1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * Generic hugetlb support. 46d49e352SNadia Yvette Chambers * (C) Nadia Yvette Chambers, April 2004 51da177e4SLinus Torvalds */ 61da177e4SLinus Torvalds #include <linux/list.h> 71da177e4SLinus Torvalds #include <linux/init.h> 81da177e4SLinus Torvalds #include <linux/mm.h> 9e1759c21SAlexey Dobriyan #include <linux/seq_file.h> 101da177e4SLinus Torvalds #include <linux/sysctl.h> 111da177e4SLinus Torvalds #include <linux/highmem.h> 12cddb8a5cSAndrea Arcangeli #include <linux/mmu_notifier.h> 131da177e4SLinus Torvalds #include <linux/nodemask.h> 1463551ae0SDavid Gibson #include <linux/pagemap.h> 155da7ca86SChristoph Lameter #include <linux/mempolicy.h> 163b32123dSGideon Israel Dsouza #include <linux/compiler.h> 17aea47ff3SChristoph Lameter #include <linux/cpuset.h> 183935baa9SDavid Gibson #include <linux/mutex.h> 1997ad1087SMike Rapoport #include <linux/memblock.h> 20a3437870SNishanth Aravamudan #include <linux/sysfs.h> 215a0e3ad6STejun Heo #include <linux/slab.h> 22bbe88753SJoonsoo Kim #include <linux/sched/mm.h> 2363489f8eSMike Kravetz #include <linux/mmdebug.h> 24174cd4b1SIngo Molnar #include <linux/sched/signal.h> 250fe6e20bSNaoya Horiguchi #include <linux/rmap.h> 26c6247f72SMatthew Wilcox #include <linux/string_helpers.h> 27fd6a03edSNaoya Horiguchi #include <linux/swap.h> 28fd6a03edSNaoya Horiguchi #include <linux/swapops.h> 298382d914SDavidlohr Bueso #include <linux/jhash.h> 3098fa15f3SAnshuman Khandual #include <linux/numa.h> 31c77c0a8aSWaiman Long #include <linux/llist.h> 32cf11e85fSRoman Gushchin #include <linux/cma.h> 338cc5fcbbSMina Almasry #include <linux/migrate.h> 34f9317f77SMike Kravetz #include <linux/nospec.h> 35d6606683SLinus Torvalds 3663551ae0SDavid Gibson #include <asm/page.h> 37ca15ca40SMike Rapoport #include <asm/pgalloc.h> 3824669e58SAneesh Kumar K.V #include <asm/tlb.h> 3963551ae0SDavid Gibson 4024669e58SAneesh Kumar K.V #include <linux/io.h> 4163551ae0SDavid Gibson #include <linux/hugetlb.h> 429dd540e2SAneesh Kumar K.V #include <linux/hugetlb_cgroup.h> 439a305230SLee Schermerhorn #include <linux/node.h> 44ab5ac90aSMichal Hocko #include <linux/page_owner.h> 457835e98bSNick Piggin #include "internal.h" 46f41f2ed4SMuchun Song #include "hugetlb_vmemmap.h" 471da177e4SLinus Torvalds 48c3f38a38SAneesh Kumar K.V int hugetlb_max_hstate __read_mostly; 49e5ff2159SAndi Kleen unsigned int default_hstate_idx; 50e5ff2159SAndi Kleen struct hstate hstates[HUGE_MAX_HSTATE]; 51cf11e85fSRoman Gushchin 52dbda8feaSBarry Song #ifdef CONFIG_CMA 53cf11e85fSRoman Gushchin static struct cma *hugetlb_cma[MAX_NUMNODES]; 5438e719abSBaolin Wang static unsigned long hugetlb_cma_size_in_node[MAX_NUMNODES] __initdata; 55a01f4390SMike Kravetz static bool hugetlb_cma_page(struct page *page, unsigned int order) 56a01f4390SMike Kravetz { 57a01f4390SMike Kravetz return cma_pages_valid(hugetlb_cma[page_to_nid(page)], page, 58a01f4390SMike Kravetz 1 << order); 59a01f4390SMike Kravetz } 60a01f4390SMike Kravetz #else 61a01f4390SMike Kravetz static bool hugetlb_cma_page(struct page *page, unsigned int order) 62a01f4390SMike Kravetz { 63a01f4390SMike Kravetz return false; 64a01f4390SMike Kravetz } 65dbda8feaSBarry Song #endif 66dbda8feaSBarry Song static unsigned long hugetlb_cma_size __initdata; 67cf11e85fSRoman Gushchin 68641844f5SNaoya Horiguchi /* 69641844f5SNaoya Horiguchi * Minimum page order among possible hugepage sizes, set to a proper value 70641844f5SNaoya Horiguchi * at boot time. 71641844f5SNaoya Horiguchi */ 72641844f5SNaoya Horiguchi static unsigned int minimum_order __read_mostly = UINT_MAX; 73e5ff2159SAndi Kleen 7453ba51d2SJon Tollefson __initdata LIST_HEAD(huge_boot_pages); 7553ba51d2SJon Tollefson 76e5ff2159SAndi Kleen /* for command line parsing */ 77e5ff2159SAndi Kleen static struct hstate * __initdata parsed_hstate; 78e5ff2159SAndi Kleen static unsigned long __initdata default_hstate_max_huge_pages; 799fee021dSVaishali Thakkar static bool __initdata parsed_valid_hugepagesz = true; 80282f4214SMike Kravetz static bool __initdata parsed_default_hugepagesz; 81b5389086SZhenguo Yao static unsigned int default_hugepages_in_node[MAX_NUMNODES] __initdata; 82e5ff2159SAndi Kleen 833935baa9SDavid Gibson /* 8431caf665SNaoya Horiguchi * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, 8531caf665SNaoya Horiguchi * free_huge_pages, and surplus_huge_pages. 863935baa9SDavid Gibson */ 87c3f38a38SAneesh Kumar K.V DEFINE_SPINLOCK(hugetlb_lock); 880bd0f9fbSEric Paris 898382d914SDavidlohr Bueso /* 908382d914SDavidlohr Bueso * Serializes faults on the same logical page. This is used to 918382d914SDavidlohr Bueso * prevent spurious OOMs when the hugepage pool is fully utilized. 928382d914SDavidlohr Bueso */ 938382d914SDavidlohr Bueso static int num_fault_mutexes; 94c672c7f2SMike Kravetz struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp; 958382d914SDavidlohr Bueso 967ca02d0aSMike Kravetz /* Forward declaration */ 977ca02d0aSMike Kravetz static int hugetlb_acct_memory(struct hstate *h, long delta); 987ca02d0aSMike Kravetz 991d88433bSMiaohe Lin static inline bool subpool_is_free(struct hugepage_subpool *spool) 1001d88433bSMiaohe Lin { 1011d88433bSMiaohe Lin if (spool->count) 1021d88433bSMiaohe Lin return false; 1031d88433bSMiaohe Lin if (spool->max_hpages != -1) 1041d88433bSMiaohe Lin return spool->used_hpages == 0; 1051d88433bSMiaohe Lin if (spool->min_hpages != -1) 1061d88433bSMiaohe Lin return spool->rsv_hpages == spool->min_hpages; 1071d88433bSMiaohe Lin 1081d88433bSMiaohe Lin return true; 1091d88433bSMiaohe Lin } 1101d88433bSMiaohe Lin 111db71ef79SMike Kravetz static inline void unlock_or_release_subpool(struct hugepage_subpool *spool, 112db71ef79SMike Kravetz unsigned long irq_flags) 11390481622SDavid Gibson { 114db71ef79SMike Kravetz spin_unlock_irqrestore(&spool->lock, irq_flags); 11590481622SDavid Gibson 11690481622SDavid Gibson /* If no pages are used, and no other handles to the subpool 1177c8de358SEthon Paul * remain, give up any reservations based on minimum size and 1187ca02d0aSMike Kravetz * free the subpool */ 1191d88433bSMiaohe Lin if (subpool_is_free(spool)) { 1207ca02d0aSMike Kravetz if (spool->min_hpages != -1) 1217ca02d0aSMike Kravetz hugetlb_acct_memory(spool->hstate, 1227ca02d0aSMike Kravetz -spool->min_hpages); 12390481622SDavid Gibson kfree(spool); 12490481622SDavid Gibson } 1257ca02d0aSMike Kravetz } 12690481622SDavid Gibson 1277ca02d0aSMike Kravetz struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, 1287ca02d0aSMike Kravetz long min_hpages) 12990481622SDavid Gibson { 13090481622SDavid Gibson struct hugepage_subpool *spool; 13190481622SDavid Gibson 132c6a91820SMike Kravetz spool = kzalloc(sizeof(*spool), GFP_KERNEL); 13390481622SDavid Gibson if (!spool) 13490481622SDavid Gibson return NULL; 13590481622SDavid Gibson 13690481622SDavid Gibson spin_lock_init(&spool->lock); 13790481622SDavid Gibson spool->count = 1; 1387ca02d0aSMike Kravetz spool->max_hpages = max_hpages; 1397ca02d0aSMike Kravetz spool->hstate = h; 1407ca02d0aSMike Kravetz spool->min_hpages = min_hpages; 1417ca02d0aSMike Kravetz 1427ca02d0aSMike Kravetz if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { 1437ca02d0aSMike Kravetz kfree(spool); 1447ca02d0aSMike Kravetz return NULL; 1457ca02d0aSMike Kravetz } 1467ca02d0aSMike Kravetz spool->rsv_hpages = min_hpages; 14790481622SDavid Gibson 14890481622SDavid Gibson return spool; 14990481622SDavid Gibson } 15090481622SDavid Gibson 15190481622SDavid Gibson void hugepage_put_subpool(struct hugepage_subpool *spool) 15290481622SDavid Gibson { 153db71ef79SMike Kravetz unsigned long flags; 154db71ef79SMike Kravetz 155db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 15690481622SDavid Gibson BUG_ON(!spool->count); 15790481622SDavid Gibson spool->count--; 158db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 15990481622SDavid Gibson } 16090481622SDavid Gibson 1611c5ecae3SMike Kravetz /* 1621c5ecae3SMike Kravetz * Subpool accounting for allocating and reserving pages. 1631c5ecae3SMike Kravetz * Return -ENOMEM if there are not enough resources to satisfy the 1649e7ee400SRandy Dunlap * request. Otherwise, return the number of pages by which the 1651c5ecae3SMike Kravetz * global pools must be adjusted (upward). The returned value may 1661c5ecae3SMike Kravetz * only be different than the passed value (delta) in the case where 1677c8de358SEthon Paul * a subpool minimum size must be maintained. 1681c5ecae3SMike Kravetz */ 1691c5ecae3SMike Kravetz static long hugepage_subpool_get_pages(struct hugepage_subpool *spool, 17090481622SDavid Gibson long delta) 17190481622SDavid Gibson { 1721c5ecae3SMike Kravetz long ret = delta; 17390481622SDavid Gibson 17490481622SDavid Gibson if (!spool) 1751c5ecae3SMike Kravetz return ret; 17690481622SDavid Gibson 177db71ef79SMike Kravetz spin_lock_irq(&spool->lock); 17890481622SDavid Gibson 1791c5ecae3SMike Kravetz if (spool->max_hpages != -1) { /* maximum size accounting */ 1801c5ecae3SMike Kravetz if ((spool->used_hpages + delta) <= spool->max_hpages) 1811c5ecae3SMike Kravetz spool->used_hpages += delta; 1821c5ecae3SMike Kravetz else { 1831c5ecae3SMike Kravetz ret = -ENOMEM; 1841c5ecae3SMike Kravetz goto unlock_ret; 1851c5ecae3SMike Kravetz } 1861c5ecae3SMike Kravetz } 1871c5ecae3SMike Kravetz 18809a95e29SMike Kravetz /* minimum size accounting */ 18909a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->rsv_hpages) { 1901c5ecae3SMike Kravetz if (delta > spool->rsv_hpages) { 1911c5ecae3SMike Kravetz /* 1921c5ecae3SMike Kravetz * Asking for more reserves than those already taken on 1931c5ecae3SMike Kravetz * behalf of subpool. Return difference. 1941c5ecae3SMike Kravetz */ 1951c5ecae3SMike Kravetz ret = delta - spool->rsv_hpages; 1961c5ecae3SMike Kravetz spool->rsv_hpages = 0; 1971c5ecae3SMike Kravetz } else { 1981c5ecae3SMike Kravetz ret = 0; /* reserves already accounted for */ 1991c5ecae3SMike Kravetz spool->rsv_hpages -= delta; 2001c5ecae3SMike Kravetz } 2011c5ecae3SMike Kravetz } 2021c5ecae3SMike Kravetz 2031c5ecae3SMike Kravetz unlock_ret: 204db71ef79SMike Kravetz spin_unlock_irq(&spool->lock); 20590481622SDavid Gibson return ret; 20690481622SDavid Gibson } 20790481622SDavid Gibson 2081c5ecae3SMike Kravetz /* 2091c5ecae3SMike Kravetz * Subpool accounting for freeing and unreserving pages. 2101c5ecae3SMike Kravetz * Return the number of global page reservations that must be dropped. 2111c5ecae3SMike Kravetz * The return value may only be different than the passed value (delta) 2121c5ecae3SMike Kravetz * in the case where a subpool minimum size must be maintained. 2131c5ecae3SMike Kravetz */ 2141c5ecae3SMike Kravetz static long hugepage_subpool_put_pages(struct hugepage_subpool *spool, 21590481622SDavid Gibson long delta) 21690481622SDavid Gibson { 2171c5ecae3SMike Kravetz long ret = delta; 218db71ef79SMike Kravetz unsigned long flags; 2191c5ecae3SMike Kravetz 22090481622SDavid Gibson if (!spool) 2211c5ecae3SMike Kravetz return delta; 22290481622SDavid Gibson 223db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 2241c5ecae3SMike Kravetz 2251c5ecae3SMike Kravetz if (spool->max_hpages != -1) /* maximum size accounting */ 22690481622SDavid Gibson spool->used_hpages -= delta; 2271c5ecae3SMike Kravetz 22809a95e29SMike Kravetz /* minimum size accounting */ 22909a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { 2301c5ecae3SMike Kravetz if (spool->rsv_hpages + delta <= spool->min_hpages) 2311c5ecae3SMike Kravetz ret = 0; 2321c5ecae3SMike Kravetz else 2331c5ecae3SMike Kravetz ret = spool->rsv_hpages + delta - spool->min_hpages; 2341c5ecae3SMike Kravetz 2351c5ecae3SMike Kravetz spool->rsv_hpages += delta; 2361c5ecae3SMike Kravetz if (spool->rsv_hpages > spool->min_hpages) 2371c5ecae3SMike Kravetz spool->rsv_hpages = spool->min_hpages; 2381c5ecae3SMike Kravetz } 2391c5ecae3SMike Kravetz 2401c5ecae3SMike Kravetz /* 2411c5ecae3SMike Kravetz * If hugetlbfs_put_super couldn't free spool due to an outstanding 2421c5ecae3SMike Kravetz * quota reference, free it now. 2431c5ecae3SMike Kravetz */ 244db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 2451c5ecae3SMike Kravetz 2461c5ecae3SMike Kravetz return ret; 24790481622SDavid Gibson } 24890481622SDavid Gibson 24990481622SDavid Gibson static inline struct hugepage_subpool *subpool_inode(struct inode *inode) 25090481622SDavid Gibson { 25190481622SDavid Gibson return HUGETLBFS_SB(inode->i_sb)->spool; 25290481622SDavid Gibson } 25390481622SDavid Gibson 25490481622SDavid Gibson static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) 25590481622SDavid Gibson { 256496ad9aaSAl Viro return subpool_inode(file_inode(vma->vm_file)); 25790481622SDavid Gibson } 25890481622SDavid Gibson 2590db9d74eSMina Almasry /* Helper that removes a struct file_region from the resv_map cache and returns 2600db9d74eSMina Almasry * it for use. 2610db9d74eSMina Almasry */ 2620db9d74eSMina Almasry static struct file_region * 2630db9d74eSMina Almasry get_file_region_entry_from_cache(struct resv_map *resv, long from, long to) 2640db9d74eSMina Almasry { 2650db9d74eSMina Almasry struct file_region *nrg = NULL; 2660db9d74eSMina Almasry 2670db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count <= 0); 2680db9d74eSMina Almasry 2690db9d74eSMina Almasry resv->region_cache_count--; 2700db9d74eSMina Almasry nrg = list_first_entry(&resv->region_cache, struct file_region, link); 2710db9d74eSMina Almasry list_del(&nrg->link); 2720db9d74eSMina Almasry 2730db9d74eSMina Almasry nrg->from = from; 2740db9d74eSMina Almasry nrg->to = to; 2750db9d74eSMina Almasry 2760db9d74eSMina Almasry return nrg; 2770db9d74eSMina Almasry } 2780db9d74eSMina Almasry 279075a61d0SMina Almasry static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg, 280075a61d0SMina Almasry struct file_region *rg) 281075a61d0SMina Almasry { 282075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 283075a61d0SMina Almasry nrg->reservation_counter = rg->reservation_counter; 284075a61d0SMina Almasry nrg->css = rg->css; 285075a61d0SMina Almasry if (rg->css) 286075a61d0SMina Almasry css_get(rg->css); 287075a61d0SMina Almasry #endif 288075a61d0SMina Almasry } 289075a61d0SMina Almasry 290075a61d0SMina Almasry /* Helper that records hugetlb_cgroup uncharge info. */ 291075a61d0SMina Almasry static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg, 292075a61d0SMina Almasry struct hstate *h, 293075a61d0SMina Almasry struct resv_map *resv, 294075a61d0SMina Almasry struct file_region *nrg) 295075a61d0SMina Almasry { 296075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 297075a61d0SMina Almasry if (h_cg) { 298075a61d0SMina Almasry nrg->reservation_counter = 299075a61d0SMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 300075a61d0SMina Almasry nrg->css = &h_cg->css; 301d85aecf2SMiaohe Lin /* 302d85aecf2SMiaohe Lin * The caller will hold exactly one h_cg->css reference for the 303d85aecf2SMiaohe Lin * whole contiguous reservation region. But this area might be 304d85aecf2SMiaohe Lin * scattered when there are already some file_regions reside in 305d85aecf2SMiaohe Lin * it. As a result, many file_regions may share only one css 306d85aecf2SMiaohe Lin * reference. In order to ensure that one file_region must hold 307d85aecf2SMiaohe Lin * exactly one h_cg->css reference, we should do css_get for 308d85aecf2SMiaohe Lin * each file_region and leave the reference held by caller 309d85aecf2SMiaohe Lin * untouched. 310d85aecf2SMiaohe Lin */ 311d85aecf2SMiaohe Lin css_get(&h_cg->css); 312075a61d0SMina Almasry if (!resv->pages_per_hpage) 313075a61d0SMina Almasry resv->pages_per_hpage = pages_per_huge_page(h); 314075a61d0SMina Almasry /* pages_per_hpage should be the same for all entries in 315075a61d0SMina Almasry * a resv_map. 316075a61d0SMina Almasry */ 317075a61d0SMina Almasry VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h)); 318075a61d0SMina Almasry } else { 319075a61d0SMina Almasry nrg->reservation_counter = NULL; 320075a61d0SMina Almasry nrg->css = NULL; 321075a61d0SMina Almasry } 322075a61d0SMina Almasry #endif 323075a61d0SMina Almasry } 324075a61d0SMina Almasry 325d85aecf2SMiaohe Lin static void put_uncharge_info(struct file_region *rg) 326d85aecf2SMiaohe Lin { 327d85aecf2SMiaohe Lin #ifdef CONFIG_CGROUP_HUGETLB 328d85aecf2SMiaohe Lin if (rg->css) 329d85aecf2SMiaohe Lin css_put(rg->css); 330d85aecf2SMiaohe Lin #endif 331d85aecf2SMiaohe Lin } 332d85aecf2SMiaohe Lin 333a9b3f867SMina Almasry static bool has_same_uncharge_info(struct file_region *rg, 334a9b3f867SMina Almasry struct file_region *org) 335a9b3f867SMina Almasry { 336a9b3f867SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 3370739eb43SBaolin Wang return rg->reservation_counter == org->reservation_counter && 338a9b3f867SMina Almasry rg->css == org->css; 339a9b3f867SMina Almasry 340a9b3f867SMina Almasry #else 341a9b3f867SMina Almasry return true; 342a9b3f867SMina Almasry #endif 343a9b3f867SMina Almasry } 344a9b3f867SMina Almasry 345a9b3f867SMina Almasry static void coalesce_file_region(struct resv_map *resv, struct file_region *rg) 346a9b3f867SMina Almasry { 347a9b3f867SMina Almasry struct file_region *nrg = NULL, *prg = NULL; 348a9b3f867SMina Almasry 349a9b3f867SMina Almasry prg = list_prev_entry(rg, link); 350a9b3f867SMina Almasry if (&prg->link != &resv->regions && prg->to == rg->from && 351a9b3f867SMina Almasry has_same_uncharge_info(prg, rg)) { 352a9b3f867SMina Almasry prg->to = rg->to; 353a9b3f867SMina Almasry 354a9b3f867SMina Almasry list_del(&rg->link); 355d85aecf2SMiaohe Lin put_uncharge_info(rg); 356a9b3f867SMina Almasry kfree(rg); 357a9b3f867SMina Almasry 3587db5e7b6SWei Yang rg = prg; 359a9b3f867SMina Almasry } 360a9b3f867SMina Almasry 361a9b3f867SMina Almasry nrg = list_next_entry(rg, link); 362a9b3f867SMina Almasry if (&nrg->link != &resv->regions && nrg->from == rg->to && 363a9b3f867SMina Almasry has_same_uncharge_info(nrg, rg)) { 364a9b3f867SMina Almasry nrg->from = rg->from; 365a9b3f867SMina Almasry 366a9b3f867SMina Almasry list_del(&rg->link); 367d85aecf2SMiaohe Lin put_uncharge_info(rg); 368a9b3f867SMina Almasry kfree(rg); 369a9b3f867SMina Almasry } 370a9b3f867SMina Almasry } 371a9b3f867SMina Almasry 3722103cf9cSPeter Xu static inline long 37384448c8eSJakob Koschel hugetlb_resv_map_add(struct resv_map *map, struct list_head *rg, long from, 3742103cf9cSPeter Xu long to, struct hstate *h, struct hugetlb_cgroup *cg, 3752103cf9cSPeter Xu long *regions_needed) 3762103cf9cSPeter Xu { 3772103cf9cSPeter Xu struct file_region *nrg; 3782103cf9cSPeter Xu 3792103cf9cSPeter Xu if (!regions_needed) { 3802103cf9cSPeter Xu nrg = get_file_region_entry_from_cache(map, from, to); 3812103cf9cSPeter Xu record_hugetlb_cgroup_uncharge_info(cg, h, map, nrg); 38284448c8eSJakob Koschel list_add(&nrg->link, rg); 3832103cf9cSPeter Xu coalesce_file_region(map, nrg); 3842103cf9cSPeter Xu } else 3852103cf9cSPeter Xu *regions_needed += 1; 3862103cf9cSPeter Xu 3872103cf9cSPeter Xu return to - from; 3882103cf9cSPeter Xu } 3892103cf9cSPeter Xu 390972a3da3SWei Yang /* 391972a3da3SWei Yang * Must be called with resv->lock held. 392972a3da3SWei Yang * 393972a3da3SWei Yang * Calling this with regions_needed != NULL will count the number of pages 394972a3da3SWei Yang * to be added but will not modify the linked list. And regions_needed will 395972a3da3SWei Yang * indicate the number of file_regions needed in the cache to carry out to add 396972a3da3SWei Yang * the regions for this range. 397d75c6af9SMina Almasry */ 398d75c6af9SMina Almasry static long add_reservation_in_range(struct resv_map *resv, long f, long t, 399075a61d0SMina Almasry struct hugetlb_cgroup *h_cg, 400972a3da3SWei Yang struct hstate *h, long *regions_needed) 401d75c6af9SMina Almasry { 4020db9d74eSMina Almasry long add = 0; 403d75c6af9SMina Almasry struct list_head *head = &resv->regions; 4040db9d74eSMina Almasry long last_accounted_offset = f; 40584448c8eSJakob Koschel struct file_region *iter, *trg = NULL; 40684448c8eSJakob Koschel struct list_head *rg = NULL; 407d75c6af9SMina Almasry 4080db9d74eSMina Almasry if (regions_needed) 4090db9d74eSMina Almasry *regions_needed = 0; 410d75c6af9SMina Almasry 4110db9d74eSMina Almasry /* In this loop, we essentially handle an entry for the range 41284448c8eSJakob Koschel * [last_accounted_offset, iter->from), at every iteration, with some 4130db9d74eSMina Almasry * bounds checking. 4140db9d74eSMina Almasry */ 41584448c8eSJakob Koschel list_for_each_entry_safe(iter, trg, head, link) { 4160db9d74eSMina Almasry /* Skip irrelevant regions that start before our range. */ 41784448c8eSJakob Koschel if (iter->from < f) { 4180db9d74eSMina Almasry /* If this region ends after the last accounted offset, 4190db9d74eSMina Almasry * then we need to update last_accounted_offset. 4200db9d74eSMina Almasry */ 42184448c8eSJakob Koschel if (iter->to > last_accounted_offset) 42284448c8eSJakob Koschel last_accounted_offset = iter->to; 4230db9d74eSMina Almasry continue; 4240db9d74eSMina Almasry } 425d75c6af9SMina Almasry 4260db9d74eSMina Almasry /* When we find a region that starts beyond our range, we've 4270db9d74eSMina Almasry * finished. 4280db9d74eSMina Almasry */ 42984448c8eSJakob Koschel if (iter->from >= t) { 43084448c8eSJakob Koschel rg = iter->link.prev; 431d75c6af9SMina Almasry break; 43284448c8eSJakob Koschel } 433d75c6af9SMina Almasry 43484448c8eSJakob Koschel /* Add an entry for last_accounted_offset -> iter->from, and 4350db9d74eSMina Almasry * update last_accounted_offset. 436d75c6af9SMina Almasry */ 43784448c8eSJakob Koschel if (iter->from > last_accounted_offset) 43884448c8eSJakob Koschel add += hugetlb_resv_map_add(resv, iter->link.prev, 4392103cf9cSPeter Xu last_accounted_offset, 44084448c8eSJakob Koschel iter->from, h, h_cg, 4412103cf9cSPeter Xu regions_needed); 442d75c6af9SMina Almasry 44384448c8eSJakob Koschel last_accounted_offset = iter->to; 4440db9d74eSMina Almasry } 4450db9d74eSMina Almasry 4460db9d74eSMina Almasry /* Handle the case where our range extends beyond 4470db9d74eSMina Almasry * last_accounted_offset. 4480db9d74eSMina Almasry */ 44984448c8eSJakob Koschel if (!rg) 45084448c8eSJakob Koschel rg = head->prev; 4512103cf9cSPeter Xu if (last_accounted_offset < t) 4522103cf9cSPeter Xu add += hugetlb_resv_map_add(resv, rg, last_accounted_offset, 4532103cf9cSPeter Xu t, h, h_cg, regions_needed); 4540db9d74eSMina Almasry 4550db9d74eSMina Almasry return add; 4560db9d74eSMina Almasry } 4570db9d74eSMina Almasry 4580db9d74eSMina Almasry /* Must be called with resv->lock acquired. Will drop lock to allocate entries. 4590db9d74eSMina Almasry */ 4600db9d74eSMina Almasry static int allocate_file_region_entries(struct resv_map *resv, 4610db9d74eSMina Almasry int regions_needed) 4620db9d74eSMina Almasry __must_hold(&resv->lock) 4630db9d74eSMina Almasry { 4640db9d74eSMina Almasry struct list_head allocated_regions; 4650db9d74eSMina Almasry int to_allocate = 0, i = 0; 4660db9d74eSMina Almasry struct file_region *trg = NULL, *rg = NULL; 4670db9d74eSMina Almasry 4680db9d74eSMina Almasry VM_BUG_ON(regions_needed < 0); 4690db9d74eSMina Almasry 4700db9d74eSMina Almasry INIT_LIST_HEAD(&allocated_regions); 4710db9d74eSMina Almasry 4720db9d74eSMina Almasry /* 4730db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 4740db9d74eSMina Almasry * the number of in progress add operations plus regions_needed. 4750db9d74eSMina Almasry * 4760db9d74eSMina Almasry * This is a while loop because when we drop the lock, some other call 4770db9d74eSMina Almasry * to region_add or region_del may have consumed some region_entries, 4780db9d74eSMina Almasry * so we keep looping here until we finally have enough entries for 4790db9d74eSMina Almasry * (adds_in_progress + regions_needed). 4800db9d74eSMina Almasry */ 4810db9d74eSMina Almasry while (resv->region_cache_count < 4820db9d74eSMina Almasry (resv->adds_in_progress + regions_needed)) { 4830db9d74eSMina Almasry to_allocate = resv->adds_in_progress + regions_needed - 4840db9d74eSMina Almasry resv->region_cache_count; 4850db9d74eSMina Almasry 4860db9d74eSMina Almasry /* At this point, we should have enough entries in the cache 487f0953a1bSIngo Molnar * for all the existing adds_in_progress. We should only be 4880db9d74eSMina Almasry * needing to allocate for regions_needed. 4890db9d74eSMina Almasry */ 4900db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count < resv->adds_in_progress); 4910db9d74eSMina Almasry 4920db9d74eSMina Almasry spin_unlock(&resv->lock); 4930db9d74eSMina Almasry for (i = 0; i < to_allocate; i++) { 4940db9d74eSMina Almasry trg = kmalloc(sizeof(*trg), GFP_KERNEL); 4950db9d74eSMina Almasry if (!trg) 4960db9d74eSMina Almasry goto out_of_memory; 4970db9d74eSMina Almasry list_add(&trg->link, &allocated_regions); 4980db9d74eSMina Almasry } 4990db9d74eSMina Almasry 5000db9d74eSMina Almasry spin_lock(&resv->lock); 5010db9d74eSMina Almasry 502d3ec7b6eSWei Yang list_splice(&allocated_regions, &resv->region_cache); 503d3ec7b6eSWei Yang resv->region_cache_count += to_allocate; 5040db9d74eSMina Almasry } 5050db9d74eSMina Almasry 5060db9d74eSMina Almasry return 0; 5070db9d74eSMina Almasry 5080db9d74eSMina Almasry out_of_memory: 5090db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, &allocated_regions, link) { 510d75c6af9SMina Almasry list_del(&rg->link); 511d75c6af9SMina Almasry kfree(rg); 512d75c6af9SMina Almasry } 5130db9d74eSMina Almasry return -ENOMEM; 514d75c6af9SMina Almasry } 515d75c6af9SMina Almasry 5161dd308a7SMike Kravetz /* 5171dd308a7SMike Kravetz * Add the huge page range represented by [f, t) to the reserve 5180db9d74eSMina Almasry * map. Regions will be taken from the cache to fill in this range. 5190db9d74eSMina Almasry * Sufficient regions should exist in the cache due to the previous 5200db9d74eSMina Almasry * call to region_chg with the same range, but in some cases the cache will not 5210db9d74eSMina Almasry * have sufficient entries due to races with other code doing region_add or 5220db9d74eSMina Almasry * region_del. The extra needed entries will be allocated. 523cf3ad20bSMike Kravetz * 5240db9d74eSMina Almasry * regions_needed is the out value provided by a previous call to region_chg. 5250db9d74eSMina Almasry * 5260db9d74eSMina Almasry * Return the number of new huge pages added to the map. This number is greater 5270db9d74eSMina Almasry * than or equal to zero. If file_region entries needed to be allocated for 5287c8de358SEthon Paul * this operation and we were not able to allocate, it returns -ENOMEM. 5290db9d74eSMina Almasry * region_add of regions of length 1 never allocate file_regions and cannot 5300db9d74eSMina Almasry * fail; region_chg will always allocate at least 1 entry and a region_add for 5310db9d74eSMina Almasry * 1 page will only require at most 1 entry. 5321dd308a7SMike Kravetz */ 5330db9d74eSMina Almasry static long region_add(struct resv_map *resv, long f, long t, 534075a61d0SMina Almasry long in_regions_needed, struct hstate *h, 535075a61d0SMina Almasry struct hugetlb_cgroup *h_cg) 53696822904SAndy Whitcroft { 5370db9d74eSMina Almasry long add = 0, actual_regions_needed = 0; 53896822904SAndy Whitcroft 5397b24d861SDavidlohr Bueso spin_lock(&resv->lock); 5400db9d74eSMina Almasry retry: 5410db9d74eSMina Almasry 5420db9d74eSMina Almasry /* Count how many regions are actually needed to execute this add. */ 543972a3da3SWei Yang add_reservation_in_range(resv, f, t, NULL, NULL, 544972a3da3SWei Yang &actual_regions_needed); 54596822904SAndy Whitcroft 5465e911373SMike Kravetz /* 5470db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 5480db9d74eSMina Almasry * this add operation. Note that actual_regions_needed may be greater 5490db9d74eSMina Almasry * than in_regions_needed, as the resv_map may have been modified since 5500db9d74eSMina Almasry * the region_chg call. In this case, we need to make sure that we 5510db9d74eSMina Almasry * allocate extra entries, such that we have enough for all the 5520db9d74eSMina Almasry * existing adds_in_progress, plus the excess needed for this 5530db9d74eSMina Almasry * operation. 5545e911373SMike Kravetz */ 5550db9d74eSMina Almasry if (actual_regions_needed > in_regions_needed && 5560db9d74eSMina Almasry resv->region_cache_count < 5570db9d74eSMina Almasry resv->adds_in_progress + 5580db9d74eSMina Almasry (actual_regions_needed - in_regions_needed)) { 5590db9d74eSMina Almasry /* region_add operation of range 1 should never need to 5600db9d74eSMina Almasry * allocate file_region entries. 5610db9d74eSMina Almasry */ 5620db9d74eSMina Almasry VM_BUG_ON(t - f <= 1); 5635e911373SMike Kravetz 5640db9d74eSMina Almasry if (allocate_file_region_entries( 5650db9d74eSMina Almasry resv, actual_regions_needed - in_regions_needed)) { 5660db9d74eSMina Almasry return -ENOMEM; 5675e911373SMike Kravetz } 5685e911373SMike Kravetz 5690db9d74eSMina Almasry goto retry; 5700db9d74eSMina Almasry } 571cf3ad20bSMike Kravetz 572972a3da3SWei Yang add = add_reservation_in_range(resv, f, t, h_cg, h, NULL); 5730db9d74eSMina Almasry 5740db9d74eSMina Almasry resv->adds_in_progress -= in_regions_needed; 5750db9d74eSMina Almasry 5767b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 577cf3ad20bSMike Kravetz return add; 57896822904SAndy Whitcroft } 57996822904SAndy Whitcroft 5801dd308a7SMike Kravetz /* 5811dd308a7SMike Kravetz * Examine the existing reserve map and determine how many 5821dd308a7SMike Kravetz * huge pages in the specified range [f, t) are NOT currently 5831dd308a7SMike Kravetz * represented. This routine is called before a subsequent 5841dd308a7SMike Kravetz * call to region_add that will actually modify the reserve 5851dd308a7SMike Kravetz * map to add the specified range [f, t). region_chg does 5861dd308a7SMike Kravetz * not change the number of huge pages represented by the 5870db9d74eSMina Almasry * map. A number of new file_region structures is added to the cache as a 5880db9d74eSMina Almasry * placeholder, for the subsequent region_add call to use. At least 1 5890db9d74eSMina Almasry * file_region structure is added. 5900db9d74eSMina Almasry * 5910db9d74eSMina Almasry * out_regions_needed is the number of regions added to the 5920db9d74eSMina Almasry * resv->adds_in_progress. This value needs to be provided to a follow up call 5930db9d74eSMina Almasry * to region_add or region_abort for proper accounting. 5945e911373SMike Kravetz * 5955e911373SMike Kravetz * Returns the number of huge pages that need to be added to the existing 5965e911373SMike Kravetz * reservation map for the range [f, t). This number is greater or equal to 5975e911373SMike Kravetz * zero. -ENOMEM is returned if a new file_region structure or cache entry 5985e911373SMike Kravetz * is needed and can not be allocated. 5991dd308a7SMike Kravetz */ 6000db9d74eSMina Almasry static long region_chg(struct resv_map *resv, long f, long t, 6010db9d74eSMina Almasry long *out_regions_needed) 60296822904SAndy Whitcroft { 60396822904SAndy Whitcroft long chg = 0; 60496822904SAndy Whitcroft 6057b24d861SDavidlohr Bueso spin_lock(&resv->lock); 6065e911373SMike Kravetz 607972a3da3SWei Yang /* Count how many hugepages in this range are NOT represented. */ 608075a61d0SMina Almasry chg = add_reservation_in_range(resv, f, t, NULL, NULL, 609972a3da3SWei Yang out_regions_needed); 6105e911373SMike Kravetz 6110db9d74eSMina Almasry if (*out_regions_needed == 0) 6120db9d74eSMina Almasry *out_regions_needed = 1; 6135e911373SMike Kravetz 6140db9d74eSMina Almasry if (allocate_file_region_entries(resv, *out_regions_needed)) 6155e911373SMike Kravetz return -ENOMEM; 6165e911373SMike Kravetz 6170db9d74eSMina Almasry resv->adds_in_progress += *out_regions_needed; 61896822904SAndy Whitcroft 6197b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 62096822904SAndy Whitcroft return chg; 62196822904SAndy Whitcroft } 62296822904SAndy Whitcroft 6231dd308a7SMike Kravetz /* 6245e911373SMike Kravetz * Abort the in progress add operation. The adds_in_progress field 6255e911373SMike Kravetz * of the resv_map keeps track of the operations in progress between 6265e911373SMike Kravetz * calls to region_chg and region_add. Operations are sometimes 6275e911373SMike Kravetz * aborted after the call to region_chg. In such cases, region_abort 6280db9d74eSMina Almasry * is called to decrement the adds_in_progress counter. regions_needed 6290db9d74eSMina Almasry * is the value returned by the region_chg call, it is used to decrement 6300db9d74eSMina Almasry * the adds_in_progress counter. 6315e911373SMike Kravetz * 6325e911373SMike Kravetz * NOTE: The range arguments [f, t) are not needed or used in this 6335e911373SMike Kravetz * routine. They are kept to make reading the calling code easier as 6345e911373SMike Kravetz * arguments will match the associated region_chg call. 6355e911373SMike Kravetz */ 6360db9d74eSMina Almasry static void region_abort(struct resv_map *resv, long f, long t, 6370db9d74eSMina Almasry long regions_needed) 6385e911373SMike Kravetz { 6395e911373SMike Kravetz spin_lock(&resv->lock); 6405e911373SMike Kravetz VM_BUG_ON(!resv->region_cache_count); 6410db9d74eSMina Almasry resv->adds_in_progress -= regions_needed; 6425e911373SMike Kravetz spin_unlock(&resv->lock); 6435e911373SMike Kravetz } 6445e911373SMike Kravetz 6455e911373SMike Kravetz /* 646feba16e2SMike Kravetz * Delete the specified range [f, t) from the reserve map. If the 647feba16e2SMike Kravetz * t parameter is LONG_MAX, this indicates that ALL regions after f 648feba16e2SMike Kravetz * should be deleted. Locate the regions which intersect [f, t) 649feba16e2SMike Kravetz * and either trim, delete or split the existing regions. 650feba16e2SMike Kravetz * 651feba16e2SMike Kravetz * Returns the number of huge pages deleted from the reserve map. 652feba16e2SMike Kravetz * In the normal case, the return value is zero or more. In the 653feba16e2SMike Kravetz * case where a region must be split, a new region descriptor must 654feba16e2SMike Kravetz * be allocated. If the allocation fails, -ENOMEM will be returned. 655feba16e2SMike Kravetz * NOTE: If the parameter t == LONG_MAX, then we will never split 656feba16e2SMike Kravetz * a region and possibly return -ENOMEM. Callers specifying 657feba16e2SMike Kravetz * t == LONG_MAX do not need to check for -ENOMEM error. 6581dd308a7SMike Kravetz */ 659feba16e2SMike Kravetz static long region_del(struct resv_map *resv, long f, long t) 66096822904SAndy Whitcroft { 6611406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 66296822904SAndy Whitcroft struct file_region *rg, *trg; 663feba16e2SMike Kravetz struct file_region *nrg = NULL; 664feba16e2SMike Kravetz long del = 0; 66596822904SAndy Whitcroft 666feba16e2SMike Kravetz retry: 6677b24d861SDavidlohr Bueso spin_lock(&resv->lock); 668feba16e2SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 669dbe409e4SMike Kravetz /* 670dbe409e4SMike Kravetz * Skip regions before the range to be deleted. file_region 671dbe409e4SMike Kravetz * ranges are normally of the form [from, to). However, there 672dbe409e4SMike Kravetz * may be a "placeholder" entry in the map which is of the form 673dbe409e4SMike Kravetz * (from, to) with from == to. Check for placeholder entries 674dbe409e4SMike Kravetz * at the beginning of the range to be deleted. 675dbe409e4SMike Kravetz */ 676dbe409e4SMike Kravetz if (rg->to <= f && (rg->to != rg->from || rg->to != f)) 677feba16e2SMike Kravetz continue; 678dbe409e4SMike Kravetz 679feba16e2SMike Kravetz if (rg->from >= t) 68096822904SAndy Whitcroft break; 68196822904SAndy Whitcroft 682feba16e2SMike Kravetz if (f > rg->from && t < rg->to) { /* Must split region */ 683feba16e2SMike Kravetz /* 684feba16e2SMike Kravetz * Check for an entry in the cache before dropping 685feba16e2SMike Kravetz * lock and attempting allocation. 686feba16e2SMike Kravetz */ 687feba16e2SMike Kravetz if (!nrg && 688feba16e2SMike Kravetz resv->region_cache_count > resv->adds_in_progress) { 689feba16e2SMike Kravetz nrg = list_first_entry(&resv->region_cache, 690feba16e2SMike Kravetz struct file_region, 691feba16e2SMike Kravetz link); 692feba16e2SMike Kravetz list_del(&nrg->link); 693feba16e2SMike Kravetz resv->region_cache_count--; 69496822904SAndy Whitcroft } 69596822904SAndy Whitcroft 696feba16e2SMike Kravetz if (!nrg) { 697feba16e2SMike Kravetz spin_unlock(&resv->lock); 698feba16e2SMike Kravetz nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); 699feba16e2SMike Kravetz if (!nrg) 700feba16e2SMike Kravetz return -ENOMEM; 701feba16e2SMike Kravetz goto retry; 702feba16e2SMike Kravetz } 703feba16e2SMike Kravetz 704feba16e2SMike Kravetz del += t - f; 70579aa925bSMike Kravetz hugetlb_cgroup_uncharge_file_region( 706d85aecf2SMiaohe Lin resv, rg, t - f, false); 707feba16e2SMike Kravetz 708feba16e2SMike Kravetz /* New entry for end of split region */ 709feba16e2SMike Kravetz nrg->from = t; 710feba16e2SMike Kravetz nrg->to = rg->to; 711075a61d0SMina Almasry 712075a61d0SMina Almasry copy_hugetlb_cgroup_uncharge_info(nrg, rg); 713075a61d0SMina Almasry 714feba16e2SMike Kravetz INIT_LIST_HEAD(&nrg->link); 715feba16e2SMike Kravetz 716feba16e2SMike Kravetz /* Original entry is trimmed */ 717feba16e2SMike Kravetz rg->to = f; 718feba16e2SMike Kravetz 719feba16e2SMike Kravetz list_add(&nrg->link, &rg->link); 720feba16e2SMike Kravetz nrg = NULL; 72196822904SAndy Whitcroft break; 722feba16e2SMike Kravetz } 723feba16e2SMike Kravetz 724feba16e2SMike Kravetz if (f <= rg->from && t >= rg->to) { /* Remove entire region */ 725feba16e2SMike Kravetz del += rg->to - rg->from; 726075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 727d85aecf2SMiaohe Lin rg->to - rg->from, true); 72896822904SAndy Whitcroft list_del(&rg->link); 72996822904SAndy Whitcroft kfree(rg); 730feba16e2SMike Kravetz continue; 73196822904SAndy Whitcroft } 7327b24d861SDavidlohr Bueso 733feba16e2SMike Kravetz if (f <= rg->from) { /* Trim beginning of region */ 734075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 735d85aecf2SMiaohe Lin t - rg->from, false); 736075a61d0SMina Almasry 73779aa925bSMike Kravetz del += t - rg->from; 73879aa925bSMike Kravetz rg->from = t; 73979aa925bSMike Kravetz } else { /* Trim end of region */ 740075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 741d85aecf2SMiaohe Lin rg->to - f, false); 74279aa925bSMike Kravetz 74379aa925bSMike Kravetz del += rg->to - f; 74479aa925bSMike Kravetz rg->to = f; 745feba16e2SMike Kravetz } 746feba16e2SMike Kravetz } 747feba16e2SMike Kravetz 7487b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 749feba16e2SMike Kravetz kfree(nrg); 750feba16e2SMike Kravetz return del; 75196822904SAndy Whitcroft } 75296822904SAndy Whitcroft 7531dd308a7SMike Kravetz /* 754b5cec28dSMike Kravetz * A rare out of memory error was encountered which prevented removal of 755b5cec28dSMike Kravetz * the reserve map region for a page. The huge page itself was free'ed 756b5cec28dSMike Kravetz * and removed from the page cache. This routine will adjust the subpool 757b5cec28dSMike Kravetz * usage count, and the global reserve count if needed. By incrementing 758b5cec28dSMike Kravetz * these counts, the reserve map entry which could not be deleted will 759b5cec28dSMike Kravetz * appear as a "reserved" entry instead of simply dangling with incorrect 760b5cec28dSMike Kravetz * counts. 761b5cec28dSMike Kravetz */ 76272e2936cSzhong jiang void hugetlb_fix_reserve_counts(struct inode *inode) 763b5cec28dSMike Kravetz { 764b5cec28dSMike Kravetz struct hugepage_subpool *spool = subpool_inode(inode); 765b5cec28dSMike Kravetz long rsv_adjust; 766da56388cSMiaohe Lin bool reserved = false; 767b5cec28dSMike Kravetz 768b5cec28dSMike Kravetz rsv_adjust = hugepage_subpool_get_pages(spool, 1); 769da56388cSMiaohe Lin if (rsv_adjust > 0) { 770b5cec28dSMike Kravetz struct hstate *h = hstate_inode(inode); 771b5cec28dSMike Kravetz 772da56388cSMiaohe Lin if (!hugetlb_acct_memory(h, 1)) 773da56388cSMiaohe Lin reserved = true; 774da56388cSMiaohe Lin } else if (!rsv_adjust) { 775da56388cSMiaohe Lin reserved = true; 776b5cec28dSMike Kravetz } 777da56388cSMiaohe Lin 778da56388cSMiaohe Lin if (!reserved) 779da56388cSMiaohe Lin pr_warn("hugetlb: Huge Page Reserved count may go negative.\n"); 780b5cec28dSMike Kravetz } 781b5cec28dSMike Kravetz 782b5cec28dSMike Kravetz /* 7831dd308a7SMike Kravetz * Count and return the number of huge pages in the reserve map 7841dd308a7SMike Kravetz * that intersect with the range [f, t). 7851dd308a7SMike Kravetz */ 7861406ec9bSJoonsoo Kim static long region_count(struct resv_map *resv, long f, long t) 78784afd99bSAndy Whitcroft { 7881406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 78984afd99bSAndy Whitcroft struct file_region *rg; 79084afd99bSAndy Whitcroft long chg = 0; 79184afd99bSAndy Whitcroft 7927b24d861SDavidlohr Bueso spin_lock(&resv->lock); 79384afd99bSAndy Whitcroft /* Locate each segment we overlap with, and count that overlap. */ 79484afd99bSAndy Whitcroft list_for_each_entry(rg, head, link) { 795f2135a4aSWang Sheng-Hui long seg_from; 796f2135a4aSWang Sheng-Hui long seg_to; 79784afd99bSAndy Whitcroft 79884afd99bSAndy Whitcroft if (rg->to <= f) 79984afd99bSAndy Whitcroft continue; 80084afd99bSAndy Whitcroft if (rg->from >= t) 80184afd99bSAndy Whitcroft break; 80284afd99bSAndy Whitcroft 80384afd99bSAndy Whitcroft seg_from = max(rg->from, f); 80484afd99bSAndy Whitcroft seg_to = min(rg->to, t); 80584afd99bSAndy Whitcroft 80684afd99bSAndy Whitcroft chg += seg_to - seg_from; 80784afd99bSAndy Whitcroft } 8087b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 80984afd99bSAndy Whitcroft 81084afd99bSAndy Whitcroft return chg; 81184afd99bSAndy Whitcroft } 81284afd99bSAndy Whitcroft 81396822904SAndy Whitcroft /* 814e7c4b0bfSAndy Whitcroft * Convert the address within this vma to the page offset within 815e7c4b0bfSAndy Whitcroft * the mapping, in pagecache page units; huge pages here. 816e7c4b0bfSAndy Whitcroft */ 817a5516438SAndi Kleen static pgoff_t vma_hugecache_offset(struct hstate *h, 818a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 819e7c4b0bfSAndy Whitcroft { 820a5516438SAndi Kleen return ((address - vma->vm_start) >> huge_page_shift(h)) + 821a5516438SAndi Kleen (vma->vm_pgoff >> huge_page_order(h)); 822e7c4b0bfSAndy Whitcroft } 823e7c4b0bfSAndy Whitcroft 8240fe6e20bSNaoya Horiguchi pgoff_t linear_hugepage_index(struct vm_area_struct *vma, 8250fe6e20bSNaoya Horiguchi unsigned long address) 8260fe6e20bSNaoya Horiguchi { 8270fe6e20bSNaoya Horiguchi return vma_hugecache_offset(hstate_vma(vma), vma, address); 8280fe6e20bSNaoya Horiguchi } 829dee41079SDan Williams EXPORT_SYMBOL_GPL(linear_hugepage_index); 8300fe6e20bSNaoya Horiguchi 83184afd99bSAndy Whitcroft /* 83208fba699SMel Gorman * Return the size of the pages allocated when backing a VMA. In the majority 83308fba699SMel Gorman * cases this will be same size as used by the page table entries. 83408fba699SMel Gorman */ 83508fba699SMel Gorman unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) 83608fba699SMel Gorman { 83705ea8860SDan Williams if (vma->vm_ops && vma->vm_ops->pagesize) 83805ea8860SDan Williams return vma->vm_ops->pagesize(vma); 83908fba699SMel Gorman return PAGE_SIZE; 84008fba699SMel Gorman } 841f340ca0fSJoerg Roedel EXPORT_SYMBOL_GPL(vma_kernel_pagesize); 84208fba699SMel Gorman 84308fba699SMel Gorman /* 8443340289dSMel Gorman * Return the page size being used by the MMU to back a VMA. In the majority 8453340289dSMel Gorman * of cases, the page size used by the kernel matches the MMU size. On 84609135cc5SDan Williams * architectures where it differs, an architecture-specific 'strong' 84709135cc5SDan Williams * version of this symbol is required. 8483340289dSMel Gorman */ 84909135cc5SDan Williams __weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) 8503340289dSMel Gorman { 8513340289dSMel Gorman return vma_kernel_pagesize(vma); 8523340289dSMel Gorman } 8533340289dSMel Gorman 8543340289dSMel Gorman /* 85584afd99bSAndy Whitcroft * Flags for MAP_PRIVATE reservations. These are stored in the bottom 85684afd99bSAndy Whitcroft * bits of the reservation map pointer, which are always clear due to 85784afd99bSAndy Whitcroft * alignment. 85884afd99bSAndy Whitcroft */ 85984afd99bSAndy Whitcroft #define HPAGE_RESV_OWNER (1UL << 0) 86084afd99bSAndy Whitcroft #define HPAGE_RESV_UNMAPPED (1UL << 1) 86104f2cbe3SMel Gorman #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) 86284afd99bSAndy Whitcroft 863a1e78772SMel Gorman /* 864a1e78772SMel Gorman * These helpers are used to track how many pages are reserved for 865a1e78772SMel Gorman * faults in a MAP_PRIVATE mapping. Only the process that called mmap() 866a1e78772SMel Gorman * is guaranteed to have their future faults succeed. 867a1e78772SMel Gorman * 868a1e78772SMel Gorman * With the exception of reset_vma_resv_huge_pages() which is called at fork(), 869a1e78772SMel Gorman * the reserve counters are updated with the hugetlb_lock held. It is safe 870a1e78772SMel Gorman * to reset the VMA at fork() time as it is not in use yet and there is no 871a1e78772SMel Gorman * chance of the global counters getting corrupted as a result of the values. 87284afd99bSAndy Whitcroft * 87384afd99bSAndy Whitcroft * The private mapping reservation is represented in a subtly different 87484afd99bSAndy Whitcroft * manner to a shared mapping. A shared mapping has a region map associated 87584afd99bSAndy Whitcroft * with the underlying file, this region map represents the backing file 87684afd99bSAndy Whitcroft * pages which have ever had a reservation assigned which this persists even 87784afd99bSAndy Whitcroft * after the page is instantiated. A private mapping has a region map 87884afd99bSAndy Whitcroft * associated with the original mmap which is attached to all VMAs which 87984afd99bSAndy Whitcroft * reference it, this region map represents those offsets which have consumed 88084afd99bSAndy Whitcroft * reservation ie. where pages have been instantiated. 