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> 36b958d4d0SMuchun Song #include <linux/memory.h> 37d6606683SLinus Torvalds 3863551ae0SDavid Gibson #include <asm/page.h> 39ca15ca40SMike Rapoport #include <asm/pgalloc.h> 4024669e58SAneesh Kumar K.V #include <asm/tlb.h> 4163551ae0SDavid Gibson 4224669e58SAneesh Kumar K.V #include <linux/io.h> 4363551ae0SDavid Gibson #include <linux/hugetlb.h> 449dd540e2SAneesh Kumar K.V #include <linux/hugetlb_cgroup.h> 459a305230SLee Schermerhorn #include <linux/node.h> 46ab5ac90aSMichal Hocko #include <linux/page_owner.h> 477835e98bSNick Piggin #include "internal.h" 48f41f2ed4SMuchun Song #include "hugetlb_vmemmap.h" 491da177e4SLinus Torvalds 50c3f38a38SAneesh Kumar K.V int hugetlb_max_hstate __read_mostly; 51e5ff2159SAndi Kleen unsigned int default_hstate_idx; 52e5ff2159SAndi Kleen struct hstate hstates[HUGE_MAX_HSTATE]; 53cf11e85fSRoman Gushchin 54dbda8feaSBarry Song #ifdef CONFIG_CMA 55cf11e85fSRoman Gushchin static struct cma *hugetlb_cma[MAX_NUMNODES]; 5638e719abSBaolin Wang static unsigned long hugetlb_cma_size_in_node[MAX_NUMNODES] __initdata; 57a01f4390SMike Kravetz static bool hugetlb_cma_page(struct page *page, unsigned int order) 58a01f4390SMike Kravetz { 59a01f4390SMike Kravetz return cma_pages_valid(hugetlb_cma[page_to_nid(page)], page, 60a01f4390SMike Kravetz 1 << order); 61a01f4390SMike Kravetz } 62a01f4390SMike Kravetz #else 63a01f4390SMike Kravetz static bool hugetlb_cma_page(struct page *page, unsigned int order) 64a01f4390SMike Kravetz { 65a01f4390SMike Kravetz return false; 66a01f4390SMike Kravetz } 67dbda8feaSBarry Song #endif 68dbda8feaSBarry Song static unsigned long hugetlb_cma_size __initdata; 69cf11e85fSRoman Gushchin 7053ba51d2SJon Tollefson __initdata LIST_HEAD(huge_boot_pages); 7153ba51d2SJon Tollefson 72e5ff2159SAndi Kleen /* for command line parsing */ 73e5ff2159SAndi Kleen static struct hstate * __initdata parsed_hstate; 74e5ff2159SAndi Kleen static unsigned long __initdata default_hstate_max_huge_pages; 759fee021dSVaishali Thakkar static bool __initdata parsed_valid_hugepagesz = true; 76282f4214SMike Kravetz static bool __initdata parsed_default_hugepagesz; 77b5389086SZhenguo Yao static unsigned int default_hugepages_in_node[MAX_NUMNODES] __initdata; 78e5ff2159SAndi Kleen 793935baa9SDavid Gibson /* 8031caf665SNaoya Horiguchi * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, 8131caf665SNaoya Horiguchi * free_huge_pages, and surplus_huge_pages. 823935baa9SDavid Gibson */ 83c3f38a38SAneesh Kumar K.V DEFINE_SPINLOCK(hugetlb_lock); 840bd0f9fbSEric Paris 858382d914SDavidlohr Bueso /* 868382d914SDavidlohr Bueso * Serializes faults on the same logical page. This is used to 878382d914SDavidlohr Bueso * prevent spurious OOMs when the hugepage pool is fully utilized. 888382d914SDavidlohr Bueso */ 898382d914SDavidlohr Bueso static int num_fault_mutexes; 90c672c7f2SMike Kravetz struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp; 918382d914SDavidlohr Bueso 927ca02d0aSMike Kravetz /* Forward declaration */ 937ca02d0aSMike Kravetz static int hugetlb_acct_memory(struct hstate *h, long delta); 947ca02d0aSMike Kravetz 951d88433bSMiaohe Lin static inline bool subpool_is_free(struct hugepage_subpool *spool) 961d88433bSMiaohe Lin { 971d88433bSMiaohe Lin if (spool->count) 981d88433bSMiaohe Lin return false; 991d88433bSMiaohe Lin if (spool->max_hpages != -1) 1001d88433bSMiaohe Lin return spool->used_hpages == 0; 1011d88433bSMiaohe Lin if (spool->min_hpages != -1) 1021d88433bSMiaohe Lin return spool->rsv_hpages == spool->min_hpages; 1031d88433bSMiaohe Lin 1041d88433bSMiaohe Lin return true; 1051d88433bSMiaohe Lin } 1061d88433bSMiaohe Lin 107db71ef79SMike Kravetz static inline void unlock_or_release_subpool(struct hugepage_subpool *spool, 108db71ef79SMike Kravetz unsigned long irq_flags) 10990481622SDavid Gibson { 110db71ef79SMike Kravetz spin_unlock_irqrestore(&spool->lock, irq_flags); 11190481622SDavid Gibson 11290481622SDavid Gibson /* If no pages are used, and no other handles to the subpool 1137c8de358SEthon Paul * remain, give up any reservations based on minimum size and 1147ca02d0aSMike Kravetz * free the subpool */ 1151d88433bSMiaohe Lin if (subpool_is_free(spool)) { 1167ca02d0aSMike Kravetz if (spool->min_hpages != -1) 1177ca02d0aSMike Kravetz hugetlb_acct_memory(spool->hstate, 1187ca02d0aSMike Kravetz -spool->min_hpages); 11990481622SDavid Gibson kfree(spool); 12090481622SDavid Gibson } 1217ca02d0aSMike Kravetz } 12290481622SDavid Gibson 1237ca02d0aSMike Kravetz struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, 1247ca02d0aSMike Kravetz long min_hpages) 12590481622SDavid Gibson { 12690481622SDavid Gibson struct hugepage_subpool *spool; 12790481622SDavid Gibson 128c6a91820SMike Kravetz spool = kzalloc(sizeof(*spool), GFP_KERNEL); 12990481622SDavid Gibson if (!spool) 13090481622SDavid Gibson return NULL; 13190481622SDavid Gibson 13290481622SDavid Gibson spin_lock_init(&spool->lock); 13390481622SDavid Gibson spool->count = 1; 1347ca02d0aSMike Kravetz spool->max_hpages = max_hpages; 1357ca02d0aSMike Kravetz spool->hstate = h; 1367ca02d0aSMike Kravetz spool->min_hpages = min_hpages; 1377ca02d0aSMike Kravetz 1387ca02d0aSMike Kravetz if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { 1397ca02d0aSMike Kravetz kfree(spool); 1407ca02d0aSMike Kravetz return NULL; 1417ca02d0aSMike Kravetz } 1427ca02d0aSMike Kravetz spool->rsv_hpages = min_hpages; 14390481622SDavid Gibson 14490481622SDavid Gibson return spool; 14590481622SDavid Gibson } 14690481622SDavid Gibson 14790481622SDavid Gibson void hugepage_put_subpool(struct hugepage_subpool *spool) 14890481622SDavid Gibson { 149db71ef79SMike Kravetz unsigned long flags; 150db71ef79SMike Kravetz 151db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 15290481622SDavid Gibson BUG_ON(!spool->count); 15390481622SDavid Gibson spool->count--; 154db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 15590481622SDavid Gibson } 15690481622SDavid Gibson 1571c5ecae3SMike Kravetz /* 1581c5ecae3SMike Kravetz * Subpool accounting for allocating and reserving pages. 1591c5ecae3SMike Kravetz * Return -ENOMEM if there are not enough resources to satisfy the 1609e7ee400SRandy Dunlap * request. Otherwise, return the number of pages by which the 1611c5ecae3SMike Kravetz * global pools must be adjusted (upward). The returned value may 1621c5ecae3SMike Kravetz * only be different than the passed value (delta) in the case where 1637c8de358SEthon Paul * a subpool minimum size must be maintained. 1641c5ecae3SMike Kravetz */ 1651c5ecae3SMike Kravetz static long hugepage_subpool_get_pages(struct hugepage_subpool *spool, 16690481622SDavid Gibson long delta) 16790481622SDavid Gibson { 1681c5ecae3SMike Kravetz long ret = delta; 16990481622SDavid Gibson 17090481622SDavid Gibson if (!spool) 1711c5ecae3SMike Kravetz return ret; 17290481622SDavid Gibson 173db71ef79SMike Kravetz spin_lock_irq(&spool->lock); 17490481622SDavid Gibson 1751c5ecae3SMike Kravetz if (spool->max_hpages != -1) { /* maximum size accounting */ 1761c5ecae3SMike Kravetz if ((spool->used_hpages + delta) <= spool->max_hpages) 1771c5ecae3SMike Kravetz spool->used_hpages += delta; 1781c5ecae3SMike Kravetz else { 1791c5ecae3SMike Kravetz ret = -ENOMEM; 1801c5ecae3SMike Kravetz goto unlock_ret; 1811c5ecae3SMike Kravetz } 1821c5ecae3SMike Kravetz } 1831c5ecae3SMike Kravetz 18409a95e29SMike Kravetz /* minimum size accounting */ 18509a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->rsv_hpages) { 1861c5ecae3SMike Kravetz if (delta > spool->rsv_hpages) { 1871c5ecae3SMike Kravetz /* 1881c5ecae3SMike Kravetz * Asking for more reserves than those already taken on 1891c5ecae3SMike Kravetz * behalf of subpool. Return difference. 1901c5ecae3SMike Kravetz */ 1911c5ecae3SMike Kravetz ret = delta - spool->rsv_hpages; 1921c5ecae3SMike Kravetz spool->rsv_hpages = 0; 1931c5ecae3SMike Kravetz } else { 1941c5ecae3SMike Kravetz ret = 0; /* reserves already accounted for */ 1951c5ecae3SMike Kravetz spool->rsv_hpages -= delta; 1961c5ecae3SMike Kravetz } 1971c5ecae3SMike Kravetz } 1981c5ecae3SMike Kravetz 1991c5ecae3SMike Kravetz unlock_ret: 200db71ef79SMike Kravetz spin_unlock_irq(&spool->lock); 20190481622SDavid Gibson return ret; 20290481622SDavid Gibson } 20390481622SDavid Gibson 2041c5ecae3SMike Kravetz /* 2051c5ecae3SMike Kravetz * Subpool accounting for freeing and unreserving pages. 2061c5ecae3SMike Kravetz * Return the number of global page reservations that must be dropped. 2071c5ecae3SMike Kravetz * The return value may only be different than the passed value (delta) 2081c5ecae3SMike Kravetz * in the case where a subpool minimum size must be maintained. 2091c5ecae3SMike Kravetz */ 2101c5ecae3SMike Kravetz static long hugepage_subpool_put_pages(struct hugepage_subpool *spool, 21190481622SDavid Gibson long delta) 21290481622SDavid Gibson { 2131c5ecae3SMike Kravetz long ret = delta; 214db71ef79SMike Kravetz unsigned long flags; 2151c5ecae3SMike Kravetz 21690481622SDavid Gibson if (!spool) 2171c5ecae3SMike Kravetz return delta; 21890481622SDavid Gibson 219db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 2201c5ecae3SMike Kravetz 2211c5ecae3SMike Kravetz if (spool->max_hpages != -1) /* maximum size accounting */ 22290481622SDavid Gibson spool->used_hpages -= delta; 2231c5ecae3SMike Kravetz 22409a95e29SMike Kravetz /* minimum size accounting */ 22509a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { 2261c5ecae3SMike Kravetz if (spool->rsv_hpages + delta <= spool->min_hpages) 2271c5ecae3SMike Kravetz ret = 0; 2281c5ecae3SMike Kravetz else 2291c5ecae3SMike Kravetz ret = spool->rsv_hpages + delta - spool->min_hpages; 2301c5ecae3SMike Kravetz 2311c5ecae3SMike Kravetz spool->rsv_hpages += delta; 2321c5ecae3SMike Kravetz if (spool->rsv_hpages > spool->min_hpages) 2331c5ecae3SMike Kravetz spool->rsv_hpages = spool->min_hpages; 2341c5ecae3SMike Kravetz } 2351c5ecae3SMike Kravetz 2361c5ecae3SMike Kravetz /* 2371c5ecae3SMike Kravetz * If hugetlbfs_put_super couldn't free spool due to an outstanding 2381c5ecae3SMike Kravetz * quota reference, free it now. 2391c5ecae3SMike Kravetz */ 240db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 2411c5ecae3SMike Kravetz 2421c5ecae3SMike Kravetz return ret; 24390481622SDavid Gibson } 24490481622SDavid Gibson 24590481622SDavid Gibson static inline struct hugepage_subpool *subpool_inode(struct inode *inode) 24690481622SDavid Gibson { 24790481622SDavid Gibson return HUGETLBFS_SB(inode->i_sb)->spool; 24890481622SDavid Gibson } 24990481622SDavid Gibson 25090481622SDavid Gibson static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) 25190481622SDavid Gibson { 252496ad9aaSAl Viro return subpool_inode(file_inode(vma->vm_file)); 25390481622SDavid Gibson } 25490481622SDavid Gibson 2550db9d74eSMina Almasry /* Helper that removes a struct file_region from the resv_map cache and returns 2560db9d74eSMina Almasry * it for use. 2570db9d74eSMina Almasry */ 2580db9d74eSMina Almasry static struct file_region * 2590db9d74eSMina Almasry get_file_region_entry_from_cache(struct resv_map *resv, long from, long to) 2600db9d74eSMina Almasry { 2613259914fSXU pengfei struct file_region *nrg; 2620db9d74eSMina Almasry 2630db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count <= 0); 2640db9d74eSMina Almasry 2650db9d74eSMina Almasry resv->region_cache_count--; 2660db9d74eSMina Almasry nrg = list_first_entry(&resv->region_cache, struct file_region, link); 2670db9d74eSMina Almasry list_del(&nrg->link); 2680db9d74eSMina Almasry 2690db9d74eSMina Almasry nrg->from = from; 2700db9d74eSMina Almasry nrg->to = to; 2710db9d74eSMina Almasry 2720db9d74eSMina Almasry return nrg; 2730db9d74eSMina Almasry } 2740db9d74eSMina Almasry 275075a61d0SMina Almasry static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg, 276075a61d0SMina Almasry struct file_region *rg) 277075a61d0SMina Almasry { 278075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 279075a61d0SMina Almasry nrg->reservation_counter = rg->reservation_counter; 280075a61d0SMina Almasry nrg->css = rg->css; 281075a61d0SMina Almasry if (rg->css) 282075a61d0SMina Almasry css_get(rg->css); 283075a61d0SMina Almasry #endif 284075a61d0SMina Almasry } 285075a61d0SMina Almasry 286075a61d0SMina Almasry /* Helper that records hugetlb_cgroup uncharge info. */ 287075a61d0SMina Almasry static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg, 288075a61d0SMina Almasry struct hstate *h, 289075a61d0SMina Almasry struct resv_map *resv, 290075a61d0SMina Almasry struct file_region *nrg) 291075a61d0SMina Almasry { 292075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 293075a61d0SMina Almasry if (h_cg) { 294075a61d0SMina Almasry nrg->reservation_counter = 295075a61d0SMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 296075a61d0SMina Almasry nrg->css = &h_cg->css; 297d85aecf2SMiaohe Lin /* 298d85aecf2SMiaohe Lin * The caller will hold exactly one h_cg->css reference for the 299d85aecf2SMiaohe Lin * whole contiguous reservation region. But this area might be 300d85aecf2SMiaohe Lin * scattered when there are already some file_regions reside in 301d85aecf2SMiaohe Lin * it. As a result, many file_regions may share only one css 302d85aecf2SMiaohe Lin * reference. In order to ensure that one file_region must hold 303d85aecf2SMiaohe Lin * exactly one h_cg->css reference, we should do css_get for 304d85aecf2SMiaohe Lin * each file_region and leave the reference held by caller 305d85aecf2SMiaohe Lin * untouched. 306d85aecf2SMiaohe Lin */ 307d85aecf2SMiaohe Lin css_get(&h_cg->css); 308075a61d0SMina Almasry if (!resv->pages_per_hpage) 309075a61d0SMina Almasry resv->pages_per_hpage = pages_per_huge_page(h); 310075a61d0SMina Almasry /* pages_per_hpage should be the same for all entries in 311075a61d0SMina Almasry * a resv_map. 312075a61d0SMina Almasry */ 313075a61d0SMina Almasry VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h)); 314075a61d0SMina Almasry } else { 315075a61d0SMina Almasry nrg->reservation_counter = NULL; 316075a61d0SMina Almasry nrg->css = NULL; 317075a61d0SMina Almasry } 318075a61d0SMina Almasry #endif 319075a61d0SMina Almasry } 320075a61d0SMina Almasry 321d85aecf2SMiaohe Lin static void put_uncharge_info(struct file_region *rg) 322d85aecf2SMiaohe Lin { 323d85aecf2SMiaohe Lin #ifdef CONFIG_CGROUP_HUGETLB 324d85aecf2SMiaohe Lin if (rg->css) 325d85aecf2SMiaohe Lin css_put(rg->css); 326d85aecf2SMiaohe Lin #endif 327d85aecf2SMiaohe Lin } 328d85aecf2SMiaohe Lin 329a9b3f867SMina Almasry static bool has_same_uncharge_info(struct file_region *rg, 330a9b3f867SMina Almasry struct file_region *org) 331a9b3f867SMina Almasry { 332a9b3f867SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 3330739eb43SBaolin Wang return rg->reservation_counter == org->reservation_counter && 334a9b3f867SMina Almasry rg->css == org->css; 335a9b3f867SMina Almasry 336a9b3f867SMina Almasry #else 337a9b3f867SMina Almasry return true; 338a9b3f867SMina Almasry #endif 339a9b3f867SMina Almasry } 340a9b3f867SMina Almasry 341a9b3f867SMina Almasry static void coalesce_file_region(struct resv_map *resv, struct file_region *rg) 342a9b3f867SMina Almasry { 3433259914fSXU pengfei struct file_region *nrg, *prg; 344a9b3f867SMina Almasry 345a9b3f867SMina Almasry prg = list_prev_entry(rg, link); 346a9b3f867SMina Almasry if (&prg->link != &resv->regions && prg->to == rg->from && 347a9b3f867SMina Almasry has_same_uncharge_info(prg, rg)) { 348a9b3f867SMina Almasry prg->to = rg->to; 349a9b3f867SMina Almasry 350a9b3f867SMina Almasry list_del(&rg->link); 351d85aecf2SMiaohe Lin put_uncharge_info(rg); 352a9b3f867SMina Almasry kfree(rg); 353a9b3f867SMina Almasry 3547db5e7b6SWei Yang rg = prg; 355a9b3f867SMina Almasry } 356a9b3f867SMina Almasry 357a9b3f867SMina Almasry nrg = list_next_entry(rg, link); 358a9b3f867SMina Almasry if (&nrg->link != &resv->regions && nrg->from == rg->to && 359a9b3f867SMina Almasry has_same_uncharge_info(nrg, rg)) { 360a9b3f867SMina Almasry nrg->from = rg->from; 361a9b3f867SMina Almasry 362a9b3f867SMina Almasry list_del(&rg->link); 363d85aecf2SMiaohe Lin put_uncharge_info(rg); 364a9b3f867SMina Almasry kfree(rg); 365a9b3f867SMina Almasry } 366a9b3f867SMina Almasry } 367a9b3f867SMina Almasry 3682103cf9cSPeter Xu static inline long 36984448c8eSJakob Koschel hugetlb_resv_map_add(struct resv_map *map, struct list_head *rg, long from, 3702103cf9cSPeter Xu long to, struct hstate *h, struct hugetlb_cgroup *cg, 3712103cf9cSPeter Xu long *regions_needed) 3722103cf9cSPeter Xu { 3732103cf9cSPeter Xu struct file_region *nrg; 3742103cf9cSPeter Xu 3752103cf9cSPeter Xu if (!regions_needed) { 3762103cf9cSPeter Xu nrg = get_file_region_entry_from_cache(map, from, to); 3772103cf9cSPeter Xu record_hugetlb_cgroup_uncharge_info(cg, h, map, nrg); 37884448c8eSJakob Koschel list_add(&nrg->link, rg); 3792103cf9cSPeter Xu coalesce_file_region(map, nrg); 3802103cf9cSPeter Xu } else 3812103cf9cSPeter Xu *regions_needed += 1; 3822103cf9cSPeter Xu 3832103cf9cSPeter Xu return to - from; 3842103cf9cSPeter Xu } 3852103cf9cSPeter Xu 386972a3da3SWei Yang /* 387972a3da3SWei Yang * Must be called with resv->lock held. 388972a3da3SWei Yang * 389972a3da3SWei Yang * Calling this with regions_needed != NULL will count the number of pages 390972a3da3SWei Yang * to be added but will not modify the linked list. And regions_needed will 391972a3da3SWei Yang * indicate the number of file_regions needed in the cache to carry out to add 392972a3da3SWei Yang * the regions for this range. 393d75c6af9SMina Almasry */ 394d75c6af9SMina Almasry static long add_reservation_in_range(struct resv_map *resv, long f, long t, 395075a61d0SMina Almasry struct hugetlb_cgroup *h_cg, 396972a3da3SWei Yang struct hstate *h, long *regions_needed) 397d75c6af9SMina Almasry { 3980db9d74eSMina Almasry long add = 0; 399d75c6af9SMina Almasry struct list_head *head = &resv->regions; 4000db9d74eSMina Almasry long last_accounted_offset = f; 40184448c8eSJakob Koschel struct file_region *iter, *trg = NULL; 40284448c8eSJakob Koschel struct list_head *rg = NULL; 403d75c6af9SMina Almasry 4040db9d74eSMina Almasry if (regions_needed) 4050db9d74eSMina Almasry *regions_needed = 0; 406d75c6af9SMina Almasry 4070db9d74eSMina Almasry /* In this loop, we essentially handle an entry for the range 40884448c8eSJakob Koschel * [last_accounted_offset, iter->from), at every iteration, with some 4090db9d74eSMina Almasry * bounds checking. 4100db9d74eSMina Almasry */ 41184448c8eSJakob Koschel list_for_each_entry_safe(iter, trg, head, link) { 4120db9d74eSMina Almasry /* Skip irrelevant regions that start before our range. */ 41384448c8eSJakob Koschel if (iter->from < f) { 4140db9d74eSMina Almasry /* If this region ends after the last accounted offset, 4150db9d74eSMina Almasry * then we need to update last_accounted_offset. 4160db9d74eSMina Almasry */ 41784448c8eSJakob Koschel if (iter->to > last_accounted_offset) 41884448c8eSJakob Koschel last_accounted_offset = iter->to; 4190db9d74eSMina Almasry continue; 4200db9d74eSMina Almasry } 421d75c6af9SMina Almasry 4220db9d74eSMina Almasry /* When we find a region that starts beyond our range, we've 4230db9d74eSMina Almasry * finished. 4240db9d74eSMina Almasry */ 42584448c8eSJakob Koschel if (iter->from >= t) { 42684448c8eSJakob Koschel rg = iter->link.prev; 427d75c6af9SMina Almasry break; 42884448c8eSJakob Koschel } 429d75c6af9SMina Almasry 43084448c8eSJakob Koschel /* Add an entry for last_accounted_offset -> iter->from, and 4310db9d74eSMina Almasry * update last_accounted_offset. 432d75c6af9SMina Almasry */ 43384448c8eSJakob Koschel if (iter->from > last_accounted_offset) 43484448c8eSJakob Koschel add += hugetlb_resv_map_add(resv, iter->link.prev, 4352103cf9cSPeter Xu last_accounted_offset, 43684448c8eSJakob Koschel iter->from, h, h_cg, 4372103cf9cSPeter Xu regions_needed); 438d75c6af9SMina Almasry 43984448c8eSJakob Koschel last_accounted_offset = iter->to; 4400db9d74eSMina Almasry } 4410db9d74eSMina Almasry 4420db9d74eSMina Almasry /* Handle the case where our range extends beyond 4430db9d74eSMina Almasry * last_accounted_offset. 4440db9d74eSMina Almasry */ 44584448c8eSJakob Koschel if (!rg) 44684448c8eSJakob Koschel rg = head->prev; 4472103cf9cSPeter Xu if (last_accounted_offset < t) 4482103cf9cSPeter Xu add += hugetlb_resv_map_add(resv, rg, last_accounted_offset, 4492103cf9cSPeter Xu t, h, h_cg, regions_needed); 4500db9d74eSMina Almasry 4510db9d74eSMina Almasry return add; 4520db9d74eSMina Almasry } 4530db9d74eSMina Almasry 4540db9d74eSMina Almasry /* Must be called with resv->lock acquired. Will drop lock to allocate entries. 4550db9d74eSMina Almasry */ 4560db9d74eSMina Almasry static int allocate_file_region_entries(struct resv_map *resv, 4570db9d74eSMina Almasry int regions_needed) 4580db9d74eSMina Almasry __must_hold(&resv->lock) 4590db9d74eSMina Almasry { 46034665341SMiaohe Lin LIST_HEAD(allocated_regions); 4610db9d74eSMina Almasry int to_allocate = 0, i = 0; 4620db9d74eSMina Almasry struct file_region *trg = NULL, *rg = NULL; 4630db9d74eSMina Almasry 4640db9d74eSMina Almasry VM_BUG_ON(regions_needed < 0); 4650db9d74eSMina Almasry 4660db9d74eSMina Almasry /* 4670db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 4680db9d74eSMina Almasry * the number of in progress add operations plus regions_needed. 4690db9d74eSMina Almasry * 4700db9d74eSMina Almasry * This is a while loop because when we drop the lock, some other call 4710db9d74eSMina Almasry * to region_add or region_del may have consumed some region_entries, 4720db9d74eSMina Almasry * so we keep looping here until we finally have enough entries for 4730db9d74eSMina Almasry * (adds_in_progress + regions_needed). 4740db9d74eSMina Almasry */ 4750db9d74eSMina Almasry while (resv->region_cache_count < 4760db9d74eSMina Almasry (resv->adds_in_progress + regions_needed)) { 4770db9d74eSMina Almasry to_allocate = resv->adds_in_progress + regions_needed - 4780db9d74eSMina Almasry resv->region_cache_count; 4790db9d74eSMina Almasry 4800db9d74eSMina Almasry /* At this point, we should have enough entries in the cache 481f0953a1bSIngo Molnar * for all the existing adds_in_progress. We should only be 4820db9d74eSMina Almasry * needing to allocate for regions_needed. 4830db9d74eSMina Almasry */ 4840db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count < resv->adds_in_progress); 4850db9d74eSMina Almasry 4860db9d74eSMina Almasry spin_unlock(&resv->lock); 4870db9d74eSMina Almasry for (i = 0; i < to_allocate; i++) { 4880db9d74eSMina Almasry trg = kmalloc(sizeof(*trg), GFP_KERNEL); 4890db9d74eSMina Almasry if (!trg) 4900db9d74eSMina Almasry goto out_of_memory; 4910db9d74eSMina Almasry list_add(&trg->link, &allocated_regions); 4920db9d74eSMina Almasry } 4930db9d74eSMina Almasry 4940db9d74eSMina Almasry spin_lock(&resv->lock); 4950db9d74eSMina Almasry 496d3ec7b6eSWei Yang list_splice(&allocated_regions, &resv->region_cache); 497d3ec7b6eSWei Yang resv->region_cache_count += to_allocate; 4980db9d74eSMina Almasry } 4990db9d74eSMina Almasry 5000db9d74eSMina Almasry return 0; 5010db9d74eSMina Almasry 5020db9d74eSMina Almasry out_of_memory: 5030db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, &allocated_regions, link) { 504d75c6af9SMina Almasry list_del(&rg->link); 505d75c6af9SMina Almasry kfree(rg); 506d75c6af9SMina Almasry } 5070db9d74eSMina Almasry return -ENOMEM; 508d75c6af9SMina Almasry } 509d75c6af9SMina Almasry 5101dd308a7SMike Kravetz /* 5111dd308a7SMike Kravetz * Add the huge page range represented by [f, t) to the reserve 5120db9d74eSMina Almasry * map. Regions will be taken from the cache to fill in this range. 5130db9d74eSMina Almasry * Sufficient regions should exist in the cache due to the previous 5140db9d74eSMina Almasry * call to region_chg with the same range, but in some cases the cache will not 5150db9d74eSMina Almasry * have sufficient entries due to races with other code doing region_add or 5160db9d74eSMina Almasry * region_del. The extra needed entries will be allocated. 517cf3ad20bSMike Kravetz * 5180db9d74eSMina Almasry * regions_needed is the out value provided by a previous call to region_chg. 5190db9d74eSMina Almasry * 5200db9d74eSMina Almasry * Return the number of new huge pages added to the map. This number is greater 5210db9d74eSMina Almasry * than or equal to zero. If file_region entries needed to be allocated for 5227c8de358SEthon Paul * this operation and we were not able to allocate, it returns -ENOMEM. 5230db9d74eSMina Almasry * region_add of regions of length 1 never allocate file_regions and cannot 5240db9d74eSMina Almasry * fail; region_chg will always allocate at least 1 entry and a region_add for 5250db9d74eSMina Almasry * 1 page will only require at most 1 entry. 5261dd308a7SMike Kravetz */ 5270db9d74eSMina Almasry static long region_add(struct resv_map *resv, long f, long t, 528075a61d0SMina Almasry long in_regions_needed, struct hstate *h, 529075a61d0SMina Almasry struct hugetlb_cgroup *h_cg) 53096822904SAndy Whitcroft { 5310db9d74eSMina Almasry long add = 0, actual_regions_needed = 0; 53296822904SAndy Whitcroft 5337b24d861SDavidlohr Bueso spin_lock(&resv->lock); 5340db9d74eSMina Almasry retry: 5350db9d74eSMina Almasry 5360db9d74eSMina Almasry /* Count how many regions are actually needed to execute this add. */ 537972a3da3SWei Yang add_reservation_in_range(resv, f, t, NULL, NULL, 538972a3da3SWei Yang &actual_regions_needed); 53996822904SAndy Whitcroft 5405e911373SMike Kravetz /* 5410db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 5420db9d74eSMina Almasry * this add operation. Note that actual_regions_needed may be greater 5430db9d74eSMina Almasry * than in_regions_needed, as the resv_map may have been modified since 5440db9d74eSMina Almasry * the region_chg call. In this case, we need to make sure that we 5450db9d74eSMina Almasry * allocate extra entries, such that we have enough for all the 5460db9d74eSMina Almasry * existing adds_in_progress, plus the excess needed for this 5470db9d74eSMina Almasry * operation. 5485e911373SMike Kravetz */ 5490db9d74eSMina Almasry if (actual_regions_needed > in_regions_needed && 5500db9d74eSMina Almasry resv->region_cache_count < 5510db9d74eSMina Almasry resv->adds_in_progress + 5520db9d74eSMina Almasry (actual_regions_needed - in_regions_needed)) { 5530db9d74eSMina Almasry /* region_add operation of range 1 should never need to 5540db9d74eSMina Almasry * allocate file_region entries. 5550db9d74eSMina Almasry */ 5560db9d74eSMina Almasry VM_BUG_ON(t - f <= 1); 5575e911373SMike Kravetz 5580db9d74eSMina Almasry if (allocate_file_region_entries( 5590db9d74eSMina Almasry resv, actual_regions_needed - in_regions_needed)) { 5600db9d74eSMina Almasry return -ENOMEM; 5615e911373SMike Kravetz } 5625e911373SMike Kravetz 5630db9d74eSMina Almasry goto retry; 5640db9d74eSMina Almasry } 565cf3ad20bSMike Kravetz 566972a3da3SWei Yang add = add_reservation_in_range(resv, f, t, h_cg, h, NULL); 5670db9d74eSMina Almasry 5680db9d74eSMina Almasry resv->adds_in_progress -= in_regions_needed; 5690db9d74eSMina Almasry 5707b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 571cf3ad20bSMike Kravetz return add; 57296822904SAndy Whitcroft } 57396822904SAndy Whitcroft 5741dd308a7SMike Kravetz /* 5751dd308a7SMike Kravetz * Examine the existing reserve map and determine how many 5761dd308a7SMike Kravetz * huge pages in the specified range [f, t) are NOT currently 5771dd308a7SMike Kravetz * represented. This routine is called before a subsequent 5781dd308a7SMike Kravetz * call to region_add that will actually modify the reserve 5791dd308a7SMike Kravetz * map to add the specified range [f, t). region_chg does 5801dd308a7SMike Kravetz * not change the number of huge pages represented by the 5810db9d74eSMina Almasry * map. A number of new file_region structures is added to the cache as a 5820db9d74eSMina Almasry * placeholder, for the subsequent region_add call to use. At least 1 5830db9d74eSMina Almasry * file_region structure is added. 5840db9d74eSMina Almasry * 5850db9d74eSMina Almasry * out_regions_needed is the number of regions added to the 5860db9d74eSMina Almasry * resv->adds_in_progress. This value needs to be provided to a follow up call 5870db9d74eSMina Almasry * to region_add or region_abort for proper accounting. 5885e911373SMike Kravetz * 5895e911373SMike Kravetz * Returns the number of huge pages that need to be added to the existing 5905e911373SMike Kravetz * reservation map for the range [f, t). This number is greater or equal to 5915e911373SMike Kravetz * zero. -ENOMEM is returned if a new file_region structure or cache entry 5925e911373SMike Kravetz * is needed and can not be allocated. 5931dd308a7SMike Kravetz */ 5940db9d74eSMina Almasry static long region_chg(struct resv_map *resv, long f, long t, 5950db9d74eSMina Almasry long *out_regions_needed) 59696822904SAndy Whitcroft { 59796822904SAndy Whitcroft long chg = 0; 59896822904SAndy Whitcroft 5997b24d861SDavidlohr Bueso spin_lock(&resv->lock); 6005e911373SMike Kravetz 601972a3da3SWei Yang /* Count how many hugepages in this range are NOT represented. */ 602075a61d0SMina Almasry chg = add_reservation_in_range(resv, f, t, NULL, NULL, 603972a3da3SWei Yang out_regions_needed); 6045e911373SMike Kravetz 6050db9d74eSMina Almasry if (*out_regions_needed == 0) 6060db9d74eSMina Almasry *out_regions_needed = 1; 6075e911373SMike Kravetz 6080db9d74eSMina Almasry if (allocate_file_region_entries(resv, *out_regions_needed)) 6095e911373SMike Kravetz return -ENOMEM; 6105e911373SMike Kravetz 6110db9d74eSMina Almasry resv->adds_in_progress += *out_regions_needed; 61296822904SAndy Whitcroft 6137b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 61496822904SAndy Whitcroft return chg; 61596822904SAndy Whitcroft } 61696822904SAndy Whitcroft 6171dd308a7SMike Kravetz /* 6185e911373SMike Kravetz * Abort the in progress add operation. The adds_in_progress field 6195e911373SMike Kravetz * of the resv_map keeps track of the operations in progress between 6205e911373SMike Kravetz * calls to region_chg and region_add. Operations are sometimes 6215e911373SMike Kravetz * aborted after the call to region_chg. In such cases, region_abort 6220db9d74eSMina Almasry * is called to decrement the adds_in_progress counter. regions_needed 6230db9d74eSMina Almasry * is the value returned by the region_chg call, it is used to decrement 6240db9d74eSMina Almasry * the adds_in_progress counter. 6255e911373SMike Kravetz * 6265e911373SMike Kravetz * NOTE: The range arguments [f, t) are not needed or used in this 6275e911373SMike Kravetz * routine. They are kept to make reading the calling code easier as 6285e911373SMike Kravetz * arguments will match the associated region_chg call. 6295e911373SMike Kravetz */ 6300db9d74eSMina Almasry static void region_abort(struct resv_map *resv, long f, long t, 6310db9d74eSMina Almasry long regions_needed) 6325e911373SMike Kravetz { 6335e911373SMike Kravetz spin_lock(&resv->lock); 6345e911373SMike Kravetz VM_BUG_ON(!resv->region_cache_count); 6350db9d74eSMina Almasry resv->adds_in_progress -= regions_needed; 6365e911373SMike Kravetz spin_unlock(&resv->lock); 6375e911373SMike Kravetz } 6385e911373SMike Kravetz 6395e911373SMike Kravetz /* 640feba16e2SMike Kravetz * Delete the specified range [f, t) from the reserve map. If the 641feba16e2SMike Kravetz * t parameter is LONG_MAX, this indicates that ALL regions after f 642feba16e2SMike Kravetz * should be deleted. Locate the regions which intersect [f, t) 643feba16e2SMike Kravetz * and either trim, delete or split the existing regions. 644feba16e2SMike Kravetz * 645feba16e2SMike Kravetz * Returns the number of huge pages deleted from the reserve map. 646feba16e2SMike Kravetz * In the normal case, the return value is zero or more. In the 647feba16e2SMike Kravetz * case where a region must be split, a new region descriptor must 648feba16e2SMike Kravetz * be allocated. If the allocation fails, -ENOMEM will be returned. 649feba16e2SMike Kravetz * NOTE: If the parameter t == LONG_MAX, then we will never split 650feba16e2SMike Kravetz * a region and possibly return -ENOMEM. Callers specifying 651feba16e2SMike Kravetz * t == LONG_MAX do not need to check for -ENOMEM error. 6521dd308a7SMike Kravetz */ 653feba16e2SMike Kravetz static long region_del(struct resv_map *resv, long f, long t) 65496822904SAndy Whitcroft { 6551406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 65696822904SAndy Whitcroft struct file_region *rg, *trg; 657feba16e2SMike Kravetz struct file_region *nrg = NULL; 658feba16e2SMike Kravetz long del = 0; 65996822904SAndy Whitcroft 660feba16e2SMike Kravetz retry: 6617b24d861SDavidlohr Bueso spin_lock(&resv->lock); 662feba16e2SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 663dbe409e4SMike Kravetz /* 664dbe409e4SMike Kravetz * Skip regions before the range to be deleted. file_region 665dbe409e4SMike Kravetz * ranges are normally of the form [from, to). However, there 666dbe409e4SMike Kravetz * may be a "placeholder" entry in the map which is of the form 667dbe409e4SMike Kravetz * (from, to) with from == to. Check for placeholder entries 668dbe409e4SMike Kravetz * at the beginning of the range to be deleted. 669dbe409e4SMike Kravetz */ 670dbe409e4SMike Kravetz if (rg->to <= f && (rg->to != rg->from || rg->to != f)) 671feba16e2SMike Kravetz continue; 672dbe409e4SMike Kravetz 673feba16e2SMike Kravetz if (rg->from >= t) 67496822904SAndy Whitcroft break; 67596822904SAndy Whitcroft 676feba16e2SMike Kravetz if (f > rg->from && t < rg->to) { /* Must split region */ 677feba16e2SMike Kravetz /* 678feba16e2SMike Kravetz * Check for an entry in the cache before dropping 679feba16e2SMike Kravetz * lock and attempting allocation. 680feba16e2SMike Kravetz */ 681feba16e2SMike Kravetz if (!nrg && 682feba16e2SMike Kravetz resv->region_cache_count > resv->adds_in_progress) { 683feba16e2SMike Kravetz nrg = list_first_entry(&resv->region_cache, 684feba16e2SMike Kravetz struct file_region, 685feba16e2SMike Kravetz link); 686feba16e2SMike Kravetz list_del(&nrg->link); 687feba16e2SMike Kravetz resv->region_cache_count--; 68896822904SAndy Whitcroft } 68996822904SAndy Whitcroft 690feba16e2SMike Kravetz if (!nrg) { 691feba16e2SMike Kravetz spin_unlock(&resv->lock); 692feba16e2SMike Kravetz nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); 693feba16e2SMike Kravetz if (!nrg) 694feba16e2SMike Kravetz return -ENOMEM; 695feba16e2SMike Kravetz goto retry; 696feba16e2SMike Kravetz } 697feba16e2SMike Kravetz 698feba16e2SMike Kravetz del += t - f; 69979aa925bSMike Kravetz hugetlb_cgroup_uncharge_file_region( 700d85aecf2SMiaohe Lin resv, rg, t - f, false); 701feba16e2SMike Kravetz 702feba16e2SMike Kravetz /* New entry for end of split region */ 703feba16e2SMike Kravetz nrg->from = t; 704feba16e2SMike Kravetz nrg->to = rg->to; 705075a61d0SMina Almasry 706075a61d0SMina Almasry copy_hugetlb_cgroup_uncharge_info(nrg, rg); 707075a61d0SMina Almasry 708feba16e2SMike Kravetz INIT_LIST_HEAD(&nrg->link); 709feba16e2SMike Kravetz 710feba16e2SMike Kravetz /* Original entry is trimmed */ 711feba16e2SMike Kravetz rg->to = f; 712feba16e2SMike Kravetz 713feba16e2SMike Kravetz list_add(&nrg->link, &rg->link); 714feba16e2SMike Kravetz nrg = NULL; 71596822904SAndy Whitcroft break; 716feba16e2SMike Kravetz } 717feba16e2SMike Kravetz 718feba16e2SMike Kravetz if (f <= rg->from && t >= rg->to) { /* Remove entire region */ 719feba16e2SMike Kravetz del += rg->to - rg->from; 720075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 721d85aecf2SMiaohe Lin rg->to - rg->from, true); 72296822904SAndy Whitcroft list_del(&rg->link); 72396822904SAndy Whitcroft kfree(rg); 724feba16e2SMike Kravetz continue; 72596822904SAndy Whitcroft } 7267b24d861SDavidlohr Bueso 727feba16e2SMike Kravetz if (f <= rg->from) { /* Trim beginning of region */ 728075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 729d85aecf2SMiaohe Lin t - rg->from, false); 730075a61d0SMina Almasry 73179aa925bSMike Kravetz del += t - rg->from; 73279aa925bSMike Kravetz rg->from = t; 73379aa925bSMike Kravetz } else { /* Trim end of region */ 734075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 735d85aecf2SMiaohe Lin rg->to - f, false); 73679aa925bSMike Kravetz 73779aa925bSMike Kravetz del += rg->to - f; 73879aa925bSMike Kravetz rg->to = f; 739feba16e2SMike Kravetz } 740feba16e2SMike Kravetz } 741feba16e2SMike Kravetz 7427b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 743feba16e2SMike Kravetz kfree(nrg); 744feba16e2SMike Kravetz return del; 74596822904SAndy Whitcroft } 74696822904SAndy Whitcroft 7471dd308a7SMike Kravetz /* 748b5cec28dSMike Kravetz * A rare out of memory error was encountered which prevented removal of 749b5cec28dSMike Kravetz * the reserve map region for a page. The huge page itself was free'ed 750b5cec28dSMike Kravetz * and removed from the page cache. This routine will adjust the subpool 751b5cec28dSMike Kravetz * usage count, and the global reserve count if needed. By incrementing 752b5cec28dSMike Kravetz * these counts, the reserve map entry which could not be deleted will 753b5cec28dSMike Kravetz * appear as a "reserved" entry instead of simply dangling with incorrect 754b5cec28dSMike Kravetz * counts. 755b5cec28dSMike Kravetz */ 75672e2936cSzhong jiang void hugetlb_fix_reserve_counts(struct inode *inode) 757b5cec28dSMike Kravetz { 758b5cec28dSMike Kravetz struct hugepage_subpool *spool = subpool_inode(inode); 759b5cec28dSMike Kravetz long rsv_adjust; 760da56388cSMiaohe Lin bool reserved = false; 761b5cec28dSMike Kravetz 762b5cec28dSMike Kravetz rsv_adjust = hugepage_subpool_get_pages(spool, 1); 763da56388cSMiaohe Lin if (rsv_adjust > 0) { 764b5cec28dSMike Kravetz struct hstate *h = hstate_inode(inode); 765b5cec28dSMike Kravetz 766da56388cSMiaohe Lin if (!hugetlb_acct_memory(h, 1)) 767da56388cSMiaohe Lin reserved = true; 768da56388cSMiaohe Lin } else if (!rsv_adjust) { 769da56388cSMiaohe Lin reserved = true; 770b5cec28dSMike Kravetz } 771da56388cSMiaohe Lin 772da56388cSMiaohe Lin if (!reserved) 773da56388cSMiaohe Lin pr_warn("hugetlb: Huge Page Reserved count may go negative.\n"); 774b5cec28dSMike Kravetz } 775b5cec28dSMike Kravetz 776b5cec28dSMike Kravetz /* 7771dd308a7SMike Kravetz * Count and return the number of huge pages in the reserve map 7781dd308a7SMike Kravetz * that intersect with the range [f, t). 7791dd308a7SMike Kravetz */ 7801406ec9bSJoonsoo Kim static long region_count(struct resv_map *resv, long f, long t) 78184afd99bSAndy Whitcroft { 7821406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 78384afd99bSAndy Whitcroft struct file_region *rg; 78484afd99bSAndy Whitcroft long chg = 0; 78584afd99bSAndy Whitcroft 7867b24d861SDavidlohr Bueso spin_lock(&resv->lock); 78784afd99bSAndy Whitcroft /* Locate each segment we overlap with, and count that overlap. */ 78884afd99bSAndy Whitcroft list_for_each_entry(rg, head, link) { 789f2135a4aSWang Sheng-Hui long seg_from; 790f2135a4aSWang Sheng-Hui long seg_to; 79184afd99bSAndy Whitcroft 79284afd99bSAndy Whitcroft if (rg->to <= f) 79384afd99bSAndy Whitcroft continue; 79484afd99bSAndy Whitcroft if (rg->from >= t) 79584afd99bSAndy Whitcroft break; 79684afd99bSAndy Whitcroft 79784afd99bSAndy Whitcroft seg_from = max(rg->from, f); 79884afd99bSAndy Whitcroft seg_to = min(rg->to, t); 79984afd99bSAndy Whitcroft 80084afd99bSAndy Whitcroft chg += seg_to - seg_from; 80184afd99bSAndy Whitcroft } 8027b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 80384afd99bSAndy Whitcroft 80484afd99bSAndy Whitcroft return chg; 80584afd99bSAndy Whitcroft } 80684afd99bSAndy Whitcroft 80796822904SAndy Whitcroft /* 808e7c4b0bfSAndy Whitcroft * Convert the address within this vma to the page offset within 809e7c4b0bfSAndy Whitcroft * the mapping, in pagecache page units; huge pages here. 810e7c4b0bfSAndy Whitcroft */ 811a5516438SAndi Kleen static pgoff_t vma_hugecache_offset(struct hstate *h, 812a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 813e7c4b0bfSAndy Whitcroft { 814a5516438SAndi Kleen return ((address - vma->vm_start) >> huge_page_shift(h)) + 815a5516438SAndi Kleen (vma->vm_pgoff >> huge_page_order(h)); 816e7c4b0bfSAndy Whitcroft } 817e7c4b0bfSAndy Whitcroft 8180fe6e20bSNaoya Horiguchi pgoff_t linear_hugepage_index(struct vm_area_struct *vma, 8190fe6e20bSNaoya Horiguchi unsigned long address) 8200fe6e20bSNaoya Horiguchi { 8210fe6e20bSNaoya Horiguchi return vma_hugecache_offset(hstate_vma(vma), vma, address); 8220fe6e20bSNaoya Horiguchi } 823dee41079SDan Williams EXPORT_SYMBOL_GPL(linear_hugepage_index); 8240fe6e20bSNaoya Horiguchi 82584afd99bSAndy Whitcroft /* 82608fba699SMel Gorman * Return the size of the pages allocated when backing a VMA. In the majority 82708fba699SMel Gorman * cases this will be same size as used by the page table entries. 82808fba699SMel Gorman */ 82908fba699SMel Gorman unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) 83008fba699SMel Gorman { 83105ea8860SDan Williams if (vma->vm_ops && vma->vm_ops->pagesize) 83205ea8860SDan Williams return vma->vm_ops->pagesize(vma); 83308fba699SMel Gorman return PAGE_SIZE; 83408fba699SMel Gorman } 835f340ca0fSJoerg Roedel EXPORT_SYMBOL_GPL(vma_kernel_pagesize); 83608fba699SMel Gorman 83708fba699SMel Gorman /* 8383340289dSMel Gorman * Return the page size being used by the MMU to back a VMA. In the majority 8393340289dSMel Gorman * of cases, the page size used by the kernel matches the MMU size. On 84009135cc5SDan Williams * architectures where it differs, an architecture-specific 'strong' 84109135cc5SDan Williams * version of this symbol is required. 8423340289dSMel Gorman */ 84309135cc5SDan Williams __weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) 8443340289dSMel Gorman { 8453340289dSMel Gorman return vma_kernel_pagesize(vma); 8463340289dSMel Gorman } 8473340289dSMel Gorman 8483340289dSMel Gorman /* 84984afd99bSAndy Whitcroft * Flags for MAP_PRIVATE reservations. These are stored in the bottom 85084afd99bSAndy Whitcroft * bits of the reservation map pointer, which are always clear due to 85184afd99bSAndy Whitcroft * alignment. 85284afd99bSAndy Whitcroft */ 85384afd99bSAndy Whitcroft #define HPAGE_RESV_OWNER (1UL << 0) 85484afd99bSAndy Whitcroft #define HPAGE_RESV_UNMAPPED (1UL << 1) 85504f2cbe3SMel Gorman #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) 85684afd99bSAndy Whitcroft 857a1e78772SMel Gorman /* 858a1e78772SMel Gorman * These helpers are used to track how many pages are reserved for 859a1e78772SMel Gorman * faults in a MAP_PRIVATE mapping. Only the process that called mmap() 860a1e78772SMel Gorman * is guaranteed to have their future faults succeed. 861a1e78772SMel Gorman * 862a1e78772SMel Gorman * With the exception of reset_vma_resv_huge_pages() which is called at fork(), 863a1e78772SMel Gorman * the reserve counters are updated with the hugetlb_lock held. It is safe 864a1e78772SMel Gorman * to reset the VMA at fork() time as it is not in use yet and there is no 865a1e78772SMel Gorman * chance of the global counters getting corrupted as a result of the values. 86684afd99bSAndy Whitcroft * 86784afd99bSAndy Whitcroft * The private mapping reservation is represented in a subtly different 86884afd99bSAndy Whitcroft * manner to a shared mapping. A shared mapping has a region map associated 86984afd99bSAndy Whitcroft * with the underlying file, this region map represents the backing file 87084afd99bSAndy Whitcroft * pages which have ever had a reservation assigned which this persists even 87184afd99bSAndy Whitcroft * after the page is instantiated. A private mapping has a region map 87284afd99bSAndy Whitcroft * associated with the original mmap which is attached to all VMAs which 87384afd99bSAndy Whitcroft * reference it, this region map represents those offsets which have consumed 87484afd99bSAndy Whitcroft * reservation ie. where pages have been instantiated. 