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> 34d6606683SLinus Torvalds 3563551ae0SDavid Gibson #include <asm/page.h> 36ca15ca40SMike Rapoport #include <asm/pgalloc.h> 3724669e58SAneesh Kumar K.V #include <asm/tlb.h> 3863551ae0SDavid Gibson 3924669e58SAneesh Kumar K.V #include <linux/io.h> 4063551ae0SDavid Gibson #include <linux/hugetlb.h> 419dd540e2SAneesh Kumar K.V #include <linux/hugetlb_cgroup.h> 429a305230SLee Schermerhorn #include <linux/node.h> 43ab5ac90aSMichal Hocko #include <linux/page_owner.h> 447835e98bSNick Piggin #include "internal.h" 45f41f2ed4SMuchun Song #include "hugetlb_vmemmap.h" 461da177e4SLinus Torvalds 47c3f38a38SAneesh Kumar K.V int hugetlb_max_hstate __read_mostly; 48e5ff2159SAndi Kleen unsigned int default_hstate_idx; 49e5ff2159SAndi Kleen struct hstate hstates[HUGE_MAX_HSTATE]; 50cf11e85fSRoman Gushchin 51dbda8feaSBarry Song #ifdef CONFIG_CMA 52cf11e85fSRoman Gushchin static struct cma *hugetlb_cma[MAX_NUMNODES]; 53a01f4390SMike Kravetz static bool hugetlb_cma_page(struct page *page, unsigned int order) 54a01f4390SMike Kravetz { 55a01f4390SMike Kravetz return cma_pages_valid(hugetlb_cma[page_to_nid(page)], page, 56a01f4390SMike Kravetz 1 << order); 57a01f4390SMike Kravetz } 58a01f4390SMike Kravetz #else 59a01f4390SMike Kravetz static bool hugetlb_cma_page(struct page *page, unsigned int order) 60a01f4390SMike Kravetz { 61a01f4390SMike Kravetz return false; 62a01f4390SMike Kravetz } 63dbda8feaSBarry Song #endif 64dbda8feaSBarry Song static unsigned long hugetlb_cma_size __initdata; 65cf11e85fSRoman Gushchin 66641844f5SNaoya Horiguchi /* 67641844f5SNaoya Horiguchi * Minimum page order among possible hugepage sizes, set to a proper value 68641844f5SNaoya Horiguchi * at boot time. 69641844f5SNaoya Horiguchi */ 70641844f5SNaoya Horiguchi static unsigned int minimum_order __read_mostly = UINT_MAX; 71e5ff2159SAndi Kleen 7253ba51d2SJon Tollefson __initdata LIST_HEAD(huge_boot_pages); 7353ba51d2SJon Tollefson 74e5ff2159SAndi Kleen /* for command line parsing */ 75e5ff2159SAndi Kleen static struct hstate * __initdata parsed_hstate; 76e5ff2159SAndi Kleen static unsigned long __initdata default_hstate_max_huge_pages; 779fee021dSVaishali Thakkar static bool __initdata parsed_valid_hugepagesz = true; 78282f4214SMike Kravetz static bool __initdata parsed_default_hugepagesz; 79e5ff2159SAndi Kleen 803935baa9SDavid Gibson /* 8131caf665SNaoya Horiguchi * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, 8231caf665SNaoya Horiguchi * free_huge_pages, and surplus_huge_pages. 833935baa9SDavid Gibson */ 84c3f38a38SAneesh Kumar K.V DEFINE_SPINLOCK(hugetlb_lock); 850bd0f9fbSEric Paris 868382d914SDavidlohr Bueso /* 878382d914SDavidlohr Bueso * Serializes faults on the same logical page. This is used to 888382d914SDavidlohr Bueso * prevent spurious OOMs when the hugepage pool is fully utilized. 898382d914SDavidlohr Bueso */ 908382d914SDavidlohr Bueso static int num_fault_mutexes; 91c672c7f2SMike Kravetz struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp; 928382d914SDavidlohr Bueso 937ca02d0aSMike Kravetz /* Forward declaration */ 947ca02d0aSMike Kravetz static int hugetlb_acct_memory(struct hstate *h, long delta); 957ca02d0aSMike Kravetz 961d88433bSMiaohe Lin static inline bool subpool_is_free(struct hugepage_subpool *spool) 971d88433bSMiaohe Lin { 981d88433bSMiaohe Lin if (spool->count) 991d88433bSMiaohe Lin return false; 1001d88433bSMiaohe Lin if (spool->max_hpages != -1) 1011d88433bSMiaohe Lin return spool->used_hpages == 0; 1021d88433bSMiaohe Lin if (spool->min_hpages != -1) 1031d88433bSMiaohe Lin return spool->rsv_hpages == spool->min_hpages; 1041d88433bSMiaohe Lin 1051d88433bSMiaohe Lin return true; 1061d88433bSMiaohe Lin } 1071d88433bSMiaohe Lin 108db71ef79SMike Kravetz static inline void unlock_or_release_subpool(struct hugepage_subpool *spool, 109db71ef79SMike Kravetz unsigned long irq_flags) 11090481622SDavid Gibson { 111db71ef79SMike Kravetz spin_unlock_irqrestore(&spool->lock, irq_flags); 11290481622SDavid Gibson 11390481622SDavid Gibson /* If no pages are used, and no other handles to the subpool 1147c8de358SEthon Paul * remain, give up any reservations based on minimum size and 1157ca02d0aSMike Kravetz * free the subpool */ 1161d88433bSMiaohe Lin if (subpool_is_free(spool)) { 1177ca02d0aSMike Kravetz if (spool->min_hpages != -1) 1187ca02d0aSMike Kravetz hugetlb_acct_memory(spool->hstate, 1197ca02d0aSMike Kravetz -spool->min_hpages); 12090481622SDavid Gibson kfree(spool); 12190481622SDavid Gibson } 1227ca02d0aSMike Kravetz } 12390481622SDavid Gibson 1247ca02d0aSMike Kravetz struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, 1257ca02d0aSMike Kravetz long min_hpages) 12690481622SDavid Gibson { 12790481622SDavid Gibson struct hugepage_subpool *spool; 12890481622SDavid Gibson 129c6a91820SMike Kravetz spool = kzalloc(sizeof(*spool), GFP_KERNEL); 13090481622SDavid Gibson if (!spool) 13190481622SDavid Gibson return NULL; 13290481622SDavid Gibson 13390481622SDavid Gibson spin_lock_init(&spool->lock); 13490481622SDavid Gibson spool->count = 1; 1357ca02d0aSMike Kravetz spool->max_hpages = max_hpages; 1367ca02d0aSMike Kravetz spool->hstate = h; 1377ca02d0aSMike Kravetz spool->min_hpages = min_hpages; 1387ca02d0aSMike Kravetz 1397ca02d0aSMike Kravetz if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { 1407ca02d0aSMike Kravetz kfree(spool); 1417ca02d0aSMike Kravetz return NULL; 1427ca02d0aSMike Kravetz } 1437ca02d0aSMike Kravetz spool->rsv_hpages = min_hpages; 14490481622SDavid Gibson 14590481622SDavid Gibson return spool; 14690481622SDavid Gibson } 14790481622SDavid Gibson 14890481622SDavid Gibson void hugepage_put_subpool(struct hugepage_subpool *spool) 14990481622SDavid Gibson { 150db71ef79SMike Kravetz unsigned long flags; 151db71ef79SMike Kravetz 152db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 15390481622SDavid Gibson BUG_ON(!spool->count); 15490481622SDavid Gibson spool->count--; 155db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 15690481622SDavid Gibson } 15790481622SDavid Gibson 1581c5ecae3SMike Kravetz /* 1591c5ecae3SMike Kravetz * Subpool accounting for allocating and reserving pages. 1601c5ecae3SMike Kravetz * Return -ENOMEM if there are not enough resources to satisfy the 1619e7ee400SRandy Dunlap * request. Otherwise, return the number of pages by which the 1621c5ecae3SMike Kravetz * global pools must be adjusted (upward). The returned value may 1631c5ecae3SMike Kravetz * only be different than the passed value (delta) in the case where 1647c8de358SEthon Paul * a subpool minimum size must be maintained. 1651c5ecae3SMike Kravetz */ 1661c5ecae3SMike Kravetz static long hugepage_subpool_get_pages(struct hugepage_subpool *spool, 16790481622SDavid Gibson long delta) 16890481622SDavid Gibson { 1691c5ecae3SMike Kravetz long ret = delta; 17090481622SDavid Gibson 17190481622SDavid Gibson if (!spool) 1721c5ecae3SMike Kravetz return ret; 17390481622SDavid Gibson 174db71ef79SMike Kravetz spin_lock_irq(&spool->lock); 17590481622SDavid Gibson 1761c5ecae3SMike Kravetz if (spool->max_hpages != -1) { /* maximum size accounting */ 1771c5ecae3SMike Kravetz if ((spool->used_hpages + delta) <= spool->max_hpages) 1781c5ecae3SMike Kravetz spool->used_hpages += delta; 1791c5ecae3SMike Kravetz else { 1801c5ecae3SMike Kravetz ret = -ENOMEM; 1811c5ecae3SMike Kravetz goto unlock_ret; 1821c5ecae3SMike Kravetz } 1831c5ecae3SMike Kravetz } 1841c5ecae3SMike Kravetz 18509a95e29SMike Kravetz /* minimum size accounting */ 18609a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->rsv_hpages) { 1871c5ecae3SMike Kravetz if (delta > spool->rsv_hpages) { 1881c5ecae3SMike Kravetz /* 1891c5ecae3SMike Kravetz * Asking for more reserves than those already taken on 1901c5ecae3SMike Kravetz * behalf of subpool. Return difference. 1911c5ecae3SMike Kravetz */ 1921c5ecae3SMike Kravetz ret = delta - spool->rsv_hpages; 1931c5ecae3SMike Kravetz spool->rsv_hpages = 0; 1941c5ecae3SMike Kravetz } else { 1951c5ecae3SMike Kravetz ret = 0; /* reserves already accounted for */ 1961c5ecae3SMike Kravetz spool->rsv_hpages -= delta; 1971c5ecae3SMike Kravetz } 1981c5ecae3SMike Kravetz } 1991c5ecae3SMike Kravetz 2001c5ecae3SMike Kravetz unlock_ret: 201db71ef79SMike Kravetz spin_unlock_irq(&spool->lock); 20290481622SDavid Gibson return ret; 20390481622SDavid Gibson } 20490481622SDavid Gibson 2051c5ecae3SMike Kravetz /* 2061c5ecae3SMike Kravetz * Subpool accounting for freeing and unreserving pages. 2071c5ecae3SMike Kravetz * Return the number of global page reservations that must be dropped. 2081c5ecae3SMike Kravetz * The return value may only be different than the passed value (delta) 2091c5ecae3SMike Kravetz * in the case where a subpool minimum size must be maintained. 2101c5ecae3SMike Kravetz */ 2111c5ecae3SMike Kravetz static long hugepage_subpool_put_pages(struct hugepage_subpool *spool, 21290481622SDavid Gibson long delta) 21390481622SDavid Gibson { 2141c5ecae3SMike Kravetz long ret = delta; 215db71ef79SMike Kravetz unsigned long flags; 2161c5ecae3SMike Kravetz 21790481622SDavid Gibson if (!spool) 2181c5ecae3SMike Kravetz return delta; 21990481622SDavid Gibson 220db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 2211c5ecae3SMike Kravetz 2221c5ecae3SMike Kravetz if (spool->max_hpages != -1) /* maximum size accounting */ 22390481622SDavid Gibson spool->used_hpages -= delta; 2241c5ecae3SMike Kravetz 22509a95e29SMike Kravetz /* minimum size accounting */ 22609a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { 2271c5ecae3SMike Kravetz if (spool->rsv_hpages + delta <= spool->min_hpages) 2281c5ecae3SMike Kravetz ret = 0; 2291c5ecae3SMike Kravetz else 2301c5ecae3SMike Kravetz ret = spool->rsv_hpages + delta - spool->min_hpages; 2311c5ecae3SMike Kravetz 2321c5ecae3SMike Kravetz spool->rsv_hpages += delta; 2331c5ecae3SMike Kravetz if (spool->rsv_hpages > spool->min_hpages) 2341c5ecae3SMike Kravetz spool->rsv_hpages = spool->min_hpages; 2351c5ecae3SMike Kravetz } 2361c5ecae3SMike Kravetz 2371c5ecae3SMike Kravetz /* 2381c5ecae3SMike Kravetz * If hugetlbfs_put_super couldn't free spool due to an outstanding 2391c5ecae3SMike Kravetz * quota reference, free it now. 2401c5ecae3SMike Kravetz */ 241db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 2421c5ecae3SMike Kravetz 2431c5ecae3SMike Kravetz return ret; 24490481622SDavid Gibson } 24590481622SDavid Gibson 24690481622SDavid Gibson static inline struct hugepage_subpool *subpool_inode(struct inode *inode) 24790481622SDavid Gibson { 24890481622SDavid Gibson return HUGETLBFS_SB(inode->i_sb)->spool; 24990481622SDavid Gibson } 25090481622SDavid Gibson 25190481622SDavid Gibson static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) 25290481622SDavid Gibson { 253496ad9aaSAl Viro return subpool_inode(file_inode(vma->vm_file)); 25490481622SDavid Gibson } 25590481622SDavid Gibson 2560db9d74eSMina Almasry /* Helper that removes a struct file_region from the resv_map cache and returns 2570db9d74eSMina Almasry * it for use. 2580db9d74eSMina Almasry */ 2590db9d74eSMina Almasry static struct file_region * 2600db9d74eSMina Almasry get_file_region_entry_from_cache(struct resv_map *resv, long from, long to) 2610db9d74eSMina Almasry { 2620db9d74eSMina Almasry struct file_region *nrg = NULL; 2630db9d74eSMina Almasry 2640db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count <= 0); 2650db9d74eSMina Almasry 2660db9d74eSMina Almasry resv->region_cache_count--; 2670db9d74eSMina Almasry nrg = list_first_entry(&resv->region_cache, struct file_region, link); 2680db9d74eSMina Almasry list_del(&nrg->link); 2690db9d74eSMina Almasry 2700db9d74eSMina Almasry nrg->from = from; 2710db9d74eSMina Almasry nrg->to = to; 2720db9d74eSMina Almasry 2730db9d74eSMina Almasry return nrg; 2740db9d74eSMina Almasry } 2750db9d74eSMina Almasry 276075a61d0SMina Almasry static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg, 277075a61d0SMina Almasry struct file_region *rg) 278075a61d0SMina Almasry { 279075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 280075a61d0SMina Almasry nrg->reservation_counter = rg->reservation_counter; 281075a61d0SMina Almasry nrg->css = rg->css; 282075a61d0SMina Almasry if (rg->css) 283075a61d0SMina Almasry css_get(rg->css); 284075a61d0SMina Almasry #endif 285075a61d0SMina Almasry } 286075a61d0SMina Almasry 287075a61d0SMina Almasry /* Helper that records hugetlb_cgroup uncharge info. */ 288075a61d0SMina Almasry static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg, 289075a61d0SMina Almasry struct hstate *h, 290075a61d0SMina Almasry struct resv_map *resv, 291075a61d0SMina Almasry struct file_region *nrg) 292075a61d0SMina Almasry { 293075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 294075a61d0SMina Almasry if (h_cg) { 295075a61d0SMina Almasry nrg->reservation_counter = 296075a61d0SMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 297075a61d0SMina Almasry nrg->css = &h_cg->css; 298d85aecf2SMiaohe Lin /* 299d85aecf2SMiaohe Lin * The caller will hold exactly one h_cg->css reference for the 300d85aecf2SMiaohe Lin * whole contiguous reservation region. But this area might be 301d85aecf2SMiaohe Lin * scattered when there are already some file_regions reside in 302d85aecf2SMiaohe Lin * it. As a result, many file_regions may share only one css 303d85aecf2SMiaohe Lin * reference. In order to ensure that one file_region must hold 304d85aecf2SMiaohe Lin * exactly one h_cg->css reference, we should do css_get for 305d85aecf2SMiaohe Lin * each file_region and leave the reference held by caller 306d85aecf2SMiaohe Lin * untouched. 307d85aecf2SMiaohe Lin */ 308d85aecf2SMiaohe Lin css_get(&h_cg->css); 309075a61d0SMina Almasry if (!resv->pages_per_hpage) 310075a61d0SMina Almasry resv->pages_per_hpage = pages_per_huge_page(h); 311075a61d0SMina Almasry /* pages_per_hpage should be the same for all entries in 312075a61d0SMina Almasry * a resv_map. 313075a61d0SMina Almasry */ 314075a61d0SMina Almasry VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h)); 315075a61d0SMina Almasry } else { 316075a61d0SMina Almasry nrg->reservation_counter = NULL; 317075a61d0SMina Almasry nrg->css = NULL; 318075a61d0SMina Almasry } 319075a61d0SMina Almasry #endif 320075a61d0SMina Almasry } 321075a61d0SMina Almasry 322d85aecf2SMiaohe Lin static void put_uncharge_info(struct file_region *rg) 323d85aecf2SMiaohe Lin { 324d85aecf2SMiaohe Lin #ifdef CONFIG_CGROUP_HUGETLB 325d85aecf2SMiaohe Lin if (rg->css) 326d85aecf2SMiaohe Lin css_put(rg->css); 327d85aecf2SMiaohe Lin #endif 328d85aecf2SMiaohe Lin } 329d85aecf2SMiaohe Lin 330a9b3f867SMina Almasry static bool has_same_uncharge_info(struct file_region *rg, 331a9b3f867SMina Almasry struct file_region *org) 332a9b3f867SMina Almasry { 333a9b3f867SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 334a9b3f867SMina Almasry return rg && org && 335a9b3f867SMina Almasry rg->reservation_counter == org->reservation_counter && 336a9b3f867SMina Almasry rg->css == org->css; 337a9b3f867SMina Almasry 338a9b3f867SMina Almasry #else 339a9b3f867SMina Almasry return true; 340a9b3f867SMina Almasry #endif 341a9b3f867SMina Almasry } 342a9b3f867SMina Almasry 343a9b3f867SMina Almasry static void coalesce_file_region(struct resv_map *resv, struct file_region *rg) 344a9b3f867SMina Almasry { 345a9b3f867SMina Almasry struct file_region *nrg = NULL, *prg = NULL; 346a9b3f867SMina Almasry 347a9b3f867SMina Almasry prg = list_prev_entry(rg, link); 348a9b3f867SMina Almasry if (&prg->link != &resv->regions && prg->to == rg->from && 349a9b3f867SMina Almasry has_same_uncharge_info(prg, rg)) { 350a9b3f867SMina Almasry prg->to = rg->to; 351a9b3f867SMina Almasry 352a9b3f867SMina Almasry list_del(&rg->link); 353d85aecf2SMiaohe Lin put_uncharge_info(rg); 354a9b3f867SMina Almasry kfree(rg); 355a9b3f867SMina Almasry 3567db5e7b6SWei Yang rg = prg; 357a9b3f867SMina Almasry } 358a9b3f867SMina Almasry 359a9b3f867SMina Almasry nrg = list_next_entry(rg, link); 360a9b3f867SMina Almasry if (&nrg->link != &resv->regions && nrg->from == rg->to && 361a9b3f867SMina Almasry has_same_uncharge_info(nrg, rg)) { 362a9b3f867SMina Almasry nrg->from = rg->from; 363a9b3f867SMina Almasry 364a9b3f867SMina Almasry list_del(&rg->link); 365d85aecf2SMiaohe Lin put_uncharge_info(rg); 366a9b3f867SMina Almasry kfree(rg); 367a9b3f867SMina Almasry } 368a9b3f867SMina Almasry } 369a9b3f867SMina Almasry 3702103cf9cSPeter Xu static inline long 3712103cf9cSPeter Xu hugetlb_resv_map_add(struct resv_map *map, struct file_region *rg, long from, 3722103cf9cSPeter Xu long to, struct hstate *h, struct hugetlb_cgroup *cg, 3732103cf9cSPeter Xu long *regions_needed) 3742103cf9cSPeter Xu { 3752103cf9cSPeter Xu struct file_region *nrg; 3762103cf9cSPeter Xu 3772103cf9cSPeter Xu if (!regions_needed) { 3782103cf9cSPeter Xu nrg = get_file_region_entry_from_cache(map, from, to); 3792103cf9cSPeter Xu record_hugetlb_cgroup_uncharge_info(cg, h, map, nrg); 3802103cf9cSPeter Xu list_add(&nrg->link, rg->link.prev); 3812103cf9cSPeter Xu coalesce_file_region(map, nrg); 3822103cf9cSPeter Xu } else 3832103cf9cSPeter Xu *regions_needed += 1; 3842103cf9cSPeter Xu 3852103cf9cSPeter Xu return to - from; 3862103cf9cSPeter Xu } 3872103cf9cSPeter Xu 388972a3da3SWei Yang /* 389972a3da3SWei Yang * Must be called with resv->lock held. 390972a3da3SWei Yang * 391972a3da3SWei Yang * Calling this with regions_needed != NULL will count the number of pages 392972a3da3SWei Yang * to be added but will not modify the linked list. And regions_needed will 393972a3da3SWei Yang * indicate the number of file_regions needed in the cache to carry out to add 394972a3da3SWei Yang * the regions for this range. 395d75c6af9SMina Almasry */ 396d75c6af9SMina Almasry static long add_reservation_in_range(struct resv_map *resv, long f, long t, 397075a61d0SMina Almasry struct hugetlb_cgroup *h_cg, 398972a3da3SWei Yang struct hstate *h, long *regions_needed) 399d75c6af9SMina Almasry { 4000db9d74eSMina Almasry long add = 0; 401d75c6af9SMina Almasry struct list_head *head = &resv->regions; 4020db9d74eSMina Almasry long last_accounted_offset = f; 4032103cf9cSPeter Xu struct file_region *rg = NULL, *trg = NULL; 404d75c6af9SMina Almasry 4050db9d74eSMina Almasry if (regions_needed) 4060db9d74eSMina Almasry *regions_needed = 0; 407d75c6af9SMina Almasry 4080db9d74eSMina Almasry /* In this loop, we essentially handle an entry for the range 4090db9d74eSMina Almasry * [last_accounted_offset, rg->from), at every iteration, with some 4100db9d74eSMina Almasry * bounds checking. 4110db9d74eSMina Almasry */ 4120db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, head, link) { 4130db9d74eSMina Almasry /* Skip irrelevant regions that start before our range. */ 4140db9d74eSMina Almasry if (rg->from < f) { 4150db9d74eSMina Almasry /* If this region ends after the last accounted offset, 4160db9d74eSMina Almasry * then we need to update last_accounted_offset. 4170db9d74eSMina Almasry */ 4180db9d74eSMina Almasry if (rg->to > last_accounted_offset) 4190db9d74eSMina Almasry last_accounted_offset = rg->to; 4200db9d74eSMina Almasry continue; 4210db9d74eSMina Almasry } 422d75c6af9SMina Almasry 4230db9d74eSMina Almasry /* When we find a region that starts beyond our range, we've 4240db9d74eSMina Almasry * finished. 4250db9d74eSMina Almasry */ 426ca7e0457SPeter Xu if (rg->from >= t) 427d75c6af9SMina Almasry break; 428d75c6af9SMina Almasry 4290db9d74eSMina Almasry /* Add an entry for last_accounted_offset -> rg->from, and 4300db9d74eSMina Almasry * update last_accounted_offset. 431d75c6af9SMina Almasry */ 4322103cf9cSPeter Xu if (rg->from > last_accounted_offset) 4332103cf9cSPeter Xu add += hugetlb_resv_map_add(resv, rg, 4342103cf9cSPeter Xu last_accounted_offset, 4352103cf9cSPeter Xu rg->from, h, h_cg, 4362103cf9cSPeter Xu regions_needed); 437d75c6af9SMina Almasry 4380db9d74eSMina Almasry last_accounted_offset = rg->to; 4390db9d74eSMina Almasry } 4400db9d74eSMina Almasry 4410db9d74eSMina Almasry /* Handle the case where our range extends beyond 4420db9d74eSMina Almasry * last_accounted_offset. 4430db9d74eSMina Almasry */ 4442103cf9cSPeter Xu if (last_accounted_offset < t) 4452103cf9cSPeter Xu add += hugetlb_resv_map_add(resv, rg, last_accounted_offset, 4462103cf9cSPeter Xu t, h, h_cg, regions_needed); 4470db9d74eSMina Almasry 4480db9d74eSMina Almasry VM_BUG_ON(add < 0); 4490db9d74eSMina Almasry return add; 4500db9d74eSMina Almasry } 4510db9d74eSMina Almasry 4520db9d74eSMina Almasry /* Must be called with resv->lock acquired. Will drop lock to allocate entries. 4530db9d74eSMina Almasry */ 4540db9d74eSMina Almasry static int allocate_file_region_entries(struct resv_map *resv, 4550db9d74eSMina Almasry int regions_needed) 4560db9d74eSMina Almasry __must_hold(&resv->lock) 4570db9d74eSMina Almasry { 4580db9d74eSMina Almasry struct list_head allocated_regions; 4590db9d74eSMina Almasry int to_allocate = 0, i = 0; 4600db9d74eSMina Almasry struct file_region *trg = NULL, *rg = NULL; 4610db9d74eSMina Almasry 4620db9d74eSMina Almasry VM_BUG_ON(regions_needed < 0); 4630db9d74eSMina Almasry 4640db9d74eSMina Almasry INIT_LIST_HEAD(&allocated_regions); 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 1017a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 1018559ec2f8SNicholas Krause static bool vma_has_reserves(struct vm_area_struct *vma, long chg) 1019a1e78772SMel Gorman { 1020af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_NORESERVE) { 1021af0ed73eSJoonsoo Kim /* 1022af0ed73eSJoonsoo Kim * This address is already reserved by other process(chg == 0), 1023af0ed73eSJoonsoo Kim * so, we should decrement reserved count. Without decrementing, 1024af0ed73eSJoonsoo Kim * reserve count remains after releasing inode, because this 1025af0ed73eSJoonsoo Kim * allocated page will go into page cache and is regarded as 1026af0ed73eSJoonsoo Kim * coming from reserved pool in releasing step. Currently, we 1027af0ed73eSJoonsoo Kim * don't have any other solution to deal with this situation 1028af0ed73eSJoonsoo Kim * properly, so add work-around here. 1029af0ed73eSJoonsoo Kim */ 1030af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE && chg == 0) 1031559ec2f8SNicholas Krause return true; 1032af0ed73eSJoonsoo Kim else 1033559ec2f8SNicholas Krause return false; 1034af0ed73eSJoonsoo Kim } 1035a63884e9SJoonsoo Kim 1036a63884e9SJoonsoo Kim /* Shared mappings always use reserves */ 10371fb1b0e9SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 10381fb1b0e9SMike Kravetz /* 10391fb1b0e9SMike Kravetz * We know VM_NORESERVE is not set. Therefore, there SHOULD 10401fb1b0e9SMike Kravetz * be a region map for all pages. The only situation where 10411fb1b0e9SMike Kravetz * there is no region map is if a hole was punched via 10427c8de358SEthon Paul * fallocate. In this case, there really are no reserves to 10431fb1b0e9SMike Kravetz * use. This situation is indicated if chg != 0. 10441fb1b0e9SMike Kravetz */ 10451fb1b0e9SMike Kravetz if (chg) 10461fb1b0e9SMike Kravetz return false; 10471fb1b0e9SMike Kravetz else 1048559ec2f8SNicholas Krause return true; 10491fb1b0e9SMike Kravetz } 1050a63884e9SJoonsoo Kim 1051a63884e9SJoonsoo Kim /* 1052a63884e9SJoonsoo Kim * Only the process that called mmap() has reserves for 1053a63884e9SJoonsoo Kim * private mappings. 1054a63884e9SJoonsoo Kim */ 105567961f9dSMike Kravetz if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 105667961f9dSMike Kravetz /* 105767961f9dSMike Kravetz * Like the shared case above, a hole punch or truncate 105867961f9dSMike Kravetz * could have been performed on the private mapping. 105967961f9dSMike Kravetz * Examine the value of chg to determine if reserves 106067961f9dSMike Kravetz * actually exist or were previously consumed. 106167961f9dSMike Kravetz * Very Subtle - The value of chg comes from a previous 106267961f9dSMike Kravetz * call to vma_needs_reserves(). The reserve map for 106367961f9dSMike Kravetz * private mappings has different (opposite) semantics 106467961f9dSMike Kravetz * than that of shared mappings. vma_needs_reserves() 106567961f9dSMike Kravetz * has already taken this difference in semantics into 106667961f9dSMike Kravetz * account. Therefore, the meaning of chg is the same 106767961f9dSMike Kravetz * as in the shared case above. Code could easily be 106867961f9dSMike Kravetz * combined, but keeping it separate draws attention to 106967961f9dSMike Kravetz * subtle differences. 107067961f9dSMike Kravetz */ 107167961f9dSMike Kravetz if (chg) 107267961f9dSMike Kravetz return false; 107367961f9dSMike Kravetz else 1074559ec2f8SNicholas Krause return true; 107567961f9dSMike Kravetz } 1076a63884e9SJoonsoo Kim 1077559ec2f8SNicholas Krause return false; 1078a1e78772SMel Gorman } 1079a1e78772SMel Gorman 1080a5516438SAndi Kleen static void enqueue_huge_page(struct hstate *h, struct page *page) 10811da177e4SLinus Torvalds { 10821da177e4SLinus Torvalds int nid = page_to_nid(page); 10839487ca60SMike Kravetz 10849487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1085b65a4edaSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1086b65a4edaSMike Kravetz 10870edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_freelists[nid]); 1088a5516438SAndi Kleen h->free_huge_pages++; 1089a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 10906c037149SMike Kravetz SetHPageFreed(page); 10911da177e4SLinus Torvalds } 10921da177e4SLinus Torvalds 109394310cbcSAnshuman Khandual static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) 1094bf50bab2SNaoya Horiguchi { 1095bf50bab2SNaoya Horiguchi struct page *page; 10961a08ae36SPavel Tatashin bool pin = !!(current->flags & PF_MEMALLOC_PIN); 1097bf50bab2SNaoya Horiguchi 10989487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1099bbe88753SJoonsoo Kim list_for_each_entry(page, &h->hugepage_freelists[nid], lru) { 11008e3560d9SPavel Tatashin if (pin && !is_pinnable_page(page)) 1101bbe88753SJoonsoo Kim continue; 1102bbe88753SJoonsoo Kim 11036664bfc8SWei Yang if (PageHWPoison(page)) 11046664bfc8SWei Yang continue; 1105bbe88753SJoonsoo Kim 11060edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_activelist); 1107a9869b83SNaoya Horiguchi set_page_refcounted(page); 11086c037149SMike Kravetz ClearHPageFreed(page); 1109bf50bab2SNaoya Horiguchi h->free_huge_pages--; 1110bf50bab2SNaoya Horiguchi h->free_huge_pages_node[nid]--; 1111bf50bab2SNaoya Horiguchi return page; 1112bf50bab2SNaoya Horiguchi } 1113bf50bab2SNaoya Horiguchi 11146664bfc8SWei Yang return NULL; 11156664bfc8SWei Yang } 11166664bfc8SWei Yang 11173e59fcb0SMichal Hocko static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid, 11183e59fcb0SMichal Hocko nodemask_t *nmask) 111994310cbcSAnshuman Khandual { 11203e59fcb0SMichal Hocko unsigned int cpuset_mems_cookie; 11213e59fcb0SMichal Hocko struct zonelist *zonelist; 11223e59fcb0SMichal Hocko struct zone *zone; 11233e59fcb0SMichal Hocko struct zoneref *z; 112498fa15f3SAnshuman Khandual int node = NUMA_NO_NODE; 11253e59fcb0SMichal Hocko 11263e59fcb0SMichal Hocko zonelist = node_zonelist(nid, gfp_mask); 11273e59fcb0SMichal Hocko 11283e59fcb0SMichal Hocko retry_cpuset: 11293e59fcb0SMichal Hocko cpuset_mems_cookie = read_mems_allowed_begin(); 11303e59fcb0SMichal Hocko for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) { 113194310cbcSAnshuman Khandual struct page *page; 113294310cbcSAnshuman Khandual 11333e59fcb0SMichal Hocko if (!cpuset_zone_allowed(zone, gfp_mask)) 11343e59fcb0SMichal Hocko continue; 11353e59fcb0SMichal Hocko /* 11363e59fcb0SMichal Hocko * no need to ask again on the same node. Pool is node rather than 11373e59fcb0SMichal Hocko * zone aware 11383e59fcb0SMichal Hocko */ 11393e59fcb0SMichal Hocko if (zone_to_nid(zone) == node) 11403e59fcb0SMichal Hocko continue; 11413e59fcb0SMichal Hocko node = zone_to_nid(zone); 114294310cbcSAnshuman Khandual 114394310cbcSAnshuman Khandual page = dequeue_huge_page_node_exact(h, node); 114494310cbcSAnshuman Khandual if (page) 114594310cbcSAnshuman Khandual return page; 114694310cbcSAnshuman Khandual } 11473e59fcb0SMichal Hocko if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie))) 11483e59fcb0SMichal Hocko goto retry_cpuset; 11493e59fcb0SMichal Hocko 115094310cbcSAnshuman Khandual return NULL; 115194310cbcSAnshuman Khandual } 115294310cbcSAnshuman Khandual 1153a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 1154a5516438SAndi Kleen struct vm_area_struct *vma, 1155af0ed73eSJoonsoo Kim unsigned long address, int avoid_reserve, 1156af0ed73eSJoonsoo Kim long chg) 11571da177e4SLinus Torvalds { 1158cfcaa66fSBen Widawsky struct page *page = NULL; 1159480eccf9SLee Schermerhorn struct mempolicy *mpol; 116004ec6264SVlastimil Babka gfp_t gfp_mask; 11613e59fcb0SMichal Hocko nodemask_t *nodemask; 116204ec6264SVlastimil Babka int nid; 11631da177e4SLinus Torvalds 1164a1e78772SMel Gorman /* 1165a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 1166a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 1167a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 1168a1e78772SMel Gorman */ 1169af0ed73eSJoonsoo Kim if (!vma_has_reserves(vma, chg) && 1170a5516438SAndi Kleen h->free_huge_pages - h->resv_huge_pages == 0) 1171c0ff7453SMiao Xie goto err; 1172a1e78772SMel Gorman 117304f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 1174a5516438SAndi Kleen if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) 11756eab04a8SJustin P. Mattock goto err; 117604f2cbe3SMel Gorman 117704ec6264SVlastimil Babka gfp_mask = htlb_alloc_mask(h); 117804ec6264SVlastimil Babka nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 1179cfcaa66fSBen Widawsky 1180cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 11813e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1182cfcaa66fSBen Widawsky 1183cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 1184cfcaa66fSBen Widawsky nodemask = NULL; 1185cfcaa66fSBen Widawsky } 1186cfcaa66fSBen Widawsky 1187cfcaa66fSBen Widawsky if (!page) 1188cfcaa66fSBen Widawsky page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1189cfcaa66fSBen Widawsky 11903e59fcb0SMichal Hocko if (page && !avoid_reserve && vma_has_reserves(vma, chg)) { 1191d6995da3SMike Kravetz SetHPageRestoreReserve(page); 1192a63884e9SJoonsoo Kim h->resv_huge_pages--; 1193bf50bab2SNaoya Horiguchi } 1194cc9a6c87SMel Gorman 1195cc9a6c87SMel Gorman mpol_cond_put(mpol); 1196cc9a6c87SMel Gorman return page; 1197cc9a6c87SMel Gorman 1198c0ff7453SMiao Xie err: 1199cc9a6c87SMel Gorman return NULL; 12001da177e4SLinus Torvalds } 12011da177e4SLinus Torvalds 12021cac6f2cSLuiz Capitulino /* 12031cac6f2cSLuiz Capitulino * common helper functions for hstate_next_node_to_{alloc|free}. 12041cac6f2cSLuiz Capitulino * We may have allocated or freed a huge page based on a different 12051cac6f2cSLuiz Capitulino * nodes_allowed previously, so h->next_node_to_{alloc|free} might 12061cac6f2cSLuiz Capitulino * be outside of *nodes_allowed. Ensure that we use an allowed 12071cac6f2cSLuiz Capitulino * node for alloc or free. 12081cac6f2cSLuiz Capitulino */ 12091cac6f2cSLuiz Capitulino static int next_node_allowed(int nid, nodemask_t *nodes_allowed) 12101cac6f2cSLuiz Capitulino { 12110edaf86cSAndrew Morton nid = next_node_in(nid, *nodes_allowed); 12121cac6f2cSLuiz Capitulino VM_BUG_ON(nid >= MAX_NUMNODES); 12131cac6f2cSLuiz Capitulino 12141cac6f2cSLuiz Capitulino return nid; 12151cac6f2cSLuiz Capitulino } 12161cac6f2cSLuiz Capitulino 12171cac6f2cSLuiz Capitulino static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) 12181cac6f2cSLuiz Capitulino { 12191cac6f2cSLuiz Capitulino if (!node_isset(nid, *nodes_allowed)) 12201cac6f2cSLuiz Capitulino nid = next_node_allowed(nid, nodes_allowed); 12211cac6f2cSLuiz Capitulino return nid; 12221cac6f2cSLuiz Capitulino } 12231cac6f2cSLuiz Capitulino 12241cac6f2cSLuiz Capitulino /* 12251cac6f2cSLuiz Capitulino * returns the previously saved node ["this node"] from which to 12261cac6f2cSLuiz Capitulino * allocate a persistent huge page for the pool and advance the 12271cac6f2cSLuiz Capitulino * next node from which to allocate, handling wrap at end of node 12281cac6f2cSLuiz Capitulino * mask. 12291cac6f2cSLuiz Capitulino */ 12301cac6f2cSLuiz Capitulino static int hstate_next_node_to_alloc(struct hstate *h, 12311cac6f2cSLuiz Capitulino nodemask_t *nodes_allowed) 12321cac6f2cSLuiz Capitulino { 12331cac6f2cSLuiz Capitulino int nid; 12341cac6f2cSLuiz Capitulino 12351cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12361cac6f2cSLuiz Capitulino 12371cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); 12381cac6f2cSLuiz Capitulino h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); 12391cac6f2cSLuiz Capitulino 12401cac6f2cSLuiz Capitulino return nid; 12411cac6f2cSLuiz Capitulino } 12421cac6f2cSLuiz Capitulino 12431cac6f2cSLuiz Capitulino /* 124410c6ec49SMike Kravetz * helper for remove_pool_huge_page() - return the previously saved 12451cac6f2cSLuiz Capitulino * node ["this node"] from which to free a huge page. Advance the 12461cac6f2cSLuiz Capitulino * next node id whether or not we find a free huge page to free so 12471cac6f2cSLuiz Capitulino * that the next attempt to free addresses the next node. 12481cac6f2cSLuiz Capitulino */ 12491cac6f2cSLuiz Capitulino static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) 12501cac6f2cSLuiz Capitulino { 12511cac6f2cSLuiz Capitulino int nid; 12521cac6f2cSLuiz Capitulino 12531cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12541cac6f2cSLuiz Capitulino 12551cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); 12561cac6f2cSLuiz Capitulino h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); 12571cac6f2cSLuiz Capitulino 12581cac6f2cSLuiz Capitulino return nid; 12591cac6f2cSLuiz Capitulino } 12601cac6f2cSLuiz Capitulino 12611cac6f2cSLuiz Capitulino #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ 12621cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 12631cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 12641cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ 12651cac6f2cSLuiz Capitulino nr_nodes--) 12661cac6f2cSLuiz Capitulino 12671cac6f2cSLuiz Capitulino #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ 12681cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 12691cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 12701cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_free(hs, mask)) || 1); \ 12711cac6f2cSLuiz Capitulino nr_nodes--) 12721cac6f2cSLuiz Capitulino 1273*8531fc6fSMike Kravetz /* used to demote non-gigantic_huge pages as well */ 127434d9e35bSMike Kravetz static void __destroy_compound_gigantic_page(struct page *page, 127534d9e35bSMike Kravetz unsigned int order, bool demote) 1276944d9fecSLuiz Capitulino { 1277944d9fecSLuiz Capitulino int i; 1278944d9fecSLuiz Capitulino int nr_pages = 1 << order; 1279944d9fecSLuiz Capitulino struct page *p = page + 1; 1280944d9fecSLuiz Capitulino 1281c8cc708aSGerald Schaefer atomic_set(compound_mapcount_ptr(page), 0); 128247e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 128347e29d32SJohn Hubbard 1284944d9fecSLuiz Capitulino for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 1285a01f4390SMike Kravetz p->mapping = NULL; 12861d798ca3SKirill A. Shutemov clear_compound_head(p); 128734d9e35bSMike Kravetz if (!demote) 1288944d9fecSLuiz Capitulino set_page_refcounted(p); 1289944d9fecSLuiz Capitulino } 1290944d9fecSLuiz Capitulino 1291944d9fecSLuiz Capitulino set_compound_order(page, 0); 1292ba9c1201SGerald Schaefer page[1].compound_nr = 0; 1293944d9fecSLuiz Capitulino __ClearPageHead(page); 1294944d9fecSLuiz Capitulino } 1295944d9fecSLuiz Capitulino 1296*8531fc6fSMike Kravetz static void destroy_compound_hugetlb_page_for_demote(struct page *page, 1297*8531fc6fSMike Kravetz unsigned int order) 1298*8531fc6fSMike Kravetz { 1299*8531fc6fSMike Kravetz __destroy_compound_gigantic_page(page, order, true); 1300*8531fc6fSMike Kravetz } 1301*8531fc6fSMike Kravetz 1302*8531fc6fSMike Kravetz #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE 130334d9e35bSMike Kravetz static void destroy_compound_gigantic_page(struct page *page, 130434d9e35bSMike Kravetz unsigned int order) 130534d9e35bSMike Kravetz { 130634d9e35bSMike Kravetz __destroy_compound_gigantic_page(page, order, false); 130734d9e35bSMike Kravetz } 130834d9e35bSMike Kravetz 1309d00181b9SKirill A. Shutemov static void free_gigantic_page(struct page *page, unsigned int order) 1310944d9fecSLuiz Capitulino { 1311cf11e85fSRoman Gushchin /* 1312cf11e85fSRoman Gushchin * If the page isn't allocated using the cma allocator, 1313cf11e85fSRoman Gushchin * cma_release() returns false. 1314cf11e85fSRoman Gushchin */ 1315dbda8feaSBarry Song #ifdef CONFIG_CMA 1316dbda8feaSBarry Song if (cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order)) 1317cf11e85fSRoman Gushchin return; 1318dbda8feaSBarry Song #endif 1319cf11e85fSRoman Gushchin 1320944d9fecSLuiz Capitulino free_contig_range(page_to_pfn(page), 1 << order); 1321944d9fecSLuiz Capitulino } 1322944d9fecSLuiz Capitulino 13234eb0716eSAlexandre Ghiti #ifdef CONFIG_CONTIG_ALLOC 1324d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 1325d9cc948fSMichal Hocko int nid, nodemask_t *nodemask) 1326944d9fecSLuiz Capitulino { 132704adbc3fSMiaohe Lin unsigned long nr_pages = pages_per_huge_page(h); 1328953f064aSLi Xinhai if (nid == NUMA_NO_NODE) 1329953f064aSLi Xinhai nid = numa_mem_id(); 1330944d9fecSLuiz Capitulino 1331dbda8feaSBarry Song #ifdef CONFIG_CMA 1332dbda8feaSBarry Song { 1333cf11e85fSRoman Gushchin struct page *page; 1334cf11e85fSRoman Gushchin int node; 1335cf11e85fSRoman Gushchin 1336953f064aSLi Xinhai if (hugetlb_cma[nid]) { 1337953f064aSLi Xinhai page = cma_alloc(hugetlb_cma[nid], nr_pages, 1338953f064aSLi Xinhai huge_page_order(h), true); 1339953f064aSLi Xinhai if (page) 1340953f064aSLi Xinhai return page; 1341953f064aSLi Xinhai } 1342953f064aSLi Xinhai 1343953f064aSLi Xinhai if (!(gfp_mask & __GFP_THISNODE)) { 1344cf11e85fSRoman Gushchin for_each_node_mask(node, *nodemask) { 1345953f064aSLi Xinhai if (node == nid || !hugetlb_cma[node]) 1346cf11e85fSRoman Gushchin continue; 1347cf11e85fSRoman Gushchin 1348cf11e85fSRoman Gushchin page = cma_alloc(hugetlb_cma[node], nr_pages, 1349cf11e85fSRoman Gushchin huge_page_order(h), true); 1350cf11e85fSRoman Gushchin if (page) 1351cf11e85fSRoman Gushchin return page; 1352cf11e85fSRoman Gushchin } 1353cf11e85fSRoman Gushchin } 1354953f064aSLi Xinhai } 1355dbda8feaSBarry Song #endif 1356cf11e85fSRoman Gushchin 13575e27a2dfSAnshuman Khandual return alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask); 1358944d9fecSLuiz Capitulino } 1359944d9fecSLuiz Capitulino 13604eb0716eSAlexandre Ghiti #else /* !CONFIG_CONTIG_ALLOC */ 13614eb0716eSAlexandre Ghiti static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 13624eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 13634eb0716eSAlexandre Ghiti { 13644eb0716eSAlexandre Ghiti return NULL; 13654eb0716eSAlexandre Ghiti } 13664eb0716eSAlexandre Ghiti #endif /* CONFIG_CONTIG_ALLOC */ 1367944d9fecSLuiz Capitulino 1368e1073d1eSAneesh Kumar K.V #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ 1369d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 13704eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 13714eb0716eSAlexandre Ghiti { 13724eb0716eSAlexandre Ghiti return NULL; 13734eb0716eSAlexandre Ghiti } 1374d00181b9SKirill A. Shutemov static inline void free_gigantic_page(struct page *page, unsigned int order) { } 1375944d9fecSLuiz Capitulino static inline void destroy_compound_gigantic_page(struct page *page, 1376d00181b9SKirill A. Shutemov unsigned int order) { } 1377944d9fecSLuiz Capitulino #endif 1378944d9fecSLuiz Capitulino 13796eb4e88aSMike Kravetz /* 13806eb4e88aSMike Kravetz * Remove hugetlb page from lists, and update dtor so that page appears 138134d9e35bSMike Kravetz * as just a compound page. 138234d9e35bSMike Kravetz * 138334d9e35bSMike Kravetz * A reference is held on the page, except in the case of demote. 