881a1e78772SMel Gorman */ 882e7c4b0bfSAndy Whitcroft static unsigned long get_vma_private_data(struct vm_area_struct *vma) 883e7c4b0bfSAndy Whitcroft { 884e7c4b0bfSAndy Whitcroft return (unsigned long)vma->vm_private_data; 885e7c4b0bfSAndy Whitcroft } 886e7c4b0bfSAndy Whitcroft 887e7c4b0bfSAndy Whitcroft static void set_vma_private_data(struct vm_area_struct *vma, 888e7c4b0bfSAndy Whitcroft unsigned long value) 889e7c4b0bfSAndy Whitcroft { 890e7c4b0bfSAndy Whitcroft vma->vm_private_data = (void *)value; 891e7c4b0bfSAndy Whitcroft } 892e7c4b0bfSAndy Whitcroft 893e9fe92aeSMina Almasry static void 894e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(struct resv_map *resv_map, 895e9fe92aeSMina Almasry struct hugetlb_cgroup *h_cg, 896e9fe92aeSMina Almasry struct hstate *h) 897e9fe92aeSMina Almasry { 898e9fe92aeSMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 899e9fe92aeSMina Almasry if (!h_cg || !h) { 900e9fe92aeSMina Almasry resv_map->reservation_counter = NULL; 901e9fe92aeSMina Almasry resv_map->pages_per_hpage = 0; 902e9fe92aeSMina Almasry resv_map->css = NULL; 903e9fe92aeSMina Almasry } else { 904e9fe92aeSMina Almasry resv_map->reservation_counter = 905e9fe92aeSMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 906e9fe92aeSMina Almasry resv_map->pages_per_hpage = pages_per_huge_page(h); 907e9fe92aeSMina Almasry resv_map->css = &h_cg->css; 908e9fe92aeSMina Almasry } 909e9fe92aeSMina Almasry #endif 910e9fe92aeSMina Almasry } 911e9fe92aeSMina Almasry 9129119a41eSJoonsoo Kim struct resv_map *resv_map_alloc(void) 91384afd99bSAndy Whitcroft { 91484afd99bSAndy Whitcroft struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); 9155e911373SMike Kravetz struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL); 9165e911373SMike Kravetz 9175e911373SMike Kravetz if (!resv_map || !rg) { 9185e911373SMike Kravetz kfree(resv_map); 9195e911373SMike Kravetz kfree(rg); 92084afd99bSAndy Whitcroft return NULL; 9215e911373SMike Kravetz } 92284afd99bSAndy Whitcroft 92384afd99bSAndy Whitcroft kref_init(&resv_map->refs); 9247b24d861SDavidlohr Bueso spin_lock_init(&resv_map->lock); 92584afd99bSAndy Whitcroft INIT_LIST_HEAD(&resv_map->regions); 92684afd99bSAndy Whitcroft 9275e911373SMike Kravetz resv_map->adds_in_progress = 0; 928e9fe92aeSMina Almasry /* 929e9fe92aeSMina Almasry * Initialize these to 0. On shared mappings, 0's here indicate these 930e9fe92aeSMina Almasry * fields don't do cgroup accounting. On private mappings, these will be 931e9fe92aeSMina Almasry * re-initialized to the proper values, to indicate that hugetlb cgroup 932e9fe92aeSMina Almasry * reservations are to be un-charged from here. 933e9fe92aeSMina Almasry */ 934e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, NULL, NULL); 9355e911373SMike Kravetz 9365e911373SMike Kravetz INIT_LIST_HEAD(&resv_map->region_cache); 9375e911373SMike Kravetz list_add(&rg->link, &resv_map->region_cache); 9385e911373SMike Kravetz resv_map->region_cache_count = 1; 9395e911373SMike Kravetz 94084afd99bSAndy Whitcroft return resv_map; 94184afd99bSAndy Whitcroft } 94284afd99bSAndy Whitcroft 9439119a41eSJoonsoo Kim void resv_map_release(struct kref *ref) 94484afd99bSAndy Whitcroft { 94584afd99bSAndy Whitcroft struct resv_map *resv_map = container_of(ref, struct resv_map, refs); 9465e911373SMike Kravetz struct list_head *head = &resv_map->region_cache; 9475e911373SMike Kravetz struct file_region *rg, *trg; 94884afd99bSAndy Whitcroft 94984afd99bSAndy Whitcroft /* Clear out any active regions before we release the map. */ 950feba16e2SMike Kravetz region_del(resv_map, 0, LONG_MAX); 9515e911373SMike Kravetz 9525e911373SMike Kravetz /* ... and any entries left in the cache */ 9535e911373SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 9545e911373SMike Kravetz list_del(&rg->link); 9555e911373SMike Kravetz kfree(rg); 9565e911373SMike Kravetz } 9575e911373SMike Kravetz 9585e911373SMike Kravetz VM_BUG_ON(resv_map->adds_in_progress); 9595e911373SMike Kravetz 96084afd99bSAndy Whitcroft kfree(resv_map); 96184afd99bSAndy Whitcroft } 96284afd99bSAndy Whitcroft 9634e35f483SJoonsoo Kim static inline struct resv_map *inode_resv_map(struct inode *inode) 9644e35f483SJoonsoo Kim { 965f27a5136SMike Kravetz /* 966f27a5136SMike Kravetz * At inode evict time, i_mapping may not point to the original 967f27a5136SMike Kravetz * address space within the inode. This original address space 968f27a5136SMike Kravetz * contains the pointer to the resv_map. So, always use the 969f27a5136SMike Kravetz * address space embedded within the inode. 970f27a5136SMike Kravetz * The VERY common case is inode->mapping == &inode->i_data but, 971f27a5136SMike Kravetz * this may not be true for device special inodes. 972f27a5136SMike Kravetz */ 973f27a5136SMike Kravetz return (struct resv_map *)(&inode->i_data)->private_data; 9744e35f483SJoonsoo Kim } 9754e35f483SJoonsoo Kim 97684afd99bSAndy Whitcroft static struct resv_map *vma_resv_map(struct vm_area_struct *vma) 977a1e78772SMel Gorman { 97881d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 9794e35f483SJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE) { 9804e35f483SJoonsoo Kim struct address_space *mapping = vma->vm_file->f_mapping; 9814e35f483SJoonsoo Kim struct inode *inode = mapping->host; 9824e35f483SJoonsoo Kim 9834e35f483SJoonsoo Kim return inode_resv_map(inode); 9844e35f483SJoonsoo Kim 9854e35f483SJoonsoo Kim } else { 98684afd99bSAndy Whitcroft return (struct resv_map *)(get_vma_private_data(vma) & 98784afd99bSAndy Whitcroft ~HPAGE_RESV_MASK); 9884e35f483SJoonsoo Kim } 989a1e78772SMel Gorman } 990a1e78772SMel Gorman 99184afd99bSAndy Whitcroft static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) 992a1e78772SMel Gorman { 99381d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 99481d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 995a1e78772SMel Gorman 99684afd99bSAndy Whitcroft set_vma_private_data(vma, (get_vma_private_data(vma) & 99784afd99bSAndy Whitcroft HPAGE_RESV_MASK) | (unsigned long)map); 99804f2cbe3SMel Gorman } 99904f2cbe3SMel Gorman 100004f2cbe3SMel Gorman static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) 100104f2cbe3SMel Gorman { 100281d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 100381d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 1004e7c4b0bfSAndy Whitcroft 1005e7c4b0bfSAndy Whitcroft set_vma_private_data(vma, get_vma_private_data(vma) | flags); 100604f2cbe3SMel Gorman } 100704f2cbe3SMel Gorman 100804f2cbe3SMel Gorman static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) 100904f2cbe3SMel Gorman { 101081d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 1011e7c4b0bfSAndy Whitcroft 1012e7c4b0bfSAndy Whitcroft return (get_vma_private_data(vma) & flag) != 0; 1013a1e78772SMel Gorman } 1014a1e78772SMel Gorman 101504f2cbe3SMel Gorman /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ 1016a1e78772SMel Gorman void reset_vma_resv_huge_pages(struct vm_area_struct *vma) 1017a1e78772SMel Gorman { 101881d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 1019f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 1020a1e78772SMel Gorman vma->vm_private_data = (void *)0; 1021a1e78772SMel Gorman } 1022a1e78772SMel Gorman 1023550a7d60SMina Almasry /* 1024550a7d60SMina Almasry * Reset and decrement one ref on hugepage private reservation. 1025550a7d60SMina Almasry * Called with mm->mmap_sem writer semaphore held. 1026550a7d60SMina Almasry * This function should be only used by move_vma() and operate on 1027550a7d60SMina Almasry * same sized vma. It should never come here with last ref on the 1028550a7d60SMina Almasry * reservation. 1029550a7d60SMina Almasry */ 1030550a7d60SMina Almasry void clear_vma_resv_huge_pages(struct vm_area_struct *vma) 1031550a7d60SMina Almasry { 1032550a7d60SMina Almasry /* 1033550a7d60SMina Almasry * Clear the old hugetlb private page reservation. 1034550a7d60SMina Almasry * It has already been transferred to new_vma. 1035550a7d60SMina Almasry * 1036550a7d60SMina Almasry * During a mremap() operation of a hugetlb vma we call move_vma() 1037550a7d60SMina Almasry * which copies vma into new_vma and unmaps vma. After the copy 1038550a7d60SMina Almasry * operation both new_vma and vma share a reference to the resv_map 1039550a7d60SMina Almasry * struct, and at that point vma is about to be unmapped. We don't 1040550a7d60SMina Almasry * want to return the reservation to the pool at unmap of vma because 1041550a7d60SMina Almasry * the reservation still lives on in new_vma, so simply decrement the 1042550a7d60SMina Almasry * ref here and remove the resv_map reference from this vma. 1043550a7d60SMina Almasry */ 1044550a7d60SMina Almasry struct resv_map *reservations = vma_resv_map(vma); 1045550a7d60SMina Almasry 1046afe041c2SBui Quang Minh if (reservations && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 1047afe041c2SBui Quang Minh resv_map_put_hugetlb_cgroup_uncharge_info(reservations); 1048550a7d60SMina Almasry kref_put(&reservations->refs, resv_map_release); 1049afe041c2SBui Quang Minh } 1050550a7d60SMina Almasry 1051550a7d60SMina Almasry reset_vma_resv_huge_pages(vma); 1052550a7d60SMina Almasry } 1053550a7d60SMina Almasry 1054a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 1055559ec2f8SNicholas Krause static bool vma_has_reserves(struct vm_area_struct *vma, long chg) 1056a1e78772SMel Gorman { 1057af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_NORESERVE) { 1058af0ed73eSJoonsoo Kim /* 1059af0ed73eSJoonsoo Kim * This address is already reserved by other process(chg == 0), 1060af0ed73eSJoonsoo Kim * so, we should decrement reserved count. Without decrementing, 1061af0ed73eSJoonsoo Kim * reserve count remains after releasing inode, because this 1062af0ed73eSJoonsoo Kim * allocated page will go into page cache and is regarded as 1063af0ed73eSJoonsoo Kim * coming from reserved pool in releasing step. Currently, we 1064af0ed73eSJoonsoo Kim * don't have any other solution to deal with this situation 1065af0ed73eSJoonsoo Kim * properly, so add work-around here. 1066af0ed73eSJoonsoo Kim */ 1067af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE && chg == 0) 1068559ec2f8SNicholas Krause return true; 1069af0ed73eSJoonsoo Kim else 1070559ec2f8SNicholas Krause return false; 1071af0ed73eSJoonsoo Kim } 1072a63884e9SJoonsoo Kim 1073a63884e9SJoonsoo Kim /* Shared mappings always use reserves */ 10741fb1b0e9SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 10751fb1b0e9SMike Kravetz /* 10761fb1b0e9SMike Kravetz * We know VM_NORESERVE is not set. Therefore, there SHOULD 10771fb1b0e9SMike Kravetz * be a region map for all pages. The only situation where 10781fb1b0e9SMike Kravetz * there is no region map is if a hole was punched via 10797c8de358SEthon Paul * fallocate. In this case, there really are no reserves to 10801fb1b0e9SMike Kravetz * use. This situation is indicated if chg != 0. 10811fb1b0e9SMike Kravetz */ 10821fb1b0e9SMike Kravetz if (chg) 10831fb1b0e9SMike Kravetz return false; 10841fb1b0e9SMike Kravetz else 1085559ec2f8SNicholas Krause return true; 10861fb1b0e9SMike Kravetz } 1087a63884e9SJoonsoo Kim 1088a63884e9SJoonsoo Kim /* 1089a63884e9SJoonsoo Kim * Only the process that called mmap() has reserves for 1090a63884e9SJoonsoo Kim * private mappings. 1091a63884e9SJoonsoo Kim */ 109267961f9dSMike Kravetz if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 109367961f9dSMike Kravetz /* 109467961f9dSMike Kravetz * Like the shared case above, a hole punch or truncate 109567961f9dSMike Kravetz * could have been performed on the private mapping. 109667961f9dSMike Kravetz * Examine the value of chg to determine if reserves 109767961f9dSMike Kravetz * actually exist or were previously consumed. 109867961f9dSMike Kravetz * Very Subtle - The value of chg comes from a previous 109967961f9dSMike Kravetz * call to vma_needs_reserves(). The reserve map for 110067961f9dSMike Kravetz * private mappings has different (opposite) semantics 110167961f9dSMike Kravetz * than that of shared mappings. vma_needs_reserves() 110267961f9dSMike Kravetz * has already taken this difference in semantics into 110367961f9dSMike Kravetz * account. Therefore, the meaning of chg is the same 110467961f9dSMike Kravetz * as in the shared case above. Code could easily be 110567961f9dSMike Kravetz * combined, but keeping it separate draws attention to 110667961f9dSMike Kravetz * subtle differences. 110767961f9dSMike Kravetz */ 110867961f9dSMike Kravetz if (chg) 110967961f9dSMike Kravetz return false; 111067961f9dSMike Kravetz else 1111559ec2f8SNicholas Krause return true; 111267961f9dSMike Kravetz } 1113a63884e9SJoonsoo Kim 1114559ec2f8SNicholas Krause return false; 1115a1e78772SMel Gorman } 1116a1e78772SMel Gorman 1117a5516438SAndi Kleen static void enqueue_huge_page(struct hstate *h, struct page *page) 11181da177e4SLinus Torvalds { 11191da177e4SLinus Torvalds int nid = page_to_nid(page); 11209487ca60SMike Kravetz 11219487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1122b65a4edaSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1123b65a4edaSMike Kravetz 11240edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_freelists[nid]); 1125a5516438SAndi Kleen h->free_huge_pages++; 1126a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 11276c037149SMike Kravetz SetHPageFreed(page); 11281da177e4SLinus Torvalds } 11291da177e4SLinus Torvalds 113094310cbcSAnshuman Khandual static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) 1131bf50bab2SNaoya Horiguchi { 1132bf50bab2SNaoya Horiguchi struct page *page; 11331a08ae36SPavel Tatashin bool pin = !!(current->flags & PF_MEMALLOC_PIN); 1134bf50bab2SNaoya Horiguchi 11359487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1136bbe88753SJoonsoo Kim list_for_each_entry(page, &h->hugepage_freelists[nid], lru) { 11378e3560d9SPavel Tatashin if (pin && !is_pinnable_page(page)) 1138bbe88753SJoonsoo Kim continue; 1139bbe88753SJoonsoo Kim 11406664bfc8SWei Yang if (PageHWPoison(page)) 11416664bfc8SWei Yang continue; 1142bbe88753SJoonsoo Kim 11430edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_activelist); 1144a9869b83SNaoya Horiguchi set_page_refcounted(page); 11456c037149SMike Kravetz ClearHPageFreed(page); 1146bf50bab2SNaoya Horiguchi h->free_huge_pages--; 1147bf50bab2SNaoya Horiguchi h->free_huge_pages_node[nid]--; 1148bf50bab2SNaoya Horiguchi return page; 1149bf50bab2SNaoya Horiguchi } 1150bf50bab2SNaoya Horiguchi 11516664bfc8SWei Yang return NULL; 11526664bfc8SWei Yang } 11536664bfc8SWei Yang 11543e59fcb0SMichal Hocko static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid, 11553e59fcb0SMichal Hocko nodemask_t *nmask) 115694310cbcSAnshuman Khandual { 11573e59fcb0SMichal Hocko unsigned int cpuset_mems_cookie; 11583e59fcb0SMichal Hocko struct zonelist *zonelist; 11593e59fcb0SMichal Hocko struct zone *zone; 11603e59fcb0SMichal Hocko struct zoneref *z; 116198fa15f3SAnshuman Khandual int node = NUMA_NO_NODE; 11623e59fcb0SMichal Hocko 11633e59fcb0SMichal Hocko zonelist = node_zonelist(nid, gfp_mask); 11643e59fcb0SMichal Hocko 11653e59fcb0SMichal Hocko retry_cpuset: 11663e59fcb0SMichal Hocko cpuset_mems_cookie = read_mems_allowed_begin(); 11673e59fcb0SMichal Hocko for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) { 116894310cbcSAnshuman Khandual struct page *page; 116994310cbcSAnshuman Khandual 11703e59fcb0SMichal Hocko if (!cpuset_zone_allowed(zone, gfp_mask)) 11713e59fcb0SMichal Hocko continue; 11723e59fcb0SMichal Hocko /* 11733e59fcb0SMichal Hocko * no need to ask again on the same node. Pool is node rather than 11743e59fcb0SMichal Hocko * zone aware 11753e59fcb0SMichal Hocko */ 11763e59fcb0SMichal Hocko if (zone_to_nid(zone) == node) 11773e59fcb0SMichal Hocko continue; 11783e59fcb0SMichal Hocko node = zone_to_nid(zone); 117994310cbcSAnshuman Khandual 118094310cbcSAnshuman Khandual page = dequeue_huge_page_node_exact(h, node); 118194310cbcSAnshuman Khandual if (page) 118294310cbcSAnshuman Khandual return page; 118394310cbcSAnshuman Khandual } 11843e59fcb0SMichal Hocko if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie))) 11853e59fcb0SMichal Hocko goto retry_cpuset; 11863e59fcb0SMichal Hocko 118794310cbcSAnshuman Khandual return NULL; 118894310cbcSAnshuman Khandual } 118994310cbcSAnshuman Khandual 1190a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 1191a5516438SAndi Kleen struct vm_area_struct *vma, 1192af0ed73eSJoonsoo Kim unsigned long address, int avoid_reserve, 1193af0ed73eSJoonsoo Kim long chg) 11941da177e4SLinus Torvalds { 1195cfcaa66fSBen Widawsky struct page *page = NULL; 1196480eccf9SLee Schermerhorn struct mempolicy *mpol; 119704ec6264SVlastimil Babka gfp_t gfp_mask; 11983e59fcb0SMichal Hocko nodemask_t *nodemask; 119904ec6264SVlastimil Babka int nid; 12001da177e4SLinus Torvalds 1201a1e78772SMel Gorman /* 1202a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 1203a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 1204a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 1205a1e78772SMel Gorman */ 1206af0ed73eSJoonsoo Kim if (!vma_has_reserves(vma, chg) && 1207a5516438SAndi Kleen h->free_huge_pages - h->resv_huge_pages == 0) 1208c0ff7453SMiao Xie goto err; 1209a1e78772SMel Gorman 121004f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 1211a5516438SAndi Kleen if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) 12126eab04a8SJustin P. Mattock goto err; 121304f2cbe3SMel Gorman 121404ec6264SVlastimil Babka gfp_mask = htlb_alloc_mask(h); 121504ec6264SVlastimil Babka nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 1216cfcaa66fSBen Widawsky 1217cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 12183e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1219cfcaa66fSBen Widawsky 1220cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 1221cfcaa66fSBen Widawsky nodemask = NULL; 1222cfcaa66fSBen Widawsky } 1223cfcaa66fSBen Widawsky 1224cfcaa66fSBen Widawsky if (!page) 1225cfcaa66fSBen Widawsky page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 1226cfcaa66fSBen Widawsky 12273e59fcb0SMichal Hocko if (page && !avoid_reserve && vma_has_reserves(vma, chg)) { 1228d6995da3SMike Kravetz SetHPageRestoreReserve(page); 1229a63884e9SJoonsoo Kim h->resv_huge_pages--; 1230bf50bab2SNaoya Horiguchi } 1231cc9a6c87SMel Gorman 1232cc9a6c87SMel Gorman mpol_cond_put(mpol); 1233cc9a6c87SMel Gorman return page; 1234cc9a6c87SMel Gorman 1235c0ff7453SMiao Xie err: 1236cc9a6c87SMel Gorman return NULL; 12371da177e4SLinus Torvalds } 12381da177e4SLinus Torvalds 12391cac6f2cSLuiz Capitulino /* 12401cac6f2cSLuiz Capitulino * common helper functions for hstate_next_node_to_{alloc|free}. 12411cac6f2cSLuiz Capitulino * We may have allocated or freed a huge page based on a different 12421cac6f2cSLuiz Capitulino * nodes_allowed previously, so h->next_node_to_{alloc|free} might 12431cac6f2cSLuiz Capitulino * be outside of *nodes_allowed. Ensure that we use an allowed 12441cac6f2cSLuiz Capitulino * node for alloc or free. 12451cac6f2cSLuiz Capitulino */ 12461cac6f2cSLuiz Capitulino static int next_node_allowed(int nid, nodemask_t *nodes_allowed) 12471cac6f2cSLuiz Capitulino { 12480edaf86cSAndrew Morton nid = next_node_in(nid, *nodes_allowed); 12491cac6f2cSLuiz Capitulino VM_BUG_ON(nid >= MAX_NUMNODES); 12501cac6f2cSLuiz Capitulino 12511cac6f2cSLuiz Capitulino return nid; 12521cac6f2cSLuiz Capitulino } 12531cac6f2cSLuiz Capitulino 12541cac6f2cSLuiz Capitulino static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) 12551cac6f2cSLuiz Capitulino { 12561cac6f2cSLuiz Capitulino if (!node_isset(nid, *nodes_allowed)) 12571cac6f2cSLuiz Capitulino nid = next_node_allowed(nid, nodes_allowed); 12581cac6f2cSLuiz Capitulino return nid; 12591cac6f2cSLuiz Capitulino } 12601cac6f2cSLuiz Capitulino 12611cac6f2cSLuiz Capitulino /* 12621cac6f2cSLuiz Capitulino * returns the previously saved node ["this node"] from which to 12631cac6f2cSLuiz Capitulino * allocate a persistent huge page for the pool and advance the 12641cac6f2cSLuiz Capitulino * next node from which to allocate, handling wrap at end of node 12651cac6f2cSLuiz Capitulino * mask. 12661cac6f2cSLuiz Capitulino */ 12671cac6f2cSLuiz Capitulino static int hstate_next_node_to_alloc(struct hstate *h, 12681cac6f2cSLuiz Capitulino nodemask_t *nodes_allowed) 12691cac6f2cSLuiz Capitulino { 12701cac6f2cSLuiz Capitulino int nid; 12711cac6f2cSLuiz Capitulino 12721cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12731cac6f2cSLuiz Capitulino 12741cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); 12751cac6f2cSLuiz Capitulino h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); 12761cac6f2cSLuiz Capitulino 12771cac6f2cSLuiz Capitulino return nid; 12781cac6f2cSLuiz Capitulino } 12791cac6f2cSLuiz Capitulino 12801cac6f2cSLuiz Capitulino /* 128110c6ec49SMike Kravetz * helper for remove_pool_huge_page() - return the previously saved 12821cac6f2cSLuiz Capitulino * node ["this node"] from which to free a huge page. Advance the 12831cac6f2cSLuiz Capitulino * next node id whether or not we find a free huge page to free so 12841cac6f2cSLuiz Capitulino * that the next attempt to free addresses the next node. 12851cac6f2cSLuiz Capitulino */ 12861cac6f2cSLuiz Capitulino static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) 12871cac6f2cSLuiz Capitulino { 12881cac6f2cSLuiz Capitulino int nid; 12891cac6f2cSLuiz Capitulino 12901cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12911cac6f2cSLuiz Capitulino 12921cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); 12931cac6f2cSLuiz Capitulino h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); 12941cac6f2cSLuiz Capitulino 12951cac6f2cSLuiz Capitulino return nid; 12961cac6f2cSLuiz Capitulino } 12971cac6f2cSLuiz Capitulino 12981cac6f2cSLuiz Capitulino #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ 12991cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 13001cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 13011cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ 13021cac6f2cSLuiz Capitulino nr_nodes--) 13031cac6f2cSLuiz Capitulino 13041cac6f2cSLuiz Capitulino #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ 13051cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 13061cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 13071cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_free(hs, mask)) || 1); \ 13081cac6f2cSLuiz Capitulino nr_nodes--) 13091cac6f2cSLuiz Capitulino 13108531fc6fSMike Kravetz /* used to demote non-gigantic_huge pages as well */ 131134d9e35bSMike Kravetz static void __destroy_compound_gigantic_page(struct page *page, 131234d9e35bSMike Kravetz unsigned int order, bool demote) 1313944d9fecSLuiz Capitulino { 1314944d9fecSLuiz Capitulino int i; 1315944d9fecSLuiz Capitulino int nr_pages = 1 << order; 1316944d9fecSLuiz Capitulino struct page *p = page + 1; 1317944d9fecSLuiz Capitulino 1318c8cc708aSGerald Schaefer atomic_set(compound_mapcount_ptr(page), 0); 131947e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 132047e29d32SJohn Hubbard 1321944d9fecSLuiz Capitulino for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 1322a01f4390SMike Kravetz p->mapping = NULL; 13231d798ca3SKirill A. Shutemov clear_compound_head(p); 132434d9e35bSMike Kravetz if (!demote) 1325944d9fecSLuiz Capitulino set_page_refcounted(p); 1326944d9fecSLuiz Capitulino } 1327944d9fecSLuiz Capitulino 1328944d9fecSLuiz Capitulino set_compound_order(page, 0); 13295232c63fSMatthew Wilcox (Oracle) #ifdef CONFIG_64BIT 1330ba9c1201SGerald Schaefer page[1].compound_nr = 0; 13315232c63fSMatthew Wilcox (Oracle) #endif 1332944d9fecSLuiz Capitulino __ClearPageHead(page); 1333944d9fecSLuiz Capitulino } 1334944d9fecSLuiz Capitulino 13358531fc6fSMike Kravetz static void destroy_compound_hugetlb_page_for_demote(struct page *page, 13368531fc6fSMike Kravetz unsigned int order) 13378531fc6fSMike Kravetz { 13388531fc6fSMike Kravetz __destroy_compound_gigantic_page(page, order, true); 13398531fc6fSMike Kravetz } 13408531fc6fSMike Kravetz 13418531fc6fSMike Kravetz #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE 134234d9e35bSMike Kravetz static void destroy_compound_gigantic_page(struct page *page, 134334d9e35bSMike Kravetz unsigned int order) 134434d9e35bSMike Kravetz { 134534d9e35bSMike Kravetz __destroy_compound_gigantic_page(page, order, false); 134634d9e35bSMike Kravetz } 134734d9e35bSMike Kravetz 1348d00181b9SKirill A. Shutemov static void free_gigantic_page(struct page *page, unsigned int order) 1349944d9fecSLuiz Capitulino { 1350cf11e85fSRoman Gushchin /* 1351cf11e85fSRoman Gushchin * If the page isn't allocated using the cma allocator, 1352cf11e85fSRoman Gushchin * cma_release() returns false. 1353cf11e85fSRoman Gushchin */ 1354dbda8feaSBarry Song #ifdef CONFIG_CMA 1355dbda8feaSBarry Song if (cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order)) 1356cf11e85fSRoman Gushchin return; 1357dbda8feaSBarry Song #endif 1358cf11e85fSRoman Gushchin 1359944d9fecSLuiz Capitulino free_contig_range(page_to_pfn(page), 1 << order); 1360944d9fecSLuiz Capitulino } 1361944d9fecSLuiz Capitulino 13624eb0716eSAlexandre Ghiti #ifdef CONFIG_CONTIG_ALLOC 1363d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 1364d9cc948fSMichal Hocko int nid, nodemask_t *nodemask) 1365944d9fecSLuiz Capitulino { 136604adbc3fSMiaohe Lin unsigned long nr_pages = pages_per_huge_page(h); 1367953f064aSLi Xinhai if (nid == NUMA_NO_NODE) 1368953f064aSLi Xinhai nid = numa_mem_id(); 1369944d9fecSLuiz Capitulino 1370dbda8feaSBarry Song #ifdef CONFIG_CMA 1371dbda8feaSBarry Song { 1372cf11e85fSRoman Gushchin struct page *page; 1373cf11e85fSRoman Gushchin int node; 1374cf11e85fSRoman Gushchin 1375953f064aSLi Xinhai if (hugetlb_cma[nid]) { 1376953f064aSLi Xinhai page = cma_alloc(hugetlb_cma[nid], nr_pages, 1377953f064aSLi Xinhai huge_page_order(h), true); 1378953f064aSLi Xinhai if (page) 1379953f064aSLi Xinhai return page; 1380953f064aSLi Xinhai } 1381953f064aSLi Xinhai 1382953f064aSLi Xinhai if (!(gfp_mask & __GFP_THISNODE)) { 1383cf11e85fSRoman Gushchin for_each_node_mask(node, *nodemask) { 1384953f064aSLi Xinhai if (node == nid || !hugetlb_cma[node]) 1385cf11e85fSRoman Gushchin continue; 1386cf11e85fSRoman Gushchin 1387cf11e85fSRoman Gushchin page = cma_alloc(hugetlb_cma[node], nr_pages, 1388cf11e85fSRoman Gushchin huge_page_order(h), true); 1389cf11e85fSRoman Gushchin if (page) 1390cf11e85fSRoman Gushchin return page; 1391cf11e85fSRoman Gushchin } 1392cf11e85fSRoman Gushchin } 1393953f064aSLi Xinhai } 1394dbda8feaSBarry Song #endif 1395cf11e85fSRoman Gushchin 13965e27a2dfSAnshuman Khandual return alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask); 1397944d9fecSLuiz Capitulino } 1398944d9fecSLuiz Capitulino 13994eb0716eSAlexandre Ghiti #else /* !CONFIG_CONTIG_ALLOC */ 14004eb0716eSAlexandre Ghiti static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 14014eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 14024eb0716eSAlexandre Ghiti { 14034eb0716eSAlexandre Ghiti return NULL; 14044eb0716eSAlexandre Ghiti } 14054eb0716eSAlexandre Ghiti #endif /* CONFIG_CONTIG_ALLOC */ 1406944d9fecSLuiz Capitulino 1407e1073d1eSAneesh Kumar K.V #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ 1408d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 14094eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 14104eb0716eSAlexandre Ghiti { 14114eb0716eSAlexandre Ghiti return NULL; 14124eb0716eSAlexandre Ghiti } 1413d00181b9SKirill A. Shutemov static inline void free_gigantic_page(struct page *page, unsigned int order) { } 1414944d9fecSLuiz Capitulino static inline void destroy_compound_gigantic_page(struct page *page, 1415d00181b9SKirill A. Shutemov unsigned int order) { } 1416944d9fecSLuiz Capitulino #endif 1417944d9fecSLuiz Capitulino 14186eb4e88aSMike Kravetz /* 14196eb4e88aSMike Kravetz * Remove hugetlb page from lists, and update dtor so that page appears 142034d9e35bSMike Kravetz * as just a compound page. 142134d9e35bSMike Kravetz * 142234d9e35bSMike Kravetz * A reference is held on the page, except in the case of demote. 14236eb4e88aSMike Kravetz * 14246eb4e88aSMike Kravetz * Must be called with hugetlb lock held. 14256eb4e88aSMike Kravetz */ 142634d9e35bSMike Kravetz static void __remove_hugetlb_page(struct hstate *h, struct page *page, 142734d9e35bSMike Kravetz bool adjust_surplus, 142834d9e35bSMike Kravetz bool demote) 14296eb4e88aSMike Kravetz { 14306eb4e88aSMike Kravetz int nid = page_to_nid(page); 14316eb4e88aSMike Kravetz 14326eb4e88aSMike Kravetz VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); 14336eb4e88aSMike Kravetz VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); 14346eb4e88aSMike Kravetz 14359487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 14366eb4e88aSMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 14376eb4e88aSMike Kravetz return; 14386eb4e88aSMike Kravetz 14396eb4e88aSMike Kravetz list_del(&page->lru); 14406eb4e88aSMike Kravetz 14416eb4e88aSMike Kravetz if (HPageFreed(page)) { 14426eb4e88aSMike Kravetz h->free_huge_pages--; 14436eb4e88aSMike Kravetz h->free_huge_pages_node[nid]--; 14446eb4e88aSMike Kravetz } 14456eb4e88aSMike Kravetz if (adjust_surplus) { 14466eb4e88aSMike Kravetz h->surplus_huge_pages--; 14476eb4e88aSMike Kravetz h->surplus_huge_pages_node[nid]--; 14486eb4e88aSMike Kravetz } 14496eb4e88aSMike Kravetz 1450e32d20c0SMike Kravetz /* 1451e32d20c0SMike Kravetz * Very subtle 1452e32d20c0SMike Kravetz * 1453e32d20c0SMike Kravetz * For non-gigantic pages set the destructor to the normal compound 1454e32d20c0SMike Kravetz * page dtor. This is needed in case someone takes an additional 1455e32d20c0SMike Kravetz * temporary ref to the page, and freeing is delayed until they drop 1456e32d20c0SMike Kravetz * their reference. 1457e32d20c0SMike Kravetz * 1458e32d20c0SMike Kravetz * For gigantic pages set the destructor to the null dtor. This 1459e32d20c0SMike Kravetz * destructor will never be called. Before freeing the gigantic 1460e32d20c0SMike Kravetz * page destroy_compound_gigantic_page will turn the compound page 1461e32d20c0SMike Kravetz * into a simple group of pages. After this the destructor does not 1462e32d20c0SMike Kravetz * apply. 1463e32d20c0SMike Kravetz * 1464e32d20c0SMike Kravetz * This handles the case where more than one ref is held when and 1465e32d20c0SMike Kravetz * after update_and_free_page is called. 146634d9e35bSMike Kravetz * 146734d9e35bSMike Kravetz * In the case of demote we do not ref count the page as it will soon 146834d9e35bSMike Kravetz * be turned into a page of smaller size. 1469e32d20c0SMike Kravetz */ 147034d9e35bSMike Kravetz if (!demote) 14716eb4e88aSMike Kravetz set_page_refcounted(page); 1472e32d20c0SMike Kravetz if (hstate_is_gigantic(h)) 14736eb4e88aSMike Kravetz set_compound_page_dtor(page, NULL_COMPOUND_DTOR); 1474e32d20c0SMike Kravetz else 1475e32d20c0SMike Kravetz set_compound_page_dtor(page, COMPOUND_PAGE_DTOR); 14766eb4e88aSMike Kravetz 14776eb4e88aSMike Kravetz h->nr_huge_pages--; 14786eb4e88aSMike Kravetz h->nr_huge_pages_node[nid]--; 14796eb4e88aSMike Kravetz } 14806eb4e88aSMike Kravetz 148134d9e35bSMike Kravetz static void remove_hugetlb_page(struct hstate *h, struct page *page, 148234d9e35bSMike Kravetz bool adjust_surplus) 148334d9e35bSMike Kravetz { 148434d9e35bSMike Kravetz __remove_hugetlb_page(h, page, adjust_surplus, false); 148534d9e35bSMike Kravetz } 148634d9e35bSMike Kravetz 14878531fc6fSMike Kravetz static void remove_hugetlb_page_for_demote(struct hstate *h, struct page *page, 14888531fc6fSMike Kravetz bool adjust_surplus) 14898531fc6fSMike Kravetz { 14908531fc6fSMike Kravetz __remove_hugetlb_page(h, page, adjust_surplus, true); 14918531fc6fSMike Kravetz } 14928531fc6fSMike Kravetz 1493ad2fa371SMuchun Song static void add_hugetlb_page(struct hstate *h, struct page *page, 1494ad2fa371SMuchun Song bool adjust_surplus) 1495ad2fa371SMuchun Song { 1496ad2fa371SMuchun Song int zeroed; 1497ad2fa371SMuchun Song int nid = page_to_nid(page); 1498ad2fa371SMuchun Song 1499ad2fa371SMuchun Song VM_BUG_ON_PAGE(!HPageVmemmapOptimized(page), page); 1500ad2fa371SMuchun Song 1501ad2fa371SMuchun Song lockdep_assert_held(&hugetlb_lock); 1502ad2fa371SMuchun Song 1503ad2fa371SMuchun Song INIT_LIST_HEAD(&page->lru); 1504ad2fa371SMuchun Song h->nr_huge_pages++; 1505ad2fa371SMuchun Song h->nr_huge_pages_node[nid]++; 1506ad2fa371SMuchun Song 1507ad2fa371SMuchun Song if (adjust_surplus) { 1508ad2fa371SMuchun Song h->surplus_huge_pages++; 1509ad2fa371SMuchun Song h->surplus_huge_pages_node[nid]++; 1510ad2fa371SMuchun Song } 1511ad2fa371SMuchun Song 1512ad2fa371SMuchun Song set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1513ad2fa371SMuchun Song set_page_private(page, 0); 1514ad2fa371SMuchun Song SetHPageVmemmapOptimized(page); 1515ad2fa371SMuchun Song 1516ad2fa371SMuchun Song /* 1517b65a4edaSMike Kravetz * This page is about to be managed by the hugetlb allocator and 1518b65a4edaSMike Kravetz * should have no users. Drop our reference, and check for others 1519b65a4edaSMike Kravetz * just in case. 1520ad2fa371SMuchun Song */ 1521ad2fa371SMuchun Song zeroed = put_page_testzero(page); 1522b65a4edaSMike Kravetz if (!zeroed) 1523b65a4edaSMike Kravetz /* 1524b65a4edaSMike Kravetz * It is VERY unlikely soneone else has taken a ref on 1525b65a4edaSMike Kravetz * the page. In this case, we simply return as the 1526b65a4edaSMike Kravetz * hugetlb destructor (free_huge_page) will be called 1527b65a4edaSMike Kravetz * when this other ref is dropped. 1528b65a4edaSMike Kravetz */ 1529b65a4edaSMike Kravetz return; 1530b65a4edaSMike Kravetz 1531ad2fa371SMuchun Song arch_clear_hugepage_flags(page); 1532ad2fa371SMuchun Song enqueue_huge_page(h, page); 1533ad2fa371SMuchun Song } 1534ad2fa371SMuchun Song 1535b65d4adbSMuchun Song static void __update_and_free_page(struct hstate *h, struct page *page) 15366af2acb6SAdam Litke { 15376af2acb6SAdam Litke int i; 1538dbfee5aeSMike Kravetz struct page *subpage = page; 1539a5516438SAndi Kleen 15404eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 1541944d9fecSLuiz Capitulino return; 154218229df5SAndy Whitcroft 15435981611dSMuchun Song if (hugetlb_vmemmap_alloc(h, page)) { 1544ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 1545ad2fa371SMuchun Song /* 1546ad2fa371SMuchun Song * If we cannot allocate vmemmap pages, just refuse to free the 1547ad2fa371SMuchun Song * page and put the page back on the hugetlb free list and treat 1548ad2fa371SMuchun Song * as a surplus page. 1549ad2fa371SMuchun Song */ 1550ad2fa371SMuchun Song add_hugetlb_page(h, page, true); 1551ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 1552ad2fa371SMuchun Song return; 1553ad2fa371SMuchun Song } 1554ad2fa371SMuchun Song 1555dbfee5aeSMike Kravetz for (i = 0; i < pages_per_huge_page(h); 1556dbfee5aeSMike Kravetz i++, subpage = mem_map_next(subpage, page, i)) { 1557dbfee5aeSMike Kravetz subpage->flags &= ~(1 << PG_locked | 1 << PG_error | 155832f84528SChris Forbes 1 << PG_referenced | 1 << PG_dirty | 1559a7407a27SLuiz Capitulino 1 << PG_active | 1 << PG_private | 1560a7407a27SLuiz Capitulino 1 << PG_writeback); 15616af2acb6SAdam Litke } 1562a01f4390SMike Kravetz 1563a01f4390SMike Kravetz /* 1564a01f4390SMike Kravetz * Non-gigantic pages demoted from CMA allocated gigantic pages 1565a01f4390SMike Kravetz * need to be given back to CMA in free_gigantic_page. 1566a01f4390SMike Kravetz */ 1567a01f4390SMike Kravetz if (hstate_is_gigantic(h) || 1568a01f4390SMike Kravetz hugetlb_cma_page(page, huge_page_order(h))) { 1569944d9fecSLuiz Capitulino destroy_compound_gigantic_page(page, huge_page_order(h)); 1570944d9fecSLuiz Capitulino free_gigantic_page(page, huge_page_order(h)); 1571944d9fecSLuiz Capitulino } else { 1572a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 15736af2acb6SAdam Litke } 1574944d9fecSLuiz Capitulino } 15756af2acb6SAdam Litke 1576b65d4adbSMuchun Song /* 1577b65d4adbSMuchun Song * As update_and_free_page() can be called under any context, so we cannot 1578b65d4adbSMuchun Song * use GFP_KERNEL to allocate vmemmap pages. However, we can defer the 1579b65d4adbSMuchun Song * actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate 1580b65d4adbSMuchun Song * the vmemmap pages. 1581b65d4adbSMuchun Song * 1582b65d4adbSMuchun Song * free_hpage_workfn() locklessly retrieves the linked list of pages to be 1583b65d4adbSMuchun Song * freed and frees them one-by-one. As the page->mapping pointer is going 1584b65d4adbSMuchun Song * to be cleared in free_hpage_workfn() anyway, it is reused as the llist_node 1585b65d4adbSMuchun Song * structure of a lockless linked list of huge pages to be freed. 1586b65d4adbSMuchun Song */ 1587b65d4adbSMuchun Song static LLIST_HEAD(hpage_freelist); 1588b65d4adbSMuchun Song 1589b65d4adbSMuchun Song static void free_hpage_workfn(struct work_struct *work) 1590b65d4adbSMuchun Song { 1591b65d4adbSMuchun Song struct llist_node *node; 1592b65d4adbSMuchun Song 1593b65d4adbSMuchun Song node = llist_del_all(&hpage_freelist); 1594b65d4adbSMuchun Song 1595b65d4adbSMuchun Song while (node) { 1596b65d4adbSMuchun Song struct page *page; 1597b65d4adbSMuchun Song struct hstate *h; 1598b65d4adbSMuchun Song 1599b65d4adbSMuchun Song page = container_of((struct address_space **)node, 1600b65d4adbSMuchun Song struct page, mapping); 1601b65d4adbSMuchun Song node = node->next; 1602b65d4adbSMuchun Song page->mapping = NULL; 1603b65d4adbSMuchun Song /* 1604b65d4adbSMuchun Song * The VM_BUG_ON_PAGE(!PageHuge(page), page) in page_hstate() 1605b65d4adbSMuchun Song * is going to trigger because a previous call to 1606b65d4adbSMuchun Song * remove_hugetlb_page() will set_compound_page_dtor(page, 1607b65d4adbSMuchun Song * NULL_COMPOUND_DTOR), so do not use page_hstate() directly. 1608b65d4adbSMuchun Song */ 1609b65d4adbSMuchun Song h = size_to_hstate(page_size(page)); 1610b65d4adbSMuchun Song 1611b65d4adbSMuchun Song __update_and_free_page(h, page); 1612b65d4adbSMuchun Song 1613b65d4adbSMuchun Song cond_resched(); 1614b65d4adbSMuchun Song } 1615b65d4adbSMuchun Song } 1616b65d4adbSMuchun Song static DECLARE_WORK(free_hpage_work, free_hpage_workfn); 1617b65d4adbSMuchun Song 1618b65d4adbSMuchun Song static inline void flush_free_hpage_work(struct hstate *h) 1619b65d4adbSMuchun Song { 16205981611dSMuchun Song if (hugetlb_optimize_vmemmap_pages(h)) 1621b65d4adbSMuchun Song flush_work(&free_hpage_work); 1622b65d4adbSMuchun Song } 1623b65d4adbSMuchun Song 1624b65d4adbSMuchun Song static void update_and_free_page(struct hstate *h, struct page *page, 1625b65d4adbSMuchun Song bool atomic) 1626b65d4adbSMuchun Song { 1627ad2fa371SMuchun Song if (!HPageVmemmapOptimized(page) || !atomic) { 1628b65d4adbSMuchun Song __update_and_free_page(h, page); 1629b65d4adbSMuchun Song return; 1630b65d4adbSMuchun Song } 1631b65d4adbSMuchun Song 1632b65d4adbSMuchun Song /* 1633b65d4adbSMuchun Song * Defer freeing to avoid using GFP_ATOMIC to allocate vmemmap pages. 1634b65d4adbSMuchun Song * 1635b65d4adbSMuchun Song * Only call schedule_work() if hpage_freelist is previously 1636b65d4adbSMuchun Song * empty. Otherwise, schedule_work() had been called but the workfn 1637b65d4adbSMuchun Song * hasn't retrieved the list yet. 1638b65d4adbSMuchun Song */ 1639b65d4adbSMuchun Song if (llist_add((struct llist_node *)&page->mapping, &hpage_freelist)) 1640b65d4adbSMuchun Song schedule_work(&free_hpage_work); 1641b65d4adbSMuchun Song } 1642b65d4adbSMuchun Song 164310c6ec49SMike Kravetz static void update_and_free_pages_bulk(struct hstate *h, struct list_head *list) 164410c6ec49SMike Kravetz { 164510c6ec49SMike Kravetz struct page *page, *t_page; 164610c6ec49SMike Kravetz 164710c6ec49SMike Kravetz list_for_each_entry_safe(page, t_page, list, lru) { 1648b65d4adbSMuchun Song update_and_free_page(h, page, false); 164910c6ec49SMike Kravetz cond_resched(); 165010c6ec49SMike Kravetz } 165110c6ec49SMike Kravetz } 165210c6ec49SMike Kravetz 1653e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 1654e5ff2159SAndi Kleen { 1655e5ff2159SAndi Kleen struct hstate *h; 1656e5ff2159SAndi Kleen 1657e5ff2159SAndi Kleen for_each_hstate(h) { 1658e5ff2159SAndi Kleen if (huge_page_size(h) == size) 1659e5ff2159SAndi Kleen return h; 1660e5ff2159SAndi Kleen } 1661e5ff2159SAndi Kleen return NULL; 1662e5ff2159SAndi Kleen } 1663e5ff2159SAndi Kleen 1664db71ef79SMike Kravetz void free_huge_page(struct page *page) 166527a85ef1SDavid Gibson { 1666a5516438SAndi Kleen /* 1667a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 1668a5516438SAndi Kleen * compound page destructor. 1669a5516438SAndi Kleen */ 1670e5ff2159SAndi Kleen struct hstate *h = page_hstate(page); 16717893d1d5SAdam Litke int nid = page_to_nid(page); 1672d6995da3SMike Kravetz struct hugepage_subpool *spool = hugetlb_page_subpool(page); 167307443a85SJoonsoo Kim bool restore_reserve; 1674db71ef79SMike Kravetz unsigned long flags; 167527a85ef1SDavid Gibson 1676b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1677b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_mapcount(page), page); 16788ace22bcSYongkai Wu 1679d6995da3SMike Kravetz hugetlb_set_page_subpool(page, NULL); 168078fbe906SDavid Hildenbrand if (PageAnon(page)) 168178fbe906SDavid Hildenbrand __ClearPageAnonExclusive(page); 16828ace22bcSYongkai Wu page->mapping = NULL; 1683d6995da3SMike Kravetz restore_reserve = HPageRestoreReserve(page); 1684d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 168527a85ef1SDavid Gibson 16861c5ecae3SMike Kravetz /* 1687d6995da3SMike Kravetz * If HPageRestoreReserve was set on page, page allocation consumed a 16880919e1b6SMike Kravetz * reservation. If the page was associated with a subpool, there 16890919e1b6SMike Kravetz * would have been a page reserved in the subpool before allocation 16900919e1b6SMike Kravetz * via hugepage_subpool_get_pages(). Since we are 'restoring' the 16916c26d310SMiaohe Lin * reservation, do not call hugepage_subpool_put_pages() as this will 16920919e1b6SMike Kravetz * remove the reserved page from the subpool. 16930919e1b6SMike Kravetz */ 16940919e1b6SMike Kravetz if (!restore_reserve) { 16950919e1b6SMike Kravetz /* 16960919e1b6SMike Kravetz * A return code of zero implies that the subpool will be 16970919e1b6SMike Kravetz * under its minimum size if the reservation is not restored 16980919e1b6SMike Kravetz * after page is free. Therefore, force restore_reserve 16990919e1b6SMike Kravetz * operation. 17001c5ecae3SMike Kravetz */ 17011c5ecae3SMike Kravetz if (hugepage_subpool_put_pages(spool, 1) == 0) 17021c5ecae3SMike Kravetz restore_reserve = true; 17030919e1b6SMike Kravetz } 17041c5ecae3SMike Kravetz 1705db71ef79SMike Kravetz spin_lock_irqsave(&hugetlb_lock, flags); 17068f251a3dSMike Kravetz ClearHPageMigratable(page); 17076d76dcf4SAneesh Kumar K.V hugetlb_cgroup_uncharge_page(hstate_index(h), 17086d76dcf4SAneesh Kumar K.V pages_per_huge_page(h), page); 170908cf9fafSMina Almasry hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 171008cf9fafSMina Almasry pages_per_huge_page(h), page); 171107443a85SJoonsoo Kim if (restore_reserve) 171207443a85SJoonsoo Kim h->resv_huge_pages++; 171307443a85SJoonsoo Kim 17149157c311SMike Kravetz if (HPageTemporary(page)) { 17156eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 1716db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1717b65d4adbSMuchun Song update_and_free_page(h, page, true); 1718ab5ac90aSMichal Hocko } else if (h->surplus_huge_pages_node[nid]) { 17190edaecfaSAneesh Kumar K.V /* remove the page from active list */ 17206eb4e88aSMike Kravetz remove_hugetlb_page(h, page, true); 1721db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1722b65d4adbSMuchun Song update_and_free_page(h, page, true); 17237893d1d5SAdam Litke } else { 17245d3a551cSWill Deacon arch_clear_hugepage_flags(page); 1725a5516438SAndi Kleen enqueue_huge_page(h, page); 1726db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 172727a85ef1SDavid Gibson } 17281121828aSMike Kravetz } 172927a85ef1SDavid Gibson 1730d3d99fccSOscar Salvador /* 1731d3d99fccSOscar Salvador * Must be called with the hugetlb lock held 1732d3d99fccSOscar Salvador */ 1733d3d99fccSOscar Salvador static void __prep_account_new_huge_page(struct hstate *h, int nid) 1734d3d99fccSOscar Salvador { 1735d3d99fccSOscar Salvador lockdep_assert_held(&hugetlb_lock); 1736d3d99fccSOscar Salvador h->nr_huge_pages++; 1737d3d99fccSOscar Salvador h->nr_huge_pages_node[nid]++; 1738d3d99fccSOscar Salvador } 1739d3d99fccSOscar Salvador 1740f41f2ed4SMuchun Song static void __prep_new_huge_page(struct hstate *h, struct page *page) 1741b7ba30c6SAndi Kleen { 17425981611dSMuchun Song hugetlb_vmemmap_free(h, page); 17430edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&page->lru); 1744f1e61557SKirill A. Shutemov set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1745ff546117SMike Kravetz hugetlb_set_page_subpool(page, NULL); 17469dd540e2SAneesh Kumar K.V set_hugetlb_cgroup(page, NULL); 17471adc4d41SMina Almasry set_hugetlb_cgroup_rsvd(page, NULL); 1748d3d99fccSOscar Salvador } 1749d3d99fccSOscar Salvador 1750d3d99fccSOscar Salvador static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) 1751d3d99fccSOscar Salvador { 1752f41f2ed4SMuchun Song __prep_new_huge_page(h, page); 1753db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 1754d3d99fccSOscar Salvador __prep_account_new_huge_page(h, nid); 1755db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 1756b7ba30c6SAndi Kleen } 1757b7ba30c6SAndi Kleen 175834d9e35bSMike Kravetz static bool __prep_compound_gigantic_page(struct page *page, unsigned int order, 175934d9e35bSMike Kravetz bool demote) 176020a0307cSWu Fengguang { 17617118fc29SMike Kravetz int i, j; 176220a0307cSWu Fengguang int nr_pages = 1 << order; 176320a0307cSWu Fengguang struct page *p = page + 1; 176420a0307cSWu Fengguang 176520a0307cSWu Fengguang /* we rely on prep_new_huge_page to set the destructor */ 176620a0307cSWu Fengguang set_compound_order(page, order); 1767ef5a22beSAndrea Arcangeli __ClearPageReserved(page); 1768de09d31dSKirill A. Shutemov __SetPageHead(page); 176920a0307cSWu Fengguang for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 1770ef5a22beSAndrea Arcangeli /* 1771ef5a22beSAndrea Arcangeli * For gigantic hugepages allocated through bootmem at 1772ef5a22beSAndrea Arcangeli * boot, it's safer to be consistent with the not-gigantic 1773ef5a22beSAndrea Arcangeli * hugepages and clear the PG_reserved bit from all tail pages 17747c8de358SEthon Paul * too. Otherwise drivers using get_user_pages() to access tail 1775ef5a22beSAndrea Arcangeli * pages may get the reference counting wrong if they see 1776ef5a22beSAndrea Arcangeli * PG_reserved set on a tail page (despite the head page not 1777ef5a22beSAndrea Arcangeli * having PG_reserved set). Enforcing this consistency between 1778ef5a22beSAndrea Arcangeli * head and tail pages allows drivers to optimize away a check 1779ef5a22beSAndrea Arcangeli * on the head page when they need know if put_page() is needed 1780ef5a22beSAndrea Arcangeli * after get_user_pages(). 