875a1e78772SMel Gorman */ 876e7c4b0bfSAndy Whitcroft static unsigned long get_vma_private_data(struct vm_area_struct *vma) 877e7c4b0bfSAndy Whitcroft { 878e7c4b0bfSAndy Whitcroft return (unsigned long)vma->vm_private_data; 879e7c4b0bfSAndy Whitcroft } 880e7c4b0bfSAndy Whitcroft 881e7c4b0bfSAndy Whitcroft static void set_vma_private_data(struct vm_area_struct *vma, 882e7c4b0bfSAndy Whitcroft unsigned long value) 883e7c4b0bfSAndy Whitcroft { 884e7c4b0bfSAndy Whitcroft vma->vm_private_data = (void *)value; 885e7c4b0bfSAndy Whitcroft } 886e7c4b0bfSAndy Whitcroft 887e9fe92aeSMina Almasry static void 888e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(struct resv_map *resv_map, 889e9fe92aeSMina Almasry struct hugetlb_cgroup *h_cg, 890e9fe92aeSMina Almasry struct hstate *h) 891e9fe92aeSMina Almasry { 892e9fe92aeSMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 893e9fe92aeSMina Almasry if (!h_cg || !h) { 894e9fe92aeSMina Almasry resv_map->reservation_counter = NULL; 895e9fe92aeSMina Almasry resv_map->pages_per_hpage = 0; 896e9fe92aeSMina Almasry resv_map->css = NULL; 897e9fe92aeSMina Almasry } else { 898e9fe92aeSMina Almasry resv_map->reservation_counter = 899e9fe92aeSMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 900e9fe92aeSMina Almasry resv_map->pages_per_hpage = pages_per_huge_page(h); 901e9fe92aeSMina Almasry resv_map->css = &h_cg->css; 902e9fe92aeSMina Almasry } 903e9fe92aeSMina Almasry #endif 904e9fe92aeSMina Almasry } 905e9fe92aeSMina Almasry 9069119a41eSJoonsoo Kim struct resv_map *resv_map_alloc(void) 90784afd99bSAndy Whitcroft { 90884afd99bSAndy Whitcroft struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); 9095e911373SMike Kravetz struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL); 9105e911373SMike Kravetz 9115e911373SMike Kravetz if (!resv_map || !rg) { 9125e911373SMike Kravetz kfree(resv_map); 9135e911373SMike Kravetz kfree(rg); 91484afd99bSAndy Whitcroft return NULL; 9155e911373SMike Kravetz } 91684afd99bSAndy Whitcroft 91784afd99bSAndy Whitcroft kref_init(&resv_map->refs); 9187b24d861SDavidlohr Bueso spin_lock_init(&resv_map->lock); 91984afd99bSAndy Whitcroft INIT_LIST_HEAD(&resv_map->regions); 92084afd99bSAndy Whitcroft 9215e911373SMike Kravetz resv_map->adds_in_progress = 0; 922e9fe92aeSMina Almasry /* 923e9fe92aeSMina Almasry * Initialize these to 0. On shared mappings, 0's here indicate these 924e9fe92aeSMina Almasry * fields don't do cgroup accounting. On private mappings, these will be 925e9fe92aeSMina Almasry * re-initialized to the proper values, to indicate that hugetlb cgroup 926e9fe92aeSMina Almasry * reservations are to be un-charged from here. 927e9fe92aeSMina Almasry */ 928e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, NULL, NULL); 9295e911373SMike Kravetz 9305e911373SMike Kravetz INIT_LIST_HEAD(&resv_map->region_cache); 9315e911373SMike Kravetz list_add(&rg->link, &resv_map->region_cache); 9325e911373SMike Kravetz resv_map->region_cache_count = 1; 9335e911373SMike Kravetz 93484afd99bSAndy Whitcroft return resv_map; 93584afd99bSAndy Whitcroft } 93684afd99bSAndy Whitcroft 9379119a41eSJoonsoo Kim void resv_map_release(struct kref *ref) 93884afd99bSAndy Whitcroft { 93984afd99bSAndy Whitcroft struct resv_map *resv_map = container_of(ref, struct resv_map, refs); 9405e911373SMike Kravetz struct list_head *head = &resv_map->region_cache; 9415e911373SMike Kravetz struct file_region *rg, *trg; 94284afd99bSAndy Whitcroft 94384afd99bSAndy Whitcroft /* Clear out any active regions before we release the map. */ 944feba16e2SMike Kravetz region_del(resv_map, 0, LONG_MAX); 9455e911373SMike Kravetz 9465e911373SMike Kravetz /* ... and any entries left in the cache */ 9475e911373SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 9485e911373SMike Kravetz list_del(&rg->link); 9495e911373SMike Kravetz kfree(rg); 9505e911373SMike Kravetz } 9515e911373SMike Kravetz 9525e911373SMike Kravetz VM_BUG_ON(resv_map->adds_in_progress); 9535e911373SMike Kravetz 95484afd99bSAndy Whitcroft kfree(resv_map); 95584afd99bSAndy Whitcroft } 95684afd99bSAndy Whitcroft 9574e35f483SJoonsoo Kim static inline struct resv_map *inode_resv_map(struct inode *inode) 9584e35f483SJoonsoo Kim { 959f27a5136SMike Kravetz /* 960f27a5136SMike Kravetz * At inode evict time, i_mapping may not point to the original 961f27a5136SMike Kravetz * address space within the inode. This original address space 962f27a5136SMike Kravetz * contains the pointer to the resv_map. So, always use the 963f27a5136SMike Kravetz * address space embedded within the inode. 964f27a5136SMike Kravetz * The VERY common case is inode->mapping == &inode->i_data but, 965f27a5136SMike Kravetz * this may not be true for device special inodes. 966f27a5136SMike Kravetz */ 967f27a5136SMike Kravetz return (struct resv_map *)(&inode->i_data)->private_data; 9684e35f483SJoonsoo Kim } 9694e35f483SJoonsoo Kim 97084afd99bSAndy Whitcroft static struct resv_map *vma_resv_map(struct vm_area_struct *vma) 971a1e78772SMel Gorman { 97281d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 9734e35f483SJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE) { 9744e35f483SJoonsoo Kim struct address_space *mapping = vma->vm_file->f_mapping; 9754e35f483SJoonsoo Kim struct inode *inode = mapping->host; 9764e35f483SJoonsoo Kim 9774e35f483SJoonsoo Kim return inode_resv_map(inode); 9784e35f483SJoonsoo Kim 9794e35f483SJoonsoo Kim } else { 98084afd99bSAndy Whitcroft return (struct resv_map *)(get_vma_private_data(vma) & 98184afd99bSAndy Whitcroft ~HPAGE_RESV_MASK); 9824e35f483SJoonsoo Kim } 983a1e78772SMel Gorman } 984a1e78772SMel Gorman 98584afd99bSAndy Whitcroft static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) 986a1e78772SMel Gorman { 98781d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 98881d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 989a1e78772SMel Gorman 99084afd99bSAndy Whitcroft set_vma_private_data(vma, (get_vma_private_data(vma) & 99184afd99bSAndy Whitcroft HPAGE_RESV_MASK) | (unsigned long)map); 99204f2cbe3SMel Gorman } 99304f2cbe3SMel Gorman 99404f2cbe3SMel Gorman static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) 99504f2cbe3SMel Gorman { 99681d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 99781d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 998e7c4b0bfSAndy Whitcroft 999e7c4b0bfSAndy Whitcroft set_vma_private_data(vma, get_vma_private_data(vma) | flags); 100004f2cbe3SMel Gorman } 100104f2cbe3SMel Gorman 100204f2cbe3SMel Gorman static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) 100304f2cbe3SMel Gorman { 100481d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 1005e7c4b0bfSAndy Whitcroft 1006e7c4b0bfSAndy Whitcroft return (get_vma_private_data(vma) & flag) != 0; 1007a1e78772SMel Gorman } 1008a1e78772SMel Gorman 100904f2cbe3SMel Gorman /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ 1010a1e78772SMel Gorman void reset_vma_resv_huge_pages(struct vm_area_struct *vma) 1011a1e78772SMel Gorman { 101281d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 1013f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 1014a1e78772SMel Gorman vma->vm_private_data = (void *)0; 1015a1e78772SMel Gorman } 1016a1e78772SMel Gorman 1017550a7d60SMina Almasry /* 1018550a7d60SMina Almasry * Reset and decrement one ref on hugepage private reservation. 1019550a7d60SMina Almasry * Called with mm->mmap_sem writer semaphore held. 1020550a7d60SMina Almasry * This function should be only used by move_vma() and operate on 1021550a7d60SMina Almasry * same sized vma. It should never come here with last ref on the 1022550a7d60SMina Almasry * reservation. 1023550a7d60SMina Almasry */ 1024550a7d60SMina Almasry void clear_vma_resv_huge_pages(struct vm_area_struct *vma) 1025550a7d60SMina Almasry { 1026550a7d60SMina Almasry /* 1027550a7d60SMina Almasry * Clear the old hugetlb private page reservation. 1028550a7d60SMina Almasry * It has already been transferred to new_vma. 1029550a7d60SMina Almasry * 1030550a7d60SMina Almasry * During a mremap() operation of a hugetlb vma we call move_vma() 1031550a7d60SMina Almasry * which copies vma into new_vma and unmaps vma. After the copy 1032550a7d60SMina Almasry * operation both new_vma and vma share a reference to the resv_map 1033550a7d60SMina Almasry * struct, and at that point vma is about to be unmapped. We don't 1034550a7d60SMina Almasry * want to return the reservation to the pool at unmap of vma because 1035550a7d60SMina Almasry * the reservation still lives on in new_vma, so simply decrement the 1036550a7d60SMina Almasry * ref here and remove the resv_map reference from this vma. 1037550a7d60SMina Almasry */ 1038550a7d60SMina Almasry struct resv_map *reservations = vma_resv_map(vma); 1039550a7d60SMina Almasry 1040afe041c2SBui Quang Minh if (reservations && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 1041afe041c2SBui Quang Minh resv_map_put_hugetlb_cgroup_uncharge_info(reservations); 1042550a7d60SMina Almasry kref_put(&reservations->refs, resv_map_release); 1043afe041c2SBui Quang Minh } 1044550a7d60SMina Almasry 1045550a7d60SMina Almasry reset_vma_resv_huge_pages(vma); 1046550a7d60SMina Almasry } 1047550a7d60SMina Almasry 1048a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 1049559ec2f8SNicholas Krause static bool vma_has_reserves(struct vm_area_struct *vma, long chg) 1050a1e78772SMel Gorman { 1051af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_NORESERVE) { 1052af0ed73eSJoonsoo Kim /* 1053af0ed73eSJoonsoo Kim * This address is already reserved by other process(chg == 0), 1054af0ed73eSJoonsoo Kim * so, we should decrement reserved count. Without decrementing, 1055af0ed73eSJoonsoo Kim * reserve count remains after releasing inode, because this 1056af0ed73eSJoonsoo Kim * allocated page will go into page cache and is regarded as 1057af0ed73eSJoonsoo Kim * coming from reserved pool in releasing step. Currently, we 1058af0ed73eSJoonsoo Kim * don't have any other solution to deal with this situation 1059af0ed73eSJoonsoo Kim * properly, so add work-around here. 1060af0ed73eSJoonsoo Kim */ 1061af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE && chg == 0) 1062559ec2f8SNicholas Krause return true; 1063af0ed73eSJoonsoo Kim else 1064559ec2f8SNicholas Krause return false; 1065af0ed73eSJoonsoo Kim } 1066a63884e9SJoonsoo Kim 1067a63884e9SJoonsoo Kim /* Shared mappings always use reserves */ 10681fb1b0e9SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 10691fb1b0e9SMike Kravetz /* 10701fb1b0e9SMike Kravetz * We know VM_NORESERVE is not set. Therefore, there SHOULD 10711fb1b0e9SMike Kravetz * be a region map for all pages. The only situation where 10721fb1b0e9SMike Kravetz * there is no region map is if a hole was punched via 10737c8de358SEthon Paul * fallocate. In this case, there really are no reserves to 10741fb1b0e9SMike Kravetz * use. This situation is indicated if chg != 0. 10751fb1b0e9SMike Kravetz */ 10761fb1b0e9SMike Kravetz if (chg) 10771fb1b0e9SMike Kravetz return false; 10781fb1b0e9SMike Kravetz else 1079559ec2f8SNicholas Krause return true; 10801fb1b0e9SMike Kravetz } 1081a63884e9SJoonsoo Kim 1082a63884e9SJoonsoo Kim /* 1083a63884e9SJoonsoo Kim * Only the process that called mmap() has reserves for 1084a63884e9SJoonsoo Kim * private mappings. 1085a63884e9SJoonsoo Kim */ 108667961f9dSMike Kravetz if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 108767961f9dSMike Kravetz /* 108867961f9dSMike Kravetz * Like the shared case above, a hole punch or truncate 108967961f9dSMike Kravetz * could have been performed on the private mapping. 109067961f9dSMike Kravetz * Examine the value of chg to determine if reserves 109167961f9dSMike Kravetz * actually exist or were previously consumed. 109267961f9dSMike Kravetz * Very Subtle - The value of chg comes from a previous 109367961f9dSMike Kravetz * call to vma_needs_reserves(). The reserve map for 109467961f9dSMike Kravetz * private mappings has different (opposite) semantics 109567961f9dSMike Kravetz * than that of shared mappings. vma_needs_reserves() 109667961f9dSMike Kravetz * has already taken this difference in semantics into 109767961f9dSMike Kravetz * account. Therefore, the meaning of chg is the same 109867961f9dSMike Kravetz * as in the shared case above. Code could easily be 109967961f9dSMike Kravetz * combined, but keeping it separate draws attention to 110067961f9dSMike Kravetz * subtle differences. 110167961f9dSMike Kravetz */ 110267961f9dSMike Kravetz if (chg) 110367961f9dSMike Kravetz return false; 110467961f9dSMike Kravetz else 1105559ec2f8SNicholas Krause return true; 110667961f9dSMike Kravetz } 1107a63884e9SJoonsoo Kim 1108559ec2f8SNicholas Krause return false; 1109a1e78772SMel Gorman } 1110a1e78772SMel Gorman 1111a5516438SAndi Kleen static void enqueue_huge_page(struct hstate *h, struct page *page) 11121da177e4SLinus Torvalds { 11131da177e4SLinus Torvalds int nid = page_to_nid(page); 11149487ca60SMike Kravetz 11159487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1116b65a4edaSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1117b65a4edaSMike Kravetz 11180edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_freelists[nid]); 1119a5516438SAndi Kleen h->free_huge_pages++; 1120a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 11216c037149SMike Kravetz SetHPageFreed(page); 11221da177e4SLinus Torvalds } 11231da177e4SLinus Torvalds 112494310cbcSAnshuman Khandual static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) 1125bf50bab2SNaoya Horiguchi { 1126bf50bab2SNaoya Horiguchi struct page *page; 11271a08ae36SPavel Tatashin bool pin = !!(current->flags & PF_MEMALLOC_PIN); 1128bf50bab2SNaoya Horiguchi 11299487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1130bbe88753SJoonsoo Kim list_for_each_entry(page, &h->hugepage_freelists[nid], lru) { 11316077c943SAlex Sierra if (pin && !is_longterm_pinnable_page(page)) 1132bbe88753SJoonsoo Kim continue; 1133bbe88753SJoonsoo Kim 11346664bfc8SWei Yang if (PageHWPoison(page)) 11356664bfc8SWei Yang continue; 1136bbe88753SJoonsoo Kim 11370edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_activelist); 1138a9869b83SNaoya Horiguchi set_page_refcounted(page); 11396c037149SMike Kravetz ClearHPageFreed(page); 1140bf50bab2SNaoya Horiguchi h->free_huge_pages--; 1141bf50bab2SNaoya Horiguchi h->free_huge_pages_node[nid]--; 1142bf50bab2SNaoya Horiguchi return page; 1143bf50bab2SNaoya Horiguchi } 1144bf50bab2SNaoya Horiguchi 11456664bfc8SWei Yang return NULL; 11466664bfc8SWei Yang } 11476664bfc8SWei Yang 11483e59fcb0SMichal Hocko static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid, 11493e59fcb0SMichal Hocko nodemask_t *nmask) 115094310cbcSAnshuman Khandual { 11513e59fcb0SMichal Hocko unsigned int cpuset_mems_cookie; 11523e59fcb0SMichal Hocko struct zonelist *zonelist; 11533e59fcb0SMichal Hocko struct zone *zone; 11543e59fcb0SMichal Hocko struct zoneref *z; 115598fa15f3SAnshuman Khandual int node = NUMA_NO_NODE; 11563e59fcb0SMichal Hocko 11573e59fcb0SMichal Hocko zonelist = node_zonelist(nid, gfp_mask); 11583e59fcb0SMichal Hocko 11593e59fcb0SMichal Hocko retry_cpuset: 11603e59fcb0SMichal Hocko cpuset_mems_cookie = read_mems_allowed_begin(); 11613e59fcb0SMichal Hocko for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) { 116294310cbcSAnshuman Khandual struct page *page; 116394310cbcSAnshuman Khandual 11643e59fcb0SMichal Hocko if (!cpuset_zone_allowed(zone, gfp_mask)) 11653e59fcb0SMichal Hocko continue; 11663e59fcb0SMichal Hocko /* 11673e59fcb0SMichal Hocko * no need to ask again on the same node. Pool is node rather than 11683e59fcb0SMichal Hocko * zone aware 11693e59fcb0SMichal Hocko */ 11703e59fcb0SMichal Hocko if (zone_to_nid(zone) == node) 11713e59fcb0SMichal Hocko continue; 11723e59fcb0SMichal Hocko node = zone_to_nid(zone); 117394310cbcSAnshuman Khandual 117494310cbcSAnshuman Khandual page = dequeue_huge_page_node_exact(h, node); 117594310cbcSAnshuman Khandual if (page) 117694310cbcSAnshuman Khandual return page; 117794310cbcSAnshuman Khandual } 11783e59fcb0SMichal Hocko if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie))) 11793e59fcb0SMichal Hocko goto retry_cpuset; 11803e59fcb0SMichal Hocko 118194310cbcSAnshuman Khandual return NULL; 118294310cbcSAnshuman Khandual } 118394310cbcSAnshuman Khandual 1184a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 1185a5516438SAndi Kleen struct vm_area_struct *vma, 1186af0ed73eSJoonsoo Kim unsigned long address, int avoid_reserve, 1187af0ed73eSJoonsoo Kim long chg) 11881da177e4SLinus Torvalds { 1189cfcaa66fSBen Widawsky struct page *page = NULL; 1190480eccf9SLee Schermerhorn struct mempolicy *mpol; 119104ec6264SVlastimil Babka gfp_t gfp_mask; 11923e59fcb0SMichal Hocko nodemask_t *nodemask; 119304ec6264SVlastimil Babka int nid; 11941da177e4SLinus Torvalds 1195a1e78772SMel Gorman /* 1196a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 1197a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 1198a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 1199a1e78772SMel Gorman */ 1200af0ed73eSJoonsoo Kim if (!vma_has_reserves(vma, chg) && 1201a5516438SAndi Kleen h->free_huge_pages - h->resv_huge_pages == 0) 1202c0ff7453SMiao Xie goto err; 1203a1e78772SMel Gorman 120404f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 1205a5516438SAndi Kleen if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) 12066eab04a8SJustin P. Mattock goto err; 120704f2cbe3SMel Gorman 120804ec6264SVlastimil Babka gfp_mask = htlb_alloc_mask(h); 120904ec6264SVlastimil Babka nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 1210cfcaa66fSBen Widawsky 1211cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 12123e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1213cfcaa66fSBen Widawsky 1214cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 1215cfcaa66fSBen Widawsky nodemask = NULL; 1216cfcaa66fSBen Widawsky } 1217cfcaa66fSBen Widawsky 1218cfcaa66fSBen Widawsky if (!page) 1219cfcaa66fSBen Widawsky page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1220cfcaa66fSBen Widawsky 12213e59fcb0SMichal Hocko if (page && !avoid_reserve && vma_has_reserves(vma, chg)) { 1222d6995da3SMike Kravetz SetHPageRestoreReserve(page); 1223a63884e9SJoonsoo Kim h->resv_huge_pages--; 1224bf50bab2SNaoya Horiguchi } 1225cc9a6c87SMel Gorman 1226cc9a6c87SMel Gorman mpol_cond_put(mpol); 1227cc9a6c87SMel Gorman return page; 1228cc9a6c87SMel Gorman 1229c0ff7453SMiao Xie err: 1230cc9a6c87SMel Gorman return NULL; 12311da177e4SLinus Torvalds } 12321da177e4SLinus Torvalds 12331cac6f2cSLuiz Capitulino /* 12341cac6f2cSLuiz Capitulino * common helper functions for hstate_next_node_to_{alloc|free}. 12351cac6f2cSLuiz Capitulino * We may have allocated or freed a huge page based on a different 12361cac6f2cSLuiz Capitulino * nodes_allowed previously, so h->next_node_to_{alloc|free} might 12371cac6f2cSLuiz Capitulino * be outside of *nodes_allowed. Ensure that we use an allowed 12381cac6f2cSLuiz Capitulino * node for alloc or free. 12391cac6f2cSLuiz Capitulino */ 12401cac6f2cSLuiz Capitulino static int next_node_allowed(int nid, nodemask_t *nodes_allowed) 12411cac6f2cSLuiz Capitulino { 12420edaf86cSAndrew Morton nid = next_node_in(nid, *nodes_allowed); 12431cac6f2cSLuiz Capitulino VM_BUG_ON(nid >= MAX_NUMNODES); 12441cac6f2cSLuiz Capitulino 12451cac6f2cSLuiz Capitulino return nid; 12461cac6f2cSLuiz Capitulino } 12471cac6f2cSLuiz Capitulino 12481cac6f2cSLuiz Capitulino static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) 12491cac6f2cSLuiz Capitulino { 12501cac6f2cSLuiz Capitulino if (!node_isset(nid, *nodes_allowed)) 12511cac6f2cSLuiz Capitulino nid = next_node_allowed(nid, nodes_allowed); 12521cac6f2cSLuiz Capitulino return nid; 12531cac6f2cSLuiz Capitulino } 12541cac6f2cSLuiz Capitulino 12551cac6f2cSLuiz Capitulino /* 12561cac6f2cSLuiz Capitulino * returns the previously saved node ["this node"] from which to 12571cac6f2cSLuiz Capitulino * allocate a persistent huge page for the pool and advance the 12581cac6f2cSLuiz Capitulino * next node from which to allocate, handling wrap at end of node 12591cac6f2cSLuiz Capitulino * mask. 12601cac6f2cSLuiz Capitulino */ 12611cac6f2cSLuiz Capitulino static int hstate_next_node_to_alloc(struct hstate *h, 12621cac6f2cSLuiz Capitulino nodemask_t *nodes_allowed) 12631cac6f2cSLuiz Capitulino { 12641cac6f2cSLuiz Capitulino int nid; 12651cac6f2cSLuiz Capitulino 12661cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12671cac6f2cSLuiz Capitulino 12681cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); 12691cac6f2cSLuiz Capitulino h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); 12701cac6f2cSLuiz Capitulino 12711cac6f2cSLuiz Capitulino return nid; 12721cac6f2cSLuiz Capitulino } 12731cac6f2cSLuiz Capitulino 12741cac6f2cSLuiz Capitulino /* 127510c6ec49SMike Kravetz * helper for remove_pool_huge_page() - return the previously saved 12761cac6f2cSLuiz Capitulino * node ["this node"] from which to free a huge page. Advance the 12771cac6f2cSLuiz Capitulino * next node id whether or not we find a free huge page to free so 12781cac6f2cSLuiz Capitulino * that the next attempt to free addresses the next node. 12791cac6f2cSLuiz Capitulino */ 12801cac6f2cSLuiz Capitulino static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) 12811cac6f2cSLuiz Capitulino { 12821cac6f2cSLuiz Capitulino int nid; 12831cac6f2cSLuiz Capitulino 12841cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12851cac6f2cSLuiz Capitulino 12861cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); 12871cac6f2cSLuiz Capitulino h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); 12881cac6f2cSLuiz Capitulino 12891cac6f2cSLuiz Capitulino return nid; 12901cac6f2cSLuiz Capitulino } 12911cac6f2cSLuiz Capitulino 12921cac6f2cSLuiz Capitulino #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ 12931cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 12941cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 12951cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ 12961cac6f2cSLuiz Capitulino nr_nodes--) 12971cac6f2cSLuiz Capitulino 12981cac6f2cSLuiz Capitulino #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ 12991cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 13001cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 13011cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_free(hs, mask)) || 1); \ 13021cac6f2cSLuiz Capitulino nr_nodes--) 13031cac6f2cSLuiz Capitulino 13048531fc6fSMike Kravetz /* used to demote non-gigantic_huge pages as well */ 130534d9e35bSMike Kravetz static void __destroy_compound_gigantic_page(struct page *page, 130634d9e35bSMike Kravetz unsigned int order, bool demote) 1307944d9fecSLuiz Capitulino { 1308944d9fecSLuiz Capitulino int i; 1309944d9fecSLuiz Capitulino int nr_pages = 1 << order; 131014455eabSCheng Li struct page *p; 1311944d9fecSLuiz Capitulino 1312c8cc708aSGerald Schaefer atomic_set(compound_mapcount_ptr(page), 0); 131347e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 131447e29d32SJohn Hubbard 131514455eabSCheng Li for (i = 1; i < nr_pages; i++) { 131614455eabSCheng Li p = nth_page(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); 1509a9e1eab2SMiaohe Lin /* 1510a9e1eab2SMiaohe Lin * We have to set HPageVmemmapOptimized again as above 1511a9e1eab2SMiaohe Lin * set_page_private(page, 0) cleared it. 1512a9e1eab2SMiaohe Lin */ 1513ad2fa371SMuchun Song SetHPageVmemmapOptimized(page); 1514ad2fa371SMuchun Song 1515ad2fa371SMuchun Song /* 1516b65a4edaSMike Kravetz * This page is about to be managed by the hugetlb allocator and 1517b65a4edaSMike Kravetz * should have no users. Drop our reference, and check for others 1518b65a4edaSMike Kravetz * just in case. 1519ad2fa371SMuchun Song */ 1520ad2fa371SMuchun Song zeroed = put_page_testzero(page); 1521b65a4edaSMike Kravetz if (!zeroed) 1522b65a4edaSMike Kravetz /* 1523b65a4edaSMike Kravetz * It is VERY unlikely soneone else has taken a ref on 1524b65a4edaSMike Kravetz * the page. In this case, we simply return as the 1525b65a4edaSMike Kravetz * hugetlb destructor (free_huge_page) will be called 1526b65a4edaSMike Kravetz * when this other ref is dropped. 1527b65a4edaSMike Kravetz */ 1528b65a4edaSMike Kravetz return; 1529b65a4edaSMike Kravetz 1530ad2fa371SMuchun Song arch_clear_hugepage_flags(page); 1531ad2fa371SMuchun Song enqueue_huge_page(h, page); 1532ad2fa371SMuchun Song } 1533ad2fa371SMuchun Song 1534b65d4adbSMuchun Song static void __update_and_free_page(struct hstate *h, struct page *page) 15356af2acb6SAdam Litke { 15366af2acb6SAdam Litke int i; 153714455eabSCheng Li struct page *subpage; 1538a5516438SAndi Kleen 15394eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 1540944d9fecSLuiz Capitulino return; 154118229df5SAndy Whitcroft 1542161df60eSNaoya Horiguchi /* 1543161df60eSNaoya Horiguchi * If we don't know which subpages are hwpoisoned, we can't free 1544161df60eSNaoya Horiguchi * the hugepage, so it's leaked intentionally. 1545161df60eSNaoya Horiguchi */ 1546161df60eSNaoya Horiguchi if (HPageRawHwpUnreliable(page)) 1547161df60eSNaoya Horiguchi return; 1548161df60eSNaoya Horiguchi 15496213834cSMuchun Song if (hugetlb_vmemmap_restore(h, page)) { 1550ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 1551ad2fa371SMuchun Song /* 1552ad2fa371SMuchun Song * If we cannot allocate vmemmap pages, just refuse to free the 1553ad2fa371SMuchun Song * page and put the page back on the hugetlb free list and treat 1554ad2fa371SMuchun Song * as a surplus page. 1555ad2fa371SMuchun Song */ 1556ad2fa371SMuchun Song add_hugetlb_page(h, page, true); 1557ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 1558ad2fa371SMuchun Song return; 1559ad2fa371SMuchun Song } 1560ad2fa371SMuchun Song 1561161df60eSNaoya Horiguchi /* 1562161df60eSNaoya Horiguchi * Move PageHWPoison flag from head page to the raw error pages, 1563161df60eSNaoya Horiguchi * which makes any healthy subpages reusable. 1564161df60eSNaoya Horiguchi */ 1565161df60eSNaoya Horiguchi if (unlikely(PageHWPoison(page))) 1566161df60eSNaoya Horiguchi hugetlb_clear_page_hwpoison(page); 1567161df60eSNaoya Horiguchi 156814455eabSCheng Li for (i = 0; i < pages_per_huge_page(h); i++) { 156914455eabSCheng Li subpage = nth_page(page, i); 1570dbfee5aeSMike Kravetz subpage->flags &= ~(1 << PG_locked | 1 << PG_error | 157132f84528SChris Forbes 1 << PG_referenced | 1 << PG_dirty | 1572a7407a27SLuiz Capitulino 1 << PG_active | 1 << PG_private | 1573a7407a27SLuiz Capitulino 1 << PG_writeback); 15746af2acb6SAdam Litke } 1575a01f4390SMike Kravetz 1576a01f4390SMike Kravetz /* 1577a01f4390SMike Kravetz * Non-gigantic pages demoted from CMA allocated gigantic pages 1578a01f4390SMike Kravetz * need to be given back to CMA in free_gigantic_page. 1579a01f4390SMike Kravetz */ 1580a01f4390SMike Kravetz if (hstate_is_gigantic(h) || 1581a01f4390SMike Kravetz hugetlb_cma_page(page, huge_page_order(h))) { 1582944d9fecSLuiz Capitulino destroy_compound_gigantic_page(page, huge_page_order(h)); 1583944d9fecSLuiz Capitulino free_gigantic_page(page, huge_page_order(h)); 1584944d9fecSLuiz Capitulino } else { 1585a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 15866af2acb6SAdam Litke } 1587944d9fecSLuiz Capitulino } 15886af2acb6SAdam Litke 1589b65d4adbSMuchun Song /* 1590b65d4adbSMuchun Song * As update_and_free_page() can be called under any context, so we cannot 1591b65d4adbSMuchun Song * use GFP_KERNEL to allocate vmemmap pages. However, we can defer the 1592b65d4adbSMuchun Song * actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate 1593b65d4adbSMuchun Song * the vmemmap pages. 1594b65d4adbSMuchun Song * 1595b65d4adbSMuchun Song * free_hpage_workfn() locklessly retrieves the linked list of pages to be 1596b65d4adbSMuchun Song * freed and frees them one-by-one. As the page->mapping pointer is going 1597b65d4adbSMuchun Song * to be cleared in free_hpage_workfn() anyway, it is reused as the llist_node 1598b65d4adbSMuchun Song * structure of a lockless linked list of huge pages to be freed. 1599b65d4adbSMuchun Song */ 1600b65d4adbSMuchun Song static LLIST_HEAD(hpage_freelist); 1601b65d4adbSMuchun Song 1602b65d4adbSMuchun Song static void free_hpage_workfn(struct work_struct *work) 1603b65d4adbSMuchun Song { 1604b65d4adbSMuchun Song struct llist_node *node; 1605b65d4adbSMuchun Song 1606b65d4adbSMuchun Song node = llist_del_all(&hpage_freelist); 1607b65d4adbSMuchun Song 1608b65d4adbSMuchun Song while (node) { 1609b65d4adbSMuchun Song struct page *page; 1610b65d4adbSMuchun Song struct hstate *h; 1611b65d4adbSMuchun Song 1612b65d4adbSMuchun Song page = container_of((struct address_space **)node, 1613b65d4adbSMuchun Song struct page, mapping); 1614b65d4adbSMuchun Song node = node->next; 1615b65d4adbSMuchun Song page->mapping = NULL; 1616b65d4adbSMuchun Song /* 1617b65d4adbSMuchun Song * The VM_BUG_ON_PAGE(!PageHuge(page), page) in page_hstate() 1618b65d4adbSMuchun Song * is going to trigger because a previous call to 1619b65d4adbSMuchun Song * remove_hugetlb_page() will set_compound_page_dtor(page, 1620b65d4adbSMuchun Song * NULL_COMPOUND_DTOR), so do not use page_hstate() directly. 1621b65d4adbSMuchun Song */ 1622b65d4adbSMuchun Song h = size_to_hstate(page_size(page)); 1623b65d4adbSMuchun Song 1624b65d4adbSMuchun Song __update_and_free_page(h, page); 1625b65d4adbSMuchun Song 1626b65d4adbSMuchun Song cond_resched(); 1627b65d4adbSMuchun Song } 1628b65d4adbSMuchun Song } 1629b65d4adbSMuchun Song static DECLARE_WORK(free_hpage_work, free_hpage_workfn); 1630b65d4adbSMuchun Song 1631b65d4adbSMuchun Song static inline void flush_free_hpage_work(struct hstate *h) 1632b65d4adbSMuchun Song { 16336213834cSMuchun Song if (hugetlb_vmemmap_optimizable(h)) 1634b65d4adbSMuchun Song flush_work(&free_hpage_work); 1635b65d4adbSMuchun Song } 1636b65d4adbSMuchun Song 1637b65d4adbSMuchun Song static void update_and_free_page(struct hstate *h, struct page *page, 1638b65d4adbSMuchun Song bool atomic) 1639b65d4adbSMuchun Song { 1640ad2fa371SMuchun Song if (!HPageVmemmapOptimized(page) || !atomic) { 1641b65d4adbSMuchun Song __update_and_free_page(h, page); 1642b65d4adbSMuchun Song return; 1643b65d4adbSMuchun Song } 1644b65d4adbSMuchun Song 1645b65d4adbSMuchun Song /* 1646b65d4adbSMuchun Song * Defer freeing to avoid using GFP_ATOMIC to allocate vmemmap pages. 1647b65d4adbSMuchun Song * 1648b65d4adbSMuchun Song * Only call schedule_work() if hpage_freelist is previously 1649b65d4adbSMuchun Song * empty. Otherwise, schedule_work() had been called but the workfn 1650b65d4adbSMuchun Song * hasn't retrieved the list yet. 1651b65d4adbSMuchun Song */ 1652b65d4adbSMuchun Song if (llist_add((struct llist_node *)&page->mapping, &hpage_freelist)) 1653b65d4adbSMuchun Song schedule_work(&free_hpage_work); 1654b65d4adbSMuchun Song } 1655b65d4adbSMuchun Song 165610c6ec49SMike Kravetz static void update_and_free_pages_bulk(struct hstate *h, struct list_head *list) 165710c6ec49SMike Kravetz { 165810c6ec49SMike Kravetz struct page *page, *t_page; 165910c6ec49SMike Kravetz 166010c6ec49SMike Kravetz list_for_each_entry_safe(page, t_page, list, lru) { 1661b65d4adbSMuchun Song update_and_free_page(h, page, false); 166210c6ec49SMike Kravetz cond_resched(); 166310c6ec49SMike Kravetz } 166410c6ec49SMike Kravetz } 166510c6ec49SMike Kravetz 1666e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 1667e5ff2159SAndi Kleen { 1668e5ff2159SAndi Kleen struct hstate *h; 1669e5ff2159SAndi Kleen 1670e5ff2159SAndi Kleen for_each_hstate(h) { 1671e5ff2159SAndi Kleen if (huge_page_size(h) == size) 1672e5ff2159SAndi Kleen return h; 1673e5ff2159SAndi Kleen } 1674e5ff2159SAndi Kleen return NULL; 1675e5ff2159SAndi Kleen } 1676e5ff2159SAndi Kleen 1677db71ef79SMike Kravetz void free_huge_page(struct page *page) 167827a85ef1SDavid Gibson { 1679a5516438SAndi Kleen /* 1680a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 1681a5516438SAndi Kleen * compound page destructor. 1682a5516438SAndi Kleen */ 1683e5ff2159SAndi Kleen struct hstate *h = page_hstate(page); 16847893d1d5SAdam Litke int nid = page_to_nid(page); 1685d6995da3SMike Kravetz struct hugepage_subpool *spool = hugetlb_page_subpool(page); 168607443a85SJoonsoo Kim bool restore_reserve; 1687db71ef79SMike Kravetz unsigned long flags; 168827a85ef1SDavid Gibson 1689b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1690b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_mapcount(page), page); 16918ace22bcSYongkai Wu 1692d6995da3SMike Kravetz hugetlb_set_page_subpool(page, NULL); 169378fbe906SDavid Hildenbrand if (PageAnon(page)) 169478fbe906SDavid Hildenbrand __ClearPageAnonExclusive(page); 16958ace22bcSYongkai Wu page->mapping = NULL; 1696d6995da3SMike Kravetz restore_reserve = HPageRestoreReserve(page); 1697d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 169827a85ef1SDavid Gibson 16991c5ecae3SMike Kravetz /* 1700d6995da3SMike Kravetz * If HPageRestoreReserve was set on page, page allocation consumed a 17010919e1b6SMike Kravetz * reservation. If the page was associated with a subpool, there 17020919e1b6SMike Kravetz * would have been a page reserved in the subpool before allocation 17030919e1b6SMike Kravetz * via hugepage_subpool_get_pages(). Since we are 'restoring' the 17046c26d310SMiaohe Lin * reservation, do not call hugepage_subpool_put_pages() as this will 17050919e1b6SMike Kravetz * remove the reserved page from the subpool. 17060919e1b6SMike Kravetz */ 17070919e1b6SMike Kravetz if (!restore_reserve) { 17080919e1b6SMike Kravetz /* 17090919e1b6SMike Kravetz * A return code of zero implies that the subpool will be 17100919e1b6SMike Kravetz * under its minimum size if the reservation is not restored 17110919e1b6SMike Kravetz * after page is free. Therefore, force restore_reserve 17120919e1b6SMike Kravetz * operation. 17131c5ecae3SMike Kravetz */ 17141c5ecae3SMike Kravetz if (hugepage_subpool_put_pages(spool, 1) == 0) 17151c5ecae3SMike Kravetz restore_reserve = true; 17160919e1b6SMike Kravetz } 17171c5ecae3SMike Kravetz 1718db71ef79SMike Kravetz spin_lock_irqsave(&hugetlb_lock, flags); 17198f251a3dSMike Kravetz ClearHPageMigratable(page); 17206d76dcf4SAneesh Kumar K.V hugetlb_cgroup_uncharge_page(hstate_index(h), 17216d76dcf4SAneesh Kumar K.V pages_per_huge_page(h), page); 172208cf9fafSMina Almasry hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 172308cf9fafSMina Almasry pages_per_huge_page(h), page); 172407443a85SJoonsoo Kim if (restore_reserve) 172507443a85SJoonsoo Kim h->resv_huge_pages++; 172607443a85SJoonsoo Kim 17279157c311SMike Kravetz if (HPageTemporary(page)) { 17286eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 1729db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1730b65d4adbSMuchun Song update_and_free_page(h, page, true); 1731ab5ac90aSMichal Hocko } else if (h->surplus_huge_pages_node[nid]) { 17320edaecfaSAneesh Kumar K.V /* remove the page from active list */ 17336eb4e88aSMike Kravetz remove_hugetlb_page(h, page, true); 1734db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1735b65d4adbSMuchun Song update_and_free_page(h, page, true); 17367893d1d5SAdam Litke } else { 17375d3a551cSWill Deacon arch_clear_hugepage_flags(page); 1738a5516438SAndi Kleen enqueue_huge_page(h, page); 1739db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 174027a85ef1SDavid Gibson } 17411121828aSMike Kravetz } 174227a85ef1SDavid Gibson 1743d3d99fccSOscar Salvador /* 1744d3d99fccSOscar Salvador * Must be called with the hugetlb lock held 1745d3d99fccSOscar Salvador */ 1746d3d99fccSOscar Salvador static void __prep_account_new_huge_page(struct hstate *h, int nid) 1747d3d99fccSOscar Salvador { 1748d3d99fccSOscar Salvador lockdep_assert_held(&hugetlb_lock); 1749d3d99fccSOscar Salvador h->nr_huge_pages++; 1750d3d99fccSOscar Salvador h->nr_huge_pages_node[nid]++; 1751d3d99fccSOscar Salvador } 1752d3d99fccSOscar Salvador 1753f41f2ed4SMuchun Song static void __prep_new_huge_page(struct hstate *h, struct page *page) 1754b7ba30c6SAndi Kleen { 17556213834cSMuchun Song hugetlb_vmemmap_optimize(h, page); 17560edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&page->lru); 1757f1e61557SKirill A. Shutemov set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1758ff546117SMike Kravetz hugetlb_set_page_subpool(page, NULL); 17599dd540e2SAneesh Kumar K.V set_hugetlb_cgroup(page, NULL); 17601adc4d41SMina Almasry set_hugetlb_cgroup_rsvd(page, NULL); 1761d3d99fccSOscar Salvador } 1762d3d99fccSOscar Salvador 1763d3d99fccSOscar Salvador static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) 1764d3d99fccSOscar Salvador { 1765f41f2ed4SMuchun Song __prep_new_huge_page(h, page); 1766db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 1767d3d99fccSOscar Salvador __prep_account_new_huge_page(h, nid); 1768db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 1769b7ba30c6SAndi Kleen } 1770b7ba30c6SAndi Kleen 177134d9e35bSMike Kravetz static bool __prep_compound_gigantic_page(struct page *page, unsigned int order, 177234d9e35bSMike Kravetz bool demote) 177320a0307cSWu Fengguang { 17747118fc29SMike Kravetz int i, j; 177520a0307cSWu Fengguang int nr_pages = 1 << order; 177614455eabSCheng Li struct page *p; 177720a0307cSWu Fengguang 177820a0307cSWu Fengguang /* we rely on prep_new_huge_page to set the destructor */ 177920a0307cSWu Fengguang set_compound_order(page, order); 1780ef5a22beSAndrea Arcangeli __ClearPageReserved(page); 1781de09d31dSKirill A. Shutemov __SetPageHead(page); 178214455eabSCheng Li for (i = 1; i < nr_pages; i++) { 178314455eabSCheng Li p = nth_page(page, i); 178414455eabSCheng Li 1785ef5a22beSAndrea Arcangeli /* 1786ef5a22beSAndrea Arcangeli * For gigantic hugepages allocated through bootmem at 1787ef5a22beSAndrea Arcangeli * boot, it's safer to be consistent with the not-gigantic 1788ef5a22beSAndrea Arcangeli * hugepages and clear the PG_reserved bit from all tail pages 17897c8de358SEthon Paul * too. Otherwise drivers using get_user_pages() to access tail 1790ef5a22beSAndrea Arcangeli * pages may get the reference counting wrong if they see 1791ef5a22beSAndrea Arcangeli * PG_reserved set on a tail page (despite the head page not 1792ef5a22beSAndrea Arcangeli * having PG_reserved set). Enforcing this consistency between 1793ef5a22beSAndrea Arcangeli * head and tail pages allows drivers to optimize away a check 1794ef5a22beSAndrea Arcangeli * on the head page when they need know if put_page() is needed 1795ef5a22beSAndrea Arcangeli * after get_user_pages(). 1796ef5a22beSAndrea Arcangeli */ 1797ef5a22beSAndrea Arcangeli __ClearPageReserved(p); 17987118fc29SMike Kravetz /* 17997118fc29SMike Kravetz * Subtle and very unlikely 18007118fc29SMike Kravetz * 18017118fc29SMike Kravetz * Gigantic 'page allocators' such as memblock or cma will 18027118fc29SMike Kravetz * return a set of pages with each page ref counted. We need 18037118fc29SMike Kravetz * to turn this set of pages into a compound page with tail 18047118fc29SMike Kravetz * page ref counts set to zero. Code such as speculative page 18057118fc29SMike Kravetz * cache adding could take a ref on a 'to be' tail page. 18067118fc29SMike Kravetz * We need to respect any increased ref count, and only set 18077118fc29SMike Kravetz * the ref count to zero if count is currently 1. If count 1808416d85edSMike Kravetz * is not 1, we return an error. An error return indicates 1809416d85edSMike Kravetz * the set of pages can not be converted to a gigantic page. 1810416d85edSMike Kravetz * The caller who allocated the pages should then discard the 1811416d85edSMike Kravetz * pages using the appropriate free interface. 181234d9e35bSMike Kravetz * 181334d9e35bSMike Kravetz * In the case of demote, the ref count will be zero. 18147118fc29SMike Kravetz */ 181534d9e35bSMike Kravetz if (!demote) { 18167118fc29SMike Kravetz if (!page_ref_freeze(p, 1)) { 1817416d85edSMike Kravetz pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n"); 18187118fc29SMike Kravetz goto out_error; 18197118fc29SMike Kravetz } 182034d9e35bSMike Kravetz } else { 182134d9e35bSMike Kravetz VM_BUG_ON_PAGE(page_count(p), p); 182234d9e35bSMike Kravetz } 18231d798ca3SKirill A. Shutemov set_compound_head(p, page); 182420a0307cSWu Fengguang } 1825b4330afbSMike Kravetz atomic_set(compound_mapcount_ptr(page), -1); 182647e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 18277118fc29SMike Kravetz return true; 18287118fc29SMike Kravetz 18297118fc29SMike Kravetz out_error: 18307118fc29SMike Kravetz /* undo tail page modifications made above */ 183114455eabSCheng Li for (j = 1; j < i; j++) { 183214455eabSCheng Li p = nth_page(page, j); 18337118fc29SMike Kravetz clear_compound_head(p); 18347118fc29SMike Kravetz set_page_refcounted(p); 18357118fc29SMike Kravetz } 18367118fc29SMike Kravetz /* need to clear PG_reserved on remaining tail pages */ 183714455eabSCheng Li for (; j < nr_pages; j++) { 183814455eabSCheng Li p = nth_page(page, j); 18397118fc29SMike Kravetz __ClearPageReserved(p); 184014455eabSCheng Li } 18417118fc29SMike Kravetz set_compound_order(page, 0); 18425232c63fSMatthew Wilcox (Oracle) #ifdef CONFIG_64BIT 18437118fc29SMike Kravetz page[1].compound_nr = 0; 18445232c63fSMatthew Wilcox (Oracle) #endif 18457118fc29SMike Kravetz __ClearPageHead(page); 18467118fc29SMike Kravetz return false; 184720a0307cSWu Fengguang } 184820a0307cSWu Fengguang 184934d9e35bSMike Kravetz static bool prep_compound_gigantic_page(struct page *page, unsigned int order) 185034d9e35bSMike Kravetz { 185134d9e35bSMike Kravetz return __prep_compound_gigantic_page(page, order, false); 185234d9e35bSMike Kravetz } 185334d9e35bSMike Kravetz 18548531fc6fSMike Kravetz static bool prep_compound_gigantic_page_for_demote(struct page *page, 18558531fc6fSMike Kravetz unsigned int order) 18568531fc6fSMike Kravetz { 18578531fc6fSMike Kravetz return __prep_compound_gigantic_page(page, order, true); 18588531fc6fSMike Kravetz } 18598531fc6fSMike Kravetz 18607795912cSAndrew Morton /* 18617795912cSAndrew Morton * PageHuge() only returns true for hugetlbfs pages, but not for normal or 18627795912cSAndrew Morton * transparent huge pages. See the PageTransHuge() documentation for more 18637795912cSAndrew Morton * details. 18647795912cSAndrew Morton */ 186520a0307cSWu Fengguang int PageHuge(struct page *page) 186620a0307cSWu Fengguang { 186720a0307cSWu Fengguang if (!PageCompound(page)) 186820a0307cSWu Fengguang return 0; 186920a0307cSWu Fengguang 187020a0307cSWu Fengguang page = compound_head(page); 1871f1e61557SKirill A. Shutemov return page[1].compound_dtor == HUGETLB_PAGE_DTOR; 187220a0307cSWu Fengguang } 187343131e14SNaoya Horiguchi EXPORT_SYMBOL_GPL(PageHuge); 187443131e14SNaoya Horiguchi 187527c73ae7SAndrea Arcangeli /* 187627c73ae7SAndrea Arcangeli * PageHeadHuge() only returns true for hugetlbfs head page, but not for 187727c73ae7SAndrea Arcangeli * normal or transparent huge pages. 187827c73ae7SAndrea Arcangeli */ 187927c73ae7SAndrea Arcangeli int PageHeadHuge(struct page *page_head) 188027c73ae7SAndrea Arcangeli { 188127c73ae7SAndrea Arcangeli if (!PageHead(page_head)) 188227c73ae7SAndrea Arcangeli return 0; 188327c73ae7SAndrea Arcangeli 1884d4af73e3SVlastimil Babka return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR; 188527c73ae7SAndrea Arcangeli } 18864e936eccSDavid Howells EXPORT_SYMBOL_GPL(PageHeadHuge); 188727c73ae7SAndrea Arcangeli 1888c0d0381aSMike Kravetz /* 1889c0d0381aSMike Kravetz * Find and lock address space (mapping) in write mode. 1890c0d0381aSMike Kravetz * 1891336bf30eSMike Kravetz * Upon entry, the page is locked which means that page_mapping() is 1892336bf30eSMike Kravetz * stable. Due to locking order, we can only trylock_write. If we can 1893336bf30eSMike Kravetz * not get the lock, simply return NULL to caller. 1894c0d0381aSMike Kravetz */ 1895c0d0381aSMike Kravetz struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage) 1896c0d0381aSMike Kravetz { 1897336bf30eSMike Kravetz struct address_space *mapping = page_mapping(hpage); 1898c0d0381aSMike Kravetz 1899c0d0381aSMike Kravetz if (!mapping) 1900c0d0381aSMike Kravetz return mapping; 1901c0d0381aSMike Kravetz 1902c0d0381aSMike Kravetz if (i_mmap_trylock_write(mapping)) 1903c0d0381aSMike Kravetz return mapping; 1904c0d0381aSMike Kravetz 1905c0d0381aSMike Kravetz return NULL; 1906c0d0381aSMike Kravetz } 1907c0d0381aSMike Kravetz 1908fe19bd3dSHugh Dickins pgoff_t hugetlb_basepage_index(struct page *page) 190913d60f4bSZhang Yi { 191013d60f4bSZhang Yi struct page *page_head = compound_head(page); 191113d60f4bSZhang Yi pgoff_t index = page_index(page_head); 191213d60f4bSZhang Yi unsigned long compound_idx; 191313d60f4bSZhang Yi 191413d60f4bSZhang Yi if (compound_order(page_head) >= MAX_ORDER) 191513d60f4bSZhang Yi compound_idx = page_to_pfn(page) - page_to_pfn(page_head); 191613d60f4bSZhang Yi else 191713d60f4bSZhang Yi compound_idx = page - page_head; 191813d60f4bSZhang Yi 191913d60f4bSZhang Yi return (index << compound_order(page_head)) + compound_idx; 192013d60f4bSZhang Yi } 192113d60f4bSZhang Yi 19220c397daeSMichal Hocko static struct page *alloc_buddy_huge_page(struct hstate *h, 1923f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1924f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 19251da177e4SLinus Torvalds { 1926af0fb9dfSMichal Hocko int order = huge_page_order(h); 19271da177e4SLinus Torvalds struct page *page; 1928f60858f9SMike Kravetz bool alloc_try_hard = true; 1929f96efd58SJoe Jin 1930f60858f9SMike Kravetz /* 1931f60858f9SMike Kravetz * By default we always try hard to allocate the page with 1932f60858f9SMike Kravetz * __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in 1933f60858f9SMike Kravetz * a loop (to adjust global huge page counts) and previous allocation 1934f60858f9SMike Kravetz * failed, do not continue to try hard on the same node. Use the 1935f60858f9SMike Kravetz * node_alloc_noretry bitmap to manage this state information. 1936f60858f9SMike Kravetz */ 1937f60858f9SMike Kravetz if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry)) 1938f60858f9SMike Kravetz alloc_try_hard = false; 1939f60858f9SMike Kravetz gfp_mask |= __GFP_COMP|__GFP_NOWARN; 1940f60858f9SMike Kravetz if (alloc_try_hard) 1941f60858f9SMike Kravetz gfp_mask |= __GFP_RETRY_MAYFAIL; 1942af0fb9dfSMichal Hocko if (nid == NUMA_NO_NODE) 1943af0fb9dfSMichal Hocko nid = numa_mem_id(); 194484172f4bSMatthew Wilcox (Oracle) page = __alloc_pages(gfp_mask, order, nid, nmask); 1945af0fb9dfSMichal Hocko if (page) 1946af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC); 1947af0fb9dfSMichal Hocko else 1948af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 194963b4613cSNishanth Aravamudan 1950f60858f9SMike Kravetz /* 1951f60858f9SMike Kravetz * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this 1952f60858f9SMike Kravetz * indicates an overall state change. Clear bit so that we resume 1953f60858f9SMike Kravetz * normal 'try hard' allocations. 1954f60858f9SMike Kravetz */ 1955f60858f9SMike Kravetz if (node_alloc_noretry && page && !alloc_try_hard) 1956f60858f9SMike Kravetz node_clear(nid, *node_alloc_noretry); 1957f60858f9SMike Kravetz 1958f60858f9SMike Kravetz /* 1959f60858f9SMike Kravetz * If we tried hard to get a page but failed, set bit so that 1960f60858f9SMike Kravetz * subsequent attempts will not try as hard until there is an 1961f60858f9SMike Kravetz * overall state change. 