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> 33d6606683SLinus Torvalds 3463551ae0SDavid Gibson #include <asm/page.h> 35ca15ca40SMike Rapoport #include <asm/pgalloc.h> 3624669e58SAneesh Kumar K.V #include <asm/tlb.h> 3763551ae0SDavid Gibson 3824669e58SAneesh Kumar K.V #include <linux/io.h> 3963551ae0SDavid Gibson #include <linux/hugetlb.h> 409dd540e2SAneesh Kumar K.V #include <linux/hugetlb_cgroup.h> 419a305230SLee Schermerhorn #include <linux/node.h> 421a1aad8aSMike Kravetz #include <linux/userfaultfd_k.h> 43ab5ac90aSMichal Hocko #include <linux/page_owner.h> 447835e98bSNick Piggin #include "internal.h" 451da177e4SLinus Torvalds 46c3f38a38SAneesh Kumar K.V int hugetlb_max_hstate __read_mostly; 47e5ff2159SAndi Kleen unsigned int default_hstate_idx; 48e5ff2159SAndi Kleen struct hstate hstates[HUGE_MAX_HSTATE]; 49cf11e85fSRoman Gushchin 50dbda8feaSBarry Song #ifdef CONFIG_CMA 51cf11e85fSRoman Gushchin static struct cma *hugetlb_cma[MAX_NUMNODES]; 52dbda8feaSBarry Song #endif 53dbda8feaSBarry Song static unsigned long hugetlb_cma_size __initdata; 54cf11e85fSRoman Gushchin 55641844f5SNaoya Horiguchi /* 56641844f5SNaoya Horiguchi * Minimum page order among possible hugepage sizes, set to a proper value 57641844f5SNaoya Horiguchi * at boot time. 58641844f5SNaoya Horiguchi */ 59641844f5SNaoya Horiguchi static unsigned int minimum_order __read_mostly = UINT_MAX; 60e5ff2159SAndi Kleen 6153ba51d2SJon Tollefson __initdata LIST_HEAD(huge_boot_pages); 6253ba51d2SJon Tollefson 63e5ff2159SAndi Kleen /* for command line parsing */ 64e5ff2159SAndi Kleen static struct hstate * __initdata parsed_hstate; 65e5ff2159SAndi Kleen static unsigned long __initdata default_hstate_max_huge_pages; 669fee021dSVaishali Thakkar static bool __initdata parsed_valid_hugepagesz = true; 67282f4214SMike Kravetz static bool __initdata parsed_default_hugepagesz; 68e5ff2159SAndi Kleen 693935baa9SDavid Gibson /* 7031caf665SNaoya Horiguchi * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, 7131caf665SNaoya Horiguchi * free_huge_pages, and surplus_huge_pages. 723935baa9SDavid Gibson */ 73c3f38a38SAneesh Kumar K.V DEFINE_SPINLOCK(hugetlb_lock); 740bd0f9fbSEric Paris 758382d914SDavidlohr Bueso /* 768382d914SDavidlohr Bueso * Serializes faults on the same logical page. This is used to 778382d914SDavidlohr Bueso * prevent spurious OOMs when the hugepage pool is fully utilized. 788382d914SDavidlohr Bueso */ 798382d914SDavidlohr Bueso static int num_fault_mutexes; 80c672c7f2SMike Kravetz struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp; 818382d914SDavidlohr Bueso 827ca02d0aSMike Kravetz /* Forward declaration */ 837ca02d0aSMike Kravetz static int hugetlb_acct_memory(struct hstate *h, long delta); 847ca02d0aSMike Kravetz 851d88433bSMiaohe Lin static inline bool subpool_is_free(struct hugepage_subpool *spool) 861d88433bSMiaohe Lin { 871d88433bSMiaohe Lin if (spool->count) 881d88433bSMiaohe Lin return false; 891d88433bSMiaohe Lin if (spool->max_hpages != -1) 901d88433bSMiaohe Lin return spool->used_hpages == 0; 911d88433bSMiaohe Lin if (spool->min_hpages != -1) 921d88433bSMiaohe Lin return spool->rsv_hpages == spool->min_hpages; 931d88433bSMiaohe Lin 941d88433bSMiaohe Lin return true; 951d88433bSMiaohe Lin } 961d88433bSMiaohe Lin 9790481622SDavid Gibson static inline void unlock_or_release_subpool(struct hugepage_subpool *spool) 9890481622SDavid Gibson { 9990481622SDavid Gibson spin_unlock(&spool->lock); 10090481622SDavid Gibson 10190481622SDavid Gibson /* If no pages are used, and no other handles to the subpool 1027c8de358SEthon Paul * remain, give up any reservations based on minimum size and 1037ca02d0aSMike Kravetz * free the subpool */ 1041d88433bSMiaohe Lin if (subpool_is_free(spool)) { 1057ca02d0aSMike Kravetz if (spool->min_hpages != -1) 1067ca02d0aSMike Kravetz hugetlb_acct_memory(spool->hstate, 1077ca02d0aSMike Kravetz -spool->min_hpages); 10890481622SDavid Gibson kfree(spool); 10990481622SDavid Gibson } 1107ca02d0aSMike Kravetz } 11190481622SDavid Gibson 1127ca02d0aSMike Kravetz struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, 1137ca02d0aSMike Kravetz long min_hpages) 11490481622SDavid Gibson { 11590481622SDavid Gibson struct hugepage_subpool *spool; 11690481622SDavid Gibson 117c6a91820SMike Kravetz spool = kzalloc(sizeof(*spool), GFP_KERNEL); 11890481622SDavid Gibson if (!spool) 11990481622SDavid Gibson return NULL; 12090481622SDavid Gibson 12190481622SDavid Gibson spin_lock_init(&spool->lock); 12290481622SDavid Gibson spool->count = 1; 1237ca02d0aSMike Kravetz spool->max_hpages = max_hpages; 1247ca02d0aSMike Kravetz spool->hstate = h; 1257ca02d0aSMike Kravetz spool->min_hpages = min_hpages; 1267ca02d0aSMike Kravetz 1277ca02d0aSMike Kravetz if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { 1287ca02d0aSMike Kravetz kfree(spool); 1297ca02d0aSMike Kravetz return NULL; 1307ca02d0aSMike Kravetz } 1317ca02d0aSMike Kravetz spool->rsv_hpages = min_hpages; 13290481622SDavid Gibson 13390481622SDavid Gibson return spool; 13490481622SDavid Gibson } 13590481622SDavid Gibson 13690481622SDavid Gibson void hugepage_put_subpool(struct hugepage_subpool *spool) 13790481622SDavid Gibson { 13890481622SDavid Gibson spin_lock(&spool->lock); 13990481622SDavid Gibson BUG_ON(!spool->count); 14090481622SDavid Gibson spool->count--; 14190481622SDavid Gibson unlock_or_release_subpool(spool); 14290481622SDavid Gibson } 14390481622SDavid Gibson 1441c5ecae3SMike Kravetz /* 1451c5ecae3SMike Kravetz * Subpool accounting for allocating and reserving pages. 1461c5ecae3SMike Kravetz * Return -ENOMEM if there are not enough resources to satisfy the 1479e7ee400SRandy Dunlap * request. Otherwise, return the number of pages by which the 1481c5ecae3SMike Kravetz * global pools must be adjusted (upward). The returned value may 1491c5ecae3SMike Kravetz * only be different than the passed value (delta) in the case where 1507c8de358SEthon Paul * a subpool minimum size must be maintained. 1511c5ecae3SMike Kravetz */ 1521c5ecae3SMike Kravetz static long hugepage_subpool_get_pages(struct hugepage_subpool *spool, 15390481622SDavid Gibson long delta) 15490481622SDavid Gibson { 1551c5ecae3SMike Kravetz long ret = delta; 15690481622SDavid Gibson 15790481622SDavid Gibson if (!spool) 1581c5ecae3SMike Kravetz return ret; 15990481622SDavid Gibson 16090481622SDavid Gibson spin_lock(&spool->lock); 16190481622SDavid Gibson 1621c5ecae3SMike Kravetz if (spool->max_hpages != -1) { /* maximum size accounting */ 1631c5ecae3SMike Kravetz if ((spool->used_hpages + delta) <= spool->max_hpages) 1641c5ecae3SMike Kravetz spool->used_hpages += delta; 1651c5ecae3SMike Kravetz else { 1661c5ecae3SMike Kravetz ret = -ENOMEM; 1671c5ecae3SMike Kravetz goto unlock_ret; 1681c5ecae3SMike Kravetz } 1691c5ecae3SMike Kravetz } 1701c5ecae3SMike Kravetz 17109a95e29SMike Kravetz /* minimum size accounting */ 17209a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->rsv_hpages) { 1731c5ecae3SMike Kravetz if (delta > spool->rsv_hpages) { 1741c5ecae3SMike Kravetz /* 1751c5ecae3SMike Kravetz * Asking for more reserves than those already taken on 1761c5ecae3SMike Kravetz * behalf of subpool. Return difference. 1771c5ecae3SMike Kravetz */ 1781c5ecae3SMike Kravetz ret = delta - spool->rsv_hpages; 1791c5ecae3SMike Kravetz spool->rsv_hpages = 0; 1801c5ecae3SMike Kravetz } else { 1811c5ecae3SMike Kravetz ret = 0; /* reserves already accounted for */ 1821c5ecae3SMike Kravetz spool->rsv_hpages -= delta; 1831c5ecae3SMike Kravetz } 1841c5ecae3SMike Kravetz } 1851c5ecae3SMike Kravetz 1861c5ecae3SMike Kravetz unlock_ret: 1871c5ecae3SMike Kravetz spin_unlock(&spool->lock); 18890481622SDavid Gibson return ret; 18990481622SDavid Gibson } 19090481622SDavid Gibson 1911c5ecae3SMike Kravetz /* 1921c5ecae3SMike Kravetz * Subpool accounting for freeing and unreserving pages. 1931c5ecae3SMike Kravetz * Return the number of global page reservations that must be dropped. 1941c5ecae3SMike Kravetz * The return value may only be different than the passed value (delta) 1951c5ecae3SMike Kravetz * in the case where a subpool minimum size must be maintained. 1961c5ecae3SMike Kravetz */ 1971c5ecae3SMike Kravetz static long hugepage_subpool_put_pages(struct hugepage_subpool *spool, 19890481622SDavid Gibson long delta) 19990481622SDavid Gibson { 2001c5ecae3SMike Kravetz long ret = delta; 2011c5ecae3SMike Kravetz 20290481622SDavid Gibson if (!spool) 2031c5ecae3SMike Kravetz return delta; 20490481622SDavid Gibson 20590481622SDavid Gibson spin_lock(&spool->lock); 2061c5ecae3SMike Kravetz 2071c5ecae3SMike Kravetz if (spool->max_hpages != -1) /* maximum size accounting */ 20890481622SDavid Gibson spool->used_hpages -= delta; 2091c5ecae3SMike Kravetz 21009a95e29SMike Kravetz /* minimum size accounting */ 21109a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { 2121c5ecae3SMike Kravetz if (spool->rsv_hpages + delta <= spool->min_hpages) 2131c5ecae3SMike Kravetz ret = 0; 2141c5ecae3SMike Kravetz else 2151c5ecae3SMike Kravetz ret = spool->rsv_hpages + delta - spool->min_hpages; 2161c5ecae3SMike Kravetz 2171c5ecae3SMike Kravetz spool->rsv_hpages += delta; 2181c5ecae3SMike Kravetz if (spool->rsv_hpages > spool->min_hpages) 2191c5ecae3SMike Kravetz spool->rsv_hpages = spool->min_hpages; 2201c5ecae3SMike Kravetz } 2211c5ecae3SMike Kravetz 2221c5ecae3SMike Kravetz /* 2231c5ecae3SMike Kravetz * If hugetlbfs_put_super couldn't free spool due to an outstanding 2241c5ecae3SMike Kravetz * quota reference, free it now. 2251c5ecae3SMike Kravetz */ 22690481622SDavid Gibson unlock_or_release_subpool(spool); 2271c5ecae3SMike Kravetz 2281c5ecae3SMike Kravetz return ret; 22990481622SDavid Gibson } 23090481622SDavid Gibson 23190481622SDavid Gibson static inline struct hugepage_subpool *subpool_inode(struct inode *inode) 23290481622SDavid Gibson { 23390481622SDavid Gibson return HUGETLBFS_SB(inode->i_sb)->spool; 23490481622SDavid Gibson } 23590481622SDavid Gibson 23690481622SDavid Gibson static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) 23790481622SDavid Gibson { 238496ad9aaSAl Viro return subpool_inode(file_inode(vma->vm_file)); 23990481622SDavid Gibson } 24090481622SDavid Gibson 2410db9d74eSMina Almasry /* Helper that removes a struct file_region from the resv_map cache and returns 2420db9d74eSMina Almasry * it for use. 2430db9d74eSMina Almasry */ 2440db9d74eSMina Almasry static struct file_region * 2450db9d74eSMina Almasry get_file_region_entry_from_cache(struct resv_map *resv, long from, long to) 2460db9d74eSMina Almasry { 2470db9d74eSMina Almasry struct file_region *nrg = NULL; 2480db9d74eSMina Almasry 2490db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count <= 0); 2500db9d74eSMina Almasry 2510db9d74eSMina Almasry resv->region_cache_count--; 2520db9d74eSMina Almasry nrg = list_first_entry(&resv->region_cache, struct file_region, link); 2530db9d74eSMina Almasry list_del(&nrg->link); 2540db9d74eSMina Almasry 2550db9d74eSMina Almasry nrg->from = from; 2560db9d74eSMina Almasry nrg->to = to; 2570db9d74eSMina Almasry 2580db9d74eSMina Almasry return nrg; 2590db9d74eSMina Almasry } 2600db9d74eSMina Almasry 261075a61d0SMina Almasry static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg, 262075a61d0SMina Almasry struct file_region *rg) 263075a61d0SMina Almasry { 264075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 265075a61d0SMina Almasry nrg->reservation_counter = rg->reservation_counter; 266075a61d0SMina Almasry nrg->css = rg->css; 267075a61d0SMina Almasry if (rg->css) 268075a61d0SMina Almasry css_get(rg->css); 269075a61d0SMina Almasry #endif 270075a61d0SMina Almasry } 271075a61d0SMina Almasry 272075a61d0SMina Almasry /* Helper that records hugetlb_cgroup uncharge info. */ 273075a61d0SMina Almasry static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg, 274075a61d0SMina Almasry struct hstate *h, 275075a61d0SMina Almasry struct resv_map *resv, 276075a61d0SMina Almasry struct file_region *nrg) 277075a61d0SMina Almasry { 278075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 279075a61d0SMina Almasry if (h_cg) { 280075a61d0SMina Almasry nrg->reservation_counter = 281075a61d0SMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 282075a61d0SMina Almasry nrg->css = &h_cg->css; 283d85aecf2SMiaohe Lin /* 284d85aecf2SMiaohe Lin * The caller will hold exactly one h_cg->css reference for the 285d85aecf2SMiaohe Lin * whole contiguous reservation region. But this area might be 286d85aecf2SMiaohe Lin * scattered when there are already some file_regions reside in 287d85aecf2SMiaohe Lin * it. As a result, many file_regions may share only one css 288d85aecf2SMiaohe Lin * reference. In order to ensure that one file_region must hold 289d85aecf2SMiaohe Lin * exactly one h_cg->css reference, we should do css_get for 290d85aecf2SMiaohe Lin * each file_region and leave the reference held by caller 291d85aecf2SMiaohe Lin * untouched. 292d85aecf2SMiaohe Lin */ 293d85aecf2SMiaohe Lin css_get(&h_cg->css); 294075a61d0SMina Almasry if (!resv->pages_per_hpage) 295075a61d0SMina Almasry resv->pages_per_hpage = pages_per_huge_page(h); 296075a61d0SMina Almasry /* pages_per_hpage should be the same for all entries in 297075a61d0SMina Almasry * a resv_map. 298075a61d0SMina Almasry */ 299075a61d0SMina Almasry VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h)); 300075a61d0SMina Almasry } else { 301075a61d0SMina Almasry nrg->reservation_counter = NULL; 302075a61d0SMina Almasry nrg->css = NULL; 303075a61d0SMina Almasry } 304075a61d0SMina Almasry #endif 305075a61d0SMina Almasry } 306075a61d0SMina Almasry 307d85aecf2SMiaohe Lin static void put_uncharge_info(struct file_region *rg) 308d85aecf2SMiaohe Lin { 309d85aecf2SMiaohe Lin #ifdef CONFIG_CGROUP_HUGETLB 310d85aecf2SMiaohe Lin if (rg->css) 311d85aecf2SMiaohe Lin css_put(rg->css); 312d85aecf2SMiaohe Lin #endif 313d85aecf2SMiaohe Lin } 314d85aecf2SMiaohe Lin 315a9b3f867SMina Almasry static bool has_same_uncharge_info(struct file_region *rg, 316a9b3f867SMina Almasry struct file_region *org) 317a9b3f867SMina Almasry { 318a9b3f867SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 319a9b3f867SMina Almasry return rg && org && 320a9b3f867SMina Almasry rg->reservation_counter == org->reservation_counter && 321a9b3f867SMina Almasry rg->css == org->css; 322a9b3f867SMina Almasry 323a9b3f867SMina Almasry #else 324a9b3f867SMina Almasry return true; 325a9b3f867SMina Almasry #endif 326a9b3f867SMina Almasry } 327a9b3f867SMina Almasry 328a9b3f867SMina Almasry static void coalesce_file_region(struct resv_map *resv, struct file_region *rg) 329a9b3f867SMina Almasry { 330a9b3f867SMina Almasry struct file_region *nrg = NULL, *prg = NULL; 331a9b3f867SMina Almasry 332a9b3f867SMina Almasry prg = list_prev_entry(rg, link); 333a9b3f867SMina Almasry if (&prg->link != &resv->regions && prg->to == rg->from && 334a9b3f867SMina Almasry has_same_uncharge_info(prg, rg)) { 335a9b3f867SMina Almasry prg->to = rg->to; 336a9b3f867SMina Almasry 337a9b3f867SMina Almasry list_del(&rg->link); 338d85aecf2SMiaohe Lin put_uncharge_info(rg); 339a9b3f867SMina Almasry kfree(rg); 340a9b3f867SMina Almasry 3417db5e7b6SWei Yang rg = prg; 342a9b3f867SMina Almasry } 343a9b3f867SMina Almasry 344a9b3f867SMina Almasry nrg = list_next_entry(rg, link); 345a9b3f867SMina Almasry if (&nrg->link != &resv->regions && nrg->from == rg->to && 346a9b3f867SMina Almasry has_same_uncharge_info(nrg, rg)) { 347a9b3f867SMina Almasry nrg->from = rg->from; 348a9b3f867SMina Almasry 349a9b3f867SMina Almasry list_del(&rg->link); 350d85aecf2SMiaohe Lin put_uncharge_info(rg); 351a9b3f867SMina Almasry kfree(rg); 352a9b3f867SMina Almasry } 353a9b3f867SMina Almasry } 354a9b3f867SMina Almasry 3552103cf9cSPeter Xu static inline long 3562103cf9cSPeter Xu hugetlb_resv_map_add(struct resv_map *map, struct file_region *rg, long from, 3572103cf9cSPeter Xu long to, struct hstate *h, struct hugetlb_cgroup *cg, 3582103cf9cSPeter Xu long *regions_needed) 3592103cf9cSPeter Xu { 3602103cf9cSPeter Xu struct file_region *nrg; 3612103cf9cSPeter Xu 3622103cf9cSPeter Xu if (!regions_needed) { 3632103cf9cSPeter Xu nrg = get_file_region_entry_from_cache(map, from, to); 3642103cf9cSPeter Xu record_hugetlb_cgroup_uncharge_info(cg, h, map, nrg); 3652103cf9cSPeter Xu list_add(&nrg->link, rg->link.prev); 3662103cf9cSPeter Xu coalesce_file_region(map, nrg); 3672103cf9cSPeter Xu } else 3682103cf9cSPeter Xu *regions_needed += 1; 3692103cf9cSPeter Xu 3702103cf9cSPeter Xu return to - from; 3712103cf9cSPeter Xu } 3722103cf9cSPeter Xu 373972a3da3SWei Yang /* 374972a3da3SWei Yang * Must be called with resv->lock held. 375972a3da3SWei Yang * 376972a3da3SWei Yang * Calling this with regions_needed != NULL will count the number of pages 377972a3da3SWei Yang * to be added but will not modify the linked list. And regions_needed will 378972a3da3SWei Yang * indicate the number of file_regions needed in the cache to carry out to add 379972a3da3SWei Yang * the regions for this range. 380d75c6af9SMina Almasry */ 381d75c6af9SMina Almasry static long add_reservation_in_range(struct resv_map *resv, long f, long t, 382075a61d0SMina Almasry struct hugetlb_cgroup *h_cg, 383972a3da3SWei Yang struct hstate *h, long *regions_needed) 384d75c6af9SMina Almasry { 3850db9d74eSMina Almasry long add = 0; 386d75c6af9SMina Almasry struct list_head *head = &resv->regions; 3870db9d74eSMina Almasry long last_accounted_offset = f; 3882103cf9cSPeter Xu struct file_region *rg = NULL, *trg = NULL; 389d75c6af9SMina Almasry 3900db9d74eSMina Almasry if (regions_needed) 3910db9d74eSMina Almasry *regions_needed = 0; 392d75c6af9SMina Almasry 3930db9d74eSMina Almasry /* In this loop, we essentially handle an entry for the range 3940db9d74eSMina Almasry * [last_accounted_offset, rg->from), at every iteration, with some 3950db9d74eSMina Almasry * bounds checking. 3960db9d74eSMina Almasry */ 3970db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, head, link) { 3980db9d74eSMina Almasry /* Skip irrelevant regions that start before our range. */ 3990db9d74eSMina Almasry if (rg->from < f) { 4000db9d74eSMina Almasry /* If this region ends after the last accounted offset, 4010db9d74eSMina Almasry * then we need to update last_accounted_offset. 4020db9d74eSMina Almasry */ 4030db9d74eSMina Almasry if (rg->to > last_accounted_offset) 4040db9d74eSMina Almasry last_accounted_offset = rg->to; 4050db9d74eSMina Almasry continue; 4060db9d74eSMina Almasry } 407d75c6af9SMina Almasry 4080db9d74eSMina Almasry /* When we find a region that starts beyond our range, we've 4090db9d74eSMina Almasry * finished. 4100db9d74eSMina Almasry */ 411ca7e0457SPeter Xu if (rg->from >= t) 412d75c6af9SMina Almasry break; 413d75c6af9SMina Almasry 4140db9d74eSMina Almasry /* Add an entry for last_accounted_offset -> rg->from, and 4150db9d74eSMina Almasry * update last_accounted_offset. 416d75c6af9SMina Almasry */ 4172103cf9cSPeter Xu if (rg->from > last_accounted_offset) 4182103cf9cSPeter Xu add += hugetlb_resv_map_add(resv, rg, 4192103cf9cSPeter Xu last_accounted_offset, 4202103cf9cSPeter Xu rg->from, h, h_cg, 4212103cf9cSPeter Xu regions_needed); 422d75c6af9SMina Almasry 4230db9d74eSMina Almasry last_accounted_offset = rg->to; 4240db9d74eSMina Almasry } 4250db9d74eSMina Almasry 4260db9d74eSMina Almasry /* Handle the case where our range extends beyond 4270db9d74eSMina Almasry * last_accounted_offset. 4280db9d74eSMina Almasry */ 4292103cf9cSPeter Xu if (last_accounted_offset < t) 4302103cf9cSPeter Xu add += hugetlb_resv_map_add(resv, rg, last_accounted_offset, 4312103cf9cSPeter Xu t, h, h_cg, regions_needed); 4320db9d74eSMina Almasry 4330db9d74eSMina Almasry VM_BUG_ON(add < 0); 4340db9d74eSMina Almasry return add; 4350db9d74eSMina Almasry } 4360db9d74eSMina Almasry 4370db9d74eSMina Almasry /* Must be called with resv->lock acquired. Will drop lock to allocate entries. 4380db9d74eSMina Almasry */ 4390db9d74eSMina Almasry static int allocate_file_region_entries(struct resv_map *resv, 4400db9d74eSMina Almasry int regions_needed) 4410db9d74eSMina Almasry __must_hold(&resv->lock) 4420db9d74eSMina Almasry { 4430db9d74eSMina Almasry struct list_head allocated_regions; 4440db9d74eSMina Almasry int to_allocate = 0, i = 0; 4450db9d74eSMina Almasry struct file_region *trg = NULL, *rg = NULL; 4460db9d74eSMina Almasry 4470db9d74eSMina Almasry VM_BUG_ON(regions_needed < 0); 4480db9d74eSMina Almasry 4490db9d74eSMina Almasry INIT_LIST_HEAD(&allocated_regions); 4500db9d74eSMina Almasry 4510db9d74eSMina Almasry /* 4520db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 4530db9d74eSMina Almasry * the number of in progress add operations plus regions_needed. 4540db9d74eSMina Almasry * 4550db9d74eSMina Almasry * This is a while loop because when we drop the lock, some other call 4560db9d74eSMina Almasry * to region_add or region_del may have consumed some region_entries, 4570db9d74eSMina Almasry * so we keep looping here until we finally have enough entries for 4580db9d74eSMina Almasry * (adds_in_progress + regions_needed). 4590db9d74eSMina Almasry */ 4600db9d74eSMina Almasry while (resv->region_cache_count < 4610db9d74eSMina Almasry (resv->adds_in_progress + regions_needed)) { 4620db9d74eSMina Almasry to_allocate = resv->adds_in_progress + regions_needed - 4630db9d74eSMina Almasry resv->region_cache_count; 4640db9d74eSMina Almasry 4650db9d74eSMina Almasry /* At this point, we should have enough entries in the cache 4660db9d74eSMina Almasry * for all the existings adds_in_progress. We should only be 4670db9d74eSMina Almasry * needing to allocate for regions_needed. 4680db9d74eSMina Almasry */ 4690db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count < resv->adds_in_progress); 4700db9d74eSMina Almasry 4710db9d74eSMina Almasry spin_unlock(&resv->lock); 4720db9d74eSMina Almasry for (i = 0; i < to_allocate; i++) { 4730db9d74eSMina Almasry trg = kmalloc(sizeof(*trg), GFP_KERNEL); 4740db9d74eSMina Almasry if (!trg) 4750db9d74eSMina Almasry goto out_of_memory; 4760db9d74eSMina Almasry list_add(&trg->link, &allocated_regions); 4770db9d74eSMina Almasry } 4780db9d74eSMina Almasry 4790db9d74eSMina Almasry spin_lock(&resv->lock); 4800db9d74eSMina Almasry 481d3ec7b6eSWei Yang list_splice(&allocated_regions, &resv->region_cache); 482d3ec7b6eSWei Yang resv->region_cache_count += to_allocate; 4830db9d74eSMina Almasry } 4840db9d74eSMina Almasry 4850db9d74eSMina Almasry return 0; 4860db9d74eSMina Almasry 4870db9d74eSMina Almasry out_of_memory: 4880db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, &allocated_regions, link) { 489d75c6af9SMina Almasry list_del(&rg->link); 490d75c6af9SMina Almasry kfree(rg); 491d75c6af9SMina Almasry } 4920db9d74eSMina Almasry return -ENOMEM; 493d75c6af9SMina Almasry } 494d75c6af9SMina Almasry 4951dd308a7SMike Kravetz /* 4961dd308a7SMike Kravetz * Add the huge page range represented by [f, t) to the reserve 4970db9d74eSMina Almasry * map. Regions will be taken from the cache to fill in this range. 4980db9d74eSMina Almasry * Sufficient regions should exist in the cache due to the previous 4990db9d74eSMina Almasry * call to region_chg with the same range, but in some cases the cache will not 5000db9d74eSMina Almasry * have sufficient entries due to races with other code doing region_add or 5010db9d74eSMina Almasry * region_del. The extra needed entries will be allocated. 502cf3ad20bSMike Kravetz * 5030db9d74eSMina Almasry * regions_needed is the out value provided by a previous call to region_chg. 5040db9d74eSMina Almasry * 5050db9d74eSMina Almasry * Return the number of new huge pages added to the map. This number is greater 5060db9d74eSMina Almasry * than or equal to zero. If file_region entries needed to be allocated for 5077c8de358SEthon Paul * this operation and we were not able to allocate, it returns -ENOMEM. 5080db9d74eSMina Almasry * region_add of regions of length 1 never allocate file_regions and cannot 5090db9d74eSMina Almasry * fail; region_chg will always allocate at least 1 entry and a region_add for 5100db9d74eSMina Almasry * 1 page will only require at most 1 entry. 5111dd308a7SMike Kravetz */ 5120db9d74eSMina Almasry static long region_add(struct resv_map *resv, long f, long t, 513075a61d0SMina Almasry long in_regions_needed, struct hstate *h, 514075a61d0SMina Almasry struct hugetlb_cgroup *h_cg) 51596822904SAndy Whitcroft { 5160db9d74eSMina Almasry long add = 0, actual_regions_needed = 0; 51796822904SAndy Whitcroft 5187b24d861SDavidlohr Bueso spin_lock(&resv->lock); 5190db9d74eSMina Almasry retry: 5200db9d74eSMina Almasry 5210db9d74eSMina Almasry /* Count how many regions are actually needed to execute this add. */ 522972a3da3SWei Yang add_reservation_in_range(resv, f, t, NULL, NULL, 523972a3da3SWei Yang &actual_regions_needed); 52496822904SAndy Whitcroft 5255e911373SMike Kravetz /* 5260db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 5270db9d74eSMina Almasry * this add operation. Note that actual_regions_needed may be greater 5280db9d74eSMina Almasry * than in_regions_needed, as the resv_map may have been modified since 5290db9d74eSMina Almasry * the region_chg call. In this case, we need to make sure that we 5300db9d74eSMina Almasry * allocate extra entries, such that we have enough for all the 5310db9d74eSMina Almasry * existing adds_in_progress, plus the excess needed for this 5320db9d74eSMina Almasry * operation. 5335e911373SMike Kravetz */ 5340db9d74eSMina Almasry if (actual_regions_needed > in_regions_needed && 5350db9d74eSMina Almasry resv->region_cache_count < 5360db9d74eSMina Almasry resv->adds_in_progress + 5370db9d74eSMina Almasry (actual_regions_needed - in_regions_needed)) { 5380db9d74eSMina Almasry /* region_add operation of range 1 should never need to 5390db9d74eSMina Almasry * allocate file_region entries. 5400db9d74eSMina Almasry */ 5410db9d74eSMina Almasry VM_BUG_ON(t - f <= 1); 5425e911373SMike Kravetz 5430db9d74eSMina Almasry if (allocate_file_region_entries( 5440db9d74eSMina Almasry resv, actual_regions_needed - in_regions_needed)) { 5450db9d74eSMina Almasry return -ENOMEM; 5465e911373SMike Kravetz } 5475e911373SMike Kravetz 5480db9d74eSMina Almasry goto retry; 5490db9d74eSMina Almasry } 550cf3ad20bSMike Kravetz 551972a3da3SWei Yang add = add_reservation_in_range(resv, f, t, h_cg, h, NULL); 5520db9d74eSMina Almasry 5530db9d74eSMina Almasry resv->adds_in_progress -= in_regions_needed; 5540db9d74eSMina Almasry 5557b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 556cf3ad20bSMike Kravetz return add; 55796822904SAndy Whitcroft } 55896822904SAndy Whitcroft 5591dd308a7SMike Kravetz /* 5601dd308a7SMike Kravetz * Examine the existing reserve map and determine how many 5611dd308a7SMike Kravetz * huge pages in the specified range [f, t) are NOT currently 5621dd308a7SMike Kravetz * represented. This routine is called before a subsequent 5631dd308a7SMike Kravetz * call to region_add that will actually modify the reserve 5641dd308a7SMike Kravetz * map to add the specified range [f, t). region_chg does 5651dd308a7SMike Kravetz * not change the number of huge pages represented by the 5660db9d74eSMina Almasry * map. A number of new file_region structures is added to the cache as a 5670db9d74eSMina Almasry * placeholder, for the subsequent region_add call to use. At least 1 5680db9d74eSMina Almasry * file_region structure is added. 5690db9d74eSMina Almasry * 5700db9d74eSMina Almasry * out_regions_needed is the number of regions added to the 5710db9d74eSMina Almasry * resv->adds_in_progress. This value needs to be provided to a follow up call 5720db9d74eSMina Almasry * to region_add or region_abort for proper accounting. 5735e911373SMike Kravetz * 5745e911373SMike Kravetz * Returns the number of huge pages that need to be added to the existing 5755e911373SMike Kravetz * reservation map for the range [f, t). This number is greater or equal to 5765e911373SMike Kravetz * zero. -ENOMEM is returned if a new file_region structure or cache entry 5775e911373SMike Kravetz * is needed and can not be allocated. 5781dd308a7SMike Kravetz */ 5790db9d74eSMina Almasry static long region_chg(struct resv_map *resv, long f, long t, 5800db9d74eSMina Almasry long *out_regions_needed) 58196822904SAndy Whitcroft { 58296822904SAndy Whitcroft long chg = 0; 58396822904SAndy Whitcroft 5847b24d861SDavidlohr Bueso spin_lock(&resv->lock); 5855e911373SMike Kravetz 586972a3da3SWei Yang /* Count how many hugepages in this range are NOT represented. */ 587075a61d0SMina Almasry chg = add_reservation_in_range(resv, f, t, NULL, NULL, 588972a3da3SWei Yang out_regions_needed); 5895e911373SMike Kravetz 5900db9d74eSMina Almasry if (*out_regions_needed == 0) 5910db9d74eSMina Almasry *out_regions_needed = 1; 5925e911373SMike Kravetz 5930db9d74eSMina Almasry if (allocate_file_region_entries(resv, *out_regions_needed)) 5945e911373SMike Kravetz return -ENOMEM; 5955e911373SMike Kravetz 5960db9d74eSMina Almasry resv->adds_in_progress += *out_regions_needed; 59796822904SAndy Whitcroft 5987b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 59996822904SAndy Whitcroft return chg; 60096822904SAndy Whitcroft } 60196822904SAndy Whitcroft 6021dd308a7SMike Kravetz /* 6035e911373SMike Kravetz * Abort the in progress add operation. The adds_in_progress field 6045e911373SMike Kravetz * of the resv_map keeps track of the operations in progress between 6055e911373SMike Kravetz * calls to region_chg and region_add. Operations are sometimes 6065e911373SMike Kravetz * aborted after the call to region_chg. In such cases, region_abort 6070db9d74eSMina Almasry * is called to decrement the adds_in_progress counter. regions_needed 6080db9d74eSMina Almasry * is the value returned by the region_chg call, it is used to decrement 6090db9d74eSMina Almasry * the adds_in_progress counter. 