchun Song __prep_new_huge_page(h, page); 1748db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 1749d3d99fccSOscar Salvador __prep_account_new_huge_page(h, nid); 1750db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 1751b7ba30c6SAndi Kleen } 1752b7ba30c6SAndi Kleen 175334d9e35bSMike Kravetz static bool __prep_compound_gigantic_page(struct page *page, unsigned int order, 175434d9e35bSMike Kravetz bool demote) 175520a0307cSWu Fengguang { 17567118fc29SMike Kravetz int i, j; 175720a0307cSWu Fengguang int nr_pages = 1 << order; 175820a0307cSWu Fengguang struct page *p = page + 1; 175920a0307cSWu Fengguang 176020a0307cSWu Fengguang /* we rely on prep_new_huge_page to set the destructor */ 176120a0307cSWu Fengguang set_compound_order(page, order); 1762ef5a22beSAndrea Arcangeli __ClearPageReserved(page); 1763de09d31dSKirill A. Shutemov __SetPageHead(page); 176420a0307cSWu Fengguang for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 1765ef5a22beSAndrea Arcangeli /* 1766ef5a22beSAndrea Arcangeli * For gigantic hugepages allocated through bootmem at 1767ef5a22beSAndrea Arcangeli * boot, it's safer to be consistent with the not-gigantic 1768ef5a22beSAndrea Arcangeli * hugepages and clear the PG_reserved bit from all tail pages 17697c8de358SEthon Paul * too. Otherwise drivers using get_user_pages() to access tail 1770ef5a22beSAndrea Arcangeli * pages may get the reference counting wrong if they see 1771ef5a22beSAndrea Arcangeli * PG_reserved set on a tail page (despite the head page not 1772ef5a22beSAndrea Arcangeli * having PG_reserved set). Enforcing this consistency between 1773ef5a22beSAndrea Arcangeli * head and tail pages allows drivers to optimize away a check 1774ef5a22beSAndrea Arcangeli * on the head page when they need know if put_page() is needed 1775ef5a22beSAndrea Arcangeli * after get_user_pages(). 1776ef5a22beSAndrea Arcangeli */ 1777ef5a22beSAndrea Arcangeli __ClearPageReserved(p); 17787118fc29SMike Kravetz /* 17797118fc29SMike Kravetz * Subtle and very unlikely 17807118fc29SMike Kravetz * 17817118fc29SMike Kravetz * Gigantic 'page allocators' such as memblock or cma will 17827118fc29SMike Kravetz * return a set of pages with each page ref counted. We need 17837118fc29SMike Kravetz * to turn this set of pages into a compound page with tail 17847118fc29SMike Kravetz * page ref counts set to zero. Code such as speculative page 17857118fc29SMike Kravetz * cache adding could take a ref on a 'to be' tail page. 17867118fc29SMike Kravetz * We need to respect any increased ref count, and only set 17877118fc29SMike Kravetz * the ref count to zero if count is currently 1. If count 1788416d85edSMike Kravetz * is not 1, we return an error. An error return indicates 1789416d85edSMike Kravetz * the set of pages can not be converted to a gigantic page. 1790416d85edSMike Kravetz * The caller who allocated the pages should then discard the 1791416d85edSMike Kravetz * pages using the appropriate free interface. 179234d9e35bSMike Kravetz * 179334d9e35bSMike Kravetz * In the case of demote, the ref count will be zero. 17947118fc29SMike Kravetz */ 179534d9e35bSMike Kravetz if (!demote) { 17967118fc29SMike Kravetz if (!page_ref_freeze(p, 1)) { 1797416d85edSMike Kravetz pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n"); 17987118fc29SMike Kravetz goto out_error; 17997118fc29SMike Kravetz } 180034d9e35bSMike Kravetz } else { 180134d9e35bSMike Kravetz VM_BUG_ON_PAGE(page_count(p), p); 180234d9e35bSMike Kravetz } 18031d798ca3SKirill A. Shutemov set_compound_head(p, page); 180420a0307cSWu Fengguang } 1805b4330afbSMike Kravetz atomic_set(compound_mapcount_ptr(page), -1); 180647e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 18077118fc29SMike Kravetz return true; 18087118fc29SMike Kravetz 18097118fc29SMike Kravetz out_error: 18107118fc29SMike Kravetz /* undo tail page modifications made above */ 18117118fc29SMike Kravetz p = page + 1; 18127118fc29SMike Kravetz for (j = 1; j < i; j++, p = mem_map_next(p, page, j)) { 18137118fc29SMike Kravetz clear_compound_head(p); 18147118fc29SMike Kravetz set_page_refcounted(p); 18157118fc29SMike Kravetz } 18167118fc29SMike Kravetz /* need to clear PG_reserved on remaining tail pages */ 18177118fc29SMike Kravetz for (; j < nr_pages; j++, p = mem_map_next(p, page, j)) 18187118fc29SMike Kravetz __ClearPageReserved(p); 18197118fc29SMike Kravetz set_compound_order(page, 0); 18205232c63fSMatthew Wilcox (Oracle) #ifdef CONFIG_64BIT 18217118fc29SMike Kravetz page[1].compound_nr = 0; 18225232c63fSMatthew Wilcox (Oracle) #endif 18237118fc29SMike Kravetz __ClearPageHead(page); 18247118fc29SMike Kravetz return false; 182520a0307cSWu Fengguang } 182620a0307cSWu Fengguang 182734d9e35bSMike Kravetz static bool prep_compound_gigantic_page(struct page *page, unsigned int order) 182834d9e35bSMike Kravetz { 182934d9e35bSMike Kravetz return __prep_compound_gigantic_page(page, order, false); 183034d9e35bSMike Kravetz } 183134d9e35bSMike Kravetz 18328531fc6fSMike Kravetz static bool prep_compound_gigantic_page_for_demote(struct page *page, 18338531fc6fSMike Kravetz unsigned int order) 18348531fc6fSMike Kravetz { 18358531fc6fSMike Kravetz return __prep_compound_gigantic_page(page, order, true); 18368531fc6fSMike Kravetz } 18378531fc6fSMike Kravetz 18387795912cSAndrew Morton /* 18397795912cSAndrew Morton * PageHuge() only returns true for hugetlbfs pages, but not for normal or 18407795912cSAndrew Morton * transparent huge pages. See the PageTransHuge() documentation for more 18417795912cSAndrew Morton * details. 18427795912cSAndrew Morton */ 184320a0307cSWu Fengguang int PageHuge(struct page *page) 184420a0307cSWu Fengguang { 184520a0307cSWu Fengguang if (!PageCompound(page)) 184620a0307cSWu Fengguang return 0; 184720a0307cSWu Fengguang 184820a0307cSWu Fengguang page = compound_head(page); 1849f1e61557SKirill A. Shutemov return page[1].compound_dtor == HUGETLB_PAGE_DTOR; 185020a0307cSWu Fengguang } 185143131e14SNaoya Horiguchi EXPORT_SYMBOL_GPL(PageHuge); 185243131e14SNaoya Horiguchi 185327c73ae7SAndrea Arcangeli /* 185427c73ae7SAndrea Arcangeli * PageHeadHuge() only returns true for hugetlbfs head page, but not for 185527c73ae7SAndrea Arcangeli * normal or transparent huge pages. 185627c73ae7SAndrea Arcangeli */ 185727c73ae7SAndrea Arcangeli int PageHeadHuge(struct page *page_head) 185827c73ae7SAndrea Arcangeli { 185927c73ae7SAndrea Arcangeli if (!PageHead(page_head)) 186027c73ae7SAndrea Arcangeli return 0; 186127c73ae7SAndrea Arcangeli 1862d4af73e3SVlastimil Babka return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR; 186327c73ae7SAndrea Arcangeli } 18644e936eccSDavid Howells EXPORT_SYMBOL_GPL(PageHeadHuge); 186527c73ae7SAndrea Arcangeli 1866c0d0381aSMike Kravetz /* 1867c0d0381aSMike Kravetz * Find and lock address space (mapping) in write mode. 1868c0d0381aSMike Kravetz * 1869336bf30eSMike Kravetz * Upon entry, the page is locked which means that page_mapping() is 1870336bf30eSMike Kravetz * stable. Due to locking order, we can only trylock_write. If we can 1871336bf30eSMike Kravetz * not get the lock, simply return NULL to caller. 1872c0d0381aSMike Kravetz */ 1873c0d0381aSMike Kravetz struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage) 1874c0d0381aSMike Kravetz { 1875336bf30eSMike Kravetz struct address_space *mapping = page_mapping(hpage); 1876c0d0381aSMike Kravetz 1877c0d0381aSMike Kravetz if (!mapping) 1878c0d0381aSMike Kravetz return mapping; 1879c0d0381aSMike Kravetz 1880c0d0381aSMike Kravetz if (i_mmap_trylock_write(mapping)) 1881c0d0381aSMike Kravetz return mapping; 1882c0d0381aSMike Kravetz 1883c0d0381aSMike Kravetz return NULL; 1884c0d0381aSMike Kravetz } 1885c0d0381aSMike Kravetz 1886fe19bd3dSHugh Dickins pgoff_t hugetlb_basepage_index(struct page *page) 188713d60f4bSZhang Yi { 188813d60f4bSZhang Yi struct page *page_head = compound_head(page); 188913d60f4bSZhang Yi pgoff_t index = page_index(page_head); 189013d60f4bSZhang Yi unsigned long compound_idx; 189113d60f4bSZhang Yi 189213d60f4bSZhang Yi if (compound_order(page_head) >= MAX_ORDER) 189313d60f4bSZhang Yi compound_idx = page_to_pfn(page) - page_to_pfn(page_head); 189413d60f4bSZhang Yi else 189513d60f4bSZhang Yi compound_idx = page - page_head; 189613d60f4bSZhang Yi 189713d60f4bSZhang Yi return (index << compound_order(page_head)) + compound_idx; 189813d60f4bSZhang Yi } 189913d60f4bSZhang Yi 19000c397daeSMichal Hocko static struct page *alloc_buddy_huge_page(struct hstate *h, 1901f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1902f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 19031da177e4SLinus Torvalds { 1904af0fb9dfSMichal Hocko int order = huge_page_order(h); 19051da177e4SLinus Torvalds struct page *page; 1906f60858f9SMike Kravetz bool alloc_try_hard = true; 1907f96efd58SJoe Jin 1908f60858f9SMike Kravetz /* 1909f60858f9SMike Kravetz * By default we always try hard to allocate the page with 1910f60858f9SMike Kravetz * __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in 1911f60858f9SMike Kravetz * a loop (to adjust global huge page counts) and previous allocation 1912f60858f9SMike Kravetz * failed, do not continue to try hard on the same node. Use the 1913f60858f9SMike Kravetz * node_alloc_noretry bitmap to manage this state information. 1914f60858f9SMike Kravetz */ 1915f60858f9SMike Kravetz if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry)) 1916f60858f9SMike Kravetz alloc_try_hard = false; 1917f60858f9SMike Kravetz gfp_mask |= __GFP_COMP|__GFP_NOWARN; 1918f60858f9SMike Kravetz if (alloc_try_hard) 1919f60858f9SMike Kravetz gfp_mask |= __GFP_RETRY_MAYFAIL; 1920af0fb9dfSMichal Hocko if (nid == NUMA_NO_NODE) 1921af0fb9dfSMichal Hocko nid = numa_mem_id(); 192284172f4bSMatthew Wilcox (Oracle) page = __alloc_pages(gfp_mask, order, nid, nmask); 1923af0fb9dfSMichal Hocko if (page) 1924af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC); 1925af0fb9dfSMichal Hocko else 1926af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 192763b4613cSNishanth Aravamudan 1928f60858f9SMike Kravetz /* 1929f60858f9SMike Kravetz * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this 1930f60858f9SMike Kravetz * indicates an overall state change. Clear bit so that we resume 1931f60858f9SMike Kravetz * normal 'try hard' allocations. 1932f60858f9SMike Kravetz */ 1933f60858f9SMike Kravetz if (node_alloc_noretry && page && !alloc_try_hard) 1934f60858f9SMike Kravetz node_clear(nid, *node_alloc_noretry); 1935f60858f9SMike Kravetz 1936f60858f9SMike Kravetz /* 1937f60858f9SMike Kravetz * If we tried hard to get a page but failed, set bit so that 1938f60858f9SMike Kravetz * subsequent attempts will not try as hard until there is an 1939f60858f9SMike Kravetz * overall state change. 1940f60858f9SMike Kravetz */ 1941f60858f9SMike Kravetz if (node_alloc_noretry && !page && alloc_try_hard) 1942f60858f9SMike Kravetz node_set(nid, *node_alloc_noretry); 1943f60858f9SMike Kravetz 194463b4613cSNishanth Aravamudan return page; 194563b4613cSNishanth Aravamudan } 194663b4613cSNishanth Aravamudan 1947af0fb9dfSMichal Hocko /* 19480c397daeSMichal Hocko * Common helper to allocate a fresh hugetlb page. All specific allocators 19490c397daeSMichal Hocko * should use this function to get new hugetlb pages 19500c397daeSMichal Hocko */ 19510c397daeSMichal Hocko static struct page *alloc_fresh_huge_page(struct hstate *h, 1952f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1953f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 19540c397daeSMichal Hocko { 19550c397daeSMichal Hocko struct page *page; 19567118fc29SMike Kravetz bool retry = false; 19570c397daeSMichal Hocko 19587118fc29SMike Kravetz retry: 19590c397daeSMichal Hocko if (hstate_is_gigantic(h)) 19600c397daeSMichal Hocko page = alloc_gigantic_page(h, gfp_mask, nid, nmask); 19610c397daeSMichal Hocko else 19620c397daeSMichal Hocko page = alloc_buddy_huge_page(h, gfp_mask, 1963f60858f9SMike Kravetz nid, nmask, node_alloc_noretry); 19640c397daeSMichal Hocko if (!page) 19650c397daeSMichal Hocko return NULL; 19660c397daeSMichal Hocko 19677118fc29SMike Kravetz if (hstate_is_gigantic(h)) { 19687118fc29SMike Kravetz if (!prep_compound_gigantic_page(page, huge_page_order(h))) { 19697118fc29SMike Kravetz /* 19707118fc29SMike Kravetz * Rare failure to convert pages to compound page. 19717118fc29SMike Kravetz * Free pages and try again - ONCE! 19727118fc29SMike Kravetz */ 19737118fc29SMike Kravetz free_gigantic_page(page, huge_page_order(h)); 19747118fc29SMike Kravetz if (!retry) { 19757118fc29SMike Kravetz retry = true; 19767118fc29SMike Kravetz goto retry; 19777118fc29SMike Kravetz } 19787118fc29SMike Kravetz return NULL; 19797118fc29SMike Kravetz } 19807118fc29SMike Kravetz } 19810c397daeSMichal Hocko prep_new_huge_page(h, page, page_to_nid(page)); 19820c397daeSMichal Hocko 19830c397daeSMichal Hocko return page; 19840c397daeSMichal Hocko } 19850c397daeSMichal Hocko 19860c397daeSMichal Hocko /* 1987af0fb9dfSMichal Hocko * Allocates a fresh page to the hugetlb allocator pool in the node interleaved 1988af0fb9dfSMichal Hocko * manner. 1989af0fb9dfSMichal Hocko */ 1990f60858f9SMike Kravetz static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 1991f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 1992b2261026SJoonsoo Kim { 1993b2261026SJoonsoo Kim struct page *page; 1994b2261026SJoonsoo Kim int nr_nodes, node; 1995af0fb9dfSMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 1996b2261026SJoonsoo Kim 1997b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 1998f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed, 1999f60858f9SMike Kravetz node_alloc_noretry); 2000af0fb9dfSMichal Hocko if (page) 2001b2261026SJoonsoo Kim break; 2002b2261026SJoonsoo Kim } 2003b2261026SJoonsoo Kim 2004af0fb9dfSMichal Hocko if (!page) 2005af0fb9dfSMichal Hocko return 0; 2006b2261026SJoonsoo Kim 2007af0fb9dfSMichal Hocko put_page(page); /* free it into the hugepage allocator */ 2008af0fb9dfSMichal Hocko 2009af0fb9dfSMichal Hocko return 1; 2010b2261026SJoonsoo Kim } 2011b2261026SJoonsoo Kim 2012e8c5c824SLee Schermerhorn /* 201310c6ec49SMike Kravetz * Remove huge page from pool from next node to free. Attempt to keep 201410c6ec49SMike Kravetz * persistent huge pages more or less balanced over allowed nodes. 201510c6ec49SMike Kravetz * This routine only 'removes' the hugetlb page. The caller must make 201610c6ec49SMike Kravetz * an additional call to free the page to low level allocators. 2017e8c5c824SLee Schermerhorn * Called with hugetlb_lock locked. 2018e8c5c824SLee Schermerhorn */ 201910c6ec49SMike Kravetz static struct page *remove_pool_huge_page(struct hstate *h, 202010c6ec49SMike Kravetz nodemask_t *nodes_allowed, 20216ae11b27SLee Schermerhorn bool acct_surplus) 2022e8c5c824SLee Schermerhorn { 2023b2261026SJoonsoo Kim int nr_nodes, node; 202410c6ec49SMike Kravetz struct page *page = NULL; 2025e8c5c824SLee Schermerhorn 20269487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2027b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 2028685f3457SLee Schermerhorn /* 2029685f3457SLee Schermerhorn * If we're returning unused surplus pages, only examine 2030685f3457SLee Schermerhorn * nodes with surplus pages. 2031685f3457SLee Schermerhorn */ 2032b2261026SJoonsoo Kim if ((!acct_surplus || h->surplus_huge_pages_node[node]) && 2033b2261026SJoonsoo Kim !list_empty(&h->hugepage_freelists[node])) { 203410c6ec49SMike Kravetz page = list_entry(h->hugepage_freelists[node].next, 2035e8c5c824SLee Schermerhorn struct page, lru); 20366eb4e88aSMike Kravetz remove_hugetlb_page(h, page, acct_surplus); 20379a76db09SLee Schermerhorn break; 2038e8c5c824SLee Schermerhorn } 2039b2261026SJoonsoo Kim } 2040e8c5c824SLee Schermerhorn 204110c6ec49SMike Kravetz return page; 2042e8c5c824SLee Schermerhorn } 2043e8c5c824SLee Schermerhorn 2044c8721bbbSNaoya Horiguchi /* 2045c8721bbbSNaoya Horiguchi * Dissolve a given free hugepage into free buddy pages. This function does 2046faf53defSNaoya Horiguchi * nothing for in-use hugepages and non-hugepages. 2047faf53defSNaoya Horiguchi * This function returns values like below: 2048faf53defSNaoya Horiguchi * 2049ad2fa371SMuchun Song * -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages 2050ad2fa371SMuchun Song * when the system is under memory pressure and the feature of 2051ad2fa371SMuchun Song * freeing unused vmemmap pages associated with each hugetlb page 2052ad2fa371SMuchun Song * is enabled. 2053faf53defSNaoya Horiguchi * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use 2054faf53defSNaoya Horiguchi * (allocated or reserved.) 2055faf53defSNaoya Horiguchi * 0: successfully dissolved free hugepages or the page is not a 2056faf53defSNaoya Horiguchi * hugepage (considered as already dissolved) 2057c8721bbbSNaoya Horiguchi */ 2058c3114a84SAnshuman Khandual int dissolve_free_huge_page(struct page *page) 2059c8721bbbSNaoya Horiguchi { 20606bc9b564SNaoya Horiguchi int rc = -EBUSY; 2061082d5b6bSGerald Schaefer 20627ffddd49SMuchun Song retry: 2063faf53defSNaoya Horiguchi /* Not to disrupt normal path by vainly holding hugetlb_lock */ 2064faf53defSNaoya Horiguchi if (!PageHuge(page)) 2065faf53defSNaoya Horiguchi return 0; 2066faf53defSNaoya Horiguchi 2067db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2068faf53defSNaoya Horiguchi if (!PageHuge(page)) { 2069faf53defSNaoya Horiguchi rc = 0; 2070faf53defSNaoya Horiguchi goto out; 2071faf53defSNaoya Horiguchi } 2072faf53defSNaoya Horiguchi 2073faf53defSNaoya Horiguchi if (!page_count(page)) { 20742247bb33SGerald Schaefer struct page *head = compound_head(page); 20752247bb33SGerald Schaefer struct hstate *h = page_hstate(head); 20766bc9b564SNaoya Horiguchi if (h->free_huge_pages - h->resv_huge_pages == 0) 2077082d5b6bSGerald Schaefer goto out; 20787ffddd49SMuchun Song 20797ffddd49SMuchun Song /* 20807ffddd49SMuchun Song * We should make sure that the page is already on the free list 20817ffddd49SMuchun Song * when it is dissolved. 20827ffddd49SMuchun Song */ 20836c037149SMike Kravetz if (unlikely(!HPageFreed(head))) { 2084db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 20857ffddd49SMuchun Song cond_resched(); 20867ffddd49SMuchun Song 20877ffddd49SMuchun Song /* 20887ffddd49SMuchun Song * Theoretically, we should return -EBUSY when we 20897ffddd49SMuchun Song * encounter this race. In fact, we have a chance 20907ffddd49SMuchun Song * to successfully dissolve the page if we do a 20917ffddd49SMuchun Song * retry. Because the race window is quite small. 20927ffddd49SMuchun Song * If we seize this opportunity, it is an optimization 20937ffddd49SMuchun Song * for increasing the success rate of dissolving page. 20947ffddd49SMuchun Song */ 20957ffddd49SMuchun Song goto retry; 20967ffddd49SMuchun Song } 20977ffddd49SMuchun Song 2098ad2fa371SMuchun Song remove_hugetlb_page(h, head, false); 2099ad2fa371SMuchun Song h->max_huge_pages--; 2100ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2101ad2fa371SMuchun Song 2102c3114a84SAnshuman Khandual /* 2103ad2fa371SMuchun Song * Normally update_and_free_page will allocate required vmemmmap 2104ad2fa371SMuchun Song * before freeing the page. update_and_free_page will fail to 2105ad2fa371SMuchun Song * free the page if it can not allocate required vmemmap. We 2106ad2fa371SMuchun Song * need to adjust max_huge_pages if the page is not freed. 2107ad2fa371SMuchun Song * Attempt to allocate vmemmmap here so that we can take 2108ad2fa371SMuchun Song * appropriate action on failure. 2109ad2fa371SMuchun Song */ 21105981611dSMuchun Song rc = hugetlb_vmemmap_alloc(h, head); 2111ad2fa371SMuchun Song if (!rc) { 2112ad2fa371SMuchun Song /* 2113ad2fa371SMuchun Song * Move PageHWPoison flag from head page to the raw 2114ad2fa371SMuchun Song * error page, which makes any subpages rather than 2115ad2fa371SMuchun Song * the error page reusable. 2116c3114a84SAnshuman Khandual */ 2117c3114a84SAnshuman Khandual if (PageHWPoison(head) && page != head) { 2118c3114a84SAnshuman Khandual SetPageHWPoison(page); 2119c3114a84SAnshuman Khandual ClearPageHWPoison(head); 2120c3114a84SAnshuman Khandual } 2121b65d4adbSMuchun Song update_and_free_page(h, head, false); 2122ad2fa371SMuchun Song } else { 2123ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 2124ad2fa371SMuchun Song add_hugetlb_page(h, head, false); 2125ad2fa371SMuchun Song h->max_huge_pages++; 2126ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2127ad2fa371SMuchun Song } 2128ad2fa371SMuchun Song 2129ad2fa371SMuchun Song return rc; 2130c8721bbbSNaoya Horiguchi } 2131082d5b6bSGerald Schaefer out: 2132db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2133082d5b6bSGerald Schaefer return rc; 2134c8721bbbSNaoya Horiguchi } 2135c8721bbbSNaoya Horiguchi 2136c8721bbbSNaoya Horiguchi /* 2137c8721bbbSNaoya Horiguchi * Dissolve free hugepages in a given pfn range. Used by memory hotplug to 2138c8721bbbSNaoya Horiguchi * make specified memory blocks removable from the system. 21392247bb33SGerald Schaefer * Note that this will dissolve a free gigantic hugepage completely, if any 21402247bb33SGerald Schaefer * part of it lies within the given range. 2141082d5b6bSGerald Schaefer * Also note that if dissolve_free_huge_page() returns with an error, all 2142082d5b6bSGerald Schaefer * free hugepages that were dissolved before that error are lost. 2143c8721bbbSNaoya Horiguchi */ 2144082d5b6bSGerald Schaefer int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) 2145c8721bbbSNaoya Horiguchi { 2146c8721bbbSNaoya Horiguchi unsigned long pfn; 2147eb03aa00SGerald Schaefer struct page *page; 2148082d5b6bSGerald Schaefer int rc = 0; 2149dc2628f3SMuchun Song unsigned int order; 2150dc2628f3SMuchun Song struct hstate *h; 2151c8721bbbSNaoya Horiguchi 2152d0177639SLi Zhong if (!hugepages_supported()) 2153082d5b6bSGerald Schaefer return rc; 2154d0177639SLi Zhong 2155dc2628f3SMuchun Song order = huge_page_order(&default_hstate); 2156dc2628f3SMuchun Song for_each_hstate(h) 2157dc2628f3SMuchun Song order = min(order, huge_page_order(h)); 2158dc2628f3SMuchun Song 2159dc2628f3SMuchun Song for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << order) { 2160eb03aa00SGerald Schaefer page = pfn_to_page(pfn); 2161eb03aa00SGerald Schaefer rc = dissolve_free_huge_page(page); 2162eb03aa00SGerald Schaefer if (rc) 2163082d5b6bSGerald Schaefer break; 2164eb03aa00SGerald Schaefer } 2165082d5b6bSGerald Schaefer 2166082d5b6bSGerald Schaefer return rc; 2167c8721bbbSNaoya Horiguchi } 2168c8721bbbSNaoya Horiguchi 2169ab5ac90aSMichal Hocko /* 2170ab5ac90aSMichal Hocko * Allocates a fresh surplus page from the page allocator. 2171ab5ac90aSMichal Hocko */ 21720c397daeSMichal Hocko static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, 2173b65a4edaSMike Kravetz int nid, nodemask_t *nmask, bool zero_ref) 21747893d1d5SAdam Litke { 21759980d744SMichal Hocko struct page *page = NULL; 2176b65a4edaSMike Kravetz bool retry = false; 21777893d1d5SAdam Litke 2178bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2179aa888a74SAndi Kleen return NULL; 2180aa888a74SAndi Kleen 2181db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 21829980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) 21839980d744SMichal Hocko goto out_unlock; 2184db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2185d1c3fb1fSNishanth Aravamudan 2186b65a4edaSMike Kravetz retry: 2187f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 21889980d744SMichal Hocko if (!page) 21890c397daeSMichal Hocko return NULL; 2190d1c3fb1fSNishanth Aravamudan 2191db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 21929980d744SMichal Hocko /* 21939980d744SMichal Hocko * We could have raced with the pool size change. 21949980d744SMichal Hocko * Double check that and simply deallocate the new page 21959980d744SMichal Hocko * if we would end up overcommiting the surpluses. Abuse 21969980d744SMichal Hocko * temporary page to workaround the nasty free_huge_page 21979980d744SMichal Hocko * codeflow 21989980d744SMichal Hocko */ 21999980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 22009157c311SMike Kravetz SetHPageTemporary(page); 2201db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 22029980d744SMichal Hocko put_page(page); 22032bf753e6SKai Shen return NULL; 2204b65a4edaSMike Kravetz } 2205b65a4edaSMike Kravetz 2206b65a4edaSMike Kravetz if (zero_ref) { 2207b65a4edaSMike Kravetz /* 2208b65a4edaSMike Kravetz * Caller requires a page with zero ref count. 2209b65a4edaSMike Kravetz * We will drop ref count here. If someone else is holding 2210b65a4edaSMike Kravetz * a ref, the page will be freed when they drop it. Abuse 2211b65a4edaSMike Kravetz * temporary page flag to accomplish this. 2212b65a4edaSMike Kravetz */ 2213b65a4edaSMike Kravetz SetHPageTemporary(page); 2214b65a4edaSMike Kravetz if (!put_page_testzero(page)) { 2215b65a4edaSMike Kravetz /* 2216b65a4edaSMike Kravetz * Unexpected inflated ref count on freshly allocated 2217b65a4edaSMike Kravetz * huge. Retry once. 2218b65a4edaSMike Kravetz */ 2219b65a4edaSMike Kravetz pr_info("HugeTLB unexpected inflated ref count on freshly allocated page\n"); 2220b65a4edaSMike Kravetz spin_unlock_irq(&hugetlb_lock); 2221b65a4edaSMike Kravetz if (retry) 2222b65a4edaSMike Kravetz return NULL; 2223b65a4edaSMike Kravetz 2224b65a4edaSMike Kravetz retry = true; 2225b65a4edaSMike Kravetz goto retry; 2226b65a4edaSMike Kravetz } 2227b65a4edaSMike Kravetz ClearHPageTemporary(page); 2228b65a4edaSMike Kravetz } 2229b65a4edaSMike Kravetz 22309980d744SMichal Hocko h->surplus_huge_pages++; 22314704dea3SMichal Hocko h->surplus_huge_pages_node[page_to_nid(page)]++; 22329980d744SMichal Hocko 22339980d744SMichal Hocko out_unlock: 2234db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 22357893d1d5SAdam Litke 22367893d1d5SAdam Litke return page; 22377893d1d5SAdam Litke } 22387893d1d5SAdam Litke 2239bbe88753SJoonsoo Kim static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, 2240ab5ac90aSMichal Hocko int nid, nodemask_t *nmask) 2241ab5ac90aSMichal Hocko { 2242ab5ac90aSMichal Hocko struct page *page; 2243ab5ac90aSMichal Hocko 2244ab5ac90aSMichal Hocko if (hstate_is_gigantic(h)) 2245ab5ac90aSMichal Hocko return NULL; 2246ab5ac90aSMichal Hocko 2247f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 2248ab5ac90aSMichal Hocko if (!page) 2249ab5ac90aSMichal Hocko return NULL; 2250ab5ac90aSMichal Hocko 2251ab5ac90aSMichal Hocko /* 2252ab5ac90aSMichal Hocko * We do not account these pages as surplus because they are only 2253ab5ac90aSMichal Hocko * temporary and will be released properly on the last reference 2254ab5ac90aSMichal Hocko */ 22559157c311SMike Kravetz SetHPageTemporary(page); 2256ab5ac90aSMichal Hocko 2257ab5ac90aSMichal Hocko return page; 2258ab5ac90aSMichal Hocko } 2259ab5ac90aSMichal Hocko 2260e4e574b7SAdam Litke /* 2261099730d6SDave Hansen * Use the VMA's mpolicy to allocate a huge page from the buddy. 2262099730d6SDave Hansen */ 2263e0ec90eeSDave Hansen static 22640c397daeSMichal Hocko struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h, 2265099730d6SDave Hansen struct vm_area_struct *vma, unsigned long addr) 2266099730d6SDave Hansen { 2267cfcaa66fSBen Widawsky struct page *page = NULL; 2268aaf14e40SMichal Hocko struct mempolicy *mpol; 2269aaf14e40SMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h); 2270aaf14e40SMichal Hocko int nid; 2271aaf14e40SMichal Hocko nodemask_t *nodemask; 2272aaf14e40SMichal Hocko 2273aaf14e40SMichal Hocko nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); 2274cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 2275cfcaa66fSBen Widawsky gfp_t gfp = gfp_mask | __GFP_NOWARN; 2276cfcaa66fSBen Widawsky 2277cfcaa66fSBen Widawsky gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL); 2278cfcaa66fSBen Widawsky page = alloc_surplus_huge_page(h, gfp, nid, nodemask, false); 2279cfcaa66fSBen Widawsky 2280cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 2281cfcaa66fSBen Widawsky nodemask = NULL; 2282cfcaa66fSBen Widawsky } 2283cfcaa66fSBen Widawsky 2284cfcaa66fSBen Widawsky if (!page) 2285b65a4edaSMike Kravetz page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask, false); 2286aaf14e40SMichal Hocko mpol_cond_put(mpol); 2287aaf14e40SMichal Hocko return page; 2288099730d6SDave Hansen } 2289099730d6SDave Hansen 2290ab5ac90aSMichal Hocko /* page migration callback function */ 22913e59fcb0SMichal Hocko struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, 2292d92bbc27SJoonsoo Kim nodemask_t *nmask, gfp_t gfp_mask) 22934db9b2efSMichal Hocko { 2294db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 22954db9b2efSMichal Hocko if (h->free_huge_pages - h->resv_huge_pages > 0) { 22963e59fcb0SMichal Hocko struct page *page; 22973e59fcb0SMichal Hocko 22983e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask); 22993e59fcb0SMichal Hocko if (page) { 2300db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 23013e59fcb0SMichal Hocko return page; 23024db9b2efSMichal Hocko } 23034db9b2efSMichal Hocko } 2304db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 23054db9b2efSMichal Hocko 23060c397daeSMichal Hocko return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask); 23074db9b2efSMichal Hocko } 23084db9b2efSMichal Hocko 2309ebd63723SMichal Hocko /* mempolicy aware migration callback */ 2310389c8178SMichal Hocko struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, 2311389c8178SMichal Hocko unsigned long address) 2312ebd63723SMichal Hocko { 2313ebd63723SMichal Hocko struct mempolicy *mpol; 2314ebd63723SMichal Hocko nodemask_t *nodemask; 2315ebd63723SMichal Hocko struct page *page; 2316ebd63723SMichal Hocko gfp_t gfp_mask; 2317ebd63723SMichal Hocko int node; 2318ebd63723SMichal Hocko 2319ebd63723SMichal Hocko gfp_mask = htlb_alloc_mask(h); 2320ebd63723SMichal Hocko node = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 2321d92bbc27SJoonsoo Kim page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask); 2322ebd63723SMichal Hocko mpol_cond_put(mpol); 2323ebd63723SMichal Hocko 2324ebd63723SMichal Hocko return page; 2325ebd63723SMichal Hocko } 2326ebd63723SMichal Hocko 2327bf50bab2SNaoya Horiguchi /* 232825985edcSLucas De Marchi * Increase the hugetlb pool such that it can accommodate a reservation 2329e4e574b7SAdam Litke * of size 'delta'. 2330e4e574b7SAdam Litke */ 23310a4f3d1bSLiu Xiang static int gather_surplus_pages(struct hstate *h, long delta) 23321b2a1e7bSJules Irenge __must_hold(&hugetlb_lock) 2333e4e574b7SAdam Litke { 2334e4e574b7SAdam Litke struct list_head surplus_list; 2335e4e574b7SAdam Litke struct page *page, *tmp; 23360a4f3d1bSLiu Xiang int ret; 23370a4f3d1bSLiu Xiang long i; 23380a4f3d1bSLiu Xiang long needed, allocated; 233928073b02SHillf Danton bool alloc_ok = true; 2340e4e574b7SAdam Litke 23419487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2342a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 2343ac09b3a1SAdam Litke if (needed <= 0) { 2344a5516438SAndi Kleen h->resv_huge_pages += delta; 2345e4e574b7SAdam Litke return 0; 2346ac09b3a1SAdam Litke } 2347e4e574b7SAdam Litke 2348e4e574b7SAdam Litke allocated = 0; 2349e4e574b7SAdam Litke INIT_LIST_HEAD(&surplus_list); 2350e4e574b7SAdam Litke 2351e4e574b7SAdam Litke ret = -ENOMEM; 2352e4e574b7SAdam Litke retry: 2353db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2354e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 23550c397daeSMichal Hocko page = alloc_surplus_huge_page(h, htlb_alloc_mask(h), 2356b65a4edaSMike Kravetz NUMA_NO_NODE, NULL, true); 235728073b02SHillf Danton if (!page) { 235828073b02SHillf Danton alloc_ok = false; 235928073b02SHillf Danton break; 236028073b02SHillf Danton } 2361e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 236269ed779aSDavid Rientjes cond_resched(); 2363e4e574b7SAdam Litke } 236428073b02SHillf Danton allocated += i; 2365e4e574b7SAdam Litke 2366e4e574b7SAdam Litke /* 2367e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 2368e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 2369e4e574b7SAdam Litke */ 2370db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2371a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 2372a5516438SAndi Kleen (h->free_huge_pages + allocated); 237328073b02SHillf Danton if (needed > 0) { 237428073b02SHillf Danton if (alloc_ok) 2375e4e574b7SAdam Litke goto retry; 237628073b02SHillf Danton /* 237728073b02SHillf Danton * We were not able to allocate enough pages to 237828073b02SHillf Danton * satisfy the entire reservation so we free what 237928073b02SHillf Danton * we've allocated so far. 238028073b02SHillf Danton */ 238128073b02SHillf Danton goto free; 238228073b02SHillf Danton } 2383e4e574b7SAdam Litke /* 2384e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 238525985edcSLucas De Marchi * needed to accommodate the reservation. Add the appropriate number 2386e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 2387ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 2388ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 2389ac09b3a1SAdam Litke * before they are reserved. 2390e4e574b7SAdam Litke */ 2391e4e574b7SAdam Litke needed += allocated; 2392a5516438SAndi Kleen h->resv_huge_pages += delta; 2393e4e574b7SAdam Litke ret = 0; 2394a9869b83SNaoya Horiguchi 239519fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 239619fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 239719fc3f0aSAdam Litke if ((--needed) < 0) 239819fc3f0aSAdam Litke break; 2399b65a4edaSMike Kravetz /* Add the page to the hugetlb allocator */ 2400a5516438SAndi Kleen enqueue_huge_page(h, page); 240119fc3f0aSAdam Litke } 240228073b02SHillf Danton free: 2403db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 240419fc3f0aSAdam Litke 2405b65a4edaSMike Kravetz /* 2406b65a4edaSMike Kravetz * Free unnecessary surplus pages to the buddy allocator. 2407b65a4edaSMike Kravetz * Pages have no ref count, call free_huge_page directly. 2408b65a4edaSMike Kravetz */ 2409c0d934baSJoonsoo Kim list_for_each_entry_safe(page, tmp, &surplus_list, lru) 2410b65a4edaSMike Kravetz free_huge_page(page); 2411db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2412e4e574b7SAdam Litke 2413e4e574b7SAdam Litke return ret; 2414e4e574b7SAdam Litke } 2415e4e574b7SAdam Litke 2416e4e574b7SAdam Litke /* 2417e5bbc8a6SMike Kravetz * This routine has two main purposes: 2418e5bbc8a6SMike Kravetz * 1) Decrement the reservation count (resv_huge_pages) by the value passed 2419e5bbc8a6SMike Kravetz * in unused_resv_pages. This corresponds to the prior adjustments made 2420e5bbc8a6SMike Kravetz * to the associated reservation map. 2421e5bbc8a6SMike Kravetz * 2) Free any unused surplus pages that may have been allocated to satisfy 2422e5bbc8a6SMike Kravetz * the reservation. As many as unused_resv_pages may be freed. 2423e4e574b7SAdam Litke */ 2424a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 2425a5516438SAndi Kleen unsigned long unused_resv_pages) 2426e4e574b7SAdam Litke { 2427e4e574b7SAdam Litke unsigned long nr_pages; 242810c6ec49SMike Kravetz struct page *page; 242910c6ec49SMike Kravetz LIST_HEAD(page_list); 243010c6ec49SMike Kravetz 24319487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 243210c6ec49SMike Kravetz /* Uncommit the reservation */ 243310c6ec49SMike Kravetz h->resv_huge_pages -= unused_resv_pages; 2434e4e574b7SAdam Litke 2435aa888a74SAndi Kleen /* Cannot return gigantic pages currently */ 2436bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2437e5bbc8a6SMike Kravetz goto out; 2438aa888a74SAndi Kleen 2439e5bbc8a6SMike Kravetz /* 2440e5bbc8a6SMike Kravetz * Part (or even all) of the reservation could have been backed 2441e5bbc8a6SMike Kravetz * by pre-allocated pages. Only free surplus pages. 