1962f60858f9SMike Kravetz */ 1963f60858f9SMike Kravetz if (node_alloc_noretry && !page && alloc_try_hard) 1964f60858f9SMike Kravetz node_set(nid, *node_alloc_noretry); 1965f60858f9SMike Kravetz 196663b4613cSNishanth Aravamudan return page; 196763b4613cSNishanth Aravamudan } 196863b4613cSNishanth Aravamudan 1969af0fb9dfSMichal Hocko /* 19700c397daeSMichal Hocko * Common helper to allocate a fresh hugetlb page. All specific allocators 19710c397daeSMichal Hocko * should use this function to get new hugetlb pages 19720c397daeSMichal Hocko */ 19730c397daeSMichal Hocko static struct page *alloc_fresh_huge_page(struct hstate *h, 1974f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1975f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 19760c397daeSMichal Hocko { 19770c397daeSMichal Hocko struct page *page; 19787118fc29SMike Kravetz bool retry = false; 19790c397daeSMichal Hocko 19807118fc29SMike Kravetz retry: 19810c397daeSMichal Hocko if (hstate_is_gigantic(h)) 19820c397daeSMichal Hocko page = alloc_gigantic_page(h, gfp_mask, nid, nmask); 19830c397daeSMichal Hocko else 19840c397daeSMichal Hocko page = alloc_buddy_huge_page(h, gfp_mask, 1985f60858f9SMike Kravetz nid, nmask, node_alloc_noretry); 19860c397daeSMichal Hocko if (!page) 19870c397daeSMichal Hocko return NULL; 19880c397daeSMichal Hocko 19897118fc29SMike Kravetz if (hstate_is_gigantic(h)) { 19907118fc29SMike Kravetz if (!prep_compound_gigantic_page(page, huge_page_order(h))) { 19917118fc29SMike Kravetz /* 19927118fc29SMike Kravetz * Rare failure to convert pages to compound page. 19937118fc29SMike Kravetz * Free pages and try again - ONCE! 19947118fc29SMike Kravetz */ 19957118fc29SMike Kravetz free_gigantic_page(page, huge_page_order(h)); 19967118fc29SMike Kravetz if (!retry) { 19977118fc29SMike Kravetz retry = true; 19987118fc29SMike Kravetz goto retry; 19997118fc29SMike Kravetz } 20007118fc29SMike Kravetz return NULL; 20017118fc29SMike Kravetz } 20027118fc29SMike Kravetz } 20030c397daeSMichal Hocko prep_new_huge_page(h, page, page_to_nid(page)); 20040c397daeSMichal Hocko 20050c397daeSMichal Hocko return page; 20060c397daeSMichal Hocko } 20070c397daeSMichal Hocko 20080c397daeSMichal Hocko /* 2009af0fb9dfSMichal Hocko * Allocates a fresh page to the hugetlb allocator pool in the node interleaved 2010af0fb9dfSMichal Hocko * manner. 2011af0fb9dfSMichal Hocko */ 2012f60858f9SMike Kravetz static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 2013f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 2014b2261026SJoonsoo Kim { 2015b2261026SJoonsoo Kim struct page *page; 2016b2261026SJoonsoo Kim int nr_nodes, node; 2017af0fb9dfSMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 2018b2261026SJoonsoo Kim 2019b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 2020f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed, 2021f60858f9SMike Kravetz node_alloc_noretry); 2022af0fb9dfSMichal Hocko if (page) 2023b2261026SJoonsoo Kim break; 2024b2261026SJoonsoo Kim } 2025b2261026SJoonsoo Kim 2026af0fb9dfSMichal Hocko if (!page) 2027af0fb9dfSMichal Hocko return 0; 2028b2261026SJoonsoo Kim 2029af0fb9dfSMichal Hocko put_page(page); /* free it into the hugepage allocator */ 2030af0fb9dfSMichal Hocko 2031af0fb9dfSMichal Hocko return 1; 2032b2261026SJoonsoo Kim } 2033b2261026SJoonsoo Kim 2034e8c5c824SLee Schermerhorn /* 203510c6ec49SMike Kravetz * Remove huge page from pool from next node to free. Attempt to keep 203610c6ec49SMike Kravetz * persistent huge pages more or less balanced over allowed nodes. 203710c6ec49SMike Kravetz * This routine only 'removes' the hugetlb page. The caller must make 203810c6ec49SMike Kravetz * an additional call to free the page to low level allocators. 2039e8c5c824SLee Schermerhorn * Called with hugetlb_lock locked. 2040e8c5c824SLee Schermerhorn */ 204110c6ec49SMike Kravetz static struct page *remove_pool_huge_page(struct hstate *h, 204210c6ec49SMike Kravetz nodemask_t *nodes_allowed, 20436ae11b27SLee Schermerhorn bool acct_surplus) 2044e8c5c824SLee Schermerhorn { 2045b2261026SJoonsoo Kim int nr_nodes, node; 204610c6ec49SMike Kravetz struct page *page = NULL; 2047e8c5c824SLee Schermerhorn 20489487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2049b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 2050685f3457SLee Schermerhorn /* 2051685f3457SLee Schermerhorn * If we're returning unused surplus pages, only examine 2052685f3457SLee Schermerhorn * nodes with surplus pages. 2053685f3457SLee Schermerhorn */ 2054b2261026SJoonsoo Kim if ((!acct_surplus || h->surplus_huge_pages_node[node]) && 2055b2261026SJoonsoo Kim !list_empty(&h->hugepage_freelists[node])) { 205610c6ec49SMike Kravetz page = list_entry(h->hugepage_freelists[node].next, 2057e8c5c824SLee Schermerhorn struct page, lru); 20586eb4e88aSMike Kravetz remove_hugetlb_page(h, page, acct_surplus); 20599a76db09SLee Schermerhorn break; 2060e8c5c824SLee Schermerhorn } 2061b2261026SJoonsoo Kim } 2062e8c5c824SLee Schermerhorn 206310c6ec49SMike Kravetz return page; 2064e8c5c824SLee Schermerhorn } 2065e8c5c824SLee Schermerhorn 2066c8721bbbSNaoya Horiguchi /* 2067c8721bbbSNaoya Horiguchi * Dissolve a given free hugepage into free buddy pages. This function does 2068faf53defSNaoya Horiguchi * nothing for in-use hugepages and non-hugepages. 2069faf53defSNaoya Horiguchi * This function returns values like below: 2070faf53defSNaoya Horiguchi * 2071ad2fa371SMuchun Song * -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages 2072ad2fa371SMuchun Song * when the system is under memory pressure and the feature of 2073ad2fa371SMuchun Song * freeing unused vmemmap pages associated with each hugetlb page 2074ad2fa371SMuchun Song * is enabled. 2075faf53defSNaoya Horiguchi * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use 2076faf53defSNaoya Horiguchi * (allocated or reserved.) 2077faf53defSNaoya Horiguchi * 0: successfully dissolved free hugepages or the page is not a 2078faf53defSNaoya Horiguchi * hugepage (considered as already dissolved) 2079c8721bbbSNaoya Horiguchi */ 2080c3114a84SAnshuman Khandual int dissolve_free_huge_page(struct page *page) 2081c8721bbbSNaoya Horiguchi { 20826bc9b564SNaoya Horiguchi int rc = -EBUSY; 2083082d5b6bSGerald Schaefer 20847ffddd49SMuchun Song retry: 2085faf53defSNaoya Horiguchi /* Not to disrupt normal path by vainly holding hugetlb_lock */ 2086faf53defSNaoya Horiguchi if (!PageHuge(page)) 2087faf53defSNaoya Horiguchi return 0; 2088faf53defSNaoya Horiguchi 2089db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2090faf53defSNaoya Horiguchi if (!PageHuge(page)) { 2091faf53defSNaoya Horiguchi rc = 0; 2092faf53defSNaoya Horiguchi goto out; 2093faf53defSNaoya Horiguchi } 2094faf53defSNaoya Horiguchi 2095faf53defSNaoya Horiguchi if (!page_count(page)) { 20962247bb33SGerald Schaefer struct page *head = compound_head(page); 20972247bb33SGerald Schaefer struct hstate *h = page_hstate(head); 20986bc9b564SNaoya Horiguchi if (h->free_huge_pages - h->resv_huge_pages == 0) 2099082d5b6bSGerald Schaefer goto out; 21007ffddd49SMuchun Song 21017ffddd49SMuchun Song /* 21027ffddd49SMuchun Song * We should make sure that the page is already on the free list 21037ffddd49SMuchun Song * when it is dissolved. 21047ffddd49SMuchun Song */ 21056c037149SMike Kravetz if (unlikely(!HPageFreed(head))) { 2106db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 21077ffddd49SMuchun Song cond_resched(); 21087ffddd49SMuchun Song 21097ffddd49SMuchun Song /* 21107ffddd49SMuchun Song * Theoretically, we should return -EBUSY when we 21117ffddd49SMuchun Song * encounter this race. In fact, we have a chance 21127ffddd49SMuchun Song * to successfully dissolve the page if we do a 21137ffddd49SMuchun Song * retry. Because the race window is quite small. 21147ffddd49SMuchun Song * If we seize this opportunity, it is an optimization 21157ffddd49SMuchun Song * for increasing the success rate of dissolving page. 21167ffddd49SMuchun Song */ 21177ffddd49SMuchun Song goto retry; 21187ffddd49SMuchun Song } 21197ffddd49SMuchun Song 2120ad2fa371SMuchun Song remove_hugetlb_page(h, head, false); 2121ad2fa371SMuchun Song h->max_huge_pages--; 2122ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2123ad2fa371SMuchun Song 2124c3114a84SAnshuman Khandual /* 2125ad2fa371SMuchun Song * Normally update_and_free_page will allocate required vmemmmap 2126ad2fa371SMuchun Song * before freeing the page. update_and_free_page will fail to 2127ad2fa371SMuchun Song * free the page if it can not allocate required vmemmap. We 2128ad2fa371SMuchun Song * need to adjust max_huge_pages if the page is not freed. 2129ad2fa371SMuchun Song * Attempt to allocate vmemmmap here so that we can take 2130ad2fa371SMuchun Song * appropriate action on failure. 2131ad2fa371SMuchun Song */ 21326213834cSMuchun Song rc = hugetlb_vmemmap_restore(h, head); 2133ad2fa371SMuchun Song if (!rc) { 2134b65d4adbSMuchun Song update_and_free_page(h, head, false); 2135ad2fa371SMuchun Song } else { 2136ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 2137ad2fa371SMuchun Song add_hugetlb_page(h, head, false); 2138ad2fa371SMuchun Song h->max_huge_pages++; 2139ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2140ad2fa371SMuchun Song } 2141ad2fa371SMuchun Song 2142ad2fa371SMuchun Song return rc; 2143c8721bbbSNaoya Horiguchi } 2144082d5b6bSGerald Schaefer out: 2145db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2146082d5b6bSGerald Schaefer return rc; 2147c8721bbbSNaoya Horiguchi } 2148c8721bbbSNaoya Horiguchi 2149c8721bbbSNaoya Horiguchi /* 2150c8721bbbSNaoya Horiguchi * Dissolve free hugepages in a given pfn range. Used by memory hotplug to 2151c8721bbbSNaoya Horiguchi * make specified memory blocks removable from the system. 21522247bb33SGerald Schaefer * Note that this will dissolve a free gigantic hugepage completely, if any 21532247bb33SGerald Schaefer * part of it lies within the given range. 2154082d5b6bSGerald Schaefer * Also note that if dissolve_free_huge_page() returns with an error, all 2155082d5b6bSGerald Schaefer * free hugepages that were dissolved before that error are lost. 2156c8721bbbSNaoya Horiguchi */ 2157082d5b6bSGerald Schaefer int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) 2158c8721bbbSNaoya Horiguchi { 2159c8721bbbSNaoya Horiguchi unsigned long pfn; 2160eb03aa00SGerald Schaefer struct page *page; 2161082d5b6bSGerald Schaefer int rc = 0; 2162dc2628f3SMuchun Song unsigned int order; 2163dc2628f3SMuchun Song struct hstate *h; 2164c8721bbbSNaoya Horiguchi 2165d0177639SLi Zhong if (!hugepages_supported()) 2166082d5b6bSGerald Schaefer return rc; 2167d0177639SLi Zhong 2168dc2628f3SMuchun Song order = huge_page_order(&default_hstate); 2169dc2628f3SMuchun Song for_each_hstate(h) 2170dc2628f3SMuchun Song order = min(order, huge_page_order(h)); 2171dc2628f3SMuchun Song 2172dc2628f3SMuchun Song for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << order) { 2173eb03aa00SGerald Schaefer page = pfn_to_page(pfn); 2174eb03aa00SGerald Schaefer rc = dissolve_free_huge_page(page); 2175eb03aa00SGerald Schaefer if (rc) 2176082d5b6bSGerald Schaefer break; 2177eb03aa00SGerald Schaefer } 2178082d5b6bSGerald Schaefer 2179082d5b6bSGerald Schaefer return rc; 2180c8721bbbSNaoya Horiguchi } 2181c8721bbbSNaoya Horiguchi 2182ab5ac90aSMichal Hocko /* 2183ab5ac90aSMichal Hocko * Allocates a fresh surplus page from the page allocator. 2184ab5ac90aSMichal Hocko */ 21850c397daeSMichal Hocko static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, 2186b65a4edaSMike Kravetz int nid, nodemask_t *nmask, bool zero_ref) 21877893d1d5SAdam Litke { 21889980d744SMichal Hocko struct page *page = NULL; 2189b65a4edaSMike Kravetz bool retry = false; 21907893d1d5SAdam Litke 2191bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2192aa888a74SAndi Kleen return NULL; 2193aa888a74SAndi Kleen 2194db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 21959980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) 21969980d744SMichal Hocko goto out_unlock; 2197db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2198d1c3fb1fSNishanth Aravamudan 2199b65a4edaSMike Kravetz retry: 2200f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 22019980d744SMichal Hocko if (!page) 22020c397daeSMichal Hocko return NULL; 2203d1c3fb1fSNishanth Aravamudan 2204db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 22059980d744SMichal Hocko /* 22069980d744SMichal Hocko * We could have raced with the pool size change. 22079980d744SMichal Hocko * Double check that and simply deallocate the new page 22089980d744SMichal Hocko * if we would end up overcommiting the surpluses. Abuse 22099980d744SMichal Hocko * temporary page to workaround the nasty free_huge_page 22109980d744SMichal Hocko * codeflow 22119980d744SMichal Hocko */ 22129980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 22139157c311SMike Kravetz SetHPageTemporary(page); 2214db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 22159980d744SMichal Hocko put_page(page); 22162bf753e6SKai Shen return NULL; 2217b65a4edaSMike Kravetz } 2218b65a4edaSMike Kravetz 2219b65a4edaSMike Kravetz if (zero_ref) { 2220b65a4edaSMike Kravetz /* 2221b65a4edaSMike Kravetz * Caller requires a page with zero ref count. 2222b65a4edaSMike Kravetz * We will drop ref count here. If someone else is holding 2223b65a4edaSMike Kravetz * a ref, the page will be freed when they drop it. Abuse 2224b65a4edaSMike Kravetz * temporary page flag to accomplish this. 2225b65a4edaSMike Kravetz */ 2226b65a4edaSMike Kravetz SetHPageTemporary(page); 2227b65a4edaSMike Kravetz if (!put_page_testzero(page)) { 2228b65a4edaSMike Kravetz /* 2229b65a4edaSMike Kravetz * Unexpected inflated ref count on freshly allocated 2230b65a4edaSMike Kravetz * huge. Retry once. 2231b65a4edaSMike Kravetz */ 2232b65a4edaSMike Kravetz pr_info("HugeTLB unexpected inflated ref count on freshly allocated page\n"); 2233b65a4edaSMike Kravetz spin_unlock_irq(&hugetlb_lock); 2234b65a4edaSMike Kravetz if (retry) 2235b65a4edaSMike Kravetz return NULL; 2236b65a4edaSMike Kravetz 2237b65a4edaSMike Kravetz retry = true; 2238b65a4edaSMike Kravetz goto retry; 2239b65a4edaSMike Kravetz } 2240b65a4edaSMike Kravetz ClearHPageTemporary(page); 2241b65a4edaSMike Kravetz } 2242b65a4edaSMike Kravetz 22439980d744SMichal Hocko h->surplus_huge_pages++; 22444704dea3SMichal Hocko h->surplus_huge_pages_node[page_to_nid(page)]++; 22459980d744SMichal Hocko 22469980d744SMichal Hocko out_unlock: 2247db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 22487893d1d5SAdam Litke 22497893d1d5SAdam Litke return page; 22507893d1d5SAdam Litke } 22517893d1d5SAdam Litke 2252bbe88753SJoonsoo Kim static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, 2253ab5ac90aSMichal Hocko int nid, nodemask_t *nmask) 2254ab5ac90aSMichal Hocko { 2255ab5ac90aSMichal Hocko struct page *page; 2256ab5ac90aSMichal Hocko 2257ab5ac90aSMichal Hocko if (hstate_is_gigantic(h)) 2258ab5ac90aSMichal Hocko return NULL; 2259ab5ac90aSMichal Hocko 2260f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 2261ab5ac90aSMichal Hocko if (!page) 2262ab5ac90aSMichal Hocko return NULL; 2263ab5ac90aSMichal Hocko 2264ab5ac90aSMichal Hocko /* 2265ab5ac90aSMichal Hocko * We do not account these pages as surplus because they are only 2266ab5ac90aSMichal Hocko * temporary and will be released properly on the last reference 2267ab5ac90aSMichal Hocko */ 22689157c311SMike Kravetz SetHPageTemporary(page); 2269ab5ac90aSMichal Hocko 2270ab5ac90aSMichal Hocko return page; 2271ab5ac90aSMichal Hocko } 2272ab5ac90aSMichal Hocko 2273e4e574b7SAdam Litke /* 2274099730d6SDave Hansen * Use the VMA's mpolicy to allocate a huge page from the buddy. 2275099730d6SDave Hansen */ 2276e0ec90eeSDave Hansen static 22770c397daeSMichal Hocko struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h, 2278099730d6SDave Hansen struct vm_area_struct *vma, unsigned long addr) 2279099730d6SDave Hansen { 2280cfcaa66fSBen Widawsky struct page *page = NULL; 2281aaf14e40SMichal Hocko struct mempolicy *mpol; 2282aaf14e40SMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h); 2283aaf14e40SMichal Hocko int nid; 2284aaf14e40SMichal Hocko nodemask_t *nodemask; 2285aaf14e40SMichal Hocko 2286aaf14e40SMichal Hocko nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); 2287cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 2288cfcaa66fSBen Widawsky gfp_t gfp = gfp_mask | __GFP_NOWARN; 2289cfcaa66fSBen Widawsky 2290cfcaa66fSBen Widawsky gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL); 2291cfcaa66fSBen Widawsky page = alloc_surplus_huge_page(h, gfp, nid, nodemask, false); 2292cfcaa66fSBen Widawsky 2293cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 2294cfcaa66fSBen Widawsky nodemask = NULL; 2295cfcaa66fSBen Widawsky } 2296cfcaa66fSBen Widawsky 2297cfcaa66fSBen Widawsky if (!page) 2298b65a4edaSMike Kravetz page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask, false); 2299aaf14e40SMichal Hocko mpol_cond_put(mpol); 2300aaf14e40SMichal Hocko return page; 2301099730d6SDave Hansen } 2302099730d6SDave Hansen 2303ab5ac90aSMichal Hocko /* page migration callback function */ 23043e59fcb0SMichal Hocko struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, 2305d92bbc27SJoonsoo Kim nodemask_t *nmask, gfp_t gfp_mask) 23064db9b2efSMichal Hocko { 2307db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 23084db9b2efSMichal Hocko if (h->free_huge_pages - h->resv_huge_pages > 0) { 23093e59fcb0SMichal Hocko struct page *page; 23103e59fcb0SMichal Hocko 23113e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask); 23123e59fcb0SMichal Hocko if (page) { 2313db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 23143e59fcb0SMichal Hocko return page; 23154db9b2efSMichal Hocko } 23164db9b2efSMichal Hocko } 2317db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 23184db9b2efSMichal Hocko 23190c397daeSMichal Hocko return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask); 23204db9b2efSMichal Hocko } 23214db9b2efSMichal Hocko 2322ebd63723SMichal Hocko /* mempolicy aware migration callback */ 2323389c8178SMichal Hocko struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, 2324389c8178SMichal Hocko unsigned long address) 2325ebd63723SMichal Hocko { 2326ebd63723SMichal Hocko struct mempolicy *mpol; 2327ebd63723SMichal Hocko nodemask_t *nodemask; 2328ebd63723SMichal Hocko struct page *page; 2329ebd63723SMichal Hocko gfp_t gfp_mask; 2330ebd63723SMichal Hocko int node; 2331ebd63723SMichal Hocko 2332ebd63723SMichal Hocko gfp_mask = htlb_alloc_mask(h); 2333ebd63723SMichal Hocko node = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 2334d92bbc27SJoonsoo Kim page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask); 2335ebd63723SMichal Hocko mpol_cond_put(mpol); 2336ebd63723SMichal Hocko 2337ebd63723SMichal Hocko return page; 2338ebd63723SMichal Hocko } 2339ebd63723SMichal Hocko 2340bf50bab2SNaoya Horiguchi /* 234125985edcSLucas De Marchi * Increase the hugetlb pool such that it can accommodate a reservation 2342e4e574b7SAdam Litke * of size 'delta'. 2343e4e574b7SAdam Litke */ 23440a4f3d1bSLiu Xiang static int gather_surplus_pages(struct hstate *h, long delta) 23451b2a1e7bSJules Irenge __must_hold(&hugetlb_lock) 2346e4e574b7SAdam Litke { 234734665341SMiaohe Lin LIST_HEAD(surplus_list); 2348e4e574b7SAdam Litke struct page *page, *tmp; 23490a4f3d1bSLiu Xiang int ret; 23500a4f3d1bSLiu Xiang long i; 23510a4f3d1bSLiu Xiang long needed, allocated; 235228073b02SHillf Danton bool alloc_ok = true; 2353e4e574b7SAdam Litke 23549487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2355a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 2356ac09b3a1SAdam Litke if (needed <= 0) { 2357a5516438SAndi Kleen h->resv_huge_pages += delta; 2358e4e574b7SAdam Litke return 0; 2359ac09b3a1SAdam Litke } 2360e4e574b7SAdam Litke 2361e4e574b7SAdam Litke allocated = 0; 2362e4e574b7SAdam Litke 2363e4e574b7SAdam Litke ret = -ENOMEM; 2364e4e574b7SAdam Litke retry: 2365db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2366e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 23670c397daeSMichal Hocko page = alloc_surplus_huge_page(h, htlb_alloc_mask(h), 2368b65a4edaSMike Kravetz NUMA_NO_NODE, NULL, true); 236928073b02SHillf Danton if (!page) { 237028073b02SHillf Danton alloc_ok = false; 237128073b02SHillf Danton break; 237228073b02SHillf Danton } 2373e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 237469ed779aSDavid Rientjes cond_resched(); 2375e4e574b7SAdam Litke } 237628073b02SHillf Danton allocated += i; 2377e4e574b7SAdam Litke 2378e4e574b7SAdam Litke /* 2379e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 2380e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 2381e4e574b7SAdam Litke */ 2382db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2383a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 2384a5516438SAndi Kleen (h->free_huge_pages + allocated); 238528073b02SHillf Danton if (needed > 0) { 238628073b02SHillf Danton if (alloc_ok) 2387e4e574b7SAdam Litke goto retry; 238828073b02SHillf Danton /* 238928073b02SHillf Danton * We were not able to allocate enough pages to 239028073b02SHillf Danton * satisfy the entire reservation so we free what 239128073b02SHillf Danton * we've allocated so far. 239228073b02SHillf Danton */ 239328073b02SHillf Danton goto free; 239428073b02SHillf Danton } 2395e4e574b7SAdam Litke /* 2396e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 239725985edcSLucas De Marchi * needed to accommodate the reservation. Add the appropriate number 2398e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 2399ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 2400ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 2401ac09b3a1SAdam Litke * before they are reserved. 2402e4e574b7SAdam Litke */ 2403e4e574b7SAdam Litke needed += allocated; 2404a5516438SAndi Kleen h->resv_huge_pages += delta; 2405e4e574b7SAdam Litke ret = 0; 2406a9869b83SNaoya Horiguchi 240719fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 240819fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 240919fc3f0aSAdam Litke if ((--needed) < 0) 241019fc3f0aSAdam Litke break; 2411b65a4edaSMike Kravetz /* Add the page to the hugetlb allocator */ 2412a5516438SAndi Kleen enqueue_huge_page(h, page); 241319fc3f0aSAdam Litke } 241428073b02SHillf Danton free: 2415db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 241619fc3f0aSAdam Litke 2417b65a4edaSMike Kravetz /* 2418b65a4edaSMike Kravetz * Free unnecessary surplus pages to the buddy allocator. 2419b65a4edaSMike Kravetz * Pages have no ref count, call free_huge_page directly. 2420b65a4edaSMike Kravetz */ 2421c0d934baSJoonsoo Kim list_for_each_entry_safe(page, tmp, &surplus_list, lru) 2422b65a4edaSMike Kravetz free_huge_page(page); 2423db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2424e4e574b7SAdam Litke 2425e4e574b7SAdam Litke return ret; 2426e4e574b7SAdam Litke } 2427e4e574b7SAdam Litke 2428e4e574b7SAdam Litke /* 2429e5bbc8a6SMike Kravetz * This routine has two main purposes: 2430e5bbc8a6SMike Kravetz * 1) Decrement the reservation count (resv_huge_pages) by the value passed 2431e5bbc8a6SMike Kravetz * in unused_resv_pages. This corresponds to the prior adjustments made 2432e5bbc8a6SMike Kravetz * to the associated reservation map. 2433e5bbc8a6SMike Kravetz * 2) Free any unused surplus pages that may have been allocated to satisfy 2434e5bbc8a6SMike Kravetz * the reservation. As many as unused_resv_pages may be freed. 2435e4e574b7SAdam Litke */ 2436a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 2437a5516438SAndi Kleen unsigned long unused_resv_pages) 2438e4e574b7SAdam Litke { 2439e4e574b7SAdam Litke unsigned long nr_pages; 244010c6ec49SMike Kravetz struct page *page; 244110c6ec49SMike Kravetz LIST_HEAD(page_list); 244210c6ec49SMike Kravetz 24439487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 244410c6ec49SMike Kravetz /* Uncommit the reservation */ 244510c6ec49SMike Kravetz h->resv_huge_pages -= unused_resv_pages; 2446e4e574b7SAdam Litke 2447c0531714SNaoya Horiguchi if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 2448e5bbc8a6SMike Kravetz goto out; 2449aa888a74SAndi Kleen 2450e5bbc8a6SMike Kravetz /* 2451e5bbc8a6SMike Kravetz * Part (or even all) of the reservation could have been backed 2452e5bbc8a6SMike Kravetz * by pre-allocated pages. Only free surplus pages. 2453e5bbc8a6SMike Kravetz */ 2454a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 2455e4e574b7SAdam Litke 2456685f3457SLee Schermerhorn /* 2457685f3457SLee Schermerhorn * We want to release as many surplus pages as possible, spread 24589b5e5d0fSLee Schermerhorn * evenly across all nodes with memory. Iterate across these nodes 24599b5e5d0fSLee Schermerhorn * until we can no longer free unreserved surplus pages. This occurs 24609b5e5d0fSLee Schermerhorn * when the nodes with surplus pages have no free pages. 246110c6ec49SMike Kravetz * remove_pool_huge_page() will balance the freed pages across the 24629b5e5d0fSLee Schermerhorn * on-line nodes with memory and will handle the hstate accounting. 2463685f3457SLee Schermerhorn */ 2464685f3457SLee Schermerhorn while (nr_pages--) { 246510c6ec49SMike Kravetz page = remove_pool_huge_page(h, &node_states[N_MEMORY], 1); 246610c6ec49SMike Kravetz if (!page) 2467e5bbc8a6SMike Kravetz goto out; 246810c6ec49SMike Kravetz 246910c6ec49SMike Kravetz list_add(&page->lru, &page_list); 2470e4e574b7SAdam Litke } 2471e5bbc8a6SMike Kravetz 2472e5bbc8a6SMike Kravetz out: 2473db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 247410c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 2475db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2476e4e574b7SAdam Litke } 2477e4e574b7SAdam Litke 24785e911373SMike Kravetz 2479c37f9fb1SAndy Whitcroft /* 2480feba16e2SMike Kravetz * vma_needs_reservation, vma_commit_reservation and vma_end_reservation 24815e911373SMike Kravetz * are used by the huge page allocation routines to manage reservations. 2482cf3ad20bSMike Kravetz * 2483cf3ad20bSMike Kravetz * vma_needs_reservation is called to determine if the huge page at addr 2484cf3ad20bSMike Kravetz * within the vma has an associated reservation. If a reservation is 2485cf3ad20bSMike Kravetz * needed, the value 1 is returned. The caller is then responsible for 2486cf3ad20bSMike Kravetz * managing the global reservation and subpool usage counts. After 2487cf3ad20bSMike Kravetz * the huge page has been allocated, vma_commit_reservation is called 2488feba16e2SMike Kravetz * to add the page to the reservation map. If the page allocation fails, 2489feba16e2SMike Kravetz * the reservation must be ended instead of committed. vma_end_reservation 2490feba16e2SMike Kravetz * is called in such cases. 2491cf3ad20bSMike Kravetz * 2492cf3ad20bSMike Kravetz * In the normal case, vma_commit_reservation returns the same value 2493cf3ad20bSMike Kravetz * as the preceding vma_needs_reservation call. The only time this 2494cf3ad20bSMike Kravetz * is not the case is if a reserve map was changed between calls. It 2495cf3ad20bSMike Kravetz * is the responsibility of the caller to notice the difference and 2496cf3ad20bSMike Kravetz * take appropriate action. 249796b96a96SMike Kravetz * 249896b96a96SMike Kravetz * vma_add_reservation is used in error paths where a reservation must 249996b96a96SMike Kravetz * be restored when a newly allocated huge page must be freed. It is 250096b96a96SMike Kravetz * to be called after calling vma_needs_reservation to determine if a 250196b96a96SMike Kravetz * reservation exists. 2502846be085SMike Kravetz * 2503846be085SMike Kravetz * vma_del_reservation is used in error paths where an entry in the reserve 2504846be085SMike Kravetz * map was created during huge page allocation and must be removed. It is to 2505846be085SMike Kravetz * be called after calling vma_needs_reservation to determine if a reservation 2506846be085SMike Kravetz * exists. 2507c37f9fb1SAndy Whitcroft */ 25085e911373SMike Kravetz enum vma_resv_mode { 25095e911373SMike Kravetz VMA_NEEDS_RESV, 25105e911373SMike Kravetz VMA_COMMIT_RESV, 2511feba16e2SMike Kravetz VMA_END_RESV, 251296b96a96SMike Kravetz VMA_ADD_RESV, 2513846be085SMike Kravetz VMA_DEL_RESV, 25145e911373SMike Kravetz }; 2515cf3ad20bSMike Kravetz static long __vma_reservation_common(struct hstate *h, 2516cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr, 25175e911373SMike Kravetz enum vma_resv_mode mode) 2518c37f9fb1SAndy Whitcroft { 25194e35f483SJoonsoo Kim struct resv_map *resv; 25204e35f483SJoonsoo Kim pgoff_t idx; 2521cf3ad20bSMike Kravetz long ret; 25220db9d74eSMina Almasry long dummy_out_regions_needed; 2523c37f9fb1SAndy Whitcroft 25244e35f483SJoonsoo Kim resv = vma_resv_map(vma); 25254e35f483SJoonsoo Kim if (!resv) 2526c37f9fb1SAndy Whitcroft return 1; 2527c37f9fb1SAndy Whitcroft 25284e35f483SJoonsoo Kim idx = vma_hugecache_offset(h, vma, addr); 25295e911373SMike Kravetz switch (mode) { 25305e911373SMike Kravetz case VMA_NEEDS_RESV: 25310db9d74eSMina Almasry ret = region_chg(resv, idx, idx + 1, &dummy_out_regions_needed); 25320db9d74eSMina Almasry /* We assume that vma_reservation_* routines always operate on 25330db9d74eSMina Almasry * 1 page, and that adding to resv map a 1 page entry can only 25340db9d74eSMina Almasry * ever require 1 region. 25350db9d74eSMina Almasry */ 25360db9d74eSMina Almasry VM_BUG_ON(dummy_out_regions_needed != 1); 25375e911373SMike Kravetz break; 25385e911373SMike Kravetz case VMA_COMMIT_RESV: 2539075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 25400db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 25410db9d74eSMina Almasry VM_BUG_ON(ret < 0); 25425e911373SMike Kravetz break; 2543feba16e2SMike Kravetz case VMA_END_RESV: 25440db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 25455e911373SMike Kravetz ret = 0; 25465e911373SMike Kravetz break; 254796b96a96SMike Kravetz case VMA_ADD_RESV: 25480db9d74eSMina Almasry if (vma->vm_flags & VM_MAYSHARE) { 2549075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 25500db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 25510db9d74eSMina Almasry VM_BUG_ON(ret < 0); 25520db9d74eSMina Almasry } else { 25530db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 255496b96a96SMike Kravetz ret = region_del(resv, idx, idx + 1); 255596b96a96SMike Kravetz } 255696b96a96SMike Kravetz break; 2557846be085SMike Kravetz case VMA_DEL_RESV: 2558846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 2559846be085SMike Kravetz region_abort(resv, idx, idx + 1, 1); 2560846be085SMike Kravetz ret = region_del(resv, idx, idx + 1); 2561846be085SMike Kravetz } else { 2562846be085SMike Kravetz ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 2563846be085SMike Kravetz /* region_add calls of range 1 should never fail. */ 2564846be085SMike Kravetz VM_BUG_ON(ret < 0); 2565846be085SMike Kravetz } 2566846be085SMike Kravetz break; 25675e911373SMike Kravetz default: 25685e911373SMike Kravetz BUG(); 25695e911373SMike Kravetz } 257084afd99bSAndy Whitcroft 2571846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE || mode == VMA_DEL_RESV) 2572cf3ad20bSMike Kravetz return ret; 257367961f9dSMike Kravetz /* 2574bf3d12b9SMiaohe Lin * We know private mapping must have HPAGE_RESV_OWNER set. 2575bf3d12b9SMiaohe Lin * 257667961f9dSMike Kravetz * In most cases, reserves always exist for private mappings. 257767961f9dSMike Kravetz * However, a file associated with mapping could have been 257867961f9dSMike Kravetz * hole punched or truncated after reserves were consumed. 257967961f9dSMike Kravetz * As subsequent fault on such a range will not use reserves. 258067961f9dSMike Kravetz * Subtle - The reserve map for private mappings has the 258167961f9dSMike Kravetz * opposite meaning than that of shared mappings. If NO 258267961f9dSMike Kravetz * entry is in the reserve map, it means a reservation exists. 258367961f9dSMike Kravetz * If an entry exists in the reserve map, it means the 258467961f9dSMike Kravetz * reservation has already been consumed. As a result, the 258567961f9dSMike Kravetz * return value of this routine is the opposite of the 258667961f9dSMike Kravetz * value returned from reserve map manipulation routines above. 258767961f9dSMike Kravetz */ 2588bf3d12b9SMiaohe Lin if (ret > 0) 258967961f9dSMike Kravetz return 0; 2590bf3d12b9SMiaohe Lin if (ret == 0) 259167961f9dSMike Kravetz return 1; 2592bf3d12b9SMiaohe Lin return ret; 259384afd99bSAndy Whitcroft } 2594cf3ad20bSMike Kravetz 2595cf3ad20bSMike Kravetz static long vma_needs_reservation(struct hstate *h, 2596a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 2597c37f9fb1SAndy Whitcroft { 25985e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV); 2599cf3ad20bSMike Kravetz } 2600c37f9fb1SAndy Whitcroft 2601cf3ad20bSMike Kravetz static long vma_commit_reservation(struct hstate *h, 2602cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr) 2603cf3ad20bSMike Kravetz { 26045e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV); 26055e911373SMike Kravetz } 26065e911373SMike Kravetz 2607feba16e2SMike Kravetz static void vma_end_reservation(struct hstate *h, 26085e911373SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 26095e911373SMike Kravetz { 2610feba16e2SMike Kravetz (void)__vma_reservation_common(h, vma, addr, VMA_END_RESV); 2611c37f9fb1SAndy Whitcroft } 2612c37f9fb1SAndy Whitcroft 261396b96a96SMike Kravetz static long vma_add_reservation(struct hstate *h, 261496b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 261596b96a96SMike Kravetz { 261696b96a96SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV); 261796b96a96SMike Kravetz } 261896b96a96SMike Kravetz 2619846be085SMike Kravetz static long vma_del_reservation(struct hstate *h, 2620846be085SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 262196b96a96SMike Kravetz { 2622846be085SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_DEL_RESV); 2623846be085SMike Kravetz } 2624846be085SMike Kravetz 2625846be085SMike Kravetz /* 2626846be085SMike Kravetz * This routine is called to restore reservation information on error paths. 2627846be085SMike Kravetz * It should ONLY be called for pages allocated via alloc_huge_page(), and 2628846be085SMike Kravetz * the hugetlb mutex should remain held when calling this routine. 2629846be085SMike Kravetz * 2630846be085SMike Kravetz * It handles two specific cases: 2631846be085SMike Kravetz * 1) A reservation was in place and the page consumed the reservation. 2632846be085SMike Kravetz * HPageRestoreReserve is set in the page. 2633846be085SMike Kravetz * 2) No reservation was in place for the page, so HPageRestoreReserve is 2634846be085SMike Kravetz * not set. However, alloc_huge_page always updates the reserve map. 2635846be085SMike Kravetz * 2636846be085SMike Kravetz * In case 1, free_huge_page later in the error path will increment the 2637846be085SMike Kravetz * global reserve count. But, free_huge_page does not have enough context 2638846be085SMike Kravetz * to adjust the reservation map. This case deals primarily with private 2639846be085SMike Kravetz * mappings. Adjust the reserve map here to be consistent with global 2640846be085SMike Kravetz * reserve count adjustments to be made by free_huge_page. Make sure the 2641846be085SMike Kravetz * reserve map indicates there is a reservation present. 2642846be085SMike Kravetz * 2643846be085SMike Kravetz * In case 2, simply undo reserve map modifications done by alloc_huge_page. 2644846be085SMike Kravetz */ 2645846be085SMike Kravetz void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma, 2646846be085SMike Kravetz unsigned long address, struct page *page) 2647846be085SMike Kravetz { 264896b96a96SMike Kravetz long rc = vma_needs_reservation(h, vma, address); 264996b96a96SMike Kravetz 2650846be085SMike Kravetz if (HPageRestoreReserve(page)) { 2651846be085SMike Kravetz if (unlikely(rc < 0)) 265296b96a96SMike Kravetz /* 265396b96a96SMike Kravetz * Rare out of memory condition in reserve map 2654d6995da3SMike Kravetz * manipulation. Clear HPageRestoreReserve so that 265596b96a96SMike Kravetz * global reserve count will not be incremented 265696b96a96SMike Kravetz * by free_huge_page. This will make it appear 265796b96a96SMike Kravetz * as though the reservation for this page was 265896b96a96SMike Kravetz * consumed. This may prevent the task from 265996b96a96SMike Kravetz * faulting in the page at a later time. This 266096b96a96SMike Kravetz * is better than inconsistent global huge page 266196b96a96SMike Kravetz * accounting of reserve counts. 266296b96a96SMike Kravetz */ 2663d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 2664846be085SMike Kravetz else if (rc) 2665846be085SMike Kravetz (void)vma_add_reservation(h, vma, address); 2666846be085SMike Kravetz else 2667846be085SMike Kravetz vma_end_reservation(h, vma, address); 2668846be085SMike Kravetz } else { 2669846be085SMike Kravetz if (!rc) { 267096b96a96SMike Kravetz /* 2671846be085SMike Kravetz * This indicates there is an entry in the reserve map 2672c7b1850dSMike Kravetz * not added by alloc_huge_page. We know it was added 2673846be085SMike Kravetz * before the alloc_huge_page call, otherwise 2674846be085SMike Kravetz * HPageRestoreReserve would be set on the page. 2675846be085SMike Kravetz * Remove the entry so that a subsequent allocation 2676846be085SMike Kravetz * does not consume a reservation. 267796b96a96SMike Kravetz */ 2678846be085SMike Kravetz rc = vma_del_reservation(h, vma, address); 2679846be085SMike Kravetz if (rc < 0) 2680846be085SMike Kravetz /* 2681846be085SMike Kravetz * VERY rare out of memory condition. Since 2682846be085SMike Kravetz * we can not delete the entry, set 2683846be085SMike Kravetz * HPageRestoreReserve so that the reserve 2684846be085SMike Kravetz * count will be incremented when the page 2685846be085SMike Kravetz * is freed. This reserve will be consumed 2686846be085SMike Kravetz * on a subsequent allocation. 2687846be085SMike Kravetz */ 2688846be085SMike Kravetz SetHPageRestoreReserve(page); 2689846be085SMike Kravetz } else if (rc < 0) { 2690846be085SMike Kravetz /* 2691846be085SMike Kravetz * Rare out of memory condition from 2692846be085SMike Kravetz * vma_needs_reservation call. Memory allocation is 2693846be085SMike Kravetz * only attempted if a new entry is needed. Therefore, 2694846be085SMike Kravetz * this implies there is not an entry in the 2695846be085SMike Kravetz * reserve map. 2696846be085SMike Kravetz * 2697846be085SMike Kravetz * For shared mappings, no entry in the map indicates 2698846be085SMike Kravetz * no reservation. We are done. 2699846be085SMike Kravetz */ 2700846be085SMike Kravetz if (!(vma->vm_flags & VM_MAYSHARE)) 2701846be085SMike Kravetz /* 2702846be085SMike Kravetz * For private mappings, no entry indicates 2703846be085SMike Kravetz * a reservation is present. Since we can 2704846be085SMike Kravetz * not add an entry, set SetHPageRestoreReserve 2705846be085SMike Kravetz * on the page so reserve count will be 2706846be085SMike Kravetz * incremented when freed. This reserve will 2707846be085SMike Kravetz * be consumed on a subsequent allocation. 2708846be085SMike Kravetz */ 2709846be085SMike Kravetz SetHPageRestoreReserve(page); 271096b96a96SMike Kravetz } else 2711846be085SMike Kravetz /* 2712846be085SMike Kravetz * No reservation present, do nothing 2713846be085SMike Kravetz */ 271496b96a96SMike Kravetz vma_end_reservation(h, vma, address); 271596b96a96SMike Kravetz } 271696b96a96SMike Kravetz } 271796b96a96SMike Kravetz 2718369fa227SOscar Salvador /* 2719369fa227SOscar Salvador * alloc_and_dissolve_huge_page - Allocate a new page and dissolve the old one 2720369fa227SOscar Salvador * @h: struct hstate old page belongs to 2721369fa227SOscar Salvador * @old_page: Old page to dissolve 2722ae37c7ffSOscar Salvador * @list: List to isolate the page in case we need to 2723369fa227SOscar Salvador * Returns 0 on success, otherwise negated error. 2724369fa227SOscar Salvador */ 2725ae37c7ffSOscar Salvador static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, 2726ae37c7ffSOscar Salvador struct list_head *list) 2727369fa227SOscar Salvador { 2728369fa227SOscar Salvador gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 2729369fa227SOscar Salvador int nid = page_to_nid(old_page); 2730b65a4edaSMike Kravetz bool alloc_retry = false; 2731369fa227SOscar Salvador struct page *new_page; 2732369fa227SOscar Salvador int ret = 0; 2733369fa227SOscar Salvador 2734369fa227SOscar Salvador /* 2735369fa227SOscar Salvador * Before dissolving the page, we need to allocate a new one for the 2736f41f2ed4SMuchun Song * pool to remain stable. Here, we allocate the page and 'prep' it 2737f41f2ed4SMuchun Song * by doing everything but actually updating counters and adding to 2738f41f2ed4SMuchun Song * the pool. This simplifies and let us do most of the processing 2739f41f2ed4SMuchun Song * under the lock. 2740369fa227SOscar Salvador */ 2741b65a4edaSMike Kravetz alloc_retry: 2742369fa227SOscar Salvador new_page = alloc_buddy_huge_page(h, gfp_mask, nid, NULL, NULL); 2743369fa227SOscar Salvador if (!new_page) 2744369fa227SOscar Salvador return -ENOMEM; 2745b65a4edaSMike Kravetz /* 2746b65a4edaSMike Kravetz * If all goes well, this page will be directly added to the free 2747b65a4edaSMike Kravetz * list in the pool. For this the ref count needs to be zero. 2748b65a4edaSMike Kravetz * Attempt to drop now, and retry once if needed. It is VERY 2749b65a4edaSMike Kravetz * unlikely there is another ref on the page. 2750b65a4edaSMike Kravetz * 2751b65a4edaSMike Kravetz * If someone else has a reference to the page, it will be freed 2752b65a4edaSMike Kravetz * when they drop their ref. Abuse temporary page flag to accomplish 2753b65a4edaSMike Kravetz * this. Retry once if there is an inflated ref count. 2754b65a4edaSMike Kravetz */ 2755b65a4edaSMike Kravetz SetHPageTemporary(new_page); 2756b65a4edaSMike Kravetz if (!put_page_testzero(new_page)) { 2757b65a4edaSMike Kravetz if (alloc_retry) 2758b65a4edaSMike Kravetz return -EBUSY; 2759b65a4edaSMike Kravetz 2760b65a4edaSMike Kravetz alloc_retry = true; 2761b65a4edaSMike Kravetz goto alloc_retry; 2762b65a4edaSMike Kravetz } 2763b65a4edaSMike Kravetz ClearHPageTemporary(new_page); 2764b65a4edaSMike Kravetz 2765f41f2ed4SMuchun Song __prep_new_huge_page(h, new_page); 2766369fa227SOscar Salvador 2767369fa227SOscar Salvador retry: 2768369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2769369fa227SOscar Salvador if (!PageHuge(old_page)) { 2770369fa227SOscar Salvador /* 2771369fa227SOscar Salvador * Freed from under us. Drop new_page too. 2772369fa227SOscar Salvador */ 2773369fa227SOscar Salvador goto free_new; 2774369fa227SOscar Salvador } else if (page_count(old_page)) { 2775369fa227SOscar Salvador /* 2776ae37c7ffSOscar Salvador * Someone has grabbed the page, try to isolate it here. 2777ae37c7ffSOscar Salvador * Fail with -EBUSY if not possible. 2778369fa227SOscar Salvador */ 2779ae37c7ffSOscar Salvador spin_unlock_irq(&hugetlb_lock); 27807ce82f4cSMiaohe Lin ret = isolate_hugetlb(old_page, list); 2781ae37c7ffSOscar Salvador spin_lock_irq(&hugetlb_lock); 2782369fa227SOscar Salvador goto free_new; 2783369fa227SOscar Salvador } else if (!HPageFreed(old_page)) { 2784369fa227SOscar Salvador /* 2785369fa227SOscar Salvador * Page's refcount is 0 but it has not been enqueued in the 2786369fa227SOscar Salvador * freelist yet. Race window is small, so we can succeed here if 2787369fa227SOscar Salvador * we retry. 2788369fa227SOscar Salvador */ 2789369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2790369fa227SOscar Salvador cond_resched(); 2791369fa227SOscar Salvador goto retry; 2792369fa227SOscar Salvador } else { 2793369fa227SOscar Salvador /* 2794369fa227SOscar Salvador * Ok, old_page is still a genuine free hugepage. Remove it from 2795369fa227SOscar Salvador * the freelist and decrease the counters. These will be 2796369fa227SOscar Salvador * incremented again when calling __prep_account_new_huge_page() 2797369fa227SOscar Salvador * and enqueue_huge_page() for new_page. The counters will remain 2798369fa227SOscar Salvador * stable since this happens under the lock. 2799369fa227SOscar Salvador */ 2800369fa227SOscar Salvador remove_hugetlb_page(h, old_page, false); 2801369fa227SOscar Salvador 2802369fa227SOscar Salvador /* 2803b65a4edaSMike Kravetz * Ref count on new page is already zero as it was dropped 2804b65a4edaSMike Kravetz * earlier. It can be directly added to the pool free list. 2805369fa227SOscar Salvador */ 2806369fa227SOscar Salvador __prep_account_new_huge_page(h, nid); 2807369fa227SOscar Salvador enqueue_huge_page(h, new_page); 2808369fa227SOscar Salvador 2809369fa227SOscar Salvador /* 2810369fa227SOscar Salvador * Pages have been replaced, we can safely free the old one. 2811369fa227SOscar Salvador */ 2812369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2813b65d4adbSMuchun Song update_and_free_page(h, old_page, false); 2814369fa227SOscar Salvador } 2815369fa227SOscar Salvador 2816369fa227SOscar Salvador return ret; 2817369fa227SOscar Salvador 2818369fa227SOscar Salvador free_new: 2819369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2820b65a4edaSMike Kravetz /* Page has a zero ref count, but needs a ref to be freed */ 2821b65a4edaSMike Kravetz set_page_refcounted(new_page); 2822b65d4adbSMuchun Song update_and_free_page(h, new_page, false); 2823369fa227SOscar Salvador 2824369fa227SOscar Salvador return ret; 2825369fa227SOscar Salvador } 2826369fa227SOscar Salvador 2827ae37c7ffSOscar Salvador int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list) 2828369fa227SOscar Salvador { 2829369fa227SOscar Salvador struct hstate *h; 2830369fa227SOscar Salvador struct page *head; 2831ae37c7ffSOscar Salvador int ret = -EBUSY; 2832369fa227SOscar Salvador 2833369fa227SOscar Salvador /* 2834369fa227SOscar Salvador * The page might have been dissolved from under our feet, so make sure 2835369fa227SOscar Salvador * to carefully check the state under the lock. 2836369fa227SOscar Salvador * Return success when racing as if we dissolved the page ourselves. 