6105e911373SMike Kravetz * 6115e911373SMike Kravetz * NOTE: The range arguments [f, t) are not needed or used in this 6125e911373SMike Kravetz * routine. They are kept to make reading the calling code easier as 6135e911373SMike Kravetz * arguments will match the associated region_chg call. 6145e911373SMike Kravetz */ 6150db9d74eSMina Almasry static void region_abort(struct resv_map *resv, long f, long t, 6160db9d74eSMina Almasry long regions_needed) 6175e911373SMike Kravetz { 6185e911373SMike Kravetz spin_lock(&resv->lock); 6195e911373SMike Kravetz VM_BUG_ON(!resv->region_cache_count); 6200db9d74eSMina Almasry resv->adds_in_progress -= regions_needed; 6215e911373SMike Kravetz spin_unlock(&resv->lock); 6225e911373SMike Kravetz } 6235e911373SMike Kravetz 6245e911373SMike Kravetz /* 625feba16e2SMike Kravetz * Delete the specified range [f, t) from the reserve map. If the 626feba16e2SMike Kravetz * t parameter is LONG_MAX, this indicates that ALL regions after f 627feba16e2SMike Kravetz * should be deleted. Locate the regions which intersect [f, t) 628feba16e2SMike Kravetz * and either trim, delete or split the existing regions. 629feba16e2SMike Kravetz * 630feba16e2SMike Kravetz * Returns the number of huge pages deleted from the reserve map. 631feba16e2SMike Kravetz * In the normal case, the return value is zero or more. In the 632feba16e2SMike Kravetz * case where a region must be split, a new region descriptor must 633feba16e2SMike Kravetz * be allocated. If the allocation fails, -ENOMEM will be returned. 634feba16e2SMike Kravetz * NOTE: If the parameter t == LONG_MAX, then we will never split 635feba16e2SMike Kravetz * a region and possibly return -ENOMEM. Callers specifying 636feba16e2SMike Kravetz * t == LONG_MAX do not need to check for -ENOMEM error. 6371dd308a7SMike Kravetz */ 638feba16e2SMike Kravetz static long region_del(struct resv_map *resv, long f, long t) 63996822904SAndy Whitcroft { 6401406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 64196822904SAndy Whitcroft struct file_region *rg, *trg; 642feba16e2SMike Kravetz struct file_region *nrg = NULL; 643feba16e2SMike Kravetz long del = 0; 64496822904SAndy Whitcroft 645feba16e2SMike Kravetz retry: 6467b24d861SDavidlohr Bueso spin_lock(&resv->lock); 647feba16e2SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 648dbe409e4SMike Kravetz /* 649dbe409e4SMike Kravetz * Skip regions before the range to be deleted. file_region 650dbe409e4SMike Kravetz * ranges are normally of the form [from, to). However, there 651dbe409e4SMike Kravetz * may be a "placeholder" entry in the map which is of the form 652dbe409e4SMike Kravetz * (from, to) with from == to. Check for placeholder entries 653dbe409e4SMike Kravetz * at the beginning of the range to be deleted. 654dbe409e4SMike Kravetz */ 655dbe409e4SMike Kravetz if (rg->to <= f && (rg->to != rg->from || rg->to != f)) 656feba16e2SMike Kravetz continue; 657dbe409e4SMike Kravetz 658feba16e2SMike Kravetz if (rg->from >= t) 65996822904SAndy Whitcroft break; 66096822904SAndy Whitcroft 661feba16e2SMike Kravetz if (f > rg->from && t < rg->to) { /* Must split region */ 662feba16e2SMike Kravetz /* 663feba16e2SMike Kravetz * Check for an entry in the cache before dropping 664feba16e2SMike Kravetz * lock and attempting allocation. 665feba16e2SMike Kravetz */ 666feba16e2SMike Kravetz if (!nrg && 667feba16e2SMike Kravetz resv->region_cache_count > resv->adds_in_progress) { 668feba16e2SMike Kravetz nrg = list_first_entry(&resv->region_cache, 669feba16e2SMike Kravetz struct file_region, 670feba16e2SMike Kravetz link); 671feba16e2SMike Kravetz list_del(&nrg->link); 672feba16e2SMike Kravetz resv->region_cache_count--; 67396822904SAndy Whitcroft } 67496822904SAndy Whitcroft 675feba16e2SMike Kravetz if (!nrg) { 676feba16e2SMike Kravetz spin_unlock(&resv->lock); 677feba16e2SMike Kravetz nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); 678feba16e2SMike Kravetz if (!nrg) 679feba16e2SMike Kravetz return -ENOMEM; 680feba16e2SMike Kravetz goto retry; 681feba16e2SMike Kravetz } 682feba16e2SMike Kravetz 683feba16e2SMike Kravetz del += t - f; 68479aa925bSMike Kravetz hugetlb_cgroup_uncharge_file_region( 685d85aecf2SMiaohe Lin resv, rg, t - f, false); 686feba16e2SMike Kravetz 687feba16e2SMike Kravetz /* New entry for end of split region */ 688feba16e2SMike Kravetz nrg->from = t; 689feba16e2SMike Kravetz nrg->to = rg->to; 690075a61d0SMina Almasry 691075a61d0SMina Almasry copy_hugetlb_cgroup_uncharge_info(nrg, rg); 692075a61d0SMina Almasry 693feba16e2SMike Kravetz INIT_LIST_HEAD(&nrg->link); 694feba16e2SMike Kravetz 695feba16e2SMike Kravetz /* Original entry is trimmed */ 696feba16e2SMike Kravetz rg->to = f; 697feba16e2SMike Kravetz 698feba16e2SMike Kravetz list_add(&nrg->link, &rg->link); 699feba16e2SMike Kravetz nrg = NULL; 70096822904SAndy Whitcroft break; 701feba16e2SMike Kravetz } 702feba16e2SMike Kravetz 703feba16e2SMike Kravetz if (f <= rg->from && t >= rg->to) { /* Remove entire region */ 704feba16e2SMike Kravetz del += rg->to - rg->from; 705075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 706d85aecf2SMiaohe Lin rg->to - rg->from, true); 70796822904SAndy Whitcroft list_del(&rg->link); 70896822904SAndy Whitcroft kfree(rg); 709feba16e2SMike Kravetz continue; 71096822904SAndy Whitcroft } 7117b24d861SDavidlohr Bueso 712feba16e2SMike Kravetz if (f <= rg->from) { /* Trim beginning of region */ 713075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 714d85aecf2SMiaohe Lin t - rg->from, false); 715075a61d0SMina Almasry 71679aa925bSMike Kravetz del += t - rg->from; 71779aa925bSMike Kravetz rg->from = t; 71879aa925bSMike Kravetz } else { /* Trim end of region */ 719075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 720d85aecf2SMiaohe Lin rg->to - f, false); 72179aa925bSMike Kravetz 72279aa925bSMike Kravetz del += rg->to - f; 72379aa925bSMike Kravetz rg->to = f; 724feba16e2SMike Kravetz } 725feba16e2SMike Kravetz } 726feba16e2SMike Kravetz 7277b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 728feba16e2SMike Kravetz kfree(nrg); 729feba16e2SMike Kravetz return del; 73096822904SAndy Whitcroft } 73196822904SAndy Whitcroft 7321dd308a7SMike Kravetz /* 733b5cec28dSMike Kravetz * A rare out of memory error was encountered which prevented removal of 734b5cec28dSMike Kravetz * the reserve map region for a page. The huge page itself was free'ed 735b5cec28dSMike Kravetz * and removed from the page cache. This routine will adjust the subpool 736b5cec28dSMike Kravetz * usage count, and the global reserve count if needed. By incrementing 737b5cec28dSMike Kravetz * these counts, the reserve map entry which could not be deleted will 738b5cec28dSMike Kravetz * appear as a "reserved" entry instead of simply dangling with incorrect 739b5cec28dSMike Kravetz * counts. 740b5cec28dSMike Kravetz */ 74172e2936cSzhong jiang void hugetlb_fix_reserve_counts(struct inode *inode) 742b5cec28dSMike Kravetz { 743b5cec28dSMike Kravetz struct hugepage_subpool *spool = subpool_inode(inode); 744b5cec28dSMike Kravetz long rsv_adjust; 745b5cec28dSMike Kravetz 746b5cec28dSMike Kravetz rsv_adjust = hugepage_subpool_get_pages(spool, 1); 74772e2936cSzhong jiang if (rsv_adjust) { 748b5cec28dSMike Kravetz struct hstate *h = hstate_inode(inode); 749b5cec28dSMike Kravetz 750b5cec28dSMike Kravetz hugetlb_acct_memory(h, 1); 751b5cec28dSMike Kravetz } 752b5cec28dSMike Kravetz } 753b5cec28dSMike Kravetz 754b5cec28dSMike Kravetz /* 7551dd308a7SMike Kravetz * Count and return the number of huge pages in the reserve map 7561dd308a7SMike Kravetz * that intersect with the range [f, t). 7571dd308a7SMike Kravetz */ 7581406ec9bSJoonsoo Kim static long region_count(struct resv_map *resv, long f, long t) 75984afd99bSAndy Whitcroft { 7601406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 76184afd99bSAndy Whitcroft struct file_region *rg; 76284afd99bSAndy Whitcroft long chg = 0; 76384afd99bSAndy Whitcroft 7647b24d861SDavidlohr Bueso spin_lock(&resv->lock); 76584afd99bSAndy Whitcroft /* Locate each segment we overlap with, and count that overlap. */ 76684afd99bSAndy Whitcroft list_for_each_entry(rg, head, link) { 767f2135a4aSWang Sheng-Hui long seg_from; 768f2135a4aSWang Sheng-Hui long seg_to; 76984afd99bSAndy Whitcroft 77084afd99bSAndy Whitcroft if (rg->to <= f) 77184afd99bSAndy Whitcroft continue; 77284afd99bSAndy Whitcroft if (rg->from >= t) 77384afd99bSAndy Whitcroft break; 77484afd99bSAndy Whitcroft 77584afd99bSAndy Whitcroft seg_from = max(rg->from, f); 77684afd99bSAndy Whitcroft seg_to = min(rg->to, t); 77784afd99bSAndy Whitcroft 77884afd99bSAndy Whitcroft chg += seg_to - seg_from; 77984afd99bSAndy Whitcroft } 7807b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 78184afd99bSAndy Whitcroft 78284afd99bSAndy Whitcroft return chg; 78384afd99bSAndy Whitcroft } 78484afd99bSAndy Whitcroft 78596822904SAndy Whitcroft /* 786e7c4b0bfSAndy Whitcroft * Convert the address within this vma to the page offset within 787e7c4b0bfSAndy Whitcroft * the mapping, in pagecache page units; huge pages here. 788e7c4b0bfSAndy Whitcroft */ 789a5516438SAndi Kleen static pgoff_t vma_hugecache_offset(struct hstate *h, 790a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 791e7c4b0bfSAndy Whitcroft { 792a5516438SAndi Kleen return ((address - vma->vm_start) >> huge_page_shift(h)) + 793a5516438SAndi Kleen (vma->vm_pgoff >> huge_page_order(h)); 794e7c4b0bfSAndy Whitcroft } 795e7c4b0bfSAndy Whitcroft 7960fe6e20bSNaoya Horiguchi pgoff_t linear_hugepage_index(struct vm_area_struct *vma, 7970fe6e20bSNaoya Horiguchi unsigned long address) 7980fe6e20bSNaoya Horiguchi { 7990fe6e20bSNaoya Horiguchi return vma_hugecache_offset(hstate_vma(vma), vma, address); 8000fe6e20bSNaoya Horiguchi } 801dee41079SDan Williams EXPORT_SYMBOL_GPL(linear_hugepage_index); 8020fe6e20bSNaoya Horiguchi 80384afd99bSAndy Whitcroft /* 80408fba699SMel Gorman * Return the size of the pages allocated when backing a VMA. In the majority 80508fba699SMel Gorman * cases this will be same size as used by the page table entries. 80608fba699SMel Gorman */ 80708fba699SMel Gorman unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) 80808fba699SMel Gorman { 80905ea8860SDan Williams if (vma->vm_ops && vma->vm_ops->pagesize) 81005ea8860SDan Williams return vma->vm_ops->pagesize(vma); 81108fba699SMel Gorman return PAGE_SIZE; 81208fba699SMel Gorman } 813f340ca0fSJoerg Roedel EXPORT_SYMBOL_GPL(vma_kernel_pagesize); 81408fba699SMel Gorman 81508fba699SMel Gorman /* 8163340289dSMel Gorman * Return the page size being used by the MMU to back a VMA. In the majority 8173340289dSMel Gorman * of cases, the page size used by the kernel matches the MMU size. On 81809135cc5SDan Williams * architectures where it differs, an architecture-specific 'strong' 81909135cc5SDan Williams * version of this symbol is required. 8203340289dSMel Gorman */ 82109135cc5SDan Williams __weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) 8223340289dSMel Gorman { 8233340289dSMel Gorman return vma_kernel_pagesize(vma); 8243340289dSMel Gorman } 8253340289dSMel Gorman 8263340289dSMel Gorman /* 82784afd99bSAndy Whitcroft * Flags for MAP_PRIVATE reservations. These are stored in the bottom 82884afd99bSAndy Whitcroft * bits of the reservation map pointer, which are always clear due to 82984afd99bSAndy Whitcroft * alignment. 83084afd99bSAndy Whitcroft */ 83184afd99bSAndy Whitcroft #define HPAGE_RESV_OWNER (1UL << 0) 83284afd99bSAndy Whitcroft #define HPAGE_RESV_UNMAPPED (1UL << 1) 83304f2cbe3SMel Gorman #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) 83484afd99bSAndy Whitcroft 835a1e78772SMel Gorman /* 836a1e78772SMel Gorman * These helpers are used to track how many pages are reserved for 837a1e78772SMel Gorman * faults in a MAP_PRIVATE mapping. Only the process that called mmap() 838a1e78772SMel Gorman * is guaranteed to have their future faults succeed. 839a1e78772SMel Gorman * 840a1e78772SMel Gorman * With the exception of reset_vma_resv_huge_pages() which is called at fork(), 841a1e78772SMel Gorman * the reserve counters are updated with the hugetlb_lock held. It is safe 842a1e78772SMel Gorman * to reset the VMA at fork() time as it is not in use yet and there is no 843a1e78772SMel Gorman * chance of the global counters getting corrupted as a result of the values. 84484afd99bSAndy Whitcroft * 84584afd99bSAndy Whitcroft * The private mapping reservation is represented in a subtly different 84684afd99bSAndy Whitcroft * manner to a shared mapping. A shared mapping has a region map associated 84784afd99bSAndy Whitcroft * with the underlying file, this region map represents the backing file 84884afd99bSAndy Whitcroft * pages which have ever had a reservation assigned which this persists even 84984afd99bSAndy Whitcroft * after the page is instantiated. A private mapping has a region map 85084afd99bSAndy Whitcroft * associated with the original mmap which is attached to all VMAs which 85184afd99bSAndy Whitcroft * reference it, this region map represents those offsets which have consumed 85284afd99bSAndy Whitcroft * reservation ie. where pages have been instantiated. 853a1e78772SMel Gorman */ 854e7c4b0bfSAndy Whitcroft static unsigned long get_vma_private_data(struct vm_area_struct *vma) 855e7c4b0bfSAndy Whitcroft { 856e7c4b0bfSAndy Whitcroft return (unsigned long)vma->vm_private_data; 857e7c4b0bfSAndy Whitcroft } 858e7c4b0bfSAndy Whitcroft 859e7c4b0bfSAndy Whitcroft static void set_vma_private_data(struct vm_area_struct *vma, 860e7c4b0bfSAndy Whitcroft unsigned long value) 861e7c4b0bfSAndy Whitcroft { 862e7c4b0bfSAndy Whitcroft vma->vm_private_data = (void *)value; 863e7c4b0bfSAndy Whitcroft } 864e7c4b0bfSAndy Whitcroft 865e9fe92aeSMina Almasry static void 866e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(struct resv_map *resv_map, 867e9fe92aeSMina Almasry struct hugetlb_cgroup *h_cg, 868e9fe92aeSMina Almasry struct hstate *h) 869e9fe92aeSMina Almasry { 870e9fe92aeSMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 871e9fe92aeSMina Almasry if (!h_cg || !h) { 872e9fe92aeSMina Almasry resv_map->reservation_counter = NULL; 873e9fe92aeSMina Almasry resv_map->pages_per_hpage = 0; 874e9fe92aeSMina Almasry resv_map->css = NULL; 875e9fe92aeSMina Almasry } else { 876e9fe92aeSMina Almasry resv_map->reservation_counter = 877e9fe92aeSMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 878e9fe92aeSMina Almasry resv_map->pages_per_hpage = pages_per_huge_page(h); 879e9fe92aeSMina Almasry resv_map->css = &h_cg->css; 880e9fe92aeSMina Almasry } 881e9fe92aeSMina Almasry #endif 882e9fe92aeSMina Almasry } 883e9fe92aeSMina Almasry 8849119a41eSJoonsoo Kim struct resv_map *resv_map_alloc(void) 88584afd99bSAndy Whitcroft { 88684afd99bSAndy Whitcroft struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); 8875e911373SMike Kravetz struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL); 8885e911373SMike Kravetz 8895e911373SMike Kravetz if (!resv_map || !rg) { 8905e911373SMike Kravetz kfree(resv_map); 8915e911373SMike Kravetz kfree(rg); 89284afd99bSAndy Whitcroft return NULL; 8935e911373SMike Kravetz } 89484afd99bSAndy Whitcroft 89584afd99bSAndy Whitcroft kref_init(&resv_map->refs); 8967b24d861SDavidlohr Bueso spin_lock_init(&resv_map->lock); 89784afd99bSAndy Whitcroft INIT_LIST_HEAD(&resv_map->regions); 89884afd99bSAndy Whitcroft 8995e911373SMike Kravetz resv_map->adds_in_progress = 0; 900e9fe92aeSMina Almasry /* 901e9fe92aeSMina Almasry * Initialize these to 0. On shared mappings, 0's here indicate these 902e9fe92aeSMina Almasry * fields don't do cgroup accounting. On private mappings, these will be 903e9fe92aeSMina Almasry * re-initialized to the proper values, to indicate that hugetlb cgroup 904e9fe92aeSMina Almasry * reservations are to be un-charged from here. 905e9fe92aeSMina Almasry */ 906e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, NULL, NULL); 9075e911373SMike Kravetz 9085e911373SMike Kravetz INIT_LIST_HEAD(&resv_map->region_cache); 9095e911373SMike Kravetz list_add(&rg->link, &resv_map->region_cache); 9105e911373SMike Kravetz resv_map->region_cache_count = 1; 9115e911373SMike Kravetz 91284afd99bSAndy Whitcroft return resv_map; 91384afd99bSAndy Whitcroft } 91484afd99bSAndy Whitcroft 9159119a41eSJoonsoo Kim void resv_map_release(struct kref *ref) 91684afd99bSAndy Whitcroft { 91784afd99bSAndy Whitcroft struct resv_map *resv_map = container_of(ref, struct resv_map, refs); 9185e911373SMike Kravetz struct list_head *head = &resv_map->region_cache; 9195e911373SMike Kravetz struct file_region *rg, *trg; 92084afd99bSAndy Whitcroft 92184afd99bSAndy Whitcroft /* Clear out any active regions before we release the map. */ 922feba16e2SMike Kravetz region_del(resv_map, 0, LONG_MAX); 9235e911373SMike Kravetz 9245e911373SMike Kravetz /* ... and any entries left in the cache */ 9255e911373SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 9265e911373SMike Kravetz list_del(&rg->link); 9275e911373SMike Kravetz kfree(rg); 9285e911373SMike Kravetz } 9295e911373SMike Kravetz 9305e911373SMike Kravetz VM_BUG_ON(resv_map->adds_in_progress); 9315e911373SMike Kravetz 93284afd99bSAndy Whitcroft kfree(resv_map); 93384afd99bSAndy Whitcroft } 93484afd99bSAndy Whitcroft 9354e35f483SJoonsoo Kim static inline struct resv_map *inode_resv_map(struct inode *inode) 9364e35f483SJoonsoo Kim { 937f27a5136SMike Kravetz /* 938f27a5136SMike Kravetz * At inode evict time, i_mapping may not point to the original 939f27a5136SMike Kravetz * address space within the inode. This original address space 940f27a5136SMike Kravetz * contains the pointer to the resv_map. So, always use the 941f27a5136SMike Kravetz * address space embedded within the inode. 942f27a5136SMike Kravetz * The VERY common case is inode->mapping == &inode->i_data but, 943f27a5136SMike Kravetz * this may not be true for device special inodes. 944f27a5136SMike Kravetz */ 945f27a5136SMike Kravetz return (struct resv_map *)(&inode->i_data)->private_data; 9464e35f483SJoonsoo Kim } 9474e35f483SJoonsoo Kim 94884afd99bSAndy Whitcroft static struct resv_map *vma_resv_map(struct vm_area_struct *vma) 949a1e78772SMel Gorman { 95081d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 9514e35f483SJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE) { 9524e35f483SJoonsoo Kim struct address_space *mapping = vma->vm_file->f_mapping; 9534e35f483SJoonsoo Kim struct inode *inode = mapping->host; 9544e35f483SJoonsoo Kim 9554e35f483SJoonsoo Kim return inode_resv_map(inode); 9564e35f483SJoonsoo Kim 9574e35f483SJoonsoo Kim } else { 95884afd99bSAndy Whitcroft return (struct resv_map *)(get_vma_private_data(vma) & 95984afd99bSAndy Whitcroft ~HPAGE_RESV_MASK); 9604e35f483SJoonsoo Kim } 961a1e78772SMel Gorman } 962a1e78772SMel Gorman 96384afd99bSAndy Whitcroft static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) 964a1e78772SMel Gorman { 96581d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 96681d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 967a1e78772SMel Gorman 96884afd99bSAndy Whitcroft set_vma_private_data(vma, (get_vma_private_data(vma) & 96984afd99bSAndy Whitcroft HPAGE_RESV_MASK) | (unsigned long)map); 97004f2cbe3SMel Gorman } 97104f2cbe3SMel Gorman 97204f2cbe3SMel Gorman static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) 97304f2cbe3SMel Gorman { 97481d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 97581d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 976e7c4b0bfSAndy Whitcroft 977e7c4b0bfSAndy Whitcroft set_vma_private_data(vma, get_vma_private_data(vma) | flags); 97804f2cbe3SMel Gorman } 97904f2cbe3SMel Gorman 98004f2cbe3SMel Gorman static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) 98104f2cbe3SMel Gorman { 98281d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 983e7c4b0bfSAndy Whitcroft 984e7c4b0bfSAndy Whitcroft return (get_vma_private_data(vma) & flag) != 0; 985a1e78772SMel Gorman } 986a1e78772SMel Gorman 98704f2cbe3SMel Gorman /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ 988a1e78772SMel Gorman void reset_vma_resv_huge_pages(struct vm_area_struct *vma) 989a1e78772SMel Gorman { 99081d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 991f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 992a1e78772SMel Gorman vma->vm_private_data = (void *)0; 993a1e78772SMel Gorman } 994a1e78772SMel Gorman 995a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 996559ec2f8SNicholas Krause static bool vma_has_reserves(struct vm_area_struct *vma, long chg) 997a1e78772SMel Gorman { 998af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_NORESERVE) { 999af0ed73eSJoonsoo Kim /* 1000af0ed73eSJoonsoo Kim * This address is already reserved by other process(chg == 0), 1001af0ed73eSJoonsoo Kim * so, we should decrement reserved count. Without decrementing, 1002af0ed73eSJoonsoo Kim * reserve count remains after releasing inode, because this 1003af0ed73eSJoonsoo Kim * allocated page will go into page cache and is regarded as 1004af0ed73eSJoonsoo Kim * coming from reserved pool in releasing step. Currently, we 1005af0ed73eSJoonsoo Kim * don't have any other solution to deal with this situation 1006af0ed73eSJoonsoo Kim * properly, so add work-around here. 1007af0ed73eSJoonsoo Kim */ 1008af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE && chg == 0) 1009559ec2f8SNicholas Krause return true; 1010af0ed73eSJoonsoo Kim else 1011559ec2f8SNicholas Krause return false; 1012af0ed73eSJoonsoo Kim } 1013a63884e9SJoonsoo Kim 1014a63884e9SJoonsoo Kim /* Shared mappings always use reserves */ 10151fb1b0e9SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 10161fb1b0e9SMike Kravetz /* 10171fb1b0e9SMike Kravetz * We know VM_NORESERVE is not set. Therefore, there SHOULD 10181fb1b0e9SMike Kravetz * be a region map for all pages. The only situation where 10191fb1b0e9SMike Kravetz * there is no region map is if a hole was punched via 10207c8de358SEthon Paul * fallocate. In this case, there really are no reserves to 10211fb1b0e9SMike Kravetz * use. This situation is indicated if chg != 0. 10221fb1b0e9SMike Kravetz */ 10231fb1b0e9SMike Kravetz if (chg) 10241fb1b0e9SMike Kravetz return false; 10251fb1b0e9SMike Kravetz else 1026559ec2f8SNicholas Krause return true; 10271fb1b0e9SMike Kravetz } 1028a63884e9SJoonsoo Kim 1029a63884e9SJoonsoo Kim /* 1030a63884e9SJoonsoo Kim * Only the process that called mmap() has reserves for 1031a63884e9SJoonsoo Kim * private mappings. 1032a63884e9SJoonsoo Kim */ 103367961f9dSMike Kravetz if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 103467961f9dSMike Kravetz /* 103567961f9dSMike Kravetz * Like the shared case above, a hole punch or truncate 103667961f9dSMike Kravetz * could have been performed on the private mapping. 103767961f9dSMike Kravetz * Examine the value of chg to determine if reserves 103867961f9dSMike Kravetz * actually exist or were previously consumed. 103967961f9dSMike Kravetz * Very Subtle - The value of chg comes from a previous 104067961f9dSMike Kravetz * call to vma_needs_reserves(). The reserve map for 104167961f9dSMike Kravetz * private mappings has different (opposite) semantics 104267961f9dSMike Kravetz * than that of shared mappings. vma_needs_reserves() 104367961f9dSMike Kravetz * has already taken this difference in semantics into 104467961f9dSMike Kravetz * account. Therefore, the meaning of chg is the same 104567961f9dSMike Kravetz * as in the shared case above. Code could easily be 104667961f9dSMike Kravetz * combined, but keeping it separate draws attention to 104767961f9dSMike Kravetz * subtle differences. 104867961f9dSMike Kravetz */ 104967961f9dSMike Kravetz if (chg) 105067961f9dSMike Kravetz return false; 105167961f9dSMike Kravetz else 1052559ec2f8SNicholas Krause return true; 105367961f9dSMike Kravetz } 1054a63884e9SJoonsoo Kim 1055559ec2f8SNicholas Krause return false; 1056a1e78772SMel Gorman } 1057a1e78772SMel Gorman 1058a5516438SAndi Kleen static void enqueue_huge_page(struct hstate *h, struct page *page) 10591da177e4SLinus Torvalds { 10601da177e4SLinus Torvalds int nid = page_to_nid(page); 10610edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_freelists[nid]); 1062a5516438SAndi Kleen h->free_huge_pages++; 1063a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 10646c037149SMike Kravetz SetHPageFreed(page); 10651da177e4SLinus Torvalds } 10661da177e4SLinus Torvalds 106794310cbcSAnshuman Khandual static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) 1068bf50bab2SNaoya Horiguchi { 1069bf50bab2SNaoya Horiguchi struct page *page; 1070bbe88753SJoonsoo Kim bool nocma = !!(current->flags & PF_MEMALLOC_NOCMA); 1071bf50bab2SNaoya Horiguchi 1072bbe88753SJoonsoo Kim list_for_each_entry(page, &h->hugepage_freelists[nid], lru) { 1073bbe88753SJoonsoo Kim if (nocma && is_migrate_cma_page(page)) 1074bbe88753SJoonsoo Kim continue; 1075bbe88753SJoonsoo Kim 10766664bfc8SWei Yang if (PageHWPoison(page)) 10776664bfc8SWei Yang continue; 1078bbe88753SJoonsoo Kim 10790edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_activelist); 1080a9869b83SNaoya Horiguchi set_page_refcounted(page); 10816c037149SMike Kravetz ClearHPageFreed(page); 1082bf50bab2SNaoya Horiguchi h->free_huge_pages--; 1083bf50bab2SNaoya Horiguchi h->free_huge_pages_node[nid]--; 1084bf50bab2SNaoya Horiguchi return page; 1085bf50bab2SNaoya Horiguchi } 1086bf50bab2SNaoya Horiguchi 10876664bfc8SWei Yang return NULL; 10886664bfc8SWei Yang } 10896664bfc8SWei Yang 10903e59fcb0SMichal Hocko static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid, 10913e59fcb0SMichal Hocko nodemask_t *nmask) 109294310cbcSAnshuman Khandual { 10933e59fcb0SMichal Hocko unsigned int cpuset_mems_cookie; 10943e59fcb0SMichal Hocko struct zonelist *zonelist; 10953e59fcb0SMichal Hocko struct zone *zone; 10963e59fcb0SMichal Hocko struct zoneref *z; 109798fa15f3SAnshuman Khandual int node = NUMA_NO_NODE; 10983e59fcb0SMichal Hocko 10993e59fcb0SMichal Hocko zonelist = node_zonelist(nid, gfp_mask); 11003e59fcb0SMichal Hocko 11013e59fcb0SMichal Hocko retry_cpuset: 11023e59fcb0SMichal Hocko cpuset_mems_cookie = read_mems_allowed_begin(); 11033e59fcb0SMichal Hocko for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) { 110494310cbcSAnshuman Khandual struct page *page; 110594310cbcSAnshuman Khandual 11063e59fcb0SMichal Hocko if (!cpuset_zone_allowed(zone, gfp_mask)) 11073e59fcb0SMichal Hocko continue; 11083e59fcb0SMichal Hocko /* 11093e59fcb0SMichal Hocko * no need to ask again on the same node. Pool is node rather than 11103e59fcb0SMichal Hocko * zone aware 11113e59fcb0SMichal Hocko */ 11123e59fcb0SMichal Hocko if (zone_to_nid(zone) == node) 11133e59fcb0SMichal Hocko continue; 11143e59fcb0SMichal Hocko node = zone_to_nid(zone); 111594310cbcSAnshuman Khandual 111694310cbcSAnshuman Khandual page = dequeue_huge_page_node_exact(h, node); 111794310cbcSAnshuman Khandual if (page) 111894310cbcSAnshuman Khandual return page; 111994310cbcSAnshuman Khandual } 11203e59fcb0SMichal Hocko if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie))) 11213e59fcb0SMichal Hocko goto retry_cpuset; 11223e59fcb0SMichal Hocko 112394310cbcSAnshuman Khandual return NULL; 112494310cbcSAnshuman Khandual } 112594310cbcSAnshuman Khandual 1126a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 1127a5516438SAndi Kleen struct vm_area_struct *vma, 1128af0ed73eSJoonsoo Kim unsigned long address, int avoid_reserve, 1129af0ed73eSJoonsoo Kim long chg) 11301da177e4SLinus Torvalds { 11313e59fcb0SMichal Hocko struct page *page; 1132480eccf9SLee Schermerhorn struct mempolicy *mpol; 113304ec6264SVlastimil Babka gfp_t gfp_mask; 11343e59fcb0SMichal Hocko nodemask_t *nodemask; 113504ec6264SVlastimil Babka int nid; 11361da177e4SLinus Torvalds 1137a1e78772SMel Gorman /* 1138a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 1139a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 1140a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 1141a1e78772SMel Gorman */ 1142af0ed73eSJoonsoo Kim if (!vma_has_reserves(vma, chg) && 1143a5516438SAndi Kleen h->free_huge_pages - h->resv_huge_pages == 0) 1144c0ff7453SMiao Xie goto err; 1145a1e78772SMel Gorman 114604f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 1147a5516438SAndi Kleen if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) 11486eab04a8SJustin P. Mattock goto err; 114904f2cbe3SMel Gorman 115004ec6264SVlastimil Babka gfp_mask = htlb_alloc_mask(h); 115104ec6264SVlastimil Babka nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 11523e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 11533e59fcb0SMichal Hocko if (page && !avoid_reserve && vma_has_reserves(vma, chg)) { 1154d6995da3SMike Kravetz SetHPageRestoreReserve(page); 1155a63884e9SJoonsoo Kim h->resv_huge_pages--; 1156bf50bab2SNaoya Horiguchi } 1157cc9a6c87SMel Gorman 1158cc9a6c87SMel Gorman mpol_cond_put(mpol); 1159cc9a6c87SMel Gorman return page; 1160cc9a6c87SMel Gorman 1161c0ff7453SMiao Xie err: 1162cc9a6c87SMel Gorman return NULL; 11631da177e4SLinus Torvalds } 11641da177e4SLinus Torvalds 11651cac6f2cSLuiz Capitulino /* 11661cac6f2cSLuiz Capitulino * common helper functions for hstate_next_node_to_{alloc|free}. 