13846eb4e88aSMike Kravetz * 13856eb4e88aSMike Kravetz * Must be called with hugetlb lock held. 13866eb4e88aSMike Kravetz */ 138734d9e35bSMike Kravetz static void __remove_hugetlb_page(struct hstate *h, struct page *page, 138834d9e35bSMike Kravetz bool adjust_surplus, 138934d9e35bSMike Kravetz bool demote) 13906eb4e88aSMike Kravetz { 13916eb4e88aSMike Kravetz int nid = page_to_nid(page); 13926eb4e88aSMike Kravetz 13936eb4e88aSMike Kravetz VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); 13946eb4e88aSMike Kravetz VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); 13956eb4e88aSMike Kravetz 13969487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 13976eb4e88aSMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 13986eb4e88aSMike Kravetz return; 13996eb4e88aSMike Kravetz 14006eb4e88aSMike Kravetz list_del(&page->lru); 14016eb4e88aSMike Kravetz 14026eb4e88aSMike Kravetz if (HPageFreed(page)) { 14036eb4e88aSMike Kravetz h->free_huge_pages--; 14046eb4e88aSMike Kravetz h->free_huge_pages_node[nid]--; 14056eb4e88aSMike Kravetz } 14066eb4e88aSMike Kravetz if (adjust_surplus) { 14076eb4e88aSMike Kravetz h->surplus_huge_pages--; 14086eb4e88aSMike Kravetz h->surplus_huge_pages_node[nid]--; 14096eb4e88aSMike Kravetz } 14106eb4e88aSMike Kravetz 1411e32d20c0SMike Kravetz /* 1412e32d20c0SMike Kravetz * Very subtle 1413e32d20c0SMike Kravetz * 1414e32d20c0SMike Kravetz * For non-gigantic pages set the destructor to the normal compound 1415e32d20c0SMike Kravetz * page dtor. This is needed in case someone takes an additional 1416e32d20c0SMike Kravetz * temporary ref to the page, and freeing is delayed until they drop 1417e32d20c0SMike Kravetz * their reference. 1418e32d20c0SMike Kravetz * 1419e32d20c0SMike Kravetz * For gigantic pages set the destructor to the null dtor. This 1420e32d20c0SMike Kravetz * destructor will never be called. Before freeing the gigantic 1421e32d20c0SMike Kravetz * page destroy_compound_gigantic_page will turn the compound page 1422e32d20c0SMike Kravetz * into a simple group of pages. After this the destructor does not 1423e32d20c0SMike Kravetz * apply. 1424e32d20c0SMike Kravetz * 1425e32d20c0SMike Kravetz * This handles the case where more than one ref is held when and 1426e32d20c0SMike Kravetz * after update_and_free_page is called. 142734d9e35bSMike Kravetz * 142834d9e35bSMike Kravetz * In the case of demote we do not ref count the page as it will soon 142934d9e35bSMike Kravetz * be turned into a page of smaller size. 1430e32d20c0SMike Kravetz */ 143134d9e35bSMike Kravetz if (!demote) 14326eb4e88aSMike Kravetz set_page_refcounted(page); 1433e32d20c0SMike Kravetz if (hstate_is_gigantic(h)) 14346eb4e88aSMike Kravetz set_compound_page_dtor(page, NULL_COMPOUND_DTOR); 1435e32d20c0SMike Kravetz else 1436e32d20c0SMike Kravetz set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); 14376eb4e88aSMike Kravetz 14386eb4e88aSMike Kravetz h->nr_huge_pages--; 14396eb4e88aSMike Kravetz h->nr_huge_pages_node[nid]--; 14406eb4e88aSMike Kravetz } 14416eb4e88aSMike Kravetz 144234d9e35bSMike Kravetz static void remove_hugetlb_page(struct hstate *h, struct page *page, 144334d9e35bSMike Kravetz bool adjust_surplus) 144434d9e35bSMike Kravetz { 144534d9e35bSMike Kravetz __remove_hugetlb_page(h, page, adjust_surplus, false); 144634d9e35bSMike Kravetz } 144734d9e35bSMike Kravetz 1448*8531fc6fSMike Kravetz static void remove_hugetlb_page_for_demote(struct hstate *h, struct page *page, 1449*8531fc6fSMike Kravetz bool adjust_surplus) 1450*8531fc6fSMike Kravetz { 1451*8531fc6fSMike Kravetz __remove_hugetlb_page(h, page, adjust_surplus, true); 1452*8531fc6fSMike Kravetz } 1453*8531fc6fSMike Kravetz 1454ad2fa371SMuchun Song static void add_hugetlb_page(struct hstate *h, struct page *page, 1455ad2fa371SMuchun Song bool adjust_surplus) 1456ad2fa371SMuchun Song { 1457ad2fa371SMuchun Song int zeroed; 1458ad2fa371SMuchun Song int nid = page_to_nid(page); 1459ad2fa371SMuchun Song 1460ad2fa371SMuchun Song VM_BUG_ON_PAGE(!HPageVmemmapOptimized(page), page); 1461ad2fa371SMuchun Song 1462ad2fa371SMuchun Song lockdep_assert_held(&hugetlb_lock); 1463ad2fa371SMuchun Song 1464ad2fa371SMuchun Song INIT_LIST_HEAD(&page->lru); 1465ad2fa371SMuchun Song h->nr_huge_pages++; 1466ad2fa371SMuchun Song h->nr_huge_pages_node[nid]++; 1467ad2fa371SMuchun Song 1468ad2fa371SMuchun Song if (adjust_surplus) { 1469ad2fa371SMuchun Song h->surplus_huge_pages++; 1470ad2fa371SMuchun Song h->surplus_huge_pages_node[nid]++; 1471ad2fa371SMuchun Song } 1472ad2fa371SMuchun Song 1473ad2fa371SMuchun Song set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1474ad2fa371SMuchun Song set_page_private(page, 0); 1475ad2fa371SMuchun Song SetHPageVmemmapOptimized(page); 1476ad2fa371SMuchun Song 1477ad2fa371SMuchun Song /* 1478b65a4edaSMike Kravetz * This page is about to be managed by the hugetlb allocator and 1479b65a4edaSMike Kravetz * should have no users. Drop our reference, and check for others 1480b65a4edaSMike Kravetz * just in case. 1481ad2fa371SMuchun Song */ 1482ad2fa371SMuchun Song zeroed = put_page_testzero(page); 1483b65a4edaSMike Kravetz if (!zeroed) 1484b65a4edaSMike Kravetz /* 1485b65a4edaSMike Kravetz * It is VERY unlikely soneone else has taken a ref on 1486b65a4edaSMike Kravetz * the page. In this case, we simply return as the 1487b65a4edaSMike Kravetz * hugetlb destructor (free_huge_page) will be called 1488b65a4edaSMike Kravetz * when this other ref is dropped. 1489b65a4edaSMike Kravetz */ 1490b65a4edaSMike Kravetz return; 1491b65a4edaSMike Kravetz 1492ad2fa371SMuchun Song arch_clear_hugepage_flags(page); 1493ad2fa371SMuchun Song enqueue_huge_page(h, page); 1494ad2fa371SMuchun Song } 1495ad2fa371SMuchun Song 1496b65d4adbSMuchun Song static void __update_and_free_page(struct hstate *h, struct page *page) 14976af2acb6SAdam Litke { 14986af2acb6SAdam Litke int i; 1499dbfee5aeSMike Kravetz struct page *subpage = page; 1500a5516438SAndi Kleen 15014eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 1502944d9fecSLuiz Capitulino return; 150318229df5SAndy Whitcroft 1504ad2fa371SMuchun Song if (alloc_huge_page_vmemmap(h, page)) { 1505ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 1506ad2fa371SMuchun Song /* 1507ad2fa371SMuchun Song * If we cannot allocate vmemmap pages, just refuse to free the 1508ad2fa371SMuchun Song * page and put the page back on the hugetlb free list and treat 1509ad2fa371SMuchun Song * as a surplus page. 1510ad2fa371SMuchun Song */ 1511ad2fa371SMuchun Song add_hugetlb_page(h, page, true); 1512ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 1513ad2fa371SMuchun Song return; 1514ad2fa371SMuchun Song } 1515ad2fa371SMuchun Song 1516dbfee5aeSMike Kravetz for (i = 0; i < pages_per_huge_page(h); 1517dbfee5aeSMike Kravetz i++, subpage = mem_map_next(subpage, page, i)) { 1518dbfee5aeSMike Kravetz subpage->flags &= ~(1 << PG_locked | 1 << PG_error | 151932f84528SChris Forbes 1 << PG_referenced | 1 << PG_dirty | 1520a7407a27SLuiz Capitulino 1 << PG_active | 1 << PG_private | 1521a7407a27SLuiz Capitulino 1 << PG_writeback); 15226af2acb6SAdam Litke } 1523a01f4390SMike Kravetz 1524a01f4390SMike Kravetz /* 1525a01f4390SMike Kravetz * Non-gigantic pages demoted from CMA allocated gigantic pages 1526a01f4390SMike Kravetz * need to be given back to CMA in free_gigantic_page. 1527a01f4390SMike Kravetz */ 1528a01f4390SMike Kravetz if (hstate_is_gigantic(h) || 1529a01f4390SMike Kravetz hugetlb_cma_page(page, huge_page_order(h))) { 1530944d9fecSLuiz Capitulino destroy_compound_gigantic_page(page, huge_page_order(h)); 1531944d9fecSLuiz Capitulino free_gigantic_page(page, huge_page_order(h)); 1532944d9fecSLuiz Capitulino } else { 1533a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 15346af2acb6SAdam Litke } 1535944d9fecSLuiz Capitulino } 15366af2acb6SAdam Litke 1537b65d4adbSMuchun Song /* 1538b65d4adbSMuchun Song * As update_and_free_page() can be called under any context, so we cannot 1539b65d4adbSMuchun Song * use GFP_KERNEL to allocate vmemmap pages. However, we can defer the 1540b65d4adbSMuchun Song * actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate 1541b65d4adbSMuchun Song * the vmemmap pages. 1542b65d4adbSMuchun Song * 1543b65d4adbSMuchun Song * free_hpage_workfn() locklessly retrieves the linked list of pages to be 1544b65d4adbSMuchun Song * freed and frees them one-by-one. As the page->mapping pointer is going 1545b65d4adbSMuchun Song * to be cleared in free_hpage_workfn() anyway, it is reused as the llist_node 1546b65d4adbSMuchun Song * structure of a lockless linked list of huge pages to be freed. 1547b65d4adbSMuchun Song */ 1548b65d4adbSMuchun Song static LLIST_HEAD(hpage_freelist); 1549b65d4adbSMuchun Song 1550b65d4adbSMuchun Song static void free_hpage_workfn(struct work_struct *work) 1551b65d4adbSMuchun Song { 1552b65d4adbSMuchun Song struct llist_node *node; 1553b65d4adbSMuchun Song 1554b65d4adbSMuchun Song node = llist_del_all(&hpage_freelist); 1555b65d4adbSMuchun Song 1556b65d4adbSMuchun Song while (node) { 1557b65d4adbSMuchun Song struct page *page; 1558b65d4adbSMuchun Song struct hstate *h; 1559b65d4adbSMuchun Song 1560b65d4adbSMuchun Song page = container_of((struct address_space **)node, 1561b65d4adbSMuchun Song struct page, mapping); 1562b65d4adbSMuchun Song node = node->next; 1563b65d4adbSMuchun Song page->mapping = NULL; 1564b65d4adbSMuchun Song /* 1565b65d4adbSMuchun Song * The VM_BUG_ON_PAGE(!PageHuge(page), page) in page_hstate() 1566b65d4adbSMuchun Song * is going to trigger because a previous call to 1567b65d4adbSMuchun Song * remove_hugetlb_page() will set_compound_page_dtor(page, 1568b65d4adbSMuchun Song * NULL_COMPOUND_DTOR), so do not use page_hstate() directly. 1569b65d4adbSMuchun Song */ 1570b65d4adbSMuchun Song h = size_to_hstate(page_size(page)); 1571b65d4adbSMuchun Song 1572b65d4adbSMuchun Song __update_and_free_page(h, page); 1573b65d4adbSMuchun Song 1574b65d4adbSMuchun Song cond_resched(); 1575b65d4adbSMuchun Song } 1576b65d4adbSMuchun Song } 1577b65d4adbSMuchun Song static DECLARE_WORK(free_hpage_work, free_hpage_workfn); 1578b65d4adbSMuchun Song 1579b65d4adbSMuchun Song static inline void flush_free_hpage_work(struct hstate *h) 1580b65d4adbSMuchun Song { 1581b65d4adbSMuchun Song if (free_vmemmap_pages_per_hpage(h)) 1582b65d4adbSMuchun Song flush_work(&free_hpage_work); 1583b65d4adbSMuchun Song } 1584b65d4adbSMuchun Song 1585b65d4adbSMuchun Song static void update_and_free_page(struct hstate *h, struct page *page, 1586b65d4adbSMuchun Song bool atomic) 1587b65d4adbSMuchun Song { 1588ad2fa371SMuchun Song if (!HPageVmemmapOptimized(page) || !atomic) { 1589b65d4adbSMuchun Song __update_and_free_page(h, page); 1590b65d4adbSMuchun Song return; 1591b65d4adbSMuchun Song } 1592b65d4adbSMuchun Song 1593b65d4adbSMuchun Song /* 1594b65d4adbSMuchun Song * Defer freeing to avoid using GFP_ATOMIC to allocate vmemmap pages. 1595b65d4adbSMuchun Song * 1596b65d4adbSMuchun Song * Only call schedule_work() if hpage_freelist is previously 1597b65d4adbSMuchun Song * empty. Otherwise, schedule_work() had been called but the workfn 1598b65d4adbSMuchun Song * hasn't retrieved the list yet. 1599b65d4adbSMuchun Song */ 1600b65d4adbSMuchun Song if (llist_add((struct llist_node *)&page->mapping, &hpage_freelist)) 1601b65d4adbSMuchun Song schedule_work(&free_hpage_work); 1602b65d4adbSMuchun Song } 1603b65d4adbSMuchun Song 160410c6ec49SMike Kravetz static void update_and_free_pages_bulk(struct hstate *h, struct list_head *list) 160510c6ec49SMike Kravetz { 160610c6ec49SMike Kravetz struct page *page, *t_page; 160710c6ec49SMike Kravetz 160810c6ec49SMike Kravetz list_for_each_entry_safe(page, t_page, list, lru) { 1609b65d4adbSMuchun Song update_and_free_page(h, page, false); 161010c6ec49SMike Kravetz cond_resched(); 161110c6ec49SMike Kravetz } 161210c6ec49SMike Kravetz } 161310c6ec49SMike Kravetz 1614e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 1615e5ff2159SAndi Kleen { 1616e5ff2159SAndi Kleen struct hstate *h; 1617e5ff2159SAndi Kleen 1618e5ff2159SAndi Kleen for_each_hstate(h) { 1619e5ff2159SAndi Kleen if (huge_page_size(h) == size) 1620e5ff2159SAndi Kleen return h; 1621e5ff2159SAndi Kleen } 1622e5ff2159SAndi Kleen return NULL; 1623e5ff2159SAndi Kleen } 1624e5ff2159SAndi Kleen 1625db71ef79SMike Kravetz void free_huge_page(struct page *page) 162627a85ef1SDavid Gibson { 1627a5516438SAndi Kleen /* 1628a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 1629a5516438SAndi Kleen * compound page destructor. 1630a5516438SAndi Kleen */ 1631e5ff2159SAndi Kleen struct hstate *h = page_hstate(page); 16327893d1d5SAdam Litke int nid = page_to_nid(page); 1633d6995da3SMike Kravetz struct hugepage_subpool *spool = hugetlb_page_subpool(page); 163407443a85SJoonsoo Kim bool restore_reserve; 1635db71ef79SMike Kravetz unsigned long flags; 163627a85ef1SDavid Gibson 1637b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1638b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_mapcount(page), page); 16398ace22bcSYongkai Wu 1640d6995da3SMike Kravetz hugetlb_set_page_subpool(page, NULL); 16418ace22bcSYongkai Wu page->mapping = NULL; 1642d6995da3SMike Kravetz restore_reserve = HPageRestoreReserve(page); 1643d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 164427a85ef1SDavid Gibson 16451c5ecae3SMike Kravetz /* 1646d6995da3SMike Kravetz * If HPageRestoreReserve was set on page, page allocation consumed a 16470919e1b6SMike Kravetz * reservation. If the page was associated with a subpool, there 16480919e1b6SMike Kravetz * would have been a page reserved in the subpool before allocation 16490919e1b6SMike Kravetz * via hugepage_subpool_get_pages(). Since we are 'restoring' the 16506c26d310SMiaohe Lin * reservation, do not call hugepage_subpool_put_pages() as this will 16510919e1b6SMike Kravetz * remove the reserved page from the subpool. 16520919e1b6SMike Kravetz */ 16530919e1b6SMike Kravetz if (!restore_reserve) { 16540919e1b6SMike Kravetz /* 16550919e1b6SMike Kravetz * A return code of zero implies that the subpool will be 16560919e1b6SMike Kravetz * under its minimum size if the reservation is not restored 16570919e1b6SMike Kravetz * after page is free. Therefore, force restore_reserve 16580919e1b6SMike Kravetz * operation. 16591c5ecae3SMike Kravetz */ 16601c5ecae3SMike Kravetz if (hugepage_subpool_put_pages(spool, 1) == 0) 16611c5ecae3SMike Kravetz restore_reserve = true; 16620919e1b6SMike Kravetz } 16631c5ecae3SMike Kravetz 1664db71ef79SMike Kravetz spin_lock_irqsave(&hugetlb_lock, flags); 16658f251a3dSMike Kravetz ClearHPageMigratable(page); 16666d76dcf4SAneesh Kumar K.V hugetlb_cgroup_uncharge_page(hstate_index(h), 16676d76dcf4SAneesh Kumar K.V pages_per_huge_page(h), page); 166808cf9fafSMina Almasry hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 166908cf9fafSMina Almasry pages_per_huge_page(h), page); 167007443a85SJoonsoo Kim if (restore_reserve) 167107443a85SJoonsoo Kim h->resv_huge_pages++; 167207443a85SJoonsoo Kim 16739157c311SMike Kravetz if (HPageTemporary(page)) { 16746eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 1675db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1676b65d4adbSMuchun Song update_and_free_page(h, page, true); 1677ab5ac90aSMichal Hocko } else if (h->surplus_huge_pages_node[nid]) { 16780edaecfaSAneesh Kumar K.V /* remove the page from active list */ 16796eb4e88aSMike Kravetz remove_hugetlb_page(h, page, true); 1680db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1681b65d4adbSMuchun Song update_and_free_page(h, page, true); 16827893d1d5SAdam Litke } else { 16835d3a551cSWill Deacon arch_clear_hugepage_flags(page); 1684a5516438SAndi Kleen enqueue_huge_page(h, page); 1685db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 168627a85ef1SDavid Gibson } 16871121828aSMike Kravetz } 168827a85ef1SDavid Gibson 1689d3d99fccSOscar Salvador /* 1690d3d99fccSOscar Salvador * Must be called with the hugetlb lock held 1691d3d99fccSOscar Salvador */ 1692d3d99fccSOscar Salvador static void __prep_account_new_huge_page(struct hstate *h, int nid) 1693d3d99fccSOscar Salvador { 1694d3d99fccSOscar Salvador lockdep_assert_held(&hugetlb_lock); 1695d3d99fccSOscar Salvador h->nr_huge_pages++; 1696d3d99fccSOscar Salvador h->nr_huge_pages_node[nid]++; 1697d3d99fccSOscar Salvador } 1698d3d99fccSOscar Salvador 1699f41f2ed4SMuchun Song static void __prep_new_huge_page(struct hstate *h, struct page *page) 1700b7ba30c6SAndi Kleen { 1701f41f2ed4SMuchun Song free_huge_page_vmemmap(h, page); 17020edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&page->lru); 1703f1e61557SKirill A. Shutemov set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1704ff546117SMike Kravetz hugetlb_set_page_subpool(page, NULL); 17059dd540e2SAneesh Kumar K.V set_hugetlb_cgroup(page, NULL); 17061adc4d41SMina Almasry set_hugetlb_cgroup_rsvd(page, NULL); 1707d3d99fccSOscar Salvador } 1708d3d99fccSOscar Salvador 1709d3d99fccSOscar Salvador static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) 1710d3d99fccSOscar Salvador { 1711f41f2ed4SMuchun Song __prep_new_huge_page(h, page); 1712db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 1713d3d99fccSOscar Salvador __prep_account_new_huge_page(h, nid); 1714db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 1715b7ba30c6SAndi Kleen } 1716b7ba30c6SAndi Kleen 171734d9e35bSMike Kravetz static bool __prep_compound_gigantic_page(struct page *page, unsigned int order, 171834d9e35bSMike Kravetz bool demote) 171920a0307cSWu Fengguang { 17207118fc29SMike Kravetz int i, j; 172120a0307cSWu Fengguang int nr_pages = 1 << order; 172220a0307cSWu Fengguang struct page *p = page + 1; 172320a0307cSWu Fengguang 172420a0307cSWu Fengguang /* we rely on prep_new_huge_page to set the destructor */ 172520a0307cSWu Fengguang set_compound_order(page, order); 1726ef5a22beSAndrea Arcangeli __ClearPageReserved(page); 1727de09d31dSKirill A. Shutemov __SetPageHead(page); 172820a0307cSWu Fengguang for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 1729ef5a22beSAndrea Arcangeli /* 1730ef5a22beSAndrea Arcangeli * For gigantic hugepages allocated through bootmem at 1731ef5a22beSAndrea Arcangeli * boot, it's safer to be consistent with the not-gigantic 1732ef5a22beSAndrea Arcangeli * hugepages and clear the PG_reserved bit from all tail pages 17337c8de358SEthon Paul * too. Otherwise drivers using get_user_pages() to access tail 1734ef5a22beSAndrea Arcangeli * pages may get the reference counting wrong if they see 1735ef5a22beSAndrea Arcangeli * PG_reserved set on a tail page (despite the head page not 1736ef5a22beSAndrea Arcangeli * having PG_reserved set). Enforcing this consistency between 1737ef5a22beSAndrea Arcangeli * head and tail pages allows drivers to optimize away a check 1738ef5a22beSAndrea Arcangeli * on the head page when they need know if put_page() is needed 1739ef5a22beSAndrea Arcangeli * after get_user_pages(). 1740ef5a22beSAndrea Arcangeli */ 1741ef5a22beSAndrea Arcangeli __ClearPageReserved(p); 17427118fc29SMike Kravetz /* 17437118fc29SMike Kravetz * Subtle and very unlikely 17447118fc29SMike Kravetz * 17457118fc29SMike Kravetz * Gigantic 'page allocators' such as memblock or cma will 17467118fc29SMike Kravetz * return a set of pages with each page ref counted. We need 17477118fc29SMike Kravetz * to turn this set of pages into a compound page with tail 17487118fc29SMike Kravetz * page ref counts set to zero. Code such as speculative page 17497118fc29SMike Kravetz * cache adding could take a ref on a 'to be' tail page. 17507118fc29SMike Kravetz * We need to respect any increased ref count, and only set 17517118fc29SMike Kravetz * the ref count to zero if count is currently 1. If count 1752416d85edSMike Kravetz * is not 1, we return an error. An error return indicates 1753416d85edSMike Kravetz * the set of pages can not be converted to a gigantic page. 1754416d85edSMike Kravetz * The caller who allocated the pages should then discard the 1755416d85edSMike Kravetz * pages using the appropriate free interface. 175634d9e35bSMike Kravetz * 175734d9e35bSMike Kravetz * In the case of demote, the ref count will be zero. 17587118fc29SMike Kravetz */ 175934d9e35bSMike Kravetz if (!demote) { 17607118fc29SMike Kravetz if (!page_ref_freeze(p, 1)) { 1761416d85edSMike Kravetz pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n"); 17627118fc29SMike Kravetz goto out_error; 17637118fc29SMike Kravetz } 176434d9e35bSMike Kravetz } else { 176534d9e35bSMike Kravetz VM_BUG_ON_PAGE(page_count(p), p); 176634d9e35bSMike Kravetz } 176758a84aa9SYouquan Song set_page_count(p, 0); 17681d798ca3SKirill A. Shutemov set_compound_head(p, page); 176920a0307cSWu Fengguang } 1770b4330afbSMike Kravetz atomic_set(compound_mapcount_ptr(page), -1); 177147e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 17727118fc29SMike Kravetz return true; 17737118fc29SMike Kravetz 17747118fc29SMike Kravetz out_error: 17757118fc29SMike Kravetz /* undo tail page modifications made above */ 17767118fc29SMike Kravetz p = page + 1; 17777118fc29SMike Kravetz for (j = 1; j < i; j++, p = mem_map_next(p, page, j)) { 17787118fc29SMike Kravetz clear_compound_head(p); 17797118fc29SMike Kravetz set_page_refcounted(p); 17807118fc29SMike Kravetz } 17817118fc29SMike Kravetz /* need to clear PG_reserved on remaining tail pages */ 17827118fc29SMike Kravetz for (; j < nr_pages; j++, p = mem_map_next(p, page, j)) 17837118fc29SMike Kravetz __ClearPageReserved(p); 17847118fc29SMike Kravetz set_compound_order(page, 0); 17857118fc29SMike Kravetz page[1].compound_nr = 0; 17867118fc29SMike Kravetz __ClearPageHead(page); 17877118fc29SMike Kravetz return false; 178820a0307cSWu Fengguang } 178920a0307cSWu Fengguang 179034d9e35bSMike Kravetz static bool prep_compound_gigantic_page(struct page *page, unsigned int order) 179134d9e35bSMike Kravetz { 179234d9e35bSMike Kravetz return __prep_compound_gigantic_page(page, order, false); 179334d9e35bSMike Kravetz } 179434d9e35bSMike Kravetz 1795*8531fc6fSMike Kravetz static bool prep_compound_gigantic_page_for_demote(struct page *page, 1796*8531fc6fSMike Kravetz unsigned int order) 1797*8531fc6fSMike Kravetz { 1798*8531fc6fSMike Kravetz return __prep_compound_gigantic_page(page, order, true); 1799*8531fc6fSMike Kravetz } 1800*8531fc6fSMike Kravetz 18017795912cSAndrew Morton /* 18027795912cSAndrew Morton * PageHuge() only returns true for hugetlbfs pages, but not for normal or 18037795912cSAndrew Morton * transparent huge pages. See the PageTransHuge() documentation for more 18047795912cSAndrew Morton * details. 18057795912cSAndrew Morton */ 180620a0307cSWu Fengguang int PageHuge(struct page *page) 180720a0307cSWu Fengguang { 180820a0307cSWu Fengguang if (!PageCompound(page)) 180920a0307cSWu Fengguang return 0; 181020a0307cSWu Fengguang 181120a0307cSWu Fengguang page = compound_head(page); 1812f1e61557SKirill A. Shutemov return page[1].compound_dtor == HUGETLB_PAGE_DTOR; 181320a0307cSWu Fengguang } 181443131e14SNaoya Horiguchi EXPORT_SYMBOL_GPL(PageHuge); 181543131e14SNaoya Horiguchi 181627c73ae7SAndrea Arcangeli /* 181727c73ae7SAndrea Arcangeli * PageHeadHuge() only returns true for hugetlbfs head page, but not for 181827c73ae7SAndrea Arcangeli * normal or transparent huge pages. 181927c73ae7SAndrea Arcangeli */ 182027c73ae7SAndrea Arcangeli int PageHeadHuge(struct page *page_head) 182127c73ae7SAndrea Arcangeli { 182227c73ae7SAndrea Arcangeli if (!PageHead(page_head)) 182327c73ae7SAndrea Arcangeli return 0; 182427c73ae7SAndrea Arcangeli 1825d4af73e3SVlastimil Babka return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR; 182627c73ae7SAndrea Arcangeli } 182727c73ae7SAndrea Arcangeli 1828c0d0381aSMike Kravetz /* 1829c0d0381aSMike Kravetz * Find and lock address space (mapping) in write mode. 1830c0d0381aSMike Kravetz * 1831336bf30eSMike Kravetz * Upon entry, the page is locked which means that page_mapping() is 1832336bf30eSMike Kravetz * stable. Due to locking order, we can only trylock_write. If we can 1833336bf30eSMike Kravetz * not get the lock, simply return NULL to caller. 1834c0d0381aSMike Kravetz */ 1835c0d0381aSMike Kravetz struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage) 1836c0d0381aSMike Kravetz { 1837336bf30eSMike Kravetz struct address_space *mapping = page_mapping(hpage); 1838c0d0381aSMike Kravetz 1839c0d0381aSMike Kravetz if (!mapping) 1840c0d0381aSMike Kravetz return mapping; 1841c0d0381aSMike Kravetz 1842c0d0381aSMike Kravetz if (i_mmap_trylock_write(mapping)) 1843c0d0381aSMike Kravetz return mapping; 1844c0d0381aSMike Kravetz 1845c0d0381aSMike Kravetz return NULL; 1846c0d0381aSMike Kravetz } 1847c0d0381aSMike Kravetz 1848fe19bd3dSHugh Dickins pgoff_t hugetlb_basepage_index(struct page *page) 184913d60f4bSZhang Yi { 185013d60f4bSZhang Yi struct page *page_head = compound_head(page); 185113d60f4bSZhang Yi pgoff_t index = page_index(page_head); 185213d60f4bSZhang Yi unsigned long compound_idx; 185313d60f4bSZhang Yi 185413d60f4bSZhang Yi if (compound_order(page_head) >= MAX_ORDER) 185513d60f4bSZhang Yi compound_idx = page_to_pfn(page) - page_to_pfn(page_head); 185613d60f4bSZhang Yi else 185713d60f4bSZhang Yi compound_idx = page - page_head; 185813d60f4bSZhang Yi 185913d60f4bSZhang Yi return (index << compound_order(page_head)) + compound_idx; 186013d60f4bSZhang Yi } 186113d60f4bSZhang Yi 18620c397daeSMichal Hocko static struct page *alloc_buddy_huge_page(struct hstate *h, 1863f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1864f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 18651da177e4SLinus Torvalds { 1866af0fb9dfSMichal Hocko int order = huge_page_order(h); 18671da177e4SLinus Torvalds struct page *page; 1868f60858f9SMike Kravetz bool alloc_try_hard = true; 1869f96efd58SJoe Jin 1870f60858f9SMike Kravetz /* 1871f60858f9SMike Kravetz * By default we always try hard to allocate the page with 1872f60858f9SMike Kravetz * __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in 1873f60858f9SMike Kravetz * a loop (to adjust global huge page counts) and previous allocation 1874f60858f9SMike Kravetz * failed, do not continue to try hard on the same node. Use the 1875f60858f9SMike Kravetz * node_alloc_noretry bitmap to manage this state information. 1876f60858f9SMike Kravetz */ 1877f60858f9SMike Kravetz if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry)) 1878f60858f9SMike Kravetz alloc_try_hard = false; 1879f60858f9SMike Kravetz gfp_mask |= __GFP_COMP|__GFP_NOWARN; 1880f60858f9SMike Kravetz if (alloc_try_hard) 1881f60858f9SMike Kravetz gfp_mask |= __GFP_RETRY_MAYFAIL; 1882af0fb9dfSMichal Hocko if (nid == NUMA_NO_NODE) 1883af0fb9dfSMichal Hocko nid = numa_mem_id(); 188484172f4bSMatthew Wilcox (Oracle) page = __alloc_pages(gfp_mask, order, nid, nmask); 1885af0fb9dfSMichal Hocko if (page) 1886af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC); 1887af0fb9dfSMichal Hocko else 1888af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 188963b4613cSNishanth Aravamudan 1890f60858f9SMike Kravetz /* 1891f60858f9SMike Kravetz * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this 1892f60858f9SMike Kravetz * indicates an overall state change. Clear bit so that we resume 1893f60858f9SMike Kravetz * normal 'try hard' allocations. 1894f60858f9SMike Kravetz */ 1895f60858f9SMike Kravetz if (node_alloc_noretry && page && !alloc_try_hard) 1896f60858f9SMike Kravetz node_clear(nid, *node_alloc_noretry); 1897f60858f9SMike Kravetz 1898f60858f9SMike Kravetz /* 1899f60858f9SMike Kravetz * If we tried hard to get a page but failed, set bit so that 1900f60858f9SMike Kravetz * subsequent attempts will not try as hard until there is an 1901f60858f9SMike Kravetz * overall state change. 1902f60858f9SMike Kravetz */ 1903f60858f9SMike Kravetz if (node_alloc_noretry && !page && alloc_try_hard) 1904f60858f9SMike Kravetz node_set(nid, *node_alloc_noretry); 1905f60858f9SMike Kravetz 190663b4613cSNishanth Aravamudan return page; 190763b4613cSNishanth Aravamudan } 190863b4613cSNishanth Aravamudan 1909af0fb9dfSMichal Hocko /* 19100c397daeSMichal Hocko * Common helper to allocate a fresh hugetlb page. All specific allocators 19110c397daeSMichal Hocko * should use this function to get new hugetlb pages 19120c397daeSMichal Hocko */ 19130c397daeSMichal Hocko static struct page *alloc_fresh_huge_page(struct hstate *h, 1914f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1915f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 19160c397daeSMichal Hocko { 19170c397daeSMichal Hocko struct page *page; 19187118fc29SMike Kravetz bool retry = false; 19190c397daeSMichal Hocko 19207118fc29SMike Kravetz retry: 19210c397daeSMichal Hocko if (hstate_is_gigantic(h)) 19220c397daeSMichal Hocko page = alloc_gigantic_page(h, gfp_mask, nid, nmask); 19230c397daeSMichal Hocko else 19240c397daeSMichal Hocko page = alloc_buddy_huge_page(h, gfp_mask, 1925f60858f9SMike Kravetz nid, nmask, node_alloc_noretry); 19260c397daeSMichal Hocko if (!page) 19270c397daeSMichal Hocko return NULL; 19280c397daeSMichal Hocko 19297118fc29SMike Kravetz if (hstate_is_gigantic(h)) { 19307118fc29SMike Kravetz if (!prep_compound_gigantic_page(page, huge_page_order(h))) { 19317118fc29SMike Kravetz /* 19327118fc29SMike Kravetz * Rare failure to convert pages to compound page. 19337118fc29SMike Kravetz * Free pages and try again - ONCE! 19347118fc29SMike Kravetz */ 19357118fc29SMike Kravetz free_gigantic_page(page, huge_page_order(h)); 19367118fc29SMike Kravetz if (!retry) { 19377118fc29SMike Kravetz retry = true; 19387118fc29SMike Kravetz goto retry; 19397118fc29SMike Kravetz } 19407118fc29SMike Kravetz return NULL; 19417118fc29SMike Kravetz } 19427118fc29SMike Kravetz } 19430c397daeSMichal Hocko prep_new_huge_page(h, page, page_to_nid(page)); 19440c397daeSMichal Hocko 19450c397daeSMichal Hocko return page; 19460c397daeSMichal Hocko } 19470c397daeSMichal Hocko 19480c397daeSMichal Hocko /* 1949af0fb9dfSMichal Hocko * Allocates a fresh page to the hugetlb allocator pool in the node interleaved 1950af0fb9dfSMichal Hocko * manner. 1951af0fb9dfSMichal Hocko */ 1952f60858f9SMike Kravetz static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 1953f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 1954b2261026SJoonsoo Kim { 1955b2261026SJoonsoo Kim struct page *page; 1956b2261026SJoonsoo Kim int nr_nodes, node; 1957af0fb9dfSMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 1958b2261026SJoonsoo Kim 1959b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 1960f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed, 1961f60858f9SMike Kravetz node_alloc_noretry); 1962af0fb9dfSMichal Hocko if (page) 1963b2261026SJoonsoo Kim break; 1964b2261026SJoonsoo Kim } 1965b2261026SJoonsoo Kim 1966af0fb9dfSMichal Hocko if (!page) 1967af0fb9dfSMichal Hocko return 0; 1968b2261026SJoonsoo Kim 1969af0fb9dfSMichal Hocko put_page(page); /* free it into the hugepage allocator */ 1970af0fb9dfSMichal Hocko 1971af0fb9dfSMichal Hocko return 1; 1972b2261026SJoonsoo Kim } 1973b2261026SJoonsoo Kim 1974e8c5c824SLee Schermerhorn /* 197510c6ec49SMike Kravetz * Remove huge page from pool from next node to free. Attempt to keep 197610c6ec49SMike Kravetz * persistent huge pages more or less balanced over allowed nodes. 197710c6ec49SMike Kravetz * This routine only 'removes' the hugetlb page. The caller must make 197810c6ec49SMike Kravetz * an additional call to free the page to low level allocators. 1979e8c5c824SLee Schermerhorn * Called with hugetlb_lock locked. 1980e8c5c824SLee Schermerhorn */ 198110c6ec49SMike Kravetz static struct page *remove_pool_huge_page(struct hstate *h, 198210c6ec49SMike Kravetz nodemask_t *nodes_allowed, 19836ae11b27SLee Schermerhorn bool acct_surplus) 1984e8c5c824SLee Schermerhorn { 1985b2261026SJoonsoo Kim int nr_nodes, node; 198610c6ec49SMike Kravetz struct page *page = NULL; 1987e8c5c824SLee Schermerhorn 19889487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1989b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 1990685f3457SLee Schermerhorn /* 1991685f3457SLee Schermerhorn * If we're returning unused surplus pages, only examine 1992685f3457SLee Schermerhorn * nodes with surplus pages. 1993685f3457SLee Schermerhorn */ 1994b2261026SJoonsoo Kim if ((!acct_surplus || h->surplus_huge_pages_node[node]) && 1995b2261026SJoonsoo Kim !list_empty(&h->hugepage_freelists[node])) { 199610c6ec49SMike Kravetz page = list_entry(h->hugepage_freelists[node].next, 1997e8c5c824SLee Schermerhorn struct page, lru); 19986eb4e88aSMike Kravetz remove_hugetlb_page(h, page, acct_surplus); 19999a76db09SLee Schermerhorn break; 2000e8c5c824SLee Schermerhorn } 2001b2261026SJoonsoo Kim } 2002e8c5c824SLee Schermerhorn 200310c6ec49SMike Kravetz return page; 2004e8c5c824SLee Schermerhorn } 2005e8c5c824SLee Schermerhorn 2006c8721bbbSNaoya Horiguchi /* 2007c8721bbbSNaoya Horiguchi * Dissolve a given free hugepage into free buddy pages. This function does 2008faf53defSNaoya Horiguchi * nothing for in-use hugepages and non-hugepages. 2009faf53defSNaoya Horiguchi * This function returns values like below: 2010faf53defSNaoya Horiguchi * 2011ad2fa371SMuchun Song * -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages 2012ad2fa371SMuchun Song * when the system is under memory pressure and the feature of 2013ad2fa371SMuchun Song * freeing unused vmemmap pages associated with each hugetlb page 2014ad2fa371SMuchun Song * is enabled. 2015faf53defSNaoya Horiguchi * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use 2016faf53defSNaoya Horiguchi * (allocated or reserved.) 2017faf53defSNaoya Horiguchi * 0: successfully dissolved free hugepages or the page is not a 2018faf53defSNaoya Horiguchi * hugepage (considered as already dissolved) 2019c8721bbbSNaoya Horiguchi */ 2020c3114a84SAnshuman Khandual int dissolve_free_huge_page(struct page *page) 2021c8721bbbSNaoya Horiguchi { 20226bc9b564SNaoya Horiguchi int rc = -EBUSY; 2023082d5b6bSGerald Schaefer 20247ffddd49SMuchun Song retry: 2025faf53defSNaoya Horiguchi /* Not to disrupt normal path by vainly holding hugetlb_lock */ 2026faf53defSNaoya Horiguchi if (!PageHuge(page)) 2027faf53defSNaoya Horiguchi return 0; 2028faf53defSNaoya Horiguchi 2029db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2030faf53defSNaoya Horiguchi if (!PageHuge(page)) { 2031faf53defSNaoya Horiguchi rc = 0; 2032faf53defSNaoya Horiguchi goto out; 2033faf53defSNaoya Horiguchi } 2034faf53defSNaoya Horiguchi 2035faf53defSNaoya Horiguchi if (!page_count(page)) { 20362247bb33SGerald Schaefer struct page *head = compound_head(page); 20372247bb33SGerald Schaefer struct hstate *h = page_hstate(head); 20386bc9b564SNaoya Horiguchi if (h->free_huge_pages - h->resv_huge_pages == 0) 2039082d5b6bSGerald Schaefer goto out; 20407ffddd49SMuchun Song 20417ffddd49SMuchun Song /* 20427ffddd49SMuchun Song * We should make sure that the page is already on the free list 20437ffddd49SMuchun Song * when it is dissolved. 20447ffddd49SMuchun Song */ 20456c037149SMike Kravetz if (unlikely(!HPageFreed(head))) { 2046db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 20477ffddd49SMuchun Song cond_resched(); 20487ffddd49SMuchun Song 20497ffddd49SMuchun Song /* 20507ffddd49SMuchun Song * Theoretically, we should return -EBUSY when we 20517ffddd49SMuchun Song * encounter this race. In fact, we have a chance 20527ffddd49SMuchun Song * to successfully dissolve the page if we do a 20537ffddd49SMuchun Song * retry. Because the race window is quite small. 20547ffddd49SMuchun Song * If we seize this opportunity, it is an optimization 20557ffddd49SMuchun Song * for increasing the success rate of dissolving page. 20567ffddd49SMuchun Song */ 20577ffddd49SMuchun Song goto retry; 20587ffddd49SMuchun Song } 20597ffddd49SMuchun Song 2060ad2fa371SMuchun Song remove_hugetlb_page(h, head, false); 2061ad2fa371SMuchun Song h->max_huge_pages--; 2062ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2063ad2fa371SMuchun Song 2064c3114a84SAnshuman Khandual /* 2065ad2fa371SMuchun Song * Normally update_and_free_page will allocate required vmemmmap 2066ad2fa371SMuchun Song * before freeing the page. update_and_free_page will fail to 2067ad2fa371SMuchun Song * free the page if it can not allocate required vmemmap. We 2068ad2fa371SMuchun Song * need to adjust max_huge_pages if the page is not freed. 2069ad2fa371SMuchun Song * Attempt to allocate vmemmmap here so that we can take 2070ad2fa371SMuchun Song * appropriate action on failure. 2071ad2fa371SMuchun Song */ 2072ad2fa371SMuchun Song rc = alloc_huge_page_vmemmap(h, head); 2073ad2fa371SMuchun Song if (!rc) { 2074ad2fa371SMuchun Song /* 2075ad2fa371SMuchun Song * Move PageHWPoison flag from head page to the raw 2076ad2fa371SMuchun Song * error page, which makes any subpages rather than 2077ad2fa371SMuchun Song * the error page reusable. 2078c3114a84SAnshuman Khandual */ 2079c3114a84SAnshuman Khandual if (PageHWPoison(head) && page != head) { 2080c3114a84SAnshuman Khandual SetPageHWPoison(page); 2081c3114a84SAnshuman Khandual ClearPageHWPoison(head); 2082c3114a84SAnshuman Khandual } 2083b65d4adbSMuchun Song update_and_free_page(h, head, false); 2084ad2fa371SMuchun Song } else { 2085ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 2086ad2fa371SMuchun Song add_hugetlb_page(h, head, false); 2087ad2fa371SMuchun Song h->max_huge_pages++; 2088ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2089ad2fa371SMuchun Song } 2090ad2fa371SMuchun Song 2091ad2fa371SMuchun Song return rc; 2092c8721bbbSNaoya Horiguchi } 2093082d5b6bSGerald Schaefer out: 2094db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2095082d5b6bSGerald Schaefer return rc; 2096c8721bbbSNaoya Horiguchi } 2097c8721bbbSNaoya Horiguchi 2098c8721bbbSNaoya Horiguchi /* 2099c8721bbbSNaoya Horiguchi * Dissolve free hugepages in a given pfn range. Used by memory hotplug to 2100c8721bbbSNaoya Horiguchi * make specified memory blocks removable from the system. 21012247bb33SGerald Schaefer * Note that this will dissolve a free gigantic hugepage completely, if any 21022247bb33SGerald Schaefer * part of it lies within the given range. 2103082d5b6bSGerald Schaefer * Also note that if dissolve_free_huge_page() returns with an error, all 2104082d5b6bSGerald Schaefer * free hugepages that were dissolved before that error are lost. 2105c8721bbbSNaoya Horiguchi */ 2106082d5b6bSGerald Schaefer int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) 2107c8721bbbSNaoya Horiguchi { 2108c8721bbbSNaoya Horiguchi unsigned long pfn; 2109eb03aa00SGerald Schaefer struct page *page; 2110082d5b6bSGerald Schaefer int rc = 0; 2111c8721bbbSNaoya Horiguchi 2112d0177639SLi Zhong if (!hugepages_supported()) 2113082d5b6bSGerald Schaefer return rc; 2114d0177639SLi Zhong 2115eb03aa00SGerald Schaefer for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) { 2116eb03aa00SGerald Schaefer page = pfn_to_page(pfn); 2117eb03aa00SGerald Schaefer rc = dissolve_free_huge_page(page); 2118eb03aa00SGerald Schaefer if (rc) 2119082d5b6bSGerald Schaefer break; 2120eb03aa00SGerald Schaefer } 2121082d5b6bSGerald Schaefer 2122082d5b6bSGerald Schaefer return rc; 2123c8721bbbSNaoya Horiguchi } 2124c8721bbbSNaoya Horiguchi 2125ab5ac90aSMichal Hocko /* 2126ab5ac90aSMichal Hocko * Allocates a fresh surplus page from the page allocator. 