1781ef5a22beSAndrea Arcangeli */ 1782ef5a22beSAndrea Arcangeli __ClearPageReserved(p); 17837118fc29SMike Kravetz /* 17847118fc29SMike Kravetz * Subtle and very unlikely 17857118fc29SMike Kravetz * 17867118fc29SMike Kravetz * Gigantic 'page allocators' such as memblock or cma will 17877118fc29SMike Kravetz * return a set of pages with each page ref counted. We need 17887118fc29SMike Kravetz * to turn this set of pages into a compound page with tail 17897118fc29SMike Kravetz * page ref counts set to zero. Code such as speculative page 17907118fc29SMike Kravetz * cache adding could take a ref on a 'to be' tail page. 17917118fc29SMike Kravetz * We need to respect any increased ref count, and only set 17927118fc29SMike Kravetz * the ref count to zero if count is currently 1. If count 1793416d85edSMike Kravetz * is not 1, we return an error. An error return indicates 1794416d85edSMike Kravetz * the set of pages can not be converted to a gigantic page. 1795416d85edSMike Kravetz * The caller who allocated the pages should then discard the 1796416d85edSMike Kravetz * pages using the appropriate free interface. 179734d9e35bSMike Kravetz * 179834d9e35bSMike Kravetz * In the case of demote, the ref count will be zero. 17997118fc29SMike Kravetz */ 180034d9e35bSMike Kravetz if (!demote) { 18017118fc29SMike Kravetz if (!page_ref_freeze(p, 1)) { 1802416d85edSMike Kravetz pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n"); 18037118fc29SMike Kravetz goto out_error; 18047118fc29SMike Kravetz } 180534d9e35bSMike Kravetz } else { 180634d9e35bSMike Kravetz VM_BUG_ON_PAGE(page_count(p), p); 180734d9e35bSMike Kravetz } 18081d798ca3SKirill A. Shutemov set_compound_head(p, page); 180920a0307cSWu Fengguang } 1810b4330afbSMike Kravetz atomic_set(compound_mapcount_ptr(page), -1); 181147e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 18127118fc29SMike Kravetz return true; 18137118fc29SMike Kravetz 18147118fc29SMike Kravetz out_error: 18157118fc29SMike Kravetz /* undo tail page modifications made above */ 18167118fc29SMike Kravetz p = page + 1; 18177118fc29SMike Kravetz for (j = 1; j < i; j++, p = mem_map_next(p, page, j)) { 18187118fc29SMike Kravetz clear_compound_head(p); 18197118fc29SMike Kravetz set_page_refcounted(p); 18207118fc29SMike Kravetz } 18217118fc29SMike Kravetz /* need to clear PG_reserved on remaining tail pages */ 18227118fc29SMike Kravetz for (; j < nr_pages; j++, p = mem_map_next(p, page, j)) 18237118fc29SMike Kravetz __ClearPageReserved(p); 18247118fc29SMike Kravetz set_compound_order(page, 0); 18255232c63fSMatthew Wilcox (Oracle) #ifdef CONFIG_64BIT 18267118fc29SMike Kravetz page[1].compound_nr = 0; 18275232c63fSMatthew Wilcox (Oracle) #endif 18287118fc29SMike Kravetz __ClearPageHead(page); 18297118fc29SMike Kravetz return false; 183020a0307cSWu Fengguang } 183120a0307cSWu Fengguang 183234d9e35bSMike Kravetz static bool prep_compound_gigantic_page(struct page *page, unsigned int order) 183334d9e35bSMike Kravetz { 183434d9e35bSMike Kravetz return __prep_compound_gigantic_page(page, order, false); 183534d9e35bSMike Kravetz } 183634d9e35bSMike Kravetz 18378531fc6fSMike Kravetz static bool prep_compound_gigantic_page_for_demote(struct page *page, 18388531fc6fSMike Kravetz unsigned int order) 18398531fc6fSMike Kravetz { 18408531fc6fSMike Kravetz return __prep_compound_gigantic_page(page, order, true); 18418531fc6fSMike Kravetz } 18428531fc6fSMike Kravetz 18437795912cSAndrew Morton /* 18447795912cSAndrew Morton * PageHuge() only returns true for hugetlbfs pages, but not for normal or 18457795912cSAndrew Morton * transparent huge pages. See the PageTransHuge() documentation for more 18467795912cSAndrew Morton * details. 18477795912cSAndrew Morton */ 184820a0307cSWu Fengguang int PageHuge(struct page *page) 184920a0307cSWu Fengguang { 185020a0307cSWu Fengguang if (!PageCompound(page)) 185120a0307cSWu Fengguang return 0; 185220a0307cSWu Fengguang 185320a0307cSWu Fengguang page = compound_head(page); 1854f1e61557SKirill A. Shutemov return page[1].compound_dtor == HUGETLB_PAGE_DTOR; 185520a0307cSWu Fengguang } 185643131e14SNaoya Horiguchi EXPORT_SYMBOL_GPL(PageHuge); 185743131e14SNaoya Horiguchi 185827c73ae7SAndrea Arcangeli /* 185927c73ae7SAndrea Arcangeli * PageHeadHuge() only returns true for hugetlbfs head page, but not for 186027c73ae7SAndrea Arcangeli * normal or transparent huge pages. 186127c73ae7SAndrea Arcangeli */ 186227c73ae7SAndrea Arcangeli int PageHeadHuge(struct page *page_head) 186327c73ae7SAndrea Arcangeli { 186427c73ae7SAndrea Arcangeli if (!PageHead(page_head)) 186527c73ae7SAndrea Arcangeli return 0; 186627c73ae7SAndrea Arcangeli 1867d4af73e3SVlastimil Babka return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR; 186827c73ae7SAndrea Arcangeli } 18694e936eccSDavid Howells EXPORT_SYMBOL_GPL(PageHeadHuge); 187027c73ae7SAndrea Arcangeli 1871c0d0381aSMike Kravetz /* 1872c0d0381aSMike Kravetz * Find and lock address space (mapping) in write mode. 1873c0d0381aSMike Kravetz * 1874336bf30eSMike Kravetz * Upon entry, the page is locked which means that page_mapping() is 1875336bf30eSMike Kravetz * stable. Due to locking order, we can only trylock_write. If we can 1876336bf30eSMike Kravetz * not get the lock, simply return NULL to caller. 1877c0d0381aSMike Kravetz */ 1878c0d0381aSMike Kravetz struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage) 1879c0d0381aSMike Kravetz { 1880336bf30eSMike Kravetz struct address_space *mapping = page_mapping(hpage); 1881c0d0381aSMike Kravetz 1882c0d0381aSMike Kravetz if (!mapping) 1883c0d0381aSMike Kravetz return mapping; 1884c0d0381aSMike Kravetz 1885c0d0381aSMike Kravetz if (i_mmap_trylock_write(mapping)) 1886c0d0381aSMike Kravetz return mapping; 1887c0d0381aSMike Kravetz 1888c0d0381aSMike Kravetz return NULL; 1889c0d0381aSMike Kravetz } 1890c0d0381aSMike Kravetz 1891fe19bd3dSHugh Dickins pgoff_t hugetlb_basepage_index(struct page *page) 189213d60f4bSZhang Yi { 189313d60f4bSZhang Yi struct page *page_head = compound_head(page); 189413d60f4bSZhang Yi pgoff_t index = page_index(page_head); 189513d60f4bSZhang Yi unsigned long compound_idx; 189613d60f4bSZhang Yi 189713d60f4bSZhang Yi if (compound_order(page_head) >= MAX_ORDER) 189813d60f4bSZhang Yi compound_idx = page_to_pfn(page) - page_to_pfn(page_head); 189913d60f4bSZhang Yi else 190013d60f4bSZhang Yi compound_idx = page - page_head; 190113d60f4bSZhang Yi 190213d60f4bSZhang Yi return (index << compound_order(page_head)) + compound_idx; 190313d60f4bSZhang Yi } 190413d60f4bSZhang Yi 19050c397daeSMichal Hocko static struct page *alloc_buddy_huge_page(struct hstate *h, 1906f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1907f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 19081da177e4SLinus Torvalds { 1909af0fb9dfSMichal Hocko int order = huge_page_order(h); 19101da177e4SLinus Torvalds struct page *page; 1911f60858f9SMike Kravetz bool alloc_try_hard = true; 1912f96efd58SJoe Jin 1913f60858f9SMike Kravetz /* 1914f60858f9SMike Kravetz * By default we always try hard to allocate the page with 1915f60858f9SMike Kravetz * __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in 1916f60858f9SMike Kravetz * a loop (to adjust global huge page counts) and previous allocation 1917f60858f9SMike Kravetz * failed, do not continue to try hard on the same node. Use the 1918f60858f9SMike Kravetz * node_alloc_noretry bitmap to manage this state information. 1919f60858f9SMike Kravetz */ 1920f60858f9SMike Kravetz if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry)) 1921f60858f9SMike Kravetz alloc_try_hard = false; 1922f60858f9SMike Kravetz gfp_mask |= __GFP_COMP|__GFP_NOWARN; 1923f60858f9SMike Kravetz if (alloc_try_hard) 1924f60858f9SMike Kravetz gfp_mask |= __GFP_RETRY_MAYFAIL; 1925af0fb9dfSMichal Hocko if (nid == NUMA_NO_NODE) 1926af0fb9dfSMichal Hocko nid = numa_mem_id(); 192784172f4bSMatthew Wilcox (Oracle) page = __alloc_pages(gfp_mask, order, nid, nmask); 1928af0fb9dfSMichal Hocko if (page) 1929af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC); 1930af0fb9dfSMichal Hocko else 1931af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 193263b4613cSNishanth Aravamudan 1933f60858f9SMike Kravetz /* 1934f60858f9SMike Kravetz * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this 1935f60858f9SMike Kravetz * indicates an overall state change. Clear bit so that we resume 1936f60858f9SMike Kravetz * normal 'try hard' allocations. 1937f60858f9SMike Kravetz */ 1938f60858f9SMike Kravetz if (node_alloc_noretry && page && !alloc_try_hard) 1939f60858f9SMike Kravetz node_clear(nid, *node_alloc_noretry); 1940f60858f9SMike Kravetz 1941f60858f9SMike Kravetz /* 1942f60858f9SMike Kravetz * If we tried hard to get a page but failed, set bit so that 1943f60858f9SMike Kravetz * subsequent attempts will not try as hard until there is an 1944f60858f9SMike Kravetz * overall state change. 1945f60858f9SMike Kravetz */ 1946f60858f9SMike Kravetz if (node_alloc_noretry && !page && alloc_try_hard) 1947f60858f9SMike Kravetz node_set(nid, *node_alloc_noretry); 1948f60858f9SMike Kravetz 194963b4613cSNishanth Aravamudan return page; 195063b4613cSNishanth Aravamudan } 195163b4613cSNishanth Aravamudan 1952af0fb9dfSMichal Hocko /* 19530c397daeSMichal Hocko * Common helper to allocate a fresh hugetlb page. All specific allocators 19540c397daeSMichal Hocko * should use this function to get new hugetlb pages 19550c397daeSMichal Hocko */ 19560c397daeSMichal Hocko static struct page *alloc_fresh_huge_page(struct hstate *h, 1957f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1958f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 19590c397daeSMichal Hocko { 19600c397daeSMichal Hocko struct page *page; 19617118fc29SMike Kravetz bool retry = false; 19620c397daeSMichal Hocko 19637118fc29SMike Kravetz retry: 19640c397daeSMichal Hocko if (hstate_is_gigantic(h)) 19650c397daeSMichal Hocko page = alloc_gigantic_page(h, gfp_mask, nid, nmask); 19660c397daeSMichal Hocko else 19670c397daeSMichal Hocko page = alloc_buddy_huge_page(h, gfp_mask, 1968f60858f9SMike Kravetz nid, nmask, node_alloc_noretry); 19690c397daeSMichal Hocko if (!page) 19700c397daeSMichal Hocko return NULL; 19710c397daeSMichal Hocko 19727118fc29SMike Kravetz if (hstate_is_gigantic(h)) { 19737118fc29SMike Kravetz if (!prep_compound_gigantic_page(page, huge_page_order(h))) { 19747118fc29SMike Kravetz /* 19757118fc29SMike Kravetz * Rare failure to convert pages to compound page. 19767118fc29SMike Kravetz * Free pages and try again - ONCE! 19777118fc29SMike Kravetz */ 19787118fc29SMike Kravetz free_gigantic_page(page, huge_page_order(h)); 19797118fc29SMike Kravetz if (!retry) { 19807118fc29SMike Kravetz retry = true; 19817118fc29SMike Kravetz goto retry; 19827118fc29SMike Kravetz } 19837118fc29SMike Kravetz return NULL; 19847118fc29SMike Kravetz } 19857118fc29SMike Kravetz } 19860c397daeSMichal Hocko prep_new_huge_page(h, page, page_to_nid(page)); 19870c397daeSMichal Hocko 19880c397daeSMichal Hocko return page; 19890c397daeSMichal Hocko } 19900c397daeSMichal Hocko 19910c397daeSMichal Hocko /* 1992af0fb9dfSMichal Hocko * Allocates a fresh page to the hugetlb allocator pool in the node interleaved 1993af0fb9dfSMichal Hocko * manner. 1994af0fb9dfSMichal Hocko */ 1995f60858f9SMike Kravetz static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 1996f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 1997b2261026SJoonsoo Kim { 1998b2261026SJoonsoo Kim struct page *page; 1999b2261026SJoonsoo Kim int nr_nodes, node; 2000af0fb9dfSMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 2001b2261026SJoonsoo Kim 2002b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 2003f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed, 2004f60858f9SMike Kravetz node_alloc_noretry); 2005af0fb9dfSMichal Hocko if (page) 2006b2261026SJoonsoo Kim break; 2007b2261026SJoonsoo Kim } 2008b2261026SJoonsoo Kim 2009af0fb9dfSMichal Hocko if (!page) 2010af0fb9dfSMichal Hocko return 0; 2011b2261026SJoonsoo Kim 2012af0fb9dfSMichal Hocko put_page(page); /* free it into the hugepage allocator */ 2013af0fb9dfSMichal Hocko 2014af0fb9dfSMichal Hocko return 1; 2015b2261026SJoonsoo Kim } 2016b2261026SJoonsoo Kim 2017e8c5c824SLee Schermerhorn /* 201810c6ec49SMike Kravetz * Remove huge page from pool from next node to free. Attempt to keep 201910c6ec49SMike Kravetz * persistent huge pages more or less balanced over allowed nodes. 202010c6ec49SMike Kravetz * This routine only 'removes' the hugetlb page. The caller must make 202110c6ec49SMike Kravetz * an additional call to free the page to low level allocators. 2022e8c5c824SLee Schermerhorn * Called with hugetlb_lock locked. 2023e8c5c824SLee Schermerhorn */ 202410c6ec49SMike Kravetz static struct page *remove_pool_huge_page(struct hstate *h, 202510c6ec49SMike Kravetz nodemask_t *nodes_allowed, 20266ae11b27SLee Schermerhorn bool acct_surplus) 2027e8c5c824SLee Schermerhorn { 2028b2261026SJoonsoo Kim int nr_nodes, node; 202910c6ec49SMike Kravetz struct page *page = NULL; 2030e8c5c824SLee Schermerhorn 20319487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2032b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 2033685f3457SLee Schermerhorn /* 2034685f3457SLee Schermerhorn * If we're returning unused surplus pages, only examine 2035685f3457SLee Schermerhorn * nodes with surplus pages. 2036685f3457SLee Schermerhorn */ 2037b2261026SJoonsoo Kim if ((!acct_surplus || h->surplus_huge_pages_node[node]) && 2038b2261026SJoonsoo Kim !list_empty(&h->hugepage_freelists[node])) { 203910c6ec49SMike Kravetz page = list_entry(h->hugepage_freelists[node].next, 2040e8c5c824SLee Schermerhorn struct page, lru); 20416eb4e88aSMike Kravetz remove_hugetlb_page(h, page, acct_surplus); 20429a76db09SLee Schermerhorn break; 2043e8c5c824SLee Schermerhorn } 2044b2261026SJoonsoo Kim } 2045e8c5c824SLee Schermerhorn 204610c6ec49SMike Kravetz return page; 2047e8c5c824SLee Schermerhorn } 2048e8c5c824SLee Schermerhorn 2049c8721bbbSNaoya Horiguchi /* 2050c8721bbbSNaoya Horiguchi * Dissolve a given free hugepage into free buddy pages. This function does 2051faf53defSNaoya Horiguchi * nothing for in-use hugepages and non-hugepages. 2052faf53defSNaoya Horiguchi * This function returns values like below: 2053faf53defSNaoya Horiguchi * 2054ad2fa371SMuchun Song * -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages 2055ad2fa371SMuchun Song * when the system is under memory pressure and the feature of 2056ad2fa371SMuchun Song * freeing unused vmemmap pages associated with each hugetlb page 2057ad2fa371SMuchun Song * is enabled. 2058faf53defSNaoya Horiguchi * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use 2059faf53defSNaoya Horiguchi * (allocated or reserved.) 2060faf53defSNaoya Horiguchi * 0: successfully dissolved free hugepages or the page is not a 2061faf53defSNaoya Horiguchi * hugepage (considered as already dissolved) 2062c8721bbbSNaoya Horiguchi */ 2063c3114a84SAnshuman Khandual int dissolve_free_huge_page(struct page *page) 2064c8721bbbSNaoya Horiguchi { 20656bc9b564SNaoya Horiguchi int rc = -EBUSY; 2066082d5b6bSGerald Schaefer 20677ffddd49SMuchun Song retry: 2068faf53defSNaoya Horiguchi /* Not to disrupt normal path by vainly holding hugetlb_lock */ 2069faf53defSNaoya Horiguchi if (!PageHuge(page)) 2070faf53defSNaoya Horiguchi return 0; 2071faf53defSNaoya Horiguchi 2072db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2073faf53defSNaoya Horiguchi if (!PageHuge(page)) { 2074faf53defSNaoya Horiguchi rc = 0; 2075faf53defSNaoya Horiguchi goto out; 2076faf53defSNaoya Horiguchi } 2077faf53defSNaoya Horiguchi 2078faf53defSNaoya Horiguchi if (!page_count(page)) { 20792247bb33SGerald Schaefer struct page *head = compound_head(page); 20802247bb33SGerald Schaefer struct hstate *h = page_hstate(head); 20816bc9b564SNaoya Horiguchi if (h->free_huge_pages - h->resv_huge_pages == 0) 2082082d5b6bSGerald Schaefer goto out; 20837ffddd49SMuchun Song 20847ffddd49SMuchun Song /* 20857ffddd49SMuchun Song * We should make sure that the page is already on the free list 20867ffddd49SMuchun Song * when it is dissolved. 20877ffddd49SMuchun Song */ 20886c037149SMike Kravetz if (unlikely(!HPageFreed(head))) { 2089db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 20907ffddd49SMuchun Song cond_resched(); 20917ffddd49SMuchun Song 20927ffddd49SMuchun Song /* 20937ffddd49SMuchun Song * Theoretically, we should return -EBUSY when we 20947ffddd49SMuchun Song * encounter this race. In fact, we have a chance 20957ffddd49SMuchun Song * to successfully dissolve the page if we do a 20967ffddd49SMuchun Song * retry. Because the race window is quite small. 20977ffddd49SMuchun Song * If we seize this opportunity, it is an optimization 20987ffddd49SMuchun Song * for increasing the success rate of dissolving page. 20997ffddd49SMuchun Song */ 21007ffddd49SMuchun Song goto retry; 21017ffddd49SMuchun Song } 21027ffddd49SMuchun Song 2103ad2fa371SMuchun Song remove_hugetlb_page(h, head, false); 2104ad2fa371SMuchun Song h->max_huge_pages--; 2105ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2106ad2fa371SMuchun Song 2107c3114a84SAnshuman Khandual /* 2108ad2fa371SMuchun Song * Normally update_and_free_page will allocate required vmemmmap 2109ad2fa371SMuchun Song * before freeing the page. update_and_free_page will fail to 2110ad2fa371SMuchun Song * free the page if it can not allocate required vmemmap. We 2111ad2fa371SMuchun Song * need to adjust max_huge_pages if the page is not freed. 2112ad2fa371SMuchun Song * Attempt to allocate vmemmmap here so that we can take 2113ad2fa371SMuchun Song * appropriate action on failure. 2114ad2fa371SMuchun Song */ 21155981611dSMuchun Song rc = hugetlb_vmemmap_alloc(h, head); 2116ad2fa371SMuchun Song if (!rc) { 2117ad2fa371SMuchun Song /* 2118ad2fa371SMuchun Song * Move PageHWPoison flag from head page to the raw 2119ad2fa371SMuchun Song * error page, which makes any subpages rather than 2120ad2fa371SMuchun Song * the error page reusable. 2121c3114a84SAnshuman Khandual */ 2122c3114a84SAnshuman Khandual if (PageHWPoison(head) && page != head) { 2123c3114a84SAnshuman Khandual SetPageHWPoison(page); 2124c3114a84SAnshuman Khandual ClearPageHWPoison(head); 2125c3114a84SAnshuman Khandual } 2126b65d4adbSMuchun Song update_and_free_page(h, head, false); 2127ad2fa371SMuchun Song } else { 2128ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 2129ad2fa371SMuchun Song add_hugetlb_page(h, head, false); 2130ad2fa371SMuchun Song h->max_huge_pages++; 2131ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 2132ad2fa371SMuchun Song } 2133ad2fa371SMuchun Song 2134ad2fa371SMuchun Song return rc; 2135c8721bbbSNaoya Horiguchi } 2136082d5b6bSGerald Schaefer out: 2137db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2138082d5b6bSGerald Schaefer return rc; 2139c8721bbbSNaoya Horiguchi } 2140c8721bbbSNaoya Horiguchi 2141c8721bbbSNaoya Horiguchi /* 2142c8721bbbSNaoya Horiguchi * Dissolve free hugepages in a given pfn range. Used by memory hotplug to 2143c8721bbbSNaoya Horiguchi * make specified memory blocks removable from the system. 21442247bb33SGerald Schaefer * Note that this will dissolve a free gigantic hugepage completely, if any 21452247bb33SGerald Schaefer * part of it lies within the given range. 2146082d5b6bSGerald Schaefer * Also note that if dissolve_free_huge_page() returns with an error, all 2147082d5b6bSGerald Schaefer * free hugepages that were dissolved before that error are lost. 2148c8721bbbSNaoya Horiguchi */ 2149082d5b6bSGerald Schaefer int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) 2150c8721bbbSNaoya Horiguchi { 2151c8721bbbSNaoya Horiguchi unsigned long pfn; 2152eb03aa00SGerald Schaefer struct page *page; 2153082d5b6bSGerald Schaefer int rc = 0; 2154c8721bbbSNaoya Horiguchi 2155d0177639SLi Zhong if (!hugepages_supported()) 2156082d5b6bSGerald Schaefer return rc; 2157d0177639SLi Zhong 2158eb03aa00SGerald Schaefer for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) { 2159eb03aa00SGerald Schaefer page = pfn_to_page(pfn); 2160eb03aa00SGerald Schaefer rc = dissolve_free_huge_page(page); 2161eb03aa00SGerald Schaefer if (rc) 2162082d5b6bSGerald Schaefer break; 2163eb03aa00SGerald Schaefer } 2164082d5b6bSGerald Schaefer 2165082d5b6bSGerald Schaefer return rc; 2166c8721bbbSNaoya Horiguchi } 2167c8721bbbSNaoya Horiguchi 2168ab5ac90aSMichal Hocko /* 2169ab5ac90aSMichal Hocko * Allocates a fresh surplus page from the page allocator. 2170ab5ac90aSMichal Hocko */ 21710c397daeSMichal Hocko static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, 2172b65a4edaSMike Kravetz int nid, nodemask_t *nmask, bool zero_ref) 21737893d1d5SAdam Litke { 21749980d744SMichal Hocko struct page *page = NULL; 2175b65a4edaSMike Kravetz bool retry = false; 21767893d1d5SAdam Litke 2177bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2178aa888a74SAndi Kleen return NULL; 2179aa888a74SAndi Kleen 2180db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 21819980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) 21829980d744SMichal Hocko goto out_unlock; 2183db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2184d1c3fb1fSNishanth Aravamudan 2185b65a4edaSMike Kravetz retry: 2186f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 21879980d744SMichal Hocko if (!page) 21880c397daeSMichal Hocko return NULL; 2189d1c3fb1fSNishanth Aravamudan 2190db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 21919980d744SMichal Hocko /* 21929980d744SMichal Hocko * We could have raced with the pool size change. 21939980d744SMichal Hocko * Double check that and simply deallocate the new page 21949980d744SMichal Hocko * if we would end up overcommiting the surpluses. Abuse 21959980d744SMichal Hocko * temporary page to workaround the nasty free_huge_page 21969980d744SMichal Hocko * codeflow 21979980d744SMichal Hocko */ 21989980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 21999157c311SMike Kravetz SetHPageTemporary(page); 2200db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 22019980d744SMichal Hocko put_page(page); 22022bf753e6SKai Shen return NULL; 2203b65a4edaSMike Kravetz } 2204b65a4edaSMike Kravetz 2205b65a4edaSMike Kravetz if (zero_ref) { 2206b65a4edaSMike Kravetz /* 2207b65a4edaSMike Kravetz * Caller requires a page with zero ref count. 2208b65a4edaSMike Kravetz * We will drop ref count here. If someone else is holding 2209b65a4edaSMike Kravetz * a ref, the page will be freed when they drop it. Abuse 2210b65a4edaSMike Kravetz * temporary page flag to accomplish this. 2211b65a4edaSMike Kravetz */ 2212b65a4edaSMike Kravetz SetHPageTemporary(page); 2213b65a4edaSMike Kravetz if (!put_page_testzero(page)) { 2214b65a4edaSMike Kravetz /* 2215b65a4edaSMike Kravetz * Unexpected inflated ref count on freshly allocated 2216b65a4edaSMike Kravetz * huge. Retry once. 2217b65a4edaSMike Kravetz */ 2218b65a4edaSMike Kravetz pr_info("HugeTLB unexpected inflated ref count on freshly allocated page\n"); 2219b65a4edaSMike Kravetz spin_unlock_irq(&hugetlb_lock); 2220b65a4edaSMike Kravetz if (retry) 2221b65a4edaSMike Kravetz return NULL; 2222b65a4edaSMike Kravetz 2223b65a4edaSMike Kravetz retry = true; 2224b65a4edaSMike Kravetz goto retry; 2225b65a4edaSMike Kravetz } 2226b65a4edaSMike Kravetz ClearHPageTemporary(page); 2227b65a4edaSMike Kravetz } 2228b65a4edaSMike Kravetz 22299980d744SMichal Hocko h->surplus_huge_pages++; 22304704dea3SMichal Hocko h->surplus_huge_pages_node[page_to_nid(page)]++; 22319980d744SMichal Hocko 22329980d744SMichal Hocko out_unlock: 2233db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 22347893d1d5SAdam Litke 22357893d1d5SAdam Litke return page; 22367893d1d5SAdam Litke } 22377893d1d5SAdam Litke 2238bbe88753SJoonsoo Kim static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, 2239ab5ac90aSMichal Hocko int nid, nodemask_t *nmask) 2240ab5ac90aSMichal Hocko { 2241ab5ac90aSMichal Hocko struct page *page; 2242ab5ac90aSMichal Hocko 2243ab5ac90aSMichal Hocko if (hstate_is_gigantic(h)) 2244ab5ac90aSMichal Hocko return NULL; 2245ab5ac90aSMichal Hocko 2246f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 2247ab5ac90aSMichal Hocko if (!page) 2248ab5ac90aSMichal Hocko return NULL; 2249ab5ac90aSMichal Hocko 2250ab5ac90aSMichal Hocko /* 2251ab5ac90aSMichal Hocko * We do not account these pages as surplus because they are only 2252ab5ac90aSMichal Hocko * temporary and will be released properly on the last reference 2253ab5ac90aSMichal Hocko */ 22549157c311SMike Kravetz SetHPageTemporary(page); 2255ab5ac90aSMichal Hocko 2256ab5ac90aSMichal Hocko return page; 2257ab5ac90aSMichal Hocko } 2258ab5ac90aSMichal Hocko 2259e4e574b7SAdam Litke /* 2260099730d6SDave Hansen * Use the VMA's mpolicy to allocate a huge page from the buddy. 2261099730d6SDave Hansen */ 2262e0ec90eeSDave Hansen static 22630c397daeSMichal Hocko struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h, 2264099730d6SDave Hansen struct vm_area_struct *vma, unsigned long addr) 2265099730d6SDave Hansen { 2266cfcaa66fSBen Widawsky struct page *page = NULL; 2267aaf14e40SMichal Hocko struct mempolicy *mpol; 2268aaf14e40SMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h); 2269aaf14e40SMichal Hocko int nid; 2270aaf14e40SMichal Hocko nodemask_t *nodemask; 2271aaf14e40SMichal Hocko 2272aaf14e40SMichal Hocko nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); 2273cfcaa66fSBen Widawsky if (mpol_is_preferred_many(mpol)) { 2274cfcaa66fSBen Widawsky gfp_t gfp = gfp_mask | __GFP_NOWARN; 2275cfcaa66fSBen Widawsky 2276cfcaa66fSBen Widawsky gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL); 2277cfcaa66fSBen Widawsky page = alloc_surplus_huge_page(h, gfp, nid, nodemask, false); 2278cfcaa66fSBen Widawsky 2279cfcaa66fSBen Widawsky /* Fallback to all nodes if page==NULL */ 2280cfcaa66fSBen Widawsky nodemask = NULL; 2281cfcaa66fSBen Widawsky } 2282cfcaa66fSBen Widawsky 2283cfcaa66fSBen Widawsky if (!page) 2284b65a4edaSMike Kravetz page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask, false); 2285aaf14e40SMichal Hocko mpol_cond_put(mpol); 2286aaf14e40SMichal Hocko return page; 2287099730d6SDave Hansen } 2288099730d6SDave Hansen 2289ab5ac90aSMichal Hocko /* page migration callback function */ 22903e59fcb0SMichal Hocko struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, 2291d92bbc27SJoonsoo Kim nodemask_t *nmask, gfp_t gfp_mask) 22924db9b2efSMichal Hocko { 2293db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 22944db9b2efSMichal Hocko if (h->free_huge_pages - h->resv_huge_pages > 0) { 22953e59fcb0SMichal Hocko struct page *page; 22963e59fcb0SMichal Hocko 22973e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask); 22983e59fcb0SMichal Hocko if (page) { 2299db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 23003e59fcb0SMichal Hocko return page; 23014db9b2efSMichal Hocko } 23024db9b2efSMichal Hocko } 2303db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 23044db9b2efSMichal Hocko 23050c397daeSMichal Hocko return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask); 23064db9b2efSMichal Hocko } 23074db9b2efSMichal Hocko 2308ebd63723SMichal Hocko /* mempolicy aware migration callback */ 2309389c8178SMichal Hocko struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, 2310389c8178SMichal Hocko unsigned long address) 2311ebd63723SMichal Hocko { 2312ebd63723SMichal Hocko struct mempolicy *mpol; 2313ebd63723SMichal Hocko nodemask_t *nodemask; 2314ebd63723SMichal Hocko struct page *page; 2315ebd63723SMichal Hocko gfp_t gfp_mask; 2316ebd63723SMichal Hocko int node; 2317ebd63723SMichal Hocko 2318ebd63723SMichal Hocko gfp_mask = htlb_alloc_mask(h); 2319ebd63723SMichal Hocko node = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 2320d92bbc27SJoonsoo Kim page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask); 2321ebd63723SMichal Hocko mpol_cond_put(mpol); 2322ebd63723SMichal Hocko 2323ebd63723SMichal Hocko return page; 2324ebd63723SMichal Hocko } 2325ebd63723SMichal Hocko 2326bf50bab2SNaoya Horiguchi /* 232725985edcSLucas De Marchi * Increase the hugetlb pool such that it can accommodate a reservation 2328e4e574b7SAdam Litke * of size 'delta'. 2329e4e574b7SAdam Litke */ 23300a4f3d1bSLiu Xiang static int gather_surplus_pages(struct hstate *h, long delta) 23311b2a1e7bSJules Irenge __must_hold(&hugetlb_lock) 2332e4e574b7SAdam Litke { 2333e4e574b7SAdam Litke struct list_head surplus_list; 2334e4e574b7SAdam Litke struct page *page, *tmp; 23350a4f3d1bSLiu Xiang int ret; 23360a4f3d1bSLiu Xiang long i; 23370a4f3d1bSLiu Xiang long needed, allocated; 233828073b02SHillf Danton bool alloc_ok = true; 2339e4e574b7SAdam Litke 23409487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2341a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 2342ac09b3a1SAdam Litke if (needed <= 0) { 2343a5516438SAndi Kleen h->resv_huge_pages += delta; 2344e4e574b7SAdam Litke return 0; 2345ac09b3a1SAdam Litke } 2346e4e574b7SAdam Litke 2347e4e574b7SAdam Litke allocated = 0; 2348e4e574b7SAdam Litke INIT_LIST_HEAD(&surplus_list); 2349e4e574b7SAdam Litke 2350e4e574b7SAdam Litke ret = -ENOMEM; 2351e4e574b7SAdam Litke retry: 2352db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2353e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 23540c397daeSMichal Hocko page = alloc_surplus_huge_page(h, htlb_alloc_mask(h), 2355b65a4edaSMike Kravetz NUMA_NO_NODE, NULL, true); 235628073b02SHillf Danton if (!page) { 235728073b02SHillf Danton alloc_ok = false; 235828073b02SHillf Danton break; 235928073b02SHillf Danton } 2360e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 236169ed779aSDavid Rientjes cond_resched(); 2362e4e574b7SAdam Litke } 236328073b02SHillf Danton allocated += i; 2364e4e574b7SAdam Litke 2365e4e574b7SAdam Litke /* 2366e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 2367e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 2368e4e574b7SAdam Litke */ 2369db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2370a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 2371a5516438SAndi Kleen (h->free_huge_pages + allocated); 237228073b02SHillf Danton if (needed > 0) { 237328073b02SHillf Danton if (alloc_ok) 2374e4e574b7SAdam Litke goto retry; 237528073b02SHillf Danton /* 237628073b02SHillf Danton * We were not able to allocate enough pages to 237728073b02SHillf Danton * satisfy the entire reservation so we free what 237828073b02SHillf Danton * we've allocated so far. 237928073b02SHillf Danton */ 238028073b02SHillf Danton goto free; 238128073b02SHillf Danton } 2382e4e574b7SAdam Litke /* 2383e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 238425985edcSLucas De Marchi * needed to accommodate the reservation. Add the appropriate number 2385e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 2386ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 2387ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 2388ac09b3a1SAdam Litke * before they are reserved. 2389e4e574b7SAdam Litke */ 2390e4e574b7SAdam Litke needed += allocated; 2391a5516438SAndi Kleen h->resv_huge_pages += delta; 2392e4e574b7SAdam Litke ret = 0; 2393a9869b83SNaoya Horiguchi 239419fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 239519fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 239619fc3f0aSAdam Litke if ((--needed) < 0) 239719fc3f0aSAdam Litke break; 2398b65a4edaSMike Kravetz /* Add the page to the hugetlb allocator */ 2399a5516438SAndi Kleen enqueue_huge_page(h, page); 240019fc3f0aSAdam Litke } 240128073b02SHillf Danton free: 2402db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 240319fc3f0aSAdam Litke 2404b65a4edaSMike Kravetz /* 2405b65a4edaSMike Kravetz * Free unnecessary surplus pages to the buddy allocator. 2406b65a4edaSMike Kravetz * Pages have no ref count, call free_huge_page directly. 2407b65a4edaSMike Kravetz */ 2408c0d934baSJoonsoo Kim list_for_each_entry_safe(page, tmp, &surplus_list, lru) 2409b65a4edaSMike Kravetz free_huge_page(page); 2410db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2411e4e574b7SAdam Litke 2412e4e574b7SAdam Litke return ret; 2413e4e574b7SAdam Litke } 2414e4e574b7SAdam Litke 2415e4e574b7SAdam Litke /* 2416e5bbc8a6SMike Kravetz * This routine has two main purposes: 2417e5bbc8a6SMike Kravetz * 1) Decrement the reservation count (resv_huge_pages) by the value passed 2418e5bbc8a6SMike Kravetz * in unused_resv_pages. This corresponds to the prior adjustments made 2419e5bbc8a6SMike Kravetz * to the associated reservation map. 2420e5bbc8a6SMike Kravetz * 2) Free any unused surplus pages that may have been allocated to satisfy 2421e5bbc8a6SMike Kravetz * the reservation. As many as unused_resv_pages may be freed. 2422e4e574b7SAdam Litke */ 2423a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 2424a5516438SAndi Kleen unsigned long unused_resv_pages) 2425e4e574b7SAdam Litke { 2426e4e574b7SAdam Litke unsigned long nr_pages; 242710c6ec49SMike Kravetz struct page *page; 242810c6ec49SMike Kravetz LIST_HEAD(page_list); 242910c6ec49SMike Kravetz 24309487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 243110c6ec49SMike Kravetz /* Uncommit the reservation */ 243210c6ec49SMike Kravetz h->resv_huge_pages -= unused_resv_pages; 2433e4e574b7SAdam Litke 2434aa888a74SAndi Kleen /* Cannot return gigantic pages currently */ 2435bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2436e5bbc8a6SMike Kravetz goto out; 2437aa888a74SAndi Kleen 2438e5bbc8a6SMike Kravetz /* 2439e5bbc8a6SMike Kravetz * Part (or even all) of the reservation could have been backed 2440e5bbc8a6SMike Kravetz * by pre-allocated pages. Only free surplus pages. 2441e5bbc8a6SMike Kravetz */ 2442a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 2443e4e574b7SAdam Litke 2444685f3457SLee Schermerhorn /* 2445685f3457SLee Schermerhorn * We want to release as many surplus pages as possible, spread 24469b5e5d0fSLee Schermerhorn * evenly across all nodes with memory. Iterate across these nodes 24479b5e5d0fSLee Schermerhorn * until we can no longer free unreserved surplus pages. This occurs 24489b5e5d0fSLee Schermerhorn * when the nodes with surplus pages have no free pages. 244910c6ec49SMike Kravetz * remove_pool_huge_page() will balance the freed pages across the 24509b5e5d0fSLee Schermerhorn * on-line nodes with memory and will handle the hstate accounting. 2451685f3457SLee Schermerhorn */ 2452685f3457SLee Schermerhorn while (nr_pages--) { 245310c6ec49SMike Kravetz page = remove_pool_huge_page(h, &node_states[N_MEMORY], 1); 245410c6ec49SMike Kravetz if (!page) 2455e5bbc8a6SMike Kravetz goto out; 245610c6ec49SMike Kravetz 245710c6ec49SMike Kravetz list_add(&page->lru, &page_list); 2458e4e574b7SAdam Litke } 2459e5bbc8a6SMike Kravetz 2460e5bbc8a6SMike Kravetz out: 2461db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 246210c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 2463db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2464e4e574b7SAdam Litke } 2465e4e574b7SAdam Litke 24665e911373SMike Kravetz 2467c37f9fb1SAndy Whitcroft /* 2468feba16e2SMike Kravetz * vma_needs_reservation, vma_commit_reservation and vma_end_reservation 24695e911373SMike Kravetz * are used by the huge page allocation routines to manage reservations. 2470cf3ad20bSMike Kravetz * 2471cf3ad20bSMike Kravetz * vma_needs_reservation is called to determine if the huge page at addr 2472cf3ad20bSMike Kravetz * within the vma has an associated reservation. If a reservation is 2473cf3ad20bSMike Kravetz * needed, the value 1 is returned. The caller is then responsible for 2474cf3ad20bSMike Kravetz * managing the global reservation and subpool usage counts. After 2475cf3ad20bSMike Kravetz * the huge page has been allocated, vma_commit_reservation is called 2476feba16e2SMike Kravetz * to add the page to the reservation map. If the page allocation fails, 2477feba16e2SMike Kravetz * the reservation must be ended instead of committed. vma_end_reservation 2478feba16e2SMike Kravetz * is called in such cases. 2479cf3ad20bSMike Kravetz * 2480cf3ad20bSMike Kravetz * In the normal case, vma_commit_reservation returns the same value 2481cf3ad20bSMike Kravetz * as the preceding vma_needs_reservation call. The only time this 2482cf3ad20bSMike Kravetz * is not the case is if a reserve map was changed between calls. It 2483cf3ad20bSMike Kravetz * is the responsibility of the caller to notice the difference and 2484cf3ad20bSMike Kravetz * take appropriate action. 248596b96a96SMike Kravetz * 248696b96a96SMike Kravetz * vma_add_reservation is used in error paths where a reservation must 248796b96a96SMike Kravetz * be restored when a newly allocated huge page must be freed. It is 248896b96a96SMike Kravetz * to be called after calling vma_needs_reservation to determine if a 248996b96a96SMike Kravetz * reservation exists. 2490846be085SMike Kravetz * 2491846be085SMike Kravetz * vma_del_reservation is used in error paths where an entry in the reserve 2492846be085SMike Kravetz * map was created during huge page allocation and must be removed. It is to 2493846be085SMike Kravetz * be called after calling vma_needs_reservation to determine if a reservation 2494846be085SMike Kravetz * exists. 2495c37f9fb1SAndy Whitcroft */ 24965e911373SMike Kravetz enum vma_resv_mode { 24975e911373SMike Kravetz VMA_NEEDS_RESV, 24985e911373SMike Kravetz VMA_COMMIT_RESV, 2499feba16e2SMike Kravetz VMA_END_RESV, 250096b96a96SMike Kravetz VMA_ADD_RESV, 2501846be085SMike Kravetz VMA_DEL_RESV, 25025e911373SMike Kravetz }; 2503cf3ad20bSMike Kravetz static long __vma_reservation_common(struct hstate *h, 2504cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr, 25055e911373SMike Kravetz enum vma_resv_mode mode) 2506c37f9fb1SAndy Whitcroft { 25074e35f483SJoonsoo Kim struct resv_map *resv; 25084e35f483SJoonsoo Kim pgoff_t idx; 2509cf3ad20bSMike Kravetz long ret; 25100db9d74eSMina Almasry long dummy_out_regions_needed; 2511c37f9fb1SAndy Whitcroft 25124e35f483SJoonsoo Kim resv = vma_resv_map(vma); 25134e35f483SJoonsoo Kim if (!resv) 2514c37f9fb1SAndy Whitcroft return 1; 2515c37f9fb1SAndy Whitcroft 25164e35f483SJoonsoo Kim idx = vma_hugecache_offset(h, vma, addr); 25175e911373SMike Kravetz switch (mode) { 25185e911373SMike Kravetz case VMA_NEEDS_RESV: 25190db9d74eSMina Almasry ret = region_chg(resv, idx, idx + 1, &dummy_out_regions_needed); 25200db9d74eSMina Almasry /* We assume that vma_reservation_* routines always operate on 25210db9d74eSMina Almasry * 1 page, and that adding to resv map a 1 page entry can only 25220db9d74eSMina Almasry * ever require 1 region. 25230db9d74eSMina Almasry */ 25240db9d74eSMina Almasry VM_BUG_ON(dummy_out_regions_needed != 1); 25255e911373SMike Kravetz break; 25265e911373SMike Kravetz case VMA_COMMIT_RESV: 2527075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 25280db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 25290db9d74eSMina Almasry VM_BUG_ON(ret < 0); 25305e911373SMike Kravetz break; 2531feba16e2SMike Kravetz case VMA_END_RESV: 25320db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 25335e911373SMike Kravetz ret = 0; 25345e911373SMike Kravetz break; 253596b96a96SMike Kravetz case VMA_ADD_RESV: 25360db9d74eSMina Almasry if (vma->vm_flags & VM_MAYSHARE) { 2537075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 25380db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 25390db9d74eSMina Almasry VM_BUG_ON(ret < 0); 25400db9d74eSMina Almasry } else { 25410db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 254296b96a96SMike Kravetz ret = region_del(resv, idx, idx + 1); 254396b96a96SMike Kravetz } 254496b96a96SMike Kravetz break; 2545846be085SMike Kravetz case VMA_DEL_RESV: 2546846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 2547846be085SMike Kravetz region_abort(resv, idx, idx + 1, 1); 2548846be085SMike Kravetz ret = region_del(resv, idx, idx + 1); 2549846be085SMike Kravetz } else { 2550846be085SMike Kravetz ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 2551846be085SMike Kravetz /* region_add calls of range 1 should never fail. */ 2552846be085SMike Kravetz VM_BUG_ON(ret < 0); 2553846be085SMike Kravetz } 2554846be085SMike Kravetz break; 25555e911373SMike Kravetz default: 25565e911373SMike Kravetz BUG(); 25575e911373SMike Kravetz } 255884afd99bSAndy Whitcroft 2559846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE || mode == VMA_DEL_RESV) 2560cf3ad20bSMike Kravetz return ret; 256167961f9dSMike Kravetz /* 2562bf3d12b9SMiaohe Lin * We know private mapping must have HPAGE_RESV_OWNER set. 2563bf3d12b9SMiaohe Lin * 256467961f9dSMike Kravetz * In most cases, reserves always exist for private mappings. 256567961f9dSMike Kravetz * However, a file associated with mapping could have been 256667961f9dSMike Kravetz * hole punched or truncated after reserves were consumed. 256767961f9dSMike Kravetz * As subsequent fault on such a range will not use reserves. 256867961f9dSMike Kravetz * Subtle - The reserve map for private mappings has the 256967961f9dSMike Kravetz * opposite meaning than that of shared mappings. If NO 257067961f9dSMike Kravetz * entry is in the reserve map, it means a reservation exists. 257167961f9dSMike Kravetz * If an entry exists in the reserve map, it means the 257267961f9dSMike Kravetz * reservation has already been consumed. As a result, the 257367961f9dSMike Kravetz * return value of this routine is the opposite of the 257467961f9dSMike Kravetz * value returned from reserve map manipulation routines above. 257567961f9dSMike Kravetz */ 2576bf3d12b9SMiaohe Lin if (ret > 0) 257767961f9dSMike Kravetz return 0; 2578bf3d12b9SMiaohe Lin if (ret == 0) 257967961f9dSMike Kravetz return 1; 2580bf3d12b9SMiaohe Lin return ret; 258184afd99bSAndy Whitcroft } 2582cf3ad20bSMike Kravetz 2583cf3ad20bSMike Kravetz static long vma_needs_reservation(struct hstate *h, 2584a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 2585c37f9fb1SAndy Whitcroft { 25865e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV); 2587cf3ad20bSMike Kravetz } 2588c37f9fb1SAndy Whitcroft 2589cf3ad20bSMike Kravetz static long vma_commit_reservation(struct hstate *h, 2590cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr) 2591cf3ad20bSMike Kravetz { 25925e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV); 25935e911373SMike Kravetz } 25945e911373SMike Kravetz 2595feba16e2SMike Kravetz static void vma_end_reservation(struct hstate *h, 25965e911373SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 25975e911373SMike Kravetz { 2598feba16e2SMike Kravetz (void)__vma_reservation_common(h, vma, addr, VMA_END_RESV); 2599c37f9fb1SAndy Whitcroft } 2600c37f9fb1SAndy Whitcroft 260196b96a96SMike Kravetz static long vma_add_reservation(struct hstate *h, 260296b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 260396b96a96SMike Kravetz { 260496b96a96SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV); 260596b96a96SMike Kravetz } 260696b96a96SMike Kravetz 2607846be085SMike Kravetz static long vma_del_reservation(struct hstate *h, 2608846be085SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 260996b96a96SMike Kravetz { 2610846be085SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_DEL_RESV); 2611846be085SMike Kravetz } 2612846be085SMike Kravetz 2613846be085SMike Kravetz /* 2614846be085SMike Kravetz * This routine is called to restore reservation information on error paths. 2615846be085SMike Kravetz * It should ONLY be called for pages allocated via alloc_huge_page(), and 2616846be085SMike Kravetz * the hugetlb mutex should remain held when calling this routine. 2617846be085SMike Kravetz * 2618846be085SMike Kravetz * It handles two specific cases: 2619846be085SMike Kravetz * 1) A reservation was in place and the page consumed the reservation. 2620846be085SMike Kravetz * HPageRestoreReserve is set in the page. 2621846be085SMike Kravetz * 2) No reservation was in place for the page, so HPageRestoreReserve is 2622846be085SMike Kravetz * not set. However, alloc_huge_page always updates the reserve map. 2623846be085SMike Kravetz * 2624846be085SMike Kravetz * In case 1, free_huge_page later in the error path will increment the 2625846be085SMike Kravetz * global reserve count. But, free_huge_page does not have enough context 2626846be085SMike Kravetz * to adjust the reservation map. This case deals primarily with private 2627846be085SMike Kravetz * mappings. Adjust the reserve map here to be consistent with global 2628846be085SMike Kravetz * reserve count adjustments to be made by free_huge_page. Make sure the 2629846be085SMike Kravetz * reserve map indicates there is a reservation present. 2630846be085SMike Kravetz * 2631846be085SMike Kravetz * In case 2, simply undo reserve map modifications done by alloc_huge_page. 2632846be085SMike Kravetz */ 2633846be085SMike Kravetz void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma, 2634846be085SMike Kravetz unsigned long address, struct page *page) 2635846be085SMike Kravetz { 263696b96a96SMike Kravetz long rc = vma_needs_reservation(h, vma, address); 263796b96a96SMike Kravetz 2638846be085SMike Kravetz if (HPageRestoreReserve(page)) { 2639846be085SMike Kravetz if (unlikely(rc < 0)) 264096b96a96SMike Kravetz /* 264196b96a96SMike Kravetz * Rare out of memory condition in reserve map 2642d6995da3SMike Kravetz * manipulation. Clear HPageRestoreReserve so that 264396b96a96SMike Kravetz * global reserve count will not be incremented 264496b96a96SMike Kravetz * by free_huge_page. This will make it appear 264596b96a96SMike Kravetz * as though the reservation for this page was 264696b96a96SMike Kravetz * consumed. This may prevent the task from 264796b96a96SMike Kravetz * faulting in the page at a later time. This 264896b96a96SMike Kravetz * is better than inconsistent global huge page 264996b96a96SMike Kravetz * accounting of reserve counts. 265096b96a96SMike Kravetz */ 2651d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 2652846be085SMike Kravetz else if (rc) 2653846be085SMike Kravetz (void)vma_add_reservation(h, vma, address); 2654846be085SMike Kravetz else 2655846be085SMike Kravetz vma_end_reservation(h, vma, address); 2656846be085SMike Kravetz } else { 2657846be085SMike Kravetz if (!rc) { 265896b96a96SMike Kravetz /* 2659846be085SMike Kravetz * This indicates there is an entry in the reserve map 2660c7b1850dSMike Kravetz * not added by alloc_huge_page. We know it was added 2661846be085SMike Kravetz * before the alloc_huge_page call, otherwise 2662846be085SMike Kravetz * HPageRestoreReserve would be set on the page. 2663846be085SMike Kravetz * Remove the entry so that a subsequent allocation 2664846be085SMike Kravetz * does not consume a reservation. 266596b96a96SMike Kravetz */ 2666846be085SMike Kravetz rc = vma_del_reservation(h, vma, address); 2667846be085SMike Kravetz if (rc < 0) 2668846be085SMike Kravetz /* 2669846be085SMike Kravetz * VERY rare out of memory condition. Since 2670846be085SMike Kravetz * we can not delete the entry, set 2671846be085SMike Kravetz * HPageRestoreReserve so that the reserve 2672846be085SMike Kravetz * count will be incremented when the page 2673846be085SMike Kravetz * is freed. This reserve will be consumed 2674846be085SMike Kravetz * on a subsequent allocation. 