11671cac6f2cSLuiz Capitulino * We may have allocated or freed a huge page based on a different 11681cac6f2cSLuiz Capitulino * nodes_allowed previously, so h->next_node_to_{alloc|free} might 11691cac6f2cSLuiz Capitulino * be outside of *nodes_allowed. Ensure that we use an allowed 11701cac6f2cSLuiz Capitulino * node for alloc or free. 11711cac6f2cSLuiz Capitulino */ 11721cac6f2cSLuiz Capitulino static int next_node_allowed(int nid, nodemask_t *nodes_allowed) 11731cac6f2cSLuiz Capitulino { 11740edaf86cSAndrew Morton nid = next_node_in(nid, *nodes_allowed); 11751cac6f2cSLuiz Capitulino VM_BUG_ON(nid >= MAX_NUMNODES); 11761cac6f2cSLuiz Capitulino 11771cac6f2cSLuiz Capitulino return nid; 11781cac6f2cSLuiz Capitulino } 11791cac6f2cSLuiz Capitulino 11801cac6f2cSLuiz Capitulino static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) 11811cac6f2cSLuiz Capitulino { 11821cac6f2cSLuiz Capitulino if (!node_isset(nid, *nodes_allowed)) 11831cac6f2cSLuiz Capitulino nid = next_node_allowed(nid, nodes_allowed); 11841cac6f2cSLuiz Capitulino return nid; 11851cac6f2cSLuiz Capitulino } 11861cac6f2cSLuiz Capitulino 11871cac6f2cSLuiz Capitulino /* 11881cac6f2cSLuiz Capitulino * returns the previously saved node ["this node"] from which to 11891cac6f2cSLuiz Capitulino * allocate a persistent huge page for the pool and advance the 11901cac6f2cSLuiz Capitulino * next node from which to allocate, handling wrap at end of node 11911cac6f2cSLuiz Capitulino * mask. 11921cac6f2cSLuiz Capitulino */ 11931cac6f2cSLuiz Capitulino static int hstate_next_node_to_alloc(struct hstate *h, 11941cac6f2cSLuiz Capitulino nodemask_t *nodes_allowed) 11951cac6f2cSLuiz Capitulino { 11961cac6f2cSLuiz Capitulino int nid; 11971cac6f2cSLuiz Capitulino 11981cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 11991cac6f2cSLuiz Capitulino 12001cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); 12011cac6f2cSLuiz Capitulino h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); 12021cac6f2cSLuiz Capitulino 12031cac6f2cSLuiz Capitulino return nid; 12041cac6f2cSLuiz Capitulino } 12051cac6f2cSLuiz Capitulino 12061cac6f2cSLuiz Capitulino /* 12071cac6f2cSLuiz Capitulino * helper for free_pool_huge_page() - return the previously saved 12081cac6f2cSLuiz Capitulino * node ["this node"] from which to free a huge page. Advance the 12091cac6f2cSLuiz Capitulino * next node id whether or not we find a free huge page to free so 12101cac6f2cSLuiz Capitulino * that the next attempt to free addresses the next node. 12111cac6f2cSLuiz Capitulino */ 12121cac6f2cSLuiz Capitulino static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) 12131cac6f2cSLuiz Capitulino { 12141cac6f2cSLuiz Capitulino int nid; 12151cac6f2cSLuiz Capitulino 12161cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 12171cac6f2cSLuiz Capitulino 12181cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); 12191cac6f2cSLuiz Capitulino h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); 12201cac6f2cSLuiz Capitulino 12211cac6f2cSLuiz Capitulino return nid; 12221cac6f2cSLuiz Capitulino } 12231cac6f2cSLuiz Capitulino 12241cac6f2cSLuiz Capitulino #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ 12251cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 12261cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 12271cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ 12281cac6f2cSLuiz Capitulino nr_nodes--) 12291cac6f2cSLuiz Capitulino 12301cac6f2cSLuiz Capitulino #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ 12311cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 12321cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 12331cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_free(hs, mask)) || 1); \ 12341cac6f2cSLuiz Capitulino nr_nodes--) 12351cac6f2cSLuiz Capitulino 1236e1073d1eSAneesh Kumar K.V #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE 1237944d9fecSLuiz Capitulino static void destroy_compound_gigantic_page(struct page *page, 1238d00181b9SKirill A. Shutemov unsigned int order) 1239944d9fecSLuiz Capitulino { 1240944d9fecSLuiz Capitulino int i; 1241944d9fecSLuiz Capitulino int nr_pages = 1 << order; 1242944d9fecSLuiz Capitulino struct page *p = page + 1; 1243944d9fecSLuiz Capitulino 1244c8cc708aSGerald Schaefer atomic_set(compound_mapcount_ptr(page), 0); 124547e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 124647e29d32SJohn Hubbard 1247944d9fecSLuiz Capitulino for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 12481d798ca3SKirill A. Shutemov clear_compound_head(p); 1249944d9fecSLuiz Capitulino set_page_refcounted(p); 1250944d9fecSLuiz Capitulino } 1251944d9fecSLuiz Capitulino 1252944d9fecSLuiz Capitulino set_compound_order(page, 0); 1253ba9c1201SGerald Schaefer page[1].compound_nr = 0; 1254944d9fecSLuiz Capitulino __ClearPageHead(page); 1255944d9fecSLuiz Capitulino } 1256944d9fecSLuiz Capitulino 1257d00181b9SKirill A. Shutemov static void free_gigantic_page(struct page *page, unsigned int order) 1258944d9fecSLuiz Capitulino { 1259cf11e85fSRoman Gushchin /* 1260cf11e85fSRoman Gushchin * If the page isn't allocated using the cma allocator, 1261cf11e85fSRoman Gushchin * cma_release() returns false. 1262cf11e85fSRoman Gushchin */ 1263dbda8feaSBarry Song #ifdef CONFIG_CMA 1264dbda8feaSBarry Song if (cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order)) 1265cf11e85fSRoman Gushchin return; 1266dbda8feaSBarry Song #endif 1267cf11e85fSRoman Gushchin 1268944d9fecSLuiz Capitulino free_contig_range(page_to_pfn(page), 1 << order); 1269944d9fecSLuiz Capitulino } 1270944d9fecSLuiz Capitulino 12714eb0716eSAlexandre Ghiti #ifdef CONFIG_CONTIG_ALLOC 1272d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 1273d9cc948fSMichal Hocko int nid, nodemask_t *nodemask) 1274944d9fecSLuiz Capitulino { 127504adbc3fSMiaohe Lin unsigned long nr_pages = pages_per_huge_page(h); 1276953f064aSLi Xinhai if (nid == NUMA_NO_NODE) 1277953f064aSLi Xinhai nid = numa_mem_id(); 1278944d9fecSLuiz Capitulino 1279dbda8feaSBarry Song #ifdef CONFIG_CMA 1280dbda8feaSBarry Song { 1281cf11e85fSRoman Gushchin struct page *page; 1282cf11e85fSRoman Gushchin int node; 1283cf11e85fSRoman Gushchin 1284953f064aSLi Xinhai if (hugetlb_cma[nid]) { 1285953f064aSLi Xinhai page = cma_alloc(hugetlb_cma[nid], nr_pages, 1286953f064aSLi Xinhai huge_page_order(h), true); 1287953f064aSLi Xinhai if (page) 1288953f064aSLi Xinhai return page; 1289953f064aSLi Xinhai } 1290953f064aSLi Xinhai 1291953f064aSLi Xinhai if (!(gfp_mask & __GFP_THISNODE)) { 1292cf11e85fSRoman Gushchin for_each_node_mask(node, *nodemask) { 1293953f064aSLi Xinhai if (node == nid || !hugetlb_cma[node]) 1294cf11e85fSRoman Gushchin continue; 1295cf11e85fSRoman Gushchin 1296cf11e85fSRoman Gushchin page = cma_alloc(hugetlb_cma[node], nr_pages, 1297cf11e85fSRoman Gushchin huge_page_order(h), true); 1298cf11e85fSRoman Gushchin if (page) 1299cf11e85fSRoman Gushchin return page; 1300cf11e85fSRoman Gushchin } 1301cf11e85fSRoman Gushchin } 1302953f064aSLi Xinhai } 1303dbda8feaSBarry Song #endif 1304cf11e85fSRoman Gushchin 13055e27a2dfSAnshuman Khandual return alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask); 1306944d9fecSLuiz Capitulino } 1307944d9fecSLuiz Capitulino 1308944d9fecSLuiz Capitulino static void prep_new_huge_page(struct hstate *h, struct page *page, int nid); 1309d00181b9SKirill A. Shutemov static void prep_compound_gigantic_page(struct page *page, unsigned int order); 13104eb0716eSAlexandre Ghiti #else /* !CONFIG_CONTIG_ALLOC */ 13114eb0716eSAlexandre Ghiti static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 13124eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 13134eb0716eSAlexandre Ghiti { 13144eb0716eSAlexandre Ghiti return NULL; 13154eb0716eSAlexandre Ghiti } 13164eb0716eSAlexandre Ghiti #endif /* CONFIG_CONTIG_ALLOC */ 1317944d9fecSLuiz Capitulino 1318e1073d1eSAneesh Kumar K.V #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ 1319d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 13204eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 13214eb0716eSAlexandre Ghiti { 13224eb0716eSAlexandre Ghiti return NULL; 13234eb0716eSAlexandre Ghiti } 1324d00181b9SKirill A. Shutemov static inline void free_gigantic_page(struct page *page, unsigned int order) { } 1325944d9fecSLuiz Capitulino static inline void destroy_compound_gigantic_page(struct page *page, 1326d00181b9SKirill A. Shutemov unsigned int order) { } 1327944d9fecSLuiz Capitulino #endif 1328944d9fecSLuiz Capitulino 1329a5516438SAndi Kleen static void update_and_free_page(struct hstate *h, struct page *page) 13306af2acb6SAdam Litke { 13316af2acb6SAdam Litke int i; 1332dbfee5aeSMike Kravetz struct page *subpage = page; 1333a5516438SAndi Kleen 13344eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 1335944d9fecSLuiz Capitulino return; 133618229df5SAndy Whitcroft 1337a5516438SAndi Kleen h->nr_huge_pages--; 1338a5516438SAndi Kleen h->nr_huge_pages_node[page_to_nid(page)]--; 1339dbfee5aeSMike Kravetz for (i = 0; i < pages_per_huge_page(h); 1340dbfee5aeSMike Kravetz i++, subpage = mem_map_next(subpage, page, i)) { 1341dbfee5aeSMike Kravetz subpage->flags &= ~(1 << PG_locked | 1 << PG_error | 134232f84528SChris Forbes 1 << PG_referenced | 1 << PG_dirty | 1343a7407a27SLuiz Capitulino 1 << PG_active | 1 << PG_private | 1344a7407a27SLuiz Capitulino 1 << PG_writeback); 13456af2acb6SAdam Litke } 1346309381feSSasha Levin VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); 13471adc4d41SMina Almasry VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); 1348f1e61557SKirill A. Shutemov set_compound_page_dtor(page, NULL_COMPOUND_DTOR); 13496af2acb6SAdam Litke set_page_refcounted(page); 1350944d9fecSLuiz Capitulino if (hstate_is_gigantic(h)) { 1351cf11e85fSRoman Gushchin /* 1352cf11e85fSRoman Gushchin * Temporarily drop the hugetlb_lock, because 1353cf11e85fSRoman Gushchin * we might block in free_gigantic_page(). 1354cf11e85fSRoman Gushchin */ 1355cf11e85fSRoman Gushchin spin_unlock(&hugetlb_lock); 1356944d9fecSLuiz Capitulino destroy_compound_gigantic_page(page, huge_page_order(h)); 1357944d9fecSLuiz Capitulino free_gigantic_page(page, huge_page_order(h)); 1358cf11e85fSRoman Gushchin spin_lock(&hugetlb_lock); 1359944d9fecSLuiz Capitulino } else { 1360a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 13616af2acb6SAdam Litke } 1362944d9fecSLuiz Capitulino } 13636af2acb6SAdam Litke 1364e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 1365e5ff2159SAndi Kleen { 1366e5ff2159SAndi Kleen struct hstate *h; 1367e5ff2159SAndi Kleen 1368e5ff2159SAndi Kleen for_each_hstate(h) { 1369e5ff2159SAndi Kleen if (huge_page_size(h) == size) 1370e5ff2159SAndi Kleen return h; 1371e5ff2159SAndi Kleen } 1372e5ff2159SAndi Kleen return NULL; 1373e5ff2159SAndi Kleen } 1374e5ff2159SAndi Kleen 1375c77c0a8aSWaiman Long static void __free_huge_page(struct page *page) 137627a85ef1SDavid Gibson { 1377a5516438SAndi Kleen /* 1378a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 1379a5516438SAndi Kleen * compound page destructor. 1380a5516438SAndi Kleen */ 1381e5ff2159SAndi Kleen struct hstate *h = page_hstate(page); 13827893d1d5SAdam Litke int nid = page_to_nid(page); 1383d6995da3SMike Kravetz struct hugepage_subpool *spool = hugetlb_page_subpool(page); 138407443a85SJoonsoo Kim bool restore_reserve; 138527a85ef1SDavid Gibson 1386b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1387b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_mapcount(page), page); 13888ace22bcSYongkai Wu 1389d6995da3SMike Kravetz hugetlb_set_page_subpool(page, NULL); 13908ace22bcSYongkai Wu page->mapping = NULL; 1391d6995da3SMike Kravetz restore_reserve = HPageRestoreReserve(page); 1392d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 139327a85ef1SDavid Gibson 13941c5ecae3SMike Kravetz /* 1395d6995da3SMike Kravetz * If HPageRestoreReserve was set on page, page allocation consumed a 13960919e1b6SMike Kravetz * reservation. If the page was associated with a subpool, there 13970919e1b6SMike Kravetz * would have been a page reserved in the subpool before allocation 13980919e1b6SMike Kravetz * via hugepage_subpool_get_pages(). Since we are 'restoring' the 13996c26d310SMiaohe Lin * reservation, do not call hugepage_subpool_put_pages() as this will 14000919e1b6SMike Kravetz * remove the reserved page from the subpool. 14010919e1b6SMike Kravetz */ 14020919e1b6SMike Kravetz if (!restore_reserve) { 14030919e1b6SMike Kravetz /* 14040919e1b6SMike Kravetz * A return code of zero implies that the subpool will be 14050919e1b6SMike Kravetz * under its minimum size if the reservation is not restored 14060919e1b6SMike Kravetz * after page is free. Therefore, force restore_reserve 14070919e1b6SMike Kravetz * operation. 14081c5ecae3SMike Kravetz */ 14091c5ecae3SMike Kravetz if (hugepage_subpool_put_pages(spool, 1) == 0) 14101c5ecae3SMike Kravetz restore_reserve = true; 14110919e1b6SMike Kravetz } 14121c5ecae3SMike Kravetz 141327a85ef1SDavid Gibson spin_lock(&hugetlb_lock); 14148f251a3dSMike Kravetz ClearHPageMigratable(page); 14156d76dcf4SAneesh Kumar K.V hugetlb_cgroup_uncharge_page(hstate_index(h), 14166d76dcf4SAneesh Kumar K.V pages_per_huge_page(h), page); 141708cf9fafSMina Almasry hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 141808cf9fafSMina Almasry pages_per_huge_page(h), page); 141907443a85SJoonsoo Kim if (restore_reserve) 142007443a85SJoonsoo Kim h->resv_huge_pages++; 142107443a85SJoonsoo Kim 14229157c311SMike Kravetz if (HPageTemporary(page)) { 1423ab5ac90aSMichal Hocko list_del(&page->lru); 14249157c311SMike Kravetz ClearHPageTemporary(page); 1425ab5ac90aSMichal Hocko update_and_free_page(h, page); 1426ab5ac90aSMichal Hocko } else if (h->surplus_huge_pages_node[nid]) { 14270edaecfaSAneesh Kumar K.V /* remove the page from active list */ 14280edaecfaSAneesh Kumar K.V list_del(&page->lru); 1429a5516438SAndi Kleen update_and_free_page(h, page); 1430a5516438SAndi Kleen h->surplus_huge_pages--; 1431a5516438SAndi Kleen h->surplus_huge_pages_node[nid]--; 14327893d1d5SAdam Litke } else { 14335d3a551cSWill Deacon arch_clear_hugepage_flags(page); 1434a5516438SAndi Kleen enqueue_huge_page(h, page); 14357893d1d5SAdam Litke } 143627a85ef1SDavid Gibson spin_unlock(&hugetlb_lock); 143727a85ef1SDavid Gibson } 143827a85ef1SDavid Gibson 1439c77c0a8aSWaiman Long /* 1440c77c0a8aSWaiman Long * As free_huge_page() can be called from a non-task context, we have 1441c77c0a8aSWaiman Long * to defer the actual freeing in a workqueue to prevent potential 1442c77c0a8aSWaiman Long * hugetlb_lock deadlock. 1443c77c0a8aSWaiman Long * 1444c77c0a8aSWaiman Long * free_hpage_workfn() locklessly retrieves the linked list of pages to 1445c77c0a8aSWaiman Long * be freed and frees them one-by-one. As the page->mapping pointer is 1446c77c0a8aSWaiman Long * going to be cleared in __free_huge_page() anyway, it is reused as the 1447c77c0a8aSWaiman Long * llist_node structure of a lockless linked list of huge pages to be freed. 1448c77c0a8aSWaiman Long */ 1449c77c0a8aSWaiman Long static LLIST_HEAD(hpage_freelist); 1450c77c0a8aSWaiman Long 1451c77c0a8aSWaiman Long static void free_hpage_workfn(struct work_struct *work) 1452c77c0a8aSWaiman Long { 1453c77c0a8aSWaiman Long struct llist_node *node; 1454c77c0a8aSWaiman Long struct page *page; 1455c77c0a8aSWaiman Long 1456c77c0a8aSWaiman Long node = llist_del_all(&hpage_freelist); 1457c77c0a8aSWaiman Long 1458c77c0a8aSWaiman Long while (node) { 1459c77c0a8aSWaiman Long page = container_of((struct address_space **)node, 1460c77c0a8aSWaiman Long struct page, mapping); 1461c77c0a8aSWaiman Long node = node->next; 1462c77c0a8aSWaiman Long __free_huge_page(page); 1463c77c0a8aSWaiman Long } 1464c77c0a8aSWaiman Long } 1465c77c0a8aSWaiman Long static DECLARE_WORK(free_hpage_work, free_hpage_workfn); 1466c77c0a8aSWaiman Long 1467c77c0a8aSWaiman Long void free_huge_page(struct page *page) 1468c77c0a8aSWaiman Long { 1469c77c0a8aSWaiman Long /* 1470c77c0a8aSWaiman Long * Defer freeing if in non-task context to avoid hugetlb_lock deadlock. 1471c77c0a8aSWaiman Long */ 1472c77c0a8aSWaiman Long if (!in_task()) { 1473c77c0a8aSWaiman Long /* 1474c77c0a8aSWaiman Long * Only call schedule_work() if hpage_freelist is previously 1475c77c0a8aSWaiman Long * empty. Otherwise, schedule_work() had been called but the 1476c77c0a8aSWaiman Long * workfn hasn't retrieved the list yet. 1477c77c0a8aSWaiman Long */ 1478c77c0a8aSWaiman Long if (llist_add((struct llist_node *)&page->mapping, 1479c77c0a8aSWaiman Long &hpage_freelist)) 1480c77c0a8aSWaiman Long schedule_work(&free_hpage_work); 1481c77c0a8aSWaiman Long return; 1482c77c0a8aSWaiman Long } 1483c77c0a8aSWaiman Long 1484c77c0a8aSWaiman Long __free_huge_page(page); 1485c77c0a8aSWaiman Long } 1486c77c0a8aSWaiman Long 1487a5516438SAndi Kleen static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) 1488b7ba30c6SAndi Kleen { 14890edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&page->lru); 1490f1e61557SKirill A. Shutemov set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1491ff546117SMike Kravetz hugetlb_set_page_subpool(page, NULL); 14929dd540e2SAneesh Kumar K.V set_hugetlb_cgroup(page, NULL); 14931adc4d41SMina Almasry set_hugetlb_cgroup_rsvd(page, NULL); 14942f37511cSWei Yang spin_lock(&hugetlb_lock); 1495a5516438SAndi Kleen h->nr_huge_pages++; 1496a5516438SAndi Kleen h->nr_huge_pages_node[nid]++; 14976c037149SMike Kravetz ClearHPageFreed(page); 1498b7ba30c6SAndi Kleen spin_unlock(&hugetlb_lock); 1499b7ba30c6SAndi Kleen } 1500b7ba30c6SAndi Kleen 1501d00181b9SKirill A. Shutemov static void prep_compound_gigantic_page(struct page *page, unsigned int order) 150220a0307cSWu Fengguang { 150320a0307cSWu Fengguang int i; 150420a0307cSWu Fengguang int nr_pages = 1 << order; 150520a0307cSWu Fengguang struct page *p = page + 1; 150620a0307cSWu Fengguang 150720a0307cSWu Fengguang /* we rely on prep_new_huge_page to set the destructor */ 150820a0307cSWu Fengguang set_compound_order(page, order); 1509ef5a22beSAndrea Arcangeli __ClearPageReserved(page); 1510de09d31dSKirill A. Shutemov __SetPageHead(page); 151120a0307cSWu Fengguang for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 1512ef5a22beSAndrea Arcangeli /* 1513ef5a22beSAndrea Arcangeli * For gigantic hugepages allocated through bootmem at 1514ef5a22beSAndrea Arcangeli * boot, it's safer to be consistent with the not-gigantic 1515ef5a22beSAndrea Arcangeli * hugepages and clear the PG_reserved bit from all tail pages 15167c8de358SEthon Paul * too. Otherwise drivers using get_user_pages() to access tail 1517ef5a22beSAndrea Arcangeli * pages may get the reference counting wrong if they see 1518ef5a22beSAndrea Arcangeli * PG_reserved set on a tail page (despite the head page not 1519ef5a22beSAndrea Arcangeli * having PG_reserved set). Enforcing this consistency between 1520ef5a22beSAndrea Arcangeli * head and tail pages allows drivers to optimize away a check 1521ef5a22beSAndrea Arcangeli * on the head page when they need know if put_page() is needed 1522ef5a22beSAndrea Arcangeli * after get_user_pages(). 1523ef5a22beSAndrea Arcangeli */ 1524ef5a22beSAndrea Arcangeli __ClearPageReserved(p); 152558a84aa9SYouquan Song set_page_count(p, 0); 15261d798ca3SKirill A. Shutemov set_compound_head(p, page); 152720a0307cSWu Fengguang } 1528b4330afbSMike Kravetz atomic_set(compound_mapcount_ptr(page), -1); 152947e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 153020a0307cSWu Fengguang } 153120a0307cSWu Fengguang 15327795912cSAndrew Morton /* 15337795912cSAndrew Morton * PageHuge() only returns true for hugetlbfs pages, but not for normal or 15347795912cSAndrew Morton * transparent huge pages. See the PageTransHuge() documentation for more 15357795912cSAndrew Morton * details. 15367795912cSAndrew Morton */ 153720a0307cSWu Fengguang int PageHuge(struct page *page) 153820a0307cSWu Fengguang { 153920a0307cSWu Fengguang if (!PageCompound(page)) 154020a0307cSWu Fengguang return 0; 154120a0307cSWu Fengguang 154220a0307cSWu Fengguang page = compound_head(page); 1543f1e61557SKirill A. Shutemov return page[1].compound_dtor == HUGETLB_PAGE_DTOR; 154420a0307cSWu Fengguang } 154543131e14SNaoya Horiguchi EXPORT_SYMBOL_GPL(PageHuge); 154643131e14SNaoya Horiguchi 154727c73ae7SAndrea Arcangeli /* 154827c73ae7SAndrea Arcangeli * PageHeadHuge() only returns true for hugetlbfs head page, but not for 154927c73ae7SAndrea Arcangeli * normal or transparent huge pages. 155027c73ae7SAndrea Arcangeli */ 155127c73ae7SAndrea Arcangeli int PageHeadHuge(struct page *page_head) 155227c73ae7SAndrea Arcangeli { 155327c73ae7SAndrea Arcangeli if (!PageHead(page_head)) 155427c73ae7SAndrea Arcangeli return 0; 155527c73ae7SAndrea Arcangeli 1556d4af73e3SVlastimil Babka return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR; 155727c73ae7SAndrea Arcangeli } 155827c73ae7SAndrea Arcangeli 1559c0d0381aSMike Kravetz /* 1560c0d0381aSMike Kravetz * Find and lock address space (mapping) in write mode. 1561c0d0381aSMike Kravetz * 1562336bf30eSMike Kravetz * Upon entry, the page is locked which means that page_mapping() is 1563336bf30eSMike Kravetz * stable. Due to locking order, we can only trylock_write. If we can 1564336bf30eSMike Kravetz * not get the lock, simply return NULL to caller. 1565c0d0381aSMike Kravetz */ 1566c0d0381aSMike Kravetz struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage) 1567c0d0381aSMike Kravetz { 1568336bf30eSMike Kravetz struct address_space *mapping = page_mapping(hpage); 1569c0d0381aSMike Kravetz 1570c0d0381aSMike Kravetz if (!mapping) 1571c0d0381aSMike Kravetz return mapping; 1572c0d0381aSMike Kravetz 1573c0d0381aSMike Kravetz if (i_mmap_trylock_write(mapping)) 1574c0d0381aSMike Kravetz return mapping; 1575c0d0381aSMike Kravetz 1576c0d0381aSMike Kravetz return NULL; 1577c0d0381aSMike Kravetz } 1578c0d0381aSMike Kravetz 157913d60f4bSZhang Yi pgoff_t __basepage_index(struct page *page) 158013d60f4bSZhang Yi { 158113d60f4bSZhang Yi struct page *page_head = compound_head(page); 158213d60f4bSZhang Yi pgoff_t index = page_index(page_head); 158313d60f4bSZhang Yi unsigned long compound_idx; 158413d60f4bSZhang Yi 158513d60f4bSZhang Yi if (!PageHuge(page_head)) 158613d60f4bSZhang Yi return page_index(page); 158713d60f4bSZhang Yi 158813d60f4bSZhang Yi if (compound_order(page_head) >= MAX_ORDER) 158913d60f4bSZhang Yi compound_idx = page_to_pfn(page) - page_to_pfn(page_head); 159013d60f4bSZhang Yi else 159113d60f4bSZhang Yi compound_idx = page - page_head; 159213d60f4bSZhang Yi 159313d60f4bSZhang Yi return (index << compound_order(page_head)) + compound_idx; 159413d60f4bSZhang Yi } 159513d60f4bSZhang Yi 15960c397daeSMichal Hocko static struct page *alloc_buddy_huge_page(struct hstate *h, 1597f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1598f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 15991da177e4SLinus Torvalds { 1600af0fb9dfSMichal Hocko int order = huge_page_order(h); 16011da177e4SLinus Torvalds struct page *page; 1602f60858f9SMike Kravetz bool alloc_try_hard = true; 1603f96efd58SJoe Jin 1604f60858f9SMike Kravetz /* 1605f60858f9SMike Kravetz * By default we always try hard to allocate the page with 1606f60858f9SMike Kravetz * __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in 1607f60858f9SMike Kravetz * a loop (to adjust global huge page counts) and previous allocation 1608f60858f9SMike Kravetz * failed, do not continue to try hard on the same node. Use the 1609f60858f9SMike Kravetz * node_alloc_noretry bitmap to manage this state information. 1610f60858f9SMike Kravetz */ 1611f60858f9SMike Kravetz if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry)) 1612f60858f9SMike Kravetz alloc_try_hard = false; 1613f60858f9SMike Kravetz gfp_mask |= __GFP_COMP|__GFP_NOWARN; 1614f60858f9SMike Kravetz if (alloc_try_hard) 1615f60858f9SMike Kravetz gfp_mask |= __GFP_RETRY_MAYFAIL; 1616af0fb9dfSMichal Hocko if (nid == NUMA_NO_NODE) 1617af0fb9dfSMichal Hocko nid = numa_mem_id(); 161884172f4bSMatthew Wilcox (Oracle) page = __alloc_pages(gfp_mask, order, nid, nmask); 1619af0fb9dfSMichal Hocko if (page) 1620af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC); 1621af0fb9dfSMichal Hocko else 1622af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 162363b4613cSNishanth Aravamudan 1624f60858f9SMike Kravetz /* 1625f60858f9SMike Kravetz * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this 1626f60858f9SMike Kravetz * indicates an overall state change. Clear bit so that we resume 1627f60858f9SMike Kravetz * normal 'try hard' allocations. 1628f60858f9SMike Kravetz */ 1629f60858f9SMike Kravetz if (node_alloc_noretry && page && !alloc_try_hard) 1630f60858f9SMike Kravetz node_clear(nid, *node_alloc_noretry); 1631f60858f9SMike Kravetz 1632f60858f9SMike Kravetz /* 1633f60858f9SMike Kravetz * If we tried hard to get a page but failed, set bit so that 1634f60858f9SMike Kravetz * subsequent attempts will not try as hard until there is an 1635f60858f9SMike Kravetz * overall state change. 1636f60858f9SMike Kravetz */ 1637f60858f9SMike Kravetz if (node_alloc_noretry && !page && alloc_try_hard) 1638f60858f9SMike Kravetz node_set(nid, *node_alloc_noretry); 1639f60858f9SMike Kravetz 164063b4613cSNishanth Aravamudan return page; 164163b4613cSNishanth Aravamudan } 164263b4613cSNishanth Aravamudan 1643af0fb9dfSMichal Hocko /* 16440c397daeSMichal Hocko * Common helper to allocate a fresh hugetlb page. All specific allocators 16450c397daeSMichal Hocko * should use this function to get new hugetlb pages 16460c397daeSMichal Hocko */ 16470c397daeSMichal Hocko static struct page *alloc_fresh_huge_page(struct hstate *h, 1648f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1649f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 16500c397daeSMichal Hocko { 16510c397daeSMichal Hocko struct page *page; 16520c397daeSMichal Hocko 16530c397daeSMichal Hocko if (hstate_is_gigantic(h)) 16540c397daeSMichal Hocko page = alloc_gigantic_page(h, gfp_mask, nid, nmask); 16550c397daeSMichal Hocko else 16560c397daeSMichal Hocko page = alloc_buddy_huge_page(h, gfp_mask, 1657f60858f9SMike Kravetz nid, nmask, node_alloc_noretry); 16580c397daeSMichal Hocko if (!page) 16590c397daeSMichal Hocko return NULL; 16600c397daeSMichal Hocko 16610c397daeSMichal Hocko if (hstate_is_gigantic(h)) 16620c397daeSMichal Hocko prep_compound_gigantic_page(page, huge_page_order(h)); 16630c397daeSMichal Hocko prep_new_huge_page(h, page, page_to_nid(page)); 16640c397daeSMichal Hocko 16650c397daeSMichal Hocko return page; 16660c397daeSMichal Hocko } 16670c397daeSMichal Hocko 16680c397daeSMichal Hocko /* 1669af0fb9dfSMichal Hocko * Allocates a fresh page to the hugetlb allocator pool in the node interleaved 1670af0fb9dfSMichal Hocko * manner. 1671af0fb9dfSMichal Hocko */ 1672f60858f9SMike Kravetz static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 1673f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 1674b2261026SJoonsoo Kim { 1675b2261026SJoonsoo Kim struct page *page; 1676b2261026SJoonsoo Kim int nr_nodes, node; 1677af0fb9dfSMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 1678b2261026SJoonsoo Kim 1679b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 1680f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed, 1681f60858f9SMike Kravetz node_alloc_noretry); 1682af0fb9dfSMichal Hocko if (page) 1683b2261026SJoonsoo Kim break; 1684b2261026SJoonsoo Kim } 1685b2261026SJoonsoo Kim 1686af0fb9dfSMichal Hocko if (!page) 1687af0fb9dfSMichal Hocko return 0; 1688b2261026SJoonsoo Kim 1689af0fb9dfSMichal Hocko put_page(page); /* free it into the hugepage allocator */ 1690af0fb9dfSMichal Hocko 1691af0fb9dfSMichal Hocko return 1; 1692b2261026SJoonsoo Kim } 1693b2261026SJoonsoo Kim 1694e8c5c824SLee Schermerhorn /* 1695e8c5c824SLee Schermerhorn * Free huge page from pool from next node to free. 1696e8c5c824SLee Schermerhorn * Attempt to keep persistent huge pages more or less 1697e8c5c824SLee Schermerhorn * balanced over allowed nodes. 1698e8c5c824SLee Schermerhorn * Called with hugetlb_lock locked. 1699e8c5c824SLee Schermerhorn */ 17006ae11b27SLee Schermerhorn static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 17016ae11b27SLee Schermerhorn bool acct_surplus) 1702e8c5c824SLee Schermerhorn { 1703b2261026SJoonsoo Kim int nr_nodes, node; 1704e8c5c824SLee Schermerhorn int ret = 0; 1705e8c5c824SLee Schermerhorn 1706b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 1707685f3457SLee Schermerhorn /* 1708685f3457SLee Schermerhorn * If we're returning unused surplus pages, only examine 1709685f3457SLee Schermerhorn * nodes with surplus pages. 1710685f3457SLee Schermerhorn */ 1711b2261026SJoonsoo Kim if ((!acct_surplus || h->surplus_huge_pages_node[node]) && 1712b2261026SJoonsoo Kim !list_empty(&h->hugepage_freelists[node])) { 1713e8c5c824SLee Schermerhorn struct page *page = 1714b2261026SJoonsoo Kim list_entry(h->hugepage_freelists[node].next, 1715e8c5c824SLee Schermerhorn struct page, lru); 1716e8c5c824SLee Schermerhorn list_del(&page->lru); 1717e8c5c824SLee Schermerhorn h->free_huge_pages--; 1718b2261026SJoonsoo Kim h->free_huge_pages_node[node]--; 1719685f3457SLee Schermerhorn if (acct_surplus) { 1720685f3457SLee Schermerhorn h->surplus_huge_pages--; 1721b2261026SJoonsoo Kim h->surplus_huge_pages_node[node]--; 1722685f3457SLee Schermerhorn } 1723e8c5c824SLee Schermerhorn update_and_free_page(h, page); 1724e8c5c824SLee Schermerhorn ret = 1; 17259a76db09SLee Schermerhorn break; 1726e8c5c824SLee Schermerhorn } 1727b2261026SJoonsoo Kim } 1728e8c5c824SLee Schermerhorn 1729e8c5c824SLee Schermerhorn return ret; 1730e8c5c824SLee Schermerhorn } 1731e8c5c824SLee Schermerhorn 1732c8721bbbSNaoya Horiguchi /* 1733c8721bbbSNaoya Horiguchi * Dissolve a given free hugepage into free buddy pages. This function does 1734faf53defSNaoya Horiguchi * nothing for in-use hugepages and non-hugepages. 1735faf53defSNaoya Horiguchi * This function returns values like below: 1736faf53defSNaoya Horiguchi * 1737faf53defSNaoya Horiguchi * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use 1738faf53defSNaoya Horiguchi * (allocated or reserved.) 