2837369fa227SOscar Salvador */ 2838369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2839369fa227SOscar Salvador if (PageHuge(page)) { 2840369fa227SOscar Salvador head = compound_head(page); 2841369fa227SOscar Salvador h = page_hstate(head); 2842369fa227SOscar Salvador } else { 2843369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2844369fa227SOscar Salvador return 0; 2845369fa227SOscar Salvador } 2846369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2847369fa227SOscar Salvador 2848369fa227SOscar Salvador /* 2849369fa227SOscar Salvador * Fence off gigantic pages as there is a cyclic dependency between 2850369fa227SOscar Salvador * alloc_contig_range and them. Return -ENOMEM as this has the effect 2851369fa227SOscar Salvador * of bailing out right away without further retrying. 2852369fa227SOscar Salvador */ 2853369fa227SOscar Salvador if (hstate_is_gigantic(h)) 2854369fa227SOscar Salvador return -ENOMEM; 2855369fa227SOscar Salvador 28567ce82f4cSMiaohe Lin if (page_count(head) && !isolate_hugetlb(head, list)) 2857ae37c7ffSOscar Salvador ret = 0; 2858ae37c7ffSOscar Salvador else if (!page_count(head)) 2859ae37c7ffSOscar Salvador ret = alloc_and_dissolve_huge_page(h, head, list); 2860ae37c7ffSOscar Salvador 2861ae37c7ffSOscar Salvador return ret; 2862369fa227SOscar Salvador } 2863369fa227SOscar Salvador 286470c3547eSMike Kravetz struct page *alloc_huge_page(struct vm_area_struct *vma, 286504f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 2866348ea204SAdam Litke { 286790481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 2868a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 2869348ea204SAdam Litke struct page *page; 2870d85f69b0SMike Kravetz long map_chg, map_commit; 2871d85f69b0SMike Kravetz long gbl_chg; 28726d76dcf4SAneesh Kumar K.V int ret, idx; 28736d76dcf4SAneesh Kumar K.V struct hugetlb_cgroup *h_cg; 287408cf9fafSMina Almasry bool deferred_reserve; 28752fc39cecSAdam Litke 28766d76dcf4SAneesh Kumar K.V idx = hstate_index(h); 2877a1e78772SMel Gorman /* 2878d85f69b0SMike Kravetz * Examine the region/reserve map to determine if the process 2879d85f69b0SMike Kravetz * has a reservation for the page to be allocated. A return 2880d85f69b0SMike Kravetz * code of zero indicates a reservation exists (no change). 2881a1e78772SMel Gorman */ 2882d85f69b0SMike Kravetz map_chg = gbl_chg = vma_needs_reservation(h, vma, addr); 2883d85f69b0SMike Kravetz if (map_chg < 0) 288476dcee75SAneesh Kumar K.V return ERR_PTR(-ENOMEM); 2885d85f69b0SMike Kravetz 2886d85f69b0SMike Kravetz /* 2887d85f69b0SMike Kravetz * Processes that did not create the mapping will have no 2888d85f69b0SMike Kravetz * reserves as indicated by the region/reserve map. Check 2889d85f69b0SMike Kravetz * that the allocation will not exceed the subpool limit. 2890d85f69b0SMike Kravetz * Allocations for MAP_NORESERVE mappings also need to be 2891d85f69b0SMike Kravetz * checked against any subpool limit. 2892d85f69b0SMike Kravetz */ 2893d85f69b0SMike Kravetz if (map_chg || avoid_reserve) { 2894d85f69b0SMike Kravetz gbl_chg = hugepage_subpool_get_pages(spool, 1); 2895d85f69b0SMike Kravetz if (gbl_chg < 0) { 2896feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 289776dcee75SAneesh Kumar K.V return ERR_PTR(-ENOSPC); 28985e911373SMike Kravetz } 289990d8b7e6SAdam Litke 2900d85f69b0SMike Kravetz /* 2901d85f69b0SMike Kravetz * Even though there was no reservation in the region/reserve 2902d85f69b0SMike Kravetz * map, there could be reservations associated with the 2903d85f69b0SMike Kravetz * subpool that can be used. This would be indicated if the 2904d85f69b0SMike Kravetz * return value of hugepage_subpool_get_pages() is zero. 2905d85f69b0SMike Kravetz * However, if avoid_reserve is specified we still avoid even 2906d85f69b0SMike Kravetz * the subpool reservations. 2907d85f69b0SMike Kravetz */ 2908d85f69b0SMike Kravetz if (avoid_reserve) 2909d85f69b0SMike Kravetz gbl_chg = 1; 2910d85f69b0SMike Kravetz } 2911d85f69b0SMike Kravetz 291208cf9fafSMina Almasry /* If this allocation is not consuming a reservation, charge it now. 291308cf9fafSMina Almasry */ 29146501fe5fSMiaohe Lin deferred_reserve = map_chg || avoid_reserve; 291508cf9fafSMina Almasry if (deferred_reserve) { 291608cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup_rsvd( 291708cf9fafSMina Almasry idx, pages_per_huge_page(h), &h_cg); 29188f34af6fSJianyu Zhan if (ret) 29198f34af6fSJianyu Zhan goto out_subpool_put; 292008cf9fafSMina Almasry } 292108cf9fafSMina Almasry 292208cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); 292308cf9fafSMina Almasry if (ret) 292408cf9fafSMina Almasry goto out_uncharge_cgroup_reservation; 29258f34af6fSJianyu Zhan 2926db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2927d85f69b0SMike Kravetz /* 2928d85f69b0SMike Kravetz * glb_chg is passed to indicate whether or not a page must be taken 2929d85f69b0SMike Kravetz * from the global free pool (global change). gbl_chg == 0 indicates 2930d85f69b0SMike Kravetz * a reservation exists for the allocation. 2931d85f69b0SMike Kravetz */ 2932d85f69b0SMike Kravetz page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg); 293381a6fcaeSJoonsoo Kim if (!page) { 2934db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 29350c397daeSMichal Hocko page = alloc_buddy_huge_page_with_mpol(h, vma, addr); 29368f34af6fSJianyu Zhan if (!page) 29378f34af6fSJianyu Zhan goto out_uncharge_cgroup; 2938a88c7695SNaoya Horiguchi if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { 2939d6995da3SMike Kravetz SetHPageRestoreReserve(page); 2940a88c7695SNaoya Horiguchi h->resv_huge_pages--; 2941a88c7695SNaoya Horiguchi } 2942db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 294315a8d68eSWei Yang list_add(&page->lru, &h->hugepage_activelist); 294481a6fcaeSJoonsoo Kim /* Fall through */ 2945a1e78772SMel Gorman } 294681a6fcaeSJoonsoo Kim hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); 294708cf9fafSMina Almasry /* If allocation is not consuming a reservation, also store the 294808cf9fafSMina Almasry * hugetlb_cgroup pointer on the page. 294908cf9fafSMina Almasry */ 295008cf9fafSMina Almasry if (deferred_reserve) { 295108cf9fafSMina Almasry hugetlb_cgroup_commit_charge_rsvd(idx, pages_per_huge_page(h), 295208cf9fafSMina Almasry h_cg, page); 295308cf9fafSMina Almasry } 295408cf9fafSMina Almasry 2955db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2956a1e78772SMel Gorman 2957d6995da3SMike Kravetz hugetlb_set_page_subpool(page, spool); 2958a1e78772SMel Gorman 2959d85f69b0SMike Kravetz map_commit = vma_commit_reservation(h, vma, addr); 2960d85f69b0SMike Kravetz if (unlikely(map_chg > map_commit)) { 296133039678SMike Kravetz /* 296233039678SMike Kravetz * The page was added to the reservation map between 296333039678SMike Kravetz * vma_needs_reservation and vma_commit_reservation. 296433039678SMike Kravetz * This indicates a race with hugetlb_reserve_pages. 296533039678SMike Kravetz * Adjust for the subpool count incremented above AND 296633039678SMike Kravetz * in hugetlb_reserve_pages for the same page. Also, 296733039678SMike Kravetz * the reservation count added in hugetlb_reserve_pages 296833039678SMike Kravetz * no longer applies. 296933039678SMike Kravetz */ 297033039678SMike Kravetz long rsv_adjust; 297133039678SMike Kravetz 297233039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 1); 297333039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 297479aa925bSMike Kravetz if (deferred_reserve) 297579aa925bSMike Kravetz hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 297679aa925bSMike Kravetz pages_per_huge_page(h), page); 297733039678SMike Kravetz } 29787893d1d5SAdam Litke return page; 29798f34af6fSJianyu Zhan 29808f34af6fSJianyu Zhan out_uncharge_cgroup: 29818f34af6fSJianyu Zhan hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); 298208cf9fafSMina Almasry out_uncharge_cgroup_reservation: 298308cf9fafSMina Almasry if (deferred_reserve) 298408cf9fafSMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h), 298508cf9fafSMina Almasry h_cg); 29868f34af6fSJianyu Zhan out_subpool_put: 2987d85f69b0SMike Kravetz if (map_chg || avoid_reserve) 29888f34af6fSJianyu Zhan hugepage_subpool_put_pages(spool, 1); 2989feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 29908f34af6fSJianyu Zhan return ERR_PTR(-ENOSPC); 2991b45b5bd6SDavid Gibson } 2992b45b5bd6SDavid Gibson 2993b5389086SZhenguo Yao int alloc_bootmem_huge_page(struct hstate *h, int nid) 2994e24a1307SAneesh Kumar K.V __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); 2995b5389086SZhenguo Yao int __alloc_bootmem_huge_page(struct hstate *h, int nid) 2996aa888a74SAndi Kleen { 2997b5389086SZhenguo Yao struct huge_bootmem_page *m = NULL; /* initialize for clang */ 2998b2261026SJoonsoo Kim int nr_nodes, node; 2999aa888a74SAndi Kleen 3000b5389086SZhenguo Yao /* do node specific alloc */ 3001b5389086SZhenguo Yao if (nid != NUMA_NO_NODE) { 3002b5389086SZhenguo Yao m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h), 3003b5389086SZhenguo Yao 0, MEMBLOCK_ALLOC_ACCESSIBLE, nid); 3004b5389086SZhenguo Yao if (!m) 3005b5389086SZhenguo Yao return 0; 3006b5389086SZhenguo Yao goto found; 3007b5389086SZhenguo Yao } 3008b5389086SZhenguo Yao /* allocate from next node when distributing huge pages */ 3009b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { 3010b5389086SZhenguo Yao m = memblock_alloc_try_nid_raw( 30118b89a116SGrygorii Strashko huge_page_size(h), huge_page_size(h), 301297ad1087SMike Rapoport 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); 3013aa888a74SAndi Kleen /* 3014aa888a74SAndi Kleen * Use the beginning of the huge page to store the 3015aa888a74SAndi Kleen * huge_bootmem_page struct (until gather_bootmem 3016aa888a74SAndi Kleen * puts them into the mem_map). 3017aa888a74SAndi Kleen */ 3018b5389086SZhenguo Yao if (!m) 3019b5389086SZhenguo Yao return 0; 3020aa888a74SAndi Kleen goto found; 3021aa888a74SAndi Kleen } 3022aa888a74SAndi Kleen 3023aa888a74SAndi Kleen found: 3024aa888a74SAndi Kleen /* Put them into a private list first because mem_map is not up yet */ 3025330d6e48SCannon Matthews INIT_LIST_HEAD(&m->list); 3026aa888a74SAndi Kleen list_add(&m->list, &huge_boot_pages); 3027aa888a74SAndi Kleen m->hstate = h; 3028aa888a74SAndi Kleen return 1; 3029aa888a74SAndi Kleen } 3030aa888a74SAndi Kleen 303148b8d744SMike Kravetz /* 303248b8d744SMike Kravetz * Put bootmem huge pages into the standard lists after mem_map is up. 303348b8d744SMike Kravetz * Note: This only applies to gigantic (order > MAX_ORDER) pages. 303448b8d744SMike Kravetz */ 3035aa888a74SAndi Kleen static void __init gather_bootmem_prealloc(void) 3036aa888a74SAndi Kleen { 3037aa888a74SAndi Kleen struct huge_bootmem_page *m; 3038aa888a74SAndi Kleen 3039aa888a74SAndi Kleen list_for_each_entry(m, &huge_boot_pages, list) { 304040d18ebfSMike Kravetz struct page *page = virt_to_page(m); 3041aa888a74SAndi Kleen struct hstate *h = m->hstate; 3042ee8f248dSBecky Bruce 304348b8d744SMike Kravetz VM_BUG_ON(!hstate_is_gigantic(h)); 3044aa888a74SAndi Kleen WARN_ON(page_count(page) != 1); 30457118fc29SMike Kravetz if (prep_compound_gigantic_page(page, huge_page_order(h))) { 3046ef5a22beSAndrea Arcangeli WARN_ON(PageReserved(page)); 3047aa888a74SAndi Kleen prep_new_huge_page(h, page, page_to_nid(page)); 30487118fc29SMike Kravetz put_page(page); /* add to the hugepage allocator */ 30497118fc29SMike Kravetz } else { 3050416d85edSMike Kravetz /* VERY unlikely inflated ref count on a tail page */ 30517118fc29SMike Kravetz free_gigantic_page(page, huge_page_order(h)); 30527118fc29SMike Kravetz } 3053af0fb9dfSMichal Hocko 3054b0320c7bSRafael Aquini /* 305548b8d744SMike Kravetz * We need to restore the 'stolen' pages to totalram_pages 305648b8d744SMike Kravetz * in order to fix confusing memory reports from free(1) and 305748b8d744SMike Kravetz * other side-effects, like CommitLimit going negative. 3058b0320c7bSRafael Aquini */ 3059c78a7f36SMiaohe Lin adjust_managed_page_count(page, pages_per_huge_page(h)); 3060520495feSCannon Matthews cond_resched(); 3061aa888a74SAndi Kleen } 3062aa888a74SAndi Kleen } 3063b5389086SZhenguo Yao static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid) 3064b5389086SZhenguo Yao { 3065b5389086SZhenguo Yao unsigned long i; 3066b5389086SZhenguo Yao char buf[32]; 3067b5389086SZhenguo Yao 3068b5389086SZhenguo Yao for (i = 0; i < h->max_huge_pages_node[nid]; ++i) { 3069b5389086SZhenguo Yao if (hstate_is_gigantic(h)) { 3070b5389086SZhenguo Yao if (!alloc_bootmem_huge_page(h, nid)) 3071b5389086SZhenguo Yao break; 3072b5389086SZhenguo Yao } else { 3073b5389086SZhenguo Yao struct page *page; 3074b5389086SZhenguo Yao gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 3075b5389086SZhenguo Yao 3076b5389086SZhenguo Yao page = alloc_fresh_huge_page(h, gfp_mask, nid, 3077b5389086SZhenguo Yao &node_states[N_MEMORY], NULL); 3078b5389086SZhenguo Yao if (!page) 3079b5389086SZhenguo Yao break; 3080b5389086SZhenguo Yao put_page(page); /* free it into the hugepage allocator */ 3081b5389086SZhenguo Yao } 3082b5389086SZhenguo Yao cond_resched(); 3083b5389086SZhenguo Yao } 3084b5389086SZhenguo Yao if (i == h->max_huge_pages_node[nid]) 3085b5389086SZhenguo Yao return; 3086b5389086SZhenguo Yao 3087b5389086SZhenguo Yao string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3088b5389086SZhenguo Yao pr_warn("HugeTLB: allocating %u of page size %s failed node%d. Only allocated %lu hugepages.\n", 3089b5389086SZhenguo Yao h->max_huge_pages_node[nid], buf, nid, i); 3090b5389086SZhenguo Yao h->max_huge_pages -= (h->max_huge_pages_node[nid] - i); 3091b5389086SZhenguo Yao h->max_huge_pages_node[nid] = i; 3092b5389086SZhenguo Yao } 3093aa888a74SAndi Kleen 30948faa8b07SAndi Kleen static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 30951da177e4SLinus Torvalds { 30961da177e4SLinus Torvalds unsigned long i; 3097f60858f9SMike Kravetz nodemask_t *node_alloc_noretry; 3098b5389086SZhenguo Yao bool node_specific_alloc = false; 3099f60858f9SMike Kravetz 3100b5389086SZhenguo Yao /* skip gigantic hugepages allocation if hugetlb_cma enabled */ 3101b5389086SZhenguo Yao if (hstate_is_gigantic(h) && hugetlb_cma_size) { 3102b5389086SZhenguo Yao pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n"); 3103b5389086SZhenguo Yao return; 3104b5389086SZhenguo Yao } 3105b5389086SZhenguo Yao 3106b5389086SZhenguo Yao /* do node specific alloc */ 31070a7a0f6fSPeng Liu for_each_online_node(i) { 3108b5389086SZhenguo Yao if (h->max_huge_pages_node[i] > 0) { 3109b5389086SZhenguo Yao hugetlb_hstate_alloc_pages_onenode(h, i); 3110b5389086SZhenguo Yao node_specific_alloc = true; 3111b5389086SZhenguo Yao } 3112b5389086SZhenguo Yao } 3113b5389086SZhenguo Yao 3114b5389086SZhenguo Yao if (node_specific_alloc) 3115b5389086SZhenguo Yao return; 3116b5389086SZhenguo Yao 3117b5389086SZhenguo Yao /* below will do all node balanced alloc */ 3118f60858f9SMike Kravetz if (!hstate_is_gigantic(h)) { 3119f60858f9SMike Kravetz /* 3120f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3121f60858f9SMike Kravetz * Ignore errors as lower level routines can deal with 3122f60858f9SMike Kravetz * node_alloc_noretry == NULL. If this kmalloc fails at boot 3123f60858f9SMike Kravetz * time, we are likely in bigger trouble. 3124f60858f9SMike Kravetz */ 3125f60858f9SMike Kravetz node_alloc_noretry = kmalloc(sizeof(*node_alloc_noretry), 3126f60858f9SMike Kravetz GFP_KERNEL); 3127f60858f9SMike Kravetz } else { 3128f60858f9SMike Kravetz /* allocations done at boot time */ 3129f60858f9SMike Kravetz node_alloc_noretry = NULL; 3130f60858f9SMike Kravetz } 3131f60858f9SMike Kravetz 3132f60858f9SMike Kravetz /* bit mask controlling how hard we retry per-node allocations */ 3133f60858f9SMike Kravetz if (node_alloc_noretry) 3134f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 31351da177e4SLinus Torvalds 3136e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 3137bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) { 3138b5389086SZhenguo Yao if (!alloc_bootmem_huge_page(h, NUMA_NO_NODE)) 3139aa888a74SAndi Kleen break; 31400c397daeSMichal Hocko } else if (!alloc_pool_huge_page(h, 3141f60858f9SMike Kravetz &node_states[N_MEMORY], 3142f60858f9SMike Kravetz node_alloc_noretry)) 31431da177e4SLinus Torvalds break; 314469ed779aSDavid Rientjes cond_resched(); 31451da177e4SLinus Torvalds } 3146d715cf80SLiam R. Howlett if (i < h->max_huge_pages) { 3147d715cf80SLiam R. Howlett char buf[32]; 3148d715cf80SLiam R. Howlett 3149c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3150d715cf80SLiam R. Howlett pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n", 3151d715cf80SLiam R. Howlett h->max_huge_pages, buf, i); 31528faa8b07SAndi Kleen h->max_huge_pages = i; 3153e5ff2159SAndi Kleen } 3154f60858f9SMike Kravetz kfree(node_alloc_noretry); 3155d715cf80SLiam R. Howlett } 3156e5ff2159SAndi Kleen 3157e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 3158e5ff2159SAndi Kleen { 315979dfc695SMike Kravetz struct hstate *h, *h2; 3160e5ff2159SAndi Kleen 3161e5ff2159SAndi Kleen for_each_hstate(h) { 31628faa8b07SAndi Kleen /* oversize hugepages were init'ed in early boot */ 3163bae7f4aeSLuiz Capitulino if (!hstate_is_gigantic(h)) 31648faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(h); 316579dfc695SMike Kravetz 316679dfc695SMike Kravetz /* 316779dfc695SMike Kravetz * Set demote order for each hstate. Note that 316879dfc695SMike Kravetz * h->demote_order is initially 0. 316979dfc695SMike Kravetz * - We can not demote gigantic pages if runtime freeing 317079dfc695SMike Kravetz * is not supported, so skip this. 3171a01f4390SMike Kravetz * - If CMA allocation is possible, we can not demote 3172a01f4390SMike Kravetz * HUGETLB_PAGE_ORDER or smaller size pages. 317379dfc695SMike Kravetz */ 317479dfc695SMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 317579dfc695SMike Kravetz continue; 3176a01f4390SMike Kravetz if (hugetlb_cma_size && h->order <= HUGETLB_PAGE_ORDER) 3177a01f4390SMike Kravetz continue; 317879dfc695SMike Kravetz for_each_hstate(h2) { 317979dfc695SMike Kravetz if (h2 == h) 318079dfc695SMike Kravetz continue; 318179dfc695SMike Kravetz if (h2->order < h->order && 318279dfc695SMike Kravetz h2->order > h->demote_order) 318379dfc695SMike Kravetz h->demote_order = h2->order; 318479dfc695SMike Kravetz } 3185e5ff2159SAndi Kleen } 3186e5ff2159SAndi Kleen } 3187e5ff2159SAndi Kleen 3188e5ff2159SAndi Kleen static void __init report_hugepages(void) 3189e5ff2159SAndi Kleen { 3190e5ff2159SAndi Kleen struct hstate *h; 3191e5ff2159SAndi Kleen 3192e5ff2159SAndi Kleen for_each_hstate(h) { 31934abd32dbSAndi Kleen char buf[32]; 3194c6247f72SMatthew Wilcox 3195c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 31966213834cSMuchun Song pr_info("HugeTLB: registered %s page size, pre-allocated %ld pages\n", 3197c6247f72SMatthew Wilcox buf, h->free_huge_pages); 31986213834cSMuchun Song pr_info("HugeTLB: %d KiB vmemmap can be freed for a %s page\n", 31996213834cSMuchun Song hugetlb_vmemmap_optimizable_size(h) / SZ_1K, buf); 3200e5ff2159SAndi Kleen } 3201e5ff2159SAndi Kleen } 3202e5ff2159SAndi Kleen 32031da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 32046ae11b27SLee Schermerhorn static void try_to_free_low(struct hstate *h, unsigned long count, 32056ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 32061da177e4SLinus Torvalds { 32074415cc8dSChristoph Lameter int i; 32081121828aSMike Kravetz LIST_HEAD(page_list); 32094415cc8dSChristoph Lameter 32109487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 3211bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3212aa888a74SAndi Kleen return; 3213aa888a74SAndi Kleen 32141121828aSMike Kravetz /* 32151121828aSMike Kravetz * Collect pages to be freed on a list, and free after dropping lock 32161121828aSMike Kravetz */ 32176ae11b27SLee Schermerhorn for_each_node_mask(i, *nodes_allowed) { 321810c6ec49SMike Kravetz struct page *page, *next; 3219a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 3220a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 3221a5516438SAndi Kleen if (count >= h->nr_huge_pages) 32221121828aSMike Kravetz goto out; 32231da177e4SLinus Torvalds if (PageHighMem(page)) 32241da177e4SLinus Torvalds continue; 32256eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 32261121828aSMike Kravetz list_add(&page->lru, &page_list); 32271121828aSMike Kravetz } 32281121828aSMike Kravetz } 32291121828aSMike Kravetz 32301121828aSMike Kravetz out: 3231db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 323210c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3233db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 32341da177e4SLinus Torvalds } 32351da177e4SLinus Torvalds #else 32366ae11b27SLee Schermerhorn static inline void try_to_free_low(struct hstate *h, unsigned long count, 32376ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 32381da177e4SLinus Torvalds { 32391da177e4SLinus Torvalds } 32401da177e4SLinus Torvalds #endif 32411da177e4SLinus Torvalds 324220a0307cSWu Fengguang /* 324320a0307cSWu Fengguang * Increment or decrement surplus_huge_pages. Keep node-specific counters 324420a0307cSWu Fengguang * balanced by operating on them in a round-robin fashion. 324520a0307cSWu Fengguang * Returns 1 if an adjustment was made. 324620a0307cSWu Fengguang */ 32476ae11b27SLee Schermerhorn static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, 32486ae11b27SLee Schermerhorn int delta) 324920a0307cSWu Fengguang { 3250b2261026SJoonsoo Kim int nr_nodes, node; 325120a0307cSWu Fengguang 32529487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 325320a0307cSWu Fengguang VM_BUG_ON(delta != -1 && delta != 1); 325420a0307cSWu Fengguang 3255e8c5c824SLee Schermerhorn if (delta < 0) { 3256b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 3257b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node]) 3258b2261026SJoonsoo Kim goto found; 3259b2261026SJoonsoo Kim } 3260b2261026SJoonsoo Kim } else { 3261b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 3262b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node] < 3263b2261026SJoonsoo Kim h->nr_huge_pages_node[node]) 3264b2261026SJoonsoo Kim goto found; 3265e8c5c824SLee Schermerhorn } 32669a76db09SLee Schermerhorn } 3267b2261026SJoonsoo Kim return 0; 326820a0307cSWu Fengguang 3269b2261026SJoonsoo Kim found: 327020a0307cSWu Fengguang h->surplus_huge_pages += delta; 3271b2261026SJoonsoo Kim h->surplus_huge_pages_node[node] += delta; 3272b2261026SJoonsoo Kim return 1; 327320a0307cSWu Fengguang } 327420a0307cSWu Fengguang 3275a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 3276fd875dcaSMike Kravetz static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, 32776ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 32781da177e4SLinus Torvalds { 32797893d1d5SAdam Litke unsigned long min_count, ret; 328010c6ec49SMike Kravetz struct page *page; 328110c6ec49SMike Kravetz LIST_HEAD(page_list); 3282f60858f9SMike Kravetz NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL); 3283f60858f9SMike Kravetz 3284f60858f9SMike Kravetz /* 3285f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3286f60858f9SMike Kravetz * If we can not allocate the bit mask, do not attempt to allocate 3287f60858f9SMike Kravetz * the requested huge pages. 3288f60858f9SMike Kravetz */ 3289f60858f9SMike Kravetz if (node_alloc_noretry) 3290f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 3291f60858f9SMike Kravetz else 3292f60858f9SMike Kravetz return -ENOMEM; 32931da177e4SLinus Torvalds 329429383967SMike Kravetz /* 329529383967SMike Kravetz * resize_lock mutex prevents concurrent adjustments to number of 329629383967SMike Kravetz * pages in hstate via the proc/sysfs interfaces. 329729383967SMike Kravetz */ 329829383967SMike Kravetz mutex_lock(&h->resize_lock); 3299b65d4adbSMuchun Song flush_free_hpage_work(h); 3300db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 33014eb0716eSAlexandre Ghiti 33024eb0716eSAlexandre Ghiti /* 3303fd875dcaSMike Kravetz * Check for a node specific request. 3304fd875dcaSMike Kravetz * Changing node specific huge page count may require a corresponding 3305fd875dcaSMike Kravetz * change to the global count. In any case, the passed node mask 3306fd875dcaSMike Kravetz * (nodes_allowed) will restrict alloc/free to the specified node. 3307fd875dcaSMike Kravetz */ 3308fd875dcaSMike Kravetz if (nid != NUMA_NO_NODE) { 3309fd875dcaSMike Kravetz unsigned long old_count = count; 3310fd875dcaSMike Kravetz 3311fd875dcaSMike Kravetz count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; 3312fd875dcaSMike Kravetz /* 3313fd875dcaSMike Kravetz * User may have specified a large count value which caused the 3314fd875dcaSMike Kravetz * above calculation to overflow. In this case, they wanted 3315fd875dcaSMike Kravetz * to allocate as many huge pages as possible. Set count to 3316fd875dcaSMike Kravetz * largest possible value to align with their intention. 3317fd875dcaSMike Kravetz */ 3318fd875dcaSMike Kravetz if (count < old_count) 3319fd875dcaSMike Kravetz count = ULONG_MAX; 3320fd875dcaSMike Kravetz } 3321fd875dcaSMike Kravetz 3322fd875dcaSMike Kravetz /* 33234eb0716eSAlexandre Ghiti * Gigantic pages runtime allocation depend on the capability for large 33244eb0716eSAlexandre Ghiti * page range allocation. 33254eb0716eSAlexandre Ghiti * If the system does not provide this feature, return an error when 33264eb0716eSAlexandre Ghiti * the user tries to allocate gigantic pages but let the user free the 33274eb0716eSAlexandre Ghiti * boottime allocated gigantic pages. 33284eb0716eSAlexandre Ghiti */ 33294eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) { 33304eb0716eSAlexandre Ghiti if (count > persistent_huge_pages(h)) { 3331db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 333229383967SMike Kravetz mutex_unlock(&h->resize_lock); 3333f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 33344eb0716eSAlexandre Ghiti return -EINVAL; 33354eb0716eSAlexandre Ghiti } 33364eb0716eSAlexandre Ghiti /* Fall through to decrease pool */ 33374eb0716eSAlexandre Ghiti } 3338aa888a74SAndi Kleen 33397893d1d5SAdam Litke /* 33407893d1d5SAdam Litke * Increase the pool size 33417893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 33427893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 3343d1c3fb1fSNishanth Aravamudan * 33440c397daeSMichal Hocko * We might race with alloc_surplus_huge_page() here and be unable 3345d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 3346d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 3347d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 3348d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 33497893d1d5SAdam Litke */ 3350a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 33516ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, -1)) 33527893d1d5SAdam Litke break; 33537893d1d5SAdam Litke } 33547893d1d5SAdam Litke 3355a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 33567893d1d5SAdam Litke /* 33577893d1d5SAdam Litke * If this allocation races such that we no longer need the 33587893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 33597893d1d5SAdam Litke * and reducing the surplus. 33607893d1d5SAdam Litke */ 3361db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3362649920c6SJia He 3363649920c6SJia He /* yield cpu to avoid soft lockup */ 3364649920c6SJia He cond_resched(); 3365649920c6SJia He 3366f60858f9SMike Kravetz ret = alloc_pool_huge_page(h, nodes_allowed, 3367f60858f9SMike Kravetz node_alloc_noretry); 3368db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 33697893d1d5SAdam Litke if (!ret) 33707893d1d5SAdam Litke goto out; 33717893d1d5SAdam Litke 3372536240f2SMel Gorman /* Bail for signals. Probably ctrl-c from user */ 3373536240f2SMel Gorman if (signal_pending(current)) 3374536240f2SMel Gorman goto out; 33757893d1d5SAdam Litke } 33767893d1d5SAdam Litke 33777893d1d5SAdam Litke /* 33787893d1d5SAdam Litke * Decrease the pool size 33797893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 33807893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 33817893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 33827893d1d5SAdam Litke * to the desired size as pages become free. 3383d1c3fb1fSNishanth Aravamudan * 3384d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 3385d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 3386d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 33870c397daeSMichal Hocko * alloc_surplus_huge_page() is checking the global counter, 3388d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 3389d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 3390d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 33917893d1d5SAdam Litke */ 3392a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 33936b0c880dSAdam Litke min_count = max(count, min_count); 33946ae11b27SLee Schermerhorn try_to_free_low(h, min_count, nodes_allowed); 339510c6ec49SMike Kravetz 339610c6ec49SMike Kravetz /* 339710c6ec49SMike Kravetz * Collect pages to be removed on list without dropping lock 339810c6ec49SMike Kravetz */ 3399a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 340010c6ec49SMike Kravetz page = remove_pool_huge_page(h, nodes_allowed, 0); 340110c6ec49SMike Kravetz if (!page) 34021da177e4SLinus Torvalds break; 340310c6ec49SMike Kravetz 340410c6ec49SMike Kravetz list_add(&page->lru, &page_list); 34051da177e4SLinus Torvalds } 340610c6ec49SMike Kravetz /* free the pages after dropping lock */ 3407db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 340810c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3409b65d4adbSMuchun Song flush_free_hpage_work(h); 3410db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 341110c6ec49SMike Kravetz 3412a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 34136ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, 1)) 34147893d1d5SAdam Litke break; 34157893d1d5SAdam Litke } 34167893d1d5SAdam Litke out: 34174eb0716eSAlexandre Ghiti h->max_huge_pages = persistent_huge_pages(h); 3418db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 341929383967SMike Kravetz mutex_unlock(&h->resize_lock); 34204eb0716eSAlexandre Ghiti 3421f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 3422f60858f9SMike Kravetz 34234eb0716eSAlexandre Ghiti return 0; 34241da177e4SLinus Torvalds } 34251da177e4SLinus Torvalds 34268531fc6fSMike Kravetz static int demote_free_huge_page(struct hstate *h, struct page *page) 34278531fc6fSMike Kravetz { 34288531fc6fSMike Kravetz int i, nid = page_to_nid(page); 34298531fc6fSMike Kravetz struct hstate *target_hstate; 343031731452SDoug Berger struct page *subpage; 34318531fc6fSMike Kravetz int rc = 0; 34328531fc6fSMike Kravetz 34338531fc6fSMike Kravetz target_hstate = size_to_hstate(PAGE_SIZE << h->demote_order); 34348531fc6fSMike Kravetz 34358531fc6fSMike Kravetz remove_hugetlb_page_for_demote(h, page, false); 34368531fc6fSMike Kravetz spin_unlock_irq(&hugetlb_lock); 34378531fc6fSMike Kravetz 34386213834cSMuchun Song rc = hugetlb_vmemmap_restore(h, page); 34398531fc6fSMike Kravetz if (rc) { 34408531fc6fSMike Kravetz /* Allocation of vmemmmap failed, we can not demote page */ 34418531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 34428531fc6fSMike Kravetz set_page_refcounted(page); 34438531fc6fSMike Kravetz add_hugetlb_page(h, page, false); 34448531fc6fSMike Kravetz return rc; 34458531fc6fSMike Kravetz } 34468531fc6fSMike Kravetz 34478531fc6fSMike Kravetz /* 34488531fc6fSMike Kravetz * Use destroy_compound_hugetlb_page_for_demote for all huge page 34498531fc6fSMike Kravetz * sizes as it will not ref count pages. 34508531fc6fSMike Kravetz */ 34518531fc6fSMike Kravetz destroy_compound_hugetlb_page_for_demote(page, huge_page_order(h)); 34528531fc6fSMike Kravetz 34538531fc6fSMike Kravetz /* 34548531fc6fSMike Kravetz * Taking target hstate mutex synchronizes with set_max_huge_pages. 34558531fc6fSMike Kravetz * Without the mutex, pages added to target hstate could be marked 34568531fc6fSMike Kravetz * as surplus. 34578531fc6fSMike Kravetz * 34588531fc6fSMike Kravetz * Note that we already hold h->resize_lock. To prevent deadlock, 34598531fc6fSMike Kravetz * use the convention of always taking larger size hstate mutex first. 34608531fc6fSMike Kravetz */ 34618531fc6fSMike Kravetz mutex_lock(&target_hstate->resize_lock); 34628531fc6fSMike Kravetz for (i = 0; i < pages_per_huge_page(h); 34638531fc6fSMike Kravetz i += pages_per_huge_page(target_hstate)) { 346431731452SDoug Berger subpage = nth_page(page, i); 34658531fc6fSMike Kravetz if (hstate_is_gigantic(target_hstate)) 346631731452SDoug Berger prep_compound_gigantic_page_for_demote(subpage, 34678531fc6fSMike Kravetz target_hstate->order); 34688531fc6fSMike Kravetz else 346931731452SDoug Berger prep_compound_page(subpage, target_hstate->order); 347031731452SDoug Berger set_page_private(subpage, 0); 347131731452SDoug Berger set_page_refcounted(subpage); 347231731452SDoug Berger prep_new_huge_page(target_hstate, subpage, nid); 347331731452SDoug Berger put_page(subpage); 34748531fc6fSMike Kravetz } 34758531fc6fSMike Kravetz mutex_unlock(&target_hstate->resize_lock); 34768531fc6fSMike Kravetz 34778531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 34788531fc6fSMike Kravetz 34798531fc6fSMike Kravetz /* 34808531fc6fSMike Kravetz * Not absolutely necessary, but for consistency update max_huge_pages 34818531fc6fSMike Kravetz * based on pool changes for the demoted page. 34828531fc6fSMike Kravetz */ 34838531fc6fSMike Kravetz h->max_huge_pages--; 3484a43a83c7SMiaohe Lin target_hstate->max_huge_pages += 3485a43a83c7SMiaohe Lin pages_per_huge_page(h) / pages_per_huge_page(target_hstate); 34868531fc6fSMike Kravetz 34878531fc6fSMike Kravetz return rc; 34888531fc6fSMike Kravetz } 34898531fc6fSMike Kravetz 349079dfc695SMike Kravetz static int demote_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed) 349179dfc695SMike Kravetz __must_hold(&hugetlb_lock) 349279dfc695SMike Kravetz { 34938531fc6fSMike Kravetz int nr_nodes, node; 34948531fc6fSMike Kravetz struct page *page; 349579dfc695SMike Kravetz 349679dfc695SMike Kravetz lockdep_assert_held(&hugetlb_lock); 349779dfc695SMike Kravetz 349879dfc695SMike Kravetz /* We should never get here if no demote order */ 349979dfc695SMike Kravetz if (!h->demote_order) { 350079dfc695SMike Kravetz pr_warn("HugeTLB: NULL demote order passed to demote_pool_huge_page.\n"); 350179dfc695SMike Kravetz return -EINVAL; /* internal error */ 350279dfc695SMike Kravetz } 350379dfc695SMike Kravetz 35048531fc6fSMike Kravetz for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 35055a317412SMike Kravetz list_for_each_entry(page, &h->hugepage_freelists[node], lru) { 35065a317412SMike Kravetz if (PageHWPoison(page)) 35075a317412SMike Kravetz continue; 35085a317412SMike Kravetz 35095a317412SMike Kravetz return demote_free_huge_page(h, page); 35108531fc6fSMike Kravetz } 35118531fc6fSMike Kravetz } 35128531fc6fSMike Kravetz 35135a317412SMike Kravetz /* 35145a317412SMike Kravetz * Only way to get here is if all pages on free lists are poisoned. 35155a317412SMike Kravetz * Return -EBUSY so that caller will not retry. 35165a317412SMike Kravetz */ 35175a317412SMike Kravetz return -EBUSY; 351879dfc695SMike Kravetz } 351979dfc695SMike Kravetz 3520a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 3521a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 3522a3437870SNishanth Aravamudan 352379dfc695SMike Kravetz #define HSTATE_ATTR_WO(_name) \ 352479dfc695SMike Kravetz static struct kobj_attribute _name##_attr = __ATTR_WO(_name) 352579dfc695SMike Kravetz 3526a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 352798bc26acSMiaohe Lin static struct kobj_attribute _name##_attr = __ATTR_RW(_name) 3528a3437870SNishanth Aravamudan 3529a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 3530a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 3531a3437870SNishanth Aravamudan 35329a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); 35339a305230SLee Schermerhorn 35349a305230SLee Schermerhorn static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) 3535a3437870SNishanth Aravamudan { 3536a3437870SNishanth Aravamudan int i; 35379a305230SLee Schermerhorn 3538a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 35399a305230SLee Schermerhorn if (hstate_kobjs[i] == kobj) { 35409a305230SLee Schermerhorn if (nidp) 35419a305230SLee Schermerhorn *nidp = NUMA_NO_NODE; 3542a3437870SNishanth Aravamudan return &hstates[i]; 35439a305230SLee Schermerhorn } 35449a305230SLee Schermerhorn 35459a305230SLee Schermerhorn return kobj_to_node_hstate(kobj, nidp); 3546a3437870SNishanth Aravamudan } 3547a3437870SNishanth Aravamudan 354806808b08SLee Schermerhorn static ssize_t nr_hugepages_show_common(struct kobject *kobj, 3549a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3550a3437870SNishanth Aravamudan { 35519a305230SLee Schermerhorn struct hstate *h; 35529a305230SLee Schermerhorn unsigned long nr_huge_pages; 35539a305230SLee Schermerhorn int nid; 35549a305230SLee Schermerhorn 35559a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 35569a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 35579a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages; 35589a305230SLee Schermerhorn else 35599a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages_node[nid]; 35609a305230SLee Schermerhorn 3561ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", nr_huge_pages); 3562a3437870SNishanth Aravamudan } 3563adbe8726SEric B Munson 3564238d3c13SDavid Rientjes static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, 3565238d3c13SDavid Rientjes struct hstate *h, int nid, 3566238d3c13SDavid Rientjes unsigned long count, size_t len) 3567a3437870SNishanth Aravamudan { 3568a3437870SNishanth Aravamudan int err; 35692d0adf7eSOscar Salvador nodemask_t nodes_allowed, *n_mask; 3570a3437870SNishanth Aravamudan 35712d0adf7eSOscar Salvador if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 35722d0adf7eSOscar Salvador return -EINVAL; 3573adbe8726SEric B Munson 35749a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) { 35759a305230SLee Schermerhorn /* 35769a305230SLee Schermerhorn * global hstate attribute 35779a305230SLee Schermerhorn */ 35789a305230SLee Schermerhorn if (!(obey_mempolicy && 35792d0adf7eSOscar Salvador init_nodemask_of_mempolicy(&nodes_allowed))) 35802d0adf7eSOscar Salvador n_mask = &node_states[N_MEMORY]; 35812d0adf7eSOscar Salvador else 35822d0adf7eSOscar Salvador n_mask = &nodes_allowed; 35832d0adf7eSOscar Salvador } else { 35849a305230SLee Schermerhorn /* 3585fd875dcaSMike Kravetz * Node specific request. count adjustment happens in 3586fd875dcaSMike Kravetz * set_max_huge_pages() after acquiring hugetlb_lock. 35879a305230SLee Schermerhorn */ 35882d0adf7eSOscar Salvador init_nodemask_of_node(&nodes_allowed, nid); 35892d0adf7eSOscar Salvador n_mask = &nodes_allowed; 3590fd875dcaSMike Kravetz } 35919a305230SLee Schermerhorn 35922d0adf7eSOscar Salvador err = set_max_huge_pages(h, count, nid, n_mask); 359306808b08SLee Schermerhorn 35944eb0716eSAlexandre Ghiti return err ? err : len; 359506808b08SLee Schermerhorn } 359606808b08SLee Schermerhorn 3597238d3c13SDavid Rientjes static ssize_t nr_hugepages_store_common(bool obey_mempolicy, 3598238d3c13SDavid Rientjes struct kobject *kobj, const char *buf, 3599238d3c13SDavid Rientjes size_t len) 3600238d3c13SDavid Rientjes { 3601238d3c13SDavid Rientjes struct hstate *h; 3602238d3c13SDavid Rientjes unsigned long count; 3603238d3c13SDavid Rientjes int nid; 3604238d3c13SDavid Rientjes int err; 3605238d3c13SDavid Rientjes 3606238d3c13SDavid Rientjes err = kstrtoul(buf, 10, &count); 3607238d3c13SDavid Rientjes if (err) 3608238d3c13SDavid Rientjes return err; 3609238d3c13SDavid Rientjes 3610238d3c13SDavid Rientjes h = kobj_to_hstate(kobj, &nid); 3611238d3c13SDavid Rientjes return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); 3612238d3c13SDavid Rientjes } 3613238d3c13SDavid Rientjes 361406808b08SLee Schermerhorn static ssize_t nr_hugepages_show(struct kobject *kobj, 361506808b08SLee Schermerhorn struct kobj_attribute *attr, char *buf) 361606808b08SLee Schermerhorn { 361706808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 361806808b08SLee Schermerhorn } 361906808b08SLee Schermerhorn 362006808b08SLee Schermerhorn static ssize_t nr_hugepages_store(struct kobject *kobj, 362106808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 362206808b08SLee Schermerhorn { 3623238d3c13SDavid Rientjes return nr_hugepages_store_common(false, kobj, buf, len); 3624a3437870SNishanth Aravamudan } 3625a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 3626a3437870SNishanth Aravamudan 362706808b08SLee Schermerhorn #ifdef CONFIG_NUMA 362806808b08SLee Schermerhorn 362906808b08SLee Schermerhorn /* 363006808b08SLee Schermerhorn * hstate attribute for optionally mempolicy-based constraint on persistent 363106808b08SLee Schermerhorn * huge page alloc/free. 363206808b08SLee Schermerhorn */ 363306808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, 3634ae7a927dSJoe Perches struct kobj_attribute *attr, 3635ae7a927dSJoe Perches char *buf) 363606808b08SLee Schermerhorn { 363706808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 363806808b08SLee Schermerhorn } 363906808b08SLee Schermerhorn 364006808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, 364106808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 364206808b08SLee Schermerhorn { 3643238d3c13SDavid Rientjes return nr_hugepages_store_common(true, kobj, buf, len); 364406808b08SLee Schermerhorn } 364506808b08SLee Schermerhorn HSTATE_ATTR(nr_hugepages_mempolicy); 364606808b08SLee Schermerhorn #endif 364706808b08SLee Schermerhorn 364806808b08SLee Schermerhorn 3649a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 3650a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3651a3437870SNishanth Aravamudan { 36529a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3653ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->nr_overcommit_huge_pages); 3654a3437870SNishanth Aravamudan } 3655adbe8726SEric B Munson 3656a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 3657a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 3658a3437870SNishanth Aravamudan { 3659a3437870SNishanth Aravamudan int err; 3660a3437870SNishanth Aravamudan unsigned long input; 36619a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3662a3437870SNishanth Aravamudan 3663bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3664adbe8726SEric B Munson return -EINVAL; 3665adbe8726SEric B Munson 36663dbb95f7SJingoo Han err = kstrtoul(buf, 10, &input); 3667a3437870SNishanth Aravamudan if (err) 366873ae31e5SEric B Munson return err; 3669a3437870SNishanth Aravamudan 3670db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 3671a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 3672db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3673a3437870SNishanth Aravamudan 3674a3437870SNishanth Aravamudan return count; 3675a3437870SNishanth Aravamudan } 3676a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 3677a3437870SNishanth Aravamudan 3678a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 3679a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3680a3437870SNishanth Aravamudan { 36819a305230SLee Schermerhorn struct hstate *h; 36829a305230SLee Schermerhorn unsigned long free_huge_pages; 36839a305230SLee Schermerhorn int nid; 36849a305230SLee Schermerhorn 36859a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 36869a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 36879a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages; 36889a305230SLee Schermerhorn else 36899a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages_node[nid]; 36909a305230SLee Schermerhorn 3691ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", free_huge_pages); 3692a3437870SNishanth Aravamudan } 3693a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 3694a3437870SNishanth Aravamudan 3695a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 3696a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3697a3437870SNishanth Aravamudan { 36989a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3699ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->resv_huge_pages); 3700a3437870SNishanth Aravamudan } 3701a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 3702a3437870SNishanth Aravamudan 3703a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 3704a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3705a3437870SNishanth Aravamudan { 37069a305230SLee Schermerhorn struct hstate *h; 37079a305230SLee Schermerhorn unsigned long surplus_huge_pages; 37089a305230SLee Schermerhorn int nid; 37099a305230SLee Schermerhorn 37109a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 37119a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 37129a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages; 37139a305230SLee Schermerhorn else 37149a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages_node[nid]; 37159a305230SLee Schermerhorn 3716ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", surplus_huge_pages); 3717a3437870SNishanth Aravamudan } 3718a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 3719a3437870SNishanth Aravamudan 372079dfc695SMike Kravetz static ssize_t demote_store(struct kobject *kobj, 372179dfc695SMike Kravetz struct kobj_attribute *attr, const char *buf, size_t len) 372279dfc695SMike Kravetz { 372379dfc695SMike