2442e5bbc8a6SMike Kravetz */ 2443a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 2444e4e574b7SAdam Litke 2445685f3457SLee Schermerhorn /* 2446685f3457SLee Schermerhorn * We want to release as many surplus pages as possible, spread 24479b5e5d0fSLee Schermerhorn * evenly across all nodes with memory. Iterate across these nodes 24489b5e5d0fSLee Schermerhorn * until we can no longer free unreserved surplus pages. This occurs 24499b5e5d0fSLee Schermerhorn * when the nodes with surplus pages have no free pages. 245010c6ec49SMike Kravetz * remove_pool_huge_page() will balance the freed pages across the 24519b5e5d0fSLee Schermerhorn * on-line nodes with memory and will handle the hstate accounting. 2452685f3457SLee Schermerhorn */ 2453685f3457SLee Schermerhorn while (nr_pages--) { 245410c6ec49SMike Kravetz page = remove_pool_huge_page(h, &node_states[N_MEMORY], 1); 245510c6ec49SMike Kravetz if (!page) 2456e5bbc8a6SMike Kravetz goto out; 245710c6ec49SMike Kravetz 245810c6ec49SMike Kravetz list_add(&page->lru, &page_list); 2459e4e574b7SAdam Litke } 2460e5bbc8a6SMike Kravetz 2461e5bbc8a6SMike Kravetz out: 2462db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 246310c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 2464db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2465e4e574b7SAdam Litke } 2466e4e574b7SAdam Litke 24675e911373SMike Kravetz 2468c37f9fb1SAndy Whitcroft /* 2469feba16e2SMike Kravetz * vma_needs_reservation, vma_commit_reservation and vma_end_reservation 24705e911373SMike Kravetz * are used by the huge page allocation routines to manage reservations. 2471cf3ad20bSMike Kravetz * 2472cf3ad20bSMike Kravetz * vma_needs_reservation is called to determine if the huge page at addr 2473cf3ad20bSMike Kravetz * within the vma has an associated reservation. If a reservation is 2474cf3ad20bSMike Kravetz * needed, the value 1 is returned. The caller is then responsible for 2475cf3ad20bSMike Kravetz * managing the global reservation and subpool usage counts. After 2476cf3ad20bSMike Kravetz * the huge page has been allocated, vma_commit_reservation is called 2477feba16e2SMike Kravetz * to add the page to the reservation map. If the page allocation fails, 2478feba16e2SMike Kravetz * the reservation must be ended instead of committed. vma_end_reservation 2479feba16e2SMike Kravetz * is called in such cases. 2480cf3ad20bSMike Kravetz * 2481cf3ad20bSMike Kravetz * In the normal case, vma_commit_reservation returns the same value 2482cf3ad20bSMike Kravetz * as the preceding vma_needs_reservation call. The only time this 2483cf3ad20bSMike Kravetz * is not the case is if a reserve map was changed between calls. It 2484cf3ad20bSMike Kravetz * is the responsibility of the caller to notice the difference and 2485cf3ad20bSMike Kravetz * take appropriate action. 248696b96a96SMike Kravetz * 248796b96a96SMike Kravetz * vma_add_reservation is used in error paths where a reservation must 248896b96a96SMike Kravetz * be restored when a newly allocated huge page must be freed. It is 248996b96a96SMike Kravetz * to be called after calling vma_needs_reservation to determine if a 249096b96a96SMike Kravetz * reservation exists. 2491846be085SMike Kravetz * 2492846be085SMike Kravetz * vma_del_reservation is used in error paths where an entry in the reserve 2493846be085SMike Kravetz * map was created during huge page allocation and must be removed. It is to 2494846be085SMike Kravetz * be called after calling vma_needs_reservation to determine if a reservation 2495846be085SMike Kravetz * exists. 2496c37f9fb1SAndy Whitcroft */ 24975e911373SMike Kravetz enum vma_resv_mode { 24985e911373SMike Kravetz VMA_NEEDS_RESV, 24995e911373SMike Kravetz VMA_COMMIT_RESV, 2500feba16e2SMike Kravetz VMA_END_RESV, 250196b96a96SMike Kravetz VMA_ADD_RESV, 2502846be085SMike Kravetz VMA_DEL_RESV, 25035e911373SMike Kravetz }; 2504cf3ad20bSMike Kravetz static long __vma_reservation_common(struct hstate *h, 2505cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr, 25065e911373SMike Kravetz enum vma_resv_mode mode) 2507c37f9fb1SAndy Whitcroft { 25084e35f483SJoonsoo Kim struct resv_map *resv; 25094e35f483SJoonsoo Kim pgoff_t idx; 2510cf3ad20bSMike Kravetz long ret; 25110db9d74eSMina Almasry long dummy_out_regions_needed; 2512c37f9fb1SAndy Whitcroft 25134e35f483SJoonsoo Kim resv = vma_resv_map(vma); 25144e35f483SJoonsoo Kim if (!resv) 2515c37f9fb1SAndy Whitcroft return 1; 2516c37f9fb1SAndy Whitcroft 25174e35f483SJoonsoo Kim idx = vma_hugecache_offset(h, vma, addr); 25185e911373SMike Kravetz switch (mode) { 25195e911373SMike Kravetz case VMA_NEEDS_RESV: 25200db9d74eSMina Almasry ret = region_chg(resv, idx, idx + 1, &dummy_out_regions_needed); 25210db9d74eSMina Almasry /* We assume that vma_reservation_* routines always operate on 25220db9d74eSMina Almasry * 1 page, and that adding to resv map a 1 page entry can only 25230db9d74eSMina Almasry * ever require 1 region. 25240db9d74eSMina Almasry */ 25250db9d74eSMina Almasry VM_BUG_ON(dummy_out_regions_needed != 1); 25265e911373SMike Kravetz break; 25275e911373SMike Kravetz case VMA_COMMIT_RESV: 2528075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 25290db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 25300db9d74eSMina Almasry VM_BUG_ON(ret < 0); 25315e911373SMike Kravetz break; 2532feba16e2SMike Kravetz case VMA_END_RESV: 25330db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 25345e911373SMike Kravetz ret = 0; 25355e911373SMike Kravetz break; 253696b96a96SMike Kravetz case VMA_ADD_RESV: 25370db9d74eSMina Almasry if (vma->vm_flags & VM_MAYSHARE) { 2538075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 25390db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 25400db9d74eSMina Almasry VM_BUG_ON(ret < 0); 25410db9d74eSMina Almasry } else { 25420db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 254396b96a96SMike Kravetz ret = region_del(resv, idx, idx + 1); 254496b96a96SMike Kravetz } 254596b96a96SMike Kravetz break; 2546846be085SMike Kravetz case VMA_DEL_RESV: 2547846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 2548846be085SMike Kravetz region_abort(resv, idx, idx + 1, 1); 2549846be085SMike Kravetz ret = region_del(resv, idx, idx + 1); 2550846be085SMike Kravetz } else { 2551846be085SMike Kravetz ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 2552846be085SMike Kravetz /* region_add calls of range 1 should never fail. */ 2553846be085SMike Kravetz VM_BUG_ON(ret < 0); 2554846be085SMike Kravetz } 2555846be085SMike Kravetz break; 25565e911373SMike Kravetz default: 25575e911373SMike Kravetz BUG(); 25585e911373SMike Kravetz } 255984afd99bSAndy Whitcroft 2560846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE || mode == VMA_DEL_RESV) 2561cf3ad20bSMike Kravetz return ret; 256267961f9dSMike Kravetz /* 2563bf3d12b9SMiaohe Lin * We know private mapping must have HPAGE_RESV_OWNER set. 2564bf3d12b9SMiaohe Lin * 256567961f9dSMike Kravetz * In most cases, reserves always exist for private mappings. 256667961f9dSMike Kravetz * However, a file associated with mapping could have been 256767961f9dSMike Kravetz * hole punched or truncated after reserves were consumed. 256867961f9dSMike Kravetz * As subsequent fault on such a range will not use reserves. 256967961f9dSMike Kravetz * Subtle - The reserve map for private mappings has the 257067961f9dSMike Kravetz * opposite meaning than that of shared mappings. If NO 257167961f9dSMike Kravetz * entry is in the reserve map, it means a reservation exists. 257267961f9dSMike Kravetz * If an entry exists in the reserve map, it means the 257367961f9dSMike Kravetz * reservation has already been consumed. As a result, the 257467961f9dSMike Kravetz * return value of this routine is the opposite of the 257567961f9dSMike Kravetz * value returned from reserve map manipulation routines above. 257667961f9dSMike Kravetz */ 2577bf3d12b9SMiaohe Lin if (ret > 0) 257867961f9dSMike Kravetz return 0; 2579bf3d12b9SMiaohe Lin if (ret == 0) 258067961f9dSMike Kravetz return 1; 2581bf3d12b9SMiaohe Lin return ret; 258284afd99bSAndy Whitcroft } 2583cf3ad20bSMike Kravetz 2584cf3ad20bSMike Kravetz static long vma_needs_reservation(struct hstate *h, 2585a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 2586c37f9fb1SAndy Whitcroft { 25875e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV); 2588cf3ad20bSMike Kravetz } 2589c37f9fb1SAndy Whitcroft 2590cf3ad20bSMike Kravetz static long vma_commit_reservation(struct hstate *h, 2591cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr) 2592cf3ad20bSMike Kravetz { 25935e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV); 25945e911373SMike Kravetz } 25955e911373SMike Kravetz 2596feba16e2SMike Kravetz static void vma_end_reservation(struct hstate *h, 25975e911373SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 25985e911373SMike Kravetz { 2599feba16e2SMike Kravetz (void)__vma_reservation_common(h, vma, addr, VMA_END_RESV); 2600c37f9fb1SAndy Whitcroft } 2601c37f9fb1SAndy Whitcroft 260296b96a96SMike Kravetz static long vma_add_reservation(struct hstate *h, 260396b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 260496b96a96SMike Kravetz { 260596b96a96SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV); 260696b96a96SMike Kravetz } 260796b96a96SMike Kravetz 2608846be085SMike Kravetz static long vma_del_reservation(struct hstate *h, 2609846be085SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 261096b96a96SMike Kravetz { 2611846be085SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_DEL_RESV); 2612846be085SMike Kravetz } 2613846be085SMike Kravetz 2614846be085SMike Kravetz /* 2615846be085SMike Kravetz * This routine is called to restore reservation information on error paths. 2616846be085SMike Kravetz * It should ONLY be called for pages allocated via alloc_huge_page(), and 2617846be085SMike Kravetz * the hugetlb mutex should remain held when calling this routine. 2618846be085SMike Kravetz * 2619846be085SMike Kravetz * It handles two specific cases: 2620846be085SMike Kravetz * 1) A reservation was in place and the page consumed the reservation. 2621846be085SMike Kravetz * HPageRestoreReserve is set in the page. 2622846be085SMike Kravetz * 2) No reservation was in place for the page, so HPageRestoreReserve is 2623846be085SMike Kravetz * not set. However, alloc_huge_page always updates the reserve map. 2624846be085SMike Kravetz * 2625846be085SMike Kravetz * In case 1, free_huge_page later in the error path will increment the 2626846be085SMike Kravetz * global reserve count. But, free_huge_page does not have enough context 2627846be085SMike Kravetz * to adjust the reservation map. This case deals primarily with private 2628846be085SMike Kravetz * mappings. Adjust the reserve map here to be consistent with global 2629846be085SMike Kravetz * reserve count adjustments to be made by free_huge_page. Make sure the 2630846be085SMike Kravetz * reserve map indicates there is a reservation present. 2631846be085SMike Kravetz * 2632846be085SMike Kravetz * In case 2, simply undo reserve map modifications done by alloc_huge_page. 2633846be085SMike Kravetz */ 2634846be085SMike Kravetz void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma, 2635846be085SMike Kravetz unsigned long address, struct page *page) 2636846be085SMike Kravetz { 263796b96a96SMike Kravetz long rc = vma_needs_reservation(h, vma, address); 263896b96a96SMike Kravetz 2639846be085SMike Kravetz if (HPageRestoreReserve(page)) { 2640846be085SMike Kravetz if (unlikely(rc < 0)) 264196b96a96SMike Kravetz /* 264296b96a96SMike Kravetz * Rare out of memory condition in reserve map 2643d6995da3SMike Kravetz * manipulation. Clear HPageRestoreReserve so that 264496b96a96SMike Kravetz * global reserve count will not be incremented 264596b96a96SMike Kravetz * by free_huge_page. This will make it appear 264696b96a96SMike Kravetz * as though the reservation for this page was 264796b96a96SMike Kravetz * consumed. This may prevent the task from 264896b96a96SMike Kravetz * faulting in the page at a later time. This 264996b96a96SMike Kravetz * is better than inconsistent global huge page 265096b96a96SMike Kravetz * accounting of reserve counts. 265196b96a96SMike Kravetz */ 2652d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 2653846be085SMike Kravetz else if (rc) 2654846be085SMike Kravetz (void)vma_add_reservation(h, vma, address); 2655846be085SMike Kravetz else 2656846be085SMike Kravetz vma_end_reservation(h, vma, address); 2657846be085SMike Kravetz } else { 2658846be085SMike Kravetz if (!rc) { 265996b96a96SMike Kravetz /* 2660846be085SMike Kravetz * This indicates there is an entry in the reserve map 2661c7b1850dSMike Kravetz * not added by alloc_huge_page. We know it was added 2662846be085SMike Kravetz * before the alloc_huge_page call, otherwise 2663846be085SMike Kravetz * HPageRestoreReserve would be set on the page. 2664846be085SMike Kravetz * Remove the entry so that a subsequent allocation 2665846be085SMike Kravetz * does not consume a reservation. 266696b96a96SMike Kravetz */ 2667846be085SMike Kravetz rc = vma_del_reservation(h, vma, address); 2668846be085SMike Kravetz if (rc < 0) 2669846be085SMike Kravetz /* 2670846be085SMike Kravetz * VERY rare out of memory condition. Since 2671846be085SMike Kravetz * we can not delete the entry, set 2672846be085SMike Kravetz * HPageRestoreReserve so that the reserve 2673846be085SMike Kravetz * count will be incremented when the page 2674846be085SMike Kravetz * is freed. This reserve will be consumed 2675846be085SMike Kravetz * on a subsequent allocation. 2676846be085SMike Kravetz */ 2677846be085SMike Kravetz SetHPageRestoreReserve(page); 2678846be085SMike Kravetz } else if (rc < 0) { 2679846be085SMike Kravetz /* 2680846be085SMike Kravetz * Rare out of memory condition from 2681846be085SMike Kravetz * vma_needs_reservation call. Memory allocation is 2682846be085SMike Kravetz * only attempted if a new entry is needed. Therefore, 2683846be085SMike Kravetz * this implies there is not an entry in the 2684846be085SMike Kravetz * reserve map. 2685846be085SMike Kravetz * 2686846be085SMike Kravetz * For shared mappings, no entry in the map indicates 2687846be085SMike Kravetz * no reservation. We are done. 2688846be085SMike Kravetz */ 2689846be085SMike Kravetz if (!(vma->vm_flags & VM_MAYSHARE)) 2690846be085SMike Kravetz /* 2691846be085SMike Kravetz * For private mappings, no entry indicates 2692846be085SMike Kravetz * a reservation is present. Since we can 2693846be085SMike Kravetz * not add an entry, set SetHPageRestoreReserve 2694846be085SMike Kravetz * on the page so reserve count will be 2695846be085SMike Kravetz * incremented when freed. This reserve will 2696846be085SMike Kravetz * be consumed on a subsequent allocation. 2697846be085SMike Kravetz */ 2698846be085SMike Kravetz SetHPageRestoreReserve(page); 269996b96a96SMike Kravetz } else 2700846be085SMike Kravetz /* 2701846be085SMike Kravetz * No reservation present, do nothing 2702846be085SMike Kravetz */ 270396b96a96SMike Kravetz vma_end_reservation(h, vma, address); 270496b96a96SMike Kravetz } 270596b96a96SMike Kravetz } 270696b96a96SMike Kravetz 2707369fa227SOscar Salvador /* 2708369fa227SOscar Salvador * alloc_and_dissolve_huge_page - Allocate a new page and dissolve the old one 2709369fa227SOscar Salvador * @h: struct hstate old page belongs to 2710369fa227SOscar Salvador * @old_page: Old page to dissolve 2711ae37c7ffSOscar Salvador * @list: List to isolate the page in case we need to 2712369fa227SOscar Salvador * Returns 0 on success, otherwise negated error. 2713369fa227SOscar Salvador */ 2714ae37c7ffSOscar Salvador static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, 2715ae37c7ffSOscar Salvador struct list_head *list) 2716369fa227SOscar Salvador { 2717369fa227SOscar Salvador gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 2718369fa227SOscar Salvador int nid = page_to_nid(old_page); 2719b65a4edaSMike Kravetz bool alloc_retry = false; 2720369fa227SOscar Salvador struct page *new_page; 2721369fa227SOscar Salvador int ret = 0; 2722369fa227SOscar Salvador 2723369fa227SOscar Salvador /* 2724369fa227SOscar Salvador * Before dissolving the page, we need to allocate a new one for the 2725f41f2ed4SMuchun Song * pool to remain stable. Here, we allocate the page and 'prep' it 2726f41f2ed4SMuchun Song * by doing everything but actually updating counters and adding to 2727f41f2ed4SMuchun Song * the pool. This simplifies and let us do most of the processing 2728f41f2ed4SMuchun Song * under the lock. 2729369fa227SOscar Salvador */ 2730b65a4edaSMike Kravetz alloc_retry: 2731369fa227SOscar Salvador new_page = alloc_buddy_huge_page(h, gfp_mask, nid, NULL, NULL); 2732369fa227SOscar Salvador if (!new_page) 2733369fa227SOscar Salvador return -ENOMEM; 2734b65a4edaSMike Kravetz /* 2735b65a4edaSMike Kravetz * If all goes well, this page will be directly added to the free 2736b65a4edaSMike Kravetz * list in the pool. For this the ref count needs to be zero. 2737b65a4edaSMike Kravetz * Attempt to drop now, and retry once if needed. It is VERY 2738b65a4edaSMike Kravetz * unlikely there is another ref on the page. 2739b65a4edaSMike Kravetz * 2740b65a4edaSMike Kravetz * If someone else has a reference to the page, it will be freed 2741b65a4edaSMike Kravetz * when they drop their ref. Abuse temporary page flag to accomplish 2742b65a4edaSMike Kravetz * this. Retry once if there is an inflated ref count. 2743b65a4edaSMike Kravetz */ 2744b65a4edaSMike Kravetz SetHPageTemporary(new_page); 2745b65a4edaSMike Kravetz if (!put_page_testzero(new_page)) { 2746b65a4edaSMike Kravetz if (alloc_retry) 2747b65a4edaSMike Kravetz return -EBUSY; 2748b65a4edaSMike Kravetz 2749b65a4edaSMike Kravetz alloc_retry = true; 2750b65a4edaSMike Kravetz goto alloc_retry; 2751b65a4edaSMike Kravetz } 2752b65a4edaSMike Kravetz ClearHPageTemporary(new_page); 2753b65a4edaSMike Kravetz 2754f41f2ed4SMuchun Song __prep_new_huge_page(h, new_page); 2755369fa227SOscar Salvador 2756369fa227SOscar Salvador retry: 2757369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2758369fa227SOscar Salvador if (!PageHuge(old_page)) { 2759369fa227SOscar Salvador /* 2760369fa227SOscar Salvador * Freed from under us. Drop new_page too. 2761369fa227SOscar Salvador */ 2762369fa227SOscar Salvador goto free_new; 2763369fa227SOscar Salvador } else if (page_count(old_page)) { 2764369fa227SOscar Salvador /* 2765ae37c7ffSOscar Salvador * Someone has grabbed the page, try to isolate it here. 2766ae37c7ffSOscar Salvador * Fail with -EBUSY if not possible. 2767369fa227SOscar Salvador */ 2768ae37c7ffSOscar Salvador spin_unlock_irq(&hugetlb_lock); 27697ce82f4cSMiaohe Lin ret = isolate_hugetlb(old_page, list); 2770ae37c7ffSOscar Salvador spin_lock_irq(&hugetlb_lock); 2771369fa227SOscar Salvador goto free_new; 2772369fa227SOscar Salvador } else if (!HPageFreed(old_page)) { 2773369fa227SOscar Salvador /* 2774369fa227SOscar Salvador * Page's refcount is 0 but it has not been enqueued in the 2775369fa227SOscar Salvador * freelist yet. Race window is small, so we can succeed here if 2776369fa227SOscar Salvador * we retry. 2777369fa227SOscar Salvador */ 2778369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2779369fa227SOscar Salvador cond_resched(); 2780369fa227SOscar Salvador goto retry; 2781369fa227SOscar Salvador } else { 2782369fa227SOscar Salvador /* 2783369fa227SOscar Salvador * Ok, old_page is still a genuine free hugepage. Remove it from 2784369fa227SOscar Salvador * the freelist and decrease the counters. These will be 2785369fa227SOscar Salvador * incremented again when calling __prep_account_new_huge_page() 2786369fa227SOscar Salvador * and enqueue_huge_page() for new_page. The counters will remain 2787369fa227SOscar Salvador * stable since this happens under the lock. 2788369fa227SOscar Salvador */ 2789369fa227SOscar Salvador remove_hugetlb_page(h, old_page, false); 2790369fa227SOscar Salvador 2791369fa227SOscar Salvador /* 2792b65a4edaSMike Kravetz * Ref count on new page is already zero as it was dropped 2793b65a4edaSMike Kravetz * earlier. It can be directly added to the pool free list. 2794369fa227SOscar Salvador */ 2795369fa227SOscar Salvador __prep_account_new_huge_page(h, nid); 2796369fa227SOscar Salvador enqueue_huge_page(h, new_page); 2797369fa227SOscar Salvador 2798369fa227SOscar Salvador /* 2799369fa227SOscar Salvador * Pages have been replaced, we can safely free the old one. 2800369fa227SOscar Salvador */ 2801369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2802b65d4adbSMuchun Song update_and_free_page(h, old_page, false); 2803369fa227SOscar Salvador } 2804369fa227SOscar Salvador 2805369fa227SOscar Salvador return ret; 2806369fa227SOscar Salvador 2807369fa227SOscar Salvador free_new: 2808369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2809b65a4edaSMike Kravetz /* Page has a zero ref count, but needs a ref to be freed */ 2810b65a4edaSMike Kravetz set_page_refcounted(new_page); 2811b65d4adbSMuchun Song update_and_free_page(h, new_page, false); 2812369fa227SOscar Salvador 2813369fa227SOscar Salvador return ret; 2814369fa227SOscar Salvador } 2815369fa227SOscar Salvador 2816ae37c7ffSOscar Salvador int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list) 2817369fa227SOscar Salvador { 2818369fa227SOscar Salvador struct hstate *h; 2819369fa227SOscar Salvador struct page *head; 2820ae37c7ffSOscar Salvador int ret = -EBUSY; 2821369fa227SOscar Salvador 2822369fa227SOscar Salvador /* 2823369fa227SOscar Salvador * The page might have been dissolved from under our feet, so make sure 2824369fa227SOscar Salvador * to carefully check the state under the lock. 2825369fa227SOscar Salvador * Return success when racing as if we dissolved the page ourselves. 2826369fa227SOscar Salvador */ 2827369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2828369fa227SOscar Salvador if (PageHuge(page)) { 2829369fa227SOscar Salvador head = compound_head(page); 2830369fa227SOscar Salvador h = page_hstate(head); 2831369fa227SOscar Salvador } else { 2832369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2833369fa227SOscar Salvador return 0; 2834369fa227SOscar Salvador } 2835369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2836369fa227SOscar Salvador 2837369fa227SOscar Salvador /* 2838369fa227SOscar Salvador * Fence off gigantic pages as there is a cyclic dependency between 2839369fa227SOscar Salvador * alloc_contig_range and them. Return -ENOMEM as this has the effect 2840369fa227SOscar Salvador * of bailing out right away without further retrying. 2841369fa227SOscar Salvador */ 2842369fa227SOscar Salvador if (hstate_is_gigantic(h)) 2843369fa227SOscar Salvador return -ENOMEM; 2844369fa227SOscar Salvador 28457ce82f4cSMiaohe Lin if (page_count(head) && !isolate_hugetlb(head, list)) 2846ae37c7ffSOscar Salvador ret = 0; 2847ae37c7ffSOscar Salvador else if (!page_count(head)) 2848ae37c7ffSOscar Salvador ret = alloc_and_dissolve_huge_page(h, head, list); 2849ae37c7ffSOscar Salvador 2850ae37c7ffSOscar Salvador return ret; 2851369fa227SOscar Salvador } 2852369fa227SOscar Salvador 285370c3547eSMike Kravetz struct page *alloc_huge_page(struct vm_area_struct *vma, 285404f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 2855348ea204SAdam Litke { 285690481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 2857a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 2858348ea204SAdam Litke struct page *page; 2859d85f69b0SMike Kravetz long map_chg, map_commit; 2860d85f69b0SMike Kravetz long gbl_chg; 28616d76dcf4SAneesh Kumar K.V int ret, idx; 28626d76dcf4SAneesh Kumar K.V struct hugetlb_cgroup *h_cg; 286308cf9fafSMina Almasry bool deferred_reserve; 28642fc39cecSAdam Litke 28656d76dcf4SAneesh Kumar K.V idx = hstate_index(h); 2866a1e78772SMel Gorman /* 2867d85f69b0SMike Kravetz * Examine the region/reserve map to determine if the process 2868d85f69b0SMike Kravetz * has a reservation for the page to be allocated. A return 2869d85f69b0SMike Kravetz * code of zero indicates a reservation exists (no change). 2870a1e78772SMel Gorman */ 2871d85f69b0SMike Kravetz map_chg = gbl_chg = vma_needs_reservation(h, vma, addr); 2872d85f69b0SMike Kravetz if (map_chg < 0) 287376dcee75SAneesh Kumar K.V return ERR_PTR(-ENOMEM); 2874d85f69b0SMike Kravetz 2875d85f69b0SMike Kravetz /* 2876d85f69b0SMike Kravetz * Processes that did not create the mapping will have no 2877d85f69b0SMike Kravetz * reserves as indicated by the region/reserve map. Check 2878d85f69b0SMike Kravetz * that the allocation will not exceed the subpool limit. 2879d85f69b0SMike Kravetz * Allocations for MAP_NORESERVE mappings also need to be 2880d85f69b0SMike Kravetz * checked against any subpool limit. 2881d85f69b0SMike Kravetz */ 2882d85f69b0SMike Kravetz if (map_chg || avoid_reserve) { 2883d85f69b0SMike Kravetz gbl_chg = hugepage_subpool_get_pages(spool, 1); 2884d85f69b0SMike Kravetz if (gbl_chg < 0) { 2885feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 288676dcee75SAneesh Kumar K.V return ERR_PTR(-ENOSPC); 28875e911373SMike Kravetz } 288890d8b7e6SAdam Litke 2889d85f69b0SMike Kravetz /* 2890d85f69b0SMike Kravetz * Even though there was no reservation in the region/reserve 2891d85f69b0SMike Kravetz * map, there could be reservations associated with the 2892d85f69b0SMike Kravetz * subpool that can be used. This would be indicated if the 2893d85f69b0SMike Kravetz * return value of hugepage_subpool_get_pages() is zero. 2894d85f69b0SMike Kravetz * However, if avoid_reserve is specified we still avoid even 2895d85f69b0SMike Kravetz * the subpool reservations. 2896d85f69b0SMike Kravetz */ 2897d85f69b0SMike Kravetz if (avoid_reserve) 2898d85f69b0SMike Kravetz gbl_chg = 1; 2899d85f69b0SMike Kravetz } 2900d85f69b0SMike Kravetz 290108cf9fafSMina Almasry /* If this allocation is not consuming a reservation, charge it now. 290208cf9fafSMina Almasry */ 29036501fe5fSMiaohe Lin deferred_reserve = map_chg || avoid_reserve; 290408cf9fafSMina Almasry if (deferred_reserve) { 290508cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup_rsvd( 290608cf9fafSMina Almasry idx, pages_per_huge_page(h), &h_cg); 29078f34af6fSJianyu Zhan if (ret) 29088f34af6fSJianyu Zhan goto out_subpool_put; 290908cf9fafSMina Almasry } 291008cf9fafSMina Almasry 291108cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); 291208cf9fafSMina Almasry if (ret) 291308cf9fafSMina Almasry goto out_uncharge_cgroup_reservation; 29148f34af6fSJianyu Zhan 2915db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2916d85f69b0SMike Kravetz /* 2917d85f69b0SMike Kravetz * glb_chg is passed to indicate whether or not a page must be taken 2918d85f69b0SMike Kravetz * from the global free pool (global change). gbl_chg == 0 indicates 2919d85f69b0SMike Kravetz * a reservation exists for the allocation. 2920d85f69b0SMike Kravetz */ 2921d85f69b0SMike Kravetz page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg); 292281a6fcaeSJoonsoo Kim if (!page) { 2923db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 29240c397daeSMichal Hocko page = alloc_buddy_huge_page_with_mpol(h, vma, addr); 29258f34af6fSJianyu Zhan if (!page) 29268f34af6fSJianyu Zhan goto out_uncharge_cgroup; 2927a88c7695SNaoya Horiguchi if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { 2928d6995da3SMike Kravetz SetHPageRestoreReserve(page); 2929a88c7695SNaoya Horiguchi h->resv_huge_pages--; 2930a88c7695SNaoya Horiguchi } 2931db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 293215a8d68eSWei Yang list_add(&page->lru, &h->hugepage_activelist); 293381a6fcaeSJoonsoo Kim /* Fall through */ 2934a1e78772SMel Gorman } 293581a6fcaeSJoonsoo Kim hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); 293608cf9fafSMina Almasry /* If allocation is not consuming a reservation, also store the 293708cf9fafSMina Almasry * hugetlb_cgroup pointer on the page. 293808cf9fafSMina Almasry */ 293908cf9fafSMina Almasry if (deferred_reserve) { 294008cf9fafSMina Almasry hugetlb_cgroup_commit_charge_rsvd(idx, pages_per_huge_page(h), 294108cf9fafSMina Almasry h_cg, page); 294208cf9fafSMina Almasry } 294308cf9fafSMina Almasry 2944db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2945a1e78772SMel Gorman 2946d6995da3SMike Kravetz hugetlb_set_page_subpool(page, spool); 2947a1e78772SMel Gorman 2948d85f69b0SMike Kravetz map_commit = vma_commit_reservation(h, vma, addr); 2949d85f69b0SMike Kravetz if (unlikely(map_chg > map_commit)) { 295033039678SMike Kravetz /* 295133039678SMike Kravetz * The page was added to the reservation map between 295233039678SMike Kravetz * vma_needs_reservation and vma_commit_reservation. 295333039678SMike Kravetz * This indicates a race with hugetlb_reserve_pages. 295433039678SMike Kravetz * Adjust for the subpool count incremented above AND 295533039678SMike Kravetz * in hugetlb_reserve_pages for the same page. Also, 295633039678SMike Kravetz * the reservation count added in hugetlb_reserve_pages 295733039678SMike Kravetz * no longer applies. 295833039678SMike Kravetz */ 295933039678SMike Kravetz long rsv_adjust; 296033039678SMike Kravetz 296133039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 1); 296233039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 296379aa925bSMike Kravetz if (deferred_reserve) 296479aa925bSMike Kravetz hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 296579aa925bSMike Kravetz pages_per_huge_page(h), page); 296633039678SMike Kravetz } 29677893d1d5SAdam Litke return page; 29688f34af6fSJianyu Zhan 29698f34af6fSJianyu Zhan out_uncharge_cgroup: 29708f34af6fSJianyu Zhan hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); 297108cf9fafSMina Almasry out_uncharge_cgroup_reservation: 297208cf9fafSMina Almasry if (deferred_reserve) 297308cf9fafSMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h), 297408cf9fafSMina Almasry h_cg); 29758f34af6fSJianyu Zhan out_subpool_put: 2976d85f69b0SMike Kravetz if (map_chg || avoid_reserve) 29778f34af6fSJianyu Zhan hugepage_subpool_put_pages(spool, 1); 2978feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 29798f34af6fSJianyu Zhan return ERR_PTR(-ENOSPC); 2980b45b5bd6SDavid Gibson } 2981b45b5bd6SDavid Gibson 2982b5389086SZhenguo Yao int alloc_bootmem_huge_page(struct hstate *h, int nid) 2983e24a1307SAneesh Kumar K.V __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); 2984b5389086SZhenguo Yao int __alloc_bootmem_huge_page(struct hstate *h, int nid) 2985aa888a74SAndi Kleen { 2986b5389086SZhenguo Yao struct huge_bootmem_page *m = NULL; /* initialize for clang */ 2987b2261026SJoonsoo Kim int nr_nodes, node; 2988aa888a74SAndi Kleen 2989b5389086SZhenguo Yao /* do node specific alloc */ 2990b5389086SZhenguo Yao if (nid != NUMA_NO_NODE) { 2991b5389086SZhenguo Yao m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h), 2992b5389086SZhenguo Yao 0, MEMBLOCK_ALLOC_ACCESSIBLE, nid); 2993b5389086SZhenguo Yao if (!m) 2994b5389086SZhenguo Yao return 0; 2995b5389086SZhenguo Yao goto found; 2996b5389086SZhenguo Yao } 2997b5389086SZhenguo Yao /* allocate from next node when distributing huge pages */ 2998b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { 2999b5389086SZhenguo Yao m = memblock_alloc_try_nid_raw( 30008b89a116SGrygorii Strashko huge_page_size(h), huge_page_size(h), 300197ad1087SMike Rapoport 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); 3002aa888a74SAndi Kleen /* 3003aa888a74SAndi Kleen * Use the beginning of the huge page to store the 3004aa888a74SAndi Kleen * huge_bootmem_page struct (until gather_bootmem 3005aa888a74SAndi Kleen * puts them into the mem_map). 3006aa888a74SAndi Kleen */ 3007b5389086SZhenguo Yao if (!m) 3008b5389086SZhenguo Yao return 0; 3009aa888a74SAndi Kleen goto found; 3010aa888a74SAndi Kleen } 3011aa888a74SAndi Kleen 3012aa888a74SAndi Kleen found: 3013aa888a74SAndi Kleen /* Put them into a private list first because mem_map is not up yet */ 3014330d6e48SCannon Matthews INIT_LIST_HEAD(&m->list); 3015aa888a74SAndi Kleen list_add(&m->list, &huge_boot_pages); 3016aa888a74SAndi Kleen m->hstate = h; 3017aa888a74SAndi Kleen return 1; 3018aa888a74SAndi Kleen } 3019aa888a74SAndi Kleen 302048b8d744SMike Kravetz /* 302148b8d744SMike Kravetz * Put bootmem huge pages into the standard lists after mem_map is up. 302248b8d744SMike Kravetz * Note: This only applies to gigantic (order > MAX_ORDER) pages. 302348b8d744SMike Kravetz */ 3024aa888a74SAndi Kleen static void __init gather_bootmem_prealloc(void) 3025aa888a74SAndi Kleen { 3026aa888a74SAndi Kleen struct huge_bootmem_page *m; 3027aa888a74SAndi Kleen 3028aa888a74SAndi Kleen list_for_each_entry(m, &huge_boot_pages, list) { 302940d18ebfSMike Kravetz struct page *page = virt_to_page(m); 3030aa888a74SAndi Kleen struct hstate *h = m->hstate; 3031ee8f248dSBecky Bruce 303248b8d744SMike Kravetz VM_BUG_ON(!hstate_is_gigantic(h)); 3033aa888a74SAndi Kleen WARN_ON(page_count(page) != 1); 30347118fc29SMike Kravetz if (prep_compound_gigantic_page(page, huge_page_order(h))) { 3035ef5a22beSAndrea Arcangeli WARN_ON(PageReserved(page)); 3036aa888a74SAndi Kleen prep_new_huge_page(h, page, page_to_nid(page)); 30377118fc29SMike Kravetz put_page(page); /* add to the hugepage allocator */ 30387118fc29SMike Kravetz } else { 3039416d85edSMike Kravetz /* VERY unlikely inflated ref count on a tail page */ 30407118fc29SMike Kravetz free_gigantic_page(page, huge_page_order(h)); 30417118fc29SMike Kravetz } 3042af0fb9dfSMichal Hocko 3043b0320c7bSRafael Aquini /* 304448b8d744SMike Kravetz * We need to restore the 'stolen' pages to totalram_pages 304548b8d744SMike Kravetz * in order to fix confusing memory reports from free(1) and 304648b8d744SMike Kravetz * other side-effects, like CommitLimit going negative. 3047b0320c7bSRafael Aquini */ 3048c78a7f36SMiaohe Lin adjust_managed_page_count(page, pages_per_huge_page(h)); 3049520495feSCannon Matthews cond_resched(); 3050aa888a74SAndi Kleen } 3051aa888a74SAndi Kleen } 3052b5389086SZhenguo Yao static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid) 3053b5389086SZhenguo Yao { 3054b5389086SZhenguo Yao unsigned long i; 3055b5389086SZhenguo Yao char buf[32]; 3056b5389086SZhenguo Yao 3057b5389086SZhenguo Yao for (i = 0; i < h->max_huge_pages_node[nid]; ++i) { 3058b5389086SZhenguo Yao if (hstate_is_gigantic(h)) { 3059b5389086SZhenguo Yao if (!alloc_bootmem_huge_page(h, nid)) 3060b5389086SZhenguo Yao break; 3061b5389086SZhenguo Yao } else { 3062b5389086SZhenguo Yao struct page *page; 3063b5389086SZhenguo Yao gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 3064b5389086SZhenguo Yao 3065b5389086SZhenguo Yao page = alloc_fresh_huge_page(h, gfp_mask, nid, 3066b5389086SZhenguo Yao &node_states[N_MEMORY], NULL); 3067b5389086SZhenguo Yao if (!page) 3068b5389086SZhenguo Yao break; 3069b5389086SZhenguo Yao put_page(page); /* free it into the hugepage allocator */ 3070b5389086SZhenguo Yao } 3071b5389086SZhenguo Yao cond_resched(); 3072b5389086SZhenguo Yao } 3073b5389086SZhenguo Yao if (i == h->max_huge_pages_node[nid]) 3074b5389086SZhenguo Yao return; 3075b5389086SZhenguo Yao 3076b5389086SZhenguo Yao string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3077b5389086SZhenguo Yao pr_warn("HugeTLB: allocating %u of page size %s failed node%d. Only allocated %lu hugepages.