1739faf53defSNaoya Horiguchi * 0: successfully dissolved free hugepages or the page is not a 1740faf53defSNaoya Horiguchi * hugepage (considered as already dissolved) 1741c8721bbbSNaoya Horiguchi */ 1742c3114a84SAnshuman Khandual int dissolve_free_huge_page(struct page *page) 1743c8721bbbSNaoya Horiguchi { 17446bc9b564SNaoya Horiguchi int rc = -EBUSY; 1745082d5b6bSGerald Schaefer 17467ffddd49SMuchun Song retry: 1747faf53defSNaoya Horiguchi /* Not to disrupt normal path by vainly holding hugetlb_lock */ 1748faf53defSNaoya Horiguchi if (!PageHuge(page)) 1749faf53defSNaoya Horiguchi return 0; 1750faf53defSNaoya Horiguchi 1751c8721bbbSNaoya Horiguchi spin_lock(&hugetlb_lock); 1752faf53defSNaoya Horiguchi if (!PageHuge(page)) { 1753faf53defSNaoya Horiguchi rc = 0; 1754faf53defSNaoya Horiguchi goto out; 1755faf53defSNaoya Horiguchi } 1756faf53defSNaoya Horiguchi 1757faf53defSNaoya Horiguchi if (!page_count(page)) { 17582247bb33SGerald Schaefer struct page *head = compound_head(page); 17592247bb33SGerald Schaefer struct hstate *h = page_hstate(head); 17602247bb33SGerald Schaefer int nid = page_to_nid(head); 17616bc9b564SNaoya Horiguchi if (h->free_huge_pages - h->resv_huge_pages == 0) 1762082d5b6bSGerald Schaefer goto out; 17637ffddd49SMuchun Song 17647ffddd49SMuchun Song /* 17657ffddd49SMuchun Song * We should make sure that the page is already on the free list 17667ffddd49SMuchun Song * when it is dissolved. 17677ffddd49SMuchun Song */ 17686c037149SMike Kravetz if (unlikely(!HPageFreed(head))) { 17697ffddd49SMuchun Song spin_unlock(&hugetlb_lock); 17707ffddd49SMuchun Song cond_resched(); 17717ffddd49SMuchun Song 17727ffddd49SMuchun Song /* 17737ffddd49SMuchun Song * Theoretically, we should return -EBUSY when we 17747ffddd49SMuchun Song * encounter this race. In fact, we have a chance 17757ffddd49SMuchun Song * to successfully dissolve the page if we do a 17767ffddd49SMuchun Song * retry. Because the race window is quite small. 17777ffddd49SMuchun Song * If we seize this opportunity, it is an optimization 17787ffddd49SMuchun Song * for increasing the success rate of dissolving page. 17797ffddd49SMuchun Song */ 17807ffddd49SMuchun Song goto retry; 17817ffddd49SMuchun Song } 17827ffddd49SMuchun Song 1783c3114a84SAnshuman Khandual /* 1784c3114a84SAnshuman Khandual * Move PageHWPoison flag from head page to the raw error page, 1785c3114a84SAnshuman Khandual * which makes any subpages rather than the error page reusable. 1786c3114a84SAnshuman Khandual */ 1787c3114a84SAnshuman Khandual if (PageHWPoison(head) && page != head) { 1788c3114a84SAnshuman Khandual SetPageHWPoison(page); 1789c3114a84SAnshuman Khandual ClearPageHWPoison(head); 1790c3114a84SAnshuman Khandual } 17912247bb33SGerald Schaefer list_del(&head->lru); 1792c8721bbbSNaoya Horiguchi h->free_huge_pages--; 1793c8721bbbSNaoya Horiguchi h->free_huge_pages_node[nid]--; 1794c1470b33Szhong jiang h->max_huge_pages--; 17952247bb33SGerald Schaefer update_and_free_page(h, head); 17966bc9b564SNaoya Horiguchi rc = 0; 1797c8721bbbSNaoya Horiguchi } 1798082d5b6bSGerald Schaefer out: 1799c8721bbbSNaoya Horiguchi spin_unlock(&hugetlb_lock); 1800082d5b6bSGerald Schaefer return rc; 1801c8721bbbSNaoya Horiguchi } 1802c8721bbbSNaoya Horiguchi 1803c8721bbbSNaoya Horiguchi /* 1804c8721bbbSNaoya Horiguchi * Dissolve free hugepages in a given pfn range. Used by memory hotplug to 1805c8721bbbSNaoya Horiguchi * make specified memory blocks removable from the system. 18062247bb33SGerald Schaefer * Note that this will dissolve a free gigantic hugepage completely, if any 18072247bb33SGerald Schaefer * part of it lies within the given range. 1808082d5b6bSGerald Schaefer * Also note that if dissolve_free_huge_page() returns with an error, all 1809082d5b6bSGerald Schaefer * free hugepages that were dissolved before that error are lost. 1810c8721bbbSNaoya Horiguchi */ 1811082d5b6bSGerald Schaefer int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) 1812c8721bbbSNaoya Horiguchi { 1813c8721bbbSNaoya Horiguchi unsigned long pfn; 1814eb03aa00SGerald Schaefer struct page *page; 1815082d5b6bSGerald Schaefer int rc = 0; 1816c8721bbbSNaoya Horiguchi 1817d0177639SLi Zhong if (!hugepages_supported()) 1818082d5b6bSGerald Schaefer return rc; 1819d0177639SLi Zhong 1820eb03aa00SGerald Schaefer for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) { 1821eb03aa00SGerald Schaefer page = pfn_to_page(pfn); 1822eb03aa00SGerald Schaefer rc = dissolve_free_huge_page(page); 1823eb03aa00SGerald Schaefer if (rc) 1824082d5b6bSGerald Schaefer break; 1825eb03aa00SGerald Schaefer } 1826082d5b6bSGerald Schaefer 1827082d5b6bSGerald Schaefer return rc; 1828c8721bbbSNaoya Horiguchi } 1829c8721bbbSNaoya Horiguchi 1830ab5ac90aSMichal Hocko /* 1831ab5ac90aSMichal Hocko * Allocates a fresh surplus page from the page allocator. 1832ab5ac90aSMichal Hocko */ 18330c397daeSMichal Hocko static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, 1834aaf14e40SMichal Hocko int nid, nodemask_t *nmask) 18357893d1d5SAdam Litke { 18369980d744SMichal Hocko struct page *page = NULL; 18377893d1d5SAdam Litke 1838bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 1839aa888a74SAndi Kleen return NULL; 1840aa888a74SAndi Kleen 1841d1c3fb1fSNishanth Aravamudan spin_lock(&hugetlb_lock); 18429980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) 18439980d744SMichal Hocko goto out_unlock; 1844d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 1845d1c3fb1fSNishanth Aravamudan 1846f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 18479980d744SMichal Hocko if (!page) 18480c397daeSMichal Hocko return NULL; 1849d1c3fb1fSNishanth Aravamudan 18507893d1d5SAdam Litke spin_lock(&hugetlb_lock); 18519980d744SMichal Hocko /* 18529980d744SMichal Hocko * We could have raced with the pool size change. 18539980d744SMichal Hocko * Double check that and simply deallocate the new page 18549980d744SMichal Hocko * if we would end up overcommiting the surpluses. Abuse 18559980d744SMichal Hocko * temporary page to workaround the nasty free_huge_page 18569980d744SMichal Hocko * codeflow 18579980d744SMichal Hocko */ 18589980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 18599157c311SMike Kravetz SetHPageTemporary(page); 18602bf753e6SKai Shen spin_unlock(&hugetlb_lock); 18619980d744SMichal Hocko put_page(page); 18622bf753e6SKai Shen return NULL; 18639980d744SMichal Hocko } else { 18649980d744SMichal Hocko h->surplus_huge_pages++; 18654704dea3SMichal Hocko h->surplus_huge_pages_node[page_to_nid(page)]++; 18667893d1d5SAdam Litke } 18679980d744SMichal Hocko 18689980d744SMichal Hocko out_unlock: 1869d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 18707893d1d5SAdam Litke 18717893d1d5SAdam Litke return page; 18727893d1d5SAdam Litke } 18737893d1d5SAdam Litke 1874bbe88753SJoonsoo Kim static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, 1875ab5ac90aSMichal Hocko int nid, nodemask_t *nmask) 1876ab5ac90aSMichal Hocko { 1877ab5ac90aSMichal Hocko struct page *page; 1878ab5ac90aSMichal Hocko 1879ab5ac90aSMichal Hocko if (hstate_is_gigantic(h)) 1880ab5ac90aSMichal Hocko return NULL; 1881ab5ac90aSMichal Hocko 1882f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 1883ab5ac90aSMichal Hocko if (!page) 1884ab5ac90aSMichal Hocko return NULL; 1885ab5ac90aSMichal Hocko 1886ab5ac90aSMichal Hocko /* 1887ab5ac90aSMichal Hocko * We do not account these pages as surplus because they are only 1888ab5ac90aSMichal Hocko * temporary and will be released properly on the last reference 1889ab5ac90aSMichal Hocko */ 18909157c311SMike Kravetz SetHPageTemporary(page); 1891ab5ac90aSMichal Hocko 1892ab5ac90aSMichal Hocko return page; 1893ab5ac90aSMichal Hocko } 1894ab5ac90aSMichal Hocko 1895e4e574b7SAdam Litke /* 1896099730d6SDave Hansen * Use the VMA's mpolicy to allocate a huge page from the buddy. 1897099730d6SDave Hansen */ 1898e0ec90eeSDave Hansen static 18990c397daeSMichal Hocko struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h, 1900099730d6SDave Hansen struct vm_area_struct *vma, unsigned long addr) 1901099730d6SDave Hansen { 1902aaf14e40SMichal Hocko struct page *page; 1903aaf14e40SMichal Hocko struct mempolicy *mpol; 1904aaf14e40SMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h); 1905aaf14e40SMichal Hocko int nid; 1906aaf14e40SMichal Hocko nodemask_t *nodemask; 1907aaf14e40SMichal Hocko 1908aaf14e40SMichal Hocko nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); 19090c397daeSMichal Hocko page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask); 1910aaf14e40SMichal Hocko mpol_cond_put(mpol); 1911aaf14e40SMichal Hocko 1912aaf14e40SMichal Hocko return page; 1913099730d6SDave Hansen } 1914099730d6SDave Hansen 1915ab5ac90aSMichal Hocko /* page migration callback function */ 19163e59fcb0SMichal Hocko struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, 1917d92bbc27SJoonsoo Kim nodemask_t *nmask, gfp_t gfp_mask) 19184db9b2efSMichal Hocko { 19194db9b2efSMichal Hocko spin_lock(&hugetlb_lock); 19204db9b2efSMichal Hocko if (h->free_huge_pages - h->resv_huge_pages > 0) { 19213e59fcb0SMichal Hocko struct page *page; 19223e59fcb0SMichal Hocko 19233e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask); 19243e59fcb0SMichal Hocko if (page) { 19253e59fcb0SMichal Hocko spin_unlock(&hugetlb_lock); 19263e59fcb0SMichal Hocko return page; 19274db9b2efSMichal Hocko } 19284db9b2efSMichal Hocko } 19294db9b2efSMichal Hocko spin_unlock(&hugetlb_lock); 19304db9b2efSMichal Hocko 19310c397daeSMichal Hocko return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask); 19324db9b2efSMichal Hocko } 19334db9b2efSMichal Hocko 1934ebd63723SMichal Hocko /* mempolicy aware migration callback */ 1935389c8178SMichal Hocko struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, 1936389c8178SMichal Hocko unsigned long address) 1937ebd63723SMichal Hocko { 1938ebd63723SMichal Hocko struct mempolicy *mpol; 1939ebd63723SMichal Hocko nodemask_t *nodemask; 1940ebd63723SMichal Hocko struct page *page; 1941ebd63723SMichal Hocko gfp_t gfp_mask; 1942ebd63723SMichal Hocko int node; 1943ebd63723SMichal Hocko 1944ebd63723SMichal Hocko gfp_mask = htlb_alloc_mask(h); 1945ebd63723SMichal Hocko node = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 1946d92bbc27SJoonsoo Kim page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask); 1947ebd63723SMichal Hocko mpol_cond_put(mpol); 1948ebd63723SMichal Hocko 1949ebd63723SMichal Hocko return page; 1950ebd63723SMichal Hocko } 1951ebd63723SMichal Hocko 1952bf50bab2SNaoya Horiguchi /* 195325985edcSLucas De Marchi * Increase the hugetlb pool such that it can accommodate a reservation 1954e4e574b7SAdam Litke * of size 'delta'. 1955e4e574b7SAdam Litke */ 19560a4f3d1bSLiu Xiang static int gather_surplus_pages(struct hstate *h, long delta) 19571b2a1e7bSJules Irenge __must_hold(&hugetlb_lock) 1958e4e574b7SAdam Litke { 1959e4e574b7SAdam Litke struct list_head surplus_list; 1960e4e574b7SAdam Litke struct page *page, *tmp; 19610a4f3d1bSLiu Xiang int ret; 19620a4f3d1bSLiu Xiang long i; 19630a4f3d1bSLiu Xiang long needed, allocated; 196428073b02SHillf Danton bool alloc_ok = true; 1965e4e574b7SAdam Litke 1966a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 1967ac09b3a1SAdam Litke if (needed <= 0) { 1968a5516438SAndi Kleen h->resv_huge_pages += delta; 1969e4e574b7SAdam Litke return 0; 1970ac09b3a1SAdam Litke } 1971e4e574b7SAdam Litke 1972e4e574b7SAdam Litke allocated = 0; 1973e4e574b7SAdam Litke INIT_LIST_HEAD(&surplus_list); 1974e4e574b7SAdam Litke 1975e4e574b7SAdam Litke ret = -ENOMEM; 1976e4e574b7SAdam Litke retry: 1977e4e574b7SAdam Litke spin_unlock(&hugetlb_lock); 1978e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 19790c397daeSMichal Hocko page = alloc_surplus_huge_page(h, htlb_alloc_mask(h), 1980aaf14e40SMichal Hocko NUMA_NO_NODE, NULL); 198128073b02SHillf Danton if (!page) { 198228073b02SHillf Danton alloc_ok = false; 198328073b02SHillf Danton break; 198428073b02SHillf Danton } 1985e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 198669ed779aSDavid Rientjes cond_resched(); 1987e4e574b7SAdam Litke } 198828073b02SHillf Danton allocated += i; 1989e4e574b7SAdam Litke 1990e4e574b7SAdam Litke /* 1991e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 1992e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 1993e4e574b7SAdam Litke */ 1994e4e574b7SAdam Litke spin_lock(&hugetlb_lock); 1995a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 1996a5516438SAndi Kleen (h->free_huge_pages + allocated); 199728073b02SHillf Danton if (needed > 0) { 199828073b02SHillf Danton if (alloc_ok) 1999e4e574b7SAdam Litke goto retry; 200028073b02SHillf Danton /* 200128073b02SHillf Danton * We were not able to allocate enough pages to 200228073b02SHillf Danton * satisfy the entire reservation so we free what 200328073b02SHillf Danton * we've allocated so far. 200428073b02SHillf Danton */ 200528073b02SHillf Danton goto free; 200628073b02SHillf Danton } 2007e4e574b7SAdam Litke /* 2008e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 200925985edcSLucas De Marchi * needed to accommodate the reservation. Add the appropriate number 2010e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 2011ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 2012ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 2013ac09b3a1SAdam Litke * before they are reserved. 2014e4e574b7SAdam Litke */ 2015e4e574b7SAdam Litke needed += allocated; 2016a5516438SAndi Kleen h->resv_huge_pages += delta; 2017e4e574b7SAdam Litke ret = 0; 2018a9869b83SNaoya Horiguchi 201919fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 202019fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 2021e558464bSMuchun Song int zeroed; 2022e558464bSMuchun Song 202319fc3f0aSAdam Litke if ((--needed) < 0) 202419fc3f0aSAdam Litke break; 2025a9869b83SNaoya Horiguchi /* 2026a9869b83SNaoya Horiguchi * This page is now managed by the hugetlb allocator and has 2027a9869b83SNaoya Horiguchi * no users -- drop the buddy allocator's reference. 2028a9869b83SNaoya Horiguchi */ 2029e558464bSMuchun Song zeroed = put_page_testzero(page); 2030e558464bSMuchun Song VM_BUG_ON_PAGE(!zeroed, page); 2031a5516438SAndi Kleen enqueue_huge_page(h, page); 203219fc3f0aSAdam Litke } 203328073b02SHillf Danton free: 2034b0365c8dSHillf Danton spin_unlock(&hugetlb_lock); 203519fc3f0aSAdam Litke 203619fc3f0aSAdam Litke /* Free unnecessary surplus pages to the buddy allocator */ 2037c0d934baSJoonsoo Kim list_for_each_entry_safe(page, tmp, &surplus_list, lru) 2038a9869b83SNaoya Horiguchi put_page(page); 203919fc3f0aSAdam Litke spin_lock(&hugetlb_lock); 2040e4e574b7SAdam Litke 2041e4e574b7SAdam Litke return ret; 2042e4e574b7SAdam Litke } 2043e4e574b7SAdam Litke 2044e4e574b7SAdam Litke /* 2045e5bbc8a6SMike Kravetz * This routine has two main purposes: 2046e5bbc8a6SMike Kravetz * 1) Decrement the reservation count (resv_huge_pages) by the value passed 2047e5bbc8a6SMike Kravetz * in unused_resv_pages. This corresponds to the prior adjustments made 2048e5bbc8a6SMike Kravetz * to the associated reservation map. 2049e5bbc8a6SMike Kravetz * 2) Free any unused surplus pages that may have been allocated to satisfy 2050e5bbc8a6SMike Kravetz * the reservation. As many as unused_resv_pages may be freed. 2051e5bbc8a6SMike Kravetz * 2052e5bbc8a6SMike Kravetz * Called with hugetlb_lock held. However, the lock could be dropped (and 2053e5bbc8a6SMike Kravetz * reacquired) during calls to cond_resched_lock. Whenever dropping the lock, 2054e5bbc8a6SMike Kravetz * we must make sure nobody else can claim pages we are in the process of 2055e5bbc8a6SMike Kravetz * freeing. Do this by ensuring resv_huge_page always is greater than the 2056e5bbc8a6SMike Kravetz * number of huge pages we plan to free when dropping the lock. 2057e4e574b7SAdam Litke */ 2058a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 2059a5516438SAndi Kleen unsigned long unused_resv_pages) 2060e4e574b7SAdam Litke { 2061e4e574b7SAdam Litke unsigned long nr_pages; 2062e4e574b7SAdam Litke 2063aa888a74SAndi Kleen /* Cannot return gigantic pages currently */ 2064bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2065e5bbc8a6SMike Kravetz goto out; 2066aa888a74SAndi Kleen 2067e5bbc8a6SMike Kravetz /* 2068e5bbc8a6SMike Kravetz * Part (or even all) of the reservation could have been backed 2069e5bbc8a6SMike Kravetz * by pre-allocated pages. Only free surplus pages. 2070e5bbc8a6SMike Kravetz */ 2071a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 2072e4e574b7SAdam Litke 2073685f3457SLee Schermerhorn /* 2074685f3457SLee Schermerhorn * We want to release as many surplus pages as possible, spread 20759b5e5d0fSLee Schermerhorn * evenly across all nodes with memory. Iterate across these nodes 20769b5e5d0fSLee Schermerhorn * until we can no longer free unreserved surplus pages. This occurs 20779b5e5d0fSLee Schermerhorn * when the nodes with surplus pages have no free pages. 20789e7ee400SRandy Dunlap * free_pool_huge_page() will balance the freed pages across the 20799b5e5d0fSLee Schermerhorn * on-line nodes with memory and will handle the hstate accounting. 2080e5bbc8a6SMike Kravetz * 2081e5bbc8a6SMike Kravetz * Note that we decrement resv_huge_pages as we free the pages. If 2082e5bbc8a6SMike Kravetz * we drop the lock, resv_huge_pages will still be sufficiently large 2083e5bbc8a6SMike Kravetz * to cover subsequent pages we may free. 2084685f3457SLee Schermerhorn */ 2085685f3457SLee Schermerhorn while (nr_pages--) { 2086e5bbc8a6SMike Kravetz h->resv_huge_pages--; 2087e5bbc8a6SMike Kravetz unused_resv_pages--; 20888cebfcd0SLai Jiangshan if (!free_pool_huge_page(h, &node_states[N_MEMORY], 1)) 2089e5bbc8a6SMike Kravetz goto out; 20907848a4bfSMizuma, Masayoshi cond_resched_lock(&hugetlb_lock); 2091e4e574b7SAdam Litke } 2092e5bbc8a6SMike Kravetz 2093e5bbc8a6SMike Kravetz out: 2094e5bbc8a6SMike Kravetz /* Fully uncommit the reservation */ 2095e5bbc8a6SMike Kravetz h->resv_huge_pages -= unused_resv_pages; 2096e4e574b7SAdam Litke } 2097e4e574b7SAdam Litke 20985e911373SMike Kravetz 2099c37f9fb1SAndy Whitcroft /* 2100feba16e2SMike Kravetz * vma_needs_reservation, vma_commit_reservation and vma_end_reservation 21015e911373SMike Kravetz * are used by the huge page allocation routines to manage reservations. 2102cf3ad20bSMike Kravetz * 2103cf3ad20bSMike Kravetz * vma_needs_reservation is called to determine if the huge page at addr 2104cf3ad20bSMike Kravetz * within the vma has an associated reservation. If a reservation is 2105cf3ad20bSMike Kravetz * needed, the value 1 is returned. The caller is then responsible for 2106cf3ad20bSMike Kravetz * managing the global reservation and subpool usage counts. After 2107cf3ad20bSMike Kravetz * the huge page has been allocated, vma_commit_reservation is called 2108feba16e2SMike Kravetz * to add the page to the reservation map. If the page allocation fails, 2109feba16e2SMike Kravetz * the reservation must be ended instead of committed. vma_end_reservation 2110feba16e2SMike Kravetz * is called in such cases. 2111cf3ad20bSMike Kravetz * 2112cf3ad20bSMike Kravetz * In the normal case, vma_commit_reservation returns the same value 2113cf3ad20bSMike Kravetz * as the preceding vma_needs_reservation call. The only time this 2114cf3ad20bSMike Kravetz * is not the case is if a reserve map was changed between calls. It 2115cf3ad20bSMike Kravetz * is the responsibility of the caller to notice the difference and 2116cf3ad20bSMike Kravetz * take appropriate action. 211796b96a96SMike Kravetz * 211896b96a96SMike Kravetz * vma_add_reservation is used in error paths where a reservation must 211996b96a96SMike Kravetz * be restored when a newly allocated huge page must be freed. It is 212096b96a96SMike Kravetz * to be called after calling vma_needs_reservation to determine if a 212196b96a96SMike Kravetz * reservation exists. 2122c37f9fb1SAndy Whitcroft */ 21235e911373SMike Kravetz enum vma_resv_mode { 21245e911373SMike Kravetz VMA_NEEDS_RESV, 21255e911373SMike Kravetz VMA_COMMIT_RESV, 2126feba16e2SMike Kravetz VMA_END_RESV, 212796b96a96SMike Kravetz VMA_ADD_RESV, 21285e911373SMike Kravetz }; 2129cf3ad20bSMike Kravetz static long __vma_reservation_common(struct hstate *h, 2130cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr, 21315e911373SMike Kravetz enum vma_resv_mode mode) 2132c37f9fb1SAndy Whitcroft { 21334e35f483SJoonsoo Kim struct resv_map *resv; 21344e35f483SJoonsoo Kim pgoff_t idx; 2135cf3ad20bSMike Kravetz long ret; 21360db9d74eSMina Almasry long dummy_out_regions_needed; 2137c37f9fb1SAndy Whitcroft 21384e35f483SJoonsoo Kim resv = vma_resv_map(vma); 21394e35f483SJoonsoo Kim if (!resv) 2140c37f9fb1SAndy Whitcroft return 1; 2141c37f9fb1SAndy Whitcroft 21424e35f483SJoonsoo Kim idx = vma_hugecache_offset(h, vma, addr); 21435e911373SMike Kravetz switch (mode) { 21445e911373SMike Kravetz case VMA_NEEDS_RESV: 21450db9d74eSMina Almasry ret = region_chg(resv, idx, idx + 1, &dummy_out_regions_needed); 21460db9d74eSMina Almasry /* We assume that vma_reservation_* routines always operate on 21470db9d74eSMina Almasry * 1 page, and that adding to resv map a 1 page entry can only 21480db9d74eSMina Almasry * ever require 1 region. 21490db9d74eSMina Almasry */ 21500db9d74eSMina Almasry VM_BUG_ON(dummy_out_regions_needed != 1); 21515e911373SMike Kravetz break; 21525e911373SMike Kravetz case VMA_COMMIT_RESV: 2153075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 21540db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 21550db9d74eSMina Almasry VM_BUG_ON(ret < 0); 21565e911373SMike Kravetz break; 2157feba16e2SMike Kravetz case VMA_END_RESV: 21580db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 21595e911373SMike Kravetz ret = 0; 21605e911373SMike Kravetz break; 216196b96a96SMike Kravetz case VMA_ADD_RESV: 21620db9d74eSMina Almasry if (vma->vm_flags & VM_MAYSHARE) { 2163075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 21640db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 21650db9d74eSMina Almasry VM_BUG_ON(ret < 0); 21660db9d74eSMina Almasry } else { 21670db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 216896b96a96SMike Kravetz ret = region_del(resv, idx, idx + 1); 216996b96a96SMike Kravetz } 217096b96a96SMike Kravetz break; 21715e911373SMike Kravetz default: 21725e911373SMike Kravetz BUG(); 21735e911373SMike Kravetz } 217484afd99bSAndy Whitcroft 21754e35f483SJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE) 2176cf3ad20bSMike Kravetz return ret; 217767961f9dSMike Kravetz /* 2178bf3d12b9SMiaohe Lin * We know private mapping must have HPAGE_RESV_OWNER set. 2179bf3d12b9SMiaohe Lin * 218067961f9dSMike Kravetz * In most cases, reserves always exist for private mappings. 218167961f9dSMike Kravetz * However, a file associated with mapping could have been 218267961f9dSMike Kravetz * hole punched or truncated after reserves were consumed. 218367961f9dSMike Kravetz * As subsequent fault on such a range will not use reserves. 218467961f9dSMike Kravetz * Subtle - The reserve map for private mappings has the 218567961f9dSMike Kravetz * opposite meaning than that of shared mappings. If NO 218667961f9dSMike Kravetz * entry is in the reserve map, it means a reservation exists. 218767961f9dSMike Kravetz * If an entry exists in the reserve map, it means the 218867961f9dSMike Kravetz * reservation has already been consumed. As a result, the 218967961f9dSMike Kravetz * return value of this routine is the opposite of the 219067961f9dSMike Kravetz * value returned from reserve map manipulation routines above. 219167961f9dSMike Kravetz */ 2192bf3d12b9SMiaohe Lin if (ret > 0) 219367961f9dSMike Kravetz return 0; 2194bf3d12b9SMiaohe Lin if (ret == 0) 219567961f9dSMike Kravetz return 1; 2196bf3d12b9SMiaohe Lin return ret; 219784afd99bSAndy Whitcroft } 2198cf3ad20bSMike Kravetz 2199cf3ad20bSMike Kravetz static long vma_needs_reservation(struct hstate *h, 2200a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 2201c37f9fb1SAndy Whitcroft { 22025e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV); 2203cf3ad20bSMike Kravetz } 2204c37f9fb1SAndy Whitcroft 2205cf3ad20bSMike Kravetz static long vma_commit_reservation(struct hstate *h, 2206cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr) 2207cf3ad20bSMike Kravetz { 22085e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV); 22095e911373SMike Kravetz } 22105e911373SMike Kravetz 2211feba16e2SMike Kravetz static void vma_end_reservation(struct hstate *h, 22125e911373SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 22135e911373SMike Kravetz { 2214feba16e2SMike Kravetz (void)__vma_reservation_common(h, vma, addr, VMA_END_RESV); 2215c37f9fb1SAndy Whitcroft } 2216c37f9fb1SAndy Whitcroft 221796b96a96SMike Kravetz static long vma_add_reservation(struct hstate *h, 221896b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 221996b96a96SMike Kravetz { 222096b96a96SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV); 222196b96a96SMike Kravetz } 222296b96a96SMike Kravetz 222396b96a96SMike Kravetz /* 222496b96a96SMike Kravetz * This routine is called to restore a reservation on error paths. In the 222596b96a96SMike Kravetz * specific error paths, a huge page was allocated (via alloc_huge_page) 222696b96a96SMike Kravetz * and is about to be freed. If a reservation for the page existed, 2227d6995da3SMike Kravetz * alloc_huge_page would have consumed the reservation and set 2228d6995da3SMike Kravetz * HPageRestoreReserve in the newly allocated page. When the page is freed 2229d6995da3SMike Kravetz * via free_huge_page, the global reservation count will be incremented if 2230d6995da3SMike Kravetz * HPageRestoreReserve is set. However, free_huge_page can not adjust the 2231d6995da3SMike Kravetz * reserve map. Adjust the reserve map here to be consistent with global 2232d6995da3SMike Kravetz * reserve count adjustments to be made by free_huge_page. 223396b96a96SMike Kravetz */ 223496b96a96SMike Kravetz static void restore_reserve_on_error(struct hstate *h, 223596b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long address, 223696b96a96SMike Kravetz struct page *page) 223796b96a96SMike Kravetz { 2238d6995da3SMike Kravetz if (unlikely(HPageRestoreReserve(page))) { 223996b96a96SMike Kravetz long rc = vma_needs_reservation(h, vma, address); 224096b96a96SMike Kravetz 224196b96a96SMike Kravetz if (unlikely(rc < 0)) { 224296b96a96SMike Kravetz /* 224396b96a96SMike Kravetz * Rare out of memory condition in reserve map 2244d6995da3SMike Kravetz * manipulation. Clear HPageRestoreReserve so that 224596b96a96SMike Kravetz * global reserve count will not be incremented 224696b96a96SMike Kravetz * by free_huge_page. This will make it appear 224796b96a96SMike Kravetz * as though the reservation for this page was 224896b96a96SMike Kravetz * consumed. This may prevent the task from 224996b96a96SMike Kravetz * faulting in the page at a later time. This 225096b96a96SMike Kravetz * is better than inconsistent global huge page 225196b96a96SMike Kravetz * accounting of reserve counts. 225296b96a96SMike Kravetz */ 2253d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 225496b96a96SMike Kravetz } else if (rc) { 225596b96a96SMike Kravetz rc = vma_add_reservation(h, vma, address); 225696b96a96SMike Kravetz if (unlikely(rc < 0)) 225796b96a96SMike Kravetz /* 225896b96a96SMike Kravetz * See above comment about rare out of 225996b96a96SMike Kravetz * memory condition. 226096b96a96SMike Kravetz */ 2261d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 226296b96a96SMike Kravetz } else 226396b96a96SMike Kravetz vma_end_reservation(h, vma, address); 226496b96a96SMike Kravetz } 226596b96a96SMike Kravetz } 226696b96a96SMike Kravetz 226770c3547eSMike Kravetz struct page *alloc_huge_page(struct vm_area_struct *vma, 226804f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 2269348ea204SAdam Litke { 227090481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 2271a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 2272348ea204SAdam Litke struct page *page; 2273d85f69b0SMike Kravetz long map_chg, map_commit; 2274d85f69b0SMike Kravetz long gbl_chg; 22756d76dcf4SAneesh Kumar K.V int ret, idx; 22766d76dcf4SAneesh Kumar K.V struct hugetlb_cgroup *h_cg; 227708cf9fafSMina Almasry bool deferred_reserve; 22782fc39cecSAdam Litke 22796d76dcf4SAneesh Kumar K.V idx = hstate_index(h); 2280a1e78772SMel Gorman /* 2281d85f69b0SMike Kravetz * Examine the region/reserve map to determine if the process 2282d85f69b0SMike Kravetz * has a reservation for the page to be allocated. A return 2283d85f69b0SMike Kravetz * code of zero indicates a reservation exists (no change). 2284a1e78772SMel Gorman */ 2285d85f69b0SMike Kravetz map_chg = gbl_chg = vma_needs_reservation(h, vma, addr); 2286d85f69b0SMike Kravetz if (map_chg < 0) 228776dcee75SAneesh Kumar K.V return ERR_PTR(-ENOMEM); 2288d85f69b0SMike Kravetz 2289d85f69b0SMike Kravetz /* 2290d85f69b0SMike Kravetz * Processes that did not create the mapping will have no 2291d85f69b0SMike Kravetz * reserves as indicated by the region/reserve map. Check 2292d85f69b0SMike Kravetz * that the allocation will not exceed the subpool limit. 2293d85f69b0SMike Kravetz * Allocations for MAP_NORESERVE mappings also need to be 2294d85f69b0SMike Kravetz * checked against any subpool limit. 2295d85f69b0SMike Kravetz */ 2296d85f69b0SMike Kravetz if (map_chg || avoid_reserve) { 2297d85f69b0SMike Kravetz gbl_chg = hugepage_subpool_get_pages(spool, 1); 2298d85f69b0SMike Kravetz if (gbl_chg < 0) { 2299feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 230076dcee75SAneesh Kumar K.V return ERR_PTR(-ENOSPC); 23015e911373SMike Kravetz } 230290d8b7e6SAdam Litke 2303d85f69b0SMike Kravetz /* 2304d85f69b0SMike Kravetz * Even though there was no reservation in the region/reserve 2305d85f69b0SMike Kravetz * map, there could be reservations associated with the 2306d85f69b0SMike Kravetz * subpool that can be used. This would be indicated if the 2307d85f69b0SMike Kravetz * return value of hugepage_subpool_get_pages() is zero. 2308d85f69b0SMike Kravetz * However, if avoid_reserve is specified we still avoid even 2309d85f69b0SMike Kravetz * the subpool reservations. 