2127ab5ac90aSMichal Hocko */ 21280c397daeSMichal Hocko static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, 2129b65a4edaSMike Kravetz int nid, nodemask_t *nmask, bool zero_ref) 21307893d1d5SAdam Litke { 21319980d744SMichal Hocko struct page *page = NULL; 2132b65a4edaSMike Kravetz bool retry = false; 21337893d1d5SAdam Litke 2134bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2135aa888a74SAndi Kleen return NULL; 2136aa888a74SAndi Kleen 2137db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 21389980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) 21399980d744SMichal Hocko goto out_unlock; 2140db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2141d1c3fb1fSNishanth Aravamudan 2142b65a4edaSMike Kravetz retry: 2143f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 21449980d744SMichal Hocko if (!page) 21450c397daeSMichal Hocko return NULL; 2146d1c3fb1fSNishanth Aravamudan 2147db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 21489980d744SMichal Hocko /* 21499980d744SMichal Hocko * We could have raced with the pool size change. 21509980d744SMichal Hocko * Double check that and simply deallocate the new page 21519980d744SMichal Hocko * if we would end up overcommiting the surpluses. Abuse 21529980d744SMichal Hocko * temporary page to workaround the nasty free_huge_page 21539980d744SMichal Hocko * codeflow 21549980d744SMichal Hocko */ 21559980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 21569157c311SMike Kravetz SetHPageTemporary(page); 2157db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 21589980d744SMichal Hocko put_page(page); 21592bf753e6SKai Shen return NULL; 2160b65a4edaSMike Kravetz } 2161b65a4edaSMike Kravetz 2162b65a4edaSMike Kravetz if (zero_ref) { 2163b65a4edaSMike Kravetz /* 2164b65a4edaSMike Kravetz * Caller requires a page with zero ref count. 2165b65a4edaSMike Kravetz * We will drop ref count here. If someone else is holding 2166b65a4edaSMike Kravetz * a ref, the page will be freed when they drop it. Abuse 2167b65a4edaSMike Kravetz * temporary page flag to accomplish this. 2168b65a4edaSMike Kravetz */ 2169b65a4edaSMike Kravetz SetHPageTemporary(page); 2170b65a4edaSMike Kravetz if (!put_page_testzero(page)) { 2171b65a4edaSMike Kravetz /* 2172b65a4edaSMike Kravetz * Unexpected inflated ref count on freshly allocated 2173b65a4edaSMike Kravetz * huge. Retry once. 2174b65a4edaSMike Kravetz */ 2175b65a4edaSMike Kravetz pr_info("HugeTLB unexpected inflated ref count on freshly allocated page\n"); 2176b65a4edaSMike Kravetz spin_unlock_irq(&hugetlb_lock); 2177b65a4edaSMike Kravetz if (retry) 2178b65a4edaSMike Kravetz return NULL; 2179b65a4edaSMike Kravetz 2180b65a4edaSMike Kravetz retry = true; 2181b65a4edaSMike Kravetz goto retry; 2182b65a4edaSMike Kravetz } 2183b65a4edaSMike Kravetz ClearHPageTemporary(page); 2184b65a4edaSMike Kravetz } 2185b65a4edaSMike Kravetz 21869980d744SMichal Hocko h->surplus_huge_pages++; 21874704dea3SMichal Hocko h->surplus_huge_pages_node[page_to_nid(page)]++; 21889980d744SMichal Hocko 21899980d744SMichal Hocko out_unlock: 2190db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 21917893d1d5SAdam Litke 21927893d1d5SAdam Litke return page; 21937893d1d5SAdam Litke } 21947893d1d5SAdam Litke 2195bbe88753SJoonsoo Kim static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, 2196ab5ac90aSMichal Hocko int nid, nodemask_t *nmask) 2197ab5ac90aSMichal Hocko { 2198ab5ac90aSMichal Hocko struct page *page; 2199ab5ac90aSMichal Hocko 2200ab5ac90aSMichal Hocko if (hstate_is_gigantic(h)) 2201ab5ac90aSMichal Hocko return NULL; 2202ab5ac90aSMichal Hocko 2203f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 2204ab5ac90aSMichal Hocko if (!page) 2205ab5ac90aSMichal Hocko return NULL; 2206ab5ac90aSMichal Hocko 2207ab5ac90aSMichal Hocko /* 2208ab5ac90aSMichal Hocko * We do not account these pages as surplus because they are only 2209ab5ac90aSMichal Hocko * temporary and will be released properly on the last reference 2210ab5ac90aSMichal Hocko */ 22119157c311SMike Kravetz SetHPageTemporary(page); 2212ab5ac90aSMichal Hocko 2213ab5ac90aSMichal Hocko return page; 2214ab5ac90aSMichal Hocko } 2215ab5ac90aSMichal Hocko 2216e4e574b7SAdam Litke /* 2217099730d6SDave Hansen * Use the VMA's mpolicy to allocate a huge page from the buddy. 2218099730d6SDave Hansen */ 2219e0ec90eeSDave Hansen static 22200c397daeSMichal Hocko struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h, 2221099730d6SDave Hansen struct vm_area_struct *vma, unsigned long addr) 2222099730d6SDave Hansen { 2223cfcaa66fSBen Widawsky struct page *page = NULL; 2224aaf14e40SMichal Hocko struct mempolicy *mpol; 2225aaf14e40SMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h); 2226aaf14e40SMichal Hocko int nid; 2227aaf14e40SMichal Hocko nodemask_t *nodemask; 2228aaf14e40SMichal Hocko 2229aaf14e40SMichal Hocko nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); 2230cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 2231cfcaa66fSBen Widawsky gfp_t gfp = gfp_mask | __GFP_NOWARN; 2232cfcaa66fSBen Widawsky 2233cfcaa66fSBen Widawsky gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL); 2234cfcaa66fSBen Widawsky page = alloc_surplus_huge_page(h, gfp, nid, nodemask, false); 2235cfcaa66fSBen Widawsky 2236cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 2237cfcaa66fSBen Widawsky nodemask = NULL; 2238cfcaa66fSBen Widawsky } 2239cfcaa66fSBen Widawsky 2240cfcaa66fSBen Widawsky if (!page) 2241b65a4edaSMike Kravetz page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask, false); 2242aaf14e40SMichal Hocko mpol_cond_put(mpol); 2243aaf14e40SMichal Hocko return page; 2244099730d6SDave Hansen } 2245099730d6SDave Hansen 2246ab5ac90aSMichal Hocko /* page migration callback function */ 22473e59fcb0SMichal Hocko struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, 2248d92bbc27SJoonsoo Kim nodemask_t *nmask, gfp_t gfp_mask) 22494db9b2efSMichal Hocko { 2250db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 22514db9b2efSMichal Hocko if (h->free_huge_pages - h->resv_huge_pages > 0) { 22523e59fcb0SMichal Hocko struct page *page; 22533e59fcb0SMichal Hocko 22543e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask); 22553e59fcb0SMichal Hocko if (page) { 2256db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 22573e59fcb0SMichal Hocko return page; 22584db9b2efSMichal Hocko } 22594db9b2efSMichal Hocko } 2260db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 22614db9b2efSMichal Hocko 22620c397daeSMichal Hocko return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask); 22634db9b2efSMichal Hocko } 22644db9b2efSMichal Hocko 2265ebd63723SMichal Hocko /* mempolicy aware migration callback */ 2266389c8178SMichal Hocko struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, 2267389c8178SMichal Hocko unsigned long address) 2268ebd63723SMichal Hocko { 2269ebd63723SMichal Hocko struct mempolicy *mpol; 2270ebd63723SMichal Hocko nodemask_t *nodemask; 2271ebd63723SMichal Hocko struct page *page; 2272ebd63723SMichal Hocko gfp_t gfp_mask; 2273ebd63723SMichal Hocko int node; 2274ebd63723SMichal Hocko 2275ebd63723SMichal Hocko gfp_mask = htlb_alloc_mask(h); 2276ebd63723SMichal Hocko node = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 2277d92bbc27SJoonsoo Kim page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask); 2278ebd63723SMichal Hocko mpol_cond_put(mpol); 2279ebd63723SMichal Hocko 2280ebd63723SMichal Hocko return page; 2281ebd63723SMichal Hocko } 2282ebd63723SMichal Hocko 2283bf50bab2SNaoya Horiguchi /* 228425985edcSLucas De Marchi * Increase the hugetlb pool such that it can accommodate a reservation 2285e4e574b7SAdam Litke * of size 'delta'. 2286e4e574b7SAdam Litke */ 22870a4f3d1bSLiu Xiang static int gather_surplus_pages(struct hstate *h, long delta) 22881b2a1e7bSJules Irenge __must_hold(&hugetlb_lock) 2289e4e574b7SAdam Litke { 2290e4e574b7SAdam Litke struct list_head surplus_list; 2291e4e574b7SAdam Litke struct page *page, *tmp; 22920a4f3d1bSLiu Xiang int ret; 22930a4f3d1bSLiu Xiang long i; 22940a4f3d1bSLiu Xiang long needed, allocated; 229528073b02SHillf Danton bool alloc_ok = true; 2296e4e574b7SAdam Litke 22979487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2298a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 2299ac09b3a1SAdam Litke if (needed <= 0) { 2300a5516438SAndi Kleen h->resv_huge_pages += delta; 2301e4e574b7SAdam Litke return 0; 2302ac09b3a1SAdam Litke } 2303e4e574b7SAdam Litke 2304e4e574b7SAdam Litke allocated = 0; 2305e4e574b7SAdam Litke INIT_LIST_HEAD(&surplus_list); 2306e4e574b7SAdam Litke 2307e4e574b7SAdam Litke ret = -ENOMEM; 2308e4e574b7SAdam Litke retry: 2309db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2310e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 23110c397daeSMichal Hocko page = alloc_surplus_huge_page(h, htlb_alloc_mask(h), 2312b65a4edaSMike Kravetz NUMA_NO_NODE, NULL, true); 231328073b02SHillf Danton if (!page) { 231428073b02SHillf Danton alloc_ok = false; 231528073b02SHillf Danton break; 231628073b02SHillf Danton } 2317e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 231869ed779aSDavid Rientjes cond_resched(); 2319e4e574b7SAdam Litke } 232028073b02SHillf Danton allocated += i; 2321e4e574b7SAdam Litke 2322e4e574b7SAdam Litke /* 2323e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 2324e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 2325e4e574b7SAdam Litke */ 2326db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2327a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 2328a5516438SAndi Kleen (h->free_huge_pages + allocated); 232928073b02SHillf Danton if (needed > 0) { 233028073b02SHillf Danton if (alloc_ok) 2331e4e574b7SAdam Litke goto retry; 233228073b02SHillf Danton /* 233328073b02SHillf Danton * We were not able to allocate enough pages to 233428073b02SHillf Danton * satisfy the entire reservation so we free what 233528073b02SHillf Danton * we've allocated so far. 233628073b02SHillf Danton */ 233728073b02SHillf Danton goto free; 233828073b02SHillf Danton } 2339e4e574b7SAdam Litke /* 2340e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 234125985edcSLucas De Marchi * needed to accommodate the reservation. Add the appropriate number 2342e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 2343ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 2344ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 2345ac09b3a1SAdam Litke * before they are reserved. 2346e4e574b7SAdam Litke */ 2347e4e574b7SAdam Litke needed += allocated; 2348a5516438SAndi Kleen h->resv_huge_pages += delta; 2349e4e574b7SAdam Litke ret = 0; 2350a9869b83SNaoya Horiguchi 235119fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 235219fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 235319fc3f0aSAdam Litke if ((--needed) < 0) 235419fc3f0aSAdam Litke break; 2355b65a4edaSMike Kravetz /* Add the page to the hugetlb allocator */ 2356a5516438SAndi Kleen enqueue_huge_page(h, page); 235719fc3f0aSAdam Litke } 235828073b02SHillf Danton free: 2359db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 236019fc3f0aSAdam Litke 2361b65a4edaSMike Kravetz /* 2362b65a4edaSMike Kravetz * Free unnecessary surplus pages to the buddy allocator. 2363b65a4edaSMike Kravetz * Pages have no ref count, call free_huge_page directly. 2364b65a4edaSMike Kravetz */ 2365c0d934baSJoonsoo Kim list_for_each_entry_safe(page, tmp, &surplus_list, lru) 2366b65a4edaSMike Kravetz free_huge_page(page); 2367db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2368e4e574b7SAdam Litke 2369e4e574b7SAdam Litke return ret; 2370e4e574b7SAdam Litke } 2371e4e574b7SAdam Litke 2372e4e574b7SAdam Litke /* 2373e5bbc8a6SMike Kravetz * This routine has two main purposes: 2374e5bbc8a6SMike Kravetz * 1) Decrement the reservation count (resv_huge_pages) by the value passed 2375e5bbc8a6SMike Kravetz * in unused_resv_pages. This corresponds to the prior adjustments made 2376e5bbc8a6SMike Kravetz * to the associated reservation map. 2377e5bbc8a6SMike Kravetz * 2) Free any unused surplus pages that may have been allocated to satisfy 2378e5bbc8a6SMike Kravetz * the reservation. As many as unused_resv_pages may be freed. 2379e4e574b7SAdam Litke */ 2380a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 2381a5516438SAndi Kleen unsigned long unused_resv_pages) 2382e4e574b7SAdam Litke { 2383e4e574b7SAdam Litke unsigned long nr_pages; 238410c6ec49SMike Kravetz struct page *page; 238510c6ec49SMike Kravetz LIST_HEAD(page_list); 238610c6ec49SMike Kravetz 23879487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 238810c6ec49SMike Kravetz /* Uncommit the reservation */ 238910c6ec49SMike Kravetz h->resv_huge_pages -= unused_resv_pages; 2390e4e574b7SAdam Litke 2391aa888a74SAndi Kleen /* Cannot return gigantic pages currently */ 2392bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2393e5bbc8a6SMike Kravetz goto out; 2394aa888a74SAndi Kleen 2395e5bbc8a6SMike Kravetz /* 2396e5bbc8a6SMike Kravetz * Part (or even all) of the reservation could have been backed 2397e5bbc8a6SMike Kravetz * by pre-allocated pages. Only free surplus pages. 2398e5bbc8a6SMike Kravetz */ 2399a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 2400e4e574b7SAdam Litke 2401685f3457SLee Schermerhorn /* 2402685f3457SLee Schermerhorn * We want to release as many surplus pages as possible, spread 24039b5e5d0fSLee Schermerhorn * evenly across all nodes with memory. Iterate across these nodes 24049b5e5d0fSLee Schermerhorn * until we can no longer free unreserved surplus pages. This occurs 24059b5e5d0fSLee Schermerhorn * when the nodes with surplus pages have no free pages. 240610c6ec49SMike Kravetz * remove_pool_huge_page() will balance the freed pages across the 24079b5e5d0fSLee Schermerhorn * on-line nodes with memory and will handle the hstate accounting. 2408685f3457SLee Schermerhorn */ 2409685f3457SLee Schermerhorn while (nr_pages--) { 241010c6ec49SMike Kravetz page = remove_pool_huge_page(h, &node_states[N_MEMORY], 1); 241110c6ec49SMike Kravetz if (!page) 2412e5bbc8a6SMike Kravetz goto out; 241310c6ec49SMike Kravetz 241410c6ec49SMike Kravetz list_add(&page->lru, &page_list); 2415e4e574b7SAdam Litke } 2416e5bbc8a6SMike Kravetz 2417e5bbc8a6SMike Kravetz out: 2418db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 241910c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 2420db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2421e4e574b7SAdam Litke } 2422e4e574b7SAdam Litke 24235e911373SMike Kravetz 2424c37f9fb1SAndy Whitcroft /* 2425feba16e2SMike Kravetz * vma_needs_reservation, vma_commit_reservation and vma_end_reservation 24265e911373SMike Kravetz * are used by the huge page allocation routines to manage reservations. 2427cf3ad20bSMike Kravetz * 2428cf3ad20bSMike Kravetz * vma_needs_reservation is called to determine if the huge page at addr 2429cf3ad20bSMike Kravetz * within the vma has an associated reservation. If a reservation is 2430cf3ad20bSMike Kravetz * needed, the value 1 is returned. The caller is then responsible for 2431cf3ad20bSMike Kravetz * managing the global reservation and subpool usage counts. After 2432cf3ad20bSMike Kravetz * the huge page has been allocated, vma_commit_reservation is called 2433feba16e2SMike Kravetz * to add the page to the reservation map. If the page allocation fails, 2434feba16e2SMike Kravetz * the reservation must be ended instead of committed. vma_end_reservation 2435feba16e2SMike Kravetz * is called in such cases. 2436cf3ad20bSMike Kravetz * 2437cf3ad20bSMike Kravetz * In the normal case, vma_commit_reservation returns the same value 2438cf3ad20bSMike Kravetz * as the preceding vma_needs_reservation call. The only time this 2439cf3ad20bSMike Kravetz * is not the case is if a reserve map was changed between calls. It 2440cf3ad20bSMike Kravetz * is the responsibility of the caller to notice the difference and 2441cf3ad20bSMike Kravetz * take appropriate action. 244296b96a96SMike Kravetz * 244396b96a96SMike Kravetz * vma_add_reservation is used in error paths where a reservation must 244496b96a96SMike Kravetz * be restored when a newly allocated huge page must be freed. It is 244596b96a96SMike Kravetz * to be called after calling vma_needs_reservation to determine if a 244696b96a96SMike Kravetz * reservation exists. 2447846be085SMike Kravetz * 2448846be085SMike Kravetz * vma_del_reservation is used in error paths where an entry in the reserve 2449846be085SMike Kravetz * map was created during huge page allocation and must be removed. It is to 2450846be085SMike Kravetz * be called after calling vma_needs_reservation to determine if a reservation 2451846be085SMike Kravetz * exists. 2452c37f9fb1SAndy Whitcroft */ 24535e911373SMike Kravetz enum vma_resv_mode { 24545e911373SMike Kravetz VMA_NEEDS_RESV, 24555e911373SMike Kravetz VMA_COMMIT_RESV, 2456feba16e2SMike Kravetz VMA_END_RESV, 245796b96a96SMike Kravetz VMA_ADD_RESV, 2458846be085SMike Kravetz VMA_DEL_RESV, 24595e911373SMike Kravetz }; 2460cf3ad20bSMike Kravetz static long __vma_reservation_common(struct hstate *h, 2461cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr, 24625e911373SMike Kravetz enum vma_resv_mode mode) 2463c37f9fb1SAndy Whitcroft { 24644e35f483SJoonsoo Kim struct resv_map *resv; 24654e35f483SJoonsoo Kim pgoff_t idx; 2466cf3ad20bSMike Kravetz long ret; 24670db9d74eSMina Almasry long dummy_out_regions_needed; 2468c37f9fb1SAndy Whitcroft 24694e35f483SJoonsoo Kim resv = vma_resv_map(vma); 24704e35f483SJoonsoo Kim if (!resv) 2471c37f9fb1SAndy Whitcroft return 1; 2472c37f9fb1SAndy Whitcroft 24734e35f483SJoonsoo Kim idx = vma_hugecache_offset(h, vma, addr); 24745e911373SMike Kravetz switch (mode) { 24755e911373SMike Kravetz case VMA_NEEDS_RESV: 24760db9d74eSMina Almasry ret = region_chg(resv, idx, idx + 1, &dummy_out_regions_needed); 24770db9d74eSMina Almasry /* We assume that vma_reservation_* routines always operate on 24780db9d74eSMina Almasry * 1 page, and that adding to resv map a 1 page entry can only 24790db9d74eSMina Almasry * ever require 1 region. 24800db9d74eSMina Almasry */ 24810db9d74eSMina Almasry VM_BUG_ON(dummy_out_regions_needed != 1); 24825e911373SMike Kravetz break; 24835e911373SMike Kravetz case VMA_COMMIT_RESV: 2484075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 24850db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 24860db9d74eSMina Almasry VM_BUG_ON(ret < 0); 24875e911373SMike Kravetz break; 2488feba16e2SMike Kravetz case VMA_END_RESV: 24890db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 24905e911373SMike Kravetz ret = 0; 24915e911373SMike Kravetz break; 249296b96a96SMike Kravetz case VMA_ADD_RESV: 24930db9d74eSMina Almasry if (vma->vm_flags & VM_MAYSHARE) { 2494075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 24950db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 24960db9d74eSMina Almasry VM_BUG_ON(ret < 0); 24970db9d74eSMina Almasry } else { 24980db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 249996b96a96SMike Kravetz ret = region_del(resv, idx, idx + 1); 250096b96a96SMike Kravetz } 250196b96a96SMike Kravetz break; 2502846be085SMike Kravetz case VMA_DEL_RESV: 2503846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 2504846be085SMike Kravetz region_abort(resv, idx, idx + 1, 1); 2505846be085SMike Kravetz ret = region_del(resv, idx, idx + 1); 2506846be085SMike Kravetz } else { 2507846be085SMike Kravetz ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 2508846be085SMike Kravetz /* region_add calls of range 1 should never fail. */ 2509846be085SMike Kravetz VM_BUG_ON(ret < 0); 2510846be085SMike Kravetz } 2511846be085SMike Kravetz break; 25125e911373SMike Kravetz default: 25135e911373SMike Kravetz BUG(); 25145e911373SMike Kravetz } 251584afd99bSAndy Whitcroft 2516846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE || mode == VMA_DEL_RESV) 2517cf3ad20bSMike Kravetz return ret; 251867961f9dSMike Kravetz /* 2519bf3d12b9SMiaohe Lin * We know private mapping must have HPAGE_RESV_OWNER set. 2520bf3d12b9SMiaohe Lin * 252167961f9dSMike Kravetz * In most cases, reserves always exist for private mappings. 252267961f9dSMike Kravetz * However, a file associated with mapping could have been 252367961f9dSMike Kravetz * hole punched or truncated after reserves were consumed. 252467961f9dSMike Kravetz * As subsequent fault on such a range will not use reserves. 252567961f9dSMike Kravetz * Subtle - The reserve map for private mappings has the 252667961f9dSMike Kravetz * opposite meaning than that of shared mappings. If NO 252767961f9dSMike Kravetz * entry is in the reserve map, it means a reservation exists. 252867961f9dSMike Kravetz * If an entry exists in the reserve map, it means the 252967961f9dSMike Kravetz * reservation has already been consumed. As a result, the 253067961f9dSMike Kravetz * return value of this routine is the opposite of the 253167961f9dSMike Kravetz * value returned from reserve map manipulation routines above. 253267961f9dSMike Kravetz */ 2533bf3d12b9SMiaohe Lin if (ret > 0) 253467961f9dSMike Kravetz return 0; 2535bf3d12b9SMiaohe Lin if (ret == 0) 253667961f9dSMike Kravetz return 1; 2537bf3d12b9SMiaohe Lin return ret; 253884afd99bSAndy Whitcroft } 2539cf3ad20bSMike Kravetz 2540cf3ad20bSMike Kravetz static long vma_needs_reservation(struct hstate *h, 2541a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 2542c37f9fb1SAndy Whitcroft { 25435e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV); 2544cf3ad20bSMike Kravetz } 2545c37f9fb1SAndy Whitcroft 2546cf3ad20bSMike Kravetz static long vma_commit_reservation(struct hstate *h, 2547cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr) 2548cf3ad20bSMike Kravetz { 25495e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV); 25505e911373SMike Kravetz } 25515e911373SMike Kravetz 2552feba16e2SMike Kravetz static void vma_end_reservation(struct hstate *h, 25535e911373SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 25545e911373SMike Kravetz { 2555feba16e2SMike Kravetz (void)__vma_reservation_common(h, vma, addr, VMA_END_RESV); 2556c37f9fb1SAndy Whitcroft } 2557c37f9fb1SAndy Whitcroft 255896b96a96SMike Kravetz static long vma_add_reservation(struct hstate *h, 255996b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 256096b96a96SMike Kravetz { 256196b96a96SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV); 256296b96a96SMike Kravetz } 256396b96a96SMike Kravetz 2564846be085SMike Kravetz static long vma_del_reservation(struct hstate *h, 2565846be085SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 256696b96a96SMike Kravetz { 2567846be085SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_DEL_RESV); 2568846be085SMike Kravetz } 2569846be085SMike Kravetz 2570846be085SMike Kravetz /* 2571846be085SMike Kravetz * This routine is called to restore reservation information on error paths. 2572846be085SMike Kravetz * It should ONLY be called for pages allocated via alloc_huge_page(), and 2573846be085SMike Kravetz * the hugetlb mutex should remain held when calling this routine. 2574846be085SMike Kravetz * 2575846be085SMike Kravetz * It handles two specific cases: 2576846be085SMike Kravetz * 1) A reservation was in place and the page consumed the reservation. 2577846be085SMike Kravetz * HPageRestoreReserve is set in the page. 2578846be085SMike Kravetz * 2) No reservation was in place for the page, so HPageRestoreReserve is 2579846be085SMike Kravetz * not set. However, alloc_huge_page always updates the reserve map. 2580846be085SMike Kravetz * 2581846be085SMike Kravetz * In case 1, free_huge_page later in the error path will increment the 2582846be085SMike Kravetz * global reserve count. But, free_huge_page does not have enough context 2583846be085SMike Kravetz * to adjust the reservation map. This case deals primarily with private 2584846be085SMike Kravetz * mappings. Adjust the reserve map here to be consistent with global 2585846be085SMike Kravetz * reserve count adjustments to be made by free_huge_page. Make sure the 2586846be085SMike Kravetz * reserve map indicates there is a reservation present. 2587846be085SMike Kravetz * 2588846be085SMike Kravetz * In case 2, simply undo reserve map modifications done by alloc_huge_page. 2589846be085SMike Kravetz */ 2590846be085SMike Kravetz void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma, 2591846be085SMike Kravetz unsigned long address, struct page *page) 2592846be085SMike Kravetz { 259396b96a96SMike Kravetz long rc = vma_needs_reservation(h, vma, address); 259496b96a96SMike Kravetz 2595846be085SMike Kravetz if (HPageRestoreReserve(page)) { 2596846be085SMike Kravetz if (unlikely(rc < 0)) 259796b96a96SMike Kravetz /* 259896b96a96SMike Kravetz * Rare out of memory condition in reserve map 2599d6995da3SMike Kravetz * manipulation. Clear HPageRestoreReserve so that 260096b96a96SMike Kravetz * global reserve count will not be incremented 260196b96a96SMike Kravetz * by free_huge_page. This will make it appear 260296b96a96SMike Kravetz * as though the reservation for this page was 260396b96a96SMike Kravetz * consumed. This may prevent the task from 260496b96a96SMike Kravetz * faulting in the page at a later time. This 260596b96a96SMike Kravetz * is better than inconsistent global huge page 260696b96a96SMike Kravetz * accounting of reserve counts. 260796b96a96SMike Kravetz */ 2608d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 2609846be085SMike Kravetz else if (rc) 2610846be085SMike Kravetz (void)vma_add_reservation(h, vma, address); 2611846be085SMike Kravetz else 2612846be085SMike Kravetz vma_end_reservation(h, vma, address); 2613846be085SMike Kravetz } else { 2614846be085SMike Kravetz if (!rc) { 261596b96a96SMike Kravetz /* 2616846be085SMike Kravetz * This indicates there is an entry in the reserve map 2617c7b1850dSMike Kravetz * not added by alloc_huge_page. We know it was added 2618846be085SMike Kravetz * before the alloc_huge_page call, otherwise 2619846be085SMike Kravetz * HPageRestoreReserve would be set on the page. 2620846be085SMike Kravetz * Remove the entry so that a subsequent allocation 2621846be085SMike Kravetz * does not consume a reservation. 262296b96a96SMike Kravetz */ 2623846be085SMike Kravetz rc = vma_del_reservation(h, vma, address); 2624846be085SMike Kravetz if (rc < 0) 2625846be085SMike Kravetz /* 2626846be085SMike Kravetz * VERY rare out of memory condition. Since 2627846be085SMike Kravetz * we can not delete the entry, set 2628846be085SMike Kravetz * HPageRestoreReserve so that the reserve 2629846be085SMike Kravetz * count will be incremented when the page 2630846be085SMike Kravetz * is freed. This reserve will be consumed 2631846be085SMike Kravetz * on a subsequent allocation. 2632846be085SMike Kravetz */ 2633846be085SMike Kravetz SetHPageRestoreReserve(page); 2634846be085SMike Kravetz } else if (rc < 0) { 2635846be085SMike Kravetz /* 2636846be085SMike Kravetz * Rare out of memory condition from 2637846be085SMike Kravetz * vma_needs_reservation call. Memory allocation is 2638846be085SMike Kravetz * only attempted if a new entry is needed. Therefore, 2639846be085SMike Kravetz * this implies there is not an entry in the 2640846be085SMike Kravetz * reserve map. 2641846be085SMike Kravetz * 2642846be085SMike Kravetz * For shared mappings, no entry in the map indicates 2643846be085SMike Kravetz * no reservation. We are done. 2644846be085SMike Kravetz */ 2645846be085SMike Kravetz if (!(vma->vm_flags & VM_MAYSHARE)) 2646846be085SMike Kravetz /* 2647846be085SMike Kravetz * For private mappings, no entry indicates 2648846be085SMike Kravetz * a reservation is present. Since we can 2649846be085SMike Kravetz * not add an entry, set SetHPageRestoreReserve 2650846be085SMike Kravetz * on the page so reserve count will be 2651846be085SMike Kravetz * incremented when freed. This reserve will 2652846be085SMike Kravetz * be consumed on a subsequent allocation. 2653846be085SMike Kravetz */ 2654846be085SMike Kravetz SetHPageRestoreReserve(page); 265596b96a96SMike Kravetz } else 2656846be085SMike Kravetz /* 2657846be085SMike Kravetz * No reservation present, do nothing 2658846be085SMike Kravetz */ 265996b96a96SMike Kravetz vma_end_reservation(h, vma, address); 266096b96a96SMike Kravetz } 266196b96a96SMike Kravetz } 266296b96a96SMike Kravetz 2663369fa227SOscar Salvador /* 2664369fa227SOscar Salvador * alloc_and_dissolve_huge_page - Allocate a new page and dissolve the old one 2665369fa227SOscar Salvador * @h: struct hstate old page belongs to 2666369fa227SOscar Salvador * @old_page: Old page to dissolve 2667ae37c7ffSOscar Salvador * @list: List to isolate the page in case we need to 2668369fa227SOscar Salvador * Returns 0 on success, otherwise negated error. 2669369fa227SOscar Salvador */ 2670ae37c7ffSOscar Salvador static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, 2671ae37c7ffSOscar Salvador struct list_head *list) 2672369fa227SOscar Salvador { 2673369fa227SOscar Salvador gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 2674369fa227SOscar Salvador int nid = page_to_nid(old_page); 2675b65a4edaSMike Kravetz bool alloc_retry = false; 2676369fa227SOscar Salvador struct page *new_page; 2677369fa227SOscar Salvador int ret = 0; 2678369fa227SOscar Salvador 2679369fa227SOscar Salvador /* 2680369fa227SOscar Salvador * Before dissolving the page, we need to allocate a new one for the 2681f41f2ed4SMuchun Song * pool to remain stable. Here, we allocate the page and 'prep' it 2682f41f2ed4SMuchun Song * by doing everything but actually updating counters and adding to 2683f41f2ed4SMuchun Song * the pool. This simplifies and let us do most of the processing 2684f41f2ed4SMuchun Song * under the lock. 2685369fa227SOscar Salvador */ 2686b65a4edaSMike Kravetz alloc_retry: 2687369fa227SOscar Salvador new_page = alloc_buddy_huge_page(h, gfp_mask, nid, NULL, NULL); 2688369fa227SOscar Salvador if (!new_page) 2689369fa227SOscar Salvador return -ENOMEM; 2690b65a4edaSMike Kravetz /* 2691b65a4edaSMike Kravetz * If all goes well, this page will be directly added to the free 2692b65a4edaSMike Kravetz * list in the pool. For this the ref count needs to be zero. 2693b65a4edaSMike Kravetz * Attempt to drop now, and retry once if needed. It is VERY 2694b65a4edaSMike Kravetz * unlikely there is another ref on the page. 2695b65a4edaSMike Kravetz * 2696b65a4edaSMike Kravetz * If someone else has a reference to the page, it will be freed 2697b65a4edaSMike Kravetz * when they drop their ref. Abuse temporary page flag to accomplish 2698b65a4edaSMike Kravetz * this. Retry once if there is an inflated ref count. 2699b65a4edaSMike Kravetz */ 2700b65a4edaSMike Kravetz SetHPageTemporary(new_page); 2701b65a4edaSMike Kravetz if (!put_page_testzero(new_page)) { 2702b65a4edaSMike Kravetz if (alloc_retry) 2703b65a4edaSMike Kravetz return -EBUSY; 2704b65a4edaSMike Kravetz 2705b65a4edaSMike Kravetz alloc_retry = true; 2706b65a4edaSMike Kravetz goto alloc_retry; 2707b65a4edaSMike Kravetz } 2708b65a4edaSMike Kravetz ClearHPageTemporary(new_page); 2709b65a4edaSMike Kravetz 2710f41f2ed4SMuchun Song __prep_new_huge_page(h, new_page); 2711369fa227SOscar Salvador 2712369fa227SOscar Salvador retry: 2713369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2714369fa227SOscar Salvador if (!PageHuge(old_page)) { 2715369fa227SOscar Salvador /* 2716369fa227SOscar Salvador * Freed from under us. Drop new_page too. 2717369fa227SOscar Salvador */ 2718369fa227SOscar Salvador goto free_new; 2719369fa227SOscar Salvador } else if (page_count(old_page)) { 2720369fa227SOscar Salvador /* 2721ae37c7ffSOscar Salvador * Someone has grabbed the page, try to isolate it here. 2722ae37c7ffSOscar Salvador * Fail with -EBUSY if not possible. 2723369fa227SOscar Salvador */ 2724ae37c7ffSOscar Salvador spin_unlock_irq(&hugetlb_lock); 2725ae37c7ffSOscar Salvador if (!isolate_huge_page(old_page, list)) 2726369fa227SOscar Salvador ret = -EBUSY; 2727ae37c7ffSOscar Salvador spin_lock_irq(&hugetlb_lock); 2728369fa227SOscar Salvador goto free_new; 2729369fa227SOscar Salvador } else if (!HPageFreed(old_page)) { 2730369fa227SOscar Salvador /* 2731369fa227SOscar Salvador * Page's refcount is 0 but it has not been enqueued in the 2732369fa227SOscar Salvador * freelist yet. Race window is small, so we can succeed here if 2733369fa227SOscar Salvador * we retry. 2734369fa227SOscar Salvador */ 2735369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2736369fa227SOscar Salvador cond_resched(); 2737369fa227SOscar Salvador goto retry; 2738369fa227SOscar Salvador } else { 2739369fa227SOscar Salvador /* 2740369fa227SOscar Salvador * Ok, old_page is still a genuine free hugepage. Remove it from 2741369fa227SOscar Salvador * the freelist and decrease the counters. These will be 2742369fa227SOscar Salvador * incremented again when calling __prep_account_new_huge_page() 2743369fa227SOscar Salvador * and enqueue_huge_page() for new_page. The counters will remain 2744369fa227SOscar Salvador * stable since this happens under the lock. 2745369fa227SOscar Salvador */ 2746369fa227SOscar Salvador remove_hugetlb_page(h, old_page, false); 2747369fa227SOscar Salvador 2748369fa227SOscar Salvador /* 2749b65a4edaSMike Kravetz * Ref count on new page is already zero as it was dropped 2750b65a4edaSMike Kravetz * earlier. It can be directly added to the pool free list. 2751369fa227SOscar Salvador */ 2752369fa227SOscar Salvador __prep_account_new_huge_page(h, nid); 2753369fa227SOscar Salvador enqueue_huge_page(h, new_page); 2754369fa227SOscar Salvador 2755369fa227SOscar Salvador /* 2756369fa227SOscar Salvador * Pages have been replaced, we can safely free the old one. 2757369fa227SOscar Salvador */ 2758369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2759b65d4adbSMuchun Song update_and_free_page(h, old_page, false); 2760369fa227SOscar Salvador } 2761369fa227SOscar Salvador 2762369fa227SOscar Salvador return ret; 2763369fa227SOscar Salvador 2764369fa227SOscar Salvador free_new: 2765369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2766b65a4edaSMike Kravetz /* Page has a zero ref count, but needs a ref to be freed */ 2767b65a4edaSMike Kravetz set_page_refcounted(new_page); 2768b65d4adbSMuchun Song update_and_free_page(h, new_page, false); 2769369fa227SOscar Salvador 2770369fa227SOscar Salvador return ret; 2771369fa227SOscar Salvador } 2772369fa227SOscar Salvador 2773ae37c7ffSOscar Salvador int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list) 2774369fa227SOscar Salvador { 2775369fa227SOscar Salvador struct hstate *h; 2776369fa227SOscar Salvador struct page *head; 2777ae37c7ffSOscar Salvador int ret = -EBUSY; 2778369fa227SOscar Salvador 2779369fa227SOscar Salvador /* 2780369fa227SOscar Salvador * The page might have been dissolved from under our feet, so make sure 2781369fa227SOscar Salvador * to carefully check the state under the lock. 2782369fa227SOscar Salvador * Return success when racing as if we dissolved the page ourselves. 2783369fa227SOscar Salvador */ 2784369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2785369fa227SOscar Salvador if (PageHuge(page)) { 2786369fa227SOscar Salvador head = compound_head(page); 2787369fa227SOscar Salvador h = page_hstate(head); 2788369fa227SOscar Salvador } else { 2789369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2790369fa227SOscar Salvador return 0; 2791369fa227SOscar Salvador } 2792369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2793369fa227SOscar Salvador 2794369fa227SOscar Salvador /* 2795369fa227SOscar Salvador * Fence off gigantic pages as there is a cyclic dependency between 2796369fa227SOscar Salvador * alloc_contig_range and them. Return -ENOMEM as this has the effect 2797369fa227SOscar Salvador * of bailing out right away without further retrying. 2798369fa227SOscar Salvador */ 2799369fa227SOscar Salvador if (hstate_is_gigantic(h)) 2800369fa227SOscar Salvador return -ENOMEM; 2801369fa227SOscar Salvador 2802ae37c7ffSOscar Salvador if (page_count(head) && isolate_huge_page(head, list)) 2803ae37c7ffSOscar Salvador ret = 0; 2804ae37c7ffSOscar Salvador else if (!page_count(head)) 2805ae37c7ffSOscar Salvador ret = alloc_and_dissolve_huge_page(h, head, list); 2806ae37c7ffSOscar Salvador 2807ae37c7ffSOscar Salvador return ret; 2808369fa227SOscar Salvador } 2809369fa227SOscar Salvador 281070c3547eSMike Kravetz struct page *alloc_huge_page(struct vm_area_struct *vma, 281104f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 2812348ea204SAdam Litke { 281390481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 2814a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 2815348ea204SAdam Litke struct page *page; 2816d85f69b0SMike Kravetz long map_chg, map_commit; 2817d85f69b0SMike Kravetz long gbl_chg; 28186d76dcf4SAneesh Kumar K.V int ret, idx; 28196d76dcf4SAneesh Kumar K.V struct hugetlb_cgroup *h_cg; 282008cf9fafSMina Almasry bool deferred_reserve; 28212fc39cecSAdam Litke 28226d76dcf4SAneesh Kumar K.V idx = hstate_index(h); 2823a1e78772SMel Gorman /* 2824d85f69b0SMike Kravetz * Examine the region/reserve map to determine if the process 2825d85f69b0SMike Kravetz * has a reservation for the page to be allocated. A return 2826d85f69b0SMike Kravetz * code of zero indicates a reservation exists (no change). 2827a1e78772SMel Gorman */ 2828d85f69b0SMike Kravetz map_chg = gbl_chg = vma_needs_reservation(h, vma, addr); 2829d85f69b0SMike Kravetz if (map_chg < 0) 283076dcee75SAneesh Kumar K.V return ERR_PTR(-ENOMEM); 2831d85f69b0SMike Kravetz 2832d85f69b0SMike Kravetz /* 2833d85f69b0SMike Kravetz * Processes that did not create the mapping will have no 2834d85f69b0SMike Kravetz * reserves as indicated by the region/reserve map. Check 2835d85f69b0SMike Kravetz * that the allocation will not exceed the subpool limit. 2836d85f69b0SMike Kravetz * Allocations for MAP_NORESERVE mappings also need to be 2837d85f69b0SMike Kravetz * checked against any subpool limit. 2838d85f69b0SMike Kravetz */ 2839d85f69b0SMike Kravetz if (map_chg || avoid_reserve) { 2840d85f69b0SMike Kravetz gbl_chg = hugepage_subpool_get_pages(spool, 1); 2841d85f69b0SMike Kravetz if (gbl_chg < 0) { 2842feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 284376dcee75SAneesh Kumar K.V return ERR_PTR(-ENOSPC); 28445e911373SMike Kravetz } 284590d8b7e6SAdam Litke 2846d85f69b0SMike Kravetz /* 2847d85f69b0SMike Kravetz * Even though there was no reservation in the region/reserve 2848d85f69b0SMike Kravetz * map, there could be reservations associated with the 2849d85f69b0SMike Kravetz * subpool that can be used. This would be indicated if the 2850d85f69b0SMike Kravetz * return value of hugepage_subpool_get_pages() is zero. 2851d85f69b0SMike Kravetz * However, if avoid_reserve is specified we still avoid even 2852d85f69b0SMike Kravetz * the subpool reservations. 2853d85f69b0SMike Kravetz */ 2854d85f69b0SMike Kravetz if (avoid_reserve) 2855d85f69b0SMike Kravetz gbl_chg = 1; 2856d85f69b0SMike Kravetz } 2857d85f69b0SMike Kravetz 285808cf9fafSMina Almasry /* If this allocation is not consuming a reservation, charge it now. 285908cf9fafSMina Almasry */ 28606501fe5fSMiaohe Lin deferred_reserve = map_chg || avoid_reserve; 286108cf9fafSMina Almasry if (deferred_reserve) { 286208cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup_rsvd( 286308cf9fafSMina Almasry idx, pages_per_huge_page(h), &h_cg); 28648f34af6fSJianyu Zhan if (ret) 28658f34af6fSJianyu Zhan goto out_subpool_put; 286608cf9fafSMina Almasry } 286708cf9fafSMina Almasry 286808cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); 286908cf9fafSMina Almasry if (ret) 287008cf9fafSMina Almasry goto out_uncharge_cgroup_reservation; 28718f34af6fSJianyu Zhan 2872db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2873d85f69b0SMike Kravetz /* 2874d85f69b0SMike Kravetz * glb_chg is passed to indicate whether or not a page must be taken 2875d85f69b0SMike Kravetz * from the global free pool (global change). gbl_chg == 0 indicates 2876d85f69b0SMike Kravetz * a reservation exists for the allocation. 