\n", 3078b5389086SZhenguo Yao h->max_huge_pages_node[nid], buf, nid, i); 3079b5389086SZhenguo Yao h->max_huge_pages -= (h->max_huge_pages_node[nid] - i); 3080b5389086SZhenguo Yao h->max_huge_pages_node[nid] = i; 3081b5389086SZhenguo Yao } 3082aa888a74SAndi Kleen 30838faa8b07SAndi Kleen static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 30841da177e4SLinus Torvalds { 30851da177e4SLinus Torvalds unsigned long i; 3086f60858f9SMike Kravetz nodemask_t *node_alloc_noretry; 3087b5389086SZhenguo Yao bool node_specific_alloc = false; 3088f60858f9SMike Kravetz 3089b5389086SZhenguo Yao /* skip gigantic hugepages allocation if hugetlb_cma enabled */ 3090b5389086SZhenguo Yao if (hstate_is_gigantic(h) && hugetlb_cma_size) { 3091b5389086SZhenguo Yao pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n"); 3092b5389086SZhenguo Yao return; 3093b5389086SZhenguo Yao } 3094b5389086SZhenguo Yao 3095b5389086SZhenguo Yao /* do node specific alloc */ 30960a7a0f6fSPeng Liu for_each_online_node(i) { 3097b5389086SZhenguo Yao if (h->max_huge_pages_node[i] > 0) { 3098b5389086SZhenguo Yao hugetlb_hstate_alloc_pages_onenode(h, i); 3099b5389086SZhenguo Yao node_specific_alloc = true; 3100b5389086SZhenguo Yao } 3101b5389086SZhenguo Yao } 3102b5389086SZhenguo Yao 3103b5389086SZhenguo Yao if (node_specific_alloc) 3104b5389086SZhenguo Yao return; 3105b5389086SZhenguo Yao 3106b5389086SZhenguo Yao /* below will do all node balanced alloc */ 3107f60858f9SMike Kravetz if (!hstate_is_gigantic(h)) { 3108f60858f9SMike Kravetz /* 3109f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3110f60858f9SMike Kravetz * Ignore errors as lower level routines can deal with 3111f60858f9SMike Kravetz * node_alloc_noretry == NULL. If this kmalloc fails at boot 3112f60858f9SMike Kravetz * time, we are likely in bigger trouble. 3113f60858f9SMike Kravetz */ 3114f60858f9SMike Kravetz node_alloc_noretry = kmalloc(sizeof(*node_alloc_noretry), 3115f60858f9SMike Kravetz GFP_KERNEL); 3116f60858f9SMike Kravetz } else { 3117f60858f9SMike Kravetz /* allocations done at boot time */ 3118f60858f9SMike Kravetz node_alloc_noretry = NULL; 3119f60858f9SMike Kravetz } 3120f60858f9SMike Kravetz 3121f60858f9SMike Kravetz /* bit mask controlling how hard we retry per-node allocations */ 3122f60858f9SMike Kravetz if (node_alloc_noretry) 3123f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 31241da177e4SLinus Torvalds 3125e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 3126bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) { 3127b5389086SZhenguo Yao if (!alloc_bootmem_huge_page(h, NUMA_NO_NODE)) 3128aa888a74SAndi Kleen break; 31290c397daeSMichal Hocko } else if (!alloc_pool_huge_page(h, 3130f60858f9SMike Kravetz &node_states[N_MEMORY], 3131f60858f9SMike Kravetz node_alloc_noretry)) 31321da177e4SLinus Torvalds break; 313369ed779aSDavid Rientjes cond_resched(); 31341da177e4SLinus Torvalds } 3135d715cf80SLiam R. Howlett if (i < h->max_huge_pages) { 3136d715cf80SLiam R. Howlett char buf[32]; 3137d715cf80SLiam R. Howlett 3138c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3139d715cf80SLiam R. Howlett pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n", 3140d715cf80SLiam R. Howlett h->max_huge_pages, buf, i); 31418faa8b07SAndi Kleen h->max_huge_pages = i; 3142e5ff2159SAndi Kleen } 3143f60858f9SMike Kravetz kfree(node_alloc_noretry); 3144d715cf80SLiam R. Howlett } 3145e5ff2159SAndi Kleen 3146e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 3147e5ff2159SAndi Kleen { 314879dfc695SMike Kravetz struct hstate *h, *h2; 3149e5ff2159SAndi Kleen 3150e5ff2159SAndi Kleen for_each_hstate(h) { 31518faa8b07SAndi Kleen /* oversize hugepages were init'ed in early boot */ 3152bae7f4aeSLuiz Capitulino if (!hstate_is_gigantic(h)) 31538faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(h); 315479dfc695SMike Kravetz 315579dfc695SMike Kravetz /* 315679dfc695SMike Kravetz * Set demote order for each hstate. Note that 315779dfc695SMike Kravetz * h->demote_order is initially 0. 315879dfc695SMike Kravetz * - We can not demote gigantic pages if runtime freeing 315979dfc695SMike Kravetz * is not supported, so skip this. 3160a01f4390SMike Kravetz * - If CMA allocation is possible, we can not demote 3161a01f4390SMike Kravetz * HUGETLB_PAGE_ORDER or smaller size pages. 316279dfc695SMike Kravetz */ 316379dfc695SMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 316479dfc695SMike Kravetz continue; 3165a01f4390SMike Kravetz if (hugetlb_cma_size && h->order <= HUGETLB_PAGE_ORDER) 3166a01f4390SMike Kravetz continue; 316779dfc695SMike Kravetz for_each_hstate(h2) { 316879dfc695SMike Kravetz if (h2 == h) 316979dfc695SMike Kravetz continue; 317079dfc695SMike Kravetz if (h2->order < h->order && 317179dfc695SMike Kravetz h2->order > h->demote_order) 317279dfc695SMike Kravetz h->demote_order = h2->order; 317379dfc695SMike Kravetz } 3174e5ff2159SAndi Kleen } 3175e5ff2159SAndi Kleen } 3176e5ff2159SAndi Kleen 3177e5ff2159SAndi Kleen static void __init report_hugepages(void) 3178e5ff2159SAndi Kleen { 3179e5ff2159SAndi Kleen struct hstate *h; 3180e5ff2159SAndi Kleen 3181e5ff2159SAndi Kleen for_each_hstate(h) { 31824abd32dbSAndi Kleen char buf[32]; 3183c6247f72SMatthew Wilcox 3184c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3185ffb22af5SAndrew Morton pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n", 3186c6247f72SMatthew Wilcox buf, h->free_huge_pages); 3187e5ff2159SAndi Kleen } 3188e5ff2159SAndi Kleen } 3189e5ff2159SAndi Kleen 31901da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 31916ae11b27SLee Schermerhorn static void try_to_free_low(struct hstate *h, unsigned long count, 31926ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 31931da177e4SLinus Torvalds { 31944415cc8dSChristoph Lameter int i; 31951121828aSMike Kravetz LIST_HEAD(page_list); 31964415cc8dSChristoph Lameter 31979487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 3198bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3199aa888a74SAndi Kleen return; 3200aa888a74SAndi Kleen 32011121828aSMike Kravetz /* 32021121828aSMike Kravetz * Collect pages to be freed on a list, and free after dropping lock 32031121828aSMike Kravetz */ 32046ae11b27SLee Schermerhorn for_each_node_mask(i, *nodes_allowed) { 320510c6ec49SMike Kravetz struct page *page, *next; 3206a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 3207a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 3208a5516438SAndi Kleen if (count >= h->nr_huge_pages) 32091121828aSMike Kravetz goto out; 32101da177e4SLinus Torvalds if (PageHighMem(page)) 32111da177e4SLinus Torvalds continue; 32126eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 32131121828aSMike Kravetz list_add(&page->lru, &page_list); 32141121828aSMike Kravetz } 32151121828aSMike Kravetz } 32161121828aSMike Kravetz 32171121828aSMike Kravetz out: 3218db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 321910c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3220db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 32211da177e4SLinus Torvalds } 32221da177e4SLinus Torvalds #else 32236ae11b27SLee Schermerhorn static inline void try_to_free_low(struct hstate *h, unsigned long count, 32246ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 32251da177e4SLinus Torvalds { 32261da177e4SLinus Torvalds } 32271da177e4SLinus Torvalds #endif 32281da177e4SLinus Torvalds 322920a0307cSWu Fengguang /* 323020a0307cSWu Fengguang * Increment or decrement surplus_huge_pages. Keep node-specific counters 323120a0307cSWu Fengguang * balanced by operating on them in a round-robin fashion. 323220a0307cSWu Fengguang * Returns 1 if an adjustment was made. 323320a0307cSWu Fengguang */ 32346ae11b27SLee Schermerhorn static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, 32356ae11b27SLee Schermerhorn int delta) 323620a0307cSWu Fengguang { 3237b2261026SJoonsoo Kim int nr_nodes, node; 323820a0307cSWu Fengguang 32399487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 324020a0307cSWu Fengguang VM_BUG_ON(delta != -1 && delta != 1); 324120a0307cSWu Fengguang 3242e8c5c824SLee Schermerhorn if (delta < 0) { 3243b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 3244b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node]) 3245b2261026SJoonsoo Kim goto found; 3246b2261026SJoonsoo Kim } 3247b2261026SJoonsoo Kim } else { 3248b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 3249b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node] < 3250b2261026SJoonsoo Kim h->nr_huge_pages_node[node]) 3251b2261026SJoonsoo Kim goto found; 3252e8c5c824SLee Schermerhorn } 32539a76db09SLee Schermerhorn } 3254b2261026SJoonsoo Kim return 0; 325520a0307cSWu Fengguang 3256b2261026SJoonsoo Kim found: 325720a0307cSWu Fengguang h->surplus_huge_pages += delta; 3258b2261026SJoonsoo Kim h->surplus_huge_pages_node[node] += delta; 3259b2261026SJoonsoo Kim return 1; 326020a0307cSWu Fengguang } 326120a0307cSWu Fengguang 3262a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 3263fd875dcaSMike Kravetz static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, 32646ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 32651da177e4SLinus Torvalds { 32667893d1d5SAdam Litke unsigned long min_count, ret; 326710c6ec49SMike Kravetz struct page *page; 326810c6ec49SMike Kravetz LIST_HEAD(page_list); 3269f60858f9SMike Kravetz NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL); 3270f60858f9SMike Kravetz 3271f60858f9SMike Kravetz /* 3272f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3273f60858f9SMike Kravetz * If we can not allocate the bit mask, do not attempt to allocate 3274f60858f9SMike Kravetz * the requested huge pages. 3275f60858f9SMike Kravetz */ 3276f60858f9SMike Kravetz if (node_alloc_noretry) 3277f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 3278f60858f9SMike Kravetz else 3279f60858f9SMike Kravetz return -ENOMEM; 32801da177e4SLinus Torvalds 328129383967SMike Kravetz /* 328229383967SMike Kravetz * resize_lock mutex prevents concurrent adjustments to number of 328329383967SMike Kravetz * pages in hstate via the proc/sysfs interfaces. 328429383967SMike Kravetz */ 328529383967SMike Kravetz mutex_lock(&h->resize_lock); 3286b65d4adbSMuchun Song flush_free_hpage_work(h); 3287db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 32884eb0716eSAlexandre Ghiti 32894eb0716eSAlexandre Ghiti /* 3290fd875dcaSMike Kravetz * Check for a node specific request. 3291fd875dcaSMike Kravetz * Changing node specific huge page count may require a corresponding 3292fd875dcaSMike Kravetz * change to the global count. In any case, the passed node mask 3293fd875dcaSMike Kravetz * (nodes_allowed) will restrict alloc/free to the specified node. 3294fd875dcaSMike Kravetz */ 3295fd875dcaSMike Kravetz if (nid != NUMA_NO_NODE) { 3296fd875dcaSMike Kravetz unsigned long old_count = count; 3297fd875dcaSMike Kravetz 3298fd875dcaSMike Kravetz count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; 3299fd875dcaSMike Kravetz /* 3300fd875dcaSMike Kravetz * User may have specified a large count value which caused the 3301fd875dcaSMike Kravetz * above calculation to overflow. In this case, they wanted 3302fd875dcaSMike Kravetz * to allocate as many huge pages as possible. Set count to 3303fd875dcaSMike Kravetz * largest possible value to align with their intention. 3304fd875dcaSMike Kravetz */ 3305fd875dcaSMike Kravetz if (count < old_count) 3306fd875dcaSMike Kravetz count = ULONG_MAX; 3307fd875dcaSMike Kravetz } 3308fd875dcaSMike Kravetz 3309fd875dcaSMike Kravetz /* 33104eb0716eSAlexandre Ghiti * Gigantic pages runtime allocation depend on the capability for large 33114eb0716eSAlexandre Ghiti * page range allocation. 33124eb0716eSAlexandre Ghiti * If the system does not provide this feature, return an error when 33134eb0716eSAlexandre Ghiti * the user tries to allocate gigantic pages but let the user free the 33144eb0716eSAlexandre Ghiti * boottime allocated gigantic pages. 33154eb0716eSAlexandre Ghiti */ 33164eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) { 33174eb0716eSAlexandre Ghiti if (count > persistent_huge_pages(h)) { 3318db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 331929383967SMike Kravetz mutex_unlock(&h->resize_lock); 3320f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 33214eb0716eSAlexandre Ghiti return -EINVAL; 33224eb0716eSAlexandre Ghiti } 33234eb0716eSAlexandre Ghiti /* Fall through to decrease pool */ 33244eb0716eSAlexandre Ghiti } 3325aa888a74SAndi Kleen 33267893d1d5SAdam Litke /* 33277893d1d5SAdam Litke * Increase the pool size 33287893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 33297893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 3330d1c3fb1fSNishanth Aravamudan * 33310c397daeSMichal Hocko * We might race with alloc_surplus_huge_page() here and be unable 3332d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 3333d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 3334d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 3335d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 33367893d1d5SAdam Litke */ 3337a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 33386ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, -1)) 33397893d1d5SAdam Litke break; 33407893d1d5SAdam Litke } 33417893d1d5SAdam Litke 3342a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 33437893d1d5SAdam Litke /* 33447893d1d5SAdam Litke * If this allocation races such that we no longer need the 33457893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 33467893d1d5SAdam Litke * and reducing the surplus. 33477893d1d5SAdam Litke */ 3348db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3349649920c6SJia He 3350649920c6SJia He /* yield cpu to avoid soft lockup */ 3351649920c6SJia He cond_resched(); 3352649920c6SJia He 3353f60858f9SMike Kravetz ret = alloc_pool_huge_page(h, nodes_allowed, 3354f60858f9SMike Kravetz node_alloc_noretry); 3355db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 33567893d1d5SAdam Litke if (!ret) 33577893d1d5SAdam Litke goto out; 33587893d1d5SAdam Litke 3359536240f2SMel Gorman /* Bail for signals. Probably ctrl-c from user */ 3360536240f2SMel Gorman if (signal_pending(current)) 3361536240f2SMel Gorman goto out; 33627893d1d5SAdam Litke } 33637893d1d5SAdam Litke 33647893d1d5SAdam Litke /* 33657893d1d5SAdam Litke * Decrease the pool size 33667893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 33677893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 33687893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 33697893d1d5SAdam Litke * to the desired size as pages become free. 3370d1c3fb1fSNishanth Aravamudan * 3371d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 3372d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 3373d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 33740c397daeSMichal Hocko * alloc_surplus_huge_page() is checking the global counter, 3375d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 3376d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 3377d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 33787893d1d5SAdam Litke */ 3379a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 33806b0c880dSAdam Litke min_count = max(count, min_count); 33816ae11b27SLee Schermerhorn try_to_free_low(h, min_count, nodes_allowed); 338210c6ec49SMike Kravetz 338310c6ec49SMike Kravetz /* 338410c6ec49SMike Kravetz * Collect pages to be removed on list without dropping lock 338510c6ec49SMike Kravetz */ 3386a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 338710c6ec49SMike Kravetz page = remove_pool_huge_page(h, nodes_allowed, 0); 338810c6ec49SMike Kravetz if (!page) 33891da177e4SLinus Torvalds break; 339010c6ec49SMike Kravetz 339110c6ec49SMike Kravetz list_add(&page->lru, &page_list); 33921da177e4SLinus Torvalds } 339310c6ec49SMike Kravetz /* free the pages after dropping lock */ 3394db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 339510c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3396b65d4adbSMuchun Song flush_free_hpage_work(h); 3397db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 339810c6ec49SMike Kravetz 3399a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 34006ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, 1)) 34017893d1d5SAdam Litke break; 34027893d1d5SAdam Litke } 34037893d1d5SAdam Litke out: 34044eb0716eSAlexandre Ghiti h->max_huge_pages = persistent_huge_pages(h); 3405db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 340629383967SMike Kravetz mutex_unlock(&h->resize_lock); 34074eb0716eSAlexandre Ghiti 3408f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 3409f60858f9SMike Kravetz 34104eb0716eSAlexandre Ghiti return 0; 34111da177e4SLinus Torvalds } 34121da177e4SLinus Torvalds 34138531fc6fSMike Kravetz static int demote_free_huge_page(struct hstate *h, struct page *page) 34148531fc6fSMike Kravetz { 34158531fc6fSMike Kravetz int i, nid = page_to_nid(page); 34168531fc6fSMike Kravetz struct hstate *target_hstate; 34178531fc6fSMike Kravetz int rc = 0; 34188531fc6fSMike Kravetz 34198531fc6fSMike Kravetz target_hstate = size_to_hstate(PAGE_SIZE << h->demote_order); 34208531fc6fSMike Kravetz 34218531fc6fSMike Kravetz remove_hugetlb_page_for_demote(h, page, false); 34228531fc6fSMike Kravetz spin_unlock_irq(&hugetlb_lock); 34238531fc6fSMike Kravetz 34245981611dSMuchun Song rc = hugetlb_vmemmap_alloc(h, page); 34258531fc6fSMike Kravetz if (rc) { 34268531fc6fSMike Kravetz /* Allocation of vmemmmap failed, we can not demote page */ 34278531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 34288531fc6fSMike Kravetz set_page_refcounted(page); 34298531fc6fSMike Kravetz add_hugetlb_page(h, page, false); 34308531fc6fSMike Kravetz return rc; 34318531fc6fSMike Kravetz } 34328531fc6fSMike Kravetz 34338531fc6fSMike Kravetz /* 34348531fc6fSMike Kravetz * Use destroy_compound_hugetlb_page_for_demote for all huge page 34358531fc6fSMike Kravetz * sizes as it will not ref count pages. 34368531fc6fSMike Kravetz */ 34378531fc6fSMike Kravetz destroy_compound_hugetlb_page_for_demote(page, huge_page_order(h)); 34388531fc6fSMike Kravetz 34398531fc6fSMike Kravetz /* 34408531fc6fSMike Kravetz * Taking target hstate mutex synchronizes with set_max_huge_pages. 34418531fc6fSMike Kravetz * Without the mutex, pages added to target hstate could be marked 34428531fc6fSMike Kravetz * as surplus. 34438531fc6fSMike Kravetz * 34448531fc6fSMike Kravetz * Note that we already hold h->resize_lock. To prevent deadlock, 34458531fc6fSMike Kravetz * use the convention of always taking larger size hstate mutex first. 34468531fc6fSMike Kravetz */ 34478531fc6fSMike Kravetz mutex_lock(&target_hstate->resize_lock); 34488531fc6fSMike Kravetz for (i = 0; i < pages_per_huge_page(h); 34498531fc6fSMike Kravetz i += pages_per_huge_page(target_hstate)) { 34508531fc6fSMike Kravetz if (hstate_is_gigantic(target_hstate)) 34518531fc6fSMike Kravetz prep_compound_gigantic_page_for_demote(page + i, 34528531fc6fSMike Kravetz target_hstate->order); 34538531fc6fSMike Kravetz else 34548531fc6fSMike Kravetz prep_compound_page(page + i, target_hstate->order); 34558531fc6fSMike Kravetz set_page_private(page + i, 0); 34568531fc6fSMike Kravetz set_page_refcounted(page + i); 34578531fc6fSMike Kravetz prep_new_huge_page(target_hstate, page + i, nid); 34588531fc6fSMike Kravetz put_page(page + i); 34598531fc6fSMike Kravetz } 34608531fc6fSMike Kravetz mutex_unlock(&target_hstate->resize_lock); 34618531fc6fSMike Kravetz 34628531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 34638531fc6fSMike Kravetz 34648531fc6fSMike Kravetz /* 34658531fc6fSMike Kravetz * Not absolutely necessary, but for consistency update max_huge_pages 34668531fc6fSMike Kravetz * based on pool changes for the demoted page. 34678531fc6fSMike Kravetz */ 34688531fc6fSMike Kravetz h->max_huge_pages--; 34698531fc6fSMike Kravetz target_hstate->max_huge_pages += pages_per_huge_page(h); 34708531fc6fSMike Kravetz 34718531fc6fSMike Kravetz return rc; 34728531fc6fSMike Kravetz } 34738531fc6fSMike Kravetz 347479dfc695SMike Kravetz static int demote_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed) 347579dfc695SMike Kravetz __must_hold(&hugetlb_lock) 347679dfc695SMike Kravetz { 34778531fc6fSMike Kravetz int nr_nodes, node; 34788531fc6fSMike Kravetz struct page *page; 347979dfc695SMike Kravetz 348079dfc695SMike Kravetz lockdep_assert_held(&hugetlb_lock); 348179dfc695SMike Kravetz 348279dfc695SMike Kravetz /* We should never get here if no demote order */ 348379dfc695SMike Kravetz if (!h->demote_order) { 348479dfc695SMike Kravetz pr_warn("HugeTLB: NULL demote order passed to demote_pool_huge_page.\n"); 348579dfc695SMike Kravetz return -EINVAL; /* internal error */ 348679dfc695SMike Kravetz } 348779dfc695SMike Kravetz 34888531fc6fSMike Kravetz for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 34895a317412SMike Kravetz list_for_each_entry(page, &h->hugepage_freelists[node], lru) { 34905a317412SMike Kravetz if (PageHWPoison(page)) 34915a317412SMike Kravetz continue; 34925a317412SMike Kravetz 34935a317412SMike Kravetz return demote_free_huge_page(h, page); 34948531fc6fSMike Kravetz } 34958531fc6fSMike Kravetz } 34968531fc6fSMike Kravetz 34975a317412SMike Kravetz /* 34985a317412SMike Kravetz * Only way to get here is if all pages on free lists are poisoned. 34995a317412SMike Kravetz * Return -EBUSY so that caller will not retry. 35005a317412SMike Kravetz */ 35015a317412SMike Kravetz return -EBUSY; 350279dfc695SMike Kravetz } 350379dfc695SMike Kravetz 3504a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 3505a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 3506a3437870SNishanth Aravamudan 350779dfc695SMike Kravetz #define HSTATE_ATTR_WO(_name) \ 350879dfc695SMike Kravetz static struct kobj_attribute _name##_attr = __ATTR_WO(_name) 350979dfc695SMike Kravetz 3510a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 351198bc26acSMiaohe Lin static struct kobj_attribute _name##_attr = __ATTR_RW(_name) 3512a3437870SNishanth Aravamudan 3513a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 3514a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 3515a3437870SNishanth Aravamudan 35169a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); 35179a305230SLee Schermerhorn 35189a305230SLee Schermerhorn static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) 3519a3437870SNishanth Aravamudan { 3520a3437870SNishanth Aravamudan int i; 35219a305230SLee Schermerhorn 3522a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 35239a305230SLee Schermerhorn if (hstate_kobjs[i] == kobj) { 35249a305230SLee Schermerhorn if (nidp) 35259a305230SLee Schermerhorn *nidp = NUMA_NO_NODE; 3526a3437870SNishanth Aravamudan return &hstates[i]; 35279a305230SLee Schermerhorn } 35289a305230SLee Schermerhorn 35299a305230SLee Schermerhorn return kobj_to_node_hstate(kobj, nidp); 3530a3437870SNishanth Aravamudan } 3531a3437870SNishanth Aravamudan 353206808b08SLee Schermerhorn static ssize_t nr_hugepages_show_common(struct kobject *kobj, 3533a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3534a3437870SNishanth Aravamudan { 35359a305230SLee Schermerhorn struct hstate *h; 35369a305230SLee Schermerhorn unsigned long nr_huge_pages; 35379a305230SLee Schermerhorn int nid; 35389a305230SLee Schermerhorn 35399a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 35409a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 35419a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages; 35429a305230SLee Schermerhorn else 35439a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages_node[nid]; 35449a305230SLee Schermerhorn 3545ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", nr_huge_pages); 3546a3437870SNishanth Aravamudan } 3547adbe8726SEric B Munson 3548238d3c13SDavid Rientjes static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, 3549238d3c13SDavid Rientjes struct hstate *h, int nid, 3550238d3c13SDavid Rientjes unsigned long count, size_t len) 3551a3437870SNishanth Aravamudan { 3552a3437870SNishanth Aravamudan int err; 35532d0adf7eSOscar Salvador nodemask_t nodes_allowed, *n_mask; 3554a3437870SNishanth Aravamudan 35552d0adf7eSOscar Salvador if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 35562d0adf7eSOscar Salvador return -EINVAL; 3557adbe8726SEric B Munson 35589a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) { 35599a305230SLee Schermerhorn /* 35609a305230SLee Schermerhorn * global hstate attribute 35619a305230SLee Schermerhorn */ 35629a305230SLee Schermerhorn if (!(obey_mempolicy && 35632d0adf7eSOscar Salvador init_nodemask_of_mempolicy(&nodes_allowed))) 35642d0adf7eSOscar Salvador n_mask = &node_states[N_MEMORY]; 35652d0adf7eSOscar Salvador else 35662d0adf7eSOscar Salvador n_mask = &nodes_allowed; 35672d0adf7eSOscar Salvador } else { 35689a305230SLee Schermerhorn /* 3569fd875dcaSMike Kravetz * Node specific request. count adjustment happens in 3570fd875dcaSMike Kravetz * set_max_huge_pages() after acquiring hugetlb_lock. 35719a305230SLee Schermerhorn */ 35722d0adf7eSOscar Salvador init_nodemask_of_node(&nodes_allowed, nid); 35732d0adf7eSOscar Salvador n_mask = &nodes_allowed; 3574fd875dcaSMike Kravetz } 35759a305230SLee Schermerhorn 35762d0adf7eSOscar Salvador err = set_max_huge_pages(h, count, nid, n_mask); 357706808b08SLee Schermerhorn 35784eb0716eSAlexandre Ghiti return err ? err : len; 357906808b08SLee Schermerhorn } 358006808b08SLee Schermerhorn 3581238d3c13SDavid Rientjes static ssize_t nr_hugepages_store_common(bool obey_mempolicy, 3582238d3c13SDavid Rientjes struct kobject *kobj, const char *buf, 3583238d3c13SDavid Rientjes size_t len) 3584238d3c13SDavid Rientjes { 3585238d3c13SDavid Rientjes struct hstate *h; 3586238d3c13SDavid Rientjes unsigned long count; 3587238d3c13SDavid Rientjes int nid; 3588238d3c13SDavid Rientjes int err; 3589238d3c13SDavid Rientjes 3590238d3c13SDavid Rientjes err = kstrtoul(buf, 10, &count); 3591238d3c13SDavid Rientjes if (err) 3592238d3c13SDavid Rientjes return err; 3593238d3c13SDavid Rientjes 3594238d3c13SDavid Rientjes h = kobj_to_hstate(kobj, &nid); 3595238d3c13SDavid Rientjes return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); 3596238d3c13SDavid Rientjes } 3597238d3c13SDavid Rientjes 359806808b08SLee Schermerhorn static ssize_t nr_hugepages_show(struct kobject *kobj, 359906808b08SLee Schermerhorn struct kobj_attribute *attr, char *buf) 360006808b08SLee Schermerhorn { 360106808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 360206808b08SLee Schermerhorn } 360306808b08SLee Schermerhorn 360406808b08SLee Schermerhorn static ssize_t nr_hugepages_store(struct kobject *kobj, 360506808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 360606808b08SLee Schermerhorn { 3607238d3c13SDavid Rientjes return nr_hugepages_store_common(false, kobj, buf, len); 3608a3437870SNishanth Aravamudan } 3609a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 3610a3437870SNishanth Aravamudan 361106808b08SLee Schermerhorn #ifdef CONFIG_NUMA 361206808b08SLee Schermerhorn 361306808b08SLee Schermerhorn /* 361406808b08SLee Schermerhorn * hstate attribute for optionally mempolicy-based constraint on persistent 361506808b08SLee Schermerhorn * huge page alloc/free. 361606808b08SLee Schermerhorn */ 361706808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, 3618ae7a927dSJoe Perches struct kobj_attribute *attr, 3619ae7a927dSJoe Perches char *buf) 362006808b08SLee Schermerhorn { 362106808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 362206808b08SLee Schermerhorn } 362306808b08SLee Schermerhorn 362406808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, 362506808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 362606808b08SLee Schermerhorn { 3627238d3c13SDavid Rientjes return nr_hugepages_store_common(true, kobj, buf, len); 362806808b08SLee Schermerhorn } 362906808b08SLee Schermerhorn HSTATE_ATTR(nr_hugepages_mempolicy); 363006808b08SLee Schermerhorn #endif 363106808b08SLee Schermerhorn 363206808b08SLee Schermerhorn 3633a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 3634a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3635a3437870SNishanth Aravamudan { 36369a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3637ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->nr_overcommit_huge_pages); 3638a3437870SNishanth Aravamudan } 3639adbe8726SEric B Munson 3640a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 3641a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 3642a3437870SNishanth Aravamudan { 3643a3437870SNishanth Aravamudan int err; 3644a3437870SNishanth Aravamudan unsigned long input; 36459a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3646a3437870SNishanth Aravamudan 3647bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3648adbe8726SEric B Munson return -EINVAL; 3649adbe8726SEric B Munson 36503dbb95f7SJingoo Han err = kstrtoul(buf, 10, &input); 3651a3437870SNishanth Aravamudan if (err) 365273ae31e5SEric B Munson return err; 3653a3437870SNishanth Aravamudan 3654db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 3655a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 3656db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3657a3437870SNishanth Aravamudan 3658a3437870SNishanth Aravamudan return count; 3659a3437870SNishanth Aravamudan } 3660a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 3661a3437870SNishanth Aravamudan 3662a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 3663a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3664a3437870SNishanth Aravamudan { 36659a305230SLee Schermerhorn struct hstate *h; 36669a305230SLee Schermerhorn unsigned long free_huge_pages; 36679a305230SLee Schermerhorn int nid; 36689a305230SLee Schermerhorn 36699a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 36709a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 36719a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages; 36729a305230SLee Schermerhorn else 36739a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages_node[nid]; 36749a305230SLee Schermerhorn 3675ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", free_huge_pages); 3676a3437870SNishanth Aravamudan } 3677a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 3678a3437870SNishanth Aravamudan 3679a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 3680a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3681a3437870SNishanth Aravamudan { 36829a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3683ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->resv_huge_pages); 3684a3437870SNishanth Aravamudan } 3685a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 3686a3437870SNishanth Aravamudan 3687a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 3688a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3689a3437870SNishanth Aravamudan { 36909a305230SLee Schermerhorn struct hstate *h; 36919a305230SLee Schermerhorn unsigned long surplus_huge_pages; 36929a305230SLee Schermerhorn int nid; 36939a305230SLee Schermerhorn 36949a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 36959a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 36969a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages; 36979a305230SLee Schermerhorn else 36989a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages_node[nid]; 36999a305230SLee Schermerhorn 3700ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", surplus_huge_pages); 3701a3437870SNishanth Aravamudan } 3702a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 3703a3437870SNishanth Aravamudan 370479dfc695SMike Kravetz static ssize_t demote_store(struct kobject *kobj, 370579dfc695SMike Kravetz struct kobj_attribute *attr, const char *buf, size_t len) 370679dfc695SMike Kravetz { 370779dfc695SMike Kravetz unsigned long nr_demote; 370879dfc695SMike Kravetz unsigned long nr_available; 370979dfc695SMike Kravetz nodemask_t nodes_allowed, *n_mask; 371079dfc695SMike Kravetz struct hstate *h; 371179dfc695SMike Kravetz int err = 0; 371279dfc695SMike Kravetz int nid; 371379dfc695SMike Kravetz 371479dfc695SMike Kravetz err = kstrtoul(buf, 10, &nr_demote); 371579dfc695SMike Kravetz if (err) 371679dfc695SMike Kravetz return err; 371779dfc695SMike Kravetz h = kobj_to_hstate(kobj, &nid); 371879dfc695SMike Kravetz 371979dfc695SMike Kravetz if (nid != NUMA_NO_NODE) { 372079dfc695SMike Kravetz init_nodemask_of_node(&nodes_allowed, nid); 372179dfc695SMike Kravetz n_mask = &nodes_allowed; 372279dfc695SMike Kravetz } else { 372379dfc695SMike Kravetz n_mask = &node_states[N_MEMORY]; 372479dfc695SMike Kravetz } 372579dfc695SMike Kravetz 372679dfc695SMike Kravetz /* Synchronize with other sysfs operations modifying huge pages */ 372779dfc695SMike Kravetz mutex_lock(&h->resize_lock); 372879dfc695SMike Kravetz spin_lock_irq(&hugetlb_lock); 372979dfc695SMike Kravetz 373079dfc695SMike Kravetz while (nr_demote) { 373179dfc695SMike Kravetz /* 373279dfc695SMike Kravetz * Check for available pages to demote each time thorough the 373379dfc695SMike Kravetz * loop as demote_pool_huge_page will drop hugetlb_lock. 373479dfc695SMike Kravetz */ 373579dfc695SMike Kravetz if (nid != NUMA_NO_NODE) 373679dfc695SMike Kravetz nr_available = h->free_huge_pages_node[nid]; 373779dfc695SMike Kravetz else 373879dfc695SMike Kravetz nr_available = h->free_huge_pages; 373979dfc695SMike Kravetz nr_available -= h->resv_huge_pages; 374079dfc695SMike Kravetz if (!nr_available) 374179dfc695SMike Kravetz break; 374279dfc695SMike Kravetz 374379dfc695SMike Kravetz err = demote_pool_huge_page(h, n_mask); 374479dfc695SMike Kravetz if (err) 374579dfc695SMike Kravetz break; 374679dfc695SMike Kravetz 374779dfc695SMike Kravetz nr_demote--; 374879dfc695SMike Kravetz } 374979dfc695SMike Kravetz 375079dfc695SMike Kravetz spin_unlock_irq(&hugetlb_lock); 375179dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 375279dfc695SMike Kravetz 375379dfc695SMike Kravetz if (err) 375479dfc695SMike Kravetz return err; 375579dfc695SMike Kravetz return len; 375679dfc695SMike Kravetz } 375779dfc695SMike Kravetz HSTATE_ATTR_WO(demote); 375879dfc695SMike Kravetz 375979dfc695SMike Kravetz static ssize_t demote_size_show(struct kobject *kobj, 376079dfc695SMike Kravetz struct kobj_attribute *attr, char *buf) 376179dfc695SMike Kravetz { 376279dfc695SMike Kravetz int nid; 376379dfc695SMike Kravetz struct hstate *h = kobj_to_hstate(kobj, &nid); 376479dfc695SMike Kravetz unsigned long demote_size = (PAGE_SIZE << h->demote_order) / SZ_1K; 376579dfc695SMike Kravetz 376679dfc695SMike Kravetz return sysfs_emit(buf, "%lukB\n", demote_size); 376779dfc695SMike Kravetz } 376879dfc695SMike Kravetz 376979dfc695SMike Kravetz static ssize_t demote_size_store(struct kobject *kobj, 377079dfc695SMike Kravetz struct kobj_attribute *attr, 377179dfc695SMike Kravetz const char *buf, size_t count) 377279dfc695SMike Kravetz { 377379dfc695SMike Kravetz struct hstate *h, *demote_hstate; 377479dfc695SMike Kravetz unsigned long demote_size; 377579dfc695SMike Kravetz unsigned int demote_order; 377679dfc695SMike Kravetz int nid; 377779dfc695SMike Kravetz 377879dfc695SMike Kravetz demote_size = (unsigned long)memparse(buf, NULL); 377979dfc695SMike Kravetz 378079dfc695SMike Kravetz demote_hstate = size_to_hstate(demote_size); 378179dfc695SMike Kravetz if (!demote_hstate) 378279dfc695SMike Kravetz return -EINVAL; 378379dfc695SMike Kravetz demote_order = demote_hstate->order; 3784a01f4390SMike Kravetz if (demote_order < HUGETLB_PAGE_ORDER) 3785a01f4390SMike Kravetz return -EINVAL; 378679dfc695SMike Kravetz 378779dfc695SMike Kravetz /* demote order must be smaller than hstate order */ 378879dfc695SMike Kravetz h = kobj_to_hstate(kobj, &nid); 378979dfc695SMike Kravetz if (demote_order >= h->order) 379079dfc695SMike Kravetz return -EINVAL; 379179dfc695SMike Kravetz 379279dfc695SMike Kravetz /* resize_lock synchronizes access to demote size and writes */ 379379dfc695SMike Kravetz mutex_lock(&h->resize_lock); 379479dfc695SMike Kravetz h->demote_order = demote_order; 379579dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 379679dfc695SMike Kravetz 379779dfc695SMike Kravetz return count; 379879dfc695SMike Kravetz } 379979dfc695SMike Kravetz HSTATE_ATTR(demote_size); 380079dfc695SMike Kravetz 3801a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 3802a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 3803a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 3804a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 3805a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 3806a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 380706808b08SLee Schermerhorn #ifdef CONFIG_NUMA 380806808b08SLee Schermerhorn &nr_hugepages_mempolicy_attr.attr, 380906808b08SLee Schermerhorn #endif 3810a3437870SNishanth Aravamudan NULL, 3811a3437870SNishanth Aravamudan }; 3812a3437870SNishanth Aravamudan 381367e5ed96SArvind Yadav static const struct attribute_group hstate_attr_group = { 3814a3437870SNishanth Aravamudan .attrs = hstate_attrs, 3815a3437870SNishanth Aravamudan }; 3816a3437870SNishanth Aravamudan 381779dfc695SMike Kravetz static struct attribute *hstate_demote_attrs[] = { 381879dfc695SMike Kravetz &demote_size_attr.attr, 381979dfc695SMike Kravetz &demote_attr.attr, 382079dfc695SMike Kravetz NULL, 382179dfc695SMike Kravetz }; 382279dfc695SMike Kravetz 382379dfc695SMike Kravetz static const struct attribute_group hstate_demote_attr_group = { 382479dfc695SMike Kravetz .attrs = hstate_demote_attrs, 382579dfc695SMike Kravetz }; 382679dfc695SMike Kravetz 3827094e9539SJeff Mahoney static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, 38289a305230SLee Schermerhorn struct kobject **hstate_kobjs, 382967e5ed96SArvind Yadav const struct attribute_group *hstate_attr_group) 3830a3437870SNishanth Aravamudan { 3831a3437870SNishanth Aravamudan int retval; 3832972dc4deSAneesh Kumar K.V int hi = hstate_index(h); 3833a3437870SNishanth Aravamudan 38349a305230SLee Schermerhorn hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); 38359a305230SLee Schermerhorn if (!hstate_kobjs[hi]) 3836a3437870SNishanth Aravamudan return -ENOMEM; 3837a3437870SNishanth Aravamudan 38389a305230SLee Schermerhorn retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); 3839cc2205a6SMiaohe Lin if (retval) { 38409a305230SLee Schermerhorn kobject_put(hstate_kobjs[hi]); 3841cc2205a6SMiaohe Lin hstate_kobjs[hi] = NULL; 3842cc2205a6SMiaohe Lin } 3843a3437870SNishanth Aravamudan 384479dfc695SMike Kravetz if (h->demote_order) { 384579dfc695SMike Kravetz if (sysfs_create_group(hstate_kobjs[hi], 384679dfc695SMike Kravetz &hstate_demote_attr_group)) 384779dfc695SMike Kravetz pr_warn("HugeTLB unable to create demote interfaces for %s\n", h->name); 384879dfc695SMike Kravetz } 384979dfc695SMike Kravetz 3850a3437870SNishanth Aravamudan return retval; 3851a3437870SNishanth Aravamudan } 3852a3437870SNishanth Aravamudan 3853a3437870SNishanth Aravamudan static void __init hugetlb_sysfs_init(void) 3854a3437870SNishanth Aravamudan { 3855a3437870SNishanth Aravamudan struct hstate *h; 3856a3437870SNishanth Aravamudan int err; 3857a3437870SNishanth Aravamudan 3858a3437870SNishanth Aravamudan hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 3859a3437870SNishanth Aravamudan if (!hugepages_kobj) 3860a3437870SNishanth Aravamudan return; 3861a3437870SNishanth Aravamudan 3862a3437870SNishanth Aravamudan for_each_hstate(h) { 38639a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, 38649a305230SLee Schermerhorn hstate_kobjs, &hstate_attr_group); 3865a3437870SNishanth Aravamudan if (err) 3866282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s", h->name); 3867a3437870SNishanth Aravamudan } 3868a3437870SNishanth Aravamudan } 3869a3437870SNishanth Aravamudan 38709a305230SLee Schermerhorn #ifdef CONFIG_NUMA 38719a305230SLee Schermerhorn 38729a305230SLee Schermerhorn /* 38739a305230SLee Schermerhorn * node_hstate/s - associate per node hstate attributes, via their kobjects, 387410fbcf4cSKay Sievers * with node devices in node_devices[] using a parallel array. The array 387510fbcf4cSKay Sievers * index of a node device or _hstate == node id. 387610fbcf4cSKay Sievers * This is here to avoid any static dependency of the node device driver, in 38779a305230SLee Schermerhorn * the base kernel, on the hugetlb module. 