2310d85f69b0SMike Kravetz */ 2311d85f69b0SMike Kravetz if (avoid_reserve) 2312d85f69b0SMike Kravetz gbl_chg = 1; 2313d85f69b0SMike Kravetz } 2314d85f69b0SMike Kravetz 231508cf9fafSMina Almasry /* If this allocation is not consuming a reservation, charge it now. 231608cf9fafSMina Almasry */ 23176501fe5fSMiaohe Lin deferred_reserve = map_chg || avoid_reserve; 231808cf9fafSMina Almasry if (deferred_reserve) { 231908cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup_rsvd( 232008cf9fafSMina Almasry idx, pages_per_huge_page(h), &h_cg); 23218f34af6fSJianyu Zhan if (ret) 23228f34af6fSJianyu Zhan goto out_subpool_put; 232308cf9fafSMina Almasry } 232408cf9fafSMina Almasry 232508cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); 232608cf9fafSMina Almasry if (ret) 232708cf9fafSMina Almasry goto out_uncharge_cgroup_reservation; 23288f34af6fSJianyu Zhan 2329a1e78772SMel Gorman spin_lock(&hugetlb_lock); 2330d85f69b0SMike Kravetz /* 2331d85f69b0SMike Kravetz * glb_chg is passed to indicate whether or not a page must be taken 2332d85f69b0SMike Kravetz * from the global free pool (global change). gbl_chg == 0 indicates 2333d85f69b0SMike Kravetz * a reservation exists for the allocation. 2334d85f69b0SMike Kravetz */ 2335d85f69b0SMike Kravetz page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg); 233681a6fcaeSJoonsoo Kim if (!page) { 233794ae8ba7SAneesh Kumar K.V spin_unlock(&hugetlb_lock); 23380c397daeSMichal Hocko page = alloc_buddy_huge_page_with_mpol(h, vma, addr); 23398f34af6fSJianyu Zhan if (!page) 23408f34af6fSJianyu Zhan goto out_uncharge_cgroup; 2341a88c7695SNaoya Horiguchi if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { 2342d6995da3SMike Kravetz SetHPageRestoreReserve(page); 2343a88c7695SNaoya Horiguchi h->resv_huge_pages--; 2344a88c7695SNaoya Horiguchi } 234579dbb236SAneesh Kumar K.V spin_lock(&hugetlb_lock); 234615a8d68eSWei Yang list_add(&page->lru, &h->hugepage_activelist); 234781a6fcaeSJoonsoo Kim /* Fall through */ 2348a1e78772SMel Gorman } 234981a6fcaeSJoonsoo Kim hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); 235008cf9fafSMina Almasry /* If allocation is not consuming a reservation, also store the 235108cf9fafSMina Almasry * hugetlb_cgroup pointer on the page. 235208cf9fafSMina Almasry */ 235308cf9fafSMina Almasry if (deferred_reserve) { 235408cf9fafSMina Almasry hugetlb_cgroup_commit_charge_rsvd(idx, pages_per_huge_page(h), 235508cf9fafSMina Almasry h_cg, page); 235608cf9fafSMina Almasry } 235708cf9fafSMina Almasry 235881a6fcaeSJoonsoo Kim spin_unlock(&hugetlb_lock); 2359a1e78772SMel Gorman 2360d6995da3SMike Kravetz hugetlb_set_page_subpool(page, spool); 2361a1e78772SMel Gorman 2362d85f69b0SMike Kravetz map_commit = vma_commit_reservation(h, vma, addr); 2363d85f69b0SMike Kravetz if (unlikely(map_chg > map_commit)) { 236433039678SMike Kravetz /* 236533039678SMike Kravetz * The page was added to the reservation map between 236633039678SMike Kravetz * vma_needs_reservation and vma_commit_reservation. 236733039678SMike Kravetz * This indicates a race with hugetlb_reserve_pages. 236833039678SMike Kravetz * Adjust for the subpool count incremented above AND 236933039678SMike Kravetz * in hugetlb_reserve_pages for the same page. Also, 237033039678SMike Kravetz * the reservation count added in hugetlb_reserve_pages 237133039678SMike Kravetz * no longer applies. 237233039678SMike Kravetz */ 237333039678SMike Kravetz long rsv_adjust; 237433039678SMike Kravetz 237533039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 1); 237633039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 237779aa925bSMike Kravetz if (deferred_reserve) 237879aa925bSMike Kravetz hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 237979aa925bSMike Kravetz pages_per_huge_page(h), page); 238033039678SMike Kravetz } 23817893d1d5SAdam Litke return page; 23828f34af6fSJianyu Zhan 23838f34af6fSJianyu Zhan out_uncharge_cgroup: 23848f34af6fSJianyu Zhan hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); 238508cf9fafSMina Almasry out_uncharge_cgroup_reservation: 238608cf9fafSMina Almasry if (deferred_reserve) 238708cf9fafSMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h), 238808cf9fafSMina Almasry h_cg); 23898f34af6fSJianyu Zhan out_subpool_put: 2390d85f69b0SMike Kravetz if (map_chg || avoid_reserve) 23918f34af6fSJianyu Zhan hugepage_subpool_put_pages(spool, 1); 2392feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 23938f34af6fSJianyu Zhan return ERR_PTR(-ENOSPC); 2394b45b5bd6SDavid Gibson } 2395b45b5bd6SDavid Gibson 2396e24a1307SAneesh Kumar K.V int alloc_bootmem_huge_page(struct hstate *h) 2397e24a1307SAneesh Kumar K.V __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); 2398e24a1307SAneesh Kumar K.V int __alloc_bootmem_huge_page(struct hstate *h) 2399aa888a74SAndi Kleen { 2400aa888a74SAndi Kleen struct huge_bootmem_page *m; 2401b2261026SJoonsoo Kim int nr_nodes, node; 2402aa888a74SAndi Kleen 2403b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { 2404aa888a74SAndi Kleen void *addr; 2405aa888a74SAndi Kleen 2406eb31d559SMike Rapoport addr = memblock_alloc_try_nid_raw( 24078b89a116SGrygorii Strashko huge_page_size(h), huge_page_size(h), 240897ad1087SMike Rapoport 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); 2409aa888a74SAndi Kleen if (addr) { 2410aa888a74SAndi Kleen /* 2411aa888a74SAndi Kleen * Use the beginning of the huge page to store the 2412aa888a74SAndi Kleen * huge_bootmem_page struct (until gather_bootmem 2413aa888a74SAndi Kleen * puts them into the mem_map). 2414aa888a74SAndi Kleen */ 2415aa888a74SAndi Kleen m = addr; 2416aa888a74SAndi Kleen goto found; 2417aa888a74SAndi Kleen } 2418aa888a74SAndi Kleen } 2419aa888a74SAndi Kleen return 0; 2420aa888a74SAndi Kleen 2421aa888a74SAndi Kleen found: 2422df994eadSLuiz Capitulino BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h))); 2423aa888a74SAndi Kleen /* Put them into a private list first because mem_map is not up yet */ 2424330d6e48SCannon Matthews INIT_LIST_HEAD(&m->list); 2425aa888a74SAndi Kleen list_add(&m->list, &huge_boot_pages); 2426aa888a74SAndi Kleen m->hstate = h; 2427aa888a74SAndi Kleen return 1; 2428aa888a74SAndi Kleen } 2429aa888a74SAndi Kleen 2430d00181b9SKirill A. Shutemov static void __init prep_compound_huge_page(struct page *page, 2431d00181b9SKirill A. Shutemov unsigned int order) 243218229df5SAndy Whitcroft { 243318229df5SAndy Whitcroft if (unlikely(order > (MAX_ORDER - 1))) 243418229df5SAndy Whitcroft prep_compound_gigantic_page(page, order); 243518229df5SAndy Whitcroft else 243618229df5SAndy Whitcroft prep_compound_page(page, order); 243718229df5SAndy Whitcroft } 243818229df5SAndy Whitcroft 2439aa888a74SAndi Kleen /* Put bootmem huge pages into the standard lists after mem_map is up */ 2440aa888a74SAndi Kleen static void __init gather_bootmem_prealloc(void) 2441aa888a74SAndi Kleen { 2442aa888a74SAndi Kleen struct huge_bootmem_page *m; 2443aa888a74SAndi Kleen 2444aa888a74SAndi Kleen list_for_each_entry(m, &huge_boot_pages, list) { 244540d18ebfSMike Kravetz struct page *page = virt_to_page(m); 2446aa888a74SAndi Kleen struct hstate *h = m->hstate; 2447ee8f248dSBecky Bruce 2448aa888a74SAndi Kleen WARN_ON(page_count(page) != 1); 2449c78a7f36SMiaohe Lin prep_compound_huge_page(page, huge_page_order(h)); 2450ef5a22beSAndrea Arcangeli WARN_ON(PageReserved(page)); 2451aa888a74SAndi Kleen prep_new_huge_page(h, page, page_to_nid(page)); 2452af0fb9dfSMichal Hocko put_page(page); /* free it into the hugepage allocator */ 2453af0fb9dfSMichal Hocko 2454b0320c7bSRafael Aquini /* 2455b0320c7bSRafael Aquini * If we had gigantic hugepages allocated at boot time, we need 2456b0320c7bSRafael Aquini * to restore the 'stolen' pages to totalram_pages in order to 2457b0320c7bSRafael Aquini * fix confusing memory reports from free(1) and another 2458b0320c7bSRafael Aquini * side-effects, like CommitLimit going negative. 2459b0320c7bSRafael Aquini */ 2460bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2461c78a7f36SMiaohe Lin adjust_managed_page_count(page, pages_per_huge_page(h)); 2462520495feSCannon Matthews cond_resched(); 2463aa888a74SAndi Kleen } 2464aa888a74SAndi Kleen } 2465aa888a74SAndi Kleen 24668faa8b07SAndi Kleen static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 24671da177e4SLinus Torvalds { 24681da177e4SLinus Torvalds unsigned long i; 2469f60858f9SMike Kravetz nodemask_t *node_alloc_noretry; 2470f60858f9SMike Kravetz 2471f60858f9SMike Kravetz if (!hstate_is_gigantic(h)) { 2472f60858f9SMike Kravetz /* 2473f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 2474f60858f9SMike Kravetz * Ignore errors as lower level routines can deal with 2475f60858f9SMike Kravetz * node_alloc_noretry == NULL. If this kmalloc fails at boot 2476f60858f9SMike Kravetz * time, we are likely in bigger trouble. 2477f60858f9SMike Kravetz */ 2478f60858f9SMike Kravetz node_alloc_noretry = kmalloc(sizeof(*node_alloc_noretry), 2479f60858f9SMike Kravetz GFP_KERNEL); 2480f60858f9SMike Kravetz } else { 2481f60858f9SMike Kravetz /* allocations done at boot time */ 2482f60858f9SMike Kravetz node_alloc_noretry = NULL; 2483f60858f9SMike Kravetz } 2484f60858f9SMike Kravetz 2485f60858f9SMike Kravetz /* bit mask controlling how hard we retry per-node allocations */ 2486f60858f9SMike Kravetz if (node_alloc_noretry) 2487f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 24881da177e4SLinus Torvalds 2489e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 2490bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) { 2491dbda8feaSBarry Song if (hugetlb_cma_size) { 2492cf11e85fSRoman Gushchin pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n"); 24937ecc9565SChen Wandun goto free; 2494cf11e85fSRoman Gushchin } 2495aa888a74SAndi Kleen if (!alloc_bootmem_huge_page(h)) 2496aa888a74SAndi Kleen break; 24970c397daeSMichal Hocko } else if (!alloc_pool_huge_page(h, 2498f60858f9SMike Kravetz &node_states[N_MEMORY], 2499f60858f9SMike Kravetz node_alloc_noretry)) 25001da177e4SLinus Torvalds break; 250169ed779aSDavid Rientjes cond_resched(); 25021da177e4SLinus Torvalds } 2503d715cf80SLiam R. Howlett if (i < h->max_huge_pages) { 2504d715cf80SLiam R. Howlett char buf[32]; 2505d715cf80SLiam R. Howlett 2506c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 2507d715cf80SLiam R. Howlett pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n", 2508d715cf80SLiam R. Howlett h->max_huge_pages, buf, i); 25098faa8b07SAndi Kleen h->max_huge_pages = i; 2510e5ff2159SAndi Kleen } 25117ecc9565SChen Wandun free: 2512f60858f9SMike Kravetz kfree(node_alloc_noretry); 2513d715cf80SLiam R. Howlett } 2514e5ff2159SAndi Kleen 2515e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 2516e5ff2159SAndi Kleen { 2517e5ff2159SAndi Kleen struct hstate *h; 2518e5ff2159SAndi Kleen 2519e5ff2159SAndi Kleen for_each_hstate(h) { 2520641844f5SNaoya Horiguchi if (minimum_order > huge_page_order(h)) 2521641844f5SNaoya Horiguchi minimum_order = huge_page_order(h); 2522641844f5SNaoya Horiguchi 25238faa8b07SAndi Kleen /* oversize hugepages were init'ed in early boot */ 2524bae7f4aeSLuiz Capitulino if (!hstate_is_gigantic(h)) 25258faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(h); 2526e5ff2159SAndi Kleen } 2527641844f5SNaoya Horiguchi VM_BUG_ON(minimum_order == UINT_MAX); 2528e5ff2159SAndi Kleen } 2529e5ff2159SAndi Kleen 2530e5ff2159SAndi Kleen static void __init report_hugepages(void) 2531e5ff2159SAndi Kleen { 2532e5ff2159SAndi Kleen struct hstate *h; 2533e5ff2159SAndi Kleen 2534e5ff2159SAndi Kleen for_each_hstate(h) { 25354abd32dbSAndi Kleen char buf[32]; 2536c6247f72SMatthew Wilcox 2537c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 2538ffb22af5SAndrew Morton pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n", 2539c6247f72SMatthew Wilcox buf, h->free_huge_pages); 2540e5ff2159SAndi Kleen } 2541e5ff2159SAndi Kleen } 2542e5ff2159SAndi Kleen 25431da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 25446ae11b27SLee Schermerhorn static void try_to_free_low(struct hstate *h, unsigned long count, 25456ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 25461da177e4SLinus Torvalds { 25474415cc8dSChristoph Lameter int i; 25484415cc8dSChristoph Lameter 2549bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2550aa888a74SAndi Kleen return; 2551aa888a74SAndi Kleen 25526ae11b27SLee Schermerhorn for_each_node_mask(i, *nodes_allowed) { 25531da177e4SLinus Torvalds struct page *page, *next; 2554a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 2555a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 2556a5516438SAndi Kleen if (count >= h->nr_huge_pages) 25576b0c880dSAdam Litke return; 25581da177e4SLinus Torvalds if (PageHighMem(page)) 25591da177e4SLinus Torvalds continue; 25601da177e4SLinus Torvalds list_del(&page->lru); 2561e5ff2159SAndi Kleen update_and_free_page(h, page); 2562a5516438SAndi Kleen h->free_huge_pages--; 2563a5516438SAndi Kleen h->free_huge_pages_node[page_to_nid(page)]--; 25641da177e4SLinus Torvalds } 25651da177e4SLinus Torvalds } 25661da177e4SLinus Torvalds } 25671da177e4SLinus Torvalds #else 25686ae11b27SLee Schermerhorn static inline void try_to_free_low(struct hstate *h, unsigned long count, 25696ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 25701da177e4SLinus Torvalds { 25711da177e4SLinus Torvalds } 25721da177e4SLinus Torvalds #endif 25731da177e4SLinus Torvalds 257420a0307cSWu Fengguang /* 257520a0307cSWu Fengguang * Increment or decrement surplus_huge_pages. Keep node-specific counters 257620a0307cSWu Fengguang * balanced by operating on them in a round-robin fashion. 257720a0307cSWu Fengguang * Returns 1 if an adjustment was made. 257820a0307cSWu Fengguang */ 25796ae11b27SLee Schermerhorn static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, 25806ae11b27SLee Schermerhorn int delta) 258120a0307cSWu Fengguang { 2582b2261026SJoonsoo Kim int nr_nodes, node; 258320a0307cSWu Fengguang 258420a0307cSWu Fengguang VM_BUG_ON(delta != -1 && delta != 1); 258520a0307cSWu Fengguang 2586e8c5c824SLee Schermerhorn if (delta < 0) { 2587b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 2588b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node]) 2589b2261026SJoonsoo Kim goto found; 2590b2261026SJoonsoo Kim } 2591b2261026SJoonsoo Kim } else { 2592b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 2593b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node] < 2594b2261026SJoonsoo Kim h->nr_huge_pages_node[node]) 2595b2261026SJoonsoo Kim goto found; 2596e8c5c824SLee Schermerhorn } 25979a76db09SLee Schermerhorn } 2598b2261026SJoonsoo Kim return 0; 259920a0307cSWu Fengguang 2600b2261026SJoonsoo Kim found: 260120a0307cSWu Fengguang h->surplus_huge_pages += delta; 2602b2261026SJoonsoo Kim h->surplus_huge_pages_node[node] += delta; 2603b2261026SJoonsoo Kim return 1; 260420a0307cSWu Fengguang } 260520a0307cSWu Fengguang 2606a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 2607fd875dcaSMike Kravetz static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, 26086ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 26091da177e4SLinus Torvalds { 26107893d1d5SAdam Litke unsigned long min_count, ret; 2611f60858f9SMike Kravetz NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL); 2612f60858f9SMike Kravetz 2613f60858f9SMike Kravetz /* 2614f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 2615f60858f9SMike Kravetz * If we can not allocate the bit mask, do not attempt to allocate 2616f60858f9SMike Kravetz * the requested huge pages. 2617f60858f9SMike Kravetz */ 2618f60858f9SMike Kravetz if (node_alloc_noretry) 2619f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 2620f60858f9SMike Kravetz else 2621f60858f9SMike Kravetz return -ENOMEM; 26221da177e4SLinus Torvalds 26234eb0716eSAlexandre Ghiti spin_lock(&hugetlb_lock); 26244eb0716eSAlexandre Ghiti 26254eb0716eSAlexandre Ghiti /* 2626fd875dcaSMike Kravetz * Check for a node specific request. 2627fd875dcaSMike Kravetz * Changing node specific huge page count may require a corresponding 2628fd875dcaSMike Kravetz * change to the global count. In any case, the passed node mask 2629fd875dcaSMike Kravetz * (nodes_allowed) will restrict alloc/free to the specified node. 2630fd875dcaSMike Kravetz */ 2631fd875dcaSMike Kravetz if (nid != NUMA_NO_NODE) { 2632fd875dcaSMike Kravetz unsigned long old_count = count; 2633fd875dcaSMike Kravetz 2634fd875dcaSMike Kravetz count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; 2635fd875dcaSMike Kravetz /* 2636fd875dcaSMike Kravetz * User may have specified a large count value which caused the 2637fd875dcaSMike Kravetz * above calculation to overflow. In this case, they wanted 2638fd875dcaSMike Kravetz * to allocate as many huge pages as possible. Set count to 2639fd875dcaSMike Kravetz * largest possible value to align with their intention. 2640fd875dcaSMike Kravetz */ 2641fd875dcaSMike Kravetz if (count < old_count) 2642fd875dcaSMike Kravetz count = ULONG_MAX; 2643fd875dcaSMike Kravetz } 2644fd875dcaSMike Kravetz 2645fd875dcaSMike Kravetz /* 26464eb0716eSAlexandre Ghiti * Gigantic pages runtime allocation depend on the capability for large 26474eb0716eSAlexandre Ghiti * page range allocation. 26484eb0716eSAlexandre Ghiti * If the system does not provide this feature, return an error when 26494eb0716eSAlexandre Ghiti * the user tries to allocate gigantic pages but let the user free the 26504eb0716eSAlexandre Ghiti * boottime allocated gigantic pages. 26514eb0716eSAlexandre Ghiti */ 26524eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) { 26534eb0716eSAlexandre Ghiti if (count > persistent_huge_pages(h)) { 26544eb0716eSAlexandre Ghiti spin_unlock(&hugetlb_lock); 2655f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 26564eb0716eSAlexandre Ghiti return -EINVAL; 26574eb0716eSAlexandre Ghiti } 26584eb0716eSAlexandre Ghiti /* Fall through to decrease pool */ 26594eb0716eSAlexandre Ghiti } 2660aa888a74SAndi Kleen 26617893d1d5SAdam Litke /* 26627893d1d5SAdam Litke * Increase the pool size 26637893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 26647893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 2665d1c3fb1fSNishanth Aravamudan * 26660c397daeSMichal Hocko * We might race with alloc_surplus_huge_page() here and be unable 2667d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 2668d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 2669d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 2670d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 26717893d1d5SAdam Litke */ 2672a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 26736ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, -1)) 26747893d1d5SAdam Litke break; 26757893d1d5SAdam Litke } 26767893d1d5SAdam Litke 2677a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 26787893d1d5SAdam Litke /* 26797893d1d5SAdam Litke * If this allocation races such that we no longer need the 26807893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 26817893d1d5SAdam Litke * and reducing the surplus. 26827893d1d5SAdam Litke */ 26837893d1d5SAdam Litke spin_unlock(&hugetlb_lock); 2684649920c6SJia He 2685649920c6SJia He /* yield cpu to avoid soft lockup */ 2686649920c6SJia He cond_resched(); 2687649920c6SJia He 2688f60858f9SMike Kravetz ret = alloc_pool_huge_page(h, nodes_allowed, 2689f60858f9SMike Kravetz node_alloc_noretry); 26907893d1d5SAdam Litke spin_lock(&hugetlb_lock); 26917893d1d5SAdam Litke if (!ret) 26927893d1d5SAdam Litke goto out; 26937893d1d5SAdam Litke 2694536240f2SMel Gorman /* Bail for signals. Probably ctrl-c from user */ 2695536240f2SMel Gorman if (signal_pending(current)) 2696536240f2SMel Gorman goto out; 26977893d1d5SAdam Litke } 26987893d1d5SAdam Litke 26997893d1d5SAdam Litke /* 27007893d1d5SAdam Litke * Decrease the pool size 27017893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 27027893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 27037893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 27047893d1d5SAdam Litke * to the desired size as pages become free. 2705d1c3fb1fSNishanth Aravamudan * 2706d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 2707d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 2708d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 27090c397daeSMichal Hocko * alloc_surplus_huge_page() is checking the global counter, 2710d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 2711d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 2712d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 27137893d1d5SAdam Litke */ 2714a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 27156b0c880dSAdam Litke min_count = max(count, min_count); 27166ae11b27SLee Schermerhorn try_to_free_low(h, min_count, nodes_allowed); 2717a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 27186ae11b27SLee Schermerhorn if (!free_pool_huge_page(h, nodes_allowed, 0)) 27191da177e4SLinus Torvalds break; 272055f67141SMizuma, Masayoshi cond_resched_lock(&hugetlb_lock); 27211da177e4SLinus Torvalds } 2722a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 27236ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, 1)) 27247893d1d5SAdam Litke break; 27257893d1d5SAdam Litke } 27267893d1d5SAdam Litke out: 27274eb0716eSAlexandre Ghiti h->max_huge_pages = persistent_huge_pages(h); 27281da177e4SLinus Torvalds spin_unlock(&hugetlb_lock); 27294eb0716eSAlexandre Ghiti 2730f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 2731f60858f9SMike Kravetz 27324eb0716eSAlexandre Ghiti return 0; 27331da177e4SLinus Torvalds } 27341da177e4SLinus Torvalds 2735a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 2736a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 2737a3437870SNishanth Aravamudan 2738a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 2739a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = \ 2740a3437870SNishanth Aravamudan __ATTR(_name, 0644, _name##_show, _name##_store) 2741a3437870SNishanth Aravamudan 2742a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 2743a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 2744a3437870SNishanth Aravamudan 27459a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); 27469a305230SLee Schermerhorn 27479a305230SLee Schermerhorn static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) 2748a3437870SNishanth Aravamudan { 2749a3437870SNishanth Aravamudan int i; 27509a305230SLee Schermerhorn 2751a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 27529a305230SLee Schermerhorn if (hstate_kobjs[i] == kobj) { 27539a305230SLee Schermerhorn if (nidp) 27549a305230SLee Schermerhorn *nidp = NUMA_NO_NODE; 2755a3437870SNishanth Aravamudan return &hstates[i]; 27569a305230SLee Schermerhorn } 27579a305230SLee Schermerhorn 27589a305230SLee Schermerhorn return kobj_to_node_hstate(kobj, nidp); 2759a3437870SNishanth Aravamudan } 2760a3437870SNishanth Aravamudan 276106808b08SLee Schermerhorn static ssize_t nr_hugepages_show_common(struct kobject *kobj, 2762a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2763a3437870SNishanth Aravamudan { 27649a305230SLee Schermerhorn struct hstate *h; 27659a305230SLee Schermerhorn unsigned long nr_huge_pages; 27669a305230SLee Schermerhorn int nid; 27679a305230SLee Schermerhorn 27689a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 27699a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 27709a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages; 27719a305230SLee Schermerhorn else 27729a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages_node[nid]; 27739a305230SLee Schermerhorn 2774ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", nr_huge_pages); 2775a3437870SNishanth Aravamudan } 2776adbe8726SEric B Munson 2777238d3c13SDavid Rientjes static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, 2778238d3c13SDavid Rientjes struct hstate *h, int nid, 2779238d3c13SDavid Rientjes unsigned long count, size_t len) 2780a3437870SNishanth Aravamudan { 2781a3437870SNishanth Aravamudan int err; 27822d0adf7eSOscar Salvador nodemask_t nodes_allowed, *n_mask; 2783a3437870SNishanth Aravamudan 27842d0adf7eSOscar Salvador if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 27852d0adf7eSOscar Salvador return -EINVAL; 2786adbe8726SEric B Munson 27879a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) { 27889a305230SLee Schermerhorn /* 27899a305230SLee Schermerhorn * global hstate attribute 27909a305230SLee Schermerhorn */ 27919a305230SLee Schermerhorn if (!(obey_mempolicy && 27922d0adf7eSOscar Salvador init_nodemask_of_mempolicy(&nodes_allowed))) 27932d0adf7eSOscar Salvador n_mask = &node_states[N_MEMORY]; 27942d0adf7eSOscar Salvador else 27952d0adf7eSOscar Salvador n_mask = &nodes_allowed; 27962d0adf7eSOscar Salvador } else { 27979a305230SLee Schermerhorn /* 2798fd875dcaSMike Kravetz * Node specific request. count adjustment happens in 2799fd875dcaSMike Kravetz * set_max_huge_pages() after acquiring hugetlb_lock. 28009a305230SLee Schermerhorn */ 28012d0adf7eSOscar Salvador init_nodemask_of_node(&nodes_allowed, nid); 28022d0adf7eSOscar Salvador n_mask = &nodes_allowed; 2803fd875dcaSMike Kravetz } 28049a305230SLee Schermerhorn 28052d0adf7eSOscar Salvador err = set_max_huge_pages(h, count, nid, n_mask); 280606808b08SLee Schermerhorn 28074eb0716eSAlexandre Ghiti return err ? err : len; 280806808b08SLee Schermerhorn } 280906808b08SLee Schermerhorn 2810238d3c13SDavid Rientjes static ssize_t nr_hugepages_store_common(bool obey_mempolicy, 2811238d3c13SDavid Rientjes struct kobject *kobj, const char *buf, 2812238d3c13SDavid Rientjes size_t len) 2813238d3c13SDavid Rientjes { 2814238d3c13SDavid Rientjes struct hstate *h; 2815238d3c13SDavid Rientjes unsigned long count; 2816238d3c13SDavid Rientjes int nid; 2817238d3c13SDavid Rientjes int err; 2818238d3c13SDavid Rientjes 2819238d3c13SDavid Rientjes err = kstrtoul(buf, 10, &count); 2820238d3c13SDavid Rientjes if (err) 2821238d3c13SDavid Rientjes return err; 2822238d3c13SDavid Rientjes 2823238d3c13SDavid Rientjes h = kobj_to_hstate(kobj, &nid); 2824238d3c13SDavid Rientjes return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); 2825238d3c13SDavid Rientjes } 2826238d3c13SDavid Rientjes 282706808b08SLee Schermerhorn static ssize_t nr_hugepages_show(struct kobject *kobj, 282806808b08SLee Schermerhorn struct kobj_attribute *attr, char *buf) 282906808b08SLee Schermerhorn { 283006808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 283106808b08SLee Schermerhorn } 283206808b08SLee Schermerhorn 283306808b08SLee Schermerhorn static ssize_t nr_hugepages_store(struct kobject *kobj, 283406808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 283506808b08SLee Schermerhorn { 2836238d3c13SDavid Rientjes return nr_hugepages_store_common(false, kobj, buf, len); 2837a3437870SNishanth Aravamudan } 2838a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 2839a3437870SNishanth Aravamudan 284006808b08SLee Schermerhorn #ifdef CONFIG_NUMA 284106808b08SLee Schermerhorn 284206808b08SLee Schermerhorn /* 284306808b08SLee Schermerhorn * hstate attribute for optionally mempolicy-based constraint on persistent 284406808b08SLee Schermerhorn * huge page alloc/free. 284506808b08SLee Schermerhorn */ 284606808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, 2847ae7a927dSJoe Perches struct kobj_attribute *attr, 2848ae7a927dSJoe Perches char *buf) 284906808b08SLee Schermerhorn { 285006808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 285106808b08SLee Schermerhorn } 285206808b08SLee Schermerhorn 285306808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, 285406808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 285506808b08SLee Schermerhorn { 2856238d3c13SDavid Rientjes return nr_hugepages_store_common(true, kobj, buf, len); 285706808b08SLee Schermerhorn } 285806808b08SLee Schermerhorn HSTATE_ATTR(nr_hugepages_mempolicy); 285906808b08SLee Schermerhorn #endif 286006808b08SLee Schermerhorn 286106808b08SLee Schermerhorn 2862a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 2863a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2864a3437870SNishanth Aravamudan { 28659a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 2866ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->nr_overcommit_huge_pages); 2867a3437870SNishanth Aravamudan } 2868adbe8726SEric B Munson 2869a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 2870a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 2871a3437870SNishanth Aravamudan { 2872a3437870SNishanth Aravamudan int err; 2873a3437870SNishanth Aravamudan unsigned long input; 28749a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 2875a3437870SNishanth Aravamudan 2876bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2877adbe8726SEric B Munson return -EINVAL; 2878adbe8726SEric B Munson 28793dbb95f7SJingoo Han err = kstrtoul(buf, 10, &input); 2880a3437870SNishanth Aravamudan if (err) 288173ae31e5SEric B Munson return err; 2882a3437870SNishanth Aravamudan 2883a3437870SNishanth Aravamudan spin_lock(&hugetlb_lock); 2884a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 2885a3437870SNishanth Aravamudan spin_unlock(&hugetlb_lock); 2886a3437870SNishanth Aravamudan 2887a3437870SNishanth Aravamudan return count; 2888a3437870SNishanth Aravamudan } 2889a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 2890a3437870SNishanth Aravamudan 2891a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 2892a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2893a3437870SNishanth