1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * Generic hugetlb support. 46d49e352SNadia Yvette Chambers * (C) Nadia Yvette Chambers, April 2004 51da177e4SLinus Torvalds */ 61da177e4SLinus Torvalds #include <linux/list.h> 71da177e4SLinus Torvalds #include <linux/init.h> 81da177e4SLinus Torvalds #include <linux/mm.h> 9e1759c21SAlexey Dobriyan #include <linux/seq_file.h> 101da177e4SLinus Torvalds #include <linux/sysctl.h> 111da177e4SLinus Torvalds #include <linux/highmem.h> 12cddb8a5cSAndrea Arcangeli #include <linux/mmu_notifier.h> 131da177e4SLinus Torvalds #include <linux/nodemask.h> 1463551ae0SDavid Gibson #include <linux/pagemap.h> 155da7ca86SChristoph Lameter #include <linux/mempolicy.h> 163b32123dSGideon Israel Dsouza #include <linux/compiler.h> 17aea47ff3SChristoph Lameter #include <linux/cpuset.h> 183935baa9SDavid Gibson #include <linux/mutex.h> 1997ad1087SMike Rapoport #include <linux/memblock.h> 20a3437870SNishanth Aravamudan #include <linux/sysfs.h> 215a0e3ad6STejun Heo #include <linux/slab.h> 22bbe88753SJoonsoo Kim #include <linux/sched/mm.h> 2363489f8eSMike Kravetz #include <linux/mmdebug.h> 24174cd4b1SIngo Molnar #include <linux/sched/signal.h> 250fe6e20bSNaoya Horiguchi #include <linux/rmap.h> 26c6247f72SMatthew Wilcox #include <linux/string_helpers.h> 27fd6a03edSNaoya Horiguchi #include <linux/swap.h> 28fd6a03edSNaoya Horiguchi #include <linux/swapops.h> 298382d914SDavidlohr Bueso #include <linux/jhash.h> 3098fa15f3SAnshuman Khandual #include <linux/numa.h> 31c77c0a8aSWaiman Long #include <linux/llist.h> 32cf11e85fSRoman Gushchin #include <linux/cma.h> 338cc5fcbbSMina Almasry #include <linux/migrate.h> 34d6606683SLinus Torvalds 3563551ae0SDavid Gibson #include <asm/page.h> 36ca15ca40SMike Rapoport #include <asm/pgalloc.h> 3724669e58SAneesh Kumar K.V #include <asm/tlb.h> 3863551ae0SDavid Gibson 3924669e58SAneesh Kumar K.V #include <linux/io.h> 4063551ae0SDavid Gibson #include <linux/hugetlb.h> 419dd540e2SAneesh Kumar K.V #include <linux/hugetlb_cgroup.h> 429a305230SLee Schermerhorn #include <linux/node.h> 43ab5ac90aSMichal Hocko #include <linux/page_owner.h> 447835e98bSNick Piggin #include "internal.h" 45f41f2ed4SMuchun Song #include "hugetlb_vmemmap.h" 461da177e4SLinus Torvalds 47c3f38a38SAneesh Kumar K.V int hugetlb_max_hstate __read_mostly; 48e5ff2159SAndi Kleen unsigned int default_hstate_idx; 49e5ff2159SAndi Kleen struct hstate hstates[HUGE_MAX_HSTATE]; 50cf11e85fSRoman Gushchin 51dbda8feaSBarry Song #ifdef CONFIG_CMA 52cf11e85fSRoman Gushchin static struct cma *hugetlb_cma[MAX_NUMNODES]; 53dbda8feaSBarry Song #endif 54dbda8feaSBarry Song static unsigned long hugetlb_cma_size __initdata; 55cf11e85fSRoman Gushchin 56641844f5SNaoya Horiguchi /* 57641844f5SNaoya Horiguchi * Minimum page order among possible hugepage sizes, set to a proper value 58641844f5SNaoya Horiguchi * at boot time. 59641844f5SNaoya Horiguchi */ 60641844f5SNaoya Horiguchi static unsigned int minimum_order __read_mostly = UINT_MAX; 61e5ff2159SAndi Kleen 6253ba51d2SJon Tollefson __initdata LIST_HEAD(huge_boot_pages); 6353ba51d2SJon Tollefson 64e5ff2159SAndi Kleen /* for command line parsing */ 65e5ff2159SAndi Kleen static struct hstate * __initdata parsed_hstate; 66e5ff2159SAndi Kleen static unsigned long __initdata default_hstate_max_huge_pages; 679fee021dSVaishali Thakkar static bool __initdata parsed_valid_hugepagesz = true; 68282f4214SMike Kravetz static bool __initdata parsed_default_hugepagesz; 69e5ff2159SAndi Kleen 703935baa9SDavid Gibson /* 7131caf665SNaoya Horiguchi * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, 7231caf665SNaoya Horiguchi * free_huge_pages, and surplus_huge_pages. 733935baa9SDavid Gibson */ 74c3f38a38SAneesh Kumar K.V DEFINE_SPINLOCK(hugetlb_lock); 750bd0f9fbSEric Paris 768382d914SDavidlohr Bueso /* 778382d914SDavidlohr Bueso * Serializes faults on the same logical page. This is used to 788382d914SDavidlohr Bueso * prevent spurious OOMs when the hugepage pool is fully utilized. 798382d914SDavidlohr Bueso */ 808382d914SDavidlohr Bueso static int num_fault_mutexes; 81c672c7f2SMike Kravetz struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp; 828382d914SDavidlohr Bueso 837ca02d0aSMike Kravetz /* Forward declaration */ 847ca02d0aSMike Kravetz static int hugetlb_acct_memory(struct hstate *h, long delta); 857ca02d0aSMike Kravetz 861d88433bSMiaohe Lin static inline bool subpool_is_free(struct hugepage_subpool *spool) 871d88433bSMiaohe Lin { 881d88433bSMiaohe Lin if (spool->count) 891d88433bSMiaohe Lin return false; 901d88433bSMiaohe Lin if (spool->max_hpages != -1) 911d88433bSMiaohe Lin return spool->used_hpages == 0; 921d88433bSMiaohe Lin if (spool->min_hpages != -1) 931d88433bSMiaohe Lin return spool->rsv_hpages == spool->min_hpages; 941d88433bSMiaohe Lin 951d88433bSMiaohe Lin return true; 961d88433bSMiaohe Lin } 971d88433bSMiaohe Lin 98db71ef79SMike Kravetz static inline void unlock_or_release_subpool(struct hugepage_subpool *spool, 99db71ef79SMike Kravetz unsigned long irq_flags) 10090481622SDavid Gibson { 101db71ef79SMike Kravetz spin_unlock_irqrestore(&spool->lock, irq_flags); 10290481622SDavid Gibson 10390481622SDavid Gibson /* If no pages are used, and no other handles to the subpool 1047c8de358SEthon Paul * remain, give up any reservations based on minimum size and 1057ca02d0aSMike Kravetz * free the subpool */ 1061d88433bSMiaohe Lin if (subpool_is_free(spool)) { 1077ca02d0aSMike Kravetz if (spool->min_hpages != -1) 1087ca02d0aSMike Kravetz hugetlb_acct_memory(spool->hstate, 1097ca02d0aSMike Kravetz -spool->min_hpages); 11090481622SDavid Gibson kfree(spool); 11190481622SDavid Gibson } 1127ca02d0aSMike Kravetz } 11390481622SDavid Gibson 1147ca02d0aSMike Kravetz struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, 1157ca02d0aSMike Kravetz long min_hpages) 11690481622SDavid Gibson { 11790481622SDavid Gibson struct hugepage_subpool *spool; 11890481622SDavid Gibson 119c6a91820SMike Kravetz spool = kzalloc(sizeof(*spool), GFP_KERNEL); 12090481622SDavid Gibson if (!spool) 12190481622SDavid Gibson return NULL; 12290481622SDavid Gibson 12390481622SDavid Gibson spin_lock_init(&spool->lock); 12490481622SDavid Gibson spool->count = 1; 1257ca02d0aSMike Kravetz spool->max_hpages = max_hpages; 1267ca02d0aSMike Kravetz spool->hstate = h; 1277ca02d0aSMike Kravetz spool->min_hpages = min_hpages; 1287ca02d0aSMike Kravetz 1297ca02d0aSMike Kravetz if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { 1307ca02d0aSMike Kravetz kfree(spool); 1317ca02d0aSMike Kravetz return NULL; 1327ca02d0aSMike Kravetz } 1337ca02d0aSMike Kravetz spool->rsv_hpages = min_hpages; 13490481622SDavid Gibson 13590481622SDavid Gibson return spool; 13690481622SDavid Gibson } 13790481622SDavid Gibson 13890481622SDavid Gibson void hugepage_put_subpool(struct hugepage_subpool *spool) 13990481622SDavid Gibson { 140db71ef79SMike Kravetz unsigned long flags; 141db71ef79SMike Kravetz 142db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 14390481622SDavid Gibson BUG_ON(!spool->count); 14490481622SDavid Gibson spool->count--; 145db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 14690481622SDavid Gibson } 14790481622SDavid Gibson 1481c5ecae3SMike Kravetz /* 1491c5ecae3SMike Kravetz * Subpool accounting for allocating and reserving pages. 1501c5ecae3SMike Kravetz * Return -ENOMEM if there are not enough resources to satisfy the 1519e7ee400SRandy Dunlap * request. Otherwise, return the number of pages by which the 1521c5ecae3SMike Kravetz * global pools must be adjusted (upward). The returned value may 1531c5ecae3SMike Kravetz * only be different than the passed value (delta) in the case where 1547c8de358SEthon Paul * a subpool minimum size must be maintained. 1551c5ecae3SMike Kravetz */ 1561c5ecae3SMike Kravetz static long hugepage_subpool_get_pages(struct hugepage_subpool *spool, 15790481622SDavid Gibson long delta) 15890481622SDavid Gibson { 1591c5ecae3SMike Kravetz long ret = delta; 16090481622SDavid Gibson 16190481622SDavid Gibson if (!spool) 1621c5ecae3SMike Kravetz return ret; 16390481622SDavid Gibson 164db71ef79SMike Kravetz spin_lock_irq(&spool->lock); 16590481622SDavid Gibson 1661c5ecae3SMike Kravetz if (spool->max_hpages != -1) { /* maximum size accounting */ 1671c5ecae3SMike Kravetz if ((spool->used_hpages + delta) <= spool->max_hpages) 1681c5ecae3SMike Kravetz spool->used_hpages += delta; 1691c5ecae3SMike Kravetz else { 1701c5ecae3SMike Kravetz ret = -ENOMEM; 1711c5ecae3SMike Kravetz goto unlock_ret; 1721c5ecae3SMike Kravetz } 1731c5ecae3SMike Kravetz } 1741c5ecae3SMike Kravetz 17509a95e29SMike Kravetz /* minimum size accounting */ 17609a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->rsv_hpages) { 1771c5ecae3SMike Kravetz if (delta > spool->rsv_hpages) { 1781c5ecae3SMike Kravetz /* 1791c5ecae3SMike Kravetz * Asking for more reserves than those already taken on 1801c5ecae3SMike Kravetz * behalf of subpool. Return difference. 1811c5ecae3SMike Kravetz */ 1821c5ecae3SMike Kravetz ret = delta - spool->rsv_hpages; 1831c5ecae3SMike Kravetz spool->rsv_hpages = 0; 1841c5ecae3SMike Kravetz } else { 1851c5ecae3SMike Kravetz ret = 0; /* reserves already accounted for */ 1861c5ecae3SMike Kravetz spool->rsv_hpages -= delta; 1871c5ecae3SMike Kravetz } 1881c5ecae3SMike Kravetz } 1891c5ecae3SMike Kravetz 1901c5ecae3SMike Kravetz unlock_ret: 191db71ef79SMike Kravetz spin_unlock_irq(&spool->lock); 19290481622SDavid Gibson return ret; 19390481622SDavid Gibson } 19490481622SDavid Gibson 1951c5ecae3SMike Kravetz /* 1961c5ecae3SMike Kravetz * Subpool accounting for freeing and unreserving pages. 1971c5ecae3SMike Kravetz * Return the number of global page reservations that must be dropped. 1981c5ecae3SMike Kravetz * The return value may only be different than the passed value (delta) 1991c5ecae3SMike Kravetz * in the case where a subpool minimum size must be maintained. 2001c5ecae3SMike Kravetz */ 2011c5ecae3SMike Kravetz static long hugepage_subpool_put_pages(struct hugepage_subpool *spool, 20290481622SDavid Gibson long delta) 20390481622SDavid Gibson { 2041c5ecae3SMike Kravetz long ret = delta; 205db71ef79SMike Kravetz unsigned long flags; 2061c5ecae3SMike Kravetz 20790481622SDavid Gibson if (!spool) 2081c5ecae3SMike Kravetz return delta; 20990481622SDavid Gibson 210db71ef79SMike Kravetz spin_lock_irqsave(&spool->lock, flags); 2111c5ecae3SMike Kravetz 2121c5ecae3SMike Kravetz if (spool->max_hpages != -1) /* maximum size accounting */ 21390481622SDavid Gibson spool->used_hpages -= delta; 2141c5ecae3SMike Kravetz 21509a95e29SMike Kravetz /* minimum size accounting */ 21609a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { 2171c5ecae3SMike Kravetz if (spool->rsv_hpages + delta <= spool->min_hpages) 2181c5ecae3SMike Kravetz ret = 0; 2191c5ecae3SMike Kravetz else 2201c5ecae3SMike Kravetz ret = spool->rsv_hpages + delta - spool->min_hpages; 2211c5ecae3SMike Kravetz 2221c5ecae3SMike Kravetz spool->rsv_hpages += delta; 2231c5ecae3SMike Kravetz if (spool->rsv_hpages > spool->min_hpages) 2241c5ecae3SMike Kravetz spool->rsv_hpages = spool->min_hpages; 2251c5ecae3SMike Kravetz } 2261c5ecae3SMike Kravetz 2271c5ecae3SMike Kravetz /* 2281c5ecae3SMike Kravetz * If hugetlbfs_put_super couldn't free spool due to an outstanding 2291c5ecae3SMike Kravetz * quota reference, free it now. 2301c5ecae3SMike Kravetz */ 231db71ef79SMike Kravetz unlock_or_release_subpool(spool, flags); 2321c5ecae3SMike Kravetz 2331c5ecae3SMike Kravetz return ret; 23490481622SDavid Gibson } 23590481622SDavid Gibson 23690481622SDavid Gibson static inline struct hugepage_subpool *subpool_inode(struct inode *inode) 23790481622SDavid Gibson { 23890481622SDavid Gibson return HUGETLBFS_SB(inode->i_sb)->spool; 23990481622SDavid Gibson } 24090481622SDavid Gibson 24190481622SDavid Gibson static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) 24290481622SDavid Gibson { 243496ad9aaSAl Viro return subpool_inode(file_inode(vma->vm_file)); 24490481622SDavid Gibson } 24590481622SDavid Gibson 2460db9d74eSMina Almasry /* Helper that removes a struct file_region from the resv_map cache and returns 2470db9d74eSMina Almasry * it for use. 2480db9d74eSMina Almasry */ 2490db9d74eSMina Almasry static struct file_region * 2500db9d74eSMina Almasry get_file_region_entry_from_cache(struct resv_map *resv, long from, long to) 2510db9d74eSMina Almasry { 2520db9d74eSMina Almasry struct file_region *nrg = NULL; 2530db9d74eSMina Almasry 2540db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count <= 0); 2550db9d74eSMina Almasry 2560db9d74eSMina Almasry resv->region_cache_count--; 2570db9d74eSMina Almasry nrg = list_first_entry(&resv->region_cache, struct file_region, link); 2580db9d74eSMina Almasry list_del(&nrg->link); 2590db9d74eSMina Almasry 2600db9d74eSMina Almasry nrg->from = from; 2610db9d74eSMina Almasry nrg->to = to; 2620db9d74eSMina Almasry 2630db9d74eSMina Almasry return nrg; 2640db9d74eSMina Almasry } 2650db9d74eSMina Almasry 266075a61d0SMina Almasry static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg, 267075a61d0SMina Almasry struct file_region *rg) 268075a61d0SMina Almasry { 269075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 270075a61d0SMina Almasry nrg->reservation_counter = rg->reservation_counter; 271075a61d0SMina Almasry nrg->css = rg->css; 272075a61d0SMina Almasry if (rg->css) 273075a61d0SMina Almasry css_get(rg->css); 274075a61d0SMina Almasry #endif 275075a61d0SMina Almasry } 276075a61d0SMina Almasry 277075a61d0SMina Almasry /* Helper that records hugetlb_cgroup uncharge info. */ 278075a61d0SMina Almasry static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg, 279075a61d0SMina Almasry struct hstate *h, 280075a61d0SMina Almasry struct resv_map *resv, 281075a61d0SMina Almasry struct file_region *nrg) 282075a61d0SMina Almasry { 283075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 284075a61d0SMina Almasry if (h_cg) { 285075a61d0SMina Almasry nrg->reservation_counter = 286075a61d0SMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 287075a61d0SMina Almasry nrg->css = &h_cg->css; 288d85aecf2SMiaohe Lin /* 289d85aecf2SMiaohe Lin * The caller will hold exactly one h_cg->css reference for the 290d85aecf2SMiaohe Lin * whole contiguous reservation region. But this area might be 291d85aecf2SMiaohe Lin * scattered when there are already some file_regions reside in 292d85aecf2SMiaohe Lin * it. As a result, many file_regions may share only one css 293d85aecf2SMiaohe Lin * reference. In order to ensure that one file_region must hold 294d85aecf2SMiaohe Lin * exactly one h_cg->css reference, we should do css_get for 295d85aecf2SMiaohe Lin * each file_region and leave the reference held by caller 296d85aecf2SMiaohe Lin * untouched. 297d85aecf2SMiaohe Lin */ 298d85aecf2SMiaohe Lin css_get(&h_cg->css); 299075a61d0SMina Almasry if (!resv->pages_per_hpage) 300075a61d0SMina Almasry resv->pages_per_hpage = pages_per_huge_page(h); 301075a61d0SMina Almasry /* pages_per_hpage should be the same for all entries in 302075a61d0SMina Almasry * a resv_map. 303075a61d0SMina Almasry */ 304075a61d0SMina Almasry VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h)); 305075a61d0SMina Almasry } else { 306075a61d0SMina Almasry nrg->reservation_counter = NULL; 307075a61d0SMina Almasry nrg->css = NULL; 308075a61d0SMina Almasry } 309075a61d0SMina Almasry #endif 310075a61d0SMina Almasry } 311075a61d0SMina Almasry 312d85aecf2SMiaohe Lin static void put_uncharge_info(struct file_region *rg) 313d85aecf2SMiaohe Lin { 314d85aecf2SMiaohe Lin #ifdef CONFIG_CGROUP_HUGETLB 315d85aecf2SMiaohe Lin if (rg->css) 316d85aecf2SMiaohe Lin css_put(rg->css); 317d85aecf2SMiaohe Lin #endif 318d85aecf2SMiaohe Lin } 319d85aecf2SMiaohe Lin 320a9b3f867SMina Almasry static bool has_same_uncharge_info(struct file_region *rg, 321a9b3f867SMina Almasry struct file_region *org) 322a9b3f867SMina Almasry { 323a9b3f867SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 324a9b3f867SMina Almasry return rg && org && 325a9b3f867SMina Almasry rg->reservation_counter == org->reservation_counter && 326a9b3f867SMina Almasry rg->css == org->css; 327a9b3f867SMina Almasry 328a9b3f867SMina Almasry #else 329a9b3f867SMina Almasry return true; 330a9b3f867SMina Almasry #endif 331a9b3f867SMina Almasry } 332a9b3f867SMina Almasry 333a9b3f867SMina Almasry static void coalesce_file_region(struct resv_map *resv, struct file_region *rg) 334a9b3f867SMina Almasry { 335a9b3f867SMina Almasry struct file_region *nrg = NULL, *prg = NULL; 336a9b3f867SMina Almasry 337a9b3f867SMina Almasry prg = list_prev_entry(rg, link); 338a9b3f867SMina Almasry if (&prg->link != &resv->regions && prg->to == rg->from && 339a9b3f867SMina Almasry has_same_uncharge_info(prg, rg)) { 340a9b3f867SMina Almasry prg->to = rg->to; 341a9b3f867SMina Almasry 342a9b3f867SMina Almasry list_del(&rg->link); 343d85aecf2SMiaohe Lin put_uncharge_info(rg); 344a9b3f867SMina Almasry kfree(rg); 345a9b3f867SMina Almasry 3467db5e7b6SWei Yang rg = prg; 347a9b3f867SMina Almasry } 348a9b3f867SMina Almasry 349a9b3f867SMina Almasry nrg = list_next_entry(rg, link); 350a9b3f867SMina Almasry if (&nrg->link != &resv->regions && nrg->from == rg->to && 351a9b3f867SMina Almasry has_same_uncharge_info(nrg, rg)) { 352a9b3f867SMina Almasry nrg->from = rg->from; 353a9b3f867SMina Almasry 354a9b3f867SMina Almasry list_del(&rg->link); 355d85aecf2SMiaohe Lin put_uncharge_info(rg); 356a9b3f867SMina Almasry kfree(rg); 357a9b3f867SMina Almasry } 358a9b3f867SMina Almasry } 359a9b3f867SMina Almasry 3602103cf9cSPeter Xu static inline long 3612103cf9cSPeter Xu hugetlb_resv_map_add(struct resv_map *map, struct file_region *rg, long from, 3622103cf9cSPeter Xu long to, struct hstate *h, struct hugetlb_cgroup *cg, 3632103cf9cSPeter Xu long *regions_needed) 3642103cf9cSPeter Xu { 3652103cf9cSPeter Xu struct file_region *nrg; 3662103cf9cSPeter Xu 3672103cf9cSPeter Xu if (!regions_needed) { 3682103cf9cSPeter Xu nrg = get_file_region_entry_from_cache(map, from, to); 3692103cf9cSPeter Xu record_hugetlb_cgroup_uncharge_info(cg, h, map, nrg); 3702103cf9cSPeter Xu list_add(&nrg->link, rg->link.prev); 3712103cf9cSPeter Xu coalesce_file_region(map, nrg); 3722103cf9cSPeter Xu } else 3732103cf9cSPeter Xu *regions_needed += 1; 3742103cf9cSPeter Xu 3752103cf9cSPeter Xu return to - from; 3762103cf9cSPeter Xu } 3772103cf9cSPeter Xu 378972a3da3SWei Yang /* 379972a3da3SWei Yang * Must be called with resv->lock held. 380972a3da3SWei Yang * 381972a3da3SWei Yang * Calling this with regions_needed != NULL will count the number of pages 382972a3da3SWei Yang * to be added but will not modify the linked list. And regions_needed will 383972a3da3SWei Yang * indicate the number of file_regions needed in the cache to carry out to add 384972a3da3SWei Yang * the regions for this range. 385d75c6af9SMina Almasry */ 386d75c6af9SMina Almasry static long add_reservation_in_range(struct resv_map *resv, long f, long t, 387075a61d0SMina Almasry struct hugetlb_cgroup *h_cg, 388972a3da3SWei Yang struct hstate *h, long *regions_needed) 389d75c6af9SMina Almasry { 3900db9d74eSMina Almasry long add = 0; 391d75c6af9SMina Almasry struct list_head *head = &resv->regions; 3920db9d74eSMina Almasry long last_accounted_offset = f; 3932103cf9cSPeter Xu struct file_region *rg = NULL, *trg = NULL; 394d75c6af9SMina Almasry 3950db9d74eSMina Almasry if (regions_needed) 3960db9d74eSMina Almasry *regions_needed = 0; 397d75c6af9SMina Almasry 3980db9d74eSMina Almasry /* In this loop, we essentially handle an entry for the range 3990db9d74eSMina Almasry * [last_accounted_offset, rg->from), at every iteration, with some 4000db9d74eSMina Almasry * bounds checking. 4010db9d74eSMina Almasry */ 4020db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, head, link) { 4030db9d74eSMina Almasry /* Skip irrelevant regions that start before our range. */ 4040db9d74eSMina Almasry if (rg->from < f) { 4050db9d74eSMina Almasry /* If this region ends after the last accounted offset, 4060db9d74eSMina Almasry * then we need to update last_accounted_offset. 4070db9d74eSMina Almasry */ 4080db9d74eSMina Almasry if (rg->to > last_accounted_offset) 4090db9d74eSMina Almasry last_accounted_offset = rg->to; 4100db9d74eSMina Almasry continue; 4110db9d74eSMina Almasry } 412d75c6af9SMina Almasry 4130db9d74eSMina Almasry /* When we find a region that starts beyond our range, we've 4140db9d74eSMina Almasry * finished. 4150db9d74eSMina Almasry */ 416ca7e0457SPeter Xu if (rg->from >= t) 417d75c6af9SMina Almasry break; 418d75c6af9SMina Almasry 4190db9d74eSMina Almasry /* Add an entry for last_accounted_offset -> rg->from, and 4200db9d74eSMina Almasry * update last_accounted_offset. 421d75c6af9SMina Almasry */ 4222103cf9cSPeter Xu if (rg->from > last_accounted_offset) 4232103cf9cSPeter Xu add += hugetlb_resv_map_add(resv, rg, 4242103cf9cSPeter Xu last_accounted_offset, 4252103cf9cSPeter Xu rg->from, h, h_cg, 4262103cf9cSPeter Xu regions_needed); 427d75c6af9SMina Almasry 4280db9d74eSMina Almasry last_accounted_offset = rg->to; 4290db9d74eSMina Almasry } 4300db9d74eSMina Almasry 4310db9d74eSMina Almasry /* Handle the case where our range extends beyond 4320db9d74eSMina Almasry * last_accounted_offset. 4330db9d74eSMina Almasry */ 4342103cf9cSPeter Xu if (last_accounted_offset < t) 4352103cf9cSPeter Xu add += hugetlb_resv_map_add(resv, rg, last_accounted_offset, 4362103cf9cSPeter Xu t, h, h_cg, regions_needed); 4370db9d74eSMina Almasry 4380db9d74eSMina Almasry VM_BUG_ON(add < 0); 4390db9d74eSMina Almasry return add; 4400db9d74eSMina Almasry } 4410db9d74eSMina Almasry 4420db9d74eSMina Almasry /* Must be called with resv->lock acquired. Will drop lock to allocate entries. 4430db9d74eSMina Almasry */ 4440db9d74eSMina Almasry static int allocate_file_region_entries(struct resv_map *resv, 4450db9d74eSMina Almasry int regions_needed) 4460db9d74eSMina Almasry __must_hold(&resv->lock) 4470db9d74eSMina Almasry { 4480db9d74eSMina Almasry struct list_head allocated_regions; 4490db9d74eSMina Almasry int to_allocate = 0, i = 0; 4500db9d74eSMina Almasry struct file_region *trg = NULL, *rg = NULL; 4510db9d74eSMina Almasry 4520db9d74eSMina Almasry VM_BUG_ON(regions_needed < 0); 4530db9d74eSMina Almasry 4540db9d74eSMina Almasry INIT_LIST_HEAD(&allocated_regions); 4550db9d74eSMina Almasry 4560db9d74eSMina Almasry /* 4570db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 4580db9d74eSMina Almasry * the number of in progress add operations plus regions_needed. 4590db9d74eSMina Almasry * 4600db9d74eSMina Almasry * This is a while loop because when we drop the lock, some other call 4610db9d74eSMina Almasry * to region_add or region_del may have consumed some region_entries, 4620db9d74eSMina Almasry * so we keep looping here until we finally have enough entries for 4630db9d74eSMina Almasry * (adds_in_progress + regions_needed). 4640db9d74eSMina Almasry */ 4650db9d74eSMina Almasry while (resv->region_cache_count < 4660db9d74eSMina Almasry (resv->adds_in_progress + regions_needed)) { 4670db9d74eSMina Almasry to_allocate = resv->adds_in_progress + regions_needed - 4680db9d74eSMina Almasry resv->region_cache_count; 4690db9d74eSMina Almasry 4700db9d74eSMina Almasry /* At this point, we should have enough entries in the cache 471f0953a1bSIngo Molnar * for all the existing adds_in_progress. We should only be 4720db9d74eSMina Almasry * needing to allocate for regions_needed. 4730db9d74eSMina Almasry */ 4740db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count < resv->adds_in_progress); 4750db9d74eSMina Almasry 4760db9d74eSMina Almasry spin_unlock(&resv->lock); 4770db9d74eSMina Almasry for (i = 0; i < to_allocate; i++) { 4780db9d74eSMina Almasry trg = kmalloc(sizeof(*trg), GFP_KERNEL); 4790db9d74eSMina Almasry if (!trg) 4800db9d74eSMina Almasry goto out_of_memory; 4810db9d74eSMina Almasry list_add(&trg->link, &allocated_regions); 4820db9d74eSMina Almasry } 4830db9d74eSMina Almasry 4840db9d74eSMina Almasry spin_lock(&resv->lock); 4850db9d74eSMina Almasry 486d3ec7b6eSWei Yang list_splice(&allocated_regions, &resv->region_cache); 487d3ec7b6eSWei Yang resv->region_cache_count += to_allocate; 4880db9d74eSMina Almasry } 4890db9d74eSMina Almasry 4900db9d74eSMina Almasry return 0; 4910db9d74eSMina Almasry 4920db9d74eSMina Almasry out_of_memory: 4930db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, &allocated_regions, link) { 494d75c6af9SMina Almasry list_del(&rg->link); 495d75c6af9SMina Almasry kfree(rg); 496d75c6af9SMina Almasry } 4970db9d74eSMina Almasry return -ENOMEM; 498d75c6af9SMina Almasry } 499d75c6af9SMina Almasry 5001dd308a7SMike Kravetz /* 5011dd308a7SMike Kravetz * Add the huge page range represented by [f, t) to the reserve 5020db9d74eSMina Almasry * map. Regions will be taken from the cache to fill in this range. 5030db9d74eSMina Almasry * Sufficient regions should exist in the cache due to the previous 5040db9d74eSMina Almasry * call to region_chg with the same range, but in some cases the cache will not 5050db9d74eSMina Almasry * have sufficient entries due to races with other code doing region_add or 5060db9d74eSMina Almasry * region_del. The extra needed entries will be allocated. 507cf3ad20bSMike Kravetz * 5080db9d74eSMina Almasry * regions_needed is the out value provided by a previous call to region_chg. 5090db9d74eSMina Almasry * 5100db9d74eSMina Almasry * Return the number of new huge pages added to the map. This number is greater 5110db9d74eSMina Almasry * than or equal to zero. If file_region entries needed to be allocated for 5127c8de358SEthon Paul * this operation and we were not able to allocate, it returns -ENOMEM. 5130db9d74eSMina Almasry * region_add of regions of length 1 never allocate file_regions and cannot 5140db9d74eSMina Almasry * fail; region_chg will always allocate at least 1 entry and a region_add for 5150db9d74eSMina Almasry * 1 page will only require at most 1 entry. 5161dd308a7SMike Kravetz */ 5170db9d74eSMina Almasry static long region_add(struct resv_map *resv, long f, long t, 518075a61d0SMina Almasry long in_regions_needed, struct hstate *h, 519075a61d0SMina Almasry struct hugetlb_cgroup *h_cg) 52096822904SAndy Whitcroft { 5210db9d74eSMina Almasry long add = 0, actual_regions_needed = 0; 52296822904SAndy Whitcroft 5237b24d861SDavidlohr Bueso spin_lock(&resv->lock); 5240db9d74eSMina Almasry retry: 5250db9d74eSMina Almasry 5260db9d74eSMina Almasry /* Count how many regions are actually needed to execute this add. */ 527972a3da3SWei Yang add_reservation_in_range(resv, f, t, NULL, NULL, 528972a3da3SWei Yang &actual_regions_needed); 52996822904SAndy Whitcroft 5305e911373SMike Kravetz /* 5310db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 5320db9d74eSMina Almasry * this add operation. Note that actual_regions_needed may be greater 5330db9d74eSMina Almasry * than in_regions_needed, as the resv_map may have been modified since 5340db9d74eSMina Almasry * the region_chg call. In this case, we need to make sure that we 5350db9d74eSMina Almasry * allocate extra entries, such that we have enough for all the 5360db9d74eSMina Almasry * existing adds_in_progress, plus the excess needed for this 5370db9d74eSMina Almasry * operation. 5385e911373SMike Kravetz */ 5390db9d74eSMina Almasry if (actual_regions_needed > in_regions_needed && 5400db9d74eSMina Almasry resv->region_cache_count < 5410db9d74eSMina Almasry resv->adds_in_progress + 5420db9d74eSMina Almasry (actual_regions_needed - in_regions_needed)) { 5430db9d74eSMina Almasry /* region_add operation of range 1 should never need to 5440db9d74eSMina Almasry * allocate file_region entries. 5450db9d74eSMina Almasry */ 5460db9d74eSMina Almasry VM_BUG_ON(t - f <= 1); 5475e911373SMike Kravetz 5480db9d74eSMina Almasry if (allocate_file_region_entries( 5490db9d74eSMina Almasry resv, actual_regions_needed - in_regions_needed)) { 5500db9d74eSMina Almasry return -ENOMEM; 5515e911373SMike Kravetz } 5525e911373SMike Kravetz 5530db9d74eSMina Almasry goto retry; 5540db9d74eSMina Almasry } 555cf3ad20bSMike Kravetz 556972a3da3SWei Yang add = add_reservation_in_range(resv, f, t, h_cg, h, NULL); 5570db9d74eSMina Almasry 5580db9d74eSMina Almasry resv->adds_in_progress -= in_regions_needed; 5590db9d74eSMina Almasry 5607b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 561cf3ad20bSMike Kravetz return add; 56296822904SAndy Whitcroft } 56396822904SAndy Whitcroft 5641dd308a7SMike Kravetz /* 5651dd308a7SMike Kravetz * Examine the existing reserve map and determine how many 5661dd308a7SMike Kravetz * huge pages in the specified range [f, t) are NOT currently 5671dd308a7SMike Kravetz * represented. This routine is called before a subsequent 5681dd308a7SMike Kravetz * call to region_add that will actually modify the reserve 5691dd308a7SMike Kravetz * map to add the specified range [f, t). region_chg does 5701dd308a7SMike Kravetz * not change the number of huge pages represented by the 5710db9d74eSMina Almasry * map. A number of new file_region structures is added to the cache as a 5720db9d74eSMina Almasry * placeholder, for the subsequent region_add call to use. At least 1 5730db9d74eSMina Almasry * file_region structure is added. 5740db9d74eSMina Almasry * 5750db9d74eSMina Almasry * out_regions_needed is the number of regions added to the 5760db9d74eSMina Almasry * resv->adds_in_progress. This value needs to be provided to a follow up call 5770db9d74eSMina Almasry * to region_add or region_abort for proper accounting. 5785e911373SMike Kravetz * 5795e911373SMike Kravetz * Returns the number of huge pages that need to be added to the existing 5805e911373SMike Kravetz * reservation map for the range [f, t). This number is greater or equal to 5815e911373SMike Kravetz * zero. -ENOMEM is returned if a new file_region structure or cache entry 5825e911373SMike Kravetz * is needed and can not be allocated. 5831dd308a7SMike Kravetz */ 5840db9d74eSMina Almasry static long region_chg(struct resv_map *resv, long f, long t, 5850db9d74eSMina Almasry long *out_regions_needed) 58696822904SAndy Whitcroft { 58796822904SAndy Whitcroft long chg = 0; 58896822904SAndy Whitcroft 5897b24d861SDavidlohr Bueso spin_lock(&resv->lock); 5905e911373SMike Kravetz 591972a3da3SWei Yang /* Count how many hugepages in this range are NOT represented. */ 592075a61d0SMina Almasry chg = add_reservation_in_range(resv, f, t, NULL, NULL, 593972a3da3SWei Yang out_regions_needed); 5945e911373SMike Kravetz 5950db9d74eSMina Almasry if (*out_regions_needed == 0) 5960db9d74eSMina Almasry *out_regions_needed = 1; 5975e911373SMike Kravetz 5980db9d74eSMina Almasry if (allocate_file_region_entries(resv, *out_regions_needed)) 5995e911373SMike Kravetz return -ENOMEM; 6005e911373SMike Kravetz 6010db9d74eSMina Almasry resv->adds_in_progress += *out_regions_needed; 60296822904SAndy Whitcroft 6037b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 60496822904SAndy Whitcroft return chg; 60596822904SAndy Whitcroft } 60696822904SAndy Whitcroft 6071dd308a7SMike Kravetz /* 6085e911373SMike Kravetz * Abort the in progress add operation. The adds_in_progress field 6095e911373SMike Kravetz * of the resv_map keeps track of the operations in progress between 6105e911373SMike Kravetz * calls to region_chg and region_add. Operations are sometimes 6115e911373SMike Kravetz * aborted after the call to region_chg. In such cases, region_abort 6120db9d74eSMina Almasry * is called to decrement the adds_in_progress counter. regions_needed 6130db9d74eSMina Almasry * is the value returned by the region_chg call, it is used to decrement 6140db9d74eSMina Almasry * the adds_in_progress counter. 6155e911373SMike Kravetz * 6165e911373SMike Kravetz * NOTE: The range arguments [f, t) are not needed or used in this 6175e911373SMike Kravetz * routine. They are kept to make reading the calling code easier as 6185e911373SMike Kravetz * arguments will match the associated region_chg call. 6195e911373SMike Kravetz */ 6200db9d74eSMina Almasry static void region_abort(struct resv_map *resv, long f, long t, 6210db9d74eSMina Almasry long regions_needed) 6225e911373SMike Kravetz { 6235e911373SMike Kravetz spin_lock(&resv->lock); 6245e911373SMike Kravetz VM_BUG_ON(!resv->region_cache_count); 6250db9d74eSMina Almasry resv->adds_in_progress -= regions_needed; 6265e911373SMike Kravetz spin_unlock(&resv->lock); 6275e911373SMike Kravetz } 6285e911373SMike Kravetz 6295e911373SMike Kravetz /* 630feba16e2SMike Kravetz * Delete the specified range [f, t) from the reserve map. If the 631feba16e2SMike Kravetz * t parameter is LONG_MAX, this indicates that ALL regions after f 632feba16e2SMike Kravetz * should be deleted. Locate the regions which intersect [f, t) 633feba16e2SMike Kravetz * and either trim, delete or split the existing regions. 634feba16e2SMike Kravetz * 635feba16e2SMike Kravetz * Returns the number of huge pages deleted from the reserve map. 636feba16e2SMike Kravetz * In the normal case, the return value is zero or more. In the 637feba16e2SMike Kravetz * case where a region must be split, a new region descriptor must 638feba16e2SMike Kravetz * be allocated. If the allocation fails, -ENOMEM will be returned. 639feba16e2SMike Kravetz * NOTE: If the parameter t == LONG_MAX, then we will never split 640feba16e2SMike Kravetz * a region and possibly return -ENOMEM. Callers specifying 641feba16e2SMike Kravetz * t == LONG_MAX do not need to check for -ENOMEM error. 6421dd308a7SMike Kravetz */ 643feba16e2SMike Kravetz static long region_del(struct resv_map *resv, long f, long t) 64496822904SAndy Whitcroft { 6451406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 64696822904SAndy Whitcroft struct file_region *rg, *trg; 647feba16e2SMike Kravetz struct file_region *nrg = NULL; 648feba16e2SMike Kravetz long del = 0; 64996822904SAndy Whitcroft 650feba16e2SMike Kravetz retry: 6517b24d861SDavidlohr Bueso spin_lock(&resv->lock); 652feba16e2SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 653dbe409e4SMike Kravetz /* 654dbe409e4SMike Kravetz * Skip regions before the range to be deleted. file_region 655dbe409e4SMike Kravetz * ranges are normally of the form [from, to). However, there 656dbe409e4SMike Kravetz * may be a "placeholder" entry in the map which is of the form 657dbe409e4SMike Kravetz * (from, to) with from == to. Check for placeholder entries 658dbe409e4SMike Kravetz * at the beginning of the range to be deleted. 659dbe409e4SMike Kravetz */ 660dbe409e4SMike Kravetz if (rg->to <= f && (rg->to != rg->from || rg->to != f)) 661feba16e2SMike Kravetz continue; 662dbe409e4SMike Kravetz 663feba16e2SMike Kravetz if (rg->from >= t) 66496822904SAndy Whitcroft break; 66596822904SAndy Whitcroft 666feba16e2SMike Kravetz if (f > rg->from && t < rg->to) { /* Must split region */ 667feba16e2SMike Kravetz /* 668feba16e2SMike Kravetz * Check for an entry in the cache before dropping 669feba16e2SMike Kravetz * lock and attempting allocation. 670feba16e2SMike Kravetz */ 671feba16e2SMike Kravetz if (!nrg && 672feba16e2SMike Kravetz resv->region_cache_count > resv->adds_in_progress) { 673feba16e2SMike Kravetz nrg = list_first_entry(&resv->region_cache, 674feba16e2SMike Kravetz struct file_region, 675feba16e2SMike Kravetz link); 676feba16e2SMike Kravetz list_del(&nrg->link); 677feba16e2SMike Kravetz resv->region_cache_count--; 67896822904SAndy Whitcroft } 67996822904SAndy Whitcroft 680feba16e2SMike Kravetz if (!nrg) { 681feba16e2SMike Kravetz spin_unlock(&resv->lock); 682feba16e2SMike Kravetz nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); 683feba16e2SMike Kravetz if (!nrg) 684feba16e2SMike Kravetz return -ENOMEM; 685feba16e2SMike Kravetz goto retry; 686feba16e2SMike Kravetz } 687feba16e2SMike Kravetz 688feba16e2SMike Kravetz del += t - f; 68979aa925bSMike Kravetz hugetlb_cgroup_uncharge_file_region( 690d85aecf2SMiaohe Lin resv, rg, t - f, false); 691feba16e2SMike Kravetz 692feba16e2SMike Kravetz /* New entry for end of split region */ 693feba16e2SMike Kravetz nrg->from = t; 694feba16e2SMike Kravetz nrg->to = rg->to; 695075a61d0SMina Almasry 696075a61d0SMina Almasry copy_hugetlb_cgroup_uncharge_info(nrg, rg); 697075a61d0SMina Almasry 698feba16e2SMike Kravetz INIT_LIST_HEAD(&nrg->link); 699feba16e2SMike Kravetz 700feba16e2SMike Kravetz /* Original entry is trimmed */ 701feba16e2SMike Kravetz rg->to = f; 702feba16e2SMike Kravetz 703feba16e2SMike Kravetz list_add(&nrg->link, &rg->link); 704feba16e2SMike Kravetz nrg = NULL; 70596822904SAndy Whitcroft break; 706feba16e2SMike Kravetz } 707feba16e2SMike Kravetz 708feba16e2SMike Kravetz if (f <= rg->from && t >= rg->to) { /* Remove entire region */ 709feba16e2SMike Kravetz del += rg->to - rg->from; 710075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 711d85aecf2SMiaohe Lin rg->to - rg->from, true); 71296822904SAndy Whitcroft list_del(&rg->link); 71396822904SAndy Whitcroft kfree(rg); 714feba16e2SMike Kravetz continue; 71596822904SAndy Whitcroft } 7167b24d861SDavidlohr Bueso 717feba16e2SMike Kravetz if (f <= rg->from) { /* Trim beginning of region */ 718075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 719d85aecf2SMiaohe Lin t - rg->from, false); 720075a61d0SMina Almasry 72179aa925bSMike Kravetz del += t - rg->from; 72279aa925bSMike Kravetz rg->from = t; 72379aa925bSMike Kravetz } else { /* Trim end of region */ 724075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 725d85aecf2SMiaohe Lin rg->to - f, false); 72679aa925bSMike Kravetz 72779aa925bSMike Kravetz del += rg->to - f; 72879aa925bSMike Kravetz rg->to = f; 729feba16e2SMike Kravetz } 730feba16e2SMike Kravetz } 731feba16e2SMike Kravetz 7327b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 733feba16e2SMike Kravetz kfree(nrg); 734feba16e2SMike Kravetz return del; 73596822904SAndy Whitcroft } 73696822904SAndy Whitcroft 7371dd308a7SMike Kravetz /* 738b5cec28dSMike Kravetz * A rare out of memory error was encountered which prevented removal of 739b5cec28dSMike Kravetz * the reserve map region for a page. The huge page itself was free'ed 740b5cec28dSMike Kravetz * and removed from the page cache. This routine will adjust the subpool 741b5cec28dSMike Kravetz * usage count, and the global reserve count if needed. By incrementing 742b5cec28dSMike Kravetz * these counts, the reserve map entry which could not be deleted will 743b5cec28dSMike Kravetz * appear as a "reserved" entry instead of simply dangling with incorrect 744b5cec28dSMike Kravetz * counts. 745b5cec28dSMike Kravetz */ 74672e2936cSzhong jiang void hugetlb_fix_reserve_counts(struct inode *inode) 747b5cec28dSMike Kravetz { 748b5cec28dSMike Kravetz struct hugepage_subpool *spool = subpool_inode(inode); 749b5cec28dSMike Kravetz long rsv_adjust; 750da56388cSMiaohe Lin bool reserved = false; 751b5cec28dSMike Kravetz 752b5cec28dSMike Kravetz rsv_adjust = hugepage_subpool_get_pages(spool, 1); 753da56388cSMiaohe Lin if (rsv_adjust > 0) { 754b5cec28dSMike Kravetz struct hstate *h = hstate_inode(inode); 755b5cec28dSMike Kravetz 756da56388cSMiaohe Lin if (!hugetlb_acct_memory(h, 1)) 757da56388cSMiaohe Lin reserved = true; 758da56388cSMiaohe Lin } else if (!rsv_adjust) { 759da56388cSMiaohe Lin reserved = true; 760b5cec28dSMike Kravetz } 761da56388cSMiaohe Lin 762da56388cSMiaohe Lin if (!reserved) 763da56388cSMiaohe Lin pr_warn("hugetlb: Huge Page Reserved count may go negative.\n"); 764b5cec28dSMike Kravetz } 765b5cec28dSMike Kravetz 766b5cec28dSMike Kravetz /* 7671dd308a7SMike Kravetz * Count and return the number of huge pages in the reserve map 7681dd308a7SMike Kravetz * that intersect with the range [f, t). 