Kravetz unsigned long nr_demote; 372479dfc695SMike Kravetz unsigned long nr_available; 372579dfc695SMike Kravetz nodemask_t nodes_allowed, *n_mask; 372679dfc695SMike Kravetz struct hstate *h; 37278eeda55fSLi zeming int err; 372879dfc695SMike Kravetz int nid; 372979dfc695SMike Kravetz 373079dfc695SMike Kravetz err = kstrtoul(buf, 10, &nr_demote); 373179dfc695SMike Kravetz if (err) 373279dfc695SMike Kravetz return err; 373379dfc695SMike Kravetz h = kobj_to_hstate(kobj, &nid); 373479dfc695SMike Kravetz 373579dfc695SMike Kravetz if (nid != NUMA_NO_NODE) { 373679dfc695SMike Kravetz init_nodemask_of_node(&nodes_allowed, nid); 373779dfc695SMike Kravetz n_mask = &nodes_allowed; 373879dfc695SMike Kravetz } else { 373979dfc695SMike Kravetz n_mask = &node_states[N_MEMORY]; 374079dfc695SMike Kravetz } 374179dfc695SMike Kravetz 374279dfc695SMike Kravetz /* Synchronize with other sysfs operations modifying huge pages */ 374379dfc695SMike Kravetz mutex_lock(&h->resize_lock); 374479dfc695SMike Kravetz spin_lock_irq(&hugetlb_lock); 374579dfc695SMike Kravetz 374679dfc695SMike Kravetz while (nr_demote) { 374779dfc695SMike Kravetz /* 374879dfc695SMike Kravetz * Check for available pages to demote each time thorough the 374979dfc695SMike Kravetz * loop as demote_pool_huge_page will drop hugetlb_lock. 375079dfc695SMike Kravetz */ 375179dfc695SMike Kravetz if (nid != NUMA_NO_NODE) 375279dfc695SMike Kravetz nr_available = h->free_huge_pages_node[nid]; 375379dfc695SMike Kravetz else 375479dfc695SMike Kravetz nr_available = h->free_huge_pages; 375579dfc695SMike Kravetz nr_available -= h->resv_huge_pages; 375679dfc695SMike Kravetz if (!nr_available) 375779dfc695SMike Kravetz break; 375879dfc695SMike Kravetz 375979dfc695SMike Kravetz err = demote_pool_huge_page(h, n_mask); 376079dfc695SMike Kravetz if (err) 376179dfc695SMike Kravetz break; 376279dfc695SMike Kravetz 376379dfc695SMike Kravetz nr_demote--; 376479dfc695SMike Kravetz } 376579dfc695SMike Kravetz 376679dfc695SMike Kravetz spin_unlock_irq(&hugetlb_lock); 376779dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 376879dfc695SMike Kravetz 376979dfc695SMike Kravetz if (err) 377079dfc695SMike Kravetz return err; 377179dfc695SMike Kravetz return len; 377279dfc695SMike Kravetz } 377379dfc695SMike Kravetz HSTATE_ATTR_WO(demote); 377479dfc695SMike Kravetz 377579dfc695SMike Kravetz static ssize_t demote_size_show(struct kobject *kobj, 377679dfc695SMike Kravetz struct kobj_attribute *attr, char *buf) 377779dfc695SMike Kravetz { 377812658abfSMiaohe Lin struct hstate *h = kobj_to_hstate(kobj, NULL); 377979dfc695SMike Kravetz unsigned long demote_size = (PAGE_SIZE << h->demote_order) / SZ_1K; 378079dfc695SMike Kravetz 378179dfc695SMike Kravetz return sysfs_emit(buf, "%lukB\n", demote_size); 378279dfc695SMike Kravetz } 378379dfc695SMike Kravetz 378479dfc695SMike Kravetz static ssize_t demote_size_store(struct kobject *kobj, 378579dfc695SMike Kravetz struct kobj_attribute *attr, 378679dfc695SMike Kravetz const char *buf, size_t count) 378779dfc695SMike Kravetz { 378879dfc695SMike Kravetz struct hstate *h, *demote_hstate; 378979dfc695SMike Kravetz unsigned long demote_size; 379079dfc695SMike Kravetz unsigned int demote_order; 379179dfc695SMike Kravetz 379279dfc695SMike Kravetz demote_size = (unsigned long)memparse(buf, NULL); 379379dfc695SMike Kravetz 379479dfc695SMike Kravetz demote_hstate = size_to_hstate(demote_size); 379579dfc695SMike Kravetz if (!demote_hstate) 379679dfc695SMike Kravetz return -EINVAL; 379779dfc695SMike Kravetz demote_order = demote_hstate->order; 3798a01f4390SMike Kravetz if (demote_order < HUGETLB_PAGE_ORDER) 3799a01f4390SMike Kravetz return -EINVAL; 380079dfc695SMike Kravetz 380179dfc695SMike Kravetz /* demote order must be smaller than hstate order */ 380212658abfSMiaohe Lin h = kobj_to_hstate(kobj, NULL); 380379dfc695SMike Kravetz if (demote_order >= h->order) 380479dfc695SMike Kravetz return -EINVAL; 380579dfc695SMike Kravetz 380679dfc695SMike Kravetz /* resize_lock synchronizes access to demote size and writes */ 380779dfc695SMike Kravetz mutex_lock(&h->resize_lock); 380879dfc695SMike Kravetz h->demote_order = demote_order; 380979dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 381079dfc695SMike Kravetz 381179dfc695SMike Kravetz return count; 381279dfc695SMike Kravetz } 381379dfc695SMike Kravetz HSTATE_ATTR(demote_size); 381479dfc695SMike Kravetz 3815a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 3816a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 3817a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 3818a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 3819a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 3820a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 382106808b08SLee Schermerhorn #ifdef CONFIG_NUMA 382206808b08SLee Schermerhorn &nr_hugepages_mempolicy_attr.attr, 382306808b08SLee Schermerhorn #endif 3824a3437870SNishanth Aravamudan NULL, 3825a3437870SNishanth Aravamudan }; 3826a3437870SNishanth Aravamudan 382767e5ed96SArvind Yadav static const struct attribute_group hstate_attr_group = { 3828a3437870SNishanth Aravamudan .attrs = hstate_attrs, 3829a3437870SNishanth Aravamudan }; 3830a3437870SNishanth Aravamudan 383179dfc695SMike Kravetz static struct attribute *hstate_demote_attrs[] = { 383279dfc695SMike Kravetz &demote_size_attr.attr, 383379dfc695SMike Kravetz &demote_attr.attr, 383479dfc695SMike Kravetz NULL, 383579dfc695SMike Kravetz }; 383679dfc695SMike Kravetz 383779dfc695SMike Kravetz static const struct attribute_group hstate_demote_attr_group = { 383879dfc695SMike Kravetz .attrs = hstate_demote_attrs, 383979dfc695SMike Kravetz }; 384079dfc695SMike Kravetz 3841094e9539SJeff Mahoney static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, 38429a305230SLee Schermerhorn struct kobject **hstate_kobjs, 384367e5ed96SArvind Yadav const struct attribute_group *hstate_attr_group) 3844a3437870SNishanth Aravamudan { 3845a3437870SNishanth Aravamudan int retval; 3846972dc4deSAneesh Kumar K.V int hi = hstate_index(h); 3847a3437870SNishanth Aravamudan 38489a305230SLee Schermerhorn hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); 38499a305230SLee Schermerhorn if (!hstate_kobjs[hi]) 3850a3437870SNishanth Aravamudan return -ENOMEM; 3851a3437870SNishanth Aravamudan 38529a305230SLee Schermerhorn retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); 3853cc2205a6SMiaohe Lin if (retval) { 38549a305230SLee Schermerhorn kobject_put(hstate_kobjs[hi]); 3855cc2205a6SMiaohe Lin hstate_kobjs[hi] = NULL; 38563a6bdda0SMiaohe Lin return retval; 3857cc2205a6SMiaohe Lin } 3858a3437870SNishanth Aravamudan 385979dfc695SMike Kravetz if (h->demote_order) { 386001088a60SMiaohe Lin retval = sysfs_create_group(hstate_kobjs[hi], 386101088a60SMiaohe Lin &hstate_demote_attr_group); 386201088a60SMiaohe Lin if (retval) { 386379dfc695SMike Kravetz pr_warn("HugeTLB unable to create demote interfaces for %s\n", h->name); 386401088a60SMiaohe Lin sysfs_remove_group(hstate_kobjs[hi], hstate_attr_group); 386501088a60SMiaohe Lin kobject_put(hstate_kobjs[hi]); 386601088a60SMiaohe Lin hstate_kobjs[hi] = NULL; 386701088a60SMiaohe Lin return retval; 386801088a60SMiaohe Lin } 386979dfc695SMike Kravetz } 387079dfc695SMike Kravetz 387101088a60SMiaohe Lin return 0; 3872a3437870SNishanth Aravamudan } 3873a3437870SNishanth Aravamudan 38749a305230SLee Schermerhorn #ifdef CONFIG_NUMA 3875a4a00b45SMuchun Song static bool hugetlb_sysfs_initialized __ro_after_init; 38769a305230SLee Schermerhorn 38779a305230SLee Schermerhorn /* 38789a305230SLee Schermerhorn * node_hstate/s - associate per node hstate attributes, via their kobjects, 387910fbcf4cSKay Sievers * with node devices in node_devices[] using a parallel array. The array 388010fbcf4cSKay Sievers * index of a node device or _hstate == node id. 388110fbcf4cSKay Sievers * This is here to avoid any static dependency of the node device driver, in 38829a305230SLee Schermerhorn * the base kernel, on the hugetlb module. 38839a305230SLee Schermerhorn */ 38849a305230SLee Schermerhorn struct node_hstate { 38859a305230SLee Schermerhorn struct kobject *hugepages_kobj; 38869a305230SLee Schermerhorn struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 38879a305230SLee Schermerhorn }; 3888b4e289a6SAlexander Kuleshov static struct node_hstate node_hstates[MAX_NUMNODES]; 38899a305230SLee Schermerhorn 38909a305230SLee Schermerhorn /* 389110fbcf4cSKay Sievers * A subset of global hstate attributes for node devices 38929a305230SLee Schermerhorn */ 38939a305230SLee Schermerhorn static struct attribute *per_node_hstate_attrs[] = { 38949a305230SLee Schermerhorn &nr_hugepages_attr.attr, 38959a305230SLee Schermerhorn &free_hugepages_attr.attr, 38969a305230SLee Schermerhorn &surplus_hugepages_attr.attr, 38979a305230SLee Schermerhorn NULL, 38989a305230SLee Schermerhorn }; 38999a305230SLee Schermerhorn 390067e5ed96SArvind Yadav static const struct attribute_group per_node_hstate_attr_group = { 39019a305230SLee Schermerhorn .attrs = per_node_hstate_attrs, 39029a305230SLee Schermerhorn }; 39039a305230SLee Schermerhorn 39049a305230SLee Schermerhorn /* 390510fbcf4cSKay Sievers * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. 39069a305230SLee Schermerhorn * Returns node id via non-NULL nidp. 39079a305230SLee Schermerhorn */ 39089a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 39099a305230SLee Schermerhorn { 39109a305230SLee Schermerhorn int nid; 39119a305230SLee Schermerhorn 39129a305230SLee Schermerhorn for (nid = 0; nid < nr_node_ids; nid++) { 39139a305230SLee Schermerhorn struct node_hstate *nhs = &node_hstates[nid]; 39149a305230SLee Schermerhorn int i; 39159a305230SLee Schermerhorn for (i = 0; i < HUGE_MAX_HSTATE; i++) 39169a305230SLee Schermerhorn if (nhs->hstate_kobjs[i] == kobj) { 39179a305230SLee Schermerhorn if (nidp) 39189a305230SLee Schermerhorn *nidp = nid; 39199a305230SLee Schermerhorn return &hstates[i]; 39209a305230SLee Schermerhorn } 39219a305230SLee Schermerhorn } 39229a305230SLee Schermerhorn 39239a305230SLee Schermerhorn BUG(); 39249a305230SLee Schermerhorn return NULL; 39259a305230SLee Schermerhorn } 39269a305230SLee Schermerhorn 39279a305230SLee Schermerhorn /* 392810fbcf4cSKay Sievers * Unregister hstate attributes from a single node device. 39299a305230SLee Schermerhorn * No-op if no hstate attributes attached. 39309a305230SLee Schermerhorn */ 3931a4a00b45SMuchun Song void hugetlb_unregister_node(struct node *node) 39329a305230SLee Schermerhorn { 39339a305230SLee Schermerhorn struct hstate *h; 393410fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 39359a305230SLee Schermerhorn 39369a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 39379b5e5d0fSLee Schermerhorn return; /* no hstate attributes */ 39389a305230SLee Schermerhorn 3939972dc4deSAneesh Kumar K.V for_each_hstate(h) { 3940972dc4deSAneesh Kumar K.V int idx = hstate_index(h); 394101088a60SMiaohe Lin struct kobject *hstate_kobj = nhs->hstate_kobjs[idx]; 394201088a60SMiaohe Lin 394301088a60SMiaohe Lin if (!hstate_kobj) 394401088a60SMiaohe Lin continue; 394501088a60SMiaohe Lin if (h->demote_order) 394601088a60SMiaohe Lin sysfs_remove_group(hstate_kobj, &hstate_demote_attr_group); 394701088a60SMiaohe Lin sysfs_remove_group(hstate_kobj, &per_node_hstate_attr_group); 394801088a60SMiaohe Lin kobject_put(hstate_kobj); 3949972dc4deSAneesh Kumar K.V nhs->hstate_kobjs[idx] = NULL; 3950972dc4deSAneesh Kumar K.V } 39519a305230SLee Schermerhorn 39529a305230SLee Schermerhorn kobject_put(nhs->hugepages_kobj); 39539a305230SLee Schermerhorn nhs->hugepages_kobj = NULL; 39549a305230SLee Schermerhorn } 39559a305230SLee Schermerhorn 39569a305230SLee Schermerhorn 39579a305230SLee Schermerhorn /* 395810fbcf4cSKay Sievers * Register hstate attributes for a single node device. 39599a305230SLee Schermerhorn * No-op if attributes already registered. 39609a305230SLee Schermerhorn */ 3961a4a00b45SMuchun Song void hugetlb_register_node(struct node *node) 39629a305230SLee Schermerhorn { 39639a305230SLee Schermerhorn struct hstate *h; 396410fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 39659a305230SLee Schermerhorn int err; 39669a305230SLee Schermerhorn 3967a4a00b45SMuchun Song if (!hugetlb_sysfs_initialized) 3968a4a00b45SMuchun Song return; 3969a4a00b45SMuchun Song 39709a305230SLee Schermerhorn if (nhs->hugepages_kobj) 39719a305230SLee Schermerhorn return; /* already allocated */ 39729a305230SLee Schermerhorn 39739a305230SLee Schermerhorn nhs->hugepages_kobj = kobject_create_and_add("hugepages", 397410fbcf4cSKay Sievers &node->dev.kobj); 39759a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 39769a305230SLee Schermerhorn return; 39779a305230SLee Schermerhorn 39789a305230SLee Schermerhorn for_each_hstate(h) { 39799a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, 39809a305230SLee Schermerhorn nhs->hstate_kobjs, 39819a305230SLee Schermerhorn &per_node_hstate_attr_group); 39829a305230SLee Schermerhorn if (err) { 3983282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s for node %d\n", 398410fbcf4cSKay Sievers h->name, node->dev.id); 39859a305230SLee Schermerhorn hugetlb_unregister_node(node); 39869a305230SLee Schermerhorn break; 39879a305230SLee Schermerhorn } 39889a305230SLee Schermerhorn } 39899a305230SLee Schermerhorn } 39909a305230SLee Schermerhorn 39919a305230SLee Schermerhorn /* 39929b5e5d0fSLee Schermerhorn * hugetlb init time: register hstate attributes for all registered node 399310fbcf4cSKay Sievers * devices of nodes that have memory. All on-line nodes should have 399410fbcf4cSKay Sievers * registered their associated device by this time. 39959a305230SLee Schermerhorn */ 39967d9ca000SLuiz Capitulino static void __init hugetlb_register_all_nodes(void) 39979a305230SLee Schermerhorn { 39989a305230SLee Schermerhorn int nid; 39999a305230SLee Schermerhorn 4000a4a00b45SMuchun Song for_each_online_node(nid) 4001b958d4d0SMuchun Song hugetlb_register_node(node_devices[nid]); 40029a305230SLee Schermerhorn } 40039a305230SLee Schermerhorn #else /* !CONFIG_NUMA */ 40049a305230SLee Schermerhorn 40059a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 40069a305230SLee Schermerhorn { 40079a305230SLee Schermerhorn BUG(); 40089a305230SLee Schermerhorn if (nidp) 40099a305230SLee Schermerhorn *nidp = -1; 40109a305230SLee Schermerhorn return NULL; 40119a305230SLee Schermerhorn } 40129a305230SLee Schermerhorn 40139a305230SLee Schermerhorn static void hugetlb_register_all_nodes(void) { } 40149a305230SLee Schermerhorn 40159a305230SLee Schermerhorn #endif 40169a305230SLee Schermerhorn 4017263b8998SMiaohe Lin #ifdef CONFIG_CMA 4018263b8998SMiaohe Lin static void __init hugetlb_cma_check(void); 4019263b8998SMiaohe Lin #else 4020263b8998SMiaohe Lin static inline __init void hugetlb_cma_check(void) 4021263b8998SMiaohe Lin { 4022263b8998SMiaohe Lin } 4023263b8998SMiaohe Lin #endif 4024263b8998SMiaohe Lin 4025a4a00b45SMuchun Song static void __init hugetlb_sysfs_init(void) 4026a4a00b45SMuchun Song { 4027a4a00b45SMuchun Song struct hstate *h; 4028a4a00b45SMuchun Song int err; 4029a4a00b45SMuchun Song 4030a4a00b45SMuchun Song hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 4031a4a00b45SMuchun Song if (!hugepages_kobj) 4032a4a00b45SMuchun Song return; 4033a4a00b45SMuchun Song 4034a4a00b45SMuchun Song for_each_hstate(h) { 4035a4a00b45SMuchun Song err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, 4036a4a00b45SMuchun Song hstate_kobjs, &hstate_attr_group); 4037a4a00b45SMuchun Song if (err) 4038a4a00b45SMuchun Song pr_err("HugeTLB: Unable to add hstate %s", h->name); 4039a4a00b45SMuchun Song } 4040a4a00b45SMuchun Song 4041a4a00b45SMuchun Song #ifdef CONFIG_NUMA 4042a4a00b45SMuchun Song hugetlb_sysfs_initialized = true; 4043a4a00b45SMuchun Song #endif 4044a4a00b45SMuchun Song hugetlb_register_all_nodes(); 4045a4a00b45SMuchun Song } 4046a4a00b45SMuchun Song 4047a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 4048a3437870SNishanth Aravamudan { 40498382d914SDavidlohr Bueso int i; 40508382d914SDavidlohr Bueso 4051d6995da3SMike Kravetz BUILD_BUG_ON(sizeof_field(struct page, private) * BITS_PER_BYTE < 4052d6995da3SMike Kravetz __NR_HPAGEFLAGS); 4053d6995da3SMike Kravetz 4054c2833a5bSMike Kravetz if (!hugepages_supported()) { 4055c2833a5bSMike Kravetz if (hugetlb_max_hstate || default_hstate_max_huge_pages) 4056c2833a5bSMike Kravetz pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n"); 40570ef89d25SBenjamin Herrenschmidt return 0; 4058d715cf80SLiam R. Howlett } 4059d715cf80SLiam R. Howlett 4060282f4214SMike Kravetz /* 4061282f4214SMike Kravetz * Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some 4062282f4214SMike Kravetz * architectures depend on setup being done here. 4063282f4214SMike Kravetz */ 4064a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 4065282f4214SMike Kravetz if (!parsed_default_hugepagesz) { 4066282f4214SMike Kravetz /* 4067282f4214SMike Kravetz * If we did not parse a default huge page size, set 4068282f4214SMike Kravetz * default_hstate_idx to HPAGE_SIZE hstate. And, if the 4069282f4214SMike Kravetz * number of huge pages for this default size was implicitly 4070282f4214SMike Kravetz * specified, set that here as well. 4071282f4214SMike Kravetz * Note that the implicit setting will overwrite an explicit 4072282f4214SMike Kravetz * setting. A warning will be printed in this case. 4073282f4214SMike Kravetz */ 4074282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(HPAGE_SIZE)); 4075f8b74815SVaishali Thakkar if (default_hstate_max_huge_pages) { 4076282f4214SMike Kravetz if (default_hstate.max_huge_pages) { 4077282f4214SMike Kravetz char buf[32]; 4078282f4214SMike Kravetz 4079282f4214SMike Kravetz string_get_size(huge_page_size(&default_hstate), 4080282f4214SMike Kravetz 1, STRING_UNITS_2, buf, 32); 4081282f4214SMike Kravetz pr_warn("HugeTLB: Ignoring hugepages=%lu associated with %s page size\n", 4082282f4214SMike Kravetz default_hstate.max_huge_pages, buf); 4083282f4214SMike Kravetz pr_warn("HugeTLB: Using hugepages=%lu for number of default huge pages\n", 4084282f4214SMike Kravetz default_hstate_max_huge_pages); 4085282f4214SMike Kravetz } 4086282f4214SMike Kravetz default_hstate.max_huge_pages = 4087282f4214SMike Kravetz default_hstate_max_huge_pages; 4088b5389086SZhenguo Yao 40890a7a0f6fSPeng Liu for_each_online_node(i) 4090b5389086SZhenguo Yao default_hstate.max_huge_pages_node[i] = 4091b5389086SZhenguo Yao default_hugepages_in_node[i]; 4092282f4214SMike Kravetz } 4093f8b74815SVaishali Thakkar } 4094a3437870SNishanth Aravamudan 4095cf11e85fSRoman Gushchin hugetlb_cma_check(); 4096a3437870SNishanth Aravamudan hugetlb_init_hstates(); 4097aa888a74SAndi Kleen gather_bootmem_prealloc(); 4098a3437870SNishanth Aravamudan report_hugepages(); 4099a3437870SNishanth Aravamudan 4100a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 41017179e7bfSJianguo Wu hugetlb_cgroup_file_init(); 41029a305230SLee Schermerhorn 41038382d914SDavidlohr Bueso #ifdef CONFIG_SMP 41048382d914SDavidlohr Bueso num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); 41058382d914SDavidlohr Bueso #else 41068382d914SDavidlohr Bueso num_fault_mutexes = 1; 41078382d914SDavidlohr Bueso #endif 4108c672c7f2SMike Kravetz hugetlb_fault_mutex_table = 41096da2ec56SKees Cook kmalloc_array(num_fault_mutexes, sizeof(struct mutex), 41106da2ec56SKees Cook GFP_KERNEL); 4111c672c7f2SMike Kravetz BUG_ON(!hugetlb_fault_mutex_table); 41128382d914SDavidlohr Bueso 41138382d914SDavidlohr Bueso for (i = 0; i < num_fault_mutexes; i++) 4114c672c7f2SMike Kravetz mutex_init(&hugetlb_fault_mutex_table[i]); 4115a3437870SNishanth Aravamudan return 0; 4116a3437870SNishanth Aravamudan } 41173e89e1c5SPaul Gortmaker subsys_initcall(hugetlb_init); 4118a3437870SNishanth Aravamudan 4119ae94da89SMike Kravetz /* Overwritten by architectures with more huge page sizes */ 4120ae94da89SMike Kravetz bool __init __attribute((weak)) arch_hugetlb_valid_size(unsigned long size) 41219fee021dSVaishali Thakkar { 4122ae94da89SMike Kravetz return size == HPAGE_SIZE; 41239fee021dSVaishali Thakkar } 41249fee021dSVaishali Thakkar 4125d00181b9SKirill A. Shutemov void __init hugetlb_add_hstate(unsigned int order) 4126a3437870SNishanth Aravamudan { 4127a3437870SNishanth Aravamudan struct hstate *h; 41288faa8b07SAndi Kleen unsigned long i; 41298faa8b07SAndi Kleen 4130a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 4131a3437870SNishanth Aravamudan return; 4132a3437870SNishanth Aravamudan } 413347d38344SAneesh Kumar K.V BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); 4134a3437870SNishanth Aravamudan BUG_ON(order == 0); 413547d38344SAneesh Kumar K.V h = &hstates[hugetlb_max_hstate++]; 413629383967SMike Kravetz mutex_init(&h->resize_lock); 4137a3437870SNishanth Aravamudan h->order = order; 4138aca78307SMiaohe Lin h->mask = ~(huge_page_size(h) - 1); 41398faa8b07SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 41408faa8b07SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 41410edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&h->hugepage_activelist); 414254f18d35SAndrew Morton h->next_nid_to_alloc = first_memory_node; 414354f18d35SAndrew Morton h->next_nid_to_free = first_memory_node; 4144a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 4145c2c3a60aSMiaohe Lin huge_page_size(h)/SZ_1K); 41468faa8b07SAndi Kleen 4147a3437870SNishanth Aravamudan parsed_hstate = h; 4148a3437870SNishanth Aravamudan } 4149a3437870SNishanth Aravamudan 4150b5389086SZhenguo Yao bool __init __weak hugetlb_node_alloc_supported(void) 4151b5389086SZhenguo Yao { 4152b5389086SZhenguo Yao return true; 4153b5389086SZhenguo Yao } 4154f87442f4SPeng Liu 4155f87442f4SPeng Liu static void __init hugepages_clear_pages_in_node(void) 4156f87442f4SPeng Liu { 4157f87442f4SPeng Liu if (!hugetlb_max_hstate) { 4158f87442f4SPeng Liu default_hstate_max_huge_pages = 0; 4159f87442f4SPeng Liu memset(default_hugepages_in_node, 0, 416010395680SMiaohe Lin sizeof(default_hugepages_in_node)); 4161f87442f4SPeng Liu } else { 4162f87442f4SPeng Liu parsed_hstate->max_huge_pages = 0; 4163f87442f4SPeng Liu memset(parsed_hstate->max_huge_pages_node, 0, 416410395680SMiaohe Lin sizeof(parsed_hstate->max_huge_pages_node)); 4165f87442f4SPeng Liu } 4166f87442f4SPeng Liu } 4167f87442f4SPeng Liu 4168282f4214SMike Kravetz /* 4169282f4214SMike Kravetz * hugepages command line processing 4170282f4214SMike Kravetz * hugepages normally follows a valid hugepagsz or default_hugepagsz 4171282f4214SMike Kravetz * specification. If not, ignore the hugepages value. hugepages can also 4172282f4214SMike Kravetz * be the first huge page command line option in which case it implicitly 4173282f4214SMike Kravetz * specifies the number of huge pages for the default size. 4174282f4214SMike Kravetz */ 4175282f4214SMike Kravetz static int __init hugepages_setup(char *s) 4176a3437870SNishanth Aravamudan { 4177a3437870SNishanth Aravamudan unsigned long *mhp; 41788faa8b07SAndi Kleen static unsigned long *last_mhp; 4179b5389086SZhenguo Yao int node = NUMA_NO_NODE; 4180b5389086SZhenguo Yao int count; 4181b5389086SZhenguo Yao unsigned long tmp; 4182b5389086SZhenguo Yao char *p = s; 4183a3437870SNishanth Aravamudan 41849fee021dSVaishali Thakkar if (!parsed_valid_hugepagesz) { 4185282f4214SMike Kravetz pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s); 41869fee021dSVaishali Thakkar parsed_valid_hugepagesz = true; 4187f81f6e4bSPeng Liu return 1; 41889fee021dSVaishali Thakkar } 4189282f4214SMike Kravetz 4190a3437870SNishanth Aravamudan /* 4191282f4214SMike Kravetz * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter 4192282f4214SMike Kravetz * yet, so this hugepages= parameter goes to the "default hstate". 4193282f4214SMike Kravetz * Otherwise, it goes with the previously parsed hugepagesz or 4194282f4214SMike Kravetz * default_hugepagesz. 4195a3437870SNishanth Aravamudan */ 41969fee021dSVaishali Thakkar else if (!hugetlb_max_hstate) 4197a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 4198a3437870SNishanth Aravamudan else 4199a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 4200a3437870SNishanth Aravamudan 42018faa8b07SAndi Kleen if (mhp == last_mhp) { 4202282f4214SMike Kravetz pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s); 4203f81f6e4bSPeng Liu return 1; 42048faa8b07SAndi Kleen } 42058faa8b07SAndi Kleen 4206b5389086SZhenguo Yao while (*p) { 4207b5389086SZhenguo Yao count = 0; 4208b5389086SZhenguo Yao if (sscanf(p, "%lu%n", &tmp, &count) != 1) 4209b5389086SZhenguo Yao goto invalid; 4210b5389086SZhenguo Yao /* Parameter is node format */ 4211b5389086SZhenguo Yao if (p[count] == ':') { 4212b5389086SZhenguo Yao if (!hugetlb_node_alloc_supported()) { 4213b5389086SZhenguo Yao pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n"); 4214f81f6e4bSPeng Liu return 1; 4215b5389086SZhenguo Yao } 42160a7a0f6fSPeng Liu if (tmp >= MAX_NUMNODES || !node_online(tmp)) 4217e79ce983SLiu Yuntao goto invalid; 42180a7a0f6fSPeng Liu node = array_index_nospec(tmp, MAX_NUMNODES); 4219b5389086SZhenguo Yao p += count + 1; 4220b5389086SZhenguo Yao /* Parse hugepages */ 4221b5389086SZhenguo Yao if (sscanf(p, "%lu%n", &tmp, &count) != 1) 4222b5389086SZhenguo Yao goto invalid; 4223b5389086SZhenguo Yao if (!hugetlb_max_hstate) 4224b5389086SZhenguo Yao default_hugepages_in_node[node] = tmp; 4225b5389086SZhenguo Yao else 4226b5389086SZhenguo Yao parsed_hstate->max_huge_pages_node[node] = tmp; 4227b5389086SZhenguo Yao *mhp += tmp; 4228b5389086SZhenguo Yao /* Go to parse next node*/ 4229b5389086SZhenguo Yao if (p[count] == ',') 4230b5389086SZhenguo Yao p += count + 1; 4231b5389086SZhenguo Yao else 4232b5389086SZhenguo Yao break; 4233b5389086SZhenguo Yao } else { 4234b5389086SZhenguo Yao if (p != s) 4235b5389086SZhenguo Yao goto invalid; 4236b5389086SZhenguo Yao *mhp = tmp; 4237b5389086SZhenguo Yao break; 4238b5389086SZhenguo Yao } 4239b5389086SZhenguo Yao } 4240a3437870SNishanth Aravamudan 42418faa8b07SAndi Kleen /* 42428faa8b07SAndi Kleen * Global state is always initialized later in hugetlb_init. 424304adbc3fSMiaohe Lin * But we need to allocate gigantic hstates here early to still 42448faa8b07SAndi Kleen * use the bootmem allocator. 42458faa8b07SAndi Kleen */ 424604adbc3fSMiaohe Lin if (hugetlb_max_hstate && hstate_is_gigantic(parsed_hstate)) 42478faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(parsed_hstate); 42488faa8b07SAndi Kleen 42498faa8b07SAndi Kleen last_mhp = mhp; 42508faa8b07SAndi Kleen 4251a3437870SNishanth Aravamudan return 1; 4252b5389086SZhenguo Yao 4253b5389086SZhenguo Yao invalid: 4254b5389086SZhenguo Yao pr_warn("HugeTLB: Invalid hugepages parameter %s\n", p); 4255f87442f4SPeng Liu hugepages_clear_pages_in_node(); 4256f81f6e4bSPeng Liu return 1; 4257a3437870SNishanth Aravamudan } 4258282f4214SMike Kravetz __setup("hugepages=", hugepages_setup); 4259e11bfbfcSNick Piggin 4260282f4214SMike Kravetz /* 4261282f4214SMike Kravetz * hugepagesz command line processing 4262282f4214SMike Kravetz * A specific huge page size can only be specified once with hugepagesz. 4263282f4214SMike Kravetz * hugepagesz is followed by hugepages on the command line. The global 4264282f4214SMike Kravetz * variable 'parsed_valid_hugepagesz' is used to determine if prior 4265282f4214SMike Kravetz * hugepagesz argument was valid. 4266282f4214SMike Kravetz */ 4267359f2544SMike Kravetz static int __init hugepagesz_setup(char *s) 4268e11bfbfcSNick Piggin { 4269359f2544SMike Kravetz unsigned long size; 4270282f4214SMike Kravetz struct hstate *h; 4271282f4214SMike Kravetz 4272282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4273359f2544SMike Kravetz size = (unsigned long)memparse(s, NULL); 4274359f2544SMike Kravetz 4275359f2544SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4276282f4214SMike Kravetz pr_err("HugeTLB: unsupported hugepagesz=%s\n", s); 4277f81f6e4bSPeng Liu return 1; 4278359f2544SMike Kravetz } 4279359f2544SMike Kravetz 4280282f4214SMike Kravetz h = size_to_hstate(size); 4281282f4214SMike Kravetz if (h) { 4282282f4214SMike Kravetz /* 4283282f4214SMike Kravetz * hstate for this size already exists. This is normally 4284282f4214SMike Kravetz * an error, but is allowed if the existing hstate is the 4285282f4214SMike Kravetz * default hstate. More specifically, it is only allowed if 4286282f4214SMike Kravetz * the number of huge pages for the default hstate was not 4287282f4214SMike Kravetz * previously specified. 4288282f4214SMike Kravetz */ 4289282f4214SMike Kravetz if (!parsed_default_hugepagesz || h != &default_hstate || 4290282f4214SMike Kravetz default_hstate.max_huge_pages) { 4291282f4214SMike Kravetz pr_warn("HugeTLB: hugepagesz=%s specified twice, ignoring\n", s); 4292f81f6e4bSPeng Liu return 1; 429338237830SMike Kravetz } 429438237830SMike Kravetz 4295282f4214SMike Kravetz /* 4296282f4214SMike Kravetz * No need to call hugetlb_add_hstate() as hstate already 4297282f4214SMike Kravetz * exists. But, do set parsed_hstate so that a following 4298282f4214SMike Kravetz * hugepages= parameter will be applied to this hstate. 4299282f4214SMike Kravetz */ 4300282f4214SMike Kravetz parsed_hstate = h; 4301282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4302e11bfbfcSNick Piggin return 1; 4303e11bfbfcSNick Piggin } 4304282f4214SMike Kravetz 4305359f2544SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4306282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4307359f2544SMike Kravetz return 1; 4308359f2544SMike Kravetz } 4309359f2544SMike Kravetz __setup("hugepagesz=", hugepagesz_setup); 4310359f2544SMike Kravetz 4311282f4214SMike Kravetz /* 4312282f4214SMike Kravetz * default_hugepagesz command line input 4313282f4214SMike Kravetz * Only one instance of default_hugepagesz allowed on command line. 4314282f4214SMike Kravetz */ 4315ae94da89SMike Kravetz static int __init default_hugepagesz_setup(char *s) 4316e11bfbfcSNick Piggin { 4317ae94da89SMike Kravetz unsigned long size; 4318b5389086SZhenguo Yao int i; 4319ae94da89SMike Kravetz 4320282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4321282f4214SMike Kravetz if (parsed_default_hugepagesz) { 4322282f4214SMike Kravetz pr_err("HugeTLB: default_hugepagesz previously specified, ignoring %s\n", s); 4323f81f6e4bSPeng Liu return 1; 4324282f4214SMike Kravetz } 4325282f4214SMike Kravetz 4326282f4214SMike Kravetz size = (unsigned long)memparse(s, NULL); 4327282f4214SMike Kravetz 4328282f4214SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4329282f4214SMike Kravetz pr_err("HugeTLB: unsupported default_hugepagesz=%s\n", s); 4330f81f6e4bSPeng Liu return 1; 4331282f4214SMike Kravetz } 4332282f4214SMike Kravetz 4333282f4214SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4334282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4335282f4214SMike Kravetz parsed_default_hugepagesz = true; 4336282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(size)); 4337282f4214SMike Kravetz 4338282f4214SMike Kravetz /* 4339282f4214SMike Kravetz * The number of default huge pages (for this size) could have been 4340282f4214SMike Kravetz * specified as the first hugetlb parameter: hugepages=X. If so, 4341282f4214SMike Kravetz * then default_hstate_max_huge_pages is set. If the default huge 4342282f4214SMike Kravetz * page size is gigantic (>= MAX_ORDER), then the pages must be 4343282f4214SMike Kravetz * allocated here from bootmem allocator. 4344282f4214SMike Kravetz */ 4345282f4214SMike Kravetz if (default_hstate_max_huge_pages) { 4346282f4214SMike Kravetz default_hstate.max_huge_pages = default_hstate_max_huge_pages; 43470a7a0f6fSPeng Liu for_each_online_node(i) 4348b5389086SZhenguo Yao default_hstate.max_huge_pages_node[i] = 4349b5389086SZhenguo Yao default_hugepages_in_node[i]; 4350282f4214SMike Kravetz if (hstate_is_gigantic(&default_hstate)) 4351282f4214SMike Kravetz hugetlb_hstate_alloc_pages(&default_hstate); 4352282f4214SMike Kravetz default_hstate_max_huge_pages = 0; 4353282f4214SMike Kravetz } 4354282f4214SMike Kravetz 4355e11bfbfcSNick Piggin return 1; 4356e11bfbfcSNick Piggin } 4357ae94da89SMike Kravetz __setup("default_hugepagesz=", default_hugepagesz_setup); 4358a3437870SNishanth Aravamudan 4359d2226ebdSFeng Tang static nodemask_t *policy_mbind_nodemask(gfp_t gfp) 4360d2226ebdSFeng Tang { 4361d2226ebdSFeng Tang #ifdef CONFIG_NUMA 4362d2226ebdSFeng Tang struct mempolicy *mpol = get_task_policy(current); 4363d2226ebdSFeng Tang 4364d2226ebdSFeng Tang /* 4365d2226ebdSFeng Tang * Only enforce MPOL_BIND policy which overlaps with cpuset policy 4366d2226ebdSFeng Tang * (from policy_nodemask) specifically for hugetlb case 4367d2226ebdSFeng Tang */ 4368d2226ebdSFeng Tang if (mpol->mode == MPOL_BIND && 4369d2226ebdSFeng Tang (apply_policy_zone(mpol, gfp_zone(gfp)) && 4370d2226ebdSFeng Tang cpuset_nodemask_valid_mems_allowed(&mpol->nodes))) 4371d2226ebdSFeng Tang return &mpol->nodes; 4372d2226ebdSFeng Tang #endif 4373d2226ebdSFeng Tang return NULL; 4374d2226ebdSFeng Tang } 4375d2226ebdSFeng Tang 43768ca39e68SMuchun Song static unsigned int allowed_mems_nr(struct hstate *h) 43778a213460SNishanth Aravamudan { 43788a213460SNishanth Aravamudan int node; 43798a213460SNishanth Aravamudan unsigned int nr = 0; 4380d2226ebdSFeng Tang nodemask_t *mbind_nodemask; 43818ca39e68SMuchun Song unsigned int *array = h->free_huge_pages_node; 43828ca39e68SMuchun Song gfp_t gfp_mask = htlb_alloc_mask(h); 43838a213460SNishanth Aravamudan 4384d2226ebdSFeng Tang mbind_nodemask = policy_mbind_nodemask(gfp_mask); 43858ca39e68SMuchun Song for_each_node_mask(node, cpuset_current_mems_allowed) { 4386d2226ebdSFeng Tang if (!mbind_nodemask || node_isset(node, *mbind_nodemask)) 43878a213460SNishanth Aravamudan nr += array[node]; 43888ca39e68SMuchun Song } 43898a213460SNishanth Aravamudan 43908a213460SNishanth Aravamudan return nr; 43918a213460SNishanth Aravamudan } 43928a213460SNishanth Aravamudan 43938a213460SNishanth Aravamudan #ifdef CONFIG_SYSCTL 439417743798SMuchun Song static int proc_hugetlb_doulongvec_minmax(struct ctl_table *table, int write, 439517743798SMuchun Song void *buffer, size_t *length, 439617743798SMuchun Song loff_t *ppos, unsigned long *out) 439717743798SMuchun Song { 439817743798SMuchun Song struct ctl_table dup_table; 439917743798SMuchun Song 440017743798SMuchun Song /* 440117743798SMuchun Song * In order to avoid races with __do_proc_doulongvec_minmax(), we 440217743798SMuchun Song * can duplicate the @table and alter the duplicate of it. 440317743798SMuchun Song */ 440417743798SMuchun Song dup_table = *table; 440517743798SMuchun Song dup_table.data = out; 440617743798SMuchun Song 440717743798SMuchun Song return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos); 440817743798SMuchun Song } 440917743798SMuchun Song 441006808b08SLee Schermerhorn static int hugetlb_sysctl_handler_common(bool obey_mempolicy, 441106808b08SLee Schermerhorn struct ctl_table *table, int write, 441232927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 44131da177e4SLinus Torvalds { 4414e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 4415238d3c13SDavid Rientjes unsigned long tmp = h->max_huge_pages; 441608d4a246SMichal Hocko int ret; 4417e5ff2159SAndi Kleen 4418457c1b27SNishanth Aravamudan if (!hugepages_supported()) 441986613628SJan Stancek return -EOPNOTSUPP; 4420457c1b27SNishanth Aravamudan 442117743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 442217743798SMuchun Song &tmp); 442308d4a246SMichal Hocko if (ret) 442408d4a246SMichal Hocko goto out; 4425e5ff2159SAndi Kleen 4426238d3c13SDavid Rientjes if (write) 4427238d3c13SDavid Rientjes ret = __nr_hugepages_store_common(obey_mempolicy, h, 4428238d3c13SDavid Rientjes NUMA_NO_NODE, tmp, *length); 442908d4a246SMichal Hocko out: 443008d4a246SMichal Hocko return ret; 44311da177e4SLinus Torvalds } 4432396faf03SMel Gorman 443306808b08SLee Schermerhorn int hugetlb_sysctl_handler(struct ctl_table *table, int write, 443432927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 443506808b08SLee Schermerhorn { 443606808b08SLee Schermerhorn 443706808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(false, table, write, 443806808b08SLee Schermerhorn buffer, length, ppos); 443906808b08SLee Schermerhorn } 444006808b08SLee Schermerhorn 444106808b08SLee Schermerhorn #ifdef CONFIG_NUMA 444206808b08SLee Schermerhorn int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, 444332927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 444406808b08SLee Schermerhorn { 444506808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(true, table, write, 444606808b08SLee Schermerhorn buffer, length, ppos); 444706808b08SLee Schermerhorn } 444806808b08SLee Schermerhorn #endif /* CONFIG_NUMA */ 444906808b08SLee Schermerhorn 4450a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 445132927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 4452a3d0c6aaSNishanth Aravamudan { 4453a5516438SAndi Kleen struct hstate *h = &default_hstate; 4454e5ff2159SAndi Kleen unsigned long tmp; 445508d4a246SMichal Hocko int ret; 4456e5ff2159SAndi Kleen 4457457c1b27SNishanth Aravamudan if (!hugepages_supported()) 445886613628SJan Stancek return -EOPNOTSUPP; 4459457c1b27SNishanth Aravamudan 4460e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 4461e5ff2159SAndi Kleen 4462bae7f4aeSLuiz Capitulino if (write && hstate_is_gigantic(h)) 4463adbe8726SEric B Munson return -EINVAL; 4464adbe8726SEric B Munson 446517743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 446617743798SMuchun Song &tmp); 446708d4a246SMichal Hocko if (ret) 446808d4a246SMichal Hocko goto out; 4469e5ff2159SAndi Kleen 4470e5ff2159SAndi Kleen if (write) { 4471db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4472e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 4473db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4474e5ff2159SAndi Kleen } 447508d4a246SMichal Hocko out: 447608d4a246SMichal Hocko return ret; 4477a3d0c6aaSNishanth Aravamudan } 4478a3d0c6aaSNishanth Aravamudan 44791da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 44801da177e4SLinus Torvalds 4481e1759c21SAlexey Dobriyan void hugetlb_report_meminfo(struct seq_file *m) 44821da177e4SLinus Torvalds { 4483fcb2b0c5SRoman Gushchin struct hstate *h; 4484fcb2b0c5SRoman Gushchin unsigned long total = 0; 4485fcb2b0c5SRoman Gushchin 4486457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4487457c1b27SNishanth Aravamudan return; 4488fcb2b0c5SRoman Gushchin 4489fcb2b0c5SRoman Gushchin for_each_hstate(h) { 4490fcb2b0c5SRoman Gushchin unsigned long count = h->nr_huge_pages; 4491fcb2b0c5SRoman Gushchin 4492aca78307SMiaohe Lin total += huge_page_size(h) * count; 4493fcb2b0c5SRoman Gushchin 4494fcb2b0c5SRoman Gushchin if (h == &default_hstate) 4495e1759c21SAlexey Dobriyan seq_printf(m, 44961da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 44971da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 4498b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 44997893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 45004f98a2feSRik van Riel "Hugepagesize: %8lu kB\n", 4501fcb2b0c5SRoman Gushchin count, 4502a5516438SAndi Kleen h->free_huge_pages, 4503a5516438SAndi Kleen h->resv_huge_pages, 4504a5516438SAndi Kleen h->surplus_huge_pages, 4505aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4506fcb2b0c5SRoman Gushchin } 4507fcb2b0c5SRoman Gushchin 4508aca78307SMiaohe Lin seq_printf(m, "Hugetlb: %8lu kB\n", total / SZ_1K); 45091da177e4SLinus Torvalds } 45101da177e4SLinus Torvalds 45117981593bSJoe Perches int hugetlb_report_node_meminfo(char *buf, int len, int nid) 45121da177e4SLinus Torvalds { 4513a5516438SAndi Kleen struct hstate *h = &default_hstate; 45147981593bSJoe Perches 4515457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4516457c1b27SNishanth Aravamudan return 0; 45177981593bSJoe Perches 45187981593bSJoe Perches return sysfs_emit_at(buf, len, 45191da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 4520a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 4521a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 4522a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 4523a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 4524a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 45251da177e4SLinus Torvalds } 45261da177e4SLinus Torvalds 4527dcadcf1cSGang Li void hugetlb_show_meminfo_node(int nid) 4528949f7ec5SDavid Rientjes { 4529949f7ec5SDavid Rientjes struct hstate *h; 4530949f7ec5SDavid Rientjes 4531457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4532457c1b27SNishanth Aravamudan return; 4533457c1b27SNishanth Aravamudan 4534949f7ec5SDavid Rientjes for_each_hstate(h) 4535dcadcf1cSGang Li printk("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", 4536949f7ec5SDavid Rientjes nid, 4537949f7ec5SDavid Rientjes h->nr_huge_pages_node[nid], 4538949f7ec5SDavid Rientjes h->free_huge_pages_node[nid], 4539949f7ec5SDavid Rientjes h->surplus_huge_pages_node[nid], 4540aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4541949f7ec5SDavid Rientjes } 4542949f7ec5SDavid Rientjes 45435d317b2bSNaoya Horiguchi void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm) 45445d317b2bSNaoya Horiguchi { 45455d317b2bSNaoya Horiguchi seq_printf(m, "HugetlbPages:\t%8lu kB\n", 45465d317b2bSNaoya Horiguchi atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10)); 45475d317b2bSNaoya Horiguchi } 45485d317b2bSNaoya Horiguchi 45491da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 45501da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 45511da177e4SLinus Torvalds { 4552d0028588SWanpeng Li struct hstate *h; 4553d0028588SWanpeng Li unsigned long nr_total_pages = 0; 4554d0028588SWanpeng Li 4555d0028588SWanpeng Li for_each_hstate(h) 4556d0028588SWanpeng Li nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); 4557d0028588SWanpeng Li return nr_total_pages; 45581da177e4SLinus Torvalds } 45591da177e4SLinus Torvalds 4560a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 4561fc1b8a73SMel Gorman { 4562fc1b8a73SMel Gorman int ret = -ENOMEM; 4563fc1b8a73SMel Gorman 45640aa7f354SMiaohe Lin if (!delta) 45650aa7f354SMiaohe Lin return 0; 45660aa7f354SMiaohe Lin 4567db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4568fc1b8a73SMel Gorman /* 4569fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 4570fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 4571fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 4572fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 4573fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 4574fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 4575fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 4576fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 4577fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 4578fc1b8a73SMel Gorman * 4579fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 4580fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 4581fc1b8a73SMel Gorman * we fall back to check against current free page availability as 4582fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 4583fc1b8a73SMel Gorman * semantics that cpuset has. 45848ca39e68SMuchun Song * 45858ca39e68SMuchun Song * Apart from cpuset, we also have memory policy mechanism that 45868ca39e68SMuchun Song * also determines from which node the kernel will allocate memory 45878ca39e68SMuchun Song * in a NUMA system. So similar to cpuset, we also should consider 45888ca39e68SMuchun Song * the memory policy of the current task. Similar to the description 45898ca39e68SMuchun Song * above. 4590fc1b8a73SMel Gorman */ 4591fc1b8a73SMel Gorman if (delta > 0) { 4592a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 4593fc1b8a73SMel Gorman goto out; 4594fc1b8a73SMel Gorman 45958ca39e68SMuchun Song if (delta > allowed_mems_nr(h)) { 4596a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 4597fc1b8a73SMel Gorman goto out; 4598fc1b8a73SMel Gorman } 4599fc1b8a73SMel Gorman } 4600fc1b8a73SMel Gorman 4601fc1b8a73SMel Gorman ret = 0; 4602fc1b8a73SMel Gorman if (delta < 0) 4603a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 4604fc1b8a73SMel Gorman 4605fc1b8a73SMel Gorman out: 4606db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4607fc1b8a73SMel Gorman return ret; 4608fc1b8a73SMel Gorman } 4609fc1b8a73SMel Gorman 461084afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 461184afd99bSAndy Whitcroft { 4612f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 461384afd99bSAndy Whitcroft 461484afd99bSAndy Whitcroft /* 461584afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 461684afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 461784afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 461825985edcSLucas De Marchi * has a reference to the reservation map it cannot disappear until 461984afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 462084afd99bSAndy Whitcroft * new reference here without additional locking. 