2675846be085SMike Kravetz */ 2676846be085SMike Kravetz SetHPageRestoreReserve(page); 2677846be085SMike Kravetz } else if (rc < 0) { 2678846be085SMike Kravetz /* 2679846be085SMike Kravetz * Rare out of memory condition from 2680846be085SMike Kravetz * vma_needs_reservation call. Memory allocation is 2681846be085SMike Kravetz * only attempted if a new entry is needed. Therefore, 2682846be085SMike Kravetz * this implies there is not an entry in the 2683846be085SMike Kravetz * reserve map. 2684846be085SMike Kravetz * 2685846be085SMike Kravetz * For shared mappings, no entry in the map indicates 2686846be085SMike Kravetz * no reservation. We are done. 2687846be085SMike Kravetz */ 2688846be085SMike Kravetz if (!(vma->vm_flags & VM_MAYSHARE)) 2689846be085SMike Kravetz /* 2690846be085SMike Kravetz * For private mappings, no entry indicates 2691846be085SMike Kravetz * a reservation is present. Since we can 2692846be085SMike Kravetz * not add an entry, set SetHPageRestoreReserve 2693846be085SMike Kravetz * on the page so reserve count will be 2694846be085SMike Kravetz * incremented when freed. This reserve will 2695846be085SMike Kravetz * be consumed on a subsequent allocation. 2696846be085SMike Kravetz */ 2697846be085SMike Kravetz SetHPageRestoreReserve(page); 269896b96a96SMike Kravetz } else 2699846be085SMike Kravetz /* 2700846be085SMike Kravetz * No reservation present, do nothing 2701846be085SMike Kravetz */ 270296b96a96SMike Kravetz vma_end_reservation(h, vma, address); 270396b96a96SMike Kravetz } 270496b96a96SMike Kravetz } 270596b96a96SMike Kravetz 2706369fa227SOscar Salvador /* 2707369fa227SOscar Salvador * alloc_and_dissolve_huge_page - Allocate a new page and dissolve the old one 2708369fa227SOscar Salvador * @h: struct hstate old page belongs to 2709369fa227SOscar Salvador * @old_page: Old page to dissolve 2710ae37c7ffSOscar Salvador * @list: List to isolate the page in case we need to 2711369fa227SOscar Salvador * Returns 0 on success, otherwise negated error. 2712369fa227SOscar Salvador */ 2713ae37c7ffSOscar Salvador static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, 2714ae37c7ffSOscar Salvador struct list_head *list) 2715369fa227SOscar Salvador { 2716369fa227SOscar Salvador gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 2717369fa227SOscar Salvador int nid = page_to_nid(old_page); 2718b65a4edaSMike Kravetz bool alloc_retry = false; 2719369fa227SOscar Salvador struct page *new_page; 2720369fa227SOscar Salvador int ret = 0; 2721369fa227SOscar Salvador 2722369fa227SOscar Salvador /* 2723369fa227SOscar Salvador * Before dissolving the page, we need to allocate a new one for the 2724f41f2ed4SMuchun Song * pool to remain stable. Here, we allocate the page and 'prep' it 2725f41f2ed4SMuchun Song * by doing everything but actually updating counters and adding to 2726f41f2ed4SMuchun Song * the pool. This simplifies and let us do most of the processing 2727f41f2ed4SMuchun Song * under the lock. 2728369fa227SOscar Salvador */ 2729b65a4edaSMike Kravetz alloc_retry: 2730369fa227SOscar Salvador new_page = alloc_buddy_huge_page(h, gfp_mask, nid, NULL, NULL); 2731369fa227SOscar Salvador if (!new_page) 2732369fa227SOscar Salvador return -ENOMEM; 2733b65a4edaSMike Kravetz /* 2734b65a4edaSMike Kravetz * If all goes well, this page will be directly added to the free 2735b65a4edaSMike Kravetz * list in the pool. For this the ref count needs to be zero. 2736b65a4edaSMike Kravetz * Attempt to drop now, and retry once if needed. It is VERY 2737b65a4edaSMike Kravetz * unlikely there is another ref on the page. 2738b65a4edaSMike Kravetz * 2739b65a4edaSMike Kravetz * If someone else has a reference to the page, it will be freed 2740b65a4edaSMike Kravetz * when they drop their ref. Abuse temporary page flag to accomplish 2741b65a4edaSMike Kravetz * this. Retry once if there is an inflated ref count. 2742b65a4edaSMike Kravetz */ 2743b65a4edaSMike Kravetz SetHPageTemporary(new_page); 2744b65a4edaSMike Kravetz if (!put_page_testzero(new_page)) { 2745b65a4edaSMike Kravetz if (alloc_retry) 2746b65a4edaSMike Kravetz return -EBUSY; 2747b65a4edaSMike Kravetz 2748b65a4edaSMike Kravetz alloc_retry = true; 2749b65a4edaSMike Kravetz goto alloc_retry; 2750b65a4edaSMike Kravetz } 2751b65a4edaSMike Kravetz ClearHPageTemporary(new_page); 2752b65a4edaSMike Kravetz 2753f41f2ed4SMuchun Song __prep_new_huge_page(h, new_page); 2754369fa227SOscar Salvador 2755369fa227SOscar Salvador retry: 2756369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2757369fa227SOscar Salvador if (!PageHuge(old_page)) { 2758369fa227SOscar Salvador /* 2759369fa227SOscar Salvador * Freed from under us. Drop new_page too. 2760369fa227SOscar Salvador */ 2761369fa227SOscar Salvador goto free_new; 2762369fa227SOscar Salvador } else if (page_count(old_page)) { 2763369fa227SOscar Salvador /* 2764ae37c7ffSOscar Salvador * Someone has grabbed the page, try to isolate it here. 2765ae37c7ffSOscar Salvador * Fail with -EBUSY if not possible. 2766369fa227SOscar Salvador */ 2767ae37c7ffSOscar Salvador spin_unlock_irq(&hugetlb_lock); 2768ae37c7ffSOscar Salvador if (!isolate_huge_page(old_page, list)) 2769369fa227SOscar Salvador ret = -EBUSY; 2770ae37c7ffSOscar Salvador spin_lock_irq(&hugetlb_lock); 2771369fa227SOscar Salvador goto free_new; 2772369fa227SOscar Salvador } else if (!HPageFreed(old_page)) { 2773369fa227SOscar Salvador /* 2774369fa227SOscar Salvador * Page's refcount is 0 but it has not been enqueued in the 2775369fa227SOscar Salvador * freelist yet. Race window is small, so we can succeed here if 2776369fa227SOscar Salvador * we retry. 2777369fa227SOscar Salvador */ 2778369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2779369fa227SOscar Salvador cond_resched(); 2780369fa227SOscar Salvador goto retry; 2781369fa227SOscar Salvador } else { 2782369fa227SOscar Salvador /* 2783369fa227SOscar Salvador * Ok, old_page is still a genuine free hugepage. Remove it from 2784369fa227SOscar Salvador * the freelist and decrease the counters. These will be 2785369fa227SOscar Salvador * incremented again when calling __prep_account_new_huge_page() 2786369fa227SOscar Salvador * and enqueue_huge_page() for new_page. The counters will remain 2787369fa227SOscar Salvador * stable since this happens under the lock. 2788369fa227SOscar Salvador */ 2789369fa227SOscar Salvador remove_hugetlb_page(h, old_page, false); 2790369fa227SOscar Salvador 2791369fa227SOscar Salvador /* 2792b65a4edaSMike Kravetz * Ref count on new page is already zero as it was dropped 2793b65a4edaSMike Kravetz * earlier. It can be directly added to the pool free list. 2794369fa227SOscar Salvador */ 2795369fa227SOscar Salvador __prep_account_new_huge_page(h, nid); 2796369fa227SOscar Salvador enqueue_huge_page(h, new_page); 2797369fa227SOscar Salvador 2798369fa227SOscar Salvador /* 2799369fa227SOscar Salvador * Pages have been replaced, we can safely free the old one. 2800369fa227SOscar Salvador */ 2801369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2802b65d4adbSMuchun Song update_and_free_page(h, old_page, false); 2803369fa227SOscar Salvador } 2804369fa227SOscar Salvador 2805369fa227SOscar Salvador return ret; 2806369fa227SOscar Salvador 2807369fa227SOscar Salvador free_new: 2808369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2809b65a4edaSMike Kravetz /* Page has a zero ref count, but needs a ref to be freed */ 2810b65a4edaSMike Kravetz set_page_refcounted(new_page); 2811b65d4adbSMuchun Song update_and_free_page(h, new_page, false); 2812369fa227SOscar Salvador 2813369fa227SOscar Salvador return ret; 2814369fa227SOscar Salvador } 2815369fa227SOscar Salvador 2816ae37c7ffSOscar Salvador int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list) 2817369fa227SOscar Salvador { 2818369fa227SOscar Salvador struct hstate *h; 2819369fa227SOscar Salvador struct page *head; 2820ae37c7ffSOscar Salvador int ret = -EBUSY; 2821369fa227SOscar Salvador 2822369fa227SOscar Salvador /* 2823369fa227SOscar Salvador * The page might have been dissolved from under our feet, so make sure 2824369fa227SOscar Salvador * to carefully check the state under the lock. 2825369fa227SOscar Salvador * Return success when racing as if we dissolved the page ourselves. 2826369fa227SOscar Salvador */ 2827369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2828369fa227SOscar Salvador if (PageHuge(page)) { 2829369fa227SOscar Salvador head = compound_head(page); 2830369fa227SOscar Salvador h = page_hstate(head); 2831369fa227SOscar Salvador } else { 2832369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2833369fa227SOscar Salvador return 0; 2834369fa227SOscar Salvador } 2835369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2836369fa227SOscar Salvador 2837369fa227SOscar Salvador /* 2838369fa227SOscar Salvador * Fence off gigantic pages as there is a cyclic dependency between 2839369fa227SOscar Salvador * alloc_contig_range and them. Return -ENOMEM as this has the effect 2840369fa227SOscar Salvador * of bailing out right away without further retrying. 2841369fa227SOscar Salvador */ 2842369fa227SOscar Salvador if (hstate_is_gigantic(h)) 2843369fa227SOscar Salvador return -ENOMEM; 2844369fa227SOscar Salvador 2845ae37c7ffSOscar Salvador if (page_count(head) && isolate_huge_page(head, list)) 2846ae37c7ffSOscar Salvador ret = 0; 2847ae37c7ffSOscar Salvador else if (!page_count(head)) 2848ae37c7ffSOscar Salvador ret = alloc_and_dissolve_huge_page(h, head, list); 2849ae37c7ffSOscar Salvador 2850ae37c7ffSOscar Salvador return ret; 2851369fa227SOscar Salvador } 2852369fa227SOscar Salvador 285370c3547eSMike Kravetz struct page *alloc_huge_page(struct vm_area_struct *vma, 285404f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 2855348ea204SAdam Litke { 285690481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 2857a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 2858348ea204SAdam Litke struct page *page; 2859d85f69b0SMike Kravetz long map_chg, map_commit; 2860d85f69b0SMike Kravetz long gbl_chg; 28616d76dcf4SAneesh Kumar K.V int ret, idx; 28626d76dcf4SAneesh Kumar K.V struct hugetlb_cgroup *h_cg; 286308cf9fafSMina Almasry bool deferred_reserve; 28642fc39cecSAdam Litke 28656d76dcf4SAneesh Kumar K.V idx = hstate_index(h); 2866a1e78772SMel Gorman /* 2867d85f69b0SMike Kravetz * Examine the region/reserve map to determine if the process 2868d85f69b0SMike Kravetz * has a reservation for the page to be allocated. A return 2869d85f69b0SMike Kravetz * code of zero indicates a reservation exists (no change). 2870a1e78772SMel Gorman */ 2871d85f69b0SMike Kravetz map_chg = gbl_chg = vma_needs_reservation(h, vma, addr); 2872d85f69b0SMike Kravetz if (map_chg < 0) 287376dcee75SAneesh Kumar K.V return ERR_PTR(-ENOMEM); 2874d85f69b0SMike Kravetz 2875d85f69b0SMike Kravetz /* 2876d85f69b0SMike Kravetz * Processes that did not create the mapping will have no 2877d85f69b0SMike Kravetz * reserves as indicated by the region/reserve map. Check 2878d85f69b0SMike Kravetz * that the allocation will not exceed the subpool limit. 2879d85f69b0SMike Kravetz * Allocations for MAP_NORESERVE mappings also need to be 2880d85f69b0SMike Kravetz * checked against any subpool limit. 2881d85f69b0SMike Kravetz */ 2882d85f69b0SMike Kravetz if (map_chg || avoid_reserve) { 2883d85f69b0SMike Kravetz gbl_chg = hugepage_subpool_get_pages(spool, 1); 2884d85f69b0SMike Kravetz if (gbl_chg < 0) { 2885feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 288676dcee75SAneesh Kumar K.V return ERR_PTR(-ENOSPC); 28875e911373SMike Kravetz } 288890d8b7e6SAdam Litke 2889d85f69b0SMike Kravetz /* 2890d85f69b0SMike Kravetz * Even though there was no reservation in the region/reserve 2891d85f69b0SMike Kravetz * map, there could be reservations associated with the 2892d85f69b0SMike Kravetz * subpool that can be used. This would be indicated if the 2893d85f69b0SMike Kravetz * return value of hugepage_subpool_get_pages() is zero. 2894d85f69b0SMike Kravetz * However, if avoid_reserve is specified we still avoid even 2895d85f69b0SMike Kravetz * the subpool reservations. 2896d85f69b0SMike Kravetz */ 2897d85f69b0SMike Kravetz if (avoid_reserve) 2898d85f69b0SMike Kravetz gbl_chg = 1; 2899d85f69b0SMike Kravetz } 2900d85f69b0SMike Kravetz 290108cf9fafSMina Almasry /* If this allocation is not consuming a reservation, charge it now. 290208cf9fafSMina Almasry */ 29036501fe5fSMiaohe Lin deferred_reserve = map_chg || avoid_reserve; 290408cf9fafSMina Almasry if (deferred_reserve) { 290508cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup_rsvd( 290608cf9fafSMina Almasry idx, pages_per_huge_page(h), &h_cg); 29078f34af6fSJianyu Zhan if (ret) 29088f34af6fSJianyu Zhan goto out_subpool_put; 290908cf9fafSMina Almasry } 291008cf9fafSMina Almasry 291108cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); 291208cf9fafSMina Almasry if (ret) 291308cf9fafSMina Almasry goto out_uncharge_cgroup_reservation; 29148f34af6fSJianyu Zhan 2915db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2916d85f69b0SMike Kravetz /* 2917d85f69b0SMike Kravetz * glb_chg is passed to indicate whether or not a page must be taken 2918d85f69b0SMike Kravetz * from the global free pool (global change). gbl_chg == 0 indicates 2919d85f69b0SMike Kravetz * a reservation exists for the allocation. 2920d85f69b0SMike Kravetz */ 2921d85f69b0SMike Kravetz page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg); 292281a6fcaeSJoonsoo Kim if (!page) { 2923db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 29240c397daeSMichal Hocko page = alloc_buddy_huge_page_with_mpol(h, vma, addr); 29258f34af6fSJianyu Zhan if (!page) 29268f34af6fSJianyu Zhan goto out_uncharge_cgroup; 2927a88c7695SNaoya Horiguchi if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { 2928d6995da3SMike Kravetz SetHPageRestoreReserve(page); 2929a88c7695SNaoya Horiguchi h->resv_huge_pages--; 2930a88c7695SNaoya Horiguchi } 2931db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 293215a8d68eSWei Yang list_add(&page->lru, &h->hugepage_activelist); 293381a6fcaeSJoonsoo Kim /* Fall through */ 2934a1e78772SMel Gorman } 293581a6fcaeSJoonsoo Kim hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); 293608cf9fafSMina Almasry /* If allocation is not consuming a reservation, also store the 293708cf9fafSMina Almasry * hugetlb_cgroup pointer on the page. 293808cf9fafSMina Almasry */ 293908cf9fafSMina Almasry if (deferred_reserve) { 294008cf9fafSMina Almasry hugetlb_cgroup_commit_charge_rsvd(idx, pages_per_huge_page(h), 294108cf9fafSMina Almasry h_cg, page); 294208cf9fafSMina Almasry } 294308cf9fafSMina Almasry 2944db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2945a1e78772SMel Gorman 2946d6995da3SMike Kravetz hugetlb_set_page_subpool(page, spool); 2947a1e78772SMel Gorman 2948d85f69b0SMike Kravetz map_commit = vma_commit_reservation(h, vma, addr); 2949d85f69b0SMike Kravetz if (unlikely(map_chg > map_commit)) { 295033039678SMike Kravetz /* 295133039678SMike Kravetz * The page was added to the reservation map between 295233039678SMike Kravetz * vma_needs_reservation and vma_commit_reservation. 295333039678SMike Kravetz * This indicates a race with hugetlb_reserve_pages. 295433039678SMike Kravetz * Adjust for the subpool count incremented above AND 295533039678SMike Kravetz * in hugetlb_reserve_pages for the same page. Also, 295633039678SMike Kravetz * the reservation count added in hugetlb_reserve_pages 295733039678SMike Kravetz * no longer applies. 295833039678SMike Kravetz */ 295933039678SMike Kravetz long rsv_adjust; 296033039678SMike Kravetz 296133039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 1); 296233039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 296379aa925bSMike Kravetz if (deferred_reserve) 296479aa925bSMike Kravetz hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 296579aa925bSMike Kravetz pages_per_huge_page(h), page); 296633039678SMike Kravetz } 29677893d1d5SAdam Litke return page; 29688f34af6fSJianyu Zhan 29698f34af6fSJianyu Zhan out_uncharge_cgroup: 29708f34af6fSJianyu Zhan hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); 297108cf9fafSMina Almasry out_uncharge_cgroup_reservation: 297208cf9fafSMina Almasry if (deferred_reserve) 297308cf9fafSMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h), 297408cf9fafSMina Almasry h_cg); 29758f34af6fSJianyu Zhan out_subpool_put: 2976d85f69b0SMike Kravetz if (map_chg || avoid_reserve) 29778f34af6fSJianyu Zhan hugepage_subpool_put_pages(spool, 1); 2978feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 29798f34af6fSJianyu Zhan return ERR_PTR(-ENOSPC); 2980b45b5bd6SDavid Gibson } 2981b45b5bd6SDavid Gibson 2982b5389086SZhenguo Yao int alloc_bootmem_huge_page(struct hstate *h, int nid) 2983e24a1307SAneesh Kumar K.V __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); 2984b5389086SZhenguo Yao int __alloc_bootmem_huge_page(struct hstate *h, int nid) 2985aa888a74SAndi Kleen { 2986b5389086SZhenguo Yao struct huge_bootmem_page *m = NULL; /* initialize for clang */ 2987b2261026SJoonsoo Kim int nr_nodes, node; 2988aa888a74SAndi Kleen 2989b5389086SZhenguo Yao /* do node specific alloc */ 2990b5389086SZhenguo Yao if (nid != NUMA_NO_NODE) { 2991b5389086SZhenguo Yao m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h), 2992b5389086SZhenguo Yao 0, MEMBLOCK_ALLOC_ACCESSIBLE, nid); 2993b5389086SZhenguo Yao if (!m) 2994b5389086SZhenguo Yao return 0; 2995b5389086SZhenguo Yao goto found; 2996b5389086SZhenguo Yao } 2997b5389086SZhenguo Yao /* allocate from next node when distributing huge pages */ 2998b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { 2999b5389086SZhenguo Yao m = memblock_alloc_try_nid_raw( 30008b89a116SGrygorii Strashko huge_page_size(h), huge_page_size(h), 300197ad1087SMike Rapoport 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); 3002aa888a74SAndi Kleen /* 3003aa888a74SAndi Kleen * Use the beginning of the huge page to store the 3004aa888a74SAndi Kleen * huge_bootmem_page struct (until gather_bootmem 3005aa888a74SAndi Kleen * puts them into the mem_map). 3006aa888a74SAndi Kleen */ 3007b5389086SZhenguo Yao if (!m) 3008b5389086SZhenguo Yao return 0; 3009aa888a74SAndi Kleen goto found; 3010aa888a74SAndi Kleen } 3011aa888a74SAndi Kleen 3012aa888a74SAndi Kleen found: 3013aa888a74SAndi Kleen /* Put them into a private list first because mem_map is not up yet */ 3014330d6e48SCannon Matthews INIT_LIST_HEAD(&m->list); 3015aa888a74SAndi Kleen list_add(&m->list, &huge_boot_pages); 3016aa888a74SAndi Kleen m->hstate = h; 3017aa888a74SAndi Kleen return 1; 3018aa888a74SAndi Kleen } 3019aa888a74SAndi Kleen 302048b8d744SMike Kravetz /* 302148b8d744SMike Kravetz * Put bootmem huge pages into the standard lists after mem_map is up. 302248b8d744SMike Kravetz * Note: This only applies to gigantic (order > MAX_ORDER) pages. 302348b8d744SMike Kravetz */ 3024aa888a74SAndi Kleen static void __init gather_bootmem_prealloc(void) 3025aa888a74SAndi Kleen { 3026aa888a74SAndi Kleen struct huge_bootmem_page *m; 3027aa888a74SAndi Kleen 3028aa888a74SAndi Kleen list_for_each_entry(m, &huge_boot_pages, list) { 302940d18ebfSMike Kravetz struct page *page = virt_to_page(m); 3030aa888a74SAndi Kleen struct hstate *h = m->hstate; 3031ee8f248dSBecky Bruce 303248b8d744SMike Kravetz VM_BUG_ON(!hstate_is_gigantic(h)); 3033aa888a74SAndi Kleen WARN_ON(page_count(page) != 1); 30347118fc29SMike Kravetz if (prep_compound_gigantic_page(page, huge_page_order(h))) { 3035ef5a22beSAndrea Arcangeli WARN_ON(PageReserved(page)); 3036aa888a74SAndi Kleen prep_new_huge_page(h, page, page_to_nid(page)); 30377118fc29SMike Kravetz put_page(page); /* add to the hugepage allocator */ 30387118fc29SMike Kravetz } else { 3039416d85edSMike Kravetz /* VERY unlikely inflated ref count on a tail page */ 30407118fc29SMike Kravetz free_gigantic_page(page, huge_page_order(h)); 30417118fc29SMike Kravetz } 3042af0fb9dfSMichal Hocko 3043b0320c7bSRafael Aquini /* 304448b8d744SMike Kravetz * We need to restore the 'stolen' pages to totalram_pages 304548b8d744SMike Kravetz * in order to fix confusing memory reports from free(1) and 304648b8d744SMike Kravetz * other side-effects, like CommitLimit going negative. 3047b0320c7bSRafael Aquini */ 3048c78a7f36SMiaohe Lin adjust_managed_page_count(page, pages_per_huge_page(h)); 3049520495feSCannon Matthews cond_resched(); 3050aa888a74SAndi Kleen } 3051aa888a74SAndi Kleen } 3052b5389086SZhenguo Yao static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid) 3053b5389086SZhenguo Yao { 3054b5389086SZhenguo Yao unsigned long i; 3055b5389086SZhenguo Yao char buf[32]; 3056b5389086SZhenguo Yao 3057b5389086SZhenguo Yao for (i = 0; i < h->max_huge_pages_node[nid]; ++i) { 3058b5389086SZhenguo Yao if (hstate_is_gigantic(h)) { 3059b5389086SZhenguo Yao if (!alloc_bootmem_huge_page(h, nid)) 3060b5389086SZhenguo Yao break; 3061b5389086SZhenguo Yao } else { 3062b5389086SZhenguo Yao struct page *page; 3063b5389086SZhenguo Yao gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 3064b5389086SZhenguo Yao 3065b5389086SZhenguo Yao page = alloc_fresh_huge_page(h, gfp_mask, nid, 3066b5389086SZhenguo Yao &node_states[N_MEMORY], NULL); 3067b5389086SZhenguo Yao if (!page) 3068b5389086SZhenguo Yao break; 3069b5389086SZhenguo Yao put_page(page); /* free it into the hugepage allocator */ 3070b5389086SZhenguo Yao } 3071b5389086SZhenguo Yao cond_resched(); 3072b5389086SZhenguo Yao } 3073b5389086SZhenguo Yao if (i == h->max_huge_pages_node[nid]) 3074b5389086SZhenguo Yao return; 3075b5389086SZhenguo Yao 3076b5389086SZhenguo Yao string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3077b5389086SZhenguo Yao pr_warn("HugeTLB: allocating %u of page size %s failed node%d. Only allocated %lu hugepages.\n", 3078b5389086SZhenguo Yao h->max_huge_pages_node[nid], buf, nid, i); 3079b5389086SZhenguo Yao h->max_huge_pages -= (h->max_huge_pages_node[nid] - i); 3080b5389086SZhenguo Yao h->max_huge_pages_node[nid] = i; 3081b5389086SZhenguo Yao } 3082aa888a74SAndi Kleen 30838faa8b07SAndi Kleen static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 30841da177e4SLinus Torvalds { 30851da177e4SLinus Torvalds unsigned long i; 3086f60858f9SMike Kravetz nodemask_t *node_alloc_noretry; 3087b5389086SZhenguo Yao bool node_specific_alloc = false; 3088f60858f9SMike Kravetz 3089b5389086SZhenguo Yao /* skip gigantic hugepages allocation if hugetlb_cma enabled */ 3090b5389086SZhenguo Yao if (hstate_is_gigantic(h) && hugetlb_cma_size) { 3091b5389086SZhenguo Yao pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n"); 3092b5389086SZhenguo Yao return; 3093b5389086SZhenguo Yao } 3094b5389086SZhenguo Yao 3095b5389086SZhenguo Yao /* do node specific alloc */ 30960a7a0f6fSPeng Liu for_each_online_node(i) { 3097b5389086SZhenguo Yao if (h->max_huge_pages_node[i] > 0) { 3098b5389086SZhenguo Yao hugetlb_hstate_alloc_pages_onenode(h, i); 3099b5389086SZhenguo Yao node_specific_alloc = true; 3100b5389086SZhenguo Yao } 3101b5389086SZhenguo Yao } 3102b5389086SZhenguo Yao 3103b5389086SZhenguo Yao if (node_specific_alloc) 3104b5389086SZhenguo Yao return; 3105b5389086SZhenguo Yao 3106b5389086SZhenguo Yao /* below will do all node balanced alloc */ 3107f60858f9SMike Kravetz if (!hstate_is_gigantic(h)) { 3108f60858f9SMike Kravetz /* 3109f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3110f60858f9SMike Kravetz * Ignore errors as lower level routines can deal with 3111f60858f9SMike Kravetz * node_alloc_noretry == NULL. If this kmalloc fails at boot 3112f60858f9SMike Kravetz * time, we are likely in bigger trouble. 3113f60858f9SMike Kravetz */ 3114f60858f9SMike Kravetz node_alloc_noretry = kmalloc(sizeof(*node_alloc_noretry), 3115f60858f9SMike Kravetz GFP_KERNEL); 3116f60858f9SMike Kravetz } else { 3117f60858f9SMike Kravetz /* allocations done at boot time */ 3118f60858f9SMike Kravetz node_alloc_noretry = NULL; 3119f60858f9SMike Kravetz } 3120f60858f9SMike Kravetz 3121f60858f9SMike Kravetz /* bit mask controlling how hard we retry per-node allocations */ 3122f60858f9SMike Kravetz if (node_alloc_noretry) 3123f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 31241da177e4SLinus Torvalds 3125e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 3126bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) { 3127b5389086SZhenguo Yao if (!alloc_bootmem_huge_page(h, NUMA_NO_NODE)) 3128aa888a74SAndi Kleen break; 31290c397daeSMichal Hocko } else if (!alloc_pool_huge_page(h, 3130f60858f9SMike Kravetz &node_states[N_MEMORY], 3131f60858f9SMike Kravetz node_alloc_noretry)) 31321da177e4SLinus Torvalds break; 313369ed779aSDavid Rientjes cond_resched(); 31341da177e4SLinus Torvalds } 3135d715cf80SLiam R. Howlett if (i < h->max_huge_pages) { 3136d715cf80SLiam R. Howlett char buf[32]; 3137d715cf80SLiam R. Howlett 3138c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3139d715cf80SLiam R. Howlett pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n", 3140d715cf80SLiam R. Howlett h->max_huge_pages, buf, i); 31418faa8b07SAndi Kleen h->max_huge_pages = i; 3142e5ff2159SAndi Kleen } 3143f60858f9SMike Kravetz kfree(node_alloc_noretry); 3144d715cf80SLiam R. Howlett } 3145e5ff2159SAndi Kleen 3146e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 3147e5ff2159SAndi Kleen { 314879dfc695SMike Kravetz struct hstate *h, *h2; 3149e5ff2159SAndi Kleen 3150e5ff2159SAndi Kleen for_each_hstate(h) { 3151641844f5SNaoya Horiguchi if (minimum_order > huge_page_order(h)) 3152641844f5SNaoya Horiguchi minimum_order = huge_page_order(h); 3153641844f5SNaoya Horiguchi 31548faa8b07SAndi Kleen /* oversize hugepages were init'ed in early boot */ 3155bae7f4aeSLuiz Capitulino if (!hstate_is_gigantic(h)) 31568faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(h); 315779dfc695SMike Kravetz 315879dfc695SMike Kravetz /* 315979dfc695SMike Kravetz * Set demote order for each hstate. Note that 316079dfc695SMike Kravetz * h->demote_order is initially 0. 316179dfc695SMike Kravetz * - We can not demote gigantic pages if runtime freeing 316279dfc695SMike Kravetz * is not supported, so skip this. 3163a01f4390SMike Kravetz * - If CMA allocation is possible, we can not demote 3164a01f4390SMike Kravetz * HUGETLB_PAGE_ORDER or smaller size pages. 316579dfc695SMike Kravetz */ 316679dfc695SMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 316779dfc695SMike Kravetz continue; 3168a01f4390SMike Kravetz if (hugetlb_cma_size && h->order <= HUGETLB_PAGE_ORDER) 3169a01f4390SMike Kravetz continue; 317079dfc695SMike Kravetz for_each_hstate(h2) { 317179dfc695SMike Kravetz if (h2 == h) 317279dfc695SMike Kravetz continue; 317379dfc695SMike Kravetz if (h2->order < h->order && 317479dfc695SMike Kravetz h2->order > h->demote_order) 317579dfc695SMike Kravetz h->demote_order = h2->order; 317679dfc695SMike Kravetz } 3177e5ff2159SAndi Kleen } 3178641844f5SNaoya Horiguchi VM_BUG_ON(minimum_order == UINT_MAX); 3179e5ff2159SAndi Kleen } 3180e5ff2159SAndi Kleen 3181e5ff2159SAndi Kleen static void __init report_hugepages(void) 3182e5ff2159SAndi Kleen { 3183e5ff2159SAndi Kleen struct hstate *h; 3184e5ff2159SAndi Kleen 3185e5ff2159SAndi Kleen for_each_hstate(h) { 31864abd32dbSAndi Kleen char buf[32]; 3187c6247f72SMatthew Wilcox 3188c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 3189ffb22af5SAndrew Morton pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n", 3190c6247f72SMatthew Wilcox buf, h->free_huge_pages); 3191e5ff2159SAndi Kleen } 3192e5ff2159SAndi Kleen } 3193e5ff2159SAndi Kleen 31941da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 31956ae11b27SLee Schermerhorn static void try_to_free_low(struct hstate *h, unsigned long count, 31966ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 31971da177e4SLinus Torvalds { 31984415cc8dSChristoph Lameter int i; 31991121828aSMike Kravetz LIST_HEAD(page_list); 32004415cc8dSChristoph Lameter 32019487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 3202bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3203aa888a74SAndi Kleen return; 3204aa888a74SAndi Kleen 32051121828aSMike Kravetz /* 32061121828aSMike Kravetz * Collect pages to be freed on a list, and free after dropping lock 32071121828aSMike Kravetz */ 32086ae11b27SLee Schermerhorn for_each_node_mask(i, *nodes_allowed) { 320910c6ec49SMike Kravetz struct page *page, *next; 3210a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 3211a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 3212a5516438SAndi Kleen if (count >= h->nr_huge_pages) 32131121828aSMike Kravetz goto out; 32141da177e4SLinus Torvalds if (PageHighMem(page)) 32151da177e4SLinus Torvalds continue; 32166eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 32171121828aSMike Kravetz list_add(&page->lru, &page_list); 32181121828aSMike Kravetz } 32191121828aSMike Kravetz } 32201121828aSMike Kravetz 32211121828aSMike Kravetz out: 3222db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 322310c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3224db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 32251da177e4SLinus Torvalds } 32261da177e4SLinus Torvalds #else 32276ae11b27SLee Schermerhorn static inline void try_to_free_low(struct hstate *h, unsigned long count, 32286ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 32291da177e4SLinus Torvalds { 32301da177e4SLinus Torvalds } 32311da177e4SLinus Torvalds #endif 32321da177e4SLinus Torvalds 323320a0307cSWu Fengguang /* 323420a0307cSWu Fengguang * Increment or decrement surplus_huge_pages. Keep node-specific counters 323520a0307cSWu Fengguang * balanced by operating on them in a round-robin fashion. 323620a0307cSWu Fengguang * Returns 1 if an adjustment was made. 323720a0307cSWu Fengguang */ 32386ae11b27SLee Schermerhorn static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, 32396ae11b27SLee Schermerhorn int delta) 324020a0307cSWu Fengguang { 3241b2261026SJoonsoo Kim int nr_nodes, node; 324220a0307cSWu Fengguang 32439487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 324420a0307cSWu Fengguang VM_BUG_ON(delta != -1 && delta != 1); 324520a0307cSWu Fengguang 3246e8c5c824SLee Schermerhorn if (delta < 0) { 3247b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 3248b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node]) 3249b2261026SJoonsoo Kim goto found; 3250b2261026SJoonsoo Kim } 3251b2261026SJoonsoo Kim } else { 3252b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 3253b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node] < 3254b2261026SJoonsoo Kim h->nr_huge_pages_node[node]) 3255b2261026SJoonsoo Kim goto found; 3256e8c5c824SLee Schermerhorn } 32579a76db09SLee Schermerhorn } 3258b2261026SJoonsoo Kim return 0; 325920a0307cSWu Fengguang 3260b2261026SJoonsoo Kim found: 326120a0307cSWu Fengguang h->surplus_huge_pages += delta; 3262b2261026SJoonsoo Kim h->surplus_huge_pages_node[node] += delta; 3263b2261026SJoonsoo Kim return 1; 326420a0307cSWu Fengguang } 326520a0307cSWu Fengguang 3266a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 3267fd875dcaSMike Kravetz static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, 32686ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 32691da177e4SLinus Torvalds { 32707893d1d5SAdam Litke unsigned long min_count, ret; 327110c6ec49SMike Kravetz struct page *page; 327210c6ec49SMike Kravetz LIST_HEAD(page_list); 3273f60858f9SMike Kravetz NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL); 3274f60858f9SMike Kravetz 3275f60858f9SMike Kravetz /* 3276f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 3277f60858f9SMike Kravetz * If we can not allocate the bit mask, do not attempt to allocate 3278f60858f9SMike Kravetz * the requested huge pages. 3279f60858f9SMike Kravetz */ 3280f60858f9SMike Kravetz if (node_alloc_noretry) 3281f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 3282f60858f9SMike Kravetz else 3283f60858f9SMike Kravetz return -ENOMEM; 32841da177e4SLinus Torvalds 328529383967SMike Kravetz /* 328629383967SMike Kravetz * resize_lock mutex prevents concurrent adjustments to number of 328729383967SMike Kravetz * pages in hstate via the proc/sysfs interfaces. 328829383967SMike Kravetz */ 328929383967SMike Kravetz mutex_lock(&h->resize_lock); 3290b65d4adbSMuchun Song flush_free_hpage_work(h); 3291db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 32924eb0716eSAlexandre Ghiti 32934eb0716eSAlexandre Ghiti /* 3294fd875dcaSMike Kravetz * Check for a node specific request. 3295fd875dcaSMike Kravetz * Changing node specific huge page count may require a corresponding 3296fd875dcaSMike Kravetz * change to the global count. In any case, the passed node mask 3297fd875dcaSMike Kravetz * (nodes_allowed) will restrict alloc/free to the specified node. 3298fd875dcaSMike Kravetz */ 3299fd875dcaSMike Kravetz if (nid != NUMA_NO_NODE) { 3300fd875dcaSMike Kravetz unsigned long old_count = count; 3301fd875dcaSMike Kravetz 3302fd875dcaSMike Kravetz count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; 3303fd875dcaSMike Kravetz /* 3304fd875dcaSMike Kravetz * User may have specified a large count value which caused the 3305fd875dcaSMike Kravetz * above calculation to overflow. In this case, they wanted 3306fd875dcaSMike Kravetz * to allocate as many huge pages as possible. Set count to 3307fd875dcaSMike Kravetz * largest possible value to align with their intention. 3308fd875dcaSMike Kravetz */ 3309fd875dcaSMike Kravetz if (count < old_count) 3310fd875dcaSMike Kravetz count = ULONG_MAX; 3311fd875dcaSMike Kravetz } 3312fd875dcaSMike Kravetz 3313fd875dcaSMike Kravetz /* 33144eb0716eSAlexandre Ghiti * Gigantic pages runtime allocation depend on the capability for large 33154eb0716eSAlexandre Ghiti * page range allocation. 33164eb0716eSAlexandre Ghiti * If the system does not provide this feature, return an error when 33174eb0716eSAlexandre Ghiti * the user tries to allocate gigantic pages but let the user free the 33184eb0716eSAlexandre Ghiti * boottime allocated gigantic pages. 33194eb0716eSAlexandre Ghiti */ 33204eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) { 33214eb0716eSAlexandre Ghiti if (count > persistent_huge_pages(h)) { 3322db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 332329383967SMike Kravetz mutex_unlock(&h->resize_lock); 3324f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 33254eb0716eSAlexandre Ghiti return -EINVAL; 33264eb0716eSAlexandre Ghiti } 33274eb0716eSAlexandre Ghiti /* Fall through to decrease pool */ 33284eb0716eSAlexandre Ghiti } 3329aa888a74SAndi Kleen 33307893d1d5SAdam Litke /* 33317893d1d5SAdam Litke * Increase the pool size 33327893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 33337893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 3334d1c3fb1fSNishanth Aravamudan * 33350c397daeSMichal Hocko * We might race with alloc_surplus_huge_page() here and be unable 3336d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 3337d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 3338d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 3339d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 33407893d1d5SAdam Litke */ 3341a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 33426ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, -1)) 33437893d1d5SAdam Litke break; 33447893d1d5SAdam Litke } 33457893d1d5SAdam Litke 3346a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 33477893d1d5SAdam Litke /* 33487893d1d5SAdam Litke * If this allocation races such that we no longer need the 33497893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 33507893d1d5SAdam Litke * and reducing the surplus. 33517893d1d5SAdam Litke */ 3352db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3353649920c6SJia He 3354649920c6SJia He /* yield cpu to avoid soft lockup */ 3355649920c6SJia He cond_resched(); 3356649920c6SJia He 3357f60858f9SMike Kravetz ret = alloc_pool_huge_page(h, nodes_allowed, 3358f60858f9SMike Kravetz node_alloc_noretry); 3359db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 33607893d1d5SAdam Litke if (!ret) 33617893d1d5SAdam Litke goto out; 33627893d1d5SAdam Litke 3363536240f2SMel Gorman /* Bail for signals. Probably ctrl-c from user */ 3364536240f2SMel Gorman if (signal_pending(current)) 3365536240f2SMel Gorman goto out; 33667893d1d5SAdam Litke } 33677893d1d5SAdam Litke 33687893d1d5SAdam Litke /* 33697893d1d5SAdam Litke * Decrease the pool size 33707893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 33717893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 33727893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 33737893d1d5SAdam Litke * to the desired size as pages become free. 3374d1c3fb1fSNishanth Aravamudan * 3375d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 3376d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 3377d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 33780c397daeSMichal Hocko * alloc_surplus_huge_page() is checking the global counter, 3379d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 3380d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 3381d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 33827893d1d5SAdam Litke */ 3383a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 33846b0c880dSAdam Litke min_count = max(count, min_count); 33856ae11b27SLee Schermerhorn try_to_free_low(h, min_count, nodes_allowed); 338610c6ec49SMike Kravetz 338710c6ec49SMike Kravetz /* 338810c6ec49SMike Kravetz * Collect pages to be removed on list without dropping lock 338910c6ec49SMike Kravetz */ 3390a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 339110c6ec49SMike Kravetz page = remove_pool_huge_page(h, nodes_allowed, 0); 339210c6ec49SMike Kravetz if (!page) 33931da177e4SLinus Torvalds break; 339410c6ec49SMike Kravetz 339510c6ec49SMike Kravetz list_add(&page->lru, &page_list); 33961da177e4SLinus Torvalds } 339710c6ec49SMike Kravetz /* free the pages after dropping lock */ 3398db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 339910c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3400b65d4adbSMuchun Song flush_free_hpage_work(h); 3401db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 340210c6ec49SMike Kravetz 3403a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 34046ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, 1)) 34057893d1d5SAdam Litke break; 34067893d1d5SAdam Litke } 34077893d1d5SAdam Litke out: 34084eb0716eSAlexandre Ghiti h->max_huge_pages = persistent_huge_pages(h); 3409db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 341029383967SMike Kravetz mutex_unlock(&h->resize_lock); 34114eb0716eSAlexandre Ghiti 3412f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 3413f60858f9SMike Kravetz 34144eb0716eSAlexandre Ghiti return 0; 34151da177e4SLinus Torvalds } 34161da177e4SLinus Torvalds 34178531fc6fSMike Kravetz static int demote_free_huge_page(struct hstate *h, struct page *page) 34188531fc6fSMike Kravetz { 34198531fc6fSMike Kravetz int i, nid = page_to_nid(page); 34208531fc6fSMike Kravetz struct hstate *target_hstate; 34218531fc6fSMike Kravetz int rc = 0; 34228531fc6fSMike Kravetz 34238531fc6fSMike Kravetz target_hstate = size_to_hstate(PAGE_SIZE << h->demote_order); 34248531fc6fSMike Kravetz 34258531fc6fSMike Kravetz remove_hugetlb_page_for_demote(h, page, false); 34268531fc6fSMike Kravetz spin_unlock_irq(&hugetlb_lock); 34278531fc6fSMike Kravetz 34285981611dSMuchun Song rc = hugetlb_vmemmap_alloc(h, page); 34298531fc6fSMike Kravetz if (rc) { 34308531fc6fSMike Kravetz /* Allocation of vmemmmap failed, we can not demote page */ 34318531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 34328531fc6fSMike Kravetz set_page_refcounted(page); 34338531fc6fSMike Kravetz add_hugetlb_page(h, page, false); 34348531fc6fSMike Kravetz return rc; 34358531fc6fSMike Kravetz } 34368531fc6fSMike Kravetz 34378531fc6fSMike Kravetz /* 34388531fc6fSMike Kravetz * Use destroy_compound_hugetlb_page_for_demote for all huge page 34398531fc6fSMike Kravetz * sizes as it will not ref count pages. 34408531fc6fSMike Kravetz */ 34418531fc6fSMike Kravetz destroy_compound_hugetlb_page_for_demote(page, huge_page_order(h)); 34428531fc6fSMike Kravetz 34438531fc6fSMike Kravetz /* 34448531fc6fSMike Kravetz * Taking target hstate mutex synchronizes with set_max_huge_pages. 34458531fc6fSMike Kravetz * Without the mutex, pages added to target hstate could be marked 34468531fc6fSMike Kravetz * as surplus. 34478531fc6fSMike Kravetz * 34488531fc6fSMike Kravetz * Note that we already hold h->resize_lock. To prevent deadlock, 34498531fc6fSMike Kravetz * use the convention of always taking larger size hstate mutex first. 34508531fc6fSMike Kravetz */ 34518531fc6fSMike Kravetz mutex_lock(&target_hstate->resize_lock); 34528531fc6fSMike Kravetz for (i = 0; i < pages_per_huge_page(h); 34538531fc6fSMike Kravetz i += pages_per_huge_page(target_hstate)) { 34548531fc6fSMike Kravetz if (hstate_is_gigantic(target_hstate)) 34558531fc6fSMike Kravetz prep_compound_gigantic_page_for_demote(page + i, 34568531fc6fSMike Kravetz target_hstate->order); 34578531fc6fSMike Kravetz else 34588531fc6fSMike Kravetz prep_compound_page(page + i, target_hstate->order); 34598531fc6fSMike Kravetz set_page_private(page + i, 0); 34608531fc6fSMike Kravetz set_page_refcounted(page + i); 34618531fc6fSMike Kravetz prep_new_huge_page(target_hstate, page + i, nid); 34628531fc6fSMike Kravetz put_page(page + i); 34638531fc6fSMike Kravetz } 34648531fc6fSMike Kravetz mutex_unlock(&target_hstate->resize_lock); 34658531fc6fSMike Kravetz 34668531fc6fSMike Kravetz spin_lock_irq(&hugetlb_lock); 34678531fc6fSMike Kravetz 34688531fc6fSMike Kravetz /* 34698531fc6fSMike Kravetz * Not absolutely necessary, but for consistency update max_huge_pages 34708531fc6fSMike Kravetz * based on pool changes for the demoted page. 34718531fc6fSMike Kravetz */ 34728531fc6fSMike Kravetz h->max_huge_pages--; 34738531fc6fSMike Kravetz target_hstate->max_huge_pages += pages_per_huge_page(h); 34748531fc6fSMike Kravetz 34758531fc6fSMike Kravetz return rc; 34768531fc6fSMike Kravetz } 34778531fc6fSMike Kravetz 347879dfc695SMike Kravetz static int demote_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed) 347979dfc695SMike Kravetz __must_hold(&hugetlb_lock) 348079dfc695SMike Kravetz { 34818531fc6fSMike Kravetz int nr_nodes, node; 34828531fc6fSMike Kravetz struct page *page; 348379dfc695SMike Kravetz 348479dfc695SMike Kravetz lockdep_assert_held(&hugetlb_lock); 348579dfc695SMike Kravetz 348679dfc695SMike Kravetz /* We should never get here if no demote order */ 348779dfc695SMike Kravetz if (!h->demote_order) { 348879dfc695SMike Kravetz pr_warn("HugeTLB: NULL demote order passed to demote_pool_huge_page.\n"); 348979dfc695SMike Kravetz return -EINVAL; /* internal error */ 349079dfc695SMike Kravetz } 349179dfc695SMike Kravetz 34928531fc6fSMike Kravetz for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 34935a317412SMike Kravetz list_for_each_entry(page, &h->hugepage_freelists[node], lru) { 34945a317412SMike Kravetz if (PageHWPoison(page)) 34955a317412SMike Kravetz continue; 34965a317412SMike Kravetz 34975a317412SMike Kravetz return demote_free_huge_page(h, page); 34988531fc6fSMike Kravetz } 34998531fc6fSMike Kravetz } 35008531fc6fSMike Kravetz 35015a317412SMike Kravetz /* 35025a317412SMike Kravetz * Only way to get here is if all pages on free lists are poisoned. 35035a317412SMike Kravetz * Return -EBUSY so that caller will not retry. 35045a317412SMike Kravetz */ 35055a317412SMike Kravetz return -EBUSY; 350679dfc695SMike Kravetz } 350779dfc695SMike Kravetz 3508a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 3509a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 3510a3437870SNishanth Aravamudan 351179dfc695SMike Kravetz #define HSTATE_ATTR_WO(_name) \ 351279dfc695SMike Kravetz static struct kobj_attribute _name##_attr = __ATTR_WO(_name) 351379dfc695SMike Kravetz 3514a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 351598bc26acSMiaohe Lin static struct kobj_attribute _name##_attr = __ATTR_RW(_name) 3516a3437870SNishanth Aravamudan 3517a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 3518a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 3519a3437870SNishanth Aravamudan 35209a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); 35219a305230SLee Schermerhorn 35229a305230SLee Schermerhorn static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) 3523a3437870SNishanth Aravamudan { 3524a3437870SNishanth Aravamudan int i; 35259a305230SLee Schermerhorn 3526a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 35279a305230SLee Schermerhorn if (hstate_kobjs[i] == kobj) { 35289a305230SLee Schermerhorn if (nidp) 35299a305230SLee Schermerhorn *nidp = NUMA_NO_NODE; 3530a3437870SNishanth Aravamudan return &hstates[i]; 35319a305230SLee Schermerhorn } 35329a305230SLee Schermerhorn 35339a305230SLee Schermerhorn return kobj_to_node_hstate(kobj, nidp); 3534a3437870SNishanth Aravamudan } 3535a3437870SNishanth Aravamudan 353606808b08SLee Schermerhorn static ssize_t nr_hugepages_show_common(struct kobject *kobj, 3537a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3538a3437870SNishanth Aravamudan { 35399a305230SLee Schermerhorn struct hstate *h; 35409a305230SLee Schermerhorn unsigned long nr_huge_pages; 35419a305230SLee Schermerhorn int nid; 35429a305230SLee Schermerhorn 35439a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 35449a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 35459a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages; 35469a305230SLee Schermerhorn else 35479a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages_node[nid]; 35489a305230SLee Schermerhorn 3549ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", nr_huge_pages); 3550a3437870SNishanth Aravamudan } 3551adbe8726SEric B Munson 3552238d3c13SDavid Rientjes static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, 3553238d3c13SDavid Rientjes struct hstate *h, int nid, 3554238d3c13SDavid Rientjes unsigned long count, size_t len) 3555a3437870SNishanth Aravamudan { 3556a3437870SNishanth Aravamudan int err; 35572d0adf7eSOscar Salvador nodemask_t nodes_allowed, *n_mask; 3558a3437870SNishanth Aravamudan 35592d0adf7eSOscar Salvador if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 35602d0adf7eSOscar Salvador return -EINVAL; 3561adbe8726SEric B Munson 35629a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) { 35639a305230SLee Schermerhorn /* 35649a305230SLee Schermerhorn * global hstate attribute 35659a305230SLee Schermerhorn */ 35669a305230SLee Schermerhorn if (!