2877d85f69b0SMike Kravetz */ 2878d85f69b0SMike Kravetz page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg); 287981a6fcaeSJoonsoo Kim if (!page) { 2880db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 28810c397daeSMichal Hocko page = alloc_buddy_huge_page_with_mpol(h, vma, addr); 28828f34af6fSJianyu Zhan if (!page) 28838f34af6fSJianyu Zhan goto out_uncharge_cgroup; 2884a88c7695SNaoya Horiguchi if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { 2885d6995da3SMike Kravetz SetHPageRestoreReserve(page); 2886a88c7695SNaoya Horiguchi h->resv_huge_pages--; 2887a88c7695SNaoya Horiguchi } 2888db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 288915a8d68eSWei Yang list_add(&page->lru, &h->hugepage_activelist); 289081a6fcaeSJoonsoo Kim /* Fall through */ 2891a1e78772SMel Gorman } 289281a6fcaeSJoonsoo Kim hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); 289308cf9fafSMina Almasry /* If allocation is not consuming a reservation, also store the 289408cf9fafSMina Almasry * hugetlb_cgroup pointer on the page. 289508cf9fafSMina Almasry */ 289608cf9fafSMina Almasry if (deferred_reserve) { 289708cf9fafSMina Almasry hugetlb_cgroup_commit_charge_rsvd(idx, pages_per_huge_page(h), 289808cf9fafSMina Almasry h_cg, page); 289908cf9fafSMina Almasry } 290008cf9fafSMina Almasry 2901db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2902a1e78772SMel Gorman 2903d6995da3SMike Kravetz hugetlb_set_page_subpool(page, spool); 2904a1e78772SMel Gorman 2905d85f69b0SMike Kravetz map_commit = vma_commit_reservation(h, vma, addr); 2906d85f69b0SMike Kravetz if (unlikely(map_chg > map_commit)) { 290733039678SMike Kravetz /* 290833039678SMike Kravetz * The page was added to the reservation map between 290933039678SMike Kravetz * vma_needs_reservation and vma_commit_reservation. 291033039678SMike Kravetz * This indicates a race with hugetlb_reserve_pages. 291133039678SMike Kravetz * Adjust for the subpool count incremented above AND 291233039678SMike Kravetz * in hugetlb_reserve_pages for the same page. Also, 291333039678SMike Kravetz * the reservation count added in hugetlb_reserve_pages 291433039678SMike Kravetz * no longer applies. 291533039678SMike Kravetz */ 291633039678SMike Kravetz long rsv_adjust; 291733039678SMike Kravetz 291833039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 1); 291933039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 292079aa925bSMike Kravetz if (deferred_reserve) 292179aa925bSMike Kravetz hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 292279aa925bSMike Kravetz pages_per_huge_page(h), page); 292333039678SMike Kravetz } 29247893d1d5SAdam Litke return page; 29258f34af6fSJianyu Zhan 29268f34af6fSJianyu Zhan out_uncharge_cgroup: 29278f34af6fSJianyu Zhan hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); 292808cf9fafSMina Almasry out_uncharge_cgroup_reservation: 292908cf9fafSMina Almasry if (deferred_reserve) 293008cf9fafSMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h), 293108cf9fafSMina Almasry h_cg); 29328f34af6fSJianyu Zhan out_subpool_put: 2933d85f69b0SMike Kravetz if (map_chg || avoid_reserve) 29348f34af6fSJianyu Zhan hugepage_subpool_put_pages(spool, 1); 2935feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 29368f34af6fSJianyu Zhan return ERR_PTR(-ENOSPC); 2937b45b5bd6SDavid Gibson } 2938b45b5bd6SDavid Gibson 2939e24a1307SAneesh Kumar K.V int alloc_bootmem_huge_page(struct hstate *h) 2940e24a1307SAneesh Kumar K.V __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); 2941e24a1307SAneesh Kumar K.V int __alloc_bootmem_huge_page(struct hstate *h) 2942aa888a74SAndi Kleen { 2943aa888a74SAndi Kleen struct huge_bootmem_page *m; 2944b2261026SJoonsoo Kim int nr_nodes, node; 2945aa888a74SAndi Kleen 2946b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { 2947aa888a74SAndi Kleen void *addr; 2948aa888a74SAndi Kleen 2949eb31d559SMike Rapoport addr = memblock_alloc_try_nid_raw( 29508b89a116SGrygorii Strashko huge_page_size(h), huge_page_size(h), 295197ad1087SMike Rapoport 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); 2952aa888a74SAndi Kleen if (addr) { 2953aa888a74SAndi Kleen /* 2954aa888a74SAndi Kleen * Use the beginning of the huge page to store the 2955aa888a74SAndi Kleen * huge_bootmem_page struct (until gather_bootmem 2956aa888a74SAndi Kleen * puts them into the mem_map). 2957aa888a74SAndi Kleen */ 2958aa888a74SAndi Kleen m = addr; 2959aa888a74SAndi Kleen goto found; 2960aa888a74SAndi Kleen } 2961aa888a74SAndi Kleen } 2962aa888a74SAndi Kleen return 0; 2963aa888a74SAndi Kleen 2964aa888a74SAndi Kleen found: 2965df994eadSLuiz Capitulino BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h))); 2966aa888a74SAndi Kleen /* Put them into a private list first because mem_map is not up yet */ 2967330d6e48SCannon Matthews INIT_LIST_HEAD(&m->list); 2968aa888a74SAndi Kleen list_add(&m->list, &huge_boot_pages); 2969aa888a74SAndi Kleen m->hstate = h; 2970aa888a74SAndi Kleen return 1; 2971aa888a74SAndi Kleen } 2972aa888a74SAndi Kleen 297348b8d744SMike Kravetz /* 297448b8d744SMike Kravetz * Put bootmem huge pages into the standard lists after mem_map is up. 297548b8d744SMike Kravetz * Note: This only applies to gigantic (order > MAX_ORDER) pages. 297648b8d744SMike Kravetz */ 2977aa888a74SAndi Kleen static void __init gather_bootmem_prealloc(void) 2978aa888a74SAndi Kleen { 2979aa888a74SAndi Kleen struct huge_bootmem_page *m; 2980aa888a74SAndi Kleen 2981aa888a74SAndi Kleen list_for_each_entry(m, &huge_boot_pages, list) { 298240d18ebfSMike Kravetz struct page *page = virt_to_page(m); 2983aa888a74SAndi Kleen struct hstate *h = m->hstate; 2984ee8f248dSBecky Bruce 298548b8d744SMike Kravetz VM_BUG_ON(!hstate_is_gigantic(h)); 2986aa888a74SAndi Kleen WARN_ON(page_count(page) != 1); 29877118fc29SMike Kravetz if (prep_compound_gigantic_page(page, huge_page_order(h))) { 2988ef5a22beSAndrea Arcangeli WARN_ON(PageReserved(page)); 2989aa888a74SAndi Kleen prep_new_huge_page(h, page, page_to_nid(page)); 29907118fc29SMike Kravetz put_page(page); /* add to the hugepage allocator */ 29917118fc29SMike Kravetz } else { 2992416d85edSMike Kravetz /* VERY unlikely inflated ref count on a tail page */ 29937118fc29SMike Kravetz free_gigantic_page(page, huge_page_order(h)); 29947118fc29SMike Kravetz } 2995af0fb9dfSMichal Hocko 2996b0320c7bSRafael Aquini /* 299748b8d744SMike Kravetz * We need to restore the 'stolen' pages to totalram_pages 299848b8d744SMike Kravetz * in order to fix confusing memory reports from free(1) and 299948b8d744SMike Kravetz * other side-effects, like CommitLimit going negative. 3000b0320c7bSRafael Aquini */ 3001c78a7f36SMiaohe Lin adjust_managed_page_count(page, pages_per_huge_page(h)); 3002520495feSCannon Matthews cond_resched(); 3003aa888a74SAndi Kleen } 3004aa888a74SAndi Kleen } 3005aa888a74SAndi Kleen 30068faa8b07SAndi Kleen static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 30071da177e4SLinus Torvalds { 30081da177e4SLinus Torvalds unsigned long i; 3009f60858f9SMike Kravetz nodemask_t *node_alloc_noretry; 3010f60858f9SMike Kravetz 3011f60858f9SMike Kravetz if (!hstate_is_gigantic(h)) { 3012f60858f9SMike Kravetz /* 3013f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3014f60858f9SMike Kravetz * Ignore errors as lower level routines can deal with 3015f60858f9SMike Kravetz * node_alloc_noretry == NULL. If this kmalloc fails at boot 3016f60858f9SMike Kravetz * time, we are likely in bigger trouble. 3017f60858f9SMike Kravetz */ 3018f60858f9SMike Kravetz node_alloc_noretry = kmalloc(sizeof(*node_alloc_noretry), 3019f60858f9SMike Kravetz GFP_KERNEL); 3020f60858f9SMike Kravetz } else { 3021f60858f9SMike Kravetz /* allocations done at boot time */ 3022f60858f9SMike Kravetz node_alloc_noretry = NULL; 3023f60858f9SMike Kravetz } 3024f60858f9SMike Kravetz 3025f60858f9SMike Kravetz /* bit mask controlling how hard we retry per-node allocations */ 3026f60858f9SMike Kravetz if (node_alloc_noretry) 3027f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 30281da177e4SLinus Torvalds 3029e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 3030bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) { 3031dbda8feaSBarry Song if (hugetlb_cma_size) { 3032cf11e85fSRoman Gushchin pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n"); 30337ecc9565SChen Wandun goto free; 3034cf11e85fSRoman Gushchin } 3035aa888a74SAndi Kleen if (!alloc_bootmem_huge_page(h)) 3036aa888a74SAndi Kleen break; 30370c397daeSMichal Hocko } else if (!alloc_pool_huge_page(h, 3038f60858f9SMike Kravetz &node_states[N_MEMORY], 3039f60858f9SMike Kravetz node_alloc_noretry)) 30401da177e4SLinus Torvalds break; 304169ed779aSDavid Rientjes cond_resched(); 30421da177e4SLinus Torvalds } 3043d715cf80SLiam R. Howlett if (i < h->max_huge_pages) { 3044d715cf80SLiam R. Howlett char buf[32]; 3045d715cf80SLiam R. Howlett 3046c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3047d715cf80SLiam R. Howlett pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n", 3048d715cf80SLiam R. Howlett h->max_huge_pages, buf, i); 30498faa8b07SAndi Kleen h->max_huge_pages = i; 3050e5ff2159SAndi Kleen } 30517ecc9565SChen Wandun free: 3052f60858f9SMike Kravetz kfree(node_alloc_noretry); 3053d715cf80SLiam R. Howlett } 3054e5ff2159SAndi Kleen 3055e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 3056e5ff2159SAndi Kleen { 305779dfc695SMike Kravetz struct hstate *h, *h2; 3058e5ff2159SAndi Kleen 3059e5ff2159SAndi Kleen for_each_hstate(h) { 3060641844f5SNaoya Horiguchi if (minimum_order > huge_page_order(h)) 3061641844f5SNaoya Horiguchi minimum_order = huge_page_order(h); 3062641844f5SNaoya Horiguchi 30638faa8b07SAndi Kleen /* oversize hugepages were init'ed in early boot */ 3064bae7f4aeSLuiz Capitulino if (!hstate_is_gigantic(h)) 30658faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(h); 306679dfc695SMike Kravetz 306779dfc695SMike Kravetz /* 306879dfc695SMike Kravetz * Set demote order for each hstate. Note that 306979dfc695SMike Kravetz * h->demote_order is initially 0. 307079dfc695SMike Kravetz * - We can not demote gigantic pages if runtime freeing 307179dfc695SMike Kravetz * is not supported, so skip this. 3072a01f4390SMike Kravetz * - If CMA allocation is possible, we can not demote 3073a01f4390SMike Kravetz * HUGETLB_PAGE_ORDER or smaller size pages. 307479dfc695SMike Kravetz */ 307579dfc695SMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 307679dfc695SMike Kravetz continue; 3077a01f4390SMike Kravetz if (hugetlb_cma_size && h->order <= HUGETLB_PAGE_ORDER) 3078a01f4390SMike Kravetz continue; 307979dfc695SMike Kravetz for_each_hstate(h2) { 308079dfc695SMike Kravetz if (h2 == h) 308179dfc695SMike Kravetz continue; 308279dfc695SMike Kravetz if (h2->order < h->order && 308379dfc695SMike Kravetz h2->order > h->demote_order) 308479dfc695SMike Kravetz h->demote_order = h2->order; 308579dfc695SMike Kravetz } 3086e5ff2159SAndi Kleen } 3087641844f5SNaoya Horiguchi VM_BUG_ON(minimum_order == UINT_MAX); 3088e5ff2159SAndi Kleen } 3089e5ff2159SAndi Kleen 3090e5ff2159SAndi Kleen static void __init report_hugepages(void) 3091e5ff2159SAndi Kleen { 3092e5ff2159SAndi Kleen struct hstate *h; 3093e5ff2159SAndi Kleen 3094e5ff2159SAndi Kleen for_each_hstate(h) { 30954abd32dbSAndi Kleen char buf[32]; 3096c6247f72SMatthew Wilcox 3097c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3098ffb22af5SAndrew Morton pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n", 3099c6247f72SMatthew Wilcox buf, h->free_huge_pages); 3100e5ff2159SAndi Kleen } 3101e5ff2159SAndi Kleen } 3102e5ff2159SAndi Kleen 31031da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 31046ae11b27SLee Schermerhorn static void try_to_free_low(struct hstate *h, unsigned long count, 31056ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 31061da177e4SLinus Torvalds { 31074415cc8dSChristoph Lameter int i; 31081121828aSMike Kravetz LIST_HEAD(page_list); 31094415cc8dSChristoph Lameter 31109487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 3111bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3112aa888a74SAndi Kleen return; 3113aa888a74SAndi Kleen 31141121828aSMike Kravetz /* 31151121828aSMike Kravetz * Collect pages to be freed on a list, and free after dropping lock 31161121828aSMike Kravetz */ 31176ae11b27SLee Schermerhorn for_each_node_mask(i, *nodes_allowed) { 311810c6ec49SMike Kravetz struct page *page, *next; 3119a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 3120a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 3121a5516438SAndi Kleen if (count >= h->nr_huge_pages) 31221121828aSMike Kravetz goto out; 31231da177e4SLinus Torvalds if (PageHighMem(page)) 31241da177e4SLinus Torvalds continue; 31256eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 31261121828aSMike Kravetz list_add(&page->lru, &page_list); 31271121828aSMike Kravetz } 31281121828aSMike Kravetz } 31291121828aSMike Kravetz 31301121828aSMike Kravetz out: 3131db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 313210c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3133db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 31341da177e4SLinus Torvalds } 31351da177e4SLinus Torvalds #else 31366ae11b27SLee Schermerhorn static inline void try_to_free_low(struct hstate *h, unsigned long count, 31376ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 31381da177e4SLinus Torvalds { 31391da177e4SLinus Torvalds } 31401da177e4SLinus Torvalds #endif 31411da177e4SLinus Torvalds 314220a0307cSWu Fengguang /* 314320a0307cSWu Fengguang * Increment or decrement surplus_huge_pages. Keep node-specific counters 314420a0307cSWu Fengguang * balanced by operating on them in a round-robin fashion. 314520a0307cSWu Fengguang * Returns 1 if an adjustment was made. 314620a0307cSWu Fengguang */ 31476ae11b27SLee Schermerhorn static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, 31486ae11b27SLee Schermerhorn int delta) 314920a0307cSWu Fengguang { 3150b2261026SJoonsoo Kim int nr_nodes, node; 315120a0307cSWu Fengguang 31529487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 315320a0307cSWu Fengguang VM_BUG_ON(delta != -1 && delta != 1); 315420a0307cSWu Fengguang 3155e8c5c824SLee Schermerhorn if (delta < 0) { 3156b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 3157b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node]) 3158b2261026SJoonsoo Kim goto found; 3159b2261026SJoonsoo Kim } 3160b2261026SJoonsoo Kim } else { 3161b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 3162b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node] < 3163b2261026SJoonsoo Kim h->nr_huge_pages_node[node]) 3164b2261026SJoonsoo Kim goto found; 3165e8c5c824SLee Schermerhorn } 31669a76db09SLee Schermerhorn } 3167b2261026SJoonsoo Kim return 0; 316820a0307cSWu Fengguang 3169b2261026SJoonsoo Kim found: 317020a0307cSWu Fengguang h->surplus_huge_pages += delta; 3171b2261026SJoonsoo Kim h->surplus_huge_pages_node[node] += delta; 3172b2261026SJoonsoo Kim return 1; 317320a0307cSWu Fengguang } 317420a0307cSWu Fengguang 3175a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 3176fd875dcaSMike Kravetz static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, 31776ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 31781da177e4SLinus Torvalds { 31797893d1d5SAdam Litke unsigned long min_count, ret; 318010c6ec49SMike Kravetz struct page *page; 318110c6ec49SMike Kravetz LIST_HEAD(page_list); 3182f60858f9SMike Kravetz NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL); 3183f60858f9SMike Kravetz 3184f60858f9SMike Kravetz /* 3185f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3186f60858f9SMike Kravetz * If we can not allocate the bit mask, do not attempt to allocate 3187f60858f9SMike Kravetz * the requested huge pages. 3188f60858f9SMike Kravetz */ 3189f60858f9SMike Kravetz if (node_alloc_noretry) 3190f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 3191f60858f9SMike Kravetz else 3192f60858f9SMike Kravetz return -ENOMEM; 31931da177e4SLinus Torvalds 319429383967SMike Kravetz /* 319529383967SMike Kravetz * resize_lock mutex prevents concurrent adjustments to number of 319629383967SMike Kravetz * pages in hstate via the proc/sysfs interfaces. 319729383967SMike Kravetz */ 319829383967SMike Kravetz mutex_lock(&h->resize_lock); 3199b65d4adbSMuchun Song flush_free_hpage_work(h); 3200db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 32014eb0716eSAlexandre Ghiti 32024eb0716eSAlexandre Ghiti /* 3203fd875dcaSMike Kravetz * Check for a node specific request. 3204fd875dcaSMike Kravetz * Changing node specific huge page count may require a corresponding 3205fd875dcaSMike Kravetz * change to the global count. In any case, the passed node mask 3206fd875dcaSMike Kravetz * (nodes_allowed) will restrict alloc/free to the specified node. 3207fd875dcaSMike Kravetz */ 3208fd875dcaSMike Kravetz if (nid != NUMA_NO_NODE) { 3209fd875dcaSMike Kravetz unsigned long old_count = count; 3210fd875dcaSMike Kravetz 3211fd875dcaSMike Kravetz count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; 3212fd875dcaSMike Kravetz /* 3213fd875dcaSMike Kravetz * User may have specified a large count value which caused the 3214fd875dcaSMike Kravetz * above calculation to overflow. In this case, they wanted 3215fd875dcaSMike Kravetz * to allocate as many huge pages as possible. Set count to 3216fd875dcaSMike Kravetz * largest possible value to align with their intention. 3217fd875dcaSMike Kravetz */ 3218fd875dcaSMike Kravetz if (count < old_count) 3219fd875dcaSMike Kravetz count = ULONG_MAX; 3220fd875dcaSMike Kravetz } 3221fd875dcaSMike Kravetz 3222fd875dcaSMike Kravetz /* 32234eb0716eSAlexandre Ghiti * Gigantic pages runtime allocation depend on the capability for large 32244eb0716eSAlexandre Ghiti * page range allocation. 32254eb0716eSAlexandre Ghiti * If the system does not provide this feature, return an error when 32264eb0716eSAlexandre Ghiti * the user tries to allocate gigantic pages but let the user free the 32274eb0716eSAlexandre Ghiti * boottime allocated gigantic pages. 32284eb0716eSAlexandre Ghiti */ 32294eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) { 32304eb0716eSAlexandre Ghiti if (count > persistent_huge_pages(h)) { 3231db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 323229383967SMike Kravetz mutex_unlock(&h->resize_lock); 3233f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 32344eb0716eSAlexandre Ghiti return -EINVAL; 32354eb0716eSAlexandre Ghiti } 32364eb0716eSAlexandre Ghiti /* Fall through to decrease pool */ 32374eb0716eSAlexandre Ghiti } 3238aa888a74SAndi Kleen 32397893d1d5SAdam Litke /* 32407893d1d5SAdam Litke * Increase the pool size 32417893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 32427893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 3243d1c3fb1fSNishanth Aravamudan * 32440c397daeSMichal Hocko * We might race with alloc_surplus_huge_page() here and be unable 3245d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 3246d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 3247d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 3248d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 32497893d1d5SAdam Litke */ 3250a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 32516ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, -1)) 32527893d1d5SAdam Litke break; 32537893d1d5SAdam Litke } 32547893d1d5SAdam Litke 3255a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 32567893d1d5SAdam Litke /* 32577893d1d5SAdam Litke * If this allocation races such that we no longer need the 32587893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 32597893d1d5SAdam Litke * and reducing the surplus. 32607893d1d5SAdam Litke */ 3261db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3262649920c6SJia He 3263649920c6SJia He /* yield cpu to avoid soft lockup */ 3264649920c6SJia He cond_resched(); 3265649920c6SJia He 3266f60858f9SMike Kravetz ret = alloc_pool_huge_page(h, nodes_allowed, 3267f60858f9SMike Kravetz node_alloc_noretry); 3268db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 32697893d1d5SAdam Litke if (!ret) 32707893d1d5SAdam Litke goto out; 32717893d1d5SAdam Litke 3272536240f2SMel Gorman /* Bail for signals. Probably ctrl-c from user */ 3273536240f2SMel Gorman if (signal_pending(current)) 3274536240f2SMel Gorman goto out; 32757893d1d5SAdam Litke } 32767893d1d5SAdam Litke 32777893d1d5SAdam Litke /* 32787893d1d5SAdam Litke * Decrease the pool size 32797893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 32807893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 32817893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 32827893d1d5SAdam Litke * to the desired size as pages become free. 3283d1c3fb1fSNishanth Aravamudan * 3284d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 3285d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 3286d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 32870c397daeSMichal Hocko * alloc_surplus_huge_page() is checking the global counter, 3288d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 3289d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 3290d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 32917893d1d5SAdam Litke */ 3292a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 32936b0c880dSAdam Litke min_count = max(count, min_count); 32946ae11b27SLee Schermerhorn try_to_free_low(h, min_count, nodes_allowed); 329510c6ec49SMike Kravetz 329610c6ec49SMike Kravetz /* 329710c6ec49SMike Kravetz * Collect pages to be removed on list without dropping lock 329810c6ec49SMike Kravetz */ 3299a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 330010c6ec49SMike Kravetz page = remove_pool_huge_page(h, nodes_allowed, 0); 330110c6ec49SMike Kravetz if (!page) 33021da177e4SLinus Torvalds break; 330310c6ec49SMike Kravetz 330410c6ec49SMike Kravetz list_add(&page->lru, &page_list); 33051da177e4SLinus Torvalds } 330610c6ec49SMike Kravetz /* free the pages after dropping lock */ 3307db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 330810c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3309b65d4adbSMuchun Song flush_free_hpage_work(h); 3310db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 331110c6ec49SMike Kravetz 3312a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 33136ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, 1)) 33147893d1d5SAdam Litke break; 33157893d1d5SAdam Litke } 33167893d1d5SAdam Litke out: 33174eb0716eSAlexandre Ghiti h->max_huge_pages = persistent_huge_pages(h); 3318db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 331929383967SMike Kravetz mutex_unlock(&h->resize_lock); 33204eb0716eSAlexandre Ghiti 3321f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 3322f60858f9SMike Kravetz 33234eb0716eSAlexandre Ghiti return 0; 33241da177e4SLinus Torvalds } 33251da177e4SLinus Torvalds 3326*8531fc6fSMike Kravetz static int demote_free_huge_page(struct hstate *h, struct page *page) 3327*8531fc6fSMike Kravetz { 3328*8531fc6fSMike Kravetz int i, nid = page_to_nid(page); 3329*8531fc6fSMike Kravetz struct hstate *target_hstate; 3330*8531fc6fSMike Kravetz int rc = 0; 3331*8531fc6fSMike Kravetz 3332*8531fc6fSMike Kravetz target_hstate = size_to_hstate(PAGE_SIZE << h->demote_order); 3333*8531fc6fSMike Kravetz 3334*8531fc6fSMike Kravetz remove_hugetlb_page_for_demote(h, page, false); 3335*8531fc6fSMike Kravetz spin_unlock_irq(&hugetlb_lock); 3336*8531fc6fSMike Kravetz 3337*8531fc6fSMike Kravetz rc = alloc_huge_page_vmemmap(h, page); 3338*8531fc6fSMike Kravetz if (rc) { 3339*8531fc6fSMike Kravetz /* Allocation of vmemmmap failed, we can not demote page */ 3340*8531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 3341*8531fc6fSMike Kravetz set_page_refcounted(page); 3342*8531fc6fSMike Kravetz add_hugetlb_page(h, page, false); 3343*8531fc6fSMike Kravetz return rc; 3344*8531fc6fSMike Kravetz } 3345*8531fc6fSMike Kravetz 3346*8531fc6fSMike Kravetz /* 3347*8531fc6fSMike Kravetz * Use destroy_compound_hugetlb_page_for_demote for all huge page 3348*8531fc6fSMike Kravetz * sizes as it will not ref count pages. 3349*8531fc6fSMike Kravetz */ 3350*8531fc6fSMike Kravetz destroy_compound_hugetlb_page_for_demote(page, huge_page_order(h)); 3351*8531fc6fSMike Kravetz 3352*8531fc6fSMike Kravetz /* 3353*8531fc6fSMike Kravetz * Taking target hstate mutex synchronizes with set_max_huge_pages. 3354*8531fc6fSMike Kravetz * Without the mutex, pages added to target hstate could be marked 3355*8531fc6fSMike Kravetz * as surplus. 3356*8531fc6fSMike Kravetz * 3357*8531fc6fSMike Kravetz * Note that we already hold h->resize_lock. To prevent deadlock, 3358*8531fc6fSMike Kravetz * use the convention of always taking larger size hstate mutex first. 3359*8531fc6fSMike Kravetz */ 3360*8531fc6fSMike Kravetz mutex_lock(&target_hstate->resize_lock); 3361*8531fc6fSMike Kravetz for (i = 0; i < pages_per_huge_page(h); 3362*8531fc6fSMike Kravetz i += pages_per_huge_page(target_hstate)) { 3363*8531fc6fSMike Kravetz if (hstate_is_gigantic(target_hstate)) 3364*8531fc6fSMike Kravetz prep_compound_gigantic_page_for_demote(page + i, 3365*8531fc6fSMike Kravetz target_hstate->order); 3366*8531fc6fSMike Kravetz else 3367*8531fc6fSMike Kravetz prep_compound_page(page + i, target_hstate->order); 3368*8531fc6fSMike Kravetz set_page_private(page + i, 0); 3369*8531fc6fSMike Kravetz set_page_refcounted(page + i); 3370*8531fc6fSMike Kravetz prep_new_huge_page(target_hstate, page + i, nid); 3371*8531fc6fSMike Kravetz put_page(page + i); 3372*8531fc6fSMike Kravetz } 3373*8531fc6fSMike Kravetz mutex_unlock(&target_hstate->resize_lock); 3374*8531fc6fSMike Kravetz 3375*8531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 3376*8531fc6fSMike Kravetz 3377*8531fc6fSMike Kravetz /* 3378*8531fc6fSMike Kravetz * Not absolutely necessary, but for consistency update max_huge_pages 3379*8531fc6fSMike Kravetz * based on pool changes for the demoted page. 3380*8531fc6fSMike Kravetz */ 3381*8531fc6fSMike Kravetz h->max_huge_pages--; 3382*8531fc6fSMike Kravetz target_hstate->max_huge_pages += pages_per_huge_page(h); 3383*8531fc6fSMike Kravetz 3384*8531fc6fSMike Kravetz return rc; 3385*8531fc6fSMike Kravetz } 3386*8531fc6fSMike Kravetz 338779dfc695SMike Kravetz static int demote_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed) 338879dfc695SMike Kravetz __must_hold(&hugetlb_lock) 338979dfc695SMike Kravetz { 3390*8531fc6fSMike Kravetz int nr_nodes, node; 3391*8531fc6fSMike Kravetz struct page *page; 339279dfc695SMike Kravetz int rc = 0; 339379dfc695SMike Kravetz 339479dfc695SMike Kravetz lockdep_assert_held(&hugetlb_lock); 339579dfc695SMike Kravetz 339679dfc695SMike Kravetz /* We should never get here if no demote order */ 339779dfc695SMike Kravetz if (!h->demote_order) { 339879dfc695SMike Kravetz pr_warn("HugeTLB: NULL demote order passed to demote_pool_huge_page.\n"); 339979dfc695SMike Kravetz return -EINVAL; /* internal error */ 340079dfc695SMike Kravetz } 340179dfc695SMike Kravetz 3402*8531fc6fSMike Kravetz for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 3403*8531fc6fSMike Kravetz if (!list_empty(&h->hugepage_freelists[node])) { 3404*8531fc6fSMike Kravetz page = list_entry(h->hugepage_freelists[node].next, 3405*8531fc6fSMike Kravetz struct page, lru); 3406*8531fc6fSMike Kravetz rc = demote_free_huge_page(h, page); 3407*8531fc6fSMike Kravetz break; 3408*8531fc6fSMike Kravetz } 3409*8531fc6fSMike Kravetz } 3410*8531fc6fSMike Kravetz 341179dfc695SMike Kravetz return rc; 341279dfc695SMike Kravetz } 341379dfc695SMike Kravetz 3414a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 3415a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 3416a3437870SNishanth Aravamudan 341779dfc695SMike Kravetz #define HSTATE_ATTR_WO(_name) \ 341879dfc695SMike Kravetz static struct kobj_attribute _name##_attr = __ATTR_WO(_name) 341979dfc695SMike Kravetz 3420a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 3421a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = \ 3422a3437870SNishanth Aravamudan __ATTR(_name, 0644, _name##_show, _name##_store) 3423a3437870SNishanth Aravamudan 3424a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 3425a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 3426a3437870SNishanth Aravamudan 34279a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); 34289a305230SLee Schermerhorn 34299a305230SLee Schermerhorn static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) 3430a3437870SNishanth Aravamudan { 3431a3437870SNishanth Aravamudan int i; 34329a305230SLee Schermerhorn 3433a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 34349a305230SLee Schermerhorn if (hstate_kobjs[i] == kobj) { 34359a305230SLee Schermerhorn if (nidp) 34369a305230SLee Schermerhorn *nidp = NUMA_NO_NODE; 3437a3437870SNishanth Aravamudan return &hstates[i]; 34389a305230SLee Schermerhorn } 34399a305230SLee Schermerhorn 34409a305230SLee Schermerhorn return kobj_to_node_hstate(kobj, nidp); 3441a3437870SNishanth Aravamudan } 3442a3437870SNishanth Aravamudan 344306808b08SLee Schermerhorn static ssize_t nr_hugepages_show_common(struct kobject *kobj, 3444a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3445a3437870SNishanth Aravamudan { 34469a305230SLee Schermerhorn struct hstate *h; 34479a305230SLee Schermerhorn unsigned long nr_huge_pages; 34489a305230SLee Schermerhorn int nid; 34499a305230SLee Schermerhorn 34509a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 34519a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 34529a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages; 34539a305230SLee Schermerhorn else 34549a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages_node[nid]; 34559a305230SLee Schermerhorn 3456ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", nr_huge_pages); 3457a3437870SNishanth Aravamudan } 3458adbe8726SEric B Munson 3459238d3c13SDavid Rientjes static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, 3460238d3c13SDavid Rientjes struct hstate *h, int nid, 3461238d3c13SDavid Rientjes unsigned long count, size_t len) 3462a3437870SNishanth Aravamudan { 3463a3437870SNishanth Aravamudan int err; 34642d0adf7eSOscar Salvador nodemask_t nodes_allowed, *n_mask; 3465a3437870SNishanth Aravamudan 34662d0adf7eSOscar Salvador if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 34672d0adf7eSOscar Salvador return -EINVAL; 3468adbe8726SEric B Munson 34699a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) { 34709a305230SLee Schermerhorn /* 34719a305230SLee Schermerhorn * global hstate attribute 34729a305230SLee Schermerhorn */ 34739a305230SLee Schermerhorn if (!(obey_mempolicy && 34742d0adf7eSOscar Salvador init_nodemask_of_mempolicy(&nodes_allowed))) 34752d0adf7eSOscar Salvador n_mask = &node_states[N_MEMORY]; 34762d0adf7eSOscar Salvador else 34772d0adf7eSOscar Salvador n_mask = &nodes_allowed; 34782d0adf7eSOscar Salvador } else { 34799a305230SLee Schermerhorn /* 3480fd875dcaSMike Kravetz * Node specific request. count adjustment happens in 3481fd875dcaSMike Kravetz * set_max_huge_pages() after acquiring hugetlb_lock. 34829a305230SLee Schermerhorn */ 34832d0adf7eSOscar Salvador init_nodemask_of_node(&nodes_allowed, nid); 34842d0adf7eSOscar Salvador n_mask = &nodes_allowed; 3485fd875dcaSMike Kravetz } 34869a305230SLee Schermerhorn 34872d0adf7eSOscar Salvador err = set_max_huge_pages(h, count, nid, n_mask); 348806808b08SLee Schermerhorn 34894eb0716eSAlexandre Ghiti return err ? err : len; 349006808b08SLee Schermerhorn } 349106808b08SLee Schermerhorn 3492238d3c13SDavid Rientjes static ssize_t nr_hugepages_store_common(bool obey_mempolicy, 3493238d3c13SDavid Rientjes struct kobject *kobj, const char *buf, 3494238d3c13SDavid Rientjes size_t len) 3495238d3c13SDavid Rientjes { 3496238d3c13SDavid Rientjes struct hstate *h; 3497238d3c13SDavid Rientjes unsigned long count; 3498238d3c13SDavid Rientjes int nid; 3499238d3c13SDavid Rientjes int err; 3500238d3c13SDavid Rientjes 3501238d3c13SDavid Rientjes err = kstrtoul(buf, 10, &count); 3502238d3c13SDavid Rientjes if (err) 3503238d3c13SDavid Rientjes return err; 3504238d3c13SDavid Rientjes 3505238d3c13SDavid Rientjes h = kobj_to_hstate(kobj, &nid); 3506238d3c13SDavid Rientjes return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); 3507238d3c13SDavid Rientjes } 3508238d3c13SDavid Rientjes 350906808b08SLee Schermerhorn static ssize_t nr_hugepages_show(struct kobject *kobj, 351006808b08SLee Schermerhorn struct kobj_attribute *attr, char *buf) 351106808b08SLee Schermerhorn { 351206808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 351306808b08SLee Schermerhorn } 351406808b08SLee Schermerhorn 351506808b08SLee Schermerhorn static ssize_t nr_hugepages_store(struct kobject *kobj, 351606808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 351706808b08SLee Schermerhorn { 3518238d3c13SDavid Rientjes return nr_hugepages_store_common(false, kobj, buf, len); 3519a3437870SNishanth Aravamudan } 3520a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 3521a3437870SNishanth Aravamudan 352206808b08SLee Schermerhorn #ifdef CONFIG_NUMA 352306808b08SLee Schermerhorn 352406808b08SLee Schermerhorn /* 352506808b08SLee Schermerhorn * hstate attribute for optionally mempolicy-based constraint on persistent 352606808b08SLee Schermerhorn * huge page alloc/free. 352706808b08SLee Schermerhorn */ 352806808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, 3529ae7a927dSJoe Perches struct kobj_attribute *attr, 3530ae7a927dSJoe Perches char *buf) 353106808b08SLee Schermerhorn { 353206808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 353306808b08SLee Schermerhorn } 353406808b08SLee Schermerhorn 353506808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, 353606808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 353706808b08SLee Schermerhorn { 3538238d3c13SDavid Rientjes return nr_hugepages_store_common(true, kobj, buf, len); 353906808b08SLee Schermerhorn } 354006808b08SLee Schermerhorn HSTATE_ATTR(nr_hugepages_mempolicy); 354106808b08SLee Schermerhorn #endif 354206808b08SLee Schermerhorn 354306808b08SLee Schermerhorn 3544a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 3545a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3546a3437870SNishanth Aravamudan { 35479a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3548ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->nr_overcommit_huge_pages); 3549a3437870SNishanth Aravamudan } 3550adbe8726SEric B Munson 3551a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 3552a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 3553a3437870SNishanth Aravamudan { 3554a3437870SNishanth Aravamudan int err; 3555a3437870SNishanth Aravamudan unsigned long input; 35569a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3557a3437870SNishanth Aravamudan 3558bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3559adbe8726SEric B Munson return -EINVAL; 3560adbe8726SEric B Munson 35613dbb95f7SJingoo Han err = kstrtoul(buf, 10, &input); 3562a3437870SNishanth Aravamudan if (err) 356373ae31e5SEric B Munson return err; 3564a3437870SNishanth Aravamudan 3565db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 3566a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 3567db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3568a3437870SNishanth Aravamudan 3569a3437870SNishanth Aravamudan return count; 3570a3437870SNishanth Aravamudan } 3571a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 3572a3437870SNishanth Aravamudan 3573a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 3574a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3575a3437870SNishanth Aravamudan { 35769a305230SLee Schermerhorn struct hstate *h; 35779a305230SLee Schermerhorn unsigned long free_huge_pages; 35789a305230SLee Schermerhorn int nid; 35799a305230SLee Schermerhorn 35809a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 35819a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 35829a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages; 35839a305230SLee Schermerhorn else 35849a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages_node[nid]; 35859a305230SLee Schermerhorn 3586ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", free_huge_pages); 3587a3437870SNishanth Aravamudan } 3588a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 3589a3437870SNishanth Aravamudan 3590a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 3591a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3592a3437870SNishanth Aravamudan { 35939a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3594ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->resv_huge_pages); 3595a3437870SNishanth Aravamudan } 3596a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 3597a3437870SNishanth Aravamudan 3598a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 3599a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3600a3437870SNishanth Aravamudan { 36019a305230SLee Schermerhorn struct hstate *h; 36029a305230SLee Schermerhorn unsigned long surplus_huge_pages; 36039a305230SLee Schermerhorn int nid; 36049a305230SLee Schermerhorn 36059a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 36069a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 36079a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages; 36089a305230SLee Schermerhorn else 36099a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages_node[nid]; 36109a305230SLee Schermerhorn 3611ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", surplus_huge_pages); 3612a3437870SNishanth Aravamudan } 3613a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 3614a3437870SNishanth Aravamudan 361579dfc695SMike Kravetz static ssize_t demote_store(struct kobject *kobj, 361679dfc695SMike Kravetz struct kobj_attribute *attr, const char *buf, size_t len) 361779dfc695SMike Kravetz { 361879dfc695SMike Kravetz unsigned long nr_demote; 361979dfc695SMike Kravetz unsigned long nr_available; 362079dfc695SMike Kravetz nodemask_t nodes_allowed, *n_mask; 362179dfc695SMike Kravetz struct hstate *h; 362279dfc695SMike Kravetz int err = 0; 362379dfc695SMike Kravetz int nid; 362479dfc695SMike Kravetz 362579dfc695SMike Kravetz err = kstrtoul(buf, 10, &nr_demote); 362679dfc695SMike Kravetz if (err) 362779dfc695SMike Kravetz return err; 362879dfc695SMike Kravetz h = kobj_to_hstate(kobj, &nid); 362979dfc695SMike Kravetz 363079dfc695SMike Kravetz if (nid != NUMA_NO_NODE) { 363179dfc695SMike Kravetz init_nodemask_of_node(&nodes_allowed, nid); 363279dfc695SMike Kravetz n_mask = &nodes_allowed; 363379dfc695SMike Kravetz } else { 363479dfc695SMike Kravetz n_mask = &node_states[N_MEMORY]; 363579dfc695SMike Kravetz } 363679dfc695SMike Kravetz 363779dfc695SMike Kravetz /* Synchronize with other sysfs operations modifying huge pages */ 363879dfc695SMike Kravetz mutex_lock(&h->resize_lock); 363979dfc695SMike Kravetz spin_lock_irq(&hugetlb_lock); 364079dfc695SMike Kravetz 364179dfc695SMike Kravetz while (nr_demote) { 364279dfc695SMike Kravetz /* 364379dfc695SMike Kravetz * Check for available pages to demote each time thorough the 364479dfc695SMike Kravetz * loop as demote_pool_huge_page will drop hugetlb_lock. 364579dfc695SMike Kravetz */ 364679dfc695SMike Kravetz if (nid != NUMA_NO_NODE) 364779dfc695SMike Kravetz nr_available = h->free_huge_pages_node[nid]; 364879dfc695SMike Kravetz else 364979dfc695SMike Kravetz nr_available = h->free_huge_pages; 365079dfc695SMike Kravetz nr_available -= h->resv_huge_pages; 365179dfc695SMike Kravetz if (!nr_available) 365279dfc695SMike Kravetz break; 365379dfc695SMike Kravetz 365479dfc695SMike Kravetz err = demote_pool_huge_page(h, n_mask); 365579dfc695SMike Kravetz if (err) 365679dfc695SMike Kravetz break; 365779dfc695SMike Kravetz 365879dfc695SMike Kravetz nr_demote--; 365979dfc695SMike Kravetz } 366079dfc695SMike Kravetz 366179dfc695SMike