38789a305230SLee Schermerhorn */ 38799a305230SLee Schermerhorn struct node_hstate { 38809a305230SLee Schermerhorn struct kobject *hugepages_kobj; 38819a305230SLee Schermerhorn struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 38829a305230SLee Schermerhorn }; 3883b4e289a6SAlexander Kuleshov static struct node_hstate node_hstates[MAX_NUMNODES]; 38849a305230SLee Schermerhorn 38859a305230SLee Schermerhorn /* 388610fbcf4cSKay Sievers * A subset of global hstate attributes for node devices 38879a305230SLee Schermerhorn */ 38889a305230SLee Schermerhorn static struct attribute *per_node_hstate_attrs[] = { 38899a305230SLee Schermerhorn &nr_hugepages_attr.attr, 38909a305230SLee Schermerhorn &free_hugepages_attr.attr, 38919a305230SLee Schermerhorn &surplus_hugepages_attr.attr, 38929a305230SLee Schermerhorn NULL, 38939a305230SLee Schermerhorn }; 38949a305230SLee Schermerhorn 389567e5ed96SArvind Yadav static const struct attribute_group per_node_hstate_attr_group = { 38969a305230SLee Schermerhorn .attrs = per_node_hstate_attrs, 38979a305230SLee Schermerhorn }; 38989a305230SLee Schermerhorn 38999a305230SLee Schermerhorn /* 390010fbcf4cSKay Sievers * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. 39019a305230SLee Schermerhorn * Returns node id via non-NULL nidp. 39029a305230SLee Schermerhorn */ 39039a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 39049a305230SLee Schermerhorn { 39059a305230SLee Schermerhorn int nid; 39069a305230SLee Schermerhorn 39079a305230SLee Schermerhorn for (nid = 0; nid < nr_node_ids; nid++) { 39089a305230SLee Schermerhorn struct node_hstate *nhs = &node_hstates[nid]; 39099a305230SLee Schermerhorn int i; 39109a305230SLee Schermerhorn for (i = 0; i < HUGE_MAX_HSTATE; i++) 39119a305230SLee Schermerhorn if (nhs->hstate_kobjs[i] == kobj) { 39129a305230SLee Schermerhorn if (nidp) 39139a305230SLee Schermerhorn *nidp = nid; 39149a305230SLee Schermerhorn return &hstates[i]; 39159a305230SLee Schermerhorn } 39169a305230SLee Schermerhorn } 39179a305230SLee Schermerhorn 39189a305230SLee Schermerhorn BUG(); 39199a305230SLee Schermerhorn return NULL; 39209a305230SLee Schermerhorn } 39219a305230SLee Schermerhorn 39229a305230SLee Schermerhorn /* 392310fbcf4cSKay Sievers * Unregister hstate attributes from a single node device. 39249a305230SLee Schermerhorn * No-op if no hstate attributes attached. 39259a305230SLee Schermerhorn */ 39263cd8b44fSClaudiu Ghioc static void hugetlb_unregister_node(struct node *node) 39279a305230SLee Schermerhorn { 39289a305230SLee Schermerhorn struct hstate *h; 392910fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 39309a305230SLee Schermerhorn 39319a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 39329b5e5d0fSLee Schermerhorn return; /* no hstate attributes */ 39339a305230SLee Schermerhorn 3934972dc4deSAneesh Kumar K.V for_each_hstate(h) { 3935972dc4deSAneesh Kumar K.V int idx = hstate_index(h); 3936972dc4deSAneesh Kumar K.V if (nhs->hstate_kobjs[idx]) { 3937972dc4deSAneesh Kumar K.V kobject_put(nhs->hstate_kobjs[idx]); 3938972dc4deSAneesh Kumar K.V nhs->hstate_kobjs[idx] = NULL; 3939972dc4deSAneesh Kumar K.V } 39409a305230SLee Schermerhorn } 39419a305230SLee Schermerhorn 39429a305230SLee Schermerhorn kobject_put(nhs->hugepages_kobj); 39439a305230SLee Schermerhorn nhs->hugepages_kobj = NULL; 39449a305230SLee Schermerhorn } 39459a305230SLee Schermerhorn 39469a305230SLee Schermerhorn 39479a305230SLee Schermerhorn /* 394810fbcf4cSKay Sievers * Register hstate attributes for a single node device. 39499a305230SLee Schermerhorn * No-op if attributes already registered. 39509a305230SLee Schermerhorn */ 39513cd8b44fSClaudiu Ghioc static void hugetlb_register_node(struct node *node) 39529a305230SLee Schermerhorn { 39539a305230SLee Schermerhorn struct hstate *h; 395410fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 39559a305230SLee Schermerhorn int err; 39569a305230SLee Schermerhorn 39579a305230SLee Schermerhorn if (nhs->hugepages_kobj) 39589a305230SLee Schermerhorn return; /* already allocated */ 39599a305230SLee Schermerhorn 39609a305230SLee Schermerhorn nhs->hugepages_kobj = kobject_create_and_add("hugepages", 396110fbcf4cSKay Sievers &node->dev.kobj); 39629a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 39639a305230SLee Schermerhorn return; 39649a305230SLee Schermerhorn 39659a305230SLee Schermerhorn for_each_hstate(h) { 39669a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, 39679a305230SLee Schermerhorn nhs->hstate_kobjs, 39689a305230SLee Schermerhorn &per_node_hstate_attr_group); 39699a305230SLee Schermerhorn if (err) { 3970282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s for node %d\n", 397110fbcf4cSKay Sievers h->name, node->dev.id); 39729a305230SLee Schermerhorn hugetlb_unregister_node(node); 39739a305230SLee Schermerhorn break; 39749a305230SLee Schermerhorn } 39759a305230SLee Schermerhorn } 39769a305230SLee Schermerhorn } 39779a305230SLee Schermerhorn 39789a305230SLee Schermerhorn /* 39799b5e5d0fSLee Schermerhorn * hugetlb init time: register hstate attributes for all registered node 398010fbcf4cSKay Sievers * devices of nodes that have memory. All on-line nodes should have 398110fbcf4cSKay Sievers * registered their associated device by this time. 39829a305230SLee Schermerhorn */ 39837d9ca000SLuiz Capitulino static void __init hugetlb_register_all_nodes(void) 39849a305230SLee Schermerhorn { 39859a305230SLee Schermerhorn int nid; 39869a305230SLee Schermerhorn 39878cebfcd0SLai Jiangshan for_each_node_state(nid, N_MEMORY) { 39888732794bSWen Congyang struct node *node = node_devices[nid]; 398910fbcf4cSKay Sievers if (node->dev.id == nid) 39909a305230SLee Schermerhorn hugetlb_register_node(node); 39919a305230SLee Schermerhorn } 39929a305230SLee Schermerhorn 39939a305230SLee Schermerhorn /* 399410fbcf4cSKay Sievers * Let the node device driver know we're here so it can 39959a305230SLee Schermerhorn * [un]register hstate attributes on node hotplug. 39969a305230SLee Schermerhorn */ 39979a305230SLee Schermerhorn register_hugetlbfs_with_node(hugetlb_register_node, 39989a305230SLee Schermerhorn hugetlb_unregister_node); 39999a305230SLee Schermerhorn } 40009a305230SLee Schermerhorn #else /* !CONFIG_NUMA */ 40019a305230SLee Schermerhorn 40029a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 40039a305230SLee Schermerhorn { 40049a305230SLee Schermerhorn BUG(); 40059a305230SLee Schermerhorn if (nidp) 40069a305230SLee Schermerhorn *nidp = -1; 40079a305230SLee Schermerhorn return NULL; 40089a305230SLee Schermerhorn } 40099a305230SLee Schermerhorn 40109a305230SLee Schermerhorn static void hugetlb_register_all_nodes(void) { } 40119a305230SLee Schermerhorn 40129a305230SLee Schermerhorn #endif 40139a305230SLee Schermerhorn 4014a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 4015a3437870SNishanth Aravamudan { 40168382d914SDavidlohr Bueso int i; 40178382d914SDavidlohr Bueso 4018d6995da3SMike Kravetz BUILD_BUG_ON(sizeof_field(struct page, private) * BITS_PER_BYTE < 4019d6995da3SMike Kravetz __NR_HPAGEFLAGS); 4020d6995da3SMike Kravetz 4021c2833a5bSMike Kravetz if (!hugepages_supported()) { 4022c2833a5bSMike Kravetz if (hugetlb_max_hstate || default_hstate_max_huge_pages) 4023c2833a5bSMike Kravetz pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n"); 40240ef89d25SBenjamin Herrenschmidt return 0; 4025d715cf80SLiam R. Howlett } 4026d715cf80SLiam R. Howlett 4027282f4214SMike Kravetz /* 4028282f4214SMike Kravetz * Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some 4029282f4214SMike Kravetz * architectures depend on setup being done here. 4030282f4214SMike Kravetz */ 4031a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 4032282f4214SMike Kravetz if (!parsed_default_hugepagesz) { 4033282f4214SMike Kravetz /* 4034282f4214SMike Kravetz * If we did not parse a default huge page size, set 4035282f4214SMike Kravetz * default_hstate_idx to HPAGE_SIZE hstate. And, if the 4036282f4214SMike Kravetz * number of huge pages for this default size was implicitly 4037282f4214SMike Kravetz * specified, set that here as well. 4038282f4214SMike Kravetz * Note that the implicit setting will overwrite an explicit 4039282f4214SMike Kravetz * setting. A warning will be printed in this case. 4040282f4214SMike Kravetz */ 4041282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(HPAGE_SIZE)); 4042f8b74815SVaishali Thakkar if (default_hstate_max_huge_pages) { 4043282f4214SMike Kravetz if (default_hstate.max_huge_pages) { 4044282f4214SMike Kravetz char buf[32]; 4045282f4214SMike Kravetz 4046282f4214SMike Kravetz string_get_size(huge_page_size(&default_hstate), 4047282f4214SMike Kravetz 1, STRING_UNITS_2, buf, 32); 4048282f4214SMike Kravetz pr_warn("HugeTLB: Ignoring hugepages=%lu associated with %s page size\n", 4049282f4214SMike Kravetz default_hstate.max_huge_pages, buf); 4050282f4214SMike Kravetz pr_warn("HugeTLB: Using hugepages=%lu for number of default huge pages\n", 4051282f4214SMike Kravetz default_hstate_max_huge_pages); 4052282f4214SMike Kravetz } 4053282f4214SMike Kravetz default_hstate.max_huge_pages = 4054282f4214SMike Kravetz default_hstate_max_huge_pages; 4055b5389086SZhenguo Yao 40560a7a0f6fSPeng Liu for_each_online_node(i) 4057b5389086SZhenguo Yao default_hstate.max_huge_pages_node[i] = 4058b5389086SZhenguo Yao default_hugepages_in_node[i]; 4059282f4214SMike Kravetz } 4060f8b74815SVaishali Thakkar } 4061a3437870SNishanth Aravamudan 4062cf11e85fSRoman Gushchin hugetlb_cma_check(); 4063a3437870SNishanth Aravamudan hugetlb_init_hstates(); 4064aa888a74SAndi Kleen gather_bootmem_prealloc(); 4065a3437870SNishanth Aravamudan report_hugepages(); 4066a3437870SNishanth Aravamudan 4067a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 40689a305230SLee Schermerhorn hugetlb_register_all_nodes(); 40697179e7bfSJianguo Wu hugetlb_cgroup_file_init(); 40709a305230SLee Schermerhorn 40718382d914SDavidlohr Bueso #ifdef CONFIG_SMP 40728382d914SDavidlohr Bueso num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); 40738382d914SDavidlohr Bueso #else 40748382d914SDavidlohr Bueso num_fault_mutexes = 1; 40758382d914SDavidlohr Bueso #endif 4076c672c7f2SMike Kravetz hugetlb_fault_mutex_table = 40776da2ec56SKees Cook kmalloc_array(num_fault_mutexes, sizeof(struct mutex), 40786da2ec56SKees Cook GFP_KERNEL); 4079c672c7f2SMike Kravetz BUG_ON(!hugetlb_fault_mutex_table); 40808382d914SDavidlohr Bueso 40818382d914SDavidlohr Bueso for (i = 0; i < num_fault_mutexes; i++) 4082c672c7f2SMike Kravetz mutex_init(&hugetlb_fault_mutex_table[i]); 4083a3437870SNishanth Aravamudan return 0; 4084a3437870SNishanth Aravamudan } 40853e89e1c5SPaul Gortmaker subsys_initcall(hugetlb_init); 4086a3437870SNishanth Aravamudan 4087ae94da89SMike Kravetz /* Overwritten by architectures with more huge page sizes */ 4088ae94da89SMike Kravetz bool __init __attribute((weak)) arch_hugetlb_valid_size(unsigned long size) 40899fee021dSVaishali Thakkar { 4090ae94da89SMike Kravetz return size == HPAGE_SIZE; 40919fee021dSVaishali Thakkar } 40929fee021dSVaishali Thakkar 4093d00181b9SKirill A. Shutemov void __init hugetlb_add_hstate(unsigned int order) 4094a3437870SNishanth Aravamudan { 4095a3437870SNishanth Aravamudan struct hstate *h; 40968faa8b07SAndi Kleen unsigned long i; 40978faa8b07SAndi Kleen 4098a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 4099a3437870SNishanth Aravamudan return; 4100a3437870SNishanth Aravamudan } 410147d38344SAneesh Kumar K.V BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); 4102a3437870SNishanth Aravamudan BUG_ON(order == 0); 410347d38344SAneesh Kumar K.V h = &hstates[hugetlb_max_hstate++]; 410429383967SMike Kravetz mutex_init(&h->resize_lock); 4105a3437870SNishanth Aravamudan h->order = order; 4106aca78307SMiaohe Lin h->mask = ~(huge_page_size(h) - 1); 41078faa8b07SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 41088faa8b07SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 41090edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&h->hugepage_activelist); 411054f18d35SAndrew Morton h->next_nid_to_alloc = first_memory_node; 411154f18d35SAndrew Morton h->next_nid_to_free = first_memory_node; 4112a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 4113a3437870SNishanth Aravamudan huge_page_size(h)/1024); 411477490587SMuchun Song hugetlb_vmemmap_init(h); 41158faa8b07SAndi Kleen 4116a3437870SNishanth Aravamudan parsed_hstate = h; 4117a3437870SNishanth Aravamudan } 4118a3437870SNishanth Aravamudan 4119b5389086SZhenguo Yao bool __init __weak hugetlb_node_alloc_supported(void) 4120b5389086SZhenguo Yao { 4121b5389086SZhenguo Yao return true; 4122b5389086SZhenguo Yao } 4123f87442f4SPeng Liu 4124f87442f4SPeng Liu static void __init hugepages_clear_pages_in_node(void) 4125f87442f4SPeng Liu { 4126f87442f4SPeng Liu if (!hugetlb_max_hstate) { 4127f87442f4SPeng Liu default_hstate_max_huge_pages = 0; 4128f87442f4SPeng Liu memset(default_hugepages_in_node, 0, 4129f87442f4SPeng Liu MAX_NUMNODES * sizeof(unsigned int)); 4130f87442f4SPeng Liu } else { 4131f87442f4SPeng Liu parsed_hstate->max_huge_pages = 0; 4132f87442f4SPeng Liu memset(parsed_hstate->max_huge_pages_node, 0, 4133f87442f4SPeng Liu MAX_NUMNODES * sizeof(unsigned int)); 4134f87442f4SPeng Liu } 4135f87442f4SPeng Liu } 4136f87442f4SPeng Liu 4137282f4214SMike Kravetz /* 4138282f4214SMike Kravetz * hugepages command line processing 4139282f4214SMike Kravetz * hugepages normally follows a valid hugepagsz or default_hugepagsz 4140282f4214SMike Kravetz * specification. If not, ignore the hugepages value. hugepages can also 4141282f4214SMike Kravetz * be the first huge page command line option in which case it implicitly 4142282f4214SMike Kravetz * specifies the number of huge pages for the default size. 4143282f4214SMike Kravetz */ 4144282f4214SMike Kravetz static int __init hugepages_setup(char *s) 4145a3437870SNishanth Aravamudan { 4146a3437870SNishanth Aravamudan unsigned long *mhp; 41478faa8b07SAndi Kleen static unsigned long *last_mhp; 4148b5389086SZhenguo Yao int node = NUMA_NO_NODE; 4149b5389086SZhenguo Yao int count; 4150b5389086SZhenguo Yao unsigned long tmp; 4151b5389086SZhenguo Yao char *p = s; 4152a3437870SNishanth Aravamudan 41539fee021dSVaishali Thakkar if (!parsed_valid_hugepagesz) { 4154282f4214SMike Kravetz pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s); 41559fee021dSVaishali Thakkar parsed_valid_hugepagesz = true; 4156f81f6e4bSPeng Liu return 1; 41579fee021dSVaishali Thakkar } 4158282f4214SMike Kravetz 4159a3437870SNishanth Aravamudan /* 4160282f4214SMike Kravetz * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter 4161282f4214SMike Kravetz * yet, so this hugepages= parameter goes to the "default hstate". 4162282f4214SMike Kravetz * Otherwise, it goes with the previously parsed hugepagesz or 4163282f4214SMike Kravetz * default_hugepagesz. 4164a3437870SNishanth Aravamudan */ 41659fee021dSVaishali Thakkar else if (!hugetlb_max_hstate) 4166a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 4167a3437870SNishanth Aravamudan else 4168a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 4169a3437870SNishanth Aravamudan 41708faa8b07SAndi Kleen if (mhp == last_mhp) { 4171282f4214SMike Kravetz pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s); 4172f81f6e4bSPeng Liu return 1; 41738faa8b07SAndi Kleen } 41748faa8b07SAndi Kleen 4175b5389086SZhenguo Yao while (*p) { 4176b5389086SZhenguo Yao count = 0; 4177b5389086SZhenguo Yao if (sscanf(p, "%lu%n", &tmp, &count) != 1) 4178b5389086SZhenguo Yao goto invalid; 4179b5389086SZhenguo Yao /* Parameter is node format */ 4180b5389086SZhenguo Yao if (p[count] == ':') { 4181b5389086SZhenguo Yao if (!hugetlb_node_alloc_supported()) { 4182b5389086SZhenguo Yao pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n"); 4183f81f6e4bSPeng Liu return 1; 4184b5389086SZhenguo Yao } 41850a7a0f6fSPeng Liu if (tmp >= MAX_NUMNODES || !node_online(tmp)) 4186e79ce983SLiu Yuntao goto invalid; 41870a7a0f6fSPeng Liu node = array_index_nospec(tmp, MAX_NUMNODES); 4188b5389086SZhenguo Yao p += count + 1; 4189b5389086SZhenguo Yao /* Parse hugepages */ 4190b5389086SZhenguo Yao if (sscanf(p, "%lu%n", &tmp, &count) != 1) 4191b5389086SZhenguo Yao goto invalid; 4192b5389086SZhenguo Yao if (!hugetlb_max_hstate) 4193b5389086SZhenguo Yao default_hugepages_in_node[node] = tmp; 4194b5389086SZhenguo Yao else 4195b5389086SZhenguo Yao parsed_hstate->max_huge_pages_node[node] = tmp; 4196b5389086SZhenguo Yao *mhp += tmp; 4197b5389086SZhenguo Yao /* Go to parse next node*/ 4198b5389086SZhenguo Yao if (p[count] == ',') 4199b5389086SZhenguo Yao p += count + 1; 4200b5389086SZhenguo Yao else 4201b5389086SZhenguo Yao break; 4202b5389086SZhenguo Yao } else { 4203b5389086SZhenguo Yao if (p != s) 4204b5389086SZhenguo Yao goto invalid; 4205b5389086SZhenguo Yao *mhp = tmp; 4206b5389086SZhenguo Yao break; 4207b5389086SZhenguo Yao } 4208b5389086SZhenguo Yao } 4209a3437870SNishanth Aravamudan 42108faa8b07SAndi Kleen /* 42118faa8b07SAndi Kleen * Global state is always initialized later in hugetlb_init. 421204adbc3fSMiaohe Lin * But we need to allocate gigantic hstates here early to still 42138faa8b07SAndi Kleen * use the bootmem allocator. 42148faa8b07SAndi Kleen */ 421504adbc3fSMiaohe Lin if (hugetlb_max_hstate && hstate_is_gigantic(parsed_hstate)) 42168faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(parsed_hstate); 42178faa8b07SAndi Kleen 42188faa8b07SAndi Kleen last_mhp = mhp; 42198faa8b07SAndi Kleen 4220a3437870SNishanth Aravamudan return 1; 4221b5389086SZhenguo Yao 4222b5389086SZhenguo Yao invalid: 4223b5389086SZhenguo Yao pr_warn("HugeTLB: Invalid hugepages parameter %s\n", p); 4224f87442f4SPeng Liu hugepages_clear_pages_in_node(); 4225f81f6e4bSPeng Liu return 1; 4226a3437870SNishanth Aravamudan } 4227282f4214SMike Kravetz __setup("hugepages=", hugepages_setup); 4228e11bfbfcSNick Piggin 4229282f4214SMike Kravetz /* 4230282f4214SMike Kravetz * hugepagesz command line processing 4231282f4214SMike Kravetz * A specific huge page size can only be specified once with hugepagesz. 4232282f4214SMike Kravetz * hugepagesz is followed by hugepages on the command line. The global 4233282f4214SMike Kravetz * variable 'parsed_valid_hugepagesz' is used to determine if prior 4234282f4214SMike Kravetz * hugepagesz argument was valid. 4235282f4214SMike Kravetz */ 4236359f2544SMike Kravetz static int __init hugepagesz_setup(char *s) 4237e11bfbfcSNick Piggin { 4238359f2544SMike Kravetz unsigned long size; 4239282f4214SMike Kravetz struct hstate *h; 4240282f4214SMike Kravetz 4241282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4242359f2544SMike Kravetz size = (unsigned long)memparse(s, NULL); 4243359f2544SMike Kravetz 4244359f2544SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4245282f4214SMike Kravetz pr_err("HugeTLB: unsupported hugepagesz=%s\n", s); 4246f81f6e4bSPeng Liu return 1; 4247359f2544SMike Kravetz } 4248359f2544SMike Kravetz 4249282f4214SMike Kravetz h = size_to_hstate(size); 4250282f4214SMike Kravetz if (h) { 4251282f4214SMike Kravetz /* 4252282f4214SMike Kravetz * hstate for this size already exists. This is normally 4253282f4214SMike Kravetz * an error, but is allowed if the existing hstate is the 4254282f4214SMike Kravetz * default hstate. More specifically, it is only allowed if 4255282f4214SMike Kravetz * the number of huge pages for the default hstate was not 4256282f4214SMike Kravetz * previously specified. 4257282f4214SMike Kravetz */ 4258282f4214SMike Kravetz if (!parsed_default_hugepagesz || h != &default_hstate || 4259282f4214SMike Kravetz default_hstate.max_huge_pages) { 4260282f4214SMike Kravetz pr_warn("HugeTLB: hugepagesz=%s specified twice, ignoring\n", s); 4261f81f6e4bSPeng Liu return 1; 426238237830SMike Kravetz } 426338237830SMike Kravetz 4264282f4214SMike Kravetz /* 4265282f4214SMike Kravetz * No need to call hugetlb_add_hstate() as hstate already 4266282f4214SMike Kravetz * exists. But, do set parsed_hstate so that a following 4267282f4214SMike Kravetz * hugepages= parameter will be applied to this hstate. 4268282f4214SMike Kravetz */ 4269282f4214SMike Kravetz parsed_hstate = h; 4270282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4271e11bfbfcSNick Piggin return 1; 4272e11bfbfcSNick Piggin } 4273282f4214SMike Kravetz 4274359f2544SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4275282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4276359f2544SMike Kravetz return 1; 4277359f2544SMike Kravetz } 4278359f2544SMike Kravetz __setup("hugepagesz=", hugepagesz_setup); 4279359f2544SMike Kravetz 4280282f4214SMike Kravetz /* 4281282f4214SMike Kravetz * default_hugepagesz command line input 4282282f4214SMike Kravetz * Only one instance of default_hugepagesz allowed on command line. 4283282f4214SMike Kravetz */ 4284ae94da89SMike Kravetz static int __init default_hugepagesz_setup(char *s) 4285e11bfbfcSNick Piggin { 4286ae94da89SMike Kravetz unsigned long size; 4287b5389086SZhenguo Yao int i; 4288ae94da89SMike Kravetz 4289282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4290282f4214SMike Kravetz if (parsed_default_hugepagesz) { 4291282f4214SMike Kravetz pr_err("HugeTLB: default_hugepagesz previously specified, ignoring %s\n", s); 4292f81f6e4bSPeng Liu return 1; 4293282f4214SMike Kravetz } 4294282f4214SMike Kravetz 4295282f4214SMike Kravetz size = (unsigned long)memparse(s, NULL); 4296282f4214SMike Kravetz 4297282f4214SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4298282f4214SMike Kravetz pr_err("HugeTLB: unsupported default_hugepagesz=%s\n", s); 4299f81f6e4bSPeng Liu return 1; 4300282f4214SMike Kravetz } 4301282f4214SMike Kravetz 4302282f4214SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4303282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4304282f4214SMike Kravetz parsed_default_hugepagesz = true; 4305282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(size)); 4306282f4214SMike Kravetz 4307282f4214SMike Kravetz /* 4308282f4214SMike Kravetz * The number of default huge pages (for this size) could have been 4309282f4214SMike Kravetz * specified as the first hugetlb parameter: hugepages=X. If so, 4310282f4214SMike Kravetz * then default_hstate_max_huge_pages is set. If the default huge 4311282f4214SMike Kravetz * page size is gigantic (>= MAX_ORDER), then the pages must be 4312282f4214SMike Kravetz * allocated here from bootmem allocator. 4313282f4214SMike Kravetz */ 4314282f4214SMike Kravetz if (default_hstate_max_huge_pages) { 4315282f4214SMike Kravetz default_hstate.max_huge_pages = default_hstate_max_huge_pages; 43160a7a0f6fSPeng Liu for_each_online_node(i) 4317b5389086SZhenguo Yao default_hstate.max_huge_pages_node[i] = 4318b5389086SZhenguo Yao default_hugepages_in_node[i]; 4319282f4214SMike Kravetz if (hstate_is_gigantic(&default_hstate)) 4320282f4214SMike Kravetz hugetlb_hstate_alloc_pages(&default_hstate); 4321282f4214SMike Kravetz default_hstate_max_huge_pages = 0; 4322282f4214SMike Kravetz } 4323282f4214SMike Kravetz 4324e11bfbfcSNick Piggin return 1; 4325e11bfbfcSNick Piggin } 4326ae94da89SMike Kravetz __setup("default_hugepagesz=", default_hugepagesz_setup); 4327a3437870SNishanth Aravamudan 43288ca39e68SMuchun Song static unsigned int allowed_mems_nr(struct hstate *h) 43298a213460SNishanth Aravamudan { 43308a213460SNishanth Aravamudan int node; 43318a213460SNishanth Aravamudan unsigned int nr = 0; 43328ca39e68SMuchun Song nodemask_t *mpol_allowed; 43338ca39e68SMuchun Song unsigned int *array = h->free_huge_pages_node; 43348ca39e68SMuchun Song gfp_t gfp_mask = htlb_alloc_mask(h); 43358a213460SNishanth Aravamudan 43368ca39e68SMuchun Song mpol_allowed = policy_nodemask_current(gfp_mask); 43378ca39e68SMuchun Song 43388ca39e68SMuchun Song for_each_node_mask(node, cpuset_current_mems_allowed) { 4339c93b0a99SJiapeng Zhong if (!mpol_allowed || node_isset(node, *mpol_allowed)) 43408a213460SNishanth Aravamudan nr += array[node]; 43418ca39e68SMuchun Song } 43428a213460SNishanth Aravamudan 43438a213460SNishanth Aravamudan return nr; 43448a213460SNishanth Aravamudan } 43458a213460SNishanth Aravamudan 43468a213460SNishanth Aravamudan #ifdef CONFIG_SYSCTL 434717743798SMuchun Song static int proc_hugetlb_doulongvec_minmax(struct ctl_table *table, int write, 434817743798SMuchun Song void *buffer, size_t *length, 434917743798SMuchun Song loff_t *ppos, unsigned long *out) 435017743798SMuchun Song { 435117743798SMuchun Song struct ctl_table dup_table; 435217743798SMuchun Song 435317743798SMuchun Song /* 435417743798SMuchun Song * In order to avoid races with __do_proc_doulongvec_minmax(), we 435517743798SMuchun Song * can duplicate the @table and alter the duplicate of it. 435617743798SMuchun Song */ 435717743798SMuchun Song dup_table = *table; 435817743798SMuchun Song dup_table.data = out; 435917743798SMuchun Song 436017743798SMuchun Song return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos); 436117743798SMuchun Song } 436217743798SMuchun Song 436306808b08SLee Schermerhorn static int hugetlb_sysctl_handler_common(bool obey_mempolicy, 436406808b08SLee Schermerhorn struct ctl_table *table, int write, 436532927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 43661da177e4SLinus Torvalds { 4367e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 4368238d3c13SDavid Rientjes unsigned long tmp = h->max_huge_pages; 436908d4a246SMichal Hocko int ret; 4370e5ff2159SAndi Kleen 4371457c1b27SNishanth Aravamudan if (!hugepages_supported()) 437286613628SJan Stancek return -EOPNOTSUPP; 4373457c1b27SNishanth Aravamudan 437417743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 437517743798SMuchun Song &tmp); 437608d4a246SMichal Hocko if (ret) 437708d4a246SMichal Hocko goto out; 4378e5ff2159SAndi Kleen 4379238d3c13SDavid Rientjes if (write) 4380238d3c13SDavid Rientjes ret = __nr_hugepages_store_common(obey_mempolicy, h, 4381238d3c13SDavid Rientjes NUMA_NO_NODE, tmp, *length); 438208d4a246SMichal Hocko out: 438308d4a246SMichal Hocko return ret; 43841da177e4SLinus Torvalds } 4385396faf03SMel Gorman 438606808b08SLee Schermerhorn int hugetlb_sysctl_handler(struct ctl_table *table, int write, 438732927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 438806808b08SLee Schermerhorn { 438906808b08SLee Schermerhorn 439006808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(false, table, write, 439106808b08SLee Schermerhorn buffer, length, ppos); 439206808b08SLee Schermerhorn } 439306808b08SLee Schermerhorn 439406808b08SLee Schermerhorn #ifdef CONFIG_NUMA 439506808b08SLee Schermerhorn int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, 439632927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 439706808b08SLee Schermerhorn { 439806808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(true, table, write, 439906808b08SLee Schermerhorn buffer, length, ppos); 440006808b08SLee Schermerhorn } 440106808b08SLee Schermerhorn #endif /* CONFIG_NUMA */ 440206808b08SLee Schermerhorn 4403a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 440432927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 4405a3d0c6aaSNishanth Aravamudan { 4406a5516438SAndi Kleen struct hstate *h = &default_hstate; 4407e5ff2159SAndi Kleen unsigned long tmp; 440808d4a246SMichal Hocko int ret; 4409e5ff2159SAndi Kleen 4410457c1b27SNishanth Aravamudan if (!hugepages_supported()) 441186613628SJan Stancek return -EOPNOTSUPP; 4412457c1b27SNishanth Aravamudan 4413e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 4414e5ff2159SAndi Kleen 4415bae7f4aeSLuiz Capitulino if (write && hstate_is_gigantic(h)) 4416adbe8726SEric B Munson return -EINVAL; 4417adbe8726SEric B Munson 441817743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 441917743798SMuchun Song &tmp); 442008d4a246SMichal Hocko if (ret) 442108d4a246SMichal Hocko goto out; 4422e5ff2159SAndi Kleen 4423e5ff2159SAndi Kleen if (write) { 4424db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4425e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 4426db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4427e5ff2159SAndi Kleen } 442808d4a246SMichal Hocko out: 442908d4a246SMichal Hocko return ret; 4430a3d0c6aaSNishanth Aravamudan } 4431a3d0c6aaSNishanth Aravamudan 44321da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 44331da177e4SLinus Torvalds 4434e1759c21SAlexey Dobriyan void hugetlb_report_meminfo(struct seq_file *m) 44351da177e4SLinus Torvalds { 4436fcb2b0c5SRoman Gushchin struct hstate *h; 4437fcb2b0c5SRoman Gushchin unsigned long total = 0; 4438fcb2b0c5SRoman Gushchin 4439457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4440457c1b27SNishanth Aravamudan return; 4441fcb2b0c5SRoman Gushchin 4442fcb2b0c5SRoman Gushchin for_each_hstate(h) { 4443fcb2b0c5SRoman Gushchin unsigned long count = h->nr_huge_pages; 4444fcb2b0c5SRoman Gushchin 4445aca78307SMiaohe Lin total += huge_page_size(h) * count; 4446fcb2b0c5SRoman Gushchin 4447fcb2b0c5SRoman Gushchin if (h == &default_hstate) 4448e1759c21SAlexey Dobriyan seq_printf(m, 44491da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 44501da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 4451b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 44527893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 44534f98a2feSRik van Riel "Hugepagesize: %8lu kB\n", 4454fcb2b0c5SRoman Gushchin count, 4455a5516438SAndi Kleen h->free_huge_pages, 4456a5516438SAndi Kleen h->resv_huge_pages, 4457a5516438SAndi Kleen h->surplus_huge_pages, 4458aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4459fcb2b0c5SRoman Gushchin } 4460fcb2b0c5SRoman Gushchin 4461aca78307SMiaohe Lin seq_printf(m, "Hugetlb: %8lu kB\n", total / SZ_1K); 44621da177e4SLinus Torvalds } 44631da177e4SLinus Torvalds 44647981593bSJoe Perches int hugetlb_report_node_meminfo(char *buf, int len, int nid) 44651da177e4SLinus Torvalds { 4466a5516438SAndi Kleen struct hstate *h = &default_hstate; 44677981593bSJoe Perches 4468457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4469457c1b27SNishanth Aravamudan return 0; 44707981593bSJoe Perches 44717981593bSJoe Perches return sysfs_emit_at(buf, len, 44721da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 4473a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 4474a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 4475a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 4476a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 4477a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 44781da177e4SLinus Torvalds } 44791da177e4SLinus Torvalds 4480949f7ec5SDavid Rientjes void hugetlb_show_meminfo(void) 4481949f7ec5SDavid Rientjes { 4482949f7ec5SDavid Rientjes struct hstate *h; 4483949f7ec5SDavid Rientjes int nid; 4484949f7ec5SDavid Rientjes 4485457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4486457c1b27SNishanth Aravamudan return; 4487457c1b27SNishanth Aravamudan 4488949f7ec5SDavid Rientjes for_each_node_state(nid, N_MEMORY) 4489949f7ec5SDavid Rientjes for_each_hstate(h) 4490949f7ec5SDavid Rientjes pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", 4491949f7ec5SDavid Rientjes nid, 4492949f7ec5SDavid Rientjes h->nr_huge_pages_node[nid], 4493949f7ec5SDavid Rientjes h->free_huge_pages_node[nid], 4494949f7ec5SDavid Rientjes h->surplus_huge_pages_node[nid], 4495aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4496949f7ec5SDavid Rientjes } 4497949f7ec5SDavid Rientjes 44985d317b2bSNaoya Horiguchi void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm) 44995d317b2bSNaoya Horiguchi { 45005d317b2bSNaoya Horiguchi seq_printf(m, "HugetlbPages:\t%8lu kB\n", 45015d317b2bSNaoya Horiguchi atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10)); 45025d317b2bSNaoya Horiguchi } 45035d317b2bSNaoya Horiguchi 45041da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 45051da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 45061da177e4SLinus Torvalds { 4507d0028588SWanpeng Li struct hstate *h; 4508d0028588SWanpeng Li unsigned long nr_total_pages = 0; 4509d0028588SWanpeng Li 4510d0028588SWanpeng Li for_each_hstate(h) 4511d0028588SWanpeng Li nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); 4512d0028588SWanpeng Li return nr_total_pages; 45131da177e4SLinus Torvalds } 45141da177e4SLinus Torvalds 4515a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 4516fc1b8a73SMel Gorman { 4517fc1b8a73SMel Gorman int ret = -ENOMEM; 4518fc1b8a73SMel Gorman 45190aa7f354SMiaohe Lin if (!delta) 45200aa7f354SMiaohe Lin return 0; 45210aa7f354SMiaohe Lin 4522db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4523fc1b8a73SMel Gorman /* 4524fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 4525fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 4526fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 4527fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 4528fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 4529fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 4530fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 4531fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 4532fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 4533fc1b8a73SMel Gorman * 4534fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 4535fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 4536fc1b8a73SMel Gorman * we fall back to check against current free page availability as 4537fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 4538fc1b8a73SMel Gorman * semantics that cpuset has. 45398ca39e68SMuchun Song * 45408ca39e68SMuchun Song * Apart from cpuset, we also have memory policy mechanism that 45418ca39e68SMuchun Song * also determines from which node the kernel will allocate memory 45428ca39e68SMuchun Song * in a NUMA system. So similar to cpuset, we also should consider 45438ca39e68SMuchun Song * the memory policy of the current task. Similar to the description 45448ca39e68SMuchun Song * above. 