7691dd308a7SMike Kravetz */ 7701406ec9bSJoonsoo Kim static long region_count(struct resv_map *resv, long f, long t) 77184afd99bSAndy Whitcroft { 7721406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 77384afd99bSAndy Whitcroft struct file_region *rg; 77484afd99bSAndy Whitcroft long chg = 0; 77584afd99bSAndy Whitcroft 7767b24d861SDavidlohr Bueso spin_lock(&resv->lock); 77784afd99bSAndy Whitcroft /* Locate each segment we overlap with, and count that overlap. */ 77884afd99bSAndy Whitcroft list_for_each_entry(rg, head, link) { 779f2135a4aSWang Sheng-Hui long seg_from; 780f2135a4aSWang Sheng-Hui long seg_to; 78184afd99bSAndy Whitcroft 78284afd99bSAndy Whitcroft if (rg->to <= f) 78384afd99bSAndy Whitcroft continue; 78484afd99bSAndy Whitcroft if (rg->from >= t) 78584afd99bSAndy Whitcroft break; 78684afd99bSAndy Whitcroft 78784afd99bSAndy Whitcroft seg_from = max(rg->from, f); 78884afd99bSAndy Whitcroft seg_to = min(rg->to, t); 78984afd99bSAndy Whitcroft 79084afd99bSAndy Whitcroft chg += seg_to - seg_from; 79184afd99bSAndy Whitcroft } 7927b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 79384afd99bSAndy Whitcroft 79484afd99bSAndy Whitcroft return chg; 79584afd99bSAndy Whitcroft } 79684afd99bSAndy Whitcroft 79796822904SAndy Whitcroft /* 798e7c4b0bfSAndy Whitcroft * Convert the address within this vma to the page offset within 799e7c4b0bfSAndy Whitcroft * the mapping, in pagecache page units; huge pages here. 800e7c4b0bfSAndy Whitcroft */ 801a5516438SAndi Kleen static pgoff_t vma_hugecache_offset(struct hstate *h, 802a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 803e7c4b0bfSAndy Whitcroft { 804a5516438SAndi Kleen return ((address - vma->vm_start) >> huge_page_shift(h)) + 805a5516438SAndi Kleen (vma->vm_pgoff >> huge_page_order(h)); 806e7c4b0bfSAndy Whitcroft } 807e7c4b0bfSAndy Whitcroft 8080fe6e20bSNaoya Horiguchi pgoff_t linear_hugepage_index(struct vm_area_struct *vma, 8090fe6e20bSNaoya Horiguchi unsigned long address) 8100fe6e20bSNaoya Horiguchi { 8110fe6e20bSNaoya Horiguchi return vma_hugecache_offset(hstate_vma(vma), vma, address); 8120fe6e20bSNaoya Horiguchi } 813dee41079SDan Williams EXPORT_SYMBOL_GPL(linear_hugepage_index); 8140fe6e20bSNaoya Horiguchi 81584afd99bSAndy Whitcroft /* 81608fba699SMel Gorman * Return the size of the pages allocated when backing a VMA. In the majority 81708fba699SMel Gorman * cases this will be same size as used by the page table entries. 81808fba699SMel Gorman */ 81908fba699SMel Gorman unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) 82008fba699SMel Gorman { 82105ea8860SDan Williams if (vma->vm_ops && vma->vm_ops->pagesize) 82205ea8860SDan Williams return vma->vm_ops->pagesize(vma); 82308fba699SMel Gorman return PAGE_SIZE; 82408fba699SMel Gorman } 825f340ca0fSJoerg Roedel EXPORT_SYMBOL_GPL(vma_kernel_pagesize); 82608fba699SMel Gorman 82708fba699SMel Gorman /* 8283340289dSMel Gorman * Return the page size being used by the MMU to back a VMA. In the majority 8293340289dSMel Gorman * of cases, the page size used by the kernel matches the MMU size. On 83009135cc5SDan Williams * architectures where it differs, an architecture-specific 'strong' 83109135cc5SDan Williams * version of this symbol is required. 8323340289dSMel Gorman */ 83309135cc5SDan Williams __weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) 8343340289dSMel Gorman { 8353340289dSMel Gorman return vma_kernel_pagesize(vma); 8363340289dSMel Gorman } 8373340289dSMel Gorman 8383340289dSMel Gorman /* 83984afd99bSAndy Whitcroft * Flags for MAP_PRIVATE reservations. These are stored in the bottom 84084afd99bSAndy Whitcroft * bits of the reservation map pointer, which are always clear due to 84184afd99bSAndy Whitcroft * alignment. 84284afd99bSAndy Whitcroft */ 84384afd99bSAndy Whitcroft #define HPAGE_RESV_OWNER (1UL << 0) 84484afd99bSAndy Whitcroft #define HPAGE_RESV_UNMAPPED (1UL << 1) 84504f2cbe3SMel Gorman #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) 84684afd99bSAndy Whitcroft 847a1e78772SMel Gorman /* 848a1e78772SMel Gorman * These helpers are used to track how many pages are reserved for 849a1e78772SMel Gorman * faults in a MAP_PRIVATE mapping. Only the process that called mmap() 850a1e78772SMel Gorman * is guaranteed to have their future faults succeed. 851a1e78772SMel Gorman * 852a1e78772SMel Gorman * With the exception of reset_vma_resv_huge_pages() which is called at fork(), 853a1e78772SMel Gorman * the reserve counters are updated with the hugetlb_lock held. It is safe 854a1e78772SMel Gorman * to reset the VMA at fork() time as it is not in use yet and there is no 855a1e78772SMel Gorman * chance of the global counters getting corrupted as a result of the values. 85684afd99bSAndy Whitcroft * 85784afd99bSAndy Whitcroft * The private mapping reservation is represented in a subtly different 85884afd99bSAndy Whitcroft * manner to a shared mapping. A shared mapping has a region map associated 85984afd99bSAndy Whitcroft * with the underlying file, this region map represents the backing file 86084afd99bSAndy Whitcroft * pages which have ever had a reservation assigned which this persists even 86184afd99bSAndy Whitcroft * after the page is instantiated. A private mapping has a region map 86284afd99bSAndy Whitcroft * associated with the original mmap which is attached to all VMAs which 86384afd99bSAndy Whitcroft * reference it, this region map represents those offsets which have consumed 86484afd99bSAndy Whitcroft * reservation ie. where pages have been instantiated. 865a1e78772SMel Gorman */ 866e7c4b0bfSAndy Whitcroft static unsigned long get_vma_private_data(struct vm_area_struct *vma) 867e7c4b0bfSAndy Whitcroft { 868e7c4b0bfSAndy Whitcroft return (unsigned long)vma->vm_private_data; 869e7c4b0bfSAndy Whitcroft } 870e7c4b0bfSAndy Whitcroft 871e7c4b0bfSAndy Whitcroft static void set_vma_private_data(struct vm_area_struct *vma, 872e7c4b0bfSAndy Whitcroft unsigned long value) 873e7c4b0bfSAndy Whitcroft { 874e7c4b0bfSAndy Whitcroft vma->vm_private_data = (void *)value; 875e7c4b0bfSAndy Whitcroft } 876e7c4b0bfSAndy Whitcroft 877e9fe92aeSMina Almasry static void 878e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(struct resv_map *resv_map, 879e9fe92aeSMina Almasry struct hugetlb_cgroup *h_cg, 880e9fe92aeSMina Almasry struct hstate *h) 881e9fe92aeSMina Almasry { 882e9fe92aeSMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 883e9fe92aeSMina Almasry if (!h_cg || !h) { 884e9fe92aeSMina Almasry resv_map->reservation_counter = NULL; 885e9fe92aeSMina Almasry resv_map->pages_per_hpage = 0; 886e9fe92aeSMina Almasry resv_map->css = NULL; 887e9fe92aeSMina Almasry } else { 888e9fe92aeSMina Almasry resv_map->reservation_counter = 889e9fe92aeSMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 890e9fe92aeSMina Almasry resv_map->pages_per_hpage = pages_per_huge_page(h); 891e9fe92aeSMina Almasry resv_map->css = &h_cg->css; 892e9fe92aeSMina Almasry } 893e9fe92aeSMina Almasry #endif 894e9fe92aeSMina Almasry } 895e9fe92aeSMina Almasry 8969119a41eSJoonsoo Kim struct resv_map *resv_map_alloc(void) 89784afd99bSAndy Whitcroft { 89884afd99bSAndy Whitcroft struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); 8995e911373SMike Kravetz struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL); 9005e911373SMike Kravetz 9015e911373SMike Kravetz if (!resv_map || !rg) { 9025e911373SMike Kravetz kfree(resv_map); 9035e911373SMike Kravetz kfree(rg); 90484afd99bSAndy Whitcroft return NULL; 9055e911373SMike Kravetz } 90684afd99bSAndy Whitcroft 90784afd99bSAndy Whitcroft kref_init(&resv_map->refs); 9087b24d861SDavidlohr Bueso spin_lock_init(&resv_map->lock); 90984afd99bSAndy Whitcroft INIT_LIST_HEAD(&resv_map->regions); 91084afd99bSAndy Whitcroft 9115e911373SMike Kravetz resv_map->adds_in_progress = 0; 912e9fe92aeSMina Almasry /* 913e9fe92aeSMina Almasry * Initialize these to 0. On shared mappings, 0's here indicate these 914e9fe92aeSMina Almasry * fields don't do cgroup accounting. On private mappings, these will be 915e9fe92aeSMina Almasry * re-initialized to the proper values, to indicate that hugetlb cgroup 916e9fe92aeSMina Almasry * reservations are to be un-charged from here. 917e9fe92aeSMina Almasry */ 918e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, NULL, NULL); 9195e911373SMike Kravetz 9205e911373SMike Kravetz INIT_LIST_HEAD(&resv_map->region_cache); 9215e911373SMike Kravetz list_add(&rg->link, &resv_map->region_cache); 9225e911373SMike Kravetz resv_map->region_cache_count = 1; 9235e911373SMike Kravetz 92484afd99bSAndy Whitcroft return resv_map; 92584afd99bSAndy Whitcroft } 92684afd99bSAndy Whitcroft 9279119a41eSJoonsoo Kim void resv_map_release(struct kref *ref) 92884afd99bSAndy Whitcroft { 92984afd99bSAndy Whitcroft struct resv_map *resv_map = container_of(ref, struct resv_map, refs); 9305e911373SMike Kravetz struct list_head *head = &resv_map->region_cache; 9315e911373SMike Kravetz struct file_region *rg, *trg; 93284afd99bSAndy Whitcroft 93384afd99bSAndy Whitcroft /* Clear out any active regions before we release the map. */ 934feba16e2SMike Kravetz region_del(resv_map, 0, LONG_MAX); 9355e911373SMike Kravetz 9365e911373SMike Kravetz /* ... and any entries left in the cache */ 9375e911373SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 9385e911373SMike Kravetz list_del(&rg->link); 9395e911373SMike Kravetz kfree(rg); 9405e911373SMike Kravetz } 9415e911373SMike Kravetz 9425e911373SMike Kravetz VM_BUG_ON(resv_map->adds_in_progress); 9435e911373SMike Kravetz 94484afd99bSAndy Whitcroft kfree(resv_map); 94584afd99bSAndy Whitcroft } 94684afd99bSAndy Whitcroft 9474e35f483SJoonsoo Kim static inline struct resv_map *inode_resv_map(struct inode *inode) 9484e35f483SJoonsoo Kim { 949f27a5136SMike Kravetz /* 950f27a5136SMike Kravetz * At inode evict time, i_mapping may not point to the original 951f27a5136SMike Kravetz * address space within the inode. This original address space 952f27a5136SMike Kravetz * contains the pointer to the resv_map. So, always use the 953f27a5136SMike Kravetz * address space embedded within the inode. 954f27a5136SMike Kravetz * The VERY common case is inode->mapping == &inode->i_data but, 955f27a5136SMike Kravetz * this may not be true for device special inodes. 956f27a5136SMike Kravetz */ 957f27a5136SMike Kravetz return (struct resv_map *)(&inode->i_data)->private_data; 9584e35f483SJoonsoo Kim } 9594e35f483SJoonsoo Kim 96084afd99bSAndy Whitcroft static struct resv_map *vma_resv_map(struct vm_area_struct *vma) 961a1e78772SMel Gorman { 96281d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 9634e35f483SJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE) { 9644e35f483SJoonsoo Kim struct address_space *mapping = vma->vm_file->f_mapping; 9654e35f483SJoonsoo Kim struct inode *inode = mapping->host; 9664e35f483SJoonsoo Kim 9674e35f483SJoonsoo Kim return inode_resv_map(inode); 9684e35f483SJoonsoo Kim 9694e35f483SJoonsoo Kim } else { 97084afd99bSAndy Whitcroft return (struct resv_map *)(get_vma_private_data(vma) & 97184afd99bSAndy Whitcroft ~HPAGE_RESV_MASK); 9724e35f483SJoonsoo Kim } 973a1e78772SMel Gorman } 974a1e78772SMel Gorman 97584afd99bSAndy Whitcroft static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) 976a1e78772SMel Gorman { 97781d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 97881d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 979a1e78772SMel Gorman 98084afd99bSAndy Whitcroft set_vma_private_data(vma, (get_vma_private_data(vma) & 98184afd99bSAndy Whitcroft HPAGE_RESV_MASK) | (unsigned long)map); 98204f2cbe3SMel Gorman } 98304f2cbe3SMel Gorman 98404f2cbe3SMel Gorman static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) 98504f2cbe3SMel Gorman { 98681d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 98781d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 988e7c4b0bfSAndy Whitcroft 989e7c4b0bfSAndy Whitcroft set_vma_private_data(vma, get_vma_private_data(vma) | flags); 99004f2cbe3SMel Gorman } 99104f2cbe3SMel Gorman 99204f2cbe3SMel Gorman static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) 99304f2cbe3SMel Gorman { 99481d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 995e7c4b0bfSAndy Whitcroft 996e7c4b0bfSAndy Whitcroft return (get_vma_private_data(vma) & flag) != 0; 997a1e78772SMel Gorman } 998a1e78772SMel Gorman 99904f2cbe3SMel Gorman /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ 1000a1e78772SMel Gorman void reset_vma_resv_huge_pages(struct vm_area_struct *vma) 1001a1e78772SMel Gorman { 100281d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 1003f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 1004a1e78772SMel Gorman vma->vm_private_data = (void *)0; 1005a1e78772SMel Gorman } 1006a1e78772SMel Gorman 1007a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 1008559ec2f8SNicholas Krause static bool vma_has_reserves(struct vm_area_struct *vma, long chg) 1009a1e78772SMel Gorman { 1010af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_NORESERVE) { 1011af0ed73eSJoonsoo Kim /* 1012af0ed73eSJoonsoo Kim * This address is already reserved by other process(chg == 0), 1013af0ed73eSJoonsoo Kim * so, we should decrement reserved count. Without decrementing, 1014af0ed73eSJoonsoo Kim * reserve count remains after releasing inode, because this 1015af0ed73eSJoonsoo Kim * allocated page will go into page cache and is regarded as 1016af0ed73eSJoonsoo Kim * coming from reserved pool in releasing step. Currently, we 1017af0ed73eSJoonsoo Kim * don't have any other solution to deal with this situation 1018af0ed73eSJoonsoo Kim * properly, so add work-around here. 1019af0ed73eSJoonsoo Kim */ 1020af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE && chg == 0) 1021559ec2f8SNicholas Krause return true; 1022af0ed73eSJoonsoo Kim else 1023559ec2f8SNicholas Krause return false; 1024af0ed73eSJoonsoo Kim } 1025a63884e9SJoonsoo Kim 1026a63884e9SJoonsoo Kim /* Shared mappings always use reserves */ 10271fb1b0e9SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 10281fb1b0e9SMike Kravetz /* 10291fb1b0e9SMike Kravetz * We know VM_NORESERVE is not set. Therefore, there SHOULD 10301fb1b0e9SMike Kravetz * be a region map for all pages. The only situation where 10311fb1b0e9SMike Kravetz * there is no region map is if a hole was punched via 10327c8de358SEthon Paul * fallocate. In this case, there really are no reserves to 10331fb1b0e9SMike Kravetz * use. This situation is indicated if chg != 0. 10341fb1b0e9SMike Kravetz */ 10351fb1b0e9SMike Kravetz if (chg) 10361fb1b0e9SMike Kravetz return false; 10371fb1b0e9SMike Kravetz else 1038559ec2f8SNicholas Krause return true; 10391fb1b0e9SMike Kravetz } 1040a63884e9SJoonsoo Kim 1041a63884e9SJoonsoo Kim /* 1042a63884e9SJoonsoo Kim * Only the process that called mmap() has reserves for 1043a63884e9SJoonsoo Kim * private mappings. 1044a63884e9SJoonsoo Kim */ 104567961f9dSMike Kravetz if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 104667961f9dSMike Kravetz /* 104767961f9dSMike Kravetz * Like the shared case above, a hole punch or truncate 104867961f9dSMike Kravetz * could have been performed on the private mapping. 104967961f9dSMike Kravetz * Examine the value of chg to determine if reserves 105067961f9dSMike Kravetz * actually exist or were previously consumed. 105167961f9dSMike Kravetz * Very Subtle - The value of chg comes from a previous 105267961f9dSMike Kravetz * call to vma_needs_reserves(). The reserve map for 105367961f9dSMike Kravetz * private mappings has different (opposite) semantics 105467961f9dSMike Kravetz * than that of shared mappings. vma_needs_reserves() 105567961f9dSMike Kravetz * has already taken this difference in semantics into 105667961f9dSMike Kravetz * account. Therefore, the meaning of chg is the same 105767961f9dSMike Kravetz * as in the shared case above. Code could easily be 105867961f9dSMike Kravetz * combined, but keeping it separate draws attention to 105967961f9dSMike Kravetz * subtle differences. 106067961f9dSMike Kravetz */ 106167961f9dSMike Kravetz if (chg) 106267961f9dSMike Kravetz return false; 106367961f9dSMike Kravetz else 1064559ec2f8SNicholas Krause return true; 106567961f9dSMike Kravetz } 1066a63884e9SJoonsoo Kim 1067559ec2f8SNicholas Krause return false; 1068a1e78772SMel Gorman } 1069a1e78772SMel Gorman 1070a5516438SAndi Kleen static void enqueue_huge_page(struct hstate *h, struct page *page) 10711da177e4SLinus Torvalds { 10721da177e4SLinus Torvalds int nid = page_to_nid(page); 10739487ca60SMike Kravetz 10749487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 10750edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_freelists[nid]); 1076a5516438SAndi Kleen h->free_huge_pages++; 1077a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 10786c037149SMike Kravetz SetHPageFreed(page); 10791da177e4SLinus Torvalds } 10801da177e4SLinus Torvalds 108194310cbcSAnshuman Khandual static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) 1082bf50bab2SNaoya Horiguchi { 1083bf50bab2SNaoya Horiguchi struct page *page; 10841a08ae36SPavel Tatashin bool pin = !!(current->flags & PF_MEMALLOC_PIN); 1085bf50bab2SNaoya Horiguchi 10869487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1087bbe88753SJoonsoo Kim list_for_each_entry(page, &h->hugepage_freelists[nid], lru) { 10888e3560d9SPavel Tatashin if (pin && !is_pinnable_page(page)) 1089bbe88753SJoonsoo Kim continue; 1090bbe88753SJoonsoo Kim 10916664bfc8SWei Yang if (PageHWPoison(page)) 10926664bfc8SWei Yang continue; 1093bbe88753SJoonsoo Kim 10940edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_activelist); 1095a9869b83SNaoya Horiguchi set_page_refcounted(page); 10966c037149SMike Kravetz ClearHPageFreed(page); 1097bf50bab2SNaoya Horiguchi h->free_huge_pages--; 1098bf50bab2SNaoya Horiguchi h->free_huge_pages_node[nid]--; 1099bf50bab2SNaoya Horiguchi return page; 1100bf50bab2SNaoya Horiguchi } 1101bf50bab2SNaoya Horiguchi 11026664bfc8SWei Yang return NULL; 11036664bfc8SWei Yang } 11046664bfc8SWei Yang 11053e59fcb0SMichal Hocko static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid, 11063e59fcb0SMichal Hocko nodemask_t *nmask) 110794310cbcSAnshuman Khandual { 11083e59fcb0SMichal Hocko unsigned int cpuset_mems_cookie; 11093e59fcb0SMichal Hocko struct zonelist *zonelist; 11103e59fcb0SMichal Hocko struct zone *zone; 11113e59fcb0SMichal Hocko struct zoneref *z; 111298fa15f3SAnshuman Khandual int node = NUMA_NO_NODE; 11133e59fcb0SMichal Hocko 11143e59fcb0SMichal Hocko zonelist = node_zonelist(nid, gfp_mask); 11153e59fcb0SMichal Hocko 11163e59fcb0SMichal Hocko retry_cpuset: 11173e59fcb0SMichal Hocko cpuset_mems_cookie = read_mems_allowed_begin(); 11183e59fcb0SMichal Hocko for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) { 111994310cbcSAnshuman Khandual struct page *page; 112094310cbcSAnshuman Khandual 11213e59fcb0SMichal Hocko if (!cpuset_zone_allowed(zone, gfp_mask)) 11223e59fcb0SMichal Hocko continue; 11233e59fcb0SMichal Hocko /* 11243e59fcb0SMichal Hocko * no need to ask again on the same node. Pool is node rather than 11253e59fcb0SMichal Hocko * zone aware 11263e59fcb0SMichal Hocko */ 11273e59fcb0SMichal Hocko if (zone_to_nid(zone) == node) 11283e59fcb0SMichal Hocko continue; 11293e59fcb0SMichal Hocko node = zone_to_nid(zone); 113094310cbcSAnshuman Khandual 113194310cbcSAnshuman Khandual page = dequeue_huge_page_node_exact(h, node); 113294310cbcSAnshuman Khandual if (page) 113394310cbcSAnshuman Khandual return page; 113494310cbcSAnshuman Khandual } 11353e59fcb0SMichal Hocko if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie))) 11363e59fcb0SMichal Hocko goto retry_cpuset; 11373e59fcb0SMichal Hocko 113894310cbcSAnshuman Khandual return NULL; 113994310cbcSAnshuman Khandual } 114094310cbcSAnshuman Khandual 1141a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 1142a5516438SAndi Kleen struct vm_area_struct *vma, 1143af0ed73eSJoonsoo Kim unsigned long address, int avoid_reserve, 1144af0ed73eSJoonsoo Kim long chg) 11451da177e4SLinus Torvalds { 11463e59fcb0SMichal Hocko struct page *page; 1147480eccf9SLee Schermerhorn struct mempolicy *mpol; 114804ec6264SVlastimil Babka gfp_t gfp_mask; 11493e59fcb0SMichal Hocko nodemask_t *nodemask; 115004ec6264SVlastimil Babka int nid; 11511da177e4SLinus Torvalds 1152a1e78772SMel Gorman /* 1153a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 1154a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 1155a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 1156a1e78772SMel Gorman */ 1157af0ed73eSJoonsoo Kim if (!vma_has_reserves(vma, chg) && 1158a5516438SAndi Kleen h->free_huge_pages - h->resv_huge_pages == 0) 1159c0ff7453SMiao Xie goto err; 1160a1e78772SMel Gorman 116104f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 1162a5516438SAndi Kleen if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) 11636eab04a8SJustin P. Mattock goto err; 116404f2cbe3SMel Gorman 116504ec6264SVlastimil Babka gfp_mask = htlb_alloc_mask(h); 116604ec6264SVlastimil Babka nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 11673e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 11683e59fcb0SMichal Hocko if (page && !avoid_reserve && vma_has_reserves(vma, chg)) { 1169d6995da3SMike Kravetz SetHPageRestoreReserve(page); 1170a63884e9SJoonsoo Kim h->resv_huge_pages--; 1171bf50bab2SNaoya Horiguchi } 1172cc9a6c87SMel Gorman 1173cc9a6c87SMel Gorman mpol_cond_put(mpol); 1174cc9a6c87SMel Gorman return page; 1175cc9a6c87SMel Gorman 1176c0ff7453SMiao Xie err: 1177cc9a6c87SMel Gorman return NULL; 11781da177e4SLinus Torvalds } 11791da177e4SLinus Torvalds 11801cac6f2cSLuiz Capitulino /* 11811cac6f2cSLuiz Capitulino * common helper functions for hstate_next_node_to_{alloc|free}. 11821cac6f2cSLuiz Capitulino * We may have allocated or freed a huge page based on a different 11831cac6f2cSLuiz Capitulino * nodes_allowed previously, so h->next_node_to_{alloc|free} might 11841cac6f2cSLuiz Capitulino * be outside of *nodes_allowed. Ensure that we use an allowed 11851cac6f2cSLuiz Capitulino * node for alloc or free. 11861cac6f2cSLuiz Capitulino */ 11871cac6f2cSLuiz Capitulino static int next_node_allowed(int nid, nodemask_t *nodes_allowed) 11881cac6f2cSLuiz Capitulino { 11890edaf86cSAndrew Morton nid = next_node_in(nid, *nodes_allowed); 11901cac6f2cSLuiz Capitulino VM_BUG_ON(nid >= MAX_NUMNODES); 11911cac6f2cSLuiz Capitulino 11921cac6f2cSLuiz Capitulino return nid; 11931cac6f2cSLuiz Capitulino } 11941cac6f2cSLuiz Capitulino 11951cac6f2cSLuiz Capitulino static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) 11961cac6f2cSLuiz Capitulino { 11971cac6f2cSLuiz Capitulino if (!node_isset(nid, *nodes_allowed)) 11981cac6f2cSLuiz Capitulino nid = next_node_allowed(nid, nodes_allowed); 11991cac6f2cSLuiz Capitulino return nid; 12001cac6f2cSLuiz Capitulino } 12011cac6f2cSLuiz Capitulino 12021cac6f2cSLuiz Capitulino /* 12031cac6f2cSLuiz Capitulino * returns the previously saved node ["this node"] from which to 12041cac6f2cSLuiz Capitulino * allocate a persistent huge page for the pool and advance the 12051cac6f2cSLuiz Capitulino * next node from which to allocate, handling wrap at end of node 12061cac6f2cSLuiz Capitulino * mask. 12071cac6f2cSLuiz Capitulino */ 12081cac6f2cSLuiz Capitulino static int hstate_next_node_to_alloc(struct hstate *h, 12091cac6f2cSLuiz Capitulino nodemask_t *nodes_allowed) 12101cac6f2cSLuiz Capitulino { 12111cac6f2cSLuiz Capitulino int nid; 12121cac6f2cSLuiz Capitulino 12131cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12141cac6f2cSLuiz Capitulino 12151cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); 12161cac6f2cSLuiz Capitulino h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); 12171cac6f2cSLuiz Capitulino 12181cac6f2cSLuiz Capitulino return nid; 12191cac6f2cSLuiz Capitulino } 12201cac6f2cSLuiz Capitulino 12211cac6f2cSLuiz Capitulino /* 122210c6ec49SMike Kravetz * helper for remove_pool_huge_page() - return the previously saved 12231cac6f2cSLuiz Capitulino * node ["this node"] from which to free a huge page. Advance the 12241cac6f2cSLuiz Capitulino * next node id whether or not we find a free huge page to free so 12251cac6f2cSLuiz Capitulino * that the next attempt to free addresses the next node. 12261cac6f2cSLuiz Capitulino */ 12271cac6f2cSLuiz Capitulino static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) 12281cac6f2cSLuiz Capitulino { 12291cac6f2cSLuiz Capitulino int nid; 12301cac6f2cSLuiz Capitulino 12311cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12321cac6f2cSLuiz Capitulino 12331cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); 12341cac6f2cSLuiz Capitulino h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); 12351cac6f2cSLuiz Capitulino 12361cac6f2cSLuiz Capitulino return nid; 12371cac6f2cSLuiz Capitulino } 12381cac6f2cSLuiz Capitulino 12391cac6f2cSLuiz Capitulino #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ 12401cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 12411cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 12421cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ 12431cac6f2cSLuiz Capitulino nr_nodes--) 12441cac6f2cSLuiz Capitulino 12451cac6f2cSLuiz Capitulino #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ 12461cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 12471cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 12481cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_free(hs, mask)) || 1); \ 12491cac6f2cSLuiz Capitulino nr_nodes--) 12501cac6f2cSLuiz Capitulino 1251e1073d1eSAneesh Kumar K.V #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE 1252944d9fecSLuiz Capitulino static void destroy_compound_gigantic_page(struct page *page, 1253d00181b9SKirill A. Shutemov unsigned int order) 1254944d9fecSLuiz Capitulino { 1255944d9fecSLuiz Capitulino int i; 1256944d9fecSLuiz Capitulino int nr_pages = 1 << order; 1257944d9fecSLuiz Capitulino struct page *p = page + 1; 1258944d9fecSLuiz Capitulino 1259c8cc708aSGerald Schaefer atomic_set(compound_mapcount_ptr(page), 0); 126047e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 126147e29d32SJohn Hubbard 1262944d9fecSLuiz Capitulino for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 12631d798ca3SKirill A. Shutemov clear_compound_head(p); 1264944d9fecSLuiz Capitulino set_page_refcounted(p); 1265944d9fecSLuiz Capitulino } 1266944d9fecSLuiz Capitulino 1267944d9fecSLuiz Capitulino set_compound_order(page, 0); 1268ba9c1201SGerald Schaefer page[1].compound_nr = 0; 1269944d9fecSLuiz Capitulino __ClearPageHead(page); 1270944d9fecSLuiz Capitulino } 1271944d9fecSLuiz Capitulino 1272d00181b9SKirill A. Shutemov static void free_gigantic_page(struct page *page, unsigned int order) 1273944d9fecSLuiz Capitulino { 1274cf11e85fSRoman Gushchin /* 1275cf11e85fSRoman Gushchin * If the page isn't allocated using the cma allocator, 1276cf11e85fSRoman Gushchin * cma_release() returns false. 1277cf11e85fSRoman Gushchin */ 1278dbda8feaSBarry Song #ifdef CONFIG_CMA 1279dbda8feaSBarry Song if (cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order)) 1280cf11e85fSRoman Gushchin return; 1281dbda8feaSBarry Song #endif 1282cf11e85fSRoman Gushchin 1283944d9fecSLuiz Capitulino free_contig_range(page_to_pfn(page), 1 << order); 1284944d9fecSLuiz Capitulino } 1285944d9fecSLuiz Capitulino 12864eb0716eSAlexandre Ghiti #ifdef CONFIG_CONTIG_ALLOC 1287d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 1288d9cc948fSMichal Hocko int nid, nodemask_t *nodemask) 1289944d9fecSLuiz Capitulino { 129004adbc3fSMiaohe Lin unsigned long nr_pages = pages_per_huge_page(h); 1291953f064aSLi Xinhai if (nid == NUMA_NO_NODE) 1292953f064aSLi Xinhai nid = numa_mem_id(); 1293944d9fecSLuiz Capitulino 1294dbda8feaSBarry Song #ifdef CONFIG_CMA 1295dbda8feaSBarry Song { 1296cf11e85fSRoman Gushchin struct page *page; 1297cf11e85fSRoman Gushchin int node; 1298cf11e85fSRoman Gushchin 1299953f064aSLi Xinhai if (hugetlb_cma[nid]) { 1300953f064aSLi Xinhai page = cma_alloc(hugetlb_cma[nid], nr_pages, 1301953f064aSLi Xinhai huge_page_order(h), true); 1302953f064aSLi Xinhai if (page) 1303953f064aSLi Xinhai return page; 1304953f064aSLi Xinhai } 1305953f064aSLi Xinhai 1306953f064aSLi Xinhai if (!(gfp_mask & __GFP_THISNODE)) { 1307cf11e85fSRoman Gushchin for_each_node_mask(node, *nodemask) { 1308953f064aSLi Xinhai if (node == nid || !hugetlb_cma[node]) 1309cf11e85fSRoman Gushchin continue; 1310cf11e85fSRoman Gushchin 1311cf11e85fSRoman Gushchin page = cma_alloc(hugetlb_cma[node], nr_pages, 1312cf11e85fSRoman Gushchin huge_page_order(h), true); 1313cf11e85fSRoman Gushchin if (page) 1314cf11e85fSRoman Gushchin return page; 1315cf11e85fSRoman Gushchin } 1316cf11e85fSRoman Gushchin } 1317953f064aSLi Xinhai } 1318dbda8feaSBarry Song #endif 1319cf11e85fSRoman Gushchin 13205e27a2dfSAnshuman Khandual return alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask); 1321944d9fecSLuiz Capitulino } 1322944d9fecSLuiz Capitulino 13234eb0716eSAlexandre Ghiti #else /* !CONFIG_CONTIG_ALLOC */ 13244eb0716eSAlexandre Ghiti static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 13254eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 13264eb0716eSAlexandre Ghiti { 13274eb0716eSAlexandre Ghiti return NULL; 13284eb0716eSAlexandre Ghiti } 13294eb0716eSAlexandre Ghiti #endif /* CONFIG_CONTIG_ALLOC */ 1330944d9fecSLuiz Capitulino 1331e1073d1eSAneesh Kumar K.V #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ 1332d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 13334eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 13344eb0716eSAlexandre Ghiti { 13354eb0716eSAlexandre Ghiti return NULL; 13364eb0716eSAlexandre Ghiti } 1337d00181b9SKirill A. Shutemov static inline void free_gigantic_page(struct page *page, unsigned int order) { } 1338944d9fecSLuiz Capitulino static inline void destroy_compound_gigantic_page(struct page *page, 1339d00181b9SKirill A. Shutemov unsigned int order) { } 1340944d9fecSLuiz Capitulino #endif 1341944d9fecSLuiz Capitulino 13426eb4e88aSMike Kravetz /* 13436eb4e88aSMike Kravetz * Remove hugetlb page from lists, and update dtor so that page appears 13446eb4e88aSMike Kravetz * as just a compound page. A reference is held on the page. 13456eb4e88aSMike Kravetz * 13466eb4e88aSMike Kravetz * Must be called with hugetlb lock held. 13476eb4e88aSMike Kravetz */ 13486eb4e88aSMike Kravetz static void remove_hugetlb_page(struct hstate *h, struct page *page, 13496eb4e88aSMike Kravetz bool adjust_surplus) 13506eb4e88aSMike Kravetz { 13516eb4e88aSMike Kravetz int nid = page_to_nid(page); 13526eb4e88aSMike Kravetz 13536eb4e88aSMike Kravetz VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); 13546eb4e88aSMike Kravetz VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); 13556eb4e88aSMike Kravetz 13569487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 13576eb4e88aSMike Kravetz if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 13586eb4e88aSMike Kravetz return; 13596eb4e88aSMike Kravetz 13606eb4e88aSMike Kravetz list_del(&page->lru); 13616eb4e88aSMike Kravetz 13626eb4e88aSMike Kravetz if (HPageFreed(page)) { 13636eb4e88aSMike Kravetz h->free_huge_pages--; 13646eb4e88aSMike Kravetz h->free_huge_pages_node[nid]--; 13656eb4e88aSMike Kravetz } 13666eb4e88aSMike Kravetz if (adjust_surplus) { 13676eb4e88aSMike Kravetz h->surplus_huge_pages--; 13686eb4e88aSMike Kravetz h->surplus_huge_pages_node[nid]--; 13696eb4e88aSMike Kravetz } 13706eb4e88aSMike Kravetz 13716eb4e88aSMike Kravetz set_page_refcounted(page); 13726eb4e88aSMike Kravetz set_compound_page_dtor(page, NULL_COMPOUND_DTOR); 13736eb4e88aSMike Kravetz 13746eb4e88aSMike Kravetz h->nr_huge_pages--; 13756eb4e88aSMike Kravetz h->nr_huge_pages_node[nid]--; 13766eb4e88aSMike Kravetz } 13776eb4e88aSMike Kravetz 1378ad2fa371SMuchun Song static void add_hugetlb_page(struct hstate *h, struct page *page, 1379ad2fa371SMuchun Song bool adjust_surplus) 1380ad2fa371SMuchun Song { 1381ad2fa371SMuchun Song int zeroed; 1382ad2fa371SMuchun Song int nid = page_to_nid(page); 1383ad2fa371SMuchun Song 1384ad2fa371SMuchun Song VM_BUG_ON_PAGE(!HPageVmemmapOptimized(page), page); 1385ad2fa371SMuchun Song 1386ad2fa371SMuchun Song lockdep_assert_held(&hugetlb_lock); 1387ad2fa371SMuchun Song 1388ad2fa371SMuchun Song INIT_LIST_HEAD(&page->lru); 1389ad2fa371SMuchun Song h->nr_huge_pages++; 1390ad2fa371SMuchun Song h->nr_huge_pages_node[nid]++; 1391ad2fa371SMuchun Song 1392ad2fa371SMuchun Song if (adjust_surplus) { 1393ad2fa371SMuchun Song h->surplus_huge_pages++; 1394ad2fa371SMuchun Song h->surplus_huge_pages_node[nid]++; 1395ad2fa371SMuchun Song } 1396ad2fa371SMuchun Song 1397ad2fa371SMuchun Song set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1398ad2fa371SMuchun Song set_page_private(page, 0); 1399ad2fa371SMuchun Song SetHPageVmemmapOptimized(page); 1400ad2fa371SMuchun Song 1401ad2fa371SMuchun Song /* 1402ad2fa371SMuchun Song * This page is now managed by the hugetlb allocator and has 1403ad2fa371SMuchun Song * no users -- drop the last reference. 1404ad2fa371SMuchun Song */ 1405ad2fa371SMuchun Song zeroed = put_page_testzero(page); 1406ad2fa371SMuchun Song VM_BUG_ON_PAGE(!zeroed, page); 1407ad2fa371SMuchun Song arch_clear_hugepage_flags(page); 1408ad2fa371SMuchun Song enqueue_huge_page(h, page); 1409ad2fa371SMuchun Song } 1410ad2fa371SMuchun Song 1411b65d4adbSMuchun Song static void __update_and_free_page(struct hstate *h, struct page *page) 14126af2acb6SAdam Litke { 14136af2acb6SAdam Litke int i; 1414dbfee5aeSMike Kravetz struct page *subpage = page; 1415a5516438SAndi Kleen 14164eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 1417944d9fecSLuiz Capitulino return; 141818229df5SAndy Whitcroft 1419ad2fa371SMuchun Song if (alloc_huge_page_vmemmap(h, page)) { 1420ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 1421ad2fa371SMuchun Song /* 1422ad2fa371SMuchun Song * If we cannot allocate vmemmap pages, just refuse to free the 1423ad2fa371SMuchun Song * page and put the page back on the hugetlb free list and treat 1424ad2fa371SMuchun Song * as a surplus page. 1425ad2fa371SMuchun Song */ 1426ad2fa371SMuchun Song add_hugetlb_page(h, page, true); 1427ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 1428ad2fa371SMuchun Song return; 1429ad2fa371SMuchun Song } 1430ad2fa371SMuchun Song 1431dbfee5aeSMike Kravetz for (i = 0; i < pages_per_huge_page(h); 1432dbfee5aeSMike Kravetz i++, subpage = mem_map_next(subpage, page, i)) { 1433dbfee5aeSMike Kravetz subpage->flags &= ~(1 << PG_locked | 1 << PG_error | 143432f84528SChris Forbes 1 << PG_referenced | 1 << PG_dirty | 1435a7407a27SLuiz Capitulino 1 << PG_active | 1 << PG_private | 1436a7407a27SLuiz Capitulino 1 << PG_writeback); 14376af2acb6SAdam Litke } 1438944d9fecSLuiz Capitulino if (hstate_is_gigantic(h)) { 1439944d9fecSLuiz Capitulino destroy_compound_gigantic_page(page, huge_page_order(h)); 1440944d9fecSLuiz Capitulino free_gigantic_page(page, huge_page_order(h)); 1441944d9fecSLuiz Capitulino } else { 1442a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 14436af2acb6SAdam Litke } 1444944d9fecSLuiz Capitulino } 14456af2acb6SAdam Litke 1446b65d4adbSMuchun Song /* 1447b65d4adbSMuchun Song * As update_and_free_page() can be called under any context, so we cannot 1448b65d4adbSMuchun Song * use GFP_KERNEL to allocate vmemmap pages. However, we can defer the 1449b65d4adbSMuchun Song * actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate 1450b65d4adbSMuchun Song * the vmemmap pages. 1451b65d4adbSMuchun Song * 1452b65d4adbSMuchun Song * free_hpage_workfn() locklessly retrieves the linked list of pages to be 1453b65d4adbSMuchun Song * freed and frees them one-by-one. As the page->mapping pointer is going 1454b65d4adbSMuchun Song * to be cleared in free_hpage_workfn() anyway, it is reused as the llist_node 1455b65d4adbSMuchun Song * structure of a lockless linked list of huge pages to be freed. 1456b65d4adbSMuchun Song */ 1457b65d4adbSMuchun Song static LLIST_HEAD(hpage_freelist); 1458b65d4adbSMuchun Song 1459b65d4adbSMuchun Song static void free_hpage_workfn(struct work_struct *work) 1460b65d4adbSMuchun Song { 1461b65d4adbSMuchun Song struct llist_node *node; 1462b65d4adbSMuchun Song 1463b65d4adbSMuchun Song node = llist_del_all(&hpage_freelist); 1464b65d4adbSMuchun Song 1465b65d4adbSMuchun Song while (node) { 1466b65d4adbSMuchun Song struct page *page; 1467b65d4adbSMuchun Song struct hstate *h; 1468b65d4adbSMuchun Song 1469b65d4adbSMuchun Song page = container_of((struct address_space **)node, 1470b65d4adbSMuchun Song struct page, mapping); 1471b65d4adbSMuchun Song node = node->next; 1472b65d4adbSMuchun Song page->mapping = NULL; 1473b65d4adbSMuchun Song /* 1474b65d4adbSMuchun Song * The VM_BUG_ON_PAGE(!PageHuge(page), page) in page_hstate() 1475b65d4adbSMuchun Song * is going to trigger because a previous call to 1476b65d4adbSMuchun Song * remove_hugetlb_page() will set_compound_page_dtor(page, 1477b65d4adbSMuchun Song * NULL_COMPOUND_DTOR), so do not use page_hstate() directly. 1478b65d4adbSMuchun Song */ 1479b65d4adbSMuchun Song h = size_to_hstate(page_size(page)); 1480b65d4adbSMuchun Song 1481b65d4adbSMuchun Song __update_and_free_page(h, page); 1482b65d4adbSMuchun Song 1483b65d4adbSMuchun Song cond_resched(); 1484b65d4adbSMuchun Song } 1485b65d4adbSMuchun Song } 1486b65d4adbSMuchun Song static DECLARE_WORK(free_hpage_work, free_hpage_workfn); 1487b65d4adbSMuchun Song 1488b65d4adbSMuchun Song static inline void flush_free_hpage_work(struct hstate *h) 1489b65d4adbSMuchun Song { 1490b65d4adbSMuchun Song if (free_vmemmap_pages_per_hpage(h)) 1491b65d4adbSMuchun Song flush_work(&free_hpage_work); 1492b65d4adbSMuchun Song } 1493b65d4adbSMuchun Song 1494b65d4adbSMuchun Song static void update_and_free_page(struct hstate *h, struct page *page, 1495b65d4adbSMuchun Song bool atomic) 1496b65d4adbSMuchun Song { 1497ad2fa371SMuchun Song if (!HPageVmemmapOptimized(page) || !atomic) { 1498b65d4adbSMuchun Song __update_and_free_page(h, page); 1499b65d4adbSMuchun Song return; 1500b65d4adbSMuchun Song } 1501b65d4adbSMuchun Song 1502b65d4adbSMuchun Song /* 1503b65d4adbSMuchun Song * Defer freeing to avoid using GFP_ATOMIC to allocate vmemmap pages. 1504b65d4adbSMuchun Song * 1505b65d4adbSMuchun Song * Only call schedule_work() if hpage_freelist is previously 1506b65d4adbSMuchun Song * empty. Otherwise, schedule_work() had been called but the workfn 1507b65d4adbSMuchun Song * hasn't retrieved the list yet. 1508b65d4adbSMuchun Song */ 1509b65d4adbSMuchun Song if (llist_add((struct llist_node *)&page->mapping, &hpage_freelist)) 1510b65d4adbSMuchun Song schedule_work(&free_hpage_work); 1511b65d4adbSMuchun Song } 1512b65d4adbSMuchun Song 151310c6ec49SMike Kravetz static void update_and_free_pages_bulk(struct hstate *h, struct list_head *list) 151410c6ec49SMike Kravetz { 151510c6ec49SMike Kravetz struct page *page, *t_page; 151610c6ec49SMike Kravetz 151710c6ec49SMike Kravetz list_for_each_entry_safe(page, t_page, list, lru) { 1518b65d4adbSMuchun Song update_and_free_page(h, page, false); 151910c6ec49SMike Kravetz cond_resched(); 152010c6ec49SMike Kravetz } 152110c6ec49SMike Kravetz } 152210c6ec49SMike Kravetz 1523e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 1524e5ff2159SAndi Kleen { 1525e5ff2159SAndi Kleen struct hstate *h; 1526e5ff2159SAndi Kleen 1527e5ff2159SAndi Kleen for_each_hstate(h) { 1528e5ff2159SAndi Kleen if (huge_page_size(h) == size) 1529e5ff2159SAndi Kleen return h; 1530e5ff2159SAndi Kleen } 1531e5ff2159SAndi Kleen return NULL; 1532e5ff2159SAndi Kleen } 1533e5ff2159SAndi Kleen 1534db71ef79SMike Kravetz void free_huge_page(struct page *page) 153527a85ef1SDavid Gibson { 1536a5516438SAndi Kleen /* 1537a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 1538a5516438SAndi Kleen * compound page destructor. 1539a5516438SAndi Kleen */ 1540e5ff2159SAndi Kleen struct hstate *h = page_hstate(page); 15417893d1d5SAdam Litke int nid = page_to_nid(page); 1542d6995da3SMike Kravetz struct hugepage_subpool *spool = hugetlb_page_subpool(page); 154307443a85SJoonsoo Kim bool restore_reserve; 1544db71ef79SMike Kravetz unsigned long flags; 154527a85ef1SDavid Gibson 1546b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1547b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_mapcount(page), page); 15488ace22bcSYongkai Wu 1549d6995da3SMike Kravetz hugetlb_set_page_subpool(page, NULL); 15508ace22bcSYongkai Wu page->mapping = NULL; 1551d6995da3SMike Kravetz restore_reserve = HPageRestoreReserve(page); 1552d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 155327a85ef1SDavid Gibson 15541c5ecae3SMike Kravetz /* 1555d6995da3SMike Kravetz * If HPageRestoreReserve was set on page, page allocation consumed a 15560919e1b6SMike Kravetz * reservation. If the page was associated with a subpool, there 15570919e1b6SMike Kravetz * would have been a page reserved in the subpool before allocation 15580919e1b6SMike Kravetz * via hugepage_subpool_get_pages(). Since we are 'restoring' the 15596c26d310SMiaohe Lin * reservation, do not call hugepage_subpool_put_pages() as this will 15600919e1b6SMike Kravetz * remove the reserved page from the subpool. 15610919e1b6SMike Kravetz */ 15620919e1b6SMike Kravetz if (!restore_reserve) { 15630919e1b6SMike Kravetz /* 15640919e1b6SMike Kravetz * A return code of zero implies that the subpool will be 15650919e1b6SMike Kravetz * under its minimum size if the reservation is not restored 15660919e1b6SMike Kravetz * after page is free. Therefore, force restore_reserve 15670919e1b6SMike Kravetz * operation. 