462184afd99bSAndy Whitcroft */ 462209a26e83SMike Kravetz if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 462309a26e83SMike Kravetz resv_map_dup_hugetlb_cgroup_uncharge_info(resv); 4624f522c3acSJoonsoo Kim kref_get(&resv->refs); 462584afd99bSAndy Whitcroft } 462609a26e83SMike Kravetz } 462784afd99bSAndy Whitcroft 4628a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 4629a1e78772SMel Gorman { 4630a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 4631f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 463290481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 46334e35f483SJoonsoo Kim unsigned long reserve, start, end; 46341c5ecae3SMike Kravetz long gbl_reserve; 463584afd99bSAndy Whitcroft 46364e35f483SJoonsoo Kim if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 46374e35f483SJoonsoo Kim return; 46384e35f483SJoonsoo Kim 4639a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 4640a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 464184afd99bSAndy Whitcroft 46424e35f483SJoonsoo Kim reserve = (end - start) - region_count(resv, start, end); 4643e9fe92aeSMina Almasry hugetlb_cgroup_uncharge_counter(resv, start, end); 46447251ff78SAdam Litke if (reserve) { 46451c5ecae3SMike Kravetz /* 46461c5ecae3SMike Kravetz * Decrement reserve counts. The global reserve count may be 46471c5ecae3SMike Kravetz * adjusted if the subpool has a minimum size. 46481c5ecae3SMike Kravetz */ 46491c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, reserve); 46501c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 46517251ff78SAdam Litke } 4652e9fe92aeSMina Almasry 4653e9fe92aeSMina Almasry kref_put(&resv->refs, resv_map_release); 4654a1e78772SMel Gorman } 4655a1e78772SMel Gorman 465631383c68SDan Williams static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) 465731383c68SDan Williams { 465831383c68SDan Williams if (addr & ~(huge_page_mask(hstate_vma(vma)))) 465931383c68SDan Williams return -EINVAL; 466031383c68SDan Williams return 0; 466131383c68SDan Williams } 466231383c68SDan Williams 466305ea8860SDan Williams static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) 466405ea8860SDan Williams { 4665aca78307SMiaohe Lin return huge_page_size(hstate_vma(vma)); 466605ea8860SDan Williams } 466705ea8860SDan Williams 46681da177e4SLinus Torvalds /* 46691da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 46701da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 46716c26d310SMiaohe Lin * hugepage VMA. do_page_fault() is supposed to trap this, so BUG is we get 46721da177e4SLinus Torvalds * this far. 46731da177e4SLinus Torvalds */ 4674b3ec9f33SSouptick Joarder static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf) 46751da177e4SLinus Torvalds { 46761da177e4SLinus Torvalds BUG(); 4677d0217ac0SNick Piggin return 0; 46781da177e4SLinus Torvalds } 46791da177e4SLinus Torvalds 4680eec3636aSJane Chu /* 4681eec3636aSJane Chu * When a new function is introduced to vm_operations_struct and added 4682eec3636aSJane Chu * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops. 4683eec3636aSJane Chu * This is because under System V memory model, mappings created via 4684eec3636aSJane Chu * shmget/shmat with "huge page" specified are backed by hugetlbfs files, 4685eec3636aSJane Chu * their original vm_ops are overwritten with shm_vm_ops. 4686eec3636aSJane Chu */ 4687f0f37e2fSAlexey Dobriyan const struct vm_operations_struct hugetlb_vm_ops = { 4688d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 468984afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 4690a1e78772SMel Gorman .close = hugetlb_vm_op_close, 4691dd3b614fSDmitry Safonov .may_split = hugetlb_vm_op_split, 469205ea8860SDan Williams .pagesize = hugetlb_vm_op_pagesize, 46931da177e4SLinus Torvalds }; 46941da177e4SLinus Torvalds 46951e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 46961e8f889bSDavid Gibson int writable) 469763551ae0SDavid Gibson { 469863551ae0SDavid Gibson pte_t entry; 469979c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 470063551ae0SDavid Gibson 47011e8f889bSDavid Gibson if (writable) { 4702106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, 4703106c992aSGerald Schaefer vma->vm_page_prot))); 470463551ae0SDavid Gibson } else { 4705106c992aSGerald Schaefer entry = huge_pte_wrprotect(mk_huge_pte(page, 4706106c992aSGerald Schaefer vma->vm_page_prot)); 470763551ae0SDavid Gibson } 470863551ae0SDavid Gibson entry = pte_mkyoung(entry); 470979c1c594SChristophe Leroy entry = arch_make_huge_pte(entry, shift, vma->vm_flags); 471063551ae0SDavid Gibson 471163551ae0SDavid Gibson return entry; 471263551ae0SDavid Gibson } 471363551ae0SDavid Gibson 47141e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 47151e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 47161e8f889bSDavid Gibson { 47171e8f889bSDavid Gibson pte_t entry; 47181e8f889bSDavid Gibson 4719106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); 472032f84528SChris Forbes if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) 47214b3073e1SRussell King update_mmu_cache(vma, address, ptep); 47221e8f889bSDavid Gibson } 47231e8f889bSDavid Gibson 4724d5ed7444SAneesh Kumar K.V bool is_hugetlb_entry_migration(pte_t pte) 47254a705fefSNaoya Horiguchi { 47264a705fefSNaoya Horiguchi swp_entry_t swp; 47274a705fefSNaoya Horiguchi 47284a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 4729d5ed7444SAneesh Kumar K.V return false; 47304a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4731d79d176aSBaoquan He if (is_migration_entry(swp)) 4732d5ed7444SAneesh Kumar K.V return true; 47334a705fefSNaoya Horiguchi else 4734d5ed7444SAneesh Kumar K.V return false; 47354a705fefSNaoya Horiguchi } 47364a705fefSNaoya Horiguchi 47373e5c3600SBaoquan He static bool is_hugetlb_entry_hwpoisoned(pte_t pte) 47384a705fefSNaoya Horiguchi { 47394a705fefSNaoya Horiguchi swp_entry_t swp; 47404a705fefSNaoya Horiguchi 47414a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 47423e5c3600SBaoquan He return false; 47434a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4744d79d176aSBaoquan He if (is_hwpoison_entry(swp)) 47453e5c3600SBaoquan He return true; 47464a705fefSNaoya Horiguchi else 47473e5c3600SBaoquan He return false; 47484a705fefSNaoya Horiguchi } 47491e8f889bSDavid Gibson 47504eae4efaSPeter Xu static void 47514eae4efaSPeter Xu hugetlb_install_page(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr, 47524eae4efaSPeter Xu struct page *new_page) 47534eae4efaSPeter Xu { 47544eae4efaSPeter Xu __SetPageUptodate(new_page); 47554eae4efaSPeter Xu hugepage_add_new_anon_rmap(new_page, vma, addr); 47561eba86c0SPasha Tatashin set_huge_pte_at(vma->vm_mm, addr, ptep, make_huge_pte(vma, new_page, 1)); 47574eae4efaSPeter Xu hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm); 47584eae4efaSPeter Xu ClearHPageRestoreReserve(new_page); 47594eae4efaSPeter Xu SetHPageMigratable(new_page); 47604eae4efaSPeter Xu } 47614eae4efaSPeter Xu 476263551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 4763bc70fbf2SPeter Xu struct vm_area_struct *dst_vma, 4764bc70fbf2SPeter Xu struct vm_area_struct *src_vma) 476563551ae0SDavid Gibson { 47663aa4ed80SMiaohe Lin pte_t *src_pte, *dst_pte, entry; 476763551ae0SDavid Gibson struct page *ptepage; 47681c59827dSHugh Dickins unsigned long addr; 4769bc70fbf2SPeter Xu bool cow = is_cow_mapping(src_vma->vm_flags); 4770bc70fbf2SPeter Xu struct hstate *h = hstate_vma(src_vma); 4771a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 47724eae4efaSPeter Xu unsigned long npages = pages_per_huge_page(h); 4773ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 4774e95a9851SMike Kravetz unsigned long last_addr_mask; 4775e8569dd2SAndreas Sandberg int ret = 0; 47761e8f889bSDavid Gibson 4777ac46d4f3SJérôme Glisse if (cow) { 4778bc70fbf2SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, src_vma, src, 4779bc70fbf2SPeter Xu src_vma->vm_start, 4780bc70fbf2SPeter Xu src_vma->vm_end); 4781ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4782623a1ddfSDavid Hildenbrand mmap_assert_write_locked(src); 4783623a1ddfSDavid Hildenbrand raw_write_seqcount_begin(&src->write_protect_seq); 4784ac46d4f3SJérôme Glisse } 4785e8569dd2SAndreas Sandberg 4786e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 4787bc70fbf2SPeter Xu for (addr = src_vma->vm_start; addr < src_vma->vm_end; addr += sz) { 4788cb900f41SKirill A. Shutemov spinlock_t *src_ptl, *dst_ptl; 47897868a208SPunit Agrawal src_pte = huge_pte_offset(src, addr, sz); 4790e95a9851SMike Kravetz if (!src_pte) { 4791e95a9851SMike Kravetz addr |= last_addr_mask; 4792c74df32cSHugh Dickins continue; 4793e95a9851SMike Kravetz } 4794bc70fbf2SPeter Xu dst_pte = huge_pte_alloc(dst, dst_vma, addr, sz); 4795e8569dd2SAndreas Sandberg if (!dst_pte) { 4796e8569dd2SAndreas Sandberg ret = -ENOMEM; 4797e8569dd2SAndreas Sandberg break; 4798e8569dd2SAndreas Sandberg } 4799c5c99429SLarry Woodman 48005e41540cSMike Kravetz /* 48015e41540cSMike Kravetz * If the pagetables are shared don't copy or take references. 48025e41540cSMike Kravetz * 48033aa4ed80SMiaohe Lin * dst_pte == src_pte is the common case of src/dest sharing. 48045e41540cSMike Kravetz * However, src could have 'unshared' and dst shares with 48053aa4ed80SMiaohe Lin * another vma. So page_count of ptep page is checked instead 48063aa4ed80SMiaohe Lin * to reliably determine whether pte is shared. 48075e41540cSMike Kravetz */ 48083aa4ed80SMiaohe Lin if (page_count(virt_to_page(dst_pte)) > 1) { 4809e95a9851SMike Kravetz addr |= last_addr_mask; 4810c5c99429SLarry Woodman continue; 4811e95a9851SMike Kravetz } 4812c5c99429SLarry Woodman 4813cb900f41SKirill A. Shutemov dst_ptl = huge_pte_lock(h, dst, dst_pte); 4814cb900f41SKirill A. Shutemov src_ptl = huge_pte_lockptr(h, src, src_pte); 4815cb900f41SKirill A. Shutemov spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 48164a705fefSNaoya Horiguchi entry = huge_ptep_get(src_pte); 48174eae4efaSPeter Xu again: 48183aa4ed80SMiaohe Lin if (huge_pte_none(entry)) { 48195e41540cSMike Kravetz /* 48203aa4ed80SMiaohe Lin * Skip if src entry none. 48215e41540cSMike Kravetz */ 48224a705fefSNaoya Horiguchi ; 4823c2cb0dccSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) { 4824c2cb0dccSNaoya Horiguchi bool uffd_wp = huge_pte_uffd_wp(entry); 4825c2cb0dccSNaoya Horiguchi 4826c2cb0dccSNaoya Horiguchi if (!userfaultfd_wp(dst_vma) && uffd_wp) 4827c2cb0dccSNaoya Horiguchi entry = huge_pte_clear_uffd_wp(entry); 4828c2cb0dccSNaoya Horiguchi set_huge_pte_at(dst, addr, dst_pte, entry); 4829c2cb0dccSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_migration(entry))) { 48304a705fefSNaoya Horiguchi swp_entry_t swp_entry = pte_to_swp_entry(entry); 4831bc70fbf2SPeter Xu bool uffd_wp = huge_pte_uffd_wp(entry); 48324a705fefSNaoya Horiguchi 48336c287605SDavid Hildenbrand if (!is_readable_migration_entry(swp_entry) && cow) { 48344a705fefSNaoya Horiguchi /* 48354a705fefSNaoya Horiguchi * COW mappings require pages in both 48364a705fefSNaoya Horiguchi * parent and child to be set to read. 48374a705fefSNaoya Horiguchi */ 48384dd845b5SAlistair Popple swp_entry = make_readable_migration_entry( 48394dd845b5SAlistair Popple swp_offset(swp_entry)); 48404a705fefSNaoya Horiguchi entry = swp_entry_to_pte(swp_entry); 4841bc70fbf2SPeter Xu if (userfaultfd_wp(src_vma) && uffd_wp) 4842bc70fbf2SPeter Xu entry = huge_pte_mkuffd_wp(entry); 484318f39629SQi Zheng set_huge_pte_at(src, addr, src_pte, entry); 48444a705fefSNaoya Horiguchi } 4845bc70fbf2SPeter Xu if (!userfaultfd_wp(dst_vma) && uffd_wp) 4846bc70fbf2SPeter Xu entry = huge_pte_clear_uffd_wp(entry); 484718f39629SQi Zheng set_huge_pte_at(dst, addr, dst_pte, entry); 4848bc70fbf2SPeter Xu } else if (unlikely(is_pte_marker(entry))) { 4849bc70fbf2SPeter Xu /* 4850bc70fbf2SPeter Xu * We copy the pte marker only if the dst vma has 4851bc70fbf2SPeter Xu * uffd-wp enabled. 4852bc70fbf2SPeter Xu */ 4853bc70fbf2SPeter Xu if (userfaultfd_wp(dst_vma)) 4854bc70fbf2SPeter Xu set_huge_pte_at(dst, addr, dst_pte, entry); 48554a705fefSNaoya Horiguchi } else { 48564eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 48574eae4efaSPeter Xu ptepage = pte_page(entry); 48584eae4efaSPeter Xu get_page(ptepage); 48594eae4efaSPeter Xu 48604eae4efaSPeter Xu /* 4861fb3d824dSDavid Hildenbrand * Failing to duplicate the anon rmap is a rare case 4862fb3d824dSDavid Hildenbrand * where we see pinned hugetlb pages while they're 4863fb3d824dSDavid Hildenbrand * prone to COW. We need to do the COW earlier during 4864fb3d824dSDavid Hildenbrand * fork. 48654eae4efaSPeter Xu * 48664eae4efaSPeter Xu * When pre-allocating the page or copying data, we 48674eae4efaSPeter Xu * need to be without the pgtable locks since we could 48684eae4efaSPeter Xu * sleep during the process. 48694eae4efaSPeter Xu */ 4870fb3d824dSDavid Hildenbrand if (!PageAnon(ptepage)) { 4871fb3d824dSDavid Hildenbrand page_dup_file_rmap(ptepage, true); 4872bc70fbf2SPeter Xu } else if (page_try_dup_anon_rmap(ptepage, true, 4873bc70fbf2SPeter Xu src_vma)) { 48744eae4efaSPeter Xu pte_t src_pte_old = entry; 48754eae4efaSPeter Xu struct page *new; 48764eae4efaSPeter Xu 48774eae4efaSPeter Xu spin_unlock(src_ptl); 48784eae4efaSPeter Xu spin_unlock(dst_ptl); 48794eae4efaSPeter Xu /* Do not use reserve as it's private owned */ 4880bc70fbf2SPeter Xu new = alloc_huge_page(dst_vma, addr, 1); 48814eae4efaSPeter Xu if (IS_ERR(new)) { 48824eae4efaSPeter Xu put_page(ptepage); 48834eae4efaSPeter Xu ret = PTR_ERR(new); 48844eae4efaSPeter Xu break; 48854eae4efaSPeter Xu } 4886bc70fbf2SPeter Xu copy_user_huge_page(new, ptepage, addr, dst_vma, 48874eae4efaSPeter Xu npages); 48884eae4efaSPeter Xu put_page(ptepage); 48894eae4efaSPeter Xu 48904eae4efaSPeter Xu /* Install the new huge page if src pte stable */ 48914eae4efaSPeter Xu dst_ptl = huge_pte_lock(h, dst, dst_pte); 48924eae4efaSPeter Xu src_ptl = huge_pte_lockptr(h, src, src_pte); 48934eae4efaSPeter Xu spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 48944eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 48954eae4efaSPeter Xu if (!pte_same(src_pte_old, entry)) { 4896bc70fbf2SPeter Xu restore_reserve_on_error(h, dst_vma, addr, 4897846be085SMike Kravetz new); 48984eae4efaSPeter Xu put_page(new); 48993aa4ed80SMiaohe Lin /* huge_ptep of dst_pte won't change as in child */ 49004eae4efaSPeter Xu goto again; 49014eae4efaSPeter Xu } 4902bc70fbf2SPeter Xu hugetlb_install_page(dst_vma, dst_pte, addr, new); 49034eae4efaSPeter Xu spin_unlock(src_ptl); 49044eae4efaSPeter Xu spin_unlock(dst_ptl); 49054eae4efaSPeter Xu continue; 49064eae4efaSPeter Xu } 49074eae4efaSPeter Xu 490834ee645eSJoerg Roedel if (cow) { 49090f10851eSJérôme Glisse /* 49100f10851eSJérôme Glisse * No need to notify as we are downgrading page 49110f10851eSJérôme Glisse * table protection not changing it to point 49120f10851eSJérôme Glisse * to a new page. 49130f10851eSJérôme Glisse * 4914ee65728eSMike Rapoport * See Documentation/mm/mmu_notifier.rst 49150f10851eSJérôme Glisse */ 49167f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 491784894e1cSPeter Xu entry = huge_pte_wrprotect(entry); 491834ee645eSJoerg Roedel } 49194eae4efaSPeter Xu 492063551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 49214eae4efaSPeter Xu hugetlb_count_add(npages, dst); 49221c59827dSHugh Dickins } 4923cb900f41SKirill A. Shutemov spin_unlock(src_ptl); 4924cb900f41SKirill A. Shutemov spin_unlock(dst_ptl); 492563551ae0SDavid Gibson } 492663551ae0SDavid Gibson 4927623a1ddfSDavid Hildenbrand if (cow) { 4928623a1ddfSDavid Hildenbrand raw_write_seqcount_end(&src->write_protect_seq); 4929ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 4930623a1ddfSDavid Hildenbrand } 4931e8569dd2SAndreas Sandberg 4932e8569dd2SAndreas Sandberg return ret; 493363551ae0SDavid Gibson } 493463551ae0SDavid Gibson 4935550a7d60SMina Almasry static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr, 4936db110a99SAneesh Kumar K.V unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte) 4937550a7d60SMina Almasry { 4938550a7d60SMina Almasry struct hstate *h = hstate_vma(vma); 4939550a7d60SMina Almasry struct mm_struct *mm = vma->vm_mm; 4940550a7d60SMina Almasry spinlock_t *src_ptl, *dst_ptl; 4941db110a99SAneesh Kumar K.V pte_t pte; 4942550a7d60SMina Almasry 4943550a7d60SMina Almasry dst_ptl = huge_pte_lock(h, mm, dst_pte); 4944550a7d60SMina Almasry src_ptl = huge_pte_lockptr(h, mm, src_pte); 4945550a7d60SMina Almasry 4946550a7d60SMina Almasry /* 4947550a7d60SMina Almasry * We don't have to worry about the ordering of src and dst ptlocks 4948550a7d60SMina Almasry * because exclusive mmap_sem (or the i_mmap_lock) prevents deadlock. 4949550a7d60SMina Almasry */ 4950550a7d60SMina Almasry if (src_ptl != dst_ptl) 4951550a7d60SMina Almasry spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 4952550a7d60SMina Almasry 4953550a7d60SMina Almasry pte = huge_ptep_get_and_clear(mm, old_addr, src_pte); 4954550a7d60SMina Almasry set_huge_pte_at(mm, new_addr, dst_pte, pte); 4955550a7d60SMina Almasry 4956550a7d60SMina Almasry if (src_ptl != dst_ptl) 4957550a7d60SMina Almasry spin_unlock(src_ptl); 4958550a7d60SMina Almasry spin_unlock(dst_ptl); 4959550a7d60SMina Almasry } 4960550a7d60SMina Almasry 4961550a7d60SMina Almasry int move_hugetlb_page_tables(struct vm_area_struct *vma, 4962550a7d60SMina Almasry struct vm_area_struct *new_vma, 4963550a7d60SMina Almasry unsigned long old_addr, unsigned long new_addr, 4964550a7d60SMina Almasry unsigned long len) 4965550a7d60SMina Almasry { 4966550a7d60SMina Almasry struct hstate *h = hstate_vma(vma); 4967550a7d60SMina Almasry struct address_space *mapping = vma->vm_file->f_mapping; 4968550a7d60SMina Almasry unsigned long sz = huge_page_size(h); 4969550a7d60SMina Almasry struct mm_struct *mm = vma->vm_mm; 4970550a7d60SMina Almasry unsigned long old_end = old_addr + len; 4971e95a9851SMike Kravetz unsigned long last_addr_mask; 4972550a7d60SMina Almasry pte_t *src_pte, *dst_pte; 4973550a7d60SMina Almasry struct mmu_notifier_range range; 49743d0b95cdSBaolin Wang bool shared_pmd = false; 4975550a7d60SMina Almasry 4976550a7d60SMina Almasry mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, old_addr, 4977550a7d60SMina Almasry old_end); 4978550a7d60SMina Almasry adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 49793d0b95cdSBaolin Wang /* 49803d0b95cdSBaolin Wang * In case of shared PMDs, we should cover the maximum possible 49813d0b95cdSBaolin Wang * range. 49823d0b95cdSBaolin Wang */ 49833d0b95cdSBaolin Wang flush_cache_range(vma, range.start, range.end); 49843d0b95cdSBaolin Wang 4985550a7d60SMina Almasry mmu_notifier_invalidate_range_start(&range); 4986e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 4987550a7d60SMina Almasry /* Prevent race with file truncation */ 4988550a7d60SMina Almasry i_mmap_lock_write(mapping); 4989550a7d60SMina Almasry for (; old_addr < old_end; old_addr += sz, new_addr += sz) { 4990550a7d60SMina Almasry src_pte = huge_pte_offset(mm, old_addr, sz); 4991e95a9851SMike Kravetz if (!src_pte) { 4992e95a9851SMike Kravetz old_addr |= last_addr_mask; 4993e95a9851SMike Kravetz new_addr |= last_addr_mask; 4994550a7d60SMina Almasry continue; 4995e95a9851SMike Kravetz } 4996550a7d60SMina Almasry if (huge_pte_none(huge_ptep_get(src_pte))) 4997550a7d60SMina Almasry continue; 4998550a7d60SMina Almasry 49994ddb4d91SMike Kravetz if (huge_pmd_unshare(mm, vma, old_addr, src_pte)) { 50003d0b95cdSBaolin Wang shared_pmd = true; 50014ddb4d91SMike Kravetz old_addr |= last_addr_mask; 50024ddb4d91SMike Kravetz new_addr |= last_addr_mask; 5003550a7d60SMina Almasry continue; 50043d0b95cdSBaolin Wang } 5005550a7d60SMina Almasry 5006550a7d60SMina Almasry dst_pte = huge_pte_alloc(mm, new_vma, new_addr, sz); 5007550a7d60SMina Almasry if (!dst_pte) 5008550a7d60SMina Almasry break; 5009550a7d60SMina Almasry 5010db110a99SAneesh Kumar K.V move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte); 5011550a7d60SMina Almasry } 50123d0b95cdSBaolin Wang 50133d0b95cdSBaolin Wang if (shared_pmd) 50143d0b95cdSBaolin Wang flush_tlb_range(vma, range.start, range.end); 50153d0b95cdSBaolin Wang else 5016550a7d60SMina Almasry flush_tlb_range(vma, old_end - len, old_end); 5017550a7d60SMina Almasry mmu_notifier_invalidate_range_end(&range); 501813e4ad2cSNadav Amit i_mmap_unlock_write(mapping); 5019550a7d60SMina Almasry 5020550a7d60SMina Almasry return len + old_addr - old_end; 5021550a7d60SMina Almasry } 5022550a7d60SMina Almasry 502373c54763SPeter Xu static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, 502424669e58SAneesh Kumar K.V unsigned long start, unsigned long end, 502505e90bd0SPeter Xu struct page *ref_page, zap_flags_t zap_flags) 502663551ae0SDavid Gibson { 502763551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 502863551ae0SDavid Gibson unsigned long address; 5029c7546f8fSDavid Gibson pte_t *ptep; 503063551ae0SDavid Gibson pte_t pte; 5031cb900f41SKirill A. Shutemov spinlock_t *ptl; 503263551ae0SDavid Gibson struct page *page; 5033a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 5034a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 5035ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 5036e95a9851SMike Kravetz unsigned long last_addr_mask; 5037a4a118f2SNadav Amit bool force_flush = false; 5038a5516438SAndi Kleen 503963551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 5040a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 5041a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 504263551ae0SDavid Gibson 504307e32661SAneesh Kumar K.V /* 504407e32661SAneesh Kumar K.V * This is a hugetlb vma, all the pte entries should point 504507e32661SAneesh Kumar K.V * to huge page. 504607e32661SAneesh Kumar K.V */ 5047ed6a7935SPeter Zijlstra tlb_change_page_size(tlb, sz); 504824669e58SAneesh Kumar K.V tlb_start_vma(tlb, vma); 5049dff11abeSMike Kravetz 5050dff11abeSMike Kravetz /* 5051dff11abeSMike Kravetz * If sharing possible, alert mmu notifiers of worst case. 5052dff11abeSMike Kravetz */ 50536f4f13e8SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, mm, start, 50546f4f13e8SJérôme Glisse end); 5055ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 5056ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 5057e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 5058569f48b8SHillf Danton address = start; 5059569f48b8SHillf Danton for (; address < end; address += sz) { 50607868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, sz); 5061e95a9851SMike Kravetz if (!ptep) { 5062e95a9851SMike Kravetz address |= last_addr_mask; 5063c7546f8fSDavid Gibson continue; 5064e95a9851SMike Kravetz } 5065c7546f8fSDavid Gibson 5066cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 50674ddb4d91SMike Kravetz if (huge_pmd_unshare(mm, vma, address, ptep)) { 506831d49da5SAneesh Kumar K.V spin_unlock(ptl); 5069a4a118f2SNadav Amit tlb_flush_pmd_range(tlb, address & PUD_MASK, PUD_SIZE); 5070a4a118f2SNadav Amit force_flush = true; 50714ddb4d91SMike Kravetz address |= last_addr_mask; 507231d49da5SAneesh Kumar K.V continue; 507331d49da5SAneesh Kumar K.V } 507439dde65cSChen, Kenneth W 50756629326bSHillf Danton pte = huge_ptep_get(ptep); 507631d49da5SAneesh Kumar K.V if (huge_pte_none(pte)) { 507731d49da5SAneesh Kumar K.V spin_unlock(ptl); 507831d49da5SAneesh Kumar K.V continue; 507931d49da5SAneesh Kumar K.V } 50806629326bSHillf Danton 50816629326bSHillf Danton /* 50829fbc1f63SNaoya Horiguchi * Migrating hugepage or HWPoisoned hugepage is already 50839fbc1f63SNaoya Horiguchi * unmapped and its refcount is dropped, so just clear pte here. 50846629326bSHillf Danton */ 50859fbc1f63SNaoya Horiguchi if (unlikely(!pte_present(pte))) { 508605e90bd0SPeter Xu /* 508705e90bd0SPeter Xu * If the pte was wr-protected by uffd-wp in any of the 508805e90bd0SPeter Xu * swap forms, meanwhile the caller does not want to 508905e90bd0SPeter Xu * drop the uffd-wp bit in this zap, then replace the 509005e90bd0SPeter Xu * pte with a marker. 509105e90bd0SPeter Xu */ 509205e90bd0SPeter Xu if (pte_swp_uffd_wp_any(pte) && 509305e90bd0SPeter Xu !(zap_flags & ZAP_FLAG_DROP_MARKER)) 509405e90bd0SPeter Xu set_huge_pte_at(mm, address, ptep, 509505e90bd0SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 509605e90bd0SPeter Xu else 50979386fac3SPunit Agrawal huge_pte_clear(mm, address, ptep, sz); 509831d49da5SAneesh Kumar K.V spin_unlock(ptl); 509931d49da5SAneesh Kumar K.V continue; 51008c4894c6SNaoya Horiguchi } 51016629326bSHillf Danton 51026629326bSHillf Danton page = pte_page(pte); 510304f2cbe3SMel Gorman /* 510404f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 510504f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 510604f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 510704f2cbe3SMel Gorman */ 510804f2cbe3SMel Gorman if (ref_page) { 510931d49da5SAneesh Kumar K.V if (page != ref_page) { 511031d49da5SAneesh Kumar K.V spin_unlock(ptl); 511131d49da5SAneesh Kumar K.V continue; 511231d49da5SAneesh Kumar K.V } 511304f2cbe3SMel Gorman /* 511404f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 511504f2cbe3SMel Gorman * future faults in this VMA will fail rather than 511604f2cbe3SMel Gorman * looking like data was lost 511704f2cbe3SMel Gorman */ 511804f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 511904f2cbe3SMel Gorman } 512004f2cbe3SMel Gorman 5121c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 5122b528e4b6SAneesh Kumar K.V tlb_remove_huge_tlb_entry(h, tlb, ptep, address); 5123106c992aSGerald Schaefer if (huge_pte_dirty(pte)) 51246649a386SKen Chen set_page_dirty(page); 512505e90bd0SPeter Xu /* Leave a uffd-wp pte marker if needed */ 512605e90bd0SPeter Xu if (huge_pte_uffd_wp(pte) && 512705e90bd0SPeter Xu !(zap_flags & ZAP_FLAG_DROP_MARKER)) 512805e90bd0SPeter Xu set_huge_pte_at(mm, address, ptep, 512905e90bd0SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 51305d317b2bSNaoya Horiguchi hugetlb_count_sub(pages_per_huge_page(h), mm); 5131cea86fe2SHugh Dickins page_remove_rmap(page, vma, true); 513231d49da5SAneesh Kumar K.V 5133cb900f41SKirill A. Shutemov spin_unlock(ptl); 5134e77b0852SAneesh Kumar K.V tlb_remove_page_size(tlb, page, huge_page_size(h)); 513524669e58SAneesh Kumar K.V /* 513631d49da5SAneesh Kumar K.V * Bail out after unmapping reference page if supplied 513724669e58SAneesh Kumar K.V */ 513831d49da5SAneesh Kumar K.V if (ref_page) 513931d49da5SAneesh Kumar K.V break; 5140fe1668aeSChen, Kenneth W } 5141ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 514224669e58SAneesh Kumar K.V tlb_end_vma(tlb, vma); 5143a4a118f2SNadav Amit 5144a4a118f2SNadav Amit /* 5145a4a118f2SNadav Amit * If we unshared PMDs, the TLB flush was not recorded in mmu_gather. We 5146a4a118f2SNadav Amit * could defer the flush until now, since by holding i_mmap_rwsem we 5147a4a118f2SNadav Amit * guaranteed that the last refernece would not be dropped. But we must 5148a4a118f2SNadav Amit * do the flushing before we return, as otherwise i_mmap_rwsem will be 5149a4a118f2SNadav Amit * dropped and the last reference to the shared PMDs page might be 5150a4a118f2SNadav Amit * dropped as well. 5151a4a118f2SNadav Amit * 5152a4a118f2SNadav Amit * In theory we could defer the freeing of the PMD pages as well, but 5153a4a118f2SNadav Amit * huge_pmd_unshare() relies on the exact page_count for the PMD page to 5154a4a118f2SNadav Amit * detect sharing, so we cannot defer the release of the page either. 5155a4a118f2SNadav Amit * Instead, do flush now. 5156a4a118f2SNadav Amit */ 5157a4a118f2SNadav Amit if (force_flush) 5158a4a118f2SNadav Amit tlb_flush_mmu_tlbonly(tlb); 51591da177e4SLinus Torvalds } 516063551ae0SDavid Gibson 5161d833352aSMel Gorman void __unmap_hugepage_range_final(struct mmu_gather *tlb, 5162d833352aSMel Gorman struct vm_area_struct *vma, unsigned long start, 516305e90bd0SPeter Xu unsigned long end, struct page *ref_page, 516405e90bd0SPeter Xu zap_flags_t zap_flags) 5165d833352aSMel Gorman { 516605e90bd0SPeter Xu __unmap_hugepage_range(tlb, vma, start, end, ref_page, zap_flags); 5167d833352aSMel Gorman 5168d833352aSMel Gorman /* 5169d833352aSMel Gorman * Clear this flag so that x86's huge_pmd_share page_table_shareable 5170d833352aSMel Gorman * test will fail on a vma being torn down, and not grab a page table 5171d833352aSMel Gorman * on its way out. We're lucky that the flag has such an appropriate 5172d833352aSMel Gorman * name, and can in fact be safely cleared here. We could clear it 5173d833352aSMel Gorman * before the __unmap_hugepage_range above, but all that's necessary 5174c8c06efaSDavidlohr Bueso * is to clear it before releasing the i_mmap_rwsem. This works 5175d833352aSMel Gorman * because in the context this is called, the VMA is about to be 5176c8c06efaSDavidlohr Bueso * destroyed and the i_mmap_rwsem is held. 5177d833352aSMel Gorman */ 5178d833352aSMel Gorman vma->vm_flags &= ~VM_MAYSHARE; 5179d833352aSMel Gorman } 5180d833352aSMel Gorman 5181502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 518205e90bd0SPeter Xu unsigned long end, struct page *ref_page, 518305e90bd0SPeter Xu zap_flags_t zap_flags) 5184502717f4SChen, Kenneth W { 518524669e58SAneesh Kumar K.V struct mmu_gather tlb; 5186dff11abeSMike Kravetz 5187a72afd87SWill Deacon tlb_gather_mmu(&tlb, vma->vm_mm); 518805e90bd0SPeter Xu __unmap_hugepage_range(&tlb, vma, start, end, ref_page, zap_flags); 5189ae8eba8bSWill Deacon tlb_finish_mmu(&tlb); 5190502717f4SChen, Kenneth W } 5191502717f4SChen, Kenneth W 519204f2cbe3SMel Gorman /* 519304f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 5194578b7725SZhiyuan Dai * mapping it owns the reserve page for. The intention is to unmap the page 519504f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 519604f2cbe3SMel Gorman * same region. 519704f2cbe3SMel Gorman */ 51982f4612afSDavidlohr Bueso static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, 51992a4b3dedSHarvey Harrison struct page *page, unsigned long address) 520004f2cbe3SMel Gorman { 52017526674dSAdam Litke struct hstate *h = hstate_vma(vma); 520204f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 520304f2cbe3SMel Gorman struct address_space *mapping; 520404f2cbe3SMel Gorman pgoff_t pgoff; 520504f2cbe3SMel Gorman 520604f2cbe3SMel Gorman /* 520704f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 520804f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 520904f2cbe3SMel Gorman */ 52107526674dSAdam Litke address = address & huge_page_mask(h); 521136e4f20aSMichal Hocko pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + 521236e4f20aSMichal Hocko vma->vm_pgoff; 521393c76a3dSAl Viro mapping = vma->vm_file->f_mapping; 521404f2cbe3SMel Gorman 52154eb2b1dcSMel Gorman /* 52164eb2b1dcSMel Gorman * Take the mapping lock for the duration of the table walk. As 52174eb2b1dcSMel Gorman * this mapping should be shared between all the VMAs, 52184eb2b1dcSMel Gorman * __unmap_hugepage_range() is called as the lock is already held 52194eb2b1dcSMel Gorman */ 522083cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 52216b2dbba8SMichel Lespinasse vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { 522204f2cbe3SMel Gorman /* Do not unmap the current VMA */ 522304f2cbe3SMel Gorman if (iter_vma == vma) 522404f2cbe3SMel Gorman continue; 522504f2cbe3SMel Gorman 522604f2cbe3SMel Gorman /* 52272f84a899SMel Gorman * Shared VMAs have their own reserves and do not affect 52282f84a899SMel Gorman * MAP_PRIVATE accounting but it is possible that a shared 52292f84a899SMel Gorman * VMA is using the same page so check and skip such VMAs. 52302f84a899SMel Gorman */ 52312f84a899SMel Gorman if (iter_vma->vm_flags & VM_MAYSHARE) 52322f84a899SMel Gorman continue; 52332f84a899SMel Gorman 52342f84a899SMel Gorman /* 523504f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 523604f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 523704f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 523804f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 523904f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 524004f2cbe3SMel Gorman */ 524104f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 524224669e58SAneesh Kumar K.V unmap_hugepage_range(iter_vma, address, 524305e90bd0SPeter Xu address + huge_page_size(h), page, 0); 524404f2cbe3SMel Gorman } 524583cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 524604f2cbe3SMel Gorman } 524704f2cbe3SMel Gorman 52480fe6e20bSNaoya Horiguchi /* 5249c89357e2SDavid Hildenbrand * hugetlb_wp() should be called with page lock of the original hugepage held. 5250aa6d2e8cSBaolin Wang * Called with hugetlb_fault_mutex_table held and pte_page locked so we 5251ef009b25SMichal Hocko * cannot race with other handlers or page migration. 5252ef009b25SMichal Hocko * Keep the pte_same checks anyway to make transition from the mutex easier. 52530fe6e20bSNaoya Horiguchi */ 5254c89357e2SDavid Hildenbrand static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma, 5255c89357e2SDavid Hildenbrand unsigned long address, pte_t *ptep, unsigned int flags, 5256cb900f41SKirill A. Shutemov struct page *pagecache_page, spinlock_t *ptl) 52571e8f889bSDavid Gibson { 5258c89357e2SDavid Hildenbrand const bool unshare = flags & FAULT_FLAG_UNSHARE; 52593999f52eSAneesh Kumar K.V pte_t pte; 5260a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 52611e8f889bSDavid Gibson struct page *old_page, *new_page; 52622b740303SSouptick Joarder int outside_reserve = 0; 52632b740303SSouptick Joarder vm_fault_t ret = 0; 5264974e6d66SHuang Ying unsigned long haddr = address & huge_page_mask(h); 5265ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 52661e8f889bSDavid Gibson 5267c89357e2SDavid Hildenbrand VM_BUG_ON(unshare && (flags & FOLL_WRITE)); 5268c89357e2SDavid Hildenbrand VM_BUG_ON(!unshare && !(flags & FOLL_WRITE)); 5269c89357e2SDavid Hildenbrand 52701d8d1464SDavid Hildenbrand /* 52711d8d1464SDavid Hildenbrand * hugetlb does not support FOLL_FORCE-style write faults that keep the 52721d8d1464SDavid Hildenbrand * PTE mapped R/O such as maybe_mkwrite() would do. 52731d8d1464SDavid Hildenbrand */ 52741d8d1464SDavid Hildenbrand if (WARN_ON_ONCE(!unshare && !(vma->vm_flags & VM_WRITE))) 52751d8d1464SDavid Hildenbrand return VM_FAULT_SIGSEGV; 52761d8d1464SDavid Hildenbrand 52771d8d1464SDavid Hildenbrand /* Let's take out MAP_SHARED mappings first. */ 52781d8d1464SDavid Hildenbrand if (vma->vm_flags & VM_MAYSHARE) { 52791d8d1464SDavid Hildenbrand if (unlikely(unshare)) 52801d8d1464SDavid Hildenbrand return 0; 52811d8d1464SDavid Hildenbrand set_huge_ptep_writable(vma, haddr, ptep); 52821d8d1464SDavid Hildenbrand return 0; 52831d8d1464SDavid Hildenbrand } 52841d8d1464SDavid Hildenbrand 52853999f52eSAneesh Kumar K.V pte = huge_ptep_get(ptep); 52861e8f889bSDavid Gibson old_page = pte_page(pte); 52871e8f889bSDavid Gibson 5288662ce1dcSYang Yang delayacct_wpcopy_start(); 5289662ce1dcSYang Yang 529004f2cbe3SMel Gorman retry_avoidcopy: 5291c89357e2SDavid Hildenbrand /* 5292c89357e2SDavid Hildenbrand * If no-one else is actually using this page, we're the exclusive 5293c89357e2SDavid Hildenbrand * owner and can reuse this page. 5294c89357e2SDavid Hildenbrand */ 529537a2140dSJoonsoo Kim if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { 5296c89357e2SDavid Hildenbrand if (!PageAnonExclusive(old_page)) 52975a49973dSHugh Dickins page_move_anon_rmap(old_page, vma); 5298c89357e2SDavid Hildenbrand if (likely(!unshare)) 52995b7a1d40SHuang Ying set_huge_ptep_writable(vma, haddr, ptep); 5300662ce1dcSYang Yang 5301662ce1dcSYang Yang delayacct_wpcopy_end(); 530283c54070SNick Piggin return 0; 53031e8f889bSDavid Gibson } 53046c287605SDavid Hildenbrand VM_BUG_ON_PAGE(PageAnon(old_page) && PageAnonExclusive(old_page), 53056c287605SDavid Hildenbrand old_page); 53061e8f889bSDavid Gibson 530704f2cbe3SMel Gorman /* 530804f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 530904f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 531004f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 531104f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 531204f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 531304f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 531404f2cbe3SMel Gorman * of the full address range. 531504f2cbe3SMel Gorman */ 53165944d011SJoonsoo Kim if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 531704f2cbe3SMel Gorman old_page != pagecache_page) 531804f2cbe3SMel Gorman outside_reserve = 1; 531904f2cbe3SMel Gorman 532009cbfeafSKirill A. Shutemov get_page(old_page); 5321b76c8cfbSLarry Woodman 5322ad4404a2SDavidlohr Bueso /* 5323ad4404a2SDavidlohr Bueso * Drop page table lock as buddy allocator may be called. It will 5324ad4404a2SDavidlohr Bueso * be acquired again before returning to the caller, as expected. 5325ad4404a2SDavidlohr Bueso */ 5326cb900f41SKirill A. Shutemov spin_unlock(ptl); 53275b7a1d40SHuang Ying new_page = alloc_huge_page(vma, haddr, outside_reserve); 53281e8f889bSDavid Gibson 53292fc39cecSAdam Litke if (IS_ERR(new_page)) { 533004f2cbe3SMel Gorman /* 533104f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 533204f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 533304f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 533404f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 533504f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 533604f2cbe3SMel Gorman */ 533704f2cbe3SMel Gorman if (outside_reserve) { 533809cbfeafSKirill A. Shutemov put_page(old_page); 53395b7a1d40SHuang Ying unmap_ref_private(mm, vma, old_page, haddr); 5340cb900f41SKirill A. Shutemov spin_lock(ptl); 53415b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5342a9af0c5dSNaoya Horiguchi if (likely(ptep && 5343a9af0c5dSNaoya Horiguchi pte_same(huge_ptep_get(ptep), pte))) 534404f2cbe3SMel Gorman goto retry_avoidcopy; 5345a734bcc8SHillf Danton /* 5346cb900f41SKirill A. Shutemov * race occurs while re-acquiring page table 5347cb900f41SKirill A. Shutemov * lock, and our job is done. 5348a734bcc8SHillf Danton */ 5349662ce1dcSYang Yang delayacct_wpcopy_end(); 5350a734bcc8SHillf Danton return 0; 535104f2cbe3SMel Gorman } 535204f2cbe3SMel Gorman 53532b740303SSouptick Joarder ret = vmf_error(PTR_ERR(new_page)); 5354ad4404a2SDavidlohr Bueso goto out_release_old; 53551e8f889bSDavid Gibson } 53561e8f889bSDavid Gibson 53570fe6e20bSNaoya Horiguchi /* 53580fe6e20bSNaoya Horiguchi * When the original hugepage is shared one, it does not have 53590fe6e20bSNaoya Horiguchi * anon_vma prepared. 53600fe6e20bSNaoya Horiguchi */ 536144e2aa93SDean Nelson if (unlikely(anon_vma_prepare(vma))) { 5362ad4404a2SDavidlohr Bueso ret = VM_FAULT_OOM; 5363ad4404a2SDavidlohr Bueso goto out_release_all; 536444e2aa93SDean Nelson } 53650fe6e20bSNaoya Horiguchi 5366974e6d66SHuang Ying copy_user_huge_page(new_page, old_page, address, vma, 536747ad8475SAndrea Arcangeli pages_per_huge_page(h)); 53680ed361deSNick Piggin __SetPageUptodate(new_page); 53691e8f889bSDavid Gibson 53707269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr, 53716f4f13e8SJérôme Glisse haddr + huge_page_size(h)); 5372ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 5373ad4404a2SDavidlohr Bueso 5374b76c8cfbSLarry Woodman /* 5375cb900f41SKirill A. Shutemov * Retake the page table lock to check for racing updates 5376b76c8cfbSLarry Woodman * before the page tables are altered 5377b76c8cfbSLarry Woodman */ 5378cb900f41SKirill A. Shutemov spin_lock(ptl); 53795b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5380a9af0c5dSNaoya Horiguchi if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { 5381d6995da3SMike Kravetz ClearHPageRestoreReserve(new_page); 538207443a85SJoonsoo Kim 5383c89357e2SDavid Hildenbrand /* Break COW or unshare */ 53845b7a1d40SHuang Ying huge_ptep_clear_flush(vma, haddr, ptep); 5385ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range(mm, range.start, range.end); 5386cea86fe2SHugh Dickins page_remove_rmap(old_page, vma, true); 53875b7a1d40SHuang Ying hugepage_add_new_anon_rmap(new_page, vma, haddr); 53881eba86c0SPasha Tatashin set_huge_pte_at(mm, haddr, ptep, 5389c89357e2SDavid Hildenbrand make_huge_pte(vma, new_page, !unshare)); 53908f251a3dSMike Kravetz SetHPageMigratable(new_page); 53911e8f889bSDavid Gibson /* Make the old page be freed below */ 53921e8f889bSDavid Gibson new_page = old_page; 53931e8f889bSDavid Gibson } 5394cb900f41SKirill A. Shutemov spin_unlock(ptl); 5395ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 5396ad4404a2SDavidlohr Bueso out_release_all: 5397c89357e2SDavid Hildenbrand /* 5398c89357e2SDavid Hildenbrand * No restore in case of successful pagetable update (Break COW or 5399c89357e2SDavid Hildenbrand * unshare) 5400c89357e2SDavid Hildenbrand */ 5401c7b1850dSMike Kravetz if (new_page != old_page) 54025b7a1d40SHuang Ying restore_reserve_on_error(h, vma, haddr, new_page); 540309cbfeafSKirill A. Shutemov put_page(new_page); 5404ad4404a2SDavidlohr Bueso out_release_old: 540509cbfeafSKirill A. Shutemov put_page(old_page); 54068312034fSJoonsoo Kim 5407ad4404a2SDavidlohr Bueso spin_lock(ptl); /* Caller expects lock to be held */ 5408662ce1dcSYang Yang 5409662ce1dcSYang Yang delayacct_wpcopy_end(); 5410ad4404a2SDavidlohr Bueso return ret; 54111e8f889bSDavid Gibson } 54121e8f889bSDavid Gibson 54133ae77f43SHugh Dickins /* 54143ae77f43SHugh Dickins * Return whether there is a pagecache page to back given address within VMA. 54153ae77f43SHugh Dickins * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. 54163ae77f43SHugh Dickins */ 54173ae77f43SHugh Dickins static bool hugetlbfs_pagecache_present(struct hstate *h, 54182a15efc9SHugh Dickins struct vm_area_struct *vma, unsigned long address) 54192a15efc9SHugh Dickins { 54202a15efc9SHugh Dickins struct address_space *mapping; 54212a15efc9SHugh Dickins pgoff_t idx; 54222a15efc9SHugh Dickins struct page *page; 54232a15efc9SHugh Dickins 54242a15efc9SHugh Dickins mapping = vma->vm_file->f_mapping; 54252a15efc9SHugh Dickins idx = vma_hugecache_offset(h, vma, address); 54262a15efc9SHugh Dickins 54272a15efc9SHugh Dickins page = find_get_page(mapping, idx); 54282a15efc9SHugh Dickins if (page) 54292a15efc9SHugh Dickins put_page(page); 54302a15efc9SHugh Dickins return page != NULL; 54312a15efc9SHugh Dickins } 54322a15efc9SHugh Dickins 5433ab76ad54SMike Kravetz int huge_add_to_page_cache(struct page *page, struct address_space *mapping, 5434ab76ad54SMike Kravetz pgoff_t idx) 5435ab76ad54SMike Kravetz { 5436d9ef44deSMatthew Wilcox (Oracle) struct folio *folio = page_folio(page); 5437ab76ad54SMike Kravetz struct inode *inode = mapping->host; 5438ab76ad54SMike Kravetz struct hstate *h = hstate_inode(inode); 5439d9ef44deSMatthew Wilcox (Oracle) int err; 5440ab76ad54SMike Kravetz 5441d9ef44deSMatthew Wilcox (Oracle) __folio_set_locked(folio); 5442d9ef44deSMatthew Wilcox (Oracle) err = __filemap_add_folio(mapping, folio, idx, GFP_KERNEL, NULL); 5443d9ef44deSMatthew Wilcox (Oracle) 5444d9ef44deSMatthew Wilcox (Oracle) if (unlikely(err)) { 5445d9ef44deSMatthew Wilcox (Oracle) __folio_clear_locked(folio); 5446ab76ad54SMike Kravetz return err; 5447d9ef44deSMatthew Wilcox (Oracle) } 5448d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 5449ab76ad54SMike Kravetz 545022146c3cSMike Kravetz /* 5451d9ef44deSMatthew Wilcox (Oracle) * mark folio dirty so that it will not be removed from cache/file 545222146c3cSMike Kravetz * by non-hugetlbfs specific code paths. 545322146c3cSMike Kravetz */ 5454d9ef44deSMatthew Wilcox (Oracle) folio_mark_dirty(folio); 545522146c3cSMike Kravetz 5456ab76ad54SMike Kravetz spin_lock(&inode->i_lock); 5457ab76ad54SMike Kravetz inode->i_blocks += blocks_per_huge_page(h); 5458ab76ad54SMike Kravetz spin_unlock(&inode->i_lock); 5459ab76ad54SMike Kravetz return 0; 5460ab76ad54SMike Kravetz } 5461ab76ad54SMike Kravetz 54627677f7fdSAxel Rasmussen static inline vm_fault_t hugetlb_handle_userfault(struct vm_area_struct *vma, 54637677f7fdSAxel Rasmussen struct address_space *mapping, 54647677f7fdSAxel Rasmussen pgoff_t idx, 54657677f7fdSAxel Rasmussen unsigned int flags, 54667677f7fdSAxel Rasmussen unsigned long haddr, 5467824ddc60SNadav Amit unsigned long addr, 54687677f7fdSAxel Rasmussen unsigned long reason) 54697677f7fdSAxel Rasmussen { 54707677f7fdSAxel Rasmussen vm_fault_t ret; 54717677f7fdSAxel Rasmussen u32 hash; 54727677f7fdSAxel Rasmussen struct vm_fault vmf = { 54737677f7fdSAxel Rasmussen .vma = vma, 54747677f7fdSAxel Rasmussen .address = haddr, 5475824ddc60SNadav Amit .real_address = addr, 54767677f7fdSAxel Rasmussen .flags = flags, 54777677f7fdSAxel Rasmussen 54787677f7fdSAxel Rasmussen /* 54797677f7fdSAxel Rasmussen * Hard to debug if it ends up being 54807677f7fdSAxel Rasmussen * used by a callee that assumes 54817677f7fdSAxel Rasmussen * something about the other 54827677f7fdSAxel Rasmussen * uninitialized fields... same as in 54837677f7fdSAxel Rasmussen * memory.c 54847677f7fdSAxel Rasmussen */ 54857677f7fdSAxel Rasmussen }; 54867677f7fdSAxel Rasmussen 54877677f7fdSAxel Rasmussen /* 54887677f7fdSAxel Rasmussen * hugetlb_fault_mutex and i_mmap_rwsem must be 54897677f7fdSAxel Rasmussen * dropped before handling userfault. Reacquire 54907677f7fdSAxel Rasmussen * after handling fault to make calling code simpler. 54917677f7fdSAxel Rasmussen */ 54927677f7fdSAxel Rasmussen hash = hugetlb_fault_mutex_hash(mapping, idx); 54937677f7fdSAxel Rasmussen mutex_unlock(&hugetlb_fault_mutex_table[hash]); 54947677f7fdSAxel Rasmussen ret = handle_userfault(&vmf, reason); 54957677f7fdSAxel Rasmussen mutex_lock(&hugetlb_fault_mutex_table[hash]); 54967677f7fdSAxel Rasmussen 54977677f7fdSAxel Rasmussen return ret; 54987677f7fdSAxel Rasmussen } 54997677f7fdSAxel Rasmussen 55002b740303SSouptick Joarder static vm_fault_t hugetlb_no_page(struct mm_struct *mm, 55012b740303SSouptick Joarder struct vm_area_struct *vma, 55028382d914SDavidlohr Bueso struct address_space *mapping, pgoff_t idx, 5503c64e912cSPeter Xu unsigned long address, pte_t *ptep, 5504c64e912cSPeter Xu pte_t old_pte, unsigned int flags) 5505ac9b9c66SHugh Dickins { 5506a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 55072b740303SSouptick Joarder vm_fault_t ret = VM_FAULT_SIGBUS; 5508409eb8c2SHillf Danton int anon_rmap = 0; 55094c887265SAdam Litke unsigned long size; 55104c887265SAdam Litke struct page *page; 55111e8f889bSDavid Gibson pte_t new_pte; 5512cb900f41SKirill A. Shutemov spinlock_t *ptl; 5513285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 5514c7b1850dSMike Kravetz bool new_page, new_pagecache_page = false; 55154c887265SAdam Litke 551604f2cbe3SMel Gorman /* 551704f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 551804f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 5519c89357e2SDavid Hildenbrand * COW/unsharing. Warn that such a situation has occurred as it may not 5520c89357e2SDavid Hildenbrand * be obvious. 