(obey_mempolicy && 35672d0adf7eSOscar Salvador init_nodemask_of_mempolicy(&nodes_allowed))) 35682d0adf7eSOscar Salvador n_mask = &node_states[N_MEMORY]; 35692d0adf7eSOscar Salvador else 35702d0adf7eSOscar Salvador n_mask = &nodes_allowed; 35712d0adf7eSOscar Salvador } else { 35729a305230SLee Schermerhorn /* 3573fd875dcaSMike Kravetz * Node specific request. count adjustment happens in 3574fd875dcaSMike Kravetz * set_max_huge_pages() after acquiring hugetlb_lock. 35759a305230SLee Schermerhorn */ 35762d0adf7eSOscar Salvador init_nodemask_of_node(&nodes_allowed, nid); 35772d0adf7eSOscar Salvador n_mask = &nodes_allowed; 3578fd875dcaSMike Kravetz } 35799a305230SLee Schermerhorn 35802d0adf7eSOscar Salvador err = set_max_huge_pages(h, count, nid, n_mask); 358106808b08SLee Schermerhorn 35824eb0716eSAlexandre Ghiti return err ? err : len; 358306808b08SLee Schermerhorn } 358406808b08SLee Schermerhorn 3585238d3c13SDavid Rientjes static ssize_t nr_hugepages_store_common(bool obey_mempolicy, 3586238d3c13SDavid Rientjes struct kobject *kobj, const char *buf, 3587238d3c13SDavid Rientjes size_t len) 3588238d3c13SDavid Rientjes { 3589238d3c13SDavid Rientjes struct hstate *h; 3590238d3c13SDavid Rientjes unsigned long count; 3591238d3c13SDavid Rientjes int nid; 3592238d3c13SDavid Rientjes int err; 3593238d3c13SDavid Rientjes 3594238d3c13SDavid Rientjes err = kstrtoul(buf, 10, &count); 3595238d3c13SDavid Rientjes if (err) 3596238d3c13SDavid Rientjes return err; 3597238d3c13SDavid Rientjes 3598238d3c13SDavid Rientjes h = kobj_to_hstate(kobj, &nid); 3599238d3c13SDavid Rientjes return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); 3600238d3c13SDavid Rientjes } 3601238d3c13SDavid Rientjes 360206808b08SLee Schermerhorn static ssize_t nr_hugepages_show(struct kobject *kobj, 360306808b08SLee Schermerhorn struct kobj_attribute *attr, char *buf) 360406808b08SLee Schermerhorn { 360506808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 360606808b08SLee Schermerhorn } 360706808b08SLee Schermerhorn 360806808b08SLee Schermerhorn static ssize_t nr_hugepages_store(struct kobject *kobj, 360906808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 361006808b08SLee Schermerhorn { 3611238d3c13SDavid Rientjes return nr_hugepages_store_common(false, kobj, buf, len); 3612a3437870SNishanth Aravamudan } 3613a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 3614a3437870SNishanth Aravamudan 361506808b08SLee Schermerhorn #ifdef CONFIG_NUMA 361606808b08SLee Schermerhorn 361706808b08SLee Schermerhorn /* 361806808b08SLee Schermerhorn * hstate attribute for optionally mempolicy-based constraint on persistent 361906808b08SLee Schermerhorn * huge page alloc/free. 362006808b08SLee Schermerhorn */ 362106808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, 3622ae7a927dSJoe Perches struct kobj_attribute *attr, 3623ae7a927dSJoe Perches char *buf) 362406808b08SLee Schermerhorn { 362506808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 362606808b08SLee Schermerhorn } 362706808b08SLee Schermerhorn 362806808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, 362906808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 363006808b08SLee Schermerhorn { 3631238d3c13SDavid Rientjes return nr_hugepages_store_common(true, kobj, buf, len); 363206808b08SLee Schermerhorn } 363306808b08SLee Schermerhorn HSTATE_ATTR(nr_hugepages_mempolicy); 363406808b08SLee Schermerhorn #endif 363506808b08SLee Schermerhorn 363606808b08SLee Schermerhorn 3637a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 3638a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3639a3437870SNishanth Aravamudan { 36409a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3641ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->nr_overcommit_huge_pages); 3642a3437870SNishanth Aravamudan } 3643adbe8726SEric B Munson 3644a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 3645a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 3646a3437870SNishanth Aravamudan { 3647a3437870SNishanth Aravamudan int err; 3648a3437870SNishanth Aravamudan unsigned long input; 36499a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3650a3437870SNishanth Aravamudan 3651bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3652adbe8726SEric B Munson return -EINVAL; 3653adbe8726SEric B Munson 36543dbb95f7SJingoo Han err = kstrtoul(buf, 10, &input); 3655a3437870SNishanth Aravamudan if (err) 365673ae31e5SEric B Munson return err; 3657a3437870SNishanth Aravamudan 3658db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 3659a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 3660db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3661a3437870SNishanth Aravamudan 3662a3437870SNishanth Aravamudan return count; 3663a3437870SNishanth Aravamudan } 3664a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 3665a3437870SNishanth Aravamudan 3666a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 3667a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3668a3437870SNishanth Aravamudan { 36699a305230SLee Schermerhorn struct hstate *h; 36709a305230SLee Schermerhorn unsigned long free_huge_pages; 36719a305230SLee Schermerhorn int nid; 36729a305230SLee Schermerhorn 36739a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 36749a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 36759a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages; 36769a305230SLee Schermerhorn else 36779a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages_node[nid]; 36789a305230SLee Schermerhorn 3679ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", free_huge_pages); 3680a3437870SNishanth Aravamudan } 3681a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 3682a3437870SNishanth Aravamudan 3683a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 3684a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3685a3437870SNishanth Aravamudan { 36869a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3687ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->resv_huge_pages); 3688a3437870SNishanth Aravamudan } 3689a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 3690a3437870SNishanth Aravamudan 3691a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 3692a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3693a3437870SNishanth Aravamudan { 36949a305230SLee Schermerhorn struct hstate *h; 36959a305230SLee Schermerhorn unsigned long surplus_huge_pages; 36969a305230SLee Schermerhorn int nid; 36979a305230SLee Schermerhorn 36989a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 36999a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 37009a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages; 37019a305230SLee Schermerhorn else 37029a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages_node[nid]; 37039a305230SLee Schermerhorn 3704ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", surplus_huge_pages); 3705a3437870SNishanth Aravamudan } 3706a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 3707a3437870SNishanth Aravamudan 370879dfc695SMike Kravetz static ssize_t demote_store(struct kobject *kobj, 370979dfc695SMike Kravetz struct kobj_attribute *attr, const char *buf, size_t len) 371079dfc695SMike Kravetz { 371179dfc695SMike Kravetz unsigned long nr_demote; 371279dfc695SMike Kravetz unsigned long nr_available; 371379dfc695SMike Kravetz nodemask_t nodes_allowed, *n_mask; 371479dfc695SMike Kravetz struct hstate *h; 371579dfc695SMike Kravetz int err = 0; 371679dfc695SMike Kravetz int nid; 371779dfc695SMike Kravetz 371879dfc695SMike Kravetz err = kstrtoul(buf, 10, &nr_demote); 371979dfc695SMike Kravetz if (err) 372079dfc695SMike Kravetz return err; 372179dfc695SMike Kravetz h = kobj_to_hstate(kobj, &nid); 372279dfc695SMike Kravetz 372379dfc695SMike Kravetz if (nid != NUMA_NO_NODE) { 372479dfc695SMike Kravetz init_nodemask_of_node(&nodes_allowed, nid); 372579dfc695SMike Kravetz n_mask = &nodes_allowed; 372679dfc695SMike Kravetz } else { 372779dfc695SMike Kravetz n_mask = &node_states[N_MEMORY]; 372879dfc695SMike Kravetz } 372979dfc695SMike Kravetz 373079dfc695SMike Kravetz /* Synchronize with other sysfs operations modifying huge pages */ 373179dfc695SMike Kravetz mutex_lock(&h->resize_lock); 373279dfc695SMike Kravetz spin_lock_irq(&hugetlb_lock); 373379dfc695SMike Kravetz 373479dfc695SMike Kravetz while (nr_demote) { 373579dfc695SMike Kravetz /* 373679dfc695SMike Kravetz * Check for available pages to demote each time thorough the 373779dfc695SMike Kravetz * loop as demote_pool_huge_page will drop hugetlb_lock. 373879dfc695SMike Kravetz */ 373979dfc695SMike Kravetz if (nid != NUMA_NO_NODE) 374079dfc695SMike Kravetz nr_available = h->free_huge_pages_node[nid]; 374179dfc695SMike Kravetz else 374279dfc695SMike Kravetz nr_available = h->free_huge_pages; 374379dfc695SMike Kravetz nr_available -= h->resv_huge_pages; 374479dfc695SMike Kravetz if (!nr_available) 374579dfc695SMike Kravetz break; 374679dfc695SMike Kravetz 374779dfc695SMike Kravetz err = demote_pool_huge_page(h, n_mask); 374879dfc695SMike Kravetz if (err) 374979dfc695SMike Kravetz break; 375079dfc695SMike Kravetz 375179dfc695SMike Kravetz nr_demote--; 375279dfc695SMike Kravetz } 375379dfc695SMike Kravetz 375479dfc695SMike Kravetz spin_unlock_irq(&hugetlb_lock); 375579dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 375679dfc695SMike Kravetz 375779dfc695SMike Kravetz if (err) 375879dfc695SMike Kravetz return err; 375979dfc695SMike Kravetz return len; 376079dfc695SMike Kravetz } 376179dfc695SMike Kravetz HSTATE_ATTR_WO(demote); 376279dfc695SMike Kravetz 376379dfc695SMike Kravetz static ssize_t demote_size_show(struct kobject *kobj, 376479dfc695SMike Kravetz struct kobj_attribute *attr, char *buf) 376579dfc695SMike Kravetz { 376679dfc695SMike Kravetz int nid; 376779dfc695SMike Kravetz struct hstate *h = kobj_to_hstate(kobj, &nid); 376879dfc695SMike Kravetz unsigned long demote_size = (PAGE_SIZE << h->demote_order) / SZ_1K; 376979dfc695SMike Kravetz 377079dfc695SMike Kravetz return sysfs_emit(buf, "%lukB\n", demote_size); 377179dfc695SMike Kravetz } 377279dfc695SMike Kravetz 377379dfc695SMike Kravetz static ssize_t demote_size_store(struct kobject *kobj, 377479dfc695SMike Kravetz struct kobj_attribute *attr, 377579dfc695SMike Kravetz const char *buf, size_t count) 377679dfc695SMike Kravetz { 377779dfc695SMike Kravetz struct hstate *h, *demote_hstate; 377879dfc695SMike Kravetz unsigned long demote_size; 377979dfc695SMike Kravetz unsigned int demote_order; 378079dfc695SMike Kravetz int nid; 378179dfc695SMike Kravetz 378279dfc695SMike Kravetz demote_size = (unsigned long)memparse(buf, NULL); 378379dfc695SMike Kravetz 378479dfc695SMike Kravetz demote_hstate = size_to_hstate(demote_size); 378579dfc695SMike Kravetz if (!demote_hstate) 378679dfc695SMike Kravetz return -EINVAL; 378779dfc695SMike Kravetz demote_order = demote_hstate->order; 3788a01f4390SMike Kravetz if (demote_order < HUGETLB_PAGE_ORDER) 3789a01f4390SMike Kravetz return -EINVAL; 379079dfc695SMike Kravetz 379179dfc695SMike Kravetz /* demote order must be smaller than hstate order */ 379279dfc695SMike Kravetz h = kobj_to_hstate(kobj, &nid); 379379dfc695SMike Kravetz if (demote_order >= h->order) 379479dfc695SMike Kravetz return -EINVAL; 379579dfc695SMike Kravetz 379679dfc695SMike Kravetz /* resize_lock synchronizes access to demote size and writes */ 379779dfc695SMike Kravetz mutex_lock(&h->resize_lock); 379879dfc695SMike Kravetz h->demote_order = demote_order; 379979dfc695SMike Kravetz mutex_unlock(&h->resize_lock); 380079dfc695SMike Kravetz 380179dfc695SMike Kravetz return count; 380279dfc695SMike Kravetz } 380379dfc695SMike Kravetz HSTATE_ATTR(demote_size); 380479dfc695SMike Kravetz 3805a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 3806a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 3807a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 3808a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 3809a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 3810a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 381106808b08SLee Schermerhorn #ifdef CONFIG_NUMA 381206808b08SLee Schermerhorn &nr_hugepages_mempolicy_attr.attr, 381306808b08SLee Schermerhorn #endif 3814a3437870SNishanth Aravamudan NULL, 3815a3437870SNishanth Aravamudan }; 3816a3437870SNishanth Aravamudan 381767e5ed96SArvind Yadav static const struct attribute_group hstate_attr_group = { 3818a3437870SNishanth Aravamudan .attrs = hstate_attrs, 3819a3437870SNishanth Aravamudan }; 3820a3437870SNishanth Aravamudan 382179dfc695SMike Kravetz static struct attribute *hstate_demote_attrs[] = { 382279dfc695SMike Kravetz &demote_size_attr.attr, 382379dfc695SMike Kravetz &demote_attr.attr, 382479dfc695SMike Kravetz NULL, 382579dfc695SMike Kravetz }; 382679dfc695SMike Kravetz 382779dfc695SMike Kravetz static const struct attribute_group hstate_demote_attr_group = { 382879dfc695SMike Kravetz .attrs = hstate_demote_attrs, 382979dfc695SMike Kravetz }; 383079dfc695SMike Kravetz 3831094e9539SJeff Mahoney static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, 38329a305230SLee Schermerhorn struct kobject **hstate_kobjs, 383367e5ed96SArvind Yadav const struct attribute_group *hstate_attr_group) 3834a3437870SNishanth Aravamudan { 3835a3437870SNishanth Aravamudan int retval; 3836972dc4deSAneesh Kumar K.V int hi = hstate_index(h); 3837a3437870SNishanth Aravamudan 38389a305230SLee Schermerhorn hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); 38399a305230SLee Schermerhorn if (!hstate_kobjs[hi]) 3840a3437870SNishanth Aravamudan return -ENOMEM; 3841a3437870SNishanth Aravamudan 38429a305230SLee Schermerhorn retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); 3843cc2205a6SMiaohe Lin if (retval) { 38449a305230SLee Schermerhorn kobject_put(hstate_kobjs[hi]); 3845cc2205a6SMiaohe Lin hstate_kobjs[hi] = NULL; 3846cc2205a6SMiaohe Lin } 3847a3437870SNishanth Aravamudan 384879dfc695SMike Kravetz if (h->demote_order) { 384979dfc695SMike Kravetz if (sysfs_create_group(hstate_kobjs[hi], 385079dfc695SMike Kravetz &hstate_demote_attr_group)) 385179dfc695SMike Kravetz pr_warn("HugeTLB unable to create demote interfaces for %s\n", h->name); 385279dfc695SMike Kravetz } 385379dfc695SMike Kravetz 3854a3437870SNishanth Aravamudan return retval; 3855a3437870SNishanth Aravamudan } 3856a3437870SNishanth Aravamudan 3857a3437870SNishanth Aravamudan static void __init hugetlb_sysfs_init(void) 3858a3437870SNishanth Aravamudan { 3859a3437870SNishanth Aravamudan struct hstate *h; 3860a3437870SNishanth Aravamudan int err; 3861a3437870SNishanth Aravamudan 3862a3437870SNishanth Aravamudan hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 3863a3437870SNishanth Aravamudan if (!hugepages_kobj) 3864a3437870SNishanth Aravamudan return; 3865a3437870SNishanth Aravamudan 3866a3437870SNishanth Aravamudan for_each_hstate(h) { 38679a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, 38689a305230SLee Schermerhorn hstate_kobjs, &hstate_attr_group); 3869a3437870SNishanth Aravamudan if (err) 3870282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s", h->name); 3871a3437870SNishanth Aravamudan } 3872a3437870SNishanth Aravamudan } 3873a3437870SNishanth Aravamudan 38749a305230SLee Schermerhorn #ifdef CONFIG_NUMA 38759a305230SLee Schermerhorn 38769a305230SLee Schermerhorn /* 38779a305230SLee Schermerhorn * node_hstate/s - associate per node hstate attributes, via their kobjects, 387810fbcf4cSKay Sievers * with node devices in node_devices[] using a parallel array. The array 387910fbcf4cSKay Sievers * index of a node device or _hstate == node id. 388010fbcf4cSKay Sievers * This is here to avoid any static dependency of the node device driver, in 38819a305230SLee Schermerhorn * the base kernel, on the hugetlb module. 38829a305230SLee Schermerhorn */ 38839a305230SLee Schermerhorn struct node_hstate { 38849a305230SLee Schermerhorn struct kobject *hugepages_kobj; 38859a305230SLee Schermerhorn struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 38869a305230SLee Schermerhorn }; 3887b4e289a6SAlexander Kuleshov static struct node_hstate node_hstates[MAX_NUMNODES]; 38889a305230SLee Schermerhorn 38899a305230SLee Schermerhorn /* 389010fbcf4cSKay Sievers * A subset of global hstate attributes for node devices 38919a305230SLee Schermerhorn */ 38929a305230SLee Schermerhorn static struct attribute *per_node_hstate_attrs[] = { 38939a305230SLee Schermerhorn &nr_hugepages_attr.attr, 38949a305230SLee Schermerhorn &free_hugepages_attr.attr, 38959a305230SLee Schermerhorn &surplus_hugepages_attr.attr, 38969a305230SLee Schermerhorn NULL, 38979a305230SLee Schermerhorn }; 38989a305230SLee Schermerhorn 389967e5ed96SArvind Yadav static const struct attribute_group per_node_hstate_attr_group = { 39009a305230SLee Schermerhorn .attrs = per_node_hstate_attrs, 39019a305230SLee Schermerhorn }; 39029a305230SLee Schermerhorn 39039a305230SLee Schermerhorn /* 390410fbcf4cSKay Sievers * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. 39059a305230SLee Schermerhorn * Returns node id via non-NULL nidp. 39069a305230SLee Schermerhorn */ 39079a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 39089a305230SLee Schermerhorn { 39099a305230SLee Schermerhorn int nid; 39109a305230SLee Schermerhorn 39119a305230SLee Schermerhorn for (nid = 0; nid < nr_node_ids; nid++) { 39129a305230SLee Schermerhorn struct node_hstate *nhs = &node_hstates[nid]; 39139a305230SLee Schermerhorn int i; 39149a305230SLee Schermerhorn for (i = 0; i < HUGE_MAX_HSTATE; i++) 39159a305230SLee Schermerhorn if (nhs->hstate_kobjs[i] == kobj) { 39169a305230SLee Schermerhorn if (nidp) 39179a305230SLee Schermerhorn *nidp = nid; 39189a305230SLee Schermerhorn return &hstates[i]; 39199a305230SLee Schermerhorn } 39209a305230SLee Schermerhorn } 39219a305230SLee Schermerhorn 39229a305230SLee Schermerhorn BUG(); 39239a305230SLee Schermerhorn return NULL; 39249a305230SLee Schermerhorn } 39259a305230SLee Schermerhorn 39269a305230SLee Schermerhorn /* 392710fbcf4cSKay Sievers * Unregister hstate attributes from a single node device. 39289a305230SLee Schermerhorn * No-op if no hstate attributes attached. 39299a305230SLee Schermerhorn */ 39303cd8b44fSClaudiu Ghioc static void hugetlb_unregister_node(struct node *node) 39319a305230SLee Schermerhorn { 39329a305230SLee Schermerhorn struct hstate *h; 393310fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 39349a305230SLee Schermerhorn 39359a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 39369b5e5d0fSLee Schermerhorn return; /* no hstate attributes */ 39379a305230SLee Schermerhorn 3938972dc4deSAneesh Kumar K.V for_each_hstate(h) { 3939972dc4deSAneesh Kumar K.V int idx = hstate_index(h); 3940972dc4deSAneesh Kumar K.V if (nhs->hstate_kobjs[idx]) { 3941972dc4deSAneesh Kumar K.V kobject_put(nhs->hstate_kobjs[idx]); 3942972dc4deSAneesh Kumar K.V nhs->hstate_kobjs[idx] = NULL; 3943972dc4deSAneesh Kumar K.V } 39449a305230SLee Schermerhorn } 39459a305230SLee Schermerhorn 39469a305230SLee Schermerhorn kobject_put(nhs->hugepages_kobj); 39479a305230SLee Schermerhorn nhs->hugepages_kobj = NULL; 39489a305230SLee Schermerhorn } 39499a305230SLee Schermerhorn 39509a305230SLee Schermerhorn 39519a305230SLee Schermerhorn /* 395210fbcf4cSKay Sievers * Register hstate attributes for a single node device. 39539a305230SLee Schermerhorn * No-op if attributes already registered. 39549a305230SLee Schermerhorn */ 39553cd8b44fSClaudiu Ghioc static void hugetlb_register_node(struct node *node) 39569a305230SLee Schermerhorn { 39579a305230SLee Schermerhorn struct hstate *h; 395810fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 39599a305230SLee Schermerhorn int err; 39609a305230SLee Schermerhorn 39619a305230SLee Schermerhorn if (nhs->hugepages_kobj) 39629a305230SLee Schermerhorn return; /* already allocated */ 39639a305230SLee Schermerhorn 39649a305230SLee Schermerhorn nhs->hugepages_kobj = kobject_create_and_add("hugepages", 396510fbcf4cSKay Sievers &node->dev.kobj); 39669a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 39679a305230SLee Schermerhorn return; 39689a305230SLee Schermerhorn 39699a305230SLee Schermerhorn for_each_hstate(h) { 39709a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, 39719a305230SLee Schermerhorn nhs->hstate_kobjs, 39729a305230SLee Schermerhorn &per_node_hstate_attr_group); 39739a305230SLee Schermerhorn if (err) { 3974282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s for node %d\n", 397510fbcf4cSKay Sievers h->name, node->dev.id); 39769a305230SLee Schermerhorn hugetlb_unregister_node(node); 39779a305230SLee Schermerhorn break; 39789a305230SLee Schermerhorn } 39799a305230SLee Schermerhorn } 39809a305230SLee Schermerhorn } 39819a305230SLee Schermerhorn 39829a305230SLee Schermerhorn /* 39839b5e5d0fSLee Schermerhorn * hugetlb init time: register hstate attributes for all registered node 398410fbcf4cSKay Sievers * devices of nodes that have memory. All on-line nodes should have 398510fbcf4cSKay Sievers * registered their associated device by this time. 39869a305230SLee Schermerhorn */ 39877d9ca000SLuiz Capitulino static void __init hugetlb_register_all_nodes(void) 39889a305230SLee Schermerhorn { 39899a305230SLee Schermerhorn int nid; 39909a305230SLee Schermerhorn 39918cebfcd0SLai Jiangshan for_each_node_state(nid, N_MEMORY) { 39928732794bSWen Congyang struct node *node = node_devices[nid]; 399310fbcf4cSKay Sievers if (node->dev.id == nid) 39949a305230SLee Schermerhorn hugetlb_register_node(node); 39959a305230SLee Schermerhorn } 39969a305230SLee Schermerhorn 39979a305230SLee Schermerhorn /* 399810fbcf4cSKay Sievers * Let the node device driver know we're here so it can 39999a305230SLee Schermerhorn * [un]register hstate attributes on node hotplug. 40009a305230SLee Schermerhorn */ 40019a305230SLee Schermerhorn register_hugetlbfs_with_node(hugetlb_register_node, 40029a305230SLee Schermerhorn hugetlb_unregister_node); 40039a305230SLee Schermerhorn } 40049a305230SLee Schermerhorn #else /* !CONFIG_NUMA */ 40059a305230SLee Schermerhorn 40069a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 40079a305230SLee Schermerhorn { 40089a305230SLee Schermerhorn BUG(); 40099a305230SLee Schermerhorn if (nidp) 40109a305230SLee Schermerhorn *nidp = -1; 40119a305230SLee Schermerhorn return NULL; 40129a305230SLee Schermerhorn } 40139a305230SLee Schermerhorn 40149a305230SLee Schermerhorn static void hugetlb_register_all_nodes(void) { } 40159a305230SLee Schermerhorn 40169a305230SLee Schermerhorn #endif 40179a305230SLee Schermerhorn 4018a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 4019a3437870SNishanth Aravamudan { 40208382d914SDavidlohr Bueso int i; 40218382d914SDavidlohr Bueso 4022d6995da3SMike Kravetz BUILD_BUG_ON(sizeof_field(struct page, private) * BITS_PER_BYTE < 4023d6995da3SMike Kravetz __NR_HPAGEFLAGS); 4024d6995da3SMike Kravetz 4025c2833a5bSMike Kravetz if (!hugepages_supported()) { 4026c2833a5bSMike Kravetz if (hugetlb_max_hstate || default_hstate_max_huge_pages) 4027c2833a5bSMike Kravetz pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n"); 40280ef89d25SBenjamin Herrenschmidt return 0; 4029d715cf80SLiam R. Howlett } 4030d715cf80SLiam R. Howlett 4031282f4214SMike Kravetz /* 4032282f4214SMike Kravetz * Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some 4033282f4214SMike Kravetz * architectures depend on setup being done here. 4034282f4214SMike Kravetz */ 4035a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 4036282f4214SMike Kravetz if (!parsed_default_hugepagesz) { 4037282f4214SMike Kravetz /* 4038282f4214SMike Kravetz * If we did not parse a default huge page size, set 4039282f4214SMike Kravetz * default_hstate_idx to HPAGE_SIZE hstate. And, if the 4040282f4214SMike Kravetz * number of huge pages for this default size was implicitly 4041282f4214SMike Kravetz * specified, set that here as well. 4042282f4214SMike Kravetz * Note that the implicit setting will overwrite an explicit 4043282f4214SMike Kravetz * setting. A warning will be printed in this case. 4044282f4214SMike Kravetz */ 4045282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(HPAGE_SIZE)); 4046f8b74815SVaishali Thakkar if (default_hstate_max_huge_pages) { 4047282f4214SMike Kravetz if (default_hstate.max_huge_pages) { 4048282f4214SMike Kravetz char buf[32]; 4049282f4214SMike Kravetz 4050282f4214SMike Kravetz string_get_size(huge_page_size(&default_hstate), 4051282f4214SMike Kravetz 1, STRING_UNITS_2, buf, 32); 4052282f4214SMike Kravetz pr_warn("HugeTLB: Ignoring hugepages=%lu associated with %s page size\n", 4053282f4214SMike Kravetz default_hstate.max_huge_pages, buf); 4054282f4214SMike Kravetz pr_warn("HugeTLB: Using hugepages=%lu for number of default huge pages\n", 4055282f4214SMike Kravetz default_hstate_max_huge_pages); 4056282f4214SMike Kravetz } 4057282f4214SMike Kravetz default_hstate.max_huge_pages = 4058282f4214SMike Kravetz default_hstate_max_huge_pages; 4059b5389086SZhenguo Yao 40600a7a0f6fSPeng Liu for_each_online_node(i) 4061b5389086SZhenguo Yao default_hstate.max_huge_pages_node[i] = 4062b5389086SZhenguo Yao default_hugepages_in_node[i]; 4063282f4214SMike Kravetz } 4064f8b74815SVaishali Thakkar } 4065a3437870SNishanth Aravamudan 4066cf11e85fSRoman Gushchin hugetlb_cma_check(); 4067a3437870SNishanth Aravamudan hugetlb_init_hstates(); 4068aa888a74SAndi Kleen gather_bootmem_prealloc(); 4069a3437870SNishanth Aravamudan report_hugepages(); 4070a3437870SNishanth Aravamudan 4071a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 40729a305230SLee Schermerhorn hugetlb_register_all_nodes(); 40737179e7bfSJianguo Wu hugetlb_cgroup_file_init(); 40749a305230SLee Schermerhorn 40758382d914SDavidlohr Bueso #ifdef CONFIG_SMP 40768382d914SDavidlohr Bueso num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); 40778382d914SDavidlohr Bueso #else 40788382d914SDavidlohr Bueso num_fault_mutexes = 1; 40798382d914SDavidlohr Bueso #endif 4080c672c7f2SMike Kravetz hugetlb_fault_mutex_table = 40816da2ec56SKees Cook kmalloc_array(num_fault_mutexes, sizeof(struct mutex), 40826da2ec56SKees Cook GFP_KERNEL); 4083c672c7f2SMike Kravetz BUG_ON(!hugetlb_fault_mutex_table); 40848382d914SDavidlohr Bueso 40858382d914SDavidlohr Bueso for (i = 0; i < num_fault_mutexes; i++) 4086c672c7f2SMike Kravetz mutex_init(&hugetlb_fault_mutex_table[i]); 4087a3437870SNishanth Aravamudan return 0; 4088a3437870SNishanth Aravamudan } 40893e89e1c5SPaul Gortmaker subsys_initcall(hugetlb_init); 4090a3437870SNishanth Aravamudan 4091ae94da89SMike Kravetz /* Overwritten by architectures with more huge page sizes */ 4092ae94da89SMike Kravetz bool __init __attribute((weak)) arch_hugetlb_valid_size(unsigned long size) 40939fee021dSVaishali Thakkar { 4094ae94da89SMike Kravetz return size == HPAGE_SIZE; 40959fee021dSVaishali Thakkar } 40969fee021dSVaishali Thakkar 4097d00181b9SKirill A. Shutemov void __init hugetlb_add_hstate(unsigned int order) 4098a3437870SNishanth Aravamudan { 4099a3437870SNishanth Aravamudan struct hstate *h; 41008faa8b07SAndi Kleen unsigned long i; 41018faa8b07SAndi Kleen 4102a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 4103a3437870SNishanth Aravamudan return; 4104a3437870SNishanth Aravamudan } 410547d38344SAneesh Kumar K.V BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); 4106a3437870SNishanth Aravamudan BUG_ON(order == 0); 410747d38344SAneesh Kumar K.V h = &hstates[hugetlb_max_hstate++]; 410829383967SMike Kravetz mutex_init(&h->resize_lock); 4109a3437870SNishanth Aravamudan h->order = order; 4110aca78307SMiaohe Lin h->mask = ~(huge_page_size(h) - 1); 41118faa8b07SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 41128faa8b07SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 41130edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&h->hugepage_activelist); 411454f18d35SAndrew Morton h->next_nid_to_alloc = first_memory_node; 411554f18d35SAndrew Morton h->next_nid_to_free = first_memory_node; 4116a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 4117a3437870SNishanth Aravamudan huge_page_size(h)/1024); 411877490587SMuchun Song hugetlb_vmemmap_init(h); 41198faa8b07SAndi Kleen 4120a3437870SNishanth Aravamudan parsed_hstate = h; 4121a3437870SNishanth Aravamudan } 4122a3437870SNishanth Aravamudan 4123b5389086SZhenguo Yao bool __init __weak hugetlb_node_alloc_supported(void) 4124b5389086SZhenguo Yao { 4125b5389086SZhenguo Yao return true; 4126b5389086SZhenguo Yao } 4127f87442f4SPeng Liu 4128f87442f4SPeng Liu static void __init hugepages_clear_pages_in_node(void) 4129f87442f4SPeng Liu { 4130f87442f4SPeng Liu if (!hugetlb_max_hstate) { 4131f87442f4SPeng Liu default_hstate_max_huge_pages = 0; 4132f87442f4SPeng Liu memset(default_hugepages_in_node, 0, 4133f87442f4SPeng Liu MAX_NUMNODES * sizeof(unsigned int)); 4134f87442f4SPeng Liu } else { 4135f87442f4SPeng Liu parsed_hstate->max_huge_pages = 0; 4136f87442f4SPeng Liu memset(parsed_hstate->max_huge_pages_node, 0, 4137f87442f4SPeng Liu MAX_NUMNODES * sizeof(unsigned int)); 4138f87442f4SPeng Liu } 4139f87442f4SPeng Liu } 4140f87442f4SPeng Liu 4141282f4214SMike Kravetz /* 4142282f4214SMike Kravetz * hugepages command line processing 4143282f4214SMike Kravetz * hugepages normally follows a valid hugepagsz or default_hugepagsz 4144282f4214SMike Kravetz * specification. If not, ignore the hugepages value. hugepages can also 4145282f4214SMike Kravetz * be the first huge page command line option in which case it implicitly 4146282f4214SMike Kravetz * specifies the number of huge pages for the default size. 4147282f4214SMike Kravetz */ 4148282f4214SMike Kravetz static int __init hugepages_setup(char *s) 4149a3437870SNishanth Aravamudan { 4150a3437870SNishanth Aravamudan unsigned long *mhp; 41518faa8b07SAndi Kleen static unsigned long *last_mhp; 4152b5389086SZhenguo Yao int node = NUMA_NO_NODE; 4153b5389086SZhenguo Yao int count; 4154b5389086SZhenguo Yao unsigned long tmp; 4155b5389086SZhenguo Yao char *p = s; 4156a3437870SNishanth Aravamudan 41579fee021dSVaishali Thakkar if (!parsed_valid_hugepagesz) { 4158282f4214SMike Kravetz pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s); 41599fee021dSVaishali Thakkar parsed_valid_hugepagesz = true; 4160f81f6e4bSPeng Liu return 1; 41619fee021dSVaishali Thakkar } 4162282f4214SMike Kravetz 4163a3437870SNishanth Aravamudan /* 4164282f4214SMike Kravetz * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter 4165282f4214SMike Kravetz * yet, so this hugepages= parameter goes to the "default hstate". 4166282f4214SMike Kravetz * Otherwise, it goes with the previously parsed hugepagesz or 4167282f4214SMike Kravetz * default_hugepagesz. 4168a3437870SNishanth Aravamudan */ 41699fee021dSVaishali Thakkar else if (!hugetlb_max_hstate) 4170a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 4171a3437870SNishanth Aravamudan else 4172a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 4173a3437870SNishanth Aravamudan 41748faa8b07SAndi Kleen if (mhp == last_mhp) { 4175282f4214SMike Kravetz pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s); 4176f81f6e4bSPeng Liu return 1; 41778faa8b07SAndi Kleen } 41788faa8b07SAndi Kleen 4179b5389086SZhenguo Yao while (*p) { 4180b5389086SZhenguo Yao count = 0; 4181b5389086SZhenguo Yao if (sscanf(p, "%lu%n", &tmp, &count) != 1) 4182b5389086SZhenguo Yao goto invalid; 4183b5389086SZhenguo Yao /* Parameter is node format */ 4184b5389086SZhenguo Yao if (p[count] == ':') { 4185b5389086SZhenguo Yao if (!hugetlb_node_alloc_supported()) { 4186b5389086SZhenguo Yao pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n"); 4187f81f6e4bSPeng Liu return 1; 4188b5389086SZhenguo Yao } 41890a7a0f6fSPeng Liu if (tmp >= MAX_NUMNODES || !node_online(tmp)) 4190e79ce983SLiu Yuntao goto invalid; 41910a7a0f6fSPeng Liu node = array_index_nospec(tmp, MAX_NUMNODES); 4192b5389086SZhenguo Yao p += count + 1; 4193b5389086SZhenguo Yao /* Parse hugepages */ 4194b5389086SZhenguo Yao if (sscanf(p, "%lu%n", &tmp, &count) != 1) 4195b5389086SZhenguo Yao goto invalid; 4196b5389086SZhenguo Yao if (!hugetlb_max_hstate) 4197b5389086SZhenguo Yao default_hugepages_in_node[node] = tmp; 4198b5389086SZhenguo Yao else 4199b5389086SZhenguo Yao parsed_hstate->max_huge_pages_node[node] = tmp; 4200b5389086SZhenguo Yao *mhp += tmp; 4201b5389086SZhenguo Yao /* Go to parse next node*/ 4202b5389086SZhenguo Yao if (p[count] == ',') 4203b5389086SZhenguo Yao p += count + 1; 4204b5389086SZhenguo Yao else 4205b5389086SZhenguo Yao break; 4206b5389086SZhenguo Yao } else { 4207b5389086SZhenguo Yao if (p != s) 4208b5389086SZhenguo Yao goto invalid; 4209b5389086SZhenguo Yao *mhp = tmp; 4210b5389086SZhenguo Yao break; 4211b5389086SZhenguo Yao } 4212b5389086SZhenguo Yao } 4213a3437870SNishanth Aravamudan 42148faa8b07SAndi Kleen /* 42158faa8b07SAndi Kleen * Global state is always initialized later in hugetlb_init. 421604adbc3fSMiaohe Lin * But we need to allocate gigantic hstates here early to still 42178faa8b07SAndi Kleen * use the bootmem allocator. 42188faa8b07SAndi Kleen */ 421904adbc3fSMiaohe Lin if (hugetlb_max_hstate && hstate_is_gigantic(parsed_hstate)) 42208faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(parsed_hstate); 42218faa8b07SAndi Kleen 42228faa8b07SAndi Kleen last_mhp = mhp; 42238faa8b07SAndi Kleen 4224a3437870SNishanth Aravamudan return 1; 4225b5389086SZhenguo Yao 4226b5389086SZhenguo Yao invalid: 4227b5389086SZhenguo Yao pr_warn("HugeTLB: Invalid hugepages parameter %s\n", p); 4228f87442f4SPeng Liu hugepages_clear_pages_in_node(); 4229f81f6e4bSPeng Liu return 1; 4230a3437870SNishanth Aravamudan } 4231282f4214SMike Kravetz __setup("hugepages=", hugepages_setup); 4232e11bfbfcSNick Piggin 4233282f4214SMike Kravetz /* 4234282f4214SMike Kravetz * hugepagesz command line processing 4235282f4214SMike Kravetz * A specific huge page size can only be specified once with hugepagesz. 4236282f4214SMike Kravetz * hugepagesz is followed by hugepages on the command line. The global 4237282f4214SMike Kravetz * variable 'parsed_valid_hugepagesz' is used to determine if prior 4238282f4214SMike Kravetz * hugepagesz argument was valid. 4239282f4214SMike Kravetz */ 4240359f2544SMike Kravetz static int __init hugepagesz_setup(char *s) 4241e11bfbfcSNick Piggin { 4242359f2544SMike Kravetz unsigned long size; 4243282f4214SMike Kravetz struct hstate *h; 4244282f4214SMike Kravetz 4245282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4246359f2544SMike Kravetz size = (unsigned long)memparse(s, NULL); 4247359f2544SMike Kravetz 4248359f2544SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4249282f4214SMike Kravetz pr_err("HugeTLB: unsupported hugepagesz=%s\n", s); 4250f81f6e4bSPeng Liu return 1; 4251359f2544SMike Kravetz } 4252359f2544SMike Kravetz 4253282f4214SMike Kravetz h = size_to_hstate(size); 4254282f4214SMike Kravetz if (h) { 4255282f4214SMike Kravetz /* 4256282f4214SMike Kravetz * hstate for this size already exists. This is normally 4257282f4214SMike Kravetz * an error, but is allowed if the existing hstate is the 4258282f4214SMike Kravetz * default hstate. More specifically, it is only allowed if 4259282f4214SMike Kravetz * the number of huge pages for the default hstate was not 4260282f4214SMike Kravetz * previously specified. 4261282f4214SMike Kravetz */ 4262282f4214SMike Kravetz if (!parsed_default_hugepagesz || h != &default_hstate || 4263282f4214SMike Kravetz default_hstate.max_huge_pages) { 4264282f4214SMike Kravetz pr_warn("HugeTLB: hugepagesz=%s specified twice, ignoring\n", s); 4265f81f6e4bSPeng Liu return 1; 426638237830SMike Kravetz } 426738237830SMike Kravetz 4268282f4214SMike Kravetz /* 4269282f4214SMike Kravetz * No need to call hugetlb_add_hstate() as hstate already 4270282f4214SMike Kravetz * exists. But, do set parsed_hstate so that a following 4271282f4214SMike Kravetz * hugepages= parameter will be applied to this hstate. 4272282f4214SMike Kravetz */ 4273282f4214SMike Kravetz parsed_hstate = h; 4274282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4275e11bfbfcSNick Piggin return 1; 4276e11bfbfcSNick Piggin } 4277282f4214SMike Kravetz 4278359f2544SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4279282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4280359f2544SMike Kravetz return 1; 4281359f2544SMike Kravetz } 4282359f2544SMike Kravetz __setup("hugepagesz=", hugepagesz_setup); 4283359f2544SMike Kravetz 4284282f4214SMike Kravetz /* 4285282f4214SMike Kravetz * default_hugepagesz command line input 4286282f4214SMike Kravetz * Only one instance of default_hugepagesz allowed on command line. 4287282f4214SMike Kravetz */ 4288ae94da89SMike Kravetz static int __init default_hugepagesz_setup(char *s) 4289e11bfbfcSNick Piggin { 4290ae94da89SMike Kravetz unsigned long size; 4291b5389086SZhenguo Yao int i; 4292ae94da89SMike Kravetz 4293282f4214SMike Kravetz parsed_valid_hugepagesz = false; 4294282f4214SMike Kravetz if (parsed_default_hugepagesz) { 4295282f4214SMike Kravetz pr_err("HugeTLB: default_hugepagesz previously specified, ignoring %s\n", s); 4296f81f6e4bSPeng Liu return 1; 4297282f4214SMike Kravetz } 4298282f4214SMike Kravetz 4299282f4214SMike Kravetz size = (unsigned long)memparse(s, NULL); 4300282f4214SMike Kravetz 4301282f4214SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 4302282f4214SMike Kravetz pr_err("HugeTLB: unsupported default_hugepagesz=%s\n", s); 4303f81f6e4bSPeng Liu return 1; 4304282f4214SMike Kravetz } 4305282f4214SMike Kravetz 4306282f4214SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 4307282f4214SMike Kravetz parsed_valid_hugepagesz = true; 4308282f4214SMike Kravetz parsed_default_hugepagesz = true; 4309282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(size)); 4310282f4214SMike Kravetz 4311282f4214SMike Kravetz /* 4312282f4214SMike Kravetz * The number of default huge pages (for this size) could have been 4313282f4214SMike Kravetz * specified as the first hugetlb parameter: hugepages=X. If so, 4314282f4214SMike Kravetz * then default_hstate_max_huge_pages is set. If the default huge 4315282f4214SMike Kravetz * page size is gigantic (>= MAX_ORDER), then the pages must be 4316282f4214SMike Kravetz * allocated here from bootmem allocator. 4317282f4214SMike Kravetz */ 4318282f4214SMike Kravetz if (default_hstate_max_huge_pages) { 4319282f4214SMike Kravetz default_hstate.max_huge_pages = default_hstate_max_huge_pages; 43200a7a0f6fSPeng Liu for_each_online_node(i) 4321b5389086SZhenguo Yao default_hstate.max_huge_pages_node[i] = 4322b5389086SZhenguo Yao default_hugepages_in_node[i]; 4323282f4214SMike Kravetz if (hstate_is_gigantic(&default_hstate)) 4324282f4214SMike Kravetz hugetlb_hstate_alloc_pages(&default_hstate); 4325282f4214SMike Kravetz default_hstate_max_huge_pages = 0; 4326282f4214SMike Kravetz } 4327282f4214SMike Kravetz 4328e11bfbfcSNick Piggin return 1; 4329e11bfbfcSNick Piggin } 4330ae94da89SMike Kravetz __setup("default_hugepagesz=", default_hugepagesz_setup); 4331a3437870SNishanth Aravamudan 43328ca39e68SMuchun Song static unsigned int allowed_mems_nr(struct hstate *h) 43338a213460SNishanth Aravamudan { 43348a213460SNishanth Aravamudan int node; 43358a213460SNishanth Aravamudan unsigned int nr = 0; 43368ca39e68SMuchun Song nodemask_t *mpol_allowed; 43378ca39e68SMuchun Song unsigned int *array = h->free_huge_pages_node; 43388ca39e68SMuchun Song gfp_t gfp_mask = htlb_alloc_mask(h); 43398a213460SNishanth Aravamudan 43408ca39e68SMuchun Song mpol_allowed = policy_nodemask_current(gfp_mask); 43418ca39e68SMuchun Song 43428ca39e68SMuchun Song for_each_node_mask(node, cpuset_current_mems_allowed) { 4343c93b0a99SJiapeng Zhong if (!mpol_allowed || node_isset(node, *mpol_allowed)) 43448a213460SNishanth Aravamudan nr += array[node]; 43458ca39e68SMuchun Song } 43468a213460SNishanth Aravamudan 43478a213460SNishanth Aravamudan return nr; 43488a213460SNishanth Aravamudan } 43498a213460SNishanth Aravamudan 43508a213460SNishanth Aravamudan #ifdef CONFIG_SYSCTL 435117743798SMuchun Song static int proc_hugetlb_doulongvec_minmax(struct ctl_table *table, int write, 435217743798SMuchun Song void *buffer, size_t *length, 435317743798SMuchun Song loff_t *ppos, unsigned long *out) 435417743798SMuchun Song { 435517743798SMuchun Song struct ctl_table dup_table; 435617743798SMuchun Song 435717743798SMuchun Song /* 435817743798SMuchun Song * In order to avoid races with __do_proc_doulongvec_minmax(), we 435917743798SMuchun Song * can duplicate the @table and alter the duplicate of it. 436017743798SMuchun Song */ 436117743798SMuchun Song dup_table = *table; 436217743798SMuchun Song dup_table.data = out; 436317743798SMuchun Song 436417743798SMuchun Song return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos); 436517743798SMuchun Song } 436617743798SMuchun Song 436706808b08SLee Schermerhorn static int hugetlb_sysctl_handler_common(bool obey_mempolicy, 436806808b08SLee Schermerhorn struct ctl_table *table, int write, 436932927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 43701da177e4SLinus Torvalds { 4371e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 4372238d3c13SDavid Rientjes unsigned long tmp = h->max_huge_pages; 437308d4a246SMichal Hocko int ret; 4374e5ff2159SAndi Kleen 4375457c1b27SNishanth Aravamudan if (!hugepages_supported()) 437686613628SJan Stancek return -EOPNOTSUPP; 4377457c1b27SNishanth Aravamudan 437817743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 437917743798SMuchun Song &tmp); 438008d4a246SMichal Hocko if (ret) 438108d4a246SMichal Hocko goto out; 4382e5ff2159SAndi Kleen 4383238d3c13SDavid Rientjes if (write) 4384238d3c13SDavid Rientjes ret = __nr_hugepages_store_common(obey_mempolicy, h, 4385238d3c13SDavid Rientjes NUMA_NO_NODE, tmp, *length); 438608d4a246SMichal Hocko out: 438708d4a246SMichal Hocko return ret; 43881da177e4SLinus Torvalds } 4389396faf03SMel Gorman 439006808b08SLee Schermerhorn int hugetlb_sysctl_handler(struct ctl_table *table, int write, 439132927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 439206808b08SLee Schermerhorn { 439306808b08SLee Schermerhorn 439406808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(false, table, write, 439506808b08SLee Schermerhorn buffer, length, ppos); 439606808b08SLee Schermerhorn } 439706808b08SLee Schermerhorn 439806808b08SLee Schermerhorn #ifdef CONFIG_NUMA 439906808b08SLee Schermerhorn int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, 440032927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 440106808b08SLee Schermerhorn { 440206808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(true, table, write, 440306808b08SLee Schermerhorn buffer, length, ppos); 440406808b08SLee Schermerhorn } 440506808b08SLee Schermerhorn #endif /* CONFIG_NUMA */ 440606808b08SLee Schermerhorn 4407a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 440832927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 4409a3d0c6aaSNishanth Aravamudan { 4410a5516438SAndi Kleen struct hstate *h = &default_hstate; 4411e5ff2159SAndi Kleen unsigned long tmp; 441208d4a246SMichal Hocko int ret; 4413e5ff2159SAndi Kleen 4414457c1b27SNishanth Aravamudan if (!hugepages_supported()) 441586613628SJan Stancek return -EOPNOTSUPP; 4416457c1b27SNishanth Aravamudan 4417e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 4418e5ff2159SAndi Kleen 4419bae7f4aeSLuiz Capitulino if (write && hstate_is_gigantic(h)) 4420adbe8726SEric B Munson return -EINVAL; 4421adbe8726SEric B Munson 442217743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 442317743798SMuchun Song &tmp); 442408d4a246SMichal Hocko if (ret) 442508d4a246SMichal Hocko goto out; 4426e5ff2159SAndi Kleen 4427e5ff2159SAndi Kleen if (write) { 4428db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4429e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 4430db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4431e5ff2159SAndi Kleen } 443208d4a246SMichal Hocko out: 443308d4a246SMichal Hocko return ret; 4434a3d0c6aaSNishanth Aravamudan } 4435a3d0c6aaSNishanth Aravamudan 44361da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 44371da177e4SLinus Torvalds 4438e1759c21SAlexey Dobriyan void hugetlb_report_meminfo(struct seq_file *m) 44391da177e4SLinus Torvalds { 4440fcb2b0c5SRoman Gushchin struct hstate *h; 4441fcb2b0c5SRoman Gushchin unsigned long total = 0; 4442fcb2b0c5SRoman Gushchin 4443457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4444457c1b27SNishanth Aravamudan return; 4445fcb2b0c5SRoman Gushchin 4446fcb2b0c5SRoman Gushchin for_each_hstate(h) { 4447fcb2b0c5SRoman Gushchin unsigned long count = h->nr_huge_pages; 4448fcb2b0c5SRoman Gushchin 4449aca78307SMiaohe Lin total += huge_page_size(h) * count; 4450fcb2b0c5SRoman Gushchin 4451fcb2b0c5SRoman Gushchin if (h == &default_hstate) 4452e1759c21SAlexey Dobriyan seq_printf(m, 44531da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 44541da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 4455b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 44567893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 44574f98a2feSRik van Riel "Hugepagesize: %8lu kB\n", 4458fcb2b0c5SRoman Gushchin count, 4459a5516438SAndi Kleen h->free_huge_pages, 4460a5516438SAndi Kleen h->resv_huge_pages, 4461a5516438SAndi Kleen h->surplus_huge_pages, 4462aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4463fcb2b0c5SRoman Gushchin } 4464fcb2b0c5SRoman Gushchin 4465aca78307SMiaohe Lin seq_printf(m, "Hugetlb: %8lu kB\n", total / SZ_1K); 44661da177e4SLinus Torvalds } 44671da177e4SLinus Torvalds 44687981593bSJoe Perches int hugetlb_report_node_meminfo(char *buf, int len, int nid) 44691da177e4SLinus Torvalds { 4470a5516438SAndi Kleen struct hstate *h = &default_hstate; 44717981593bSJoe Perches 4472457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4473457c1b27SNishanth Aravamudan return 0; 44747981593bSJoe Perches 44757981593bSJoe Perches return sysfs_emit_at(buf, len, 44761da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 4477a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 4478a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 4479a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 4480a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 4481a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 44821da177e4SLinus Torvalds } 44831da177e4SLinus Torvalds 4484949f7ec5SDavid Rientjes void hugetlb_show_meminfo(void) 4485949f7ec5SDavid Rientjes { 4486949f7ec5SDavid Rientjes struct hstate *h; 4487949f7ec5SDavid Rientjes int nid; 4488949f7ec5SDavid Rientjes 4489457c1b27SNishanth Aravamudan if (!hugepages_supported()) 4490457c1b27SNishanth Aravamudan return; 4491457c1b27SNishanth Aravamudan 4492949f7ec5SDavid Rientjes for_each_node_state(nid, N_MEMORY) 4493949f7ec5SDavid Rientjes for_each_hstate(h) 4494949f7ec5SDavid Rientjes pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", 4495949f7ec5SDavid Rientjes nid, 4496949f7ec5SDavid Rientjes h->nr_huge_pages_node[nid], 4497949f7ec5SDavid Rientjes h->free_huge_pages_node[nid], 4498949f7ec5SDavid Rientjes h->surplus_huge_pages_node[nid], 4499aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 4500949f7ec5SDavid Rientjes } 4501949f7ec5SDavid Rientjes 45025d317b2bSNaoya Horiguchi void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm) 45035d317b2bSNaoya Horiguchi { 45045d317b2bSNaoya Horiguchi seq_printf(m, "HugetlbPages:\t%8lu kB\n", 45055d317b2bSNaoya Horiguchi atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10)); 45065d317b2bSNaoya Horiguchi } 45075d317b2bSNaoya Horiguchi 45081da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 45091da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 45101da177e4SLinus Torvalds { 4511d0028588SWanpeng Li struct hstate *h; 4512d0028588SWanpeng Li unsigned long nr_total_pages = 0; 4513d0028588SWanpeng Li 4514d0028588SWanpeng Li for_each_hstate(h) 4515d0028588SWanpeng Li nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); 4516d0028588SWanpeng Li return nr_total_pages; 45171da177e4SLinus Torvalds } 45181da177e4SLinus Torvalds 4519a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 4520fc1b8a73SMel Gorman { 4521fc1b8a73SMel Gorman int ret = -ENOMEM; 4522fc1b8a73SMel Gorman 45230aa7f354SMiaohe Lin if (!delta) 45240aa7f354SMiaohe Lin return 0; 45250aa7f354SMiaohe Lin 4526db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 4527fc1b8a73SMel Gorman /* 4528fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 4529fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 4530fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 4531fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 4532fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 4533fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 4534fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 4535fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 4536fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 4537fc1b8a73SMel Gorman * 4538fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 4539fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 4540fc1b8a73SMel Gorman * we fall back to check against current free page availability as 4541fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 4542fc1b8a73SMel Gorman * semantics that cpuset has. 45438ca39e68SMuchun Song * 45448ca39e68SMuchun Song * Apart from cpuset, we also have memory policy mechanism that 45458ca39e68SMuchun Song * also determines from which node the kernel will allocate memory 45468ca39e68SMuchun Song * in a NUMA system. So similar to cpuset, we also should consider 45478ca39e68SMuchun Song * the memory policy of the current task. Similar to the description 45488ca39e68SMuchun Song * above. 