15681c5ecae3SMike Kravetz */ 15691c5ecae3SMike Kravetz if (hugepage_subpool_put_pages(spool, 1) == 0) 15701c5ecae3SMike Kravetz restore_reserve = true; 15710919e1b6SMike Kravetz } 15721c5ecae3SMike Kravetz 1573db71ef79SMike Kravetz spin_lock_irqsave(&hugetlb_lock, flags); 15748f251a3dSMike Kravetz ClearHPageMigratable(page); 15756d76dcf4SAneesh Kumar K.V hugetlb_cgroup_uncharge_page(hstate_index(h), 15766d76dcf4SAneesh Kumar K.V pages_per_huge_page(h), page); 157708cf9fafSMina Almasry hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 157808cf9fafSMina Almasry pages_per_huge_page(h), page); 157907443a85SJoonsoo Kim if (restore_reserve) 158007443a85SJoonsoo Kim h->resv_huge_pages++; 158107443a85SJoonsoo Kim 15829157c311SMike Kravetz if (HPageTemporary(page)) { 15836eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 1584db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1585b65d4adbSMuchun Song update_and_free_page(h, page, true); 1586ab5ac90aSMichal Hocko } else if (h->surplus_huge_pages_node[nid]) { 15870edaecfaSAneesh Kumar K.V /* remove the page from active list */ 15886eb4e88aSMike Kravetz remove_hugetlb_page(h, page, true); 1589db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 1590b65d4adbSMuchun Song update_and_free_page(h, page, true); 15917893d1d5SAdam Litke } else { 15925d3a551cSWill Deacon arch_clear_hugepage_flags(page); 1593a5516438SAndi Kleen enqueue_huge_page(h, page); 1594db71ef79SMike Kravetz spin_unlock_irqrestore(&hugetlb_lock, flags); 159527a85ef1SDavid Gibson } 15961121828aSMike Kravetz } 159727a85ef1SDavid Gibson 1598d3d99fccSOscar Salvador /* 1599d3d99fccSOscar Salvador * Must be called with the hugetlb lock held 1600d3d99fccSOscar Salvador */ 1601d3d99fccSOscar Salvador static void __prep_account_new_huge_page(struct hstate *h, int nid) 1602d3d99fccSOscar Salvador { 1603d3d99fccSOscar Salvador lockdep_assert_held(&hugetlb_lock); 1604d3d99fccSOscar Salvador h->nr_huge_pages++; 1605d3d99fccSOscar Salvador h->nr_huge_pages_node[nid]++; 1606d3d99fccSOscar Salvador } 1607d3d99fccSOscar Salvador 1608f41f2ed4SMuchun Song static void __prep_new_huge_page(struct hstate *h, struct page *page) 1609b7ba30c6SAndi Kleen { 1610f41f2ed4SMuchun Song free_huge_page_vmemmap(h, page); 16110edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&page->lru); 1612f1e61557SKirill A. Shutemov set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1613ff546117SMike Kravetz hugetlb_set_page_subpool(page, NULL); 16149dd540e2SAneesh Kumar K.V set_hugetlb_cgroup(page, NULL); 16151adc4d41SMina Almasry set_hugetlb_cgroup_rsvd(page, NULL); 1616d3d99fccSOscar Salvador } 1617d3d99fccSOscar Salvador 1618d3d99fccSOscar Salvador static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) 1619d3d99fccSOscar Salvador { 1620f41f2ed4SMuchun Song __prep_new_huge_page(h, page); 1621db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 1622d3d99fccSOscar Salvador __prep_account_new_huge_page(h, nid); 1623db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 1624b7ba30c6SAndi Kleen } 1625b7ba30c6SAndi Kleen 1626d00181b9SKirill A. Shutemov static void prep_compound_gigantic_page(struct page *page, unsigned int order) 162720a0307cSWu Fengguang { 162820a0307cSWu Fengguang int i; 162920a0307cSWu Fengguang int nr_pages = 1 << order; 163020a0307cSWu Fengguang struct page *p = page + 1; 163120a0307cSWu Fengguang 163220a0307cSWu Fengguang /* we rely on prep_new_huge_page to set the destructor */ 163320a0307cSWu Fengguang set_compound_order(page, order); 1634ef5a22beSAndrea Arcangeli __ClearPageReserved(page); 1635de09d31dSKirill A. Shutemov __SetPageHead(page); 163620a0307cSWu Fengguang for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 1637ef5a22beSAndrea Arcangeli /* 1638ef5a22beSAndrea Arcangeli * For gigantic hugepages allocated through bootmem at 1639ef5a22beSAndrea Arcangeli * boot, it's safer to be consistent with the not-gigantic 1640ef5a22beSAndrea Arcangeli * hugepages and clear the PG_reserved bit from all tail pages 16417c8de358SEthon Paul * too. Otherwise drivers using get_user_pages() to access tail 1642ef5a22beSAndrea Arcangeli * pages may get the reference counting wrong if they see 1643ef5a22beSAndrea Arcangeli * PG_reserved set on a tail page (despite the head page not 1644ef5a22beSAndrea Arcangeli * having PG_reserved set). Enforcing this consistency between 1645ef5a22beSAndrea Arcangeli * head and tail pages allows drivers to optimize away a check 1646ef5a22beSAndrea Arcangeli * on the head page when they need know if put_page() is needed 1647ef5a22beSAndrea Arcangeli * after get_user_pages(). 1648ef5a22beSAndrea Arcangeli */ 1649ef5a22beSAndrea Arcangeli __ClearPageReserved(p); 165058a84aa9SYouquan Song set_page_count(p, 0); 16511d798ca3SKirill A. Shutemov set_compound_head(p, page); 165220a0307cSWu Fengguang } 1653b4330afbSMike Kravetz atomic_set(compound_mapcount_ptr(page), -1); 165447e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 165520a0307cSWu Fengguang } 165620a0307cSWu Fengguang 16577795912cSAndrew Morton /* 16587795912cSAndrew Morton * PageHuge() only returns true for hugetlbfs pages, but not for normal or 16597795912cSAndrew Morton * transparent huge pages. See the PageTransHuge() documentation for more 16607795912cSAndrew Morton * details. 16617795912cSAndrew Morton */ 166220a0307cSWu Fengguang int PageHuge(struct page *page) 166320a0307cSWu Fengguang { 166420a0307cSWu Fengguang if (!PageCompound(page)) 166520a0307cSWu Fengguang return 0; 166620a0307cSWu Fengguang 166720a0307cSWu Fengguang page = compound_head(page); 1668f1e61557SKirill A. Shutemov return page[1].compound_dtor == HUGETLB_PAGE_DTOR; 166920a0307cSWu Fengguang } 167043131e14SNaoya Horiguchi EXPORT_SYMBOL_GPL(PageHuge); 167143131e14SNaoya Horiguchi 167227c73ae7SAndrea Arcangeli /* 167327c73ae7SAndrea Arcangeli * PageHeadHuge() only returns true for hugetlbfs head page, but not for 167427c73ae7SAndrea Arcangeli * normal or transparent huge pages. 167527c73ae7SAndrea Arcangeli */ 167627c73ae7SAndrea Arcangeli int PageHeadHuge(struct page *page_head) 167727c73ae7SAndrea Arcangeli { 167827c73ae7SAndrea Arcangeli if (!PageHead(page_head)) 167927c73ae7SAndrea Arcangeli return 0; 168027c73ae7SAndrea Arcangeli 1681d4af73e3SVlastimil Babka return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR; 168227c73ae7SAndrea Arcangeli } 168327c73ae7SAndrea Arcangeli 1684c0d0381aSMike Kravetz /* 1685c0d0381aSMike Kravetz * Find and lock address space (mapping) in write mode. 1686c0d0381aSMike Kravetz * 1687336bf30eSMike Kravetz * Upon entry, the page is locked which means that page_mapping() is 1688336bf30eSMike Kravetz * stable. Due to locking order, we can only trylock_write. If we can 1689336bf30eSMike Kravetz * not get the lock, simply return NULL to caller. 1690c0d0381aSMike Kravetz */ 1691c0d0381aSMike Kravetz struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage) 1692c0d0381aSMike Kravetz { 1693336bf30eSMike Kravetz struct address_space *mapping = page_mapping(hpage); 1694c0d0381aSMike Kravetz 1695c0d0381aSMike Kravetz if (!mapping) 1696c0d0381aSMike Kravetz return mapping; 1697c0d0381aSMike Kravetz 1698c0d0381aSMike Kravetz if (i_mmap_trylock_write(mapping)) 1699c0d0381aSMike Kravetz return mapping; 1700c0d0381aSMike Kravetz 1701c0d0381aSMike Kravetz return NULL; 1702c0d0381aSMike Kravetz } 1703c0d0381aSMike Kravetz 1704fe19bd3dSHugh Dickins pgoff_t hugetlb_basepage_index(struct page *page) 170513d60f4bSZhang Yi { 170613d60f4bSZhang Yi struct page *page_head = compound_head(page); 170713d60f4bSZhang Yi pgoff_t index = page_index(page_head); 170813d60f4bSZhang Yi unsigned long compound_idx; 170913d60f4bSZhang Yi 171013d60f4bSZhang Yi if (compound_order(page_head) >= MAX_ORDER) 171113d60f4bSZhang Yi compound_idx = page_to_pfn(page) - page_to_pfn(page_head); 171213d60f4bSZhang Yi else 171313d60f4bSZhang Yi compound_idx = page - page_head; 171413d60f4bSZhang Yi 171513d60f4bSZhang Yi return (index << compound_order(page_head)) + compound_idx; 171613d60f4bSZhang Yi } 171713d60f4bSZhang Yi 17180c397daeSMichal Hocko static struct page *alloc_buddy_huge_page(struct hstate *h, 1719f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1720f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 17211da177e4SLinus Torvalds { 1722af0fb9dfSMichal Hocko int order = huge_page_order(h); 17231da177e4SLinus Torvalds struct page *page; 1724f60858f9SMike Kravetz bool alloc_try_hard = true; 1725f96efd58SJoe Jin 1726f60858f9SMike Kravetz /* 1727f60858f9SMike Kravetz * By default we always try hard to allocate the page with 1728f60858f9SMike Kravetz * __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in 1729f60858f9SMike Kravetz * a loop (to adjust global huge page counts) and previous allocation 1730f60858f9SMike Kravetz * failed, do not continue to try hard on the same node. Use the 1731f60858f9SMike Kravetz * node_alloc_noretry bitmap to manage this state information. 1732f60858f9SMike Kravetz */ 1733f60858f9SMike Kravetz if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry)) 1734f60858f9SMike Kravetz alloc_try_hard = false; 1735f60858f9SMike Kravetz gfp_mask |= __GFP_COMP|__GFP_NOWARN; 1736f60858f9SMike Kravetz if (alloc_try_hard) 1737f60858f9SMike Kravetz gfp_mask |= __GFP_RETRY_MAYFAIL; 1738af0fb9dfSMichal Hocko if (nid == NUMA_NO_NODE) 1739af0fb9dfSMichal Hocko nid = numa_mem_id(); 174084172f4bSMatthew Wilcox (Oracle) page = __alloc_pages(gfp_mask, order, nid, nmask); 1741af0fb9dfSMichal Hocko if (page) 1742af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC); 1743af0fb9dfSMichal Hocko else 1744af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 174563b4613cSNishanth Aravamudan 1746f60858f9SMike Kravetz /* 1747f60858f9SMike Kravetz * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this 1748f60858f9SMike Kravetz * indicates an overall state change. Clear bit so that we resume 1749f60858f9SMike Kravetz * normal 'try hard' allocations. 1750f60858f9SMike Kravetz */ 1751f60858f9SMike Kravetz if (node_alloc_noretry && page && !alloc_try_hard) 1752f60858f9SMike Kravetz node_clear(nid, *node_alloc_noretry); 1753f60858f9SMike Kravetz 1754f60858f9SMike Kravetz /* 1755f60858f9SMike Kravetz * If we tried hard to get a page but failed, set bit so that 1756f60858f9SMike Kravetz * subsequent attempts will not try as hard until there is an 1757f60858f9SMike Kravetz * overall state change. 1758f60858f9SMike Kravetz */ 1759f60858f9SMike Kravetz if (node_alloc_noretry && !page && alloc_try_hard) 1760f60858f9SMike Kravetz node_set(nid, *node_alloc_noretry); 1761f60858f9SMike Kravetz 176263b4613cSNishanth Aravamudan return page; 176363b4613cSNishanth Aravamudan } 176463b4613cSNishanth Aravamudan 1765af0fb9dfSMichal Hocko /* 17660c397daeSMichal Hocko * Common helper to allocate a fresh hugetlb page. All specific allocators 17670c397daeSMichal Hocko * should use this function to get new hugetlb pages 17680c397daeSMichal Hocko */ 17690c397daeSMichal Hocko static struct page *alloc_fresh_huge_page(struct hstate *h, 1770f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1771f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 17720c397daeSMichal Hocko { 17730c397daeSMichal Hocko struct page *page; 17740c397daeSMichal Hocko 17750c397daeSMichal Hocko if (hstate_is_gigantic(h)) 17760c397daeSMichal Hocko page = alloc_gigantic_page(h, gfp_mask, nid, nmask); 17770c397daeSMichal Hocko else 17780c397daeSMichal Hocko page = alloc_buddy_huge_page(h, gfp_mask, 1779f60858f9SMike Kravetz nid, nmask, node_alloc_noretry); 17800c397daeSMichal Hocko if (!page) 17810c397daeSMichal Hocko return NULL; 17820c397daeSMichal Hocko 17830c397daeSMichal Hocko if (hstate_is_gigantic(h)) 17840c397daeSMichal Hocko prep_compound_gigantic_page(page, huge_page_order(h)); 17850c397daeSMichal Hocko prep_new_huge_page(h, page, page_to_nid(page)); 17860c397daeSMichal Hocko 17870c397daeSMichal Hocko return page; 17880c397daeSMichal Hocko } 17890c397daeSMichal Hocko 17900c397daeSMichal Hocko /* 1791af0fb9dfSMichal Hocko * Allocates a fresh page to the hugetlb allocator pool in the node interleaved 1792af0fb9dfSMichal Hocko * manner. 1793af0fb9dfSMichal Hocko */ 1794f60858f9SMike Kravetz static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 1795f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 1796b2261026SJoonsoo Kim { 1797b2261026SJoonsoo Kim struct page *page; 1798b2261026SJoonsoo Kim int nr_nodes, node; 1799af0fb9dfSMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 1800b2261026SJoonsoo Kim 1801b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 1802f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed, 1803f60858f9SMike Kravetz node_alloc_noretry); 1804af0fb9dfSMichal Hocko if (page) 1805b2261026SJoonsoo Kim break; 1806b2261026SJoonsoo Kim } 1807b2261026SJoonsoo Kim 1808af0fb9dfSMichal Hocko if (!page) 1809af0fb9dfSMichal Hocko return 0; 1810b2261026SJoonsoo Kim 1811af0fb9dfSMichal Hocko put_page(page); /* free it into the hugepage allocator */ 1812af0fb9dfSMichal Hocko 1813af0fb9dfSMichal Hocko return 1; 1814b2261026SJoonsoo Kim } 1815b2261026SJoonsoo Kim 1816e8c5c824SLee Schermerhorn /* 181710c6ec49SMike Kravetz * Remove huge page from pool from next node to free. Attempt to keep 181810c6ec49SMike Kravetz * persistent huge pages more or less balanced over allowed nodes. 181910c6ec49SMike Kravetz * This routine only 'removes' the hugetlb page. The caller must make 182010c6ec49SMike Kravetz * an additional call to free the page to low level allocators. 1821e8c5c824SLee Schermerhorn * Called with hugetlb_lock locked. 1822e8c5c824SLee Schermerhorn */ 182310c6ec49SMike Kravetz static struct page *remove_pool_huge_page(struct hstate *h, 182410c6ec49SMike Kravetz nodemask_t *nodes_allowed, 18256ae11b27SLee Schermerhorn bool acct_surplus) 1826e8c5c824SLee Schermerhorn { 1827b2261026SJoonsoo Kim int nr_nodes, node; 182810c6ec49SMike Kravetz struct page *page = NULL; 1829e8c5c824SLee Schermerhorn 18309487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 1831b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 1832685f3457SLee Schermerhorn /* 1833685f3457SLee Schermerhorn * If we're returning unused surplus pages, only examine 1834685f3457SLee Schermerhorn * nodes with surplus pages. 1835685f3457SLee Schermerhorn */ 1836b2261026SJoonsoo Kim if ((!acct_surplus || h->surplus_huge_pages_node[node]) && 1837b2261026SJoonsoo Kim !list_empty(&h->hugepage_freelists[node])) { 183810c6ec49SMike Kravetz page = list_entry(h->hugepage_freelists[node].next, 1839e8c5c824SLee Schermerhorn struct page, lru); 18406eb4e88aSMike Kravetz remove_hugetlb_page(h, page, acct_surplus); 18419a76db09SLee Schermerhorn break; 1842e8c5c824SLee Schermerhorn } 1843b2261026SJoonsoo Kim } 1844e8c5c824SLee Schermerhorn 184510c6ec49SMike Kravetz return page; 1846e8c5c824SLee Schermerhorn } 1847e8c5c824SLee Schermerhorn 1848c8721bbbSNaoya Horiguchi /* 1849c8721bbbSNaoya Horiguchi * Dissolve a given free hugepage into free buddy pages. This function does 1850faf53defSNaoya Horiguchi * nothing for in-use hugepages and non-hugepages. 1851faf53defSNaoya Horiguchi * This function returns values like below: 1852faf53defSNaoya Horiguchi * 1853ad2fa371SMuchun Song * -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages 1854ad2fa371SMuchun Song * when the system is under memory pressure and the feature of 1855ad2fa371SMuchun Song * freeing unused vmemmap pages associated with each hugetlb page 1856ad2fa371SMuchun Song * is enabled. 1857faf53defSNaoya Horiguchi * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use 1858faf53defSNaoya Horiguchi * (allocated or reserved.) 1859faf53defSNaoya Horiguchi * 0: successfully dissolved free hugepages or the page is not a 1860faf53defSNaoya Horiguchi * hugepage (considered as already dissolved) 1861c8721bbbSNaoya Horiguchi */ 1862c3114a84SAnshuman Khandual int dissolve_free_huge_page(struct page *page) 1863c8721bbbSNaoya Horiguchi { 18646bc9b564SNaoya Horiguchi int rc = -EBUSY; 1865082d5b6bSGerald Schaefer 18667ffddd49SMuchun Song retry: 1867faf53defSNaoya Horiguchi /* Not to disrupt normal path by vainly holding hugetlb_lock */ 1868faf53defSNaoya Horiguchi if (!PageHuge(page)) 1869faf53defSNaoya Horiguchi return 0; 1870faf53defSNaoya Horiguchi 1871db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 1872faf53defSNaoya Horiguchi if (!PageHuge(page)) { 1873faf53defSNaoya Horiguchi rc = 0; 1874faf53defSNaoya Horiguchi goto out; 1875faf53defSNaoya Horiguchi } 1876faf53defSNaoya Horiguchi 1877faf53defSNaoya Horiguchi if (!page_count(page)) { 18782247bb33SGerald Schaefer struct page *head = compound_head(page); 18792247bb33SGerald Schaefer struct hstate *h = page_hstate(head); 18806bc9b564SNaoya Horiguchi if (h->free_huge_pages - h->resv_huge_pages == 0) 1881082d5b6bSGerald Schaefer goto out; 18827ffddd49SMuchun Song 18837ffddd49SMuchun Song /* 18847ffddd49SMuchun Song * We should make sure that the page is already on the free list 18857ffddd49SMuchun Song * when it is dissolved. 18867ffddd49SMuchun Song */ 18876c037149SMike Kravetz if (unlikely(!HPageFreed(head))) { 1888db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 18897ffddd49SMuchun Song cond_resched(); 18907ffddd49SMuchun Song 18917ffddd49SMuchun Song /* 18927ffddd49SMuchun Song * Theoretically, we should return -EBUSY when we 18937ffddd49SMuchun Song * encounter this race. In fact, we have a chance 18947ffddd49SMuchun Song * to successfully dissolve the page if we do a 18957ffddd49SMuchun Song * retry. Because the race window is quite small. 18967ffddd49SMuchun Song * If we seize this opportunity, it is an optimization 18977ffddd49SMuchun Song * for increasing the success rate of dissolving page. 18987ffddd49SMuchun Song */ 18997ffddd49SMuchun Song goto retry; 19007ffddd49SMuchun Song } 19017ffddd49SMuchun Song 1902ad2fa371SMuchun Song remove_hugetlb_page(h, head, false); 1903ad2fa371SMuchun Song h->max_huge_pages--; 1904ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 1905ad2fa371SMuchun Song 1906c3114a84SAnshuman Khandual /* 1907ad2fa371SMuchun Song * Normally update_and_free_page will allocate required vmemmmap 1908ad2fa371SMuchun Song * before freeing the page. update_and_free_page will fail to 1909ad2fa371SMuchun Song * free the page if it can not allocate required vmemmap. We 1910ad2fa371SMuchun Song * need to adjust max_huge_pages if the page is not freed. 1911ad2fa371SMuchun Song * Attempt to allocate vmemmmap here so that we can take 1912ad2fa371SMuchun Song * appropriate action on failure. 1913ad2fa371SMuchun Song */ 1914ad2fa371SMuchun Song rc = alloc_huge_page_vmemmap(h, head); 1915ad2fa371SMuchun Song if (!rc) { 1916ad2fa371SMuchun Song /* 1917ad2fa371SMuchun Song * Move PageHWPoison flag from head page to the raw 1918ad2fa371SMuchun Song * error page, which makes any subpages rather than 1919ad2fa371SMuchun Song * the error page reusable. 1920c3114a84SAnshuman Khandual */ 1921c3114a84SAnshuman Khandual if (PageHWPoison(head) && page != head) { 1922c3114a84SAnshuman Khandual SetPageHWPoison(page); 1923c3114a84SAnshuman Khandual ClearPageHWPoison(head); 1924c3114a84SAnshuman Khandual } 1925b65d4adbSMuchun Song update_and_free_page(h, head, false); 1926ad2fa371SMuchun Song } else { 1927ad2fa371SMuchun Song spin_lock_irq(&hugetlb_lock); 1928ad2fa371SMuchun Song add_hugetlb_page(h, head, false); 1929ad2fa371SMuchun Song h->max_huge_pages++; 1930ad2fa371SMuchun Song spin_unlock_irq(&hugetlb_lock); 1931ad2fa371SMuchun Song } 1932ad2fa371SMuchun Song 1933ad2fa371SMuchun Song return rc; 1934c8721bbbSNaoya Horiguchi } 1935082d5b6bSGerald Schaefer out: 1936db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 1937082d5b6bSGerald Schaefer return rc; 1938c8721bbbSNaoya Horiguchi } 1939c8721bbbSNaoya Horiguchi 1940c8721bbbSNaoya Horiguchi /* 1941c8721bbbSNaoya Horiguchi * Dissolve free hugepages in a given pfn range. Used by memory hotplug to 1942c8721bbbSNaoya Horiguchi * make specified memory blocks removable from the system. 19432247bb33SGerald Schaefer * Note that this will dissolve a free gigantic hugepage completely, if any 19442247bb33SGerald Schaefer * part of it lies within the given range. 1945082d5b6bSGerald Schaefer * Also note that if dissolve_free_huge_page() returns with an error, all 1946082d5b6bSGerald Schaefer * free hugepages that were dissolved before that error are lost. 1947c8721bbbSNaoya Horiguchi */ 1948082d5b6bSGerald Schaefer int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) 1949c8721bbbSNaoya Horiguchi { 1950c8721bbbSNaoya Horiguchi unsigned long pfn; 1951eb03aa00SGerald Schaefer struct page *page; 1952082d5b6bSGerald Schaefer int rc = 0; 1953c8721bbbSNaoya Horiguchi 1954d0177639SLi Zhong if (!hugepages_supported()) 1955082d5b6bSGerald Schaefer return rc; 1956d0177639SLi Zhong 1957eb03aa00SGerald Schaefer for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) { 1958eb03aa00SGerald Schaefer page = pfn_to_page(pfn); 1959eb03aa00SGerald Schaefer rc = dissolve_free_huge_page(page); 1960eb03aa00SGerald Schaefer if (rc) 1961082d5b6bSGerald Schaefer break; 1962eb03aa00SGerald Schaefer } 1963082d5b6bSGerald Schaefer 1964082d5b6bSGerald Schaefer return rc; 1965c8721bbbSNaoya Horiguchi } 1966c8721bbbSNaoya Horiguchi 1967ab5ac90aSMichal Hocko /* 1968ab5ac90aSMichal Hocko * Allocates a fresh surplus page from the page allocator. 1969ab5ac90aSMichal Hocko */ 19700c397daeSMichal Hocko static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, 1971aaf14e40SMichal Hocko int nid, nodemask_t *nmask) 19727893d1d5SAdam Litke { 19739980d744SMichal Hocko struct page *page = NULL; 19747893d1d5SAdam Litke 1975bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 1976aa888a74SAndi Kleen return NULL; 1977aa888a74SAndi Kleen 1978db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 19799980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) 19809980d744SMichal Hocko goto out_unlock; 1981db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 1982d1c3fb1fSNishanth Aravamudan 1983f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 19849980d744SMichal Hocko if (!page) 19850c397daeSMichal Hocko return NULL; 1986d1c3fb1fSNishanth Aravamudan 1987db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 19889980d744SMichal Hocko /* 19899980d744SMichal Hocko * We could have raced with the pool size change. 19909980d744SMichal Hocko * Double check that and simply deallocate the new page 19919980d744SMichal Hocko * if we would end up overcommiting the surpluses. Abuse 19929980d744SMichal Hocko * temporary page to workaround the nasty free_huge_page 19939980d744SMichal Hocko * codeflow 19949980d744SMichal Hocko */ 19959980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 19969157c311SMike Kravetz SetHPageTemporary(page); 1997db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 19989980d744SMichal Hocko put_page(page); 19992bf753e6SKai Shen return NULL; 20009980d744SMichal Hocko } else { 20019980d744SMichal Hocko h->surplus_huge_pages++; 20024704dea3SMichal Hocko h->surplus_huge_pages_node[page_to_nid(page)]++; 20037893d1d5SAdam Litke } 20049980d744SMichal Hocko 20059980d744SMichal Hocko out_unlock: 2006db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 20077893d1d5SAdam Litke 20087893d1d5SAdam Litke return page; 20097893d1d5SAdam Litke } 20107893d1d5SAdam Litke 2011bbe88753SJoonsoo Kim static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, 2012ab5ac90aSMichal Hocko int nid, nodemask_t *nmask) 2013ab5ac90aSMichal Hocko { 2014ab5ac90aSMichal Hocko struct page *page; 2015ab5ac90aSMichal Hocko 2016ab5ac90aSMichal Hocko if (hstate_is_gigantic(h)) 2017ab5ac90aSMichal Hocko return NULL; 2018ab5ac90aSMichal Hocko 2019f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 2020ab5ac90aSMichal Hocko if (!page) 2021ab5ac90aSMichal Hocko return NULL; 2022ab5ac90aSMichal Hocko 2023ab5ac90aSMichal Hocko /* 2024ab5ac90aSMichal Hocko * We do not account these pages as surplus because they are only 2025ab5ac90aSMichal Hocko * temporary and will be released properly on the last reference 2026ab5ac90aSMichal Hocko */ 20279157c311SMike Kravetz SetHPageTemporary(page); 2028ab5ac90aSMichal Hocko 2029ab5ac90aSMichal Hocko return page; 2030ab5ac90aSMichal Hocko } 2031ab5ac90aSMichal Hocko 2032e4e574b7SAdam Litke /* 2033099730d6SDave Hansen * Use the VMA's mpolicy to allocate a huge page from the buddy. 2034099730d6SDave Hansen */ 2035e0ec90eeSDave Hansen static 20360c397daeSMichal Hocko struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h, 2037099730d6SDave Hansen struct vm_area_struct *vma, unsigned long addr) 2038099730d6SDave Hansen { 2039aaf14e40SMichal Hocko struct page *page; 2040aaf14e40SMichal Hocko struct mempolicy *mpol; 2041aaf14e40SMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h); 2042aaf14e40SMichal Hocko int nid; 2043aaf14e40SMichal Hocko nodemask_t *nodemask; 2044aaf14e40SMichal Hocko 2045aaf14e40SMichal Hocko nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); 20460c397daeSMichal Hocko page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask); 2047aaf14e40SMichal Hocko mpol_cond_put(mpol); 2048aaf14e40SMichal Hocko 2049aaf14e40SMichal Hocko return page; 2050099730d6SDave Hansen } 2051099730d6SDave Hansen 2052ab5ac90aSMichal Hocko /* page migration callback function */ 20533e59fcb0SMichal Hocko struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, 2054d92bbc27SJoonsoo Kim nodemask_t *nmask, gfp_t gfp_mask) 20554db9b2efSMichal Hocko { 2056db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 20574db9b2efSMichal Hocko if (h->free_huge_pages - h->resv_huge_pages > 0) { 20583e59fcb0SMichal Hocko struct page *page; 20593e59fcb0SMichal Hocko 20603e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask); 20613e59fcb0SMichal Hocko if (page) { 2062db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 20633e59fcb0SMichal Hocko return page; 20644db9b2efSMichal Hocko } 20654db9b2efSMichal Hocko } 2066db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 20674db9b2efSMichal Hocko 20680c397daeSMichal Hocko return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask); 20694db9b2efSMichal Hocko } 20704db9b2efSMichal Hocko 2071ebd63723SMichal Hocko /* mempolicy aware migration callback */ 2072389c8178SMichal Hocko struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, 2073389c8178SMichal Hocko unsigned long address) 2074ebd63723SMichal Hocko { 2075ebd63723SMichal Hocko struct mempolicy *mpol; 2076ebd63723SMichal Hocko nodemask_t *nodemask; 2077ebd63723SMichal Hocko struct page *page; 2078ebd63723SMichal Hocko gfp_t gfp_mask; 2079ebd63723SMichal Hocko int node; 2080ebd63723SMichal Hocko 2081ebd63723SMichal Hocko gfp_mask = htlb_alloc_mask(h); 2082ebd63723SMichal Hocko node = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 2083d92bbc27SJoonsoo Kim page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask); 2084ebd63723SMichal Hocko mpol_cond_put(mpol); 2085ebd63723SMichal Hocko 2086ebd63723SMichal Hocko return page; 2087ebd63723SMichal Hocko } 2088ebd63723SMichal Hocko 2089bf50bab2SNaoya Horiguchi /* 209025985edcSLucas De Marchi * Increase the hugetlb pool such that it can accommodate a reservation 2091e4e574b7SAdam Litke * of size 'delta'. 2092e4e574b7SAdam Litke */ 20930a4f3d1bSLiu Xiang static int gather_surplus_pages(struct hstate *h, long delta) 20941b2a1e7bSJules Irenge __must_hold(&hugetlb_lock) 2095e4e574b7SAdam Litke { 2096e4e574b7SAdam Litke struct list_head surplus_list; 2097e4e574b7SAdam Litke struct page *page, *tmp; 20980a4f3d1bSLiu Xiang int ret; 20990a4f3d1bSLiu Xiang long i; 21000a4f3d1bSLiu Xiang long needed, allocated; 210128073b02SHillf Danton bool alloc_ok = true; 2102e4e574b7SAdam Litke 21039487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2104a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 2105ac09b3a1SAdam Litke if (needed <= 0) { 2106a5516438SAndi Kleen h->resv_huge_pages += delta; 2107e4e574b7SAdam Litke return 0; 2108ac09b3a1SAdam Litke } 2109e4e574b7SAdam Litke 2110e4e574b7SAdam Litke allocated = 0; 2111e4e574b7SAdam Litke INIT_LIST_HEAD(&surplus_list); 2112e4e574b7SAdam Litke 2113e4e574b7SAdam Litke ret = -ENOMEM; 2114e4e574b7SAdam Litke retry: 2115db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2116e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 21170c397daeSMichal Hocko page = alloc_surplus_huge_page(h, htlb_alloc_mask(h), 2118aaf14e40SMichal Hocko NUMA_NO_NODE, NULL); 211928073b02SHillf Danton if (!page) { 212028073b02SHillf Danton alloc_ok = false; 212128073b02SHillf Danton break; 212228073b02SHillf Danton } 2123e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 212469ed779aSDavid Rientjes cond_resched(); 2125e4e574b7SAdam Litke } 212628073b02SHillf Danton allocated += i; 2127e4e574b7SAdam Litke 2128e4e574b7SAdam Litke /* 2129e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 2130e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 2131e4e574b7SAdam Litke */ 2132db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2133a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 2134a5516438SAndi Kleen (h->free_huge_pages + allocated); 213528073b02SHillf Danton if (needed > 0) { 213628073b02SHillf Danton if (alloc_ok) 2137e4e574b7SAdam Litke goto retry; 213828073b02SHillf Danton /* 213928073b02SHillf Danton * We were not able to allocate enough pages to 214028073b02SHillf Danton * satisfy the entire reservation so we free what 214128073b02SHillf Danton * we've allocated so far. 214228073b02SHillf Danton */ 214328073b02SHillf Danton goto free; 214428073b02SHillf Danton } 2145e4e574b7SAdam Litke /* 2146e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 214725985edcSLucas De Marchi * needed to accommodate the reservation. Add the appropriate number 2148e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 2149ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 2150ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 2151ac09b3a1SAdam Litke * before they are reserved. 2152e4e574b7SAdam Litke */ 2153e4e574b7SAdam Litke needed += allocated; 2154a5516438SAndi Kleen h->resv_huge_pages += delta; 2155e4e574b7SAdam Litke ret = 0; 2156a9869b83SNaoya Horiguchi 215719fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 215819fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 2159e558464bSMuchun Song int zeroed; 2160e558464bSMuchun Song 216119fc3f0aSAdam Litke if ((--needed) < 0) 216219fc3f0aSAdam Litke break; 2163a9869b83SNaoya Horiguchi /* 2164a9869b83SNaoya Horiguchi * This page is now managed by the hugetlb allocator and has 2165a9869b83SNaoya Horiguchi * no users -- drop the buddy allocator's reference. 2166a9869b83SNaoya Horiguchi */ 2167e558464bSMuchun Song zeroed = put_page_testzero(page); 2168e558464bSMuchun Song VM_BUG_ON_PAGE(!zeroed, page); 2169a5516438SAndi Kleen enqueue_huge_page(h, page); 217019fc3f0aSAdam Litke } 217128073b02SHillf Danton free: 2172db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 217319fc3f0aSAdam Litke 217419fc3f0aSAdam Litke /* Free unnecessary surplus pages to the buddy allocator */ 2175c0d934baSJoonsoo Kim list_for_each_entry_safe(page, tmp, &surplus_list, lru) 2176a9869b83SNaoya Horiguchi put_page(page); 2177db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2178e4e574b7SAdam Litke 2179e4e574b7SAdam Litke return ret; 2180e4e574b7SAdam Litke } 2181e4e574b7SAdam Litke 2182e4e574b7SAdam Litke /* 2183e5bbc8a6SMike Kravetz * This routine has two main purposes: 2184e5bbc8a6SMike Kravetz * 1) Decrement the reservation count (resv_huge_pages) by the value passed 2185e5bbc8a6SMike Kravetz * in unused_resv_pages. This corresponds to the prior adjustments made 2186e5bbc8a6SMike Kravetz * to the associated reservation map. 2187e5bbc8a6SMike Kravetz * 2) Free any unused surplus pages that may have been allocated to satisfy 2188e5bbc8a6SMike Kravetz * the reservation. As many as unused_resv_pages may be freed. 2189e4e574b7SAdam Litke */ 2190a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 2191a5516438SAndi Kleen unsigned long unused_resv_pages) 2192e4e574b7SAdam Litke { 2193e4e574b7SAdam Litke unsigned long nr_pages; 219410c6ec49SMike Kravetz struct page *page; 219510c6ec49SMike Kravetz LIST_HEAD(page_list); 219610c6ec49SMike Kravetz 21979487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 219810c6ec49SMike Kravetz /* Uncommit the reservation */ 219910c6ec49SMike Kravetz h->resv_huge_pages -= unused_resv_pages; 2200e4e574b7SAdam Litke 2201aa888a74SAndi Kleen /* Cannot return gigantic pages currently */ 2202bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2203e5bbc8a6SMike Kravetz goto out; 2204aa888a74SAndi Kleen 2205e5bbc8a6SMike Kravetz /* 2206e5bbc8a6SMike Kravetz * Part (or even all) of the reservation could have been backed 2207e5bbc8a6SMike Kravetz * by pre-allocated pages. Only free surplus pages. 2208e5bbc8a6SMike Kravetz */ 2209a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 2210e4e574b7SAdam Litke 2211685f3457SLee Schermerhorn /* 2212685f3457SLee Schermerhorn * We want to release as many surplus pages as possible, spread 22139b5e5d0fSLee Schermerhorn * evenly across all nodes with memory. Iterate across these nodes 22149b5e5d0fSLee Schermerhorn * until we can no longer free unreserved surplus pages. This occurs 22159b5e5d0fSLee Schermerhorn * when the nodes with surplus pages have no free pages. 221610c6ec49SMike Kravetz * remove_pool_huge_page() will balance the freed pages across the 22179b5e5d0fSLee Schermerhorn * on-line nodes with memory and will handle the hstate accounting. 2218685f3457SLee Schermerhorn */ 2219685f3457SLee Schermerhorn while (nr_pages--) { 222010c6ec49SMike Kravetz page = remove_pool_huge_page(h, &node_states[N_MEMORY], 1); 222110c6ec49SMike Kravetz if (!page) 2222e5bbc8a6SMike Kravetz goto out; 222310c6ec49SMike Kravetz 222410c6ec49SMike Kravetz list_add(&page->lru, &page_list); 2225e4e574b7SAdam Litke } 2226e5bbc8a6SMike Kravetz 2227e5bbc8a6SMike Kravetz out: 2228db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 222910c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 2230db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2231e4e574b7SAdam Litke } 2232e4e574b7SAdam Litke 22335e911373SMike Kravetz 2234c37f9fb1SAndy Whitcroft /* 2235feba16e2SMike Kravetz * vma_needs_reservation, vma_commit_reservation and vma_end_reservation 22365e911373SMike Kravetz * are used by the huge page allocation routines to manage reservations. 2237cf3ad20bSMike Kravetz * 2238cf3ad20bSMike Kravetz * vma_needs_reservation is called to determine if the huge page at addr 2239cf3ad20bSMike Kravetz * within the vma has an associated reservation. If a reservation is 2240cf3ad20bSMike Kravetz * needed, the value 1 is returned. The caller is then responsible for 2241cf3ad20bSMike Kravetz * managing the global reservation and subpool usage counts. After 2242cf3ad20bSMike Kravetz * the huge page has been allocated, vma_commit_reservation is called 2243feba16e2SMike Kravetz * to add the page to the reservation map. If the page allocation fails, 2244feba16e2SMike Kravetz * the reservation must be ended instead of committed. vma_end_reservation 2245feba16e2SMike Kravetz * is called in such cases. 2246cf3ad20bSMike Kravetz * 2247cf3ad20bSMike Kravetz * In the normal case, vma_commit_reservation returns the same value 2248cf3ad20bSMike Kravetz * as the preceding vma_needs_reservation call. The only time this 2249cf3ad20bSMike Kravetz * is not the case is if a reserve map was changed between calls. It 2250cf3ad20bSMike Kravetz * is the responsibility of the caller to notice the difference and 2251cf3ad20bSMike Kravetz * take appropriate action. 225296b96a96SMike Kravetz * 225396b96a96SMike Kravetz * vma_add_reservation is used in error paths where a reservation must 225496b96a96SMike Kravetz * be restored when a newly allocated huge page must be freed. It is 225596b96a96SMike Kravetz * to be called after calling vma_needs_reservation to determine if a 225696b96a96SMike Kravetz * reservation exists. 2257846be085SMike Kravetz * 2258846be085SMike Kravetz * vma_del_reservation is used in error paths where an entry in the reserve 2259846be085SMike Kravetz * map was created during huge page allocation and must be removed. It is to 2260846be085SMike Kravetz * be called after calling vma_needs_reservation to determine if a reservation 2261846be085SMike Kravetz * exists. 2262c37f9fb1SAndy Whitcroft */ 22635e911373SMike Kravetz enum vma_resv_mode { 22645e911373SMike Kravetz VMA_NEEDS_RESV, 22655e911373SMike Kravetz VMA_COMMIT_RESV, 2266feba16e2SMike Kravetz VMA_END_RESV, 226796b96a96SMike Kravetz VMA_ADD_RESV, 2268846be085SMike Kravetz VMA_DEL_RESV, 22695e911373SMike Kravetz }; 2270cf3ad20bSMike Kravetz static long __vma_reservation_common(struct hstate *h, 2271cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr, 22725e911373SMike Kravetz enum vma_resv_mode mode) 2273c37f9fb1SAndy Whitcroft { 22744e35f483SJoonsoo Kim struct resv_map *resv; 22754e35f483SJoonsoo Kim pgoff_t idx; 2276cf3ad20bSMike Kravetz long ret; 22770db9d74eSMina Almasry long dummy_out_regions_needed; 2278c37f9fb1SAndy Whitcroft 22794e35f483SJoonsoo Kim resv = vma_resv_map(vma); 22804e35f483SJoonsoo Kim if (!resv) 2281c37f9fb1SAndy Whitcroft return 1; 2282c37f9fb1SAndy Whitcroft 22834e35f483SJoonsoo Kim idx = vma_hugecache_offset(h, vma, addr); 22845e911373SMike Kravetz switch (mode) { 22855e911373SMike Kravetz case VMA_NEEDS_RESV: 22860db9d74eSMina Almasry ret = region_chg(resv, idx, idx + 1, &dummy_out_regions_needed); 22870db9d74eSMina Almasry /* We assume that vma_reservation_* routines always operate on 22880db9d74eSMina Almasry * 1 page, and that adding to resv map a 1 page entry can only 22890db9d74eSMina Almasry * ever require 1 region. 22900db9d74eSMina Almasry */ 22910db9d74eSMina Almasry VM_BUG_ON(dummy_out_regions_needed != 1); 22925e911373SMike Kravetz break; 22935e911373SMike Kravetz case VMA_COMMIT_RESV: 2294075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 22950db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 22960db9d74eSMina Almasry VM_BUG_ON(ret < 0); 22975e911373SMike Kravetz break; 2298feba16e2SMike Kravetz case VMA_END_RESV: 22990db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 23005e911373SMike Kravetz ret = 0; 23015e911373SMike Kravetz break; 230296b96a96SMike Kravetz case VMA_ADD_RESV: 23030db9d74eSMina Almasry if (vma->vm_flags & VM_MAYSHARE) { 2304075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 23050db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 23060db9d74eSMina Almasry VM_BUG_ON(ret < 0); 23070db9d74eSMina Almasry } else { 23080db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 230996b96a96SMike Kravetz ret = region_del(resv, idx, idx + 1); 231096b96a96SMike Kravetz } 231196b96a96SMike Kravetz break; 2312846be085SMike Kravetz case VMA_DEL_RESV: 2313846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 2314846be085SMike Kravetz region_abort(resv, idx, idx + 1, 1); 2315846be085SMike Kravetz ret = region_del(resv, idx, idx + 1); 2316846be085SMike Kravetz } else { 2317846be085SMike Kravetz ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 2318846be085SMike Kravetz /* region_add calls of range 1 should never fail. */ 2319846be085SMike Kravetz VM_BUG_ON(ret < 0); 2320846be085SMike Kravetz } 2321846be085SMike Kravetz break; 23225e911373SMike Kravetz default: 23235e911373SMike Kravetz BUG(); 23245e911373SMike Kravetz } 232584afd99bSAndy Whitcroft 2326846be085SMike Kravetz if (vma->vm_flags & VM_MAYSHARE || mode == VMA_DEL_RESV) 2327cf3ad20bSMike Kravetz return ret; 232867961f9dSMike Kravetz /* 2329bf3d12b9SMiaohe Lin * We know private mapping must have HPAGE_RESV_OWNER set. 2330bf3d12b9SMiaohe Lin * 233167961f9dSMike Kravetz * In most cases, reserves always exist for private mappings. 233267961f9dSMike Kravetz * However, a file associated with mapping could have been 233367961f9dSMike Kravetz * hole punched or truncated after reserves were consumed. 233467961f9dSMike Kravetz * As subsequent fault on such a range will not use reserves. 233567961f9dSMike Kravetz * Subtle - The reserve map for private mappings has the 233667961f9dSMike Kravetz * opposite meaning than that of shared mappings. If NO 233767961f9dSMike Kravetz * entry is in the reserve map, it means a reservation exists. 233867961f9dSMike Kravetz * If an entry exists in the reserve map, it means the 233967961f9dSMike Kravetz * reservation has already been consumed. As a result, the 234067961f9dSMike Kravetz * return value of this routine is the opposite of the 234167961f9dSMike Kravetz * value returned from reserve map manipulation routines above. 