4545fc1b8a73SMel Gorman */ 4546fc1b8a73SMel Gorman if (delta > 0) { 4547a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 4548fc1b8a73SMel Gorman goto out; 4549fc1b8a73SMel Gorman 45508ca39e68SMuchun Song if (delta > allowed_mems_nr(h)) { 4551a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 4552fc1b8a73SMel Gorman goto out; 4553fc1b8a73SMel Gorman } 4554fc1b8a73SMel Gorman } 4555fc1b8a73SMel Gorman 4556fc1b8a73SMel Gorman ret = 0; 4557fc1b8a73SMel Gorman if (delta < 0) 4558a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 4559fc1b8a73SMel Gorman 4560fc1b8a73SMel Gorman out: 4561db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4562fc1b8a73SMel Gorman return ret; 4563fc1b8a73SMel Gorman } 4564fc1b8a73SMel Gorman 456584afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 456684afd99bSAndy Whitcroft { 4567f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 456884afd99bSAndy Whitcroft 456984afd99bSAndy Whitcroft /* 457084afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 457184afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 457284afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 457325985edcSLucas De Marchi * has a reference to the reservation map it cannot disappear until 457484afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 457584afd99bSAndy Whitcroft * new reference here without additional locking. 457684afd99bSAndy Whitcroft */ 457709a26e83SMike Kravetz if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 457809a26e83SMike Kravetz resv_map_dup_hugetlb_cgroup_uncharge_info(resv); 4579f522c3acSJoonsoo Kim kref_get(&resv->refs); 458084afd99bSAndy Whitcroft } 458109a26e83SMike Kravetz } 458284afd99bSAndy Whitcroft 4583a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 4584a1e78772SMel Gorman { 4585a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 4586f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 458790481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 45884e35f483SJoonsoo Kim unsigned long reserve, start, end; 45891c5ecae3SMike Kravetz long gbl_reserve; 459084afd99bSAndy Whitcroft 45914e35f483SJoonsoo Kim if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 45924e35f483SJoonsoo Kim return; 45934e35f483SJoonsoo Kim 4594a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 4595a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 459684afd99bSAndy Whitcroft 45974e35f483SJoonsoo Kim reserve = (end - start) - region_count(resv, start, end); 4598e9fe92aeSMina Almasry hugetlb_cgroup_uncharge_counter(resv, start, end); 45997251ff78SAdam Litke if (reserve) { 46001c5ecae3SMike Kravetz /* 46011c5ecae3SMike Kravetz * Decrement reserve counts. The global reserve count may be 46021c5ecae3SMike Kravetz * adjusted if the subpool has a minimum size. 46031c5ecae3SMike Kravetz */ 46041c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, reserve); 46051c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 46067251ff78SAdam Litke } 4607e9fe92aeSMina Almasry 4608e9fe92aeSMina Almasry kref_put(&resv->refs, resv_map_release); 4609a1e78772SMel Gorman } 4610a1e78772SMel Gorman 461131383c68SDan Williams static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) 461231383c68SDan Williams { 461331383c68SDan Williams if (addr & ~(huge_page_mask(hstate_vma(vma)))) 461431383c68SDan Williams return -EINVAL; 461531383c68SDan Williams return 0; 461631383c68SDan Williams } 461731383c68SDan Williams 461805ea8860SDan Williams static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) 461905ea8860SDan Williams { 4620aca78307SMiaohe Lin return huge_page_size(hstate_vma(vma)); 462105ea8860SDan Williams } 462205ea8860SDan Williams 46231da177e4SLinus Torvalds /* 46241da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 46251da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 46266c26d310SMiaohe Lin * hugepage VMA. do_page_fault() is supposed to trap this, so BUG is we get 46271da177e4SLinus Torvalds * this far. 46281da177e4SLinus Torvalds */ 4629b3ec9f33SSouptick Joarder static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf) 46301da177e4SLinus Torvalds { 46311da177e4SLinus Torvalds BUG(); 4632d0217ac0SNick Piggin return 0; 46331da177e4SLinus Torvalds } 46341da177e4SLinus Torvalds 4635eec3636aSJane Chu /* 4636eec3636aSJane Chu * When a new function is introduced to vm_operations_struct and added 4637eec3636aSJane Chu * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops. 4638eec3636aSJane Chu * This is because under System V memory model, mappings created via 4639eec3636aSJane Chu * shmget/shmat with "huge page" specified are backed by hugetlbfs files, 4640eec3636aSJane Chu * their original vm_ops are overwritten with shm_vm_ops. 4641eec3636aSJane Chu */ 4642f0f37e2fSAlexey Dobriyan const struct vm_operations_struct hugetlb_vm_ops = { 4643d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 464484afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 4645a1e78772SMel Gorman .close = hugetlb_vm_op_close, 4646dd3b614fSDmitry Safonov .may_split = hugetlb_vm_op_split, 464705ea8860SDan Williams .pagesize = hugetlb_vm_op_pagesize, 46481da177e4SLinus Torvalds }; 46491da177e4SLinus Torvalds 46501e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 46511e8f889bSDavid Gibson int writable) 465263551ae0SDavid Gibson { 465363551ae0SDavid Gibson pte_t entry; 465479c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 465563551ae0SDavid Gibson 46561e8f889bSDavid Gibson if (writable) { 4657106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, 4658106c992aSGerald Schaefer vma->vm_page_prot))); 465963551ae0SDavid Gibson } else { 4660106c992aSGerald Schaefer entry = huge_pte_wrprotect(mk_huge_pte(page, 4661106c992aSGerald Schaefer vma->vm_page_prot)); 466263551ae0SDavid Gibson } 466363551ae0SDavid Gibson entry = pte_mkyoung(entry); 466479c1c594SChristophe Leroy entry = arch_make_huge_pte(entry, shift, vma->vm_flags); 466563551ae0SDavid Gibson 466663551ae0SDavid Gibson return entry; 466763551ae0SDavid Gibson } 466863551ae0SDavid Gibson 46691e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 46701e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 46711e8f889bSDavid Gibson { 46721e8f889bSDavid Gibson pte_t entry; 46731e8f889bSDavid Gibson 4674106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); 467532f84528SChris Forbes if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) 46764b3073e1SRussell King update_mmu_cache(vma, address, ptep); 46771e8f889bSDavid Gibson } 46781e8f889bSDavid Gibson 4679d5ed7444SAneesh Kumar K.V bool is_hugetlb_entry_migration(pte_t pte) 46804a705fefSNaoya Horiguchi { 46814a705fefSNaoya Horiguchi swp_entry_t swp; 46824a705fefSNaoya Horiguchi 46834a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 4684d5ed7444SAneesh Kumar K.V return false; 46854a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4686d79d176aSBaoquan He if (is_migration_entry(swp)) 4687d5ed7444SAneesh Kumar K.V return true; 46884a705fefSNaoya Horiguchi else 4689d5ed7444SAneesh Kumar K.V return false; 46904a705fefSNaoya Horiguchi } 46914a705fefSNaoya Horiguchi 46923e5c3600SBaoquan He static bool is_hugetlb_entry_hwpoisoned(pte_t pte) 46934a705fefSNaoya Horiguchi { 46944a705fefSNaoya Horiguchi swp_entry_t swp; 46954a705fefSNaoya Horiguchi 46964a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 46973e5c3600SBaoquan He return false; 46984a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4699d79d176aSBaoquan He if (is_hwpoison_entry(swp)) 47003e5c3600SBaoquan He return true; 47014a705fefSNaoya Horiguchi else 47023e5c3600SBaoquan He return false; 47034a705fefSNaoya Horiguchi } 47041e8f889bSDavid Gibson 47054eae4efaSPeter Xu static void 47064eae4efaSPeter Xu hugetlb_install_page(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr, 47074eae4efaSPeter Xu struct page *new_page) 47084eae4efaSPeter Xu { 47094eae4efaSPeter Xu __SetPageUptodate(new_page); 47104eae4efaSPeter Xu hugepage_add_new_anon_rmap(new_page, vma, addr); 47111eba86c0SPasha Tatashin set_huge_pte_at(vma->vm_mm, addr, ptep, make_huge_pte(vma, new_page, 1)); 47124eae4efaSPeter Xu hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm); 47134eae4efaSPeter Xu ClearHPageRestoreReserve(new_page); 47144eae4efaSPeter Xu SetHPageMigratable(new_page); 47154eae4efaSPeter Xu } 47164eae4efaSPeter Xu 471763551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 4718bc70fbf2SPeter Xu struct vm_area_struct *dst_vma, 4719bc70fbf2SPeter Xu struct vm_area_struct *src_vma) 472063551ae0SDavid Gibson { 47215e41540cSMike Kravetz pte_t *src_pte, *dst_pte, entry, dst_entry; 472263551ae0SDavid Gibson struct page *ptepage; 47231c59827dSHugh Dickins unsigned long addr; 4724bc70fbf2SPeter Xu bool cow = is_cow_mapping(src_vma->vm_flags); 4725bc70fbf2SPeter Xu struct hstate *h = hstate_vma(src_vma); 4726a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 47274eae4efaSPeter Xu unsigned long npages = pages_per_huge_page(h); 4728bc70fbf2SPeter Xu struct address_space *mapping = src_vma->vm_file->f_mapping; 4729ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 4730*e95a9851SMike Kravetz unsigned long last_addr_mask; 4731e8569dd2SAndreas Sandberg int ret = 0; 47321e8f889bSDavid Gibson 4733ac46d4f3SJérôme Glisse if (cow) { 4734bc70fbf2SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, src_vma, src, 4735bc70fbf2SPeter Xu src_vma->vm_start, 4736bc70fbf2SPeter Xu src_vma->vm_end); 4737ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4738623a1ddfSDavid Hildenbrand mmap_assert_write_locked(src); 4739623a1ddfSDavid Hildenbrand raw_write_seqcount_begin(&src->write_protect_seq); 4740c0d0381aSMike Kravetz } else { 4741c0d0381aSMike Kravetz /* 4742c0d0381aSMike Kravetz * For shared mappings i_mmap_rwsem must be held to call 4743c0d0381aSMike Kravetz * huge_pte_alloc, otherwise the returned ptep could go 4744c0d0381aSMike Kravetz * away if part of a shared pmd and another thread calls 4745c0d0381aSMike Kravetz * huge_pmd_unshare. 4746c0d0381aSMike Kravetz */ 4747c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 4748ac46d4f3SJérôme Glisse } 4749e8569dd2SAndreas Sandberg 4750*e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 4751bc70fbf2SPeter Xu for (addr = src_vma->vm_start; addr < src_vma->vm_end; addr += sz) { 4752cb900f41SKirill A. Shutemov spinlock_t *src_ptl, *dst_ptl; 47537868a208SPunit Agrawal src_pte = huge_pte_offset(src, addr, sz); 4754*e95a9851SMike Kravetz if (!src_pte) { 4755*e95a9851SMike Kravetz addr |= last_addr_mask; 4756c74df32cSHugh Dickins continue; 4757*e95a9851SMike Kravetz } 4758bc70fbf2SPeter Xu dst_pte = huge_pte_alloc(dst, dst_vma, addr, sz); 4759e8569dd2SAndreas Sandberg if (!dst_pte) { 4760e8569dd2SAndreas Sandberg ret = -ENOMEM; 4761e8569dd2SAndreas Sandberg break; 4762e8569dd2SAndreas Sandberg } 4763c5c99429SLarry Woodman 47645e41540cSMike Kravetz /* 47655e41540cSMike Kravetz * If the pagetables are shared don't copy or take references. 47665e41540cSMike Kravetz * dst_pte == src_pte is the common case of src/dest sharing. 47675e41540cSMike Kravetz * 47685e41540cSMike Kravetz * However, src could have 'unshared' and dst shares with 47695e41540cSMike Kravetz * another vma. If dst_pte !none, this implies sharing. 47705e41540cSMike Kravetz * Check here before taking page table lock, and once again 47715e41540cSMike Kravetz * after taking the lock below. 47725e41540cSMike Kravetz */ 47735e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 4774*e95a9851SMike Kravetz if ((dst_pte == src_pte) || !huge_pte_none(dst_entry)) { 4775*e95a9851SMike Kravetz addr |= last_addr_mask; 4776c5c99429SLarry Woodman continue; 4777*e95a9851SMike Kravetz } 4778c5c99429SLarry Woodman 4779cb900f41SKirill A. Shutemov dst_ptl = huge_pte_lock(h, dst, dst_pte); 4780cb900f41SKirill A. Shutemov src_ptl = huge_pte_lockptr(h, src, src_pte); 4781cb900f41SKirill A. Shutemov spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 47824a705fefSNaoya Horiguchi entry = huge_ptep_get(src_pte); 47835e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 47844eae4efaSPeter Xu again: 47855e41540cSMike Kravetz if (huge_pte_none(entry) || !huge_pte_none(dst_entry)) { 47865e41540cSMike Kravetz /* 47875e41540cSMike Kravetz * Skip if src entry none. Also, skip in the 47885e41540cSMike Kravetz * unlikely case dst entry !none as this implies 47895e41540cSMike Kravetz * sharing with another vma. 47905e41540cSMike Kravetz */ 47914a705fefSNaoya Horiguchi ; 47924a705fefSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_migration(entry) || 47934a705fefSNaoya Horiguchi is_hugetlb_entry_hwpoisoned(entry))) { 47944a705fefSNaoya Horiguchi swp_entry_t swp_entry = pte_to_swp_entry(entry); 4795bc70fbf2SPeter Xu bool uffd_wp = huge_pte_uffd_wp(entry); 47964a705fefSNaoya Horiguchi 47976c287605SDavid Hildenbrand if (!is_readable_migration_entry(swp_entry) && cow) { 47984a705fefSNaoya Horiguchi /* 47994a705fefSNaoya Horiguchi * COW mappings require pages in both 48004a705fefSNaoya Horiguchi * parent and child to be set to read. 48014a705fefSNaoya Horiguchi */ 48024dd845b5SAlistair Popple swp_entry = make_readable_migration_entry( 48034dd845b5SAlistair Popple swp_offset(swp_entry)); 48044a705fefSNaoya Horiguchi entry = swp_entry_to_pte(swp_entry); 4805bc70fbf2SPeter Xu if (userfaultfd_wp(src_vma) && uffd_wp) 4806bc70fbf2SPeter Xu entry = huge_pte_mkuffd_wp(entry); 480718f39629SQi Zheng set_huge_pte_at(src, addr, src_pte, entry); 48084a705fefSNaoya Horiguchi } 4809bc70fbf2SPeter Xu if (!userfaultfd_wp(dst_vma) && uffd_wp) 4810bc70fbf2SPeter Xu entry = huge_pte_clear_uffd_wp(entry); 481118f39629SQi Zheng set_huge_pte_at(dst, addr, dst_pte, entry); 4812bc70fbf2SPeter Xu } else if (unlikely(is_pte_marker(entry))) { 4813bc70fbf2SPeter Xu /* 4814bc70fbf2SPeter Xu * We copy the pte marker only if the dst vma has 4815bc70fbf2SPeter Xu * uffd-wp enabled. 4816bc70fbf2SPeter Xu */ 4817bc70fbf2SPeter Xu if (userfaultfd_wp(dst_vma)) 4818bc70fbf2SPeter Xu set_huge_pte_at(dst, addr, dst_pte, entry); 48194a705fefSNaoya Horiguchi } else { 48204eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 48214eae4efaSPeter Xu ptepage = pte_page(entry); 48224eae4efaSPeter Xu get_page(ptepage); 48234eae4efaSPeter Xu 48244eae4efaSPeter Xu /* 4825fb3d824dSDavid Hildenbrand * Failing to duplicate the anon rmap is a rare case 4826fb3d824dSDavid Hildenbrand * where we see pinned hugetlb pages while they're 4827fb3d824dSDavid Hildenbrand * prone to COW. We need to do the COW earlier during 4828fb3d824dSDavid Hildenbrand * fork. 48294eae4efaSPeter Xu * 48304eae4efaSPeter Xu * When pre-allocating the page or copying data, we 48314eae4efaSPeter Xu * need to be without the pgtable locks since we could 48324eae4efaSPeter Xu * sleep during the process. 48334eae4efaSPeter Xu */ 4834fb3d824dSDavid Hildenbrand if (!PageAnon(ptepage)) { 4835fb3d824dSDavid Hildenbrand page_dup_file_rmap(ptepage, true); 4836bc70fbf2SPeter Xu } else if (page_try_dup_anon_rmap(ptepage, true, 4837bc70fbf2SPeter Xu src_vma)) { 48384eae4efaSPeter Xu pte_t src_pte_old = entry; 48394eae4efaSPeter Xu struct page *new; 48404eae4efaSPeter Xu 48414eae4efaSPeter Xu spin_unlock(src_ptl); 48424eae4efaSPeter Xu spin_unlock(dst_ptl); 48434eae4efaSPeter Xu /* Do not use reserve as it's private owned */ 4844bc70fbf2SPeter Xu new = alloc_huge_page(dst_vma, addr, 1); 48454eae4efaSPeter Xu if (IS_ERR(new)) { 48464eae4efaSPeter Xu put_page(ptepage); 48474eae4efaSPeter Xu ret = PTR_ERR(new); 48484eae4efaSPeter Xu break; 48494eae4efaSPeter Xu } 4850bc70fbf2SPeter Xu copy_user_huge_page(new, ptepage, addr, dst_vma, 48514eae4efaSPeter Xu npages); 48524eae4efaSPeter Xu put_page(ptepage); 48534eae4efaSPeter Xu 48544eae4efaSPeter Xu /* Install the new huge page if src pte stable */ 48554eae4efaSPeter Xu dst_ptl = huge_pte_lock(h, dst, dst_pte); 48564eae4efaSPeter Xu src_ptl = huge_pte_lockptr(h, src, src_pte); 48574eae4efaSPeter Xu spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 48584eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 48594eae4efaSPeter Xu if (!pte_same(src_pte_old, entry)) { 4860bc70fbf2SPeter Xu restore_reserve_on_error(h, dst_vma, addr, 4861846be085SMike Kravetz new); 48624eae4efaSPeter Xu put_page(new); 48634eae4efaSPeter Xu /* dst_entry won't change as in child */ 48644eae4efaSPeter Xu goto again; 48654eae4efaSPeter Xu } 4866bc70fbf2SPeter Xu hugetlb_install_page(dst_vma, dst_pte, addr, new); 48674eae4efaSPeter Xu spin_unlock(src_ptl); 48684eae4efaSPeter Xu spin_unlock(dst_ptl); 48694eae4efaSPeter Xu continue; 48704eae4efaSPeter Xu } 48714eae4efaSPeter Xu 487234ee645eSJoerg Roedel if (cow) { 48730f10851eSJérôme Glisse /* 48740f10851eSJérôme Glisse * No need to notify as we are downgrading page 48750f10851eSJérôme Glisse * table protection not changing it to point 48760f10851eSJérôme Glisse * to a new page. 48770f10851eSJérôme Glisse * 4878ee65728eSMike Rapoport * See Documentation/mm/mmu_notifier.rst 48790f10851eSJérôme Glisse */ 48807f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 488184894e1cSPeter Xu entry = huge_pte_wrprotect(entry); 488234ee645eSJoerg Roedel } 48834eae4efaSPeter Xu 488463551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 48854eae4efaSPeter Xu hugetlb_count_add(npages, dst); 48861c59827dSHugh Dickins } 4887cb900f41SKirill A. Shutemov spin_unlock(src_ptl); 4888cb900f41SKirill A. Shutemov spin_unlock(dst_ptl); 488963551ae0SDavid Gibson } 489063551ae0SDavid Gibson 4891623a1ddfSDavid Hildenbrand if (cow) { 4892623a1ddfSDavid Hildenbrand raw_write_seqcount_end(&src->write_protect_seq); 4893ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 4894623a1ddfSDavid Hildenbrand } else { 4895c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 4896623a1ddfSDavid Hildenbrand } 4897e8569dd2SAndreas Sandberg 4898e8569dd2SAndreas Sandberg return ret; 489963551ae0SDavid Gibson } 490063551ae0SDavid Gibson 4901550a7d60SMina Almasry static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr, 4902db110a99SAneesh Kumar K.V unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte) 4903550a7d60SMina Almasry { 4904550a7d60SMina Almasry struct hstate *h = hstate_vma(vma); 4905550a7d60SMina Almasry struct mm_struct *mm = vma->vm_mm; 4906550a7d60SMina Almasry spinlock_t *src_ptl, *dst_ptl; 4907db110a99SAneesh Kumar K.V pte_t pte; 4908550a7d60SMina Almasry 4909550a7d60SMina Almasry dst_ptl = huge_pte_lock(h, mm, dst_pte); 4910550a7d60SMina Almasry src_ptl = huge_pte_lockptr(h, mm, src_pte); 4911550a7d60SMina Almasry 4912550a7d60SMina Almasry /* 4913550a7d60SMina Almasry * We don't have to worry about the ordering of src and dst ptlocks 4914550a7d60SMina Almasry * because exclusive mmap_sem (or the i_mmap_lock) prevents deadlock. 4915550a7d60SMina Almasry */ 4916550a7d60SMina Almasry if (src_ptl != dst_ptl) 4917550a7d60SMina Almasry spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 4918550a7d60SMina Almasry 4919550a7d60SMina Almasry pte = huge_ptep_get_and_clear(mm, old_addr, src_pte); 4920550a7d60SMina Almasry set_huge_pte_at(mm, new_addr, dst_pte, pte); 4921550a7d60SMina Almasry 4922550a7d60SMina Almasry if (src_ptl != dst_ptl) 4923550a7d60SMina Almasry spin_unlock(src_ptl); 4924550a7d60SMina Almasry spin_unlock(dst_ptl); 4925550a7d60SMina Almasry } 4926550a7d60SMina Almasry 4927550a7d60SMina Almasry int move_hugetlb_page_tables(struct vm_area_struct *vma, 4928550a7d60SMina Almasry struct vm_area_struct *new_vma, 4929550a7d60SMina Almasry unsigned long old_addr, unsigned long new_addr, 4930550a7d60SMina Almasry unsigned long len) 4931550a7d60SMina Almasry { 4932550a7d60SMina Almasry struct hstate *h = hstate_vma(vma); 4933550a7d60SMina Almasry struct address_space *mapping = vma->vm_file->f_mapping; 4934550a7d60SMina Almasry unsigned long sz = huge_page_size(h); 4935550a7d60SMina Almasry struct mm_struct *mm = vma->vm_mm; 4936550a7d60SMina Almasry unsigned long old_end = old_addr + len; 4937*e95a9851SMike Kravetz unsigned long last_addr_mask; 4938550a7d60SMina Almasry unsigned long old_addr_copy; 4939550a7d60SMina Almasry pte_t *src_pte, *dst_pte; 4940550a7d60SMina Almasry struct mmu_notifier_range range; 49413d0b95cdSBaolin Wang bool shared_pmd = false; 4942550a7d60SMina Almasry 4943550a7d60SMina Almasry mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, old_addr, 4944550a7d60SMina Almasry old_end); 4945550a7d60SMina Almasry adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 49463d0b95cdSBaolin Wang /* 49473d0b95cdSBaolin Wang * In case of shared PMDs, we should cover the maximum possible 49483d0b95cdSBaolin Wang * range. 49493d0b95cdSBaolin Wang */ 49503d0b95cdSBaolin Wang flush_cache_range(vma, range.start, range.end); 49513d0b95cdSBaolin Wang 4952550a7d60SMina Almasry mmu_notifier_invalidate_range_start(&range); 4953*e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 4954550a7d60SMina Almasry /* Prevent race with file truncation */ 4955550a7d60SMina Almasry i_mmap_lock_write(mapping); 4956550a7d60SMina Almasry for (; old_addr < old_end; old_addr += sz, new_addr += sz) { 4957550a7d60SMina Almasry src_pte = huge_pte_offset(mm, old_addr, sz); 4958*e95a9851SMike Kravetz if (!src_pte) { 4959*e95a9851SMike Kravetz old_addr |= last_addr_mask; 4960*e95a9851SMike Kravetz new_addr |= last_addr_mask; 4961550a7d60SMina Almasry continue; 4962*e95a9851SMike Kravetz } 4963550a7d60SMina Almasry if (huge_pte_none(huge_ptep_get(src_pte))) 4964550a7d60SMina Almasry continue; 4965550a7d60SMina Almasry 4966550a7d60SMina Almasry /* old_addr arg to huge_pmd_unshare() is a pointer and so the 4967550a7d60SMina Almasry * arg may be modified. Pass a copy instead to preserve the 4968550a7d60SMina Almasry * value in old_addr. 4969550a7d60SMina Almasry */ 4970550a7d60SMina Almasry old_addr_copy = old_addr; 4971550a7d60SMina Almasry 49723d0b95cdSBaolin Wang if (huge_pmd_unshare(mm, vma, &old_addr_copy, src_pte)) { 49733d0b95cdSBaolin Wang shared_pmd = true; 4974550a7d60SMina Almasry continue; 49753d0b95cdSBaolin Wang } 4976550a7d60SMina Almasry 4977550a7d60SMina Almasry dst_pte = huge_pte_alloc(mm, new_vma, new_addr, sz); 4978550a7d60SMina Almasry if (!dst_pte) 4979550a7d60SMina Almasry break; 4980550a7d60SMina Almasry 4981db110a99SAneesh Kumar K.V move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte); 4982550a7d60SMina Almasry } 49833d0b95cdSBaolin Wang 49843d0b95cdSBaolin Wang if (shared_pmd) 49853d0b95cdSBaolin Wang flush_tlb_range(vma, range.start, range.end); 49863d0b95cdSBaolin Wang else 4987550a7d60SMina Almasry flush_tlb_range(vma, old_end - len, old_end); 4988550a7d60SMina Almasry mmu_notifier_invalidate_range_end(&range); 498913e4ad2cSNadav Amit i_mmap_unlock_write(mapping); 4990550a7d60SMina Almasry 4991550a7d60SMina Almasry return len + old_addr - old_end; 4992550a7d60SMina Almasry } 4993550a7d60SMina Almasry 499473c54763SPeter Xu static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, 499524669e58SAneesh Kumar K.V unsigned long start, unsigned long end, 499605e90bd0SPeter Xu struct page *ref_page, zap_flags_t zap_flags) 499763551ae0SDavid Gibson { 499863551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 499963551ae0SDavid Gibson unsigned long address; 5000c7546f8fSDavid Gibson pte_t *ptep; 500163551ae0SDavid Gibson pte_t pte; 5002cb900f41SKirill A. Shutemov spinlock_t *ptl; 500363551ae0SDavid Gibson struct page *page; 5004a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 5005a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 5006ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 5007*e95a9851SMike Kravetz unsigned long last_addr_mask; 5008a4a118f2SNadav Amit bool force_flush = false; 5009a5516438SAndi Kleen 501063551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 5011a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 5012a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 501363551ae0SDavid Gibson 501407e32661SAneesh Kumar K.V /* 501507e32661SAneesh Kumar K.V * This is a hugetlb vma, all the pte entries should point 501607e32661SAneesh Kumar K.V * to huge page. 501707e32661SAneesh Kumar K.V */ 5018ed6a7935SPeter Zijlstra tlb_change_page_size(tlb, sz); 501924669e58SAneesh Kumar K.V tlb_start_vma(tlb, vma); 5020dff11abeSMike Kravetz 5021dff11abeSMike Kravetz /* 5022dff11abeSMike Kravetz * If sharing possible, alert mmu notifiers of worst case. 5023dff11abeSMike Kravetz */ 50246f4f13e8SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, mm, start, 50256f4f13e8SJérôme Glisse end); 5026ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 5027ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 5028*e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 5029569f48b8SHillf Danton address = start; 5030569f48b8SHillf Danton for (; address < end; address += sz) { 50317868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, sz); 5032*e95a9851SMike Kravetz if (!ptep) { 5033*e95a9851SMike Kravetz address |= last_addr_mask; 5034c7546f8fSDavid Gibson continue; 5035*e95a9851SMike Kravetz } 5036c7546f8fSDavid Gibson 5037cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 503834ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 503931d49da5SAneesh Kumar K.V spin_unlock(ptl); 5040a4a118f2SNadav Amit tlb_flush_pmd_range(tlb, address & PUD_MASK, PUD_SIZE); 5041a4a118f2SNadav Amit force_flush = true; 504231d49da5SAneesh Kumar K.V continue; 504331d49da5SAneesh Kumar K.V } 504439dde65cSChen, Kenneth W 50456629326bSHillf Danton pte = huge_ptep_get(ptep); 504631d49da5SAneesh Kumar K.V if (huge_pte_none(pte)) { 504731d49da5SAneesh Kumar K.V spin_unlock(ptl); 504831d49da5SAneesh Kumar K.V continue; 504931d49da5SAneesh Kumar K.V } 50506629326bSHillf Danton 50516629326bSHillf Danton /* 50529fbc1f63SNaoya Horiguchi * Migrating hugepage or HWPoisoned hugepage is already 50539fbc1f63SNaoya Horiguchi * unmapped and its refcount is dropped, so just clear pte here. 50546629326bSHillf Danton */ 50559fbc1f63SNaoya Horiguchi if (unlikely(!pte_present(pte))) { 505605e90bd0SPeter Xu /* 505705e90bd0SPeter Xu * If the pte was wr-protected by uffd-wp in any of the 505805e90bd0SPeter Xu * swap forms, meanwhile the caller does not want to 505905e90bd0SPeter Xu * drop the uffd-wp bit in this zap, then replace the 506005e90bd0SPeter Xu * pte with a marker. 506105e90bd0SPeter Xu */ 506205e90bd0SPeter Xu if (pte_swp_uffd_wp_any(pte) && 506305e90bd0SPeter Xu !(zap_flags & ZAP_FLAG_DROP_MARKER)) 506405e90bd0SPeter Xu set_huge_pte_at(mm, address, ptep, 506505e90bd0SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 506605e90bd0SPeter Xu else 50679386fac3SPunit Agrawal huge_pte_clear(mm, address, ptep, sz); 506831d49da5SAneesh Kumar K.V spin_unlock(ptl); 506931d49da5SAneesh Kumar K.V continue; 50708c4894c6SNaoya Horiguchi } 50716629326bSHillf Danton 50726629326bSHillf Danton page = pte_page(pte); 507304f2cbe3SMel Gorman /* 507404f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 507504f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 507604f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 507704f2cbe3SMel Gorman */ 507804f2cbe3SMel Gorman if (ref_page) { 507931d49da5SAneesh Kumar K.V if (page != ref_page) { 508031d49da5SAneesh Kumar K.V spin_unlock(ptl); 508131d49da5SAneesh Kumar K.V continue; 508231d49da5SAneesh Kumar K.V } 508304f2cbe3SMel Gorman /* 508404f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 508504f2cbe3SMel Gorman * future faults in this VMA will fail rather than 508604f2cbe3SMel Gorman * looking like data was lost 508704f2cbe3SMel Gorman */ 508804f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 508904f2cbe3SMel Gorman } 509004f2cbe3SMel Gorman 5091c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 5092b528e4b6SAneesh Kumar K.V tlb_remove_huge_tlb_entry(h, tlb, ptep, address); 5093106c992aSGerald Schaefer if (huge_pte_dirty(pte)) 50946649a386SKen Chen set_page_dirty(page); 509505e90bd0SPeter Xu /* Leave a uffd-wp pte marker if needed */ 509605e90bd0SPeter Xu if (huge_pte_uffd_wp(pte) && 509705e90bd0SPeter Xu !(zap_flags & ZAP_FLAG_DROP_MARKER)) 509805e90bd0SPeter Xu set_huge_pte_at(mm, address, ptep, 509905e90bd0SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 51005d317b2bSNaoya Horiguchi hugetlb_count_sub(pages_per_huge_page(h), mm); 5101cea86fe2SHugh Dickins page_remove_rmap(page, vma, true); 510231d49da5SAneesh Kumar K.V 5103cb900f41SKirill A. Shutemov spin_unlock(ptl); 5104e77b0852SAneesh Kumar K.V tlb_remove_page_size(tlb, page, huge_page_size(h)); 510524669e58SAneesh Kumar K.V /* 510631d49da5SAneesh Kumar K.V * Bail out after unmapping reference page if supplied 510724669e58SAneesh Kumar K.V */ 510831d49da5SAneesh Kumar K.V if (ref_page) 510931d49da5SAneesh Kumar K.V break; 5110fe1668aeSChen, Kenneth W } 5111ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 511224669e58SAneesh Kumar K.V tlb_end_vma(tlb, vma); 5113a4a118f2SNadav Amit 5114a4a118f2SNadav Amit /* 5115a4a118f2SNadav Amit * If we unshared PMDs, the TLB flush was not recorded in mmu_gather. We 5116a4a118f2SNadav Amit * could defer the flush until now, since by holding i_mmap_rwsem we 5117a4a118f2SNadav Amit * guaranteed that the last refernece would not be dropped. But we must 5118a4a118f2SNadav Amit * do the flushing before we return, as otherwise i_mmap_rwsem will be 5119a4a118f2SNadav Amit * dropped and the last reference to the shared PMDs page might be 5120a4a118f2SNadav Amit * dropped as well. 5121a4a118f2SNadav Amit * 5122a4a118f2SNadav Amit * In theory we could defer the freeing of the PMD pages as well, but 5123a4a118f2SNadav Amit * huge_pmd_unshare() relies on the exact page_count for the PMD page to 5124a4a118f2SNadav Amit * detect sharing, so we cannot defer the release of the page either. 5125a4a118f2SNadav Amit * Instead, do flush now. 5126a4a118f2SNadav Amit */ 5127a4a118f2SNadav Amit if (force_flush) 5128a4a118f2SNadav Amit tlb_flush_mmu_tlbonly(tlb); 51291da177e4SLinus Torvalds } 513063551ae0SDavid Gibson 5131d833352aSMel Gorman void __unmap_hugepage_range_final(struct mmu_gather *tlb, 5132d833352aSMel Gorman struct vm_area_struct *vma, unsigned long start, 513305e90bd0SPeter Xu unsigned long end, struct page *ref_page, 513405e90bd0SPeter Xu zap_flags_t zap_flags) 5135d833352aSMel Gorman { 513605e90bd0SPeter Xu __unmap_hugepage_range(tlb, vma, start, end, ref_page, zap_flags); 5137d833352aSMel Gorman 5138d833352aSMel Gorman /* 5139d833352aSMel Gorman * Clear this flag so that x86's huge_pmd_share page_table_shareable 5140d833352aSMel Gorman * test will fail on a vma being torn down, and not grab a page table 5141d833352aSMel Gorman * on its way out. We're lucky that the flag has such an appropriate 5142d833352aSMel Gorman * name, and can in fact be safely cleared here. We could clear it 5143d833352aSMel Gorman * before the __unmap_hugepage_range above, but all that's necessary 5144c8c06efaSDavidlohr Bueso * is to clear it before releasing the i_mmap_rwsem. This works 5145d833352aSMel Gorman * because in the context this is called, the VMA is about to be 5146c8c06efaSDavidlohr Bueso * destroyed and the i_mmap_rwsem is held. 5147d833352aSMel Gorman */ 5148d833352aSMel Gorman vma->vm_flags &= ~VM_MAYSHARE; 5149d833352aSMel Gorman } 5150d833352aSMel Gorman 5151502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 515205e90bd0SPeter Xu unsigned long end, struct page *ref_page, 515305e90bd0SPeter Xu zap_flags_t zap_flags) 5154502717f4SChen, Kenneth W { 515524669e58SAneesh Kumar K.V struct mmu_gather tlb; 5156dff11abeSMike Kravetz 5157a72afd87SWill Deacon tlb_gather_mmu(&tlb, vma->vm_mm); 515805e90bd0SPeter Xu __unmap_hugepage_range(&tlb, vma, start, end, ref_page, zap_flags); 5159ae8eba8bSWill Deacon tlb_finish_mmu(&tlb); 5160502717f4SChen, Kenneth W } 5161502717f4SChen, Kenneth W 516204f2cbe3SMel Gorman /* 516304f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 5164578b7725SZhiyuan Dai * mapping it owns the reserve page for. The intention is to unmap the page 516504f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 516604f2cbe3SMel Gorman * same region. 516704f2cbe3SMel Gorman */ 51682f4612afSDavidlohr Bueso static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, 51692a4b3dedSHarvey Harrison struct page *page, unsigned long address) 517004f2cbe3SMel Gorman { 51717526674dSAdam Litke struct hstate *h = hstate_vma(vma); 517204f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 517304f2cbe3SMel Gorman struct address_space *mapping; 517404f2cbe3SMel Gorman pgoff_t pgoff; 517504f2cbe3SMel Gorman 517604f2cbe3SMel Gorman /* 517704f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 517804f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 517904f2cbe3SMel Gorman */ 51807526674dSAdam Litke address = address & huge_page_mask(h); 518136e4f20aSMichal Hocko pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + 518236e4f20aSMichal Hocko vma->vm_pgoff; 518393c76a3dSAl Viro mapping = vma->vm_file->f_mapping; 518404f2cbe3SMel Gorman 51854eb2b1dcSMel Gorman /* 51864eb2b1dcSMel Gorman * Take the mapping lock for the duration of the table walk. As 51874eb2b1dcSMel Gorman * this mapping should be shared between all the VMAs, 51884eb2b1dcSMel Gorman * __unmap_hugepage_range() is called as the lock is already held 51894eb2b1dcSMel Gorman */ 519083cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 51916b2dbba8SMichel Lespinasse vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { 519204f2cbe3SMel Gorman /* Do not unmap the current VMA */ 519304f2cbe3SMel Gorman if (iter_vma == vma) 519404f2cbe3SMel Gorman continue; 519504f2cbe3SMel Gorman 519604f2cbe3SMel Gorman /* 51972f84a899SMel Gorman * Shared VMAs have their own reserves and do not affect 51982f84a899SMel Gorman * MAP_PRIVATE accounting but it is possible that a shared 51992f84a899SMel Gorman * VMA is using the same page so check and skip such VMAs. 52002f84a899SMel Gorman */ 52012f84a899SMel Gorman if (iter_vma->vm_flags & VM_MAYSHARE) 52022f84a899SMel Gorman continue; 52032f84a899SMel Gorman 52042f84a899SMel Gorman /* 520504f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 520604f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 520704f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 520804f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 520904f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 521004f2cbe3SMel Gorman */ 521104f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 521224669e58SAneesh Kumar K.V unmap_hugepage_range(iter_vma, address, 521305e90bd0SPeter Xu address + huge_page_size(h), page, 0); 521404f2cbe3SMel Gorman } 521583cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 521604f2cbe3SMel Gorman } 521704f2cbe3SMel Gorman 52180fe6e20bSNaoya Horiguchi /* 5219c89357e2SDavid Hildenbrand * hugetlb_wp() should be called with page lock of the original hugepage held. 5220aa6d2e8cSBaolin Wang * Called with hugetlb_fault_mutex_table held and pte_page locked so we 5221ef009b25SMichal Hocko * cannot race with other handlers or page migration. 