4549fc1b8a73SMel Gorman */ 4550fc1b8a73SMel Gorman if (delta > 0) { 4551a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 4552fc1b8a73SMel Gorman goto out; 4553fc1b8a73SMel Gorman 45548ca39e68SMuchun Song if (delta > allowed_mems_nr(h)) { 4555a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 4556fc1b8a73SMel Gorman goto out; 4557fc1b8a73SMel Gorman } 4558fc1b8a73SMel Gorman } 4559fc1b8a73SMel Gorman 4560fc1b8a73SMel Gorman ret = 0; 4561fc1b8a73SMel Gorman if (delta < 0) 4562a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 4563fc1b8a73SMel Gorman 4564fc1b8a73SMel Gorman out: 4565db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 4566fc1b8a73SMel Gorman return ret; 4567fc1b8a73SMel Gorman } 4568fc1b8a73SMel Gorman 456984afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 457084afd99bSAndy Whitcroft { 4571f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 457284afd99bSAndy Whitcroft 457384afd99bSAndy Whitcroft /* 457484afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 457584afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 457684afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 457725985edcSLucas De Marchi * has a reference to the reservation map it cannot disappear until 457884afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 457984afd99bSAndy Whitcroft * new reference here without additional locking. 458084afd99bSAndy Whitcroft */ 458109a26e83SMike Kravetz if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 458209a26e83SMike Kravetz resv_map_dup_hugetlb_cgroup_uncharge_info(resv); 4583f522c3acSJoonsoo Kim kref_get(&resv->refs); 458484afd99bSAndy Whitcroft } 458509a26e83SMike Kravetz } 458684afd99bSAndy Whitcroft 4587a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 4588a1e78772SMel Gorman { 4589a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 4590f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 459190481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 45924e35f483SJoonsoo Kim unsigned long reserve, start, end; 45931c5ecae3SMike Kravetz long gbl_reserve; 459484afd99bSAndy Whitcroft 45954e35f483SJoonsoo Kim if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 45964e35f483SJoonsoo Kim return; 45974e35f483SJoonsoo Kim 4598a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 4599a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 460084afd99bSAndy Whitcroft 46014e35f483SJoonsoo Kim reserve = (end - start) - region_count(resv, start, end); 4602e9fe92aeSMina Almasry hugetlb_cgroup_uncharge_counter(resv, start, end); 46037251ff78SAdam Litke if (reserve) { 46041c5ecae3SMike Kravetz /* 46051c5ecae3SMike Kravetz * Decrement reserve counts. The global reserve count may be 46061c5ecae3SMike Kravetz * adjusted if the subpool has a minimum size. 46071c5ecae3SMike Kravetz */ 46081c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, reserve); 46091c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 46107251ff78SAdam Litke } 4611e9fe92aeSMina Almasry 4612e9fe92aeSMina Almasry kref_put(&resv->refs, resv_map_release); 4613a1e78772SMel Gorman } 4614a1e78772SMel Gorman 461531383c68SDan Williams static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) 461631383c68SDan Williams { 461731383c68SDan Williams if (addr & ~(huge_page_mask(hstate_vma(vma)))) 461831383c68SDan Williams return -EINVAL; 461931383c68SDan Williams return 0; 462031383c68SDan Williams } 462131383c68SDan Williams 462205ea8860SDan Williams static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) 462305ea8860SDan Williams { 4624aca78307SMiaohe Lin return huge_page_size(hstate_vma(vma)); 462505ea8860SDan Williams } 462605ea8860SDan Williams 46271da177e4SLinus Torvalds /* 46281da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 46291da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 46306c26d310SMiaohe Lin * hugepage VMA. do_page_fault() is supposed to trap this, so BUG is we get 46311da177e4SLinus Torvalds * this far. 46321da177e4SLinus Torvalds */ 4633b3ec9f33SSouptick Joarder static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf) 46341da177e4SLinus Torvalds { 46351da177e4SLinus Torvalds BUG(); 4636d0217ac0SNick Piggin return 0; 46371da177e4SLinus Torvalds } 46381da177e4SLinus Torvalds 4639eec3636aSJane Chu /* 4640eec3636aSJane Chu * When a new function is introduced to vm_operations_struct and added 4641eec3636aSJane Chu * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops. 4642eec3636aSJane Chu * This is because under System V memory model, mappings created via 4643eec3636aSJane Chu * shmget/shmat with "huge page" specified are backed by hugetlbfs files, 4644eec3636aSJane Chu * their original vm_ops are overwritten with shm_vm_ops. 4645eec3636aSJane Chu */ 4646f0f37e2fSAlexey Dobriyan const struct vm_operations_struct hugetlb_vm_ops = { 4647d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 464884afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 4649a1e78772SMel Gorman .close = hugetlb_vm_op_close, 4650dd3b614fSDmitry Safonov .may_split = hugetlb_vm_op_split, 465105ea8860SDan Williams .pagesize = hugetlb_vm_op_pagesize, 46521da177e4SLinus Torvalds }; 46531da177e4SLinus Torvalds 46541e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 46551e8f889bSDavid Gibson int writable) 465663551ae0SDavid Gibson { 465763551ae0SDavid Gibson pte_t entry; 465879c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 465963551ae0SDavid Gibson 46601e8f889bSDavid Gibson if (writable) { 4661106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, 4662106c992aSGerald Schaefer vma->vm_page_prot))); 466363551ae0SDavid Gibson } else { 4664106c992aSGerald Schaefer entry = huge_pte_wrprotect(mk_huge_pte(page, 4665106c992aSGerald Schaefer vma->vm_page_prot)); 466663551ae0SDavid Gibson } 466763551ae0SDavid Gibson entry = pte_mkyoung(entry); 466879c1c594SChristophe Leroy entry = arch_make_huge_pte(entry, shift, vma->vm_flags); 466963551ae0SDavid Gibson 467063551ae0SDavid Gibson return entry; 467163551ae0SDavid Gibson } 467263551ae0SDavid Gibson 46731e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 46741e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 46751e8f889bSDavid Gibson { 46761e8f889bSDavid Gibson pte_t entry; 46771e8f889bSDavid Gibson 4678106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); 467932f84528SChris Forbes if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) 46804b3073e1SRussell King update_mmu_cache(vma, address, ptep); 46811e8f889bSDavid Gibson } 46821e8f889bSDavid Gibson 4683d5ed7444SAneesh Kumar K.V bool is_hugetlb_entry_migration(pte_t pte) 46844a705fefSNaoya Horiguchi { 46854a705fefSNaoya Horiguchi swp_entry_t swp; 46864a705fefSNaoya Horiguchi 46874a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 4688d5ed7444SAneesh Kumar K.V return false; 46894a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4690d79d176aSBaoquan He if (is_migration_entry(swp)) 4691d5ed7444SAneesh Kumar K.V return true; 46924a705fefSNaoya Horiguchi else 4693d5ed7444SAneesh Kumar K.V return false; 46944a705fefSNaoya Horiguchi } 46954a705fefSNaoya Horiguchi 46963e5c3600SBaoquan He static bool is_hugetlb_entry_hwpoisoned(pte_t pte) 46974a705fefSNaoya Horiguchi { 46984a705fefSNaoya Horiguchi swp_entry_t swp; 46994a705fefSNaoya Horiguchi 47004a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 47013e5c3600SBaoquan He return false; 47024a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4703d79d176aSBaoquan He if (is_hwpoison_entry(swp)) 47043e5c3600SBaoquan He return true; 47054a705fefSNaoya Horiguchi else 47063e5c3600SBaoquan He return false; 47074a705fefSNaoya Horiguchi } 47081e8f889bSDavid Gibson 47094eae4efaSPeter Xu static void 47104eae4efaSPeter Xu hugetlb_install_page(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr, 47114eae4efaSPeter Xu struct page *new_page) 47124eae4efaSPeter Xu { 47134eae4efaSPeter Xu __SetPageUptodate(new_page); 47144eae4efaSPeter Xu hugepage_add_new_anon_rmap(new_page, vma, addr); 47151eba86c0SPasha Tatashin set_huge_pte_at(vma->vm_mm, addr, ptep, make_huge_pte(vma, new_page, 1)); 47164eae4efaSPeter Xu hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm); 47174eae4efaSPeter Xu ClearHPageRestoreReserve(new_page); 47184eae4efaSPeter Xu SetHPageMigratable(new_page); 47194eae4efaSPeter Xu } 47204eae4efaSPeter Xu 472163551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 472263551ae0SDavid Gibson struct vm_area_struct *vma) 472363551ae0SDavid Gibson { 47245e41540cSMike Kravetz pte_t *src_pte, *dst_pte, entry, dst_entry; 472563551ae0SDavid Gibson struct page *ptepage; 47261c59827dSHugh Dickins unsigned long addr; 4727ca6eb14dSPeter Xu bool cow = is_cow_mapping(vma->vm_flags); 4728a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 4729a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 47304eae4efaSPeter Xu unsigned long npages = pages_per_huge_page(h); 4731c0d0381aSMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 4732ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 4733e8569dd2SAndreas Sandberg int ret = 0; 47341e8f889bSDavid Gibson 4735ac46d4f3SJérôme Glisse if (cow) { 47367269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, src, 47376f4f13e8SJérôme Glisse vma->vm_start, 4738ac46d4f3SJérôme Glisse vma->vm_end); 4739ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4740623a1ddfSDavid Hildenbrand mmap_assert_write_locked(src); 4741623a1ddfSDavid Hildenbrand raw_write_seqcount_begin(&src->write_protect_seq); 4742c0d0381aSMike Kravetz } else { 4743c0d0381aSMike Kravetz /* 4744c0d0381aSMike Kravetz * For shared mappings i_mmap_rwsem must be held to call 4745c0d0381aSMike Kravetz * huge_pte_alloc, otherwise the returned ptep could go 4746c0d0381aSMike Kravetz * away if part of a shared pmd and another thread calls 4747c0d0381aSMike Kravetz * huge_pmd_unshare. 4748c0d0381aSMike Kravetz */ 4749c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 4750ac46d4f3SJérôme Glisse } 4751e8569dd2SAndreas Sandberg 4752a5516438SAndi Kleen for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { 4753cb900f41SKirill A. Shutemov spinlock_t *src_ptl, *dst_ptl; 47547868a208SPunit Agrawal src_pte = huge_pte_offset(src, addr, sz); 4755c74df32cSHugh Dickins if (!src_pte) 4756c74df32cSHugh Dickins continue; 4757aec44e0fSPeter Xu dst_pte = huge_pte_alloc(dst, vma, addr, sz); 4758e8569dd2SAndreas Sandberg if (!dst_pte) { 4759e8569dd2SAndreas Sandberg ret = -ENOMEM; 4760e8569dd2SAndreas Sandberg break; 4761e8569dd2SAndreas Sandberg } 4762c5c99429SLarry Woodman 47635e41540cSMike Kravetz /* 47645e41540cSMike Kravetz * If the pagetables are shared don't copy or take references. 47655e41540cSMike Kravetz * dst_pte == src_pte is the common case of src/dest sharing. 47665e41540cSMike Kravetz * 47675e41540cSMike Kravetz * However, src could have 'unshared' and dst shares with 47685e41540cSMike Kravetz * another vma. If dst_pte !none, this implies sharing. 47695e41540cSMike Kravetz * Check here before taking page table lock, and once again 47705e41540cSMike Kravetz * after taking the lock below. 47715e41540cSMike Kravetz */ 47725e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 47735e41540cSMike Kravetz if ((dst_pte == src_pte) || !huge_pte_none(dst_entry)) 4774c5c99429SLarry Woodman continue; 4775c5c99429SLarry Woodman 4776cb900f41SKirill A. Shutemov dst_ptl = huge_pte_lock(h, dst, dst_pte); 4777cb900f41SKirill A. Shutemov src_ptl = huge_pte_lockptr(h, src, src_pte); 4778cb900f41SKirill A. Shutemov spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 47794a705fefSNaoya Horiguchi entry = huge_ptep_get(src_pte); 47805e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 47814eae4efaSPeter Xu again: 47825e41540cSMike Kravetz if (huge_pte_none(entry) || !huge_pte_none(dst_entry)) { 47835e41540cSMike Kravetz /* 47845e41540cSMike Kravetz * Skip if src entry none. Also, skip in the 47855e41540cSMike Kravetz * unlikely case dst entry !none as this implies 47865e41540cSMike Kravetz * sharing with another vma. 47875e41540cSMike Kravetz */ 47884a705fefSNaoya Horiguchi ; 47894a705fefSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_migration(entry) || 47904a705fefSNaoya Horiguchi is_hugetlb_entry_hwpoisoned(entry))) { 47914a705fefSNaoya Horiguchi swp_entry_t swp_entry = pte_to_swp_entry(entry); 47924a705fefSNaoya Horiguchi 47936c287605SDavid Hildenbrand if (!is_readable_migration_entry(swp_entry) && cow) { 47944a705fefSNaoya Horiguchi /* 47954a705fefSNaoya Horiguchi * COW mappings require pages in both 47964a705fefSNaoya Horiguchi * parent and child to be set to read. 47974a705fefSNaoya Horiguchi */ 47984dd845b5SAlistair Popple swp_entry = make_readable_migration_entry( 47994dd845b5SAlistair Popple swp_offset(swp_entry)); 48004a705fefSNaoya Horiguchi entry = swp_entry_to_pte(swp_entry); 4801e5251fd4SPunit Agrawal set_huge_swap_pte_at(src, addr, src_pte, 4802e5251fd4SPunit Agrawal entry, sz); 48034a705fefSNaoya Horiguchi } 4804e5251fd4SPunit Agrawal set_huge_swap_pte_at(dst, addr, dst_pte, entry, sz); 48054a705fefSNaoya Horiguchi } else { 48064eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 48074eae4efaSPeter Xu ptepage = pte_page(entry); 48084eae4efaSPeter Xu get_page(ptepage); 48094eae4efaSPeter Xu 48104eae4efaSPeter Xu /* 4811fb3d824dSDavid Hildenbrand * Failing to duplicate the anon rmap is a rare case 4812fb3d824dSDavid Hildenbrand * where we see pinned hugetlb pages while they're 4813fb3d824dSDavid Hildenbrand * prone to COW. We need to do the COW earlier during 4814fb3d824dSDavid Hildenbrand * fork. 48154eae4efaSPeter Xu * 48164eae4efaSPeter Xu * When pre-allocating the page or copying data, we 48174eae4efaSPeter Xu * need to be without the pgtable locks since we could 48184eae4efaSPeter Xu * sleep during the process. 48194eae4efaSPeter Xu */ 4820fb3d824dSDavid Hildenbrand if (!PageAnon(ptepage)) { 4821fb3d824dSDavid Hildenbrand page_dup_file_rmap(ptepage, true); 4822fb3d824dSDavid Hildenbrand } else if (page_try_dup_anon_rmap(ptepage, true, vma)) { 48234eae4efaSPeter Xu pte_t src_pte_old = entry; 48244eae4efaSPeter Xu struct page *new; 48254eae4efaSPeter Xu 48264eae4efaSPeter Xu spin_unlock(src_ptl); 48274eae4efaSPeter Xu spin_unlock(dst_ptl); 48284eae4efaSPeter Xu /* Do not use reserve as it's private owned */ 48294eae4efaSPeter Xu new = alloc_huge_page(vma, addr, 1); 48304eae4efaSPeter Xu if (IS_ERR(new)) { 48314eae4efaSPeter Xu put_page(ptepage); 48324eae4efaSPeter Xu ret = PTR_ERR(new); 48334eae4efaSPeter Xu break; 48344eae4efaSPeter Xu } 48354eae4efaSPeter Xu copy_user_huge_page(new, ptepage, addr, vma, 48364eae4efaSPeter Xu npages); 48374eae4efaSPeter Xu put_page(ptepage); 48384eae4efaSPeter Xu 48394eae4efaSPeter Xu /* Install the new huge page if src pte stable */ 48404eae4efaSPeter Xu dst_ptl = huge_pte_lock(h, dst, dst_pte); 48414eae4efaSPeter Xu src_ptl = huge_pte_lockptr(h, src, src_pte); 48424eae4efaSPeter Xu spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 48434eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 48444eae4efaSPeter Xu if (!pte_same(src_pte_old, entry)) { 4845846be085SMike Kravetz restore_reserve_on_error(h, vma, addr, 4846846be085SMike Kravetz new); 48474eae4efaSPeter Xu put_page(new); 48484eae4efaSPeter Xu /* dst_entry won't change as in child */ 48494eae4efaSPeter Xu goto again; 48504eae4efaSPeter Xu } 48514eae4efaSPeter Xu hugetlb_install_page(vma, dst_pte, addr, new); 48524eae4efaSPeter Xu spin_unlock(src_ptl); 48534eae4efaSPeter Xu spin_unlock(dst_ptl); 48544eae4efaSPeter Xu continue; 48554eae4efaSPeter Xu } 48564eae4efaSPeter Xu 485734ee645eSJoerg Roedel if (cow) { 48580f10851eSJérôme Glisse /* 48590f10851eSJérôme Glisse * No need to notify as we are downgrading page 48600f10851eSJérôme Glisse * table protection not changing it to point 48610f10851eSJérôme Glisse * to a new page. 48620f10851eSJérôme Glisse * 4863ad56b738SMike Rapoport * See Documentation/vm/mmu_notifier.rst 48640f10851eSJérôme Glisse */ 48657f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 486684894e1cSPeter Xu entry = huge_pte_wrprotect(entry); 486734ee645eSJoerg Roedel } 48684eae4efaSPeter Xu 486963551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 48704eae4efaSPeter Xu hugetlb_count_add(npages, dst); 48711c59827dSHugh Dickins } 4872cb900f41SKirill A. Shutemov spin_unlock(src_ptl); 4873cb900f41SKirill A. Shutemov spin_unlock(dst_ptl); 487463551ae0SDavid Gibson } 487563551ae0SDavid Gibson 4876623a1ddfSDavid Hildenbrand if (cow) { 4877623a1ddfSDavid Hildenbrand raw_write_seqcount_end(&src->write_protect_seq); 4878ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 4879623a1ddfSDavid Hildenbrand } else { 4880c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 4881623a1ddfSDavid Hildenbrand } 4882e8569dd2SAndreas Sandberg 4883e8569dd2SAndreas Sandberg return ret; 488463551ae0SDavid Gibson } 488563551ae0SDavid Gibson 4886550a7d60SMina Almasry static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr, 4887db110a99SAneesh Kumar K.V unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte) 4888550a7d60SMina Almasry { 4889550a7d60SMina Almasry struct hstate *h = hstate_vma(vma); 4890550a7d60SMina Almasry struct mm_struct *mm = vma->vm_mm; 4891550a7d60SMina Almasry spinlock_t *src_ptl, *dst_ptl; 4892db110a99SAneesh Kumar K.V pte_t pte; 4893550a7d60SMina Almasry 4894550a7d60SMina Almasry dst_ptl = huge_pte_lock(h, mm, dst_pte); 4895550a7d60SMina Almasry src_ptl = huge_pte_lockptr(h, mm, src_pte); 4896550a7d60SMina Almasry 4897550a7d60SMina Almasry /* 4898550a7d60SMina Almasry * We don't have to worry about the ordering of src and dst ptlocks 4899550a7d60SMina Almasry * because exclusive mmap_sem (or the i_mmap_lock) prevents deadlock. 4900550a7d60SMina Almasry */ 4901550a7d60SMina Almasry if (src_ptl != dst_ptl) 4902550a7d60SMina Almasry spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 4903550a7d60SMina Almasry 4904550a7d60SMina Almasry pte = huge_ptep_get_and_clear(mm, old_addr, src_pte); 4905550a7d60SMina Almasry set_huge_pte_at(mm, new_addr, dst_pte, pte); 4906550a7d60SMina Almasry 4907550a7d60SMina Almasry if (src_ptl != dst_ptl) 4908550a7d60SMina Almasry spin_unlock(src_ptl); 4909550a7d60SMina Almasry spin_unlock(dst_ptl); 4910550a7d60SMina Almasry } 4911550a7d60SMina Almasry 4912550a7d60SMina Almasry int move_hugetlb_page_tables(struct vm_area_struct *vma, 4913550a7d60SMina Almasry struct vm_area_struct *new_vma, 4914550a7d60SMina Almasry unsigned long old_addr, unsigned long new_addr, 4915550a7d60SMina Almasry unsigned long len) 4916550a7d60SMina Almasry { 4917550a7d60SMina Almasry struct hstate *h = hstate_vma(vma); 4918550a7d60SMina Almasry struct address_space *mapping = vma->vm_file->f_mapping; 4919550a7d60SMina Almasry unsigned long sz = huge_page_size(h); 4920550a7d60SMina Almasry struct mm_struct *mm = vma->vm_mm; 4921550a7d60SMina Almasry unsigned long old_end = old_addr + len; 4922550a7d60SMina Almasry unsigned long old_addr_copy; 4923550a7d60SMina Almasry pte_t *src_pte, *dst_pte; 4924550a7d60SMina Almasry struct mmu_notifier_range range; 49253d0b95cdSBaolin Wang bool shared_pmd = false; 4926550a7d60SMina Almasry 4927550a7d60SMina Almasry mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, old_addr, 4928550a7d60SMina Almasry old_end); 4929550a7d60SMina Almasry adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 49303d0b95cdSBaolin Wang /* 49313d0b95cdSBaolin Wang * In case of shared PMDs, we should cover the maximum possible 49323d0b95cdSBaolin Wang * range. 49333d0b95cdSBaolin Wang */ 49343d0b95cdSBaolin Wang flush_cache_range(vma, range.start, range.end); 49353d0b95cdSBaolin Wang 4936550a7d60SMina Almasry mmu_notifier_invalidate_range_start(&range); 4937550a7d60SMina Almasry /* Prevent race with file truncation */ 4938550a7d60SMina Almasry i_mmap_lock_write(mapping); 4939550a7d60SMina Almasry for (; old_addr < old_end; old_addr += sz, new_addr += sz) { 4940550a7d60SMina Almasry src_pte = huge_pte_offset(mm, old_addr, sz); 4941550a7d60SMina Almasry if (!src_pte) 4942550a7d60SMina Almasry continue; 4943550a7d60SMina Almasry if (huge_pte_none(huge_ptep_get(src_pte))) 4944550a7d60SMina Almasry continue; 4945550a7d60SMina Almasry 4946550a7d60SMina Almasry /* old_addr arg to huge_pmd_unshare() is a pointer and so the 4947550a7d60SMina Almasry * arg may be modified. Pass a copy instead to preserve the 4948550a7d60SMina Almasry * value in old_addr. 4949550a7d60SMina Almasry */ 4950550a7d60SMina Almasry old_addr_copy = old_addr; 4951550a7d60SMina Almasry 49523d0b95cdSBaolin Wang if (huge_pmd_unshare(mm, vma, &old_addr_copy, src_pte)) { 49533d0b95cdSBaolin Wang shared_pmd = true; 4954550a7d60SMina Almasry continue; 49553d0b95cdSBaolin Wang } 4956550a7d60SMina Almasry 4957550a7d60SMina Almasry dst_pte = huge_pte_alloc(mm, new_vma, new_addr, sz); 4958550a7d60SMina Almasry if (!dst_pte) 4959550a7d60SMina Almasry break; 4960550a7d60SMina Almasry 4961db110a99SAneesh Kumar K.V move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte); 4962550a7d60SMina Almasry } 49633d0b95cdSBaolin Wang 49643d0b95cdSBaolin Wang if (shared_pmd) 49653d0b95cdSBaolin Wang flush_tlb_range(vma, range.start, range.end); 49663d0b95cdSBaolin Wang else 4967550a7d60SMina Almasry flush_tlb_range(vma, old_end - len, old_end); 4968550a7d60SMina Almasry mmu_notifier_invalidate_range_end(&range); 496913e4ad2cSNadav Amit i_mmap_unlock_write(mapping); 4970550a7d60SMina Almasry 4971550a7d60SMina Almasry return len + old_addr - old_end; 4972550a7d60SMina Almasry } 4973550a7d60SMina Almasry 497473c54763SPeter Xu static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, 497524669e58SAneesh Kumar K.V unsigned long start, unsigned long end, 497624669e58SAneesh Kumar K.V struct page *ref_page) 497763551ae0SDavid Gibson { 497863551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 497963551ae0SDavid Gibson unsigned long address; 4980c7546f8fSDavid Gibson pte_t *ptep; 498163551ae0SDavid Gibson pte_t pte; 4982cb900f41SKirill A. Shutemov spinlock_t *ptl; 498363551ae0SDavid Gibson struct page *page; 4984a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 4985a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 4986ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 4987a4a118f2SNadav Amit bool force_flush = false; 4988a5516438SAndi Kleen 498963551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 4990a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 4991a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 499263551ae0SDavid Gibson 499307e32661SAneesh Kumar K.V /* 499407e32661SAneesh Kumar K.V * This is a hugetlb vma, all the pte entries should point 499507e32661SAneesh Kumar K.V * to huge page. 499607e32661SAneesh Kumar K.V */ 4997ed6a7935SPeter Zijlstra tlb_change_page_size(tlb, sz); 499824669e58SAneesh Kumar K.V tlb_start_vma(tlb, vma); 4999dff11abeSMike Kravetz 5000dff11abeSMike Kravetz /* 5001dff11abeSMike Kravetz * If sharing possible, alert mmu notifiers of worst case. 5002dff11abeSMike Kravetz */ 50036f4f13e8SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, mm, start, 50046f4f13e8SJérôme Glisse end); 5005ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 5006ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 5007569f48b8SHillf Danton address = start; 5008569f48b8SHillf Danton for (; address < end; address += sz) { 50097868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, sz); 5010c7546f8fSDavid Gibson if (!ptep) 5011c7546f8fSDavid Gibson continue; 5012c7546f8fSDavid Gibson 5013cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 501434ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 501531d49da5SAneesh Kumar K.V spin_unlock(ptl); 5016a4a118f2SNadav Amit tlb_flush_pmd_range(tlb, address & PUD_MASK, PUD_SIZE); 5017a4a118f2SNadav Amit force_flush = true; 501831d49da5SAneesh Kumar K.V continue; 501931d49da5SAneesh Kumar K.V } 502039dde65cSChen, Kenneth W 50216629326bSHillf Danton pte = huge_ptep_get(ptep); 502231d49da5SAneesh Kumar K.V if (huge_pte_none(pte)) { 502331d49da5SAneesh Kumar K.V spin_unlock(ptl); 502431d49da5SAneesh Kumar K.V continue; 502531d49da5SAneesh Kumar K.V } 50266629326bSHillf Danton 50276629326bSHillf Danton /* 50289fbc1f63SNaoya Horiguchi * Migrating hugepage or HWPoisoned hugepage is already 50299fbc1f63SNaoya Horiguchi * unmapped and its refcount is dropped, so just clear pte here. 50306629326bSHillf Danton */ 50319fbc1f63SNaoya Horiguchi if (unlikely(!pte_present(pte))) { 50329386fac3SPunit Agrawal huge_pte_clear(mm, address, ptep, sz); 503331d49da5SAneesh Kumar K.V spin_unlock(ptl); 503431d49da5SAneesh Kumar K.V continue; 50358c4894c6SNaoya Horiguchi } 50366629326bSHillf Danton 50376629326bSHillf Danton page = pte_page(pte); 503804f2cbe3SMel Gorman /* 503904f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 504004f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 504104f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 504204f2cbe3SMel Gorman */ 504304f2cbe3SMel Gorman if (ref_page) { 504431d49da5SAneesh Kumar K.V if (page != ref_page) { 504531d49da5SAneesh Kumar K.V spin_unlock(ptl); 504631d49da5SAneesh Kumar K.V continue; 504731d49da5SAneesh Kumar K.V } 504804f2cbe3SMel Gorman /* 504904f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 505004f2cbe3SMel Gorman * future faults in this VMA will fail rather than 505104f2cbe3SMel Gorman * looking like data was lost 505204f2cbe3SMel Gorman */ 505304f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 505404f2cbe3SMel Gorman } 505504f2cbe3SMel Gorman 5056c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 5057b528e4b6SAneesh Kumar K.V tlb_remove_huge_tlb_entry(h, tlb, ptep, address); 5058106c992aSGerald Schaefer if (huge_pte_dirty(pte)) 50596649a386SKen Chen set_page_dirty(page); 50609e81130bSHillf Danton 50615d317b2bSNaoya Horiguchi hugetlb_count_sub(pages_per_huge_page(h), mm); 5062cea86fe2SHugh Dickins page_remove_rmap(page, vma, true); 506331d49da5SAneesh Kumar K.V 5064cb900f41SKirill A. Shutemov spin_unlock(ptl); 5065e77b0852SAneesh Kumar K.V tlb_remove_page_size(tlb, page, huge_page_size(h)); 506624669e58SAneesh Kumar K.V /* 506731d49da5SAneesh Kumar K.V * Bail out after unmapping reference page if supplied 506824669e58SAneesh Kumar K.V */ 506931d49da5SAneesh Kumar K.V if (ref_page) 507031d49da5SAneesh Kumar K.V break; 5071fe1668aeSChen, Kenneth W } 5072ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 507324669e58SAneesh Kumar K.V tlb_end_vma(tlb, vma); 5074a4a118f2SNadav Amit 5075a4a118f2SNadav Amit /* 5076a4a118f2SNadav Amit * If we unshared PMDs, the TLB flush was not recorded in mmu_gather. We 5077a4a118f2SNadav Amit * could defer the flush until now, since by holding i_mmap_rwsem we 5078a4a118f2SNadav Amit * guaranteed that the last refernece would not be dropped. But we must 5079a4a118f2SNadav Amit * do the flushing before we return, as otherwise i_mmap_rwsem will be 5080a4a118f2SNadav Amit * dropped and the last reference to the shared PMDs page might be 5081a4a118f2SNadav Amit * dropped as well. 5082a4a118f2SNadav Amit * 5083a4a118f2SNadav Amit * In theory we could defer the freeing of the PMD pages as well, but 5084a4a118f2SNadav Amit * huge_pmd_unshare() relies on the exact page_count for the PMD page to 5085a4a118f2SNadav Amit * detect sharing, so we cannot defer the release of the page either. 5086a4a118f2SNadav Amit * Instead, do flush now. 5087a4a118f2SNadav Amit */ 5088a4a118f2SNadav Amit if (force_flush) 5089a4a118f2SNadav Amit tlb_flush_mmu_tlbonly(tlb); 50901da177e4SLinus Torvalds } 509163551ae0SDavid Gibson 5092d833352aSMel Gorman void __unmap_hugepage_range_final(struct mmu_gather *tlb, 5093d833352aSMel Gorman struct vm_area_struct *vma, unsigned long start, 5094d833352aSMel Gorman unsigned long end, struct page *ref_page) 5095d833352aSMel Gorman { 5096d833352aSMel Gorman __unmap_hugepage_range(tlb, vma, start, end, ref_page); 5097d833352aSMel Gorman 5098d833352aSMel Gorman /* 5099d833352aSMel Gorman * Clear this flag so that x86's huge_pmd_share page_table_shareable 5100d833352aSMel Gorman * test will fail on a vma being torn down, and not grab a page table 5101d833352aSMel Gorman * on its way out. We're lucky that the flag has such an appropriate 5102d833352aSMel Gorman * name, and can in fact be safely cleared here. We could clear it 5103d833352aSMel Gorman * before the __unmap_hugepage_range above, but all that's necessary 5104c8c06efaSDavidlohr Bueso * is to clear it before releasing the i_mmap_rwsem. This works 5105d833352aSMel Gorman * because in the context this is called, the VMA is about to be 5106c8c06efaSDavidlohr Bueso * destroyed and the i_mmap_rwsem is held. 5107d833352aSMel Gorman */ 5108d833352aSMel Gorman vma->vm_flags &= ~VM_MAYSHARE; 5109d833352aSMel Gorman } 5110d833352aSMel Gorman 5111502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 511204f2cbe3SMel Gorman unsigned long end, struct page *ref_page) 5113502717f4SChen, Kenneth W { 511424669e58SAneesh Kumar K.V struct mmu_gather tlb; 5115dff11abeSMike Kravetz 5116a72afd87SWill Deacon tlb_gather_mmu(&tlb, vma->vm_mm); 511724669e58SAneesh Kumar K.V __unmap_hugepage_range(&tlb, vma, start, end, ref_page); 5118ae8eba8bSWill Deacon tlb_finish_mmu(&tlb); 5119502717f4SChen, Kenneth W } 5120502717f4SChen, Kenneth W 512104f2cbe3SMel Gorman /* 512204f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 5123578b7725SZhiyuan Dai * mapping it owns the reserve page for. The intention is to unmap the page 512404f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 512504f2cbe3SMel Gorman * same region. 512604f2cbe3SMel Gorman */ 51272f4612afSDavidlohr Bueso static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, 51282a4b3dedSHarvey Harrison struct page *page, unsigned long address) 512904f2cbe3SMel Gorman { 51307526674dSAdam Litke struct hstate *h = hstate_vma(vma); 513104f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 513204f2cbe3SMel Gorman struct address_space *mapping; 513304f2cbe3SMel Gorman pgoff_t pgoff; 513404f2cbe3SMel Gorman 513504f2cbe3SMel Gorman /* 513604f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 513704f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 513804f2cbe3SMel Gorman */ 51397526674dSAdam Litke address = address & huge_page_mask(h); 514036e4f20aSMichal Hocko pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + 514136e4f20aSMichal Hocko vma->vm_pgoff; 514293c76a3dSAl Viro mapping = vma->vm_file->f_mapping; 514304f2cbe3SMel Gorman 51444eb2b1dcSMel Gorman /* 51454eb2b1dcSMel Gorman * Take the mapping lock for the duration of the table walk. As 51464eb2b1dcSMel Gorman * this mapping should be shared between all the VMAs, 51474eb2b1dcSMel Gorman * __unmap_hugepage_range() is called as the lock is already held 51484eb2b1dcSMel Gorman */ 514983cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 51506b2dbba8SMichel Lespinasse vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { 515104f2cbe3SMel Gorman /* Do not unmap the current VMA */ 515204f2cbe3SMel Gorman if (iter_vma == vma) 515304f2cbe3SMel Gorman continue; 515404f2cbe3SMel Gorman 515504f2cbe3SMel Gorman /* 51562f84a899SMel Gorman * Shared VMAs have their own reserves and do not affect 51572f84a899SMel Gorman * MAP_PRIVATE accounting but it is possible that a shared 51582f84a899SMel Gorman * VMA is using the same page so check and skip such VMAs. 51592f84a899SMel Gorman */ 51602f84a899SMel Gorman if (iter_vma->vm_flags & VM_MAYSHARE) 51612f84a899SMel Gorman continue; 51622f84a899SMel Gorman 51632f84a899SMel Gorman /* 516404f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 516504f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 516604f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 516704f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 516804f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 516904f2cbe3SMel Gorman */ 517004f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 517124669e58SAneesh Kumar K.V unmap_hugepage_range(iter_vma, address, 517224669e58SAneesh Kumar K.V address + huge_page_size(h), page); 517304f2cbe3SMel Gorman } 517483cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 517504f2cbe3SMel Gorman } 517604f2cbe3SMel Gorman 51770fe6e20bSNaoya Horiguchi /* 5178c89357e2SDavid Hildenbrand * hugetlb_wp() should be called with page lock of the original hugepage held. 5179aa6d2e8cSBaolin Wang * Called with hugetlb_fault_mutex_table held and pte_page locked so we 5180ef009b25SMichal Hocko * cannot race with other handlers or page migration. 5181ef009b25SMichal Hocko * Keep the pte_same checks anyway to make transition from the mutex easier. 51820fe6e20bSNaoya Horiguchi */ 5183c89357e2SDavid Hildenbrand static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma, 5184c89357e2SDavid Hildenbrand unsigned long address, pte_t *ptep, unsigned int flags, 5185cb900f41SKirill A. Shutemov struct page *pagecache_page, spinlock_t *ptl) 51861e8f889bSDavid Gibson { 5187c89357e2SDavid Hildenbrand const bool unshare = flags & FAULT_FLAG_UNSHARE; 51883999f52eSAneesh Kumar K.V pte_t pte; 5189a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 51901e8f889bSDavid Gibson struct page *old_page, *new_page; 51912b740303SSouptick Joarder int outside_reserve = 0; 51922b740303SSouptick Joarder vm_fault_t ret = 0; 5193974e6d66SHuang Ying unsigned long haddr = address & huge_page_mask(h); 5194ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 51951e8f889bSDavid Gibson 5196c89357e2SDavid Hildenbrand VM_BUG_ON(unshare && (flags & FOLL_WRITE)); 5197c89357e2SDavid Hildenbrand VM_BUG_ON(!unshare && !(flags & FOLL_WRITE)); 5198c89357e2SDavid Hildenbrand 51993999f52eSAneesh Kumar K.V pte = huge_ptep_get(ptep); 52001e8f889bSDavid Gibson old_page = pte_page(pte); 52011e8f889bSDavid Gibson 520204f2cbe3SMel Gorman retry_avoidcopy: 5203c89357e2SDavid Hildenbrand /* 5204c89357e2SDavid Hildenbrand * If no-one else is actually using this page, we're the exclusive 5205c89357e2SDavid Hildenbrand * owner and can reuse this page. 5206c89357e2SDavid Hildenbrand */ 520737a2140dSJoonsoo Kim if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { 5208c89357e2SDavid Hildenbrand if (!PageAnonExclusive(old_page)) 52095a49973dSHugh Dickins page_move_anon_rmap(old_page, vma); 5210c89357e2SDavid Hildenbrand if (likely(!unshare)) 52115b7a1d40SHuang Ying set_huge_ptep_writable(vma, haddr, ptep); 521283c54070SNick Piggin return 0; 52131e8f889bSDavid Gibson } 52146c287605SDavid Hildenbrand VM_BUG_ON_PAGE(PageAnon(old_page) && PageAnonExclusive(old_page), 52156c287605SDavid Hildenbrand old_page); 52161e8f889bSDavid Gibson 521704f2cbe3SMel Gorman /* 521804f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 521904f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 522004f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 522104f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 522204f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 522304f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 522404f2cbe3SMel Gorman * of the full address range. 522504f2cbe3SMel Gorman */ 52265944d011SJoonsoo Kim if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 522704f2cbe3SMel Gorman old_page != pagecache_page) 522804f2cbe3SMel Gorman outside_reserve = 1; 522904f2cbe3SMel Gorman 523009cbfeafSKirill A. Shutemov get_page(old_page); 5231b76c8cfbSLarry Woodman 5232ad4404a2SDavidlohr Bueso /* 5233ad4404a2SDavidlohr Bueso * Drop page table lock as buddy allocator may be called. It will 5234ad4404a2SDavidlohr Bueso * be acquired again before returning to the caller, as expected. 5235ad4404a2SDavidlohr Bueso */ 5236cb900f41SKirill A. Shutemov spin_unlock(ptl); 52375b7a1d40SHuang Ying new_page = alloc_huge_page(vma, haddr, outside_reserve); 52381e8f889bSDavid Gibson 52392fc39cecSAdam Litke if (IS_ERR(new_page)) { 524004f2cbe3SMel Gorman /* 524104f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 524204f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 524304f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 524404f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 524504f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 524604f2cbe3SMel Gorman */ 524704f2cbe3SMel Gorman if (outside_reserve) { 5248e7dd91c4SMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 5249e7dd91c4SMike Kravetz pgoff_t idx; 5250e7dd91c4SMike Kravetz u32 hash; 5251e7dd91c4SMike Kravetz 525209cbfeafSKirill A. Shutemov put_page(old_page); 525304f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 5254e7dd91c4SMike Kravetz /* 5255e7dd91c4SMike Kravetz * Drop hugetlb_fault_mutex and i_mmap_rwsem before 5256e7dd91c4SMike Kravetz * unmapping. unmapping needs to hold i_mmap_rwsem 5257e7dd91c4SMike Kravetz * in write mode. Dropping i_mmap_rwsem in read mode 5258e7dd91c4SMike Kravetz * here is OK as COW mappings do not interact with 5259e7dd91c4SMike Kravetz * PMD sharing. 5260e7dd91c4SMike Kravetz * 5261e7dd91c4SMike Kravetz * Reacquire both after unmap operation. 5262e7dd91c4SMike Kravetz */ 5263e7dd91c4SMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 5264e7dd91c4SMike Kravetz hash = hugetlb_fault_mutex_hash(mapping, idx); 5265e7dd91c4SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5266e7dd91c4SMike Kravetz i_mmap_unlock_read(mapping); 5267e7dd91c4SMike Kravetz 52685b7a1d40SHuang Ying unmap_ref_private(mm, vma, old_page, haddr); 5269e7dd91c4SMike Kravetz 5270e7dd91c4SMike Kravetz i_mmap_lock_read(mapping); 5271e7dd91c4SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 5272cb900f41SKirill A. Shutemov spin_lock(ptl); 52735b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5274a9af0c5dSNaoya Horiguchi if (likely(ptep && 5275a9af0c5dSNaoya Horiguchi pte_same(huge_ptep_get(ptep), pte))) 527604f2cbe3SMel Gorman goto retry_avoidcopy; 5277a734bcc8SHillf Danton /* 5278cb900f41SKirill A. Shutemov * race occurs while re-acquiring page table 5279cb900f41SKirill A. Shutemov * lock, and our job is done. 5280a734bcc8SHillf Danton */ 5281a734bcc8SHillf Danton return 0; 528204f2cbe3SMel Gorman } 528304f2cbe3SMel Gorman 52842b740303SSouptick Joarder ret = vmf_error(PTR_ERR(new_page)); 5285ad4404a2SDavidlohr Bueso goto out_release_old; 52861e8f889bSDavid Gibson } 52871e8f889bSDavid Gibson 52880fe6e20bSNaoya Horiguchi /* 52890fe6e20bSNaoya Horiguchi * When the original hugepage is shared one, it does not have 52900fe6e20bSNaoya Horiguchi * anon_vma prepared. 52910fe6e20bSNaoya Horiguchi */ 529244e2aa93SDean Nelson if (unlikely(anon_vma_prepare(vma))) { 5293ad4404a2SDavidlohr Bueso ret = VM_FAULT_OOM; 5294ad4404a2SDavidlohr Bueso goto out_release_all; 529544e2aa93SDean Nelson } 52960fe6e20bSNaoya Horiguchi 5297974e6d66SHuang Ying copy_user_huge_page(new_page, old_page, address, vma, 529847ad8475SAndrea Arcangeli pages_per_huge_page(h)); 52990ed361deSNick Piggin __SetPageUptodate(new_page); 53001e8f889bSDavid Gibson 53017269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr, 53026f4f13e8SJérôme Glisse haddr + huge_page_size(h)); 5303ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 5304ad4404a2SDavidlohr Bueso 5305b76c8cfbSLarry Woodman /* 5306cb900f41SKirill A. Shutemov * Retake the page table lock to check for racing updates 5307b76c8cfbSLarry Woodman * before the page tables are altered 5308b76c8cfbSLarry Woodman */ 5309cb900f41SKirill A. Shutemov spin_lock(ptl); 53105b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5311a9af0c5dSNaoya Horiguchi if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { 5312d6995da3SMike Kravetz ClearHPageRestoreReserve(new_page); 531307443a85SJoonsoo Kim 5314c89357e2SDavid Hildenbrand /* Break COW or unshare */ 53155b7a1d40SHuang Ying huge_ptep_clear_flush(vma, haddr, ptep); 5316ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range(mm, range.start, range.end); 5317cea86fe2SHugh Dickins page_remove_rmap(old_page, vma, true); 53185b7a1d40SHuang Ying hugepage_add_new_anon_rmap(new_page, vma, haddr); 53191eba86c0SPasha Tatashin set_huge_pte_at(mm, haddr, ptep, 5320c89357e2SDavid Hildenbrand make_huge_pte(vma, new_page, !unshare)); 53218f251a3dSMike Kravetz SetHPageMigratable(new_page); 53221e8f889bSDavid Gibson /* Make the old page be freed below */ 53231e8f889bSDavid Gibson new_page = old_page; 53241e8f889bSDavid Gibson } 5325cb900f41SKirill A. Shutemov spin_unlock(ptl); 5326ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 5327ad4404a2SDavidlohr Bueso out_release_all: 5328c89357e2SDavid Hildenbrand /* 5329c89357e2SDavid Hildenbrand * No restore in case of successful pagetable update (Break COW or 5330c89357e2SDavid Hildenbrand * unshare) 5331c89357e2SDavid Hildenbrand */ 5332c7b1850dSMike Kravetz if (new_page != old_page) 53335b7a1d40SHuang Ying restore_reserve_on_error(h, vma, haddr, new_page); 533409cbfeafSKirill A. Shutemov put_page(new_page); 5335ad4404a2SDavidlohr Bueso out_release_old: 533609cbfeafSKirill A. Shutemov put_page(old_page); 53378312034fSJoonsoo Kim 5338ad4404a2SDavidlohr Bueso spin_lock(ptl); /* Caller expects lock to be held */ 5339ad4404a2SDavidlohr Bueso return ret; 53401e8f889bSDavid Gibson } 53411e8f889bSDavid Gibson 534204f2cbe3SMel Gorman /* Return the pagecache page at a given address within a VMA */ 5343a5516438SAndi Kleen static struct page *hugetlbfs_pagecache_page(struct hstate *h, 5344a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 534504f2cbe3SMel Gorman { 534604f2cbe3SMel Gorman struct address_space *mapping; 5347e7c4b0bfSAndy Whitcroft pgoff_t idx; 534804f2cbe3SMel Gorman 534904f2cbe3SMel Gorman mapping = vma->vm_file->f_mapping; 5350a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 535104f2cbe3SMel Gorman 535204f2cbe3SMel Gorman return find_lock_page(mapping, idx); 535304f2cbe3SMel Gorman } 535404f2cbe3SMel Gorman 53553ae77f43SHugh Dickins /* 53563ae77f43SHugh Dickins * Return whether there is a pagecache page to back given address within VMA. 53573ae77f43SHugh Dickins * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. 53583ae77f43SHugh Dickins */ 53593ae77f43SHugh Dickins static bool hugetlbfs_pagecache_present(struct hstate *h, 53602a15efc9SHugh Dickins struct vm_area_struct *vma, unsigned long address) 53612a15efc9SHugh Dickins { 53622a15efc9SHugh Dickins struct address_space *mapping; 53632a15efc9SHugh Dickins pgoff_t idx; 53642a15efc9SHugh Dickins struct page *page; 53652a15efc9SHugh Dickins 53662a15efc9SHugh Dickins mapping = vma->vm_file->f_mapping; 53672a15efc9SHugh Dickins idx = vma_hugecache_offset(h, vma, address); 53682a15efc9SHugh Dickins 53692a15efc9SHugh Dickins page = find_get_page(mapping, idx); 53702a15efc9SHugh Dickins if (page) 53712a15efc9SHugh Dickins put_page(page); 53722a15efc9SHugh Dickins return page != NULL; 53732a15efc9SHugh Dickins } 53742a15efc9SHugh Dickins 5375ab76ad54SMike Kravetz int huge_add_to_page_cache(struct page *page, struct address_space *mapping, 5376ab76ad54SMike Kravetz pgoff_t idx) 5377ab76ad54SMike Kravetz { 5378ab76ad54SMike Kravetz struct inode *inode = mapping->host; 5379ab76ad54SMike Kravetz struct hstate *h = hstate_inode(inode); 5380ab76ad54SMike Kravetz int err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); 5381ab76ad54SMike Kravetz 5382ab76ad54SMike Kravetz if (err) 5383ab76ad54SMike Kravetz return err; 5384d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 5385ab76ad54SMike Kravetz 538622146c3cSMike Kravetz /* 538722146c3cSMike Kravetz * set page dirty so that it will not be removed from cache/file 538822146c3cSMike Kravetz * by non-hugetlbfs specific code paths. 