234267961f9dSMike Kravetz */ 2343bf3d12b9SMiaohe Lin if (ret > 0) 234467961f9dSMike Kravetz return 0; 2345bf3d12b9SMiaohe Lin if (ret == 0) 234667961f9dSMike Kravetz return 1; 2347bf3d12b9SMiaohe Lin return ret; 234884afd99bSAndy Whitcroft } 2349cf3ad20bSMike Kravetz 2350cf3ad20bSMike Kravetz static long vma_needs_reservation(struct hstate *h, 2351a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 2352c37f9fb1SAndy Whitcroft { 23535e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV); 2354cf3ad20bSMike Kravetz } 2355c37f9fb1SAndy Whitcroft 2356cf3ad20bSMike Kravetz static long vma_commit_reservation(struct hstate *h, 2357cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr) 2358cf3ad20bSMike Kravetz { 23595e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV); 23605e911373SMike Kravetz } 23615e911373SMike Kravetz 2362feba16e2SMike Kravetz static void vma_end_reservation(struct hstate *h, 23635e911373SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 23645e911373SMike Kravetz { 2365feba16e2SMike Kravetz (void)__vma_reservation_common(h, vma, addr, VMA_END_RESV); 2366c37f9fb1SAndy Whitcroft } 2367c37f9fb1SAndy Whitcroft 236896b96a96SMike Kravetz static long vma_add_reservation(struct hstate *h, 236996b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 237096b96a96SMike Kravetz { 237196b96a96SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV); 237296b96a96SMike Kravetz } 237396b96a96SMike Kravetz 2374846be085SMike Kravetz static long vma_del_reservation(struct hstate *h, 2375846be085SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 237696b96a96SMike Kravetz { 2377846be085SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_DEL_RESV); 2378846be085SMike Kravetz } 2379846be085SMike Kravetz 2380846be085SMike Kravetz /* 2381846be085SMike Kravetz * This routine is called to restore reservation information on error paths. 2382846be085SMike Kravetz * It should ONLY be called for pages allocated via alloc_huge_page(), and 2383846be085SMike Kravetz * the hugetlb mutex should remain held when calling this routine. 2384846be085SMike Kravetz * 2385846be085SMike Kravetz * It handles two specific cases: 2386846be085SMike Kravetz * 1) A reservation was in place and the page consumed the reservation. 2387846be085SMike Kravetz * HPageRestoreReserve is set in the page. 2388846be085SMike Kravetz * 2) No reservation was in place for the page, so HPageRestoreReserve is 2389846be085SMike Kravetz * not set. However, alloc_huge_page always updates the reserve map. 2390846be085SMike Kravetz * 2391846be085SMike Kravetz * In case 1, free_huge_page later in the error path will increment the 2392846be085SMike Kravetz * global reserve count. But, free_huge_page does not have enough context 2393846be085SMike Kravetz * to adjust the reservation map. This case deals primarily with private 2394846be085SMike Kravetz * mappings. Adjust the reserve map here to be consistent with global 2395846be085SMike Kravetz * reserve count adjustments to be made by free_huge_page. Make sure the 2396846be085SMike Kravetz * reserve map indicates there is a reservation present. 2397846be085SMike Kravetz * 2398846be085SMike Kravetz * In case 2, simply undo reserve map modifications done by alloc_huge_page. 2399846be085SMike Kravetz */ 2400846be085SMike Kravetz void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma, 2401846be085SMike Kravetz unsigned long address, struct page *page) 2402846be085SMike Kravetz { 240396b96a96SMike Kravetz long rc = vma_needs_reservation(h, vma, address); 240496b96a96SMike Kravetz 2405846be085SMike Kravetz if (HPageRestoreReserve(page)) { 2406846be085SMike Kravetz if (unlikely(rc < 0)) 240796b96a96SMike Kravetz /* 240896b96a96SMike Kravetz * Rare out of memory condition in reserve map 2409d6995da3SMike Kravetz * manipulation. Clear HPageRestoreReserve so that 241096b96a96SMike Kravetz * global reserve count will not be incremented 241196b96a96SMike Kravetz * by free_huge_page. This will make it appear 241296b96a96SMike Kravetz * as though the reservation for this page was 241396b96a96SMike Kravetz * consumed. This may prevent the task from 241496b96a96SMike Kravetz * faulting in the page at a later time. This 241596b96a96SMike Kravetz * is better than inconsistent global huge page 241696b96a96SMike Kravetz * accounting of reserve counts. 241796b96a96SMike Kravetz */ 2418d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 2419846be085SMike Kravetz else if (rc) 2420846be085SMike Kravetz (void)vma_add_reservation(h, vma, address); 2421846be085SMike Kravetz else 2422846be085SMike Kravetz vma_end_reservation(h, vma, address); 2423846be085SMike Kravetz } else { 2424846be085SMike Kravetz if (!rc) { 242596b96a96SMike Kravetz /* 2426846be085SMike Kravetz * This indicates there is an entry in the reserve map 2427846be085SMike Kravetz * added by alloc_huge_page. We know it was added 2428846be085SMike Kravetz * before the alloc_huge_page call, otherwise 2429846be085SMike Kravetz * HPageRestoreReserve would be set on the page. 2430846be085SMike Kravetz * Remove the entry so that a subsequent allocation 2431846be085SMike Kravetz * does not consume a reservation. 243296b96a96SMike Kravetz */ 2433846be085SMike Kravetz rc = vma_del_reservation(h, vma, address); 2434846be085SMike Kravetz if (rc < 0) 2435846be085SMike Kravetz /* 2436846be085SMike Kravetz * VERY rare out of memory condition. Since 2437846be085SMike Kravetz * we can not delete the entry, set 2438846be085SMike Kravetz * HPageRestoreReserve so that the reserve 2439846be085SMike Kravetz * count will be incremented when the page 2440846be085SMike Kravetz * is freed. This reserve will be consumed 2441846be085SMike Kravetz * on a subsequent allocation. 2442846be085SMike Kravetz */ 2443846be085SMike Kravetz SetHPageRestoreReserve(page); 2444846be085SMike Kravetz } else if (rc < 0) { 2445846be085SMike Kravetz /* 2446846be085SMike Kravetz * Rare out of memory condition from 2447846be085SMike Kravetz * vma_needs_reservation call. Memory allocation is 2448846be085SMike Kravetz * only attempted if a new entry is needed. Therefore, 2449846be085SMike Kravetz * this implies there is not an entry in the 2450846be085SMike Kravetz * reserve map. 2451846be085SMike Kravetz * 2452846be085SMike Kravetz * For shared mappings, no entry in the map indicates 2453846be085SMike Kravetz * no reservation. We are done. 2454846be085SMike Kravetz */ 2455846be085SMike Kravetz if (!(vma->vm_flags & VM_MAYSHARE)) 2456846be085SMike Kravetz /* 2457846be085SMike Kravetz * For private mappings, no entry indicates 2458846be085SMike Kravetz * a reservation is present. Since we can 2459846be085SMike Kravetz * not add an entry, set SetHPageRestoreReserve 2460846be085SMike Kravetz * on the page so reserve count will be 2461846be085SMike Kravetz * incremented when freed. This reserve will 2462846be085SMike Kravetz * be consumed on a subsequent allocation. 2463846be085SMike Kravetz */ 2464846be085SMike Kravetz SetHPageRestoreReserve(page); 246596b96a96SMike Kravetz } else 2466846be085SMike Kravetz /* 2467846be085SMike Kravetz * No reservation present, do nothing 2468846be085SMike Kravetz */ 246996b96a96SMike Kravetz vma_end_reservation(h, vma, address); 247096b96a96SMike Kravetz } 247196b96a96SMike Kravetz } 247296b96a96SMike Kravetz 2473369fa227SOscar Salvador /* 2474369fa227SOscar Salvador * alloc_and_dissolve_huge_page - Allocate a new page and dissolve the old one 2475369fa227SOscar Salvador * @h: struct hstate old page belongs to 2476369fa227SOscar Salvador * @old_page: Old page to dissolve 2477ae37c7ffSOscar Salvador * @list: List to isolate the page in case we need to 2478369fa227SOscar Salvador * Returns 0 on success, otherwise negated error. 2479369fa227SOscar Salvador */ 2480ae37c7ffSOscar Salvador static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, 2481ae37c7ffSOscar Salvador struct list_head *list) 2482369fa227SOscar Salvador { 2483369fa227SOscar Salvador gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 2484369fa227SOscar Salvador int nid = page_to_nid(old_page); 2485369fa227SOscar Salvador struct page *new_page; 2486369fa227SOscar Salvador int ret = 0; 2487369fa227SOscar Salvador 2488369fa227SOscar Salvador /* 2489369fa227SOscar Salvador * Before dissolving the page, we need to allocate a new one for the 2490f41f2ed4SMuchun Song * pool to remain stable. Here, we allocate the page and 'prep' it 2491f41f2ed4SMuchun Song * by doing everything but actually updating counters and adding to 2492f41f2ed4SMuchun Song * the pool. This simplifies and let us do most of the processing 2493f41f2ed4SMuchun Song * under the lock. 2494369fa227SOscar Salvador */ 2495369fa227SOscar Salvador new_page = alloc_buddy_huge_page(h, gfp_mask, nid, NULL, NULL); 2496369fa227SOscar Salvador if (!new_page) 2497369fa227SOscar Salvador return -ENOMEM; 2498f41f2ed4SMuchun Song __prep_new_huge_page(h, new_page); 2499369fa227SOscar Salvador 2500369fa227SOscar Salvador retry: 2501369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2502369fa227SOscar Salvador if (!PageHuge(old_page)) { 2503369fa227SOscar Salvador /* 2504369fa227SOscar Salvador * Freed from under us. Drop new_page too. 2505369fa227SOscar Salvador */ 2506369fa227SOscar Salvador goto free_new; 2507369fa227SOscar Salvador } else if (page_count(old_page)) { 2508369fa227SOscar Salvador /* 2509ae37c7ffSOscar Salvador * Someone has grabbed the page, try to isolate it here. 2510ae37c7ffSOscar Salvador * Fail with -EBUSY if not possible. 2511369fa227SOscar Salvador */ 2512ae37c7ffSOscar Salvador spin_unlock_irq(&hugetlb_lock); 2513ae37c7ffSOscar Salvador if (!isolate_huge_page(old_page, list)) 2514369fa227SOscar Salvador ret = -EBUSY; 2515ae37c7ffSOscar Salvador spin_lock_irq(&hugetlb_lock); 2516369fa227SOscar Salvador goto free_new; 2517369fa227SOscar Salvador } else if (!HPageFreed(old_page)) { 2518369fa227SOscar Salvador /* 2519369fa227SOscar Salvador * Page's refcount is 0 but it has not been enqueued in the 2520369fa227SOscar Salvador * freelist yet. Race window is small, so we can succeed here if 2521369fa227SOscar Salvador * we retry. 2522369fa227SOscar Salvador */ 2523369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2524369fa227SOscar Salvador cond_resched(); 2525369fa227SOscar Salvador goto retry; 2526369fa227SOscar Salvador } else { 2527369fa227SOscar Salvador /* 2528369fa227SOscar Salvador * Ok, old_page is still a genuine free hugepage. Remove it from 2529369fa227SOscar Salvador * the freelist and decrease the counters. These will be 2530369fa227SOscar Salvador * incremented again when calling __prep_account_new_huge_page() 2531369fa227SOscar Salvador * and enqueue_huge_page() for new_page. The counters will remain 2532369fa227SOscar Salvador * stable since this happens under the lock. 2533369fa227SOscar Salvador */ 2534369fa227SOscar Salvador remove_hugetlb_page(h, old_page, false); 2535369fa227SOscar Salvador 2536369fa227SOscar Salvador /* 2537369fa227SOscar Salvador * Reference count trick is needed because allocator gives us 2538369fa227SOscar Salvador * referenced page but the pool requires pages with 0 refcount. 2539369fa227SOscar Salvador */ 2540369fa227SOscar Salvador __prep_account_new_huge_page(h, nid); 2541369fa227SOscar Salvador page_ref_dec(new_page); 2542369fa227SOscar Salvador enqueue_huge_page(h, new_page); 2543369fa227SOscar Salvador 2544369fa227SOscar Salvador /* 2545369fa227SOscar Salvador * Pages have been replaced, we can safely free the old one. 2546369fa227SOscar Salvador */ 2547369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2548b65d4adbSMuchun Song update_and_free_page(h, old_page, false); 2549369fa227SOscar Salvador } 2550369fa227SOscar Salvador 2551369fa227SOscar Salvador return ret; 2552369fa227SOscar Salvador 2553369fa227SOscar Salvador free_new: 2554369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2555b65d4adbSMuchun Song update_and_free_page(h, new_page, false); 2556369fa227SOscar Salvador 2557369fa227SOscar Salvador return ret; 2558369fa227SOscar Salvador } 2559369fa227SOscar Salvador 2560ae37c7ffSOscar Salvador int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list) 2561369fa227SOscar Salvador { 2562369fa227SOscar Salvador struct hstate *h; 2563369fa227SOscar Salvador struct page *head; 2564ae37c7ffSOscar Salvador int ret = -EBUSY; 2565369fa227SOscar Salvador 2566369fa227SOscar Salvador /* 2567369fa227SOscar Salvador * The page might have been dissolved from under our feet, so make sure 2568369fa227SOscar Salvador * to carefully check the state under the lock. 2569369fa227SOscar Salvador * Return success when racing as if we dissolved the page ourselves. 2570369fa227SOscar Salvador */ 2571369fa227SOscar Salvador spin_lock_irq(&hugetlb_lock); 2572369fa227SOscar Salvador if (PageHuge(page)) { 2573369fa227SOscar Salvador head = compound_head(page); 2574369fa227SOscar Salvador h = page_hstate(head); 2575369fa227SOscar Salvador } else { 2576369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2577369fa227SOscar Salvador return 0; 2578369fa227SOscar Salvador } 2579369fa227SOscar Salvador spin_unlock_irq(&hugetlb_lock); 2580369fa227SOscar Salvador 2581369fa227SOscar Salvador /* 2582369fa227SOscar Salvador * Fence off gigantic pages as there is a cyclic dependency between 2583369fa227SOscar Salvador * alloc_contig_range and them. Return -ENOMEM as this has the effect 2584369fa227SOscar Salvador * of bailing out right away without further retrying. 2585369fa227SOscar Salvador */ 2586369fa227SOscar Salvador if (hstate_is_gigantic(h)) 2587369fa227SOscar Salvador return -ENOMEM; 2588369fa227SOscar Salvador 2589ae37c7ffSOscar Salvador if (page_count(head) && isolate_huge_page(head, list)) 2590ae37c7ffSOscar Salvador ret = 0; 2591ae37c7ffSOscar Salvador else if (!page_count(head)) 2592ae37c7ffSOscar Salvador ret = alloc_and_dissolve_huge_page(h, head, list); 2593ae37c7ffSOscar Salvador 2594ae37c7ffSOscar Salvador return ret; 2595369fa227SOscar Salvador } 2596369fa227SOscar Salvador 259770c3547eSMike Kravetz struct page *alloc_huge_page(struct vm_area_struct *vma, 259804f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 2599348ea204SAdam Litke { 260090481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 2601a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 2602348ea204SAdam Litke struct page *page; 2603d85f69b0SMike Kravetz long map_chg, map_commit; 2604d85f69b0SMike Kravetz long gbl_chg; 26056d76dcf4SAneesh Kumar K.V int ret, idx; 26066d76dcf4SAneesh Kumar K.V struct hugetlb_cgroup *h_cg; 260708cf9fafSMina Almasry bool deferred_reserve; 26082fc39cecSAdam Litke 26096d76dcf4SAneesh Kumar K.V idx = hstate_index(h); 2610a1e78772SMel Gorman /* 2611d85f69b0SMike Kravetz * Examine the region/reserve map to determine if the process 2612d85f69b0SMike Kravetz * has a reservation for the page to be allocated. A return 2613d85f69b0SMike Kravetz * code of zero indicates a reservation exists (no change). 2614a1e78772SMel Gorman */ 2615d85f69b0SMike Kravetz map_chg = gbl_chg = vma_needs_reservation(h, vma, addr); 2616d85f69b0SMike Kravetz if (map_chg < 0) 261776dcee75SAneesh Kumar K.V return ERR_PTR(-ENOMEM); 2618d85f69b0SMike Kravetz 2619d85f69b0SMike Kravetz /* 2620d85f69b0SMike Kravetz * Processes that did not create the mapping will have no 2621d85f69b0SMike Kravetz * reserves as indicated by the region/reserve map. Check 2622d85f69b0SMike Kravetz * that the allocation will not exceed the subpool limit. 2623d85f69b0SMike Kravetz * Allocations for MAP_NORESERVE mappings also need to be 2624d85f69b0SMike Kravetz * checked against any subpool limit. 2625d85f69b0SMike Kravetz */ 2626d85f69b0SMike Kravetz if (map_chg || avoid_reserve) { 2627d85f69b0SMike Kravetz gbl_chg = hugepage_subpool_get_pages(spool, 1); 2628d85f69b0SMike Kravetz if (gbl_chg < 0) { 2629feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 263076dcee75SAneesh Kumar K.V return ERR_PTR(-ENOSPC); 26315e911373SMike Kravetz } 263290d8b7e6SAdam Litke 2633d85f69b0SMike Kravetz /* 2634d85f69b0SMike Kravetz * Even though there was no reservation in the region/reserve 2635d85f69b0SMike Kravetz * map, there could be reservations associated with the 2636d85f69b0SMike Kravetz * subpool that can be used. This would be indicated if the 2637d85f69b0SMike Kravetz * return value of hugepage_subpool_get_pages() is zero. 2638d85f69b0SMike Kravetz * However, if avoid_reserve is specified we still avoid even 2639d85f69b0SMike Kravetz * the subpool reservations. 2640d85f69b0SMike Kravetz */ 2641d85f69b0SMike Kravetz if (avoid_reserve) 2642d85f69b0SMike Kravetz gbl_chg = 1; 2643d85f69b0SMike Kravetz } 2644d85f69b0SMike Kravetz 264508cf9fafSMina Almasry /* If this allocation is not consuming a reservation, charge it now. 264608cf9fafSMina Almasry */ 26476501fe5fSMiaohe Lin deferred_reserve = map_chg || avoid_reserve; 264808cf9fafSMina Almasry if (deferred_reserve) { 264908cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup_rsvd( 265008cf9fafSMina Almasry idx, pages_per_huge_page(h), &h_cg); 26518f34af6fSJianyu Zhan if (ret) 26528f34af6fSJianyu Zhan goto out_subpool_put; 265308cf9fafSMina Almasry } 265408cf9fafSMina Almasry 265508cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); 265608cf9fafSMina Almasry if (ret) 265708cf9fafSMina Almasry goto out_uncharge_cgroup_reservation; 26588f34af6fSJianyu Zhan 2659db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 2660d85f69b0SMike Kravetz /* 2661d85f69b0SMike Kravetz * glb_chg is passed to indicate whether or not a page must be taken 2662d85f69b0SMike Kravetz * from the global free pool (global change). gbl_chg == 0 indicates 2663d85f69b0SMike Kravetz * a reservation exists for the allocation. 2664d85f69b0SMike Kravetz */ 2665d85f69b0SMike Kravetz page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg); 266681a6fcaeSJoonsoo Kim if (!page) { 2667db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 26680c397daeSMichal Hocko page = alloc_buddy_huge_page_with_mpol(h, vma, addr); 26698f34af6fSJianyu Zhan if (!page) 26708f34af6fSJianyu Zhan goto out_uncharge_cgroup; 2671a88c7695SNaoya Horiguchi if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { 2672d6995da3SMike Kravetz SetHPageRestoreReserve(page); 2673a88c7695SNaoya Horiguchi h->resv_huge_pages--; 2674a88c7695SNaoya Horiguchi } 2675db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 267615a8d68eSWei Yang list_add(&page->lru, &h->hugepage_activelist); 267781a6fcaeSJoonsoo Kim /* Fall through */ 2678a1e78772SMel Gorman } 267981a6fcaeSJoonsoo Kim hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); 268008cf9fafSMina Almasry /* If allocation is not consuming a reservation, also store the 268108cf9fafSMina Almasry * hugetlb_cgroup pointer on the page. 268208cf9fafSMina Almasry */ 268308cf9fafSMina Almasry if (deferred_reserve) { 268408cf9fafSMina Almasry hugetlb_cgroup_commit_charge_rsvd(idx, pages_per_huge_page(h), 268508cf9fafSMina Almasry h_cg, page); 268608cf9fafSMina Almasry } 268708cf9fafSMina Almasry 2688db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 2689a1e78772SMel Gorman 2690d6995da3SMike Kravetz hugetlb_set_page_subpool(page, spool); 2691a1e78772SMel Gorman 2692d85f69b0SMike Kravetz map_commit = vma_commit_reservation(h, vma, addr); 2693d85f69b0SMike Kravetz if (unlikely(map_chg > map_commit)) { 269433039678SMike Kravetz /* 269533039678SMike Kravetz * The page was added to the reservation map between 269633039678SMike Kravetz * vma_needs_reservation and vma_commit_reservation. 269733039678SMike Kravetz * This indicates a race with hugetlb_reserve_pages. 269833039678SMike Kravetz * Adjust for the subpool count incremented above AND 269933039678SMike Kravetz * in hugetlb_reserve_pages for the same page. Also, 270033039678SMike Kravetz * the reservation count added in hugetlb_reserve_pages 270133039678SMike Kravetz * no longer applies. 270233039678SMike Kravetz */ 270333039678SMike Kravetz long rsv_adjust; 270433039678SMike Kravetz 270533039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 1); 270633039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 270779aa925bSMike Kravetz if (deferred_reserve) 270879aa925bSMike Kravetz hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 270979aa925bSMike Kravetz pages_per_huge_page(h), page); 271033039678SMike Kravetz } 27117893d1d5SAdam Litke return page; 27128f34af6fSJianyu Zhan 27138f34af6fSJianyu Zhan out_uncharge_cgroup: 27148f34af6fSJianyu Zhan hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); 271508cf9fafSMina Almasry out_uncharge_cgroup_reservation: 271608cf9fafSMina Almasry if (deferred_reserve) 271708cf9fafSMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h), 271808cf9fafSMina Almasry h_cg); 27198f34af6fSJianyu Zhan out_subpool_put: 2720d85f69b0SMike Kravetz if (map_chg || avoid_reserve) 27218f34af6fSJianyu Zhan hugepage_subpool_put_pages(spool, 1); 2722feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 27238f34af6fSJianyu Zhan return ERR_PTR(-ENOSPC); 2724b45b5bd6SDavid Gibson } 2725b45b5bd6SDavid Gibson 2726e24a1307SAneesh Kumar K.V int alloc_bootmem_huge_page(struct hstate *h) 2727e24a1307SAneesh Kumar K.V __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); 2728e24a1307SAneesh Kumar K.V int __alloc_bootmem_huge_page(struct hstate *h) 2729aa888a74SAndi Kleen { 2730aa888a74SAndi Kleen struct huge_bootmem_page *m; 2731b2261026SJoonsoo Kim int nr_nodes, node; 2732aa888a74SAndi Kleen 2733b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { 2734aa888a74SAndi Kleen void *addr; 2735aa888a74SAndi Kleen 2736eb31d559SMike Rapoport addr = memblock_alloc_try_nid_raw( 27378b89a116SGrygorii Strashko huge_page_size(h), huge_page_size(h), 273897ad1087SMike Rapoport 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); 2739aa888a74SAndi Kleen if (addr) { 2740aa888a74SAndi Kleen /* 2741aa888a74SAndi Kleen * Use the beginning of the huge page to store the 2742aa888a74SAndi Kleen * huge_bootmem_page struct (until gather_bootmem 2743aa888a74SAndi Kleen * puts them into the mem_map). 2744aa888a74SAndi Kleen */ 2745aa888a74SAndi Kleen m = addr; 2746aa888a74SAndi Kleen goto found; 2747aa888a74SAndi Kleen } 2748aa888a74SAndi Kleen } 2749aa888a74SAndi Kleen return 0; 2750aa888a74SAndi Kleen 2751aa888a74SAndi Kleen found: 2752df994eadSLuiz Capitulino BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h))); 2753aa888a74SAndi Kleen /* Put them into a private list first because mem_map is not up yet */ 2754330d6e48SCannon Matthews INIT_LIST_HEAD(&m->list); 2755aa888a74SAndi Kleen list_add(&m->list, &huge_boot_pages); 2756aa888a74SAndi Kleen m->hstate = h; 2757aa888a74SAndi Kleen return 1; 2758aa888a74SAndi Kleen } 2759aa888a74SAndi Kleen 2760*48b8d744SMike Kravetz /* 2761*48b8d744SMike Kravetz * Put bootmem huge pages into the standard lists after mem_map is up. 2762*48b8d744SMike Kravetz * Note: This only applies to gigantic (order > MAX_ORDER) pages. 2763*48b8d744SMike Kravetz */ 2764aa888a74SAndi Kleen static void __init gather_bootmem_prealloc(void) 2765aa888a74SAndi Kleen { 2766aa888a74SAndi Kleen struct huge_bootmem_page *m; 2767aa888a74SAndi Kleen 2768aa888a74SAndi Kleen list_for_each_entry(m, &huge_boot_pages, list) { 276940d18ebfSMike Kravetz struct page *page = virt_to_page(m); 2770aa888a74SAndi Kleen struct hstate *h = m->hstate; 2771ee8f248dSBecky Bruce 2772*48b8d744SMike Kravetz VM_BUG_ON(!hstate_is_gigantic(h)); 2773aa888a74SAndi Kleen WARN_ON(page_count(page) != 1); 2774*48b8d744SMike Kravetz prep_compound_gigantic_page(page, huge_page_order(h)); 2775ef5a22beSAndrea Arcangeli WARN_ON(PageReserved(page)); 2776aa888a74SAndi Kleen prep_new_huge_page(h, page, page_to_nid(page)); 2777af0fb9dfSMichal Hocko put_page(page); /* free it into the hugepage allocator */ 2778af0fb9dfSMichal Hocko 2779b0320c7bSRafael Aquini /* 2780*48b8d744SMike Kravetz * We need to restore the 'stolen' pages to totalram_pages 2781*48b8d744SMike Kravetz * in order to fix confusing memory reports from free(1) and 2782*48b8d744SMike Kravetz * other side-effects, like CommitLimit going negative. 2783b0320c7bSRafael Aquini */ 2784c78a7f36SMiaohe Lin adjust_managed_page_count(page, pages_per_huge_page(h)); 2785520495feSCannon Matthews cond_resched(); 2786aa888a74SAndi Kleen } 2787aa888a74SAndi Kleen } 2788aa888a74SAndi Kleen 27898faa8b07SAndi Kleen static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 27901da177e4SLinus Torvalds { 27911da177e4SLinus Torvalds unsigned long i; 2792f60858f9SMike Kravetz nodemask_t *node_alloc_noretry; 2793f60858f9SMike Kravetz 2794f60858f9SMike Kravetz if (!hstate_is_gigantic(h)) { 2795f60858f9SMike Kravetz /* 2796f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 2797f60858f9SMike Kravetz * Ignore errors as lower level routines can deal with 2798f60858f9SMike Kravetz * node_alloc_noretry == NULL. If this kmalloc fails at boot 2799f60858f9SMike Kravetz * time, we are likely in bigger trouble. 2800f60858f9SMike Kravetz */ 2801f60858f9SMike Kravetz node_alloc_noretry = kmalloc(sizeof(*node_alloc_noretry), 2802f60858f9SMike Kravetz GFP_KERNEL); 2803f60858f9SMike Kravetz } else { 2804f60858f9SMike Kravetz /* allocations done at boot time */ 2805f60858f9SMike Kravetz node_alloc_noretry = NULL; 2806f60858f9SMike Kravetz } 2807f60858f9SMike Kravetz 2808f60858f9SMike Kravetz /* bit mask controlling how hard we retry per-node allocations */ 2809f60858f9SMike Kravetz if (node_alloc_noretry) 2810f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 28111da177e4SLinus Torvalds 2812e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 2813bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) { 2814dbda8feaSBarry Song if (hugetlb_cma_size) { 2815cf11e85fSRoman Gushchin pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n"); 28167ecc9565SChen Wandun goto free; 2817cf11e85fSRoman Gushchin } 2818aa888a74SAndi Kleen if (!alloc_bootmem_huge_page(h)) 2819aa888a74SAndi Kleen break; 28200c397daeSMichal Hocko } else if (!alloc_pool_huge_page(h, 2821f60858f9SMike Kravetz &node_states[N_MEMORY], 2822f60858f9SMike Kravetz node_alloc_noretry)) 28231da177e4SLinus Torvalds break; 282469ed779aSDavid Rientjes cond_resched(); 28251da177e4SLinus Torvalds } 2826d715cf80SLiam R. Howlett if (i < h->max_huge_pages) { 2827d715cf80SLiam R. Howlett char buf[32]; 2828d715cf80SLiam R. Howlett 2829c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 2830d715cf80SLiam R. Howlett pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n", 2831d715cf80SLiam R. Howlett h->max_huge_pages, buf, i); 28328faa8b07SAndi Kleen h->max_huge_pages = i; 2833e5ff2159SAndi Kleen } 28347ecc9565SChen Wandun free: 2835f60858f9SMike Kravetz kfree(node_alloc_noretry); 2836d715cf80SLiam R. Howlett } 2837e5ff2159SAndi Kleen 2838e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 2839e5ff2159SAndi Kleen { 2840e5ff2159SAndi Kleen struct hstate *h; 2841e5ff2159SAndi Kleen 2842e5ff2159SAndi Kleen for_each_hstate(h) { 2843641844f5SNaoya Horiguchi if (minimum_order > huge_page_order(h)) 2844641844f5SNaoya Horiguchi minimum_order = huge_page_order(h); 2845641844f5SNaoya Horiguchi 28468faa8b07SAndi Kleen /* oversize hugepages were init'ed in early boot */ 2847bae7f4aeSLuiz Capitulino if (!hstate_is_gigantic(h)) 28488faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(h); 2849e5ff2159SAndi Kleen } 2850641844f5SNaoya Horiguchi VM_BUG_ON(minimum_order == UINT_MAX); 2851e5ff2159SAndi Kleen } 2852e5ff2159SAndi Kleen 2853e5ff2159SAndi Kleen static void __init report_hugepages(void) 2854e5ff2159SAndi Kleen { 2855e5ff2159SAndi Kleen struct hstate *h; 2856e5ff2159SAndi Kleen 2857e5ff2159SAndi Kleen for_each_hstate(h) { 28584abd32dbSAndi Kleen char buf[32]; 2859c6247f72SMatthew Wilcox 2860c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 2861ffb22af5SAndrew Morton pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n", 2862c6247f72SMatthew Wilcox buf, h->free_huge_pages); 2863e5ff2159SAndi Kleen } 2864e5ff2159SAndi Kleen } 2865e5ff2159SAndi Kleen 28661da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 28676ae11b27SLee Schermerhorn static void try_to_free_low(struct hstate *h, unsigned long count, 28686ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 28691da177e4SLinus Torvalds { 28704415cc8dSChristoph Lameter int i; 28711121828aSMike Kravetz LIST_HEAD(page_list); 28724415cc8dSChristoph Lameter 28739487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 2874bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2875aa888a74SAndi Kleen return; 2876aa888a74SAndi Kleen 28771121828aSMike Kravetz /* 28781121828aSMike Kravetz * Collect pages to be freed on a list, and free after dropping lock 28791121828aSMike Kravetz */ 28806ae11b27SLee Schermerhorn for_each_node_mask(i, *nodes_allowed) { 288110c6ec49SMike Kravetz struct page *page, *next; 2882a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 2883a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 2884a5516438SAndi Kleen if (count >= h->nr_huge_pages) 28851121828aSMike Kravetz goto out; 28861da177e4SLinus Torvalds if (PageHighMem(page)) 28871da177e4SLinus Torvalds continue; 28886eb4e88aSMike Kravetz remove_hugetlb_page(h, page, false); 28891121828aSMike Kravetz list_add(&page->lru, &page_list); 28901121828aSMike Kravetz } 28911121828aSMike Kravetz } 28921121828aSMike Kravetz 28931121828aSMike Kravetz out: 2894db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 289510c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 2896db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 28971da177e4SLinus Torvalds } 28981da177e4SLinus Torvalds #else 28996ae11b27SLee Schermerhorn static inline void try_to_free_low(struct hstate *h, unsigned long count, 29006ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 29011da177e4SLinus Torvalds { 29021da177e4SLinus Torvalds } 29031da177e4SLinus Torvalds #endif 29041da177e4SLinus Torvalds 290520a0307cSWu Fengguang /* 290620a0307cSWu Fengguang * Increment or decrement surplus_huge_pages. Keep node-specific counters 290720a0307cSWu Fengguang * balanced by operating on them in a round-robin fashion. 290820a0307cSWu Fengguang * Returns 1 if an adjustment was made. 290920a0307cSWu Fengguang */ 29106ae11b27SLee Schermerhorn static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, 29116ae11b27SLee Schermerhorn int delta) 291220a0307cSWu Fengguang { 2913b2261026SJoonsoo Kim int nr_nodes, node; 291420a0307cSWu Fengguang 29159487ca60SMike Kravetz lockdep_assert_held(&hugetlb_lock); 291620a0307cSWu Fengguang VM_BUG_ON(delta != -1 && delta != 1); 291720a0307cSWu Fengguang 2918e8c5c824SLee Schermerhorn if (delta < 0) { 2919b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 2920b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node]) 2921b2261026SJoonsoo Kim goto found; 2922b2261026SJoonsoo Kim } 2923b2261026SJoonsoo Kim } else { 2924b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 2925b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node] < 2926b2261026SJoonsoo Kim h->nr_huge_pages_node[node]) 2927b2261026SJoonsoo Kim goto found; 2928e8c5c824SLee Schermerhorn } 29299a76db09SLee Schermerhorn } 2930b2261026SJoonsoo Kim return 0; 293120a0307cSWu Fengguang 2932b2261026SJoonsoo Kim found: 293320a0307cSWu Fengguang h->surplus_huge_pages += delta; 2934b2261026SJoonsoo Kim h->surplus_huge_pages_node[node] += delta; 2935b2261026SJoonsoo Kim return 1; 293620a0307cSWu Fengguang } 293720a0307cSWu Fengguang 2938a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 2939fd875dcaSMike Kravetz static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, 29406ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 29411da177e4SLinus Torvalds { 29427893d1d5SAdam Litke unsigned long min_count, ret; 294310c6ec49SMike Kravetz struct page *page; 294410c6ec49SMike Kravetz LIST_HEAD(page_list); 2945f60858f9SMike Kravetz NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL); 2946f60858f9SMike Kravetz 2947f60858f9SMike Kravetz /* 2948f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 2949f60858f9SMike Kravetz * If we can not allocate the bit mask, do not attempt to allocate 2950f60858f9SMike Kravetz * the requested huge pages. 2951f60858f9SMike Kravetz */ 2952f60858f9SMike Kravetz if (node_alloc_noretry) 2953f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 2954f60858f9SMike Kravetz else 2955f60858f9SMike Kravetz return -ENOMEM; 29561da177e4SLinus Torvalds 295729383967SMike Kravetz /* 295829383967SMike Kravetz * resize_lock mutex prevents concurrent adjustments to number of 295929383967SMike Kravetz * pages in hstate via the proc/sysfs interfaces. 296029383967SMike Kravetz */ 296129383967SMike Kravetz mutex_lock(&h->resize_lock); 2962b65d4adbSMuchun Song flush_free_hpage_work(h); 2963db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 29644eb0716eSAlexandre Ghiti 29654eb0716eSAlexandre Ghiti /* 2966fd875dcaSMike Kravetz * Check for a node specific request. 2967fd875dcaSMike Kravetz * Changing node specific huge page count may require a corresponding 2968fd875dcaSMike Kravetz * change to the global count. In any case, the passed node mask 2969fd875dcaSMike Kravetz * (nodes_allowed) will restrict alloc/free to the specified node. 2970fd875dcaSMike Kravetz */ 2971fd875dcaSMike Kravetz if (nid != NUMA_NO_NODE) { 2972fd875dcaSMike Kravetz unsigned long old_count = count; 2973fd875dcaSMike Kravetz 2974fd875dcaSMike Kravetz count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; 2975fd875dcaSMike Kravetz /* 2976fd875dcaSMike Kravetz * User may have specified a large count value which caused the 2977fd875dcaSMike Kravetz * above calculation to overflow. In this case, they wanted 2978fd875dcaSMike Kravetz * to allocate as many huge pages as possible. Set count to 2979fd875dcaSMike Kravetz * largest possible value to align with their intention. 2980fd875dcaSMike Kravetz */ 2981fd875dcaSMike Kravetz if (count < old_count) 2982fd875dcaSMike Kravetz count = ULONG_MAX; 2983fd875dcaSMike Kravetz } 2984fd875dcaSMike Kravetz 2985fd875dcaSMike Kravetz /* 29864eb0716eSAlexandre Ghiti * Gigantic pages runtime allocation depend on the capability for large 29874eb0716eSAlexandre Ghiti * page range allocation. 29884eb0716eSAlexandre Ghiti * If the system does not provide this feature, return an error when 29894eb0716eSAlexandre Ghiti * the user tries to allocate gigantic pages but let the user free the 29904eb0716eSAlexandre Ghiti * boottime allocated gigantic pages. 29914eb0716eSAlexandre Ghiti */ 29924eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) { 29934eb0716eSAlexandre Ghiti if (count > persistent_huge_pages(h)) { 2994db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 299529383967SMike Kravetz mutex_unlock(&h->resize_lock); 2996f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 29974eb0716eSAlexandre Ghiti return -EINVAL; 29984eb0716eSAlexandre Ghiti } 29994eb0716eSAlexandre Ghiti /* Fall through to decrease pool */ 30004eb0716eSAlexandre Ghiti } 3001aa888a74SAndi Kleen 30027893d1d5SAdam Litke /* 30037893d1d5SAdam Litke * Increase the pool size 30047893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 30057893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 3006d1c3fb1fSNishanth Aravamudan * 30070c397daeSMichal Hocko * We might race with alloc_surplus_huge_page() here and be unable 3008d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 3009d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 3010d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 3011d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 30127893d1d5SAdam Litke */ 3013a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 30146ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, -1)) 30157893d1d5SAdam Litke break; 30167893d1d5SAdam Litke } 30177893d1d5SAdam Litke 3018a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 30197893d1d5SAdam Litke /* 30207893d1d5SAdam Litke * If this allocation races such that we no longer need the 30217893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 30227893d1d5SAdam Litke * and reducing the surplus. 30237893d1d5SAdam Litke */ 3024db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3025649920c6SJia He 3026649920c6SJia He /* yield cpu to avoid soft lockup */ 3027649920c6SJia He cond_resched(); 3028649920c6SJia He 3029f60858f9SMike Kravetz ret = alloc_pool_huge_page(h, nodes_allowed, 3030f60858f9SMike Kravetz node_alloc_noretry); 3031db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 30327893d1d5SAdam Litke if (!ret) 30337893d1d5SAdam Litke goto out; 30347893d1d5SAdam Litke 3035536240f2SMel Gorman /* Bail for signals. Probably ctrl-c from user */ 3036536240f2SMel Gorman if (signal_pending(current)) 3037536240f2SMel Gorman goto out; 30387893d1d5SAdam Litke } 30397893d1d5SAdam Litke 30407893d1d5SAdam Litke /* 30417893d1d5SAdam Litke * Decrease the pool size 30427893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 30437893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 30447893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 30457893d1d5SAdam Litke * to the desired size as pages become free. 3046d1c3fb1fSNishanth Aravamudan * 3047d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 3048d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 3049d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 30500c397daeSMichal Hocko * alloc_surplus_huge_page() is checking the global counter, 3051d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 3052d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 3053d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 30547893d1d5SAdam Litke */ 3055a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 30566b0c880dSAdam Litke min_count = max(count, min_count); 30576ae11b27SLee Schermerhorn try_to_free_low(h, min_count, nodes_allowed); 305810c6ec49SMike Kravetz 305910c6ec49SMike Kravetz /* 306010c6ec49SMike Kravetz * Collect pages to be removed on list without dropping lock 306110c6ec49SMike Kravetz */ 3062a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 306310c6ec49SMike Kravetz page = remove_pool_huge_page(h, nodes_allowed, 0); 306410c6ec49SMike Kravetz if (!page) 30651da177e4SLinus Torvalds break; 306610c6ec49SMike Kravetz 306710c6ec49SMike Kravetz list_add(&page->lru, &page_list); 30681da177e4SLinus Torvalds } 306910c6ec49SMike Kravetz /* free the pages after dropping lock */ 3070db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 307110c6ec49SMike Kravetz update_and_free_pages_bulk(h, &page_list); 3072b65d4adbSMuchun Song flush_free_hpage_work(h); 3073db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 307410c6ec49SMike Kravetz 3075a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 30766ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, 1)) 30777893d1d5SAdam Litke break; 30787893d1d5SAdam Litke } 30797893d1d5SAdam Litke out: 30804eb0716eSAlexandre Ghiti h->max_huge_pages = persistent_huge_pages(h); 3081db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 308229383967SMike Kravetz mutex_unlock(&h->resize_lock); 30834eb0716eSAlexandre Ghiti 3084f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 3085f60858f9SMike Kravetz 30864eb0716eSAlexandre Ghiti return 0; 30871da177e4SLinus Torvalds } 30881da177e4SLinus Torvalds 3089a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 3090a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 3091a3437870SNishanth Aravamudan 3092a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 3093a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = \ 3094a3437870SNishanth Aravamudan __ATTR(_name, 0644, _name##_show, _name##_store) 3095a3437870SNishanth Aravamudan 3096a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 3097a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 3098a3437870SNishanth Aravamudan 30999a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); 31009a305230SLee Schermerhorn 31019a305230SLee Schermerhorn static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) 3102a3437870SNishanth Aravamudan { 3103a3437870SNishanth Aravamudan int i; 31049a305230SLee Schermerhorn 3105a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 31069a305230SLee Schermerhorn if (hstate_kobjs[i] == kobj) { 31079a305230SLee Schermerhorn if (nidp) 31089a305230SLee Schermerhorn *nidp = NUMA_NO_NODE; 3109a3437870SNishanth Aravamudan return &hstates[i]; 31109a305230SLee Schermerhorn } 31119a305230SLee Schermerhorn 31129a305230SLee Schermerhorn return kobj_to_node_hstate(kobj, nidp); 3113a3437870SNishanth Aravamudan } 3114a3437870SNishanth Aravamudan 311506808b08SLee Schermerhorn static ssize_t nr_hugepages_show_common(struct kobject *kobj, 3116a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3117a3437870SNishanth Aravamudan { 31189a305230SLee Schermerhorn struct hstate *h; 31199a305230SLee Schermerhorn unsigned long nr_huge_pages; 31209a305230SLee Schermerhorn int nid; 31219a305230SLee Schermerhorn 31229a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 31239a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 31249a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages; 31259a305230SLee Schermerhorn else 31269a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages_node[nid]; 31279a305230SLee Schermerhorn 3128ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", nr_huge_pages); 3129a3437870SNishanth Aravamudan } 3130adbe8726SEric B Munson 3131238d3c13SDavid Rientjes static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, 3132238d3c13SDavid Rientjes struct hstate *h, int nid, 3133238d3c13SDavid Rientjes unsigned long count, size_t len) 3134a3437870SNishanth Aravamudan { 3135a3437870SNishanth Aravamudan int err; 31362d0adf7eSOscar Salvador nodemask_t nodes_allowed, *n_mask; 3137a3437870SNishanth Aravamudan 31382d0adf7eSOscar Salvador if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 31392d0adf7eSOscar Salvador return -EINVAL; 3140adbe8726SEric B Munson 31419a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) { 31429a305230SLee Schermerhorn /* 31439a305230SLee Schermerhorn * global hstate attribute 31449a305230SLee Schermerhorn */ 31459a305230SLee Schermerhorn if (!