5222ef009b25SMichal Hocko * Keep the pte_same checks anyway to make transition from the mutex easier. 52230fe6e20bSNaoya Horiguchi */ 5224c89357e2SDavid Hildenbrand static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma, 5225c89357e2SDavid Hildenbrand unsigned long address, pte_t *ptep, unsigned int flags, 5226cb900f41SKirill A. Shutemov struct page *pagecache_page, spinlock_t *ptl) 52271e8f889bSDavid Gibson { 5228c89357e2SDavid Hildenbrand const bool unshare = flags & FAULT_FLAG_UNSHARE; 52293999f52eSAneesh Kumar K.V pte_t pte; 5230a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 52311e8f889bSDavid Gibson struct page *old_page, *new_page; 52322b740303SSouptick Joarder int outside_reserve = 0; 52332b740303SSouptick Joarder vm_fault_t ret = 0; 5234974e6d66SHuang Ying unsigned long haddr = address & huge_page_mask(h); 5235ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 52361e8f889bSDavid Gibson 5237c89357e2SDavid Hildenbrand VM_BUG_ON(unshare && (flags & FOLL_WRITE)); 5238c89357e2SDavid Hildenbrand VM_BUG_ON(!unshare && !(flags & FOLL_WRITE)); 5239c89357e2SDavid Hildenbrand 52403999f52eSAneesh Kumar K.V pte = huge_ptep_get(ptep); 52411e8f889bSDavid Gibson old_page = pte_page(pte); 52421e8f889bSDavid Gibson 5243662ce1dcSYang Yang delayacct_wpcopy_start(); 5244662ce1dcSYang Yang 524504f2cbe3SMel Gorman retry_avoidcopy: 5246c89357e2SDavid Hildenbrand /* 5247c89357e2SDavid Hildenbrand * If no-one else is actually using this page, we're the exclusive 5248c89357e2SDavid Hildenbrand * owner and can reuse this page. 5249c89357e2SDavid Hildenbrand */ 525037a2140dSJoonsoo Kim if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { 5251c89357e2SDavid Hildenbrand if (!PageAnonExclusive(old_page)) 52525a49973dSHugh Dickins page_move_anon_rmap(old_page, vma); 5253c89357e2SDavid Hildenbrand if (likely(!unshare)) 52545b7a1d40SHuang Ying set_huge_ptep_writable(vma, haddr, ptep); 5255662ce1dcSYang Yang 5256662ce1dcSYang Yang delayacct_wpcopy_end(); 525783c54070SNick Piggin return 0; 52581e8f889bSDavid Gibson } 52596c287605SDavid Hildenbrand VM_BUG_ON_PAGE(PageAnon(old_page) && PageAnonExclusive(old_page), 52606c287605SDavid Hildenbrand old_page); 52611e8f889bSDavid Gibson 526204f2cbe3SMel Gorman /* 526304f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 526404f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 526504f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 526604f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 526704f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 526804f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 526904f2cbe3SMel Gorman * of the full address range. 527004f2cbe3SMel Gorman */ 52715944d011SJoonsoo Kim if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 527204f2cbe3SMel Gorman old_page != pagecache_page) 527304f2cbe3SMel Gorman outside_reserve = 1; 527404f2cbe3SMel Gorman 527509cbfeafSKirill A. Shutemov get_page(old_page); 5276b76c8cfbSLarry Woodman 5277ad4404a2SDavidlohr Bueso /* 5278ad4404a2SDavidlohr Bueso * Drop page table lock as buddy allocator may be called. It will 5279ad4404a2SDavidlohr Bueso * be acquired again before returning to the caller, as expected. 5280ad4404a2SDavidlohr Bueso */ 5281cb900f41SKirill A. Shutemov spin_unlock(ptl); 52825b7a1d40SHuang Ying new_page = alloc_huge_page(vma, haddr, outside_reserve); 52831e8f889bSDavid Gibson 52842fc39cecSAdam Litke if (IS_ERR(new_page)) { 528504f2cbe3SMel Gorman /* 528604f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 528704f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 528804f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 528904f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 529004f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 529104f2cbe3SMel Gorman */ 529204f2cbe3SMel Gorman if (outside_reserve) { 5293e7dd91c4SMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 5294e7dd91c4SMike Kravetz pgoff_t idx; 5295e7dd91c4SMike Kravetz u32 hash; 5296e7dd91c4SMike Kravetz 529709cbfeafSKirill A. Shutemov put_page(old_page); 529804f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 5299e7dd91c4SMike Kravetz /* 5300e7dd91c4SMike Kravetz * Drop hugetlb_fault_mutex and i_mmap_rwsem before 5301e7dd91c4SMike Kravetz * unmapping. unmapping needs to hold i_mmap_rwsem 5302e7dd91c4SMike Kravetz * in write mode. Dropping i_mmap_rwsem in read mode 5303e7dd91c4SMike Kravetz * here is OK as COW mappings do not interact with 5304e7dd91c4SMike Kravetz * PMD sharing. 5305e7dd91c4SMike Kravetz * 5306e7dd91c4SMike Kravetz * Reacquire both after unmap operation. 5307e7dd91c4SMike Kravetz */ 5308e7dd91c4SMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 5309e7dd91c4SMike Kravetz hash = hugetlb_fault_mutex_hash(mapping, idx); 5310e7dd91c4SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5311e7dd91c4SMike Kravetz i_mmap_unlock_read(mapping); 5312e7dd91c4SMike Kravetz 53135b7a1d40SHuang Ying unmap_ref_private(mm, vma, old_page, haddr); 5314e7dd91c4SMike Kravetz 5315e7dd91c4SMike Kravetz i_mmap_lock_read(mapping); 5316e7dd91c4SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 5317cb900f41SKirill A. Shutemov spin_lock(ptl); 53185b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5319a9af0c5dSNaoya Horiguchi if (likely(ptep && 5320a9af0c5dSNaoya Horiguchi pte_same(huge_ptep_get(ptep), pte))) 532104f2cbe3SMel Gorman goto retry_avoidcopy; 5322a734bcc8SHillf Danton /* 5323cb900f41SKirill A. Shutemov * race occurs while re-acquiring page table 5324cb900f41SKirill A. Shutemov * lock, and our job is done. 5325a734bcc8SHillf Danton */ 5326662ce1dcSYang Yang delayacct_wpcopy_end(); 5327a734bcc8SHillf Danton return 0; 532804f2cbe3SMel Gorman } 532904f2cbe3SMel Gorman 53302b740303SSouptick Joarder ret = vmf_error(PTR_ERR(new_page)); 5331ad4404a2SDavidlohr Bueso goto out_release_old; 53321e8f889bSDavid Gibson } 53331e8f889bSDavid Gibson 53340fe6e20bSNaoya Horiguchi /* 53350fe6e20bSNaoya Horiguchi * When the original hugepage is shared one, it does not have 53360fe6e20bSNaoya Horiguchi * anon_vma prepared. 53370fe6e20bSNaoya Horiguchi */ 533844e2aa93SDean Nelson if (unlikely(anon_vma_prepare(vma))) { 5339ad4404a2SDavidlohr Bueso ret = VM_FAULT_OOM; 5340ad4404a2SDavidlohr Bueso goto out_release_all; 534144e2aa93SDean Nelson } 53420fe6e20bSNaoya Horiguchi 5343974e6d66SHuang Ying copy_user_huge_page(new_page, old_page, address, vma, 534447ad8475SAndrea Arcangeli pages_per_huge_page(h)); 53450ed361deSNick Piggin __SetPageUptodate(new_page); 53461e8f889bSDavid Gibson 53477269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr, 53486f4f13e8SJérôme Glisse haddr + huge_page_size(h)); 5349ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 5350ad4404a2SDavidlohr Bueso 5351b76c8cfbSLarry Woodman /* 5352cb900f41SKirill A. Shutemov * Retake the page table lock to check for racing updates 5353b76c8cfbSLarry Woodman * before the page tables are altered 5354b76c8cfbSLarry Woodman */ 5355cb900f41SKirill A. Shutemov spin_lock(ptl); 53565b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5357a9af0c5dSNaoya Horiguchi if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { 5358d6995da3SMike Kravetz ClearHPageRestoreReserve(new_page); 535907443a85SJoonsoo Kim 5360c89357e2SDavid Hildenbrand /* Break COW or unshare */ 53615b7a1d40SHuang Ying huge_ptep_clear_flush(vma, haddr, ptep); 5362ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range(mm, range.start, range.end); 5363cea86fe2SHugh Dickins page_remove_rmap(old_page, vma, true); 53645b7a1d40SHuang Ying hugepage_add_new_anon_rmap(new_page, vma, haddr); 53651eba86c0SPasha Tatashin set_huge_pte_at(mm, haddr, ptep, 5366c89357e2SDavid Hildenbrand make_huge_pte(vma, new_page, !unshare)); 53678f251a3dSMike Kravetz SetHPageMigratable(new_page); 53681e8f889bSDavid Gibson /* Make the old page be freed below */ 53691e8f889bSDavid Gibson new_page = old_page; 53701e8f889bSDavid Gibson } 5371cb900f41SKirill A. Shutemov spin_unlock(ptl); 5372ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 5373ad4404a2SDavidlohr Bueso out_release_all: 5374c89357e2SDavid Hildenbrand /* 5375c89357e2SDavid Hildenbrand * No restore in case of successful pagetable update (Break COW or 5376c89357e2SDavid Hildenbrand * unshare) 5377c89357e2SDavid Hildenbrand */ 5378c7b1850dSMike Kravetz if (new_page != old_page) 53795b7a1d40SHuang Ying restore_reserve_on_error(h, vma, haddr, new_page); 538009cbfeafSKirill A. Shutemov put_page(new_page); 5381ad4404a2SDavidlohr Bueso out_release_old: 538209cbfeafSKirill A. Shutemov put_page(old_page); 53838312034fSJoonsoo Kim 5384ad4404a2SDavidlohr Bueso spin_lock(ptl); /* Caller expects lock to be held */ 5385662ce1dcSYang Yang 5386662ce1dcSYang Yang delayacct_wpcopy_end(); 5387ad4404a2SDavidlohr Bueso return ret; 53881e8f889bSDavid Gibson } 53891e8f889bSDavid Gibson 539004f2cbe3SMel Gorman /* Return the pagecache page at a given address within a VMA */ 5391a5516438SAndi Kleen static struct page *hugetlbfs_pagecache_page(struct hstate *h, 5392a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 539304f2cbe3SMel Gorman { 539404f2cbe3SMel Gorman struct address_space *mapping; 5395e7c4b0bfSAndy Whitcroft pgoff_t idx; 539604f2cbe3SMel Gorman 539704f2cbe3SMel Gorman mapping = vma->vm_file->f_mapping; 5398a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 539904f2cbe3SMel Gorman 540004f2cbe3SMel Gorman return find_lock_page(mapping, idx); 540104f2cbe3SMel Gorman } 540204f2cbe3SMel Gorman 54033ae77f43SHugh Dickins /* 54043ae77f43SHugh Dickins * Return whether there is a pagecache page to back given address within VMA. 54053ae77f43SHugh Dickins * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. 54063ae77f43SHugh Dickins */ 54073ae77f43SHugh Dickins static bool hugetlbfs_pagecache_present(struct hstate *h, 54082a15efc9SHugh Dickins struct vm_area_struct *vma, unsigned long address) 54092a15efc9SHugh Dickins { 54102a15efc9SHugh Dickins struct address_space *mapping; 54112a15efc9SHugh Dickins pgoff_t idx; 54122a15efc9SHugh Dickins struct page *page; 54132a15efc9SHugh Dickins 54142a15efc9SHugh Dickins mapping = vma->vm_file->f_mapping; 54152a15efc9SHugh Dickins idx = vma_hugecache_offset(h, vma, address); 54162a15efc9SHugh Dickins 54172a15efc9SHugh Dickins page = find_get_page(mapping, idx); 54182a15efc9SHugh Dickins if (page) 54192a15efc9SHugh Dickins put_page(page); 54202a15efc9SHugh Dickins return page != NULL; 54212a15efc9SHugh Dickins } 54222a15efc9SHugh Dickins 5423ab76ad54SMike Kravetz int huge_add_to_page_cache(struct page *page, struct address_space *mapping, 5424ab76ad54SMike Kravetz pgoff_t idx) 5425ab76ad54SMike Kravetz { 5426ab76ad54SMike Kravetz struct inode *inode = mapping->host; 5427ab76ad54SMike Kravetz struct hstate *h = hstate_inode(inode); 5428ab76ad54SMike Kravetz int err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); 5429ab76ad54SMike Kravetz 5430ab76ad54SMike Kravetz if (err) 5431ab76ad54SMike Kravetz return err; 5432d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 5433ab76ad54SMike Kravetz 543422146c3cSMike Kravetz /* 543522146c3cSMike Kravetz * set page dirty so that it will not be removed from cache/file 543622146c3cSMike Kravetz * by non-hugetlbfs specific code paths. 543722146c3cSMike Kravetz */ 543822146c3cSMike Kravetz set_page_dirty(page); 543922146c3cSMike Kravetz 5440ab76ad54SMike Kravetz spin_lock(&inode->i_lock); 5441ab76ad54SMike Kravetz inode->i_blocks += blocks_per_huge_page(h); 5442ab76ad54SMike Kravetz spin_unlock(&inode->i_lock); 5443ab76ad54SMike Kravetz return 0; 5444ab76ad54SMike Kravetz } 5445ab76ad54SMike Kravetz 54467677f7fdSAxel Rasmussen static inline vm_fault_t hugetlb_handle_userfault(struct vm_area_struct *vma, 54477677f7fdSAxel Rasmussen struct address_space *mapping, 54487677f7fdSAxel Rasmussen pgoff_t idx, 54497677f7fdSAxel Rasmussen unsigned int flags, 54507677f7fdSAxel Rasmussen unsigned long haddr, 5451824ddc60SNadav Amit unsigned long addr, 54527677f7fdSAxel Rasmussen unsigned long reason) 54537677f7fdSAxel Rasmussen { 54547677f7fdSAxel Rasmussen vm_fault_t ret; 54557677f7fdSAxel Rasmussen u32 hash; 54567677f7fdSAxel Rasmussen struct vm_fault vmf = { 54577677f7fdSAxel Rasmussen .vma = vma, 54587677f7fdSAxel Rasmussen .address = haddr, 5459824ddc60SNadav Amit .real_address = addr, 54607677f7fdSAxel Rasmussen .flags = flags, 54617677f7fdSAxel Rasmussen 54627677f7fdSAxel Rasmussen /* 54637677f7fdSAxel Rasmussen * Hard to debug if it ends up being 54647677f7fdSAxel Rasmussen * used by a callee that assumes 54657677f7fdSAxel Rasmussen * something about the other 54667677f7fdSAxel Rasmussen * uninitialized fields... same as in 54677677f7fdSAxel Rasmussen * memory.c 54687677f7fdSAxel Rasmussen */ 54697677f7fdSAxel Rasmussen }; 54707677f7fdSAxel Rasmussen 54717677f7fdSAxel Rasmussen /* 54727677f7fdSAxel Rasmussen * hugetlb_fault_mutex and i_mmap_rwsem must be 54737677f7fdSAxel Rasmussen * dropped before handling userfault. Reacquire 54747677f7fdSAxel Rasmussen * after handling fault to make calling code simpler. 54757677f7fdSAxel Rasmussen */ 54767677f7fdSAxel Rasmussen hash = hugetlb_fault_mutex_hash(mapping, idx); 54777677f7fdSAxel Rasmussen mutex_unlock(&hugetlb_fault_mutex_table[hash]); 54787677f7fdSAxel Rasmussen i_mmap_unlock_read(mapping); 54797677f7fdSAxel Rasmussen ret = handle_userfault(&vmf, reason); 54807677f7fdSAxel Rasmussen i_mmap_lock_read(mapping); 54817677f7fdSAxel Rasmussen mutex_lock(&hugetlb_fault_mutex_table[hash]); 54827677f7fdSAxel Rasmussen 54837677f7fdSAxel Rasmussen return ret; 54847677f7fdSAxel Rasmussen } 54857677f7fdSAxel Rasmussen 54862b740303SSouptick Joarder static vm_fault_t hugetlb_no_page(struct mm_struct *mm, 54872b740303SSouptick Joarder struct vm_area_struct *vma, 54888382d914SDavidlohr Bueso struct address_space *mapping, pgoff_t idx, 5489c64e912cSPeter Xu unsigned long address, pte_t *ptep, 5490c64e912cSPeter Xu pte_t old_pte, unsigned int flags) 5491ac9b9c66SHugh Dickins { 5492a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 54932b740303SSouptick Joarder vm_fault_t ret = VM_FAULT_SIGBUS; 5494409eb8c2SHillf Danton int anon_rmap = 0; 54954c887265SAdam Litke unsigned long size; 54964c887265SAdam Litke struct page *page; 54971e8f889bSDavid Gibson pte_t new_pte; 5498cb900f41SKirill A. Shutemov spinlock_t *ptl; 5499285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 5500c7b1850dSMike Kravetz bool new_page, new_pagecache_page = false; 55014c887265SAdam Litke 550204f2cbe3SMel Gorman /* 550304f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 550404f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 5505c89357e2SDavid Hildenbrand * COW/unsharing. Warn that such a situation has occurred as it may not 5506c89357e2SDavid Hildenbrand * be obvious. 550704f2cbe3SMel Gorman */ 550804f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 5509910154d5SGeoffrey Thomas pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n", 551004f2cbe3SMel Gorman current->pid); 551104f2cbe3SMel Gorman return ret; 551204f2cbe3SMel Gorman } 551304f2cbe3SMel Gorman 55144c887265SAdam Litke /* 551587bf91d3SMike Kravetz * We can not race with truncation due to holding i_mmap_rwsem. 551687bf91d3SMike Kravetz * i_size is modified when holding i_mmap_rwsem, so check here 551787bf91d3SMike Kravetz * once for faults beyond end of file. 55184c887265SAdam Litke */ 5519a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 5520ebed4bfcSHugh Dickins if (idx >= size) 5521ebed4bfcSHugh Dickins goto out; 55221a1aad8aSMike Kravetz 552387bf91d3SMike Kravetz retry: 5524c7b1850dSMike Kravetz new_page = false; 552587bf91d3SMike Kravetz page = find_lock_page(mapping, idx); 552687bf91d3SMike Kravetz if (!page) { 55277677f7fdSAxel Rasmussen /* Check for page in userfault range */ 55281a1aad8aSMike Kravetz if (userfaultfd_missing(vma)) { 55297677f7fdSAxel Rasmussen ret = hugetlb_handle_userfault(vma, mapping, idx, 5530824ddc60SNadav Amit flags, haddr, address, 55317677f7fdSAxel Rasmussen VM_UFFD_MISSING); 55321a1aad8aSMike Kravetz goto out; 55331a1aad8aSMike Kravetz } 55341a1aad8aSMike Kravetz 5535285b8dcaSHuang Ying page = alloc_huge_page(vma, haddr, 0); 55362fc39cecSAdam Litke if (IS_ERR(page)) { 55374643d67eSMike Kravetz /* 55384643d67eSMike Kravetz * Returning error will result in faulting task being 55394643d67eSMike Kravetz * sent SIGBUS. The hugetlb fault mutex prevents two 55404643d67eSMike Kravetz * tasks from racing to fault in the same page which 55414643d67eSMike Kravetz * could result in false unable to allocate errors. 55424643d67eSMike Kravetz * Page migration does not take the fault mutex, but 55434643d67eSMike Kravetz * does a clear then write of pte's under page table 55444643d67eSMike Kravetz * lock. Page fault code could race with migration, 55454643d67eSMike Kravetz * notice the clear pte and try to allocate a page 55464643d67eSMike Kravetz * here. Before returning error, get ptl and make 55474643d67eSMike Kravetz * sure there really is no pte entry. 55484643d67eSMike Kravetz */ 55494643d67eSMike Kravetz ptl = huge_pte_lock(h, mm, ptep); 55504643d67eSMike Kravetz ret = 0; 5551d83e6c8aSMiaohe Lin if (huge_pte_none(huge_ptep_get(ptep))) 55522b740303SSouptick Joarder ret = vmf_error(PTR_ERR(page)); 5553d83e6c8aSMiaohe Lin spin_unlock(ptl); 55546bda666aSChristoph Lameter goto out; 55556bda666aSChristoph Lameter } 555647ad8475SAndrea Arcangeli clear_huge_page(page, address, pages_per_huge_page(h)); 55570ed361deSNick Piggin __SetPageUptodate(page); 5558cb6acd01SMike Kravetz new_page = true; 5559ac9b9c66SHugh Dickins 5560f83a275dSMel Gorman if (vma->vm_flags & VM_MAYSHARE) { 5561ab76ad54SMike Kravetz int err = huge_add_to_page_cache(page, mapping, idx); 55626bda666aSChristoph Lameter if (err) { 55636bda666aSChristoph Lameter put_page(page); 55646bda666aSChristoph Lameter if (err == -EEXIST) 55656bda666aSChristoph Lameter goto retry; 55666bda666aSChristoph Lameter goto out; 55676bda666aSChristoph Lameter } 5568c7b1850dSMike Kravetz new_pagecache_page = true; 556923be7468SMel Gorman } else { 55706bda666aSChristoph Lameter lock_page(page); 55710fe6e20bSNaoya Horiguchi if (unlikely(anon_vma_prepare(vma))) { 55720fe6e20bSNaoya Horiguchi ret = VM_FAULT_OOM; 55730fe6e20bSNaoya Horiguchi goto backout_unlocked; 557423be7468SMel Gorman } 5575409eb8c2SHillf Danton anon_rmap = 1; 55760fe6e20bSNaoya Horiguchi } 55770fe6e20bSNaoya Horiguchi } else { 557857303d80SAndy Whitcroft /* 5579998b4382SNaoya Horiguchi * If memory error occurs between mmap() and fault, some process 5580998b4382SNaoya Horiguchi * don't have hwpoisoned swap entry for errored virtual address. 5581998b4382SNaoya Horiguchi * So we need to block hugepage fault by PG_hwpoison bit check. 5582fd6a03edSNaoya Horiguchi */ 5583fd6a03edSNaoya Horiguchi if (unlikely(PageHWPoison(page))) { 55840eb98f15SMiaohe Lin ret = VM_FAULT_HWPOISON_LARGE | 5585972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 5586fd6a03edSNaoya Horiguchi goto backout_unlocked; 55876bda666aSChristoph Lameter } 55887677f7fdSAxel Rasmussen 55897677f7fdSAxel Rasmussen /* Check for page in userfault range. */ 55907677f7fdSAxel Rasmussen if (userfaultfd_minor(vma)) { 55917677f7fdSAxel Rasmussen unlock_page(page); 55927677f7fdSAxel Rasmussen put_page(page); 55937677f7fdSAxel Rasmussen ret = hugetlb_handle_userfault(vma, mapping, idx, 5594824ddc60SNadav Amit flags, haddr, address, 55957677f7fdSAxel Rasmussen VM_UFFD_MINOR); 55967677f7fdSAxel Rasmussen goto out; 55977677f7fdSAxel Rasmussen } 5598998b4382SNaoya Horiguchi } 55991e8f889bSDavid Gibson 560057303d80SAndy Whitcroft /* 560157303d80SAndy Whitcroft * If we are going to COW a private mapping later, we examine the 560257303d80SAndy Whitcroft * pending reservations for this page now. This will ensure that 560357303d80SAndy Whitcroft * any allocations necessary to record that reservation occur outside 560457303d80SAndy Whitcroft * the spinlock. 560557303d80SAndy Whitcroft */ 56065e911373SMike Kravetz if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 5607285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 56082b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 56092b26736cSAndy Whitcroft goto backout_unlocked; 56102b26736cSAndy Whitcroft } 56115e911373SMike Kravetz /* Just decrements count, does not deallocate */ 5612285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 56135e911373SMike Kravetz } 561457303d80SAndy Whitcroft 56158bea8052SAneesh Kumar K.V ptl = huge_pte_lock(h, mm, ptep); 561683c54070SNick Piggin ret = 0; 5617c64e912cSPeter Xu /* If pte changed from under us, retry */ 5618c64e912cSPeter Xu if (!pte_same(huge_ptep_get(ptep), old_pte)) 56194c887265SAdam Litke goto backout; 56204c887265SAdam Litke 562107443a85SJoonsoo Kim if (anon_rmap) { 5622d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 5623285b8dcaSHuang Ying hugepage_add_new_anon_rmap(page, vma, haddr); 5624ac714904SChoi Gi-yong } else 5625fb3d824dSDavid Hildenbrand page_dup_file_rmap(page, true); 56261e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 56271e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 5628c64e912cSPeter Xu /* 5629c64e912cSPeter Xu * If this pte was previously wr-protected, keep it wr-protected even 5630c64e912cSPeter Xu * if populated. 5631c64e912cSPeter Xu */ 5632c64e912cSPeter Xu if (unlikely(pte_marker_uffd_wp(old_pte))) 5633c64e912cSPeter Xu new_pte = huge_pte_wrprotect(huge_pte_mkuffd_wp(new_pte)); 5634285b8dcaSHuang Ying set_huge_pte_at(mm, haddr, ptep, new_pte); 56351e8f889bSDavid Gibson 56365d317b2bSNaoya Horiguchi hugetlb_count_add(pages_per_huge_page(h), mm); 5637788c7df4SHugh Dickins if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 56381e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 5639c89357e2SDavid Hildenbrand ret = hugetlb_wp(mm, vma, address, ptep, flags, page, ptl); 56401e8f889bSDavid Gibson } 56411e8f889bSDavid Gibson 5642cb900f41SKirill A. Shutemov spin_unlock(ptl); 5643cb6acd01SMike Kravetz 5644cb6acd01SMike Kravetz /* 56458f251a3dSMike Kravetz * Only set HPageMigratable in newly allocated pages. Existing pages 56468f251a3dSMike Kravetz * found in the pagecache may not have HPageMigratableset if they have 56478f251a3dSMike Kravetz * been isolated for migration. 5648cb6acd01SMike Kravetz */ 5649cb6acd01SMike Kravetz if (new_page) 56508f251a3dSMike Kravetz SetHPageMigratable(page); 5651cb6acd01SMike Kravetz 56524c887265SAdam Litke unlock_page(page); 56534c887265SAdam Litke out: 5654ac9b9c66SHugh Dickins return ret; 56554c887265SAdam Litke 56564c887265SAdam Litke backout: 5657cb900f41SKirill A. Shutemov spin_unlock(ptl); 56582b26736cSAndy Whitcroft backout_unlocked: 56594c887265SAdam Litke unlock_page(page); 5660c7b1850dSMike Kravetz /* restore reserve for newly allocated pages not in page cache */ 5661c7b1850dSMike Kravetz if (new_page && !new_pagecache_page) 5662285b8dcaSHuang Ying restore_reserve_on_error(h, vma, haddr, page); 56634c887265SAdam Litke put_page(page); 56644c887265SAdam Litke goto out; 5665ac9b9c66SHugh Dickins } 5666ac9b9c66SHugh Dickins 56678382d914SDavidlohr Bueso #ifdef CONFIG_SMP 5668188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 56698382d914SDavidlohr Bueso { 56708382d914SDavidlohr Bueso unsigned long key[2]; 56718382d914SDavidlohr Bueso u32 hash; 56728382d914SDavidlohr Bueso 56738382d914SDavidlohr Bueso key[0] = (unsigned long) mapping; 56748382d914SDavidlohr Bueso key[1] = idx; 56758382d914SDavidlohr Bueso 567655254636SMike Kravetz hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0); 56778382d914SDavidlohr Bueso 56788382d914SDavidlohr Bueso return hash & (num_fault_mutexes - 1); 56798382d914SDavidlohr Bueso } 56808382d914SDavidlohr Bueso #else 56818382d914SDavidlohr Bueso /* 56826c26d310SMiaohe Lin * For uniprocessor systems we always use a single mutex, so just 56838382d914SDavidlohr Bueso * return 0 and avoid the hashing overhead. 56848382d914SDavidlohr Bueso */ 5685188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 56868382d914SDavidlohr Bueso { 56878382d914SDavidlohr Bueso return 0; 56888382d914SDavidlohr Bueso } 56898382d914SDavidlohr Bueso #endif 56908382d914SDavidlohr Bueso 56912b740303SSouptick Joarder vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 5692788c7df4SHugh Dickins unsigned long address, unsigned int flags) 569386e5216fSAdam Litke { 56948382d914SDavidlohr Bueso pte_t *ptep, entry; 5695cb900f41SKirill A. Shutemov spinlock_t *ptl; 56962b740303SSouptick Joarder vm_fault_t ret; 56978382d914SDavidlohr Bueso u32 hash; 56988382d914SDavidlohr Bueso pgoff_t idx; 56990fe6e20bSNaoya Horiguchi struct page *page = NULL; 570057303d80SAndy Whitcroft struct page *pagecache_page = NULL; 5701a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 57028382d914SDavidlohr Bueso struct address_space *mapping; 57030f792cf9SNaoya Horiguchi int need_wait_lock = 0; 5704285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 570586e5216fSAdam Litke 5706285b8dcaSHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5707fd6a03edSNaoya Horiguchi if (ptep) { 5708c0d0381aSMike Kravetz /* 5709c0d0381aSMike Kravetz * Since we hold no locks, ptep could be stale. That is 5710c0d0381aSMike Kravetz * OK as we are only making decisions based on content and 5711c0d0381aSMike Kravetz * not actually modifying content here. 5712c0d0381aSMike Kravetz */ 5713fd6a03edSNaoya Horiguchi entry = huge_ptep_get(ptep); 5714290408d4SNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(entry))) { 5715ad1ac596SMiaohe Lin migration_entry_wait_huge(vma, ptep); 5716290408d4SNaoya Horiguchi return 0; 5717290408d4SNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) 5718aa50d3a7SAndi Kleen return VM_FAULT_HWPOISON_LARGE | 5719972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 5720b43a9990SMike Kravetz } 57218382d914SDavidlohr Bueso 5722c0d0381aSMike Kravetz /* 5723c0d0381aSMike Kravetz * Acquire i_mmap_rwsem before calling huge_pte_alloc and hold 572487bf91d3SMike Kravetz * until finished with ptep. This serves two purposes: 572587bf91d3SMike Kravetz * 1) It prevents huge_pmd_unshare from being called elsewhere 572687bf91d3SMike Kravetz * and making the ptep no longer valid. 572787bf91d3SMike Kravetz * 2) It synchronizes us with i_size modifications during truncation. 5728c0d0381aSMike Kravetz * 5729c0d0381aSMike Kravetz * ptep could have already be assigned via huge_pte_offset. That 5730c0d0381aSMike Kravetz * is OK, as huge_pte_alloc will return the same value unless 5731c0d0381aSMike Kravetz * something has changed. 5732c0d0381aSMike Kravetz */ 5733ddeaab32SMike Kravetz mapping = vma->vm_file->f_mapping; 5734c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 5735aec44e0fSPeter Xu ptep = huge_pte_alloc(mm, vma, haddr, huge_page_size(h)); 5736c0d0381aSMike Kravetz if (!ptep) { 5737c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 5738c0d0381aSMike Kravetz return VM_FAULT_OOM; 5739c0d0381aSMike Kravetz } 5740ddeaab32SMike Kravetz 57413935baa9SDavid Gibson /* 57423935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 57433935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 57443935baa9SDavid Gibson * the same page in the page cache. 57453935baa9SDavid Gibson */ 5746c0d0381aSMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 5747188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 5748c672c7f2SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 57498382d914SDavidlohr Bueso 57507f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 5751c64e912cSPeter Xu /* PTE markers should be handled the same way as none pte */ 5752c64e912cSPeter Xu if (huge_pte_none_mostly(entry)) { 5753c64e912cSPeter Xu ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, 5754c64e912cSPeter Xu entry, flags); 5755b4d1d99fSDavid Gibson goto out_mutex; 57563935baa9SDavid Gibson } 575786e5216fSAdam Litke 575883c54070SNick Piggin ret = 0; 57591e8f889bSDavid Gibson 576057303d80SAndy Whitcroft /* 57610f792cf9SNaoya Horiguchi * entry could be a migration/hwpoison entry at this point, so this 57620f792cf9SNaoya Horiguchi * check prevents the kernel from going below assuming that we have 57637c8de358SEthon Paul * an active hugepage in pagecache. This goto expects the 2nd page 57647c8de358SEthon Paul * fault, and is_hugetlb_entry_(migration|hwpoisoned) check will 57657c8de358SEthon Paul * properly handle it. 57660f792cf9SNaoya Horiguchi */ 57670f792cf9SNaoya Horiguchi if (!pte_present(entry)) 57680f792cf9SNaoya Horiguchi goto out_mutex; 57690f792cf9SNaoya Horiguchi 57700f792cf9SNaoya Horiguchi /* 5771c89357e2SDavid Hildenbrand * If we are going to COW/unshare the mapping later, we examine the 5772c89357e2SDavid Hildenbrand * pending reservations for this page now. This will ensure that any 577357303d80SAndy Whitcroft * allocations necessary to record that reservation occur outside the 577457303d80SAndy Whitcroft * spinlock. For private mappings, we also lookup the pagecache 577557303d80SAndy Whitcroft * page now as it is used to determine if a reservation has been 577657303d80SAndy Whitcroft * consumed. 577757303d80SAndy Whitcroft */ 5778c89357e2SDavid Hildenbrand if ((flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) && 5779c89357e2SDavid Hildenbrand !huge_pte_write(entry)) { 5780285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 57812b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 5782b4d1d99fSDavid Gibson goto out_mutex; 57832b26736cSAndy Whitcroft } 57845e911373SMike Kravetz /* Just decrements count, does not deallocate */ 5785285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 578657303d80SAndy Whitcroft 5787f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 578857303d80SAndy Whitcroft pagecache_page = hugetlbfs_pagecache_page(h, 5789285b8dcaSHuang Ying vma, haddr); 579057303d80SAndy Whitcroft } 579157303d80SAndy Whitcroft 57920f792cf9SNaoya Horiguchi ptl = huge_pte_lock(h, mm, ptep); 57930fe6e20bSNaoya Horiguchi 5794c89357e2SDavid Hildenbrand /* Check for a racing update before calling hugetlb_wp() */ 5795b4d1d99fSDavid Gibson if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) 5796cb900f41SKirill A. Shutemov goto out_ptl; 5797b4d1d99fSDavid Gibson 5798166f3eccSPeter Xu /* Handle userfault-wp first, before trying to lock more pages */ 5799166f3eccSPeter Xu if (userfaultfd_wp(vma) && huge_pte_uffd_wp(huge_ptep_get(ptep)) && 5800166f3eccSPeter Xu (flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { 5801166f3eccSPeter Xu struct vm_fault vmf = { 5802166f3eccSPeter Xu .vma = vma, 5803166f3eccSPeter Xu .address = haddr, 5804166f3eccSPeter Xu .real_address = address, 5805166f3eccSPeter Xu .flags = flags, 5806166f3eccSPeter Xu }; 5807166f3eccSPeter Xu 5808166f3eccSPeter Xu spin_unlock(ptl); 5809166f3eccSPeter Xu if (pagecache_page) { 5810166f3eccSPeter Xu unlock_page(pagecache_page); 5811166f3eccSPeter Xu put_page(pagecache_page); 5812166f3eccSPeter Xu } 5813166f3eccSPeter Xu mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5814166f3eccSPeter Xu i_mmap_unlock_read(mapping); 5815166f3eccSPeter Xu return handle_userfault(&vmf, VM_UFFD_WP); 5816166f3eccSPeter Xu } 5817166f3eccSPeter Xu 58180f792cf9SNaoya Horiguchi /* 5819c89357e2SDavid Hildenbrand * hugetlb_wp() requires page locks of pte_page(entry) and 58200f792cf9SNaoya Horiguchi * pagecache_page, so here we need take the former one 58210f792cf9SNaoya Horiguchi * when page != pagecache_page or !pagecache_page. 58220f792cf9SNaoya Horiguchi */ 58230f792cf9SNaoya Horiguchi page = pte_page(entry); 58240f792cf9SNaoya Horiguchi if (page != pagecache_page) 58250f792cf9SNaoya Horiguchi if (!trylock_page(page)) { 58260f792cf9SNaoya Horiguchi need_wait_lock = 1; 58270f792cf9SNaoya Horiguchi goto out_ptl; 58280f792cf9SNaoya Horiguchi } 58290f792cf9SNaoya Horiguchi 58300f792cf9SNaoya Horiguchi get_page(page); 5831b4d1d99fSDavid Gibson 5832c89357e2SDavid Hildenbrand if (flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) { 5833106c992aSGerald Schaefer if (!huge_pte_write(entry)) { 5834c89357e2SDavid Hildenbrand ret = hugetlb_wp(mm, vma, address, ptep, flags, 5835cb900f41SKirill A. Shutemov pagecache_page, ptl); 58360f792cf9SNaoya Horiguchi goto out_put_page; 5837c89357e2SDavid Hildenbrand } else if (likely(flags & FAULT_FLAG_WRITE)) { 5838106c992aSGerald Schaefer entry = huge_pte_mkdirty(entry); 5839b4d1d99fSDavid Gibson } 5840c89357e2SDavid Hildenbrand } 5841b4d1d99fSDavid Gibson entry = pte_mkyoung(entry); 5842285b8dcaSHuang Ying if (huge_ptep_set_access_flags(vma, haddr, ptep, entry, 5843788c7df4SHugh Dickins flags & FAULT_FLAG_WRITE)) 5844285b8dcaSHuang Ying update_mmu_cache(vma, haddr, ptep); 58450f792cf9SNaoya Horiguchi out_put_page: 58460f792cf9SNaoya Horiguchi if (page != pagecache_page) 58470f792cf9SNaoya Horiguchi unlock_page(page); 58480f792cf9SNaoya Horiguchi put_page(page); 5849cb900f41SKirill A. Shutemov out_ptl: 5850cb900f41SKirill A. Shutemov spin_unlock(ptl); 585157303d80SAndy Whitcroft 585257303d80SAndy Whitcroft if (pagecache_page) { 585357303d80SAndy Whitcroft unlock_page(pagecache_page); 585457303d80SAndy Whitcroft put_page(pagecache_page); 585557303d80SAndy Whitcroft } 5856b4d1d99fSDavid Gibson out_mutex: 5857c672c7f2SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5858c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 58590f792cf9SNaoya Horiguchi /* 58600f792cf9SNaoya Horiguchi * Generally it's safe to hold refcount during waiting page lock. But 58610f792cf9SNaoya Horiguchi * here we just wait to defer the next page fault to avoid busy loop and 58620f792cf9SNaoya Horiguchi * the page is not used after unlocked before returning from the current 58630f792cf9SNaoya Horiguchi * page fault. So we are safe from accessing freed page, even if we wait 58640f792cf9SNaoya Horiguchi * here without taking refcount. 58650f792cf9SNaoya Horiguchi */ 58660f792cf9SNaoya Horiguchi if (need_wait_lock) 58670f792cf9SNaoya Horiguchi wait_on_page_locked(page); 58681e8f889bSDavid Gibson return ret; 586986e5216fSAdam Litke } 587086e5216fSAdam Litke 5871714c1891SAxel Rasmussen #ifdef CONFIG_USERFAULTFD 58728fb5debcSMike Kravetz /* 58738fb5debcSMike Kravetz * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with 58748fb5debcSMike Kravetz * modifications for huge pages. 58758fb5debcSMike Kravetz */ 58768fb5debcSMike Kravetz int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, 58778fb5debcSMike Kravetz pte_t *dst_pte, 58788fb5debcSMike Kravetz struct vm_area_struct *dst_vma, 58798fb5debcSMike Kravetz unsigned long dst_addr, 58808fb5debcSMike Kravetz unsigned long src_addr, 5881f6191471SAxel Rasmussen enum mcopy_atomic_mode mode, 58826041c691SPeter Xu struct page **pagep, 58836041c691SPeter Xu bool wp_copy) 58848fb5debcSMike Kravetz { 5885f6191471SAxel Rasmussen bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE); 58868cc5fcbbSMina Almasry struct hstate *h = hstate_vma(dst_vma); 58878cc5fcbbSMina Almasry struct address_space *mapping = dst_vma->vm_file->f_mapping; 58888cc5fcbbSMina Almasry pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr); 58891e392147SAndrea Arcangeli unsigned long size; 58901c9e8defSMike Kravetz int vm_shared = dst_vma->vm_flags & VM_SHARED; 58918fb5debcSMike Kravetz pte_t _dst_pte; 58928fb5debcSMike Kravetz spinlock_t *ptl; 58938cc5fcbbSMina Almasry int ret = -ENOMEM; 58948fb5debcSMike Kravetz struct page *page; 5895f6191471SAxel Rasmussen int writable; 5896cc30042dSMina Almasry bool page_in_pagecache = false; 58978fb5debcSMike Kravetz 5898f6191471SAxel Rasmussen if (is_continue) { 5899f6191471SAxel Rasmussen ret = -EFAULT; 5900f6191471SAxel Rasmussen page = find_lock_page(mapping, idx); 5901f6191471SAxel Rasmussen if (!page) 5902f6191471SAxel Rasmussen goto out; 5903cc30042dSMina Almasry page_in_pagecache = true; 5904f6191471SAxel Rasmussen } else if (!