Aravamudan { 28949a305230SLee Schermerhorn struct hstate *h; 28959a305230SLee Schermerhorn unsigned long free_huge_pages; 28969a305230SLee Schermerhorn int nid; 28979a305230SLee Schermerhorn 28989a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 28999a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 29009a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages; 29019a305230SLee Schermerhorn else 29029a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages_node[nid]; 29039a305230SLee Schermerhorn 2904ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", free_huge_pages); 2905a3437870SNishanth Aravamudan } 2906a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 2907a3437870SNishanth Aravamudan 2908a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 2909a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2910a3437870SNishanth Aravamudan { 29119a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 2912ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", h->resv_huge_pages); 2913a3437870SNishanth Aravamudan } 2914a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 2915a3437870SNishanth Aravamudan 2916a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 2917a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2918a3437870SNishanth Aravamudan { 29199a305230SLee Schermerhorn struct hstate *h; 29209a305230SLee Schermerhorn unsigned long surplus_huge_pages; 29219a305230SLee Schermerhorn int nid; 29229a305230SLee Schermerhorn 29239a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 29249a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 29259a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages; 29269a305230SLee Schermerhorn else 29279a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages_node[nid]; 29289a305230SLee Schermerhorn 2929ae7a927dSJoe Perches return sysfs_emit(buf, "%lu\n", surplus_huge_pages); 2930a3437870SNishanth Aravamudan } 2931a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 2932a3437870SNishanth Aravamudan 2933a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 2934a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 2935a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 2936a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 2937a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 2938a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 293906808b08SLee Schermerhorn #ifdef CONFIG_NUMA 294006808b08SLee Schermerhorn &nr_hugepages_mempolicy_attr.attr, 294106808b08SLee Schermerhorn #endif 2942a3437870SNishanth Aravamudan NULL, 2943a3437870SNishanth Aravamudan }; 2944a3437870SNishanth Aravamudan 294567e5ed96SArvind Yadav static const struct attribute_group hstate_attr_group = { 2946a3437870SNishanth Aravamudan .attrs = hstate_attrs, 2947a3437870SNishanth Aravamudan }; 2948a3437870SNishanth Aravamudan 2949094e9539SJeff Mahoney static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, 29509a305230SLee Schermerhorn struct kobject **hstate_kobjs, 295167e5ed96SArvind Yadav const struct attribute_group *hstate_attr_group) 2952a3437870SNishanth Aravamudan { 2953a3437870SNishanth Aravamudan int retval; 2954972dc4deSAneesh Kumar K.V int hi = hstate_index(h); 2955a3437870SNishanth Aravamudan 29569a305230SLee Schermerhorn hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); 29579a305230SLee Schermerhorn if (!hstate_kobjs[hi]) 2958a3437870SNishanth Aravamudan return -ENOMEM; 2959a3437870SNishanth Aravamudan 29609a305230SLee Schermerhorn retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); 2961cc2205a6SMiaohe Lin if (retval) { 29629a305230SLee Schermerhorn kobject_put(hstate_kobjs[hi]); 2963cc2205a6SMiaohe Lin hstate_kobjs[hi] = NULL; 2964cc2205a6SMiaohe Lin } 2965a3437870SNishanth Aravamudan 2966a3437870SNishanth Aravamudan return retval; 2967a3437870SNishanth Aravamudan } 2968a3437870SNishanth Aravamudan 2969a3437870SNishanth Aravamudan static void __init hugetlb_sysfs_init(void) 2970a3437870SNishanth Aravamudan { 2971a3437870SNishanth Aravamudan struct hstate *h; 2972a3437870SNishanth Aravamudan int err; 2973a3437870SNishanth Aravamudan 2974a3437870SNishanth Aravamudan hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 2975a3437870SNishanth Aravamudan if (!hugepages_kobj) 2976a3437870SNishanth Aravamudan return; 2977a3437870SNishanth Aravamudan 2978a3437870SNishanth Aravamudan for_each_hstate(h) { 29799a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, 29809a305230SLee Schermerhorn hstate_kobjs, &hstate_attr_group); 2981a3437870SNishanth Aravamudan if (err) 2982282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s", h->name); 2983a3437870SNishanth Aravamudan } 2984a3437870SNishanth Aravamudan } 2985a3437870SNishanth Aravamudan 29869a305230SLee Schermerhorn #ifdef CONFIG_NUMA 29879a305230SLee Schermerhorn 29889a305230SLee Schermerhorn /* 29899a305230SLee Schermerhorn * node_hstate/s - associate per node hstate attributes, via their kobjects, 299010fbcf4cSKay Sievers * with node devices in node_devices[] using a parallel array. The array 299110fbcf4cSKay Sievers * index of a node device or _hstate == node id. 299210fbcf4cSKay Sievers * This is here to avoid any static dependency of the node device driver, in 29939a305230SLee Schermerhorn * the base kernel, on the hugetlb module. 29949a305230SLee Schermerhorn */ 29959a305230SLee Schermerhorn struct node_hstate { 29969a305230SLee Schermerhorn struct kobject *hugepages_kobj; 29979a305230SLee Schermerhorn struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 29989a305230SLee Schermerhorn }; 2999b4e289a6SAlexander Kuleshov static struct node_hstate node_hstates[MAX_NUMNODES]; 30009a305230SLee Schermerhorn 30019a305230SLee Schermerhorn /* 300210fbcf4cSKay Sievers * A subset of global hstate attributes for node devices 30039a305230SLee Schermerhorn */ 30049a305230SLee Schermerhorn static struct attribute *per_node_hstate_attrs[] = { 30059a305230SLee Schermerhorn &nr_hugepages_attr.attr, 30069a305230SLee Schermerhorn &free_hugepages_attr.attr, 30079a305230SLee Schermerhorn &surplus_hugepages_attr.attr, 30089a305230SLee Schermerhorn NULL, 30099a305230SLee Schermerhorn }; 30109a305230SLee Schermerhorn 301167e5ed96SArvind Yadav static const struct attribute_group per_node_hstate_attr_group = { 30129a305230SLee Schermerhorn .attrs = per_node_hstate_attrs, 30139a305230SLee Schermerhorn }; 30149a305230SLee Schermerhorn 30159a305230SLee Schermerhorn /* 301610fbcf4cSKay Sievers * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. 30179a305230SLee Schermerhorn * Returns node id via non-NULL nidp. 30189a305230SLee Schermerhorn */ 30199a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 30209a305230SLee Schermerhorn { 30219a305230SLee Schermerhorn int nid; 30229a305230SLee Schermerhorn 30239a305230SLee Schermerhorn for (nid = 0; nid < nr_node_ids; nid++) { 30249a305230SLee Schermerhorn struct node_hstate *nhs = &node_hstates[nid]; 30259a305230SLee Schermerhorn int i; 30269a305230SLee Schermerhorn for (i = 0; i < HUGE_MAX_HSTATE; i++) 30279a305230SLee Schermerhorn if (nhs->hstate_kobjs[i] == kobj) { 30289a305230SLee Schermerhorn if (nidp) 30299a305230SLee Schermerhorn *nidp = nid; 30309a305230SLee Schermerhorn return &hstates[i]; 30319a305230SLee Schermerhorn } 30329a305230SLee Schermerhorn } 30339a305230SLee Schermerhorn 30349a305230SLee Schermerhorn BUG(); 30359a305230SLee Schermerhorn return NULL; 30369a305230SLee Schermerhorn } 30379a305230SLee Schermerhorn 30389a305230SLee Schermerhorn /* 303910fbcf4cSKay Sievers * Unregister hstate attributes from a single node device. 30409a305230SLee Schermerhorn * No-op if no hstate attributes attached. 30419a305230SLee Schermerhorn */ 30423cd8b44fSClaudiu Ghioc static void hugetlb_unregister_node(struct node *node) 30439a305230SLee Schermerhorn { 30449a305230SLee Schermerhorn struct hstate *h; 304510fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 30469a305230SLee Schermerhorn 30479a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 30489b5e5d0fSLee Schermerhorn return; /* no hstate attributes */ 30499a305230SLee Schermerhorn 3050972dc4deSAneesh Kumar K.V for_each_hstate(h) { 3051972dc4deSAneesh Kumar K.V int idx = hstate_index(h); 3052972dc4deSAneesh Kumar K.V if (nhs->hstate_kobjs[idx]) { 3053972dc4deSAneesh Kumar K.V kobject_put(nhs->hstate_kobjs[idx]); 3054972dc4deSAneesh Kumar K.V nhs->hstate_kobjs[idx] = NULL; 3055972dc4deSAneesh Kumar K.V } 30569a305230SLee Schermerhorn } 30579a305230SLee Schermerhorn 30589a305230SLee Schermerhorn kobject_put(nhs->hugepages_kobj); 30599a305230SLee Schermerhorn nhs->hugepages_kobj = NULL; 30609a305230SLee Schermerhorn } 30619a305230SLee Schermerhorn 30629a305230SLee Schermerhorn 30639a305230SLee Schermerhorn /* 306410fbcf4cSKay Sievers * Register hstate attributes for a single node device. 30659a305230SLee Schermerhorn * No-op if attributes already registered. 30669a305230SLee Schermerhorn */ 30673cd8b44fSClaudiu Ghioc static void hugetlb_register_node(struct node *node) 30689a305230SLee Schermerhorn { 30699a305230SLee Schermerhorn struct hstate *h; 307010fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 30719a305230SLee Schermerhorn int err; 30729a305230SLee Schermerhorn 30739a305230SLee Schermerhorn if (nhs->hugepages_kobj) 30749a305230SLee Schermerhorn return; /* already allocated */ 30759a305230SLee Schermerhorn 30769a305230SLee Schermerhorn nhs->hugepages_kobj = kobject_create_and_add("hugepages", 307710fbcf4cSKay Sievers &node->dev.kobj); 30789a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 30799a305230SLee Schermerhorn return; 30809a305230SLee Schermerhorn 30819a305230SLee Schermerhorn for_each_hstate(h) { 30829a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, 30839a305230SLee Schermerhorn nhs->hstate_kobjs, 30849a305230SLee Schermerhorn &per_node_hstate_attr_group); 30859a305230SLee Schermerhorn if (err) { 3086282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s for node %d\n", 308710fbcf4cSKay Sievers h->name, node->dev.id); 30889a305230SLee Schermerhorn hugetlb_unregister_node(node); 30899a305230SLee Schermerhorn break; 30909a305230SLee Schermerhorn } 30919a305230SLee Schermerhorn } 30929a305230SLee Schermerhorn } 30939a305230SLee Schermerhorn 30949a305230SLee Schermerhorn /* 30959b5e5d0fSLee Schermerhorn * hugetlb init time: register hstate attributes for all registered node 309610fbcf4cSKay Sievers * devices of nodes that have memory. All on-line nodes should have 309710fbcf4cSKay Sievers * registered their associated device by this time. 30989a305230SLee Schermerhorn */ 30997d9ca000SLuiz Capitulino static void __init hugetlb_register_all_nodes(void) 31009a305230SLee Schermerhorn { 31019a305230SLee Schermerhorn int nid; 31029a305230SLee Schermerhorn 31038cebfcd0SLai Jiangshan for_each_node_state(nid, N_MEMORY) { 31048732794bSWen Congyang struct node *node = node_devices[nid]; 310510fbcf4cSKay Sievers if (node->dev.id == nid) 31069a305230SLee Schermerhorn hugetlb_register_node(node); 31079a305230SLee Schermerhorn } 31089a305230SLee Schermerhorn 31099a305230SLee Schermerhorn /* 311010fbcf4cSKay Sievers * Let the node device driver know we're here so it can 31119a305230SLee Schermerhorn * [un]register hstate attributes on node hotplug. 31129a305230SLee Schermerhorn */ 31139a305230SLee Schermerhorn register_hugetlbfs_with_node(hugetlb_register_node, 31149a305230SLee Schermerhorn hugetlb_unregister_node); 31159a305230SLee Schermerhorn } 31169a305230SLee Schermerhorn #else /* !CONFIG_NUMA */ 31179a305230SLee Schermerhorn 31189a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 31199a305230SLee Schermerhorn { 31209a305230SLee Schermerhorn BUG(); 31219a305230SLee Schermerhorn if (nidp) 31229a305230SLee Schermerhorn *nidp = -1; 31239a305230SLee Schermerhorn return NULL; 31249a305230SLee Schermerhorn } 31259a305230SLee Schermerhorn 31269a305230SLee Schermerhorn static void hugetlb_register_all_nodes(void) { } 31279a305230SLee Schermerhorn 31289a305230SLee Schermerhorn #endif 31299a305230SLee Schermerhorn 3130a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 3131a3437870SNishanth Aravamudan { 31328382d914SDavidlohr Bueso int i; 31338382d914SDavidlohr Bueso 3134d6995da3SMike Kravetz BUILD_BUG_ON(sizeof_field(struct page, private) * BITS_PER_BYTE < 3135d6995da3SMike Kravetz __NR_HPAGEFLAGS); 3136d6995da3SMike Kravetz 3137c2833a5bSMike Kravetz if (!hugepages_supported()) { 3138c2833a5bSMike Kravetz if (hugetlb_max_hstate || default_hstate_max_huge_pages) 3139c2833a5bSMike Kravetz pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n"); 31400ef89d25SBenjamin Herrenschmidt return 0; 3141d715cf80SLiam R. Howlett } 3142d715cf80SLiam R. Howlett 3143282f4214SMike Kravetz /* 3144282f4214SMike Kravetz * Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some 3145282f4214SMike Kravetz * architectures depend on setup being done here. 3146282f4214SMike Kravetz */ 3147a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 3148282f4214SMike Kravetz if (!parsed_default_hugepagesz) { 3149282f4214SMike Kravetz /* 3150282f4214SMike Kravetz * If we did not parse a default huge page size, set 3151282f4214SMike Kravetz * default_hstate_idx to HPAGE_SIZE hstate. And, if the 3152282f4214SMike Kravetz * number of huge pages for this default size was implicitly 3153282f4214SMike Kravetz * specified, set that here as well. 3154282f4214SMike Kravetz * Note that the implicit setting will overwrite an explicit 3155282f4214SMike Kravetz * setting. A warning will be printed in this case. 3156282f4214SMike Kravetz */ 3157282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(HPAGE_SIZE)); 3158f8b74815SVaishali Thakkar if (default_hstate_max_huge_pages) { 3159282f4214SMike Kravetz if (default_hstate.max_huge_pages) { 3160282f4214SMike Kravetz char buf[32]; 3161282f4214SMike Kravetz 3162282f4214SMike Kravetz string_get_size(huge_page_size(&default_hstate), 3163282f4214SMike Kravetz 1, STRING_UNITS_2, buf, 32); 3164282f4214SMike Kravetz pr_warn("HugeTLB: Ignoring hugepages=%lu associated with %s page size\n", 3165282f4214SMike Kravetz default_hstate.max_huge_pages, buf); 3166282f4214SMike Kravetz pr_warn("HugeTLB: Using hugepages=%lu for number of default huge pages\n", 3167282f4214SMike Kravetz default_hstate_max_huge_pages); 3168282f4214SMike Kravetz } 3169282f4214SMike Kravetz default_hstate.max_huge_pages = 3170282f4214SMike Kravetz default_hstate_max_huge_pages; 3171282f4214SMike Kravetz } 3172f8b74815SVaishali Thakkar } 3173a3437870SNishanth Aravamudan 3174cf11e85fSRoman Gushchin hugetlb_cma_check(); 3175a3437870SNishanth Aravamudan hugetlb_init_hstates(); 3176aa888a74SAndi Kleen gather_bootmem_prealloc(); 3177a3437870SNishanth Aravamudan report_hugepages(); 3178a3437870SNishanth Aravamudan 3179a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 31809a305230SLee Schermerhorn hugetlb_register_all_nodes(); 31817179e7bfSJianguo Wu hugetlb_cgroup_file_init(); 31829a305230SLee Schermerhorn 31838382d914SDavidlohr Bueso #ifdef CONFIG_SMP 31848382d914SDavidlohr Bueso num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); 31858382d914SDavidlohr Bueso #else 31868382d914SDavidlohr Bueso num_fault_mutexes = 1; 31878382d914SDavidlohr Bueso #endif 3188c672c7f2SMike Kravetz hugetlb_fault_mutex_table = 31896da2ec56SKees Cook kmalloc_array(num_fault_mutexes, sizeof(struct mutex), 31906da2ec56SKees Cook GFP_KERNEL); 3191c672c7f2SMike Kravetz BUG_ON(!hugetlb_fault_mutex_table); 31928382d914SDavidlohr Bueso 31938382d914SDavidlohr Bueso for (i = 0; i < num_fault_mutexes; i++) 3194c672c7f2SMike Kravetz mutex_init(&hugetlb_fault_mutex_table[i]); 3195a3437870SNishanth Aravamudan return 0; 3196a3437870SNishanth Aravamudan } 31973e89e1c5SPaul Gortmaker subsys_initcall(hugetlb_init); 3198a3437870SNishanth Aravamudan 3199ae94da89SMike Kravetz /* Overwritten by architectures with more huge page sizes */ 3200ae94da89SMike Kravetz bool __init __attribute((weak)) arch_hugetlb_valid_size(unsigned long size) 32019fee021dSVaishali Thakkar { 3202ae94da89SMike Kravetz return size == HPAGE_SIZE; 32039fee021dSVaishali Thakkar } 32049fee021dSVaishali Thakkar 3205d00181b9SKirill A. Shutemov void __init hugetlb_add_hstate(unsigned int order) 3206a3437870SNishanth Aravamudan { 3207a3437870SNishanth Aravamudan struct hstate *h; 32088faa8b07SAndi Kleen unsigned long i; 32098faa8b07SAndi Kleen 3210a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 3211a3437870SNishanth Aravamudan return; 3212a3437870SNishanth Aravamudan } 321347d38344SAneesh Kumar K.V BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); 3214a3437870SNishanth Aravamudan BUG_ON(order == 0); 321547d38344SAneesh Kumar K.V h = &hstates[hugetlb_max_hstate++]; 3216a3437870SNishanth Aravamudan h->order = order; 3217aca78307SMiaohe Lin h->mask = ~(huge_page_size(h) - 1); 32188faa8b07SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 32198faa8b07SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 32200edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&h->hugepage_activelist); 322154f18d35SAndrew Morton h->next_nid_to_alloc = first_memory_node; 322254f18d35SAndrew Morton h->next_nid_to_free = first_memory_node; 3223a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 3224a3437870SNishanth Aravamudan huge_page_size(h)/1024); 32258faa8b07SAndi Kleen 3226a3437870SNishanth Aravamudan parsed_hstate = h; 3227a3437870SNishanth Aravamudan } 3228a3437870SNishanth Aravamudan 3229282f4214SMike Kravetz /* 3230282f4214SMike Kravetz * hugepages command line processing 3231282f4214SMike Kravetz * hugepages normally follows a valid hugepagsz or default_hugepagsz 3232282f4214SMike Kravetz * specification. If not, ignore the hugepages value. hugepages can also 3233282f4214SMike Kravetz * be the first huge page command line option in which case it implicitly 3234282f4214SMike Kravetz * specifies the number of huge pages for the default size. 3235282f4214SMike Kravetz */ 3236282f4214SMike Kravetz static int __init hugepages_setup(char *s) 3237a3437870SNishanth Aravamudan { 3238a3437870SNishanth Aravamudan unsigned long *mhp; 32398faa8b07SAndi Kleen static unsigned long *last_mhp; 3240a3437870SNishanth Aravamudan 32419fee021dSVaishali Thakkar if (!parsed_valid_hugepagesz) { 3242282f4214SMike Kravetz pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s); 32439fee021dSVaishali Thakkar parsed_valid_hugepagesz = true; 3244282f4214SMike Kravetz return 0; 32459fee021dSVaishali Thakkar } 3246282f4214SMike Kravetz 3247a3437870SNishanth Aravamudan /* 3248282f4214SMike Kravetz * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter 3249282f4214SMike Kravetz * yet, so this hugepages= parameter goes to the "default hstate". 3250282f4214SMike Kravetz * Otherwise, it goes with the previously parsed hugepagesz or 3251282f4214SMike Kravetz * default_hugepagesz. 3252a3437870SNishanth Aravamudan */ 32539fee021dSVaishali Thakkar else if (!hugetlb_max_hstate) 3254a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 3255a3437870SNishanth Aravamudan else 3256a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 3257a3437870SNishanth Aravamudan 32588faa8b07SAndi Kleen if (mhp == last_mhp) { 3259282f4214SMike Kravetz pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s); 3260282f4214SMike Kravetz return 0; 32618faa8b07SAndi Kleen } 32628faa8b07SAndi Kleen 3263a3437870SNishanth Aravamudan if (sscanf(s, "%lu", mhp) <= 0) 3264a3437870SNishanth Aravamudan *mhp = 0; 3265a3437870SNishanth Aravamudan 32668faa8b07SAndi Kleen /* 32678faa8b07SAndi Kleen * Global state is always initialized later in hugetlb_init. 326804adbc3fSMiaohe Lin * But we need to allocate gigantic hstates here early to still 32698faa8b07SAndi Kleen * use the bootmem allocator. 32708faa8b07SAndi Kleen */ 327104adbc3fSMiaohe Lin if (hugetlb_max_hstate && hstate_is_gigantic(parsed_hstate)) 32728faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(parsed_hstate); 32738faa8b07SAndi Kleen 32748faa8b07SAndi Kleen last_mhp = mhp; 32758faa8b07SAndi Kleen 3276a3437870SNishanth Aravamudan return 1; 3277a3437870SNishanth Aravamudan } 3278282f4214SMike Kravetz __setup("hugepages=", hugepages_setup); 3279e11bfbfcSNick Piggin 3280282f4214SMike Kravetz /* 3281282f4214SMike Kravetz * hugepagesz command line processing 3282282f4214SMike Kravetz * A specific huge page size can only be specified once with hugepagesz. 3283282f4214SMike Kravetz * hugepagesz is followed by hugepages on the command line. The global 3284282f4214SMike Kravetz * variable 'parsed_valid_hugepagesz' is used to determine if prior 3285282f4214SMike Kravetz * hugepagesz argument was valid. 3286282f4214SMike Kravetz */ 3287359f2544SMike Kravetz static int __init hugepagesz_setup(char *s) 3288e11bfbfcSNick Piggin { 3289359f2544SMike Kravetz unsigned long size; 3290282f4214SMike Kravetz struct hstate *h; 3291282f4214SMike Kravetz 3292282f4214SMike Kravetz parsed_valid_hugepagesz = false; 3293359f2544SMike Kravetz size = (unsigned long)memparse(s, NULL); 3294359f2544SMike Kravetz 3295359f2544SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 3296282f4214SMike Kravetz pr_err("HugeTLB: unsupported hugepagesz=%s\n", s); 3297359f2544SMike Kravetz return 0; 3298359f2544SMike Kravetz } 3299359f2544SMike Kravetz 3300282f4214SMike Kravetz h = size_to_hstate(size); 3301282f4214SMike Kravetz if (h) { 3302282f4214SMike Kravetz /* 3303282f4214SMike Kravetz * hstate for this size already exists. This is normally 3304282f4214SMike Kravetz * an error, but is allowed if the existing hstate is the 3305282f4214SMike Kravetz * default hstate. More specifically, it is only allowed if 3306282f4214SMike Kravetz * the number of huge pages for the default hstate was not 3307282f4214SMike Kravetz * previously specified. 3308282f4214SMike Kravetz */ 3309282f4214SMike Kravetz if (!parsed_default_hugepagesz || h != &default_hstate || 3310282f4214SMike Kravetz default_hstate.max_huge_pages) { 3311282f4214SMike Kravetz pr_warn("HugeTLB: hugepagesz=%s specified twice, ignoring\n", s); 331238237830SMike Kravetz return 0; 331338237830SMike Kravetz } 331438237830SMike Kravetz 3315282f4214SMike Kravetz /* 3316282f4214SMike Kravetz * No need to call hugetlb_add_hstate() as hstate already 3317282f4214SMike Kravetz * exists. But, do set parsed_hstate so that a following 3318282f4214SMike Kravetz * hugepages= parameter will be applied to this hstate. 3319282f4214SMike Kravetz */ 3320282f4214SMike Kravetz parsed_hstate = h; 3321282f4214SMike Kravetz parsed_valid_hugepagesz = true; 3322e11bfbfcSNick Piggin return 1; 3323e11bfbfcSNick Piggin } 3324282f4214SMike Kravetz 3325359f2544SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 3326282f4214SMike Kravetz parsed_valid_hugepagesz = true; 3327359f2544SMike Kravetz return 1; 3328359f2544SMike Kravetz } 3329359f2544SMike Kravetz __setup("hugepagesz=", hugepagesz_setup); 3330359f2544SMike Kravetz 3331282f4214SMike Kravetz /* 3332282f4214SMike Kravetz * default_hugepagesz command line input 3333282f4214SMike Kravetz * Only one instance of default_hugepagesz allowed on command line. 3334282f4214SMike Kravetz */ 3335ae94da89SMike Kravetz static int __init default_hugepagesz_setup(char *s) 3336e11bfbfcSNick Piggin { 3337ae94da89SMike Kravetz unsigned long size; 3338ae94da89SMike Kravetz 3339282f4214SMike Kravetz parsed_valid_hugepagesz = false; 3340282f4214SMike Kravetz if (parsed_default_hugepagesz) { 3341282f4214SMike Kravetz pr_err("HugeTLB: default_hugepagesz previously specified, ignoring %s\n", s); 3342282f4214SMike Kravetz return 0; 3343282f4214SMike Kravetz } 3344282f4214SMike Kravetz 3345282f4214SMike Kravetz size = (unsigned long)memparse(s, NULL); 3346282f4214SMike Kravetz 3347282f4214SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 3348282f4214SMike Kravetz pr_err("HugeTLB: unsupported default_hugepagesz=%s\n", s); 3349282f4214SMike Kravetz return 0; 3350282f4214SMike Kravetz } 3351282f4214SMike Kravetz 3352282f4214SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 3353282f4214SMike Kravetz parsed_valid_hugepagesz = true; 3354282f4214SMike Kravetz parsed_default_hugepagesz = true; 3355282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(size)); 3356282f4214SMike Kravetz 3357282f4214SMike Kravetz /* 3358282f4214SMike Kravetz * The number of default huge pages (for this size) could have been 3359282f4214SMike Kravetz * specified as the first hugetlb parameter: hugepages=X. If so, 3360282f4214SMike Kravetz * then default_hstate_max_huge_pages is set. If the default huge 3361282f4214SMike Kravetz * page size is gigantic (>= MAX_ORDER), then the pages must be 3362282f4214SMike Kravetz * allocated here from bootmem allocator. 3363282f4214SMike Kravetz */ 3364282f4214SMike Kravetz if (default_hstate_max_huge_pages) { 3365282f4214SMike Kravetz default_hstate.max_huge_pages = default_hstate_max_huge_pages; 3366282f4214SMike Kravetz if (hstate_is_gigantic(&default_hstate)) 3367282f4214SMike Kravetz hugetlb_hstate_alloc_pages(&default_hstate); 3368282f4214SMike Kravetz default_hstate_max_huge_pages = 0; 3369282f4214SMike Kravetz } 3370282f4214SMike Kravetz 3371e11bfbfcSNick Piggin return 1; 3372e11bfbfcSNick Piggin } 3373ae94da89SMike Kravetz __setup("default_hugepagesz=", default_hugepagesz_setup); 3374a3437870SNishanth Aravamudan 33758ca39e68SMuchun Song static unsigned int allowed_mems_nr(struct hstate *h) 33768a213460SNishanth Aravamudan { 33778a213460SNishanth Aravamudan int node; 33788a213460SNishanth Aravamudan unsigned int nr = 0; 33798ca39e68SMuchun Song nodemask_t *mpol_allowed; 33808ca39e68SMuchun Song unsigned int *array = h->free_huge_pages_node; 33818ca39e68SMuchun Song gfp_t gfp_mask = htlb_alloc_mask(h); 33828a213460SNishanth Aravamudan 33838ca39e68SMuchun Song mpol_allowed = policy_nodemask_current(gfp_mask); 33848ca39e68SMuchun Song 33858ca39e68SMuchun Song for_each_node_mask(node, cpuset_current_mems_allowed) { 3386c93b0a99SJiapeng Zhong if (!mpol_allowed || node_isset(node, *mpol_allowed)) 33878a213460SNishanth Aravamudan nr += array[node]; 33888ca39e68SMuchun Song } 33898a213460SNishanth Aravamudan 33908a213460SNishanth Aravamudan return nr; 33918a213460SNishanth Aravamudan } 33928a213460SNishanth Aravamudan 33938a213460SNishanth Aravamudan #ifdef CONFIG_SYSCTL 339417743798SMuchun Song static int proc_hugetlb_doulongvec_minmax(struct ctl_table *table, int write, 339517743798SMuchun Song void *buffer, size_t *length, 339617743798SMuchun Song loff_t *ppos, unsigned long *out) 339717743798SMuchun Song { 339817743798SMuchun Song struct ctl_table dup_table; 339917743798SMuchun Song 340017743798SMuchun Song /* 340117743798SMuchun Song * In order to avoid races with __do_proc_doulongvec_minmax(), we 340217743798SMuchun Song * can duplicate the @table and alter the duplicate of it. 340317743798SMuchun Song */ 340417743798SMuchun Song dup_table = *table; 340517743798SMuchun Song dup_table.data = out; 340617743798SMuchun Song 340717743798SMuchun Song return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos); 340817743798SMuchun Song } 340917743798SMuchun Song 341006808b08SLee Schermerhorn static int hugetlb_sysctl_handler_common(bool obey_mempolicy, 341106808b08SLee Schermerhorn struct ctl_table *table, int write, 341232927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 34131da177e4SLinus Torvalds { 3414e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 3415238d3c13SDavid Rientjes unsigned long tmp = h->max_huge_pages; 341608d4a246SMichal Hocko int ret; 3417e5ff2159SAndi Kleen 3418457c1b27SNishanth Aravamudan if (!hugepages_supported()) 341986613628SJan Stancek return -EOPNOTSUPP; 3420457c1b27SNishanth Aravamudan 342117743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 342217743798SMuchun Song &tmp); 342308d4a246SMichal Hocko if (ret) 342408d4a246SMichal Hocko goto out; 3425e5ff2159SAndi Kleen 3426238d3c13SDavid Rientjes if (write) 3427238d3c13SDavid Rientjes ret = __nr_hugepages_store_common(obey_mempolicy, h, 3428238d3c13SDavid Rientjes NUMA_NO_NODE, tmp, *length); 342908d4a246SMichal Hocko out: 343008d4a246SMichal Hocko return ret; 34311da177e4SLinus Torvalds } 3432396faf03SMel Gorman 343306808b08SLee Schermerhorn int hugetlb_sysctl_handler(struct ctl_table *table, int write, 343432927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 343506808b08SLee Schermerhorn { 343606808b08SLee Schermerhorn 343706808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(false, table, write, 343806808b08SLee Schermerhorn buffer, length, ppos); 343906808b08SLee Schermerhorn } 344006808b08SLee Schermerhorn 344106808b08SLee Schermerhorn #ifdef CONFIG_NUMA 344206808b08SLee Schermerhorn int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, 344332927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 344406808b08SLee Schermerhorn { 344506808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(true, table, write, 344606808b08SLee Schermerhorn buffer, length, ppos); 344706808b08SLee Schermerhorn } 344806808b08SLee Schermerhorn #endif /* CONFIG_NUMA */ 344906808b08SLee Schermerhorn 3450a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 345132927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 3452a3d0c6aaSNishanth Aravamudan { 3453a5516438SAndi Kleen struct hstate *h = &default_hstate; 3454e5ff2159SAndi Kleen unsigned long tmp; 345508d4a246SMichal Hocko int ret; 3456e5ff2159SAndi Kleen 3457457c1b27SNishanth Aravamudan if (!hugepages_supported()) 345886613628SJan Stancek return -EOPNOTSUPP; 3459457c1b27SNishanth Aravamudan 3460e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 3461e5ff2159SAndi Kleen 3462bae7f4aeSLuiz Capitulino if (write && hstate_is_gigantic(h)) 3463adbe8726SEric