(obey_mempolicy && 31462d0adf7eSOscar Salvador init_nodemask_of_mempolicy(&nodes_allowed))) 31472d0adf7eSOscar Salvador n_mask = &node_states[N_MEMORY]; 31482d0adf7eSOscar Salvador else 31492d0adf7eSOscar Salvador n_mask = &nodes_allowed; 31502d0adf7eSOscar Salvador } else { 31519a305230SLee Schermerhorn /* 3152fd875dcaSMike Kravetz * Node specific request. count adjustment happens in 3153fd875dcaSMike Kravetz * set_max_huge_pages() after acquiring hugetlb_lock. 31549a305230SLee Schermerhorn */ 31552d0adf7eSOscar Salvador init_nodemask_of_node(&nodes_allowed, nid); 31562d0adf7eSOscar Salvador n_mask = &nodes_allowed; 3157fd875dcaSMike Kravetz } 31589a305230SLee Schermerhorn 31592d0adf7eSOscar Salvador err = set_max_huge_pages(h, count, nid, n_mask); 316006808b08SLee Schermerhorn 31614eb0716eSAlexandre Ghiti return err ? err : len; 316206808b08SLee Schermerhorn } 316306808b08SLee Schermerhorn 3164238d3c13SDavid Rientjes static ssize_t nr_hugepages_store_common(bool obey_mempolicy, 3165238d3c13SDavid Rientjes struct kobject *kobj, const char *buf, 3166238d3c13SDavid Rientjes size_t len) 3167238d3c13SDavid Rientjes { 3168238d3c13SDavid Rientjes struct hstate *h; 3169238d3c13SDavid Rientjes unsigned long count; 3170238d3c13SDavid Rientjes int nid; 3171238d3c13SDavid Rientjes int err; 3172238d3c13SDavid Rientjes 3173238d3c13SDavid Rientjes err = kstrtoul(buf, 10, &count); 3174238d3c13SDavid Rientjes if (err) 3175238d3c13SDavid Rientjes return err; 3176238d3c13SDavid Rientjes 3177238d3c13SDavid Rientjes h = kobj_to_hstate(kobj, &nid); 3178238d3c13SDavid Rientjes return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); 3179238d3c13SDavid Rientjes } 3180238d3c13SDavid Rientjes 318106808b08SLee Schermerhorn static ssize_t nr_hugepages_show(struct kobject *kobj, 318206808b08SLee Schermerhorn struct kobj_attribute *attr, char *buf) 318306808b08SLee Schermerhorn { 318406808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 318506808b08SLee Schermerhorn } 318606808b08SLee Schermerhorn 318706808b08SLee Schermerhorn static ssize_t nr_hugepages_store(struct kobject *kobj, 318806808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 318906808b08SLee Schermerhorn { 3190238d3c13SDavid Rientjes return nr_hugepages_store_common(false, kobj, buf, len); 3191a3437870SNishanth Aravamudan } 3192a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 3193a3437870SNishanth Aravamudan 319406808b08SLee Schermerhorn #ifdef CONFIG_NUMA 319506808b08SLee Schermerhorn 319606808b08SLee Schermerhorn /* 319706808b08SLee Schermerhorn * hstate attribute for optionally mempolicy-based constraint on persistent 319806808b08SLee Schermerhorn * huge page alloc/free. 319906808b08SLee Schermerhorn */ 320006808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, 3201ae7a927dSJoe Perches struct kobj_attribute *attr, 3202ae7a927dSJoe Perches char *buf) 320306808b08SLee Schermerhorn { 320406808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 320506808b08SLee Schermerhorn } 320606808b08SLee Schermerhorn 320706808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, 320806808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 320906808b08SLee Schermerhorn { 3210238d3c13SDavid Rientjes return nr_hugepages_store_common(true, kobj, buf, len); 321106808b08SLee Schermerhorn } 321206808b08SLee Schermerhorn HSTATE_ATTR(nr_hugepages_mempolicy); 321306808b08SLee Schermerhorn #endif 321406808b08SLee Schermerhorn 321506808b08SLee Schermerhorn 3216a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 3217a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3218a3437870SNishanth Aravamudan { 32199a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3220ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->nr_overcommit_huge_pages); 3221a3437870SNishanth Aravamudan } 3222adbe8726SEric B Munson 3223a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 3224a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 3225a3437870SNishanth Aravamudan { 3226a3437870SNishanth Aravamudan int err; 3227a3437870SNishanth Aravamudan unsigned long input; 32289a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3229a3437870SNishanth Aravamudan 3230bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 3231adbe8726SEric B Munson return -EINVAL; 3232adbe8726SEric B Munson 32333dbb95f7SJingoo Han err = kstrtoul(buf, 10, &input); 3234a3437870SNishanth Aravamudan if (err) 323573ae31e5SEric B Munson return err; 3236a3437870SNishanth Aravamudan 3237db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 3238a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 3239db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3240a3437870SNishanth Aravamudan 3241a3437870SNishanth Aravamudan return count; 3242a3437870SNishanth Aravamudan } 3243a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 3244a3437870SNishanth Aravamudan 3245a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 3246a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3247a3437870SNishanth Aravamudan { 32489a305230SLee Schermerhorn struct hstate *h; 32499a305230SLee Schermerhorn unsigned long free_huge_pages; 32509a305230SLee Schermerhorn int nid; 32519a305230SLee Schermerhorn 32529a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 32539a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 32549a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages; 32559a305230SLee Schermerhorn else 32569a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages_node[nid]; 32579a305230SLee Schermerhorn 3258ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", free_huge_pages); 3259a3437870SNishanth Aravamudan } 3260a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 3261a3437870SNishanth Aravamudan 3262a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 3263a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3264a3437870SNishanth Aravamudan { 32659a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 3266ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->resv_huge_pages); 3267a3437870SNishanth Aravamudan } 3268a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 3269a3437870SNishanth Aravamudan 3270a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 3271a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 3272a3437870SNishanth Aravamudan { 32739a305230SLee Schermerhorn struct hstate *h; 32749a305230SLee Schermerhorn unsigned long surplus_huge_pages; 32759a305230SLee Schermerhorn int nid; 32769a305230SLee Schermerhorn 32779a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 32789a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 32799a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages; 32809a305230SLee Schermerhorn else 32819a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages_node[nid]; 32829a305230SLee Schermerhorn 3283ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", surplus_huge_pages); 3284a3437870SNishanth Aravamudan } 3285a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 3286a3437870SNishanth Aravamudan 3287a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 3288a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 3289a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 3290a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 3291a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 3292a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 329306808b08SLee Schermerhorn #ifdef CONFIG_NUMA 329406808b08SLee Schermerhorn &nr_hugepages_mempolicy_attr.attr, 329506808b08SLee Schermerhorn #endif 3296a3437870SNishanth Aravamudan NULL, 3297a3437870SNishanth Aravamudan }; 3298a3437870SNishanth Aravamudan 329967e5ed96SArvind Yadav static const struct attribute_group hstate_attr_group = { 3300a3437870SNishanth Aravamudan .attrs = hstate_attrs, 3301a3437870SNishanth Aravamudan }; 3302a3437870SNishanth Aravamudan 3303094e9539SJeff Mahoney static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, 33049a305230SLee Schermerhorn struct kobject **hstate_kobjs, 330567e5ed96SArvind Yadav const struct attribute_group *hstate_attr_group) 3306a3437870SNishanth Aravamudan { 3307a3437870SNishanth Aravamudan int retval; 3308972dc4deSAneesh Kumar K.V int hi = hstate_index(h); 3309a3437870SNishanth Aravamudan 33109a305230SLee Schermerhorn hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); 33119a305230SLee Schermerhorn if (!hstate_kobjs[hi]) 3312a3437870SNishanth Aravamudan return -ENOMEM; 3313a3437870SNishanth Aravamudan 33149a305230SLee Schermerhorn retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); 3315cc2205a6SMiaohe Lin if (retval) { 33169a305230SLee Schermerhorn kobject_put(hstate_kobjs[hi]); 3317cc2205a6SMiaohe Lin hstate_kobjs[hi] = NULL; 3318cc2205a6SMiaohe Lin } 3319a3437870SNishanth Aravamudan 3320a3437870SNishanth Aravamudan return retval; 3321a3437870SNishanth Aravamudan } 3322a3437870SNishanth Aravamudan 3323a3437870SNishanth Aravamudan static void __init hugetlb_sysfs_init(void) 3324a3437870SNishanth Aravamudan { 3325a3437870SNishanth Aravamudan struct hstate *h; 3326a3437870SNishanth Aravamudan int err; 3327a3437870SNishanth Aravamudan 3328a3437870SNishanth Aravamudan hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 3329a3437870SNishanth Aravamudan if (!hugepages_kobj) 3330a3437870SNishanth Aravamudan return; 3331a3437870SNishanth Aravamudan 3332a3437870SNishanth Aravamudan for_each_hstate(h) { 33339a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, 33349a305230SLee Schermerhorn hstate_kobjs, &hstate_attr_group); 3335a3437870SNishanth Aravamudan if (err) 3336282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s", h->name); 3337a3437870SNishanth Aravamudan } 3338a3437870SNishanth Aravamudan } 3339a3437870SNishanth Aravamudan 33409a305230SLee Schermerhorn #ifdef CONFIG_NUMA 33419a305230SLee Schermerhorn 33429a305230SLee Schermerhorn /* 33439a305230SLee Schermerhorn * node_hstate/s - associate per node hstate attributes, via their kobjects, 334410fbcf4cSKay Sievers * with node devices in node_devices[] using a parallel array. The array 334510fbcf4cSKay Sievers * index of a node device or _hstate == node id. 334610fbcf4cSKay Sievers * This is here to avoid any static dependency of the node device driver, in 33479a305230SLee Schermerhorn * the base kernel, on the hugetlb module. 33489a305230SLee Schermerhorn */ 33499a305230SLee Schermerhorn struct node_hstate { 33509a305230SLee Schermerhorn struct kobject *hugepages_kobj; 33519a305230SLee Schermerhorn struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 33529a305230SLee Schermerhorn }; 3353b4e289a6SAlexander Kuleshov static struct node_hstate node_hstates[MAX_NUMNODES]; 33549a305230SLee Schermerhorn 33559a305230SLee Schermerhorn /* 335610fbcf4cSKay Sievers * A subset of global hstate attributes for node devices 33579a305230SLee Schermerhorn */ 33589a305230SLee Schermerhorn static struct attribute *per_node_hstate_attrs[] = { 33599a305230SLee Schermerhorn &nr_hugepages_attr.attr, 33609a305230SLee Schermerhorn &free_hugepages_attr.attr, 33619a305230SLee Schermerhorn &surplus_hugepages_attr.attr, 33629a305230SLee Schermerhorn NULL, 33639a305230SLee Schermerhorn }; 33649a305230SLee Schermerhorn 336567e5ed96SArvind Yadav static const struct attribute_group per_node_hstate_attr_group = { 33669a305230SLee Schermerhorn .attrs = per_node_hstate_attrs, 33679a305230SLee Schermerhorn }; 33689a305230SLee Schermerhorn 33699a305230SLee Schermerhorn /* 337010fbcf4cSKay Sievers * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. 33719a305230SLee Schermerhorn * Returns node id via non-NULL nidp. 33729a305230SLee Schermerhorn */ 33739a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 33749a305230SLee Schermerhorn { 33759a305230SLee Schermerhorn int nid; 33769a305230SLee Schermerhorn 33779a305230SLee Schermerhorn for (nid = 0; nid < nr_node_ids; nid++) { 33789a305230SLee Schermerhorn struct node_hstate *nhs = &node_hstates[nid]; 33799a305230SLee Schermerhorn int i; 33809a305230SLee Schermerhorn for (i = 0; i < HUGE_MAX_HSTATE; i++) 33819a305230SLee Schermerhorn if (nhs->hstate_kobjs[i] == kobj) { 33829a305230SLee Schermerhorn if (nidp) 33839a305230SLee Schermerhorn *nidp = nid; 33849a305230SLee Schermerhorn return &hstates[i]; 33859a305230SLee Schermerhorn } 33869a305230SLee Schermerhorn } 33879a305230SLee Schermerhorn 33889a305230SLee Schermerhorn BUG(); 33899a305230SLee Schermerhorn return NULL; 33909a305230SLee Schermerhorn } 33919a305230SLee Schermerhorn 33929a305230SLee Schermerhorn /* 339310fbcf4cSKay Sievers * Unregister hstate attributes from a single node device. 33949a305230SLee Schermerhorn * No-op if no hstate attributes attached. 33959a305230SLee Schermerhorn */ 33963cd8b44fSClaudiu Ghioc static void hugetlb_unregister_node(struct node *node) 33979a305230SLee Schermerhorn { 33989a305230SLee Schermerhorn struct hstate *h; 339910fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 34009a305230SLee Schermerhorn 34019a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 34029b5e5d0fSLee Schermerhorn return; /* no hstate attributes */ 34039a305230SLee Schermerhorn 3404972dc4deSAneesh Kumar K.V for_each_hstate(h) { 3405972dc4deSAneesh Kumar K.V int idx = hstate_index(h); 3406972dc4deSAneesh Kumar K.V if (nhs->hstate_kobjs[idx]) { 3407972dc4deSAneesh Kumar K.V kobject_put(nhs->hstate_kobjs[idx]); 3408972dc4deSAneesh Kumar K.V nhs->hstate_kobjs[idx] = NULL; 3409972dc4deSAneesh Kumar K.V } 34109a305230SLee Schermerhorn } 34119a305230SLee Schermerhorn 34129a305230SLee Schermerhorn kobject_put(nhs->hugepages_kobj); 34139a305230SLee Schermerhorn nhs->hugepages_kobj = NULL; 34149a305230SLee Schermerhorn } 34159a305230SLee Schermerhorn 34169a305230SLee Schermerhorn 34179a305230SLee Schermerhorn /* 341810fbcf4cSKay Sievers * Register hstate attributes for a single node device. 34199a305230SLee Schermerhorn * No-op if attributes already registered. 34209a305230SLee Schermerhorn */ 34213cd8b44fSClaudiu Ghioc static void hugetlb_register_node(struct node *node) 34229a305230SLee Schermerhorn { 34239a305230SLee Schermerhorn struct hstate *h; 342410fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 34259a305230SLee Schermerhorn int err; 34269a305230SLee Schermerhorn 34279a305230SLee Schermerhorn if (nhs->hugepages_kobj) 34289a305230SLee Schermerhorn return; /* already allocated */ 34299a305230SLee Schermerhorn 34309a305230SLee Schermerhorn nhs->hugepages_kobj = kobject_create_and_add("hugepages", 343110fbcf4cSKay Sievers &node->dev.kobj); 34329a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 34339a305230SLee Schermerhorn return; 34349a305230SLee Schermerhorn 34359a305230SLee Schermerhorn for_each_hstate(h) { 34369a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, 34379a305230SLee Schermerhorn nhs->hstate_kobjs, 34389a305230SLee Schermerhorn &per_node_hstate_attr_group); 34399a305230SLee Schermerhorn if (err) { 3440282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s for node %d\n", 344110fbcf4cSKay Sievers h->name, node->dev.id); 34429a305230SLee Schermerhorn hugetlb_unregister_node(node); 34439a305230SLee Schermerhorn break; 34449a305230SLee Schermerhorn } 34459a305230SLee Schermerhorn } 34469a305230SLee Schermerhorn } 34479a305230SLee Schermerhorn 34489a305230SLee Schermerhorn /* 34499b5e5d0fSLee Schermerhorn * hugetlb init time: register hstate attributes for all registered node 345010fbcf4cSKay Sievers * devices of nodes that have memory. All on-line nodes should have 345110fbcf4cSKay Sievers * registered their associated device by this time. 34529a305230SLee Schermerhorn */ 34537d9ca000SLuiz Capitulino static void __init hugetlb_register_all_nodes(void) 34549a305230SLee Schermerhorn { 34559a305230SLee Schermerhorn int nid; 34569a305230SLee Schermerhorn 34578cebfcd0SLai Jiangshan for_each_node_state(nid, N_MEMORY) { 34588732794bSWen Congyang struct node *node = node_devices[nid]; 345910fbcf4cSKay Sievers if (node->dev.id == nid) 34609a305230SLee Schermerhorn hugetlb_register_node(node); 34619a305230SLee Schermerhorn } 34629a305230SLee Schermerhorn 34639a305230SLee Schermerhorn /* 346410fbcf4cSKay Sievers * Let the node device driver know we're here so it can 34659a305230SLee Schermerhorn * [un]register hstate attributes on node hotplug. 34669a305230SLee Schermerhorn */ 34679a305230SLee Schermerhorn register_hugetlbfs_with_node(hugetlb_register_node, 34689a305230SLee Schermerhorn hugetlb_unregister_node); 34699a305230SLee Schermerhorn } 34709a305230SLee Schermerhorn #else /* !CONFIG_NUMA */ 34719a305230SLee Schermerhorn 34729a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 34739a305230SLee Schermerhorn { 34749a305230SLee Schermerhorn BUG(); 34759a305230SLee Schermerhorn if (nidp) 34769a305230SLee Schermerhorn *nidp = -1; 34779a305230SLee Schermerhorn return NULL; 34789a305230SLee Schermerhorn } 34799a305230SLee Schermerhorn 34809a305230SLee Schermerhorn static void hugetlb_register_all_nodes(void) { } 34819a305230SLee Schermerhorn 34829a305230SLee Schermerhorn #endif 34839a305230SLee Schermerhorn 3484a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 3485a3437870SNishanth Aravamudan { 34868382d914SDavidlohr Bueso int i; 34878382d914SDavidlohr Bueso 3488d6995da3SMike Kravetz BUILD_BUG_ON(sizeof_field(struct page, private) * BITS_PER_BYTE < 3489d6995da3SMike Kravetz __NR_HPAGEFLAGS); 3490d6995da3SMike Kravetz 3491c2833a5bSMike Kravetz if (!hugepages_supported()) { 3492c2833a5bSMike Kravetz if (hugetlb_max_hstate || default_hstate_max_huge_pages) 3493c2833a5bSMike Kravetz pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n"); 34940ef89d25SBenjamin Herrenschmidt return 0; 3495d715cf80SLiam R. Howlett } 3496d715cf80SLiam R. Howlett 3497282f4214SMike Kravetz /* 3498282f4214SMike Kravetz * Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some 3499282f4214SMike Kravetz * architectures depend on setup being done here. 3500282f4214SMike Kravetz */ 3501a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 3502282f4214SMike Kravetz if (!parsed_default_hugepagesz) { 3503282f4214SMike Kravetz /* 3504282f4214SMike Kravetz * If we did not parse a default huge page size, set 3505282f4214SMike Kravetz * default_hstate_idx to HPAGE_SIZE hstate. And, if the 3506282f4214SMike Kravetz * number of huge pages for this default size was implicitly 3507282f4214SMike Kravetz * specified, set that here as well. 3508282f4214SMike Kravetz * Note that the implicit setting will overwrite an explicit 3509282f4214SMike Kravetz * setting. A warning will be printed in this case. 3510282f4214SMike Kravetz */ 3511282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(HPAGE_SIZE)); 3512f8b74815SVaishali Thakkar if (default_hstate_max_huge_pages) { 3513282f4214SMike Kravetz if (default_hstate.max_huge_pages) { 3514282f4214SMike Kravetz char buf[32]; 3515282f4214SMike Kravetz 3516282f4214SMike Kravetz string_get_size(huge_page_size(&default_hstate), 3517282f4214SMike Kravetz 1, STRING_UNITS_2, buf, 32); 3518282f4214SMike Kravetz pr_warn("HugeTLB: Ignoring hugepages=%lu associated with %s page size\n", 3519282f4214SMike Kravetz default_hstate.max_huge_pages, buf); 3520282f4214SMike Kravetz pr_warn("HugeTLB: Using hugepages=%lu for number of default huge pages\n", 3521282f4214SMike Kravetz default_hstate_max_huge_pages); 3522282f4214SMike Kravetz } 3523282f4214SMike Kravetz default_hstate.max_huge_pages = 3524282f4214SMike Kravetz default_hstate_max_huge_pages; 3525282f4214SMike Kravetz } 3526f8b74815SVaishali Thakkar } 3527a3437870SNishanth Aravamudan 3528cf11e85fSRoman Gushchin hugetlb_cma_check(); 3529a3437870SNishanth Aravamudan hugetlb_init_hstates(); 3530aa888a74SAndi Kleen gather_bootmem_prealloc(); 3531a3437870SNishanth Aravamudan report_hugepages(); 3532a3437870SNishanth Aravamudan 3533a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 35349a305230SLee Schermerhorn hugetlb_register_all_nodes(); 35357179e7bfSJianguo Wu hugetlb_cgroup_file_init(); 35369a305230SLee Schermerhorn 35378382d914SDavidlohr Bueso #ifdef CONFIG_SMP 35388382d914SDavidlohr Bueso num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); 35398382d914SDavidlohr Bueso #else 35408382d914SDavidlohr Bueso num_fault_mutexes = 1; 35418382d914SDavidlohr Bueso #endif 3542c672c7f2SMike Kravetz hugetlb_fault_mutex_table = 35436da2ec56SKees Cook kmalloc_array(num_fault_mutexes, sizeof(struct mutex), 35446da2ec56SKees Cook GFP_KERNEL); 3545c672c7f2SMike Kravetz BUG_ON(!hugetlb_fault_mutex_table); 35468382d914SDavidlohr Bueso 35478382d914SDavidlohr Bueso for (i = 0; i < num_fault_mutexes; i++) 3548c672c7f2SMike Kravetz mutex_init(&hugetlb_fault_mutex_table[i]); 3549a3437870SNishanth Aravamudan return 0; 3550a3437870SNishanth Aravamudan } 35513e89e1c5SPaul Gortmaker subsys_initcall(hugetlb_init); 3552a3437870SNishanth Aravamudan 3553ae94da89SMike Kravetz /* Overwritten by architectures with more huge page sizes */ 3554ae94da89SMike Kravetz bool __init __attribute((weak)) arch_hugetlb_valid_size(unsigned long size) 35559fee021dSVaishali Thakkar { 3556ae94da89SMike Kravetz return size == HPAGE_SIZE; 35579fee021dSVaishali Thakkar } 35589fee021dSVaishali Thakkar 3559d00181b9SKirill A. Shutemov void __init hugetlb_add_hstate(unsigned int order) 3560a3437870SNishanth Aravamudan { 3561a3437870SNishanth Aravamudan struct hstate *h; 35628faa8b07SAndi Kleen unsigned long i; 35638faa8b07SAndi Kleen 3564a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 3565a3437870SNishanth Aravamudan return; 3566a3437870SNishanth Aravamudan } 356747d38344SAneesh Kumar K.V BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); 3568a3437870SNishanth Aravamudan BUG_ON(order == 0); 356947d38344SAneesh Kumar K.V h = &hstates[hugetlb_max_hstate++]; 357029383967SMike Kravetz mutex_init(&h->resize_lock); 3571a3437870SNishanth Aravamudan h->order = order; 3572aca78307SMiaohe Lin h->mask = ~(huge_page_size(h) - 1); 35738faa8b07SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 35748faa8b07SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 35750edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&h->hugepage_activelist); 357654f18d35SAndrew Morton h->next_nid_to_alloc = first_memory_node; 357754f18d35SAndrew Morton h->next_nid_to_free = first_memory_node; 3578a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 3579a3437870SNishanth Aravamudan huge_page_size(h)/1024); 358077490587SMuchun Song hugetlb_vmemmap_init(h); 35818faa8b07SAndi Kleen 3582a3437870SNishanth Aravamudan parsed_hstate = h; 3583a3437870SNishanth Aravamudan } 3584a3437870SNishanth Aravamudan 3585282f4214SMike Kravetz /* 3586282f4214SMike Kravetz * hugepages command line processing 3587282f4214SMike Kravetz * hugepages normally follows a valid hugepagsz or default_hugepagsz 3588282f4214SMike Kravetz * specification. If not, ignore the hugepages value. hugepages can also 3589282f4214SMike Kravetz * be the first huge page command line option in which case it implicitly 3590282f4214SMike Kravetz * specifies the number of huge pages for the default size. 3591282f4214SMike Kravetz */ 3592282f4214SMike Kravetz static int __init hugepages_setup(char *s) 3593a3437870SNishanth Aravamudan { 3594a3437870SNishanth Aravamudan unsigned long *mhp; 35958faa8b07SAndi Kleen static unsigned long *last_mhp; 3596a3437870SNishanth Aravamudan 35979fee021dSVaishali Thakkar if (!parsed_valid_hugepagesz) { 3598282f4214SMike Kravetz pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s); 35999fee021dSVaishali Thakkar parsed_valid_hugepagesz = true; 3600282f4214SMike Kravetz return 0; 36019fee021dSVaishali Thakkar } 3602282f4214SMike Kravetz 3603a3437870SNishanth Aravamudan /* 3604282f4214SMike Kravetz * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter 3605282f4214SMike Kravetz * yet, so this hugepages= parameter goes to the "default hstate". 3606282f4214SMike Kravetz * Otherwise, it goes with the previously parsed hugepagesz or 3607282f4214SMike Kravetz * default_hugepagesz. 3608a3437870SNishanth Aravamudan */ 36099fee021dSVaishali Thakkar else if (!hugetlb_max_hstate) 3610a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 3611a3437870SNishanth Aravamudan else 3612a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 3613a3437870SNishanth Aravamudan 36148faa8b07SAndi Kleen if (mhp == last_mhp) { 3615282f4214SMike Kravetz pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s); 3616282f4214SMike Kravetz return 0; 36178faa8b07SAndi Kleen } 36188faa8b07SAndi Kleen 3619a3437870SNishanth Aravamudan if (sscanf(s, "%lu", mhp) <= 0) 3620a3437870SNishanth Aravamudan *mhp = 0; 3621a3437870SNishanth Aravamudan 36228faa8b07SAndi Kleen /* 36238faa8b07SAndi Kleen * Global state is always initialized later in hugetlb_init. 362404adbc3fSMiaohe Lin * But we need to allocate gigantic hstates here early to still 36258faa8b07SAndi Kleen * use the bootmem allocator. 36268faa8b07SAndi Kleen */ 362704adbc3fSMiaohe Lin if (hugetlb_max_hstate && hstate_is_gigantic(parsed_hstate)) 36288faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(parsed_hstate); 36298faa8b07SAndi Kleen 36308faa8b07SAndi Kleen last_mhp = mhp; 36318faa8b07SAndi Kleen 3632a3437870SNishanth Aravamudan return 1; 3633a3437870SNishanth Aravamudan } 3634282f4214SMike Kravetz __setup("hugepages=", hugepages_setup); 3635e11bfbfcSNick Piggin 3636282f4214SMike Kravetz /* 3637282f4214SMike Kravetz * hugepagesz command line processing 3638282f4214SMike Kravetz * A specific huge page size can only be specified once with hugepagesz. 3639282f4214SMike Kravetz * hugepagesz is followed by hugepages on the command line. The global 3640282f4214SMike Kravetz * variable 'parsed_valid_hugepagesz' is used to determine if prior 3641282f4214SMike Kravetz * hugepagesz argument was valid. 3642282f4214SMike Kravetz */ 3643359f2544SMike Kravetz static int __init hugepagesz_setup(char *s) 3644e11bfbfcSNick Piggin { 3645359f2544SMike Kravetz unsigned long size; 3646282f4214SMike Kravetz struct hstate *h; 3647282f4214SMike Kravetz 3648282f4214SMike Kravetz parsed_valid_hugepagesz = false; 3649359f2544SMike Kravetz size = (unsigned long)memparse(s, NULL); 3650359f2544SMike Kravetz 3651359f2544SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 3652282f4214SMike Kravetz pr_err("HugeTLB: unsupported hugepagesz=%s\n", s); 3653359f2544SMike Kravetz return 0; 3654359f2544SMike Kravetz } 3655359f2544SMike Kravetz 3656282f4214SMike Kravetz h = size_to_hstate(size); 3657282f4214SMike Kravetz if (h) { 3658282f4214SMike Kravetz /* 3659282f4214SMike Kravetz * hstate for this size already exists. This is normally 3660282f4214SMike Kravetz * an error, but is allowed if the existing hstate is the 3661282f4214SMike Kravetz * default hstate. More specifically, it is only allowed if 3662282f4214SMike Kravetz * the number of huge pages for the default hstate was not 3663282f4214SMike Kravetz * previously specified. 3664282f4214SMike Kravetz */ 3665282f4214SMike Kravetz if (!parsed_default_hugepagesz || h != &default_hstate || 3666282f4214SMike Kravetz default_hstate.max_huge_pages) { 3667282f4214SMike Kravetz pr_warn("HugeTLB: hugepagesz=%s specified twice, ignoring\n", s); 366838237830SMike Kravetz return 0; 366938237830SMike Kravetz } 367038237830SMike Kravetz 3671282f4214SMike Kravetz /* 3672282f4214SMike Kravetz * No need to call hugetlb_add_hstate() as hstate already 3673282f4214SMike Kravetz * exists. But, do set parsed_hstate so that a following 3674282f4214SMike Kravetz * hugepages= parameter will be applied to this hstate. 3675282f4214SMike Kravetz */ 3676282f4214SMike Kravetz parsed_hstate = h; 3677282f4214SMike Kravetz parsed_valid_hugepagesz = true; 3678e11bfbfcSNick Piggin return 1; 3679e11bfbfcSNick Piggin } 3680282f4214SMike Kravetz 3681359f2544SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 3682282f4214SMike Kravetz parsed_valid_hugepagesz = true; 3683359f2544SMike Kravetz return 1; 3684359f2544SMike Kravetz } 3685359f2544SMike Kravetz __setup("hugepagesz=", hugepagesz_setup); 3686359f2544SMike Kravetz 3687282f4214SMike Kravetz /* 3688282f4214SMike Kravetz * default_hugepagesz command line input 3689282f4214SMike Kravetz * Only one instance of default_hugepagesz allowed on command line. 3690282f4214SMike Kravetz */ 3691ae94da89SMike Kravetz static int __init default_hugepagesz_setup(char *s) 3692e11bfbfcSNick Piggin { 3693ae94da89SMike Kravetz unsigned long size; 3694ae94da89SMike Kravetz 3695282f4214SMike Kravetz parsed_valid_hugepagesz = false; 3696282f4214SMike Kravetz if (parsed_default_hugepagesz) { 3697282f4214SMike Kravetz pr_err("HugeTLB: default_hugepagesz previously specified, ignoring %s\n", s); 3698282f4214SMike Kravetz return 0; 3699282f4214SMike Kravetz } 3700282f4214SMike Kravetz 3701282f4214SMike Kravetz size = (unsigned long)memparse(s, NULL); 3702282f4214SMike Kravetz 3703282f4214SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 3704282f4214SMike Kravetz pr_err("HugeTLB: unsupported default_hugepagesz=%s\n", s); 3705282f4214SMike Kravetz return 0; 3706282f4214SMike Kravetz } 3707282f4214SMike Kravetz 3708282f4214SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 3709282f4214SMike Kravetz parsed_valid_hugepagesz = true; 3710282f4214SMike Kravetz parsed_default_hugepagesz = true; 3711282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(size)); 3712282f4214SMike Kravetz 3713282f4214SMike Kravetz /* 3714282f4214SMike Kravetz * The number of default huge pages (for this size) could have been 3715282f4214SMike Kravetz * specified as the first hugetlb parameter: hugepages=X. If so, 3716282f4214SMike Kravetz * then default_hstate_max_huge_pages is set. If the default huge 3717282f4214SMike Kravetz * page size is gigantic (>= MAX_ORDER), then the pages must be 3718282f4214SMike Kravetz * allocated here from bootmem allocator. 3719282f4214SMike Kravetz */ 3720282f4214SMike Kravetz if (default_hstate_max_huge_pages) { 3721282f4214SMike Kravetz default_hstate.max_huge_pages = default_hstate_max_huge_pages; 3722282f4214SMike Kravetz if (hstate_is_gigantic(&default_hstate)) 3723282f4214SMike Kravetz hugetlb_hstate_alloc_pages(&default_hstate); 3724282f4214SMike Kravetz default_hstate_max_huge_pages = 0; 3725282f4214SMike Kravetz } 3726282f4214SMike Kravetz 3727e11bfbfcSNick Piggin return 1; 3728e11bfbfcSNick Piggin } 3729ae94da89SMike Kravetz __setup("default_hugepagesz=", default_hugepagesz_setup); 3730a3437870SNishanth Aravamudan 37318ca39e68SMuchun Song static unsigned int allowed_mems_nr(struct hstate *h) 37328a213460SNishanth Aravamudan { 37338a213460SNishanth Aravamudan int node; 37348a213460SNishanth Aravamudan unsigned int nr = 0; 37358ca39e68SMuchun Song nodemask_t *mpol_allowed; 37368ca39e68SMuchun Song unsigned int *array = h->free_huge_pages_node; 37378ca39e68SMuchun Song gfp_t gfp_mask = htlb_alloc_mask(h); 37388a213460SNishanth Aravamudan 37398ca39e68SMuchun Song mpol_allowed = policy_nodemask_current(gfp_mask); 37408ca39e68SMuchun Song 37418ca39e68SMuchun Song for_each_node_mask(node, cpuset_current_mems_allowed) { 3742c93b0a99SJiapeng Zhong if (!mpol_allowed || node_isset(node, *mpol_allowed)) 37438a213460SNishanth Aravamudan nr += array[node]; 37448ca39e68SMuchun Song } 37458a213460SNishanth Aravamudan 37468a213460SNishanth Aravamudan return nr; 37478a213460SNishanth Aravamudan } 37488a213460SNishanth Aravamudan 37498a213460SNishanth Aravamudan #ifdef CONFIG_SYSCTL 375017743798SMuchun Song static int proc_hugetlb_doulongvec_minmax(struct ctl_table *table, int write, 375117743798SMuchun Song void *buffer, size_t *length, 375217743798SMuchun Song loff_t *ppos, unsigned long *out) 375317743798SMuchun Song { 375417743798SMuchun Song struct ctl_table dup_table; 375517743798SMuchun Song 375617743798SMuchun Song /* 375717743798SMuchun Song * In order to avoid races with __do_proc_doulongvec_minmax(), we 375817743798SMuchun Song * can duplicate the @table and alter the duplicate of it. 375917743798SMuchun Song */ 376017743798SMuchun Song dup_table = *table; 376117743798SMuchun Song dup_table.data = out; 376217743798SMuchun Song 376317743798SMuchun Song return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos); 376417743798SMuchun Song } 376517743798SMuchun Song 376606808b08SLee Schermerhorn static int hugetlb_sysctl_handler_common(bool obey_mempolicy, 376706808b08SLee Schermerhorn struct ctl_table *table, int write, 376832927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 37691da177e4SLinus Torvalds { 3770e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 3771238d3c13SDavid Rientjes unsigned long tmp = h->max_huge_pages; 377208d4a246SMichal Hocko int ret; 3773e5ff2159SAndi Kleen 3774457c1b27SNishanth Aravamudan if (!hugepages_supported()) 377586613628SJan Stancek return -EOPNOTSUPP; 3776457c1b27SNishanth Aravamudan 377717743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 377817743798SMuchun Song &tmp); 377908d4a246SMichal Hocko if (ret) 378008d4a246SMichal Hocko goto out; 3781e5ff2159SAndi Kleen 3782238d3c13SDavid Rientjes if (write) 3783238d3c13SDavid Rientjes ret = __nr_hugepages_store_common(obey_mempolicy, h, 3784238d3c13SDavid Rientjes NUMA_NO_NODE, tmp, *length); 378508d4a246SMichal Hocko out: 378608d4a246SMichal Hocko return ret; 37871da177e4SLinus Torvalds } 3788396faf03SMel Gorman 378906808b08SLee Schermerhorn int hugetlb_sysctl_handler(struct ctl_table *table, int write, 379032927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 379106808b08SLee Schermerhorn { 379206808b08SLee Schermerhorn 379306808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(false, table, write, 379406808b08SLee Schermerhorn buffer, length, ppos); 379506808b08SLee Schermerhorn } 379606808b08SLee Schermerhorn 379706808b08SLee Schermerhorn #ifdef CONFIG_NUMA 379806808b08SLee Schermerhorn int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, 379932927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 380006808b08SLee Schermerhorn { 380106808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(true, table, write, 380206808b08SLee Schermerhorn buffer, length, ppos); 380306808b08SLee Schermerhorn } 380406808b08SLee Schermerhorn #endif /* CONFIG_NUMA */ 380506808b08SLee Schermerhorn 3806a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 380732927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 3808a3d0c6aaSNishanth Aravamudan { 3809a5516438SAndi Kleen struct hstate *h = &default_hstate; 3810e5ff2159SAndi Kleen unsigned long tmp; 381108d4a246SMichal Hocko int ret; 3812e5ff2159SAndi Kleen 3813457c1b27SNishanth Aravamudan if (!hugepages_supported()) 381486613628SJan Stancek return -EOPNOTSUPP; 3815457c1b27SNishanth Aravamudan 3816e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 3817e5ff2159SAndi Kleen 3818bae7f4aeSLuiz Capitulino if (write && hstate_is_gigantic(h)) 3819adbe8726SEric B Munson return -EINVAL; 3820adbe8726SEric B Munson 382117743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 382217743798SMuchun Song &tmp); 382308d4a246SMichal Hocko if (ret) 382408d4a246SMichal Hocko goto out; 3825e5ff2159SAndi Kleen 3826e5ff2159SAndi Kleen if (write) { 3827db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 3828e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 3829db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3830e5ff2159SAndi Kleen } 383108d4a246SMichal Hocko out: 383208d4a246SMichal Hocko return ret; 3833a3d0c6aaSNishanth Aravamudan } 3834a3d0c6aaSNishanth Aravamudan 38351da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 38361da177e4SLinus Torvalds 3837e1759c21SAlexey Dobriyan void hugetlb_report_meminfo(struct seq_file *m) 38381da177e4SLinus Torvalds { 3839fcb2b0c5SRoman Gushchin struct hstate *h; 3840fcb2b0c5SRoman Gushchin unsigned long total = 0; 3841fcb2b0c5SRoman Gushchin 3842457c1b27SNishanth Aravamudan if (!hugepages_supported()) 3843457c1b27SNishanth Aravamudan return; 3844fcb2b0c5SRoman Gushchin 3845fcb2b0c5SRoman Gushchin for_each_hstate(h) { 3846fcb2b0c5SRoman Gushchin unsigned long count = h->nr_huge_pages; 3847fcb2b0c5SRoman Gushchin 3848aca78307SMiaohe Lin total += huge_page_size(h) * count; 3849fcb2b0c5SRoman Gushchin 3850fcb2b0c5SRoman Gushchin if (h == &default_hstate) 3851e1759c21SAlexey Dobriyan seq_printf(m, 38521da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 38531da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 3854b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 38557893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 38564f98a2feSRik van Riel "Hugepagesize: %8lu kB\n", 3857fcb2b0c5SRoman Gushchin count, 3858a5516438SAndi Kleen h->free_huge_pages, 3859a5516438SAndi Kleen h->resv_huge_pages, 3860a5516438SAndi Kleen h->surplus_huge_pages, 3861aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 3862fcb2b0c5SRoman Gushchin } 3863fcb2b0c5SRoman Gushchin 3864aca78307SMiaohe Lin seq_printf(m, "Hugetlb: %8lu kB\n", total / SZ_1K); 38651da177e4SLinus Torvalds } 38661da177e4SLinus Torvalds 38677981593bSJoe Perches int hugetlb_report_node_meminfo(char *buf, int len, int nid) 38681da177e4SLinus Torvalds { 3869a5516438SAndi Kleen struct hstate *h = &default_hstate; 38707981593bSJoe Perches 3871457c1b27SNishanth Aravamudan if (!hugepages_supported()) 3872457c1b27SNishanth Aravamudan return 0; 38737981593bSJoe Perches 38747981593bSJoe Perches return sysfs_emit_at(buf, len, 38751da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 3876a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 3877a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 3878a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 3879a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 3880a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 38811da177e4SLinus Torvalds } 38821da177e4SLinus Torvalds 3883949f7ec5SDavid Rientjes void hugetlb_show_meminfo(void) 3884949f7ec5SDavid Rientjes { 3885949f7ec5SDavid Rientjes struct hstate *h; 3886949f7ec5SDavid Rientjes int nid; 3887949f7ec5SDavid Rientjes 3888457c1b27SNishanth Aravamudan if (!hugepages_supported()) 3889457c1b27SNishanth Aravamudan return; 3890457c1b27SNishanth Aravamudan 3891949f7ec5SDavid Rientjes for_each_node_state(nid, N_MEMORY) 3892949f7ec5SDavid Rientjes for_each_hstate(h) 3893949f7ec5SDavid Rientjes pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", 3894949f7ec5SDavid Rientjes nid, 3895949f7ec5SDavid Rientjes h->nr_huge_pages_node[nid], 3896949f7ec5SDavid Rientjes h->free_huge_pages_node[nid], 3897949f7ec5SDavid Rientjes h->surplus_huge_pages_node[nid], 3898aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 3899949f7ec5SDavid Rientjes } 3900949f7ec5SDavid Rientjes 39015d317b2bSNaoya Horiguchi void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm) 39025d317b2bSNaoya Horiguchi { 39035d317b2bSNaoya Horiguchi seq_printf(m, "HugetlbPages:\t%8lu kB\n", 39045d317b2bSNaoya Horiguchi atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10)); 39055d317b2bSNaoya Horiguchi } 39065d317b2bSNaoya Horiguchi 39071da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 39081da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 39091da177e4SLinus Torvalds { 3910d0028588SWanpeng Li struct hstate *h; 3911d0028588SWanpeng Li unsigned long nr_total_pages = 0; 3912d0028588SWanpeng Li 3913d0028588SWanpeng Li for_each_hstate(h) 3914d0028588SWanpeng Li nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); 3915d0028588SWanpeng Li return nr_total_pages; 39161da177e4SLinus Torvalds } 39171da177e4SLinus Torvalds 3918a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 3919fc1b8a73SMel Gorman { 3920fc1b8a73SMel Gorman int ret = -ENOMEM; 3921fc1b8a73SMel Gorman 39220aa7f354SMiaohe Lin if (!delta) 39230aa7f354SMiaohe Lin return 0; 39240aa7f354SMiaohe Lin 3925db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 3926fc1b8a73SMel Gorman /* 3927fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 3928fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 3929fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 3930fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 3931fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 3932fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 3933fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 3934fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 3935fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 3936fc1b8a73SMel Gorman * 3937fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 3938fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 3939fc1b8a73SMel Gorman * we fall back to check against current free page availability as 3940fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 3941fc1b8a73SMel Gorman * semantics that cpuset has. 39428ca39e68SMuchun Song * 39438ca39e68SMuchun Song * Apart from cpuset, we also have memory policy mechanism that 39448ca39e68SMuchun Song * also determines from which node the kernel will allocate memory 39458ca39e68SMuchun Song * in a NUMA system. So similar to cpuset, we also should consider 39468ca39e68SMuchun Song * the memory policy of the current task. Similar to the description 39478ca39e68SMuchun Song * above. 