538922146c3cSMike Kravetz */ 539022146c3cSMike Kravetz set_page_dirty(page); 539122146c3cSMike Kravetz 5392ab76ad54SMike Kravetz spin_lock(&inode->i_lock); 5393ab76ad54SMike Kravetz inode->i_blocks += blocks_per_huge_page(h); 5394ab76ad54SMike Kravetz spin_unlock(&inode->i_lock); 5395ab76ad54SMike Kravetz return 0; 5396ab76ad54SMike Kravetz } 5397ab76ad54SMike Kravetz 53987677f7fdSAxel Rasmussen static inline vm_fault_t hugetlb_handle_userfault(struct vm_area_struct *vma, 53997677f7fdSAxel Rasmussen struct address_space *mapping, 54007677f7fdSAxel Rasmussen pgoff_t idx, 54017677f7fdSAxel Rasmussen unsigned int flags, 54027677f7fdSAxel Rasmussen unsigned long haddr, 5403824ddc60SNadav Amit unsigned long addr, 54047677f7fdSAxel Rasmussen unsigned long reason) 54057677f7fdSAxel Rasmussen { 54067677f7fdSAxel Rasmussen vm_fault_t ret; 54077677f7fdSAxel Rasmussen u32 hash; 54087677f7fdSAxel Rasmussen struct vm_fault vmf = { 54097677f7fdSAxel Rasmussen .vma = vma, 54107677f7fdSAxel Rasmussen .address = haddr, 5411824ddc60SNadav Amit .real_address = addr, 54127677f7fdSAxel Rasmussen .flags = flags, 54137677f7fdSAxel Rasmussen 54147677f7fdSAxel Rasmussen /* 54157677f7fdSAxel Rasmussen * Hard to debug if it ends up being 54167677f7fdSAxel Rasmussen * used by a callee that assumes 54177677f7fdSAxel Rasmussen * something about the other 54187677f7fdSAxel Rasmussen * uninitialized fields... same as in 54197677f7fdSAxel Rasmussen * memory.c 54207677f7fdSAxel Rasmussen */ 54217677f7fdSAxel Rasmussen }; 54227677f7fdSAxel Rasmussen 54237677f7fdSAxel Rasmussen /* 54247677f7fdSAxel Rasmussen * hugetlb_fault_mutex and i_mmap_rwsem must be 54257677f7fdSAxel Rasmussen * dropped before handling userfault. Reacquire 54267677f7fdSAxel Rasmussen * after handling fault to make calling code simpler. 54277677f7fdSAxel Rasmussen */ 54287677f7fdSAxel Rasmussen hash = hugetlb_fault_mutex_hash(mapping, idx); 54297677f7fdSAxel Rasmussen mutex_unlock(&hugetlb_fault_mutex_table[hash]); 54307677f7fdSAxel Rasmussen i_mmap_unlock_read(mapping); 54317677f7fdSAxel Rasmussen ret = handle_userfault(&vmf, reason); 54327677f7fdSAxel Rasmussen i_mmap_lock_read(mapping); 54337677f7fdSAxel Rasmussen mutex_lock(&hugetlb_fault_mutex_table[hash]); 54347677f7fdSAxel Rasmussen 54357677f7fdSAxel Rasmussen return ret; 54367677f7fdSAxel Rasmussen } 54377677f7fdSAxel Rasmussen 54382b740303SSouptick Joarder static vm_fault_t hugetlb_no_page(struct mm_struct *mm, 54392b740303SSouptick Joarder struct vm_area_struct *vma, 54408382d914SDavidlohr Bueso struct address_space *mapping, pgoff_t idx, 5441c64e912cSPeter Xu unsigned long address, pte_t *ptep, 5442c64e912cSPeter Xu pte_t old_pte, unsigned int flags) 5443ac9b9c66SHugh Dickins { 5444a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 54452b740303SSouptick Joarder vm_fault_t ret = VM_FAULT_SIGBUS; 5446409eb8c2SHillf Danton int anon_rmap = 0; 54474c887265SAdam Litke unsigned long size; 54484c887265SAdam Litke struct page *page; 54491e8f889bSDavid Gibson pte_t new_pte; 5450cb900f41SKirill A. Shutemov spinlock_t *ptl; 5451285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 5452c7b1850dSMike Kravetz bool new_page, new_pagecache_page = false; 54534c887265SAdam Litke 545404f2cbe3SMel Gorman /* 545504f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 545604f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 5457c89357e2SDavid Hildenbrand * COW/unsharing. Warn that such a situation has occurred as it may not 5458c89357e2SDavid Hildenbrand * be obvious. 545904f2cbe3SMel Gorman */ 546004f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 5461910154d5SGeoffrey Thomas pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n", 546204f2cbe3SMel Gorman current->pid); 546304f2cbe3SMel Gorman return ret; 546404f2cbe3SMel Gorman } 546504f2cbe3SMel Gorman 54664c887265SAdam Litke /* 546787bf91d3SMike Kravetz * We can not race with truncation due to holding i_mmap_rwsem. 546887bf91d3SMike Kravetz * i_size is modified when holding i_mmap_rwsem, so check here 546987bf91d3SMike Kravetz * once for faults beyond end of file. 54704c887265SAdam Litke */ 5471a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 5472ebed4bfcSHugh Dickins if (idx >= size) 5473ebed4bfcSHugh Dickins goto out; 54741a1aad8aSMike Kravetz 547587bf91d3SMike Kravetz retry: 5476c7b1850dSMike Kravetz new_page = false; 547787bf91d3SMike Kravetz page = find_lock_page(mapping, idx); 547887bf91d3SMike Kravetz if (!page) { 54797677f7fdSAxel Rasmussen /* Check for page in userfault range */ 54801a1aad8aSMike Kravetz if (userfaultfd_missing(vma)) { 54817677f7fdSAxel Rasmussen ret = hugetlb_handle_userfault(vma, mapping, idx, 5482824ddc60SNadav Amit flags, haddr, address, 54837677f7fdSAxel Rasmussen VM_UFFD_MISSING); 54841a1aad8aSMike Kravetz goto out; 54851a1aad8aSMike Kravetz } 54861a1aad8aSMike Kravetz 5487285b8dcaSHuang Ying page = alloc_huge_page(vma, haddr, 0); 54882fc39cecSAdam Litke if (IS_ERR(page)) { 54894643d67eSMike Kravetz /* 54904643d67eSMike Kravetz * Returning error will result in faulting task being 54914643d67eSMike Kravetz * sent SIGBUS. The hugetlb fault mutex prevents two 54924643d67eSMike Kravetz * tasks from racing to fault in the same page which 54934643d67eSMike Kravetz * could result in false unable to allocate errors. 54944643d67eSMike Kravetz * Page migration does not take the fault mutex, but 54954643d67eSMike Kravetz * does a clear then write of pte's under page table 54964643d67eSMike Kravetz * lock. Page fault code could race with migration, 54974643d67eSMike Kravetz * notice the clear pte and try to allocate a page 54984643d67eSMike Kravetz * here. Before returning error, get ptl and make 54994643d67eSMike Kravetz * sure there really is no pte entry. 55004643d67eSMike Kravetz */ 55014643d67eSMike Kravetz ptl = huge_pte_lock(h, mm, ptep); 55024643d67eSMike Kravetz ret = 0; 5503d83e6c8aSMiaohe Lin if (huge_pte_none(huge_ptep_get(ptep))) 55042b740303SSouptick Joarder ret = vmf_error(PTR_ERR(page)); 5505d83e6c8aSMiaohe Lin spin_unlock(ptl); 55066bda666aSChristoph Lameter goto out; 55076bda666aSChristoph Lameter } 550847ad8475SAndrea Arcangeli clear_huge_page(page, address, pages_per_huge_page(h)); 55090ed361deSNick Piggin __SetPageUptodate(page); 5510cb6acd01SMike Kravetz new_page = true; 5511ac9b9c66SHugh Dickins 5512f83a275dSMel Gorman if (vma->vm_flags & VM_MAYSHARE) { 5513ab76ad54SMike Kravetz int err = huge_add_to_page_cache(page, mapping, idx); 55146bda666aSChristoph Lameter if (err) { 55156bda666aSChristoph Lameter put_page(page); 55166bda666aSChristoph Lameter if (err == -EEXIST) 55176bda666aSChristoph Lameter goto retry; 55186bda666aSChristoph Lameter goto out; 55196bda666aSChristoph Lameter } 5520c7b1850dSMike Kravetz new_pagecache_page = true; 552123be7468SMel Gorman } else { 55226bda666aSChristoph Lameter lock_page(page); 55230fe6e20bSNaoya Horiguchi if (unlikely(anon_vma_prepare(vma))) { 55240fe6e20bSNaoya Horiguchi ret = VM_FAULT_OOM; 55250fe6e20bSNaoya Horiguchi goto backout_unlocked; 552623be7468SMel Gorman } 5527409eb8c2SHillf Danton anon_rmap = 1; 55280fe6e20bSNaoya Horiguchi } 55290fe6e20bSNaoya Horiguchi } else { 553057303d80SAndy Whitcroft /* 5531998b4382SNaoya Horiguchi * If memory error occurs between mmap() and fault, some process 5532998b4382SNaoya Horiguchi * don't have hwpoisoned swap entry for errored virtual address. 5533998b4382SNaoya Horiguchi * So we need to block hugepage fault by PG_hwpoison bit check. 5534fd6a03edSNaoya Horiguchi */ 5535fd6a03edSNaoya Horiguchi if (unlikely(PageHWPoison(page))) { 55360eb98f15SMiaohe Lin ret = VM_FAULT_HWPOISON_LARGE | 5537972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 5538fd6a03edSNaoya Horiguchi goto backout_unlocked; 55396bda666aSChristoph Lameter } 55407677f7fdSAxel Rasmussen 55417677f7fdSAxel Rasmussen /* Check for page in userfault range. */ 55427677f7fdSAxel Rasmussen if (userfaultfd_minor(vma)) { 55437677f7fdSAxel Rasmussen unlock_page(page); 55447677f7fdSAxel Rasmussen put_page(page); 55457677f7fdSAxel Rasmussen ret = hugetlb_handle_userfault(vma, mapping, idx, 5546824ddc60SNadav Amit flags, haddr, address, 55477677f7fdSAxel Rasmussen VM_UFFD_MINOR); 55487677f7fdSAxel Rasmussen goto out; 55497677f7fdSAxel Rasmussen } 5550998b4382SNaoya Horiguchi } 55511e8f889bSDavid Gibson 555257303d80SAndy Whitcroft /* 555357303d80SAndy Whitcroft * If we are going to COW a private mapping later, we examine the 555457303d80SAndy Whitcroft * pending reservations for this page now. This will ensure that 555557303d80SAndy Whitcroft * any allocations necessary to record that reservation occur outside 555657303d80SAndy Whitcroft * the spinlock. 555757303d80SAndy Whitcroft */ 55585e911373SMike Kravetz if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 5559285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 55602b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 55612b26736cSAndy Whitcroft goto backout_unlocked; 55622b26736cSAndy Whitcroft } 55635e911373SMike Kravetz /* Just decrements count, does not deallocate */ 5564285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 55655e911373SMike Kravetz } 556657303d80SAndy Whitcroft 55678bea8052SAneesh Kumar K.V ptl = huge_pte_lock(h, mm, ptep); 556883c54070SNick Piggin ret = 0; 5569c64e912cSPeter Xu /* If pte changed from under us, retry */ 5570c64e912cSPeter Xu if (!pte_same(huge_ptep_get(ptep), old_pte)) 55714c887265SAdam Litke goto backout; 55724c887265SAdam Litke 557307443a85SJoonsoo Kim if (anon_rmap) { 5574d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 5575285b8dcaSHuang Ying hugepage_add_new_anon_rmap(page, vma, haddr); 5576ac714904SChoi Gi-yong } else 5577fb3d824dSDavid Hildenbrand page_dup_file_rmap(page, true); 55781e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 55791e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 5580c64e912cSPeter Xu /* 5581c64e912cSPeter Xu * If this pte was previously wr-protected, keep it wr-protected even 5582c64e912cSPeter Xu * if populated. 5583c64e912cSPeter Xu */ 5584c64e912cSPeter Xu if (unlikely(pte_marker_uffd_wp(old_pte))) 5585c64e912cSPeter Xu new_pte = huge_pte_wrprotect(huge_pte_mkuffd_wp(new_pte)); 5586285b8dcaSHuang Ying set_huge_pte_at(mm, haddr, ptep, new_pte); 55871e8f889bSDavid Gibson 55885d317b2bSNaoya Horiguchi hugetlb_count_add(pages_per_huge_page(h), mm); 5589788c7df4SHugh Dickins if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 55901e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 5591c89357e2SDavid Hildenbrand ret = hugetlb_wp(mm, vma, address, ptep, flags, page, ptl); 55921e8f889bSDavid Gibson } 55931e8f889bSDavid Gibson 5594cb900f41SKirill A. Shutemov spin_unlock(ptl); 5595cb6acd01SMike Kravetz 5596cb6acd01SMike Kravetz /* 55978f251a3dSMike Kravetz * Only set HPageMigratable in newly allocated pages. Existing pages 55988f251a3dSMike Kravetz * found in the pagecache may not have HPageMigratableset if they have 55998f251a3dSMike Kravetz * been isolated for migration. 5600cb6acd01SMike Kravetz */ 5601cb6acd01SMike Kravetz if (new_page) 56028f251a3dSMike Kravetz SetHPageMigratable(page); 5603cb6acd01SMike Kravetz 56044c887265SAdam Litke unlock_page(page); 56054c887265SAdam Litke out: 5606ac9b9c66SHugh Dickins return ret; 56074c887265SAdam Litke 56084c887265SAdam Litke backout: 5609cb900f41SKirill A. Shutemov spin_unlock(ptl); 56102b26736cSAndy Whitcroft backout_unlocked: 56114c887265SAdam Litke unlock_page(page); 5612c7b1850dSMike Kravetz /* restore reserve for newly allocated pages not in page cache */ 5613c7b1850dSMike Kravetz if (new_page && !new_pagecache_page) 5614285b8dcaSHuang Ying restore_reserve_on_error(h, vma, haddr, page); 56154c887265SAdam Litke put_page(page); 56164c887265SAdam Litke goto out; 5617ac9b9c66SHugh Dickins } 5618ac9b9c66SHugh Dickins 56198382d914SDavidlohr Bueso #ifdef CONFIG_SMP 5620188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 56218382d914SDavidlohr Bueso { 56228382d914SDavidlohr Bueso unsigned long key[2]; 56238382d914SDavidlohr Bueso u32 hash; 56248382d914SDavidlohr Bueso 56258382d914SDavidlohr Bueso key[0] = (unsigned long) mapping; 56268382d914SDavidlohr Bueso key[1] = idx; 56278382d914SDavidlohr Bueso 562855254636SMike Kravetz hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0); 56298382d914SDavidlohr Bueso 56308382d914SDavidlohr Bueso return hash & (num_fault_mutexes - 1); 56318382d914SDavidlohr Bueso } 56328382d914SDavidlohr Bueso #else 56338382d914SDavidlohr Bueso /* 56346c26d310SMiaohe Lin * For uniprocessor systems we always use a single mutex, so just 56358382d914SDavidlohr Bueso * return 0 and avoid the hashing overhead. 56368382d914SDavidlohr Bueso */ 5637188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 56388382d914SDavidlohr Bueso { 56398382d914SDavidlohr Bueso return 0; 56408382d914SDavidlohr Bueso } 56418382d914SDavidlohr Bueso #endif 56428382d914SDavidlohr Bueso 56432b740303SSouptick Joarder vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 5644788c7df4SHugh Dickins unsigned long address, unsigned int flags) 564586e5216fSAdam Litke { 56468382d914SDavidlohr Bueso pte_t *ptep, entry; 5647cb900f41SKirill A. Shutemov spinlock_t *ptl; 56482b740303SSouptick Joarder vm_fault_t ret; 56498382d914SDavidlohr Bueso u32 hash; 56508382d914SDavidlohr Bueso pgoff_t idx; 56510fe6e20bSNaoya Horiguchi struct page *page = NULL; 565257303d80SAndy Whitcroft struct page *pagecache_page = NULL; 5653a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 56548382d914SDavidlohr Bueso struct address_space *mapping; 56550f792cf9SNaoya Horiguchi int need_wait_lock = 0; 5656285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 565786e5216fSAdam Litke 5658285b8dcaSHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 5659fd6a03edSNaoya Horiguchi if (ptep) { 5660c0d0381aSMike Kravetz /* 5661c0d0381aSMike Kravetz * Since we hold no locks, ptep could be stale. That is 5662c0d0381aSMike Kravetz * OK as we are only making decisions based on content and 5663c0d0381aSMike Kravetz * not actually modifying content here. 5664c0d0381aSMike Kravetz */ 5665fd6a03edSNaoya Horiguchi entry = huge_ptep_get(ptep); 5666290408d4SNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(entry))) { 5667cb900f41SKirill A. Shutemov migration_entry_wait_huge(vma, mm, ptep); 5668290408d4SNaoya Horiguchi return 0; 5669290408d4SNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) 5670aa50d3a7SAndi Kleen return VM_FAULT_HWPOISON_LARGE | 5671972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 5672b43a9990SMike Kravetz } 56738382d914SDavidlohr Bueso 5674c0d0381aSMike Kravetz /* 5675c0d0381aSMike Kravetz * Acquire i_mmap_rwsem before calling huge_pte_alloc and hold 567687bf91d3SMike Kravetz * until finished with ptep. This serves two purposes: 567787bf91d3SMike Kravetz * 1) It prevents huge_pmd_unshare from being called elsewhere 567887bf91d3SMike Kravetz * and making the ptep no longer valid. 567987bf91d3SMike Kravetz * 2) It synchronizes us with i_size modifications during truncation. 5680c0d0381aSMike Kravetz * 5681c0d0381aSMike Kravetz * ptep could have already be assigned via huge_pte_offset. That 5682c0d0381aSMike Kravetz * is OK, as huge_pte_alloc will return the same value unless 5683c0d0381aSMike Kravetz * something has changed. 5684c0d0381aSMike Kravetz */ 5685ddeaab32SMike Kravetz mapping = vma->vm_file->f_mapping; 5686c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 5687aec44e0fSPeter Xu ptep = huge_pte_alloc(mm, vma, haddr, huge_page_size(h)); 5688c0d0381aSMike Kravetz if (!ptep) { 5689c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 5690c0d0381aSMike Kravetz return VM_FAULT_OOM; 5691c0d0381aSMike Kravetz } 5692ddeaab32SMike Kravetz 56933935baa9SDavid Gibson /* 56943935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 56953935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 56963935baa9SDavid Gibson * the same page in the page cache. 56973935baa9SDavid Gibson */ 5698c0d0381aSMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 5699188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 5700c672c7f2SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 57018382d914SDavidlohr Bueso 57027f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 5703c64e912cSPeter Xu /* PTE markers should be handled the same way as none pte */ 5704c64e912cSPeter Xu if (huge_pte_none_mostly(entry)) { 5705c64e912cSPeter Xu ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, 5706c64e912cSPeter Xu entry, flags); 5707b4d1d99fSDavid Gibson goto out_mutex; 57083935baa9SDavid Gibson } 570986e5216fSAdam Litke 571083c54070SNick Piggin ret = 0; 57111e8f889bSDavid Gibson 571257303d80SAndy Whitcroft /* 57130f792cf9SNaoya Horiguchi * entry could be a migration/hwpoison entry at this point, so this 57140f792cf9SNaoya Horiguchi * check prevents the kernel from going below assuming that we have 57157c8de358SEthon Paul * an active hugepage in pagecache. This goto expects the 2nd page 57167c8de358SEthon Paul * fault, and is_hugetlb_entry_(migration|hwpoisoned) check will 57177c8de358SEthon Paul * properly handle it. 57180f792cf9SNaoya Horiguchi */ 57190f792cf9SNaoya Horiguchi if (!pte_present(entry)) 57200f792cf9SNaoya Horiguchi goto out_mutex; 57210f792cf9SNaoya Horiguchi 57220f792cf9SNaoya Horiguchi /* 5723c89357e2SDavid Hildenbrand * If we are going to COW/unshare the mapping later, we examine the 5724c89357e2SDavid Hildenbrand * pending reservations for this page now. This will ensure that any 572557303d80SAndy Whitcroft * allocations necessary to record that reservation occur outside the 572657303d80SAndy Whitcroft * spinlock. For private mappings, we also lookup the pagecache 572757303d80SAndy Whitcroft * page now as it is used to determine if a reservation has been 572857303d80SAndy Whitcroft * consumed. 572957303d80SAndy Whitcroft */ 5730c89357e2SDavid Hildenbrand if ((flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) && 5731c89357e2SDavid Hildenbrand !huge_pte_write(entry)) { 5732285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 57332b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 5734b4d1d99fSDavid Gibson goto out_mutex; 57352b26736cSAndy Whitcroft } 57365e911373SMike Kravetz /* Just decrements count, does not deallocate */ 5737285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 573857303d80SAndy Whitcroft 5739f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 574057303d80SAndy Whitcroft pagecache_page = hugetlbfs_pagecache_page(h, 5741285b8dcaSHuang Ying vma, haddr); 574257303d80SAndy Whitcroft } 574357303d80SAndy Whitcroft 57440f792cf9SNaoya Horiguchi ptl = huge_pte_lock(h, mm, ptep); 57450fe6e20bSNaoya Horiguchi 5746c89357e2SDavid Hildenbrand /* Check for a racing update before calling hugetlb_wp() */ 5747b4d1d99fSDavid Gibson if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) 5748cb900f41SKirill A. Shutemov goto out_ptl; 5749b4d1d99fSDavid Gibson 5750166f3eccSPeter Xu /* Handle userfault-wp first, before trying to lock more pages */ 5751166f3eccSPeter Xu if (userfaultfd_wp(vma) && huge_pte_uffd_wp(huge_ptep_get(ptep)) && 5752166f3eccSPeter Xu (flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { 5753166f3eccSPeter Xu struct vm_fault vmf = { 5754166f3eccSPeter Xu .vma = vma, 5755166f3eccSPeter Xu .address = haddr, 5756166f3eccSPeter Xu .real_address = address, 5757166f3eccSPeter Xu .flags = flags, 5758166f3eccSPeter Xu }; 5759166f3eccSPeter Xu 5760166f3eccSPeter Xu spin_unlock(ptl); 5761166f3eccSPeter Xu if (pagecache_page) { 5762166f3eccSPeter Xu unlock_page(pagecache_page); 5763166f3eccSPeter Xu put_page(pagecache_page); 5764166f3eccSPeter Xu } 5765166f3eccSPeter Xu mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5766166f3eccSPeter Xu i_mmap_unlock_read(mapping); 5767166f3eccSPeter Xu return handle_userfault(&vmf, VM_UFFD_WP); 5768166f3eccSPeter Xu } 5769166f3eccSPeter Xu 57700f792cf9SNaoya Horiguchi /* 5771c89357e2SDavid Hildenbrand * hugetlb_wp() requires page locks of pte_page(entry) and 57720f792cf9SNaoya Horiguchi * pagecache_page, so here we need take the former one 57730f792cf9SNaoya Horiguchi * when page != pagecache_page or !pagecache_page. 57740f792cf9SNaoya Horiguchi */ 57750f792cf9SNaoya Horiguchi page = pte_page(entry); 57760f792cf9SNaoya Horiguchi if (page != pagecache_page) 57770f792cf9SNaoya Horiguchi if (!trylock_page(page)) { 57780f792cf9SNaoya Horiguchi need_wait_lock = 1; 57790f792cf9SNaoya Horiguchi goto out_ptl; 57800f792cf9SNaoya Horiguchi } 57810f792cf9SNaoya Horiguchi 57820f792cf9SNaoya Horiguchi get_page(page); 5783b4d1d99fSDavid Gibson 5784c89357e2SDavid Hildenbrand if (flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) { 5785106c992aSGerald Schaefer if (!huge_pte_write(entry)) { 5786c89357e2SDavid Hildenbrand ret = hugetlb_wp(mm, vma, address, ptep, flags, 5787cb900f41SKirill A. Shutemov pagecache_page, ptl); 57880f792cf9SNaoya Horiguchi goto out_put_page; 5789c89357e2SDavid Hildenbrand } else if (likely(flags & FAULT_FLAG_WRITE)) { 5790106c992aSGerald Schaefer entry = huge_pte_mkdirty(entry); 5791b4d1d99fSDavid Gibson } 5792c89357e2SDavid Hildenbrand } 5793b4d1d99fSDavid Gibson entry = pte_mkyoung(entry); 5794285b8dcaSHuang Ying if (huge_ptep_set_access_flags(vma, haddr, ptep, entry, 5795788c7df4SHugh Dickins flags & FAULT_FLAG_WRITE)) 5796285b8dcaSHuang Ying update_mmu_cache(vma, haddr, ptep); 57970f792cf9SNaoya Horiguchi out_put_page: 57980f792cf9SNaoya Horiguchi if (page != pagecache_page) 57990f792cf9SNaoya Horiguchi unlock_page(page); 58000f792cf9SNaoya Horiguchi put_page(page); 5801cb900f41SKirill A. Shutemov out_ptl: 5802cb900f41SKirill A. Shutemov spin_unlock(ptl); 580357303d80SAndy Whitcroft 580457303d80SAndy Whitcroft if (pagecache_page) { 580557303d80SAndy Whitcroft unlock_page(pagecache_page); 580657303d80SAndy Whitcroft put_page(pagecache_page); 580757303d80SAndy Whitcroft } 5808b4d1d99fSDavid Gibson out_mutex: 5809c672c7f2SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5810c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 58110f792cf9SNaoya Horiguchi /* 58120f792cf9SNaoya Horiguchi * Generally it's safe to hold refcount during waiting page lock. But 58130f792cf9SNaoya Horiguchi * here we just wait to defer the next page fault to avoid busy loop and 58140f792cf9SNaoya Horiguchi * the page is not used after unlocked before returning from the current 58150f792cf9SNaoya Horiguchi * page fault. So we are safe from accessing freed page, even if we wait 58160f792cf9SNaoya Horiguchi * here without taking refcount. 58170f792cf9SNaoya Horiguchi */ 58180f792cf9SNaoya Horiguchi if (need_wait_lock) 58190f792cf9SNaoya Horiguchi wait_on_page_locked(page); 58201e8f889bSDavid Gibson return ret; 582186e5216fSAdam Litke } 582286e5216fSAdam Litke 5823714c1891SAxel Rasmussen #ifdef CONFIG_USERFAULTFD 58248fb5debcSMike Kravetz /* 58258fb5debcSMike Kravetz * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with 58268fb5debcSMike Kravetz * modifications for huge pages. 58278fb5debcSMike Kravetz */ 58288fb5debcSMike Kravetz int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, 58298fb5debcSMike Kravetz pte_t *dst_pte, 58308fb5debcSMike Kravetz struct vm_area_struct *dst_vma, 58318fb5debcSMike Kravetz unsigned long dst_addr, 58328fb5debcSMike Kravetz unsigned long src_addr, 5833f6191471SAxel Rasmussen enum mcopy_atomic_mode mode, 58346041c691SPeter Xu struct page **pagep, 58356041c691SPeter Xu bool wp_copy) 58368fb5debcSMike Kravetz { 5837f6191471SAxel Rasmussen bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE); 58388cc5fcbbSMina Almasry struct hstate *h = hstate_vma(dst_vma); 58398cc5fcbbSMina Almasry struct address_space *mapping = dst_vma->vm_file->f_mapping; 58408cc5fcbbSMina Almasry pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr); 58411e392147SAndrea Arcangeli unsigned long size; 58421c9e8defSMike Kravetz int vm_shared = dst_vma->vm_flags & VM_SHARED; 58438fb5debcSMike Kravetz pte_t _dst_pte; 58448fb5debcSMike Kravetz spinlock_t *ptl; 58458cc5fcbbSMina Almasry int ret = -ENOMEM; 58468fb5debcSMike Kravetz struct page *page; 5847f6191471SAxel Rasmussen int writable; 5848cc30042dSMina Almasry bool page_in_pagecache = false; 58498fb5debcSMike Kravetz 5850f6191471SAxel Rasmussen if (is_continue) { 5851f6191471SAxel Rasmussen ret = -EFAULT; 5852f6191471SAxel Rasmussen page = find_lock_page(mapping, idx); 5853f6191471SAxel Rasmussen if (!page) 5854f6191471SAxel Rasmussen goto out; 5855cc30042dSMina Almasry page_in_pagecache = true; 5856f6191471SAxel Rasmussen } else if (!*pagep) { 5857d84cf06eSMina Almasry /* If a page already exists, then it's UFFDIO_COPY for 5858d84cf06eSMina Almasry * a non-missing case. Return -EEXIST. 5859d84cf06eSMina Almasry */ 5860d84cf06eSMina Almasry if (vm_shared && 5861d84cf06eSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 5862d84cf06eSMina Almasry ret = -EEXIST; 58638fb5debcSMike Kravetz goto out; 5864d84cf06eSMina Almasry } 5865d84cf06eSMina Almasry 5866d84cf06eSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 5867d84cf06eSMina Almasry if (IS_ERR(page)) { 5868d84cf06eSMina Almasry ret = -ENOMEM; 5869d84cf06eSMina Almasry goto out; 5870d84cf06eSMina Almasry } 58718fb5debcSMike Kravetz 58728fb5debcSMike Kravetz ret = copy_huge_page_from_user(page, 58738fb5debcSMike Kravetz (const void __user *) src_addr, 5874810a56b9SMike Kravetz pages_per_huge_page(h), false); 58758fb5debcSMike Kravetz 5876c1e8d7c6SMichel Lespinasse /* fallback to copy_from_user outside mmap_lock */ 58778fb5debcSMike Kravetz if (unlikely(ret)) { 58789e368259SAndrea Arcangeli ret = -ENOENT; 58798cc5fcbbSMina Almasry /* Free the allocated page which may have 58808cc5fcbbSMina Almasry * consumed a reservation. 58818cc5fcbbSMina Almasry */ 58828cc5fcbbSMina Almasry restore_reserve_on_error(h, dst_vma, dst_addr, page); 58838cc5fcbbSMina Almasry put_page(page); 58848cc5fcbbSMina Almasry 58858cc5fcbbSMina Almasry /* Allocate a temporary page to hold the copied 58868cc5fcbbSMina Almasry * contents. 58878cc5fcbbSMina Almasry */ 58888cc5fcbbSMina Almasry page = alloc_huge_page_vma(h, dst_vma, dst_addr); 58898cc5fcbbSMina Almasry if (!page) { 58908cc5fcbbSMina Almasry ret = -ENOMEM; 58918cc5fcbbSMina Almasry goto out; 58928cc5fcbbSMina Almasry } 58938fb5debcSMike Kravetz *pagep = page; 58948cc5fcbbSMina Almasry /* Set the outparam pagep and return to the caller to 58958cc5fcbbSMina Almasry * copy the contents outside the lock. Don't free the 58968cc5fcbbSMina Almasry * page. 58978cc5fcbbSMina Almasry */ 58988fb5debcSMike Kravetz goto out; 58998fb5debcSMike Kravetz } 59008fb5debcSMike Kravetz } else { 59018cc5fcbbSMina Almasry if (vm_shared && 59028cc5fcbbSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 59038cc5fcbbSMina Almasry put_page(*pagep); 59048cc5fcbbSMina Almasry ret = -EEXIST; 59058cc5fcbbSMina Almasry *pagep = NULL; 59068cc5fcbbSMina Almasry goto out; 59078cc5fcbbSMina Almasry } 59088cc5fcbbSMina Almasry 59098cc5fcbbSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 59108cc5fcbbSMina Almasry if (IS_ERR(page)) { 59118cc5fcbbSMina Almasry ret = -ENOMEM; 59128cc5fcbbSMina Almasry *pagep = NULL; 59138cc5fcbbSMina Almasry goto out; 59148cc5fcbbSMina Almasry } 591534892366SMuchun Song copy_user_huge_page(page, *pagep, dst_addr, dst_vma, 591634892366SMuchun Song pages_per_huge_page(h)); 59178cc5fcbbSMina Almasry put_page(*pagep); 59188fb5debcSMike Kravetz *pagep = NULL; 59198fb5debcSMike Kravetz } 59208fb5debcSMike Kravetz 59218fb5debcSMike Kravetz /* 59228fb5debcSMike Kravetz * The memory barrier inside __SetPageUptodate makes sure that 59238fb5debcSMike Kravetz * preceding stores to the page contents become visible before 59248fb5debcSMike Kravetz * the set_pte_at() write. 59258fb5debcSMike Kravetz */ 59268fb5debcSMike Kravetz __SetPageUptodate(page); 59278fb5debcSMike Kravetz 5928f6191471SAxel Rasmussen /* Add shared, newly allocated pages to the page cache. */ 5929f6191471SAxel Rasmussen if (vm_shared && !is_continue) { 59301e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 59311e392147SAndrea Arcangeli ret = -EFAULT; 59321e392147SAndrea Arcangeli if (idx >= size) 59331e392147SAndrea Arcangeli goto out_release_nounlock; 59341c9e8defSMike Kravetz 59351e392147SAndrea Arcangeli /* 59361e392147SAndrea Arcangeli * Serialization between remove_inode_hugepages() and 59371e392147SAndrea Arcangeli * huge_add_to_page_cache() below happens through the 59381e392147SAndrea Arcangeli * hugetlb_fault_mutex_table that here must be hold by 59391e392147SAndrea Arcangeli * the caller. 59401e392147SAndrea Arcangeli */ 59411c9e8defSMike Kravetz ret = huge_add_to_page_cache(page, mapping, idx); 59421c9e8defSMike Kravetz if (ret) 59431c9e8defSMike Kravetz goto out_release_nounlock; 5944cc30042dSMina Almasry page_in_pagecache = true; 59451c9e8defSMike Kravetz } 59461c9e8defSMike Kravetz 59478fb5debcSMike Kravetz ptl = huge_pte_lockptr(h, dst_mm, dst_pte); 59488fb5debcSMike Kravetz spin_lock(ptl); 59498fb5debcSMike Kravetz 59501e392147SAndrea Arcangeli /* 59511e392147SAndrea Arcangeli * Recheck the i_size after holding PT lock to make sure not 59521e392147SAndrea Arcangeli * to leave any page mapped (as page_mapped()) beyond the end 59531e392147SAndrea Arcangeli * of the i_size (remove_inode_hugepages() is strict about 59541e392147SAndrea Arcangeli * enforcing that). If we bail out here, we'll also leave a 59551e392147SAndrea Arcangeli * page in the radix tree in the vm_shared case beyond the end 59561e392147SAndrea Arcangeli * of the i_size, but remove_inode_hugepages() will take care 59571e392147SAndrea Arcangeli * of it as soon as we drop the hugetlb_fault_mutex_table. 59581e392147SAndrea Arcangeli */ 59591e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 59601e392147SAndrea Arcangeli ret = -EFAULT; 59611e392147SAndrea Arcangeli if (idx >= size) 59621e392147SAndrea Arcangeli goto out_release_unlock; 59631e392147SAndrea Arcangeli 59648fb5debcSMike Kravetz ret = -EEXIST; 59656041c691SPeter Xu /* 59666041c691SPeter Xu * We allow to overwrite a pte marker: consider when both MISSING|WP 59676041c691SPeter Xu * registered, we firstly wr-protect a none pte which has no page cache 59686041c691SPeter Xu * page backing it, then access the page. 59696041c691SPeter Xu */ 59706041c691SPeter Xu if (!huge_pte_none_mostly(huge_ptep_get(dst_pte))) 59718fb5debcSMike Kravetz goto out_release_unlock; 59728fb5debcSMike Kravetz 59731c9e8defSMike Kravetz if (vm_shared) { 5974fb3d824dSDavid Hildenbrand page_dup_file_rmap(page, true); 59751c9e8defSMike Kravetz } else { 5976d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 59778fb5debcSMike Kravetz hugepage_add_new_anon_rmap(page, dst_vma, dst_addr); 59781c9e8defSMike Kravetz } 59798fb5debcSMike Kravetz 59806041c691SPeter Xu /* 59816041c691SPeter Xu * For either: (1) CONTINUE on a non-shared VMA, or (2) UFFDIO_COPY 59826041c691SPeter Xu * with wp flag set, don't set pte write bit. 59836041c691SPeter Xu */ 59846041c691SPeter Xu if (wp_copy || (is_continue && !vm_shared)) 5985f6191471SAxel Rasmussen writable = 0; 5986f6191471SAxel Rasmussen else 5987f6191471SAxel Rasmussen writable = dst_vma->vm_flags & VM_WRITE; 5988f6191471SAxel Rasmussen 5989f6191471SAxel Rasmussen _dst_pte = make_huge_pte(dst_vma, page, writable); 59906041c691SPeter Xu /* 59916041c691SPeter Xu * Always mark UFFDIO_COPY page dirty; note that this may not be 59926041c691SPeter Xu * extremely important for hugetlbfs for now since swapping is not 59936041c691SPeter Xu * supported, but we should still be clear in that this page cannot be 59946041c691SPeter Xu * thrown away at will, even if write bit not set. 59956041c691SPeter Xu */ 59968fb5debcSMike Kravetz _dst_pte = huge_pte_mkdirty(_dst_pte); 59978fb5debcSMike Kravetz _dst_pte = pte_mkyoung(_dst_pte); 59988fb5debcSMike Kravetz 59996041c691SPeter Xu if (wp_copy) 60006041c691SPeter Xu _dst_pte = huge_pte_mkuffd_wp(_dst_pte); 60016041c691SPeter Xu 60028fb5debcSMike Kravetz set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); 60038fb5debcSMike Kravetz 60048fb5debcSMike Kravetz (void)huge_ptep_set_access_flags(dst_vma, dst_addr, dst_pte, _dst_pte, 60058fb5debcSMike Kravetz dst_vma->vm_flags & VM_WRITE); 60068fb5debcSMike Kravetz hugetlb_count_add(pages_per_huge_page(h), dst_mm); 60078fb5debcSMike Kravetz 60088fb5debcSMike Kravetz /* No need to invalidate - it was non-present before */ 60098fb5debcSMike Kravetz update_mmu_cache(dst_vma, dst_addr, dst_pte); 60108fb5debcSMike Kravetz 60118fb5debcSMike Kravetz spin_unlock(ptl); 6012f6191471SAxel Rasmussen if (!is_continue) 60138f251a3dSMike Kravetz SetHPageMigratable(page); 6014f6191471SAxel Rasmussen if (vm_shared || is_continue) 60151c9e8defSMike Kravetz unlock_page(page); 60168fb5debcSMike Kravetz ret = 0; 60178fb5debcSMike Kravetz out: 60188fb5debcSMike Kravetz return ret; 60198fb5debcSMike Kravetz out_release_unlock: 60208fb5debcSMike Kravetz spin_unlock(ptl); 6021f6191471SAxel Rasmussen if (vm_shared || is_continue) 60221c9e8defSMike Kravetz unlock_page(page); 60235af10dfdSAndrea Arcangeli out_release_nounlock: 6024cc30042dSMina Almasry if (!page_in_pagecache) 6025846be085SMike Kravetz restore_reserve_on_error(h, dst_vma, dst_addr, page); 60268fb5debcSMike Kravetz put_page(page); 60278fb5debcSMike Kravetz goto out; 60288fb5debcSMike Kravetz } 6029714c1891SAxel Rasmussen #endif /* CONFIG_USERFAULTFD */ 60308fb5debcSMike Kravetz 603182e5d378SJoao Martins static void record_subpages_vmas(struct page *page, struct vm_area_struct *vma, 603282e5d378SJoao Martins int refs, struct page **pages, 603382e5d378SJoao Martins struct vm_area_struct **vmas) 603482e5d378SJoao Martins { 603582e5d378SJoao Martins int nr; 603682e5d378SJoao Martins 603782e5d378SJoao Martins for (nr = 0; nr < refs; nr++) { 603882e5d378SJoao Martins if (likely(pages)) 603982e5d378SJoao Martins pages[nr] = mem_map_offset(page, nr); 604082e5d378SJoao Martins if (vmas) 604182e5d378SJoao Martins vmas[nr] = vma; 604282e5d378SJoao Martins } 604382e5d378SJoao Martins } 604482e5d378SJoao Martins 6045a7f22660SDavid Hildenbrand static inline bool __follow_hugetlb_must_fault(unsigned int flags, pte_t *pte, 6046a7f22660SDavid Hildenbrand bool *unshare) 6047a7f22660SDavid Hildenbrand { 6048a7f22660SDavid Hildenbrand pte_t pteval = huge_ptep_get(pte); 6049a7f22660SDavid Hildenbrand 6050a7f22660SDavid Hildenbrand *unshare = false; 6051a7f22660SDavid Hildenbrand if (is_swap_pte(pteval)) 6052a7f22660SDavid Hildenbrand return true; 6053a7f22660SDavid Hildenbrand if (huge_pte_write(pteval)) 6054a7f22660SDavid Hildenbrand return false; 6055a7f22660SDavid Hildenbrand if (flags & FOLL_WRITE) 6056a7f22660SDavid Hildenbrand return true; 6057a7f22660SDavid Hildenbrand if (gup_must_unshare(flags, pte_page(pteval))) { 6058a7f22660SDavid Hildenbrand *unshare = true; 6059a7f22660SDavid Hildenbrand return true; 6060a7f22660SDavid Hildenbrand } 6061a7f22660SDavid Hildenbrand return false; 6062a7f22660SDavid Hildenbrand } 6063a7f22660SDavid Hildenbrand 606428a35716SMichel Lespinasse long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 606563551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 606628a35716SMichel Lespinasse unsigned long *position, unsigned long *nr_pages, 60674f6da934SPeter Xu long i, unsigned int flags, int *locked) 606863551ae0SDavid Gibson { 6069d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 6070d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 607128a35716SMichel Lespinasse unsigned long remainder = *nr_pages; 6072a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 60730fa5bc40SJoao Martins int err = -EFAULT, refs; 607463551ae0SDavid Gibson 607563551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 607663551ae0SDavid Gibson pte_t *pte; 6077cb900f41SKirill A. Shutemov spinlock_t *ptl = NULL; 6078a7f22660SDavid Hildenbrand bool unshare = false; 60792a15efc9SHugh Dickins int absent; 608063551ae0SDavid Gibson struct page *page; 608163551ae0SDavid Gibson 60824c887265SAdam Litke /* 608302057967SDavid Rientjes * If we have a pending SIGKILL, don't keep faulting pages and 608402057967SDavid Rientjes * potentially allocating memory. 608502057967SDavid Rientjes */ 6086fa45f116SDavidlohr Bueso if (fatal_signal_pending(current)) { 608702057967SDavid Rientjes remainder = 0; 608802057967SDavid Rientjes break; 608902057967SDavid Rientjes } 609002057967SDavid Rientjes 609102057967SDavid Rientjes /* 60924c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 60932a15efc9SHugh Dickins * each hugepage. We have to make sure we get the 60944c887265SAdam Litke * first, for the page indexing below to work. 6095cb900f41SKirill A. Shutemov * 6096cb900f41SKirill A. Shutemov * Note that page table lock is not held when pte is null. 60974c887265SAdam Litke */ 60987868a208SPunit Agrawal pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), 60997868a208SPunit Agrawal huge_page_size(h)); 6100cb900f41SKirill A. Shutemov if (pte) 6101cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, pte); 61022a15efc9SHugh Dickins absent = !pte || huge_pte_none(huge_ptep_get(pte)); 610363551ae0SDavid Gibson 61042a15efc9SHugh Dickins /* 61052a15efc9SHugh Dickins * When coredumping, it suits get_dump_page if we just return 61063ae77f43SHugh Dickins * an error where there's an empty slot with no huge pagecache 61073ae77f43SHugh Dickins * to back it. This way, we avoid allocating a hugepage, and 61083ae77f43SHugh Dickins * the sparse dumpfile avoids allocating disk blocks, but its 61093ae77f43SHugh Dickins * huge holes still show up with zeroes where they need to be. 61102a15efc9SHugh Dickins */ 61113ae77f43SHugh Dickins if (absent && (flags & FOLL_DUMP) && 61123ae77f43SHugh Dickins !hugetlbfs_pagecache_present(h, vma, vaddr)) { 6113cb900f41SKirill A. Shutemov if (pte) 6114cb900f41SKirill A. Shutemov spin_unlock(ptl); 61152a15efc9SHugh Dickins remainder = 0; 61162a15efc9SHugh Dickins break; 61172a15efc9SHugh Dickins } 61182a15efc9SHugh Dickins 61199cc3a5bdSNaoya Horiguchi /* 61209cc3a5bdSNaoya Horiguchi * We need call hugetlb_fault for both hugepages under migration 61219cc3a5bdSNaoya Horiguchi * (in which case hugetlb_fault waits for the migration,) and 61229cc3a5bdSNaoya Horiguchi * hwpoisoned hugepages (in which case we need to prevent the 61239cc3a5bdSNaoya Horiguchi * caller from accessing to them.) In order to do this, we use 61249cc3a5bdSNaoya Horiguchi * here is_swap_pte instead of is_hugetlb_entry_migration and 61259cc3a5bdSNaoya Horiguchi * is_hugetlb_entry_hwpoisoned. This is because it simply covers 61269cc3a5bdSNaoya Horiguchi * both cases, and because we can't follow correct pages 61279cc3a5bdSNaoya Horiguchi * directly from any kind of swap entries. 61289cc3a5bdSNaoya Horiguchi */ 6129a7f22660SDavid Hildenbrand if (absent || 6130a7f22660SDavid Hildenbrand __follow_hugetlb_must_fault(flags, pte, &unshare)) { 61312b740303SSouptick Joarder vm_fault_t ret; 613287ffc118SAndrea Arcangeli unsigned int fault_flags = 0; 61334c887265SAdam Litke 6134cb900f41SKirill A. Shutemov if (pte) 6135cb900f41SKirill A. Shutemov spin_unlock(ptl); 613687ffc118SAndrea Arcangeli if (flags & FOLL_WRITE) 613787ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_WRITE; 6138a7f22660SDavid Hildenbrand else if (unshare) 6139a7f22660SDavid Hildenbrand fault_flags |= FAULT_FLAG_UNSHARE; 61404f6da934SPeter Xu if (locked) 614171335f37SPeter Xu fault_flags |= FAULT_FLAG_ALLOW_RETRY | 614271335f37SPeter Xu FAULT_FLAG_KILLABLE; 614387ffc118SAndrea Arcangeli if (flags & FOLL_NOWAIT) 614487ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_ALLOW_RETRY | 614587ffc118SAndrea Arcangeli FAULT_FLAG_RETRY_NOWAIT; 614687ffc118SAndrea Arcangeli if (flags & FOLL_TRIED) { 61474426e945SPeter Xu /* 61484426e945SPeter Xu * Note: FAULT_FLAG_ALLOW_RETRY and 61494426e945SPeter Xu * FAULT_FLAG_TRIED can co-exist 61504426e945SPeter Xu */ 615187ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_TRIED; 615287ffc118SAndrea Arcangeli } 615387ffc118SAndrea Arcangeli ret = hugetlb_fault(mm, vma, vaddr, fault_flags); 615487ffc118SAndrea Arcangeli if (ret & VM_FAULT_ERROR) { 61552be7cfedSDaniel Jordan err = vm_fault_to_errno(ret, flags); 61561c59827dSHugh Dickins remainder = 0; 61571c59827dSHugh Dickins break; 61581c59827dSHugh Dickins } 615987ffc118SAndrea Arcangeli if (ret & VM_FAULT_RETRY) { 61604f6da934SPeter Xu if (locked && 61611ac25013SAndrea Arcangeli !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) 61624f6da934SPeter Xu *locked = 0; 616387ffc118SAndrea Arcangeli *nr_pages = 0; 616487ffc118SAndrea Arcangeli /* 616587ffc118SAndrea Arcangeli * VM_FAULT_RETRY must not return an 616687ffc118SAndrea Arcangeli * error, it will return zero 616787ffc118SAndrea Arcangeli * instead. 616887ffc118SAndrea Arcangeli * 616987ffc118SAndrea Arcangeli * No need to update "position" as the 617087ffc118SAndrea Arcangeli * caller will not check it after 617187ffc118SAndrea Arcangeli * *nr_pages is set to 0. 617287ffc118SAndrea Arcangeli */ 617387ffc118SAndrea Arcangeli return i; 617487ffc118SAndrea Arcangeli } 617587ffc118SAndrea Arcangeli continue; 617687ffc118SAndrea Arcangeli } 617763551ae0SDavid Gibson 6178a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 61797f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 61808fde12caSLinus Torvalds 6181b6a2619cSDavid Hildenbrand VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) && 6182b6a2619cSDavid Hildenbrand !PageAnonExclusive(page), page); 6183b6a2619cSDavid Hildenbrand 61848fde12caSLinus Torvalds /* 6185acbfb087SZhigang Lu * If subpage information not requested, update counters 6186acbfb087SZhigang Lu * and skip the same_page loop below. 6187acbfb087SZhigang Lu */ 6188acbfb087SZhigang Lu if (!pages && !vmas && !pfn_offset && 6189acbfb087SZhigang Lu (vaddr + huge_page_size(h) < vma->vm_end) && 6190acbfb087SZhigang Lu (remainder >= pages_per_huge_page(h))) { 6191acbfb087SZhigang Lu vaddr += huge_page_size(h); 6192acbfb087SZhigang Lu remainder -= pages_per_huge_page(h); 6193acbfb087SZhigang Lu i += pages_per_huge_page(h); 6194acbfb087SZhigang Lu spin_unlock(ptl); 6195acbfb087SZhigang Lu continue; 6196acbfb087SZhigang Lu } 6197acbfb087SZhigang Lu 6198d08af0a5SJoao Martins /* vaddr may not be aligned to PAGE_SIZE */ 6199d08af0a5SJoao Martins refs = min3(pages_per_huge_page(h) - pfn_offset, remainder, 6200d08af0a5SJoao Martins (vma->vm_end - ALIGN_DOWN(vaddr, PAGE_SIZE)) >> PAGE_SHIFT); 62010fa5bc40SJoao Martins 620282e5d378SJoao Martins if (pages || vmas) 620382e5d378SJoao Martins record_subpages_vmas(mem_map_offset(page, pfn_offset), 620482e5d378SJoao Martins vma, refs, 620582e5d378SJoao Martins likely(pages) ? pages + i : NULL, 620682e5d378SJoao Martins vmas ? vmas + i : NULL); 620763551ae0SDavid Gibson 620882e5d378SJoao Martins if (pages) { 62090fa5bc40SJoao Martins /* 6210822951d8SMatthew Wilcox (Oracle) * try_grab_folio() should always succeed here, 62110fa5bc40SJoao Martins * because: a) we hold the ptl lock, and b) we've just 62120fa5bc40SJoao Martins * checked that the huge page is present in the page 62130fa5bc40SJoao Martins * tables. If the huge page is present, then the tail 62140fa5bc40SJoao Martins * pages must also be present. The ptl prevents the 62150fa5bc40SJoao Martins * head page and tail pages from being rearranged in 62160fa5bc40SJoao Martins * any way. So this page must be available at this 62170fa5bc40SJoao Martins * point, unless the page refcount overflowed: 62180fa5bc40SJoao Martins */ 6219822951d8SMatthew Wilcox (Oracle) if (WARN_ON_ONCE(!try_grab_folio(pages[i], refs, 62200fa5bc40SJoao Martins flags))) { 62210fa5bc40SJoao Martins spin_unlock(ptl); 62220fa5bc40SJoao Martins remainder = 0; 62230fa5bc40SJoao Martins err = -ENOMEM; 62240fa5bc40SJoao Martins break; 62250fa5bc40SJoao Martins } 6226d5d4b0aaSChen, Kenneth W } 622782e5d378SJoao Martins 622882e5d378SJoao Martins vaddr += (refs << PAGE_SHIFT); 622982e5d378SJoao Martins remainder -= refs; 623082e5d378SJoao Martins i += refs; 623182e5d378SJoao Martins 6232cb900f41SKirill A. Shutemov spin_unlock(ptl); 623363551ae0SDavid Gibson } 623428a35716SMichel Lespinasse *nr_pages = remainder; 623587ffc118SAndrea Arcangeli /* 623687ffc118SAndrea Arcangeli * setting position is actually required only if remainder is 623787ffc118SAndrea Arcangeli * not zero but it's faster not to add a "if (remainder)" 623887ffc118SAndrea Arcangeli * branch. 623987ffc118SAndrea Arcangeli */ 624063551ae0SDavid Gibson *position = vaddr; 624163551ae0SDavid Gibson 62422be7cfedSDaniel Jordan return i ? i : err; 624363551ae0SDavid Gibson } 62448f860591SZhang, Yanmin 62457da4d641SPeter Zijlstra unsigned long hugetlb_change_protection(struct vm_area_struct *vma, 62465a90d5a1SPeter Xu unsigned long address, unsigned long end, 62475a90d5a1SPeter Xu pgprot_t newprot, unsigned long cp_flags) 62488f860591SZhang, Yanmin { 62498f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 62508f860591SZhang, Yanmin unsigned long start = address; 62518f860591SZhang, Yanmin pte_t *ptep; 62528f860591SZhang, Yanmin pte_t pte; 6253a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 6254*60dfaad6SPeter Xu unsigned long pages = 0, psize = huge_page_size(h); 6255dff11abeSMike Kravetz bool shared_pmd = false; 6256ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 62575a90d5a1SPeter Xu bool uffd_wp = cp_flags & MM_CP_UFFD_WP; 62585a90d5a1SPeter Xu bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE; 6259dff11abeSMike Kravetz 6260dff11abeSMike Kravetz /* 6261dff11abeSMike Kravetz * In the case of shared PMDs, the area to flush could be beyond 6262ac46d4f3SJérôme Glisse * start/end. Set range.start/range.end to cover the maximum possible 6263dff11abeSMike Kravetz * range if PMD sharing is possible. 6264dff11abeSMike Kravetz */ 62657269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 62667269f999SJérôme Glisse 0, vma, mm, start, end); 6267ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 62688f860591SZhang, Yanmin 62698f860591SZhang, Yanmin BUG_ON(address >= end); 6270ac46d4f3SJérôme Glisse flush_cache_range(vma, range.start, range.end); 62718f860591SZhang, Yanmin 6272ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 627383cde9e8SDavidlohr Bueso i_mmap_lock_write(vma->vm_file->f_mapping); 6274*60dfaad6SPeter Xu for (; address < end; address += psize) { 6275cb900f41SKirill A. Shutemov spinlock_t *ptl; 6276*60dfaad6SPeter Xu ptep = huge_pte_offset(mm, address, psize); 62778f860591SZhang, Yanmin if (!ptep) 62788f860591SZhang, Yanmin continue; 6279cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 628034ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 6281*60dfaad6SPeter Xu /* 6282*60dfaad6SPeter Xu * When uffd-wp is enabled on the vma, unshare 6283*60dfaad6SPeter Xu * shouldn't happen at all. Warn about it if it 6284*60dfaad6SPeter Xu * happened due to some reason. 