552104f2cbe3SMel Gorman */ 552204f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 5523910154d5SGeoffrey Thomas pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n", 552404f2cbe3SMel Gorman current->pid); 552504f2cbe3SMel Gorman return ret; 552604f2cbe3SMel Gorman } 552704f2cbe3SMel Gorman 55284c887265SAdam Litke /* 5529188a3972SMike Kravetz * Use page lock to guard against racing truncation 5530188a3972SMike Kravetz * before we get page_table_lock. 55314c887265SAdam Litke */ 5532c7b1850dSMike Kravetz new_page = false; 553387bf91d3SMike Kravetz page = find_lock_page(mapping, idx); 553487bf91d3SMike Kravetz if (!page) { 5535188a3972SMike Kravetz size = i_size_read(mapping->host) >> huge_page_shift(h); 5536188a3972SMike Kravetz if (idx >= size) 5537188a3972SMike Kravetz goto out; 55387677f7fdSAxel Rasmussen /* Check for page in userfault range */ 55391a1aad8aSMike Kravetz if (userfaultfd_missing(vma)) { 55407677f7fdSAxel Rasmussen ret = hugetlb_handle_userfault(vma, mapping, idx, 5541824ddc60SNadav Amit flags, haddr, address, 55427677f7fdSAxel Rasmussen VM_UFFD_MISSING); 55431a1aad8aSMike Kravetz goto out; 55441a1aad8aSMike Kravetz } 55451a1aad8aSMike Kravetz 5546285b8dcaSHuang Ying page = alloc_huge_page(vma, haddr, 0); 55472fc39cecSAdam Litke if (IS_ERR(page)) { 55484643d67eSMike Kravetz /* 55494643d67eSMike Kravetz * Returning error will result in faulting task being 55504643d67eSMike Kravetz * sent SIGBUS. The hugetlb fault mutex prevents two 55514643d67eSMike Kravetz * tasks from racing to fault in the same page which 55524643d67eSMike Kravetz * could result in false unable to allocate errors. 55534643d67eSMike Kravetz * Page migration does not take the fault mutex, but 55544643d67eSMike Kravetz * does a clear then write of pte's under page table 55554643d67eSMike Kravetz * lock. Page fault code could race with migration, 55564643d67eSMike Kravetz * notice the clear pte and try to allocate a page 55574643d67eSMike Kravetz * here. Before returning error, get ptl and make 55584643d67eSMike Kravetz * sure there really is no pte entry. 55594643d67eSMike Kravetz */ 55604643d67eSMike Kravetz ptl = huge_pte_lock(h, mm, ptep); 55614643d67eSMike Kravetz ret = 0; 5562d83e6c8aSMiaohe Lin if (huge_pte_none(huge_ptep_get(ptep))) 55632b740303SSouptick Joarder ret = vmf_error(PTR_ERR(page)); 5564d83e6c8aSMiaohe Lin spin_unlock(ptl); 55656bda666aSChristoph Lameter goto out; 55666bda666aSChristoph Lameter } 556747ad8475SAndrea Arcangeli clear_huge_page(page, address, pages_per_huge_page(h)); 55680ed361deSNick Piggin __SetPageUptodate(page); 5569cb6acd01SMike Kravetz new_page = true; 5570ac9b9c66SHugh Dickins 5571f83a275dSMel Gorman if (vma->vm_flags & VM_MAYSHARE) { 5572ab76ad54SMike Kravetz int err = huge_add_to_page_cache(page, mapping, idx); 55736bda666aSChristoph Lameter if (err) { 55743a5497a2SMiaohe Lin /* 55753a5497a2SMiaohe Lin * err can't be -EEXIST which implies someone 55763a5497a2SMiaohe Lin * else consumed the reservation since hugetlb 55773a5497a2SMiaohe Lin * fault mutex is held when add a hugetlb page 55783a5497a2SMiaohe Lin * to the page cache. So it's safe to call 55793a5497a2SMiaohe Lin * restore_reserve_on_error() here. 55803a5497a2SMiaohe Lin */ 55813a5497a2SMiaohe Lin restore_reserve_on_error(h, vma, haddr, page); 55826bda666aSChristoph Lameter put_page(page); 55836bda666aSChristoph Lameter goto out; 55846bda666aSChristoph Lameter } 5585c7b1850dSMike Kravetz new_pagecache_page = true; 558623be7468SMel Gorman } else { 55876bda666aSChristoph Lameter lock_page(page); 55880fe6e20bSNaoya Horiguchi if (unlikely(anon_vma_prepare(vma))) { 55890fe6e20bSNaoya Horiguchi ret = VM_FAULT_OOM; 55900fe6e20bSNaoya Horiguchi goto backout_unlocked; 559123be7468SMel Gorman } 5592409eb8c2SHillf Danton anon_rmap = 1; 55930fe6e20bSNaoya Horiguchi } 55940fe6e20bSNaoya Horiguchi } else { 559557303d80SAndy Whitcroft /* 5596998b4382SNaoya Horiguchi * If memory error occurs between mmap() and fault, some process 5597998b4382SNaoya Horiguchi * don't have hwpoisoned swap entry for errored virtual address. 5598998b4382SNaoya Horiguchi * So we need to block hugepage fault by PG_hwpoison bit check. 5599fd6a03edSNaoya Horiguchi */ 5600fd6a03edSNaoya Horiguchi if (unlikely(PageHWPoison(page))) { 56010eb98f15SMiaohe Lin ret = VM_FAULT_HWPOISON_LARGE | 5602972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 5603fd6a03edSNaoya Horiguchi goto backout_unlocked; 56046bda666aSChristoph Lameter } 56057677f7fdSAxel Rasmussen 56067677f7fdSAxel Rasmussen /* Check for page in userfault range. */ 56077677f7fdSAxel Rasmussen if (userfaultfd_minor(vma)) { 56087677f7fdSAxel Rasmussen unlock_page(page); 56097677f7fdSAxel Rasmussen put_page(page); 56107677f7fdSAxel Rasmussen ret = hugetlb_handle_userfault(vma, mapping, idx, 5611824ddc60SNadav Amit flags, haddr, address, 56127677f7fdSAxel Rasmussen VM_UFFD_MINOR); 56137677f7fdSAxel Rasmussen goto out; 56147677f7fdSAxel Rasmussen } 5615998b4382SNaoya Horiguchi } 56161e8f889bSDavid Gibson 561757303d80SAndy Whitcroft /* 561857303d80SAndy Whitcroft * If we are going to COW a private mapping later, we examine the 561957303d80SAndy Whitcroft * pending reservations for this page now. This will ensure that 562057303d80SAndy Whitcroft * any allocations necessary to record that reservation occur outside 562157303d80SAndy Whitcroft * the spinlock. 562257303d80SAndy Whitcroft */ 56235e911373SMike Kravetz if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 5624285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 56252b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 56262b26736cSAndy Whitcroft goto backout_unlocked; 56272b26736cSAndy Whitcroft } 56285e911373SMike Kravetz /* Just decrements count, does not deallocate */ 5629285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 56305e911373SMike Kravetz } 563157303d80SAndy Whitcroft 56328bea8052SAneesh Kumar K.V ptl = huge_pte_lock(h, mm, ptep); 5633188a3972SMike Kravetz size = i_size_read(mapping->host) >> huge_page_shift(h); 5634188a3972SMike Kravetz if (idx >= size) 5635188a3972SMike Kravetz goto backout; 5636188a3972SMike Kravetz 563783c54070SNick Piggin ret = 0; 5638c64e912cSPeter Xu /* If pte changed from under us, retry */ 5639c64e912cSPeter Xu if (!pte_same(huge_ptep_get(ptep), old_pte)) 56404c887265SAdam Litke goto backout; 56414c887265SAdam Litke 564207443a85SJoonsoo Kim if (anon_rmap) { 5643d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 5644285b8dcaSHuang Ying hugepage_add_new_anon_rmap(page, vma, haddr); 5645ac714904SChoi Gi-yong } else 5646fb3d824dSDavid Hildenbrand page_dup_file_rmap(page, true); 56471e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 56481e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 5649c64e912cSPeter Xu /* 5650c64e912cSPeter Xu * If this pte was previously wr-protected, keep it wr-protected even 5651c64e912cSPeter Xu * if populated. 5652c64e912cSPeter Xu */ 5653c64e912cSPeter Xu if (unlikely(pte_marker_uffd_wp(old_pte))) 5654c64e912cSPeter Xu new_pte = huge_pte_wrprotect(huge_pte_mkuffd_wp(new_pte)); 5655285b8dcaSHuang Ying set_huge_pte_at(mm, haddr, ptep, new_pte); 56561e8f889bSDavid Gibson 56575d317b2bSNaoya Horiguchi hugetlb_count_add(pages_per_huge_page(h), mm); 5658788c7df4SHugh Dickins if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 56591e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 5660c89357e2SDavid Hildenbrand ret = hugetlb_wp(mm, vma, address, ptep, flags, page, ptl); 56611e8f889bSDavid Gibson } 56621e8f889bSDavid Gibson 5663cb900f41SKirill A. Shutemov spin_unlock(ptl); 5664cb6acd01SMike Kravetz 5665cb6acd01SMike Kravetz /* 56668f251a3dSMike Kravetz * Only set HPageMigratable in newly allocated pages. Existing pages 56678f251a3dSMike Kravetz * found in the pagecache may not have HPageMigratableset if they have 56688f251a3dSMike Kravetz * been isolated for migration. 5669cb6acd01SMike Kravetz */ 5670cb6acd01SMike Kravetz if (new_page) 56718f251a3dSMike Kravetz SetHPageMigratable(page); 5672cb6acd01SMike Kravetz 56734c887265SAdam Litke unlock_page(page); 56744c887265SAdam Litke out: 5675ac9b9c66SHugh Dickins return ret; 56764c887265SAdam Litke 56774c887265SAdam Litke backout: 5678cb900f41SKirill A. Shutemov spin_unlock(ptl); 56792b26736cSAndy Whitcroft backout_unlocked: 56804c887265SAdam Litke unlock_page(page); 5681c7b1850dSMike Kravetz /* restore reserve for newly allocated pages not in page cache */ 5682c7b1850dSMike Kravetz if (new_page && !new_pagecache_page) 5683285b8dcaSHuang Ying restore_reserve_on_error(h, vma, haddr, page); 56844c887265SAdam Litke put_page(page); 56854c887265SAdam Litke goto out; 5686ac9b9c66SHugh Dickins } 5687ac9b9c66SHugh Dickins 56888382d914SDavidlohr Bueso #ifdef CONFIG_SMP 5689188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 56908382d914SDavidlohr Bueso { 56918382d914SDavidlohr Bueso unsigned long key[2]; 56928382d914SDavidlohr Bueso u32 hash; 56938382d914SDavidlohr Bueso 56948382d914SDavidlohr Bueso key[0] = (unsigned long) mapping; 56958382d914SDavidlohr Bueso key[1] = idx; 56968382d914SDavidlohr Bueso 569755254636SMike Kravetz hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0); 56988382d914SDavidlohr Bueso 56998382d914SDavidlohr Bueso return hash & (num_fault_mutexes - 1); 57008382d914SDavidlohr Bueso } 57018382d914SDavidlohr Bueso #else 57028382d914SDavidlohr Bueso /* 57036c26d310SMiaohe Lin * For uniprocessor systems we always use a single mutex, so just 57048382d914SDavidlohr Bueso * return 0 and avoid the hashing overhead. 57058382d914SDavidlohr Bueso */ 5706188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 57078382d914SDavidlohr Bueso { 57088382d914SDavidlohr Bueso return 0; 57098382d914SDavidlohr Bueso } 57108382d914SDavidlohr Bueso #endif 57118382d914SDavidlohr Bueso 57122b740303SSouptick Joarder vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 5713788c7df4SHugh Dickins unsigned long address, unsigned int flags) 571486e5216fSAdam Litke { 57158382d914SDavidlohr Bueso pte_t *ptep, entry; 5716cb900f41SKirill A. Shutemov spinlock_t *ptl; 57172b740303SSouptick Joarder vm_fault_t ret; 57188382d914SDavidlohr Bueso u32 hash; 57198382d914SDavidlohr Bueso pgoff_t idx; 57200fe6e20bSNaoya Horiguchi struct page *page = NULL; 572157303d80SAndy Whitcroft struct page *pagecache_page = NULL; 5722a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 57238382d914SDavidlohr Bueso struct address_space *mapping; 57240f792cf9SNaoya Horiguchi int need_wait_lock = 0; 5725285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 572686e5216fSAdam Litke 5727285b8dcaSHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5728fd6a03edSNaoya Horiguchi if (ptep) { 5729fd6a03edSNaoya Horiguchi entry = huge_ptep_get(ptep); 5730290408d4SNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(entry))) { 5731ad1ac596SMiaohe Lin migration_entry_wait_huge(vma, ptep); 5732290408d4SNaoya Horiguchi return 0; 5733290408d4SNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) 5734aa50d3a7SAndi Kleen return VM_FAULT_HWPOISON_LARGE | 5735972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 5736*3a47c54fSMike Kravetz } else { 5737aec44e0fSPeter Xu ptep = huge_pte_alloc(mm, vma, haddr, huge_page_size(h)); 5738*3a47c54fSMike Kravetz if (!ptep) 5739c0d0381aSMike Kravetz return VM_FAULT_OOM; 5740c0d0381aSMike Kravetz } 5741ddeaab32SMike Kravetz 5742*3a47c54fSMike Kravetz mapping = vma->vm_file->f_mapping; 5743*3a47c54fSMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 5744*3a47c54fSMike Kravetz 57453935baa9SDavid Gibson /* 57463935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 57473935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 57483935baa9SDavid Gibson * the same page in the page cache. 57493935baa9SDavid Gibson */ 5750188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 5751c672c7f2SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 57528382d914SDavidlohr Bueso 57537f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 5754c64e912cSPeter Xu /* PTE markers should be handled the same way as none pte */ 5755c64e912cSPeter Xu if (huge_pte_none_mostly(entry)) { 5756c64e912cSPeter Xu ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, 5757c64e912cSPeter Xu entry, flags); 5758b4d1d99fSDavid Gibson goto out_mutex; 57593935baa9SDavid Gibson } 576086e5216fSAdam Litke 576183c54070SNick Piggin ret = 0; 57621e8f889bSDavid Gibson 576357303d80SAndy Whitcroft /* 57640f792cf9SNaoya Horiguchi * entry could be a migration/hwpoison entry at this point, so this 57650f792cf9SNaoya Horiguchi * check prevents the kernel from going below assuming that we have 57667c8de358SEthon Paul * an active hugepage in pagecache. This goto expects the 2nd page 57677c8de358SEthon Paul * fault, and is_hugetlb_entry_(migration|hwpoisoned) check will 57687c8de358SEthon Paul * properly handle it. 57690f792cf9SNaoya Horiguchi */ 57700f792cf9SNaoya Horiguchi if (!pte_present(entry)) 57710f792cf9SNaoya Horiguchi goto out_mutex; 57720f792cf9SNaoya Horiguchi 57730f792cf9SNaoya Horiguchi /* 5774c89357e2SDavid Hildenbrand * If we are going to COW/unshare the mapping later, we examine the 5775c89357e2SDavid Hildenbrand * pending reservations for this page now. This will ensure that any 577657303d80SAndy Whitcroft * allocations necessary to record that reservation occur outside the 57771d8d1464SDavid Hildenbrand * spinlock. Also lookup the pagecache page now as it is used to 57781d8d1464SDavid Hildenbrand * determine if a reservation has been consumed. 577957303d80SAndy Whitcroft */ 5780c89357e2SDavid Hildenbrand if ((flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) && 57811d8d1464SDavid Hildenbrand !(vma->vm_flags & VM_MAYSHARE) && !huge_pte_write(entry)) { 5782285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 57832b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 5784b4d1d99fSDavid Gibson goto out_mutex; 57852b26736cSAndy Whitcroft } 57865e911373SMike Kravetz /* Just decrements count, does not deallocate */ 5787285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 578857303d80SAndy Whitcroft 578929be8426SMiaohe Lin pagecache_page = find_lock_page(mapping, idx); 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 return handle_userfault(&vmf, VM_UFFD_WP); 5815166f3eccSPeter Xu } 5816166f3eccSPeter Xu 58170f792cf9SNaoya Horiguchi /* 5818c89357e2SDavid Hildenbrand * hugetlb_wp() requires page locks of pte_page(entry) and 58190f792cf9SNaoya Horiguchi * pagecache_page, so here we need take the former one 58200f792cf9SNaoya Horiguchi * when page != pagecache_page or !pagecache_page. 58210f792cf9SNaoya Horiguchi */ 58220f792cf9SNaoya Horiguchi page = pte_page(entry); 58230f792cf9SNaoya Horiguchi if (page != pagecache_page) 58240f792cf9SNaoya Horiguchi if (!trylock_page(page)) { 58250f792cf9SNaoya Horiguchi need_wait_lock = 1; 58260f792cf9SNaoya Horiguchi goto out_ptl; 58270f792cf9SNaoya Horiguchi } 58280f792cf9SNaoya Horiguchi 58290f792cf9SNaoya Horiguchi get_page(page); 5830b4d1d99fSDavid Gibson 5831c89357e2SDavid Hildenbrand if (flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) { 5832106c992aSGerald Schaefer if (!huge_pte_write(entry)) { 5833c89357e2SDavid Hildenbrand ret = hugetlb_wp(mm, vma, address, ptep, flags, 5834cb900f41SKirill A. Shutemov pagecache_page, ptl); 58350f792cf9SNaoya Horiguchi goto out_put_page; 5836c89357e2SDavid Hildenbrand } else if (likely(flags & FAULT_FLAG_WRITE)) { 5837106c992aSGerald Schaefer entry = huge_pte_mkdirty(entry); 5838b4d1d99fSDavid Gibson } 5839c89357e2SDavid Hildenbrand } 5840b4d1d99fSDavid Gibson entry = pte_mkyoung(entry); 5841285b8dcaSHuang Ying if (huge_ptep_set_access_flags(vma, haddr, ptep, entry, 5842788c7df4SHugh Dickins flags & FAULT_FLAG_WRITE)) 5843285b8dcaSHuang Ying update_mmu_cache(vma, haddr, ptep); 58440f792cf9SNaoya Horiguchi out_put_page: 58450f792cf9SNaoya Horiguchi if (page != pagecache_page) 58460f792cf9SNaoya Horiguchi unlock_page(page); 58470f792cf9SNaoya Horiguchi put_page(page); 5848cb900f41SKirill A. Shutemov out_ptl: 5849cb900f41SKirill A. Shutemov spin_unlock(ptl); 585057303d80SAndy Whitcroft 585157303d80SAndy Whitcroft if (pagecache_page) { 585257303d80SAndy Whitcroft unlock_page(pagecache_page); 585357303d80SAndy Whitcroft put_page(pagecache_page); 585457303d80SAndy Whitcroft } 5855b4d1d99fSDavid Gibson out_mutex: 5856c672c7f2SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 58570f792cf9SNaoya Horiguchi /* 58580f792cf9SNaoya Horiguchi * Generally it's safe to hold refcount during waiting page lock. But 58590f792cf9SNaoya Horiguchi * here we just wait to defer the next page fault to avoid busy loop and 58600f792cf9SNaoya Horiguchi * the page is not used after unlocked before returning from the current 58610f792cf9SNaoya Horiguchi * page fault. So we are safe from accessing freed page, even if we wait 58620f792cf9SNaoya Horiguchi * here without taking refcount. 58630f792cf9SNaoya Horiguchi */ 58640f792cf9SNaoya Horiguchi if (need_wait_lock) 58650f792cf9SNaoya Horiguchi wait_on_page_locked(page); 58661e8f889bSDavid Gibson return ret; 586786e5216fSAdam Litke } 586886e5216fSAdam Litke 5869714c1891SAxel Rasmussen #ifdef CONFIG_USERFAULTFD 58708fb5debcSMike Kravetz /* 58718fb5debcSMike Kravetz * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with 58728fb5debcSMike Kravetz * modifications for huge pages. 58738fb5debcSMike Kravetz */ 58748fb5debcSMike Kravetz int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, 58758fb5debcSMike Kravetz pte_t *dst_pte, 58768fb5debcSMike Kravetz struct vm_area_struct *dst_vma, 58778fb5debcSMike Kravetz unsigned long dst_addr, 58788fb5debcSMike Kravetz unsigned long src_addr, 5879f6191471SAxel Rasmussen enum mcopy_atomic_mode mode, 58806041c691SPeter Xu struct page **pagep, 58816041c691SPeter Xu bool wp_copy) 58828fb5debcSMike Kravetz { 5883f6191471SAxel Rasmussen bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE); 58848cc5fcbbSMina Almasry struct hstate *h = hstate_vma(dst_vma); 58858cc5fcbbSMina Almasry struct address_space *mapping = dst_vma->vm_file->f_mapping; 58868cc5fcbbSMina Almasry pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr); 58871e392147SAndrea Arcangeli unsigned long size; 58881c9e8defSMike Kravetz int vm_shared = dst_vma->vm_flags & VM_SHARED; 58898fb5debcSMike Kravetz pte_t _dst_pte; 58908fb5debcSMike Kravetz spinlock_t *ptl; 58918cc5fcbbSMina Almasry int ret = -ENOMEM; 58928fb5debcSMike Kravetz struct page *page; 5893f6191471SAxel Rasmussen int writable; 5894cc30042dSMina Almasry bool page_in_pagecache = false; 58958fb5debcSMike Kravetz 5896f6191471SAxel Rasmussen if (is_continue) { 5897f6191471SAxel Rasmussen ret = -EFAULT; 5898f6191471SAxel Rasmussen page = find_lock_page(mapping, idx); 5899f6191471SAxel Rasmussen if (!page) 5900f6191471SAxel Rasmussen goto out; 5901cc30042dSMina Almasry page_in_pagecache = true; 5902f6191471SAxel Rasmussen } else if (!*pagep) { 5903d84cf06eSMina Almasry /* If a page already exists, then it's UFFDIO_COPY for 5904d84cf06eSMina Almasry * a non-missing case. Return -EEXIST. 5905d84cf06eSMina Almasry */ 5906d84cf06eSMina Almasry if (vm_shared && 5907d84cf06eSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 5908d84cf06eSMina Almasry ret = -EEXIST; 59098fb5debcSMike Kravetz goto out; 5910d84cf06eSMina Almasry } 5911d84cf06eSMina Almasry 5912d84cf06eSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 5913d84cf06eSMina Almasry if (IS_ERR(page)) { 5914d84cf06eSMina Almasry ret = -ENOMEM; 5915d84cf06eSMina Almasry goto out; 5916d84cf06eSMina Almasry } 59178fb5debcSMike Kravetz 59188fb5debcSMike Kravetz ret = copy_huge_page_from_user(page, 59198fb5debcSMike Kravetz (const void __user *) src_addr, 5920810a56b9SMike Kravetz pages_per_huge_page(h), false); 59218fb5debcSMike Kravetz 5922c1e8d7c6SMichel Lespinasse /* fallback to copy_from_user outside mmap_lock */ 59238fb5debcSMike Kravetz if (unlikely(ret)) { 59249e368259SAndrea Arcangeli ret = -ENOENT; 59258cc5fcbbSMina Almasry /* Free the allocated page which may have 59268cc5fcbbSMina Almasry * consumed a reservation. 59278cc5fcbbSMina Almasry */ 59288cc5fcbbSMina Almasry restore_reserve_on_error(h, dst_vma, dst_addr, page); 59298cc5fcbbSMina Almasry put_page(page); 59308cc5fcbbSMina Almasry 59318cc5fcbbSMina Almasry /* Allocate a temporary page to hold the copied 59328cc5fcbbSMina Almasry * contents. 59338cc5fcbbSMina Almasry */ 59348cc5fcbbSMina Almasry page = alloc_huge_page_vma(h, dst_vma, dst_addr); 59358cc5fcbbSMina Almasry if (!page) { 59368cc5fcbbSMina Almasry ret = -ENOMEM; 59378cc5fcbbSMina Almasry goto out; 59388cc5fcbbSMina Almasry } 59398fb5debcSMike Kravetz *pagep = page; 59408cc5fcbbSMina Almasry /* Set the outparam pagep and return to the caller to 59418cc5fcbbSMina Almasry * copy the contents outside the lock. Don't free the 59428cc5fcbbSMina Almasry * page. 59438cc5fcbbSMina Almasry */ 59448fb5debcSMike Kravetz goto out; 59458fb5debcSMike Kravetz } 59468fb5debcSMike Kravetz } else { 59478cc5fcbbSMina Almasry if (vm_shared && 59488cc5fcbbSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 59498cc5fcbbSMina Almasry put_page(*pagep); 59508cc5fcbbSMina Almasry ret = -EEXIST; 59518cc5fcbbSMina Almasry *pagep = NULL; 59528cc5fcbbSMina Almasry goto out; 59538cc5fcbbSMina Almasry } 59548cc5fcbbSMina Almasry 59558cc5fcbbSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 59568cc5fcbbSMina Almasry if (IS_ERR(page)) { 5957da9a298fSMiaohe Lin put_page(*pagep); 59588cc5fcbbSMina Almasry ret = -ENOMEM; 59598cc5fcbbSMina Almasry *pagep = NULL; 59608cc5fcbbSMina Almasry goto out; 59618cc5fcbbSMina Almasry } 596234892366SMuchun Song copy_user_huge_page(page, *pagep, dst_addr, dst_vma, 596334892366SMuchun Song pages_per_huge_page(h)); 59648cc5fcbbSMina Almasry put_page(*pagep); 59658fb5debcSMike Kravetz *pagep = NULL; 59668fb5debcSMike Kravetz } 59678fb5debcSMike Kravetz 59688fb5debcSMike Kravetz /* 59698fb5debcSMike Kravetz * The memory barrier inside __SetPageUptodate makes sure that 59708fb5debcSMike Kravetz * preceding stores to the page contents become visible before 59718fb5debcSMike Kravetz * the set_pte_at() write. 59728fb5debcSMike Kravetz */ 59738fb5debcSMike Kravetz __SetPageUptodate(page); 59748fb5debcSMike Kravetz 5975f6191471SAxel Rasmussen /* Add shared, newly allocated pages to the page cache. */ 5976f6191471SAxel Rasmussen if (vm_shared && !is_continue) { 59771e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 59781e392147SAndrea Arcangeli ret = -EFAULT; 59791e392147SAndrea Arcangeli if (idx >= size) 59801e392147SAndrea Arcangeli goto out_release_nounlock; 59811c9e8defSMike Kravetz 59821e392147SAndrea Arcangeli /* 59831e392147SAndrea Arcangeli * Serialization between remove_inode_hugepages() and 59841e392147SAndrea Arcangeli * huge_add_to_page_cache() below happens through the 59851e392147SAndrea Arcangeli * hugetlb_fault_mutex_table that here must be hold by 59861e392147SAndrea Arcangeli * the caller. 59871e392147SAndrea Arcangeli */ 59881c9e8defSMike Kravetz ret = huge_add_to_page_cache(page, mapping, idx); 59891c9e8defSMike Kravetz if (ret) 59901c9e8defSMike Kravetz goto out_release_nounlock; 5991cc30042dSMina Almasry page_in_pagecache = true; 59921c9e8defSMike Kravetz } 59931c9e8defSMike Kravetz 5994bcc66543SMiaohe Lin ptl = huge_pte_lock(h, dst_mm, dst_pte); 59958fb5debcSMike Kravetz 59961e392147SAndrea Arcangeli /* 59971e392147SAndrea Arcangeli * Recheck the i_size after holding PT lock to make sure not 59981e392147SAndrea Arcangeli * to leave any page mapped (as page_mapped()) beyond the end 59991e392147SAndrea Arcangeli * of the i_size (remove_inode_hugepages() is strict about 60001e392147SAndrea Arcangeli * enforcing that). If we bail out here, we'll also leave a 60011e392147SAndrea Arcangeli * page in the radix tree in the vm_shared case beyond the end 60021e392147SAndrea Arcangeli * of the i_size, but remove_inode_hugepages() will take care 60031e392147SAndrea Arcangeli * of it as soon as we drop the hugetlb_fault_mutex_table. 60041e392147SAndrea Arcangeli */ 60051e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 60061e392147SAndrea Arcangeli ret = -EFAULT; 60071e392147SAndrea Arcangeli if (idx >= size) 60081e392147SAndrea Arcangeli goto out_release_unlock; 60091e392147SAndrea Arcangeli 60108fb5debcSMike Kravetz ret = -EEXIST; 60116041c691SPeter Xu /* 60126041c691SPeter Xu * We allow to overwrite a pte marker: consider when both MISSING|WP 60136041c691SPeter Xu * registered, we firstly wr-protect a none pte which has no page cache 60146041c691SPeter Xu * page backing it, then access the page. 60156041c691SPeter Xu */ 60166041c691SPeter Xu if (!huge_pte_none_mostly(huge_ptep_get(dst_pte))) 60178fb5debcSMike Kravetz goto out_release_unlock; 60188fb5debcSMike Kravetz 6019ab74ef70SMiaohe Lin if (page_in_pagecache) { 6020fb3d824dSDavid Hildenbrand page_dup_file_rmap(page, true); 60211c9e8defSMike Kravetz } else { 6022d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 60238fb5debcSMike Kravetz hugepage_add_new_anon_rmap(page, dst_vma, dst_addr); 60241c9e8defSMike Kravetz } 60258fb5debcSMike Kravetz 60266041c691SPeter Xu /* 60276041c691SPeter Xu * For either: (1) CONTINUE on a non-shared VMA, or (2) UFFDIO_COPY 60286041c691SPeter Xu * with wp flag set, don't set pte write bit. 60296041c691SPeter Xu */ 60306041c691SPeter Xu if (wp_copy || (is_continue && !vm_shared)) 6031f6191471SAxel Rasmussen writable = 0; 6032f6191471SAxel Rasmussen else 6033f6191471SAxel Rasmussen writable = dst_vma->vm_flags & VM_WRITE; 6034f6191471SAxel Rasmussen 6035f6191471SAxel Rasmussen _dst_pte = make_huge_pte(dst_vma, page, writable); 60366041c691SPeter Xu /* 60376041c691SPeter Xu * Always mark UFFDIO_COPY page dirty; note that this may not be 60386041c691SPeter Xu * extremely important for hugetlbfs for now since swapping is not 60396041c691SPeter Xu * supported, but we should still be clear in that this page cannot be 60406041c691SPeter Xu * thrown away at will, even if write bit not set. 60416041c691SPeter Xu */ 60428fb5debcSMike Kravetz _dst_pte = huge_pte_mkdirty(_dst_pte); 60438fb5debcSMike Kravetz _dst_pte = pte_mkyoung(_dst_pte); 60448fb5debcSMike Kravetz 60456041c691SPeter Xu if (wp_copy) 60466041c691SPeter Xu _dst_pte = huge_pte_mkuffd_wp(_dst_pte); 60476041c691SPeter Xu 60488fb5debcSMike Kravetz set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); 60498fb5debcSMike Kravetz 60508fb5debcSMike Kravetz hugetlb_count_add(pages_per_huge_page(h), dst_mm); 60518fb5debcSMike Kravetz 60528fb5debcSMike Kravetz /* No need to invalidate - it was non-present before */ 60538fb5debcSMike Kravetz update_mmu_cache(dst_vma, dst_addr, dst_pte); 60548fb5debcSMike Kravetz 60558fb5debcSMike Kravetz spin_unlock(ptl); 6056f6191471SAxel Rasmussen if (!is_continue) 60578f251a3dSMike Kravetz SetHPageMigratable(page); 6058f6191471SAxel Rasmussen if (vm_shared || is_continue) 60591c9e8defSMike Kravetz unlock_page(page); 60608fb5debcSMike Kravetz ret = 0; 60618fb5debcSMike Kravetz out: 60628fb5debcSMike Kravetz return ret; 60638fb5debcSMike Kravetz out_release_unlock: 60648fb5debcSMike Kravetz spin_unlock(ptl); 6065f6191471SAxel Rasmussen if (vm_shared || is_continue) 60661c9e8defSMike Kravetz unlock_page(page); 60675af10dfdSAndrea Arcangeli out_release_nounlock: 6068cc30042dSMina Almasry if (!page_in_pagecache) 6069846be085SMike Kravetz restore_reserve_on_error(h, dst_vma, dst_addr, page); 60708fb5debcSMike Kravetz put_page(page); 60718fb5debcSMike Kravetz goto out; 60728fb5debcSMike Kravetz } 6073714c1891SAxel Rasmussen #endif /* CONFIG_USERFAULTFD */ 60748fb5debcSMike Kravetz 607582e5d378SJoao Martins static void record_subpages_vmas(struct page *page, struct vm_area_struct *vma, 607682e5d378SJoao Martins int refs, struct page **pages, 607782e5d378SJoao Martins struct vm_area_struct **vmas) 607882e5d378SJoao Martins { 607982e5d378SJoao Martins int nr; 608082e5d378SJoao Martins 608182e5d378SJoao Martins for (nr = 0; nr < refs; nr++) { 608282e5d378SJoao Martins if (likely(pages)) 608314455eabSCheng Li pages[nr] = nth_page(page, nr); 608482e5d378SJoao Martins if (vmas) 608582e5d378SJoao Martins vmas[nr] = vma; 608682e5d378SJoao Martins } 608782e5d378SJoao Martins } 608882e5d378SJoao Martins 6089a7f22660SDavid Hildenbrand static inline bool __follow_hugetlb_must_fault(unsigned int flags, pte_t *pte, 6090a7f22660SDavid Hildenbrand bool *unshare) 6091a7f22660SDavid Hildenbrand { 6092a7f22660SDavid Hildenbrand pte_t pteval = huge_ptep_get(pte); 6093a7f22660SDavid Hildenbrand 6094a7f22660SDavid Hildenbrand *unshare = false; 6095a7f22660SDavid Hildenbrand if (is_swap_pte(pteval)) 6096a7f22660SDavid Hildenbrand return true; 6097a7f22660SDavid Hildenbrand if (huge_pte_write(pteval)) 6098a7f22660SDavid Hildenbrand return false; 6099a7f22660SDavid Hildenbrand if (flags & FOLL_WRITE) 6100a7f22660SDavid Hildenbrand return true; 6101a7f22660SDavid Hildenbrand if (gup_must_unshare(flags, pte_page(pteval))) { 6102a7f22660SDavid Hildenbrand *unshare = true; 6103a7f22660SDavid Hildenbrand return true; 6104a7f22660SDavid Hildenbrand } 6105a7f22660SDavid Hildenbrand return false; 6106a7f22660SDavid Hildenbrand } 6107a7f22660SDavid Hildenbrand 610828a35716SMichel Lespinasse long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 610963551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 611028a35716SMichel Lespinasse unsigned long *position, unsigned long *nr_pages, 61114f6da934SPeter Xu long i, unsigned int flags, int *locked) 611263551ae0SDavid Gibson { 6113d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 6114d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 611528a35716SMichel Lespinasse unsigned long remainder = *nr_pages; 6116a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 61170fa5bc40SJoao Martins int err = -EFAULT, refs; 611863551ae0SDavid Gibson 611963551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 612063551ae0SDavid Gibson pte_t *pte; 6121cb900f41SKirill A. Shutemov spinlock_t *ptl = NULL; 6122a7f22660SDavid Hildenbrand bool unshare = false; 61232a15efc9SHugh Dickins int absent; 612463551ae0SDavid Gibson struct page *page; 612563551ae0SDavid Gibson 61264c887265SAdam Litke /* 612702057967SDavid Rientjes * If we have a pending SIGKILL, don't keep faulting pages and 612802057967SDavid Rientjes * potentially allocating memory. 612902057967SDavid Rientjes */ 6130fa45f116SDavidlohr Bueso if (fatal_signal_pending(current)) { 613102057967SDavid Rientjes remainder = 0; 613202057967SDavid Rientjes break; 613302057967SDavid Rientjes } 613402057967SDavid Rientjes 613502057967SDavid Rientjes /* 61364c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 61372a15efc9SHugh Dickins * each hugepage. We have to make sure we get the 61384c887265SAdam Litke * first, for the page indexing below to work. 6139cb900f41SKirill A. Shutemov * 6140cb900f41SKirill A. Shutemov * Note that page table lock is not held when pte is null. 61414c887265SAdam Litke */ 61427868a208SPunit Agrawal pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), 61437868a208SPunit Agrawal huge_page_size(h)); 6144cb900f41SKirill A. Shutemov if (pte) 6145cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, pte); 61462a15efc9SHugh Dickins absent = !pte || huge_pte_none(huge_ptep_get(pte)); 614763551ae0SDavid Gibson 61482a15efc9SHugh Dickins /* 61492a15efc9SHugh Dickins * When coredumping, it suits get_dump_page if we just return 61503ae77f43SHugh Dickins * an error where there's an empty slot with no huge pagecache 61513ae77f43SHugh Dickins * to back it. This way, we avoid allocating a hugepage, and 61523ae77f43SHugh Dickins * the sparse dumpfile avoids allocating disk blocks, but its 61533ae77f43SHugh Dickins * huge holes still show up with zeroes where they need to be. 61542a15efc9SHugh Dickins */ 61553ae77f43SHugh Dickins if (absent && (flags & FOLL_DUMP) && 61563ae77f43SHugh Dickins !hugetlbfs_pagecache_present(h, vma, vaddr)) { 6157cb900f41SKirill A. Shutemov if (pte) 6158cb900f41SKirill A. Shutemov spin_unlock(ptl); 61592a15efc9SHugh Dickins remainder = 0; 61602a15efc9SHugh Dickins break; 61612a15efc9SHugh Dickins } 61622a15efc9SHugh Dickins 61639cc3a5bdSNaoya Horiguchi /* 61649cc3a5bdSNaoya Horiguchi * We need call hugetlb_fault for both hugepages under migration 61659cc3a5bdSNaoya Horiguchi * (in which case hugetlb_fault waits for the migration,) and 61669cc3a5bdSNaoya Horiguchi * hwpoisoned hugepages (in which case we need to prevent the 61679cc3a5bdSNaoya Horiguchi * caller from accessing to them.) In order to do this, we use 61689cc3a5bdSNaoya Horiguchi * here is_swap_pte instead of is_hugetlb_entry_migration and 61699cc3a5bdSNaoya Horiguchi * is_hugetlb_entry_hwpoisoned. This is because it simply covers 61709cc3a5bdSNaoya Horiguchi * both cases, and because we can't follow correct pages 61719cc3a5bdSNaoya Horiguchi * directly from any kind of swap entries. 61729cc3a5bdSNaoya Horiguchi */ 6173a7f22660SDavid Hildenbrand if (absent || 6174a7f22660SDavid Hildenbrand __follow_hugetlb_must_fault(flags, pte, &unshare)) { 61752b740303SSouptick Joarder vm_fault_t ret; 617687ffc118SAndrea Arcangeli unsigned int fault_flags = 0; 61774c887265SAdam Litke 6178cb900f41SKirill A. Shutemov if (pte) 6179cb900f41SKirill A. Shutemov spin_unlock(ptl); 618087ffc118SAndrea Arcangeli if (flags & FOLL_WRITE) 618187ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_WRITE; 6182a7f22660SDavid Hildenbrand else if (unshare) 6183a7f22660SDavid Hildenbrand fault_flags |= FAULT_FLAG_UNSHARE; 61844f6da934SPeter Xu if (locked) 618571335f37SPeter Xu fault_flags |= FAULT_FLAG_ALLOW_RETRY | 618671335f37SPeter Xu FAULT_FLAG_KILLABLE; 618787ffc118SAndrea Arcangeli if (flags & FOLL_NOWAIT) 618887ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_ALLOW_RETRY | 618987ffc118SAndrea Arcangeli FAULT_FLAG_RETRY_NOWAIT; 619087ffc118SAndrea Arcangeli if (flags & FOLL_TRIED) { 61914426e945SPeter Xu /* 61924426e945SPeter Xu * Note: FAULT_FLAG_ALLOW_RETRY and 61934426e945SPeter Xu * FAULT_FLAG_TRIED can co-exist 61944426e945SPeter Xu */ 619587ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_TRIED; 619687ffc118SAndrea Arcangeli } 619787ffc118SAndrea Arcangeli ret = hugetlb_fault(mm, vma, vaddr, fault_flags); 619887ffc118SAndrea Arcangeli if (ret & VM_FAULT_ERROR) { 61992be7cfedSDaniel Jordan err = vm_fault_to_errno(ret, flags); 62001c59827dSHugh Dickins remainder = 0; 62011c59827dSHugh Dickins break; 62021c59827dSHugh Dickins } 620387ffc118SAndrea Arcangeli if (ret & VM_FAULT_RETRY) { 62044f6da934SPeter Xu if (locked && 62051ac25013SAndrea Arcangeli !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) 62064f6da934SPeter Xu *locked = 0; 620787ffc118SAndrea Arcangeli *nr_pages = 0; 620887ffc118SAndrea Arcangeli /* 620987ffc118SAndrea Arcangeli * VM_FAULT_RETRY must not return an 621087ffc118SAndrea Arcangeli * error, it will return zero 621187ffc118SAndrea Arcangeli * instead. 621287ffc118SAndrea Arcangeli * 621387ffc118SAndrea Arcangeli * No need to update "position" as the 621487ffc118SAndrea Arcangeli * caller will not check it after 621587ffc118SAndrea Arcangeli * *nr_pages is set to 0. 621687ffc118SAndrea Arcangeli */ 621787ffc118SAndrea Arcangeli return i; 621887ffc118SAndrea Arcangeli } 621987ffc118SAndrea Arcangeli continue; 622087ffc118SAndrea Arcangeli } 622163551ae0SDavid Gibson 6222a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 62237f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 62248fde12caSLinus Torvalds 6225b6a2619cSDavid Hildenbrand VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) && 6226b6a2619cSDavid Hildenbrand !PageAnonExclusive(page), page); 6227b6a2619cSDavid Hildenbrand 62288fde12caSLinus Torvalds /* 6229acbfb087SZhigang Lu * If subpage information not requested, update counters 6230acbfb087SZhigang Lu * and skip the same_page loop below. 6231acbfb087SZhigang Lu */ 6232acbfb087SZhigang Lu if (!pages && !vmas && !pfn_offset && 6233acbfb087SZhigang Lu (vaddr + huge_page_size(h) < vma->vm_end) && 6234acbfb087SZhigang Lu (remainder >= pages_per_huge_page(h))) { 6235acbfb087SZhigang Lu vaddr += huge_page_size(h); 6236acbfb087SZhigang Lu remainder -= pages_per_huge_page(h); 6237acbfb087SZhigang Lu i += pages_per_huge_page(h); 6238acbfb087SZhigang Lu spin_unlock(ptl); 6239acbfb087SZhigang Lu continue; 6240acbfb087SZhigang Lu } 6241acbfb087SZhigang Lu 6242d08af0a5SJoao Martins /* vaddr may not be aligned to PAGE_SIZE */ 6243d08af0a5SJoao Martins refs = min3(pages_per_huge_page(h) - pfn_offset, remainder, 6244d08af0a5SJoao Martins (vma->vm_end - ALIGN_DOWN(vaddr, PAGE_SIZE)) >> PAGE_SHIFT); 62450fa5bc40SJoao Martins 624682e5d378SJoao Martins if (pages || vmas) 624714455eabSCheng Li record_subpages_vmas(nth_page(page, pfn_offset), 624882e5d378SJoao Martins vma, refs, 624982e5d378SJoao Martins likely(pages) ? pages + i : NULL, 625082e5d378SJoao Martins vmas ? vmas + i : NULL); 625163551ae0SDavid Gibson 625282e5d378SJoao Martins if (pages) { 62530fa5bc40SJoao Martins /* 6254822951d8SMatthew Wilcox (Oracle) * try_grab_folio() should always succeed here, 62550fa5bc40SJoao Martins * because: a) we hold the ptl lock, and b) we've just 62560fa5bc40SJoao Martins * checked that the huge page is present in the page 62570fa5bc40SJoao Martins * tables. If the huge page is present, then the tail 62580fa5bc40SJoao Martins * pages must also be present. The ptl prevents the 62590fa5bc40SJoao Martins * head page and tail pages from being rearranged in 62600fa5bc40SJoao Martins * any way. So this page must be available at this 62610fa5bc40SJoao Martins * point, unless the page refcount overflowed: 62620fa5bc40SJoao Martins */ 6263822951d8SMatthew Wilcox (Oracle) if (WARN_ON_ONCE(!try_grab_folio(pages[i], refs, 62640fa5bc40SJoao Martins flags))) { 62650fa5bc40SJoao Martins spin_unlock(ptl); 62660fa5bc40SJoao Martins remainder = 0; 62670fa5bc40SJoao Martins err = -ENOMEM; 62680fa5bc40SJoao Martins break; 62690fa5bc40SJoao Martins } 6270d5d4b0aaSChen, Kenneth W } 627182e5d378SJoao Martins 627282e5d378SJoao Martins vaddr += (refs << PAGE_SHIFT); 627382e5d378SJoao Martins remainder -= refs; 627482e5d378SJoao Martins i += refs; 627582e5d378SJoao Martins 6276cb900f41SKirill A. Shutemov spin_unlock(ptl); 627763551ae0SDavid Gibson } 627828a35716SMichel Lespinasse *nr_pages = remainder; 627987ffc118SAndrea Arcangeli /* 628087ffc118SAndrea Arcangeli * setting position is actually required only if remainder is 628187ffc118SAndrea Arcangeli * not zero but it's faster not to add a "if (remainder)" 628287ffc118SAndrea Arcangeli * branch. 628387ffc118SAndrea Arcangeli */ 628463551ae0SDavid Gibson *position = vaddr; 628563551ae0SDavid Gibson 62862be7cfedSDaniel Jordan return i ? i : err; 628763551ae0SDavid Gibson } 62888f860591SZhang, Yanmin 62897da4d641SPeter Zijlstra unsigned long hugetlb_change_protection(struct vm_area_struct *vma, 62905a90d5a1SPeter Xu unsigned long address, unsigned long end, 62915a90d5a1SPeter Xu pgprot_t newprot, unsigned long cp_flags) 62928f860591SZhang, Yanmin { 62938f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 62948f860591SZhang, Yanmin unsigned long start = address; 62958f860591SZhang, Yanmin pte_t *ptep; 62968f860591SZhang, Yanmin pte_t pte; 6297a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 629860dfaad6SPeter Xu unsigned long pages = 0, psize = huge_page_size(h); 6299dff11abeSMike Kravetz bool shared_pmd = false; 6300ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 6301e95a9851SMike Kravetz unsigned long last_addr_mask; 63025a90d5a1SPeter Xu bool uffd_wp = cp_flags & MM_CP_UFFD_WP; 63035a90d5a1SPeter Xu bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE; 6304dff11abeSMike Kravetz 6305dff11abeSMike Kravetz /* 6306dff11abeSMike Kravetz * In the case of shared PMDs, the area to flush could be beyond 6307ac46d4f3SJérôme Glisse * start/end. Set range.start/range.end to cover the maximum possible 6308dff11abeSMike Kravetz * range if PMD sharing is possible. 6309dff11abeSMike Kravetz */ 63107269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 63117269f999SJérôme Glisse 0, vma, mm, start, end); 6312ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 63138f860591SZhang, Yanmin 63148f860591SZhang, Yanmin BUG_ON(address >= end); 6315ac46d4f3SJérôme Glisse flush_cache_range(vma, range.start, range.end); 63168f860591SZhang, Yanmin 6317ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 6318e95a9851SMike Kravetz last_addr_mask = hugetlb_mask_last_page(h); 631983cde9e8SDavidlohr Bueso i_mmap_lock_write(vma->vm_file->f_mapping); 632060dfaad6SPeter Xu for (; address < end; address += psize) { 6321cb900f41SKirill A. Shutemov spinlock_t *ptl; 632260dfaad6SPeter Xu ptep = huge_pte_offset(mm, address, psize); 6323e95a9851SMike Kravetz if (!ptep) { 6324e95a9851SMike Kravetz address |= last_addr_mask; 63258f860591SZhang, Yanmin continue; 6326e95a9851SMike Kravetz } 6327cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 63284ddb4d91SMike Kravetz if (huge_pmd_unshare(mm, vma, address, ptep)) { 632960dfaad6SPeter Xu /* 633060dfaad6SPeter Xu * When uffd-wp is enabled on the vma, unshare 633160dfaad6SPeter Xu * shouldn't happen at all. Warn about it if it 633260dfaad6SPeter Xu * happened due to some reason. 633360dfaad6SPeter Xu */ 633460dfaad6SPeter Xu WARN_ON_ONCE(uffd_wp || uffd_wp_resolve); 63357da4d641SPeter Zijlstra pages++; 6336cb900f41SKirill A. Shutemov spin_unlock(ptl); 6337dff11abeSMike Kravetz shared_pmd = true; 63384ddb4d91SMike Kravetz address |= last_addr_mask; 633939dde65cSChen, Kenneth W continue; 63407da4d641SPeter Zijlstra } 6341a8bda28dSNaoya Horiguchi pte = huge_ptep_get(ptep); 6342a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { 6343a8bda28dSNaoya Horiguchi spin_unlock(ptl); 6344a8bda28dSNaoya Horiguchi continue; 6345a8bda28dSNaoya Horiguchi } 6346a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(pte))) { 6347a8bda28dSNaoya Horiguchi swp_entry_t entry = pte_to_swp_entry(pte); 63486c287605SDavid Hildenbrand struct page *page = pfn_swap_entry_to_page(entry); 6349a8bda28dSNaoya Horiguchi 63506c287605SDavid Hildenbrand if (!is_readable_migration_entry(entry)) { 6351a8bda28dSNaoya Horiguchi pte_t newpte; 6352a8bda28dSNaoya Horiguchi 63536c287605SDavid Hildenbrand if (PageAnon(page)) 63546c287605SDavid Hildenbrand entry = make_readable_exclusive_migration_entry( 63556c287605SDavid Hildenbrand swp_offset(entry)); 63566c287605SDavid Hildenbrand else 63574dd845b5SAlistair Popple entry = make_readable_migration_entry( 63584dd845b5SAlistair Popple swp_offset(entry)); 6359a8bda28dSNaoya Horiguchi newpte = swp_entry_to_pte(entry); 63605a90d5a1SPeter Xu if (uffd_wp) 63615a90d5a1SPeter Xu newpte = pte_swp_mkuffd_wp(newpte); 63625a90d5a1SPeter Xu else if (uffd_wp_resolve) 63635a90d5a1SPeter Xu newpte = pte_swp_clear_uffd_wp(newpte); 636418f39629SQi Zheng set_huge_pte_at(mm, address, ptep, newpte); 6365a8bda28dSNaoya Horiguchi pages++; 6366a8bda28dSNaoya Horiguchi } 6367a8bda28dSNaoya Horiguchi spin_unlock(ptl); 6368a8bda28dSNaoya Horiguchi continue; 6369a8bda28dSNaoya Horiguchi } 637060dfaad6SPeter Xu if (unlikely(pte_marker_uffd_wp(pte))) { 637160dfaad6SPeter Xu /* 637260dfaad6SPeter Xu * This is changing a non-present pte into a none pte, 637360dfaad6SPeter Xu * no need for huge_ptep_modify_prot_start/commit(). 