3948fc1b8a73SMel Gorman */ 3949fc1b8a73SMel Gorman if (delta > 0) { 3950a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 3951fc1b8a73SMel Gorman goto out; 3952fc1b8a73SMel Gorman 39538ca39e68SMuchun Song if (delta > allowed_mems_nr(h)) { 3954a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 3955fc1b8a73SMel Gorman goto out; 3956fc1b8a73SMel Gorman } 3957fc1b8a73SMel Gorman } 3958fc1b8a73SMel Gorman 3959fc1b8a73SMel Gorman ret = 0; 3960fc1b8a73SMel Gorman if (delta < 0) 3961a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 3962fc1b8a73SMel Gorman 3963fc1b8a73SMel Gorman out: 3964db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 3965fc1b8a73SMel Gorman return ret; 3966fc1b8a73SMel Gorman } 3967fc1b8a73SMel Gorman 396884afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 396984afd99bSAndy Whitcroft { 3970f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 397184afd99bSAndy Whitcroft 397284afd99bSAndy Whitcroft /* 397384afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 397484afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 397584afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 397625985edcSLucas De Marchi * has a reference to the reservation map it cannot disappear until 397784afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 397884afd99bSAndy Whitcroft * new reference here without additional locking. 397984afd99bSAndy Whitcroft */ 39804e35f483SJoonsoo Kim if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 3981f522c3acSJoonsoo Kim kref_get(&resv->refs); 398284afd99bSAndy Whitcroft } 398384afd99bSAndy Whitcroft 3984a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 3985a1e78772SMel Gorman { 3986a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 3987f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 398890481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 39894e35f483SJoonsoo Kim unsigned long reserve, start, end; 39901c5ecae3SMike Kravetz long gbl_reserve; 399184afd99bSAndy Whitcroft 39924e35f483SJoonsoo Kim if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 39934e35f483SJoonsoo Kim return; 39944e35f483SJoonsoo Kim 3995a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 3996a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 399784afd99bSAndy Whitcroft 39984e35f483SJoonsoo Kim reserve = (end - start) - region_count(resv, start, end); 3999e9fe92aeSMina Almasry hugetlb_cgroup_uncharge_counter(resv, start, end); 40007251ff78SAdam Litke if (reserve) { 40011c5ecae3SMike Kravetz /* 40021c5ecae3SMike Kravetz * Decrement reserve counts. The global reserve count may be 40031c5ecae3SMike Kravetz * adjusted if the subpool has a minimum size. 40041c5ecae3SMike Kravetz */ 40051c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, reserve); 40061c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 40077251ff78SAdam Litke } 4008e9fe92aeSMina Almasry 4009e9fe92aeSMina Almasry kref_put(&resv->refs, resv_map_release); 4010a1e78772SMel Gorman } 4011a1e78772SMel Gorman 401231383c68SDan Williams static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) 401331383c68SDan Williams { 401431383c68SDan Williams if (addr & ~(huge_page_mask(hstate_vma(vma)))) 401531383c68SDan Williams return -EINVAL; 401631383c68SDan Williams return 0; 401731383c68SDan Williams } 401831383c68SDan Williams 401905ea8860SDan Williams static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) 402005ea8860SDan Williams { 4021aca78307SMiaohe Lin return huge_page_size(hstate_vma(vma)); 402205ea8860SDan Williams } 402305ea8860SDan Williams 40241da177e4SLinus Torvalds /* 40251da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 40261da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 40276c26d310SMiaohe Lin * hugepage VMA. do_page_fault() is supposed to trap this, so BUG is we get 40281da177e4SLinus Torvalds * this far. 40291da177e4SLinus Torvalds */ 4030b3ec9f33SSouptick Joarder static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf) 40311da177e4SLinus Torvalds { 40321da177e4SLinus Torvalds BUG(); 4033d0217ac0SNick Piggin return 0; 40341da177e4SLinus Torvalds } 40351da177e4SLinus Torvalds 4036eec3636aSJane Chu /* 4037eec3636aSJane Chu * When a new function is introduced to vm_operations_struct and added 4038eec3636aSJane Chu * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops. 4039eec3636aSJane Chu * This is because under System V memory model, mappings created via 4040eec3636aSJane Chu * shmget/shmat with "huge page" specified are backed by hugetlbfs files, 4041eec3636aSJane Chu * their original vm_ops are overwritten with shm_vm_ops. 4042eec3636aSJane Chu */ 4043f0f37e2fSAlexey Dobriyan const struct vm_operations_struct hugetlb_vm_ops = { 4044d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 404584afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 4046a1e78772SMel Gorman .close = hugetlb_vm_op_close, 4047dd3b614fSDmitry Safonov .may_split = hugetlb_vm_op_split, 404805ea8860SDan Williams .pagesize = hugetlb_vm_op_pagesize, 40491da177e4SLinus Torvalds }; 40501da177e4SLinus Torvalds 40511e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 40521e8f889bSDavid Gibson int writable) 405363551ae0SDavid Gibson { 405463551ae0SDavid Gibson pte_t entry; 405579c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 405663551ae0SDavid Gibson 40571e8f889bSDavid Gibson if (writable) { 4058106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, 4059106c992aSGerald Schaefer vma->vm_page_prot))); 406063551ae0SDavid Gibson } else { 4061106c992aSGerald Schaefer entry = huge_pte_wrprotect(mk_huge_pte(page, 4062106c992aSGerald Schaefer vma->vm_page_prot)); 406363551ae0SDavid Gibson } 406463551ae0SDavid Gibson entry = pte_mkyoung(entry); 406563551ae0SDavid Gibson entry = pte_mkhuge(entry); 406679c1c594SChristophe Leroy entry = arch_make_huge_pte(entry, shift, vma->vm_flags); 406763551ae0SDavid Gibson 406863551ae0SDavid Gibson return entry; 406963551ae0SDavid Gibson } 407063551ae0SDavid Gibson 40711e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 40721e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 40731e8f889bSDavid Gibson { 40741e8f889bSDavid Gibson pte_t entry; 40751e8f889bSDavid Gibson 4076106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); 407732f84528SChris Forbes if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) 40784b3073e1SRussell King update_mmu_cache(vma, address, ptep); 40791e8f889bSDavid Gibson } 40801e8f889bSDavid Gibson 4081d5ed7444SAneesh Kumar K.V bool is_hugetlb_entry_migration(pte_t pte) 40824a705fefSNaoya Horiguchi { 40834a705fefSNaoya Horiguchi swp_entry_t swp; 40844a705fefSNaoya Horiguchi 40854a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 4086d5ed7444SAneesh Kumar K.V return false; 40874a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4088d79d176aSBaoquan He if (is_migration_entry(swp)) 4089d5ed7444SAneesh Kumar K.V return true; 40904a705fefSNaoya Horiguchi else 4091d5ed7444SAneesh Kumar K.V return false; 40924a705fefSNaoya Horiguchi } 40934a705fefSNaoya Horiguchi 40943e5c3600SBaoquan He static bool is_hugetlb_entry_hwpoisoned(pte_t pte) 40954a705fefSNaoya Horiguchi { 40964a705fefSNaoya Horiguchi swp_entry_t swp; 40974a705fefSNaoya Horiguchi 40984a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 40993e5c3600SBaoquan He return false; 41004a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 4101d79d176aSBaoquan He if (is_hwpoison_entry(swp)) 41023e5c3600SBaoquan He return true; 41034a705fefSNaoya Horiguchi else 41043e5c3600SBaoquan He return false; 41054a705fefSNaoya Horiguchi } 41061e8f889bSDavid Gibson 41074eae4efaSPeter Xu static void 41084eae4efaSPeter Xu hugetlb_install_page(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr, 41094eae4efaSPeter Xu struct page *new_page) 41104eae4efaSPeter Xu { 41114eae4efaSPeter Xu __SetPageUptodate(new_page); 41124eae4efaSPeter Xu set_huge_pte_at(vma->vm_mm, addr, ptep, make_huge_pte(vma, new_page, 1)); 41134eae4efaSPeter Xu hugepage_add_new_anon_rmap(new_page, vma, addr); 41144eae4efaSPeter Xu hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm); 41154eae4efaSPeter Xu ClearHPageRestoreReserve(new_page); 41164eae4efaSPeter Xu SetHPageMigratable(new_page); 41174eae4efaSPeter Xu } 41184eae4efaSPeter Xu 411963551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 412063551ae0SDavid Gibson struct vm_area_struct *vma) 412163551ae0SDavid Gibson { 41225e41540cSMike Kravetz pte_t *src_pte, *dst_pte, entry, dst_entry; 412363551ae0SDavid Gibson struct page *ptepage; 41241c59827dSHugh Dickins unsigned long addr; 4125ca6eb14dSPeter Xu bool cow = is_cow_mapping(vma->vm_flags); 4126a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 4127a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 41284eae4efaSPeter Xu unsigned long npages = pages_per_huge_page(h); 4129c0d0381aSMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 4130ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 4131e8569dd2SAndreas Sandberg int ret = 0; 41321e8f889bSDavid Gibson 4133ac46d4f3SJérôme Glisse if (cow) { 41347269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, src, 41356f4f13e8SJérôme Glisse vma->vm_start, 4136ac46d4f3SJérôme Glisse vma->vm_end); 4137ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4138c0d0381aSMike Kravetz } else { 4139c0d0381aSMike Kravetz /* 4140c0d0381aSMike Kravetz * For shared mappings i_mmap_rwsem must be held to call 4141c0d0381aSMike Kravetz * huge_pte_alloc, otherwise the returned ptep could go 4142c0d0381aSMike Kravetz * away if part of a shared pmd and another thread calls 4143c0d0381aSMike Kravetz * huge_pmd_unshare. 4144c0d0381aSMike Kravetz */ 4145c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 4146ac46d4f3SJérôme Glisse } 4147e8569dd2SAndreas Sandberg 4148a5516438SAndi Kleen for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { 4149cb900f41SKirill A. Shutemov spinlock_t *src_ptl, *dst_ptl; 41507868a208SPunit Agrawal src_pte = huge_pte_offset(src, addr, sz); 4151c74df32cSHugh Dickins if (!src_pte) 4152c74df32cSHugh Dickins continue; 4153aec44e0fSPeter Xu dst_pte = huge_pte_alloc(dst, vma, addr, sz); 4154e8569dd2SAndreas Sandberg if (!dst_pte) { 4155e8569dd2SAndreas Sandberg ret = -ENOMEM; 4156e8569dd2SAndreas Sandberg break; 4157e8569dd2SAndreas Sandberg } 4158c5c99429SLarry Woodman 41595e41540cSMike Kravetz /* 41605e41540cSMike Kravetz * If the pagetables are shared don't copy or take references. 41615e41540cSMike Kravetz * dst_pte == src_pte is the common case of src/dest sharing. 41625e41540cSMike Kravetz * 41635e41540cSMike Kravetz * However, src could have 'unshared' and dst shares with 41645e41540cSMike Kravetz * another vma. If dst_pte !none, this implies sharing. 41655e41540cSMike Kravetz * Check here before taking page table lock, and once again 41665e41540cSMike Kravetz * after taking the lock below. 41675e41540cSMike Kravetz */ 41685e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 41695e41540cSMike Kravetz if ((dst_pte == src_pte) || !huge_pte_none(dst_entry)) 4170c5c99429SLarry Woodman continue; 4171c5c99429SLarry Woodman 4172cb900f41SKirill A. Shutemov dst_ptl = huge_pte_lock(h, dst, dst_pte); 4173cb900f41SKirill A. Shutemov src_ptl = huge_pte_lockptr(h, src, src_pte); 4174cb900f41SKirill A. Shutemov spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 41754a705fefSNaoya Horiguchi entry = huge_ptep_get(src_pte); 41765e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 41774eae4efaSPeter Xu again: 41785e41540cSMike Kravetz if (huge_pte_none(entry) || !huge_pte_none(dst_entry)) { 41795e41540cSMike Kravetz /* 41805e41540cSMike Kravetz * Skip if src entry none. Also, skip in the 41815e41540cSMike Kravetz * unlikely case dst entry !none as this implies 41825e41540cSMike Kravetz * sharing with another vma. 41835e41540cSMike Kravetz */ 41844a705fefSNaoya Horiguchi ; 41854a705fefSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_migration(entry) || 41864a705fefSNaoya Horiguchi is_hugetlb_entry_hwpoisoned(entry))) { 41874a705fefSNaoya Horiguchi swp_entry_t swp_entry = pte_to_swp_entry(entry); 41884a705fefSNaoya Horiguchi 41894a705fefSNaoya Horiguchi if (is_write_migration_entry(swp_entry) && cow) { 41904a705fefSNaoya Horiguchi /* 41914a705fefSNaoya Horiguchi * COW mappings require pages in both 41924a705fefSNaoya Horiguchi * parent and child to be set to read. 41934a705fefSNaoya Horiguchi */ 41944a705fefSNaoya Horiguchi make_migration_entry_read(&swp_entry); 41954a705fefSNaoya Horiguchi entry = swp_entry_to_pte(swp_entry); 4196e5251fd4SPunit Agrawal set_huge_swap_pte_at(src, addr, src_pte, 4197e5251fd4SPunit Agrawal entry, sz); 41984a705fefSNaoya Horiguchi } 4199e5251fd4SPunit Agrawal set_huge_swap_pte_at(dst, addr, dst_pte, entry, sz); 42004a705fefSNaoya Horiguchi } else { 42014eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 42024eae4efaSPeter Xu ptepage = pte_page(entry); 42034eae4efaSPeter Xu get_page(ptepage); 42044eae4efaSPeter Xu 42054eae4efaSPeter Xu /* 42064eae4efaSPeter Xu * This is a rare case where we see pinned hugetlb 42074eae4efaSPeter Xu * pages while they're prone to COW. We need to do the 42084eae4efaSPeter Xu * COW earlier during fork. 42094eae4efaSPeter Xu * 42104eae4efaSPeter Xu * When pre-allocating the page or copying data, we 42114eae4efaSPeter Xu * need to be without the pgtable locks since we could 42124eae4efaSPeter Xu * sleep during the process. 42134eae4efaSPeter Xu */ 42144eae4efaSPeter Xu if (unlikely(page_needs_cow_for_dma(vma, ptepage))) { 42154eae4efaSPeter Xu pte_t src_pte_old = entry; 42164eae4efaSPeter Xu struct page *new; 42174eae4efaSPeter Xu 42184eae4efaSPeter Xu spin_unlock(src_ptl); 42194eae4efaSPeter Xu spin_unlock(dst_ptl); 42204eae4efaSPeter Xu /* Do not use reserve as it's private owned */ 42214eae4efaSPeter Xu new = alloc_huge_page(vma, addr, 1); 42224eae4efaSPeter Xu if (IS_ERR(new)) { 42234eae4efaSPeter Xu put_page(ptepage); 42244eae4efaSPeter Xu ret = PTR_ERR(new); 42254eae4efaSPeter Xu break; 42264eae4efaSPeter Xu } 42274eae4efaSPeter Xu copy_user_huge_page(new, ptepage, addr, vma, 42284eae4efaSPeter Xu npages); 42294eae4efaSPeter Xu put_page(ptepage); 42304eae4efaSPeter Xu 42314eae4efaSPeter Xu /* Install the new huge page if src pte stable */ 42324eae4efaSPeter Xu dst_ptl = huge_pte_lock(h, dst, dst_pte); 42334eae4efaSPeter Xu src_ptl = huge_pte_lockptr(h, src, src_pte); 42344eae4efaSPeter Xu spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 42354eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 42364eae4efaSPeter Xu if (!pte_same(src_pte_old, entry)) { 4237846be085SMike Kravetz restore_reserve_on_error(h, vma, addr, 4238846be085SMike Kravetz new); 42394eae4efaSPeter Xu put_page(new); 42404eae4efaSPeter Xu /* dst_entry won't change as in child */ 42414eae4efaSPeter Xu goto again; 42424eae4efaSPeter Xu } 42434eae4efaSPeter Xu hugetlb_install_page(vma, dst_pte, addr, new); 42444eae4efaSPeter Xu spin_unlock(src_ptl); 42454eae4efaSPeter Xu spin_unlock(dst_ptl); 42464eae4efaSPeter Xu continue; 42474eae4efaSPeter Xu } 42484eae4efaSPeter Xu 424934ee645eSJoerg Roedel if (cow) { 42500f10851eSJérôme Glisse /* 42510f10851eSJérôme Glisse * No need to notify as we are downgrading page 42520f10851eSJérôme Glisse * table protection not changing it to point 42530f10851eSJérôme Glisse * to a new page. 42540f10851eSJérôme Glisse * 4255ad56b738SMike Rapoport * See Documentation/vm/mmu_notifier.rst 42560f10851eSJérôme Glisse */ 42577f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 425884894e1cSPeter Xu entry = huge_pte_wrprotect(entry); 425934ee645eSJoerg Roedel } 42604eae4efaSPeter Xu 426153f9263bSKirill A. Shutemov page_dup_rmap(ptepage, true); 426263551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 42634eae4efaSPeter Xu hugetlb_count_add(npages, dst); 42641c59827dSHugh Dickins } 4265cb900f41SKirill A. Shutemov spin_unlock(src_ptl); 4266cb900f41SKirill A. Shutemov spin_unlock(dst_ptl); 426763551ae0SDavid Gibson } 426863551ae0SDavid Gibson 4269e8569dd2SAndreas Sandberg if (cow) 4270ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 4271c0d0381aSMike Kravetz else 4272c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 4273e8569dd2SAndreas Sandberg 4274e8569dd2SAndreas Sandberg return ret; 427563551ae0SDavid Gibson } 427663551ae0SDavid Gibson 427724669e58SAneesh Kumar K.V void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, 427824669e58SAneesh Kumar K.V unsigned long start, unsigned long end, 427924669e58SAneesh Kumar K.V struct page *ref_page) 428063551ae0SDavid Gibson { 428163551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 428263551ae0SDavid Gibson unsigned long address; 4283c7546f8fSDavid Gibson pte_t *ptep; 428463551ae0SDavid Gibson pte_t pte; 4285cb900f41SKirill A. Shutemov spinlock_t *ptl; 428663551ae0SDavid Gibson struct page *page; 4287a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 4288a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 4289ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 4290a5516438SAndi Kleen 429163551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 4292a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 4293a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 429463551ae0SDavid Gibson 429507e32661SAneesh Kumar K.V /* 429607e32661SAneesh Kumar K.V * This is a hugetlb vma, all the pte entries should point 429707e32661SAneesh Kumar K.V * to huge page. 429807e32661SAneesh Kumar K.V */ 4299ed6a7935SPeter Zijlstra tlb_change_page_size(tlb, sz); 430024669e58SAneesh Kumar K.V tlb_start_vma(tlb, vma); 4301dff11abeSMike Kravetz 4302dff11abeSMike Kravetz /* 4303dff11abeSMike Kravetz * If sharing possible, alert mmu notifiers of worst case. 4304dff11abeSMike Kravetz */ 43056f4f13e8SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, mm, start, 43066f4f13e8SJérôme Glisse end); 4307ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 4308ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4309569f48b8SHillf Danton address = start; 4310569f48b8SHillf Danton for (; address < end; address += sz) { 43117868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, sz); 4312c7546f8fSDavid Gibson if (!ptep) 4313c7546f8fSDavid Gibson continue; 4314c7546f8fSDavid Gibson 4315cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 431634ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 431731d49da5SAneesh Kumar K.V spin_unlock(ptl); 4318dff11abeSMike Kravetz /* 4319dff11abeSMike Kravetz * We just unmapped a page of PMDs by clearing a PUD. 4320dff11abeSMike Kravetz * The caller's TLB flush range should cover this area. 4321dff11abeSMike Kravetz */ 432231d49da5SAneesh Kumar K.V continue; 432331d49da5SAneesh Kumar K.V } 432439dde65cSChen, Kenneth W 43256629326bSHillf Danton pte = huge_ptep_get(ptep); 432631d49da5SAneesh Kumar K.V if (huge_pte_none(pte)) { 432731d49da5SAneesh Kumar K.V spin_unlock(ptl); 432831d49da5SAneesh Kumar K.V continue; 432931d49da5SAneesh Kumar K.V } 43306629326bSHillf Danton 43316629326bSHillf Danton /* 43329fbc1f63SNaoya Horiguchi * Migrating hugepage or HWPoisoned hugepage is already 43339fbc1f63SNaoya Horiguchi * unmapped and its refcount is dropped, so just clear pte here. 43346629326bSHillf Danton */ 43359fbc1f63SNaoya Horiguchi if (unlikely(!pte_present(pte))) { 43369386fac3SPunit Agrawal huge_pte_clear(mm, address, ptep, sz); 433731d49da5SAneesh Kumar K.V spin_unlock(ptl); 433831d49da5SAneesh Kumar K.V continue; 43398c4894c6SNaoya Horiguchi } 43406629326bSHillf Danton 43416629326bSHillf Danton page = pte_page(pte); 434204f2cbe3SMel Gorman /* 434304f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 434404f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 434504f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 434604f2cbe3SMel Gorman */ 434704f2cbe3SMel Gorman if (ref_page) { 434831d49da5SAneesh Kumar K.V if (page != ref_page) { 434931d49da5SAneesh Kumar K.V spin_unlock(ptl); 435031d49da5SAneesh Kumar K.V continue; 435131d49da5SAneesh Kumar K.V } 435204f2cbe3SMel Gorman /* 435304f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 435404f2cbe3SMel Gorman * future faults in this VMA will fail rather than 435504f2cbe3SMel Gorman * looking like data was lost 435604f2cbe3SMel Gorman */ 435704f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 435804f2cbe3SMel Gorman } 435904f2cbe3SMel Gorman 4360c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 4361b528e4b6SAneesh Kumar K.V tlb_remove_huge_tlb_entry(h, tlb, ptep, address); 4362106c992aSGerald Schaefer if (huge_pte_dirty(pte)) 43636649a386SKen Chen set_page_dirty(page); 43649e81130bSHillf Danton 43655d317b2bSNaoya Horiguchi hugetlb_count_sub(pages_per_huge_page(h), mm); 4366d281ee61SKirill A. Shutemov page_remove_rmap(page, true); 436731d49da5SAneesh Kumar K.V 4368cb900f41SKirill A. Shutemov spin_unlock(ptl); 4369e77b0852SAneesh Kumar K.V tlb_remove_page_size(tlb, page, huge_page_size(h)); 437024669e58SAneesh Kumar K.V /* 437131d49da5SAneesh Kumar K.V * Bail out after unmapping reference page if supplied 437224669e58SAneesh Kumar K.V */ 437331d49da5SAneesh Kumar K.V if (ref_page) 437431d49da5SAneesh Kumar K.V break; 4375fe1668aeSChen, Kenneth W } 4376ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 437724669e58SAneesh Kumar K.V tlb_end_vma(tlb, vma); 43781da177e4SLinus Torvalds } 437963551ae0SDavid Gibson 4380d833352aSMel Gorman void __unmap_hugepage_range_final(struct mmu_gather *tlb, 4381d833352aSMel Gorman struct vm_area_struct *vma, unsigned long start, 4382d833352aSMel Gorman unsigned long end, struct page *ref_page) 4383d833352aSMel Gorman { 4384d833352aSMel Gorman __unmap_hugepage_range(tlb, vma, start, end, ref_page); 4385d833352aSMel Gorman 4386d833352aSMel Gorman /* 4387d833352aSMel Gorman * Clear this flag so that x86's huge_pmd_share page_table_shareable 4388d833352aSMel Gorman * test will fail on a vma being torn down, and not grab a page table 4389d833352aSMel Gorman * on its way out. We're lucky that the flag has such an appropriate 4390d833352aSMel Gorman * name, and can in fact be safely cleared here. We could clear it 4391d833352aSMel Gorman * before the __unmap_hugepage_range above, but all that's necessary 4392c8c06efaSDavidlohr Bueso * is to clear it before releasing the i_mmap_rwsem. This works 4393d833352aSMel Gorman * because in the context this is called, the VMA is about to be 4394c8c06efaSDavidlohr Bueso * destroyed and the i_mmap_rwsem is held. 4395d833352aSMel Gorman */ 4396d833352aSMel Gorman vma->vm_flags &= ~VM_MAYSHARE; 4397d833352aSMel Gorman } 4398d833352aSMel Gorman 4399502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 440004f2cbe3SMel Gorman unsigned long end, struct page *ref_page) 4401502717f4SChen, Kenneth W { 440224669e58SAneesh Kumar K.V struct mmu_gather tlb; 4403dff11abeSMike Kravetz 4404a72afd87SWill Deacon tlb_gather_mmu(&tlb, vma->vm_mm); 440524669e58SAneesh Kumar K.V __unmap_hugepage_range(&tlb, vma, start, end, ref_page); 4406ae8eba8bSWill Deacon tlb_finish_mmu(&tlb); 4407502717f4SChen, Kenneth W } 4408502717f4SChen, Kenneth W 440904f2cbe3SMel Gorman /* 441004f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 4411578b7725SZhiyuan Dai * mapping it owns the reserve page for. The intention is to unmap the page 441204f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 441304f2cbe3SMel Gorman * same region. 441404f2cbe3SMel Gorman */ 44152f4612afSDavidlohr Bueso static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, 44162a4b3dedSHarvey Harrison struct page *page, unsigned long address) 441704f2cbe3SMel Gorman { 44187526674dSAdam Litke struct hstate *h = hstate_vma(vma); 441904f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 442004f2cbe3SMel Gorman struct address_space *mapping; 442104f2cbe3SMel Gorman pgoff_t pgoff; 442204f2cbe3SMel Gorman 442304f2cbe3SMel Gorman /* 442404f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 442504f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 442604f2cbe3SMel Gorman */ 44277526674dSAdam Litke address = address & huge_page_mask(h); 442836e4f20aSMichal Hocko pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + 442936e4f20aSMichal Hocko vma->vm_pgoff; 443093c76a3dSAl Viro mapping = vma->vm_file->f_mapping; 443104f2cbe3SMel Gorman 44324eb2b1dcSMel Gorman /* 44334eb2b1dcSMel Gorman * Take the mapping lock for the duration of the table walk. As 44344eb2b1dcSMel Gorman * this mapping should be shared between all the VMAs, 44354eb2b1dcSMel Gorman * __unmap_hugepage_range() is called as the lock is already held 44364eb2b1dcSMel Gorman */ 443783cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 44386b2dbba8SMichel Lespinasse vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { 443904f2cbe3SMel Gorman /* Do not unmap the current VMA */ 444004f2cbe3SMel Gorman if (iter_vma == vma) 444104f2cbe3SMel Gorman continue; 444204f2cbe3SMel Gorman 444304f2cbe3SMel Gorman /* 44442f84a899SMel Gorman * Shared VMAs have their own reserves and do not affect 44452f84a899SMel Gorman * MAP_PRIVATE accounting but it is possible that a shared 44462f84a899SMel Gorman * VMA is using the same page so check and skip such VMAs. 44472f84a899SMel Gorman */ 44482f84a899SMel Gorman if (iter_vma->vm_flags & VM_MAYSHARE) 44492f84a899SMel Gorman continue; 44502f84a899SMel Gorman 44512f84a899SMel Gorman /* 445204f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 445304f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 445404f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 445504f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 445604f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 445704f2cbe3SMel Gorman */ 445804f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 445924669e58SAneesh Kumar K.V unmap_hugepage_range(iter_vma, address, 446024669e58SAneesh Kumar K.V address + huge_page_size(h), page); 446104f2cbe3SMel Gorman } 446283cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 446304f2cbe3SMel Gorman } 446404f2cbe3SMel Gorman 44650fe6e20bSNaoya Horiguchi /* 44660fe6e20bSNaoya Horiguchi * Hugetlb_cow() should be called with page lock of the original hugepage held. 4467ef009b25SMichal Hocko * Called with hugetlb_instantiation_mutex held and pte_page locked so we 4468ef009b25SMichal Hocko * cannot race with other handlers or page migration. 4469ef009b25SMichal Hocko * Keep the pte_same checks anyway to make transition from the mutex easier. 44700fe6e20bSNaoya Horiguchi */ 44712b740303SSouptick Joarder static vm_fault_t hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, 4472974e6d66SHuang Ying unsigned long address, pte_t *ptep, 4473cb900f41SKirill A. Shutemov struct page *pagecache_page, spinlock_t *ptl) 44741e8f889bSDavid Gibson { 44753999f52eSAneesh Kumar K.V pte_t pte; 4476a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 44771e8f889bSDavid Gibson struct page *old_page, *new_page; 44782b740303SSouptick Joarder int outside_reserve = 0; 44792b740303SSouptick Joarder vm_fault_t ret = 0; 4480974e6d66SHuang Ying unsigned long haddr = address & huge_page_mask(h); 4481ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 44821e8f889bSDavid Gibson 44833999f52eSAneesh Kumar K.V pte = huge_ptep_get(ptep); 44841e8f889bSDavid Gibson old_page = pte_page(pte); 44851e8f889bSDavid Gibson 448604f2cbe3SMel Gorman retry_avoidcopy: 44871e8f889bSDavid Gibson /* If no-one else is actually using this page, avoid the copy 44881e8f889bSDavid Gibson * and just make the page writable */ 448937a2140dSJoonsoo Kim if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { 44905a49973dSHugh Dickins page_move_anon_rmap(old_page, vma); 44915b7a1d40SHuang Ying set_huge_ptep_writable(vma, haddr, ptep); 449283c54070SNick Piggin return 0; 44931e8f889bSDavid Gibson } 44941e8f889bSDavid Gibson 449504f2cbe3SMel Gorman /* 449604f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 449704f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 449804f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 449904f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 450004f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 450104f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 450204f2cbe3SMel Gorman * of the full address range. 450304f2cbe3SMel Gorman */ 45045944d011SJoonsoo Kim if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 450504f2cbe3SMel Gorman old_page != pagecache_page) 450604f2cbe3SMel Gorman outside_reserve = 1; 450704f2cbe3SMel Gorman 450809cbfeafSKirill A. Shutemov get_page(old_page); 4509b76c8cfbSLarry Woodman 4510ad4404a2SDavidlohr Bueso /* 4511ad4404a2SDavidlohr Bueso * Drop page table lock as buddy allocator may be called. It will 4512ad4404a2SDavidlohr Bueso * be acquired again before returning to the caller, as expected. 4513ad4404a2SDavidlohr Bueso */ 4514cb900f41SKirill A. Shutemov spin_unlock(ptl); 45155b7a1d40SHuang Ying new_page = alloc_huge_page(vma, haddr, outside_reserve); 45161e8f889bSDavid Gibson 45172fc39cecSAdam Litke if (IS_ERR(new_page)) { 451804f2cbe3SMel Gorman /* 451904f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 452004f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 452104f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 452204f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 452304f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 452404f2cbe3SMel Gorman */ 452504f2cbe3SMel Gorman if (outside_reserve) { 4526e7dd91c4SMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 4527e7dd91c4SMike Kravetz pgoff_t idx; 4528e7dd91c4SMike Kravetz u32 hash; 4529e7dd91c4SMike Kravetz 453009cbfeafSKirill A. Shutemov put_page(old_page); 453104f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 4532e7dd91c4SMike Kravetz /* 4533e7dd91c4SMike Kravetz * Drop hugetlb_fault_mutex and i_mmap_rwsem before 4534e7dd91c4SMike Kravetz * unmapping. unmapping needs to hold i_mmap_rwsem 4535e7dd91c4SMike Kravetz * in write mode. Dropping i_mmap_rwsem in read mode 4536e7dd91c4SMike Kravetz * here is OK as COW mappings do not interact with 4537e7dd91c4SMike Kravetz * PMD sharing. 4538e7dd91c4SMike Kravetz * 4539e7dd91c4SMike Kravetz * Reacquire both after unmap operation. 4540e7dd91c4SMike Kravetz */ 4541e7dd91c4SMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 4542e7dd91c4SMike Kravetz hash = hugetlb_fault_mutex_hash(mapping, idx); 4543e7dd91c4SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 4544e7dd91c4SMike Kravetz i_mmap_unlock_read(mapping); 4545e7dd91c4SMike Kravetz 45465b7a1d40SHuang Ying unmap_ref_private(mm, vma, old_page, haddr); 4547e7dd91c4SMike Kravetz 4548e7dd91c4SMike Kravetz i_mmap_lock_read(mapping); 4549e7dd91c4SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 4550cb900f41SKirill A. Shutemov spin_lock(ptl); 45515b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 4552a9af0c5dSNaoya Horiguchi if (likely(ptep && 4553a9af0c5dSNaoya Horiguchi pte_same(huge_ptep_get(ptep), pte))) 455404f2cbe3SMel Gorman goto retry_avoidcopy; 4555a734bcc8SHillf Danton /* 4556cb900f41SKirill A. Shutemov * race occurs while re-acquiring page table 4557cb900f41SKirill A. Shutemov * lock, and our job is done. 4558a734bcc8SHillf Danton */ 4559a734bcc8SHillf Danton return 0; 456004f2cbe3SMel Gorman } 456104f2cbe3SMel Gorman 45622b740303SSouptick Joarder ret = vmf_error(PTR_ERR(new_page)); 4563ad4404a2SDavidlohr Bueso goto out_release_old; 45641e8f889bSDavid Gibson } 45651e8f889bSDavid Gibson 45660fe6e20bSNaoya Horiguchi /* 45670fe6e20bSNaoya Horiguchi * When the original hugepage is shared one, it does not have 45680fe6e20bSNaoya Horiguchi * anon_vma prepared. 45690fe6e20bSNaoya Horiguchi */ 457044e2aa93SDean Nelson if (unlikely(anon_vma_prepare(vma))) { 4571ad4404a2SDavidlohr Bueso ret = VM_FAULT_OOM; 4572ad4404a2SDavidlohr Bueso goto out_release_all; 457344e2aa93SDean Nelson } 45740fe6e20bSNaoya Horiguchi 4575974e6d66SHuang Ying copy_user_huge_page(new_page, old_page, address, vma, 457647ad8475SAndrea Arcangeli pages_per_huge_page(h)); 45770ed361deSNick Piggin __SetPageUptodate(new_page); 45781e8f889bSDavid Gibson 45797269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr, 45806f4f13e8SJérôme Glisse haddr + huge_page_size(h)); 4581ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4582ad4404a2SDavidlohr Bueso 4583b76c8cfbSLarry Woodman /* 4584cb900f41SKirill A. Shutemov * Retake the page table lock to check for racing updates 4585b76c8cfbSLarry Woodman * before the page tables are altered 4586b76c8cfbSLarry Woodman */ 4587cb900f41SKirill A. Shutemov spin_lock(ptl); 45885b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 4589a9af0c5dSNaoya Horiguchi if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { 4590d6995da3SMike Kravetz ClearHPageRestoreReserve(new_page); 459107443a85SJoonsoo Kim 45921e8f889bSDavid Gibson /* Break COW */ 45935b7a1d40SHuang Ying huge_ptep_clear_flush(vma, haddr, ptep); 4594ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range(mm, range.start, range.end); 45955b7a1d40SHuang Ying set_huge_pte_at(mm, haddr, ptep, 45961e8f889bSDavid Gibson make_huge_pte(vma, new_page, 1)); 4597d281ee61SKirill A. Shutemov page_remove_rmap(old_page, true); 45985b7a1d40SHuang Ying hugepage_add_new_anon_rmap(new_page, vma, haddr); 45998f251a3dSMike Kravetz SetHPageMigratable(new_page); 46001e8f889bSDavid Gibson /* Make the old page be freed below */ 46011e8f889bSDavid Gibson new_page = old_page; 46021e8f889bSDavid Gibson } 4603cb900f41SKirill A. Shutemov spin_unlock(ptl); 4604ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 4605ad4404a2SDavidlohr Bueso out_release_all: 46065b7a1d40SHuang Ying restore_reserve_on_error(h, vma, haddr, new_page); 460709cbfeafSKirill A. Shutemov put_page(new_page); 4608ad4404a2SDavidlohr Bueso out_release_old: 460909cbfeafSKirill A. Shutemov put_page(old_page); 46108312034fSJoonsoo Kim 4611ad4404a2SDavidlohr Bueso spin_lock(ptl); /* Caller expects lock to be held */ 4612ad4404a2SDavidlohr Bueso return ret; 46131e8f889bSDavid Gibson } 46141e8f889bSDavid Gibson 461504f2cbe3SMel Gorman /* Return the pagecache page at a given address within a VMA */ 4616a5516438SAndi Kleen static struct page *hugetlbfs_pagecache_page(struct hstate *h, 4617a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 461804f2cbe3SMel Gorman { 461904f2cbe3SMel Gorman struct address_space *mapping; 4620e7c4b0bfSAndy Whitcroft pgoff_t idx; 462104f2cbe3SMel Gorman 462204f2cbe3SMel Gorman mapping = vma->vm_file->f_mapping; 4623a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 462404f2cbe3SMel Gorman 462504f2cbe3SMel Gorman return find_lock_page(mapping, idx); 462604f2cbe3SMel Gorman } 462704f2cbe3SMel Gorman 46283ae77f43SHugh Dickins /* 46293ae77f43SHugh Dickins * Return whether there is a pagecache page to back given address within VMA. 46303ae77f43SHugh Dickins * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. 46313ae77f43SHugh Dickins */ 46323ae77f43SHugh Dickins static bool hugetlbfs_pagecache_present(struct hstate *h, 46332a15efc9SHugh Dickins struct vm_area_struct *vma, unsigned long address) 46342a15efc9SHugh Dickins { 46352a15efc9SHugh Dickins struct address_space *mapping; 46362a15efc9SHugh Dickins pgoff_t idx; 46372a15efc9SHugh Dickins struct page *page; 46382a15efc9SHugh Dickins 46392a15efc9SHugh Dickins mapping = vma->vm_file->f_mapping; 46402a15efc9SHugh Dickins idx = vma_hugecache_offset(h, vma, address); 46412a15efc9SHugh Dickins 46422a15efc9SHugh Dickins page = find_get_page(mapping, idx); 46432a15efc9SHugh Dickins if (page) 46442a15efc9SHugh Dickins put_page(page); 46452a15efc9SHugh Dickins return page != NULL; 46462a15efc9SHugh Dickins } 46472a15efc9SHugh Dickins 4648ab76ad54SMike Kravetz int huge_add_to_page_cache(struct page *page, struct address_space *mapping, 4649ab76ad54SMike Kravetz pgoff_t idx) 4650ab76ad54SMike Kravetz { 4651ab76ad54SMike Kravetz struct inode *inode = mapping->host; 4652ab76ad54SMike Kravetz struct hstate *h = hstate_inode(inode); 4653ab76ad54SMike Kravetz int err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); 4654ab76ad54SMike Kravetz 4655ab76ad54SMike Kravetz if (err) 4656ab76ad54SMike Kravetz return err; 4657d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 4658ab76ad54SMike Kravetz 465922146c3cSMike Kravetz /* 466022146c3cSMike Kravetz * set page dirty so that it will not be removed from cache/file 466122146c3cSMike Kravetz * by non-hugetlbfs specific code paths. 466222146c3cSMike Kravetz */ 466322146c3cSMike Kravetz set_page_dirty(page); 466422146c3cSMike Kravetz 4665ab76ad54SMike Kravetz spin_lock(&inode->i_lock); 4666ab76ad54SMike Kravetz inode->i_blocks += blocks_per_huge_page(h); 4667ab76ad54SMike Kravetz spin_unlock(&inode->i_lock); 4668ab76ad54SMike Kravetz return 0; 4669ab76ad54SMike Kravetz } 4670ab76ad54SMike Kravetz 46717677f7fdSAxel Rasmussen static inline vm_fault_t hugetlb_handle_userfault(struct vm_area_struct *vma, 46727677f7fdSAxel Rasmussen struct address_space *mapping, 46737677f7fdSAxel Rasmussen pgoff_t idx, 46747677f7fdSAxel Rasmussen unsigned int flags, 46757677f7fdSAxel Rasmussen unsigned long haddr, 46767677f7fdSAxel Rasmussen unsigned long reason) 46777677f7fdSAxel Rasmussen { 46787677f7fdSAxel Rasmussen vm_fault_t ret; 46797677f7fdSAxel Rasmussen u32 hash; 46807677f7fdSAxel Rasmussen struct vm_fault vmf = { 46817677f7fdSAxel Rasmussen .vma = vma, 46827677f7fdSAxel Rasmussen .address = haddr, 46837677f7fdSAxel Rasmussen .flags = flags, 46847677f7fdSAxel Rasmussen 46857677f7fdSAxel Rasmussen /* 46867677f7fdSAxel Rasmussen * Hard to debug if it ends up being 46877677f7fdSAxel Rasmussen * used by a callee that assumes 46887677f7fdSAxel Rasmussen * something about the other 46897677f7fdSAxel Rasmussen * uninitialized fields... same as in 46907677f7fdSAxel Rasmussen * memory.c 46917677f7fdSAxel Rasmussen */ 46927677f7fdSAxel Rasmussen }; 46937677f7fdSAxel Rasmussen 46947677f7fdSAxel Rasmussen /* 46957677f7fdSAxel Rasmussen * hugetlb_fault_mutex and i_mmap_rwsem must be 46967677f7fdSAxel Rasmussen * dropped before handling userfault. Reacquire 46977677f7fdSAxel Rasmussen * after handling fault to make calling code simpler. 