B Munson return -EINVAL; 3464adbe8726SEric B Munson 346517743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 346617743798SMuchun Song &tmp); 346708d4a246SMichal Hocko if (ret) 346808d4a246SMichal Hocko goto out; 3469e5ff2159SAndi Kleen 3470e5ff2159SAndi Kleen if (write) { 3471064d9efeSNishanth Aravamudan spin_lock(&hugetlb_lock); 3472e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 3473a3d0c6aaSNishanth Aravamudan spin_unlock(&hugetlb_lock); 3474e5ff2159SAndi Kleen } 347508d4a246SMichal Hocko out: 347608d4a246SMichal Hocko return ret; 3477a3d0c6aaSNishanth Aravamudan } 3478a3d0c6aaSNishanth Aravamudan 34791da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 34801da177e4SLinus Torvalds 3481e1759c21SAlexey Dobriyan void hugetlb_report_meminfo(struct seq_file *m) 34821da177e4SLinus Torvalds { 3483fcb2b0c5SRoman Gushchin struct hstate *h; 3484fcb2b0c5SRoman Gushchin unsigned long total = 0; 3485fcb2b0c5SRoman Gushchin 3486457c1b27SNishanth Aravamudan if (!hugepages_supported()) 3487457c1b27SNishanth Aravamudan return; 3488fcb2b0c5SRoman Gushchin 3489fcb2b0c5SRoman Gushchin for_each_hstate(h) { 3490fcb2b0c5SRoman Gushchin unsigned long count = h->nr_huge_pages; 3491fcb2b0c5SRoman Gushchin 3492aca78307SMiaohe Lin total += huge_page_size(h) * count; 3493fcb2b0c5SRoman Gushchin 3494fcb2b0c5SRoman Gushchin if (h == &default_hstate) 3495e1759c21SAlexey Dobriyan seq_printf(m, 34961da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 34971da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 3498b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 34997893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 35004f98a2feSRik van Riel "Hugepagesize: %8lu kB\n", 3501fcb2b0c5SRoman Gushchin count, 3502a5516438SAndi Kleen h->free_huge_pages, 3503a5516438SAndi Kleen h->resv_huge_pages, 3504a5516438SAndi Kleen h->surplus_huge_pages, 3505aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 3506fcb2b0c5SRoman Gushchin } 3507fcb2b0c5SRoman Gushchin 3508aca78307SMiaohe Lin seq_printf(m, "Hugetlb: %8lu kB\n", total / SZ_1K); 35091da177e4SLinus Torvalds } 35101da177e4SLinus Torvalds 35117981593bSJoe Perches int hugetlb_report_node_meminfo(char *buf, int len, int nid) 35121da177e4SLinus Torvalds { 3513a5516438SAndi Kleen struct hstate *h = &default_hstate; 35147981593bSJoe Perches 3515457c1b27SNishanth Aravamudan if (!hugepages_supported()) 3516457c1b27SNishanth Aravamudan return 0; 35177981593bSJoe Perches 35187981593bSJoe Perches return sysfs_emit_at(buf, len, 35191da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 3520a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 3521a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 3522a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 3523a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 3524a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 35251da177e4SLinus Torvalds } 35261da177e4SLinus Torvalds 3527949f7ec5SDavid Rientjes void hugetlb_show_meminfo(void) 3528949f7ec5SDavid Rientjes { 3529949f7ec5SDavid Rientjes struct hstate *h; 3530949f7ec5SDavid Rientjes int nid; 3531949f7ec5SDavid Rientjes 3532457c1b27SNishanth Aravamudan if (!hugepages_supported()) 3533457c1b27SNishanth Aravamudan return; 3534457c1b27SNishanth Aravamudan 3535949f7ec5SDavid Rientjes for_each_node_state(nid, N_MEMORY) 3536949f7ec5SDavid Rientjes for_each_hstate(h) 3537949f7ec5SDavid Rientjes pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", 3538949f7ec5SDavid Rientjes nid, 3539949f7ec5SDavid Rientjes h->nr_huge_pages_node[nid], 3540949f7ec5SDavid Rientjes h->free_huge_pages_node[nid], 3541949f7ec5SDavid Rientjes h->surplus_huge_pages_node[nid], 3542aca78307SMiaohe Lin huge_page_size(h) / SZ_1K); 3543949f7ec5SDavid Rientjes } 3544949f7ec5SDavid Rientjes 35455d317b2bSNaoya Horiguchi void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm) 35465d317b2bSNaoya Horiguchi { 35475d317b2bSNaoya Horiguchi seq_printf(m, "HugetlbPages:\t%8lu kB\n", 35485d317b2bSNaoya Horiguchi atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10)); 35495d317b2bSNaoya Horiguchi } 35505d317b2bSNaoya Horiguchi 35511da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 35521da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 35531da177e4SLinus Torvalds { 3554d0028588SWanpeng Li struct hstate *h; 3555d0028588SWanpeng Li unsigned long nr_total_pages = 0; 3556d0028588SWanpeng Li 3557d0028588SWanpeng Li for_each_hstate(h) 3558d0028588SWanpeng Li nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); 3559d0028588SWanpeng Li return nr_total_pages; 35601da177e4SLinus Torvalds } 35611da177e4SLinus Torvalds 3562a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 3563fc1b8a73SMel Gorman { 3564fc1b8a73SMel Gorman int ret = -ENOMEM; 3565fc1b8a73SMel Gorman 35660aa7f354SMiaohe Lin if (!delta) 35670aa7f354SMiaohe Lin return 0; 35680aa7f354SMiaohe Lin 3569fc1b8a73SMel Gorman spin_lock(&hugetlb_lock); 3570fc1b8a73SMel Gorman /* 3571fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 3572fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 3573fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 3574fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 3575fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 3576fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 3577fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 3578fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 3579fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 3580fc1b8a73SMel Gorman * 3581fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 3582fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 3583fc1b8a73SMel Gorman * we fall back to check against current free page availability as 3584fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 3585fc1b8a73SMel Gorman * semantics that cpuset has. 35868ca39e68SMuchun Song * 35878ca39e68SMuchun Song * Apart from cpuset, we also have memory policy mechanism that 35888ca39e68SMuchun Song * also determines from which node the kernel will allocate memory 35898ca39e68SMuchun Song * in a NUMA system. So similar to cpuset, we also should consider 35908ca39e68SMuchun Song * the memory policy of the current task. Similar to the description 35918ca39e68SMuchun Song * above. 3592fc1b8a73SMel Gorman */ 3593fc1b8a73SMel Gorman if (delta > 0) { 3594a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 3595fc1b8a73SMel Gorman goto out; 3596fc1b8a73SMel Gorman 35978ca39e68SMuchun Song if (delta > allowed_mems_nr(h)) { 3598a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 3599fc1b8a73SMel Gorman goto out; 3600fc1b8a73SMel Gorman } 3601fc1b8a73SMel Gorman } 3602fc1b8a73SMel Gorman 3603fc1b8a73SMel Gorman ret = 0; 3604fc1b8a73SMel Gorman if (delta < 0) 3605a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 3606fc1b8a73SMel Gorman 3607fc1b8a73SMel Gorman out: 3608fc1b8a73SMel Gorman spin_unlock(&hugetlb_lock); 3609fc1b8a73SMel Gorman return ret; 3610fc1b8a73SMel Gorman } 3611fc1b8a73SMel Gorman 361284afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 361384afd99bSAndy Whitcroft { 3614f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 361584afd99bSAndy Whitcroft 361684afd99bSAndy Whitcroft /* 361784afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 361884afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 361984afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 362025985edcSLucas De Marchi * has a reference to the reservation map it cannot disappear until 362184afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 362284afd99bSAndy Whitcroft * new reference here without additional locking. 362384afd99bSAndy Whitcroft */ 36244e35f483SJoonsoo Kim if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 3625f522c3acSJoonsoo Kim kref_get(&resv->refs); 362684afd99bSAndy Whitcroft } 362784afd99bSAndy Whitcroft 3628a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 3629a1e78772SMel Gorman { 3630a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 3631f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 363290481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 36334e35f483SJoonsoo Kim unsigned long reserve, start, end; 36341c5ecae3SMike Kravetz long gbl_reserve; 363584afd99bSAndy Whitcroft 36364e35f483SJoonsoo Kim if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 36374e35f483SJoonsoo Kim return; 36384e35f483SJoonsoo Kim 3639a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 3640a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 364184afd99bSAndy Whitcroft 36424e35f483SJoonsoo Kim reserve = (end - start) - region_count(resv, start, end); 3643e9fe92aeSMina Almasry hugetlb_cgroup_uncharge_counter(resv, start, end); 36447251ff78SAdam Litke if (reserve) { 36451c5ecae3SMike Kravetz /* 36461c5ecae3SMike Kravetz * Decrement reserve counts. The global reserve count may be 36471c5ecae3SMike Kravetz * adjusted if the subpool has a minimum size. 36481c5ecae3SMike Kravetz */ 36491c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, reserve); 36501c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 36517251ff78SAdam Litke } 3652e9fe92aeSMina Almasry 3653e9fe92aeSMina Almasry kref_put(&resv->refs, resv_map_release); 3654a1e78772SMel Gorman } 3655a1e78772SMel Gorman 365631383c68SDan Williams static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) 365731383c68SDan Williams { 365831383c68SDan Williams if (addr & ~(huge_page_mask(hstate_vma(vma)))) 365931383c68SDan Williams return -EINVAL; 366031383c68SDan Williams return 0; 366131383c68SDan Williams } 366231383c68SDan Williams 366305ea8860SDan Williams static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) 366405ea8860SDan Williams { 3665aca78307SMiaohe Lin return huge_page_size(hstate_vma(vma)); 366605ea8860SDan Williams } 366705ea8860SDan Williams 36681da177e4SLinus Torvalds /* 36691da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 36701da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 36716c26d310SMiaohe Lin * hugepage VMA. do_page_fault() is supposed to trap this, so BUG is we get 36721da177e4SLinus Torvalds * this far. 36731da177e4SLinus Torvalds */ 3674b3ec9f33SSouptick Joarder static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf) 36751da177e4SLinus Torvalds { 36761da177e4SLinus Torvalds BUG(); 3677d0217ac0SNick Piggin return 0; 36781da177e4SLinus Torvalds } 36791da177e4SLinus Torvalds 3680eec3636aSJane Chu /* 3681eec3636aSJane Chu * When a new function is introduced to vm_operations_struct and added 3682eec3636aSJane Chu * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops. 3683eec3636aSJane Chu * This is because under System V memory model, mappings created via 3684eec3636aSJane Chu * shmget/shmat with "huge page" specified are backed by hugetlbfs files, 3685eec3636aSJane Chu * their original vm_ops are overwritten with shm_vm_ops. 3686eec3636aSJane Chu */ 3687f0f37e2fSAlexey Dobriyan const struct vm_operations_struct hugetlb_vm_ops = { 3688d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 368984afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 3690a1e78772SMel Gorman .close = hugetlb_vm_op_close, 3691dd3b614fSDmitry Safonov .may_split = hugetlb_vm_op_split, 369205ea8860SDan Williams .pagesize = hugetlb_vm_op_pagesize, 36931da177e4SLinus Torvalds }; 36941da177e4SLinus Torvalds 36951e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 36961e8f889bSDavid Gibson int writable) 369763551ae0SDavid Gibson { 369863551ae0SDavid Gibson pte_t entry; 369963551ae0SDavid Gibson 37001e8f889bSDavid Gibson if (writable) { 3701106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, 3702106c992aSGerald Schaefer vma->vm_page_prot))); 370363551ae0SDavid Gibson } else { 3704106c992aSGerald Schaefer entry = huge_pte_wrprotect(mk_huge_pte(page, 3705106c992aSGerald Schaefer vma->vm_page_prot)); 370663551ae0SDavid Gibson } 370763551ae0SDavid Gibson entry = pte_mkyoung(entry); 370863551ae0SDavid Gibson entry = pte_mkhuge(entry); 3709d9ed9faaSChris Metcalf entry = arch_make_huge_pte(entry, vma, page, writable); 371063551ae0SDavid Gibson 371163551ae0SDavid Gibson return entry; 371263551ae0SDavid Gibson } 371363551ae0SDavid Gibson 37141e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 37151e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 37161e8f889bSDavid Gibson { 37171e8f889bSDavid Gibson pte_t entry; 37181e8f889bSDavid Gibson 3719106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); 372032f84528SChris Forbes if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) 37214b3073e1SRussell King update_mmu_cache(vma, address, ptep); 37221e8f889bSDavid Gibson } 37231e8f889bSDavid Gibson 3724d5ed7444SAneesh Kumar K.V bool is_hugetlb_entry_migration(pte_t pte) 37254a705fefSNaoya Horiguchi { 37264a705fefSNaoya Horiguchi swp_entry_t swp; 37274a705fefSNaoya Horiguchi 37284a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 3729d5ed7444SAneesh Kumar K.V return false; 37304a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 3731d79d176aSBaoquan He if (is_migration_entry(swp)) 3732d5ed7444SAneesh Kumar K.V return true; 37334a705fefSNaoya Horiguchi else 3734d5ed7444SAneesh Kumar K.V return false; 37354a705fefSNaoya Horiguchi } 37364a705fefSNaoya Horiguchi 37373e5c3600SBaoquan He static bool is_hugetlb_entry_hwpoisoned(pte_t pte) 37384a705fefSNaoya Horiguchi { 37394a705fefSNaoya Horiguchi swp_entry_t swp; 37404a705fefSNaoya Horiguchi 37414a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 37423e5c3600SBaoquan He return false; 37434a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 3744d79d176aSBaoquan He if (is_hwpoison_entry(swp)) 37453e5c3600SBaoquan He return true; 37464a705fefSNaoya Horiguchi else 37473e5c3600SBaoquan He return false; 37484a705fefSNaoya Horiguchi } 37491e8f889bSDavid Gibson 37504eae4efaSPeter Xu static void 37514eae4efaSPeter Xu hugetlb_install_page(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr, 37524eae4efaSPeter Xu struct page *new_page) 37534eae4efaSPeter Xu { 37544eae4efaSPeter Xu __SetPageUptodate(new_page); 37554eae4efaSPeter Xu set_huge_pte_at(vma->vm_mm, addr, ptep, make_huge_pte(vma, new_page, 1)); 37564eae4efaSPeter Xu hugepage_add_new_anon_rmap(new_page, vma, addr); 37574eae4efaSPeter Xu hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm); 37584eae4efaSPeter Xu ClearHPageRestoreReserve(new_page); 37594eae4efaSPeter Xu SetHPageMigratable(new_page); 37604eae4efaSPeter Xu } 37614eae4efaSPeter Xu 376263551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 376363551ae0SDavid Gibson struct vm_area_struct *vma) 376463551ae0SDavid Gibson { 37655e41540cSMike Kravetz pte_t *src_pte, *dst_pte, entry, dst_entry; 376663551ae0SDavid Gibson struct page *ptepage; 37671c59827dSHugh Dickins unsigned long addr; 3768ca6eb14dSPeter Xu bool cow = is_cow_mapping(vma->vm_flags); 3769a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 3770a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 37714eae4efaSPeter Xu unsigned long npages = pages_per_huge_page(h); 3772c0d0381aSMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 3773ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 3774e8569dd2SAndreas Sandberg int ret = 0; 37751e8f889bSDavid Gibson 3776ac46d4f3SJérôme Glisse if (cow) { 37777269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, src, 37786f4f13e8SJérôme Glisse vma->vm_start, 3779ac46d4f3SJérôme Glisse vma->vm_end); 3780ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 3781c0d0381aSMike Kravetz } else { 3782c0d0381aSMike Kravetz /* 3783c0d0381aSMike Kravetz * For shared mappings i_mmap_rwsem must be held to call 3784c0d0381aSMike Kravetz * huge_pte_alloc, otherwise the returned ptep could go 3785c0d0381aSMike Kravetz * away if part of a shared pmd and another thread calls 3786c0d0381aSMike Kravetz * huge_pmd_unshare. 3787c0d0381aSMike Kravetz */ 3788c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 3789ac46d4f3SJérôme Glisse } 3790e8569dd2SAndreas Sandberg 3791a5516438SAndi Kleen for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { 3792cb900f41SKirill A. Shutemov spinlock_t *src_ptl, *dst_ptl; 37937868a208SPunit Agrawal src_pte = huge_pte_offset(src, addr, sz); 3794c74df32cSHugh Dickins if (!src_pte) 3795c74df32cSHugh Dickins continue; 3796aec44e0fSPeter Xu dst_pte = huge_pte_alloc(dst, vma, addr, sz); 3797e8569dd2SAndreas Sandberg if (!dst_pte) { 3798e8569dd2SAndreas Sandberg ret = -ENOMEM; 3799e8569dd2SAndreas Sandberg break; 3800e8569dd2SAndreas Sandberg } 3801c5c99429SLarry Woodman 38025e41540cSMike Kravetz /* 38035e41540cSMike Kravetz * If the pagetables are shared don't copy or take references. 38045e41540cSMike Kravetz * dst_pte == src_pte is the common case of src/dest sharing. 38055e41540cSMike Kravetz * 38065e41540cSMike Kravetz * However, src could have 'unshared' and dst shares with 38075e41540cSMike Kravetz * another vma. If dst_pte !none, this implies sharing. 38085e41540cSMike Kravetz * Check here before taking page table lock, and once again 38095e41540cSMike Kravetz * after taking the lock below. 38105e41540cSMike Kravetz */ 38115e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 38125e41540cSMike Kravetz if ((dst_pte == src_pte) || !huge_pte_none(dst_entry)) 3813c5c99429SLarry Woodman continue; 3814c5c99429SLarry Woodman 3815cb900f41SKirill A. Shutemov dst_ptl = huge_pte_lock(h, dst, dst_pte); 3816cb900f41SKirill A. Shutemov src_ptl = huge_pte_lockptr(h, src, src_pte); 3817cb900f41SKirill A. Shutemov spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 38184a705fefSNaoya Horiguchi entry = huge_ptep_get(src_pte); 38195e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 38204eae4efaSPeter Xu again: 38215e41540cSMike Kravetz if (huge_pte_none(entry) || !huge_pte_none(dst_entry)) { 38225e41540cSMike Kravetz /* 38235e41540cSMike Kravetz * Skip if src entry none. Also, skip in the 38245e41540cSMike Kravetz * unlikely case dst entry !none as this implies 38255e41540cSMike Kravetz * sharing with another vma. 38265e41540cSMike Kravetz */ 38274a705fefSNaoya Horiguchi ; 38284a705fefSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_migration(entry) || 38294a705fefSNaoya Horiguchi is_hugetlb_entry_hwpoisoned(entry))) { 38304a705fefSNaoya Horiguchi swp_entry_t swp_entry = pte_to_swp_entry(entry); 38314a705fefSNaoya Horiguchi 38324a705fefSNaoya Horiguchi if (is_write_migration_entry(swp_entry) && cow) { 38334a705fefSNaoya Horiguchi /* 38344a705fefSNaoya Horiguchi * COW mappings require pages in both 38354a705fefSNaoya Horiguchi * parent and child to be set to read. 38364a705fefSNaoya Horiguchi */ 38374a705fefSNaoya Horiguchi make_migration_entry_read(&swp_entry); 38384a705fefSNaoya Horiguchi entry = swp_entry_to_pte(swp_entry); 3839e5251fd4SPunit Agrawal set_huge_swap_pte_at(src, addr, src_pte, 3840e5251fd4SPunit Agrawal entry, sz); 38414a705fefSNaoya Horiguchi } 3842e5251fd4SPunit Agrawal set_huge_swap_pte_at(dst, addr, dst_pte, entry, sz); 38434a705fefSNaoya Horiguchi } else { 38444eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 38454eae4efaSPeter Xu ptepage = pte_page(entry); 38464eae4efaSPeter Xu get_page(ptepage); 38474eae4efaSPeter Xu 38484eae4efaSPeter Xu /* 38494eae4efaSPeter Xu * This is a rare case where we see pinned hugetlb 38504eae4efaSPeter Xu * pages while they're prone to COW. We need to do the 38514eae4efaSPeter Xu * COW earlier during fork. 38524eae4efaSPeter Xu * 38534eae4efaSPeter Xu * When pre-allocating the page or copying data, we 38544eae4efaSPeter Xu * need to be without the pgtable locks since we could 38554eae4efaSPeter Xu * sleep during the process. 38564eae4efaSPeter Xu */ 38574eae4efaSPeter Xu if (unlikely(page_needs_cow_for_dma(vma, ptepage))) { 38584eae4efaSPeter Xu pte_t src_pte_old = entry; 38594eae4efaSPeter Xu struct page *new; 38604eae4efaSPeter Xu 38614eae4efaSPeter Xu spin_unlock(src_ptl); 38624eae4efaSPeter Xu spin_unlock(dst_ptl); 38634eae4efaSPeter Xu /* Do not use reserve as it's private owned */ 38644eae4efaSPeter Xu new = alloc_huge_page(vma, addr, 1); 38654eae4efaSPeter Xu if (IS_ERR(new)) { 38664eae4efaSPeter Xu put_page(ptepage); 38674eae4efaSPeter Xu ret = PTR_ERR(new); 38684eae4efaSPeter Xu break; 38694eae4efaSPeter Xu } 38704eae4efaSPeter Xu copy_user_huge_page(new, ptepage, addr, vma, 38714eae4efaSPeter Xu npages); 38724eae4efaSPeter Xu put_page(ptepage); 38734eae4efaSPeter Xu 38744eae4efaSPeter Xu /* Install the new huge page if src pte stable */ 38754eae4efaSPeter Xu dst_ptl = huge_pte_lock(h, dst, dst_pte); 38764eae4efaSPeter Xu src_ptl = huge_pte_lockptr(h, src, src_pte); 38774eae4efaSPeter Xu spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 38784eae4efaSPeter Xu entry = huge_ptep_get(src_pte); 38794eae4efaSPeter Xu if (!pte_same(src_pte_old, entry)) { 38804eae4efaSPeter Xu put_page(new); 38814eae4efaSPeter Xu /* dst_entry won't change as in child */ 38824eae4efaSPeter Xu goto again; 38834eae4efaSPeter Xu } 38844eae4efaSPeter Xu hugetlb_install_page(vma, dst_pte, addr, new); 38854eae4efaSPeter Xu spin_unlock(src_ptl); 38864eae4efaSPeter Xu spin_unlock(dst_ptl); 38874eae4efaSPeter Xu continue; 38884eae4efaSPeter Xu } 38894eae4efaSPeter Xu 389034ee645eSJoerg Roedel if (cow) { 38910f10851eSJérôme Glisse /* 38920f10851eSJérôme Glisse * No need to notify as we are downgrading page 38930f10851eSJérôme Glisse * table protection not changing it to point 38940f10851eSJérôme Glisse * to a new page. 38950f10851eSJérôme Glisse * 3896ad56b738SMike Rapoport * See Documentation/vm/mmu_notifier.rst 38970f10851eSJérôme Glisse */ 38987f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 389934ee645eSJoerg Roedel } 39004eae4efaSPeter Xu 390153f9263bSKirill A. Shutemov page_dup_rmap(ptepage, true); 390263551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 39034eae4efaSPeter Xu hugetlb_count_add(npages, dst); 39041c59827dSHugh Dickins } 3905cb900f41SKirill A. Shutemov spin_unlock(src_ptl); 3906cb900f41SKirill A. Shutemov spin_unlock(dst_ptl); 390763551ae0SDavid Gibson } 390863551ae0SDavid Gibson 3909e8569dd2SAndreas Sandberg if (cow) 3910ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 3911c0d0381aSMike Kravetz else 3912c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 3913e8569dd2SAndreas Sandberg 3914e8569dd2SAndreas Sandberg return ret; 391563551ae0SDavid Gibson } 391663551ae0SDavid Gibson 391724669e58SAneesh Kumar K.V void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, 391824669e58SAneesh Kumar K.V unsigned long start, unsigned long end, 391924669e58SAneesh Kumar K.V struct page *ref_page) 392063551ae0SDavid Gibson { 392163551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 392263551ae0SDavid Gibson unsigned long address; 3923c7546f8fSDavid Gibson pte_t *ptep; 392463551ae0SDavid Gibson pte_t pte; 3925cb900f41SKirill A. Shutemov spinlock_t *ptl; 392663551ae0SDavid Gibson struct page *page; 3927a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 3928a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 3929ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 3930a5516438SAndi Kleen 393163551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 3932a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 3933a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 393463551ae0SDavid Gibson 393507e32661SAneesh Kumar K.V /* 393607e32661SAneesh Kumar K.V * This is a hugetlb vma, all the pte entries should point 393707e32661SAneesh Kumar K.V * to huge page. 393807e32661SAneesh Kumar K.V */ 3939ed6a7935SPeter Zijlstra tlb_change_page_size(tlb, sz); 394024669e58SAneesh Kumar K.V tlb_start_vma(tlb, vma); 3941dff11abeSMike Kravetz 3942dff11abeSMike Kravetz /* 3943dff11abeSMike Kravetz * If sharing possible, alert mmu notifiers of worst case. 3944dff11abeSMike Kravetz */ 39456f4f13e8SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, mm, start, 39466f4f13e8SJérôme Glisse end); 3947ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 3948ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 3949569f48b8SHillf Danton address = start; 3950569f48b8SHillf Danton for (; address < end; address += sz) { 39517868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, sz); 3952c7546f8fSDavid Gibson if (!ptep) 3953c7546f8fSDavid Gibson continue; 3954c7546f8fSDavid Gibson 3955cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 395634ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 395731d49da5SAneesh Kumar K.V spin_unlock(ptl); 3958dff11abeSMike Kravetz /* 3959dff11abeSMike Kravetz * We just unmapped a page of PMDs by clearing a PUD. 3960dff11abeSMike Kravetz * The caller's TLB flush range should cover this area. 3961dff11abeSMike Kravetz */ 396231d49da5SAneesh Kumar K.V continue; 396331d49da5SAneesh Kumar K.V } 396439dde65cSChen, Kenneth W 39656629326bSHillf Danton pte = huge_ptep_get(ptep); 396631d49da5SAneesh Kumar K.V if (huge_pte_none(pte)) { 396731d49da5SAneesh Kumar K.V spin_unlock(ptl); 396831d49da5SAneesh Kumar K.V continue; 396931d49da5SAneesh Kumar K.V } 39706629326bSHillf Danton 39716629326bSHillf Danton /* 39729fbc1f63SNaoya Horiguchi * Migrating hugepage or HWPoisoned hugepage is already 39739fbc1f63SNaoya Horiguchi * unmapped and its refcount is dropped, so just clear pte here. 39746629326bSHillf Danton */ 39759fbc1f63SNaoya Horiguchi if (unlikely(!pte_present(pte))) { 39769386fac3SPunit Agrawal huge_pte_clear(mm, address, ptep, sz); 397731d49da5SAneesh Kumar K.V spin_unlock(ptl); 397831d49da5SAneesh Kumar K.V continue; 39798c4894c6SNaoya Horiguchi } 39806629326bSHillf Danton 39816629326bSHillf Danton page = pte_page(pte); 398204f2cbe3SMel Gorman /* 398304f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 398404f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 398504f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 398604f2cbe3SMel Gorman */ 398704f2cbe3SMel Gorman if (ref_page) { 398831d49da5SAneesh Kumar K.V if (page != ref_page) { 398931d49da5SAneesh Kumar K.V spin_unlock(ptl); 399031d49da5SAneesh Kumar K.V continue; 399131d49da5SAneesh Kumar K.V } 399204f2cbe3SMel Gorman /* 399304f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 399404f2cbe3SMel Gorman * future faults in this VMA will fail rather than 399504f2cbe3SMel Gorman * looking like data was lost 399604f2cbe3SMel Gorman */ 399704f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 399804f2cbe3SMel Gorman } 399904f2cbe3SMel Gorman 4000c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 4001b528e4b6SAneesh Kumar K.V tlb_remove_huge_tlb_entry(h, tlb, ptep, address); 4002106c992aSGerald Schaefer if (huge_pte_dirty(pte)) 40036649a386SKen Chen set_page_dirty(page); 40049e81130bSHillf Danton 40055d317b2bSNaoya Horiguchi hugetlb_count_sub(pages_per_huge_page(h), mm); 4006d281ee61SKirill A. Shutemov page_remove_rmap(page, true); 400731d49da5SAneesh Kumar K.V 4008cb900f41SKirill A. Shutemov spin_unlock(ptl); 4009e77b0852SAneesh Kumar K.V tlb_remove_page_size(tlb, page, huge_page_size(h)); 401024669e58SAneesh Kumar K.V /* 401131d49da5SAneesh Kumar K.V * Bail out after unmapping reference page if supplied 401224669e58SAneesh Kumar K.V */ 401331d49da5SAneesh Kumar K.V if (ref_page) 401431d49da5SAneesh Kumar K.V break; 4015fe1668aeSChen, Kenneth W } 4016ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 401724669e58SAneesh Kumar K.V tlb_end_vma(tlb, vma); 40181da177e4SLinus Torvalds } 401963551ae0SDavid Gibson 4020d833352aSMel Gorman void __unmap_hugepage_range_final(struct mmu_gather *tlb, 4021d833352aSMel Gorman struct vm_area_struct *vma, unsigned long start, 4022d833352aSMel Gorman unsigned long end, struct page *ref_page) 4023d833352aSMel Gorman { 4024d833352aSMel Gorman __unmap_hugepage_range(tlb, vma, start, end, ref_page); 4025d833352aSMel Gorman 4026d833352aSMel Gorman /* 4027d833352aSMel Gorman * Clear this flag so that x86's huge_pmd_share page_table_shareable 4028d833352aSMel Gorman * test will fail on a vma being torn down, and not grab a page table 4029d833352aSMel Gorman * on its way out. We're lucky that the flag has such an appropriate 4030d833352aSMel Gorman * name, and can in fact be safely cleared here. We could clear it 4031d833352aSMel Gorman * before the __unmap_hugepage_range above, but all that's necessary 4032c8c06efaSDavidlohr Bueso * is to clear it before releasing the i_mmap_rwsem. This works 4033d833352aSMel Gorman * because in the context this is called, the VMA is about to be 4034c8c06efaSDavidlohr Bueso * destroyed and the i_mmap_rwsem is held. 4035d833352aSMel Gorman */ 4036d833352aSMel Gorman vma->vm_flags &= ~VM_MAYSHARE; 4037d833352aSMel Gorman } 4038d833352aSMel Gorman 4039502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 404004f2cbe3SMel Gorman unsigned long end, struct page *ref_page) 4041502717f4SChen, Kenneth W { 404224669e58SAneesh Kumar K.V struct mmu_gather tlb; 4043dff11abeSMike Kravetz 4044a72afd87SWill Deacon tlb_gather_mmu(&tlb, vma->vm_mm); 404524669e58SAneesh Kumar K.V __unmap_hugepage_range(&tlb, vma, start, end, ref_page); 4046ae8eba8bSWill Deacon tlb_finish_mmu(&tlb); 4047502717f4SChen, Kenneth W } 4048502717f4SChen, Kenneth W 404904f2cbe3SMel Gorman /* 405004f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 4051578b7725SZhiyuan Dai * mapping it owns the reserve page for. The intention is to unmap the page 405204f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 405304f2cbe3SMel Gorman * same region. 