637460dfaad6SPeter Xu */ 637560dfaad6SPeter Xu if (uffd_wp_resolve) 637660dfaad6SPeter Xu huge_pte_clear(mm, address, ptep, psize); 637760dfaad6SPeter Xu } 6378a8bda28dSNaoya Horiguchi if (!huge_pte_none(pte)) { 6379023bdd00SAneesh Kumar K.V pte_t old_pte; 638079c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 6381023bdd00SAneesh Kumar K.V 6382023bdd00SAneesh Kumar K.V old_pte = huge_ptep_modify_prot_start(vma, address, ptep); 638316785bd7SAnshuman Khandual pte = huge_pte_modify(old_pte, newprot); 638479c1c594SChristophe Leroy pte = arch_make_huge_pte(pte, shift, vma->vm_flags); 63855a90d5a1SPeter Xu if (uffd_wp) 63865a90d5a1SPeter Xu pte = huge_pte_mkuffd_wp(huge_pte_wrprotect(pte)); 63875a90d5a1SPeter Xu else if (uffd_wp_resolve) 63885a90d5a1SPeter Xu pte = huge_pte_clear_uffd_wp(pte); 6389023bdd00SAneesh Kumar K.V huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); 63907da4d641SPeter Zijlstra pages++; 639160dfaad6SPeter Xu } else { 639260dfaad6SPeter Xu /* None pte */ 639360dfaad6SPeter Xu if (unlikely(uffd_wp)) 639460dfaad6SPeter Xu /* Safe to modify directly (none->non-present). */ 639560dfaad6SPeter Xu set_huge_pte_at(mm, address, ptep, 639660dfaad6SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 63978f860591SZhang, Yanmin } 6398cb900f41SKirill A. Shutemov spin_unlock(ptl); 63998f860591SZhang, Yanmin } 6400d833352aSMel Gorman /* 6401c8c06efaSDavidlohr Bueso * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare 6402d833352aSMel Gorman * may have cleared our pud entry and done put_page on the page table: 6403c8c06efaSDavidlohr Bueso * once we release i_mmap_rwsem, another task can do the final put_page 6404dff11abeSMike Kravetz * and that page table be reused and filled with junk. If we actually 6405dff11abeSMike Kravetz * did unshare a page of pmds, flush the range corresponding to the pud. 6406d833352aSMel Gorman */ 6407dff11abeSMike Kravetz if (shared_pmd) 6408ac46d4f3SJérôme Glisse flush_hugetlb_tlb_range(vma, range.start, range.end); 6409dff11abeSMike Kravetz else 64105491ae7bSAneesh Kumar K.V flush_hugetlb_tlb_range(vma, start, end); 64110f10851eSJérôme Glisse /* 64120f10851eSJérôme Glisse * No need to call mmu_notifier_invalidate_range() we are downgrading 64130f10851eSJérôme Glisse * page table protection not changing it to point to a new page. 64140f10851eSJérôme Glisse * 6415ee65728eSMike Rapoport * See Documentation/mm/mmu_notifier.rst 64160f10851eSJérôme Glisse */ 641783cde9e8SDavidlohr Bueso i_mmap_unlock_write(vma->vm_file->f_mapping); 6418ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 64197da4d641SPeter Zijlstra 64207da4d641SPeter Zijlstra return pages << h->order; 64218f860591SZhang, Yanmin } 64228f860591SZhang, Yanmin 642333b8f84aSMike Kravetz /* Return true if reservation was successful, false otherwise. */ 642433b8f84aSMike Kravetz bool hugetlb_reserve_pages(struct inode *inode, 6425a1e78772SMel Gorman long from, long to, 64265a6fe125SMel Gorman struct vm_area_struct *vma, 6427ca16d140SKOSAKI Motohiro vm_flags_t vm_flags) 6428e4e574b7SAdam Litke { 642933b8f84aSMike Kravetz long chg, add = -1; 6430a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 643190481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 64329119a41eSJoonsoo Kim struct resv_map *resv_map; 6433075a61d0SMina Almasry struct hugetlb_cgroup *h_cg = NULL; 64340db9d74eSMina Almasry long gbl_reserve, regions_needed = 0; 6435e4e574b7SAdam Litke 643663489f8eSMike Kravetz /* This should never happen */ 643763489f8eSMike Kravetz if (from > to) { 643863489f8eSMike Kravetz VM_WARN(1, "%s called with a negative range\n", __func__); 643933b8f84aSMike Kravetz return false; 644063489f8eSMike Kravetz } 644163489f8eSMike Kravetz 6442a1e78772SMel Gorman /* 644317c9d12eSMel Gorman * Only apply hugepage reservation if asked. At fault time, an 644417c9d12eSMel Gorman * attempt will be made for VM_NORESERVE to allocate a page 644590481622SDavid Gibson * without using reserves 644617c9d12eSMel Gorman */ 6447ca16d140SKOSAKI Motohiro if (vm_flags & VM_NORESERVE) 644833b8f84aSMike Kravetz return true; 644917c9d12eSMel Gorman 645017c9d12eSMel Gorman /* 6451a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 6452a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 6453a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 6454a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 6455a1e78772SMel Gorman */ 64569119a41eSJoonsoo Kim if (!vma || vma->vm_flags & VM_MAYSHARE) { 6457f27a5136SMike Kravetz /* 6458f27a5136SMike Kravetz * resv_map can not be NULL as hugetlb_reserve_pages is only 6459f27a5136SMike Kravetz * called for inodes for which resv_maps were created (see 6460f27a5136SMike Kravetz * hugetlbfs_get_inode). 6461f27a5136SMike Kravetz */ 64624e35f483SJoonsoo Kim resv_map = inode_resv_map(inode); 64639119a41eSJoonsoo Kim 64640db9d74eSMina Almasry chg = region_chg(resv_map, from, to, ®ions_needed); 64659119a41eSJoonsoo Kim 64669119a41eSJoonsoo Kim } else { 6467e9fe92aeSMina Almasry /* Private mapping. */ 64689119a41eSJoonsoo Kim resv_map = resv_map_alloc(); 64695a6fe125SMel Gorman if (!resv_map) 647033b8f84aSMike Kravetz return false; 64715a6fe125SMel Gorman 647217c9d12eSMel Gorman chg = to - from; 647317c9d12eSMel Gorman 64745a6fe125SMel Gorman set_vma_resv_map(vma, resv_map); 64755a6fe125SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 64765a6fe125SMel Gorman } 64775a6fe125SMel Gorman 647833b8f84aSMike Kravetz if (chg < 0) 6479c50ac050SDave Hansen goto out_err; 648017c9d12eSMel Gorman 648133b8f84aSMike Kravetz if (hugetlb_cgroup_charge_cgroup_rsvd(hstate_index(h), 648233b8f84aSMike Kravetz chg * pages_per_huge_page(h), &h_cg) < 0) 6483075a61d0SMina Almasry goto out_err; 6484075a61d0SMina Almasry 6485075a61d0SMina Almasry if (vma && !(vma->vm_flags & VM_MAYSHARE) && h_cg) { 6486075a61d0SMina Almasry /* For private mappings, the hugetlb_cgroup uncharge info hangs 6487075a61d0SMina Almasry * of the resv_map. 6488075a61d0SMina Almasry */ 6489075a61d0SMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h); 6490075a61d0SMina Almasry } 6491075a61d0SMina Almasry 64921c5ecae3SMike Kravetz /* 64931c5ecae3SMike Kravetz * There must be enough pages in the subpool for the mapping. If 64941c5ecae3SMike Kravetz * the subpool has a minimum size, there may be some global 64951c5ecae3SMike Kravetz * reservations already in place (gbl_reserve). 64961c5ecae3SMike Kravetz */ 64971c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_get_pages(spool, chg); 649833b8f84aSMike Kravetz if (gbl_reserve < 0) 6499075a61d0SMina Almasry goto out_uncharge_cgroup; 650017c9d12eSMel Gorman 650117c9d12eSMel Gorman /* 650217c9d12eSMel Gorman * Check enough hugepages are available for the reservation. 650390481622SDavid Gibson * Hand the pages back to the subpool if there are not 650417c9d12eSMel Gorman */ 650533b8f84aSMike Kravetz if (hugetlb_acct_memory(h, gbl_reserve) < 0) 6506075a61d0SMina Almasry goto out_put_pages; 650717c9d12eSMel Gorman 650817c9d12eSMel Gorman /* 650917c9d12eSMel Gorman * Account for the reservations made. Shared mappings record regions 651017c9d12eSMel Gorman * that have reservations as they are shared by multiple VMAs. 651117c9d12eSMel Gorman * When the last VMA disappears, the region map says how much 651217c9d12eSMel Gorman * the reservation was and the page cache tells how much of 651317c9d12eSMel Gorman * the reservation was consumed. Private mappings are per-VMA and 651417c9d12eSMel Gorman * only the consumed reservations are tracked. When the VMA 651517c9d12eSMel Gorman * disappears, the original reservation is the VMA size and the 651617c9d12eSMel Gorman * consumed reservations are stored in the map. Hence, nothing 651717c9d12eSMel Gorman * else has to be done for private mappings here 651817c9d12eSMel Gorman */ 651933039678SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) { 6520075a61d0SMina Almasry add = region_add(resv_map, from, to, regions_needed, h, h_cg); 652133039678SMike Kravetz 65220db9d74eSMina Almasry if (unlikely(add < 0)) { 65230db9d74eSMina Almasry hugetlb_acct_memory(h, -gbl_reserve); 6524075a61d0SMina Almasry goto out_put_pages; 65250db9d74eSMina Almasry } else if (unlikely(chg > add)) { 652633039678SMike Kravetz /* 652733039678SMike Kravetz * pages in this range were added to the reserve 652833039678SMike Kravetz * map between region_chg and region_add. This 652933039678SMike Kravetz * indicates a race with alloc_huge_page. Adjust 653033039678SMike Kravetz * the subpool and reserve counts modified above 653133039678SMike Kravetz * based on the difference. 653233039678SMike Kravetz */ 653333039678SMike Kravetz long rsv_adjust; 653433039678SMike Kravetz 6535d85aecf2SMiaohe Lin /* 6536d85aecf2SMiaohe Lin * hugetlb_cgroup_uncharge_cgroup_rsvd() will put the 6537d85aecf2SMiaohe Lin * reference to h_cg->css. See comment below for detail. 6538d85aecf2SMiaohe Lin */ 6539075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd( 6540075a61d0SMina Almasry hstate_index(h), 6541075a61d0SMina Almasry (chg - add) * pages_per_huge_page(h), h_cg); 6542075a61d0SMina Almasry 654333039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 654433039678SMike Kravetz chg - add); 654533039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 6546d85aecf2SMiaohe Lin } else if (h_cg) { 6547d85aecf2SMiaohe Lin /* 6548d85aecf2SMiaohe Lin * The file_regions will hold their own reference to 6549d85aecf2SMiaohe Lin * h_cg->css. So we should release the reference held 6550d85aecf2SMiaohe Lin * via hugetlb_cgroup_charge_cgroup_rsvd() when we are 6551d85aecf2SMiaohe Lin * done. 6552d85aecf2SMiaohe Lin */ 6553d85aecf2SMiaohe Lin hugetlb_cgroup_put_rsvd_cgroup(h_cg); 655433039678SMike Kravetz } 655533039678SMike Kravetz } 655633b8f84aSMike Kravetz return true; 655733b8f84aSMike Kravetz 6558075a61d0SMina Almasry out_put_pages: 6559075a61d0SMina Almasry /* put back original number of pages, chg */ 6560075a61d0SMina Almasry (void)hugepage_subpool_put_pages(spool, chg); 6561075a61d0SMina Almasry out_uncharge_cgroup: 6562075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h), 6563075a61d0SMina Almasry chg * pages_per_huge_page(h), h_cg); 6564c50ac050SDave Hansen out_err: 65655e911373SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) 65660db9d74eSMina Almasry /* Only call region_abort if the region_chg succeeded but the 65670db9d74eSMina Almasry * region_add failed or didn't run. 65680db9d74eSMina Almasry */ 65690db9d74eSMina Almasry if (chg >= 0 && add < 0) 65700db9d74eSMina Almasry region_abort(resv_map, from, to, regions_needed); 6571f031dd27SJoonsoo Kim if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 6572f031dd27SJoonsoo Kim kref_put(&resv_map->refs, resv_map_release); 657333b8f84aSMike Kravetz return false; 6574a43a8c39SChen, Kenneth W } 6575a43a8c39SChen, Kenneth W 6576b5cec28dSMike Kravetz long hugetlb_unreserve_pages(struct inode *inode, long start, long end, 6577b5cec28dSMike Kravetz long freed) 6578a43a8c39SChen, Kenneth W { 6579a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 65804e35f483SJoonsoo Kim struct resv_map *resv_map = inode_resv_map(inode); 65819119a41eSJoonsoo Kim long chg = 0; 658290481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 65831c5ecae3SMike Kravetz long gbl_reserve; 658445c682a6SKen Chen 6585f27a5136SMike Kravetz /* 6586f27a5136SMike Kravetz * Since this routine can be called in the evict inode path for all 6587f27a5136SMike Kravetz * hugetlbfs inodes, resv_map could be NULL. 6588f27a5136SMike Kravetz */ 6589b5cec28dSMike Kravetz if (resv_map) { 6590b5cec28dSMike Kravetz chg = region_del(resv_map, start, end); 6591b5cec28dSMike Kravetz /* 6592b5cec28dSMike Kravetz * region_del() can fail in the rare case where a region 6593b5cec28dSMike Kravetz * must be split and another region descriptor can not be 6594b5cec28dSMike Kravetz * allocated. If end == LONG_MAX, it will not fail. 6595b5cec28dSMike Kravetz */ 6596b5cec28dSMike Kravetz if (chg < 0) 6597b5cec28dSMike Kravetz return chg; 6598b5cec28dSMike Kravetz } 6599b5cec28dSMike Kravetz 660045c682a6SKen Chen spin_lock(&inode->i_lock); 6601e4c6f8beSEric Sandeen inode->i_blocks -= (blocks_per_huge_page(h) * freed); 660245c682a6SKen Chen spin_unlock(&inode->i_lock); 660345c682a6SKen Chen 66041c5ecae3SMike Kravetz /* 66051c5ecae3SMike Kravetz * If the subpool has a minimum size, the number of global 66061c5ecae3SMike Kravetz * reservations to be released may be adjusted. 6607dddf31a4SMiaohe Lin * 6608dddf31a4SMiaohe Lin * Note that !resv_map implies freed == 0. So (chg - freed) 6609dddf31a4SMiaohe Lin * won't go negative. 66101c5ecae3SMike Kravetz */ 66111c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed)); 66121c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 6613b5cec28dSMike Kravetz 6614b5cec28dSMike Kravetz return 0; 6615a43a8c39SChen, Kenneth W } 661693f70f90SNaoya Horiguchi 66173212b535SSteve Capper #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 66183212b535SSteve Capper static unsigned long page_table_shareable(struct vm_area_struct *svma, 66193212b535SSteve Capper struct vm_area_struct *vma, 66203212b535SSteve Capper unsigned long addr, pgoff_t idx) 66213212b535SSteve Capper { 66223212b535SSteve Capper unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + 66233212b535SSteve Capper svma->vm_start; 66243212b535SSteve Capper unsigned long sbase = saddr & PUD_MASK; 66253212b535SSteve Capper unsigned long s_end = sbase + PUD_SIZE; 66263212b535SSteve Capper 66273212b535SSteve Capper /* Allow segments to share if only one is marked locked */ 6628de60f5f1SEric B Munson unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; 6629de60f5f1SEric B Munson unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK; 66303212b535SSteve Capper 66313212b535SSteve Capper /* 66323212b535SSteve Capper * match the virtual addresses, permission and the alignment of the 66333212b535SSteve Capper * page table page. 66343212b535SSteve Capper */ 66353212b535SSteve Capper if (pmd_index(addr) != pmd_index(saddr) || 66363212b535SSteve Capper vm_flags != svm_flags || 663707e51edfSMiaohe Lin !range_in_vma(svma, sbase, s_end)) 66383212b535SSteve Capper return 0; 66393212b535SSteve Capper 66403212b535SSteve Capper return saddr; 66413212b535SSteve Capper } 66423212b535SSteve Capper 664331aafb45SNicholas Krause static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr) 66443212b535SSteve Capper { 66453212b535SSteve Capper unsigned long base = addr & PUD_MASK; 66463212b535SSteve Capper unsigned long end = base + PUD_SIZE; 66473212b535SSteve Capper 66483212b535SSteve Capper /* 66493212b535SSteve Capper * check on proper vm_flags and page table alignment 66503212b535SSteve Capper */ 6651017b1660SMike Kravetz if (vma->vm_flags & VM_MAYSHARE && range_in_vma(vma, base, end)) 665231aafb45SNicholas Krause return true; 665331aafb45SNicholas Krause return false; 66543212b535SSteve Capper } 66553212b535SSteve Capper 6656c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 6657c1991e07SPeter Xu { 6658c1991e07SPeter Xu #ifdef CONFIG_USERFAULTFD 6659c1991e07SPeter Xu if (uffd_disable_huge_pmd_share(vma)) 6660c1991e07SPeter Xu return false; 6661c1991e07SPeter Xu #endif 6662c1991e07SPeter Xu return vma_shareable(vma, addr); 6663c1991e07SPeter Xu } 6664c1991e07SPeter Xu 66653212b535SSteve Capper /* 6666017b1660SMike Kravetz * Determine if start,end range within vma could be mapped by shared pmd. 6667017b1660SMike Kravetz * If yes, adjust start and end to cover range associated with possible 6668017b1660SMike Kravetz * shared pmd mappings. 6669017b1660SMike Kravetz */ 6670017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 6671017b1660SMike Kravetz unsigned long *start, unsigned long *end) 6672017b1660SMike Kravetz { 6673a1ba9da8SLi Xinhai unsigned long v_start = ALIGN(vma->vm_start, PUD_SIZE), 6674a1ba9da8SLi Xinhai v_end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 6675017b1660SMike Kravetz 6676a1ba9da8SLi Xinhai /* 6677f0953a1bSIngo Molnar * vma needs to span at least one aligned PUD size, and the range 6678f0953a1bSIngo Molnar * must be at least partially within in. 6679a1ba9da8SLi Xinhai */ 6680a1ba9da8SLi Xinhai if (!(vma->vm_flags & VM_MAYSHARE) || !(v_end > v_start) || 6681a1ba9da8SLi Xinhai (*end <= v_start) || (*start >= v_end)) 6682017b1660SMike Kravetz return; 6683017b1660SMike Kravetz 668475802ca6SPeter Xu /* Extend the range to be PUD aligned for a worst case scenario */ 6685a1ba9da8SLi Xinhai if (*start > v_start) 6686a1ba9da8SLi Xinhai *start = ALIGN_DOWN(*start, PUD_SIZE); 6687017b1660SMike Kravetz 6688a1ba9da8SLi Xinhai if (*end < v_end) 6689a1ba9da8SLi Xinhai *end = ALIGN(*end, PUD_SIZE); 6690017b1660SMike Kravetz } 6691017b1660SMike Kravetz 6692017b1660SMike Kravetz /* 66933212b535SSteve Capper * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() 66943212b535SSteve Capper * and returns the corresponding pte. While this is not necessary for the 66953212b535SSteve Capper * !shared pmd case because we can allocate the pmd later as well, it makes the 6696*3a47c54fSMike Kravetz * code much cleaner. pmd allocation is essential for the shared case because 6697*3a47c54fSMike Kravetz * pud has to be populated inside the same i_mmap_rwsem section - otherwise 6698*3a47c54fSMike Kravetz * racing tasks could either miss the sharing (see huge_pte_offset) or select a 6699*3a47c54fSMike Kravetz * bad pmd for sharing. 67003212b535SSteve Capper */ 6701aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 6702aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 67033212b535SSteve Capper { 67043212b535SSteve Capper struct address_space *mapping = vma->vm_file->f_mapping; 67053212b535SSteve Capper pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + 67063212b535SSteve Capper vma->vm_pgoff; 67073212b535SSteve Capper struct vm_area_struct *svma; 67083212b535SSteve Capper unsigned long saddr; 67093212b535SSteve Capper pte_t *spte = NULL; 67103212b535SSteve Capper pte_t *pte; 6711cb900f41SKirill A. Shutemov spinlock_t *ptl; 67123212b535SSteve Capper 6713*3a47c54fSMike Kravetz i_mmap_lock_read(mapping); 67143212b535SSteve Capper vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { 67153212b535SSteve Capper if (svma == vma) 67163212b535SSteve Capper continue; 67173212b535SSteve Capper 67183212b535SSteve Capper saddr = page_table_shareable(svma, vma, addr, idx); 67193212b535SSteve Capper if (saddr) { 67207868a208SPunit Agrawal spte = huge_pte_offset(svma->vm_mm, saddr, 67217868a208SPunit Agrawal vma_mmu_pagesize(svma)); 67223212b535SSteve Capper if (spte) { 67233212b535SSteve Capper get_page(virt_to_page(spte)); 67243212b535SSteve Capper break; 67253212b535SSteve Capper } 67263212b535SSteve Capper } 67273212b535SSteve Capper } 67283212b535SSteve Capper 67293212b535SSteve Capper if (!spte) 67303212b535SSteve Capper goto out; 67313212b535SSteve Capper 67328bea8052SAneesh Kumar K.V ptl = huge_pte_lock(hstate_vma(vma), mm, spte); 6733dc6c9a35SKirill A. Shutemov if (pud_none(*pud)) { 67343212b535SSteve Capper pud_populate(mm, pud, 67353212b535SSteve Capper (pmd_t *)((unsigned long)spte & PAGE_MASK)); 6736c17b1f42SKirill A. Shutemov mm_inc_nr_pmds(mm); 6737dc6c9a35SKirill A. Shutemov } else { 67383212b535SSteve Capper put_page(virt_to_page(spte)); 6739dc6c9a35SKirill A. Shutemov } 6740cb900f41SKirill A. Shutemov spin_unlock(ptl); 67413212b535SSteve Capper out: 67423212b535SSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 6743*3a47c54fSMike Kravetz i_mmap_unlock_read(mapping); 67443212b535SSteve Capper return pte; 67453212b535SSteve Capper } 67463212b535SSteve Capper 67473212b535SSteve Capper /* 67483212b535SSteve Capper * unmap huge page backed by shared pte. 67493212b535SSteve Capper * 67503212b535SSteve Capper * Hugetlb pte page is ref counted at the time of mapping. If pte is shared 67513212b535SSteve Capper * indicated by page_count > 1, unmap is achieved by clearing pud and 67523212b535SSteve Capper * decrementing the ref count. If count == 1, the pte page is not shared. 67533212b535SSteve Capper * 6754*3a47c54fSMike Kravetz * Called with page table lock held. 67553212b535SSteve Capper * 67563212b535SSteve Capper * returns: 1 successfully unmapped a shared pte page 67573212b535SSteve Capper * 0 the underlying pte page is not shared, or it is the last user 67583212b535SSteve Capper */ 675934ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 67604ddb4d91SMike Kravetz unsigned long addr, pte_t *ptep) 67613212b535SSteve Capper { 67624ddb4d91SMike Kravetz pgd_t *pgd = pgd_offset(mm, addr); 67634ddb4d91SMike Kravetz p4d_t *p4d = p4d_offset(pgd, addr); 67644ddb4d91SMike Kravetz pud_t *pud = pud_offset(p4d, addr); 67653212b535SSteve Capper 676634ae204fSMike Kravetz i_mmap_assert_write_locked(vma->vm_file->f_mapping); 67673212b535SSteve Capper BUG_ON(page_count(virt_to_page(ptep)) == 0); 67683212b535SSteve Capper if (page_count(virt_to_page(ptep)) == 1) 67693212b535SSteve Capper return 0; 67703212b535SSteve Capper 67713212b535SSteve Capper pud_clear(pud); 67723212b535SSteve Capper put_page(virt_to_page(ptep)); 6773dc6c9a35SKirill A. Shutemov mm_dec_nr_pmds(mm); 67743212b535SSteve Capper return 1; 67753212b535SSteve Capper } 6776c1991e07SPeter Xu 67779e5fc74cSSteve Capper #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 6778aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 6779aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 67809e5fc74cSSteve Capper { 67819e5fc74cSSteve Capper return NULL; 67829e5fc74cSSteve Capper } 6783e81f2d22SZhang Zhen 678434ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 67854ddb4d91SMike Kravetz unsigned long addr, pte_t *ptep) 6786e81f2d22SZhang Zhen { 6787e81f2d22SZhang Zhen return 0; 6788e81f2d22SZhang Zhen } 6789017b1660SMike Kravetz 6790017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 6791017b1660SMike Kravetz unsigned long *start, unsigned long *end) 6792017b1660SMike Kravetz { 6793017b1660SMike Kravetz } 6794c1991e07SPeter Xu 6795c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 6796c1991e07SPeter Xu { 6797c1991e07SPeter Xu return false; 6798c1991e07SPeter Xu } 67993212b535SSteve Capper #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 68003212b535SSteve Capper 68019e5fc74cSSteve Capper #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB 6802aec44e0fSPeter Xu pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, 68039e5fc74cSSteve Capper unsigned long addr, unsigned long sz) 68049e5fc74cSSteve Capper { 68059e5fc74cSSteve Capper pgd_t *pgd; 6806c2febafcSKirill A. Shutemov p4d_t *p4d; 68079e5fc74cSSteve Capper pud_t *pud; 68089e5fc74cSSteve Capper pte_t *pte = NULL; 68099e5fc74cSSteve Capper 68109e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 6811f4f0a3d8SKirill A. Shutemov p4d = p4d_alloc(mm, pgd, addr); 6812f4f0a3d8SKirill A. Shutemov if (!p4d) 6813f4f0a3d8SKirill A. Shutemov return NULL; 6814c2febafcSKirill A. Shutemov pud = pud_alloc(mm, p4d, addr); 68159e5fc74cSSteve Capper if (pud) { 68169e5fc74cSSteve Capper if (sz == PUD_SIZE) { 68179e5fc74cSSteve Capper pte = (pte_t *)pud; 68189e5fc74cSSteve Capper } else { 68199e5fc74cSSteve Capper BUG_ON(sz != PMD_SIZE); 6820c1991e07SPeter Xu if (want_pmd_share(vma, addr) && pud_none(*pud)) 6821aec44e0fSPeter Xu pte = huge_pmd_share(mm, vma, addr, pud); 68229e5fc74cSSteve Capper else 68239e5fc74cSSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 68249e5fc74cSSteve Capper } 68259e5fc74cSSteve Capper } 68264e666314SMichal Hocko BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte)); 68279e5fc74cSSteve Capper 68289e5fc74cSSteve Capper return pte; 68299e5fc74cSSteve Capper } 68309e5fc74cSSteve Capper 68319b19df29SPunit Agrawal /* 68329b19df29SPunit Agrawal * huge_pte_offset() - Walk the page table to resolve the hugepage 68339b19df29SPunit Agrawal * entry at address @addr 68349b19df29SPunit Agrawal * 68358ac0b81aSLi Xinhai * Return: Pointer to page table entry (PUD or PMD) for 68368ac0b81aSLi Xinhai * address @addr, or NULL if a !p*d_present() entry is encountered and the 68379b19df29SPunit Agrawal * size @sz doesn't match the hugepage size at this level of the page 68389b19df29SPunit Agrawal * table. 68399b19df29SPunit Agrawal */ 68407868a208SPunit Agrawal pte_t *huge_pte_offset(struct mm_struct *mm, 68417868a208SPunit Agrawal unsigned long addr, unsigned long sz) 68429e5fc74cSSteve Capper { 68439e5fc74cSSteve Capper pgd_t *pgd; 6844c2febafcSKirill A. Shutemov p4d_t *p4d; 68458ac0b81aSLi Xinhai pud_t *pud; 68468ac0b81aSLi Xinhai pmd_t *pmd; 68479e5fc74cSSteve Capper 68489e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 6849c2febafcSKirill A. Shutemov if (!pgd_present(*pgd)) 6850c2febafcSKirill A. Shutemov return NULL; 6851c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, addr); 6852c2febafcSKirill A. Shutemov if (!p4d_present(*p4d)) 6853c2febafcSKirill A. Shutemov return NULL; 68549b19df29SPunit Agrawal 6855c2febafcSKirill A. Shutemov pud = pud_offset(p4d, addr); 68568ac0b81aSLi Xinhai if (sz == PUD_SIZE) 68578ac0b81aSLi Xinhai /* must be pud huge, non-present or none */ 68589e5fc74cSSteve Capper return (pte_t *)pud; 68598ac0b81aSLi Xinhai if (!pud_present(*pud)) 68608ac0b81aSLi Xinhai return NULL; 68618ac0b81aSLi Xinhai /* must have a valid entry and size to go further */ 68629b19df29SPunit Agrawal 68639e5fc74cSSteve Capper pmd = pmd_offset(pud, addr); 68648ac0b81aSLi Xinhai /* must be pmd huge, non-present or none */ 68659e5fc74cSSteve Capper return (pte_t *)pmd; 68669e5fc74cSSteve Capper } 68679e5fc74cSSteve Capper 6868e95a9851SMike Kravetz /* 6869e95a9851SMike Kravetz * Return a mask that can be used to update an address to the last huge 6870e95a9851SMike Kravetz * page in a page table page mapping size. Used to skip non-present 6871e95a9851SMike Kravetz * page table entries when linearly scanning address ranges. Architectures 6872e95a9851SMike Kravetz * with unique huge page to page table relationships can define their own 6873e95a9851SMike Kravetz * version of this routine. 6874e95a9851SMike Kravetz */ 6875e95a9851SMike Kravetz unsigned long hugetlb_mask_last_page(struct hstate *h) 6876e95a9851SMike Kravetz { 6877e95a9851SMike Kravetz unsigned long hp_size = huge_page_size(h); 6878e95a9851SMike Kravetz 6879e95a9851SMike Kravetz if (hp_size == PUD_SIZE) 6880e95a9851SMike Kravetz return P4D_SIZE - PUD_SIZE; 6881e95a9851SMike Kravetz else if (hp_size == PMD_SIZE) 6882e95a9851SMike Kravetz return PUD_SIZE - PMD_SIZE; 6883e95a9851SMike Kravetz else 6884e95a9851SMike Kravetz return 0UL; 6885e95a9851SMike Kravetz } 6886e95a9851SMike Kravetz 6887e95a9851SMike Kravetz #else 6888e95a9851SMike Kravetz 6889e95a9851SMike Kravetz /* See description above. Architectures can provide their own version. */ 6890e95a9851SMike Kravetz __weak unsigned long hugetlb_mask_last_page(struct hstate *h) 6891e95a9851SMike Kravetz { 68924ddb4d91SMike Kravetz #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 68934ddb4d91SMike Kravetz if (huge_page_size(h) == PMD_SIZE) 68944ddb4d91SMike Kravetz return PUD_SIZE - PMD_SIZE; 68954ddb4d91SMike Kravetz #endif 6896e95a9851SMike Kravetz return 0UL; 6897e95a9851SMike Kravetz } 6898e95a9851SMike Kravetz 689961f77edaSNaoya Horiguchi #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ 690061f77edaSNaoya Horiguchi 690161f77edaSNaoya Horiguchi /* 690261f77edaSNaoya Horiguchi * These functions are overwritable if your architecture needs its own 690361f77edaSNaoya Horiguchi * behavior. 690461f77edaSNaoya Horiguchi */ 690561f77edaSNaoya Horiguchi struct page * __weak 690661f77edaSNaoya Horiguchi follow_huge_addr(struct mm_struct *mm, unsigned long address, 690761f77edaSNaoya Horiguchi int write) 690861f77edaSNaoya Horiguchi { 690961f77edaSNaoya Horiguchi return ERR_PTR(-EINVAL); 691061f77edaSNaoya Horiguchi } 691161f77edaSNaoya Horiguchi 691261f77edaSNaoya Horiguchi struct page * __weak 69134dc71451SAneesh Kumar K.V follow_huge_pd(struct vm_area_struct *vma, 69144dc71451SAneesh Kumar K.V unsigned long address, hugepd_t hpd, int flags, int pdshift) 69154dc71451SAneesh Kumar K.V { 69164dc71451SAneesh Kumar K.V WARN(1, "hugepd follow called with no support for hugepage directory format\n"); 69174dc71451SAneesh Kumar K.V return NULL; 69184dc71451SAneesh Kumar K.V } 69194dc71451SAneesh Kumar K.V 69204dc71451SAneesh Kumar K.V struct page * __weak 69219e5fc74cSSteve Capper follow_huge_pmd(struct mm_struct *mm, unsigned long address, 6922e66f17ffSNaoya Horiguchi pmd_t *pmd, int flags) 69239e5fc74cSSteve Capper { 6924e66f17ffSNaoya Horiguchi struct page *page = NULL; 6925e66f17ffSNaoya Horiguchi spinlock_t *ptl; 6926c9d398faSNaoya Horiguchi pte_t pte; 69273faa52c0SJohn Hubbard 69288909691bSDavid Hildenbrand /* 69298909691bSDavid Hildenbrand * FOLL_PIN is not supported for follow_page(). Ordinary GUP goes via 69308909691bSDavid Hildenbrand * follow_hugetlb_page(). 69318909691bSDavid Hildenbrand */ 69328909691bSDavid Hildenbrand if (WARN_ON_ONCE(flags & FOLL_PIN)) 69333faa52c0SJohn Hubbard return NULL; 69343faa52c0SJohn Hubbard 6935e66f17ffSNaoya Horiguchi retry: 6936e66f17ffSNaoya Horiguchi ptl = pmd_lockptr(mm, pmd); 6937e66f17ffSNaoya Horiguchi spin_lock(ptl); 6938e66f17ffSNaoya Horiguchi /* 6939e66f17ffSNaoya Horiguchi * make sure that the address range covered by this pmd is not 6940e66f17ffSNaoya Horiguchi * unmapped from other threads. 6941e66f17ffSNaoya Horiguchi */ 6942e66f17ffSNaoya Horiguchi if (!pmd_huge(*pmd)) 6943e66f17ffSNaoya Horiguchi goto out; 6944c9d398faSNaoya Horiguchi pte = huge_ptep_get((pte_t *)pmd); 6945c9d398faSNaoya Horiguchi if (pte_present(pte)) { 694697534127SGerald Schaefer page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT); 69473faa52c0SJohn Hubbard /* 69483faa52c0SJohn Hubbard * try_grab_page() should always succeed here, because: a) we 69493faa52c0SJohn Hubbard * hold the pmd (ptl) lock, and b) we've just checked that the 69503faa52c0SJohn Hubbard * huge pmd (head) page is present in the page tables. The ptl 69513faa52c0SJohn Hubbard * prevents the head page and tail pages from being rearranged 69523faa52c0SJohn Hubbard * in any way. So this page must be available at this point, 69533faa52c0SJohn Hubbard * unless the page refcount overflowed: 69543faa52c0SJohn Hubbard */ 69553faa52c0SJohn Hubbard if (WARN_ON_ONCE(!try_grab_page(page, flags))) { 69563faa52c0SJohn Hubbard page = NULL; 69573faa52c0SJohn Hubbard goto out; 69583faa52c0SJohn Hubbard } 6959e66f17ffSNaoya Horiguchi } else { 6960c9d398faSNaoya Horiguchi if (is_hugetlb_entry_migration(pte)) { 6961e66f17ffSNaoya Horiguchi spin_unlock(ptl); 6962ad1ac596SMiaohe Lin __migration_entry_wait_huge((pte_t *)pmd, ptl); 6963e66f17ffSNaoya Horiguchi goto retry; 6964e66f17ffSNaoya Horiguchi } 6965e66f17ffSNaoya Horiguchi /* 6966e66f17ffSNaoya Horiguchi * hwpoisoned entry is treated as no_page_table in 6967e66f17ffSNaoya Horiguchi * follow_page_mask(). 6968e66f17ffSNaoya Horiguchi */ 6969e66f17ffSNaoya Horiguchi } 6970e66f17ffSNaoya Horiguchi out: 6971e66f17ffSNaoya Horiguchi spin_unlock(ptl); 69729e5fc74cSSteve Capper return page; 69739e5fc74cSSteve Capper } 69749e5fc74cSSteve Capper 697561f77edaSNaoya Horiguchi struct page * __weak 69769e5fc74cSSteve Capper follow_huge_pud(struct mm_struct *mm, unsigned long address, 6977e66f17ffSNaoya Horiguchi pud_t *pud, int flags) 69789e5fc74cSSteve Capper { 69793a194f3fSNaoya Horiguchi struct page *page = NULL; 69803a194f3fSNaoya Horiguchi spinlock_t *ptl; 69813a194f3fSNaoya Horiguchi pte_t pte; 69823a194f3fSNaoya Horiguchi 69833a194f3fSNaoya Horiguchi if (WARN_ON_ONCE(flags & FOLL_PIN)) 6984e66f17ffSNaoya Horiguchi return NULL; 69859e5fc74cSSteve Capper 69863a194f3fSNaoya Horiguchi retry: 69873a194f3fSNaoya Horiguchi ptl = huge_pte_lock(hstate_sizelog(PUD_SHIFT), mm, (pte_t *)pud); 69883a194f3fSNaoya Horiguchi if (!pud_huge(*pud)) 69893a194f3fSNaoya Horiguchi goto out; 69903a194f3fSNaoya Horiguchi pte = huge_ptep_get((pte_t *)pud); 69913a194f3fSNaoya Horiguchi if (pte_present(pte)) { 69923a194f3fSNaoya Horiguchi page = pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); 69933a194f3fSNaoya Horiguchi if (WARN_ON_ONCE(!try_grab_page(page, flags))) { 69943a194f3fSNaoya Horiguchi page = NULL; 69953a194f3fSNaoya Horiguchi goto out; 69963a194f3fSNaoya Horiguchi } 69973a194f3fSNaoya Horiguchi } else { 69983a194f3fSNaoya Horiguchi if (is_hugetlb_entry_migration(pte)) { 69993a194f3fSNaoya Horiguchi spin_unlock(ptl); 70003a194f3fSNaoya Horiguchi __migration_entry_wait(mm, (pte_t *)pud, ptl); 70013a194f3fSNaoya Horiguchi goto retry; 70023a194f3fSNaoya Horiguchi } 70033a194f3fSNaoya Horiguchi /* 70043a194f3fSNaoya Horiguchi * hwpoisoned entry is treated as no_page_table in 70053a194f3fSNaoya Horiguchi * follow_page_mask(). 70063a194f3fSNaoya Horiguchi */ 70073a194f3fSNaoya Horiguchi } 70083a194f3fSNaoya Horiguchi out: 70093a194f3fSNaoya Horiguchi spin_unlock(ptl); 70103a194f3fSNaoya Horiguchi return page; 70119e5fc74cSSteve Capper } 70129e5fc74cSSteve Capper 7013faaa5b62SAnshuman Khandual struct page * __weak 7014faaa5b62SAnshuman Khandual follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) 7015faaa5b62SAnshuman Khandual { 70163faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 7017faaa5b62SAnshuman Khandual return NULL; 7018faaa5b62SAnshuman Khandual 7019faaa5b62SAnshuman Khandual return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); 7020faaa5b62SAnshuman Khandual } 7021faaa5b62SAnshuman Khandual 70227ce82f4cSMiaohe Lin int isolate_hugetlb(struct page *page, struct list_head *list) 702331caf665SNaoya Horiguchi { 70247ce82f4cSMiaohe Lin int ret = 0; 7025bcc54222SNaoya Horiguchi 7026db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 70278f251a3dSMike Kravetz if (!PageHeadHuge(page) || 70288f251a3dSMike Kravetz !HPageMigratable(page) || 70290eb2df2bSMuchun Song !get_page_unless_zero(page)) { 70307ce82f4cSMiaohe Lin ret = -EBUSY; 7031bcc54222SNaoya Horiguchi goto unlock; 7032bcc54222SNaoya Horiguchi } 70338f251a3dSMike Kravetz ClearHPageMigratable(page); 703431caf665SNaoya Horiguchi list_move_tail(&page->lru, list); 7035bcc54222SNaoya Horiguchi unlock: 7036db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 7037bcc54222SNaoya Horiguchi return ret; 703831caf665SNaoya Horiguchi } 703931caf665SNaoya Horiguchi 704025182f05SNaoya Horiguchi int get_hwpoison_huge_page(struct page *page, bool *hugetlb) 704125182f05SNaoya Horiguchi { 704225182f05SNaoya Horiguchi int ret = 0; 704325182f05SNaoya Horiguchi 704425182f05SNaoya Horiguchi *hugetlb = false; 704525182f05SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 704625182f05SNaoya Horiguchi if (PageHeadHuge(page)) { 704725182f05SNaoya Horiguchi *hugetlb = true; 7048b283d983SNaoya Horiguchi if (HPageFreed(page)) 7049b283d983SNaoya Horiguchi ret = 0; 7050b283d983SNaoya Horiguchi else if (HPageMigratable(page)) 705125182f05SNaoya Horiguchi ret = get_page_unless_zero(page); 70520ed950d1SNaoya Horiguchi else 70530ed950d1SNaoya Horiguchi ret = -EBUSY; 705425182f05SNaoya Horiguchi } 705525182f05SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 705625182f05SNaoya Horiguchi return ret; 705725182f05SNaoya Horiguchi } 705825182f05SNaoya Horiguchi 7059405ce051SNaoya Horiguchi int get_huge_page_for_hwpoison(unsigned long pfn, int flags) 7060405ce051SNaoya Horiguchi { 7061405ce051SNaoya Horiguchi int ret; 7062405ce051SNaoya Horiguchi 7063405ce051SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 7064405ce051SNaoya Horiguchi ret = __get_huge_page_for_hwpoison(pfn, flags); 7065405ce051SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 7066405ce051SNaoya Horiguchi return ret; 7067405ce051SNaoya Horiguchi } 7068405ce051SNaoya Horiguchi 706931caf665SNaoya Horiguchi void putback_active_hugepage(struct page *page) 707031caf665SNaoya Horiguchi { 7071db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 70728f251a3dSMike Kravetz SetHPageMigratable(page); 707331caf665SNaoya Horiguchi list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); 7074db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 707531caf665SNaoya Horiguchi put_page(page); 707631caf665SNaoya Horiguchi } 7077ab5ac90aSMichal Hocko 7078ab5ac90aSMichal Hocko void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason) 7079ab5ac90aSMichal Hocko { 7080ab5ac90aSMichal Hocko struct hstate *h = page_hstate(oldpage); 7081ab5ac90aSMichal Hocko 7082ab5ac90aSMichal Hocko hugetlb_cgroup_migrate(oldpage, newpage); 7083ab5ac90aSMichal Hocko set_page_owner_migrate_reason(newpage, reason); 7084ab5ac90aSMichal Hocko 7085ab5ac90aSMichal Hocko /* 7086ab5ac90aSMichal Hocko * transfer temporary state of the new huge page. This is 7087ab5ac90aSMichal Hocko * reverse to other transitions because the newpage is going to 7088ab5ac90aSMichal Hocko * be final while the old one will be freed so it takes over 7089ab5ac90aSMichal Hocko * the temporary status. 7090ab5ac90aSMichal Hocko * 7091ab5ac90aSMichal Hocko * Also note that we have to transfer the per-node surplus state 7092ab5ac90aSMichal Hocko * here as well otherwise the global surplus count will not match 7093ab5ac90aSMichal Hocko * the per-node's. 7094ab5ac90aSMichal Hocko */ 70959157c311SMike Kravetz if (HPageTemporary(newpage)) { 7096ab5ac90aSMichal Hocko int old_nid = page_to_nid(oldpage); 7097ab5ac90aSMichal Hocko int new_nid = page_to_nid(newpage); 7098ab5ac90aSMichal Hocko 70999157c311SMike Kravetz SetHPageTemporary(oldpage); 71009157c311SMike Kravetz ClearHPageTemporary(newpage); 7101ab5ac90aSMichal Hocko 71025af1ab1dSMiaohe Lin /* 71035af1ab1dSMiaohe Lin * There is no need to transfer the per-node surplus state 71045af1ab1dSMiaohe Lin * when we do not cross the node. 71055af1ab1dSMiaohe Lin */ 71065af1ab1dSMiaohe Lin if (new_nid == old_nid) 71075af1ab1dSMiaohe Lin return; 7108db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 7109ab5ac90aSMichal Hocko if (h->surplus_huge_pages_node[old_nid]) { 7110ab5ac90aSMichal Hocko h->surplus_huge_pages_node[old_nid]--; 7111ab5ac90aSMichal Hocko h->surplus_huge_pages_node[new_nid]++; 7112ab5ac90aSMichal Hocko } 7113db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 7114ab5ac90aSMichal Hocko } 7115ab5ac90aSMichal Hocko } 7116cf11e85fSRoman Gushchin 71176dfeaff9SPeter Xu /* 71186dfeaff9SPeter Xu * This function will unconditionally remove all the shared pmd pgtable entries 71196dfeaff9SPeter Xu * within the specific vma for a hugetlbfs memory range. 71206dfeaff9SPeter Xu */ 71216dfeaff9SPeter Xu void hugetlb_unshare_all_pmds(struct vm_area_struct *vma) 71226dfeaff9SPeter Xu { 71236dfeaff9SPeter Xu struct hstate *h = hstate_vma(vma); 71246dfeaff9SPeter Xu unsigned long sz = huge_page_size(h); 71256dfeaff9SPeter Xu struct mm_struct *mm = vma->vm_mm; 71266dfeaff9SPeter Xu struct mmu_notifier_range range; 71276dfeaff9SPeter Xu unsigned long address, start, end; 71286dfeaff9SPeter Xu spinlock_t *ptl; 71296dfeaff9SPeter Xu pte_t *ptep; 71306dfeaff9SPeter Xu 71316dfeaff9SPeter Xu if (!(vma->vm_flags & VM_MAYSHARE)) 71326dfeaff9SPeter Xu return; 71336dfeaff9SPeter Xu 71346dfeaff9SPeter Xu start = ALIGN(vma->vm_start, PUD_SIZE); 71356dfeaff9SPeter Xu end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 71366dfeaff9SPeter Xu 71376dfeaff9SPeter Xu if (start >= end) 71386dfeaff9SPeter Xu return; 71396dfeaff9SPeter Xu 71409c8bbfacSBaolin Wang flush_cache_range(vma, start, end); 71416dfeaff9SPeter Xu /* 71426dfeaff9SPeter Xu * No need to call adjust_range_if_pmd_sharing_possible(), because 71436dfeaff9SPeter Xu * we have already done the PUD_SIZE alignment. 71446dfeaff9SPeter Xu */ 71456dfeaff9SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, 71466dfeaff9SPeter Xu start, end); 71476dfeaff9SPeter Xu mmu_notifier_invalidate_range_start(&range); 71486dfeaff9SPeter Xu i_mmap_lock_write(vma->vm_file->f_mapping); 71496dfeaff9SPeter Xu for (address = start; address < end; address += PUD_SIZE) { 71506dfeaff9SPeter Xu ptep = huge_pte_offset(mm, address, sz); 71516dfeaff9SPeter Xu if (!ptep) 71526dfeaff9SPeter Xu continue; 71536dfeaff9SPeter Xu ptl = huge_pte_lock(h, mm, ptep); 71544ddb4d91SMike Kravetz huge_pmd_unshare(mm, vma, address, ptep); 71556dfeaff9SPeter Xu spin_unlock(ptl); 71566dfeaff9SPeter Xu } 71576dfeaff9SPeter Xu flush_hugetlb_tlb_range(vma, start, end); 71586dfeaff9SPeter Xu i_mmap_unlock_write(vma->vm_file->f_mapping); 71596dfeaff9SPeter Xu /* 71606dfeaff9SPeter Xu * No need to call mmu_notifier_invalidate_range(), see 7161ee65728eSMike Rapoport * Documentation/mm/mmu_notifier.rst. 71626dfeaff9SPeter Xu */ 71636dfeaff9SPeter Xu mmu_notifier_invalidate_range_end(&range); 71646dfeaff9SPeter Xu } 71656dfeaff9SPeter Xu 7166cf11e85fSRoman Gushchin #ifdef CONFIG_CMA 7167cf11e85fSRoman Gushchin static bool cma_reserve_called __initdata; 7168cf11e85fSRoman Gushchin 7169cf11e85fSRoman Gushchin static int __init cmdline_parse_hugetlb_cma(char *p) 7170cf11e85fSRoman Gushchin { 717138e719abSBaolin Wang int nid, count = 0; 717238e719abSBaolin Wang unsigned long tmp; 717338e719abSBaolin Wang char *s = p; 717438e719abSBaolin Wang 717538e719abSBaolin Wang while (*s) { 717638e719abSBaolin Wang if (sscanf(s, "%lu%n", &tmp, &count) != 1) 717738e719abSBaolin Wang break; 717838e719abSBaolin Wang 717938e719abSBaolin Wang if (s[count] == ':') { 7180f9317f77SMike Kravetz if (tmp >= MAX_NUMNODES) 718138e719abSBaolin Wang break; 7182f9317f77SMike Kravetz nid = array_index_nospec(tmp, MAX_NUMNODES); 718338e719abSBaolin Wang 718438e719abSBaolin Wang s += count + 1; 718538e719abSBaolin Wang tmp = memparse(s, &s); 718638e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = tmp; 718738e719abSBaolin Wang hugetlb_cma_size += tmp; 718838e719abSBaolin Wang 718938e719abSBaolin Wang /* 719038e719abSBaolin Wang * Skip the separator if have one, otherwise 719138e719abSBaolin Wang * break the parsing. 719238e719abSBaolin Wang */ 719338e719abSBaolin Wang if (*s == ',') 719438e719abSBaolin Wang s++; 719538e719abSBaolin Wang else 719638e719abSBaolin Wang break; 719738e719abSBaolin Wang } else { 7198cf11e85fSRoman Gushchin hugetlb_cma_size = memparse(p, &p); 719938e719abSBaolin Wang break; 720038e719abSBaolin Wang } 720138e719abSBaolin Wang } 720238e719abSBaolin Wang 7203cf11e85fSRoman Gushchin return 0; 7204cf11e85fSRoman Gushchin } 7205cf11e85fSRoman Gushchin 7206cf11e85fSRoman Gushchin early_param("hugetlb_cma", cmdline_parse_hugetlb_cma); 7207cf11e85fSRoman Gushchin 7208cf11e85fSRoman Gushchin void __init hugetlb_cma_reserve(int order) 7209cf11e85fSRoman Gushchin { 7210cf11e85fSRoman Gushchin unsigned long size, reserved, per_node; 721138e719abSBaolin Wang bool node_specific_cma_alloc = false; 7212cf11e85fSRoman Gushchin int nid; 7213cf11e85fSRoman Gushchin 7214cf11e85fSRoman Gushchin cma_reserve_called = true; 7215cf11e85fSRoman Gushchin 7216cf11e85fSRoman Gushchin if (!hugetlb_cma_size) 7217cf11e85fSRoman Gushchin return; 7218cf11e85fSRoman Gushchin 721938e719abSBaolin Wang for (nid = 0; nid < MAX_NUMNODES; nid++) { 722038e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] == 0) 722138e719abSBaolin Wang continue; 722238e719abSBaolin Wang 722330a51400SPeng Liu if (!node_online(nid)) { 722438e719abSBaolin Wang pr_warn("hugetlb_cma: invalid node %d specified\n", nid); 722538e719abSBaolin Wang hugetlb_cma_size -= hugetlb_cma_size_in_node[nid]; 722638e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = 0; 722738e719abSBaolin Wang continue; 722838e719abSBaolin Wang } 722938e719abSBaolin Wang 723038e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] < (PAGE_SIZE << order)) { 723138e719abSBaolin Wang pr_warn("hugetlb_cma: cma area of node %d should be at least %lu MiB\n", 723238e719abSBaolin Wang nid, (PAGE_SIZE << order) / SZ_1M); 723338e719abSBaolin Wang hugetlb_cma_size -= hugetlb_cma_size_in_node[nid]; 723438e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = 0; 723538e719abSBaolin Wang } else { 723638e719abSBaolin Wang node_specific_cma_alloc = true; 723738e719abSBaolin Wang } 723838e719abSBaolin Wang } 723938e719abSBaolin Wang 724038e719abSBaolin Wang /* Validate the CMA size again in case some invalid nodes specified. */ 724138e719abSBaolin Wang if (!hugetlb_cma_size) 724238e719abSBaolin Wang return; 724338e719abSBaolin Wang 7244cf11e85fSRoman Gushchin if (hugetlb_cma_size < (PAGE_SIZE << order)) { 7245cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n", 7246cf11e85fSRoman Gushchin (PAGE_SIZE << order) / SZ_1M); 7247a01f4390SMike Kravetz hugetlb_cma_size = 0; 7248cf11e85fSRoman Gushchin return; 7249cf11e85fSRoman Gushchin } 7250cf11e85fSRoman Gushchin 725138e719abSBaolin Wang if (!node_specific_cma_alloc) { 7252cf11e85fSRoman Gushchin /* 7253cf11e85fSRoman Gushchin * If 3 GB area is requested on a machine with 4 numa nodes, 7254cf11e85fSRoman Gushchin * let's allocate 1 GB on first three nodes and ignore the last one. 7255cf11e85fSRoman Gushchin */ 7256cf11e85fSRoman Gushchin per_node = DIV_ROUND_UP(hugetlb_cma_size, nr_online_nodes); 7257cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n", 7258cf11e85fSRoman Gushchin hugetlb_cma_size / SZ_1M, per_node / SZ_1M); 725938e719abSBaolin Wang } 7260cf11e85fSRoman Gushchin 7261cf11e85fSRoman Gushchin reserved = 0; 726230a51400SPeng Liu for_each_online_node(nid) { 7263cf11e85fSRoman Gushchin int res; 72642281f797SBarry Song char name[CMA_MAX_NAME]; 7265cf11e85fSRoman Gushchin 726638e719abSBaolin Wang if (node_specific_cma_alloc) { 726738e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] == 0) 726838e719abSBaolin Wang continue; 726938e719abSBaolin Wang 727038e719abSBaolin Wang size = hugetlb_cma_size_in_node[nid]; 727138e719abSBaolin Wang } else { 7272cf11e85fSRoman Gushchin size = min(per_node, hugetlb_cma_size - reserved); 727338e719abSBaolin Wang } 727438e719abSBaolin Wang 7275cf11e85fSRoman Gushchin size = round_up(size, PAGE_SIZE << order); 7276cf11e85fSRoman Gushchin 72772281f797SBarry Song snprintf(name, sizeof(name), "hugetlb%d", nid); 7278a01f4390SMike Kravetz /* 7279a01f4390SMike Kravetz * Note that 'order per bit' is based on smallest size that 7280a01f4390SMike Kravetz * may be returned to CMA allocator in the case of 7281a01f4390SMike Kravetz * huge page demotion. 7282a01f4390SMike Kravetz */ 7283a01f4390SMike Kravetz res = cma_declare_contiguous_nid(0, size, 0, 7284a01f4390SMike Kravetz PAGE_SIZE << HUGETLB_PAGE_ORDER, 728529d0f41dSBarry Song 0, false, name, 7286cf11e85fSRoman Gushchin &hugetlb_cma[nid], nid); 7287cf11e85fSRoman Gushchin if (res) { 7288cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: reservation failed: err %d, node %d", 7289cf11e85fSRoman Gushchin res, nid); 7290cf11e85fSRoman Gushchin continue; 7291cf11e85fSRoman Gushchin } 7292cf11e85fSRoman Gushchin 7293cf11e85fSRoman Gushchin reserved += size; 7294cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserved %lu MiB on node %d\n", 7295cf11e85fSRoman Gushchin size / SZ_1M, nid); 7296cf11e85fSRoman Gushchin 7297cf11e85fSRoman Gushchin if (reserved >= hugetlb_cma_size) 7298cf11e85fSRoman Gushchin break; 7299cf11e85fSRoman Gushchin } 7300a01f4390SMike Kravetz 7301a01f4390SMike Kravetz if (!reserved) 7302a01f4390SMike Kravetz /* 7303a01f4390SMike Kravetz * hugetlb_cma_size is used to determine if allocations from 7304a01f4390SMike Kravetz * cma are possible. Set to zero if no cma regions are set up. 7305a01f4390SMike Kravetz */ 7306a01f4390SMike Kravetz hugetlb_cma_size = 0; 7307cf11e85fSRoman Gushchin } 7308cf11e85fSRoman Gushchin 7309263b8998SMiaohe Lin static void __init hugetlb_cma_check(void) 7310cf11e85fSRoman Gushchin { 7311cf11e85fSRoman Gushchin if (!hugetlb_cma_size || cma_reserve_called) 7312cf11e85fSRoman Gushchin return; 7313cf11e85fSRoman Gushchin 7314cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: the option isn't supported by current arch\n"); 7315cf11e85fSRoman Gushchin } 7316cf11e85fSRoman Gushchin 7317cf11e85fSRoman Gushchin #endif /* CONFIG_CMA */ 7318