Kravetz spin_unlock_irq(&hugetlb_lock); 366279dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 366379dfc695SMike Kravetz 366479dfc695SMike Kravetz if (err) 366579dfc695SMike Kravetz return err; 366679dfc695SMike Kravetz return len; 366779dfc695SMike Kravetz } 366879dfc695SMike Kravetz HSTATE_ATTR_WO(demote); 366979dfc695SMike Kravetz 367079dfc695SMike Kravetz static ssize_t demote_size_show(struct kobject *kobj, 367179dfc695SMike Kravetz struct kobj_attribute *attr, char *buf) 367279dfc695SMike Kravetz { 367379dfc695SMike Kravetz int nid; 367479dfc695SMike Kravetz struct hstate *h = kobj_to_hstate(kobj, &nid); 367579dfc695SMike Kravetz unsigned long demote_size = (PAGE_SIZE << h->demote_order) / SZ_1K; 367679dfc695SMike Kravetz 367779dfc695SMike Kravetz return sysfs_emit(buf, "%lukB\n", demote_size); 367879dfc695SMike Kravetz } 367979dfc695SMike Kravetz 368079dfc695SMike Kravetz static ssize_t demote_size_store(struct kobject *kobj, 368179dfc695SMike Kravetz struct kobj_attribute *attr, 368279dfc695SMike Kravetz const char *buf, size_t count) 368379dfc695SMike Kravetz { 368479dfc695SMike Kravetz struct hstate *h, *demote_hstate; 368579dfc695SMike Kravetz unsigned long demote_size; 368679dfc695SMike Kravetz unsigned int demote_order; 368779dfc695SMike Kravetz int nid; 368879dfc695SMike Kravetz 368979dfc695SMike Kravetz demote_size = (unsigned long)memparse(buf, NULL); 369079dfc695SMike Kravetz 369179dfc695SMike Kravetz demote_hstate = size_to_hstate(demote_size); 369279dfc695SMike Kravetz if (!demote_hstate) 369379dfc695SMike Kravetz return -EINVAL; 369479dfc695SMike Kravetz demote_order = demote_hstate->order; 3695a01f4390SMike Kravetz if (demote_order < HUGETLB_PAGE_ORDER) 3696a01f4390SMike Kravetz return -EINVAL; 369779dfc695SMike Kravetz 369879dfc695SMike Kravetz /* demote order must be smaller than hstate order */ 369979dfc695SMike Kravetz h = kobj_to_hstate(kobj, &nid); 370079dfc695SMike Kravetz if (demote_order >= h->order) 370179dfc695SMike Kravetz return -EINVAL; 370279dfc695SMike Kravetz 370379dfc695SMike Kravetz /* resize_lock synchronizes access to demote size and writes */ 370479dfc695SMike Kravetz mutex_lock(&h->resize_lock); 370579dfc695SMike Kravetz h->demote_order = demote_order; 370679dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 370779dfc695SMike Kravetz 370879dfc695SMike Kravetz return count; 370979dfc695SMike Kravetz } 371079dfc695SMike Kravetz HSTATE_ATTR(demote_size); 371179dfc695SMike Kravetz 3712a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 3713a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 3714a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 3715a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 3716a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 3717a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 371806808b08SLee Schermerhorn #ifdef CONFIG_NUMA 371906808b08SLee Schermerhorn &nr_hugepages_mempolicy_attr.attr, 372006808b08SLee Schermerhorn #endif 3721a3437870SNishanth Aravamudan NULL, 3722a3437870SNishanth Aravamudan }; 3723a3437870SNishanth Aravamudan 372467e5ed96SArvind Yadav static const struct attribute_group hstate_attr_group = { 3725a3437870SNishanth Aravamudan .attrs = hstate_attrs, 3726a3437870SNishanth Aravamudan }; 3727a3437870SNishanth Aravamudan 372879dfc695SMike Kravetz static struct attribute *hstate_demote_attrs[] = { 372979dfc695SMike Kravetz &demote_size_attr.attr, 373079dfc695SMike Kravetz &demote_attr.attr, 373179dfc695SMike Kravetz NULL, 373279dfc695SMike Kravetz }; 373379dfc695SMike Kravetz 373479dfc695SMike Kravetz static const struct attribute_group hstate_demote_attr_group = { 373579dfc695SMike Kravetz .attrs = hstate_demote_attrs, 373679dfc695SMike Kravetz }; 373779dfc695SMike Kravetz 3738094e9539SJeff Mahoney static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, 37399a305230SLee Schermerhorn struct kobject **hstate_kobjs, 374067e5ed96SArvind Yadav const struct attribute_group *hstate_attr_group) 3741a3437870SNishanth Aravamudan { 3742a3437870SNishanth Aravamudan int retval; 3743972dc4deSAneesh Kumar K.V int hi = hstate_index(h); 3744a3437870SNishanth Aravamudan 37459a305230SLee Schermerhorn hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); 37469a305230SLee Schermerhorn if (!hstate_kobjs[hi]) 3747a3437870SNishanth Aravamudan return -ENOMEM; 3748a3437870SNishanth Aravamudan 37499a305230SLee Schermerhorn retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); 3750cc2205a6SMiaohe Lin if (retval) { 37519a305230SLee Schermerhorn kobject_put(hstate_kobjs[hi]); 3752cc2205a6SMiaohe Lin hstate_kobjs[hi] = NULL; 3753cc2205a6SMiaohe Lin } 3754a3437870SNishanth Aravamudan 375579dfc695SMike Kravetz if (h->demote_order) { 375679dfc695SMike Kravetz if (sysfs_create_group(hstate_kobjs[hi], 375779dfc695SMike Kravetz &hstate_demote_attr_group)) 375879dfc695SMike Kravetz pr_warn("HugeTLB unable to create demote interfaces for %s\n", h->name); 375979dfc695SMike Kravetz } 376079dfc695SMike Kravetz 3761a3437870SNishanth Aravamudan return retval; 3762a3437870SNishanth Aravamudan } 3763a3437870SNishanth Aravamudan 3764a3437870SNishanth Aravamudan static void __init hugetlb_sysfs_init(void) 3765a3437870SNishanth Aravamudan { 3766a3437870SNishanth Aravamudan struct hstate *h; 3767a3437870SNishanth Aravamudan int err; 3768a3437870SNishanth Aravamudan 3769a3437870SNishanth Aravamudan hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 3770a3437870SNishanth Aravamudan if (!hugepages_kobj) 3771a3437870SNishanth Aravamudan return; 3772a3437870SNishanth Aravamudan 3773a3437870SNishanth Aravamudan for_each_hstate(h) { 37749a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, 37759a305230SLee Schermerhorn hstate_kobjs, &hstate_attr_group); 3776a3437870SNishanth Aravamudan if (err) 3777282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s", h->name); 3778a3437870SNishanth Aravamudan } 3779a3437870SNishanth Aravamudan } 3780a3437870SNishanth Aravamudan 37819a305230SLee Schermerhorn #ifdef CONFIG_NUMA 37829a305230SLee Schermerhorn 37839a305230SLee Schermerhorn /* 37849a305230SLee Schermerhorn * node_hstate/s - associate per node hstate attributes, via their kobjects, 378510fbcf4cSKay Sievers * with node devices in node_devices[] using a parallel array. The array 378610fbcf4cSKay Sievers * index of a node device or _hstate == node id. 378710fbcf4cSKay Sievers * This is here to avoid any static dependency of the node device driver, in 37889a305230SLee Schermerhorn * the base kernel, on the hugetlb module. 37899a305230SLee Schermerhorn */ 37909a305230SLee Schermerhorn struct node_hstate { 37919a305230SLee Schermerhorn struct kobject *hugepages_kobj; 37929a305230SLee Schermerhorn struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 37939a305230SLee Schermerhorn }; 3794b4e289a6SAlexander Kuleshov static struct node_hstate node_hstates[MAX_NUMNODES]; 37959a305230SLee Schermerhorn 37969a305230SLee Schermerhorn /* 379710fbcf4cSKay Sievers * A subset of global hstate attributes for node devices 37989a305230SLee Schermerhorn */ 37999a305230SLee Schermerhorn static struct attribute *per_node_hstate_attrs[] = { 38009a305230SLee Schermerhorn &nr_hugepages_attr.attr, 38019a305230SLee Schermerhorn &free_hugepages_attr.attr, 38029a305230SLee Schermerhorn &surplus_hugepages_attr.attr, 38039a305230SLee Schermerhorn NULL, 38049a305230SLee Schermerhorn }; 38059a305230SLee Schermerhorn 380667e5ed96SArvind Yadav static const struct attribute_group per_node_hstate_attr_group = { 38079a305230SLee Schermerhorn .attrs = per_node_hstate_attrs, 38089a305230SLee Schermerhorn }; 38099a305230SLee Schermerhorn 38109a305230SLee Schermerhorn /* 381110fbcf4cSKay Sievers * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. 38129a305230SLee Schermerhorn * Returns node id via non-NULL nidp. 38139a305230SLee Schermerhorn */ 38149a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 38159a305230SLee Schermerhorn { 38169a305230SLee Schermerhorn int nid; 38179a305230SLee Schermerhorn 38189a305230SLee Schermerhorn for (nid = 0; nid < nr_node_ids; nid++) { 38199a305230SLee Schermerhorn struct node_hstate *nhs = &node_hstates[nid]; 38209a305230SLee Schermerhorn int i; 38219a305230SLee Schermerhorn for (i = 0; i < HUGE_MAX_HSTATE; i++) 38229a305230SLee Schermerhorn if (nhs->hstate_kobjs[i] == kobj) { 38239a305230SLee Schermerhorn if (nidp) 38249a305230SLee Schermerhorn *nidp = nid; 38259a305230SLee Schermerhorn return &hstates[i]; 38269a305230SLee Schermerhorn } 38279a305230SLee Schermerhorn } 38289a305230SLee Schermerhorn 38299a305230SLee Schermerhorn BUG(); 38309a305230SLee Schermerhorn return NULL; 38319a305230SLee Schermerhorn } 38329a305230SLee Schermerhorn 38339a305230SLee Schermerhorn /* 383410fbcf4cSKay Sievers * Unregister hstate attributes from a single node device. 38359a305230SLee Schermerhorn * No-op if no hstate attributes attached. 38369a305230SLee Schermerhorn */ 38373cd8b44fSClaudiu Ghioc static void hugetlb_unregister_node(struct node *node) 38389a305230SLee Schermerhorn { 38399a305230SLee Schermerhorn struct hstate *h; 384010fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 38419a305230SLee Schermerhorn 38429a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 38439b5e5d0fSLee Schermerhorn return; /* no hstate attributes */ 38449a305230SLee Schermerhorn 3845972dc4deSAneesh Kumar K.V for_each_hstate(h) { 3846972dc4deSAneesh Kumar K.V int idx = hstate_index(h); 3847972dc4deSAneesh Kumar K.V if (nhs->hstate_kobjs[idx]) { 3848972dc4deSAneesh Kumar K.V kobject_put(nhs->hstate_kobjs[idx]); 3849972dc4deSAneesh Kumar K.V nhs->hstate_kobjs[idx] = NULL; 3850972dc4deSAneesh Kumar K.V } 38519a305230SLee Schermerhorn } 38529a305230SLee Schermerhorn 38539a305230SLee Schermerhorn kobject_put(nhs->hugepages_kobj); 38549a305230SLee Schermerhorn nhs->hugepages_kobj = NULL; 38559a305230SLee Schermerhorn } 38569a305230SLee Schermerhorn 38579a305230SLee Schermerhorn 38589a305230SLee Schermerhorn /* 385910fbcf4cSKay Sievers * Register hstate attributes for a single node device. 38609a305230SLee Schermerhorn * No-op if attributes already registered. 38619a305230SLee Schermerhorn */ 38623cd8b44fSClaudiu Ghioc static void hugetlb_register_node(struct node *node) 38639a305230SLee Schermerhorn { 38649a305230SLee Schermerhorn struct hstate *h; 386510fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 38669a305230SLee Schermerhorn int err; 38679a305230SLee Schermerhorn 38689a305230SLee Schermerhorn if (nhs->hugepages_kobj) 38699a305230SLee Schermerhorn return; /* already allocated */ 38709a305230SLee Schermerhorn 38719a305230SLee Schermerhorn nhs->hugepages_kobj = kobject_create_and_add("hugepages", 387210fbcf4cSKay Sievers &node->dev.kobj); 38739a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 38749a305230SLee Schermerhorn return; 38759a305230SLee Schermerhorn 38769a305230SLee Schermerhorn for_each_hstate(h) { 38779a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, 38789a305230SLee Schermerhorn nhs->hstate_kobjs, 38799a305230SLee Schermerhorn &per_node_hstate_attr_group); 38809a305230SLee Schermerhorn if (err) { 3881282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s for node %d\n", 388210fbcf4cSKay Sievers h->name, node->dev.id); 38839a305230SLee Schermerhorn hugetlb_unregister_node(node); 38849a305230SLee Schermerhorn break; 38859a305230SLee Schermerhorn } 38869a305230SLee Schermerhorn } 38879a305230SLee Schermerhorn } 38889a305230SLee Schermerhorn 38899a305230SLee Schermerhorn /* 38909b5e5d0fSLee Schermerhorn * hugetlb init time: register hstate attributes for all registered node 389110fbcf4cSKay Sievers * devices of nodes that have memory. All on-line nodes should have 389210fbcf4cSKay Sievers * registered their associated device by this time. 38939a305230SLee Schermerhorn */ 38947d9ca000SLuiz Capitulino static void __init hugetlb_register_all_nodes(void) 38959a305230SLee Schermerhorn { 38969a305230SLee Schermerhorn int nid; 38979a305230SLee Schermerhorn 38988cebfcd0SLai Jiangshan for_each_node_state(nid, N_MEMORY) { 38998732794bSWen Congyang struct node *node = node_devices[nid]; 390010fbcf4cSKay Sievers if (node->dev.id == nid) 39019a305230SLee Schermerhorn hugetlb_register_node(node); 39029a305230SLee Schermerhorn } 39039a305230SLee Schermerhorn 39049a305230SLee Schermerhorn /* 390510fbcf4cSKay Sievers * Let the node device driver know we're here so it can 39069a305230SLee Schermerhorn * [un]register hstate attributes on node hotplug. 39079a305230SLee Schermerhorn */ 39089a305230SLee Schermerhorn register_hugetlbfs_with_node(hugetlb_register_node, 39099a305230SLee Schermerhorn hugetlb_unregister_node); 39109a305230SLee Schermerhorn } 39119a305230SLee Schermerhorn #else /* !CONFIG_NUMA */ 39129a305230SLee Schermerhorn 39139a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 39149a305230SLee Schermerhorn { 39159a305230SLee Schermerhorn BUG(); 39169a305230SLee Schermerhorn if (nidp) 39179a305230SLee Schermerhorn *nidp = -1; 39189a305230SLee Schermerhorn return NULL; 39199a305230SLee Schermerhorn } 39209a305230SLee Schermerhorn 39219a305230SLee Schermerhorn static void hugetlb_register_all_nodes(void) { } 39229a305230SLee Schermerhorn 39239a305230SLee Schermerhorn #endif 39249a305230SLee Schermerhorn 3925a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 3926a3437870SNishanth Aravamudan { 39278382d914SDavidlohr Bueso int i; 39288382d914SDavidlohr Bueso 3929d6995da3SMike Kravetz BUILD_BUG_ON(sizeof_field(struct page, private) * BITS_PER_BYTE < 3930d6995da3SMike Kravetz __NR_HPAGEFLAGS); 3931d6995da3SMike Kravetz 3932c2833a5bSMike Kravetz if (!hugepages_supported()) { 3933c2833a5bSMike Kravetz if (hugetlb_max_hstate || default_hstate_max_huge_pages) 3934c2833a5bSMike Kravetz pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n"); 39350ef89d25SBenjamin Herrenschmidt return 0; 3936d715cf80SLiam R. Howlett } 3937d715cf80SLiam R. Howlett 3938282f4214SMike Kravetz /* 3939282f4214SMike Kravetz * Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some 3940282f4214SMike Kravetz * architectures depend on setup being done here. 3941282f4214SMike Kravetz */ 3942a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 3943282f4214SMike Kravetz if (!parsed_default_hugepagesz) { 3944282f4214SMike Kravetz /* 3945282f4214SMike Kravetz * If we did not parse a default huge page size, set 3946282f4214SMike Kravetz * default_hstate_idx to HPAGE_SIZE hstate. And, if the 3947282f4214SMike Kravetz * number of huge pages for this default size was implicitly 3948282f4214SMike Kravetz * specified, set that here as well. 3949282f4214SMike Kravetz * Note that the implicit setting will overwrite an explicit 3950282f4214SMike Kravetz * setting. A warning will be printed in this case. 3951282f4214SMike Kravetz */ 3952282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(HPAGE_SIZE)); 3953f8b74815SVaishali Thakkar if (default_hstate_max_huge_pages) { 3954282f4214SMike Kravetz if (default_hstate.max_huge_pages) { 3955282f4214SMike Kravetz char buf[32]; 3956282f4214SMike Kravetz 3957282f4214SMike Kravetz string_get_size(huge_page_size(&default_hstate), 3958282f4214SMike Kravetz 1, STRING_UNITS_2, buf, 32); 3959282f4214SMike Kravetz pr_warn("HugeTLB: Ignoring hugepages=%lu associated with %s page size\n", 3960282f4214SMike Kravetz default_hstate.max_huge_pages, buf); 3961282f4214SMike Kravetz pr_warn("HugeTLB: Using hugepages=%lu for number of default huge pages\n", 3962282f4214SMike Kravetz default_hstate_max_huge_pages); 3963282f4214SMike Kravetz } 3964282f4214SMike Kravetz default_hstate.max_huge_pages = 3965282f4214SMike Kravetz default_hstate_max_huge_pages; 3966282f4214SMike Kravetz } 3967f8b74815SVaishali Thakkar } 3968a3437870SNishanth Aravamudan 3969cf11e85fSRoman Gushchin hugetlb_cma_check(); 3970a3437870SNishanth Aravamudan hugetlb_init_hstates(); 3971aa888a74SAndi Kleen gather_bootmem_prealloc(); 3972a3437870SNishanth Aravamudan report_hugepages(); 3973a3437870SNishanth Aravamudan 3974a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 39759a305230SLee Schermerhorn hugetlb_register_all_nodes(); 39767179e7bfSJianguo Wu hugetlb_cgroup_file_init(); 39779a305230SLee Schermerhorn 39788382d914SDavidlohr Bueso #ifdef CONFIG_SMP 39798382d914SDavidlohr Bueso num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); 39808382d914SDavidlohr Bueso #else 39818382d914SDavidlohr Bueso num_fault_mutexes = 1; 39828382d914SDavidlohr Bueso #endif 3983c672c7f2SMike Kravetz hugetlb_fault_mutex_table = 39846da2ec56SKees Cook kmalloc_array(num_fault_mutexes, sizeof(struct mutex), 39856da2ec56SKees Cook GFP_KERNEL); 3986c672c7f2SMike Kravetz BUG_ON(!hugetlb_fault_mutex_table); 39878382d914SDavidlohr Bueso 39888382d914SDavidlohr Bueso for (i = 0; i < num_fault_mutexes; i++) 3989c672c7f2SMike Kravetz mutex_init(&hugetlb_fault_mutex_table[i]); 3990a3437870SNishanth Aravamudan return 0; 3991a3437870SNishanth Aravamudan } 39923e89e1c5SPaul Gortmaker subsys_initcall(hugetlb_init); 3993a3437870SNishanth Aravamudan 3994ae94da89SMike Kravetz /* Overwritten by architectures with more huge page sizes */ 3995ae94da89SMike Kravetz bool __init __attribute((weak)) arch_hugetlb_valid_size(unsigned long size) 39969fee021dSVaishali Thakkar { 3997ae94da89SMike Kravetz return size == HPAGE_SIZE; 39989fee021dSVaishali Thakkar } 39999fee021dSVaishali Thakkar 4000d00181b9SKirill A. Shutemov void __init hugetlb_add_hstate(unsigned int order) 4001a3437870SNishanth Aravamudan { 4002a3437870SNishanth Aravamudan struct hstate *h; 40038faa8b07SAndi Kleen unsigned long i; 40048faa8b07SAndi Kleen 4005a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 4006a3437870SNishanth Aravamudan return; 4007a3437870SNishanth Aravamudan } 400847d38344SAneesh Kumar K.V BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); 4009a3437870SNishanth Aravamudan BUG_ON(order == 0); 401047d38344SAneesh Kumar K.V h = &hstates[hugetlb_max_hstate++]; 401129383967SMike Kravetz mutex_init(&h->resize_lock); 4012a3437870SNishanth Aravamudan h->order = order; 4013aca78307SMiaohe Lin h->mask = ~(huge_page_size(h) - 1); 40148faa8b07SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 40158faa8b07SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 40160edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&h->hugepage_activelist); 401754f18d35SAndrew Morton h->next_nid_to_alloc = first_memory_node; 401854f18d35SAndrew Morton h->next_nid_to_free = first_memory_node; 4019a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 4020a3437870SNishanth Aravamudan huge_page_size(h)/1024); 402177490587SMuchun Song hugetlb_vmemmap_init(h); 40228faa8b07SAndi Kleen 4023a3437870SNishanth Aravamudan parsed_hstate = h; 4024a3437870SNishanth Aravamudan } 4025a3437870SNishanth Aravamudan 4026282f4214SMike Kravetz /* 4027282f4214SMike Kravetz * hugepages command line processing 4028282f4214SMike Kravetz * hugepages normally follows a valid hugepagsz or default_hugepagsz 4029282f4214SMike Kravetz * specification. If not, ignore the hugepages value. hugepages can also 4030282f4214SMike Kravetz * be the first huge page command line option in which case it implicitly 4031282f4214SMike Kravetz * specifies the number of huge pages for the default size. 4032282f4214SMike Kravetz */ 4033282f4214SMike Kravetz static int __init hugepages_setup(char *s) 4034a3437870SNishanth Aravamudan { 4035a3437870SNishanth Aravamudan unsigned long *mhp; 40368faa8b07SAndi Kleen static unsigned long *last_mhp; 4037a3437870SNishanth Aravamudan 40389fee021dSVaishali Thakkar if (!parsed_valid_hugepagesz) { 4039282f4214SMike Kravetz pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s); 40409fee021dSVaishali Thakkar parsed_valid_hugepagesz = true; 4041282f4214SMike Kravetz return 0; 40429fee021dSVaishali Thakkar } 4043282f4214SMike Kravetz 4044a3437870SNishanth Aravamudan /* 4045282f4214SMike Kravetz * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter 4046282f4214SMike Kravetz * yet, so this hugepages= parameter goes to the "default hstate". 4047282f4214SMike Kravetz * Otherwise, it goes with the previously parsed hugepagesz or 4048282f4214SMike Kravetz * default_hugepagesz. 4049a3437870SNishanth Aravamudan */ 40509fee021dSVaishali Thakkar else if (!hugetlb_max_hstate) 4051a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 4052a3437870SNishanth Aravamudan else 4053a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 4054a3437870SNishanth Aravamudan 40558faa8b07SAndi Kleen if (mhp == last_mhp) { 4056282f4214SMike Kravetz pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s); 4057282f4214SMike Kravetz return 0; 40588faa8b07SAndi Kleen } 40598faa8b07SAndi Kleen 4060a3437870SNishanth Aravamudan if (sscanf(s, "%lu", mhp) <= 0) 4061a3437870SNishanth Aravamudan *mhp = 0; 4062a3437870SNishanth Aravamudan 40638faa8b07SAndi Kleen /* 40648faa8b07SAndi Kleen * Global state is always initialized later in hugetlb_init. 406504adbc3fSMiaohe Lin * But we need to allocate gigantic hstates here early to still 40668faa8b07SAndi Kleen * use the bootmem allocator. 40678faa8b07SAndi Kleen */ 406804adbc3fSMiaohe Lin if (hugetlb_max_hstate && hstate_is_gigantic(parsed_hstate)) 40698faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(parsed_hstate); 40708faa8b07SAndi Kleen 40718faa8b07SAndi Kleen last_mhp = mhp; 40728faa8b07SAndi Kleen 4073a3437870SNishanth Aravamudan return 1; 4074a3437870SNishanth Aravamudan } 4075282f4214SMike Kravetz __setup("hugepages=", hugepages_setup); 4076e11bfbfcSNick Piggin 4077282f4214SMike Kravetz /* 4078282f4214SMike Kravetz * hugepagesz command line processing 4079282f4214SMike Kravetz * A specific huge page size can only be specified once with hugepagesz. 4080282f4214SMike Kravetz * hugepagesz is followed by hugepages on the command line. The global 4081282f4214SMike Kravetz * variable 'parsed_valid_hugepagesz' is used to determine if prior 4082282f4214SMike Kravetz * hugepagesz argument was valid. 4083282f4214SMike Kravetz */ 4084359f2544SMike Kravetz static int __init hugepagesz_setup(char *s) 4085e11bfbfcSNick Piggin { 4086359f2544SMike Kravetz unsigned long size; 4087282f4214SMike Kravetz struct hstate *h; 4088282f4214SMike Kravetz 4089282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4090359f2544SMike Kravetz size = (unsigned long)memparse(s, NULL); 4091359f2544SMike Kravetz 4092359f2544SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4093282f4214SMike Kravetz pr_err("HugeTLB: unsupported hugepagesz=%s\n", s); 4094359f2544SMike Kravetz return 0; 4095359f2544SMike Kravetz } 4096359f2544SMike Kravetz 4097282f4214SMike Kravetz h = size_to_hstate(size); 4098282f4214SMike Kravetz if (h) { 4099282f4214SMike Kravetz /* 4100282f4214SMike Kravetz * hstate for this size already exists. This is normally 4101282f4214SMike Kravetz * an error, but is allowed if the existing hstate is the 4102282f4214SMike Kravetz * default hstate. More specifically, it is only allowed if 4103282f4214SMike Kravetz * the number of huge pages for the default hstate was not 4104282f4214SMike Kravetz * previously specified. 4105282f4214SMike Kravetz */ 4106282f4214SMike Kravetz if (!parsed_default_hugepagesz || h != &default_hstate || 4107282f4214SMike Kravetz default_hstate.max_huge_pages) { 4108282f4214SMike Kravetz pr_warn("HugeTLB: hugepagesz=%s specified twice, ignoring\n", s); 410938237830SMike Kravetz return 0; 411038237830SMike Kravetz } 411138237830SMike Kravetz 4112282f4214SMike Kravetz /* 4113282f4214SMike Kravetz * No need to call hugetlb_add_hstate() as hstate already 4114282f4214SMike Kravetz * exists. But, do set parsed_hstate so that a following 4115282f4214SMike Kravetz * hugepages= parameter will be applied to this hstate. 4116282f4214SMike Kravetz */ 4117282f4214SMike Kravetz parsed_hstate = h; 4118282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4119e11bfbfcSNick Piggin return 1; 4120e11bfbfcSNick Piggin } 4121282f4214SMike Kravetz 4122359f2544SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4123282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4124359f2544SMike Kravetz return 1; 4125359f2544SMike Kravetz } 4126359f2544SMike Kravetz __setup("hugepagesz=", hugepagesz_setup); 4127359f2544SMike Kravetz 4128282f4214SMike Kravetz /* 4129282f4214SMike Kravetz * default_hugepagesz command line input 4130282f4214SMike Kravetz * Only one instance of default_hugepagesz allowed on command line. 4131282f4214SMike Kravetz */ 4132ae94da89SMike Kravetz static int __init default_hugepagesz_setup(char *s) 4133e11bfbfcSNick Piggin { 4134ae94da89SMike Kravetz unsigned long size; 4135ae94da89SMike Kravetz 4136282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4137282f4214SMike Kravetz if (parsed_default_hugepagesz) { 4138282f4214SMike Kravetz pr_err("HugeTLB: default_hugepagesz previously specified, ignoring %s\n", s); 4139282f4214SMike Kravetz return 0; 4140282f4214SMike Kravetz } 4141282f4214SMike Kravetz 4142282f4214SMike Kravetz size = (unsigned long)memparse(s, NULL); 4143282f4214SMike Kravetz 4144282f4214SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4145282f4214SMike Kravetz pr_err("HugeTLB: unsupported default_hugepagesz=%s\n", s); 4146282f4214SMike Kravetz return 0; 4147282f4214SMike Kravetz } 4148282f4214SMike Kravetz 4149282f4214SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4150282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4151282f4214SMike Kravetz parsed_default_hugepagesz = true; 4152282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(size)); 4153282f4214SMike Kravetz 4154282f4214SMike Kravetz /* 4155282f4214SMike Kravetz * The number of default huge pages (for this size) could have been 4156282f4214SMike Kravetz * specified as the first hugetlb parameter: hugepages=X. If so, 4157282f4214SMike Kravetz * then default_hstate_max_huge_pages is set. If the default huge 4158282f4214SMike Kravetz * page size is gigantic (>= MAX_ORDER), then the pages must be 4159282f4214SMike Kravetz * allocated here from bootmem allocator. 4160282f4214SMike Kravetz */ 4161282f4214SMike Kravetz if (default_hstate_max_huge_pages) { 4162282f4214SMike Kravetz default_hstate.max_huge_pages = default_hstate_max_huge_pages; 4163282f4214SMike Kravetz if (hstate_is_gigantic(&default_hstate)) 4164282f4214SMike Kravetz hugetlb_hstate_alloc_pages(&default_hstate); 4165282f4214SMike Kravetz default_hstate_max_huge_pages = 0; 4166282f4214SMike Kravetz } 4167282f4214SMike Kravetz 4168e11bfbfcSNick Piggin return 1; 4169e11bfbfcSNick Piggin } 4170ae94da89SMike Kravetz __setup("default_hugepagesz=", default_hugepagesz_setup); 4171a3437870SNishanth Aravamudan 41728ca39e68SMuchun Song static unsigned int allowed_mems_nr(struct hstate *h) 41738a213460SNishanth Aravamudan { 41748a213460SNishanth Aravamudan int node; 41758a213460SNishanth Aravamudan unsigned int nr = 0; 41768ca39e68SMuchun Song nodemask_t *mpol_allowed; 41778ca39e68SMuchun Song unsigned int *array = h->free_huge_pages_node; 41788ca39e68SMuchun Song gfp_t gfp_mask = htlb_alloc_mask(h); 41798a213460SNishanth Aravamudan 41808ca39e68SMuchun Song mpol_allowed = policy_nodemask_current(gfp_mask); 41818ca39e68SMuchun Song 41828ca39e68SMuchun Song for_each_node_mask(node, cpuset_current_mems_allowed) { 4183c93b0a99SJiapeng Zhong if (!mpol_allowed || node_isset(node, *mpol_allowed)) 41848a213460SNishanth Aravamudan nr += array[node]; 41858ca39e68SMuchun Song } 41868a213460SNishanth Aravamudan 41878a213460SNishanth Aravamudan return nr; 41888a213460SNishanth Aravamudan } 41898a213460SNishanth Aravamudan 41908a213460SNishanth Aravamudan #ifdef CONFIG_SYSCTL 419117743798SMuchun Song static int proc_hugetlb_doulongvec_minmax(struct ctl_table *table, int write, 419217743798SMuchun Song void *buffer, size_t *length, 419317743798SMuchun Song loff_t *ppos, unsigned long *out) 419417743798SMuchun Song { 419517743798SMuchun Song struct ctl_table dup_table; 419617743798SMuchun Song 419717743798SMuchun Song /* 419817743798SMuchun Song * In order to avoid races with __do_proc_doulongvec_minmax(), we 419917743798SMuchun Song * can duplicate the @table and alter the duplicate of it. 420017743798SMuchun Song */ 420117743798SMuchun Song dup_table = *table; 420217743798SMuchun Song dup_table.data = out; 420317743798SMuchun Song 420417743798SMuchun Song return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos); 420517743798SMuchun Song } 420617743798SMuchun Song 420706808b08SLee Schermerhorn static int hugetlb_sysctl_handler_common(bool obey_mempolicy, 420806808b08SLee Schermerhorn struct ctl_table *table, int write, 420932927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 42101da177e4SLinus Torvalds { 4211e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 4212238d3c13SDavid Rientjes unsigned long tmp = h->max_huge_pages; 421308d4a246SMichal Hocko int ret; 4214e5ff2159SAndi Kleen 4215457c1b27SNishanth Aravamudan if (!hugepages_supported()) 421686613628SJan Stancek return -EOPNOTSUPP; 4217457c1b27SNishanth Aravamudan 421817743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 421917743798SMuchun Song &tmp); 422008d4a246SMichal Hocko if (ret) 422108d4a246SMichal Hocko goto out; 4222e5ff2159SAndi Kleen 4223238d3c13SDavid Rientjes if (write) 4224238d3c13SDavid Rientjes ret = __nr_hugepages_store_common(obey_mempolicy, h, 4225238d3c13SDavid Rientjes NUMA_NO_NODE, tmp, *length); 422608d4a246SMichal Hocko out: 422708d4a246SMichal Hocko return ret; 42281da177e4SLinus Torvalds } 4229396faf03SMel Gorman 423006808b08SLee Schermerhorn int hugetlb_sysctl_handler(struct ctl_table *table, int write, 423132927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 423206808b08SLee Schermerhorn { 423306808b08SLee Schermerhorn 423406808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(false, table, write, 423506808b08SLee Schermerhorn buffer, length, ppos); 423606808b08SLee Schermerhorn } 423706808b08SLee Schermerhorn 423806808b08SLee Schermerhorn #ifdef CONFIG_NUMA 423906808b08SLee Schermerhorn int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, 424032927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 424106808b08SLee Schermerhorn { 424206808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(true, table, write, 424306808b08SLee Schermerhorn buffer, length, ppos); 424406808b08SLee Schermerhorn } 424506808b08SLee Schermerhorn #endif /* CONFIG_NUMA */ 424606808b08SLee Schermerhorn 4247a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 424832927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 4249a3d0c6aaSNishanth Aravamudan { 4250a5516438SAndi Kleen struct hstate *h = &default_hstate; 4251e5ff2159SAndi Kleen unsigned long tmp; 425208d4a246SMichal Hocko int ret; 4253e5ff2159SAndi Kleen 4254457c1b27SNishanth Aravamudan if (!hugepages_supported()) 425586613628SJan Stancek return -EOPNOTSUPP; 4256457c1b27SNishanth Aravamudan 4257e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 4258e5ff2159SAndi Kleen 4259bae7f4aeSLuiz Capitulino if (write && hstate_is_gigantic(h)) 4260adbe8726SEric B Munson return -EINVAL; 4261adbe8726SEric B Munson 426217743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 426317743798SMuchun Song &tmp); 426408d4a246SMichal Hocko if (ret) 426508d4a246SMichal Hocko goto out; 4266e5ff2159SAndi Kleen 4267e5ff2159SAndi Kleen if (write) { 4268db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4269e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 4270db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4271e5ff2159SAndi Kleen } 427208d4a246SMichal Hocko out: 427308d4a246SMichal Hocko return ret; 4274a3d0c6aaSNishanth Aravamudan } 4275a3d0c6aaSNishanth Aravamudan 42761da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 42771da177e4SLinus Torvalds 4278e1759c21SAlexey Dobriyan void hugetlb_report_meminfo(struct seq_file *m) 42791da177e4SLinus Torvalds { 4280fcb2b0c5SRoman Gushchin struct hstate *h; 4281fcb2b0c5SRoman Gushchin unsigned long total = 0; 4282fcb2b0c5SRoman Gushchin 4283457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4284457c1b27SNishanth Aravamudan return; 4285fcb2b0c5SRoman Gushchin 4286fcb2b0c5SRoman Gushchin for_each_hstate(h) { 4287fcb2b0c5SRoman Gushchin unsigned long count = h->nr_huge_pages; 4288fcb2b0c5SRoman Gushchin 4289aca78307SMiaohe Lin total += huge_page_size(h) * count; 4290fcb2b0c5SRoman Gushchin 4291fcb2b0c5SRoman Gushchin if (h == &default_hstate) 4292e1759c21SAlexey Dobriyan seq_printf(m, 42931da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 42941da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 4295b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 42967893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 42974f98a2feSRik van Riel "Hugepagesize: %8lu kB\n", 4298fcb2b0c5SRoman Gushchin count, 4299a5516438SAndi Kleen h->free_huge_pages, 4300a5516438SAndi Kleen h->resv_huge_pages, 4301a5516438SAndi Kleen h->surplus_huge_pages, 4302aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4303fcb2b0c5SRoman Gushchin } 4304fcb2b0c5SRoman Gushchin 4305aca78307SMiaohe Lin seq_printf(m, "Hugetlb: %8lu kB\n", total / SZ_1K); 43061da177e4SLinus Torvalds } 43071da177e4SLinus Torvalds 43087981593bSJoe Perches int hugetlb_report_node_meminfo(char *buf, int len, int nid) 43091da177e4SLinus Torvalds { 4310a5516438SAndi Kleen struct hstate *h = &default_hstate; 43117981593bSJoe Perches 4312457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4313457c1b27SNishanth Aravamudan return 0; 43147981593bSJoe Perches 43157981593bSJoe Perches return sysfs_emit_at(buf, len, 43161da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 4317a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 4318a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 4319a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 4320a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 4321a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 43221da177e4SLinus Torvalds } 43231da177e4SLinus Torvalds 4324949f7ec5SDavid Rientjes void hugetlb_show_meminfo(void) 4325949f7ec5SDavid Rientjes { 4326949f7ec5SDavid Rientjes struct hstate *h; 4327949f7ec5SDavid Rientjes int nid; 4328949f7ec5SDavid Rientjes 4329457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4330457c1b27SNishanth Aravamudan return; 4331457c1b27SNishanth Aravamudan 4332949f7ec5SDavid Rientjes for_each_node_state(nid, N_MEMORY) 4333949f7ec5SDavid Rientjes for_each_hstate(h) 4334949f7ec5SDavid Rientjes pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", 4335949f7ec5SDavid Rientjes nid, 4336949f7ec5SDavid Rientjes h->nr_huge_pages_node[nid], 4337949f7ec5SDavid Rientjes h->free_huge_pages_node[nid], 4338949f7ec5SDavid Rientjes h->surplus_huge_pages_node[nid], 4339aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4340949f7ec5SDavid Rientjes } 4341949f7ec5SDavid Rientjes 43425d317b2bSNaoya Horiguchi void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm) 43435d317b2bSNaoya Horiguchi { 43445d317b2bSNaoya Horiguchi seq_printf(m, "HugetlbPages:\t%8lu kB\n", 43455d317b2bSNaoya Horiguchi atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10)); 43465d317b2bSNaoya Horiguchi } 43475d317b2bSNaoya Horiguchi 43481da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 43491da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 43501da177e4SLinus Torvalds { 4351d0028588SWanpeng Li struct hstate *h; 4352d0028588SWanpeng Li unsigned long nr_total_pages = 0; 4353d0028588SWanpeng Li 4354d0028588SWanpeng Li for_each_hstate(h) 4355d0028588SWanpeng Li nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); 4356d0028588SWanpeng Li return nr_total_pages; 43571da177e4SLinus Torvalds } 43581da177e4SLinus Torvalds 4359a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 4360fc1b8a73SMel Gorman { 4361fc1b8a73SMel Gorman int ret = -ENOMEM; 4362fc1b8a73SMel Gorman 43630aa7f354SMiaohe Lin if (!delta) 43640aa7f354SMiaohe Lin return 0; 43650aa7f354SMiaohe Lin 4366db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4367fc1b8a73SMel Gorman /* 4368fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 4369fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 4370fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 4371fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 4372fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 4373fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 4374fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 4375fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 4376fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 4377fc1b8a73SMel Gorman * 4378fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 4379fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 4380fc1b8a73SMel Gorman * we fall back to check against current free page availability as 4381fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 4382fc1b8a73SMel Gorman * semantics that cpuset has. 43838ca39e68SMuchun Song * 43848ca39e68SMuchun Song * Apart from cpuset, we also have memory policy mechanism that 43858ca39e68SMuchun Song * also determines from which node the kernel will allocate memory 43868ca39e68SMuchun Song * in a NUMA system. So similar to cpuset, we also should consider 43878ca39e68SMuchun Song * the memory policy of the current task. Similar to the description 43888ca39e68SMuchun Song * above. 4389fc1b8a73SMel Gorman */ 4390fc1b8a73SMel Gorman if (delta > 0) { 4391a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 4392fc1b8a73SMel Gorman goto out; 4393fc1b8a73SMel Gorman 43948ca39e68SMuchun Song if (delta > allowed_mems_nr(h)) { 4395a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 4396fc1b8a73SMel Gorman goto out; 4397fc1b8a73SMel Gorman } 4398fc1b8a73SMel Gorman } 4399fc1b8a73SMel Gorman 4400fc1b8a73SMel Gorman ret = 0; 4401fc1b8a73SMel Gorman if (delta < 0) 4402a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 4403fc1b8a73SMel Gorman 4404fc1b8a73SMel Gorman out: 4405db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4406fc1b8a73SMel Gorman return ret; 4407fc1b8a73SMel Gorman } 4408fc1b8a73SMel Gorman 440984afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 441084afd99bSAndy Whitcroft { 4411f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 441284afd99bSAndy Whitcroft 441384afd99bSAndy Whitcroft /* 441484afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 441584afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 441684afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 441725985edcSLucas De Marchi * has a reference to the reservation map it cannot disappear until 441884afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 441984afd99bSAndy Whitcroft * new reference here without additional locking. 