6285*60dfaad6SPeter Xu */ 6286*60dfaad6SPeter Xu WARN_ON_ONCE(uffd_wp || uffd_wp_resolve); 62877da4d641SPeter Zijlstra pages++; 6288cb900f41SKirill A. Shutemov spin_unlock(ptl); 6289dff11abeSMike Kravetz shared_pmd = true; 629039dde65cSChen, Kenneth W continue; 62917da4d641SPeter Zijlstra } 6292a8bda28dSNaoya Horiguchi pte = huge_ptep_get(ptep); 6293a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { 6294a8bda28dSNaoya Horiguchi spin_unlock(ptl); 6295a8bda28dSNaoya Horiguchi continue; 6296a8bda28dSNaoya Horiguchi } 6297a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(pte))) { 6298a8bda28dSNaoya Horiguchi swp_entry_t entry = pte_to_swp_entry(pte); 62996c287605SDavid Hildenbrand struct page *page = pfn_swap_entry_to_page(entry); 6300a8bda28dSNaoya Horiguchi 63016c287605SDavid Hildenbrand if (!is_readable_migration_entry(entry)) { 6302a8bda28dSNaoya Horiguchi pte_t newpte; 6303a8bda28dSNaoya Horiguchi 63046c287605SDavid Hildenbrand if (PageAnon(page)) 63056c287605SDavid Hildenbrand entry = make_readable_exclusive_migration_entry( 63066c287605SDavid Hildenbrand swp_offset(entry)); 63076c287605SDavid Hildenbrand else 63084dd845b5SAlistair Popple entry = make_readable_migration_entry( 63094dd845b5SAlistair Popple swp_offset(entry)); 6310a8bda28dSNaoya Horiguchi newpte = swp_entry_to_pte(entry); 63115a90d5a1SPeter Xu if (uffd_wp) 63125a90d5a1SPeter Xu newpte = pte_swp_mkuffd_wp(newpte); 63135a90d5a1SPeter Xu else if (uffd_wp_resolve) 63145a90d5a1SPeter Xu newpte = pte_swp_clear_uffd_wp(newpte); 6315e5251fd4SPunit Agrawal set_huge_swap_pte_at(mm, address, ptep, 6316*60dfaad6SPeter Xu newpte, psize); 6317a8bda28dSNaoya Horiguchi pages++; 6318a8bda28dSNaoya Horiguchi } 6319a8bda28dSNaoya Horiguchi spin_unlock(ptl); 6320a8bda28dSNaoya Horiguchi continue; 6321a8bda28dSNaoya Horiguchi } 6322*60dfaad6SPeter Xu if (unlikely(pte_marker_uffd_wp(pte))) { 6323*60dfaad6SPeter Xu /* 6324*60dfaad6SPeter Xu * This is changing a non-present pte into a none pte, 6325*60dfaad6SPeter Xu * no need for huge_ptep_modify_prot_start/commit(). 6326*60dfaad6SPeter Xu */ 6327*60dfaad6SPeter Xu if (uffd_wp_resolve) 6328*60dfaad6SPeter Xu huge_pte_clear(mm, address, ptep, psize); 6329*60dfaad6SPeter Xu } 6330a8bda28dSNaoya Horiguchi if (!huge_pte_none(pte)) { 6331023bdd00SAneesh Kumar K.V pte_t old_pte; 633279c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 6333023bdd00SAneesh Kumar K.V 6334023bdd00SAneesh Kumar K.V old_pte = huge_ptep_modify_prot_start(vma, address, ptep); 633516785bd7SAnshuman Khandual pte = huge_pte_modify(old_pte, newprot); 633679c1c594SChristophe Leroy pte = arch_make_huge_pte(pte, shift, vma->vm_flags); 63375a90d5a1SPeter Xu if (uffd_wp) 63385a90d5a1SPeter Xu pte = huge_pte_mkuffd_wp(huge_pte_wrprotect(pte)); 63395a90d5a1SPeter Xu else if (uffd_wp_resolve) 63405a90d5a1SPeter Xu pte = huge_pte_clear_uffd_wp(pte); 6341023bdd00SAneesh Kumar K.V huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); 63427da4d641SPeter Zijlstra pages++; 6343*60dfaad6SPeter Xu } else { 6344*60dfaad6SPeter Xu /* None pte */ 6345*60dfaad6SPeter Xu if (unlikely(uffd_wp)) 6346*60dfaad6SPeter Xu /* Safe to modify directly (none->non-present). */ 6347*60dfaad6SPeter Xu set_huge_pte_at(mm, address, ptep, 6348*60dfaad6SPeter Xu make_pte_marker(PTE_MARKER_UFFD_WP)); 63498f860591SZhang, Yanmin } 6350cb900f41SKirill A. Shutemov spin_unlock(ptl); 63518f860591SZhang, Yanmin } 6352d833352aSMel Gorman /* 6353c8c06efaSDavidlohr Bueso * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare 6354d833352aSMel Gorman * may have cleared our pud entry and done put_page on the page table: 6355c8c06efaSDavidlohr Bueso * once we release i_mmap_rwsem, another task can do the final put_page 6356dff11abeSMike Kravetz * and that page table be reused and filled with junk. If we actually 6357dff11abeSMike Kravetz * did unshare a page of pmds, flush the range corresponding to the pud. 6358d833352aSMel Gorman */ 6359dff11abeSMike Kravetz if (shared_pmd) 6360ac46d4f3SJérôme Glisse flush_hugetlb_tlb_range(vma, range.start, range.end); 6361dff11abeSMike Kravetz else 63625491ae7bSAneesh Kumar K.V flush_hugetlb_tlb_range(vma, start, end); 63630f10851eSJérôme Glisse /* 63640f10851eSJérôme Glisse * No need to call mmu_notifier_invalidate_range() we are downgrading 63650f10851eSJérôme Glisse * page table protection not changing it to point to a new page. 63660f10851eSJérôme Glisse * 6367ad56b738SMike Rapoport * See Documentation/vm/mmu_notifier.rst 63680f10851eSJérôme Glisse */ 636983cde9e8SDavidlohr Bueso i_mmap_unlock_write(vma->vm_file->f_mapping); 6370ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 63717da4d641SPeter Zijlstra 63727da4d641SPeter Zijlstra return pages << h->order; 63738f860591SZhang, Yanmin } 63748f860591SZhang, Yanmin 637533b8f84aSMike Kravetz /* Return true if reservation was successful, false otherwise. */ 637633b8f84aSMike Kravetz bool hugetlb_reserve_pages(struct inode *inode, 6377a1e78772SMel Gorman long from, long to, 63785a6fe125SMel Gorman struct vm_area_struct *vma, 6379ca16d140SKOSAKI Motohiro vm_flags_t vm_flags) 6380e4e574b7SAdam Litke { 638133b8f84aSMike Kravetz long chg, add = -1; 6382a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 638390481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 63849119a41eSJoonsoo Kim struct resv_map *resv_map; 6385075a61d0SMina Almasry struct hugetlb_cgroup *h_cg = NULL; 63860db9d74eSMina Almasry long gbl_reserve, regions_needed = 0; 6387e4e574b7SAdam Litke 638863489f8eSMike Kravetz /* This should never happen */ 638963489f8eSMike Kravetz if (from > to) { 639063489f8eSMike Kravetz VM_WARN(1, "%s called with a negative range\n", __func__); 639133b8f84aSMike Kravetz return false; 639263489f8eSMike Kravetz } 639363489f8eSMike Kravetz 6394a1e78772SMel Gorman /* 639517c9d12eSMel Gorman * Only apply hugepage reservation if asked. At fault time, an 639617c9d12eSMel Gorman * attempt will be made for VM_NORESERVE to allocate a page 639790481622SDavid Gibson * without using reserves 639817c9d12eSMel Gorman */ 6399ca16d140SKOSAKI Motohiro if (vm_flags & VM_NORESERVE) 640033b8f84aSMike Kravetz return true; 640117c9d12eSMel Gorman 640217c9d12eSMel Gorman /* 6403a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 6404a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 6405a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 6406a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 6407a1e78772SMel Gorman */ 64089119a41eSJoonsoo Kim if (!vma || vma->vm_flags & VM_MAYSHARE) { 6409f27a5136SMike Kravetz /* 6410f27a5136SMike Kravetz * resv_map can not be NULL as hugetlb_reserve_pages is only 6411f27a5136SMike Kravetz * called for inodes for which resv_maps were created (see 6412f27a5136SMike Kravetz * hugetlbfs_get_inode). 6413f27a5136SMike Kravetz */ 64144e35f483SJoonsoo Kim resv_map = inode_resv_map(inode); 64159119a41eSJoonsoo Kim 64160db9d74eSMina Almasry chg = region_chg(resv_map, from, to, ®ions_needed); 64179119a41eSJoonsoo Kim 64189119a41eSJoonsoo Kim } else { 6419e9fe92aeSMina Almasry /* Private mapping. */ 64209119a41eSJoonsoo Kim resv_map = resv_map_alloc(); 64215a6fe125SMel Gorman if (!resv_map) 642233b8f84aSMike Kravetz return false; 64235a6fe125SMel Gorman 642417c9d12eSMel Gorman chg = to - from; 642517c9d12eSMel Gorman 64265a6fe125SMel Gorman set_vma_resv_map(vma, resv_map); 64275a6fe125SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 64285a6fe125SMel Gorman } 64295a6fe125SMel Gorman 643033b8f84aSMike Kravetz if (chg < 0) 6431c50ac050SDave Hansen goto out_err; 643217c9d12eSMel Gorman 643333b8f84aSMike Kravetz if (hugetlb_cgroup_charge_cgroup_rsvd(hstate_index(h), 643433b8f84aSMike Kravetz chg * pages_per_huge_page(h), &h_cg) < 0) 6435075a61d0SMina Almasry goto out_err; 6436075a61d0SMina Almasry 6437075a61d0SMina Almasry if (vma && !(vma->vm_flags & VM_MAYSHARE) && h_cg) { 6438075a61d0SMina Almasry /* For private mappings, the hugetlb_cgroup uncharge info hangs 6439075a61d0SMina Almasry * of the resv_map. 6440075a61d0SMina Almasry */ 6441075a61d0SMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h); 6442075a61d0SMina Almasry } 6443075a61d0SMina Almasry 64441c5ecae3SMike Kravetz /* 64451c5ecae3SMike Kravetz * There must be enough pages in the subpool for the mapping. If 64461c5ecae3SMike Kravetz * the subpool has a minimum size, there may be some global 64471c5ecae3SMike Kravetz * reservations already in place (gbl_reserve). 64481c5ecae3SMike Kravetz */ 64491c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_get_pages(spool, chg); 645033b8f84aSMike Kravetz if (gbl_reserve < 0) 6451075a61d0SMina Almasry goto out_uncharge_cgroup; 645217c9d12eSMel Gorman 645317c9d12eSMel Gorman /* 645417c9d12eSMel Gorman * Check enough hugepages are available for the reservation. 645590481622SDavid Gibson * Hand the pages back to the subpool if there are not 645617c9d12eSMel Gorman */ 645733b8f84aSMike Kravetz if (hugetlb_acct_memory(h, gbl_reserve) < 0) 6458075a61d0SMina Almasry goto out_put_pages; 645917c9d12eSMel Gorman 646017c9d12eSMel Gorman /* 646117c9d12eSMel Gorman * Account for the reservations made. Shared mappings record regions 646217c9d12eSMel Gorman * that have reservations as they are shared by multiple VMAs. 646317c9d12eSMel Gorman * When the last VMA disappears, the region map says how much 646417c9d12eSMel Gorman * the reservation was and the page cache tells how much of 646517c9d12eSMel Gorman * the reservation was consumed. Private mappings are per-VMA and 646617c9d12eSMel Gorman * only the consumed reservations are tracked. When the VMA 646717c9d12eSMel Gorman * disappears, the original reservation is the VMA size and the 646817c9d12eSMel Gorman * consumed reservations are stored in the map. Hence, nothing 646917c9d12eSMel Gorman * else has to be done for private mappings here 647017c9d12eSMel Gorman */ 647133039678SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) { 6472075a61d0SMina Almasry add = region_add(resv_map, from, to, regions_needed, h, h_cg); 647333039678SMike Kravetz 64740db9d74eSMina Almasry if (unlikely(add < 0)) { 64750db9d74eSMina Almasry hugetlb_acct_memory(h, -gbl_reserve); 6476075a61d0SMina Almasry goto out_put_pages; 64770db9d74eSMina Almasry } else if (unlikely(chg > add)) { 647833039678SMike Kravetz /* 647933039678SMike Kravetz * pages in this range were added to the reserve 648033039678SMike Kravetz * map between region_chg and region_add. This 648133039678SMike Kravetz * indicates a race with alloc_huge_page. Adjust 648233039678SMike Kravetz * the subpool and reserve counts modified above 648333039678SMike Kravetz * based on the difference. 648433039678SMike Kravetz */ 648533039678SMike Kravetz long rsv_adjust; 648633039678SMike Kravetz 6487d85aecf2SMiaohe Lin /* 6488d85aecf2SMiaohe Lin * hugetlb_cgroup_uncharge_cgroup_rsvd() will put the 6489d85aecf2SMiaohe Lin * reference to h_cg->css. See comment below for detail. 6490d85aecf2SMiaohe Lin */ 6491075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd( 6492075a61d0SMina Almasry hstate_index(h), 6493075a61d0SMina Almasry (chg - add) * pages_per_huge_page(h), h_cg); 6494075a61d0SMina Almasry 649533039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 649633039678SMike Kravetz chg - add); 649733039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 6498d85aecf2SMiaohe Lin } else if (h_cg) { 6499d85aecf2SMiaohe Lin /* 6500d85aecf2SMiaohe Lin * The file_regions will hold their own reference to 6501d85aecf2SMiaohe Lin * h_cg->css. So we should release the reference held 6502d85aecf2SMiaohe Lin * via hugetlb_cgroup_charge_cgroup_rsvd() when we are 6503d85aecf2SMiaohe Lin * done. 6504d85aecf2SMiaohe Lin */ 6505d85aecf2SMiaohe Lin hugetlb_cgroup_put_rsvd_cgroup(h_cg); 650633039678SMike Kravetz } 650733039678SMike Kravetz } 650833b8f84aSMike Kravetz return true; 650933b8f84aSMike Kravetz 6510075a61d0SMina Almasry out_put_pages: 6511075a61d0SMina Almasry /* put back original number of pages, chg */ 6512075a61d0SMina Almasry (void)hugepage_subpool_put_pages(spool, chg); 6513075a61d0SMina Almasry out_uncharge_cgroup: 6514075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h), 6515075a61d0SMina Almasry chg * pages_per_huge_page(h), h_cg); 6516c50ac050SDave Hansen out_err: 65175e911373SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) 65180db9d74eSMina Almasry /* Only call region_abort if the region_chg succeeded but the 65190db9d74eSMina Almasry * region_add failed or didn't run. 65200db9d74eSMina Almasry */ 65210db9d74eSMina Almasry if (chg >= 0 && add < 0) 65220db9d74eSMina Almasry region_abort(resv_map, from, to, regions_needed); 6523f031dd27SJoonsoo Kim if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 6524f031dd27SJoonsoo Kim kref_put(&resv_map->refs, resv_map_release); 652533b8f84aSMike Kravetz return false; 6526a43a8c39SChen, Kenneth W } 6527a43a8c39SChen, Kenneth W 6528b5cec28dSMike Kravetz long hugetlb_unreserve_pages(struct inode *inode, long start, long end, 6529b5cec28dSMike Kravetz long freed) 6530a43a8c39SChen, Kenneth W { 6531a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 65324e35f483SJoonsoo Kim struct resv_map *resv_map = inode_resv_map(inode); 65339119a41eSJoonsoo Kim long chg = 0; 653490481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 65351c5ecae3SMike Kravetz long gbl_reserve; 653645c682a6SKen Chen 6537f27a5136SMike Kravetz /* 6538f27a5136SMike Kravetz * Since this routine can be called in the evict inode path for all 6539f27a5136SMike Kravetz * hugetlbfs inodes, resv_map could be NULL. 6540f27a5136SMike Kravetz */ 6541b5cec28dSMike Kravetz if (resv_map) { 6542b5cec28dSMike Kravetz chg = region_del(resv_map, start, end); 6543b5cec28dSMike Kravetz /* 6544b5cec28dSMike Kravetz * region_del() can fail in the rare case where a region 6545b5cec28dSMike Kravetz * must be split and another region descriptor can not be 6546b5cec28dSMike Kravetz * allocated. If end == LONG_MAX, it will not fail. 6547b5cec28dSMike Kravetz */ 6548b5cec28dSMike Kravetz if (chg < 0) 6549b5cec28dSMike Kravetz return chg; 6550b5cec28dSMike Kravetz } 6551b5cec28dSMike Kravetz 655245c682a6SKen Chen spin_lock(&inode->i_lock); 6553e4c6f8beSEric Sandeen inode->i_blocks -= (blocks_per_huge_page(h) * freed); 655445c682a6SKen Chen spin_unlock(&inode->i_lock); 655545c682a6SKen Chen 65561c5ecae3SMike Kravetz /* 65571c5ecae3SMike Kravetz * If the subpool has a minimum size, the number of global 65581c5ecae3SMike Kravetz * reservations to be released may be adjusted. 6559dddf31a4SMiaohe Lin * 6560dddf31a4SMiaohe Lin * Note that !resv_map implies freed == 0. So (chg - freed) 6561dddf31a4SMiaohe Lin * won't go negative. 65621c5ecae3SMike Kravetz */ 65631c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed)); 65641c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 6565b5cec28dSMike Kravetz 6566b5cec28dSMike Kravetz return 0; 6567a43a8c39SChen, Kenneth W } 656893f70f90SNaoya Horiguchi 65693212b535SSteve Capper #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 65703212b535SSteve Capper static unsigned long page_table_shareable(struct vm_area_struct *svma, 65713212b535SSteve Capper struct vm_area_struct *vma, 65723212b535SSteve Capper unsigned long addr, pgoff_t idx) 65733212b535SSteve Capper { 65743212b535SSteve Capper unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + 65753212b535SSteve Capper svma->vm_start; 65763212b535SSteve Capper unsigned long sbase = saddr & PUD_MASK; 65773212b535SSteve Capper unsigned long s_end = sbase + PUD_SIZE; 65783212b535SSteve Capper 65793212b535SSteve Capper /* Allow segments to share if only one is marked locked */ 6580de60f5f1SEric B Munson unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; 6581de60f5f1SEric B Munson unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK; 65823212b535SSteve Capper 65833212b535SSteve Capper /* 65843212b535SSteve Capper * match the virtual addresses, permission and the alignment of the 65853212b535SSteve Capper * page table page. 65863212b535SSteve Capper */ 65873212b535SSteve Capper if (pmd_index(addr) != pmd_index(saddr) || 65883212b535SSteve Capper vm_flags != svm_flags || 658907e51edfSMiaohe Lin !range_in_vma(svma, sbase, s_end)) 65903212b535SSteve Capper return 0; 65913212b535SSteve Capper 65923212b535SSteve Capper return saddr; 65933212b535SSteve Capper } 65943212b535SSteve Capper 659531aafb45SNicholas Krause static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr) 65963212b535SSteve Capper { 65973212b535SSteve Capper unsigned long base = addr & PUD_MASK; 65983212b535SSteve Capper unsigned long end = base + PUD_SIZE; 65993212b535SSteve Capper 66003212b535SSteve Capper /* 66013212b535SSteve Capper * check on proper vm_flags and page table alignment 66023212b535SSteve Capper */ 6603017b1660SMike Kravetz if (vma->vm_flags & VM_MAYSHARE && range_in_vma(vma, base, end)) 660431aafb45SNicholas Krause return true; 660531aafb45SNicholas Krause return false; 66063212b535SSteve Capper } 66073212b535SSteve Capper 6608c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 6609c1991e07SPeter Xu { 6610c1991e07SPeter Xu #ifdef CONFIG_USERFAULTFD 6611c1991e07SPeter Xu if (uffd_disable_huge_pmd_share(vma)) 6612c1991e07SPeter Xu return false; 6613c1991e07SPeter Xu #endif 6614c1991e07SPeter Xu return vma_shareable(vma, addr); 6615c1991e07SPeter Xu } 6616c1991e07SPeter Xu 66173212b535SSteve Capper /* 6618017b1660SMike Kravetz * Determine if start,end range within vma could be mapped by shared pmd. 6619017b1660SMike Kravetz * If yes, adjust start and end to cover range associated with possible 6620017b1660SMike Kravetz * shared pmd mappings. 6621017b1660SMike Kravetz */ 6622017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 6623017b1660SMike Kravetz unsigned long *start, unsigned long *end) 6624017b1660SMike Kravetz { 6625a1ba9da8SLi Xinhai unsigned long v_start = ALIGN(vma->vm_start, PUD_SIZE), 6626a1ba9da8SLi Xinhai v_end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 6627017b1660SMike Kravetz 6628a1ba9da8SLi Xinhai /* 6629f0953a1bSIngo Molnar * vma needs to span at least one aligned PUD size, and the range 6630f0953a1bSIngo Molnar * must be at least partially within in. 6631a1ba9da8SLi Xinhai */ 6632a1ba9da8SLi Xinhai if (!(vma->vm_flags & VM_MAYSHARE) || !(v_end > v_start) || 6633a1ba9da8SLi Xinhai (*end <= v_start) || (*start >= v_end)) 6634017b1660SMike Kravetz return; 6635017b1660SMike Kravetz 663675802ca6SPeter Xu /* Extend the range to be PUD aligned for a worst case scenario */ 6637a1ba9da8SLi Xinhai if (*start > v_start) 6638a1ba9da8SLi Xinhai *start = ALIGN_DOWN(*start, PUD_SIZE); 6639017b1660SMike Kravetz 6640a1ba9da8SLi Xinhai if (*end < v_end) 6641a1ba9da8SLi Xinhai *end = ALIGN(*end, PUD_SIZE); 6642017b1660SMike Kravetz } 6643017b1660SMike Kravetz 6644017b1660SMike Kravetz /* 66453212b535SSteve Capper * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() 66463212b535SSteve Capper * and returns the corresponding pte. While this is not necessary for the 66473212b535SSteve Capper * !shared pmd case because we can allocate the pmd later as well, it makes the 6648c0d0381aSMike Kravetz * code much cleaner. 6649c0d0381aSMike Kravetz * 66500bf7b64eSMike Kravetz * This routine must be called with i_mmap_rwsem held in at least read mode if 66510bf7b64eSMike Kravetz * sharing is possible. For hugetlbfs, this prevents removal of any page 66520bf7b64eSMike Kravetz * table entries associated with the address space. This is important as we 66530bf7b64eSMike Kravetz * are setting up sharing based on existing page table entries (mappings). 66543212b535SSteve Capper */ 6655aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 6656aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 66573212b535SSteve Capper { 66583212b535SSteve Capper struct address_space *mapping = vma->vm_file->f_mapping; 66593212b535SSteve Capper pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + 66603212b535SSteve Capper vma->vm_pgoff; 66613212b535SSteve Capper struct vm_area_struct *svma; 66623212b535SSteve Capper unsigned long saddr; 66633212b535SSteve Capper pte_t *spte = NULL; 66643212b535SSteve Capper pte_t *pte; 6665cb900f41SKirill A. Shutemov spinlock_t *ptl; 66663212b535SSteve Capper 66670bf7b64eSMike Kravetz i_mmap_assert_locked(mapping); 66683212b535SSteve Capper vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { 66693212b535SSteve Capper if (svma == vma) 66703212b535SSteve Capper continue; 66713212b535SSteve Capper 66723212b535SSteve Capper saddr = page_table_shareable(svma, vma, addr, idx); 66733212b535SSteve Capper if (saddr) { 66747868a208SPunit Agrawal spte = huge_pte_offset(svma->vm_mm, saddr, 66757868a208SPunit Agrawal vma_mmu_pagesize(svma)); 66763212b535SSteve Capper if (spte) { 66773212b535SSteve Capper get_page(virt_to_page(spte)); 66783212b535SSteve Capper break; 66793212b535SSteve Capper } 66803212b535SSteve Capper } 66813212b535SSteve Capper } 66823212b535SSteve Capper 66833212b535SSteve Capper if (!spte) 66843212b535SSteve Capper goto out; 66853212b535SSteve Capper 66868bea8052SAneesh Kumar K.V ptl = huge_pte_lock(hstate_vma(vma), mm, spte); 6687dc6c9a35SKirill A. Shutemov if (pud_none(*pud)) { 66883212b535SSteve Capper pud_populate(mm, pud, 66893212b535SSteve Capper (pmd_t *)((unsigned long)spte & PAGE_MASK)); 6690c17b1f42SKirill A. Shutemov mm_inc_nr_pmds(mm); 6691dc6c9a35SKirill A. Shutemov } else { 66923212b535SSteve Capper put_page(virt_to_page(spte)); 6693dc6c9a35SKirill A. Shutemov } 6694cb900f41SKirill A. Shutemov spin_unlock(ptl); 66953212b535SSteve Capper out: 66963212b535SSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 66973212b535SSteve Capper return pte; 66983212b535SSteve Capper } 66993212b535SSteve Capper 67003212b535SSteve Capper /* 67013212b535SSteve Capper * unmap huge page backed by shared pte. 67023212b535SSteve Capper * 67033212b535SSteve Capper * Hugetlb pte page is ref counted at the time of mapping. If pte is shared 67043212b535SSteve Capper * indicated by page_count > 1, unmap is achieved by clearing pud and 67053212b535SSteve Capper * decrementing the ref count. If count == 1, the pte page is not shared. 67063212b535SSteve Capper * 6707c0d0381aSMike Kravetz * Called with page table lock held and i_mmap_rwsem held in write mode. 67083212b535SSteve Capper * 67093212b535SSteve Capper * returns: 1 successfully unmapped a shared pte page 67103212b535SSteve Capper * 0 the underlying pte page is not shared, or it is the last user 67113212b535SSteve Capper */ 671234ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 671334ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 67143212b535SSteve Capper { 67153212b535SSteve Capper pgd_t *pgd = pgd_offset(mm, *addr); 6716c2febafcSKirill A. Shutemov p4d_t *p4d = p4d_offset(pgd, *addr); 6717c2febafcSKirill A. Shutemov pud_t *pud = pud_offset(p4d, *addr); 67183212b535SSteve Capper 671934ae204fSMike Kravetz i_mmap_assert_write_locked(vma->vm_file->f_mapping); 67203212b535SSteve Capper BUG_ON(page_count(virt_to_page(ptep)) == 0); 67213212b535SSteve Capper if (page_count(virt_to_page(ptep)) == 1) 67223212b535SSteve Capper return 0; 67233212b535SSteve Capper 67243212b535SSteve Capper pud_clear(pud); 67253212b535SSteve Capper put_page(virt_to_page(ptep)); 6726dc6c9a35SKirill A. Shutemov mm_dec_nr_pmds(mm); 67273212b535SSteve Capper *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE; 67283212b535SSteve Capper return 1; 67293212b535SSteve Capper } 6730c1991e07SPeter Xu 67319e5fc74cSSteve Capper #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 6732aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 6733aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 67349e5fc74cSSteve Capper { 67359e5fc74cSSteve Capper return NULL; 67369e5fc74cSSteve Capper } 6737e81f2d22SZhang Zhen 673834ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 673934ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 6740e81f2d22SZhang Zhen { 6741e81f2d22SZhang Zhen return 0; 6742e81f2d22SZhang Zhen } 6743017b1660SMike Kravetz 6744017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 6745017b1660SMike Kravetz unsigned long *start, unsigned long *end) 6746017b1660SMike Kravetz { 6747017b1660SMike Kravetz } 6748c1991e07SPeter Xu 6749c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 6750c1991e07SPeter Xu { 6751c1991e07SPeter Xu return false; 6752c1991e07SPeter Xu } 67533212b535SSteve Capper #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 67543212b535SSteve Capper 67559e5fc74cSSteve Capper #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB 6756aec44e0fSPeter Xu pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, 67579e5fc74cSSteve Capper unsigned long addr, unsigned long sz) 67589e5fc74cSSteve Capper { 67599e5fc74cSSteve Capper pgd_t *pgd; 6760c2febafcSKirill A. Shutemov p4d_t *p4d; 67619e5fc74cSSteve Capper pud_t *pud; 67629e5fc74cSSteve Capper pte_t *pte = NULL; 67639e5fc74cSSteve Capper 67649e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 6765f4f0a3d8SKirill A. Shutemov p4d = p4d_alloc(mm, pgd, addr); 6766f4f0a3d8SKirill A. Shutemov if (!p4d) 6767f4f0a3d8SKirill A. Shutemov return NULL; 6768c2febafcSKirill A. Shutemov pud = pud_alloc(mm, p4d, addr); 67699e5fc74cSSteve Capper if (pud) { 67709e5fc74cSSteve Capper if (sz == PUD_SIZE) { 67719e5fc74cSSteve Capper pte = (pte_t *)pud; 67729e5fc74cSSteve Capper } else { 67739e5fc74cSSteve Capper BUG_ON(sz != PMD_SIZE); 6774c1991e07SPeter Xu if (want_pmd_share(vma, addr) && pud_none(*pud)) 6775aec44e0fSPeter Xu pte = huge_pmd_share(mm, vma, addr, pud); 67769e5fc74cSSteve Capper else 67779e5fc74cSSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 67789e5fc74cSSteve Capper } 67799e5fc74cSSteve Capper } 67804e666314SMichal Hocko BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte)); 67819e5fc74cSSteve Capper 67829e5fc74cSSteve Capper return pte; 67839e5fc74cSSteve Capper } 67849e5fc74cSSteve Capper 67859b19df29SPunit Agrawal /* 67869b19df29SPunit Agrawal * huge_pte_offset() - Walk the page table to resolve the hugepage 67879b19df29SPunit Agrawal * entry at address @addr 67889b19df29SPunit Agrawal * 67898ac0b81aSLi Xinhai * Return: Pointer to page table entry (PUD or PMD) for 67908ac0b81aSLi Xinhai * address @addr, or NULL if a !p*d_present() entry is encountered and the 67919b19df29SPunit Agrawal * size @sz doesn't match the hugepage size at this level of the page 67929b19df29SPunit Agrawal * table. 67939b19df29SPunit Agrawal */ 67947868a208SPunit Agrawal pte_t *huge_pte_offset(struct mm_struct *mm, 67957868a208SPunit Agrawal unsigned long addr, unsigned long sz) 67969e5fc74cSSteve Capper { 67979e5fc74cSSteve Capper pgd_t *pgd; 6798c2febafcSKirill A. Shutemov p4d_t *p4d; 67998ac0b81aSLi Xinhai pud_t *pud; 68008ac0b81aSLi Xinhai pmd_t *pmd; 68019e5fc74cSSteve Capper 68029e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 6803c2febafcSKirill A. Shutemov if (!pgd_present(*pgd)) 6804c2febafcSKirill A. Shutemov return NULL; 6805c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, addr); 6806c2febafcSKirill A. Shutemov if (!p4d_present(*p4d)) 6807c2febafcSKirill A. Shutemov return NULL; 68089b19df29SPunit Agrawal 6809c2febafcSKirill A. Shutemov pud = pud_offset(p4d, addr); 68108ac0b81aSLi Xinhai if (sz == PUD_SIZE) 68118ac0b81aSLi Xinhai /* must be pud huge, non-present or none */ 68129e5fc74cSSteve Capper return (pte_t *)pud; 68138ac0b81aSLi Xinhai if (!pud_present(*pud)) 68148ac0b81aSLi Xinhai return NULL; 68158ac0b81aSLi Xinhai /* must have a valid entry and size to go further */ 68169b19df29SPunit Agrawal 68179e5fc74cSSteve Capper pmd = pmd_offset(pud, addr); 68188ac0b81aSLi Xinhai /* must be pmd huge, non-present or none */ 68199e5fc74cSSteve Capper return (pte_t *)pmd; 68209e5fc74cSSteve Capper } 68219e5fc74cSSteve Capper 682261f77edaSNaoya Horiguchi #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ 682361f77edaSNaoya Horiguchi 682461f77edaSNaoya Horiguchi /* 682561f77edaSNaoya Horiguchi * These functions are overwritable if your architecture needs its own 682661f77edaSNaoya Horiguchi * behavior. 682761f77edaSNaoya Horiguchi */ 682861f77edaSNaoya Horiguchi struct page * __weak 682961f77edaSNaoya Horiguchi follow_huge_addr(struct mm_struct *mm, unsigned long address, 683061f77edaSNaoya Horiguchi int write) 683161f77edaSNaoya Horiguchi { 683261f77edaSNaoya Horiguchi return ERR_PTR(-EINVAL); 683361f77edaSNaoya Horiguchi } 683461f77edaSNaoya Horiguchi 683561f77edaSNaoya Horiguchi struct page * __weak 68364dc71451SAneesh Kumar K.V follow_huge_pd(struct vm_area_struct *vma, 68374dc71451SAneesh Kumar K.V unsigned long address, hugepd_t hpd, int flags, int pdshift) 68384dc71451SAneesh Kumar K.V { 68394dc71451SAneesh Kumar K.V WARN(1, "hugepd follow called with no support for hugepage directory format\n"); 68404dc71451SAneesh Kumar K.V return NULL; 68414dc71451SAneesh Kumar K.V } 68424dc71451SAneesh Kumar K.V 68434dc71451SAneesh Kumar K.V struct page * __weak 68449e5fc74cSSteve Capper follow_huge_pmd(struct mm_struct *mm, unsigned long address, 6845e66f17ffSNaoya Horiguchi pmd_t *pmd, int flags) 68469e5fc74cSSteve Capper { 6847e66f17ffSNaoya Horiguchi struct page *page = NULL; 6848e66f17ffSNaoya Horiguchi spinlock_t *ptl; 6849c9d398faSNaoya Horiguchi pte_t pte; 68503faa52c0SJohn Hubbard 68518909691bSDavid Hildenbrand /* 68528909691bSDavid Hildenbrand * FOLL_PIN is not supported for follow_page(). Ordinary GUP goes via 68538909691bSDavid Hildenbrand * follow_hugetlb_page(). 68548909691bSDavid Hildenbrand */ 68558909691bSDavid Hildenbrand if (WARN_ON_ONCE(flags & FOLL_PIN)) 68563faa52c0SJohn Hubbard return NULL; 68573faa52c0SJohn Hubbard 6858e66f17ffSNaoya Horiguchi retry: 6859e66f17ffSNaoya Horiguchi ptl = pmd_lockptr(mm, pmd); 6860e66f17ffSNaoya Horiguchi spin_lock(ptl); 6861e66f17ffSNaoya Horiguchi /* 6862e66f17ffSNaoya Horiguchi * make sure that the address range covered by this pmd is not 6863e66f17ffSNaoya Horiguchi * unmapped from other threads. 6864e66f17ffSNaoya Horiguchi */ 6865e66f17ffSNaoya Horiguchi if (!pmd_huge(*pmd)) 6866e66f17ffSNaoya Horiguchi goto out; 6867c9d398faSNaoya Horiguchi pte = huge_ptep_get((pte_t *)pmd); 6868c9d398faSNaoya Horiguchi if (pte_present(pte)) { 686997534127SGerald Schaefer page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT); 68703faa52c0SJohn Hubbard /* 68713faa52c0SJohn Hubbard * try_grab_page() should always succeed here, because: a) we 68723faa52c0SJohn Hubbard * hold the pmd (ptl) lock, and b) we've just checked that the 68733faa52c0SJohn Hubbard * huge pmd (head) page is present in the page tables. The ptl 68743faa52c0SJohn Hubbard * prevents the head page and tail pages from being rearranged 68753faa52c0SJohn Hubbard * in any way. So this page must be available at this point, 68763faa52c0SJohn Hubbard * unless the page refcount overflowed: 68773faa52c0SJohn Hubbard */ 68783faa52c0SJohn Hubbard if (WARN_ON_ONCE(!try_grab_page(page, flags))) { 68793faa52c0SJohn Hubbard page = NULL; 68803faa52c0SJohn Hubbard goto out; 68813faa52c0SJohn Hubbard } 6882e66f17ffSNaoya Horiguchi } else { 6883c9d398faSNaoya Horiguchi if (is_hugetlb_entry_migration(pte)) { 6884e66f17ffSNaoya Horiguchi spin_unlock(ptl); 6885e66f17ffSNaoya Horiguchi __migration_entry_wait(mm, (pte_t *)pmd, ptl); 6886e66f17ffSNaoya Horiguchi goto retry; 6887e66f17ffSNaoya Horiguchi } 6888e66f17ffSNaoya Horiguchi /* 6889e66f17ffSNaoya Horiguchi * hwpoisoned entry is treated as no_page_table in 6890e66f17ffSNaoya Horiguchi * follow_page_mask(). 6891e66f17ffSNaoya Horiguchi */ 6892e66f17ffSNaoya Horiguchi } 6893e66f17ffSNaoya Horiguchi out: 6894e66f17ffSNaoya Horiguchi spin_unlock(ptl); 68959e5fc74cSSteve Capper return page; 68969e5fc74cSSteve Capper } 68979e5fc74cSSteve Capper 689861f77edaSNaoya Horiguchi struct page * __weak 68999e5fc74cSSteve Capper follow_huge_pud(struct mm_struct *mm, unsigned long address, 6900e66f17ffSNaoya Horiguchi pud_t *pud, int flags) 69019e5fc74cSSteve Capper { 69023faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 6903e66f17ffSNaoya Horiguchi return NULL; 69049e5fc74cSSteve Capper 6905e66f17ffSNaoya Horiguchi return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); 69069e5fc74cSSteve Capper } 69079e5fc74cSSteve Capper 6908faaa5b62SAnshuman Khandual struct page * __weak 6909faaa5b62SAnshuman Khandual follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) 6910faaa5b62SAnshuman Khandual { 69113faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 6912faaa5b62SAnshuman Khandual return NULL; 6913faaa5b62SAnshuman Khandual 6914faaa5b62SAnshuman Khandual return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); 6915faaa5b62SAnshuman Khandual } 6916faaa5b62SAnshuman Khandual 691731caf665SNaoya Horiguchi bool isolate_huge_page(struct page *page, struct list_head *list) 691831caf665SNaoya Horiguchi { 6919bcc54222SNaoya Horiguchi bool ret = true; 6920bcc54222SNaoya Horiguchi 6921db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 69228f251a3dSMike Kravetz if (!PageHeadHuge(page) || 69238f251a3dSMike Kravetz !HPageMigratable(page) || 69240eb2df2bSMuchun Song !get_page_unless_zero(page)) { 6925bcc54222SNaoya Horiguchi ret = false; 6926bcc54222SNaoya Horiguchi goto unlock; 6927bcc54222SNaoya Horiguchi } 69288f251a3dSMike Kravetz ClearHPageMigratable(page); 692931caf665SNaoya Horiguchi list_move_tail(&page->lru, list); 6930bcc54222SNaoya Horiguchi unlock: 6931db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 6932bcc54222SNaoya Horiguchi return ret; 693331caf665SNaoya Horiguchi } 693431caf665SNaoya Horiguchi 693525182f05SNaoya Horiguchi int get_hwpoison_huge_page(struct page *page, bool *hugetlb) 693625182f05SNaoya Horiguchi { 693725182f05SNaoya Horiguchi int ret = 0; 693825182f05SNaoya Horiguchi 693925182f05SNaoya Horiguchi *hugetlb = false; 694025182f05SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 694125182f05SNaoya Horiguchi if (PageHeadHuge(page)) { 694225182f05SNaoya Horiguchi *hugetlb = true; 6943b283d983SNaoya Horiguchi if (HPageFreed(page)) 6944b283d983SNaoya Horiguchi ret = 0; 6945b283d983SNaoya Horiguchi else if (HPageMigratable(page)) 694625182f05SNaoya Horiguchi ret = get_page_unless_zero(page); 69470ed950d1SNaoya Horiguchi else 69480ed950d1SNaoya Horiguchi ret = -EBUSY; 694925182f05SNaoya Horiguchi } 695025182f05SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 695125182f05SNaoya Horiguchi return ret; 695225182f05SNaoya Horiguchi } 695325182f05SNaoya Horiguchi 6954405ce051SNaoya Horiguchi int get_huge_page_for_hwpoison(unsigned long pfn, int flags) 6955405ce051SNaoya Horiguchi { 6956405ce051SNaoya Horiguchi int ret; 6957405ce051SNaoya Horiguchi 6958405ce051SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 6959405ce051SNaoya Horiguchi ret = __get_huge_page_for_hwpoison(pfn, flags); 6960405ce051SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 6961405ce051SNaoya Horiguchi return ret; 6962405ce051SNaoya Horiguchi } 6963405ce051SNaoya Horiguchi 696431caf665SNaoya Horiguchi void putback_active_hugepage(struct page *page) 696531caf665SNaoya Horiguchi { 6966db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 69678f251a3dSMike Kravetz SetHPageMigratable(page); 696831caf665SNaoya Horiguchi list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); 6969db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 697031caf665SNaoya Horiguchi put_page(page); 697131caf665SNaoya Horiguchi } 6972ab5ac90aSMichal Hocko 6973ab5ac90aSMichal Hocko void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason) 6974ab5ac90aSMichal Hocko { 6975ab5ac90aSMichal Hocko struct hstate *h = page_hstate(oldpage); 6976ab5ac90aSMichal Hocko 6977ab5ac90aSMichal Hocko hugetlb_cgroup_migrate(oldpage, newpage); 6978ab5ac90aSMichal Hocko set_page_owner_migrate_reason(newpage, reason); 6979ab5ac90aSMichal Hocko 6980ab5ac90aSMichal Hocko /* 6981ab5ac90aSMichal Hocko * transfer temporary state of the new huge page. This is 6982ab5ac90aSMichal Hocko * reverse to other transitions because the newpage is going to 6983ab5ac90aSMichal Hocko * be final while the old one will be freed so it takes over 6984ab5ac90aSMichal Hocko * the temporary status. 6985ab5ac90aSMichal Hocko * 6986ab5ac90aSMichal Hocko * Also note that we have to transfer the per-node surplus state 6987ab5ac90aSMichal Hocko * here as well otherwise the global surplus count will not match 6988ab5ac90aSMichal Hocko * the per-node's. 6989ab5ac90aSMichal Hocko */ 69909157c311SMike Kravetz if (HPageTemporary(newpage)) { 6991ab5ac90aSMichal Hocko int old_nid = page_to_nid(oldpage); 6992ab5ac90aSMichal Hocko int new_nid = page_to_nid(newpage); 6993ab5ac90aSMichal Hocko 69949157c311SMike Kravetz SetHPageTemporary(oldpage); 69959157c311SMike Kravetz ClearHPageTemporary(newpage); 6996ab5ac90aSMichal Hocko 69975af1ab1dSMiaohe Lin /* 69985af1ab1dSMiaohe Lin * There is no need to transfer the per-node surplus state 69995af1ab1dSMiaohe Lin * when we do not cross the node. 70005af1ab1dSMiaohe Lin */ 70015af1ab1dSMiaohe Lin if (new_nid == old_nid) 70025af1ab1dSMiaohe Lin return; 7003db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 7004ab5ac90aSMichal Hocko if (h->surplus_huge_pages_node[old_nid]) { 7005ab5ac90aSMichal Hocko h->surplus_huge_pages_node[old_nid]--; 7006ab5ac90aSMichal Hocko h->surplus_huge_pages_node[new_nid]++; 7007ab5ac90aSMichal Hocko } 7008db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 7009ab5ac90aSMichal Hocko } 7010ab5ac90aSMichal Hocko } 7011cf11e85fSRoman Gushchin 70126dfeaff9SPeter Xu /* 70136dfeaff9SPeter Xu * This function will unconditionally remove all the shared pmd pgtable entries 70146dfeaff9SPeter Xu * within the specific vma for a hugetlbfs memory range. 70156dfeaff9SPeter Xu */ 70166dfeaff9SPeter Xu void hugetlb_unshare_all_pmds(struct vm_area_struct *vma) 70176dfeaff9SPeter Xu { 70186dfeaff9SPeter Xu struct hstate *h = hstate_vma(vma); 70196dfeaff9SPeter Xu unsigned long sz = huge_page_size(h); 70206dfeaff9SPeter Xu struct mm_struct *mm = vma->vm_mm; 70216dfeaff9SPeter Xu struct mmu_notifier_range range; 70226dfeaff9SPeter Xu unsigned long address, start, end; 70236dfeaff9SPeter Xu spinlock_t *ptl; 70246dfeaff9SPeter Xu pte_t *ptep; 70256dfeaff9SPeter Xu 70266dfeaff9SPeter Xu if (!(vma->vm_flags & VM_MAYSHARE)) 70276dfeaff9SPeter Xu return; 70286dfeaff9SPeter Xu 70296dfeaff9SPeter Xu start = ALIGN(vma->vm_start, PUD_SIZE); 70306dfeaff9SPeter Xu end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 70316dfeaff9SPeter Xu 70326dfeaff9SPeter Xu if (start >= end) 70336dfeaff9SPeter Xu return; 70346dfeaff9SPeter Xu 70359c8bbfacSBaolin Wang flush_cache_range(vma, start, end); 70366dfeaff9SPeter Xu /* 70376dfeaff9SPeter Xu * No need to call adjust_range_if_pmd_sharing_possible(), because 70386dfeaff9SPeter Xu * we have already done the PUD_SIZE alignment. 70396dfeaff9SPeter Xu */ 70406dfeaff9SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, 70416dfeaff9SPeter Xu start, end); 70426dfeaff9SPeter Xu mmu_notifier_invalidate_range_start(&range); 70436dfeaff9SPeter Xu i_mmap_lock_write(vma->vm_file->f_mapping); 70446dfeaff9SPeter Xu for (address = start; address < end; address += PUD_SIZE) { 70456dfeaff9SPeter Xu unsigned long tmp = address; 70466dfeaff9SPeter Xu 70476dfeaff9SPeter Xu ptep = huge_pte_offset(mm, address, sz); 70486dfeaff9SPeter Xu if (!ptep) 70496dfeaff9SPeter Xu continue; 70506dfeaff9SPeter Xu ptl = huge_pte_lock(h, mm, ptep); 70516dfeaff9SPeter Xu /* We don't want 'address' to be changed */ 70526dfeaff9SPeter Xu huge_pmd_unshare(mm, vma, &tmp, ptep); 70536dfeaff9SPeter Xu spin_unlock(ptl); 70546dfeaff9SPeter Xu } 70556dfeaff9SPeter Xu flush_hugetlb_tlb_range(vma, start, end); 70566dfeaff9SPeter Xu i_mmap_unlock_write(vma->vm_file->f_mapping); 70576dfeaff9SPeter Xu /* 70586dfeaff9SPeter Xu * No need to call mmu_notifier_invalidate_range(), see 70596dfeaff9SPeter Xu * Documentation/vm/mmu_notifier.rst. 70606dfeaff9SPeter Xu */ 70616dfeaff9SPeter Xu mmu_notifier_invalidate_range_end(&range); 70626dfeaff9SPeter Xu } 70636dfeaff9SPeter Xu 7064cf11e85fSRoman Gushchin #ifdef CONFIG_CMA 7065cf11e85fSRoman Gushchin static bool cma_reserve_called __initdata; 7066cf11e85fSRoman Gushchin 7067cf11e85fSRoman Gushchin static int __init cmdline_parse_hugetlb_cma(char *p) 7068cf11e85fSRoman Gushchin { 706938e719abSBaolin Wang int nid, count = 0; 707038e719abSBaolin Wang unsigned long tmp; 707138e719abSBaolin Wang char *s = p; 707238e719abSBaolin Wang 707338e719abSBaolin Wang while (*s) { 707438e719abSBaolin Wang if (sscanf(s, "%lu%n", &tmp, &count) != 1) 707538e719abSBaolin Wang break; 707638e719abSBaolin Wang 707738e719abSBaolin Wang if (s[count] == ':') { 7078f9317f77SMike Kravetz if (tmp >= MAX_NUMNODES) 707938e719abSBaolin Wang break; 7080f9317f77SMike Kravetz nid = array_index_nospec(tmp, MAX_NUMNODES); 708138e719abSBaolin Wang 708238e719abSBaolin Wang s += count + 1; 708338e719abSBaolin Wang tmp = memparse(s, &s); 708438e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = tmp; 708538e719abSBaolin Wang hugetlb_cma_size += tmp; 708638e719abSBaolin Wang 708738e719abSBaolin Wang /* 708838e719abSBaolin Wang * Skip the separator if have one, otherwise 708938e719abSBaolin Wang * break the parsing. 709038e719abSBaolin Wang */ 709138e719abSBaolin Wang if (*s == ',') 709238e719abSBaolin Wang s++; 709338e719abSBaolin Wang else 709438e719abSBaolin Wang break; 709538e719abSBaolin Wang } else { 7096cf11e85fSRoman Gushchin hugetlb_cma_size = memparse(p, &p); 709738e719abSBaolin Wang break; 709838e719abSBaolin Wang } 709938e719abSBaolin Wang } 710038e719abSBaolin Wang 7101cf11e85fSRoman Gushchin return 0; 7102cf11e85fSRoman Gushchin } 7103cf11e85fSRoman Gushchin 7104cf11e85fSRoman Gushchin early_param("hugetlb_cma", cmdline_parse_hugetlb_cma); 7105cf11e85fSRoman Gushchin 7106cf11e85fSRoman Gushchin void __init hugetlb_cma_reserve(int order) 7107cf11e85fSRoman Gushchin { 7108cf11e85fSRoman Gushchin unsigned long size, reserved, per_node; 710938e719abSBaolin Wang bool node_specific_cma_alloc = false; 7110cf11e85fSRoman Gushchin int nid; 7111cf11e85fSRoman Gushchin 7112cf11e85fSRoman Gushchin cma_reserve_called = true; 7113cf11e85fSRoman Gushchin 7114cf11e85fSRoman Gushchin if (!hugetlb_cma_size) 7115cf11e85fSRoman Gushchin return; 7116cf11e85fSRoman Gushchin 711738e719abSBaolin Wang for (nid = 0; nid < MAX_NUMNODES; nid++) { 711838e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] == 0) 711938e719abSBaolin Wang continue; 712038e719abSBaolin Wang 712130a51400SPeng Liu if (!node_online(nid)) { 712238e719abSBaolin Wang pr_warn("hugetlb_cma: invalid node %d specified\n", nid); 712338e719abSBaolin Wang hugetlb_cma_size -= hugetlb_cma_size_in_node[nid]; 712438e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = 0; 712538e719abSBaolin Wang continue; 712638e719abSBaolin Wang } 712738e719abSBaolin Wang 712838e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] < (PAGE_SIZE << order)) { 712938e719abSBaolin Wang pr_warn("hugetlb_cma: cma area of node %d should be at least %lu MiB\n", 713038e719abSBaolin Wang nid, (PAGE_SIZE << order) / SZ_1M); 713138e719abSBaolin Wang hugetlb_cma_size -= hugetlb_cma_size_in_node[nid]; 713238e719abSBaolin Wang hugetlb_cma_size_in_node[nid] = 0; 713338e719abSBaolin Wang } else { 713438e719abSBaolin Wang node_specific_cma_alloc = true; 713538e719abSBaolin Wang } 713638e719abSBaolin Wang } 713738e719abSBaolin Wang 713838e719abSBaolin Wang /* Validate the CMA size again in case some invalid nodes specified. */ 713938e719abSBaolin Wang if (!hugetlb_cma_size) 714038e719abSBaolin Wang return; 714138e719abSBaolin Wang 7142cf11e85fSRoman Gushchin if (hugetlb_cma_size < (PAGE_SIZE << order)) { 7143cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n", 7144cf11e85fSRoman Gushchin (PAGE_SIZE << order) / SZ_1M); 7145a01f4390SMike Kravetz hugetlb_cma_size = 0; 7146cf11e85fSRoman Gushchin return; 7147cf11e85fSRoman Gushchin } 7148cf11e85fSRoman Gushchin 714938e719abSBaolin Wang if (!node_specific_cma_alloc) { 7150cf11e85fSRoman Gushchin /* 7151cf11e85fSRoman Gushchin * If 3 GB area is requested on a machine with 4 numa nodes, 7152cf11e85fSRoman Gushchin * let's allocate 1 GB on first three nodes and ignore the last one. 7153cf11e85fSRoman Gushchin */ 7154cf11e85fSRoman Gushchin per_node = DIV_ROUND_UP(hugetlb_cma_size, nr_online_nodes); 7155cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n", 7156cf11e85fSRoman Gushchin hugetlb_cma_size / SZ_1M, per_node / SZ_1M); 715738e719abSBaolin Wang } 7158cf11e85fSRoman Gushchin 7159cf11e85fSRoman Gushchin reserved = 0; 716030a51400SPeng Liu for_each_online_node(nid) { 7161cf11e85fSRoman Gushchin int res; 71622281f797SBarry Song char name[CMA_MAX_NAME]; 7163cf11e85fSRoman Gushchin 716438e719abSBaolin Wang if (node_specific_cma_alloc) { 716538e719abSBaolin Wang if (hugetlb_cma_size_in_node[nid] == 0) 716638e719abSBaolin Wang continue; 716738e719abSBaolin Wang 716838e719abSBaolin Wang size = hugetlb_cma_size_in_node[nid]; 716938e719abSBaolin Wang } else { 7170cf11e85fSRoman Gushchin size = min(per_node, hugetlb_cma_size - reserved); 717138e719abSBaolin Wang } 717238e719abSBaolin Wang 7173cf11e85fSRoman Gushchin size = round_up(size, PAGE_SIZE << order); 7174cf11e85fSRoman Gushchin 71752281f797SBarry Song snprintf(name, sizeof(name), "hugetlb%d", nid); 7176a01f4390SMike Kravetz /* 7177a01f4390SMike Kravetz * Note that 'order per bit' is based on smallest size that 7178a01f4390SMike Kravetz * may be returned to CMA allocator in the case of 7179a01f4390SMike Kravetz * huge page demotion. 7180a01f4390SMike Kravetz */ 7181a01f4390SMike Kravetz res = cma_declare_contiguous_nid(0, size, 0, 7182a01f4390SMike Kravetz PAGE_SIZE << HUGETLB_PAGE_ORDER, 718329d0f41dSBarry Song 0, false, name, 7184cf11e85fSRoman Gushchin &hugetlb_cma[nid], nid); 7185cf11e85fSRoman Gushchin if (res) { 7186cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: reservation failed: err %d, node %d", 7187cf11e85fSRoman Gushchin res, nid); 7188cf11e85fSRoman Gushchin continue; 7189cf11e85fSRoman Gushchin } 7190cf11e85fSRoman Gushchin 7191cf11e85fSRoman Gushchin reserved += size; 7192cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserved %lu MiB on node %d\n", 7193cf11e85fSRoman Gushchin size / SZ_1M, nid); 7194cf11e85fSRoman Gushchin 7195cf11e85fSRoman Gushchin if (reserved >= hugetlb_cma_size) 7196cf11e85fSRoman Gushchin break; 7197cf11e85fSRoman Gushchin } 7198a01f4390SMike Kravetz 7199a01f4390SMike Kravetz if (!reserved) 7200a01f4390SMike Kravetz /* 7201a01f4390SMike Kravetz * hugetlb_cma_size is used to determine if allocations from 7202a01f4390SMike Kravetz * cma are possible. Set to zero if no cma regions are set up. 7203a01f4390SMike Kravetz */ 7204a01f4390SMike Kravetz hugetlb_cma_size = 0; 7205cf11e85fSRoman Gushchin } 7206cf11e85fSRoman Gushchin 7207cf11e85fSRoman Gushchin void __init hugetlb_cma_check(void) 7208cf11e85fSRoman Gushchin { 7209cf11e85fSRoman Gushchin if (!hugetlb_cma_size || cma_reserve_called) 7210cf11e85fSRoman Gushchin return; 7211cf11e85fSRoman Gushchin 7212cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: the option isn't supported by current arch\n"); 7213cf11e85fSRoman Gushchin } 7214cf11e85fSRoman Gushchin 7215cf11e85fSRoman Gushchin #endif /* CONFIG_CMA */ 7216