*pagep) { 5905d84cf06eSMina Almasry /* If a page already exists, then it's UFFDIO_COPY for 5906d84cf06eSMina Almasry * a non-missing case. Return -EEXIST. 5907d84cf06eSMina Almasry */ 5908d84cf06eSMina Almasry if (vm_shared && 5909d84cf06eSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 5910d84cf06eSMina Almasry ret = -EEXIST; 59118fb5debcSMike Kravetz goto out; 5912d84cf06eSMina Almasry } 5913d84cf06eSMina Almasry 5914d84cf06eSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 5915d84cf06eSMina Almasry if (IS_ERR(page)) { 5916d84cf06eSMina Almasry ret = -ENOMEM; 5917d84cf06eSMina Almasry goto out; 5918d84cf06eSMina Almasry } 59198fb5debcSMike Kravetz 59208fb5debcSMike Kravetz ret = copy_huge_page_from_user(page, 59218fb5debcSMike Kravetz (const void __user *) src_addr, 5922810a56b9SMike Kravetz pages_per_huge_page(h), false); 59238fb5debcSMike Kravetz 5924c1e8d7c6SMichel Lespinasse /* fallback to copy_from_user outside mmap_lock */ 59258fb5debcSMike Kravetz if (unlikely(ret)) { 59269e368259SAndrea Arcangeli ret = -ENOENT; 59278cc5fcbbSMina Almasry /* Free the allocated page which may have 59288cc5fcbbSMina Almasry * consumed a reservation. 59298cc5fcbbSMina Almasry */ 59308cc5fcbbSMina Almasry restore_reserve_on_error(h, dst_vma, dst_addr, page); 59318cc5fcbbSMina Almasry put_page(page); 59328cc5fcbbSMina Almasry 59338cc5fcbbSMina Almasry /* Allocate a temporary page to hold the copied 59348cc5fcbbSMina Almasry * contents. 59358cc5fcbbSMina Almasry */ 59368cc5fcbbSMina Almasry page = alloc_huge_page_vma(h, dst_vma, dst_addr); 59378cc5fcbbSMina Almasry if (!page) { 59388cc5fcbbSMina Almasry ret = -ENOMEM; 59398cc5fcbbSMina Almasry goto out; 59408cc5fcbbSMina Almasry } 59418fb5debcSMike Kravetz *pagep = page; 59428cc5fcbbSMina Almasry /* Set the outparam pagep and return to the caller to 59438cc5fcbbSMina Almasry * copy the contents outside the lock. Don't free the 59448cc5fcbbSMina Almasry * page. 59458cc5fcbbSMina Almasry */ 59468fb5debcSMike Kravetz goto out; 59478fb5debcSMike Kravetz } 59488fb5debcSMike Kravetz } else { 59498cc5fcbbSMina Almasry if (vm_shared && 59508cc5fcbbSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 59518cc5fcbbSMina Almasry put_page(*pagep); 59528cc5fcbbSMina Almasry ret = -EEXIST; 59538cc5fcbbSMina Almasry *pagep = NULL; 59548cc5fcbbSMina Almasry goto out; 59558cc5fcbbSMina Almasry } 59568cc5fcbbSMina Almasry 59578cc5fcbbSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 59588cc5fcbbSMina Almasry if (IS_ERR(page)) { 59598cc5fcbbSMina Almasry ret = -ENOMEM; 59608cc5fcbbSMina Almasry *pagep = NULL; 59618cc5fcbbSMina Almasry goto out; 59628cc5fcbbSMina Almasry } 596334892366SMuchun Song copy_user_huge_page(page, *pagep, dst_addr, dst_vma, 596434892366SMuchun Song pages_per_huge_page(h)); 59658cc5fcbbSMina Almasry put_page(*pagep); 59668fb5debcSMike Kravetz *pagep = NULL; 59678fb5debcSMike Kravetz } 59688fb5debcSMike Kravetz 59698fb5debcSMike Kravetz /* 59708fb5debcSMike Kravetz * The memory barrier inside __SetPageUptodate makes sure that 59718fb5debcSMike Kravetz * preceding stores to the page contents become visible before 59728fb5debcSMike Kravetz * the set_pte_at() write. 59738fb5debcSMike Kravetz */ 59748fb5debcSMike Kravetz __SetPageUptodate(page); 59758fb5debcSMike Kravetz 5976f6191471SAxel Rasmussen /* Add shared, newly allocated pages to the page cache. */ 5977f6191471SAxel Rasmussen if (vm_shared && !is_continue) { 59781e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 59791e392147SAndrea Arcangeli ret = -EFAULT; 59801e392147SAndrea Arcangeli if (idx >= size) 59811e392147SAndrea Arcangeli goto out_release_nounlock; 59821c9e8defSMike Kravetz 59831e392147SAndrea Arcangeli /* 59841e392147SAndrea Arcangeli * Serialization between remove_inode_hugepages() and 59851e392147SAndrea Arcangeli * huge_add_to_page_cache() below happens through the 59861e392147SAndrea Arcangeli * hugetlb_fault_mutex_table that here must be hold by 59871e392147SAndrea Arcangeli * the caller. 59881e392147SAndrea Arcangeli */ 59891c9e8defSMike Kravetz ret = huge_add_to_page_cache(page, mapping, idx); 59901c9e8defSMike Kravetz if (ret) 59911c9e8defSMike Kravetz goto out_release_nounlock; 5992cc30042dSMina Almasry page_in_pagecache = true; 59931c9e8defSMike Kravetz } 59941c9e8defSMike Kravetz 59958fb5debcSMike Kravetz ptl = huge_pte_lockptr(h, dst_mm, dst_pte); 59968fb5debcSMike Kravetz spin_lock(ptl); 59978fb5debcSMike Kravetz 59981e392147SAndrea Arcangeli /* 59991e392147SAndrea Arcangeli * Recheck the i_size after holding PT lock to make sure not 60001e392147SAndrea Arcangeli * to leave any page mapped (as page_mapped()) beyond the end 60011e392147SAndrea Arcangeli * of the i_size (remove_inode_hugepages() is strict about 60021e392147SAndrea Arcangeli * enforcing that). If we bail out here, we'll also leave a 60031e392147SAndrea Arcangeli * page in the radix tree in the vm_shared case beyond the end 60041e392147SAndrea Arcangeli * of the i_size, but remove_inode_hugepages() will take care 60051e392147SAndrea Arcangeli * of it as soon as we drop the hugetlb_fault_mutex_table. 60061e392147SAndrea Arcangeli */ 60071e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 60081e392147SAndrea Arcangeli ret = -EFAULT; 60091e392147SAndrea Arcangeli if (idx >= size) 60101e392147SAndrea Arcangeli goto out_release_unlock; 60111e392147SAndrea Arcangeli 60128fb5debcSMike Kravetz ret = -EEXIST; 60136041c691SPeter Xu /* 60146041c691SPeter Xu * We allow to overwrite a pte marker: consider when both MISSING|WP 60156041c691SPeter Xu * registered, we firstly wr-protect a none pte which has no page cache 60166041c691SPeter Xu * page backing it, then access the page. 60176041c691SPeter Xu */ 60186041c691SPeter Xu if (!huge_pte_none_mostly(huge_ptep_get(dst_pte))) 60198fb5debcSMike Kravetz goto out_release_unlock; 60208fb5debcSMike Kravetz 60211c9e8defSMike Kravetz if (vm_shared) { 6022fb3d824dSDavid Hildenbrand page_dup_file_rmap(page, true); 60231c9e8defSMike Kravetz } else { 6024d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 60258fb5debcSMike Kravetz hugepage_add_new_anon_rmap(page, dst_vma, dst_addr); 60261c9e8defSMike Kravetz } 60278fb5debcSMike Kravetz 60286041c691SPeter Xu /* 60296041c691SPeter Xu * For either: (1) CONTINUE on a non-shared VMA, or (2) UFFDIO_COPY 60306041c691SPeter Xu * with wp flag set, don't set pte write bit. 60316041c691SPeter Xu */ 60326041c691SPeter Xu if (wp_copy || (is_continue && !vm_shared)) 6033f6191471SAxel Rasmussen writable = 0; 6034f6191471SAxel Rasmussen else 6035f6191471SAxel Rasmussen writable = dst_vma->vm_flags & VM_WRITE; 6036f6191471SAxel Rasmussen 6037f6191471SAxel Rasmussen _dst_pte = make_huge_pte(dst_vma, page, writable); 60386041c691SPeter Xu /* 60396041c691SPeter Xu * Always mark UFFDIO_COPY page dirty; note that this may not be 60406041c691SPeter Xu * extremely important for hugetlbfs for now since swapping is not 60416041c691SPeter Xu * supported, but we should still be clear in that this page cannot be 60426041c691SPeter Xu * thrown away at will, even if write bit not set. 60436041c691SPeter Xu */ 60448fb5debcSMike Kravetz _dst_pte = huge_pte_mkdirty(_dst_pte); 60458fb5debcSMike Kravetz _dst_pte = pte_mkyoung(_dst_pte); 60468fb5debcSMike Kravetz 60476041c691SPeter Xu if (wp_copy) 60486041c691SPeter Xu _dst_pte = huge_pte_mkuffd_wp(_dst_pte); 60496041c691SPeter Xu 60508fb5debcSMike Kravetz set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); 60518fb5debcSMike Kravetz 60528fb5debcSMike Kravetz hugetlb_count_add(pages_per_huge_page(h), dst_mm); 60538fb5debcSMike Kravetz 60548fb5debcSMike Kravetz /* No need to invalidate - it was non-present before */ 60558fb5debcSMike Kravetz update_mmu_cache(dst_vma, dst_addr, dst_pte); 60568fb5debcSMike Kravetz 60578fb5debcSMike Kravetz spin_unlock(ptl); 6058f6191471SAxel Rasmussen if (!is_continue) 60598f251a3dSMike Kravetz SetHPageMigratable(page); 6060f6191471SAxel Rasmussen if (vm_shared || is_continue) 60611c9e8defSMike Kravetz unlock_page(page); 60628fb5debcSMike Kravetz ret = 0; 60638fb5debcSMike Kravetz out: 60648fb5debcSMike Kravetz return ret; 60658fb5debcSMike Kravetz out_release_unlock: 60668fb5debcSMike Kravetz spin_unlock(ptl); 6067f6191471SAxel Rasmussen if (vm_shared || is_continue) 60681c9e8defSMike Kravetz unlock_page(page); 60695af10dfdSAndrea Arcangeli out_release_nounlock: 6070cc30042dSMina Almasry if (!page_in_pagecache) 6071846be085SMike Kravetz restore_reserve_on_error(h, dst_vma, dst_addr, page); 60728fb5debcSMike Kravetz put_page(page); 60738fb5debcSMike Kravetz goto out; 60748fb5debcSMike Kravetz } 6075714c1891SAxel Rasmussen #endif /* CONFIG_USERFAULTFD */ 60768fb5debcSMike Kravetz 607782e5d378SJoao Martins static void record_subpages_vmas(struct page *page, struct vm_area_struct *vma, 607882e5d378SJoao Martins int refs, struct page **pages, 607982e5d378SJoao Martins struct vm_area_struct **vmas) 608082e5d378SJoao Martins { 608182e5d378SJoao Martins int nr; 608282e5d378SJoao Martins 608382e5d378SJoao Martins for (nr = 0; nr < refs; nr++) { 608482e5d378SJoao Martins if (likely(pages)) 608582e5d378SJoao Martins pages[nr] = mem_map_offset(page, nr); 608682e5d378SJoao Martins if (vmas) 608782e5d378SJoao Martins vmas[nr] = vma; 608882e5d378SJoao Martins } 608982e5d378SJoao Martins } 609082e5d378SJoao Martins 6091a7f22660SDavid Hildenbrand static inline bool __follow_hugetlb_must_fault(unsigned int flags, pte_t *pte, 6092a7f22660SDavid Hildenbrand bool *unshare) 6093a7f22660SDavid Hildenbrand { 6094a7f22660SDavid Hildenbrand pte_t pteval = huge_ptep_get(pte); 6095a7f22660SDavid Hildenbrand 6096a7f22660SDavid Hildenbrand *unshare = false; 6097a7f22660SDavid Hildenbrand if (is_swap_pte(pteval)) 6098a7f22660SDavid Hildenbrand return true; 6099a7f22660SDavid Hildenbrand if (huge_pte_write(pteval)) 6100a7f22660SDavid Hildenbrand return false; 6101a7f22660SDavid Hildenbrand if (flags & FOLL_WRITE) 6102a7f22660SDavid Hildenbrand return true; 6103a7f22660SDavid Hildenbrand if (gup_must_unshare(flags, pte_page(pteval))) { 6104a7f22660SDavid Hildenbrand *unshare = true; 6105a7f22660SDavid Hildenbrand return true; 6106a7f22660SDavid Hildenbrand } 6107a7f22660SDavid Hildenbrand return false; 6108a7f22660SDavid Hildenbrand } 6109a7f22660SDavid Hildenbrand 611028a35716SMichel Lespinasse long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 611163551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 611228a35716SMichel Lespinasse unsigned long *position, unsigned long *nr_pages, 61134f6da934SPeter Xu long i, unsigned int flags, int *locked) 611463551ae0SDavid Gibson { 6115d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 6116d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 611728a35716SMichel Lespinasse unsigned long remainder = *nr_pages; 6118a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 61190fa5bc40SJoao Martins int err = -EFAULT, refs; 612063551ae0SDavid Gibson 612163551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 612263551ae0SDavid Gibson pte_t *pte; 6123cb900f41SKirill A. Shutemov spinlock_t *ptl = NULL; 6124a7f22660SDavid Hildenbrand bool unshare = false; 61252a15efc9SHugh Dickins int absent; 612663551ae0SDavid Gibson struct page *page; 612763551ae0SDavid Gibson 61284c887265SAdam Litke /* 612902057967SDavid Rientjes * If we have a pending SIGKILL, don't keep faulting pages and 613002057967SDavid Rientjes * potentially allocating memory. 613102057967SDavid Rientjes */ 6132fa45f116SDavidlohr Bueso if (fatal_signal_pending(current)) { 613302057967SDavid Rientjes remainder = 0; 613402057967SDavid Rientjes break; 613502057967SDavid Rientjes } 613602057967SDavid Rientjes 613702057967SDavid Rientjes /* 61384c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 61392a15efc9SHugh Dickins * each hugepage. We have to make sure we get the 61404c887265SAdam Litke * first, for the page indexing below to work. 6141cb900f41SKirill A. Shutemov * 6142cb900f41SKirill A. Shutemov * Note that page table lock is not held when pte is null. 61434c887265SAdam Litke */ 61447868a208SPunit Agrawal pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), 61457868a208SPunit Agrawal huge_page_size(h)); 6146cb900f41SKirill A. Shutemov if (pte) 6147cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, pte); 61482a15efc9SHugh Dickins absent = !pte || huge_pte_none(huge_ptep_get(pte)); 614963551ae0SDavid Gibson 61502a15efc9SHugh Dickins /* 61512a15efc9SHugh Dickins * When coredumping, it suits get_dump_page if we just return 61523ae77f43SHugh Dickins * an error where there's an empty slot with no huge pagecache 61533ae77f43SHugh Dickins * to back it. This way, we avoid allocating a hugepage, and 61543ae77f43SHugh Dickins * the sparse dumpfile avoids allocating disk blocks, but its 61553ae77f43SHugh Dickins * huge holes still show up with zeroes where they need to be. 61562a15efc9SHugh Dickins */ 61573ae77f43SHugh Dickins if (absent && (flags & FOLL_DUMP) && 61583ae77f43SHugh Dickins !hugetlbfs_pagecache_present(h, vma, vaddr)) { 6159cb900f41SKirill A. Shutemov if (pte) 6160cb900f41SKirill A. Shutemov spin_unlock(ptl); 61612a15efc9SHugh Dickins remainder = 0; 61622a15efc9SHugh Dickins break; 61632a15efc9SHugh Dickins } 61642a15efc9SHugh Dickins 61659cc3a5bdSNaoya Horiguchi /* 61669cc3a5bdSNaoya Horiguchi * We need call hugetlb_fault for both hugepages under migration 61679cc3a5bdSNaoya Horiguchi * (in which case hugetlb_fault waits for the migration,) and 61689cc3a5bdSNaoya Horiguchi * hwpoisoned hugepages (in which case we need to prevent the 61699cc3a5bdSNaoya Horiguchi * caller from accessing to them.) In order to do this, we use 61709cc3a5bdSNaoya Horiguchi * here is_swap_pte instead of is_hugetlb_entry_migration and 61719cc3a5bdSNaoya Horiguchi * is_hugetlb_entry_hwpoisoned. This is because it simply covers 61729cc3a5bdSNaoya Horiguchi * both cases, and because we can't follow correct pages 61739cc3a5bdSNaoya Horiguchi * directly from any kind of swap entries. 61749cc3a5bdSNaoya Horiguchi */ 6175a7f22660SDavid Hildenbrand if (absent || 6176a7f22660SDavid Hildenbrand __follow_hugetlb_must_fault(flags, pte, &unshare)) { 61772b740303SSouptick Joarder vm_fault_t ret; 617887ffc118SAndrea Arcangeli unsigned int fault_flags = 0; 61794c887265SAdam Litke 6180cb900f41SKirill A. Shutemov if (pte) 6181cb900f41SKirill A. Shutemov spin_unlock(ptl); 618287ffc118SAndrea Arcangeli if (flags & FOLL_WRITE) 618387ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_WRITE; 6184a7f22660SDavid Hildenbrand else if (unshare) 6185a7f22660SDavid Hildenbrand fault_flags |= FAULT_FLAG_UNSHARE; 61864f6da934SPeter Xu if (locked) 618771335f37SPeter Xu fault_flags |= FAULT_FLAG_ALLOW_RETRY | 618871335f37SPeter Xu FAULT_FLAG_KILLABLE; 618987ffc118SAndrea Arcangeli if (flags & FOLL_NOWAIT) 619087ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_ALLOW_RETRY | 619187ffc118SAndrea Arcangeli FAULT_FLAG_RETRY_NOWAIT; 619287ffc118SAndrea Arcangeli if (flags & FOLL_TRIED) { 61934426e945SPeter Xu /* 61944426e945SPeter Xu * Note: FAULT_FLAG_ALLOW_RETRY and 61954426e945SPeter Xu * FAULT_FLAG_TRIED can co-exist 61964426e945SPeter Xu */ 619787ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_TRIED; 619887ffc118SAndrea Arcangeli } 619987ffc118SAndrea Arcangeli ret = hugetlb_fault(mm, vma, vaddr, fault_flags); 620087ffc118SAndrea Arcangeli if (ret & VM_FAULT_ERROR) { 62012be7cfedSDaniel Jordan err = vm_fault_to_errno(ret, flags); 62021c59827dSHugh Dickins remainder = 0; 62031c59827dSHugh Dickins break; 62041c59827dSHugh Dickins } 620587ffc118SAndrea Arcangeli if (ret & VM_FAULT_RETRY) { 62064f6da934SPeter Xu if (locked && 62071ac25013SAndrea Arcangeli !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) 62084f6da934SPeter Xu *locked = 0; 620987ffc118SAndrea Arcangeli *nr_pages = 0; 621087ffc118SAndrea Arcangeli /* 621187ffc118SAndrea Arcangeli * VM_FAULT_RETRY must not return an 621287ffc118SAndrea Arcangeli * error, it will return zero 621387ffc118SAndrea Arcangeli * instead. 621487ffc118SAndrea Arcangeli * 621587ffc118SAndrea Arcangeli * No need to update "position" as the 621687ffc118SAndrea Arcangeli * caller will not check it after 621787ffc118SAndrea Arcangeli * *nr_pages is set to 0. 621887ffc118SAndrea Arcangeli */ 621987ffc118SAndrea Arcangeli return i; 622087ffc118SAndrea Arcangeli } 622187ffc118SAndrea Arcangeli continue; 622287ffc118SAndrea Arcangeli } 622363551ae0SDavid Gibson 6224a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 62257f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 62268fde12caSLinus Torvalds 6227b6a2619cSDavid Hildenbrand VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) && 6228b6a2619cSDavid Hildenbrand !PageAnonExclusive(page), page); 6229b6a2619cSDavid Hildenbrand 62308fde12caSLinus Torvalds /* 6231acbfb087SZhigang Lu * If subpage information not requested, update counters 6232acbfb087SZhigang Lu * and skip the same_page loop below. 6233acbfb087SZhigang Lu */ 6234acbfb087SZhigang Lu if (!pages && !vmas && !pfn_offset && 6235acbfb087SZhigang Lu (vaddr + huge_page_size(h) < vma->vm_end) && 6236acbfb087SZhigang Lu (remainder >= pages_per_huge_page(h))) { 6237acbfb087SZhigang Lu vaddr += huge_page_size(h); 6238acbfb087SZhigang Lu remainder -= pages_per_huge_page(h); 6239acbfb087SZhigang Lu i += pages_per_huge_page(h); 6240acbfb087SZhigang Lu spin_unlock(ptl); 6241acbfb087SZhigang Lu continue; 6242acbfb087SZhigang Lu } 6243acbfb087SZhigang Lu 6244d08af0a5SJoao Martins /* vaddr may not be aligned to PAGE_SIZE */ 6245d08af0a5SJoao Martins refs = min3(pages_per_huge_page(h) - pfn_offset, remainder, 6246d08af0a5SJoao Martins (vma->vm_end - ALIGN_DOWN(vaddr, PAGE_SIZE)) >> PAGE_SHIFT); 62470fa5bc40SJoao Martins 624882e5d378SJoao Martins if (pages || vmas) 624982e5d378SJoao Martins record_subpages_vmas(mem_map_offset(page, pfn_offset), 625082e5d378SJoao Martins vma, refs, 625182e5d378SJoao Martins likely(pages) ? pages + i : NULL, 625282e5d378SJoao Martins vmas ? vmas + i : NULL); 625363551ae0SDavid Gibson 625482e5d378SJoao Martins if (pages) { 62550fa5bc40SJoao Martins /* 6256822951d8SMatthew Wilcox (Oracle) * try_grab_folio() should always succeed here, 62570fa5bc40SJoao Martins * because: a) we hold the ptl lock, and b) we've just 62580fa5bc40SJoao Martins * checked that the huge page is present in the page 62590fa5bc40SJoao Martins * tables. If the huge page is present, then the tail 62600fa5bc40SJoao Martins * pages must also be present. The ptl prevents the 62610fa5bc40SJoao Martins * head page and tail pages from being rearranged in 62620fa5bc40SJoao Martins * any way. So this page must be available at this 62630fa5bc40SJoao Martins * point, unless the page refcount overflowed: 62640fa5bc40SJoao Martins */ 6265822951d8SMatthew Wilcox (Oracle) if (WARN_ON_ONCE(!try_grab_folio(pages[i], refs, 62660fa5bc40SJoao Martins flags))) { 62670fa5bc40SJoao Martins spin_unlock(ptl); 62680fa5bc40SJoao Martins remainder = 0; 62690fa5bc40SJoao Martins err = -ENOMEM; 62700fa5bc40SJoao Martins break; 62710fa5bc40SJoao Martins } 6272d5d4b0aaSChen, Kenneth W } 627382e5d378SJoao Martins 627482e5d378SJoao Martins vaddr += (refs << PAGE_SHIFT); 627582e5d378SJoao Martins remainder -= refs; 627682e5d378SJoao Martins i += refs; 627782e5d378SJoao Martins 6278cb900f41SKirill A. Shutemov spin_unlock(ptl); 627963551ae0SDavid Gibson } 628028a35716SMichel Lespinasse *nr_pages = remainder; 628187ffc118SAndrea Arcangeli /* 628287ffc118SAndrea Arcangeli * setting position is actually required only if remainder is 628387ffc118SAndrea Arcangeli * not zero but it's faster not to add a "if (remainder)" 628487ffc118SAndrea Arcangeli * branch. 628587ffc118SAndrea Arcangeli */ 628663551ae0SDavid Gibson *position = vaddr; 628763551ae0SDavid Gibson 62882be7cfedSDaniel Jordan return i ? i : err; 628963551ae0SDavid Gibson } 62908f860591SZhang, Yanmin 62917da4d641SPeter Zijlstra unsigned long hugetlb_change_protection(struct vm_area_struct *vma, 62925a90d5a1SPeter Xu unsigned long address, unsigned long end, 62935a90d5a1SPeter Xu pgprot_t newprot, unsigned long cp_flags) 62948f860591SZhang, Yanmin { 62958f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 62968f860591SZhang, Yanmin unsigned long start = address; 62978f860591SZhang, Yanmin pte_t *ptep; 62988f860591SZhang, Yanmin pte_t pte; 6299a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 630060dfaad6SPeter Xu unsigned long pages = 0, psize = huge_page_size(h); 6301dff11abeSMike Kravetz bool shared_pmd = false; 6302ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 6303*e95a9851SMike Kravetz unsigned long last_addr_mask; 63045a90d5a1SPeter Xu bool uffd_wp = cp_flags & MM_CP_UFFD_WP; 63055a90d5a1SPeter Xu bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE; 6306dff11abeSMike Kravetz 6307dff11abeSMike Kravetz /* 6308dff11abeSMike Kravetz * In the case of shared PMDs, the area to flush could be beyond 6309ac46d4f3SJérôme Glisse * start/end. Set range.start/range.end to cover the maximum possible 6310dff11abeSMike Kravetz * range if PMD sharing is possible. 6311dff11abeSMike Kravetz */ 63127269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 63137269f999SJérôme Glisse 0, vma, mm, start, end); 6314ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 63158f860591SZhang, Yanmin 63168f860591SZhang, Yanmin BUG_ON(address >= end); 6317ac46d4f3SJérôme Glisse flush_cache_range(vma, range.start, range.end); 63188f860591SZhang, Yanmin 6319ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 6320*e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 632183cde9e8SDavidlohr Bueso i_mmap_lock_write(vma->vm_file->f_mapping); 632260dfaad6SPeter Xu for (; address < end; address += psize) { 6323cb900f41SKirill A. Shutemov spinlock_t *ptl; 632460dfaad6SPeter Xu ptep = huge_pte_offset(mm, address, psize); 6325*e95a9851SMike Kravetz if (!ptep) { 6326*e95a9851SMike Kravetz address |= last_addr_mask; 63278f860591SZhang, Yanmin continue; 6328*e95a9851SMike Kravetz } 6329cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 633034ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 633160dfaad6SPeter Xu /* 633260dfaad6SPeter Xu * When uffd-wp is enabled on the vma, unshare 633360dfaad6SPeter Xu * shouldn't happen at all. Warn about it if it 633460dfaad6SPeter Xu * happened due to some reason. 633560dfaad6SPeter Xu */ 633660dfaad6SPeter Xu WARN_ON_ONCE(uffd_wp || uffd_wp_resolve); 63377da4d641SPeter Zijlstra pages++; 6338cb900f41SKirill A. Shutemov spin_unlock(ptl); 6339dff11abeSMike Kravetz shared_pmd = true; 634039dde65cSChen, Kenneth W continue; 63417da4d641SPeter Zijlstra } 6342a8bda28dSNaoya Horiguchi pte = huge_ptep_get(ptep); 6343a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { 6344a8bda28dSNaoya Horiguchi spin_unlock(ptl); 6345a8bda28dSNaoya Horiguchi continue; 6346a8bda28dSNaoya Horiguchi } 6347a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(pte))) { 6348a8bda28dSNaoya Horiguchi swp_entry_t entry = pte_to_swp_entry(pte); 63496c287605SDavid Hildenbrand struct page *page = pfn_swap_entry_to_page(entry); 6350a8bda28dSNaoya Horiguchi 63516c287605SDavid Hildenbrand if (!is_readable_migration_entry(entry)) { 6352a8bda28dSNaoya Horiguchi pte_t newpte; 6353a8bda28dSNaoya Horiguchi 63546c287605SDavid Hildenbrand if (PageAnon(page)) 63556c287605SDavid Hildenbrand entry = make_readable_exclusive_migration_entry( 63566c287605SDavid Hildenbrand swp_offset(entry)); 63576c287605SDavid Hildenbrand else 63584dd845b5SAlistair Popple entry = make_readable_migration_entry( 63594dd845b5SAlistair Popple swp_offset(entry)); 6360a8bda28dSNaoya Horiguchi newpte = swp_entry_to_pte(entry); 63615a90d5a1SPeter Xu if (uffd_wp) 63625a90d5a1SPeter Xu newpte = pte_swp_mkuffd_wp(newpte); 63635a90d5a1SPeter Xu else if (uffd_wp_resolve) 63645a90d5a1SPeter Xu newpte = pte_swp_clear_uffd_wp(newpte); 636518f39629SQi Zheng set_huge_pte_at(mm, address, ptep, newpte); 6366a8bda28dSNaoya Horiguchi pages++; 6367a8bda28dSNaoya Horiguchi } 6368a8bda28dSNaoya Horiguchi spin_unlock(ptl); 6369a8bda28dSNaoya Horiguchi continue; 6370a8bda28dSNaoya Horiguchi } 637160dfaad6SPeter Xu if (unlikely(pte_marker_uffd_wp(pte))) { 637260dfaad6SPeter Xu /* 637360dfaad6SPeter Xu * This is changing a non-present pte into a none pte, 637460dfaad6SPeter Xu * no need for huge_ptep_modify_prot_start/commit(). 637560dfaad6SPeter Xu */ 637660dfaad6SPeter Xu if (uffd_wp_resolve) 637760dfaad6SPeter Xu huge_pte_clear(mm, address, ptep, psize); 637860dfaad6SPeter Xu } 6379a8bda28dSNaoya Horiguchi if (!huge_pte_none(pte)) { 6380023bdd00SAneesh Kumar K.V pte_t old_pte; 638179c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 6382023bdd00SAneesh Kumar K.V 6383023bdd00SAneesh Kumar K.V old_pte = huge_ptep_modify_prot_start(vma, address, ptep); 638416785bd7SAnshuman Khandual pte = huge_pte_modify(old_pte, newprot); 638579c1c594SChristophe Leroy pte = arch_make_huge_pte(pte, shift, vma->vm_flags); 63865a90d5a1SPeter Xu if (uffd_wp) 63875a90d5a1SPeter Xu pte = huge_pte_mkuffd_wp(huge_pte_wrprotect(pte)); 63885a90d5a1SPeter Xu else if (uffd_wp_resolve) 63895a90d5a1SPeter Xu pte = huge_pte_clear_uffd_wp(pte); 6390023bdd00SAneesh Kumar K.V huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); 63917da4d641SPeter Zijlstra pages++; 639260dfaad6SPeter Xu } else { 639360dfaad6SPeter Xu /* None pte */ 639460dfaad6SPeter Xu if (unlikely(uffd_wp)) 639560dfaad6SPeter Xu /* Safe to modify directly (none->non-present). */ 639660dfaad6SPeter Xu set_huge_pte_at(mm, address, ptep, 639760dfaad6SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 63988f860591SZhang, Yanmin } 6399cb900f41SKirill A. Shutemov spin_unlock(ptl); 64008f860591SZhang, Yanmin } 6401d833352aSMel Gorman /* 6402c8c06efaSDavidlohr Bueso * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare 6403d833352aSMel Gorman * may have cleared our pud entry and done put_page on the page table: 6404c8c06efaSDavidlohr Bueso * once we release i_mmap_rwsem, another task can do the final put_page 6405dff11abeSMike Kravetz * and that page table be reused and filled with junk. If we actually 6406dff11abeSMike Kravetz * did unshare a page of pmds, flush the range corresponding to the pud. 6407d833352aSMel Gorman */ 6408dff11abeSMike Kravetz if (shared_pmd) 6409ac46d4f3SJérôme Glisse flush_hugetlb_tlb_range(vma, range.start, range.end); 6410dff11abeSMike Kravetz else 64115491ae7bSAneesh Kumar K.V flush_hugetlb_tlb_range(vma, start, end); 64120f10851eSJérôme Glisse /* 64130f10851eSJérôme Glisse * No need to call mmu_notifier_invalidate_range() we are downgrading 64140f10851eSJérôme Glisse * page table protection not changing it to point to a new page. 64150f10851eSJérôme Glisse * 6416ee65728eSMike Rapoport * See Documentation/mm/mmu_notifier.rst 64170f10851eSJérôme Glisse */ 641883cde9e8SDavidlohr Bueso i_mmap_unlock_write(vma->vm_file->f_mapping); 6419ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 64207da4d641SPeter Zijlstra 64217da4d641SPeter Zijlstra return pages << h->order; 64228f860591SZhang, Yanmin } 64238f860591SZhang, Yanmin 642433b8f84aSMike Kravetz /* Return true if reservation was successful, false otherwise. */ 642533b8f84aSMike Kravetz bool hugetlb_reserve_pages(struct inode *inode, 6426a1e78772SMel Gorman long from, long to, 64275a6fe125SMel Gorman struct vm_area_struct *vma, 6428ca16d140SKOSAKI Motohiro vm_flags_t vm_flags) 6429e4e574b7SAdam Litke { 643033b8f84aSMike Kravetz long chg, add = -1; 6431a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 643290481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 64339119a41eSJoonsoo Kim struct resv_map *resv_map; 6434075a61d0SMina Almasry struct hugetlb_cgroup *h_cg = NULL; 64350db9d74eSMina Almasry long gbl_reserve, regions_needed = 0; 6436e4e574b7SAdam Litke 643763489f8eSMike Kravetz /* This should never happen */ 643863489f8eSMike Kravetz if (from > to) { 643963489f8eSMike Kravetz VM_WARN(1, "%s called with a negative range\n", __func__); 644033b8f84aSMike Kravetz return false; 644163489f8eSMike Kravetz } 644263489f8eSMike Kravetz 6443a1e78772SMel Gorman /* 644417c9d12eSMel Gorman * Only apply hugepage reservation if asked. At fault time, an 644517c9d12eSMel Gorman * attempt will be made for VM_NORESERVE to allocate a page 644690481622SDavid Gibson * without using reserves 644717c9d12eSMel Gorman */ 6448ca16d140SKOSAKI Motohiro if (vm_flags & VM_NORESERVE) 644933b8f84aSMike Kravetz return true; 645017c9d12eSMel Gorman 645117c9d12eSMel Gorman /* 6452a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 6453a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 6454a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 6455a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 6456a1e78772SMel Gorman */ 64579119a41eSJoonsoo Kim if (!vma || vma->vm_flags & VM_MAYSHARE) { 6458f27a5136SMike Kravetz /* 6459f27a5136SMike Kravetz * resv_map can not be NULL as hugetlb_reserve_pages is only 6460f27a5136SMike Kravetz * called for inodes for which resv_maps were created (see 6461f27a5136SMike Kravetz * hugetlbfs_get_inode). 6462f27a5136SMike Kravetz */ 64634e35f483SJoonsoo Kim resv_map = inode_resv_map(inode); 64649119a41eSJoonsoo Kim 64650db9d74eSMina Almasry chg = region_chg(resv_map, from, to, ®ions_needed); 64669119a41eSJoonsoo Kim 64679119a41eSJoonsoo Kim } else { 6468e9fe92aeSMina Almasry /* Private mapping. */ 64699119a41eSJoonsoo Kim resv_map = resv_map_alloc(); 64705a6fe125SMel Gorman if (!resv_map) 647133b8f84aSMike Kravetz return false; 64725a6fe125SMel Gorman 647317c9d12eSMel Gorman chg = to - from; 647417c9d12eSMel Gorman 64755a6fe125SMel Gorman set_vma_resv_map(vma, resv_map); 64765a6fe125SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 64775a6fe125SMel Gorman } 64785a6fe125SMel Gorman 647933b8f84aSMike Kravetz if (chg < 0) 6480c50ac050SDave Hansen goto out_err; 648117c9d12eSMel Gorman 648233b8f84aSMike Kravetz if (hugetlb_cgroup_charge_cgroup_rsvd(hstate_index(h), 648333b8f84aSMike Kravetz chg * pages_per_huge_page(h), &h_cg) < 0) 6484075a61d0SMina Almasry goto out_err; 6485075a61d0SMina Almasry 6486075a61d0SMina Almasry if (vma && !(vma->vm_flags & VM_MAYSHARE) && h_cg) { 6487075a61d0SMina Almasry /* For private mappings, the hugetlb_cgroup uncharge info hangs 6488075a61d0SMina Almasry * of the resv_map. 6489075a61d0SMina Almasry */ 6490075a61d0SMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h); 6491075a61d0SMina Almasry } 6492075a61d0SMina Almasry 64931c5ecae3SMike Kravetz /* 64941c5ecae3SMike Kravetz * There must be enough pages in the subpool for the mapping. If 64951c5ecae3SMike Kravetz * the subpool has a minimum size, there may be some global 64961c5ecae3SMike Kravetz * reservations already in place (gbl_reserve). 64971c5ecae3SMike Kravetz */ 64981c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_get_pages(spool, chg); 649933b8f84aSMike Kravetz if (gbl_reserve < 0) 6500075a61d0SMina Almasry goto out_uncharge_cgroup; 650117c9d12eSMel Gorman 650217c9d12eSMel Gorman /* 650317c9d12eSMel Gorman * Check enough hugepages are available for the reservation. 650490481622SDavid Gibson * Hand the pages back to the subpool if there are not 650517c9d12eSMel Gorman */ 650633b8f84aSMike Kravetz if (hugetlb_acct_memory(h, gbl_reserve) < 0) 6507075a61d0SMina Almasry goto out_put_pages; 650817c9d12eSMel Gorman 650917c9d12eSMel Gorman /* 651017c9d12eSMel Gorman * Account for the reservations made. Shared mappings record regions 651117c9d12eSMel Gorman * that have reservations as they are shared by multiple VMAs. 651217c9d12eSMel Gorman * When the last VMA disappears, the region map says how much 651317c9d12eSMel Gorman * the reservation was and the page cache tells how much of 651417c9d12eSMel Gorman * the reservation was consumed. Private mappings are per-VMA and 651517c9d12eSMel Gorman * only the consumed reservations are tracked. When the VMA 651617c9d12eSMel Gorman * disappears, the original reservation is the VMA size and the 651717c9d12eSMel Gorman * consumed reservations are stored in the map. Hence, nothing 651817c9d12eSMel Gorman * else has to be done for private mappings here 651917c9d12eSMel Gorman */ 652033039678SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) { 6521075a61d0SMina Almasry add = region_add(resv_map, from, to, regions_needed, h, h_cg); 652233039678SMike Kravetz 65230db9d74eSMina Almasry if (unlikely(add < 0)) { 65240db9d74eSMina Almasry hugetlb_acct_memory(h, -gbl_reserve); 6525075a61d0SMina Almasry goto out_put_pages; 65260db9d74eSMina Almasry } else if (unlikely(chg > add)) { 652733039678SMike Kravetz /* 652833039678SMike Kravetz * pages in this range were added to the reserve 652933039678SMike Kravetz * map between region_chg and region_add. This 653033039678SMike Kravetz * indicates a race with alloc_huge_page. Adjust 653133039678SMike Kravetz * the subpool and reserve counts modified above 653233039678SMike Kravetz * based on the difference. 653333039678SMike Kravetz */ 653433039678SMike Kravetz long rsv_adjust; 653533039678SMike Kravetz 6536d85aecf2SMiaohe Lin /* 6537d85aecf2SMiaohe Lin * hugetlb_cgroup_uncharge_cgroup_rsvd() will put the 6538d85aecf2SMiaohe Lin * reference to h_cg->css. See comment below for detail. 6539d85aecf2SMiaohe Lin */ 6540075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd( 6541075a61d0SMina Almasry hstate_index(h), 6542075a61d0SMina Almasry (chg - add) * pages_per_huge_page(h), h_cg); 6543075a61d0SMina Almasry 654433039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 654533039678SMike Kravetz chg - add); 654633039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 6547d85aecf2SMiaohe Lin } else if (h_cg) { 6548d85aecf2SMiaohe Lin /* 6549d85aecf2SMiaohe Lin * The file_regions will hold their own reference to 6550d85aecf2SMiaohe Lin * h_cg->css. So we should release the reference held 6551d85aecf2SMiaohe Lin * via hugetlb_cgroup_charge_cgroup_rsvd() when we are 6552d85aecf2SMiaohe Lin * done. 6553d85aecf2SMiaohe Lin */ 6554d85aecf2SMiaohe Lin hugetlb_cgroup_put_rsvd_cgroup(h_cg); 655533039678SMike Kravetz } 655633039678SMike Kravetz } 655733b8f84aSMike Kravetz return true; 655833b8f84aSMike Kravetz 6559075a61d0SMina Almasry out_put_pages: 6560075a61d0SMina Almasry /* put back original number of pages, chg */ 6561075a61d0SMina Almasry (void)hugepage_subpool_put_pages(spool, chg); 6562075a61d0SMina Almasry out_uncharge_cgroup: 6563075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h), 6564075a61d0SMina Almasry chg * pages_per_huge_page(h), h_cg); 6565c50ac050SDave Hansen out_err: 65665e911373SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) 65670db9d74eSMina Almasry /* Only call region_abort if the region_chg succeeded but the 65680db9d74eSMina Almasry * region_add failed or didn't run. 65690db9d74eSMina Almasry */ 65700db9d74eSMina Almasry if (chg >= 0 && add < 0) 65710db9d74eSMina Almasry region_abort(resv_map, from, to, regions_needed); 6572f031dd27SJoonsoo Kim if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 6573f031dd27SJoonsoo Kim kref_put(&resv_map->refs, resv_map_release); 657433b8f84aSMike Kravetz return false; 6575a43a8c39SChen, Kenneth W } 6576a43a8c39SChen, Kenneth W 6577b5cec28dSMike Kravetz long hugetlb_unreserve_pages(struct inode *inode, long start, long end, 6578b5cec28dSMike Kravetz long freed) 6579a43a8c39SChen, Kenneth W { 6580a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 65814e35f483SJoonsoo Kim struct resv_map *resv_map = inode_resv_map(inode); 65829119a41eSJoonsoo Kim long chg = 0; 658390481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 65841c5ecae3SMike Kravetz long gbl_reserve; 658545c682a6SKen Chen 6586f27a5136SMike Kravetz /* 6587f27a5136SMike Kravetz * Since this routine can be called in the evict inode path for all 6588f27a5136SMike Kravetz * hugetlbfs inodes, resv_map could be NULL. 6589f27a5136SMike Kravetz */ 6590b5cec28dSMike Kravetz if (resv_map) { 6591b5cec28dSMike Kravetz chg = region_del(resv_map, start, end); 6592b5cec28dSMike Kravetz /* 6593b5cec28dSMike Kravetz * region_del() can fail in the rare case where a region 6594b5cec28dSMike Kravetz * must be split and another region descriptor can not be 6595b5cec28dSMike Kravetz * allocated. If end == LONG_MAX, it will not fail. 6596b5cec28dSMike Kravetz */ 6597b5cec28dSMike Kravetz if (chg < 0) 6598b5cec28dSMike Kravetz return chg; 6599b5cec28dSMike Kravetz } 6600b5cec28dSMike Kravetz 660145c682a6SKen Chen spin_lock(&inode->i_lock); 6602e4c6f8beSEric Sandeen inode->i_blocks -= (blocks_per_huge_page(h) * freed); 660345c682a6SKen Chen spin_unlock(&inode->i_lock); 660445c682a6SKen Chen 66051c5ecae3SMike Kravetz /* 66061c5ecae3SMike Kravetz * If the subpool has a minimum size, the number of global 66071c5ecae3SMike Kravetz * reservations to be released may be adjusted. 