442084afd99bSAndy Whitcroft */ 442109a26e83SMike Kravetz if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 442209a26e83SMike Kravetz resv_map_dup_hugetlb_cgroup_uncharge_info(resv); 4423f522c3acSJoonsoo Kim kref_get(&resv->refs); 442484afd99bSAndy Whitcroft } 442509a26e83SMike Kravetz } 442684afd99bSAndy Whitcroft 4427a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 4428a1e78772SMel Gorman { 4429a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 4430f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 443190481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 44324e35f483SJoonsoo Kim unsigned long reserve, start, end; 44331c5ecae3SMike Kravetz long gbl_reserve; 443484afd99bSAndy Whitcroft 44354e35f483SJoonsoo Kim if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 44364e35f483SJoonsoo Kim return; 44374e35f483SJoonsoo Kim 4438a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 4439a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 444084afd99bSAndy Whitcroft 44414e35f483SJoonsoo Kim reserve = (end - start) - region_count(resv, start, end); 4442e9fe92aeSMina Almasry hugetlb_cgroup_uncharge_counter(resv, start, end); 44437251ff78SAdam Litke if (reserve) { 44441c5ecae3SMike Kravetz /* 44451c5ecae3SMike Kravetz * Decrement reserve counts. The global reserve count may be 44461c5ecae3SMike Kravetz * adjusted if the subpool has a minimum size. 44471c5ecae3SMike Kravetz */ 44481c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, reserve); 44491c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 44507251ff78SAdam Litke } 4451e9fe92aeSMina Almasry 4452e9fe92aeSMina Almasry kref_put(&resv->refs, resv_map_release); 4453a1e78772SMel Gorman } 4454a1e78772SMel Gorman 445531383c68SDan Williams static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) 445631383c68SDan Williams { 445731383c68SDan Williams if (addr & ~(huge_page_mask(hstate_vma(vma)))) 445831383c68SDan Williams return -EINVAL; 445931383c68SDan Williams return 0; 446031383c68SDan Williams } 446131383c68SDan Williams 446205ea8860SDan Williams static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) 446305ea8860SDan Williams { 4464aca78307SMiaohe Lin return huge_page_size(hstate_vma(vma)); 446505ea8860SDan Williams } 446605ea8860SDan Williams 44671da177e4SLinus Torvalds /* 44681da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 44691da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 44706c26d310SMiaohe Lin * hugepage VMA. do_page_fault() is supposed to trap this, so BUG is we get 44711da177e4SLinus Torvalds * this far. 44721da177e4SLinus Torvalds */ 4473b3ec9f33SSouptick Joarder static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf) 44741da177e4SLinus Torvalds { 44751da177e4SLinus Torvalds BUG(); 4476d0217ac0SNick Piggin return 0; 44771da177e4SLinus Torvalds } 44781da177e4SLinus Torvalds 4479eec3636aSJane Chu /* 4480eec3636aSJane Chu * When a new function is introduced to vm_operations_struct and added 4481eec3636aSJane Chu * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops. 4482eec3636aSJane Chu * This is because under System V memory model, mappings created via 4483eec3636aSJane Chu * shmget/shmat with "huge page" specified are backed by hugetlbfs files, 4484eec3636aSJane Chu * their original vm_ops are overwritten with shm_vm_ops. 4485eec3636aSJane Chu */ 4486f0f37e2fSAlexey Dobriyan const struct vm_operations_struct hugetlb_vm_ops = { 4487d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 448884afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 4489a1e78772SMel Gorman .close = hugetlb_vm_op_close, 4490dd3b614fSDmitry Safonov .may_split = hugetlb_vm_op_split, 449105ea8860SDan Williams .pagesize = hugetlb_vm_op_pagesize, 44921da177e4SLinus Torvalds }; 44931da177e4SLinus Torvalds 44941e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 44951e8f889bSDavid Gibson int writable) 449663551ae0SDavid Gibson { 449763551ae0SDavid Gibson pte_t entry; 449879c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 449963551ae0SDavid Gibson 45001e8f889bSDavid Gibson if (writable) { 4501106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, 4502106c992aSGerald Schaefer vma->vm_page_prot))); 450363551ae0SDavid Gibson } else { 4504106c992aSGerald Schaefer entry = huge_pte_wrprotect(mk_huge_pte(page, 4505106c992aSGerald Schaefer vma->vm_page_prot)); 450663551ae0SDavid Gibson } 450763551ae0SDavid Gibson entry = pte_mkyoung(entry); 450863551ae0SDavid Gibson entry = pte_mkhuge(entry); 450979c1c594SChristophe Leroy entry = arch_make_huge_pte(entry, shift, vma->vm_flags); 451063551ae0SDavid Gibson 451163551ae0SDavid Gibson return entry; 451263551ae0SDavid Gibson } 451363551ae0SDavid Gibson 45141e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 45151e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 45161e8f889bSDavid Gibson { 45171e8f889bSDavid Gibson pte_t entry; 45181e8f889bSDavid Gibson 4519106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); 452032f84528SChris Forbes if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) 45214b3073e1SRussell King update_mmu_cache(vma, address, ptep); 45221e8f889bSDavid Gibson } 45231e8f889bSDavid Gibson 4524d5ed7444SAneesh Kumar K.V bool is_hugetlb_entry_migration(pte_t pte) 45254a705fefSNaoya Horiguchi { 45264a705fefSNaoya Horiguchi swp_entry_t swp; 45274a705fefSNaoya Horiguchi 45284a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 4529d5ed7444SAneesh Kumar K.V return false; 45304a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4531d79d176aSBaoquan He if (is_migration_entry(swp)) 4532d5ed7444SAneesh Kumar K.V return true; 45334a705fefSNaoya Horiguchi else 4534d5ed7444SAneesh Kumar K.V return false; 45354a705fefSNaoya Horiguchi } 45364a705fefSNaoya Horiguchi 45373e5c3600SBaoquan He static bool is_hugetlb_entry_hwpoisoned(pte_t pte) 45384a705fefSNaoya Horiguchi { 45394a705fefSNaoya Horiguchi swp_entry_t swp; 45404a705fefSNaoya Horiguchi 45414a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 45423e5c3600SBaoquan He return false; 45434a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4544d79d176aSBaoquan He if (is_hwpoison_entry(swp)) 45453e5c3600SBaoquan He return true; 45464a705fefSNaoya Horiguchi else 45473e5c3600SBaoquan He return false; 45484a705fefSNaoya Horiguchi } 45491e8f889bSDavid Gibson 45504eae4efaSPeter Xu static void 45514eae4efaSPeter Xu hugetlb_install_page(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr, 45524eae4efaSPeter Xu struct page *new_page) 45534eae4efaSPeter Xu { 45544eae4efaSPeter Xu __SetPageUptodate(new_page); 45554eae4efaSPeter Xu set_huge_pte_at(vma->vm_mm, addr, ptep, make_huge_pte(vma, new_page, 1)); 45564eae4efaSPeter Xu hugepage_add_new_anon_rmap(new_page, vma, addr); 45574eae4efaSPeter Xu hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm); 45584eae4efaSPeter Xu ClearHPageRestoreReserve(new_page); 45594eae4efaSPeter Xu SetHPageMigratable(new_page); 45604eae4efaSPeter Xu } 45614eae4efaSPeter Xu 456263551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 456363551ae0SDavid Gibson struct vm_area_struct *vma) 456463551ae0SDavid Gibson { 45655e41540cSMike Kravetz pte_t *src_pte, *dst_pte, entry, dst_entry; 456663551ae0SDavid Gibson struct page *ptepage; 45671c59827dSHugh Dickins unsigned long addr; 4568ca6eb14dSPeter Xu bool cow = is_cow_mapping(vma->vm_flags); 4569a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 4570a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 45714eae4efaSPeter Xu unsigned long npages = pages_per_huge_page(h); 4572c0d0381aSMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 4573ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 4574e8569dd2SAndreas Sandberg int ret = 0; 45751e8f889bSDavid Gibson 4576ac46d4f3SJérôme Glisse if (cow) { 45777269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, src, 45786f4f13e8SJérôme Glisse vma->vm_start, 4579ac46d4f3SJérôme Glisse vma->vm_end); 4580ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4581c0d0381aSMike Kravetz } else { 4582c0d0381aSMike Kravetz /* 4583c0d0381aSMike Kravetz * For shared mappings i_mmap_rwsem must be held to call 4584c0d0381aSMike Kravetz * huge_pte_alloc, otherwise the returned ptep could go 4585c0d0381aSMike Kravetz * away if part of a shared pmd and another thread calls 4586c0d0381aSMike Kravetz * huge_pmd_unshare. 4587c0d0381aSMike Kravetz */ 4588c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 4589ac46d4f3SJérôme Glisse } 4590e8569dd2SAndreas Sandberg 4591a5516438SAndi Kleen for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { 4592cb900f41SKirill A. Shutemov spinlock_t *src_ptl, *dst_ptl; 45937868a208SPunit Agrawal src_pte = huge_pte_offset(src, addr, sz); 4594c74df32cSHugh Dickins if (!src_pte) 4595c74df32cSHugh Dickins continue; 4596aec44e0fSPeter Xu dst_pte = huge_pte_alloc(dst, vma, addr, sz); 4597e8569dd2SAndreas Sandberg if (!dst_pte) { 4598e8569dd2SAndreas Sandberg ret = -ENOMEM; 4599e8569dd2SAndreas Sandberg break; 4600e8569dd2SAndreas Sandberg } 4601c5c99429SLarry Woodman 46025e41540cSMike Kravetz /* 46035e41540cSMike Kravetz * If the pagetables are shared don't copy or take references. 46045e41540cSMike Kravetz * dst_pte == src_pte is the common case of src/dest sharing. 46055e41540cSMike Kravetz * 46065e41540cSMike Kravetz * However, src could have 'unshared' and dst shares with 46075e41540cSMike Kravetz * another vma. If dst_pte !none, this implies sharing. 46085e41540cSMike Kravetz * Check here before taking page table lock, and once again 46095e41540cSMike Kravetz * after taking the lock below. 46105e41540cSMike Kravetz */ 46115e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 46125e41540cSMike Kravetz if ((dst_pte == src_pte) || !huge_pte_none(dst_entry)) 4613c5c99429SLarry Woodman continue; 4614c5c99429SLarry Woodman 4615cb900f41SKirill A. Shutemov dst_ptl = huge_pte_lock(h, dst, dst_pte); 4616cb900f41SKirill A. Shutemov src_ptl = huge_pte_lockptr(h, src, src_pte); 4617cb900f41SKirill A. Shutemov spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 46184a705fefSNaoya Horiguchi entry = huge_ptep_get(src_pte); 46195e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 46204eae4efaSPeter Xu again: 46215e41540cSMike Kravetz if (huge_pte_none(entry) || !huge_pte_none(dst_entry)) { 46225e41540cSMike Kravetz /* 46235e41540cSMike Kravetz * Skip if src entry none. Also, skip in the 46245e41540cSMike Kravetz * unlikely case dst entry !none as this implies 46255e41540cSMike Kravetz * sharing with another vma. 46265e41540cSMike Kravetz */ 46274a705fefSNaoya Horiguchi ; 46284a705fefSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_migration(entry) || 46294a705fefSNaoya Horiguchi is_hugetlb_entry_hwpoisoned(entry))) { 46304a705fefSNaoya Horiguchi swp_entry_t swp_entry = pte_to_swp_entry(entry); 46314a705fefSNaoya Horiguchi 46324dd845b5SAlistair Popple if (is_writable_migration_entry(swp_entry) && cow) { 46334a705fefSNaoya Horiguchi /* 46344a705fefSNaoya Horiguchi * COW mappings require pages in both 46354a705fefSNaoya Horiguchi * parent and child to be set to read. 46364a705fefSNaoya Horiguchi */ 46374dd845b5SAlistair Popple swp_entry = make_readable_migration_entry( 46384dd845b5SAlistair Popple swp_offset(swp_entry)); 46394a705fefSNaoya Horiguchi entry = swp_entry_to_pte(swp_entry); 4640e5251fd4SPunit Agrawal set_huge_swap_pte_at(src, addr, src_pte, 4641e5251fd4SPunit Agrawal entry, sz); 46424a705fefSNaoya Horiguchi } 4643e5251fd4SPunit Agrawal set_huge_swap_pte_at(dst, addr, dst_pte, entry, sz); 46444a705fefSNaoya Horiguchi } else { 46454eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 46464eae4efaSPeter Xu ptepage = pte_page(entry); 46474eae4efaSPeter Xu get_page(ptepage); 46484eae4efaSPeter Xu 46494eae4efaSPeter Xu /* 46504eae4efaSPeter Xu * This is a rare case where we see pinned hugetlb 46514eae4efaSPeter Xu * pages while they're prone to COW. We need to do the 46524eae4efaSPeter Xu * COW earlier during fork. 46534eae4efaSPeter Xu * 46544eae4efaSPeter Xu * When pre-allocating the page or copying data, we 46554eae4efaSPeter Xu * need to be without the pgtable locks since we could 46564eae4efaSPeter Xu * sleep during the process. 46574eae4efaSPeter Xu */ 46584eae4efaSPeter Xu if (unlikely(page_needs_cow_for_dma(vma, ptepage))) { 46594eae4efaSPeter Xu pte_t src_pte_old = entry; 46604eae4efaSPeter Xu struct page *new; 46614eae4efaSPeter Xu 46624eae4efaSPeter Xu spin_unlock(src_ptl); 46634eae4efaSPeter Xu spin_unlock(dst_ptl); 46644eae4efaSPeter Xu /* Do not use reserve as it's private owned */ 46654eae4efaSPeter Xu new = alloc_huge_page(vma, addr, 1); 46664eae4efaSPeter Xu if (IS_ERR(new)) { 46674eae4efaSPeter Xu put_page(ptepage); 46684eae4efaSPeter Xu ret = PTR_ERR(new); 46694eae4efaSPeter Xu break; 46704eae4efaSPeter Xu } 46714eae4efaSPeter Xu copy_user_huge_page(new, ptepage, addr, vma, 46724eae4efaSPeter Xu npages); 46734eae4efaSPeter Xu put_page(ptepage); 46744eae4efaSPeter Xu 46754eae4efaSPeter Xu /* Install the new huge page if src pte stable */ 46764eae4efaSPeter Xu dst_ptl = huge_pte_lock(h, dst, dst_pte); 46774eae4efaSPeter Xu src_ptl = huge_pte_lockptr(h, src, src_pte); 46784eae4efaSPeter Xu spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 46794eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 46804eae4efaSPeter Xu if (!pte_same(src_pte_old, entry)) { 4681846be085SMike Kravetz restore_reserve_on_error(h, vma, addr, 4682846be085SMike Kravetz new); 46834eae4efaSPeter Xu put_page(new); 46844eae4efaSPeter Xu /* dst_entry won't change as in child */ 46854eae4efaSPeter Xu goto again; 46864eae4efaSPeter Xu } 46874eae4efaSPeter Xu hugetlb_install_page(vma, dst_pte, addr, new); 46884eae4efaSPeter Xu spin_unlock(src_ptl); 46894eae4efaSPeter Xu spin_unlock(dst_ptl); 46904eae4efaSPeter Xu continue; 46914eae4efaSPeter Xu } 46924eae4efaSPeter Xu 469334ee645eSJoerg Roedel if (cow) { 46940f10851eSJérôme Glisse /* 46950f10851eSJérôme Glisse * No need to notify as we are downgrading page 46960f10851eSJérôme Glisse * table protection not changing it to point 46970f10851eSJérôme Glisse * to a new page. 46980f10851eSJérôme Glisse * 4699ad56b738SMike Rapoport * See Documentation/vm/mmu_notifier.rst 47000f10851eSJérôme Glisse */ 47017f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 470284894e1cSPeter Xu entry = huge_pte_wrprotect(entry); 470334ee645eSJoerg Roedel } 47044eae4efaSPeter Xu 470553f9263bSKirill A. Shutemov page_dup_rmap(ptepage, true); 470663551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 47074eae4efaSPeter Xu hugetlb_count_add(npages, dst); 47081c59827dSHugh Dickins } 4709cb900f41SKirill A. Shutemov spin_unlock(src_ptl); 4710cb900f41SKirill A. Shutemov spin_unlock(dst_ptl); 471163551ae0SDavid Gibson } 471263551ae0SDavid Gibson 4713e8569dd2SAndreas Sandberg if (cow) 4714ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 4715c0d0381aSMike Kravetz else 4716c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 4717e8569dd2SAndreas Sandberg 4718e8569dd2SAndreas Sandberg return ret; 471963551ae0SDavid Gibson } 472063551ae0SDavid Gibson 472173c54763SPeter Xu static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, 472224669e58SAneesh Kumar K.V unsigned long start, unsigned long end, 472324669e58SAneesh Kumar K.V struct page *ref_page) 472463551ae0SDavid Gibson { 472563551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 472663551ae0SDavid Gibson unsigned long address; 4727c7546f8fSDavid Gibson pte_t *ptep; 472863551ae0SDavid Gibson pte_t pte; 4729cb900f41SKirill A. Shutemov spinlock_t *ptl; 473063551ae0SDavid Gibson struct page *page; 4731a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 4732a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 4733ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 4734a5516438SAndi Kleen 473563551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 4736a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 4737a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 473863551ae0SDavid Gibson 473907e32661SAneesh Kumar K.V /* 474007e32661SAneesh Kumar K.V * This is a hugetlb vma, all the pte entries should point 474107e32661SAneesh Kumar K.V * to huge page. 474207e32661SAneesh Kumar K.V */ 4743ed6a7935SPeter Zijlstra tlb_change_page_size(tlb, sz); 474424669e58SAneesh Kumar K.V tlb_start_vma(tlb, vma); 4745dff11abeSMike Kravetz 4746dff11abeSMike Kravetz /* 4747dff11abeSMike Kravetz * If sharing possible, alert mmu notifiers of worst case. 4748dff11abeSMike Kravetz */ 47496f4f13e8SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, mm, start, 47506f4f13e8SJérôme Glisse end); 4751ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 4752ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4753569f48b8SHillf Danton address = start; 4754569f48b8SHillf Danton for (; address < end; address += sz) { 47557868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, sz); 4756c7546f8fSDavid Gibson if (!ptep) 4757c7546f8fSDavid Gibson continue; 4758c7546f8fSDavid Gibson 4759cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 476034ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 476131d49da5SAneesh Kumar K.V spin_unlock(ptl); 4762dff11abeSMike Kravetz /* 4763dff11abeSMike Kravetz * We just unmapped a page of PMDs by clearing a PUD. 4764dff11abeSMike Kravetz * The caller's TLB flush range should cover this area. 4765dff11abeSMike Kravetz */ 476631d49da5SAneesh Kumar K.V continue; 476731d49da5SAneesh Kumar K.V } 476839dde65cSChen, Kenneth W 47696629326bSHillf Danton pte = huge_ptep_get(ptep); 477031d49da5SAneesh Kumar K.V if (huge_pte_none(pte)) { 477131d49da5SAneesh Kumar K.V spin_unlock(ptl); 477231d49da5SAneesh Kumar K.V continue; 477331d49da5SAneesh Kumar K.V } 47746629326bSHillf Danton 47756629326bSHillf Danton /* 47769fbc1f63SNaoya Horiguchi * Migrating hugepage or HWPoisoned hugepage is already 47779fbc1f63SNaoya Horiguchi * unmapped and its refcount is dropped, so just clear pte here. 47786629326bSHillf Danton */ 47799fbc1f63SNaoya Horiguchi if (unlikely(!pte_present(pte))) { 47809386fac3SPunit Agrawal huge_pte_clear(mm, address, ptep, sz); 478131d49da5SAneesh Kumar K.V spin_unlock(ptl); 478231d49da5SAneesh Kumar K.V continue; 47838c4894c6SNaoya Horiguchi } 47846629326bSHillf Danton 47856629326bSHillf Danton page = pte_page(pte); 478604f2cbe3SMel Gorman /* 478704f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 478804f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 478904f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 479004f2cbe3SMel Gorman */ 479104f2cbe3SMel Gorman if (ref_page) { 479231d49da5SAneesh Kumar K.V if (page != ref_page) { 479331d49da5SAneesh Kumar K.V spin_unlock(ptl); 479431d49da5SAneesh Kumar K.V continue; 479531d49da5SAneesh Kumar K.V } 479604f2cbe3SMel Gorman /* 479704f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 479804f2cbe3SMel Gorman * future faults in this VMA will fail rather than 479904f2cbe3SMel Gorman * looking like data was lost 480004f2cbe3SMel Gorman */ 480104f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 480204f2cbe3SMel Gorman } 480304f2cbe3SMel Gorman 4804c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 4805b528e4b6SAneesh Kumar K.V tlb_remove_huge_tlb_entry(h, tlb, ptep, address); 4806106c992aSGerald Schaefer if (huge_pte_dirty(pte)) 48076649a386SKen Chen set_page_dirty(page); 48089e81130bSHillf Danton 48095d317b2bSNaoya Horiguchi hugetlb_count_sub(pages_per_huge_page(h), mm); 4810d281ee61SKirill A. Shutemov page_remove_rmap(page, true); 481131d49da5SAneesh Kumar K.V 4812cb900f41SKirill A. Shutemov spin_unlock(ptl); 4813e77b0852SAneesh Kumar K.V tlb_remove_page_size(tlb, page, huge_page_size(h)); 481424669e58SAneesh Kumar K.V /* 481531d49da5SAneesh Kumar K.V * Bail out after unmapping reference page if supplied 481624669e58SAneesh Kumar K.V */ 481731d49da5SAneesh Kumar K.V if (ref_page) 481831d49da5SAneesh Kumar K.V break; 4819fe1668aeSChen, Kenneth W } 4820ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 482124669e58SAneesh Kumar K.V tlb_end_vma(tlb, vma); 48221da177e4SLinus Torvalds } 482363551ae0SDavid Gibson 4824d833352aSMel Gorman void __unmap_hugepage_range_final(struct mmu_gather *tlb, 4825d833352aSMel Gorman struct vm_area_struct *vma, unsigned long start, 4826d833352aSMel Gorman unsigned long end, struct page *ref_page) 4827d833352aSMel Gorman { 4828d833352aSMel Gorman __unmap_hugepage_range(tlb, vma, start, end, ref_page); 4829d833352aSMel Gorman 4830d833352aSMel Gorman /* 4831d833352aSMel Gorman * Clear this flag so that x86's huge_pmd_share page_table_shareable 4832d833352aSMel Gorman * test will fail on a vma being torn down, and not grab a page table 4833d833352aSMel Gorman * on its way out. We're lucky that the flag has such an appropriate 4834d833352aSMel Gorman * name, and can in fact be safely cleared here. We could clear it 4835d833352aSMel Gorman * before the __unmap_hugepage_range above, but all that's necessary 4836c8c06efaSDavidlohr Bueso * is to clear it before releasing the i_mmap_rwsem. This works 4837d833352aSMel Gorman * because in the context this is called, the VMA is about to be 4838c8c06efaSDavidlohr Bueso * destroyed and the i_mmap_rwsem is held. 4839d833352aSMel Gorman */ 4840d833352aSMel Gorman vma->vm_flags &= ~VM_MAYSHARE; 4841d833352aSMel Gorman } 4842d833352aSMel Gorman 4843502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 484404f2cbe3SMel Gorman unsigned long end, struct page *ref_page) 4845502717f4SChen, Kenneth W { 484624669e58SAneesh Kumar K.V struct mmu_gather tlb; 4847dff11abeSMike Kravetz 4848a72afd87SWill Deacon tlb_gather_mmu(&tlb, vma->vm_mm); 484924669e58SAneesh Kumar K.V __unmap_hugepage_range(&tlb, vma, start, end, ref_page); 4850ae8eba8bSWill Deacon tlb_finish_mmu(&tlb); 4851502717f4SChen, Kenneth W } 4852502717f4SChen, Kenneth W 485304f2cbe3SMel Gorman /* 485404f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 4855578b7725SZhiyuan Dai * mapping it owns the reserve page for. The intention is to unmap the page 485604f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 485704f2cbe3SMel Gorman * same region. 485804f2cbe3SMel Gorman */ 48592f4612afSDavidlohr Bueso static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, 48602a4b3dedSHarvey Harrison struct page *page, unsigned long address) 486104f2cbe3SMel Gorman { 48627526674dSAdam Litke struct hstate *h = hstate_vma(vma); 486304f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 486404f2cbe3SMel Gorman struct address_space *mapping; 486504f2cbe3SMel Gorman pgoff_t pgoff; 486604f2cbe3SMel Gorman 486704f2cbe3SMel Gorman /* 486804f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 486904f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 487004f2cbe3SMel Gorman */ 48717526674dSAdam Litke address = address & huge_page_mask(h); 487236e4f20aSMichal Hocko pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + 487336e4f20aSMichal Hocko vma->vm_pgoff; 487493c76a3dSAl Viro mapping = vma->vm_file->f_mapping; 487504f2cbe3SMel Gorman 48764eb2b1dcSMel Gorman /* 48774eb2b1dcSMel Gorman * Take the mapping lock for the duration of the table walk. As 48784eb2b1dcSMel Gorman * this mapping should be shared between all the VMAs, 48794eb2b1dcSMel Gorman * __unmap_hugepage_range() is called as the lock is already held 48804eb2b1dcSMel Gorman */ 488183cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 48826b2dbba8SMichel Lespinasse vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { 488304f2cbe3SMel Gorman /* Do not unmap the current VMA */ 488404f2cbe3SMel Gorman if (iter_vma == vma) 488504f2cbe3SMel Gorman continue; 488604f2cbe3SMel Gorman 488704f2cbe3SMel Gorman /* 48882f84a899SMel Gorman * Shared VMAs have their own reserves and do not affect 48892f84a899SMel Gorman * MAP_PRIVATE accounting but it is possible that a shared 48902f84a899SMel Gorman * VMA is using the same page so check and skip such VMAs. 48912f84a899SMel Gorman */ 48922f84a899SMel Gorman if (iter_vma->vm_flags & VM_MAYSHARE) 48932f84a899SMel Gorman continue; 48942f84a899SMel Gorman 48952f84a899SMel Gorman /* 489604f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 489704f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 489804f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 489904f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 490004f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 490104f2cbe3SMel Gorman */ 490204f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 490324669e58SAneesh Kumar K.V unmap_hugepage_range(iter_vma, address, 490424669e58SAneesh Kumar K.V address + huge_page_size(h), page); 490504f2cbe3SMel Gorman } 490683cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 490704f2cbe3SMel Gorman } 490804f2cbe3SMel Gorman 49090fe6e20bSNaoya Horiguchi /* 49100fe6e20bSNaoya Horiguchi * Hugetlb_cow() should be called with page lock of the original hugepage held. 4911ef009b25SMichal Hocko * Called with hugetlb_instantiation_mutex held and pte_page locked so we 4912ef009b25SMichal Hocko * cannot race with other handlers or page migration. 4913ef009b25SMichal Hocko * Keep the pte_same checks anyway to make transition from the mutex easier. 49140fe6e20bSNaoya Horiguchi */ 49152b740303SSouptick Joarder static vm_fault_t hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, 4916974e6d66SHuang Ying unsigned long address, pte_t *ptep, 4917cb900f41SKirill A. Shutemov struct page *pagecache_page, spinlock_t *ptl) 49181e8f889bSDavid Gibson { 49193999f52eSAneesh Kumar K.V pte_t pte; 4920a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 49211e8f889bSDavid Gibson struct page *old_page, *new_page; 49222b740303SSouptick Joarder int outside_reserve = 0; 49232b740303SSouptick Joarder vm_fault_t ret = 0; 4924974e6d66SHuang Ying unsigned long haddr = address & huge_page_mask(h); 4925ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 49261e8f889bSDavid Gibson 49273999f52eSAneesh Kumar K.V pte = huge_ptep_get(ptep); 49281e8f889bSDavid Gibson old_page = pte_page(pte); 49291e8f889bSDavid Gibson 493004f2cbe3SMel Gorman retry_avoidcopy: 49311e8f889bSDavid Gibson /* If no-one else is actually using this page, avoid the copy 49321e8f889bSDavid Gibson * and just make the page writable */ 493337a2140dSJoonsoo Kim if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { 49345a49973dSHugh Dickins page_move_anon_rmap(old_page, vma); 49355b7a1d40SHuang Ying set_huge_ptep_writable(vma, haddr, ptep); 493683c54070SNick Piggin return 0; 49371e8f889bSDavid Gibson } 49381e8f889bSDavid Gibson 493904f2cbe3SMel Gorman /* 494004f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 494104f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 494204f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 494304f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 494404f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 494504f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 494604f2cbe3SMel Gorman * of the full address range. 494704f2cbe3SMel Gorman */ 49485944d011SJoonsoo Kim if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 494904f2cbe3SMel Gorman old_page != pagecache_page) 495004f2cbe3SMel Gorman outside_reserve = 1; 495104f2cbe3SMel Gorman 495209cbfeafSKirill A. Shutemov get_page(old_page); 4953b76c8cfbSLarry Woodman 4954ad4404a2SDavidlohr Bueso /* 4955ad4404a2SDavidlohr Bueso * Drop page table lock as buddy allocator may be called. It will 4956ad4404a2SDavidlohr Bueso * be acquired again before returning to the caller, as expected. 4957ad4404a2SDavidlohr Bueso */ 4958cb900f41SKirill A. Shutemov spin_unlock(ptl); 49595b7a1d40SHuang Ying new_page = alloc_huge_page(vma, haddr, outside_reserve); 49601e8f889bSDavid Gibson 49612fc39cecSAdam Litke if (IS_ERR(new_page)) { 496204f2cbe3SMel Gorman /* 496304f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 496404f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 496504f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 496604f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 496704f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 496804f2cbe3SMel Gorman */ 496904f2cbe3SMel Gorman if (outside_reserve) { 4970e7dd91c4SMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 4971e7dd91c4SMike Kravetz pgoff_t idx; 4972e7dd91c4SMike Kravetz u32 hash; 4973e7dd91c4SMike Kravetz 497409cbfeafSKirill A. Shutemov put_page(old_page); 497504f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 4976e7dd91c4SMike Kravetz /* 4977e7dd91c4SMike Kravetz * Drop hugetlb_fault_mutex and i_mmap_rwsem before 4978e7dd91c4SMike Kravetz * unmapping. unmapping needs to hold i_mmap_rwsem 4979e7dd91c4SMike Kravetz * in write mode. Dropping i_mmap_rwsem in read mode 4980e7dd91c4SMike Kravetz * here is OK as COW mappings do not interact with 4981e7dd91c4SMike Kravetz * PMD sharing. 4982e7dd91c4SMike Kravetz * 4983e7dd91c4SMike Kravetz * Reacquire both after unmap operation. 4984e7dd91c4SMike Kravetz */ 4985e7dd91c4SMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 4986e7dd91c4SMike Kravetz hash = hugetlb_fault_mutex_hash(mapping, idx); 4987e7dd91c4SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 4988e7dd91c4SMike Kravetz i_mmap_unlock_read(mapping); 4989e7dd91c4SMike Kravetz 49905b7a1d40SHuang Ying unmap_ref_private(mm, vma, old_page, haddr); 4991e7dd91c4SMike Kravetz 4992e7dd91c4SMike Kravetz i_mmap_lock_read(mapping); 4993e7dd91c4SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 4994cb900f41SKirill A. Shutemov spin_lock(ptl); 49955b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 4996a9af0c5dSNaoya Horiguchi if (likely(ptep && 4997a9af0c5dSNaoya Horiguchi pte_same(huge_ptep_get(ptep), pte))) 499804f2cbe3SMel Gorman goto retry_avoidcopy; 4999a734bcc8SHillf Danton /* 5000cb900f41SKirill A. Shutemov * race occurs while re-acquiring page table 5001cb900f41SKirill A. Shutemov * lock, and our job is done. 5002a734bcc8SHillf Danton */ 5003a734bcc8SHillf Danton return 0; 500404f2cbe3SMel Gorman } 500504f2cbe3SMel Gorman 50062b740303SSouptick Joarder ret = vmf_error(PTR_ERR(new_page)); 5007ad4404a2SDavidlohr Bueso goto out_release_old; 50081e8f889bSDavid Gibson } 50091e8f889bSDavid Gibson 50100fe6e20bSNaoya Horiguchi /* 50110fe6e20bSNaoya Horiguchi * When the original hugepage is shared one, it does not have 50120fe6e20bSNaoya Horiguchi * anon_vma prepared. 50130fe6e20bSNaoya Horiguchi */ 501444e2aa93SDean Nelson if (unlikely(anon_vma_prepare(vma))) { 5015ad4404a2SDavidlohr Bueso ret = VM_FAULT_OOM; 5016ad4404a2SDavidlohr Bueso goto out_release_all; 501744e2aa93SDean Nelson } 50180fe6e20bSNaoya Horiguchi 5019974e6d66SHuang Ying copy_user_huge_page(new_page, old_page, address, vma, 502047ad8475SAndrea Arcangeli pages_per_huge_page(h)); 50210ed361deSNick Piggin __SetPageUptodate(new_page); 50221e8f889bSDavid Gibson 50237269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr, 50246f4f13e8SJérôme Glisse haddr + huge_page_size(h)); 5025ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 5026ad4404a2SDavidlohr Bueso 5027b76c8cfbSLarry Woodman /* 5028cb900f41SKirill A. Shutemov * Retake the page table lock to check for racing updates 5029b76c8cfbSLarry Woodman * before the page tables are altered 5030b76c8cfbSLarry Woodman */ 5031cb900f41SKirill A. Shutemov spin_lock(ptl); 50325b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5033a9af0c5dSNaoya Horiguchi if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { 5034d6995da3SMike Kravetz ClearHPageRestoreReserve(new_page); 503507443a85SJoonsoo Kim 50361e8f889bSDavid Gibson /* Break COW */ 50375b7a1d40SHuang Ying huge_ptep_clear_flush(vma, haddr, ptep); 5038ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range(mm, range.start, range.end); 50395b7a1d40SHuang Ying set_huge_pte_at(mm, haddr, ptep, 50401e8f889bSDavid Gibson make_huge_pte(vma, new_page, 1)); 5041d281ee61SKirill A. Shutemov page_remove_rmap(old_page, true); 50425b7a1d40SHuang Ying hugepage_add_new_anon_rmap(new_page, vma, haddr); 50438f251a3dSMike Kravetz SetHPageMigratable(new_page); 50441e8f889bSDavid Gibson /* Make the old page be freed below */ 50451e8f889bSDavid Gibson new_page = old_page; 50461e8f889bSDavid Gibson } 5047cb900f41SKirill A. Shutemov spin_unlock(ptl); 5048ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 5049ad4404a2SDavidlohr Bueso out_release_all: 5050c7b1850dSMike Kravetz /* No restore in case of successful pagetable update (Break COW) */ 5051c7b1850dSMike Kravetz if (new_page != old_page) 50525b7a1d40SHuang Ying restore_reserve_on_error(h, vma, haddr, new_page); 505309cbfeafSKirill A. Shutemov put_page(new_page); 5054ad4404a2SDavidlohr Bueso out_release_old: 505509cbfeafSKirill A. Shutemov put_page(old_page); 50568312034fSJoonsoo Kim 5057ad4404a2SDavidlohr Bueso spin_lock(ptl); /* Caller expects lock to be held */ 5058ad4404a2SDavidlohr Bueso return ret; 50591e8f889bSDavid Gibson } 50601e8f889bSDavid Gibson 506104f2cbe3SMel Gorman /* Return the pagecache page at a given address within a VMA */ 5062a5516438SAndi Kleen static struct page *hugetlbfs_pagecache_page(struct hstate *h, 5063a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 506404f2cbe3SMel Gorman { 506504f2cbe3SMel Gorman struct address_space *mapping; 5066e7c4b0bfSAndy Whitcroft pgoff_t idx; 506704f2cbe3SMel Gorman 506804f2cbe3SMel Gorman mapping = vma->vm_file->f_mapping; 5069a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 507004f2cbe3SMel Gorman 507104f2cbe3SMel Gorman return find_lock_page(mapping, idx); 507204f2cbe3SMel Gorman } 507304f2cbe3SMel Gorman 50743ae77f43SHugh Dickins /* 50753ae77f43SHugh Dickins * Return whether there is a pagecache page to back given address within VMA. 50763ae77f43SHugh Dickins * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. 50773ae77f43SHugh Dickins */ 50783ae77f43SHugh Dickins static bool hugetlbfs_pagecache_present(struct hstate *h, 50792a15efc9SHugh Dickins struct vm_area_struct *vma, unsigned long address) 50802a15efc9SHugh Dickins { 50812a15efc9SHugh Dickins struct address_space *mapping; 50822a15efc9SHugh Dickins pgoff_t idx; 50832a15efc9SHugh Dickins struct page *page; 50842a15efc9SHugh Dickins 50852a15efc9SHugh Dickins mapping = vma->vm_file->f_mapping; 50862a15efc9SHugh Dickins idx = vma_hugecache_offset(h, vma, address); 50872a15efc9SHugh Dickins 50882a15efc9SHugh Dickins page = find_get_page(mapping, idx); 50892a15efc9SHugh Dickins if (page) 50902a15efc9SHugh Dickins put_page(page); 50912a15efc9SHugh Dickins return page != NULL; 50922a15efc9SHugh Dickins } 50932a15efc9SHugh Dickins 5094ab76ad54SMike Kravetz int huge_add_to_page_cache(struct page *page, struct address_space *mapping, 5095ab76ad54SMike Kravetz pgoff_t idx) 5096ab76ad54SMike Kravetz { 5097ab76ad54SMike Kravetz struct inode *inode = mapping->host; 5098ab76ad54SMike Kravetz struct hstate *h = hstate_inode(inode); 5099ab76ad54SMike Kravetz int err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); 5100ab76ad54SMike Kravetz 5101ab76ad54SMike Kravetz if (err) 5102ab76ad54SMike Kravetz return err; 5103d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 5104ab76ad54SMike Kravetz 510522146c3cSMike Kravetz /* 510622146c3cSMike Kravetz * set page dirty so that it will not be removed from cache/file 510722146c3cSMike Kravetz * by non-hugetlbfs specific code paths. 510822146c3cSMike Kravetz */ 510922146c3cSMike Kravetz set_page_dirty(page); 511022146c3cSMike Kravetz 5111ab76ad54SMike Kravetz spin_lock(&inode->i_lock); 5112ab76ad54SMike Kravetz inode->i_blocks += blocks_per_huge_page(h); 5113ab76ad54SMike Kravetz spin_unlock(&inode->i_lock); 5114ab76ad54SMike Kravetz return 0; 5115ab76ad54SMike Kravetz } 5116ab76ad54SMike Kravetz 51177677f7fdSAxel Rasmussen static inline vm_fault_t hugetlb_handle_userfault(struct vm_area_struct *vma, 51187677f7fdSAxel Rasmussen struct address_space *mapping, 51197677f7fdSAxel Rasmussen pgoff_t idx, 51207677f7fdSAxel Rasmussen unsigned int flags, 51217677f7fdSAxel Rasmussen unsigned long haddr, 51227677f7fdSAxel Rasmussen unsigned long reason) 51237677f7fdSAxel Rasmussen { 51247677f7fdSAxel Rasmussen vm_fault_t ret; 51257677f7fdSAxel Rasmussen u32 hash; 51267677f7fdSAxel Rasmussen struct vm_fault vmf = { 51277677f7fdSAxel Rasmussen .vma = vma, 51287677f7fdSAxel Rasmussen .address = haddr, 51297677f7fdSAxel Rasmussen .flags = flags, 51307677f7fdSAxel Rasmussen 51317677f7fdSAxel Rasmussen /* 51327677f7fdSAxel Rasmussen * Hard to debug if it ends up being 51337677f7fdSAxel Rasmussen * used by a callee that assumes 51347677f7fdSAxel Rasmussen * something about the other 51357677f7fdSAxel Rasmussen * uninitialized fields... same as in 51367677f7fdSAxel Rasmussen * memory.c 51377677f7fdSAxel Rasmussen */ 51387677f7fdSAxel Rasmussen }; 51397677f7fdSAxel Rasmussen 51407677f7fdSAxel Rasmussen /* 51417677f7fdSAxel Rasmussen * hugetlb_fault_mutex and i_mmap_rwsem must be 51427677f7fdSAxel Rasmussen * dropped before handling userfault. Reacquire 51437677f7fdSAxel Rasmussen * after handling fault to make calling code simpler. 51447677f7fdSAxel Rasmussen */ 51457677f7fdSAxel Rasmussen hash = hugetlb_fault_mutex_hash(mapping, idx); 51467677f7fdSAxel Rasmussen mutex_unlock(&hugetlb_fault_mutex_table[hash]); 51477677f7fdSAxel Rasmussen i_mmap_unlock_read(mapping); 51487677f7fdSAxel Rasmussen ret = handle_userfault(&vmf, reason); 51497677f7fdSAxel Rasmussen i_mmap_lock_read(mapping); 51507677f7fdSAxel Rasmussen mutex_lock(&hugetlb_fault_mutex_table[hash]); 51517677f7fdSAxel Rasmussen 51527677f7fdSAxel Rasmussen return ret; 51537677f7fdSAxel Rasmussen } 51547677f7fdSAxel Rasmussen 51552b740303SSouptick Joarder static vm_fault_t hugetlb_no_page(struct mm_struct *mm, 51562b740303SSouptick Joarder struct vm_area_struct *vma, 51578382d914SDavidlohr Bueso struct address_space *mapping, pgoff_t idx, 5158788c7df4SHugh Dickins unsigned long address, pte_t *ptep, unsigned int flags) 5159ac9b9c66SHugh Dickins { 5160a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 51612b740303SSouptick Joarder vm_fault_t ret = VM_FAULT_SIGBUS; 5162409eb8c2SHillf Danton int anon_rmap = 0; 51634c887265SAdam Litke unsigned long size; 51644c887265SAdam Litke struct page *page; 51651e8f889bSDavid Gibson pte_t new_pte; 5166cb900f41SKirill A. Shutemov spinlock_t *ptl; 5167285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 5168c7b1850dSMike Kravetz bool new_page, new_pagecache_page = false; 51694c887265SAdam Litke 517004f2cbe3SMel Gorman /* 517104f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 517204f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 517325985edcSLucas De Marchi * COW. Warn that such a situation has occurred as it may not be obvious 517404f2cbe3SMel Gorman */ 517504f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 5176910154d5SGeoffrey Thomas pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n", 517704f2cbe3SMel Gorman current->pid); 517804f2cbe3SMel Gorman return ret; 517904f2cbe3SMel Gorman } 518004f2cbe3SMel Gorman 51814c887265SAdam Litke /* 518287bf91d3SMike Kravetz * We can not race with truncation due to holding i_mmap_rwsem. 518387bf91d3SMike Kravetz * i_size is modified when holding i_mmap_rwsem, so check here 518487bf91d3SMike Kravetz * once for faults beyond end of file. 51854c887265SAdam Litke */ 5186a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 5187ebed4bfcSHugh Dickins if (idx >= size) 5188ebed4bfcSHugh Dickins goto out; 51891a1aad8aSMike Kravetz 519087bf91d3SMike Kravetz retry: 5191c7b1850dSMike Kravetz new_page = false; 519287bf91d3SMike Kravetz page = find_lock_page(mapping, idx); 519387bf91d3SMike Kravetz if (!page) { 51947677f7fdSAxel Rasmussen /* Check for page in userfault range */ 51951a1aad8aSMike Kravetz if (userfaultfd_missing(vma)) { 51967677f7fdSAxel Rasmussen ret = hugetlb_handle_userfault(vma, mapping, idx, 51977677f7fdSAxel Rasmussen flags, haddr, 51987677f7fdSAxel Rasmussen VM_UFFD_MISSING); 51991a1aad8aSMike Kravetz goto out; 52001a1aad8aSMike Kravetz } 52011a1aad8aSMike Kravetz 5202285b8dcaSHuang Ying page = alloc_huge_page(vma, haddr, 0); 52032fc39cecSAdam Litke if (IS_ERR(page)) { 52044643d67eSMike Kravetz /* 52054643d67eSMike Kravetz * Returning error will result in faulting task being 52064643d67eSMike Kravetz * sent SIGBUS. The hugetlb fault mutex prevents two 52074643d67eSMike Kravetz * tasks from racing to fault in the same page which 52084643d67eSMike Kravetz * could result in false unable to allocate errors. 52094643d67eSMike Kravetz * Page migration does not take the fault mutex, but 52104643d67eSMike Kravetz * does a clear then write of pte's under page table 52114643d67eSMike Kravetz * lock. Page fault code could race with migration, 52124643d67eSMike Kravetz * notice the clear pte and try to allocate a page 52134643d67eSMike Kravetz * here. Before returning error, get ptl and make 52144643d67eSMike Kravetz * sure there really is no pte entry. 