46987677f7fdSAxel Rasmussen */ 46997677f7fdSAxel Rasmussen hash = hugetlb_fault_mutex_hash(mapping, idx); 47007677f7fdSAxel Rasmussen mutex_unlock(&hugetlb_fault_mutex_table[hash]); 47017677f7fdSAxel Rasmussen i_mmap_unlock_read(mapping); 47027677f7fdSAxel Rasmussen ret = handle_userfault(&vmf, reason); 47037677f7fdSAxel Rasmussen i_mmap_lock_read(mapping); 47047677f7fdSAxel Rasmussen mutex_lock(&hugetlb_fault_mutex_table[hash]); 47057677f7fdSAxel Rasmussen 47067677f7fdSAxel Rasmussen return ret; 47077677f7fdSAxel Rasmussen } 47087677f7fdSAxel Rasmussen 47092b740303SSouptick Joarder static vm_fault_t hugetlb_no_page(struct mm_struct *mm, 47102b740303SSouptick Joarder struct vm_area_struct *vma, 47118382d914SDavidlohr Bueso struct address_space *mapping, pgoff_t idx, 4712788c7df4SHugh Dickins unsigned long address, pte_t *ptep, unsigned int flags) 4713ac9b9c66SHugh Dickins { 4714a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 47152b740303SSouptick Joarder vm_fault_t ret = VM_FAULT_SIGBUS; 4716409eb8c2SHillf Danton int anon_rmap = 0; 47174c887265SAdam Litke unsigned long size; 47184c887265SAdam Litke struct page *page; 47191e8f889bSDavid Gibson pte_t new_pte; 4720cb900f41SKirill A. Shutemov spinlock_t *ptl; 4721285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 4722cb6acd01SMike Kravetz bool new_page = false; 47234c887265SAdam Litke 472404f2cbe3SMel Gorman /* 472504f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 472604f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 472725985edcSLucas De Marchi * COW. Warn that such a situation has occurred as it may not be obvious 472804f2cbe3SMel Gorman */ 472904f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 4730910154d5SGeoffrey Thomas pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n", 473104f2cbe3SMel Gorman current->pid); 473204f2cbe3SMel Gorman return ret; 473304f2cbe3SMel Gorman } 473404f2cbe3SMel Gorman 47354c887265SAdam Litke /* 473687bf91d3SMike Kravetz * We can not race with truncation due to holding i_mmap_rwsem. 473787bf91d3SMike Kravetz * i_size is modified when holding i_mmap_rwsem, so check here 473887bf91d3SMike Kravetz * once for faults beyond end of file. 47394c887265SAdam Litke */ 4740a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 4741ebed4bfcSHugh Dickins if (idx >= size) 4742ebed4bfcSHugh Dickins goto out; 47431a1aad8aSMike Kravetz 474487bf91d3SMike Kravetz retry: 474587bf91d3SMike Kravetz page = find_lock_page(mapping, idx); 474687bf91d3SMike Kravetz if (!page) { 47477677f7fdSAxel Rasmussen /* Check for page in userfault range */ 47481a1aad8aSMike Kravetz if (userfaultfd_missing(vma)) { 47497677f7fdSAxel Rasmussen ret = hugetlb_handle_userfault(vma, mapping, idx, 47507677f7fdSAxel Rasmussen flags, haddr, 47517677f7fdSAxel Rasmussen VM_UFFD_MISSING); 47521a1aad8aSMike Kravetz goto out; 47531a1aad8aSMike Kravetz } 47541a1aad8aSMike Kravetz 4755285b8dcaSHuang Ying page = alloc_huge_page(vma, haddr, 0); 47562fc39cecSAdam Litke if (IS_ERR(page)) { 47574643d67eSMike Kravetz /* 47584643d67eSMike Kravetz * Returning error will result in faulting task being 47594643d67eSMike Kravetz * sent SIGBUS. The hugetlb fault mutex prevents two 47604643d67eSMike Kravetz * tasks from racing to fault in the same page which 47614643d67eSMike Kravetz * could result in false unable to allocate errors. 47624643d67eSMike Kravetz * Page migration does not take the fault mutex, but 47634643d67eSMike Kravetz * does a clear then write of pte's under page table 47644643d67eSMike Kravetz * lock. Page fault code could race with migration, 47654643d67eSMike Kravetz * notice the clear pte and try to allocate a page 47664643d67eSMike Kravetz * here. Before returning error, get ptl and make 47674643d67eSMike Kravetz * sure there really is no pte entry. 47684643d67eSMike Kravetz */ 47694643d67eSMike Kravetz ptl = huge_pte_lock(h, mm, ptep); 47704643d67eSMike Kravetz ret = 0; 4771d83e6c8aSMiaohe Lin if (huge_pte_none(huge_ptep_get(ptep))) 47722b740303SSouptick Joarder ret = vmf_error(PTR_ERR(page)); 4773d83e6c8aSMiaohe Lin spin_unlock(ptl); 47746bda666aSChristoph Lameter goto out; 47756bda666aSChristoph Lameter } 477647ad8475SAndrea Arcangeli clear_huge_page(page, address, pages_per_huge_page(h)); 47770ed361deSNick Piggin __SetPageUptodate(page); 4778cb6acd01SMike Kravetz new_page = true; 4779ac9b9c66SHugh Dickins 4780f83a275dSMel Gorman if (vma->vm_flags & VM_MAYSHARE) { 4781ab76ad54SMike Kravetz int err = huge_add_to_page_cache(page, mapping, idx); 47826bda666aSChristoph Lameter if (err) { 47836bda666aSChristoph Lameter put_page(page); 47846bda666aSChristoph Lameter if (err == -EEXIST) 47856bda666aSChristoph Lameter goto retry; 47866bda666aSChristoph Lameter goto out; 47876bda666aSChristoph Lameter } 478823be7468SMel Gorman } else { 47896bda666aSChristoph Lameter lock_page(page); 47900fe6e20bSNaoya Horiguchi if (unlikely(anon_vma_prepare(vma))) { 47910fe6e20bSNaoya Horiguchi ret = VM_FAULT_OOM; 47920fe6e20bSNaoya Horiguchi goto backout_unlocked; 479323be7468SMel Gorman } 4794409eb8c2SHillf Danton anon_rmap = 1; 47950fe6e20bSNaoya Horiguchi } 47960fe6e20bSNaoya Horiguchi } else { 479757303d80SAndy Whitcroft /* 4798998b4382SNaoya Horiguchi * If memory error occurs between mmap() and fault, some process 4799998b4382SNaoya Horiguchi * don't have hwpoisoned swap entry for errored virtual address. 4800998b4382SNaoya Horiguchi * So we need to block hugepage fault by PG_hwpoison bit check. 4801fd6a03edSNaoya Horiguchi */ 4802fd6a03edSNaoya Horiguchi if (unlikely(PageHWPoison(page))) { 48030eb98f15SMiaohe Lin ret = VM_FAULT_HWPOISON_LARGE | 4804972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 4805fd6a03edSNaoya Horiguchi goto backout_unlocked; 48066bda666aSChristoph Lameter } 48077677f7fdSAxel Rasmussen 48087677f7fdSAxel Rasmussen /* Check for page in userfault range. */ 48097677f7fdSAxel Rasmussen if (userfaultfd_minor(vma)) { 48107677f7fdSAxel Rasmussen unlock_page(page); 48117677f7fdSAxel Rasmussen put_page(page); 48127677f7fdSAxel Rasmussen ret = hugetlb_handle_userfault(vma, mapping, idx, 48137677f7fdSAxel Rasmussen flags, haddr, 48147677f7fdSAxel Rasmussen VM_UFFD_MINOR); 48157677f7fdSAxel Rasmussen goto out; 48167677f7fdSAxel Rasmussen } 4817998b4382SNaoya Horiguchi } 48181e8f889bSDavid Gibson 481957303d80SAndy Whitcroft /* 482057303d80SAndy Whitcroft * If we are going to COW a private mapping later, we examine the 482157303d80SAndy Whitcroft * pending reservations for this page now. This will ensure that 482257303d80SAndy Whitcroft * any allocations necessary to record that reservation occur outside 482357303d80SAndy Whitcroft * the spinlock. 482457303d80SAndy Whitcroft */ 48255e911373SMike Kravetz if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 4826285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 48272b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 48282b26736cSAndy Whitcroft goto backout_unlocked; 48292b26736cSAndy Whitcroft } 48305e911373SMike Kravetz /* Just decrements count, does not deallocate */ 4831285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 48325e911373SMike Kravetz } 483357303d80SAndy Whitcroft 48348bea8052SAneesh Kumar K.V ptl = huge_pte_lock(h, mm, ptep); 483583c54070SNick Piggin ret = 0; 48367f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(ptep))) 48374c887265SAdam Litke goto backout; 48384c887265SAdam Litke 483907443a85SJoonsoo Kim if (anon_rmap) { 4840d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 4841285b8dcaSHuang Ying hugepage_add_new_anon_rmap(page, vma, haddr); 4842ac714904SChoi Gi-yong } else 484353f9263bSKirill A. Shutemov page_dup_rmap(page, true); 48441e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 48451e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 4846285b8dcaSHuang Ying set_huge_pte_at(mm, haddr, ptep, new_pte); 48471e8f889bSDavid Gibson 48485d317b2bSNaoya Horiguchi hugetlb_count_add(pages_per_huge_page(h), mm); 4849788c7df4SHugh Dickins if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 48501e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 4851974e6d66SHuang Ying ret = hugetlb_cow(mm, vma, address, ptep, page, ptl); 48521e8f889bSDavid Gibson } 48531e8f889bSDavid Gibson 4854cb900f41SKirill A. Shutemov spin_unlock(ptl); 4855cb6acd01SMike Kravetz 4856cb6acd01SMike Kravetz /* 48578f251a3dSMike Kravetz * Only set HPageMigratable in newly allocated pages. Existing pages 48588f251a3dSMike Kravetz * found in the pagecache may not have HPageMigratableset if they have 48598f251a3dSMike Kravetz * been isolated for migration. 4860cb6acd01SMike Kravetz */ 4861cb6acd01SMike Kravetz if (new_page) 48628f251a3dSMike Kravetz SetHPageMigratable(page); 4863cb6acd01SMike Kravetz 48644c887265SAdam Litke unlock_page(page); 48654c887265SAdam Litke out: 4866ac9b9c66SHugh Dickins return ret; 48674c887265SAdam Litke 48684c887265SAdam Litke backout: 4869cb900f41SKirill A. Shutemov spin_unlock(ptl); 48702b26736cSAndy Whitcroft backout_unlocked: 48714c887265SAdam Litke unlock_page(page); 4872285b8dcaSHuang Ying restore_reserve_on_error(h, vma, haddr, page); 48734c887265SAdam Litke put_page(page); 48744c887265SAdam Litke goto out; 4875ac9b9c66SHugh Dickins } 4876ac9b9c66SHugh Dickins 48778382d914SDavidlohr Bueso #ifdef CONFIG_SMP 4878188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 48798382d914SDavidlohr Bueso { 48808382d914SDavidlohr Bueso unsigned long key[2]; 48818382d914SDavidlohr Bueso u32 hash; 48828382d914SDavidlohr Bueso 48838382d914SDavidlohr Bueso key[0] = (unsigned long) mapping; 48848382d914SDavidlohr Bueso key[1] = idx; 48858382d914SDavidlohr Bueso 488655254636SMike Kravetz hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0); 48878382d914SDavidlohr Bueso 48888382d914SDavidlohr Bueso return hash & (num_fault_mutexes - 1); 48898382d914SDavidlohr Bueso } 48908382d914SDavidlohr Bueso #else 48918382d914SDavidlohr Bueso /* 48926c26d310SMiaohe Lin * For uniprocessor systems we always use a single mutex, so just 48938382d914SDavidlohr Bueso * return 0 and avoid the hashing overhead. 48948382d914SDavidlohr Bueso */ 4895188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 48968382d914SDavidlohr Bueso { 48978382d914SDavidlohr Bueso return 0; 48988382d914SDavidlohr Bueso } 48998382d914SDavidlohr Bueso #endif 49008382d914SDavidlohr Bueso 49012b740303SSouptick Joarder vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 4902788c7df4SHugh Dickins unsigned long address, unsigned int flags) 490386e5216fSAdam Litke { 49048382d914SDavidlohr Bueso pte_t *ptep, entry; 4905cb900f41SKirill A. Shutemov spinlock_t *ptl; 49062b740303SSouptick Joarder vm_fault_t ret; 49078382d914SDavidlohr Bueso u32 hash; 49088382d914SDavidlohr Bueso pgoff_t idx; 49090fe6e20bSNaoya Horiguchi struct page *page = NULL; 491057303d80SAndy Whitcroft struct page *pagecache_page = NULL; 4911a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 49128382d914SDavidlohr Bueso struct address_space *mapping; 49130f792cf9SNaoya Horiguchi int need_wait_lock = 0; 4914285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 491586e5216fSAdam Litke 4916285b8dcaSHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 4917fd6a03edSNaoya Horiguchi if (ptep) { 4918c0d0381aSMike Kravetz /* 4919c0d0381aSMike Kravetz * Since we hold no locks, ptep could be stale. That is 4920c0d0381aSMike Kravetz * OK as we are only making decisions based on content and 4921c0d0381aSMike Kravetz * not actually modifying content here. 4922c0d0381aSMike Kravetz */ 4923fd6a03edSNaoya Horiguchi entry = huge_ptep_get(ptep); 4924290408d4SNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(entry))) { 4925cb900f41SKirill A. Shutemov migration_entry_wait_huge(vma, mm, ptep); 4926290408d4SNaoya Horiguchi return 0; 4927290408d4SNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) 4928aa50d3a7SAndi Kleen return VM_FAULT_HWPOISON_LARGE | 4929972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 4930b43a9990SMike Kravetz } 49318382d914SDavidlohr Bueso 4932c0d0381aSMike Kravetz /* 4933c0d0381aSMike Kravetz * Acquire i_mmap_rwsem before calling huge_pte_alloc and hold 493487bf91d3SMike Kravetz * until finished with ptep. This serves two purposes: 493587bf91d3SMike Kravetz * 1) It prevents huge_pmd_unshare from being called elsewhere 493687bf91d3SMike Kravetz * and making the ptep no longer valid. 493787bf91d3SMike Kravetz * 2) It synchronizes us with i_size modifications during truncation. 4938c0d0381aSMike Kravetz * 4939c0d0381aSMike Kravetz * ptep could have already be assigned via huge_pte_offset. That 4940c0d0381aSMike Kravetz * is OK, as huge_pte_alloc will return the same value unless 4941c0d0381aSMike Kravetz * something has changed. 4942c0d0381aSMike Kravetz */ 4943ddeaab32SMike Kravetz mapping = vma->vm_file->f_mapping; 4944c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 4945aec44e0fSPeter Xu ptep = huge_pte_alloc(mm, vma, haddr, huge_page_size(h)); 4946c0d0381aSMike Kravetz if (!ptep) { 4947c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 4948c0d0381aSMike Kravetz return VM_FAULT_OOM; 4949c0d0381aSMike Kravetz } 4950ddeaab32SMike Kravetz 49513935baa9SDavid Gibson /* 49523935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 49533935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 49543935baa9SDavid Gibson * the same page in the page cache. 49553935baa9SDavid Gibson */ 4956c0d0381aSMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 4957188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 4958c672c7f2SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 49598382d914SDavidlohr Bueso 49607f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 49617f2e9525SGerald Schaefer if (huge_pte_none(entry)) { 49628382d914SDavidlohr Bueso ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, flags); 4963b4d1d99fSDavid Gibson goto out_mutex; 49643935baa9SDavid Gibson } 496586e5216fSAdam Litke 496683c54070SNick Piggin ret = 0; 49671e8f889bSDavid Gibson 496857303d80SAndy Whitcroft /* 49690f792cf9SNaoya Horiguchi * entry could be a migration/hwpoison entry at this point, so this 49700f792cf9SNaoya Horiguchi * check prevents the kernel from going below assuming that we have 49717c8de358SEthon Paul * an active hugepage in pagecache. This goto expects the 2nd page 49727c8de358SEthon Paul * fault, and is_hugetlb_entry_(migration|hwpoisoned) check will 49737c8de358SEthon Paul * properly handle it. 49740f792cf9SNaoya Horiguchi */ 49750f792cf9SNaoya Horiguchi if (!pte_present(entry)) 49760f792cf9SNaoya Horiguchi goto out_mutex; 49770f792cf9SNaoya Horiguchi 49780f792cf9SNaoya Horiguchi /* 497957303d80SAndy Whitcroft * If we are going to COW the mapping later, we examine the pending 498057303d80SAndy Whitcroft * reservations for this page now. This will ensure that any 498157303d80SAndy Whitcroft * allocations necessary to record that reservation occur outside the 498257303d80SAndy Whitcroft * spinlock. For private mappings, we also lookup the pagecache 498357303d80SAndy Whitcroft * page now as it is used to determine if a reservation has been 498457303d80SAndy Whitcroft * consumed. 498557303d80SAndy Whitcroft */ 4986106c992aSGerald Schaefer if ((flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { 4987285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 49882b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 4989b4d1d99fSDavid Gibson goto out_mutex; 49902b26736cSAndy Whitcroft } 49915e911373SMike Kravetz /* Just decrements count, does not deallocate */ 4992285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 499357303d80SAndy Whitcroft 4994f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 499557303d80SAndy Whitcroft pagecache_page = hugetlbfs_pagecache_page(h, 4996285b8dcaSHuang Ying vma, haddr); 499757303d80SAndy Whitcroft } 499857303d80SAndy Whitcroft 49990f792cf9SNaoya Horiguchi ptl = huge_pte_lock(h, mm, ptep); 50000fe6e20bSNaoya Horiguchi 50011e8f889bSDavid Gibson /* Check for a racing update before calling hugetlb_cow */ 5002b4d1d99fSDavid Gibson if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) 5003cb900f41SKirill A. Shutemov goto out_ptl; 5004b4d1d99fSDavid Gibson 50050f792cf9SNaoya Horiguchi /* 50060f792cf9SNaoya Horiguchi * hugetlb_cow() requires page locks of pte_page(entry) and 50070f792cf9SNaoya Horiguchi * pagecache_page, so here we need take the former one 50080f792cf9SNaoya Horiguchi * when page != pagecache_page or !pagecache_page. 50090f792cf9SNaoya Horiguchi */ 50100f792cf9SNaoya Horiguchi page = pte_page(entry); 50110f792cf9SNaoya Horiguchi if (page != pagecache_page) 50120f792cf9SNaoya Horiguchi if (!trylock_page(page)) { 50130f792cf9SNaoya Horiguchi need_wait_lock = 1; 50140f792cf9SNaoya Horiguchi goto out_ptl; 50150f792cf9SNaoya Horiguchi } 50160f792cf9SNaoya Horiguchi 50170f792cf9SNaoya Horiguchi get_page(page); 5018b4d1d99fSDavid Gibson 5019788c7df4SHugh Dickins if (flags & FAULT_FLAG_WRITE) { 5020106c992aSGerald Schaefer if (!huge_pte_write(entry)) { 5021974e6d66SHuang Ying ret = hugetlb_cow(mm, vma, address, ptep, 5022cb900f41SKirill A. Shutemov pagecache_page, ptl); 50230f792cf9SNaoya Horiguchi goto out_put_page; 5024b4d1d99fSDavid Gibson } 5025106c992aSGerald Schaefer entry = huge_pte_mkdirty(entry); 5026b4d1d99fSDavid Gibson } 5027b4d1d99fSDavid Gibson entry = pte_mkyoung(entry); 5028285b8dcaSHuang Ying if (huge_ptep_set_access_flags(vma, haddr, ptep, entry, 5029788c7df4SHugh Dickins flags & FAULT_FLAG_WRITE)) 5030285b8dcaSHuang Ying update_mmu_cache(vma, haddr, ptep); 50310f792cf9SNaoya Horiguchi out_put_page: 50320f792cf9SNaoya Horiguchi if (page != pagecache_page) 50330f792cf9SNaoya Horiguchi unlock_page(page); 50340f792cf9SNaoya Horiguchi put_page(page); 5035cb900f41SKirill A. Shutemov out_ptl: 5036cb900f41SKirill A. Shutemov spin_unlock(ptl); 503757303d80SAndy Whitcroft 503857303d80SAndy Whitcroft if (pagecache_page) { 503957303d80SAndy Whitcroft unlock_page(pagecache_page); 504057303d80SAndy Whitcroft put_page(pagecache_page); 504157303d80SAndy Whitcroft } 5042b4d1d99fSDavid Gibson out_mutex: 5043c672c7f2SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 5044c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 50450f792cf9SNaoya Horiguchi /* 50460f792cf9SNaoya Horiguchi * Generally it's safe to hold refcount during waiting page lock. But 50470f792cf9SNaoya Horiguchi * here we just wait to defer the next page fault to avoid busy loop and 50480f792cf9SNaoya Horiguchi * the page is not used after unlocked before returning from the current 50490f792cf9SNaoya Horiguchi * page fault. So we are safe from accessing freed page, even if we wait 50500f792cf9SNaoya Horiguchi * here without taking refcount. 50510f792cf9SNaoya Horiguchi */ 50520f792cf9SNaoya Horiguchi if (need_wait_lock) 50530f792cf9SNaoya Horiguchi wait_on_page_locked(page); 50541e8f889bSDavid Gibson return ret; 505586e5216fSAdam Litke } 505686e5216fSAdam Litke 5057714c1891SAxel Rasmussen #ifdef CONFIG_USERFAULTFD 50588fb5debcSMike Kravetz /* 50598fb5debcSMike Kravetz * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with 50608fb5debcSMike Kravetz * modifications for huge pages. 50618fb5debcSMike Kravetz */ 50628fb5debcSMike Kravetz int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, 50638fb5debcSMike Kravetz pte_t *dst_pte, 50648fb5debcSMike Kravetz struct vm_area_struct *dst_vma, 50658fb5debcSMike Kravetz unsigned long dst_addr, 50668fb5debcSMike Kravetz unsigned long src_addr, 5067f6191471SAxel Rasmussen enum mcopy_atomic_mode mode, 50688fb5debcSMike Kravetz struct page **pagep) 50698fb5debcSMike Kravetz { 5070f6191471SAxel Rasmussen bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE); 50718cc5fcbbSMina Almasry struct hstate *h = hstate_vma(dst_vma); 50728cc5fcbbSMina Almasry struct address_space *mapping = dst_vma->vm_file->f_mapping; 50738cc5fcbbSMina Almasry pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr); 50741e392147SAndrea Arcangeli unsigned long size; 50751c9e8defSMike Kravetz int vm_shared = dst_vma->vm_flags & VM_SHARED; 50768fb5debcSMike Kravetz pte_t _dst_pte; 50778fb5debcSMike Kravetz spinlock_t *ptl; 50788cc5fcbbSMina Almasry int ret = -ENOMEM; 50798fb5debcSMike Kravetz struct page *page; 5080f6191471SAxel Rasmussen int writable; 50818fb5debcSMike Kravetz 5082f6191471SAxel Rasmussen if (is_continue) { 5083f6191471SAxel Rasmussen ret = -EFAULT; 5084f6191471SAxel Rasmussen page = find_lock_page(mapping, idx); 5085f6191471SAxel Rasmussen if (!page) 5086f6191471SAxel Rasmussen goto out; 5087f6191471SAxel Rasmussen } else if (!*pagep) { 5088d84cf06eSMina Almasry /* If a page already exists, then it's UFFDIO_COPY for 5089d84cf06eSMina Almasry * a non-missing case. Return -EEXIST. 5090d84cf06eSMina Almasry */ 5091d84cf06eSMina Almasry if (vm_shared && 5092d84cf06eSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 5093d84cf06eSMina Almasry ret = -EEXIST; 50948fb5debcSMike Kravetz goto out; 5095d84cf06eSMina Almasry } 5096d84cf06eSMina Almasry 5097d84cf06eSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 5098d84cf06eSMina Almasry if (IS_ERR(page)) { 5099d84cf06eSMina Almasry ret = -ENOMEM; 5100d84cf06eSMina Almasry goto out; 5101d84cf06eSMina Almasry } 51028fb5debcSMike Kravetz 51038fb5debcSMike Kravetz ret = copy_huge_page_from_user(page, 51048fb5debcSMike Kravetz (const void __user *) src_addr, 5105810a56b9SMike Kravetz pages_per_huge_page(h), false); 51068fb5debcSMike Kravetz 5107c1e8d7c6SMichel Lespinasse /* fallback to copy_from_user outside mmap_lock */ 51088fb5debcSMike Kravetz if (unlikely(ret)) { 51099e368259SAndrea Arcangeli ret = -ENOENT; 51108cc5fcbbSMina Almasry /* Free the allocated page which may have 51118cc5fcbbSMina Almasry * consumed a reservation. 51128cc5fcbbSMina Almasry */ 51138cc5fcbbSMina Almasry restore_reserve_on_error(h, dst_vma, dst_addr, page); 51148cc5fcbbSMina Almasry put_page(page); 51158cc5fcbbSMina Almasry 51168cc5fcbbSMina Almasry /* Allocate a temporary page to hold the copied 51178cc5fcbbSMina Almasry * contents. 51188cc5fcbbSMina Almasry */ 51198cc5fcbbSMina Almasry page = alloc_huge_page_vma(h, dst_vma, dst_addr); 51208cc5fcbbSMina Almasry if (!page) { 51218cc5fcbbSMina Almasry ret = -ENOMEM; 51228cc5fcbbSMina Almasry goto out; 51238cc5fcbbSMina Almasry } 51248fb5debcSMike Kravetz *pagep = page; 51258cc5fcbbSMina Almasry /* Set the outparam pagep and return to the caller to 51268cc5fcbbSMina Almasry * copy the contents outside the lock. Don't free the 51278cc5fcbbSMina Almasry * page. 51288cc5fcbbSMina Almasry */ 51298fb5debcSMike Kravetz goto out; 51308fb5debcSMike Kravetz } 51318fb5debcSMike Kravetz } else { 51328cc5fcbbSMina Almasry if (vm_shared && 51338cc5fcbbSMina Almasry hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) { 51348cc5fcbbSMina Almasry put_page(*pagep); 51358cc5fcbbSMina Almasry ret = -EEXIST; 51368cc5fcbbSMina Almasry *pagep = NULL; 51378cc5fcbbSMina Almasry goto out; 51388cc5fcbbSMina Almasry } 51398cc5fcbbSMina Almasry 51408cc5fcbbSMina Almasry page = alloc_huge_page(dst_vma, dst_addr, 0); 51418cc5fcbbSMina Almasry if (IS_ERR(page)) { 51428cc5fcbbSMina Almasry ret = -ENOMEM; 51438cc5fcbbSMina Almasry *pagep = NULL; 51448cc5fcbbSMina Almasry goto out; 51458cc5fcbbSMina Almasry } 51468cc5fcbbSMina Almasry copy_huge_page(page, *pagep); 51478cc5fcbbSMina Almasry put_page(*pagep); 51488fb5debcSMike Kravetz *pagep = NULL; 51498fb5debcSMike Kravetz } 51508fb5debcSMike Kravetz 51518fb5debcSMike Kravetz /* 51528fb5debcSMike Kravetz * The memory barrier inside __SetPageUptodate makes sure that 51538fb5debcSMike Kravetz * preceding stores to the page contents become visible before 51548fb5debcSMike Kravetz * the set_pte_at() write. 51558fb5debcSMike Kravetz */ 51568fb5debcSMike Kravetz __SetPageUptodate(page); 51578fb5debcSMike Kravetz 5158f6191471SAxel Rasmussen /* Add shared, newly allocated pages to the page cache. */ 5159f6191471SAxel Rasmussen if (vm_shared && !is_continue) { 51601e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 51611e392147SAndrea Arcangeli ret = -EFAULT; 51621e392147SAndrea Arcangeli if (idx >= size) 51631e392147SAndrea Arcangeli goto out_release_nounlock; 51641c9e8defSMike Kravetz 51651e392147SAndrea Arcangeli /* 51661e392147SAndrea Arcangeli * Serialization between remove_inode_hugepages() and 51671e392147SAndrea Arcangeli * huge_add_to_page_cache() below happens through the 51681e392147SAndrea Arcangeli * hugetlb_fault_mutex_table that here must be hold by 51691e392147SAndrea Arcangeli * the caller. 51701e392147SAndrea Arcangeli */ 51711c9e8defSMike Kravetz ret = huge_add_to_page_cache(page, mapping, idx); 51721c9e8defSMike Kravetz if (ret) 51731c9e8defSMike Kravetz goto out_release_nounlock; 51741c9e8defSMike Kravetz } 51751c9e8defSMike Kravetz 51768fb5debcSMike Kravetz ptl = huge_pte_lockptr(h, dst_mm, dst_pte); 51778fb5debcSMike Kravetz spin_lock(ptl); 51788fb5debcSMike Kravetz 51791e392147SAndrea Arcangeli /* 51801e392147SAndrea Arcangeli * Recheck the i_size after holding PT lock to make sure not 51811e392147SAndrea Arcangeli * to leave any page mapped (as page_mapped()) beyond the end 51821e392147SAndrea Arcangeli * of the i_size (remove_inode_hugepages() is strict about 51831e392147SAndrea Arcangeli * enforcing that). If we bail out here, we'll also leave a 51841e392147SAndrea Arcangeli * page in the radix tree in the vm_shared case beyond the end 51851e392147SAndrea Arcangeli * of the i_size, but remove_inode_hugepages() will take care 51861e392147SAndrea Arcangeli * of it as soon as we drop the hugetlb_fault_mutex_table. 51871e392147SAndrea Arcangeli */ 51881e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 51891e392147SAndrea Arcangeli ret = -EFAULT; 51901e392147SAndrea Arcangeli if (idx >= size) 51911e392147SAndrea Arcangeli goto out_release_unlock; 51921e392147SAndrea Arcangeli 51938fb5debcSMike Kravetz ret = -EEXIST; 51948fb5debcSMike Kravetz if (!huge_pte_none(huge_ptep_get(dst_pte))) 51958fb5debcSMike Kravetz goto out_release_unlock; 51968fb5debcSMike Kravetz 51971c9e8defSMike Kravetz if (vm_shared) { 51981c9e8defSMike Kravetz page_dup_rmap(page, true); 51991c9e8defSMike Kravetz } else { 5200d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 52018fb5debcSMike Kravetz hugepage_add_new_anon_rmap(page, dst_vma, dst_addr); 52021c9e8defSMike Kravetz } 52038fb5debcSMike Kravetz 5204f6191471SAxel Rasmussen /* For CONTINUE on a non-shared VMA, don't set VM_WRITE for CoW. */ 5205f6191471SAxel Rasmussen if (is_continue && !vm_shared) 5206f6191471SAxel Rasmussen writable = 0; 5207f6191471SAxel Rasmussen else 5208f6191471SAxel Rasmussen writable = dst_vma->vm_flags & VM_WRITE; 5209f6191471SAxel Rasmussen 5210f6191471SAxel Rasmussen _dst_pte = make_huge_pte(dst_vma, page, writable); 5211f6191471SAxel Rasmussen if (writable) 52128fb5debcSMike Kravetz _dst_pte = huge_pte_mkdirty(_dst_pte); 52138fb5debcSMike Kravetz _dst_pte = pte_mkyoung(_dst_pte); 52148fb5debcSMike Kravetz 52158fb5debcSMike Kravetz set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); 52168fb5debcSMike Kravetz 52178fb5debcSMike Kravetz (void)huge_ptep_set_access_flags(dst_vma, dst_addr, dst_pte, _dst_pte, 52188fb5debcSMike Kravetz dst_vma->vm_flags & VM_WRITE); 52198fb5debcSMike Kravetz hugetlb_count_add(pages_per_huge_page(h), dst_mm); 52208fb5debcSMike Kravetz 52218fb5debcSMike Kravetz /* No need to invalidate - it was non-present before */ 52228fb5debcSMike Kravetz update_mmu_cache(dst_vma, dst_addr, dst_pte); 52238fb5debcSMike Kravetz 52248fb5debcSMike Kravetz spin_unlock(ptl); 5225f6191471SAxel Rasmussen if (!is_continue) 52268f251a3dSMike Kravetz SetHPageMigratable(page); 5227f6191471SAxel Rasmussen if (vm_shared || is_continue) 52281c9e8defSMike Kravetz unlock_page(page); 52298fb5debcSMike Kravetz ret = 0; 52308fb5debcSMike Kravetz out: 52318fb5debcSMike Kravetz return ret; 52328fb5debcSMike Kravetz out_release_unlock: 52338fb5debcSMike Kravetz spin_unlock(ptl); 5234f6191471SAxel Rasmussen if (vm_shared || is_continue) 52351c9e8defSMike Kravetz unlock_page(page); 52365af10dfdSAndrea Arcangeli out_release_nounlock: 5237846be085SMike Kravetz restore_reserve_on_error(h, dst_vma, dst_addr, page); 52388fb5debcSMike Kravetz put_page(page); 52398fb5debcSMike Kravetz goto out; 52408fb5debcSMike Kravetz } 5241714c1891SAxel Rasmussen #endif /* CONFIG_USERFAULTFD */ 52428fb5debcSMike Kravetz 524382e5d378SJoao Martins static void record_subpages_vmas(struct page *page, struct vm_area_struct *vma, 524482e5d378SJoao Martins int refs, struct page **pages, 524582e5d378SJoao Martins struct vm_area_struct **vmas) 524682e5d378SJoao Martins { 524782e5d378SJoao Martins int nr; 524882e5d378SJoao Martins 524982e5d378SJoao Martins for (nr = 0; nr < refs; nr++) { 525082e5d378SJoao Martins if (likely(pages)) 525182e5d378SJoao Martins pages[nr] = mem_map_offset(page, nr); 525282e5d378SJoao Martins if (vmas) 525382e5d378SJoao Martins vmas[nr] = vma; 525482e5d378SJoao Martins } 525582e5d378SJoao Martins } 525682e5d378SJoao Martins 525728a35716SMichel Lespinasse long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 525863551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 525928a35716SMichel Lespinasse unsigned long *position, unsigned long *nr_pages, 52604f6da934SPeter Xu long i, unsigned int flags, int *locked) 526163551ae0SDavid Gibson { 5262d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 5263d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 526428a35716SMichel Lespinasse unsigned long remainder = *nr_pages; 5265a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 52660fa5bc40SJoao Martins int err = -EFAULT, refs; 526763551ae0SDavid Gibson 526863551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 526963551ae0SDavid Gibson pte_t *pte; 5270cb900f41SKirill A. Shutemov spinlock_t *ptl = NULL; 52712a15efc9SHugh Dickins int absent; 527263551ae0SDavid Gibson struct page *page; 527363551ae0SDavid Gibson 52744c887265SAdam Litke /* 527502057967SDavid Rientjes * If we have a pending SIGKILL, don't keep faulting pages and 527602057967SDavid Rientjes * potentially allocating memory. 527702057967SDavid Rientjes */ 5278fa45f116SDavidlohr Bueso if (fatal_signal_pending(current)) { 527902057967SDavid Rientjes remainder = 0; 528002057967SDavid Rientjes break; 528102057967SDavid Rientjes } 528202057967SDavid Rientjes 528302057967SDavid Rientjes /* 52844c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 52852a15efc9SHugh Dickins * each hugepage. We have to make sure we get the 52864c887265SAdam Litke * first, for the page indexing below to work. 5287cb900f41SKirill A. Shutemov * 5288cb900f41SKirill A. Shutemov * Note that page table lock is not held when pte is null. 52894c887265SAdam Litke */ 52907868a208SPunit Agrawal pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), 52917868a208SPunit Agrawal huge_page_size(h)); 5292cb900f41SKirill A. Shutemov if (pte) 5293cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, pte); 52942a15efc9SHugh Dickins absent = !pte || huge_pte_none(huge_ptep_get(pte)); 529563551ae0SDavid Gibson 52962a15efc9SHugh Dickins /* 52972a15efc9SHugh Dickins * When coredumping, it suits get_dump_page if we just return 52983ae77f43SHugh Dickins * an error where there's an empty slot with no huge pagecache 52993ae77f43SHugh Dickins * to back it. This way, we avoid allocating a hugepage, and 53003ae77f43SHugh Dickins * the sparse dumpfile avoids allocating disk blocks, but its 53013ae77f43SHugh Dickins * huge holes still show up with zeroes where they need to be. 53022a15efc9SHugh Dickins */ 53033ae77f43SHugh Dickins if (absent && (flags & FOLL_DUMP) && 53043ae77f43SHugh Dickins !hugetlbfs_pagecache_present(h, vma, vaddr)) { 5305cb900f41SKirill A. Shutemov if (pte) 5306cb900f41SKirill A. Shutemov spin_unlock(ptl); 53072a15efc9SHugh Dickins remainder = 0; 53082a15efc9SHugh Dickins break; 53092a15efc9SHugh Dickins } 53102a15efc9SHugh Dickins 53119cc3a5bdSNaoya Horiguchi /* 53129cc3a5bdSNaoya Horiguchi * We need call hugetlb_fault for both hugepages under migration 53139cc3a5bdSNaoya Horiguchi * (in which case hugetlb_fault waits for the migration,) and 53149cc3a5bdSNaoya Horiguchi * hwpoisoned hugepages (in which case we need to prevent the 53159cc3a5bdSNaoya Horiguchi * caller from accessing to them.) In order to do this, we use 53169cc3a5bdSNaoya Horiguchi * here is_swap_pte instead of is_hugetlb_entry_migration and 53179cc3a5bdSNaoya Horiguchi * is_hugetlb_entry_hwpoisoned. This is because it simply covers 53189cc3a5bdSNaoya Horiguchi * both cases, and because we can't follow correct pages 53199cc3a5bdSNaoya Horiguchi * directly from any kind of swap entries. 53209cc3a5bdSNaoya Horiguchi */ 53219cc3a5bdSNaoya Horiguchi if (absent || is_swap_pte(huge_ptep_get(pte)) || 5322106c992aSGerald Schaefer ((flags & FOLL_WRITE) && 5323106c992aSGerald Schaefer !huge_pte_write(huge_ptep_get(pte)))) { 53242b740303SSouptick Joarder vm_fault_t ret; 532587ffc118SAndrea Arcangeli unsigned int fault_flags = 0; 53264c887265SAdam Litke 5327cb900f41SKirill A. Shutemov if (pte) 5328cb900f41SKirill A. Shutemov spin_unlock(ptl); 532987ffc118SAndrea Arcangeli if (flags & FOLL_WRITE) 533087ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_WRITE; 53314f6da934SPeter Xu if (locked) 533271335f37SPeter Xu fault_flags |= FAULT_FLAG_ALLOW_RETRY | 533371335f37SPeter Xu FAULT_FLAG_KILLABLE; 533487ffc118SAndrea Arcangeli if (flags & FOLL_NOWAIT) 533587ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_ALLOW_RETRY | 533687ffc118SAndrea Arcangeli FAULT_FLAG_RETRY_NOWAIT; 533787ffc118SAndrea Arcangeli if (flags & FOLL_TRIED) { 53384426e945SPeter Xu /* 53394426e945SPeter Xu * Note: FAULT_FLAG_ALLOW_RETRY and 53404426e945SPeter Xu * FAULT_FLAG_TRIED can co-exist 53414426e945SPeter Xu */ 534287ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_TRIED; 534387ffc118SAndrea Arcangeli } 534487ffc118SAndrea Arcangeli ret = hugetlb_fault(mm, vma, vaddr, fault_flags); 534587ffc118SAndrea Arcangeli if (ret & VM_FAULT_ERROR) { 53462be7cfedSDaniel Jordan err = vm_fault_to_errno(ret, flags); 53471c59827dSHugh Dickins remainder = 0; 53481c59827dSHugh Dickins break; 53491c59827dSHugh Dickins } 535087ffc118SAndrea Arcangeli if (ret & VM_FAULT_RETRY) { 53514f6da934SPeter Xu if (locked && 53521ac25013SAndrea Arcangeli !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) 53534f6da934SPeter Xu *locked = 0; 535487ffc118SAndrea Arcangeli *nr_pages = 0; 535587ffc118SAndrea Arcangeli /* 535687ffc118SAndrea Arcangeli * VM_FAULT_RETRY must not return an 535787ffc118SAndrea Arcangeli * error, it will return zero 535887ffc118SAndrea Arcangeli * instead. 535987ffc118SAndrea Arcangeli * 536087ffc118SAndrea Arcangeli * No need to update "position" as the 536187ffc118SAndrea Arcangeli * caller will not check it after 536287ffc118SAndrea Arcangeli * *nr_pages is set to 0. 536387ffc118SAndrea Arcangeli */ 536487ffc118SAndrea Arcangeli return i; 536587ffc118SAndrea Arcangeli } 536687ffc118SAndrea Arcangeli continue; 536787ffc118SAndrea Arcangeli } 536863551ae0SDavid Gibson 5369a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 53707f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 53718fde12caSLinus Torvalds 53728fde12caSLinus Torvalds /* 5373acbfb087SZhigang Lu * If subpage information not requested, update counters 5374acbfb087SZhigang Lu * and skip the same_page loop below. 5375acbfb087SZhigang Lu */ 5376acbfb087SZhigang Lu if (!pages && !vmas && !pfn_offset && 5377acbfb087SZhigang Lu (vaddr + huge_page_size(h) < vma->vm_end) && 5378acbfb087SZhigang Lu (remainder >= pages_per_huge_page(h))) { 5379acbfb087SZhigang Lu vaddr += huge_page_size(h); 5380acbfb087SZhigang Lu remainder -= pages_per_huge_page(h); 5381acbfb087SZhigang Lu i += pages_per_huge_page(h); 5382acbfb087SZhigang Lu spin_unlock(ptl); 5383acbfb087SZhigang Lu continue; 5384acbfb087SZhigang Lu } 5385acbfb087SZhigang Lu 538682e5d378SJoao Martins refs = min3(pages_per_huge_page(h) - pfn_offset, 538782e5d378SJoao Martins (vma->vm_end - vaddr) >> PAGE_SHIFT, remainder); 53880fa5bc40SJoao Martins 538982e5d378SJoao Martins if (pages || vmas) 539082e5d378SJoao Martins record_subpages_vmas(mem_map_offset(page, pfn_offset), 539182e5d378SJoao Martins vma, refs, 539282e5d378SJoao Martins likely(pages) ? pages + i : NULL, 539382e5d378SJoao Martins vmas ? vmas + i : NULL); 539463551ae0SDavid Gibson 539582e5d378SJoao Martins if (pages) { 53960fa5bc40SJoao Martins /* 53970fa5bc40SJoao Martins * try_grab_compound_head() should always succeed here, 53980fa5bc40SJoao Martins * because: a) we hold the ptl lock, and b) we've just 53990fa5bc40SJoao Martins * checked that the huge page is present in the page 54000fa5bc40SJoao Martins * tables. If the huge page is present, then the tail 54010fa5bc40SJoao Martins * pages must also be present. The ptl prevents the 54020fa5bc40SJoao Martins * head page and tail pages from being rearranged in 54030fa5bc40SJoao Martins * any way. So this page must be available at this 54040fa5bc40SJoao Martins * point, unless the page refcount overflowed: 54050fa5bc40SJoao Martins */ 540682e5d378SJoao Martins if (WARN_ON_ONCE(!try_grab_compound_head(pages[i], 54070fa5bc40SJoao Martins refs, 54080fa5bc40SJoao Martins flags))) { 54090fa5bc40SJoao Martins spin_unlock(ptl); 54100fa5bc40SJoao Martins remainder = 0; 54110fa5bc40SJoao Martins err = -ENOMEM; 54120fa5bc40SJoao Martins break; 54130fa5bc40SJoao Martins } 5414d5d4b0aaSChen, Kenneth W } 541582e5d378SJoao Martins 541682e5d378SJoao Martins vaddr += (refs << PAGE_SHIFT); 541782e5d378SJoao Martins remainder -= refs; 541882e5d378SJoao Martins i += refs; 541982e5d378SJoao Martins 5420cb900f41SKirill A. Shutemov spin_unlock(ptl); 542163551ae0SDavid Gibson } 542228a35716SMichel Lespinasse *nr_pages = remainder; 542387ffc118SAndrea Arcangeli /* 542487ffc118SAndrea Arcangeli * setting position is actually required only if remainder is 542587ffc118SAndrea Arcangeli * not zero but it's faster not to add a "if (remainder)" 542687ffc118SAndrea Arcangeli * branch. 542787ffc118SAndrea Arcangeli */ 542863551ae0SDavid Gibson *position = vaddr; 542963551ae0SDavid Gibson 54302be7cfedSDaniel Jordan return i ? i : err; 543163551ae0SDavid Gibson } 54328f860591SZhang, Yanmin 54337da4d641SPeter Zijlstra unsigned long hugetlb_change_protection(struct vm_area_struct *vma, 54348f860591SZhang, Yanmin unsigned long address, unsigned long end, pgprot_t newprot) 54358f860591SZhang, Yanmin { 54368f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 54378f860591SZhang, Yanmin unsigned long start = address; 54388f860591SZhang, Yanmin pte_t *ptep; 54398f860591SZhang, Yanmin pte_t pte; 5440a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 54417da4d641SPeter Zijlstra unsigned long pages = 0; 5442dff11abeSMike Kravetz bool shared_pmd = false; 5443ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 5444dff11abeSMike Kravetz 5445dff11abeSMike Kravetz /* 5446dff11abeSMike Kravetz * In the case of shared PMDs, the area to flush could be beyond 5447ac46d4f3SJérôme Glisse * start/end. Set range.start/range.end to cover the maximum possible 5448dff11abeSMike Kravetz * range if PMD sharing is possible. 