6608dddf31a4SMiaohe Lin * 6609dddf31a4SMiaohe Lin * Note that !resv_map implies freed == 0. So (chg - freed) 6610dddf31a4SMiaohe Lin * won't go negative. 66111c5ecae3SMike Kravetz */ 66121c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed)); 66131c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 6614b5cec28dSMike Kravetz 6615b5cec28dSMike Kravetz return 0; 6616a43a8c39SChen, Kenneth W } 661793f70f90SNaoya Horiguchi 66183212b535SSteve Capper #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 66193212b535SSteve Capper static unsigned long page_table_shareable(struct vm_area_struct *svma, 66203212b535SSteve Capper struct vm_area_struct *vma, 66213212b535SSteve Capper unsigned long addr, pgoff_t idx) 66223212b535SSteve Capper { 66233212b535SSteve Capper unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + 66243212b535SSteve Capper svma->vm_start; 66253212b535SSteve Capper unsigned long sbase = saddr & PUD_MASK; 66263212b535SSteve Capper unsigned long s_end = sbase + PUD_SIZE; 66273212b535SSteve Capper 66283212b535SSteve Capper /* Allow segments to share if only one is marked locked */ 6629de60f5f1SEric B Munson unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; 6630de60f5f1SEric B Munson unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK; 66313212b535SSteve Capper 66323212b535SSteve Capper /* 66333212b535SSteve Capper * match the virtual addresses, permission and the alignment of the 66343212b535SSteve Capper * page table page. 66353212b535SSteve Capper */ 66363212b535SSteve Capper if (pmd_index(addr) != pmd_index(saddr) || 66373212b535SSteve Capper vm_flags != svm_flags || 663807e51edfSMiaohe Lin !range_in_vma(svma, sbase, s_end)) 66393212b535SSteve Capper return 0; 66403212b535SSteve Capper 66413212b535SSteve Capper return saddr; 66423212b535SSteve Capper } 66433212b535SSteve Capper 664431aafb45SNicholas Krause static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr) 66453212b535SSteve Capper { 66463212b535SSteve Capper unsigned long base = addr & PUD_MASK; 66473212b535SSteve Capper unsigned long end = base + PUD_SIZE; 66483212b535SSteve Capper 66493212b535SSteve Capper /* 66503212b535SSteve Capper * check on proper vm_flags and page table alignment 66513212b535SSteve Capper */ 6652017b1660SMike Kravetz if (vma->vm_flags & VM_MAYSHARE && range_in_vma(vma, base, end)) 665331aafb45SNicholas Krause return true; 665431aafb45SNicholas Krause return false; 66553212b535SSteve Capper } 66563212b535SSteve Capper 6657c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 6658c1991e07SPeter Xu { 6659c1991e07SPeter Xu #ifdef CONFIG_USERFAULTFD 6660c1991e07SPeter Xu if (uffd_disable_huge_pmd_share(vma)) 6661c1991e07SPeter Xu return false; 6662c1991e07SPeter Xu #endif 6663c1991e07SPeter Xu return vma_shareable(vma, addr); 6664c1991e07SPeter Xu } 6665c1991e07SPeter Xu 66663212b535SSteve Capper /* 6667017b1660SMike Kravetz * Determine if start,end range within vma could be mapped by shared pmd. 6668017b1660SMike Kravetz * If yes, adjust start and end to cover range associated with possible 6669017b1660SMike Kravetz * shared pmd mappings. 6670017b1660SMike Kravetz */ 6671017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 6672017b1660SMike Kravetz unsigned long *start, unsigned long *end) 6673017b1660SMike Kravetz { 6674a1ba9da8SLi Xinhai unsigned long v_start = ALIGN(vma->vm_start, PUD_SIZE), 6675a1ba9da8SLi Xinhai v_end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 6676017b1660SMike Kravetz 6677a1ba9da8SLi Xinhai /* 6678f0953a1bSIngo Molnar * vma needs to span at least one aligned PUD size, and the range 6679f0953a1bSIngo Molnar * must be at least partially within in. 6680a1ba9da8SLi Xinhai */ 6681a1ba9da8SLi Xinhai if (!(vma->vm_flags & VM_MAYSHARE) || !(v_end > v_start) || 6682a1ba9da8SLi Xinhai (*end <= v_start) || (*start >= v_end)) 6683017b1660SMike Kravetz return; 6684017b1660SMike Kravetz 668575802ca6SPeter Xu /* Extend the range to be PUD aligned for a worst case scenario */ 6686a1ba9da8SLi Xinhai if (*start > v_start) 6687a1ba9da8SLi Xinhai *start = ALIGN_DOWN(*start, PUD_SIZE); 6688017b1660SMike Kravetz 6689a1ba9da8SLi Xinhai if (*end < v_end) 6690a1ba9da8SLi Xinhai *end = ALIGN(*end, PUD_SIZE); 6691017b1660SMike Kravetz } 6692017b1660SMike Kravetz 6693017b1660SMike Kravetz /* 66943212b535SSteve Capper * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() 66953212b535SSteve Capper * and returns the corresponding pte. While this is not necessary for the 66963212b535SSteve Capper * !shared pmd case because we can allocate the pmd later as well, it makes the 6697c0d0381aSMike Kravetz * code much cleaner. 6698c0d0381aSMike Kravetz * 66990bf7b64eSMike Kravetz * This routine must be called with i_mmap_rwsem held in at least read mode if 67000bf7b64eSMike Kravetz * sharing is possible. For hugetlbfs, this prevents removal of any page 67010bf7b64eSMike Kravetz * table entries associated with the address space. This is important as we 67020bf7b64eSMike Kravetz * are setting up sharing based on existing page table entries (mappings). 67033212b535SSteve Capper */ 6704aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 6705aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 67063212b535SSteve Capper { 67073212b535SSteve Capper struct address_space *mapping = vma->vm_file->f_mapping; 67083212b535SSteve Capper pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + 67093212b535SSteve Capper vma->vm_pgoff; 67103212b535SSteve Capper struct vm_area_struct *svma; 67113212b535SSteve Capper unsigned long saddr; 67123212b535SSteve Capper pte_t *spte = NULL; 67133212b535SSteve Capper pte_t *pte; 6714cb900f41SKirill A. Shutemov spinlock_t *ptl; 67153212b535SSteve Capper 67160bf7b64eSMike Kravetz i_mmap_assert_locked(mapping); 67173212b535SSteve Capper vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { 67183212b535SSteve Capper if (svma == vma) 67193212b535SSteve Capper continue; 67203212b535SSteve Capper 67213212b535SSteve Capper saddr = page_table_shareable(svma, vma, addr, idx); 67223212b535SSteve Capper if (saddr) { 67237868a208SPunit Agrawal spte = huge_pte_offset(svma->vm_mm, saddr, 67247868a208SPunit Agrawal vma_mmu_pagesize(svma)); 67253212b535SSteve Capper if (spte) { 67263212b535SSteve Capper get_page(virt_to_page(spte)); 67273212b535SSteve Capper break; 67283212b535SSteve Capper } 67293212b535SSteve Capper } 67303212b535SSteve Capper } 67313212b535SSteve Capper 67323212b535SSteve Capper if (!spte) 67333212b535SSteve Capper goto out; 67343212b535SSteve Capper 67358bea8052SAneesh Kumar K.V ptl = huge_pte_lock(hstate_vma(vma), mm, spte); 6736dc6c9a35SKirill A. Shutemov if (pud_none(*pud)) { 67373212b535SSteve Capper pud_populate(mm, pud, 67383212b535SSteve Capper (pmd_t *)((unsigned long)spte & PAGE_MASK)); 6739c17b1f42SKirill A. Shutemov mm_inc_nr_pmds(mm); 6740dc6c9a35SKirill A. Shutemov } else { 67413212b535SSteve Capper put_page(virt_to_page(spte)); 6742dc6c9a35SKirill A. Shutemov } 6743cb900f41SKirill A. Shutemov spin_unlock(ptl); 67443212b535SSteve Capper out: 67453212b535SSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 67463212b535SSteve Capper return pte; 67473212b535SSteve Capper } 67483212b535SSteve Capper 67493212b535SSteve Capper /* 67503212b535SSteve Capper * unmap huge page backed by shared pte. 67513212b535SSteve Capper * 67523212b535SSteve Capper * Hugetlb pte page is ref counted at the time of mapping. If pte is shared 67533212b535SSteve Capper * indicated by page_count > 1, unmap is achieved by clearing pud and 67543212b535SSteve Capper * decrementing the ref count. If count == 1, the pte page is not shared. 67553212b535SSteve Capper * 6756c0d0381aSMike Kravetz * Called with page table lock held and i_mmap_rwsem held in write mode. 67573212b535SSteve Capper * 67583212b535SSteve Capper * returns: 1 successfully unmapped a shared pte page 67593212b535SSteve Capper * 0 the underlying pte page is not shared, or it is the last user 67603212b535SSteve Capper */ 676134ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 676234ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 67633212b535SSteve Capper { 67643212b535SSteve Capper pgd_t *pgd = pgd_offset(mm, *addr); 6765c2febafcSKirill A. Shutemov p4d_t *p4d = p4d_offset(pgd, *addr); 6766c2febafcSKirill A. Shutemov pud_t *pud = pud_offset(p4d, *addr); 67673212b535SSteve Capper 676834ae204fSMike Kravetz i_mmap_assert_write_locked(vma->vm_file->f_mapping); 67693212b535SSteve Capper BUG_ON(page_count(virt_to_page(ptep)) == 0); 67703212b535SSteve Capper if (page_count(virt_to_page(ptep)) == 1) 67713212b535SSteve Capper return 0; 67723212b535SSteve Capper 67733212b535SSteve Capper pud_clear(pud); 67743212b535SSteve Capper put_page(virt_to_page(ptep)); 6775dc6c9a35SKirill A. Shutemov mm_dec_nr_pmds(mm); 677648381273SMike Kravetz /* 677748381273SMike Kravetz * This update of passed address optimizes loops sequentially 677848381273SMike Kravetz * processing addresses in increments of huge page size (PMD_SIZE 677948381273SMike Kravetz * in this case). By clearing the pud, a PUD_SIZE area is unmapped. 678048381273SMike Kravetz * Update address to the 'last page' in the cleared area so that 678148381273SMike Kravetz * calling loop can move to first page past this area. 678248381273SMike Kravetz */ 678348381273SMike Kravetz *addr |= PUD_SIZE - PMD_SIZE; 67843212b535SSteve Capper return 1; 67853212b535SSteve Capper } 6786c1991e07SPeter Xu 67879e5fc74cSSteve Capper #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 6788aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 6789aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 67909e5fc74cSSteve Capper { 67919e5fc74cSSteve Capper return NULL; 67929e5fc74cSSteve Capper } 6793e81f2d22SZhang Zhen 679434ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 679534ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 6796e81f2d22SZhang Zhen { 6797e81f2d22SZhang Zhen return 0; 6798e81f2d22SZhang Zhen } 6799017b1660SMike Kravetz 6800017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 6801017b1660SMike Kravetz unsigned long *start, unsigned long *end) 6802017b1660SMike Kravetz { 6803017b1660SMike Kravetz } 6804c1991e07SPeter Xu 6805c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 6806c1991e07SPeter Xu { 6807c1991e07SPeter Xu return false; 6808c1991e07SPeter Xu } 68093212b535SSteve Capper #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 68103212b535SSteve Capper 68119e5fc74cSSteve Capper #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB 6812aec44e0fSPeter Xu pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, 68139e5fc74cSSteve Capper unsigned long addr, unsigned long sz) 68149e5fc74cSSteve Capper { 68159e5fc74cSSteve Capper pgd_t *pgd; 6816c2febafcSKirill A. Shutemov p4d_t *p4d; 68179e5fc74cSSteve Capper pud_t *pud; 68189e5fc74cSSteve Capper pte_t *pte = NULL; 68199e5fc74cSSteve Capper 68209e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 6821f4f0a3d8SKirill A. Shutemov p4d = p4d_alloc(mm, pgd, addr); 6822f4f0a3d8SKirill A. Shutemov if (!p4d) 6823f4f0a3d8SKirill A. Shutemov return NULL; 6824c2febafcSKirill A. Shutemov pud = pud_alloc(mm, p4d, addr); 68259e5fc74cSSteve Capper if (pud) { 68269e5fc74cSSteve Capper if (sz == PUD_SIZE) { 68279e5fc74cSSteve Capper pte = (pte_t *)pud; 68289e5fc74cSSteve Capper } else { 68299e5fc74cSSteve Capper BUG_ON(sz != PMD_SIZE); 6830c1991e07SPeter Xu if (want_pmd_share(vma, addr) && pud_none(*pud)) 6831aec44e0fSPeter Xu pte = huge_pmd_share(mm, vma, addr, pud); 68329e5fc74cSSteve Capper else 68339e5fc74cSSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 68349e5fc74cSSteve Capper } 68359e5fc74cSSteve Capper } 68364e666314SMichal Hocko BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte)); 68379e5fc74cSSteve Capper 68389e5fc74cSSteve Capper return pte; 68399e5fc74cSSteve Capper } 68409e5fc74cSSteve Capper 68419b19df29SPunit Agrawal /* 68429b19df29SPunit Agrawal * huge_pte_offset() - Walk the page table to resolve the hugepage 68439b19df29SPunit Agrawal * entry at address @addr 68449b19df29SPunit Agrawal * 68458ac0b81aSLi Xinhai * Return: Pointer to page table entry (PUD or PMD) for 68468ac0b81aSLi Xinhai * address @addr, or NULL if a !p*d_present() entry is encountered and the 68479b19df29SPunit Agrawal * size @sz doesn't match the hugepage size at this level of the page 68489b19df29SPunit Agrawal * table. 68499b19df29SPunit Agrawal */ 68507868a208SPunit Agrawal pte_t *huge_pte_offset(struct mm_struct *mm, 68517868a208SPunit Agrawal unsigned long addr, unsigned long sz) 68529e5fc74cSSteve Capper { 68539e5fc74cSSteve Capper pgd_t *pgd; 6854c2febafcSKirill A. Shutemov p4d_t *p4d; 68558ac0b81aSLi Xinhai pud_t *pud; 68568ac0b81aSLi Xinhai pmd_t *pmd; 68579e5fc74cSSteve Capper 68589e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 6859c2febafcSKirill A. Shutemov if (!pgd_present(*pgd)) 6860c2febafcSKirill A. Shutemov return NULL; 6861c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, addr); 6862c2febafcSKirill A. Shutemov if (!p4d_present(*p4d)) 6863c2febafcSKirill A. Shutemov return NULL; 68649b19df29SPunit Agrawal 6865c2febafcSKirill A. Shutemov pud = pud_offset(p4d, addr); 68668ac0b81aSLi Xinhai if (sz == PUD_SIZE) 68678ac0b81aSLi Xinhai /* must be pud huge, non-present or none */ 68689e5fc74cSSteve Capper return (pte_t *)pud; 68698ac0b81aSLi Xinhai if (!pud_present(*pud)) 68708ac0b81aSLi Xinhai return NULL; 68718ac0b81aSLi Xinhai /* must have a valid entry and size to go further */ 68729b19df29SPunit Agrawal 68739e5fc74cSSteve Capper pmd = pmd_offset(pud, addr); 68748ac0b81aSLi Xinhai /* must be pmd huge, non-present or none */ 68759e5fc74cSSteve Capper return (pte_t *)pmd; 68769e5fc74cSSteve Capper } 68779e5fc74cSSteve Capper 6878*e95a9851SMike Kravetz /* 6879*e95a9851SMike Kravetz * Return a mask that can be used to update an address to the last huge 6880*e95a9851SMike Kravetz * page in a page table page mapping size. Used to skip non-present 6881*e95a9851SMike Kravetz * page table entries when linearly scanning address ranges. Architectures 6882*e95a9851SMike Kravetz * with unique huge page to page table relationships can define their own 6883*e95a9851SMike Kravetz * version of this routine. 6884*e95a9851SMike Kravetz */ 6885*e95a9851SMike Kravetz unsigned long hugetlb_mask_last_page(struct hstate *h) 6886*e95a9851SMike Kravetz { 6887*e95a9851SMike Kravetz unsigned long hp_size = huge_page_size(h); 6888*e95a9851SMike Kravetz 6889*e95a9851SMike Kravetz if (hp_size == PUD_SIZE) 6890*e95a9851SMike Kravetz return P4D_SIZE - PUD_SIZE; 6891*e95a9851SMike Kravetz else if (hp_size == PMD_SIZE) 6892*e95a9851SMike Kravetz return PUD_SIZE - PMD_SIZE; 6893*e95a9851SMike Kravetz else 6894*e95a9851SMike Kravetz return 0UL; 6895*e95a9851SMike Kravetz } 6896*e95a9851SMike Kravetz 6897*e95a9851SMike Kravetz #else 6898*e95a9851SMike Kravetz 6899*e95a9851SMike Kravetz /* See description above. Architectures can provide their own version. */ 6900*e95a9851SMike Kravetz __weak unsigned long hugetlb_mask_last_page(struct hstate *h) 6901*e95a9851SMike Kravetz { 6902*e95a9851SMike Kravetz return 0UL; 6903*e95a9851SMike Kravetz } 6904*e95a9851SMike Kravetz 690561f77edaSNaoya Horiguchi #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ 690661f77edaSNaoya Horiguchi 690761f77edaSNaoya Horiguchi /* 690861f77edaSNaoya Horiguchi * These functions are overwritable if your architecture needs its own 690961f77edaSNaoya Horiguchi * behavior. 691061f77edaSNaoya Horiguchi */ 691161f77edaSNaoya Horiguchi struct page * __weak 691261f77edaSNaoya Horiguchi follow_huge_addr(struct mm_struct *mm, unsigned long address, 691361f77edaSNaoya Horiguchi int write) 691461f77edaSNaoya Horiguchi { 691561f77edaSNaoya Horiguchi return ERR_PTR(-EINVAL); 691661f77edaSNaoya Horiguchi } 691761f77edaSNaoya Horiguchi 691861f77edaSNaoya Horiguchi struct page * __weak 69194dc71451SAneesh Kumar K.V follow_huge_pd(struct vm_area_struct *vma, 69204dc71451SAneesh Kumar K.V unsigned long address, hugepd_t hpd, int flags, int pdshift) 69214dc71451SAneesh Kumar K.V { 69224dc71451SAneesh Kumar K.V WARN(1, "hugepd follow called with no support for hugepage directory format\n"); 69234dc71451SAneesh Kumar K.V return NULL; 69244dc71451SAneesh Kumar K.V } 69254dc71451SAneesh Kumar K.V 69264dc71451SAneesh Kumar K.V struct page * __weak 69279e5fc74cSSteve Capper follow_huge_pmd(struct mm_struct *mm, unsigned long address, 6928e66f17ffSNaoya Horiguchi pmd_t *pmd, int flags) 69299e5fc74cSSteve Capper { 6930e66f17ffSNaoya Horiguchi struct page *page = NULL; 6931e66f17ffSNaoya Horiguchi spinlock_t *ptl; 6932c9d398faSNaoya Horiguchi pte_t pte; 69333faa52c0SJohn Hubbard 69348909691bSDavid Hildenbrand /* 69358909691bSDavid Hildenbrand * FOLL_PIN is not supported for follow_page(). Ordinary GUP goes via 69368909691bSDavid Hildenbrand * follow_hugetlb_page(). 69378909691bSDavid Hildenbrand */ 69388909691bSDavid Hildenbrand if (WARN_ON_ONCE(flags & FOLL_PIN)) 69393faa52c0SJohn Hubbard return NULL; 69403faa52c0SJohn Hubbard 6941e66f17ffSNaoya Horiguchi retry: 6942e66f17ffSNaoya Horiguchi ptl = pmd_lockptr(mm, pmd); 6943e66f17ffSNaoya Horiguchi spin_lock(ptl); 6944e66f17ffSNaoya Horiguchi /* 6945e66f17ffSNaoya Horiguchi * make sure that the address range covered by this pmd is not 6946e66f17ffSNaoya Horiguchi * unmapped from other threads. 6947e66f17ffSNaoya Horiguchi */ 6948e66f17ffSNaoya Horiguchi if (!pmd_huge(*pmd)) 6949e66f17ffSNaoya Horiguchi goto out; 6950c9d398faSNaoya Horiguchi pte = huge_ptep_get((pte_t *)pmd); 6951c9d398faSNaoya Horiguchi if (pte_present(pte)) { 695297534127SGerald Schaefer page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT); 69533faa52c0SJohn Hubbard /* 69543faa52c0SJohn Hubbard * try_grab_page() should always succeed here, because: a) we 69553faa52c0SJohn Hubbard * hold the pmd (ptl) lock, and b) we've just checked that the 69563faa52c0SJohn Hubbard * huge pmd (head) page is present in the page tables. The ptl 69573faa52c0SJohn Hubbard * prevents the head page and tail pages from being rearranged 69583faa52c0SJohn Hubbard * in any way. So this page must be available at this point, 69593faa52c0SJohn Hubbard * unless the page refcount overflowed: 69603faa52c0SJohn Hubbard */ 69613faa52c0SJohn Hubbard if (WARN_ON_ONCE(!try_grab_page(page, flags))) { 69623faa52c0SJohn Hubbard page = NULL; 69633faa52c0SJohn Hubbard goto out; 69643faa52c0SJohn Hubbard } 6965e66f17ffSNaoya Horiguchi } else { 6966c9d398faSNaoya Horiguchi if (is_hugetlb_entry_migration(pte)) { 6967e66f17ffSNaoya Horiguchi spin_unlock(ptl); 6968ad1ac596SMiaohe Lin __migration_entry_wait_huge((pte_t *)pmd, ptl); 6969e66f17ffSNaoya Horiguchi goto retry; 6970e66f17ffSNaoya Horiguchi } 6971e66f17ffSNaoya Horiguchi /* 6972e66f17ffSNaoya Horiguchi * hwpoisoned entry is treated as no_page_table in 6973e66f17ffSNaoya Horiguchi * follow_page_mask(). 6974e66f17ffSNaoya Horiguchi */ 6975e66f17ffSNaoya Horiguchi } 6976e66f17ffSNaoya Horiguchi out: 6977e66f17ffSNaoya Horiguchi spin_unlock(ptl); 69789e5fc74cSSteve Capper return page; 69799e5fc74cSSteve Capper } 69809e5fc74cSSteve Capper 698161f77edaSNaoya Horiguchi struct page * __weak 69829e5fc74cSSteve Capper follow_huge_pud(struct mm_struct *mm, unsigned long address, 6983e66f17ffSNaoya Horiguchi pud_t *pud, int flags) 69849e5fc74cSSteve Capper { 69853faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 6986e66f17ffSNaoya Horiguchi return NULL; 69879e5fc74cSSteve Capper 6988e66f17ffSNaoya Horiguchi return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); 69899e5fc74cSSteve Capper } 69909e5fc74cSSteve Capper 6991faaa5b62SAnshuman Khandual struct page * __weak 6992faaa5b62SAnshuman Khandual follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) 6993faaa5b62SAnshuman Khandual { 69943faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 6995faaa5b62SAnshuman Khandual return NULL; 6996faaa5b62SAnshuman Khandual 6997faaa5b62SAnshuman Khandual return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); 6998faaa5b62SAnshuman Khandual } 6999faaa5b62SAnshuman Khandual 70007ce82f4cSMiaohe Lin int isolate_hugetlb(struct page *page, struct list_head *list) 700131caf665SNaoya Horiguchi { 70027ce82f4cSMiaohe Lin int ret = 0; 7003bcc54222SNaoya Horiguchi 7004db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 70058f251a3dSMike Kravetz if (!PageHeadHuge(page) || 70068f251a3dSMike Kravetz !HPageMigratable(page) || 70070eb2df2bSMuchun Song !get_page_unless_zero(page)) { 70087ce82f4cSMiaohe Lin ret = -EBUSY; 7009bcc54222SNaoya Horiguchi goto unlock; 7010bcc54222SNaoya Horiguchi } 70118f251a3dSMike Kravetz ClearHPageMigratable(page); 701231caf665SNaoya Horiguchi list_move_tail(&page->lru, list); 7013bcc54222SNaoya Horiguchi unlock: 7014db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 7015bcc54222SNaoya Horiguchi return ret; 701631caf665SNaoya Horiguchi } 701731caf665SNaoya Horiguchi 701825182f05SNaoya Horiguchi int get_hwpoison_huge_page(struct page *page, bool *hugetlb) 701925182f05SNaoya Horiguchi { 702025182f05SNaoya Horiguchi int ret = 0; 702125182f05SNaoya Horiguchi 702225182f05SNaoya Horiguchi *hugetlb = false; 702325182f05SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 702425182f05SNaoya Horiguchi if (PageHeadHuge(page)) { 702525182f05SNaoya Horiguchi *hugetlb = true; 7026b283d983SNaoya Horiguchi if (HPageFreed(page)) 7027b283d983SNaoya Horiguchi ret = 0; 7028b283d983SNaoya Horiguchi else if (HPageMigratable(page)) 702925182f05SNaoya Horiguchi ret = get_page_unless_zero(page); 70300ed950d1SNaoya Horiguchi else 70310ed950d1SNaoya Horiguchi ret = -EBUSY; 703225182f05SNaoya Horiguchi } 703325182f05SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 703425182f05SNaoya Horiguchi return ret; 703525182f05SNaoya Horiguchi } 703625182f05SNaoya Horiguchi 7037405ce051SNaoya Horiguchi int get_huge_page_for_hwpoison(unsigned long pfn, int flags) 7038405ce051SNaoya Horiguchi { 7039405ce051SNaoya Horiguchi int ret; 7040405ce051SNaoya Horiguchi 7041405ce051SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 7042405ce051SNaoya Horiguchi ret = __get_huge_page_for_hwpoison(pfn, flags); 7043405ce051SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 7044405ce051SNaoya Horiguchi return ret; 7045405ce051SNaoya Horiguchi } 7046405ce051SNaoya Horiguchi 704731caf665SNaoya Horiguchi void putback_active_hugepage(struct page *page) 704831caf665SNaoya Horiguchi { 7049db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 70508f251a3dSMike Kravetz SetHPageMigratable(page); 705131caf665SNaoya Horiguchi list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); 7052db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 705331caf665SNaoya Horiguchi put_page(page); 705431caf665SNaoya Horiguchi } 7055ab5ac90aSMichal Hocko 7056ab5ac90aSMichal Hocko void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason) 7057ab5ac90aSMichal Hocko { 7058ab5ac90aSMichal Hocko struct hstate *h = page_hstate(oldpage); 7059ab5ac90aSMichal Hocko 7060ab5ac90aSMichal Hocko hugetlb_cgroup_migrate(oldpage, newpage); 7061ab5ac90aSMichal Hocko set_page_owner_migrate_reason(newpage, reason); 7062ab5ac90aSMichal Hocko 7063ab5ac90aSMichal Hocko /* 7064ab5ac90aSMichal Hocko * transfer temporary state of the new huge page. This is 7065ab5ac90aSMichal Hocko * reverse to other transitions because the newpage is going to 7066ab5ac90aSMichal Hocko * be final while the old one will be freed so it takes over 7067ab5ac90aSMichal Hocko * the temporary status. 7068ab5ac90aSMichal Hocko * 7069ab5ac90aSMichal Hocko * Also note that we have to transfer the per-node surplus state 7070ab5ac90aSMichal Hocko * here as well otherwise the global surplus count will not match 7071ab5ac90aSMichal Hocko * the per-node's. 7072ab5ac90aSMichal Hocko */ 70739157c311SMike Kravetz if (HPageTemporary(newpage)) { 7074ab5ac90aSMichal Hocko int old_nid = page_to_nid(oldpage); 7075ab5ac90aSMichal Hocko int new_nid = page_to_nid(newpage); 7076ab5ac90aSMichal Hocko 70779157c311SMike Kravetz SetHPageTemporary(oldpage); 70789157c311SMike Kravetz ClearHPageTemporary(newpage); 7079ab5ac90aSMichal Hocko 70805af1ab1dSMiaohe Lin /* 70815af1ab1dSMiaohe Lin * There is no need to transfer the per-node surplus state 70825af1ab1dSMiaohe Lin * when we do not cross the node. 70835af1ab1dSMiaohe Lin */ 70845af1ab1dSMiaohe Lin if (new_nid == old_nid) 70855af1ab1dSMiaohe Lin return; 7086db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 7087ab5ac90aSMichal Hocko if (h->surplus_huge_pages_node[old_nid]) { 7088ab5ac90aSMichal Hocko h->surplus_huge_pages_node[old_nid]--; 7089ab5ac90aSMichal Hocko h->surplus_huge_pages_node[new_nid]++; 7090ab5ac90aSMichal Hocko } 7091db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 7092ab5ac90aSMichal Hocko } 7093ab5ac90aSMichal Hocko } 7094cf11e85fSRoman Gushchin 70956dfeaff9SPeter Xu /* 70966dfeaff9SPeter Xu * This function will unconditionally remove all the shared pmd pgtable entries 70976dfeaff9SPeter Xu * within the specific vma for a hugetlbfs memory range. 70986dfeaff9SPeter Xu */ 70996dfeaff9SPeter Xu void hugetlb_unshare_all_pmds(struct vm_area_struct *vma) 71006dfeaff9SPeter Xu { 71016dfeaff9SPeter Xu struct hstate *h = hstate_vma(vma); 71026dfeaff9SPeter Xu unsigned long sz = huge_page_size(h); 71036dfeaff9SPeter Xu struct mm_struct *mm = vma->vm_mm; 71046dfeaff9SPeter Xu struct mmu_notifier_range range; 71056dfeaff9SPeter Xu unsigned long address, start, end; 71066dfeaff9SPeter Xu spinlock_t *ptl; 71076dfeaff9SPeter Xu pte_t *ptep; 71086dfeaff9SPeter Xu 71096dfeaff9SPeter Xu if (!(vma->vm_flags & VM_MAYSHARE)) 71106dfeaff9SPeter Xu return; 71116dfeaff9SPeter Xu 71126dfeaff9SPeter Xu start = ALIGN(vma->vm_start, PUD_SIZE); 71136dfeaff9SPeter Xu end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 71146dfeaff9SPeter Xu 71156dfeaff9SPeter Xu if (start >= end) 71166dfeaff9SPeter Xu return; 71176dfeaff9SPeter Xu 71189c8bbfacSBaolin Wang flush_cache_range(vma, start, end); 71196dfeaff9SPeter Xu /* 71206dfeaff9SPeter Xu * No need to call adjust_range_if_pmd_sharing_possible(), because 71216dfeaff9SPeter Xu * we have already done the PUD_SIZE alignment. 71226dfeaff9SPeter Xu */ 71236dfeaff9SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, 71246dfeaff9SPeter Xu start, end); 71256dfeaff9SPeter Xu mmu_notifier_invalidate_range_start(&range); 71266dfeaff9SPeter Xu i_mmap_lock_write(vma->vm_file->f_mapping); 71276dfeaff9SPeter Xu for (address = start; address < end; address += PUD_SIZE) { 71286dfeaff9SPeter Xu unsigned long tmp = address; 71296dfeaff9SPeter Xu 71306dfeaff9SPeter Xu ptep = huge_pte_offset(mm, address, sz); 71316dfeaff9SPeter Xu if (!ptep) 71326dfeaff9SPeter Xu continue; 71336dfeaff9SPeter Xu ptl = huge_pte_lock(h, mm, ptep); 71346dfeaff9SPeter Xu /* We don't want 'address' to be changed */ 71356dfeaff9SPeter Xu huge_pmd_unshare(mm, vma, &tmp, ptep); 71366dfeaff9SPeter Xu spin_unlock(ptl); 71376dfeaff9SPeter Xu } 71386dfeaff9SPeter Xu flush_hugetlb_tlb_range(vma, start, end); 71396dfeaff9SPeter Xu i_mmap_unlock_write(vma->vm_file->f_mapping); 71406dfeaff9SPeter Xu /* 71416dfeaff9SPeter Xu * No need to call mmu_notifier_invalidate_range(), see 7142ee65728eSMike Rapoport * Documentation/mm/mmu_notifier.rst. 71436dfeaff9SPeter Xu */ 71446dfeaff9SPeter Xu mmu_notifier_invalidate_range_end(&range); 71456dfeaff9SPeter Xu } 71466dfeaff9SPeter Xu 7147cf11e85fSRoman Gushchin #ifdef CONFIG_CMA 7148cf11e85fSRoman Gushchin static bool cma_reserve_called __initdata; 7149cf11e85fSRoman Gushchin 7150cf11e85fSRoman Gushchin static int __init cmdline_parse_hugetlb_cma(char *p) 7151cf11e85fSRoman Gushchin { 715238e719abSBaolin Wang int nid, count = 0; 715338e719abSBaolin Wang unsigned long tmp; 715438e719abSBaolin Wang char *s = p; 715538e719abSBaolin Wang 715638e719abSBaolin Wang while (*s) { 715738e719abSBaolin Wang if (sscanf(s, "%lu%n", &tmp, &count) != 1) 715838e719abSBaolin Wang break; 715938e719abSBaolin Wang 716038e719abSBaolin Wang if (s[count] == ':') { 7161f9317f77SMike Kravetz if (tmp >= MAX_NUMNODES) 716238e719abSBaolin Wang break; 7163f9317f77SMike Kravetz nid = array_index_nospec(tmp, MAX_NUMNODES); 716438e719abSBaolin Wang 716538e719abSBaolin Wang s += count + 1; 716638e719abSBaolin Wang tmp = memparse(s, &s); 716738e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = tmp; 716838e719abSBaolin Wang hugetlb_cma_size += tmp; 716938e719abSBaolin Wang 717038e719abSBaolin Wang /* 717138e719abSBaolin Wang * Skip the separator if have one, otherwise 717238e719abSBaolin Wang * break the parsing. 717338e719abSBaolin Wang */ 717438e719abSBaolin Wang if (*s == ',') 717538e719abSBaolin Wang s++; 717638e719abSBaolin Wang else 717738e719abSBaolin Wang break; 717838e719abSBaolin Wang } else { 7179cf11e85fSRoman Gushchin hugetlb_cma_size = memparse(p, &p); 718038e719abSBaolin Wang break; 718138e719abSBaolin Wang } 718238e719abSBaolin Wang } 718338e719abSBaolin Wang 7184cf11e85fSRoman Gushchin return 0; 7185cf11e85fSRoman Gushchin } 7186cf11e85fSRoman Gushchin 7187cf11e85fSRoman Gushchin early_param("hugetlb_cma", cmdline_parse_hugetlb_cma); 7188cf11e85fSRoman Gushchin 7189cf11e85fSRoman Gushchin void __init hugetlb_cma_reserve(int order) 7190cf11e85fSRoman Gushchin { 7191cf11e85fSRoman Gushchin unsigned long size, reserved, per_node; 719238e719abSBaolin Wang bool node_specific_cma_alloc = false; 7193cf11e85fSRoman Gushchin int nid; 7194cf11e85fSRoman Gushchin 7195cf11e85fSRoman Gushchin cma_reserve_called = true; 7196cf11e85fSRoman Gushchin 7197cf11e85fSRoman Gushchin if (!hugetlb_cma_size) 7198cf11e85fSRoman Gushchin return; 7199cf11e85fSRoman Gushchin 720038e719abSBaolin Wang for (nid = 0; nid < MAX_NUMNODES; nid++) { 720138e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] == 0) 720238e719abSBaolin Wang continue; 720338e719abSBaolin Wang 720430a51400SPeng Liu if (!node_online(nid)) { 720538e719abSBaolin Wang pr_warn("hugetlb_cma: invalid node %d specified\n", nid); 720638e719abSBaolin Wang hugetlb_cma_size -= hugetlb_cma_size_in_node[nid]; 720738e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = 0; 720838e719abSBaolin Wang continue; 720938e719abSBaolin Wang } 721038e719abSBaolin Wang 721138e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] < (PAGE_SIZE << order)) { 721238e719abSBaolin Wang pr_warn("hugetlb_cma: cma area of node %d should be at least %lu MiB\n", 721338e719abSBaolin Wang nid, (PAGE_SIZE << order) / SZ_1M); 721438e719abSBaolin Wang hugetlb_cma_size -= hugetlb_cma_size_in_node[nid]; 721538e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = 0; 721638e719abSBaolin Wang } else { 721738e719abSBaolin Wang node_specific_cma_alloc = true; 721838e719abSBaolin Wang } 721938e719abSBaolin Wang } 722038e719abSBaolin Wang 722138e719abSBaolin Wang /* Validate the CMA size again in case some invalid nodes specified. */ 722238e719abSBaolin Wang if (!hugetlb_cma_size) 722338e719abSBaolin Wang return; 722438e719abSBaolin Wang 7225cf11e85fSRoman Gushchin if (hugetlb_cma_size < (PAGE_SIZE << order)) { 7226cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n", 7227cf11e85fSRoman Gushchin (PAGE_SIZE << order) / SZ_1M); 7228a01f4390SMike Kravetz hugetlb_cma_size = 0; 7229cf11e85fSRoman Gushchin return; 7230cf11e85fSRoman Gushchin } 7231cf11e85fSRoman Gushchin 723238e719abSBaolin Wang if (!node_specific_cma_alloc) { 7233cf11e85fSRoman Gushchin /* 7234cf11e85fSRoman Gushchin * If 3 GB area is requested on a machine with 4 numa nodes, 7235cf11e85fSRoman Gushchin * let's allocate 1 GB on first three nodes and ignore the last one. 7236cf11e85fSRoman Gushchin */ 7237cf11e85fSRoman Gushchin per_node = DIV_ROUND_UP(hugetlb_cma_size, nr_online_nodes); 7238cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n", 7239cf11e85fSRoman Gushchin hugetlb_cma_size / SZ_1M, per_node / SZ_1M); 724038e719abSBaolin Wang } 7241cf11e85fSRoman Gushchin 7242cf11e85fSRoman Gushchin reserved = 0; 724330a51400SPeng Liu for_each_online_node(nid) { 7244cf11e85fSRoman Gushchin int res; 72452281f797SBarry Song char name[CMA_MAX_NAME]; 7246cf11e85fSRoman Gushchin 724738e719abSBaolin Wang if (node_specific_cma_alloc) { 724838e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] == 0) 724938e719abSBaolin Wang continue; 725038e719abSBaolin Wang 725138e719abSBaolin Wang size = hugetlb_cma_size_in_node[nid]; 725238e719abSBaolin Wang } else { 7253cf11e85fSRoman Gushchin size = min(per_node, hugetlb_cma_size - reserved); 725438e719abSBaolin Wang } 725538e719abSBaolin Wang 7256cf11e85fSRoman Gushchin size = round_up(size, PAGE_SIZE << order); 7257cf11e85fSRoman Gushchin 72582281f797SBarry Song snprintf(name, sizeof(name), "hugetlb%d", nid); 7259a01f4390SMike Kravetz /* 7260a01f4390SMike Kravetz * Note that 'order per bit' is based on smallest size that 7261a01f4390SMike Kravetz * may be returned to CMA allocator in the case of 7262a01f4390SMike Kravetz * huge page demotion. 7263a01f4390SMike Kravetz */ 7264a01f4390SMike Kravetz res = cma_declare_contiguous_nid(0, size, 0, 7265a01f4390SMike Kravetz PAGE_SIZE << HUGETLB_PAGE_ORDER, 726629d0f41dSBarry Song 0, false, name, 7267cf11e85fSRoman Gushchin &hugetlb_cma[nid], nid); 7268cf11e85fSRoman Gushchin if (res) { 7269cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: reservation failed: err %d, node %d", 7270cf11e85fSRoman Gushchin res, nid); 7271cf11e85fSRoman Gushchin continue; 7272cf11e85fSRoman Gushchin } 7273cf11e85fSRoman Gushchin 7274cf11e85fSRoman Gushchin reserved += size; 7275cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserved %lu MiB on node %d\n", 7276cf11e85fSRoman Gushchin size / SZ_1M, nid); 7277cf11e85fSRoman Gushchin 7278cf11e85fSRoman Gushchin if (reserved >= hugetlb_cma_size) 7279cf11e85fSRoman Gushchin break; 7280cf11e85fSRoman Gushchin } 7281a01f4390SMike Kravetz 7282a01f4390SMike Kravetz if (!reserved) 7283a01f4390SMike Kravetz /* 7284a01f4390SMike Kravetz * hugetlb_cma_size is used to determine if allocations from 7285a01f4390SMike Kravetz * cma are possible. Set to zero if no cma regions are set up. 7286a01f4390SMike Kravetz */ 7287a01f4390SMike Kravetz hugetlb_cma_size = 0; 7288cf11e85fSRoman Gushchin } 7289cf11e85fSRoman Gushchin 7290cf11e85fSRoman Gushchin void __init hugetlb_cma_check(void) 7291cf11e85fSRoman Gushchin { 7292cf11e85fSRoman Gushchin if (!hugetlb_cma_size || cma_reserve_called) 7293cf11e85fSRoman Gushchin return; 7294cf11e85fSRoman Gushchin 7295cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: the option isn't supported by current arch\n"); 7296cf11e85fSRoman Gushchin } 7297cf11e85fSRoman Gushchin 7298cf11e85fSRoman Gushchin #endif /* CONFIG_CMA */ 7299