52154643d67eSMike Kravetz */ 52164643d67eSMike Kravetz ptl = huge_pte_lock(h, mm, ptep); 52174643d67eSMike Kravetz ret = 0; 5218d83e6c8aSMiaohe Lin if (huge_pte_none(huge_ptep_get(ptep))) 52192b740303SSouptick Joarder ret = vmf_error(PTR_ERR(page)); 5220d83e6c8aSMiaohe Lin spin_unlock(ptl); 52216bda666aSChristoph Lameter goto out; 52226bda666aSChristoph Lameter } 522347ad8475SAndrea Arcangeli clear_huge_page(page, address, pages_per_huge_page(h)); 52240ed361deSNick Piggin __SetPageUptodate(page); 5225cb6acd01SMike Kravetz new_page = true; 5226ac9b9c66SHugh Dickins 5227f83a275dSMel Gorman if (vma->vm_flags & VM_MAYSHARE) { 5228ab76ad54SMike Kravetz int err = huge_add_to_page_cache(page, mapping, idx); 52296bda666aSChristoph Lameter if (err) { 52306bda666aSChristoph Lameter put_page(page); 52316bda666aSChristoph Lameter if (err == -EEXIST) 52326bda666aSChristoph Lameter goto retry; 52336bda666aSChristoph Lameter goto out; 52346bda666aSChristoph Lameter } 5235c7b1850dSMike Kravetz new_pagecache_page = true; 523623be7468SMel Gorman } else { 52376bda666aSChristoph Lameter lock_page(page); 52380fe6e20bSNaoya Horiguchi if (unlikely(anon_vma_prepare(vma))) { 52390fe6e20bSNaoya Horiguchi ret = VM_FAULT_OOM; 52400fe6e20bSNaoya Horiguchi goto backout_unlocked; 524123be7468SMel Gorman } 5242409eb8c2SHillf Danton anon_rmap = 1; 52430fe6e20bSNaoya Horiguchi } 52440fe6e20bSNaoya Horiguchi } else { 524557303d80SAndy Whitcroft /* 5246998b4382SNaoya Horiguchi * If memory error occurs between mmap() and fault, some process 5247998b4382SNaoya Horiguchi * don't have hwpoisoned swap entry for errored virtual address. 5248998b4382SNaoya Horiguchi * So we need to block hugepage fault by PG_hwpoison bit check. 5249fd6a03edSNaoya Horiguchi */ 5250fd6a03edSNaoya Horiguchi if (unlikely(PageHWPoison(page))) { 52510eb98f15SMiaohe Lin ret = VM_FAULT_HWPOISON_LARGE | 5252972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 5253fd6a03edSNaoya Horiguchi goto backout_unlocked; 52546bda666aSChristoph Lameter } 52557677f7fdSAxel Rasmussen 52567677f7fdSAxel Rasmussen /* Check for page in userfault range. */ 52577677f7fdSAxel Rasmussen if (userfaultfd_minor(vma)) { 52587677f7fdSAxel Rasmussen unlock_page(page); 52597677f7fdSAxel Rasmussen put_page(page); 52607677f7fdSAxel Rasmussen ret = hugetlb_handle_userfault(vma, mapping, idx, 52617677f7fdSAxel Rasmussen flags, haddr, 52627677f7fdSAxel Rasmussen VM_UFFD_MINOR); 52637677f7fdSAxel Rasmussen goto out; 52647677f7fdSAxel Rasmussen } 5265998b4382SNaoya Horiguchi } 52661e8f889bSDavid Gibson 526757303d80SAndy Whitcroft /* 526857303d80SAndy Whitcroft * If we are going to COW a private mapping later, we examine the 526957303d80SAndy Whitcroft * pending reservations for this page now. This will ensure that 527057303d80SAndy Whitcroft * any allocations necessary to record that reservation occur outside 527157303d80SAndy Whitcroft * the spinlock. 527257303d80SAndy Whitcroft */ 52735e911373SMike Kravetz if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 5274285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 52752b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 52762b26736cSAndy Whitcroft goto backout_unlocked; 52772b26736cSAndy Whitcroft } 52785e911373SMike Kravetz /* Just decrements count, does not deallocate */ 5279285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 52805e911373SMike Kravetz } 528157303d80SAndy Whitcroft 52828bea8052SAneesh Kumar K.V ptl = huge_pte_lock(h, mm, ptep); 528383c54070SNick Piggin ret = 0; 52847f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(ptep))) 52854c887265SAdam Litke goto backout; 52864c887265SAdam Litke 528707443a85SJoonsoo Kim if (anon_rmap) { 5288d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 5289285b8dcaSHuang Ying hugepage_add_new_anon_rmap(page, vma, haddr); 5290ac714904SChoi Gi-yong } else 529153f9263bSKirill A. Shutemov page_dup_rmap(page, true); 52921e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 52931e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 5294285b8dcaSHuang Ying set_huge_pte_at(mm, haddr, ptep, new_pte); 52951e8f889bSDavid Gibson 52965d317b2bSNaoya Horiguchi hugetlb_count_add(pages_per_huge_page(h), mm); 5297788c7df4SHugh Dickins if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 52981e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 5299974e6d66SHuang Ying ret = hugetlb_cow(mm, vma, address, ptep, page, ptl); 53001e8f889bSDavid Gibson } 53011e8f889bSDavid Gibson 5302cb900f41SKirill A. Shutemov spin_unlock(ptl); 5303cb6acd01SMike Kravetz 5304cb6acd01SMike Kravetz /* 53058f251a3dSMike Kravetz * Only set HPageMigratable in newly allocated pages. Existing pages 53068f251a3dSMike Kravetz * found in the pagecache may not have HPageMigratableset if they have 53078f251a3dSMike Kravetz * been isolated for migration. 5308cb6acd01SMike Kravetz */ 5309cb6acd01SMike Kravetz if (new_page) 53108f251a3dSMike Kravetz SetHPageMigratable(page); 5311cb6acd01SMike Kravetz 53124c887265SAdam Litke unlock_page(page); 53134c887265SAdam Litke out: 5314ac9b9c66SHugh Dickins return ret; 53154c887265SAdam Litke 53164c887265SAdam Litke backout: 5317cb900f41SKirill A. Shutemov spin_unlock(ptl); 53182b26736cSAndy Whitcroft backout_unlocked: 53194c887265SAdam Litke unlock_page(page); 5320c7b1850dSMike Kravetz /* restore reserve for newly allocated pages not in page cache */ 5321c7b1850dSMike Kravetz if (new_page && !new_pagecache_page) 5322285b8dcaSHuang Ying restore_reserve_on_error(h, vma, haddr, page); 53234c887265SAdam Litke put_page(page); 53244c887265SAdam Litke goto out; 5325ac9b9c66SHugh Dickins } 5326ac9b9c66SHugh Dickins 53278382d914SDavidlohr Bueso #ifdef CONFIG_SMP 5328188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 53298382d914SDavidlohr Bueso { 53308382d914SDavidlohr Bueso unsigned long key[2]; 53318382d914SDavidlohr Bueso u32 hash; 53328382d914SDavidlohr Bueso 53338382d914SDavidlohr Bueso key[0] = (unsigned long) mapping; 53348382d914SDavidlohr Bueso key[1] = idx; 53358382d914SDavidlohr Bueso 533655254636SMike Kravetz hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0); 53378382d914SDavidlohr Bueso 53388382d914SDavidlohr Bueso return hash & (num_fault_mutexes - 1); 53398382d914SDavidlohr Bueso } 53408382d914SDavidlohr Bueso #else 53418382d914SDavidlohr Bueso /* 53426c26d310SMiaohe Lin * For uniprocessor systems we always use a single mutex, so just 53438382d914SDavidlohr Bueso * return 0 and avoid the hashing overhead. 53448382d914SDavidlohr Bueso */ 5345188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 53468382d914SDavidlohr Bueso { 53478382d914SDavidlohr Bueso return 0; 53488382d914SDavidlohr Bueso } 53498382d914SDavidlohr Bueso #endif 53508382d914SDavidlohr Bueso 53512b740303SSouptick Joarder vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 5352788c7df4SHugh Dickins unsigned long address, unsigned int flags) 535386e5216fSAdam Litke { 53548382d914SDavidlohr Bueso pte_t *ptep, entry; 5355cb900f41SKirill A. Shutemov spinlock_t *ptl; 53562b740303SSouptick Joarder vm_fault_t ret; 53578382d914SDavidlohr Bueso u32 hash; 53588382d914SDavidlohr Bueso pgoff_t idx; 53590fe6e20bSNaoya Horiguchi struct page *page = NULL; 536057303d80SAndy Whitcroft struct page *pagecache_page = NULL; 5361a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 53628382d914SDavidlohr Bueso struct address_space *mapping; 53630f792cf9SNaoya Horiguchi int need_wait_lock = 0; 5364285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 536586e5216fSAdam Litke 5366285b8dcaSHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5367fd6a03edSNaoya Horiguchi if (ptep) { 5368c0d0381aSMike Kravetz /* 5369c0d0381aSMike Kravetz * Since we hold no locks, ptep could be stale. That is 5370c0d0381aSMike Kravetz * OK as we are only making decisions based on content and 5371c0d0381aSMike Kravetz * not actually modifying content here. 5372c0d0381aSMike Kravetz */ 5373fd6a03edSNaoya Horiguchi entry = huge_ptep_get(ptep); 5374290408d4SNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(entry))) { 5375cb900f41SKirill A. Shutemov migration_entry_wait_huge(vma, mm, ptep); 5376290408d4SNaoya Horiguchi return 0; 5377290408d4SNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) 5378aa50d3a7SAndi Kleen return VM_FAULT_HWPOISON_LARGE | 5379972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 5380b43a9990SMike Kravetz } 53818382d914SDavidlohr Bueso 5382c0d0381aSMike Kravetz /* 5383c0d0381aSMike Kravetz * Acquire i_mmap_rwsem before calling huge_pte_alloc and hold 538487bf91d3SMike Kravetz * until finished with ptep. This serves two purposes: 538587bf91d3SMike Kravetz * 1) It prevents huge_pmd_unshare from being called elsewhere 538687bf91d3SMike Kravetz * and making the ptep no longer valid. 538787bf91d3SMike Kravetz * 2) It synchronizes us with i_size modifications during truncation. 5388c0d0381aSMike Kravetz * 5389c0d0381aSMike Kravetz * ptep could have already be assigned via huge_pte_offset. That 5390c0d0381aSMike Kravetz * is OK, as huge_pte_alloc will return the same value unless 5391c0d0381aSMike Kravetz * something has changed. 5392c0d0381aSMike Kravetz */ 5393ddeaab32SMike Kravetz mapping = vma->vm_file->f_mapping; 5394c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 5395aec44e0fSPeter Xu ptep = huge_pte_alloc(mm, vma, haddr, huge_page_size(h)); 5396c0d0381aSMike Kravetz if (!ptep) { 5397c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 5398c0d0381aSMike Kravetz return VM_FAULT_OOM; 5399c0d0381aSMike Kravetz } 5400ddeaab32SMike Kravetz 54013935baa9SDavid Gibson /* 54023935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 54033935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 54043935baa9SDavid Gibson * the same page in the page cache. 54053935baa9SDavid Gibson */ 5406c0d0381aSMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 5407188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 5408c672c7f2SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 54098382d914SDavidlohr Bueso 54107f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 54117f2e9525SGerald Schaefer if (huge_pte_none(entry)) { 54128382d914SDavidlohr Bueso ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, flags); 5413b4d1d99fSDavid Gibson goto out_mutex; 54143935baa9SDavid Gibson } 541586e5216fSAdam Litke 541683c54070SNick Piggin ret = 0; 54171e8f889bSDavid Gibson 541857303d80SAndy Whitcroft /* 54190f792cf9SNaoya Horiguchi * entry could be a migration/hwpoison entry at this point, so this 54200f792cf9SNaoya Horiguchi * check prevents the kernel from going below assuming that we have 54217c8de358SEthon Paul * an active hugepage in pagecache. This goto expects the 2nd page 54227c8de358SEthon Paul * fault, and is_hugetlb_entry_(migration|hwpoisoned) check will 54237c8de358SEthon Paul * properly handle it. 54240f792cf9SNaoya Horiguchi */ 54250f792cf9SNaoya Horiguchi if (!pte_present(entry)) 54260f792cf9SNaoya Horiguchi goto out_mutex; 54270f792cf9SNaoya Horiguchi 54280f792cf9SNaoya Horiguchi /* 542957303d80SAndy Whitcroft * If we are going to COW the mapping later, we examine the pending 543057303d80SAndy Whitcroft * reservations for this page now. This will ensure that any 543157303d80SAndy Whitcroft * allocations necessary to record that reservation occur outside the 543257303d80SAndy Whitcroft * spinlock. For private mappings, we also lookup the pagecache 543357303d80SAndy Whitcroft * page now as it is used to determine if a reservation has been 543457303d80SAndy Whitcroft * consumed. 543557303d80SAndy Whitcroft */ 5436106c992aSGerald Schaefer if ((flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { 5437285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 54382b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 5439b4d1d99fSDavid Gibson goto out_mutex; 54402b26736cSAndy Whitcroft } 54415e911373SMike Kravetz /* Just decrements count, does not deallocate */ 5442285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 544357303d80SAndy Whitcroft 5444f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 544557303d80SAndy Whitcroft pagecache_page = hugetlbfs_pagecache_page(h, 5446285b8dcaSHuang Ying vma, haddr); 544757303d80SAndy Whitcroft } 544857303d80SAndy Whitcroft 54490f792cf9SNaoya Horiguchi ptl = huge_pte_lock(h, mm, ptep); 54500fe6e20bSNaoya Horiguchi 54511e8f889bSDavid Gibson /* Check for a racing update before calling hugetlb_cow */ 5452b4d1d99fSDavid Gibson if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) 5453cb900f41SKirill A. Shutemov goto out_ptl; 5454b4d1d99fSDavid Gibson 54550f792cf9SNaoya Horiguchi /* 54560f792cf9SNaoya Horiguchi * hugetlb_cow() requires page locks of pte_page(entry) and 54570f792cf9SNaoya Horiguchi * pagecache_page, so here we need take the former one 54580f792cf9SNaoya Horiguchi * when page != pagecache_page or !pagecache_page. 54590f792cf9SNaoya Horiguchi */ 54600f792cf9SNaoya Horiguchi page = pte_page(entry); 54610f792cf9SNaoya Horiguchi if (page != pagecache_page) 54620f792cf9SNaoya Horiguchi if (!trylock_page(page)) { 54630f792cf9SNaoya Horiguchi need_wait_lock = 1; 54640f792cf9SNaoya Horiguchi goto out_ptl; 54650f792cf9SNaoya Horiguchi } 54660f792cf9SNaoya Horiguchi 54670f792cf9SNaoya Horiguchi get_page(page); 5468b4d1d99fSDavid Gibson 5469788c7df4SHugh Dickins if (flags & FAULT_FLAG_WRITE) { 5470106c992aSGerald Schaefer if (!huge_pte_write(entry)) { 5471974e6d66SHuang Ying ret = hugetlb_cow(mm, vma, address, ptep, 5472cb900f41SKirill A. Shutemov pagecache_page, ptl); 54730f792cf9SNaoya Horiguchi goto out_put_page; 5474b4d1d99fSDavid Gibson } 5475106c992aSGerald Schaefer entry = huge_pte_mkdirty(entry); 5476b4d1d99fSDavid Gibson } 5477b4d1d99fSDavid Gibson entry = pte_mkyoung(entry); 5478285b8dcaSHuang Ying if (huge_ptep_set_access_flags(vma, haddr, ptep, entry, 5479788c7df4SHugh Dickins flags & FAULT_FLAG_WRITE)) 5480285b8dcaSHuang Ying update_mmu_cache(vma, haddr, ptep); 54810f792cf9SNaoya Horiguchi out_put_page: 54820f792cf9SNaoya Horiguchi if (page != pagecache_page) 54830f792cf9SNaoya Horiguchi unlock_page(page); 54840f792cf9SNaoya Horiguchi put_page(page); 5485cb900f41SKirill A. Shutemov out_ptl: 5486cb900f41SKirill A. Shutemov spin_unlock(ptl); 548757303d80SAndy Whitcroft 548857303d80SAndy Whitcroft if (pagecache_page) { 548957303d80SAndy Whitcroft unlock_page(pagecache_page); 549057303d80SAndy Whitcroft put_page(pagecache_page); 549157303d80SAndy Whitcroft } 5492b4d1d99fSDavid Gibson out_mutex: 5493c672c7f2SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5494c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 54950f792cf9SNaoya Horiguchi /* 54960f792cf9SNaoya Horiguchi * Generally it's safe to hold refcount during waiting page lock. But 54970f792cf9SNaoya Horiguchi * here we just wait to defer the next page fault to avoid busy loop and 54980f792cf9SNaoya Horiguchi * the page is not used after unlocked before returning from the current 54990f792cf9SNaoya Horiguchi * page fault. So we are safe from accessing freed page, even if we wait 55000f792cf9SNaoya Horiguchi * here without taking refcount. 55010f792cf9SNaoya Horiguchi */ 55020f792cf9SNaoya Horiguchi if (need_wait_lock) 55030f792cf9SNaoya Horiguchi wait_on_page_locked(page); 55041e8f889bSDavid Gibson return ret; 550586e5216fSAdam Litke } 550686e5216fSAdam Litke 5507714c1891SAxel Rasmussen #ifdef CONFIG_USERFAULTFD 55088fb5debcSMike Kravetz /* 55098fb5debcSMike Kravetz * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with 55108fb5debcSMike Kravetz * modifications for huge pages. 55118fb5debcSMike Kravetz */ 55128fb5debcSMike Kravetz int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, 55138fb5debcSMike Kravetz pte_t *dst_pte, 55148fb5debcSMike Kravetz struct vm_area_struct *dst_vma, 55158fb5debcSMike Kravetz unsigned long dst_addr, 55168fb5debcSMike Kravetz unsigned long src_addr, 5517f6191471SAxel Rasmussen enum mcopy_atomic_mode mode, 55188fb5debcSMike Kravetz struct page **pagep) 55198fb5debcSMike Kravetz { 5520f6191471SAxel Rasmussen bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE); 55218cc5fcbbSMina Almasry struct hstate *h = hstate_vma(dst_vma); 55228cc5fcbbSMina Almasry struct address_space *mapping = dst_vma->vm_file->f_mapping; 55238cc5fcbbSMina Almasry pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr); 55241e392147SAndrea Arcangeli unsigned long size; 55251c9e8defSMike Kravetz int vm_shared = dst_vma->vm_flags & VM_SHARED; 55268fb5debcSMike Kravetz pte_t _dst_pte; 55278fb5debcSMike Kravetz spinlock_t *ptl; 55288cc5fcbbSMina Almasry int ret = -ENOMEM; 55298fb5debcSMike Kravetz struct page *page; 5530f6191471SAxel Rasmussen int writable; 5531c7b1850dSMike Kravetz bool new_pagecache_page = false; 55328fb5debcSMike Kravetz 5533f6191471SAxel Rasmussen if (is_continue) { 5534f6191471SAxel Rasmussen ret = -EFAULT; 5535f6191471SAxel Rasmussen page = find_lock_page(mapping, idx); 5536f6191471SAxel Rasmussen if (!page) 5537f6191471SAxel Rasmussen goto out; 5538f6191471SAxel Rasmussen } else if (!*pagep) { 5539d84cf06eSMina Almasry /* If a page already exists, then it's UFFDIO_COPY for 5540d84cf06eSMina Almasry * a non-missing case. Return -EEXIST. 5541d84cf06eSMina Almasry */ 5542d84cf06eSMina Almasry if (vm_shared && 5543d84cf06eSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 5544d84cf06eSMina Almasry ret = -EEXIST; 55458fb5debcSMike Kravetz goto out; 5546d84cf06eSMina Almasry } 5547d84cf06eSMina Almasry 5548d84cf06eSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 5549d84cf06eSMina Almasry if (IS_ERR(page)) { 5550d84cf06eSMina Almasry ret = -ENOMEM; 5551d84cf06eSMina Almasry goto out; 5552d84cf06eSMina Almasry } 55538fb5debcSMike Kravetz 55548fb5debcSMike Kravetz ret = copy_huge_page_from_user(page, 55558fb5debcSMike Kravetz (const void __user *) src_addr, 5556810a56b9SMike Kravetz pages_per_huge_page(h), false); 55578fb5debcSMike Kravetz 5558c1e8d7c6SMichel Lespinasse /* fallback to copy_from_user outside mmap_lock */ 55598fb5debcSMike Kravetz if (unlikely(ret)) { 55609e368259SAndrea Arcangeli ret = -ENOENT; 55618cc5fcbbSMina Almasry /* Free the allocated page which may have 55628cc5fcbbSMina Almasry * consumed a reservation. 55638cc5fcbbSMina Almasry */ 55648cc5fcbbSMina Almasry restore_reserve_on_error(h, dst_vma, dst_addr, page); 55658cc5fcbbSMina Almasry put_page(page); 55668cc5fcbbSMina Almasry 55678cc5fcbbSMina Almasry /* Allocate a temporary page to hold the copied 55688cc5fcbbSMina Almasry * contents. 55698cc5fcbbSMina Almasry */ 55708cc5fcbbSMina Almasry page = alloc_huge_page_vma(h, dst_vma, dst_addr); 55718cc5fcbbSMina Almasry if (!page) { 55728cc5fcbbSMina Almasry ret = -ENOMEM; 55738cc5fcbbSMina Almasry goto out; 55748cc5fcbbSMina Almasry } 55758fb5debcSMike Kravetz *pagep = page; 55768cc5fcbbSMina Almasry /* Set the outparam pagep and return to the caller to 55778cc5fcbbSMina Almasry * copy the contents outside the lock. Don't free the 55788cc5fcbbSMina Almasry * page. 55798cc5fcbbSMina Almasry */ 55808fb5debcSMike Kravetz goto out; 55818fb5debcSMike Kravetz } 55828fb5debcSMike Kravetz } else { 55838cc5fcbbSMina Almasry if (vm_shared && 55848cc5fcbbSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 55858cc5fcbbSMina Almasry put_page(*pagep); 55868cc5fcbbSMina Almasry ret = -EEXIST; 55878cc5fcbbSMina Almasry *pagep = NULL; 55888cc5fcbbSMina Almasry goto out; 55898cc5fcbbSMina Almasry } 55908cc5fcbbSMina Almasry 55918cc5fcbbSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 55928cc5fcbbSMina Almasry if (IS_ERR(page)) { 55938cc5fcbbSMina Almasry ret = -ENOMEM; 55948cc5fcbbSMina Almasry *pagep = NULL; 55958cc5fcbbSMina Almasry goto out; 55968cc5fcbbSMina Almasry } 55978cc5fcbbSMina Almasry copy_huge_page(page, *pagep); 55988cc5fcbbSMina Almasry put_page(*pagep); 55998fb5debcSMike Kravetz *pagep = NULL; 56008fb5debcSMike Kravetz } 56018fb5debcSMike Kravetz 56028fb5debcSMike Kravetz /* 56038fb5debcSMike Kravetz * The memory barrier inside __SetPageUptodate makes sure that 56048fb5debcSMike Kravetz * preceding stores to the page contents become visible before 56058fb5debcSMike Kravetz * the set_pte_at() write. 56068fb5debcSMike Kravetz */ 56078fb5debcSMike Kravetz __SetPageUptodate(page); 56088fb5debcSMike Kravetz 5609f6191471SAxel Rasmussen /* Add shared, newly allocated pages to the page cache. */ 5610f6191471SAxel Rasmussen if (vm_shared && !is_continue) { 56111e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 56121e392147SAndrea Arcangeli ret = -EFAULT; 56131e392147SAndrea Arcangeli if (idx >= size) 56141e392147SAndrea Arcangeli goto out_release_nounlock; 56151c9e8defSMike Kravetz 56161e392147SAndrea Arcangeli /* 56171e392147SAndrea Arcangeli * Serialization between remove_inode_hugepages() and 56181e392147SAndrea Arcangeli * huge_add_to_page_cache() below happens through the 56191e392147SAndrea Arcangeli * hugetlb_fault_mutex_table that here must be hold by 56201e392147SAndrea Arcangeli * the caller. 56211e392147SAndrea Arcangeli */ 56221c9e8defSMike Kravetz ret = huge_add_to_page_cache(page, mapping, idx); 56231c9e8defSMike Kravetz if (ret) 56241c9e8defSMike Kravetz goto out_release_nounlock; 5625c7b1850dSMike Kravetz new_pagecache_page = true; 56261c9e8defSMike Kravetz } 56271c9e8defSMike Kravetz 56288fb5debcSMike Kravetz ptl = huge_pte_lockptr(h, dst_mm, dst_pte); 56298fb5debcSMike Kravetz spin_lock(ptl); 56308fb5debcSMike Kravetz 56311e392147SAndrea Arcangeli /* 56321e392147SAndrea Arcangeli * Recheck the i_size after holding PT lock to make sure not 56331e392147SAndrea Arcangeli * to leave any page mapped (as page_mapped()) beyond the end 56341e392147SAndrea Arcangeli * of the i_size (remove_inode_hugepages() is strict about 56351e392147SAndrea Arcangeli * enforcing that). If we bail out here, we'll also leave a 56361e392147SAndrea Arcangeli * page in the radix tree in the vm_shared case beyond the end 56371e392147SAndrea Arcangeli * of the i_size, but remove_inode_hugepages() will take care 56381e392147SAndrea Arcangeli * of it as soon as we drop the hugetlb_fault_mutex_table. 56391e392147SAndrea Arcangeli */ 56401e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 56411e392147SAndrea Arcangeli ret = -EFAULT; 56421e392147SAndrea Arcangeli if (idx >= size) 56431e392147SAndrea Arcangeli goto out_release_unlock; 56441e392147SAndrea Arcangeli 56458fb5debcSMike Kravetz ret = -EEXIST; 56468fb5debcSMike Kravetz if (!huge_pte_none(huge_ptep_get(dst_pte))) 56478fb5debcSMike Kravetz goto out_release_unlock; 56488fb5debcSMike Kravetz 56491c9e8defSMike Kravetz if (vm_shared) { 56501c9e8defSMike Kravetz page_dup_rmap(page, true); 56511c9e8defSMike Kravetz } else { 5652d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 56538fb5debcSMike Kravetz hugepage_add_new_anon_rmap(page, dst_vma, dst_addr); 56541c9e8defSMike Kravetz } 56558fb5debcSMike Kravetz 5656f6191471SAxel Rasmussen /* For CONTINUE on a non-shared VMA, don't set VM_WRITE for CoW. */ 5657f6191471SAxel Rasmussen if (is_continue && !vm_shared) 5658f6191471SAxel Rasmussen writable = 0; 5659f6191471SAxel Rasmussen else 5660f6191471SAxel Rasmussen writable = dst_vma->vm_flags & VM_WRITE; 5661f6191471SAxel Rasmussen 5662f6191471SAxel Rasmussen _dst_pte = make_huge_pte(dst_vma, page, writable); 5663f6191471SAxel Rasmussen if (writable) 56648fb5debcSMike Kravetz _dst_pte = huge_pte_mkdirty(_dst_pte); 56658fb5debcSMike Kravetz _dst_pte = pte_mkyoung(_dst_pte); 56668fb5debcSMike Kravetz 56678fb5debcSMike Kravetz set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); 56688fb5debcSMike Kravetz 56698fb5debcSMike Kravetz (void)huge_ptep_set_access_flags(dst_vma, dst_addr, dst_pte, _dst_pte, 56708fb5debcSMike Kravetz dst_vma->vm_flags & VM_WRITE); 56718fb5debcSMike Kravetz hugetlb_count_add(pages_per_huge_page(h), dst_mm); 56728fb5debcSMike Kravetz 56738fb5debcSMike Kravetz /* No need to invalidate - it was non-present before */ 56748fb5debcSMike Kravetz update_mmu_cache(dst_vma, dst_addr, dst_pte); 56758fb5debcSMike Kravetz 56768fb5debcSMike Kravetz spin_unlock(ptl); 5677f6191471SAxel Rasmussen if (!is_continue) 56788f251a3dSMike Kravetz SetHPageMigratable(page); 5679f6191471SAxel Rasmussen if (vm_shared || is_continue) 56801c9e8defSMike Kravetz unlock_page(page); 56818fb5debcSMike Kravetz ret = 0; 56828fb5debcSMike Kravetz out: 56838fb5debcSMike Kravetz return ret; 56848fb5debcSMike Kravetz out_release_unlock: 56858fb5debcSMike Kravetz spin_unlock(ptl); 5686f6191471SAxel Rasmussen if (vm_shared || is_continue) 56871c9e8defSMike Kravetz unlock_page(page); 56885af10dfdSAndrea Arcangeli out_release_nounlock: 5689c7b1850dSMike Kravetz if (!new_pagecache_page) 5690846be085SMike Kravetz restore_reserve_on_error(h, dst_vma, dst_addr, page); 56918fb5debcSMike Kravetz put_page(page); 56928fb5debcSMike Kravetz goto out; 56938fb5debcSMike Kravetz } 5694714c1891SAxel Rasmussen #endif /* CONFIG_USERFAULTFD */ 56958fb5debcSMike Kravetz 569682e5d378SJoao Martins static void record_subpages_vmas(struct page *page, struct vm_area_struct *vma, 569782e5d378SJoao Martins int refs, struct page **pages, 569882e5d378SJoao Martins struct vm_area_struct **vmas) 569982e5d378SJoao Martins { 570082e5d378SJoao Martins int nr; 570182e5d378SJoao Martins 570282e5d378SJoao Martins for (nr = 0; nr < refs; nr++) { 570382e5d378SJoao Martins if (likely(pages)) 570482e5d378SJoao Martins pages[nr] = mem_map_offset(page, nr); 570582e5d378SJoao Martins if (vmas) 570682e5d378SJoao Martins vmas[nr] = vma; 570782e5d378SJoao Martins } 570882e5d378SJoao Martins } 570982e5d378SJoao Martins 571028a35716SMichel Lespinasse long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 571163551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 571228a35716SMichel Lespinasse unsigned long *position, unsigned long *nr_pages, 57134f6da934SPeter Xu long i, unsigned int flags, int *locked) 571463551ae0SDavid Gibson { 5715d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 5716d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 571728a35716SMichel Lespinasse unsigned long remainder = *nr_pages; 5718a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 57190fa5bc40SJoao Martins int err = -EFAULT, refs; 572063551ae0SDavid Gibson 572163551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 572263551ae0SDavid Gibson pte_t *pte; 5723cb900f41SKirill A. Shutemov spinlock_t *ptl = NULL; 57242a15efc9SHugh Dickins int absent; 572563551ae0SDavid Gibson struct page *page; 572663551ae0SDavid Gibson 57274c887265SAdam Litke /* 572802057967SDavid Rientjes * If we have a pending SIGKILL, don't keep faulting pages and 572902057967SDavid Rientjes * potentially allocating memory. 573002057967SDavid Rientjes */ 5731fa45f116SDavidlohr Bueso if (fatal_signal_pending(current)) { 573202057967SDavid Rientjes remainder = 0; 573302057967SDavid Rientjes break; 573402057967SDavid Rientjes } 573502057967SDavid Rientjes 573602057967SDavid Rientjes /* 57374c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 57382a15efc9SHugh Dickins * each hugepage. We have to make sure we get the 57394c887265SAdam Litke * first, for the page indexing below to work. 5740cb900f41SKirill A. Shutemov * 5741cb900f41SKirill A. Shutemov * Note that page table lock is not held when pte is null. 57424c887265SAdam Litke */ 57437868a208SPunit Agrawal pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), 57447868a208SPunit Agrawal huge_page_size(h)); 5745cb900f41SKirill A. Shutemov if (pte) 5746cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, pte); 57472a15efc9SHugh Dickins absent = !pte || huge_pte_none(huge_ptep_get(pte)); 574863551ae0SDavid Gibson 57492a15efc9SHugh Dickins /* 57502a15efc9SHugh Dickins * When coredumping, it suits get_dump_page if we just return 57513ae77f43SHugh Dickins * an error where there's an empty slot with no huge pagecache 57523ae77f43SHugh Dickins * to back it. This way, we avoid allocating a hugepage, and 57533ae77f43SHugh Dickins * the sparse dumpfile avoids allocating disk blocks, but its 57543ae77f43SHugh Dickins * huge holes still show up with zeroes where they need to be. 57552a15efc9SHugh Dickins */ 57563ae77f43SHugh Dickins if (absent && (flags & FOLL_DUMP) && 57573ae77f43SHugh Dickins !hugetlbfs_pagecache_present(h, vma, vaddr)) { 5758cb900f41SKirill A. Shutemov if (pte) 5759cb900f41SKirill A. Shutemov spin_unlock(ptl); 57602a15efc9SHugh Dickins remainder = 0; 57612a15efc9SHugh Dickins break; 57622a15efc9SHugh Dickins } 57632a15efc9SHugh Dickins 57649cc3a5bdSNaoya Horiguchi /* 57659cc3a5bdSNaoya Horiguchi * We need call hugetlb_fault for both hugepages under migration 57669cc3a5bdSNaoya Horiguchi * (in which case hugetlb_fault waits for the migration,) and 57679cc3a5bdSNaoya Horiguchi * hwpoisoned hugepages (in which case we need to prevent the 57689cc3a5bdSNaoya Horiguchi * caller from accessing to them.) In order to do this, we use 57699cc3a5bdSNaoya Horiguchi * here is_swap_pte instead of is_hugetlb_entry_migration and 57709cc3a5bdSNaoya Horiguchi * is_hugetlb_entry_hwpoisoned. This is because it simply covers 57719cc3a5bdSNaoya Horiguchi * both cases, and because we can't follow correct pages 57729cc3a5bdSNaoya Horiguchi * directly from any kind of swap entries. 57739cc3a5bdSNaoya Horiguchi */ 57749cc3a5bdSNaoya Horiguchi if (absent || is_swap_pte(huge_ptep_get(pte)) || 5775106c992aSGerald Schaefer ((flags & FOLL_WRITE) && 5776106c992aSGerald Schaefer !huge_pte_write(huge_ptep_get(pte)))) { 57772b740303SSouptick Joarder vm_fault_t ret; 577887ffc118SAndrea Arcangeli unsigned int fault_flags = 0; 57794c887265SAdam Litke 5780cb900f41SKirill A. Shutemov if (pte) 5781cb900f41SKirill A. Shutemov spin_unlock(ptl); 578287ffc118SAndrea Arcangeli if (flags & FOLL_WRITE) 578387ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_WRITE; 57844f6da934SPeter Xu if (locked) 578571335f37SPeter Xu fault_flags |= FAULT_FLAG_ALLOW_RETRY | 578671335f37SPeter Xu FAULT_FLAG_KILLABLE; 578787ffc118SAndrea Arcangeli if (flags & FOLL_NOWAIT) 578887ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_ALLOW_RETRY | 578987ffc118SAndrea Arcangeli FAULT_FLAG_RETRY_NOWAIT; 579087ffc118SAndrea Arcangeli if (flags & FOLL_TRIED) { 57914426e945SPeter Xu /* 57924426e945SPeter Xu * Note: FAULT_FLAG_ALLOW_RETRY and 57934426e945SPeter Xu * FAULT_FLAG_TRIED can co-exist 57944426e945SPeter Xu */ 579587ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_TRIED; 579687ffc118SAndrea Arcangeli } 579787ffc118SAndrea Arcangeli ret = hugetlb_fault(mm, vma, vaddr, fault_flags); 579887ffc118SAndrea Arcangeli if (ret & VM_FAULT_ERROR) { 57992be7cfedSDaniel Jordan err = vm_fault_to_errno(ret, flags); 58001c59827dSHugh Dickins remainder = 0; 58011c59827dSHugh Dickins break; 58021c59827dSHugh Dickins } 580387ffc118SAndrea Arcangeli if (ret & VM_FAULT_RETRY) { 58044f6da934SPeter Xu if (locked && 58051ac25013SAndrea Arcangeli !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) 58064f6da934SPeter Xu *locked = 0; 580787ffc118SAndrea Arcangeli *nr_pages = 0; 580887ffc118SAndrea Arcangeli /* 580987ffc118SAndrea Arcangeli * VM_FAULT_RETRY must not return an 581087ffc118SAndrea Arcangeli * error, it will return zero 581187ffc118SAndrea Arcangeli * instead. 581287ffc118SAndrea Arcangeli * 581387ffc118SAndrea Arcangeli * No need to update "position" as the 581487ffc118SAndrea Arcangeli * caller will not check it after 581587ffc118SAndrea Arcangeli * *nr_pages is set to 0. 581687ffc118SAndrea Arcangeli */ 581787ffc118SAndrea Arcangeli return i; 581887ffc118SAndrea Arcangeli } 581987ffc118SAndrea Arcangeli continue; 582087ffc118SAndrea Arcangeli } 582163551ae0SDavid Gibson 5822a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 58237f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 58248fde12caSLinus Torvalds 58258fde12caSLinus Torvalds /* 5826acbfb087SZhigang Lu * If subpage information not requested, update counters 5827acbfb087SZhigang Lu * and skip the same_page loop below. 5828acbfb087SZhigang Lu */ 5829acbfb087SZhigang Lu if (!pages && !vmas && !pfn_offset && 5830acbfb087SZhigang Lu (vaddr + huge_page_size(h) < vma->vm_end) && 5831acbfb087SZhigang Lu (remainder >= pages_per_huge_page(h))) { 5832acbfb087SZhigang Lu vaddr += huge_page_size(h); 5833acbfb087SZhigang Lu remainder -= pages_per_huge_page(h); 5834acbfb087SZhigang Lu i += pages_per_huge_page(h); 5835acbfb087SZhigang Lu spin_unlock(ptl); 5836acbfb087SZhigang Lu continue; 5837acbfb087SZhigang Lu } 5838acbfb087SZhigang Lu 5839d08af0a5SJoao Martins /* vaddr may not be aligned to PAGE_SIZE */ 5840d08af0a5SJoao Martins refs = min3(pages_per_huge_page(h) - pfn_offset, remainder, 5841d08af0a5SJoao Martins (vma->vm_end - ALIGN_DOWN(vaddr, PAGE_SIZE)) >> PAGE_SHIFT); 58420fa5bc40SJoao Martins 584382e5d378SJoao Martins if (pages || vmas) 584482e5d378SJoao Martins record_subpages_vmas(mem_map_offset(page, pfn_offset), 584582e5d378SJoao Martins vma, refs, 584682e5d378SJoao Martins likely(pages) ? pages + i : NULL, 584782e5d378SJoao Martins vmas ? vmas + i : NULL); 584863551ae0SDavid Gibson 584982e5d378SJoao Martins if (pages) { 58500fa5bc40SJoao Martins /* 58510fa5bc40SJoao Martins * try_grab_compound_head() should always succeed here, 58520fa5bc40SJoao Martins * because: a) we hold the ptl lock, and b) we've just 58530fa5bc40SJoao Martins * checked that the huge page is present in the page 58540fa5bc40SJoao Martins * tables. If the huge page is present, then the tail 58550fa5bc40SJoao Martins * pages must also be present. The ptl prevents the 58560fa5bc40SJoao Martins * head page and tail pages from being rearranged in 58570fa5bc40SJoao Martins * any way. So this page must be available at this 58580fa5bc40SJoao Martins * point, unless the page refcount overflowed: 58590fa5bc40SJoao Martins */ 586082e5d378SJoao Martins if (WARN_ON_ONCE(!try_grab_compound_head(pages[i], 58610fa5bc40SJoao Martins refs, 58620fa5bc40SJoao Martins flags))) { 58630fa5bc40SJoao Martins spin_unlock(ptl); 58640fa5bc40SJoao Martins remainder = 0; 58650fa5bc40SJoao Martins err = -ENOMEM; 58660fa5bc40SJoao Martins break; 58670fa5bc40SJoao Martins } 5868d5d4b0aaSChen, Kenneth W } 586982e5d378SJoao Martins 587082e5d378SJoao Martins vaddr += (refs << PAGE_SHIFT); 587182e5d378SJoao Martins remainder -= refs; 587282e5d378SJoao Martins i += refs; 587382e5d378SJoao Martins 5874cb900f41SKirill A. Shutemov spin_unlock(ptl); 587563551ae0SDavid Gibson } 587628a35716SMichel Lespinasse *nr_pages = remainder; 587787ffc118SAndrea Arcangeli /* 587887ffc118SAndrea Arcangeli * setting position is actually required only if remainder is 587987ffc118SAndrea Arcangeli * not zero but it's faster not to add a "if (remainder)" 588087ffc118SAndrea Arcangeli * branch. 588187ffc118SAndrea Arcangeli */ 588263551ae0SDavid Gibson *position = vaddr; 588363551ae0SDavid Gibson 58842be7cfedSDaniel Jordan return i ? i : err; 588563551ae0SDavid Gibson } 58868f860591SZhang, Yanmin 58877da4d641SPeter Zijlstra unsigned long hugetlb_change_protection(struct vm_area_struct *vma, 58888f860591SZhang, Yanmin unsigned long address, unsigned long end, pgprot_t newprot) 58898f860591SZhang, Yanmin { 58908f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 58918f860591SZhang, Yanmin unsigned long start = address; 58928f860591SZhang, Yanmin pte_t *ptep; 58938f860591SZhang, Yanmin pte_t pte; 5894a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 58957da4d641SPeter Zijlstra unsigned long pages = 0; 5896dff11abeSMike Kravetz bool shared_pmd = false; 5897ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 5898dff11abeSMike Kravetz 5899dff11abeSMike Kravetz /* 5900dff11abeSMike Kravetz * In the case of shared PMDs, the area to flush could be beyond 5901ac46d4f3SJérôme Glisse * start/end. Set range.start/range.end to cover the maximum possible 5902dff11abeSMike Kravetz * range if PMD sharing is possible. 5903dff11abeSMike Kravetz */ 59047269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 59057269f999SJérôme Glisse 0, vma, mm, start, end); 5906ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 59078f860591SZhang, Yanmin 59088f860591SZhang, Yanmin BUG_ON(address >= end); 5909ac46d4f3SJérôme Glisse flush_cache_range(vma, range.start, range.end); 59108f860591SZhang, Yanmin 5911ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 591283cde9e8SDavidlohr Bueso i_mmap_lock_write(vma->vm_file->f_mapping); 5913a5516438SAndi Kleen for (; address < end; address += huge_page_size(h)) { 5914cb900f41SKirill A. Shutemov spinlock_t *ptl; 59157868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, huge_page_size(h)); 59168f860591SZhang, Yanmin if (!ptep) 59178f860591SZhang, Yanmin continue; 5918cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 591934ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 59207da4d641SPeter Zijlstra pages++; 5921cb900f41SKirill A. Shutemov spin_unlock(ptl); 5922dff11abeSMike Kravetz shared_pmd = true; 592339dde65cSChen, Kenneth W continue; 59247da4d641SPeter Zijlstra } 5925a8bda28dSNaoya Horiguchi pte = huge_ptep_get(ptep); 5926a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { 5927a8bda28dSNaoya Horiguchi spin_unlock(ptl); 5928a8bda28dSNaoya Horiguchi continue; 5929a8bda28dSNaoya Horiguchi } 5930a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(pte))) { 5931a8bda28dSNaoya Horiguchi swp_entry_t entry = pte_to_swp_entry(pte); 5932a8bda28dSNaoya Horiguchi 59334dd845b5SAlistair Popple if (is_writable_migration_entry(entry)) { 5934a8bda28dSNaoya Horiguchi pte_t newpte; 5935a8bda28dSNaoya Horiguchi 59364dd845b5SAlistair Popple entry = make_readable_migration_entry( 59374dd845b5SAlistair Popple swp_offset(entry)); 5938a8bda28dSNaoya Horiguchi newpte = swp_entry_to_pte(entry); 5939e5251fd4SPunit Agrawal set_huge_swap_pte_at(mm, address, ptep, 5940e5251fd4SPunit Agrawal newpte, huge_page_size(h)); 5941a8bda28dSNaoya Horiguchi pages++; 5942a8bda28dSNaoya Horiguchi } 5943a8bda28dSNaoya Horiguchi spin_unlock(ptl); 5944a8bda28dSNaoya Horiguchi continue; 5945a8bda28dSNaoya Horiguchi } 5946a8bda28dSNaoya Horiguchi if (!huge_pte_none(pte)) { 5947023bdd00SAneesh Kumar K.V pte_t old_pte; 594879c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 5949023bdd00SAneesh Kumar K.V 5950023bdd00SAneesh Kumar K.V old_pte = huge_ptep_modify_prot_start(vma, address, ptep); 5951023bdd00SAneesh Kumar K.V pte = pte_mkhuge(huge_pte_modify(old_pte, newprot)); 595279c1c594SChristophe Leroy pte = arch_make_huge_pte(pte, shift, vma->vm_flags); 5953023bdd00SAneesh Kumar K.V huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); 59547da4d641SPeter Zijlstra pages++; 59558f860591SZhang, Yanmin } 5956cb900f41SKirill A. Shutemov spin_unlock(ptl); 59578f860591SZhang, Yanmin } 5958d833352aSMel Gorman /* 5959c8c06efaSDavidlohr Bueso * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare 5960d833352aSMel Gorman * may have cleared our pud entry and done put_page on the page table: 5961c8c06efaSDavidlohr Bueso * once we release i_mmap_rwsem, another task can do the final put_page 5962dff11abeSMike Kravetz * and that page table be reused and filled with junk. If we actually 5963dff11abeSMike Kravetz * did unshare a page of pmds, flush the range corresponding to the pud. 5964d833352aSMel Gorman */ 5965dff11abeSMike Kravetz if (shared_pmd) 5966ac46d4f3SJérôme Glisse flush_hugetlb_tlb_range(vma, range.start, range.end); 5967dff11abeSMike Kravetz else 59685491ae7bSAneesh Kumar K.V flush_hugetlb_tlb_range(vma, start, end); 59690f10851eSJérôme Glisse /* 59700f10851eSJérôme Glisse * No need to call mmu_notifier_invalidate_range() we are downgrading 59710f10851eSJérôme Glisse * page table protection not changing it to point to a new page. 59720f10851eSJérôme Glisse * 5973ad56b738SMike Rapoport * See Documentation/vm/mmu_notifier.rst 59740f10851eSJérôme Glisse */ 597583cde9e8SDavidlohr Bueso i_mmap_unlock_write(vma->vm_file->f_mapping); 5976ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 59777da4d641SPeter Zijlstra 59787da4d641SPeter Zijlstra return pages << h->order; 59798f860591SZhang, Yanmin } 59808f860591SZhang, Yanmin 598133b8f84aSMike Kravetz /* Return true if reservation was successful, false otherwise. */ 598233b8f84aSMike Kravetz bool hugetlb_reserve_pages(struct inode *inode, 5983a1e78772SMel Gorman long from, long to, 59845a6fe125SMel Gorman struct vm_area_struct *vma, 5985ca16d140SKOSAKI Motohiro vm_flags_t vm_flags) 5986e4e574b7SAdam Litke { 598733b8f84aSMike Kravetz long chg, add = -1; 5988a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 598990481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 59909119a41eSJoonsoo Kim struct resv_map *resv_map; 5991075a61d0SMina Almasry struct hugetlb_cgroup *h_cg = NULL; 59920db9d74eSMina Almasry long gbl_reserve, regions_needed = 0; 5993e4e574b7SAdam Litke 599463489f8eSMike Kravetz /* This should never happen */ 599563489f8eSMike Kravetz if (from > to) { 599663489f8eSMike Kravetz VM_WARN(1, "%s called with a negative range\n", __func__); 599733b8f84aSMike Kravetz return false; 599863489f8eSMike Kravetz } 599963489f8eSMike Kravetz 6000a1e78772SMel Gorman /* 600117c9d12eSMel Gorman * Only apply hugepage reservation if asked. At fault time, an 600217c9d12eSMel Gorman * attempt will be made for VM_NORESERVE to allocate a page 600390481622SDavid Gibson * without using reserves 600417c9d12eSMel Gorman */ 6005ca16d140SKOSAKI Motohiro if (vm_flags & VM_NORESERVE) 600633b8f84aSMike Kravetz return true; 600717c9d12eSMel Gorman 600817c9d12eSMel Gorman /* 6009a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 6010a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 6011a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 6012a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 6013a1e78772SMel Gorman */ 60149119a41eSJoonsoo Kim if (!vma || vma->vm_flags & VM_MAYSHARE) { 6015f27a5136SMike Kravetz /* 6016f27a5136SMike Kravetz * resv_map can not be NULL as hugetlb_reserve_pages is only 6017f27a5136SMike Kravetz * called for inodes for which resv_maps were created (see 6018f27a5136SMike Kravetz * hugetlbfs_get_inode). 