5449dff11abeSMike Kravetz */ 54507269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 54517269f999SJérôme Glisse 0, vma, mm, start, end); 5452ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 54538f860591SZhang, Yanmin 54548f860591SZhang, Yanmin BUG_ON(address >= end); 5455ac46d4f3SJérôme Glisse flush_cache_range(vma, range.start, range.end); 54568f860591SZhang, Yanmin 5457ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 545883cde9e8SDavidlohr Bueso i_mmap_lock_write(vma->vm_file->f_mapping); 5459a5516438SAndi Kleen for (; address < end; address += huge_page_size(h)) { 5460cb900f41SKirill A. Shutemov spinlock_t *ptl; 54617868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, huge_page_size(h)); 54628f860591SZhang, Yanmin if (!ptep) 54638f860591SZhang, Yanmin continue; 5464cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 546534ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 54667da4d641SPeter Zijlstra pages++; 5467cb900f41SKirill A. Shutemov spin_unlock(ptl); 5468dff11abeSMike Kravetz shared_pmd = true; 546939dde65cSChen, Kenneth W continue; 54707da4d641SPeter Zijlstra } 5471a8bda28dSNaoya Horiguchi pte = huge_ptep_get(ptep); 5472a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { 5473a8bda28dSNaoya Horiguchi spin_unlock(ptl); 5474a8bda28dSNaoya Horiguchi continue; 5475a8bda28dSNaoya Horiguchi } 5476a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(pte))) { 5477a8bda28dSNaoya Horiguchi swp_entry_t entry = pte_to_swp_entry(pte); 5478a8bda28dSNaoya Horiguchi 5479a8bda28dSNaoya Horiguchi if (is_write_migration_entry(entry)) { 5480a8bda28dSNaoya Horiguchi pte_t newpte; 5481a8bda28dSNaoya Horiguchi 5482a8bda28dSNaoya Horiguchi make_migration_entry_read(&entry); 5483a8bda28dSNaoya Horiguchi newpte = swp_entry_to_pte(entry); 5484e5251fd4SPunit Agrawal set_huge_swap_pte_at(mm, address, ptep, 5485e5251fd4SPunit Agrawal newpte, huge_page_size(h)); 5486a8bda28dSNaoya Horiguchi pages++; 5487a8bda28dSNaoya Horiguchi } 5488a8bda28dSNaoya Horiguchi spin_unlock(ptl); 5489a8bda28dSNaoya Horiguchi continue; 5490a8bda28dSNaoya Horiguchi } 5491a8bda28dSNaoya Horiguchi if (!huge_pte_none(pte)) { 5492023bdd00SAneesh Kumar K.V pte_t old_pte; 549379c1c594SChristophe Leroy unsigned int shift = huge_page_shift(hstate_vma(vma)); 5494023bdd00SAneesh Kumar K.V 5495023bdd00SAneesh Kumar K.V old_pte = huge_ptep_modify_prot_start(vma, address, ptep); 5496023bdd00SAneesh Kumar K.V pte = pte_mkhuge(huge_pte_modify(old_pte, newprot)); 549779c1c594SChristophe Leroy pte = arch_make_huge_pte(pte, shift, vma->vm_flags); 5498023bdd00SAneesh Kumar K.V huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); 54997da4d641SPeter Zijlstra pages++; 55008f860591SZhang, Yanmin } 5501cb900f41SKirill A. Shutemov spin_unlock(ptl); 55028f860591SZhang, Yanmin } 5503d833352aSMel Gorman /* 5504c8c06efaSDavidlohr Bueso * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare 5505d833352aSMel Gorman * may have cleared our pud entry and done put_page on the page table: 5506c8c06efaSDavidlohr Bueso * once we release i_mmap_rwsem, another task can do the final put_page 5507dff11abeSMike Kravetz * and that page table be reused and filled with junk. If we actually 5508dff11abeSMike Kravetz * did unshare a page of pmds, flush the range corresponding to the pud. 5509d833352aSMel Gorman */ 5510dff11abeSMike Kravetz if (shared_pmd) 5511ac46d4f3SJérôme Glisse flush_hugetlb_tlb_range(vma, range.start, range.end); 5512dff11abeSMike Kravetz else 55135491ae7bSAneesh Kumar K.V flush_hugetlb_tlb_range(vma, start, end); 55140f10851eSJérôme Glisse /* 55150f10851eSJérôme Glisse * No need to call mmu_notifier_invalidate_range() we are downgrading 55160f10851eSJérôme Glisse * page table protection not changing it to point to a new page. 55170f10851eSJérôme Glisse * 5518ad56b738SMike Rapoport * See Documentation/vm/mmu_notifier.rst 55190f10851eSJérôme Glisse */ 552083cde9e8SDavidlohr Bueso i_mmap_unlock_write(vma->vm_file->f_mapping); 5521ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 55227da4d641SPeter Zijlstra 55237da4d641SPeter Zijlstra return pages << h->order; 55248f860591SZhang, Yanmin } 55258f860591SZhang, Yanmin 552633b8f84aSMike Kravetz /* Return true if reservation was successful, false otherwise. */ 552733b8f84aSMike Kravetz bool hugetlb_reserve_pages(struct inode *inode, 5528a1e78772SMel Gorman long from, long to, 55295a6fe125SMel Gorman struct vm_area_struct *vma, 5530ca16d140SKOSAKI Motohiro vm_flags_t vm_flags) 5531e4e574b7SAdam Litke { 553233b8f84aSMike Kravetz long chg, add = -1; 5533a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 553490481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 55359119a41eSJoonsoo Kim struct resv_map *resv_map; 5536075a61d0SMina Almasry struct hugetlb_cgroup *h_cg = NULL; 55370db9d74eSMina Almasry long gbl_reserve, regions_needed = 0; 5538e4e574b7SAdam Litke 553963489f8eSMike Kravetz /* This should never happen */ 554063489f8eSMike Kravetz if (from > to) { 554163489f8eSMike Kravetz VM_WARN(1, "%s called with a negative range\n", __func__); 554233b8f84aSMike Kravetz return false; 554363489f8eSMike Kravetz } 554463489f8eSMike Kravetz 5545a1e78772SMel Gorman /* 554617c9d12eSMel Gorman * Only apply hugepage reservation if asked. At fault time, an 554717c9d12eSMel Gorman * attempt will be made for VM_NORESERVE to allocate a page 554890481622SDavid Gibson * without using reserves 554917c9d12eSMel Gorman */ 5550ca16d140SKOSAKI Motohiro if (vm_flags & VM_NORESERVE) 555133b8f84aSMike Kravetz return true; 555217c9d12eSMel Gorman 555317c9d12eSMel Gorman /* 5554a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 5555a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 5556a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 5557a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 5558a1e78772SMel Gorman */ 55599119a41eSJoonsoo Kim if (!vma || vma->vm_flags & VM_MAYSHARE) { 5560f27a5136SMike Kravetz /* 5561f27a5136SMike Kravetz * resv_map can not be NULL as hugetlb_reserve_pages is only 5562f27a5136SMike Kravetz * called for inodes for which resv_maps were created (see 5563f27a5136SMike Kravetz * hugetlbfs_get_inode). 5564f27a5136SMike Kravetz */ 55654e35f483SJoonsoo Kim resv_map = inode_resv_map(inode); 55669119a41eSJoonsoo Kim 55670db9d74eSMina Almasry chg = region_chg(resv_map, from, to, ®ions_needed); 55689119a41eSJoonsoo Kim 55699119a41eSJoonsoo Kim } else { 5570e9fe92aeSMina Almasry /* Private mapping. */ 55719119a41eSJoonsoo Kim resv_map = resv_map_alloc(); 55725a6fe125SMel Gorman if (!resv_map) 557333b8f84aSMike Kravetz return false; 55745a6fe125SMel Gorman 557517c9d12eSMel Gorman chg = to - from; 557617c9d12eSMel Gorman 55775a6fe125SMel Gorman set_vma_resv_map(vma, resv_map); 55785a6fe125SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 55795a6fe125SMel Gorman } 55805a6fe125SMel Gorman 558133b8f84aSMike Kravetz if (chg < 0) 5582c50ac050SDave Hansen goto out_err; 558317c9d12eSMel Gorman 558433b8f84aSMike Kravetz if (hugetlb_cgroup_charge_cgroup_rsvd(hstate_index(h), 558533b8f84aSMike Kravetz chg * pages_per_huge_page(h), &h_cg) < 0) 5586075a61d0SMina Almasry goto out_err; 5587075a61d0SMina Almasry 5588075a61d0SMina Almasry if (vma && !(vma->vm_flags & VM_MAYSHARE) && h_cg) { 5589075a61d0SMina Almasry /* For private mappings, the hugetlb_cgroup uncharge info hangs 5590075a61d0SMina Almasry * of the resv_map. 5591075a61d0SMina Almasry */ 5592075a61d0SMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h); 5593075a61d0SMina Almasry } 5594075a61d0SMina Almasry 55951c5ecae3SMike Kravetz /* 55961c5ecae3SMike Kravetz * There must be enough pages in the subpool for the mapping. If 55971c5ecae3SMike Kravetz * the subpool has a minimum size, there may be some global 55981c5ecae3SMike Kravetz * reservations already in place (gbl_reserve). 55991c5ecae3SMike Kravetz */ 56001c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_get_pages(spool, chg); 560133b8f84aSMike Kravetz if (gbl_reserve < 0) 5602075a61d0SMina Almasry goto out_uncharge_cgroup; 560317c9d12eSMel Gorman 560417c9d12eSMel Gorman /* 560517c9d12eSMel Gorman * Check enough hugepages are available for the reservation. 560690481622SDavid Gibson * Hand the pages back to the subpool if there are not 560717c9d12eSMel Gorman */ 560833b8f84aSMike Kravetz if (hugetlb_acct_memory(h, gbl_reserve) < 0) 5609075a61d0SMina Almasry goto out_put_pages; 561017c9d12eSMel Gorman 561117c9d12eSMel Gorman /* 561217c9d12eSMel Gorman * Account for the reservations made. Shared mappings record regions 561317c9d12eSMel Gorman * that have reservations as they are shared by multiple VMAs. 561417c9d12eSMel Gorman * When the last VMA disappears, the region map says how much 561517c9d12eSMel Gorman * the reservation was and the page cache tells how much of 561617c9d12eSMel Gorman * the reservation was consumed. Private mappings are per-VMA and 561717c9d12eSMel Gorman * only the consumed reservations are tracked. When the VMA 561817c9d12eSMel Gorman * disappears, the original reservation is the VMA size and the 561917c9d12eSMel Gorman * consumed reservations are stored in the map. Hence, nothing 562017c9d12eSMel Gorman * else has to be done for private mappings here 562117c9d12eSMel Gorman */ 562233039678SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) { 5623075a61d0SMina Almasry add = region_add(resv_map, from, to, regions_needed, h, h_cg); 562433039678SMike Kravetz 56250db9d74eSMina Almasry if (unlikely(add < 0)) { 56260db9d74eSMina Almasry hugetlb_acct_memory(h, -gbl_reserve); 5627075a61d0SMina Almasry goto out_put_pages; 56280db9d74eSMina Almasry } else if (unlikely(chg > add)) { 562933039678SMike Kravetz /* 563033039678SMike Kravetz * pages in this range were added to the reserve 563133039678SMike Kravetz * map between region_chg and region_add. This 563233039678SMike Kravetz * indicates a race with alloc_huge_page. Adjust 563333039678SMike Kravetz * the subpool and reserve counts modified above 563433039678SMike Kravetz * based on the difference. 563533039678SMike Kravetz */ 563633039678SMike Kravetz long rsv_adjust; 563733039678SMike Kravetz 5638d85aecf2SMiaohe Lin /* 5639d85aecf2SMiaohe Lin * hugetlb_cgroup_uncharge_cgroup_rsvd() will put the 5640d85aecf2SMiaohe Lin * reference to h_cg->css. See comment below for detail. 5641d85aecf2SMiaohe Lin */ 5642075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd( 5643075a61d0SMina Almasry hstate_index(h), 5644075a61d0SMina Almasry (chg - add) * pages_per_huge_page(h), h_cg); 5645075a61d0SMina Almasry 564633039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 564733039678SMike Kravetz chg - add); 564833039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 5649d85aecf2SMiaohe Lin } else if (h_cg) { 5650d85aecf2SMiaohe Lin /* 5651d85aecf2SMiaohe Lin * The file_regions will hold their own reference to 5652d85aecf2SMiaohe Lin * h_cg->css. So we should release the reference held 5653d85aecf2SMiaohe Lin * via hugetlb_cgroup_charge_cgroup_rsvd() when we are 5654d85aecf2SMiaohe Lin * done. 5655d85aecf2SMiaohe Lin */ 5656d85aecf2SMiaohe Lin hugetlb_cgroup_put_rsvd_cgroup(h_cg); 565733039678SMike Kravetz } 565833039678SMike Kravetz } 565933b8f84aSMike Kravetz return true; 566033b8f84aSMike Kravetz 5661075a61d0SMina Almasry out_put_pages: 5662075a61d0SMina Almasry /* put back original number of pages, chg */ 5663075a61d0SMina Almasry (void)hugepage_subpool_put_pages(spool, chg); 5664075a61d0SMina Almasry out_uncharge_cgroup: 5665075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h), 5666075a61d0SMina Almasry chg * pages_per_huge_page(h), h_cg); 5667c50ac050SDave Hansen out_err: 56685e911373SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) 56690db9d74eSMina Almasry /* Only call region_abort if the region_chg succeeded but the 56700db9d74eSMina Almasry * region_add failed or didn't run. 56710db9d74eSMina Almasry */ 56720db9d74eSMina Almasry if (chg >= 0 && add < 0) 56730db9d74eSMina Almasry region_abort(resv_map, from, to, regions_needed); 5674f031dd27SJoonsoo Kim if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 5675f031dd27SJoonsoo Kim kref_put(&resv_map->refs, resv_map_release); 567633b8f84aSMike Kravetz return false; 5677a43a8c39SChen, Kenneth W } 5678a43a8c39SChen, Kenneth W 5679b5cec28dSMike Kravetz long hugetlb_unreserve_pages(struct inode *inode, long start, long end, 5680b5cec28dSMike Kravetz long freed) 5681a43a8c39SChen, Kenneth W { 5682a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 56834e35f483SJoonsoo Kim struct resv_map *resv_map = inode_resv_map(inode); 56849119a41eSJoonsoo Kim long chg = 0; 568590481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 56861c5ecae3SMike Kravetz long gbl_reserve; 568745c682a6SKen Chen 5688f27a5136SMike Kravetz /* 5689f27a5136SMike Kravetz * Since this routine can be called in the evict inode path for all 5690f27a5136SMike Kravetz * hugetlbfs inodes, resv_map could be NULL. 5691f27a5136SMike Kravetz */ 5692b5cec28dSMike Kravetz if (resv_map) { 5693b5cec28dSMike Kravetz chg = region_del(resv_map, start, end); 5694b5cec28dSMike Kravetz /* 5695b5cec28dSMike Kravetz * region_del() can fail in the rare case where a region 5696b5cec28dSMike Kravetz * must be split and another region descriptor can not be 5697b5cec28dSMike Kravetz * allocated. If end == LONG_MAX, it will not fail. 5698b5cec28dSMike Kravetz */ 5699b5cec28dSMike Kravetz if (chg < 0) 5700b5cec28dSMike Kravetz return chg; 5701b5cec28dSMike Kravetz } 5702b5cec28dSMike Kravetz 570345c682a6SKen Chen spin_lock(&inode->i_lock); 5704e4c6f8beSEric Sandeen inode->i_blocks -= (blocks_per_huge_page(h) * freed); 570545c682a6SKen Chen spin_unlock(&inode->i_lock); 570645c682a6SKen Chen 57071c5ecae3SMike Kravetz /* 57081c5ecae3SMike Kravetz * If the subpool has a minimum size, the number of global 57091c5ecae3SMike Kravetz * reservations to be released may be adjusted. 5710dddf31a4SMiaohe Lin * 5711dddf31a4SMiaohe Lin * Note that !resv_map implies freed == 0. So (chg - freed) 5712dddf31a4SMiaohe Lin * won't go negative. 57131c5ecae3SMike Kravetz */ 57141c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed)); 57151c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 5716b5cec28dSMike Kravetz 5717b5cec28dSMike Kravetz return 0; 5718a43a8c39SChen, Kenneth W } 571993f70f90SNaoya Horiguchi 57203212b535SSteve Capper #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 57213212b535SSteve Capper static unsigned long page_table_shareable(struct vm_area_struct *svma, 57223212b535SSteve Capper struct vm_area_struct *vma, 57233212b535SSteve Capper unsigned long addr, pgoff_t idx) 57243212b535SSteve Capper { 57253212b535SSteve Capper unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + 57263212b535SSteve Capper svma->vm_start; 57273212b535SSteve Capper unsigned long sbase = saddr & PUD_MASK; 57283212b535SSteve Capper unsigned long s_end = sbase + PUD_SIZE; 57293212b535SSteve Capper 57303212b535SSteve Capper /* Allow segments to share if only one is marked locked */ 5731de60f5f1SEric B Munson unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; 5732de60f5f1SEric B Munson unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK; 57333212b535SSteve Capper 57343212b535SSteve Capper /* 57353212b535SSteve Capper * match the virtual addresses, permission and the alignment of the 57363212b535SSteve Capper * page table page. 57373212b535SSteve Capper */ 57383212b535SSteve Capper if (pmd_index(addr) != pmd_index(saddr) || 57393212b535SSteve Capper vm_flags != svm_flags || 574007e51edfSMiaohe Lin !range_in_vma(svma, sbase, s_end)) 57413212b535SSteve Capper return 0; 57423212b535SSteve Capper 57433212b535SSteve Capper return saddr; 57443212b535SSteve Capper } 57453212b535SSteve Capper 574631aafb45SNicholas Krause static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr) 57473212b535SSteve Capper { 57483212b535SSteve Capper unsigned long base = addr & PUD_MASK; 57493212b535SSteve Capper unsigned long end = base + PUD_SIZE; 57503212b535SSteve Capper 57513212b535SSteve Capper /* 57523212b535SSteve Capper * check on proper vm_flags and page table alignment 57533212b535SSteve Capper */ 5754017b1660SMike Kravetz if (vma->vm_flags & VM_MAYSHARE && range_in_vma(vma, base, end)) 575531aafb45SNicholas Krause return true; 575631aafb45SNicholas Krause return false; 57573212b535SSteve Capper } 57583212b535SSteve Capper 5759c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 5760c1991e07SPeter Xu { 5761c1991e07SPeter Xu #ifdef CONFIG_USERFAULTFD 5762c1991e07SPeter Xu if (uffd_disable_huge_pmd_share(vma)) 5763c1991e07SPeter Xu return false; 5764c1991e07SPeter Xu #endif 5765c1991e07SPeter Xu return vma_shareable(vma, addr); 5766c1991e07SPeter Xu } 5767c1991e07SPeter Xu 57683212b535SSteve Capper /* 5769017b1660SMike Kravetz * Determine if start,end range within vma could be mapped by shared pmd. 5770017b1660SMike Kravetz * If yes, adjust start and end to cover range associated with possible 5771017b1660SMike Kravetz * shared pmd mappings. 5772017b1660SMike Kravetz */ 5773017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 5774017b1660SMike Kravetz unsigned long *start, unsigned long *end) 5775017b1660SMike Kravetz { 5776a1ba9da8SLi Xinhai unsigned long v_start = ALIGN(vma->vm_start, PUD_SIZE), 5777a1ba9da8SLi Xinhai v_end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 5778017b1660SMike Kravetz 5779a1ba9da8SLi Xinhai /* 5780f0953a1bSIngo Molnar * vma needs to span at least one aligned PUD size, and the range 5781f0953a1bSIngo Molnar * must be at least partially within in. 5782a1ba9da8SLi Xinhai */ 5783a1ba9da8SLi Xinhai if (!(vma->vm_flags & VM_MAYSHARE) || !(v_end > v_start) || 5784a1ba9da8SLi Xinhai (*end <= v_start) || (*start >= v_end)) 5785017b1660SMike Kravetz return; 5786017b1660SMike Kravetz 578775802ca6SPeter Xu /* Extend the range to be PUD aligned for a worst case scenario */ 5788a1ba9da8SLi Xinhai if (*start > v_start) 5789a1ba9da8SLi Xinhai *start = ALIGN_DOWN(*start, PUD_SIZE); 5790017b1660SMike Kravetz 5791a1ba9da8SLi Xinhai if (*end < v_end) 5792a1ba9da8SLi Xinhai *end = ALIGN(*end, PUD_SIZE); 5793017b1660SMike Kravetz } 5794017b1660SMike Kravetz 5795017b1660SMike Kravetz /* 57963212b535SSteve Capper * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() 57973212b535SSteve Capper * and returns the corresponding pte. While this is not necessary for the 57983212b535SSteve Capper * !shared pmd case because we can allocate the pmd later as well, it makes the 5799c0d0381aSMike Kravetz * code much cleaner. 5800c0d0381aSMike Kravetz * 58010bf7b64eSMike Kravetz * This routine must be called with i_mmap_rwsem held in at least read mode if 58020bf7b64eSMike Kravetz * sharing is possible. For hugetlbfs, this prevents removal of any page 58030bf7b64eSMike Kravetz * table entries associated with the address space. This is important as we 58040bf7b64eSMike Kravetz * are setting up sharing based on existing page table entries (mappings). 58050bf7b64eSMike Kravetz * 58060bf7b64eSMike Kravetz * NOTE: This routine is only called from huge_pte_alloc. Some callers of 58070bf7b64eSMike Kravetz * huge_pte_alloc know that sharing is not possible and do not take 58080bf7b64eSMike Kravetz * i_mmap_rwsem as a performance optimization. This is handled by the 58090bf7b64eSMike Kravetz * if !vma_shareable check at the beginning of the routine. i_mmap_rwsem is 58100bf7b64eSMike Kravetz * only required for subsequent processing. 58113212b535SSteve Capper */ 5812aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 5813aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 58143212b535SSteve Capper { 58153212b535SSteve Capper struct address_space *mapping = vma->vm_file->f_mapping; 58163212b535SSteve Capper pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + 58173212b535SSteve Capper vma->vm_pgoff; 58183212b535SSteve Capper struct vm_area_struct *svma; 58193212b535SSteve Capper unsigned long saddr; 58203212b535SSteve Capper pte_t *spte = NULL; 58213212b535SSteve Capper pte_t *pte; 5822cb900f41SKirill A. Shutemov spinlock_t *ptl; 58233212b535SSteve Capper 58240bf7b64eSMike Kravetz i_mmap_assert_locked(mapping); 58253212b535SSteve Capper vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { 58263212b535SSteve Capper if (svma == vma) 58273212b535SSteve Capper continue; 58283212b535SSteve Capper 58293212b535SSteve Capper saddr = page_table_shareable(svma, vma, addr, idx); 58303212b535SSteve Capper if (saddr) { 58317868a208SPunit Agrawal spte = huge_pte_offset(svma->vm_mm, saddr, 58327868a208SPunit Agrawal vma_mmu_pagesize(svma)); 58333212b535SSteve Capper if (spte) { 58343212b535SSteve Capper get_page(virt_to_page(spte)); 58353212b535SSteve Capper break; 58363212b535SSteve Capper } 58373212b535SSteve Capper } 58383212b535SSteve Capper } 58393212b535SSteve Capper 58403212b535SSteve Capper if (!spte) 58413212b535SSteve Capper goto out; 58423212b535SSteve Capper 58438bea8052SAneesh Kumar K.V ptl = huge_pte_lock(hstate_vma(vma), mm, spte); 5844dc6c9a35SKirill A. Shutemov if (pud_none(*pud)) { 58453212b535SSteve Capper pud_populate(mm, pud, 58463212b535SSteve Capper (pmd_t *)((unsigned long)spte & PAGE_MASK)); 5847c17b1f42SKirill A. Shutemov mm_inc_nr_pmds(mm); 5848dc6c9a35SKirill A. Shutemov } else { 58493212b535SSteve Capper put_page(virt_to_page(spte)); 5850dc6c9a35SKirill A. Shutemov } 5851cb900f41SKirill A. Shutemov spin_unlock(ptl); 58523212b535SSteve Capper out: 58533212b535SSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 58543212b535SSteve Capper return pte; 58553212b535SSteve Capper } 58563212b535SSteve Capper 58573212b535SSteve Capper /* 58583212b535SSteve Capper * unmap huge page backed by shared pte. 58593212b535SSteve Capper * 58603212b535SSteve Capper * Hugetlb pte page is ref counted at the time of mapping. If pte is shared 58613212b535SSteve Capper * indicated by page_count > 1, unmap is achieved by clearing pud and 58623212b535SSteve Capper * decrementing the ref count. If count == 1, the pte page is not shared. 58633212b535SSteve Capper * 5864c0d0381aSMike Kravetz * Called with page table lock held and i_mmap_rwsem held in write mode. 58653212b535SSteve Capper * 58663212b535SSteve Capper * returns: 1 successfully unmapped a shared pte page 58673212b535SSteve Capper * 0 the underlying pte page is not shared, or it is the last user 58683212b535SSteve Capper */ 586934ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 587034ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 58713212b535SSteve Capper { 58723212b535SSteve Capper pgd_t *pgd = pgd_offset(mm, *addr); 5873c2febafcSKirill A. Shutemov p4d_t *p4d = p4d_offset(pgd, *addr); 5874c2febafcSKirill A. Shutemov pud_t *pud = pud_offset(p4d, *addr); 58753212b535SSteve Capper 587634ae204fSMike Kravetz i_mmap_assert_write_locked(vma->vm_file->f_mapping); 58773212b535SSteve Capper BUG_ON(page_count(virt_to_page(ptep)) == 0); 58783212b535SSteve Capper if (page_count(virt_to_page(ptep)) == 1) 58793212b535SSteve Capper return 0; 58803212b535SSteve Capper 58813212b535SSteve Capper pud_clear(pud); 58823212b535SSteve Capper put_page(virt_to_page(ptep)); 5883dc6c9a35SKirill A. Shutemov mm_dec_nr_pmds(mm); 58843212b535SSteve Capper *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE; 58853212b535SSteve Capper return 1; 58863212b535SSteve Capper } 5887c1991e07SPeter Xu 58889e5fc74cSSteve Capper #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 5889aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 5890aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 58919e5fc74cSSteve Capper { 58929e5fc74cSSteve Capper return NULL; 58939e5fc74cSSteve Capper } 5894e81f2d22SZhang Zhen 589534ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 589634ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 5897e81f2d22SZhang Zhen { 5898e81f2d22SZhang Zhen return 0; 5899e81f2d22SZhang Zhen } 5900017b1660SMike Kravetz 5901017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 5902017b1660SMike Kravetz unsigned long *start, unsigned long *end) 5903017b1660SMike Kravetz { 5904017b1660SMike Kravetz } 5905c1991e07SPeter Xu 5906c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 5907c1991e07SPeter Xu { 5908c1991e07SPeter Xu return false; 5909c1991e07SPeter Xu } 59103212b535SSteve Capper #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 59113212b535SSteve Capper 59129e5fc74cSSteve Capper #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB 5913aec44e0fSPeter Xu pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, 59149e5fc74cSSteve Capper unsigned long addr, unsigned long sz) 59159e5fc74cSSteve Capper { 59169e5fc74cSSteve Capper pgd_t *pgd; 5917c2febafcSKirill A. Shutemov p4d_t *p4d; 59189e5fc74cSSteve Capper pud_t *pud; 59199e5fc74cSSteve Capper pte_t *pte = NULL; 59209e5fc74cSSteve Capper 59219e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 5922f4f0a3d8SKirill A. Shutemov p4d = p4d_alloc(mm, pgd, addr); 5923f4f0a3d8SKirill A. Shutemov if (!p4d) 5924f4f0a3d8SKirill A. Shutemov return NULL; 5925c2febafcSKirill A. Shutemov pud = pud_alloc(mm, p4d, addr); 59269e5fc74cSSteve Capper if (pud) { 59279e5fc74cSSteve Capper if (sz == PUD_SIZE) { 59289e5fc74cSSteve Capper pte = (pte_t *)pud; 59299e5fc74cSSteve Capper } else { 59309e5fc74cSSteve Capper BUG_ON(sz != PMD_SIZE); 5931c1991e07SPeter Xu if (want_pmd_share(vma, addr) && pud_none(*pud)) 5932aec44e0fSPeter Xu pte = huge_pmd_share(mm, vma, addr, pud); 59339e5fc74cSSteve Capper else 59349e5fc74cSSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 59359e5fc74cSSteve Capper } 59369e5fc74cSSteve Capper } 59374e666314SMichal Hocko BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte)); 59389e5fc74cSSteve Capper 59399e5fc74cSSteve Capper return pte; 59409e5fc74cSSteve Capper } 59419e5fc74cSSteve Capper 59429b19df29SPunit Agrawal /* 59439b19df29SPunit Agrawal * huge_pte_offset() - Walk the page table to resolve the hugepage 59449b19df29SPunit Agrawal * entry at address @addr 59459b19df29SPunit Agrawal * 59468ac0b81aSLi Xinhai * Return: Pointer to page table entry (PUD or PMD) for 59478ac0b81aSLi Xinhai * address @addr, or NULL if a !p*d_present() entry is encountered and the 59489b19df29SPunit Agrawal * size @sz doesn't match the hugepage size at this level of the page 59499b19df29SPunit Agrawal * table. 59509b19df29SPunit Agrawal */ 59517868a208SPunit Agrawal pte_t *huge_pte_offset(struct mm_struct *mm, 59527868a208SPunit Agrawal unsigned long addr, unsigned long sz) 59539e5fc74cSSteve Capper { 59549e5fc74cSSteve Capper pgd_t *pgd; 5955c2febafcSKirill A. Shutemov p4d_t *p4d; 59568ac0b81aSLi Xinhai pud_t *pud; 59578ac0b81aSLi Xinhai pmd_t *pmd; 59589e5fc74cSSteve Capper 59599e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 5960c2febafcSKirill A. Shutemov if (!pgd_present(*pgd)) 5961c2febafcSKirill A. Shutemov return NULL; 5962c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, addr); 5963c2febafcSKirill A. Shutemov if (!p4d_present(*p4d)) 5964c2febafcSKirill A. Shutemov return NULL; 59659b19df29SPunit Agrawal 5966c2febafcSKirill A. Shutemov pud = pud_offset(p4d, addr); 59678ac0b81aSLi Xinhai if (sz == PUD_SIZE) 59688ac0b81aSLi Xinhai /* must be pud huge, non-present or none */ 59699e5fc74cSSteve Capper return (pte_t *)pud; 59708ac0b81aSLi Xinhai if (!pud_present(*pud)) 59718ac0b81aSLi Xinhai return NULL; 59728ac0b81aSLi Xinhai /* must have a valid entry and size to go further */ 59739b19df29SPunit Agrawal 59749e5fc74cSSteve Capper pmd = pmd_offset(pud, addr); 59758ac0b81aSLi Xinhai /* must be pmd huge, non-present or none */ 59769e5fc74cSSteve Capper return (pte_t *)pmd; 59779e5fc74cSSteve Capper } 59789e5fc74cSSteve Capper 597961f77edaSNaoya Horiguchi #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ 598061f77edaSNaoya Horiguchi 598161f77edaSNaoya Horiguchi /* 598261f77edaSNaoya Horiguchi * These functions are overwritable if your architecture needs its own 598361f77edaSNaoya Horiguchi * behavior. 598461f77edaSNaoya Horiguchi */ 598561f77edaSNaoya Horiguchi struct page * __weak 598661f77edaSNaoya Horiguchi follow_huge_addr(struct mm_struct *mm, unsigned long address, 598761f77edaSNaoya Horiguchi int write) 598861f77edaSNaoya Horiguchi { 598961f77edaSNaoya Horiguchi return ERR_PTR(-EINVAL); 599061f77edaSNaoya Horiguchi } 599161f77edaSNaoya Horiguchi 599261f77edaSNaoya Horiguchi struct page * __weak 59934dc71451SAneesh Kumar K.V follow_huge_pd(struct vm_area_struct *vma, 59944dc71451SAneesh Kumar K.V unsigned long address, hugepd_t hpd, int flags, int pdshift) 59954dc71451SAneesh Kumar K.V { 59964dc71451SAneesh Kumar K.V WARN(1, "hugepd follow called with no support for hugepage directory format\n"); 59974dc71451SAneesh Kumar K.V return NULL; 59984dc71451SAneesh Kumar K.V } 59994dc71451SAneesh Kumar K.V 60004dc71451SAneesh Kumar K.V struct page * __weak 60019e5fc74cSSteve Capper follow_huge_pmd(struct mm_struct *mm, unsigned long address, 6002e66f17ffSNaoya Horiguchi pmd_t *pmd, int flags) 60039e5fc74cSSteve Capper { 6004e66f17ffSNaoya Horiguchi struct page *page = NULL; 6005e66f17ffSNaoya Horiguchi spinlock_t *ptl; 6006c9d398faSNaoya Horiguchi pte_t pte; 60073faa52c0SJohn Hubbard 60083faa52c0SJohn Hubbard /* FOLL_GET and FOLL_PIN are mutually exclusive. */ 60093faa52c0SJohn Hubbard if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == 60103faa52c0SJohn Hubbard (FOLL_PIN | FOLL_GET))) 60113faa52c0SJohn Hubbard return NULL; 60123faa52c0SJohn Hubbard 6013e66f17ffSNaoya Horiguchi retry: 6014e66f17ffSNaoya Horiguchi ptl = pmd_lockptr(mm, pmd); 6015e66f17ffSNaoya Horiguchi spin_lock(ptl); 6016e66f17ffSNaoya Horiguchi /* 6017e66f17ffSNaoya Horiguchi * make sure that the address range covered by this pmd is not 6018e66f17ffSNaoya Horiguchi * unmapped from other threads. 6019e66f17ffSNaoya Horiguchi */ 6020e66f17ffSNaoya Horiguchi if (!pmd_huge(*pmd)) 6021e66f17ffSNaoya Horiguchi goto out; 6022c9d398faSNaoya Horiguchi pte = huge_ptep_get((pte_t *)pmd); 6023c9d398faSNaoya Horiguchi if (pte_present(pte)) { 602497534127SGerald Schaefer page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT); 60253faa52c0SJohn Hubbard /* 60263faa52c0SJohn Hubbard * try_grab_page() should always succeed here, because: a) we 60273faa52c0SJohn Hubbard * hold the pmd (ptl) lock, and b) we've just checked that the 60283faa52c0SJohn Hubbard * huge pmd (head) page is present in the page tables. The ptl 60293faa52c0SJohn Hubbard * prevents the head page and tail pages from being rearranged 60303faa52c0SJohn Hubbard * in any way. So this page must be available at this point, 60313faa52c0SJohn Hubbard * unless the page refcount overflowed: 60323faa52c0SJohn Hubbard */ 60333faa52c0SJohn Hubbard if (WARN_ON_ONCE(!try_grab_page(page, flags))) { 60343faa52c0SJohn Hubbard page = NULL; 60353faa52c0SJohn Hubbard goto out; 60363faa52c0SJohn Hubbard } 6037e66f17ffSNaoya Horiguchi } else { 6038c9d398faSNaoya Horiguchi if (is_hugetlb_entry_migration(pte)) { 6039e66f17ffSNaoya Horiguchi spin_unlock(ptl); 6040e66f17ffSNaoya Horiguchi __migration_entry_wait(mm, (pte_t *)pmd, ptl); 6041e66f17ffSNaoya Horiguchi goto retry; 6042e66f17ffSNaoya Horiguchi } 6043e66f17ffSNaoya Horiguchi /* 6044e66f17ffSNaoya Horiguchi * hwpoisoned entry is treated as no_page_table in 6045e66f17ffSNaoya Horiguchi * follow_page_mask(). 6046e66f17ffSNaoya Horiguchi */ 6047e66f17ffSNaoya Horiguchi } 6048e66f17ffSNaoya Horiguchi out: 6049e66f17ffSNaoya Horiguchi spin_unlock(ptl); 60509e5fc74cSSteve Capper return page; 60519e5fc74cSSteve Capper } 60529e5fc74cSSteve Capper 605361f77edaSNaoya Horiguchi struct page * __weak 60549e5fc74cSSteve Capper follow_huge_pud(struct mm_struct *mm, unsigned long address, 6055e66f17ffSNaoya Horiguchi pud_t *pud, int flags) 60569e5fc74cSSteve Capper { 60573faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 6058e66f17ffSNaoya Horiguchi return NULL; 60599e5fc74cSSteve Capper 6060e66f17ffSNaoya Horiguchi return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); 60619e5fc74cSSteve Capper } 60629e5fc74cSSteve Capper 6063faaa5b62SAnshuman Khandual struct page * __weak 6064faaa5b62SAnshuman Khandual follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) 6065faaa5b62SAnshuman Khandual { 60663faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 6067faaa5b62SAnshuman Khandual return NULL; 6068faaa5b62SAnshuman Khandual 6069faaa5b62SAnshuman Khandual return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); 6070faaa5b62SAnshuman Khandual } 6071faaa5b62SAnshuman Khandual 607231caf665SNaoya Horiguchi bool isolate_huge_page(struct page *page, struct list_head *list) 607331caf665SNaoya Horiguchi { 6074bcc54222SNaoya Horiguchi bool ret = true; 6075bcc54222SNaoya Horiguchi 6076db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 60778f251a3dSMike Kravetz if (!PageHeadHuge(page) || 60788f251a3dSMike Kravetz !HPageMigratable(page) || 60790eb2df2bSMuchun Song !get_page_unless_zero(page)) { 6080bcc54222SNaoya Horiguchi ret = false; 6081bcc54222SNaoya Horiguchi goto unlock; 6082bcc54222SNaoya Horiguchi } 60838f251a3dSMike Kravetz ClearHPageMigratable(page); 608431caf665SNaoya Horiguchi list_move_tail(&page->lru, list); 6085bcc54222SNaoya Horiguchi unlock: 6086db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 6087bcc54222SNaoya Horiguchi return ret; 608831caf665SNaoya Horiguchi } 608931caf665SNaoya Horiguchi 609025182f05SNaoya Horiguchi int get_hwpoison_huge_page(struct page *page, bool *hugetlb) 609125182f05SNaoya Horiguchi { 609225182f05SNaoya Horiguchi int ret = 0; 609325182f05SNaoya Horiguchi 609425182f05SNaoya Horiguchi *hugetlb = false; 609525182f05SNaoya Horiguchi spin_lock_irq(&hugetlb_lock); 609625182f05SNaoya Horiguchi if (PageHeadHuge(page)) { 609725182f05SNaoya Horiguchi *hugetlb = true; 609825182f05SNaoya Horiguchi if (HPageFreed(page) || HPageMigratable(page)) 609925182f05SNaoya Horiguchi ret = get_page_unless_zero(page); 61000ed950d1SNaoya Horiguchi else 61010ed950d1SNaoya Horiguchi ret = -EBUSY; 610225182f05SNaoya Horiguchi } 610325182f05SNaoya Horiguchi spin_unlock_irq(&hugetlb_lock); 610425182f05SNaoya Horiguchi return ret; 610525182f05SNaoya Horiguchi } 610625182f05SNaoya Horiguchi 610731caf665SNaoya Horiguchi void putback_active_hugepage(struct page *page) 610831caf665SNaoya Horiguchi { 6109db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 61108f251a3dSMike Kravetz SetHPageMigratable(page); 611131caf665SNaoya Horiguchi list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); 6112db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 611331caf665SNaoya Horiguchi put_page(page); 611431caf665SNaoya Horiguchi } 6115ab5ac90aSMichal Hocko 6116ab5ac90aSMichal Hocko void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason) 6117ab5ac90aSMichal Hocko { 6118ab5ac90aSMichal Hocko struct hstate *h = page_hstate(oldpage); 6119ab5ac90aSMichal Hocko 6120ab5ac90aSMichal Hocko hugetlb_cgroup_migrate(oldpage, newpage); 6121ab5ac90aSMichal Hocko set_page_owner_migrate_reason(newpage, reason); 6122ab5ac90aSMichal Hocko 6123ab5ac90aSMichal Hocko /* 6124ab5ac90aSMichal Hocko * transfer temporary state of the new huge page. This is 6125ab5ac90aSMichal Hocko * reverse to other transitions because the newpage is going to 6126ab5ac90aSMichal Hocko * be final while the old one will be freed so it takes over 6127ab5ac90aSMichal Hocko * the temporary status. 6128ab5ac90aSMichal Hocko * 6129ab5ac90aSMichal Hocko * Also note that we have to transfer the per-node surplus state 6130ab5ac90aSMichal Hocko * here as well otherwise the global surplus count will not match 6131ab5ac90aSMichal Hocko * the per-node's. 6132ab5ac90aSMichal Hocko */ 61339157c311SMike Kravetz if (HPageTemporary(newpage)) { 6134ab5ac90aSMichal Hocko int old_nid = page_to_nid(oldpage); 6135ab5ac90aSMichal Hocko int new_nid = page_to_nid(newpage); 6136ab5ac90aSMichal Hocko 61379157c311SMike Kravetz SetHPageTemporary(oldpage); 61389157c311SMike Kravetz ClearHPageTemporary(newpage); 6139ab5ac90aSMichal Hocko 61405af1ab1dSMiaohe Lin /* 61415af1ab1dSMiaohe Lin * There is no need to transfer the per-node surplus state 61425af1ab1dSMiaohe Lin * when we do not cross the node. 61435af1ab1dSMiaohe Lin */ 61445af1ab1dSMiaohe Lin if (new_nid == old_nid) 61455af1ab1dSMiaohe Lin return; 6146db71ef79SMike Kravetz spin_lock_irq(&hugetlb_lock); 6147ab5ac90aSMichal Hocko if (h->surplus_huge_pages_node[old_nid]) { 6148ab5ac90aSMichal Hocko h->surplus_huge_pages_node[old_nid]--; 6149ab5ac90aSMichal Hocko h->surplus_huge_pages_node[new_nid]++; 6150ab5ac90aSMichal Hocko } 6151db71ef79SMike Kravetz spin_unlock_irq(&hugetlb_lock); 6152ab5ac90aSMichal Hocko } 6153ab5ac90aSMichal Hocko } 6154cf11e85fSRoman Gushchin 61556dfeaff9SPeter Xu /* 61566dfeaff9SPeter Xu * This function will unconditionally remove all the shared pmd pgtable entries 61576dfeaff9SPeter Xu * within the specific vma for a hugetlbfs memory range. 61586dfeaff9SPeter Xu */ 61596dfeaff9SPeter Xu void hugetlb_unshare_all_pmds(struct vm_area_struct *vma) 61606dfeaff9SPeter Xu { 61616dfeaff9SPeter Xu struct hstate *h = hstate_vma(vma); 61626dfeaff9SPeter Xu unsigned long sz = huge_page_size(h); 61636dfeaff9SPeter Xu struct mm_struct *mm = vma->vm_mm; 61646dfeaff9SPeter Xu struct mmu_notifier_range range; 61656dfeaff9SPeter Xu unsigned long address, start, end; 61666dfeaff9SPeter Xu spinlock_t *ptl; 61676dfeaff9SPeter Xu pte_t *ptep; 61686dfeaff9SPeter Xu 61696dfeaff9SPeter Xu if (!(vma->vm_flags & VM_MAYSHARE)) 61706dfeaff9SPeter Xu return; 61716dfeaff9SPeter Xu 61726dfeaff9SPeter Xu start = ALIGN(vma->vm_start, PUD_SIZE); 61736dfeaff9SPeter Xu end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 61746dfeaff9SPeter Xu 61756dfeaff9SPeter Xu if (start >= end) 61766dfeaff9SPeter Xu return; 61776dfeaff9SPeter Xu 61786dfeaff9SPeter Xu /* 61796dfeaff9SPeter Xu * No need to call adjust_range_if_pmd_sharing_possible(), because 61806dfeaff9SPeter Xu * we have already done the PUD_SIZE alignment. 61816dfeaff9SPeter Xu */ 61826dfeaff9SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, 61836dfeaff9SPeter Xu start, end); 61846dfeaff9SPeter Xu mmu_notifier_invalidate_range_start(&range); 61856dfeaff9SPeter Xu i_mmap_lock_write(vma->vm_file->f_mapping); 61866dfeaff9SPeter Xu for (address = start; address < end; address += PUD_SIZE) { 61876dfeaff9SPeter Xu unsigned long tmp = address; 61886dfeaff9SPeter Xu 61896dfeaff9SPeter Xu ptep = huge_pte_offset(mm, address, sz); 61906dfeaff9SPeter Xu if (!ptep) 61916dfeaff9SPeter Xu continue; 61926dfeaff9SPeter Xu ptl = huge_pte_lock(h, mm, ptep); 61936dfeaff9SPeter Xu /* We don't want 'address' to be changed */ 61946dfeaff9SPeter Xu huge_pmd_unshare(mm, vma, &tmp, ptep); 61956dfeaff9SPeter Xu spin_unlock(ptl); 61966dfeaff9SPeter Xu } 61976dfeaff9SPeter Xu flush_hugetlb_tlb_range(vma, start, end); 61986dfeaff9SPeter Xu i_mmap_unlock_write(vma->vm_file->f_mapping); 61996dfeaff9SPeter Xu /* 62006dfeaff9SPeter Xu * No need to call mmu_notifier_invalidate_range(), see 62016dfeaff9SPeter Xu * Documentation/vm/mmu_notifier.rst. 62026dfeaff9SPeter Xu */ 62036dfeaff9SPeter Xu mmu_notifier_invalidate_range_end(&range); 62046dfeaff9SPeter Xu } 62056dfeaff9SPeter Xu 6206cf11e85fSRoman Gushchin #ifdef CONFIG_CMA 6207cf11e85fSRoman Gushchin static bool cma_reserve_called __initdata; 6208cf11e85fSRoman Gushchin 6209cf11e85fSRoman Gushchin static int __init cmdline_parse_hugetlb_cma(char *p) 6210cf11e85fSRoman Gushchin { 6211cf11e85fSRoman Gushchin hugetlb_cma_size = memparse(p, &p); 6212cf11e85fSRoman Gushchin return 0; 6213cf11e85fSRoman Gushchin } 6214cf11e85fSRoman Gushchin 6215cf11e85fSRoman Gushchin early_param("hugetlb_cma", cmdline_parse_hugetlb_cma); 6216cf11e85fSRoman Gushchin 6217cf11e85fSRoman Gushchin void __init hugetlb_cma_reserve(int order) 6218cf11e85fSRoman Gushchin { 6219cf11e85fSRoman Gushchin unsigned long size, reserved, per_node; 6220cf11e85fSRoman Gushchin int nid; 6221cf11e85fSRoman Gushchin 6222cf11e85fSRoman Gushchin cma_reserve_called = true; 6223cf11e85fSRoman Gushchin 6224cf11e85fSRoman Gushchin if (!hugetlb_cma_size) 6225cf11e85fSRoman Gushchin return; 6226cf11e85fSRoman Gushchin 6227cf11e85fSRoman Gushchin if (hugetlb_cma_size < (PAGE_SIZE << order)) { 6228cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n", 6229cf11e85fSRoman Gushchin (PAGE_SIZE << order) / SZ_1M); 6230cf11e85fSRoman Gushchin return; 6231cf11e85fSRoman Gushchin } 6232cf11e85fSRoman Gushchin 6233cf11e85fSRoman Gushchin /* 6234cf11e85fSRoman Gushchin * If 3 GB area is requested on a machine with 4 numa nodes, 6235cf11e85fSRoman Gushchin * let's allocate 1 GB on first three nodes and ignore the last one. 6236cf11e85fSRoman Gushchin */ 6237cf11e85fSRoman Gushchin per_node = DIV_ROUND_UP(hugetlb_cma_size, nr_online_nodes); 6238cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n", 6239cf11e85fSRoman Gushchin hugetlb_cma_size / SZ_1M, per_node / SZ_1M); 6240cf11e85fSRoman Gushchin 6241cf11e85fSRoman Gushchin reserved = 0; 6242cf11e85fSRoman Gushchin for_each_node_state(nid, N_ONLINE) { 6243cf11e85fSRoman Gushchin int res; 62442281f797SBarry Song char name[CMA_MAX_NAME]; 6245cf11e85fSRoman Gushchin 6246cf11e85fSRoman Gushchin size = min(per_node, hugetlb_cma_size - reserved); 6247cf11e85fSRoman Gushchin size = round_up(size, PAGE_SIZE << order); 6248cf11e85fSRoman Gushchin 62492281f797SBarry Song snprintf(name, sizeof(name), "hugetlb%d", nid); 6250cf11e85fSRoman Gushchin res = cma_declare_contiguous_nid(0, size, 0, PAGE_SIZE << order, 625129d0f41dSBarry Song 0, false, name, 6252cf11e85fSRoman Gushchin &hugetlb_cma[nid], nid); 6253cf11e85fSRoman Gushchin if (res) { 6254cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: reservation failed: err %d, node %d", 6255cf11e85fSRoman Gushchin res, nid); 6256cf11e85fSRoman Gushchin continue; 6257cf11e85fSRoman Gushchin } 6258cf11e85fSRoman Gushchin 6259cf11e85fSRoman Gushchin reserved += size; 6260cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserved %lu MiB on node %d\n", 6261cf11e85fSRoman Gushchin size / SZ_1M, nid); 6262cf11e85fSRoman Gushchin 6263cf11e85fSRoman Gushchin if (reserved >= hugetlb_cma_size) 6264cf11e85fSRoman Gushchin break; 6265cf11e85fSRoman Gushchin } 6266cf11e85fSRoman Gushchin } 6267cf11e85fSRoman Gushchin 6268cf11e85fSRoman Gushchin void __init hugetlb_cma_check(void) 6269cf11e85fSRoman Gushchin { 6270cf11e85fSRoman Gushchin if (!hugetlb_cma_size || cma_reserve_called) 6271cf11e85fSRoman Gushchin return; 6272cf11e85fSRoman Gushchin 6273cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: the option isn't supported by current arch\n"); 6274cf11e85fSRoman Gushchin } 6275cf11e85fSRoman Gushchin 6276cf11e85fSRoman Gushchin #endif /* CONFIG_CMA */ 6277