6019f27a5136SMike Kravetz */ 60204e35f483SJoonsoo Kim resv_map = inode_resv_map(inode); 60219119a41eSJoonsoo Kim 60220db9d74eSMina Almasry chg = region_chg(resv_map, from, to, ®ions_needed); 60239119a41eSJoonsoo Kim 60249119a41eSJoonsoo Kim } else { 6025e9fe92aeSMina Almasry /* Private mapping. */ 60269119a41eSJoonsoo Kim resv_map = resv_map_alloc(); 60275a6fe125SMel Gorman if (!resv_map) 602833b8f84aSMike Kravetz return false; 60295a6fe125SMel Gorman 603017c9d12eSMel Gorman chg = to - from; 603117c9d12eSMel Gorman 60325a6fe125SMel Gorman set_vma_resv_map(vma, resv_map); 60335a6fe125SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 60345a6fe125SMel Gorman } 60355a6fe125SMel Gorman 603633b8f84aSMike Kravetz if (chg < 0) 6037c50ac050SDave Hansen goto out_err; 603817c9d12eSMel Gorman 603933b8f84aSMike Kravetz if (hugetlb_cgroup_charge_cgroup_rsvd(hstate_index(h), 604033b8f84aSMike Kravetz chg * pages_per_huge_page(h), &h_cg) < 0) 6041075a61d0SMina Almasry goto out_err; 6042075a61d0SMina Almasry 6043075a61d0SMina Almasry if (vma && !(vma->vm_flags & VM_MAYSHARE) && h_cg) { 6044075a61d0SMina Almasry /* For private mappings, the hugetlb_cgroup uncharge info hangs 6045075a61d0SMina Almasry * of the resv_map. 6046075a61d0SMina Almasry */ 6047075a61d0SMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h); 6048075a61d0SMina Almasry } 6049075a61d0SMina Almasry 60501c5ecae3SMike Kravetz /* 60511c5ecae3SMike Kravetz * There must be enough pages in the subpool for the mapping. If 60521c5ecae3SMike Kravetz * the subpool has a minimum size, there may be some global 60531c5ecae3SMike Kravetz * reservations already in place (gbl_reserve). 60541c5ecae3SMike Kravetz */ 60551c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_get_pages(spool, chg); 605633b8f84aSMike Kravetz if (gbl_reserve < 0) 6057075a61d0SMina Almasry goto out_uncharge_cgroup; 605817c9d12eSMel Gorman 605917c9d12eSMel Gorman /* 606017c9d12eSMel Gorman * Check enough hugepages are available for the reservation. 606190481622SDavid Gibson * Hand the pages back to the subpool if there are not 606217c9d12eSMel Gorman */ 606333b8f84aSMike Kravetz if (hugetlb_acct_memory(h, gbl_reserve) < 0) 6064075a61d0SMina Almasry goto out_put_pages; 606517c9d12eSMel Gorman 606617c9d12eSMel Gorman /* 606717c9d12eSMel Gorman * Account for the reservations made. Shared mappings record regions 606817c9d12eSMel Gorman * that have reservations as they are shared by multiple VMAs. 606917c9d12eSMel Gorman * When the last VMA disappears, the region map says how much 607017c9d12eSMel Gorman * the reservation was and the page cache tells how much of 607117c9d12eSMel Gorman * the reservation was consumed. Private mappings are per-VMA and 607217c9d12eSMel Gorman * only the consumed reservations are tracked. When the VMA 607317c9d12eSMel Gorman * disappears, the original reservation is the VMA size and the 607417c9d12eSMel Gorman * consumed reservations are stored in the map. Hence, nothing 607517c9d12eSMel Gorman * else has to be done for private mappings here 607617c9d12eSMel Gorman */ 607733039678SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) { 6078075a61d0SMina Almasry add = region_add(resv_map, from, to, regions_needed, h, h_cg); 607933039678SMike Kravetz 60800db9d74eSMina Almasry if (unlikely(add < 0)) { 60810db9d74eSMina Almasry hugetlb_acct_memory(h, -gbl_reserve); 6082075a61d0SMina Almasry goto out_put_pages; 60830db9d74eSMina Almasry } else if (unlikely(chg > add)) { 608433039678SMike Kravetz /* 608533039678SMike Kravetz * pages in this range were added to the reserve 608633039678SMike Kravetz * map between region_chg and region_add. This 608733039678SMike Kravetz * indicates a race with alloc_huge_page. Adjust 608833039678SMike Kravetz * the subpool and reserve counts modified above 608933039678SMike Kravetz * based on the difference. 609033039678SMike Kravetz */ 609133039678SMike Kravetz long rsv_adjust; 609233039678SMike Kravetz 6093d85aecf2SMiaohe Lin /* 6094d85aecf2SMiaohe Lin * hugetlb_cgroup_uncharge_cgroup_rsvd() will put the 6095d85aecf2SMiaohe Lin * reference to h_cg->css. See comment below for detail. 6096d85aecf2SMiaohe Lin */ 6097075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd( 6098075a61d0SMina Almasry hstate_index(h), 6099075a61d0SMina Almasry (chg - add) * pages_per_huge_page(h), h_cg); 6100075a61d0SMina Almasry 610133039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 610233039678SMike Kravetz chg - add); 610333039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 6104d85aecf2SMiaohe Lin } else if (h_cg) { 6105d85aecf2SMiaohe Lin /* 6106d85aecf2SMiaohe Lin * The file_regions will hold their own reference to 6107d85aecf2SMiaohe Lin * h_cg->css. So we should release the reference held 6108d85aecf2SMiaohe Lin * via hugetlb_cgroup_charge_cgroup_rsvd() when we are 6109d85aecf2SMiaohe Lin * done. 6110d85aecf2SMiaohe Lin */ 6111d85aecf2SMiaohe Lin hugetlb_cgroup_put_rsvd_cgroup(h_cg); 611233039678SMike Kravetz } 611333039678SMike Kravetz } 611433b8f84aSMike Kravetz return true; 611533b8f84aSMike Kravetz 6116075a61d0SMina Almasry out_put_pages: 6117075a61d0SMina Almasry /* put back original number of pages, chg */ 6118075a61d0SMina Almasry (void)hugepage_subpool_put_pages(spool, chg); 6119075a61d0SMina Almasry out_uncharge_cgroup: 6120075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h), 6121075a61d0SMina Almasry chg * pages_per_huge_page(h), h_cg); 6122c50ac050SDave Hansen out_err: 61235e911373SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) 61240db9d74eSMina Almasry /* Only call region_abort if the region_chg succeeded but the 61250db9d74eSMina Almasry * region_add failed or didn't run. 61260db9d74eSMina Almasry */ 61270db9d74eSMina Almasry if (chg >= 0 && add < 0) 61280db9d74eSMina Almasry region_abort(resv_map, from, to, regions_needed); 6129f031dd27SJoonsoo Kim if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 6130f031dd27SJoonsoo Kim kref_put(&resv_map->refs, resv_map_release); 613133b8f84aSMike Kravetz return false; 6132a43a8c39SChen, Kenneth W } 6133a43a8c39SChen, Kenneth W 6134b5cec28dSMike Kravetz long hugetlb_unreserve_pages(struct inode *inode, long start, long end, 6135b5cec28dSMike Kravetz long freed) 6136a43a8c39SChen, Kenneth W { 6137a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 61384e35f483SJoonsoo Kim struct resv_map *resv_map = inode_resv_map(inode); 61399119a41eSJoonsoo Kim long chg = 0; 614090481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 61411c5ecae3SMike Kravetz long gbl_reserve; 614245c682a6SKen Chen 6143f27a5136SMike Kravetz /* 6144f27a5136SMike Kravetz * Since this routine can be called in the evict inode path for all 6145f27a5136SMike Kravetz * hugetlbfs inodes, resv_map could be NULL. 6146f27a5136SMike Kravetz */ 6147b5cec28dSMike Kravetz if (resv_map) { 6148b5cec28dSMike Kravetz chg = region_del(resv_map, start, end); 6149b5cec28dSMike Kravetz /* 6150b5cec28dSMike Kravetz * region_del() can fail in the rare case where a region 6151b5cec28dSMike Kravetz * must be split and another region descriptor can not be 6152b5cec28dSMike Kravetz * allocated. If end == LONG_MAX, it will not fail. 6153b5cec28dSMike Kravetz */ 6154b5cec28dSMike Kravetz if (chg < 0) 6155b5cec28dSMike Kravetz return chg; 6156b5cec28dSMike Kravetz } 6157b5cec28dSMike Kravetz 615845c682a6SKen Chen spin_lock(&inode->i_lock); 6159e4c6f8beSEric Sandeen inode->i_blocks -= (blocks_per_huge_page(h) * freed); 616045c682a6SKen Chen spin_unlock(&inode->i_lock); 616145c682a6SKen Chen 61621c5ecae3SMike Kravetz /* 61631c5ecae3SMike Kravetz * If the subpool has a minimum size, the number of global 61641c5ecae3SMike Kravetz * reservations to be released may be adjusted. 6165dddf31a4SMiaohe Lin * 6166dddf31a4SMiaohe Lin * Note that !resv_map implies freed == 0. So (chg - freed) 6167dddf31a4SMiaohe Lin * won't go negative. 61681c5ecae3SMike Kravetz */ 61691c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed)); 61701c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 6171b5cec28dSMike Kravetz 6172b5cec28dSMike Kravetz return 0; 6173a43a8c39SChen, Kenneth W } 617493f70f90SNaoya Horiguchi 61753212b535SSteve Capper #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 61763212b535SSteve Capper static unsigned long page_table_shareable(struct vm_area_struct *svma, 61773212b535SSteve Capper struct vm_area_struct *vma, 61783212b535SSteve Capper unsigned long addr, pgoff_t idx) 61793212b535SSteve Capper { 61803212b535SSteve Capper unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + 61813212b535SSteve Capper svma->vm_start; 61823212b535SSteve Capper unsigned long sbase = saddr & PUD_MASK; 61833212b535SSteve Capper unsigned long s_end = sbase + PUD_SIZE; 61843212b535SSteve Capper 61853212b535SSteve Capper /* Allow segments to share if only one is marked locked */ 6186de60f5f1SEric B Munson unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; 6187de60f5f1SEric B Munson unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK; 61883212b535SSteve Capper 61893212b535SSteve Capper /* 61903212b535SSteve Capper * match the virtual addresses, permission and the alignment of the 61913212b535SSteve Capper * page table page. 61923212b535SSteve Capper */ 61933212b535SSteve Capper if (pmd_index(addr) != pmd_index(saddr) || 61943212b535SSteve Capper vm_flags != svm_flags || 619507e51edfSMiaohe Lin !range_in_vma(svma, sbase, s_end)) 61963212b535SSteve Capper return 0; 61973212b535SSteve Capper 61983212b535SSteve Capper return saddr; 61993212b535SSteve Capper } 62003212b535SSteve Capper 620131aafb45SNicholas Krause static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr) 62023212b535SSteve Capper { 62033212b535SSteve Capper unsigned long base = addr & PUD_MASK; 62043212b535SSteve Capper unsigned long end = base + PUD_SIZE; 62053212b535SSteve Capper 62063212b535SSteve Capper /* 62073212b535SSteve Capper * check on proper vm_flags and page table alignment 62083212b535SSteve Capper */ 6209017b1660SMike Kravetz if (vma->vm_flags & VM_MAYSHARE && range_in_vma(vma, base, end)) 621031aafb45SNicholas Krause return true; 621131aafb45SNicholas Krause return false; 62123212b535SSteve Capper } 62133212b535SSteve Capper 6214c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 6215c1991e07SPeter Xu { 6216c1991e07SPeter Xu #ifdef CONFIG_USERFAULTFD 6217c1991e07SPeter Xu if (uffd_disable_huge_pmd_share(vma)) 6218c1991e07SPeter Xu return false; 6219c1991e07SPeter Xu #endif 6220c1991e07SPeter Xu return vma_shareable(vma, addr); 6221c1991e07SPeter Xu } 6222c1991e07SPeter Xu 62233212b535SSteve Capper /* 6224017b1660SMike Kravetz * Determine if start,end range within vma could be mapped by shared pmd. 6225017b1660SMike Kravetz * If yes, adjust start and end to cover range associated with possible 6226017b1660SMike Kravetz * shared pmd mappings. 6227017b1660SMike Kravetz */ 6228017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 6229017b1660SMike Kravetz unsigned long *start, unsigned long *end) 6230017b1660SMike Kravetz { 6231a1ba9da8SLi Xinhai unsigned long v_start = ALIGN(vma->vm_start, PUD_SIZE), 6232a1ba9da8SLi Xinhai v_end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 6233017b1660SMike Kravetz 6234a1ba9da8SLi Xinhai /* 6235f0953a1bSIngo Molnar * vma needs to span at least one aligned PUD size, and the range 6236f0953a1bSIngo Molnar * must be at least partially within in. 6237a1ba9da8SLi Xinhai */ 6238a1ba9da8SLi Xinhai if (!(vma->vm_flags & VM_MAYSHARE) || !(v_end > v_start) || 6239a1ba9da8SLi Xinhai (*end <= v_start) || (*start >= v_end)) 6240017b1660SMike Kravetz return; 6241017b1660SMike Kravetz 624275802ca6SPeter Xu /* Extend the range to be PUD aligned for a worst case scenario */ 6243a1ba9da8SLi Xinhai if (*start > v_start) 6244a1ba9da8SLi Xinhai *start = ALIGN_DOWN(*start, PUD_SIZE); 6245017b1660SMike Kravetz 6246a1ba9da8SLi Xinhai if (*end < v_end) 6247a1ba9da8SLi Xinhai *end = ALIGN(*end, PUD_SIZE); 6248017b1660SMike Kravetz } 6249017b1660SMike Kravetz 6250017b1660SMike Kravetz /* 62513212b535SSteve Capper * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() 62523212b535SSteve Capper * and returns the corresponding pte. While this is not necessary for the 62533212b535SSteve Capper * !shared pmd case because we can allocate the pmd later as well, it makes the 6254c0d0381aSMike Kravetz * code much cleaner. 6255c0d0381aSMike Kravetz * 62560bf7b64eSMike Kravetz * This routine must be called with i_mmap_rwsem held in at least read mode if 62570bf7b64eSMike Kravetz * sharing is possible. For hugetlbfs, this prevents removal of any page 62580bf7b64eSMike Kravetz * table entries associated with the address space. This is important as we 62590bf7b64eSMike Kravetz * are setting up sharing based on existing page table entries (mappings). 62600bf7b64eSMike Kravetz * 62610bf7b64eSMike Kravetz * NOTE: This routine is only called from huge_pte_alloc. Some callers of 62620bf7b64eSMike Kravetz * huge_pte_alloc know that sharing is not possible and do not take 62630bf7b64eSMike Kravetz * i_mmap_rwsem as a performance optimization. This is handled by the 62640bf7b64eSMike Kravetz * if !vma_shareable check at the beginning of the routine. i_mmap_rwsem is 62650bf7b64eSMike Kravetz * only required for subsequent processing. 62663212b535SSteve Capper */ 6267aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 6268aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 62693212b535SSteve Capper { 62703212b535SSteve Capper struct address_space *mapping = vma->vm_file->f_mapping; 62713212b535SSteve Capper pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + 62723212b535SSteve Capper vma->vm_pgoff; 62733212b535SSteve Capper struct vm_area_struct *svma; 62743212b535SSteve Capper unsigned long saddr; 62753212b535SSteve Capper pte_t *spte = NULL; 62763212b535SSteve Capper pte_t *pte; 6277cb900f41SKirill A. Shutemov spinlock_t *ptl; 62783212b535SSteve Capper 62790bf7b64eSMike Kravetz i_mmap_assert_locked(mapping); 62803212b535SSteve Capper vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { 62813212b535SSteve Capper if (svma == vma) 62823212b535SSteve Capper continue; 62833212b535SSteve Capper 62843212b535SSteve Capper saddr = page_table_shareable(svma, vma, addr, idx); 62853212b535SSteve Capper if (saddr) { 62867868a208SPunit Agrawal spte = huge_pte_offset(svma->vm_mm, saddr, 62877868a208SPunit Agrawal vma_mmu_pagesize(svma)); 62883212b535SSteve Capper if (spte) { 62893212b535SSteve Capper get_page(virt_to_page(spte)); 62903212b535SSteve Capper break; 62913212b535SSteve Capper } 62923212b535SSteve Capper } 62933212b535SSteve Capper } 62943212b535SSteve Capper 62953212b535SSteve Capper if (!spte) 62963212b535SSteve Capper goto out; 62973212b535SSteve Capper 62988bea8052SAneesh Kumar K.V ptl = huge_pte_lock(hstate_vma(vma), mm, spte); 6299dc6c9a35SKirill A. Shutemov if (pud_none(*pud)) { 63003212b535SSteve Capper pud_populate(mm, pud, 63013212b535SSteve Capper (pmd_t *)((unsigned long)spte & PAGE_MASK)); 6302c17b1f42SKirill A. Shutemov mm_inc_nr_pmds(mm); 6303dc6c9a35SKirill A. Shutemov } else { 63043212b535SSteve Capper put_page(virt_to_page(spte)); 6305dc6c9a35SKirill A. Shutemov } 6306cb900f41SKirill A. Shutemov spin_unlock(ptl); 63073212b535SSteve Capper out: 63083212b535SSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 63093212b535SSteve Capper return pte; 63103212b535SSteve Capper } 63113212b535SSteve Capper 63123212b535SSteve Capper /* 63133212b535SSteve Capper * unmap huge page backed by shared pte. 63143212b535SSteve Capper * 63153212b535SSteve Capper * Hugetlb pte page is ref counted at the time of mapping. If pte is shared 63163212b535SSteve Capper * indicated by page_count > 1, unmap is achieved by clearing pud and 63173212b535SSteve Capper * decrementing the ref count. If count == 1, the pte page is not shared. 63183212b535SSteve Capper * 6319c0d0381aSMike Kravetz * Called with page table lock held and i_mmap_rwsem held in write mode. 63203212b535SSteve Capper * 63213212b535SSteve Capper * returns: 1 successfully unmapped a shared pte page 63223212b535SSteve Capper * 0 the underlying pte page is not shared, or it is the last user 63233212b535SSteve Capper */ 632434ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 632534ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 63263212b535SSteve Capper { 63273212b535SSteve Capper pgd_t *pgd = pgd_offset(mm, *addr); 6328c2febafcSKirill A. Shutemov p4d_t *p4d = p4d_offset(pgd, *addr); 6329c2febafcSKirill A. Shutemov pud_t *pud = pud_offset(p4d, *addr); 63303212b535SSteve Capper 633134ae204fSMike Kravetz i_mmap_assert_write_locked(vma->vm_file->f_mapping); 63323212b535SSteve Capper BUG_ON(page_count(virt_to_page(ptep)) == 0); 63333212b535SSteve Capper if (page_count(virt_to_page(ptep)) == 1) 63343212b535SSteve Capper return 0; 63353212b535SSteve Capper 63363212b535SSteve Capper pud_clear(pud); 63373212b535SSteve Capper put_page(virt_to_page(ptep)); 6338dc6c9a35SKirill A. Shutemov mm_dec_nr_pmds(mm); 63393212b535SSteve Capper *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE; 63403212b535SSteve Capper return 1; 63413212b535SSteve Capper } 6342c1991e07SPeter Xu 63439e5fc74cSSteve Capper #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 6344aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 6345aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 63469e5fc74cSSteve Capper { 63479e5fc74cSSteve Capper return NULL; 63489e5fc74cSSteve Capper } 6349e81f2d22SZhang Zhen 635034ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 635134ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 6352e81f2d22SZhang Zhen { 6353e81f2d22SZhang Zhen return 0; 6354e81f2d22SZhang Zhen } 6355017b1660SMike Kravetz 6356017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 6357017b1660SMike Kravetz unsigned long *start, unsigned long *end) 6358017b1660SMike Kravetz { 6359017b1660SMike Kravetz } 6360c1991e07SPeter Xu 6361c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 6362c1991e07SPeter Xu { 6363c1991e07SPeter Xu return false; 6364c1991e07SPeter Xu } 63653212b535SSteve Capper #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 63663212b535SSteve Capper 63679e5fc74cSSteve Capper #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB 6368aec44e0fSPeter Xu pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, 63699e5fc74cSSteve Capper unsigned long addr, unsigned long sz) 63709e5fc74cSSteve Capper { 63719e5fc74cSSteve Capper pgd_t *pgd; 6372c2febafcSKirill A. Shutemov p4d_t *p4d; 63739e5fc74cSSteve Capper pud_t *pud; 63749e5fc74cSSteve Capper pte_t *pte = NULL; 63759e5fc74cSSteve Capper 63769e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 6377f4f0a3d8SKirill A. Shutemov p4d = p4d_alloc(mm, pgd, addr); 6378f4f0a3d8SKirill A. Shutemov if (!p4d) 6379f4f0a3d8SKirill A. Shutemov return NULL; 6380c2febafcSKirill A. Shutemov pud = pud_alloc(mm, p4d, addr); 63819e5fc74cSSteve Capper if (pud) { 63829e5fc74cSSteve Capper if (sz == PUD_SIZE) { 63839e5fc74cSSteve Capper pte = (pte_t *)pud; 63849e5fc74cSSteve Capper } else { 63859e5fc74cSSteve Capper BUG_ON(sz != PMD_SIZE); 6386c1991e07SPeter Xu if (want_pmd_share(vma, addr) && pud_none(*pud)) 6387aec44e0fSPeter Xu pte = huge_pmd_share(mm, vma, addr, pud); 63889e5fc74cSSteve Capper else 63899e5fc74cSSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 63909e5fc74cSSteve Capper } 63919e5fc74cSSteve Capper } 63924e666314SMichal Hocko BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte)); 63939e5fc74cSSteve Capper 63949e5fc74cSSteve Capper return pte; 63959e5fc74cSSteve Capper } 63969e5fc74cSSteve Capper 63979b19df29SPunit Agrawal /* 63989b19df29SPunit Agrawal * huge_pte_offset() - Walk the page table to resolve the hugepage 63999b19df29SPunit Agrawal * entry at address @addr 64009b19df29SPunit Agrawal * 64018ac0b81aSLi Xinhai * Return: Pointer to page table entry (PUD or PMD) for 64028ac0b81aSLi Xinhai * address @addr, or NULL if a !p*d_present() entry is encountered and the 64039b19df29SPunit Agrawal * size @sz doesn't match the hugepage size at this level of the page 64049b19df29SPunit Agrawal * table. 64059b19df29SPunit Agrawal */ 64067868a208SPunit Agrawal pte_t *huge_pte_offset(struct mm_struct *mm, 64077868a208SPunit Agrawal unsigned long addr, unsigned long sz) 64089e5fc74cSSteve Capper { 64099e5fc74cSSteve Capper pgd_t *pgd; 6410c2febafcSKirill A. Shutemov p4d_t *p4d; 64118ac0b81aSLi Xinhai pud_t *pud; 64128ac0b81aSLi Xinhai pmd_t *pmd; 64139e5fc74cSSteve Capper 64149e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 6415c2febafcSKirill A. Shutemov if (!pgd_present(*pgd)) 6416c2febafcSKirill A. Shutemov return NULL; 6417c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, addr); 6418c2febafcSKirill A. Shutemov if (!p4d_present(*p4d)) 6419c2febafcSKirill A. Shutemov return NULL; 64209b19df29SPunit Agrawal 6421c2febafcSKirill A. Shutemov pud = pud_offset(p4d, addr); 64228ac0b81aSLi Xinhai if (sz == PUD_SIZE) 64238ac0b81aSLi Xinhai /* must be pud huge, non-present or none */ 64249e5fc74cSSteve Capper return (pte_t *)pud; 64258ac0b81aSLi Xinhai if (!pud_present(*pud)) 64268ac0b81aSLi Xinhai return NULL; 64278ac0b81aSLi Xinhai /* must have a valid entry and size to go further */ 64289b19df29SPunit Agrawal 64299e5fc74cSSteve Capper pmd = pmd_offset(pud, addr); 64308ac0b81aSLi Xinhai /* must be pmd huge, non-present or none */ 64319e5fc74cSSteve Capper return (pte_t *)pmd; 64329e5fc74cSSteve Capper } 64339e5fc74cSSteve Capper 643461f77edaSNaoya Horiguchi #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ 643561f77edaSNaoya Horiguchi 643661f77edaSNaoya Horiguchi /* 643761f77edaSNaoya Horiguchi * These functions are overwritable if your architecture needs its own 643861f77edaSNaoya Horiguchi * behavior. 643961f77edaSNaoya Horiguchi */ 644061f77edaSNaoya Horiguchi struct page * __weak 644161f77edaSNaoya Horiguchi follow_huge_addr(struct mm_struct *mm, unsigned long address, 644261f77edaSNaoya Horiguchi int write) 644361f77edaSNaoya Horiguchi { 644461f77edaSNaoya Horiguchi return ERR_PTR(-EINVAL); 644561f77edaSNaoya Horiguchi } 644661f77edaSNaoya Horiguchi 644761f77edaSNaoya Horiguchi struct page * __weak 64484dc71451SAneesh Kumar K.V follow_huge_pd(struct vm_area_struct *vma, 64494dc71451SAneesh Kumar K.V unsigned long address, hugepd_t hpd, int flags, int pdshift) 64504dc71451SAneesh Kumar K.V { 64514dc71451SAneesh Kumar K.V WARN(1, "hugepd follow called with no support for hugepage directory format\n"); 64524dc71451SAneesh Kumar K.V return NULL; 64534dc71451SAneesh Kumar K.V } 64544dc71451SAneesh Kumar K.V 64554dc71451SAneesh Kumar K.V struct page * __weak 64569e5fc74cSSteve Capper follow_huge_pmd(struct mm_struct *mm, unsigned long address, 6457e66f17ffSNaoya Horiguchi pmd_t *pmd, int flags) 64589e5fc74cSSteve Capper { 6459e66f17ffSNaoya Horiguchi struct page *page = NULL; 6460e66f17ffSNaoya Horiguchi spinlock_t *ptl; 6461c9d398faSNaoya Horiguchi pte_t pte; 64623faa52c0SJohn Hubbard 64633faa52c0SJohn Hubbard /* FOLL_GET and FOLL_PIN are mutually exclusive. */ 64643faa52c0SJohn Hubbard if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == 64653faa52c0SJohn Hubbard (FOLL_PIN | FOLL_GET))) 64663faa52c0SJohn Hubbard return NULL; 64673faa52c0SJohn Hubbard 6468e66f17ffSNaoya Horiguchi retry: 6469e66f17ffSNaoya Horiguchi ptl = pmd_lockptr(mm, pmd); 6470e66f17ffSNaoya Horiguchi spin_lock(ptl); 6471e66f17ffSNaoya Horiguchi /* 6472e66f17ffSNaoya Horiguchi * make sure that the address range covered by this pmd is not 6473e66f17ffSNaoya Horiguchi * unmapped from other threads. 6474e66f17ffSNaoya Horiguchi */ 6475e66f17ffSNaoya Horiguchi if (!pmd_huge(*pmd)) 6476e66f17ffSNaoya Horiguchi goto out; 6477c9d398faSNaoya Horiguchi pte = huge_ptep_get((pte_t *)pmd); 6478c9d398faSNaoya Horiguchi if (pte_present(pte)) { 647997534127SGerald Schaefer page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT); 64803faa52c0SJohn Hubbard /* 64813faa52c0SJohn Hubbard * try_grab_page() should always succeed here, because: a) we 64823faa52c0SJohn Hubbard * hold the pmd (ptl) lock, and b) we've just checked that the 64833faa52c0SJohn Hubbard * huge pmd (head) page is present in the page tables. The ptl 64843faa52c0SJohn Hubbard * prevents the head page and tail pages from being rearranged 64853faa52c0SJohn Hubbard * in any way. So this page must be available at this point, 64863faa52c0SJohn Hubbard * unless the page refcount overflowed: 64873faa52c0SJohn Hubbard */ 64883faa52c0SJohn Hubbard if (WARN_ON_ONCE(!try_grab_page(page, flags))) { 64893faa52c0SJohn Hubbard page = NULL; 64903faa52c0SJohn Hubbard goto out; 64913faa52c0SJohn Hubbard } 6492e66f17ffSNaoya Horiguchi } else { 6493c9d398faSNaoya Horiguchi if (is_hugetlb_entry_migration(pte)) { 6494e66f17ffSNaoya Horiguchi spin_unlock(ptl); 6495e66f17ffSNaoya Horiguchi __migration_entry_wait(mm, (pte_t *)pmd, ptl); 6496e66f17ffSNaoya Horiguchi goto retry; 6497e66f17ffSNaoya Horiguchi } 6498e66f17ffSNaoya Horiguchi /* 6499e66f17ffSNaoya Horiguchi * hwpoisoned entry is treated as no_page_table in 6500e66f17ffSNaoya Horiguchi * follow_page_mask(). 6501e66f17ffSNaoya Horiguchi */ 6502e66f17ffSNaoya Horiguchi } 6503e66f17ffSNaoya Horiguchi out: 6504e66f17ffSNaoya Horiguchi spin_unlock(ptl); 65059e5fc74cSSteve Capper return page; 65069e5fc74cSSteve Capper } 65079e5fc74cSSteve Capper 650861f77edaSNaoya Horiguchi struct page * __weak 65099e5fc74cSSteve Capper follow_huge_pud(struct mm_struct *mm, unsigned long address, 6510e66f17ffSNaoya Horiguchi pud_t *pud, int flags) 65119e5fc74cSSteve Capper { 65123faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 6513e66f17ffSNaoya Horiguchi return NULL; 65149e5fc74cSSteve Capper 6515e66f17ffSNaoya Horiguchi return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); 65169e5fc74cSSteve Capper } 65179e5fc74cSSteve Capper 6518faaa5b62SAnshuman Khandual struct page * __weak 6519faaa5b62SAnshuman Khandual follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) 6520faaa5b62SAnshuman Khandual { 65213faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 6522faaa5b62SAnshuman Khandual return NULL; 6523faaa5b62SAnshuman Khandual 6524faaa5b62SAnshuman Khandual return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); 6525faaa5b62SAnshuman Khandual } 6526faaa5b62SAnshuman Khandual 652731caf665SNaoya Horiguchi bool isolate_huge_page(struct page *page, struct list_head *list) 652831caf665SNaoya Horiguchi { 6529bcc54222SNaoya Horiguchi bool ret = true; 6530bcc54222SNaoya Horiguchi 6531db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 65328f251a3dSMike Kravetz if (!PageHeadHuge(page) || 65338f251a3dSMike Kravetz !HPageMigratable(page) || 65340eb2df2bSMuchun Song !get_page_unless_zero(page)) { 6535bcc54222SNaoya Horiguchi ret = false; 6536bcc54222SNaoya Horiguchi goto unlock; 6537bcc54222SNaoya Horiguchi } 65388f251a3dSMike Kravetz ClearHPageMigratable(page); 653931caf665SNaoya Horiguchi list_move_tail(&page->lru, list); 6540bcc54222SNaoya Horiguchi unlock: 6541db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 6542bcc54222SNaoya Horiguchi return ret; 654331caf665SNaoya Horiguchi } 654431caf665SNaoya Horiguchi 654525182f05SNaoya Horiguchi int get_hwpoison_huge_page(struct page *page, bool *hugetlb) 654625182f05SNaoya Horiguchi { 654725182f05SNaoya Horiguchi int ret = 0; 654825182f05SNaoya Horiguchi 654925182f05SNaoya Horiguchi *hugetlb = false; 655025182f05SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 655125182f05SNaoya Horiguchi if (PageHeadHuge(page)) { 655225182f05SNaoya Horiguchi *hugetlb = true; 655325182f05SNaoya Horiguchi if (HPageFreed(page) || HPageMigratable(page)) 655425182f05SNaoya Horiguchi ret = get_page_unless_zero(page); 65550ed950d1SNaoya Horiguchi else 65560ed950d1SNaoya Horiguchi ret = -EBUSY; 655725182f05SNaoya Horiguchi } 655825182f05SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 655925182f05SNaoya Horiguchi return ret; 656025182f05SNaoya Horiguchi } 656125182f05SNaoya Horiguchi 656231caf665SNaoya Horiguchi void putback_active_hugepage(struct page *page) 656331caf665SNaoya Horiguchi { 6564db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 65658f251a3dSMike Kravetz SetHPageMigratable(page); 656631caf665SNaoya Horiguchi list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); 6567db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 656831caf665SNaoya Horiguchi put_page(page); 656931caf665SNaoya Horiguchi } 6570ab5ac90aSMichal Hocko 6571ab5ac90aSMichal Hocko void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason) 6572ab5ac90aSMichal Hocko { 6573ab5ac90aSMichal Hocko struct hstate *h = page_hstate(oldpage); 6574ab5ac90aSMichal Hocko 6575ab5ac90aSMichal Hocko hugetlb_cgroup_migrate(oldpage, newpage); 6576ab5ac90aSMichal Hocko set_page_owner_migrate_reason(newpage, reason); 6577ab5ac90aSMichal Hocko 6578ab5ac90aSMichal Hocko /* 6579ab5ac90aSMichal Hocko * transfer temporary state of the new huge page. This is 6580ab5ac90aSMichal Hocko * reverse to other transitions because the newpage is going to 6581ab5ac90aSMichal Hocko * be final while the old one will be freed so it takes over 6582ab5ac90aSMichal Hocko * the temporary status. 6583ab5ac90aSMichal Hocko * 6584ab5ac90aSMichal Hocko * Also note that we have to transfer the per-node surplus state 6585ab5ac90aSMichal Hocko * here as well otherwise the global surplus count will not match 6586ab5ac90aSMichal Hocko * the per-node's. 6587ab5ac90aSMichal Hocko */ 65889157c311SMike Kravetz if (HPageTemporary(newpage)) { 6589ab5ac90aSMichal Hocko int old_nid = page_to_nid(oldpage); 6590ab5ac90aSMichal Hocko int new_nid = page_to_nid(newpage); 6591ab5ac90aSMichal Hocko 65929157c311SMike Kravetz SetHPageTemporary(oldpage); 65939157c311SMike Kravetz ClearHPageTemporary(newpage); 6594ab5ac90aSMichal Hocko 65955af1ab1dSMiaohe Lin /* 65965af1ab1dSMiaohe Lin * There is no need to transfer the per-node surplus state 65975af1ab1dSMiaohe Lin * when we do not cross the node. 65985af1ab1dSMiaohe Lin */ 65995af1ab1dSMiaohe Lin if (new_nid == old_nid) 66005af1ab1dSMiaohe Lin return; 6601db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 6602ab5ac90aSMichal Hocko if (h->surplus_huge_pages_node[old_nid]) { 6603ab5ac90aSMichal Hocko h->surplus_huge_pages_node[old_nid]--; 6604ab5ac90aSMichal Hocko h->surplus_huge_pages_node[new_nid]++; 6605ab5ac90aSMichal Hocko } 6606db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 6607ab5ac90aSMichal Hocko } 6608ab5ac90aSMichal Hocko } 6609cf11e85fSRoman Gushchin 66106dfeaff9SPeter Xu /* 66116dfeaff9SPeter Xu * This function will unconditionally remove all the shared pmd pgtable entries 66126dfeaff9SPeter Xu * within the specific vma for a hugetlbfs memory range. 66136dfeaff9SPeter Xu */ 66146dfeaff9SPeter Xu void hugetlb_unshare_all_pmds(struct vm_area_struct *vma) 66156dfeaff9SPeter Xu { 66166dfeaff9SPeter Xu struct hstate *h = hstate_vma(vma); 66176dfeaff9SPeter Xu unsigned long sz = huge_page_size(h); 66186dfeaff9SPeter Xu struct mm_struct *mm = vma->vm_mm; 66196dfeaff9SPeter Xu struct mmu_notifier_range range; 66206dfeaff9SPeter Xu unsigned long address, start, end; 66216dfeaff9SPeter Xu spinlock_t *ptl; 66226dfeaff9SPeter Xu pte_t *ptep; 66236dfeaff9SPeter Xu 66246dfeaff9SPeter Xu if (!(vma->vm_flags & VM_MAYSHARE)) 66256dfeaff9SPeter Xu return; 66266dfeaff9SPeter Xu 66276dfeaff9SPeter Xu start = ALIGN(vma->vm_start, PUD_SIZE); 66286dfeaff9SPeter Xu end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 66296dfeaff9SPeter Xu 66306dfeaff9SPeter Xu if (start >= end) 66316dfeaff9SPeter Xu return; 66326dfeaff9SPeter Xu 66336dfeaff9SPeter Xu /* 66346dfeaff9SPeter Xu * No need to call adjust_range_if_pmd_sharing_possible(), because 66356dfeaff9SPeter Xu * we have already done the PUD_SIZE alignment. 66366dfeaff9SPeter Xu */ 66376dfeaff9SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, 66386dfeaff9SPeter Xu start, end); 66396dfeaff9SPeter Xu mmu_notifier_invalidate_range_start(&range); 66406dfeaff9SPeter Xu i_mmap_lock_write(vma->vm_file->f_mapping); 66416dfeaff9SPeter Xu for (address = start; address < end; address += PUD_SIZE) { 66426dfeaff9SPeter Xu unsigned long tmp = address; 66436dfeaff9SPeter Xu 66446dfeaff9SPeter Xu ptep = huge_pte_offset(mm, address, sz); 66456dfeaff9SPeter Xu if (!ptep) 66466dfeaff9SPeter Xu continue; 66476dfeaff9SPeter Xu ptl = huge_pte_lock(h, mm, ptep); 66486dfeaff9SPeter Xu /* We don't want 'address' to be changed */ 66496dfeaff9SPeter Xu huge_pmd_unshare(mm, vma, &tmp, ptep); 66506dfeaff9SPeter Xu spin_unlock(ptl); 66516dfeaff9SPeter Xu } 66526dfeaff9SPeter Xu flush_hugetlb_tlb_range(vma, start, end); 66536dfeaff9SPeter Xu i_mmap_unlock_write(vma->vm_file->f_mapping); 66546dfeaff9SPeter Xu /* 66556dfeaff9SPeter Xu * No need to call mmu_notifier_invalidate_range(), see 66566dfeaff9SPeter Xu * Documentation/vm/mmu_notifier.rst. 66576dfeaff9SPeter Xu */ 66586dfeaff9SPeter Xu mmu_notifier_invalidate_range_end(&range); 66596dfeaff9SPeter Xu } 66606dfeaff9SPeter Xu 6661cf11e85fSRoman Gushchin #ifdef CONFIG_CMA 6662cf11e85fSRoman Gushchin static bool cma_reserve_called __initdata; 6663cf11e85fSRoman Gushchin 6664cf11e85fSRoman Gushchin static int __init cmdline_parse_hugetlb_cma(char *p) 6665cf11e85fSRoman Gushchin { 6666cf11e85fSRoman Gushchin hugetlb_cma_size = memparse(p, &p); 6667cf11e85fSRoman Gushchin return 0; 6668cf11e85fSRoman Gushchin } 6669cf11e85fSRoman Gushchin 6670cf11e85fSRoman Gushchin early_param("hugetlb_cma", cmdline_parse_hugetlb_cma); 6671cf11e85fSRoman Gushchin 6672cf11e85fSRoman Gushchin void __init hugetlb_cma_reserve(int order) 6673cf11e85fSRoman Gushchin { 6674cf11e85fSRoman Gushchin unsigned long size, reserved, per_node; 6675cf11e85fSRoman Gushchin int nid; 6676cf11e85fSRoman Gushchin 6677cf11e85fSRoman Gushchin cma_reserve_called = true; 6678cf11e85fSRoman Gushchin 6679cf11e85fSRoman Gushchin if (!hugetlb_cma_size) 6680cf11e85fSRoman Gushchin return; 6681cf11e85fSRoman Gushchin 6682cf11e85fSRoman Gushchin if (hugetlb_cma_size < (PAGE_SIZE << order)) { 6683cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n", 6684cf11e85fSRoman Gushchin (PAGE_SIZE << order) / SZ_1M); 6685a01f4390SMike Kravetz hugetlb_cma_size = 0; 6686cf11e85fSRoman Gushchin return; 6687cf11e85fSRoman Gushchin } 6688cf11e85fSRoman Gushchin 6689cf11e85fSRoman Gushchin /* 6690cf11e85fSRoman Gushchin * If 3 GB area is requested on a machine with 4 numa nodes, 6691cf11e85fSRoman Gushchin * let's allocate 1 GB on first three nodes and ignore the last one. 6692cf11e85fSRoman Gushchin */ 6693cf11e85fSRoman Gushchin per_node = DIV_ROUND_UP(hugetlb_cma_size, nr_online_nodes); 6694cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n", 6695cf11e85fSRoman Gushchin hugetlb_cma_size / SZ_1M, per_node / SZ_1M); 6696cf11e85fSRoman Gushchin 6697cf11e85fSRoman Gushchin reserved = 0; 6698cf11e85fSRoman Gushchin for_each_node_state(nid, N_ONLINE) { 6699cf11e85fSRoman Gushchin int res; 67002281f797SBarry Song char name[CMA_MAX_NAME]; 6701cf11e85fSRoman Gushchin 6702cf11e85fSRoman Gushchin size = min(per_node, hugetlb_cma_size - reserved); 6703cf11e85fSRoman Gushchin size = round_up(size, PAGE_SIZE << order); 6704cf11e85fSRoman Gushchin 67052281f797SBarry Song snprintf(name, sizeof(name), "hugetlb%d", nid); 6706a01f4390SMike Kravetz /* 6707a01f4390SMike Kravetz * Note that 'order per bit' is based on smallest size that 6708a01f4390SMike Kravetz * may be returned to CMA allocator in the case of 6709a01f4390SMike Kravetz * huge page demotion. 6710a01f4390SMike Kravetz */ 6711a01f4390SMike Kravetz res = cma_declare_contiguous_nid(0, size, 0, 6712a01f4390SMike Kravetz PAGE_SIZE << HUGETLB_PAGE_ORDER, 671329d0f41dSBarry Song 0, false, name, 6714cf11e85fSRoman Gushchin &hugetlb_cma[nid], nid); 6715cf11e85fSRoman Gushchin if (res) { 6716cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: reservation failed: err %d, node %d", 6717cf11e85fSRoman Gushchin res, nid); 6718cf11e85fSRoman Gushchin continue; 6719cf11e85fSRoman Gushchin } 6720cf11e85fSRoman Gushchin 6721cf11e85fSRoman Gushchin reserved += size; 6722cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserved %lu MiB on node %d\n", 6723cf11e85fSRoman Gushchin size / SZ_1M, nid); 6724cf11e85fSRoman Gushchin 6725cf11e85fSRoman Gushchin if (reserved >= hugetlb_cma_size) 6726cf11e85fSRoman Gushchin break; 6727cf11e85fSRoman Gushchin } 6728a01f4390SMike Kravetz 6729a01f4390SMike Kravetz if (!reserved) 6730a01f4390SMike Kravetz /* 6731a01f4390SMike Kravetz * hugetlb_cma_size is used to determine if allocations from 6732a01f4390SMike Kravetz * cma are possible. Set to zero if no cma regions are set up. 6733a01f4390SMike Kravetz */ 6734a01f4390SMike Kravetz hugetlb_cma_size = 0; 6735cf11e85fSRoman Gushchin } 6736cf11e85fSRoman Gushchin 6737cf11e85fSRoman Gushchin void __init hugetlb_cma_check(void) 6738cf11e85fSRoman Gushchin { 6739cf11e85fSRoman Gushchin if (!hugetlb_cma_size || cma_reserve_called) 6740cf11e85fSRoman Gushchin return; 6741cf11e85fSRoman Gushchin 6742cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: the option isn't supported by current arch\n"); 6743cf11e85fSRoman Gushchin } 6744cf11e85fSRoman Gushchin 6745cf11e85fSRoman Gushchin #endif /* CONFIG_CMA */ 6746