405404f2cbe3SMel Gorman */ 40552f4612afSDavidlohr Bueso static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, 40562a4b3dedSHarvey Harrison struct page *page, unsigned long address) 405704f2cbe3SMel Gorman { 40587526674dSAdam Litke struct hstate *h = hstate_vma(vma); 405904f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 406004f2cbe3SMel Gorman struct address_space *mapping; 406104f2cbe3SMel Gorman pgoff_t pgoff; 406204f2cbe3SMel Gorman 406304f2cbe3SMel Gorman /* 406404f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 406504f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 406604f2cbe3SMel Gorman */ 40677526674dSAdam Litke address = address & huge_page_mask(h); 406836e4f20aSMichal Hocko pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + 406936e4f20aSMichal Hocko vma->vm_pgoff; 407093c76a3dSAl Viro mapping = vma->vm_file->f_mapping; 407104f2cbe3SMel Gorman 40724eb2b1dcSMel Gorman /* 40734eb2b1dcSMel Gorman * Take the mapping lock for the duration of the table walk. As 40744eb2b1dcSMel Gorman * this mapping should be shared between all the VMAs, 40754eb2b1dcSMel Gorman * __unmap_hugepage_range() is called as the lock is already held 40764eb2b1dcSMel Gorman */ 407783cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 40786b2dbba8SMichel Lespinasse vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { 407904f2cbe3SMel Gorman /* Do not unmap the current VMA */ 408004f2cbe3SMel Gorman if (iter_vma == vma) 408104f2cbe3SMel Gorman continue; 408204f2cbe3SMel Gorman 408304f2cbe3SMel Gorman /* 40842f84a899SMel Gorman * Shared VMAs have their own reserves and do not affect 40852f84a899SMel Gorman * MAP_PRIVATE accounting but it is possible that a shared 40862f84a899SMel Gorman * VMA is using the same page so check and skip such VMAs. 40872f84a899SMel Gorman */ 40882f84a899SMel Gorman if (iter_vma->vm_flags & VM_MAYSHARE) 40892f84a899SMel Gorman continue; 40902f84a899SMel Gorman 40912f84a899SMel Gorman /* 409204f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 409304f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 409404f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 409504f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 409604f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 409704f2cbe3SMel Gorman */ 409804f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 409924669e58SAneesh Kumar K.V unmap_hugepage_range(iter_vma, address, 410024669e58SAneesh Kumar K.V address + huge_page_size(h), page); 410104f2cbe3SMel Gorman } 410283cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 410304f2cbe3SMel Gorman } 410404f2cbe3SMel Gorman 41050fe6e20bSNaoya Horiguchi /* 41060fe6e20bSNaoya Horiguchi * Hugetlb_cow() should be called with page lock of the original hugepage held. 4107ef009b25SMichal Hocko * Called with hugetlb_instantiation_mutex held and pte_page locked so we 4108ef009b25SMichal Hocko * cannot race with other handlers or page migration. 4109ef009b25SMichal Hocko * Keep the pte_same checks anyway to make transition from the mutex easier. 41100fe6e20bSNaoya Horiguchi */ 41112b740303SSouptick Joarder static vm_fault_t hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, 4112974e6d66SHuang Ying unsigned long address, pte_t *ptep, 4113cb900f41SKirill A. Shutemov struct page *pagecache_page, spinlock_t *ptl) 41141e8f889bSDavid Gibson { 41153999f52eSAneesh Kumar K.V pte_t pte; 4116a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 41171e8f889bSDavid Gibson struct page *old_page, *new_page; 41182b740303SSouptick Joarder int outside_reserve = 0; 41192b740303SSouptick Joarder vm_fault_t ret = 0; 4120974e6d66SHuang Ying unsigned long haddr = address & huge_page_mask(h); 4121ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 41221e8f889bSDavid Gibson 41233999f52eSAneesh Kumar K.V pte = huge_ptep_get(ptep); 41241e8f889bSDavid Gibson old_page = pte_page(pte); 41251e8f889bSDavid Gibson 412604f2cbe3SMel Gorman retry_avoidcopy: 41271e8f889bSDavid Gibson /* If no-one else is actually using this page, avoid the copy 41281e8f889bSDavid Gibson * and just make the page writable */ 412937a2140dSJoonsoo Kim if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { 41305a49973dSHugh Dickins page_move_anon_rmap(old_page, vma); 41315b7a1d40SHuang Ying set_huge_ptep_writable(vma, haddr, ptep); 413283c54070SNick Piggin return 0; 41331e8f889bSDavid Gibson } 41341e8f889bSDavid Gibson 413504f2cbe3SMel Gorman /* 413604f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 413704f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 413804f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 413904f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 414004f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 414104f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 414204f2cbe3SMel Gorman * of the full address range. 414304f2cbe3SMel Gorman */ 41445944d011SJoonsoo Kim if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 414504f2cbe3SMel Gorman old_page != pagecache_page) 414604f2cbe3SMel Gorman outside_reserve = 1; 414704f2cbe3SMel Gorman 414809cbfeafSKirill A. Shutemov get_page(old_page); 4149b76c8cfbSLarry Woodman 4150ad4404a2SDavidlohr Bueso /* 4151ad4404a2SDavidlohr Bueso * Drop page table lock as buddy allocator may be called. It will 4152ad4404a2SDavidlohr Bueso * be acquired again before returning to the caller, as expected. 4153ad4404a2SDavidlohr Bueso */ 4154cb900f41SKirill A. Shutemov spin_unlock(ptl); 41555b7a1d40SHuang Ying new_page = alloc_huge_page(vma, haddr, outside_reserve); 41561e8f889bSDavid Gibson 41572fc39cecSAdam Litke if (IS_ERR(new_page)) { 415804f2cbe3SMel Gorman /* 415904f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 416004f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 416104f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 416204f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 416304f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 416404f2cbe3SMel Gorman */ 416504f2cbe3SMel Gorman if (outside_reserve) { 4166e7dd91c4SMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 4167e7dd91c4SMike Kravetz pgoff_t idx; 4168e7dd91c4SMike Kravetz u32 hash; 4169e7dd91c4SMike Kravetz 417009cbfeafSKirill A. Shutemov put_page(old_page); 417104f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 4172e7dd91c4SMike Kravetz /* 4173e7dd91c4SMike Kravetz * Drop hugetlb_fault_mutex and i_mmap_rwsem before 4174e7dd91c4SMike Kravetz * unmapping. unmapping needs to hold i_mmap_rwsem 4175e7dd91c4SMike Kravetz * in write mode. Dropping i_mmap_rwsem in read mode 4176e7dd91c4SMike Kravetz * here is OK as COW mappings do not interact with 4177e7dd91c4SMike Kravetz * PMD sharing. 4178e7dd91c4SMike Kravetz * 4179e7dd91c4SMike Kravetz * Reacquire both after unmap operation. 4180e7dd91c4SMike Kravetz */ 4181e7dd91c4SMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 4182e7dd91c4SMike Kravetz hash = hugetlb_fault_mutex_hash(mapping, idx); 4183e7dd91c4SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 4184e7dd91c4SMike Kravetz i_mmap_unlock_read(mapping); 4185e7dd91c4SMike Kravetz 41865b7a1d40SHuang Ying unmap_ref_private(mm, vma, old_page, haddr); 4187e7dd91c4SMike Kravetz 4188e7dd91c4SMike Kravetz i_mmap_lock_read(mapping); 4189e7dd91c4SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 4190cb900f41SKirill A. Shutemov spin_lock(ptl); 41915b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 4192a9af0c5dSNaoya Horiguchi if (likely(ptep && 4193a9af0c5dSNaoya Horiguchi pte_same(huge_ptep_get(ptep), pte))) 419404f2cbe3SMel Gorman goto retry_avoidcopy; 4195a734bcc8SHillf Danton /* 4196cb900f41SKirill A. Shutemov * race occurs while re-acquiring page table 4197cb900f41SKirill A. Shutemov * lock, and our job is done. 4198a734bcc8SHillf Danton */ 4199a734bcc8SHillf Danton return 0; 420004f2cbe3SMel Gorman } 420104f2cbe3SMel Gorman 42022b740303SSouptick Joarder ret = vmf_error(PTR_ERR(new_page)); 4203ad4404a2SDavidlohr Bueso goto out_release_old; 42041e8f889bSDavid Gibson } 42051e8f889bSDavid Gibson 42060fe6e20bSNaoya Horiguchi /* 42070fe6e20bSNaoya Horiguchi * When the original hugepage is shared one, it does not have 42080fe6e20bSNaoya Horiguchi * anon_vma prepared. 42090fe6e20bSNaoya Horiguchi */ 421044e2aa93SDean Nelson if (unlikely(anon_vma_prepare(vma))) { 4211ad4404a2SDavidlohr Bueso ret = VM_FAULT_OOM; 4212ad4404a2SDavidlohr Bueso goto out_release_all; 421344e2aa93SDean Nelson } 42140fe6e20bSNaoya Horiguchi 4215974e6d66SHuang Ying copy_user_huge_page(new_page, old_page, address, vma, 421647ad8475SAndrea Arcangeli pages_per_huge_page(h)); 42170ed361deSNick Piggin __SetPageUptodate(new_page); 42181e8f889bSDavid Gibson 42197269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr, 42206f4f13e8SJérôme Glisse haddr + huge_page_size(h)); 4221ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4222ad4404a2SDavidlohr Bueso 4223b76c8cfbSLarry Woodman /* 4224cb900f41SKirill A. Shutemov * Retake the page table lock to check for racing updates 4225b76c8cfbSLarry Woodman * before the page tables are altered 4226b76c8cfbSLarry Woodman */ 4227cb900f41SKirill A. Shutemov spin_lock(ptl); 42285b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 4229a9af0c5dSNaoya Horiguchi if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { 4230d6995da3SMike Kravetz ClearHPageRestoreReserve(new_page); 423107443a85SJoonsoo Kim 42321e8f889bSDavid Gibson /* Break COW */ 42335b7a1d40SHuang Ying huge_ptep_clear_flush(vma, haddr, ptep); 4234ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range(mm, range.start, range.end); 42355b7a1d40SHuang Ying set_huge_pte_at(mm, haddr, ptep, 42361e8f889bSDavid Gibson make_huge_pte(vma, new_page, 1)); 4237d281ee61SKirill A. Shutemov page_remove_rmap(old_page, true); 42385b7a1d40SHuang Ying hugepage_add_new_anon_rmap(new_page, vma, haddr); 42398f251a3dSMike Kravetz SetHPageMigratable(new_page); 42401e8f889bSDavid Gibson /* Make the old page be freed below */ 42411e8f889bSDavid Gibson new_page = old_page; 42421e8f889bSDavid Gibson } 4243cb900f41SKirill A. Shutemov spin_unlock(ptl); 4244ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 4245ad4404a2SDavidlohr Bueso out_release_all: 42465b7a1d40SHuang Ying restore_reserve_on_error(h, vma, haddr, new_page); 424709cbfeafSKirill A. Shutemov put_page(new_page); 4248ad4404a2SDavidlohr Bueso out_release_old: 424909cbfeafSKirill A. Shutemov put_page(old_page); 42508312034fSJoonsoo Kim 4251ad4404a2SDavidlohr Bueso spin_lock(ptl); /* Caller expects lock to be held */ 4252ad4404a2SDavidlohr Bueso return ret; 42531e8f889bSDavid Gibson } 42541e8f889bSDavid Gibson 425504f2cbe3SMel Gorman /* Return the pagecache page at a given address within a VMA */ 4256a5516438SAndi Kleen static struct page *hugetlbfs_pagecache_page(struct hstate *h, 4257a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 425804f2cbe3SMel Gorman { 425904f2cbe3SMel Gorman struct address_space *mapping; 4260e7c4b0bfSAndy Whitcroft pgoff_t idx; 426104f2cbe3SMel Gorman 426204f2cbe3SMel Gorman mapping = vma->vm_file->f_mapping; 4263a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 426404f2cbe3SMel Gorman 426504f2cbe3SMel Gorman return find_lock_page(mapping, idx); 426604f2cbe3SMel Gorman } 426704f2cbe3SMel Gorman 42683ae77f43SHugh Dickins /* 42693ae77f43SHugh Dickins * Return whether there is a pagecache page to back given address within VMA. 42703ae77f43SHugh Dickins * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. 42713ae77f43SHugh Dickins */ 42723ae77f43SHugh Dickins static bool hugetlbfs_pagecache_present(struct hstate *h, 42732a15efc9SHugh Dickins struct vm_area_struct *vma, unsigned long address) 42742a15efc9SHugh Dickins { 42752a15efc9SHugh Dickins struct address_space *mapping; 42762a15efc9SHugh Dickins pgoff_t idx; 42772a15efc9SHugh Dickins struct page *page; 42782a15efc9SHugh Dickins 42792a15efc9SHugh Dickins mapping = vma->vm_file->f_mapping; 42802a15efc9SHugh Dickins idx = vma_hugecache_offset(h, vma, address); 42812a15efc9SHugh Dickins 42822a15efc9SHugh Dickins page = find_get_page(mapping, idx); 42832a15efc9SHugh Dickins if (page) 42842a15efc9SHugh Dickins put_page(page); 42852a15efc9SHugh Dickins return page != NULL; 42862a15efc9SHugh Dickins } 42872a15efc9SHugh Dickins 4288ab76ad54SMike Kravetz int huge_add_to_page_cache(struct page *page, struct address_space *mapping, 4289ab76ad54SMike Kravetz pgoff_t idx) 4290ab76ad54SMike Kravetz { 4291ab76ad54SMike Kravetz struct inode *inode = mapping->host; 4292ab76ad54SMike Kravetz struct hstate *h = hstate_inode(inode); 4293ab76ad54SMike Kravetz int err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); 4294ab76ad54SMike Kravetz 4295ab76ad54SMike Kravetz if (err) 4296ab76ad54SMike Kravetz return err; 4297d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 4298ab76ad54SMike Kravetz 429922146c3cSMike Kravetz /* 430022146c3cSMike Kravetz * set page dirty so that it will not be removed from cache/file 430122146c3cSMike Kravetz * by non-hugetlbfs specific code paths. 430222146c3cSMike Kravetz */ 430322146c3cSMike Kravetz set_page_dirty(page); 430422146c3cSMike Kravetz 4305ab76ad54SMike Kravetz spin_lock(&inode->i_lock); 4306ab76ad54SMike Kravetz inode->i_blocks += blocks_per_huge_page(h); 4307ab76ad54SMike Kravetz spin_unlock(&inode->i_lock); 4308ab76ad54SMike Kravetz return 0; 4309ab76ad54SMike Kravetz } 4310ab76ad54SMike Kravetz 43112b740303SSouptick Joarder static vm_fault_t hugetlb_no_page(struct mm_struct *mm, 43122b740303SSouptick Joarder struct vm_area_struct *vma, 43138382d914SDavidlohr Bueso struct address_space *mapping, pgoff_t idx, 4314788c7df4SHugh Dickins unsigned long address, pte_t *ptep, unsigned int flags) 4315ac9b9c66SHugh Dickins { 4316a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 43172b740303SSouptick Joarder vm_fault_t ret = VM_FAULT_SIGBUS; 4318409eb8c2SHillf Danton int anon_rmap = 0; 43194c887265SAdam Litke unsigned long size; 43204c887265SAdam Litke struct page *page; 43211e8f889bSDavid Gibson pte_t new_pte; 4322cb900f41SKirill A. Shutemov spinlock_t *ptl; 4323285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 4324cb6acd01SMike Kravetz bool new_page = false; 43254c887265SAdam Litke 432604f2cbe3SMel Gorman /* 432704f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 432804f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 432925985edcSLucas De Marchi * COW. Warn that such a situation has occurred as it may not be obvious 433004f2cbe3SMel Gorman */ 433104f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 4332910154d5SGeoffrey Thomas pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n", 433304f2cbe3SMel Gorman current->pid); 433404f2cbe3SMel Gorman return ret; 433504f2cbe3SMel Gorman } 433604f2cbe3SMel Gorman 43374c887265SAdam Litke /* 433887bf91d3SMike Kravetz * We can not race with truncation due to holding i_mmap_rwsem. 433987bf91d3SMike Kravetz * i_size is modified when holding i_mmap_rwsem, so check here 434087bf91d3SMike Kravetz * once for faults beyond end of file. 43414c887265SAdam Litke */ 4342a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 4343ebed4bfcSHugh Dickins if (idx >= size) 4344ebed4bfcSHugh Dickins goto out; 43451a1aad8aSMike Kravetz 434687bf91d3SMike Kravetz retry: 434787bf91d3SMike Kravetz page = find_lock_page(mapping, idx); 434887bf91d3SMike Kravetz if (!page) { 43491a1aad8aSMike Kravetz /* 43501a1aad8aSMike Kravetz * Check for page in userfault range 43511a1aad8aSMike Kravetz */ 43521a1aad8aSMike Kravetz if (userfaultfd_missing(vma)) { 43531a1aad8aSMike Kravetz u32 hash; 43541a1aad8aSMike Kravetz struct vm_fault vmf = { 43551a1aad8aSMike Kravetz .vma = vma, 4356285b8dcaSHuang Ying .address = haddr, 43571a1aad8aSMike Kravetz .flags = flags, 43581a1aad8aSMike Kravetz /* 43591a1aad8aSMike Kravetz * Hard to debug if it ends up being 43601a1aad8aSMike Kravetz * used by a callee that assumes 43611a1aad8aSMike Kravetz * something about the other 43621a1aad8aSMike Kravetz * uninitialized fields... same as in 43631a1aad8aSMike Kravetz * memory.c 43641a1aad8aSMike Kravetz */ 43651a1aad8aSMike Kravetz }; 43661a1aad8aSMike Kravetz 43671a1aad8aSMike Kravetz /* 4368c0d0381aSMike Kravetz * hugetlb_fault_mutex and i_mmap_rwsem must be 4369c0d0381aSMike Kravetz * dropped before handling userfault. Reacquire 4370c0d0381aSMike Kravetz * after handling fault to make calling code simpler. 43711a1aad8aSMike Kravetz */ 4372188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 43731a1aad8aSMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 4374c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 43751a1aad8aSMike Kravetz ret = handle_userfault(&vmf, VM_UFFD_MISSING); 4376c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 43771a1aad8aSMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 43781a1aad8aSMike Kravetz goto out; 43791a1aad8aSMike Kravetz } 43801a1aad8aSMike Kravetz 4381285b8dcaSHuang Ying page = alloc_huge_page(vma, haddr, 0); 43822fc39cecSAdam Litke if (IS_ERR(page)) { 43834643d67eSMike Kravetz /* 43844643d67eSMike Kravetz * Returning error will result in faulting task being 43854643d67eSMike Kravetz * sent SIGBUS. The hugetlb fault mutex prevents two 43864643d67eSMike Kravetz * tasks from racing to fault in the same page which 43874643d67eSMike Kravetz * could result in false unable to allocate errors. 43884643d67eSMike Kravetz * Page migration does not take the fault mutex, but 43894643d67eSMike Kravetz * does a clear then write of pte's under page table 43904643d67eSMike Kravetz * lock. Page fault code could race with migration, 43914643d67eSMike Kravetz * notice the clear pte and try to allocate a page 43924643d67eSMike Kravetz * here. Before returning error, get ptl and make 43934643d67eSMike Kravetz * sure there really is no pte entry. 43944643d67eSMike Kravetz */ 43954643d67eSMike Kravetz ptl = huge_pte_lock(h, mm, ptep); 43964643d67eSMike Kravetz ret = 0; 4397d83e6c8aSMiaohe Lin if (huge_pte_none(huge_ptep_get(ptep))) 43982b740303SSouptick Joarder ret = vmf_error(PTR_ERR(page)); 4399d83e6c8aSMiaohe Lin spin_unlock(ptl); 44006bda666aSChristoph Lameter goto out; 44016bda666aSChristoph Lameter } 440247ad8475SAndrea Arcangeli clear_huge_page(page, address, pages_per_huge_page(h)); 44030ed361deSNick Piggin __SetPageUptodate(page); 4404cb6acd01SMike Kravetz new_page = true; 4405ac9b9c66SHugh Dickins 4406f83a275dSMel Gorman if (vma->vm_flags & VM_MAYSHARE) { 4407ab76ad54SMike Kravetz int err = huge_add_to_page_cache(page, mapping, idx); 44086bda666aSChristoph Lameter if (err) { 44096bda666aSChristoph Lameter put_page(page); 44106bda666aSChristoph Lameter if (err == -EEXIST) 44116bda666aSChristoph Lameter goto retry; 44126bda666aSChristoph Lameter goto out; 44136bda666aSChristoph Lameter } 441423be7468SMel Gorman } else { 44156bda666aSChristoph Lameter lock_page(page); 44160fe6e20bSNaoya Horiguchi if (unlikely(anon_vma_prepare(vma))) { 44170fe6e20bSNaoya Horiguchi ret = VM_FAULT_OOM; 44180fe6e20bSNaoya Horiguchi goto backout_unlocked; 441923be7468SMel Gorman } 4420409eb8c2SHillf Danton anon_rmap = 1; 44210fe6e20bSNaoya Horiguchi } 44220fe6e20bSNaoya Horiguchi } else { 442357303d80SAndy Whitcroft /* 4424998b4382SNaoya Horiguchi * If memory error occurs between mmap() and fault, some process 4425998b4382SNaoya Horiguchi * don't have hwpoisoned swap entry for errored virtual address. 4426998b4382SNaoya Horiguchi * So we need to block hugepage fault by PG_hwpoison bit check. 4427fd6a03edSNaoya Horiguchi */ 4428fd6a03edSNaoya Horiguchi if (unlikely(PageHWPoison(page))) { 44290eb98f15SMiaohe Lin ret = VM_FAULT_HWPOISON_LARGE | 4430972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 4431fd6a03edSNaoya Horiguchi goto backout_unlocked; 44326bda666aSChristoph Lameter } 4433998b4382SNaoya Horiguchi } 44341e8f889bSDavid Gibson 443557303d80SAndy Whitcroft /* 443657303d80SAndy Whitcroft * If we are going to COW a private mapping later, we examine the 443757303d80SAndy Whitcroft * pending reservations for this page now. This will ensure that 443857303d80SAndy Whitcroft * any allocations necessary to record that reservation occur outside 443957303d80SAndy Whitcroft * the spinlock. 444057303d80SAndy Whitcroft */ 44415e911373SMike Kravetz if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 4442285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 44432b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 44442b26736cSAndy Whitcroft goto backout_unlocked; 44452b26736cSAndy Whitcroft } 44465e911373SMike Kravetz /* Just decrements count, does not deallocate */ 4447285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 44485e911373SMike Kravetz } 444957303d80SAndy Whitcroft 44508bea8052SAneesh Kumar K.V ptl = huge_pte_lock(h, mm, ptep); 445183c54070SNick Piggin ret = 0; 44527f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(ptep))) 44534c887265SAdam Litke goto backout; 44544c887265SAdam Litke 445507443a85SJoonsoo Kim if (anon_rmap) { 4456d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 4457285b8dcaSHuang Ying hugepage_add_new_anon_rmap(page, vma, haddr); 4458ac714904SChoi Gi-yong } else 445953f9263bSKirill A. Shutemov page_dup_rmap(page, true); 44601e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 44611e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 4462285b8dcaSHuang Ying set_huge_pte_at(mm, haddr, ptep, new_pte); 44631e8f889bSDavid Gibson 44645d317b2bSNaoya Horiguchi hugetlb_count_add(pages_per_huge_page(h), mm); 4465788c7df4SHugh Dickins if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 44661e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 4467974e6d66SHuang Ying ret = hugetlb_cow(mm, vma, address, ptep, page, ptl); 44681e8f889bSDavid Gibson } 44691e8f889bSDavid Gibson 4470cb900f41SKirill A. Shutemov spin_unlock(ptl); 4471cb6acd01SMike Kravetz 4472cb6acd01SMike Kravetz /* 44738f251a3dSMike Kravetz * Only set HPageMigratable in newly allocated pages. Existing pages 44748f251a3dSMike Kravetz * found in the pagecache may not have HPageMigratableset if they have 44758f251a3dSMike Kravetz * been isolated for migration. 4476cb6acd01SMike Kravetz */ 4477cb6acd01SMike Kravetz if (new_page) 44788f251a3dSMike Kravetz SetHPageMigratable(page); 4479cb6acd01SMike Kravetz 44804c887265SAdam Litke unlock_page(page); 44814c887265SAdam Litke out: 4482ac9b9c66SHugh Dickins return ret; 44834c887265SAdam Litke 44844c887265SAdam Litke backout: 4485cb900f41SKirill A. Shutemov spin_unlock(ptl); 44862b26736cSAndy Whitcroft backout_unlocked: 44874c887265SAdam Litke unlock_page(page); 4488285b8dcaSHuang Ying restore_reserve_on_error(h, vma, haddr, page); 44894c887265SAdam Litke put_page(page); 44904c887265SAdam Litke goto out; 4491ac9b9c66SHugh Dickins } 4492ac9b9c66SHugh Dickins 44938382d914SDavidlohr Bueso #ifdef CONFIG_SMP 4494188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 44958382d914SDavidlohr Bueso { 44968382d914SDavidlohr Bueso unsigned long key[2]; 44978382d914SDavidlohr Bueso u32 hash; 44988382d914SDavidlohr Bueso 44998382d914SDavidlohr Bueso key[0] = (unsigned long) mapping; 45008382d914SDavidlohr Bueso key[1] = idx; 45018382d914SDavidlohr Bueso 450255254636SMike Kravetz hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0); 45038382d914SDavidlohr Bueso 45048382d914SDavidlohr Bueso return hash & (num_fault_mutexes - 1); 45058382d914SDavidlohr Bueso } 45068382d914SDavidlohr Bueso #else 45078382d914SDavidlohr Bueso /* 45086c26d310SMiaohe Lin * For uniprocessor systems we always use a single mutex, so just 45098382d914SDavidlohr Bueso * return 0 and avoid the hashing overhead. 45108382d914SDavidlohr Bueso */ 4511188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 45128382d914SDavidlohr Bueso { 45138382d914SDavidlohr Bueso return 0; 45148382d914SDavidlohr Bueso } 45158382d914SDavidlohr Bueso #endif 45168382d914SDavidlohr Bueso 45172b740303SSouptick Joarder vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 4518788c7df4SHugh Dickins unsigned long address, unsigned int flags) 451986e5216fSAdam Litke { 45208382d914SDavidlohr Bueso pte_t *ptep, entry; 4521cb900f41SKirill A. Shutemov spinlock_t *ptl; 45222b740303SSouptick Joarder vm_fault_t ret; 45238382d914SDavidlohr Bueso u32 hash; 45248382d914SDavidlohr Bueso pgoff_t idx; 45250fe6e20bSNaoya Horiguchi struct page *page = NULL; 452657303d80SAndy Whitcroft struct page *pagecache_page = NULL; 4527a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 45288382d914SDavidlohr Bueso struct address_space *mapping; 45290f792cf9SNaoya Horiguchi int need_wait_lock = 0; 4530285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 453186e5216fSAdam Litke 4532285b8dcaSHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 4533fd6a03edSNaoya Horiguchi if (ptep) { 4534c0d0381aSMike Kravetz /* 4535c0d0381aSMike Kravetz * Since we hold no locks, ptep could be stale. That is 4536c0d0381aSMike Kravetz * OK as we are only making decisions based on content and 4537c0d0381aSMike Kravetz * not actually modifying content here. 4538c0d0381aSMike Kravetz */ 4539fd6a03edSNaoya Horiguchi entry = huge_ptep_get(ptep); 4540290408d4SNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(entry))) { 4541cb900f41SKirill A. Shutemov migration_entry_wait_huge(vma, mm, ptep); 4542290408d4SNaoya Horiguchi return 0; 4543290408d4SNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) 4544aa50d3a7SAndi Kleen return VM_FAULT_HWPOISON_LARGE | 4545972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 4546b43a9990SMike Kravetz } 45478382d914SDavidlohr Bueso 4548c0d0381aSMike Kravetz /* 4549c0d0381aSMike Kravetz * Acquire i_mmap_rwsem before calling huge_pte_alloc and hold 455087bf91d3SMike Kravetz * until finished with ptep. This serves two purposes: 455187bf91d3SMike Kravetz * 1) It prevents huge_pmd_unshare from being called elsewhere 455287bf91d3SMike Kravetz * and making the ptep no longer valid. 455387bf91d3SMike Kravetz * 2) It synchronizes us with i_size modifications during truncation. 4554c0d0381aSMike Kravetz * 4555c0d0381aSMike Kravetz * ptep could have already be assigned via huge_pte_offset. That 4556c0d0381aSMike Kravetz * is OK, as huge_pte_alloc will return the same value unless 4557c0d0381aSMike Kravetz * something has changed. 4558c0d0381aSMike Kravetz */ 4559ddeaab32SMike Kravetz mapping = vma->vm_file->f_mapping; 4560c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 4561aec44e0fSPeter Xu ptep = huge_pte_alloc(mm, vma, haddr, huge_page_size(h)); 4562c0d0381aSMike Kravetz if (!ptep) { 4563c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 4564c0d0381aSMike Kravetz return VM_FAULT_OOM; 4565c0d0381aSMike Kravetz } 4566ddeaab32SMike Kravetz 45673935baa9SDavid Gibson /* 45683935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 45693935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 45703935baa9SDavid Gibson * the same page in the page cache. 45713935baa9SDavid Gibson */ 4572c0d0381aSMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 4573188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 4574c672c7f2SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 45758382d914SDavidlohr Bueso 45767f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 45777f2e9525SGerald Schaefer if (huge_pte_none(entry)) { 45788382d914SDavidlohr Bueso ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, flags); 4579b4d1d99fSDavid Gibson goto out_mutex; 45803935baa9SDavid Gibson } 458186e5216fSAdam Litke 458283c54070SNick Piggin ret = 0; 45831e8f889bSDavid Gibson 458457303d80SAndy Whitcroft /* 45850f792cf9SNaoya Horiguchi * entry could be a migration/hwpoison entry at this point, so this 45860f792cf9SNaoya Horiguchi * check prevents the kernel from going below assuming that we have 45877c8de358SEthon Paul * an active hugepage in pagecache. This goto expects the 2nd page 45887c8de358SEthon Paul * fault, and is_hugetlb_entry_(migration|hwpoisoned) check will 45897c8de358SEthon Paul * properly handle it. 45900f792cf9SNaoya Horiguchi */ 45910f792cf9SNaoya Horiguchi if (!pte_present(entry)) 45920f792cf9SNaoya Horiguchi goto out_mutex; 45930f792cf9SNaoya Horiguchi 45940f792cf9SNaoya Horiguchi /* 459557303d80SAndy Whitcroft * If we are going to COW the mapping later, we examine the pending 459657303d80SAndy Whitcroft * reservations for this page now. This will ensure that any 459757303d80SAndy Whitcroft * allocations necessary to record that reservation occur outside the 459857303d80SAndy Whitcroft * spinlock. For private mappings, we also lookup the pagecache 459957303d80SAndy Whitcroft * page now as it is used to determine if a reservation has been 460057303d80SAndy Whitcroft * consumed. 460157303d80SAndy Whitcroft */ 4602106c992aSGerald Schaefer if ((flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { 4603285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 46042b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 4605b4d1d99fSDavid Gibson goto out_mutex; 46062b26736cSAndy Whitcroft } 46075e911373SMike Kravetz /* Just decrements count, does not deallocate */ 4608285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 460957303d80SAndy Whitcroft 4610f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 461157303d80SAndy Whitcroft pagecache_page = hugetlbfs_pagecache_page(h, 4612285b8dcaSHuang Ying vma, haddr); 461357303d80SAndy Whitcroft } 461457303d80SAndy Whitcroft 46150f792cf9SNaoya Horiguchi ptl = huge_pte_lock(h, mm, ptep); 46160fe6e20bSNaoya Horiguchi 46171e8f889bSDavid Gibson /* Check for a racing update before calling hugetlb_cow */ 4618b4d1d99fSDavid Gibson if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) 4619cb900f41SKirill A. Shutemov goto out_ptl; 4620b4d1d99fSDavid Gibson 46210f792cf9SNaoya Horiguchi /* 46220f792cf9SNaoya Horiguchi * hugetlb_cow() requires page locks of pte_page(entry) and 46230f792cf9SNaoya Horiguchi * pagecache_page, so here we need take the former one 46240f792cf9SNaoya Horiguchi * when page != pagecache_page or !pagecache_page. 46250f792cf9SNaoya Horiguchi */ 46260f792cf9SNaoya Horiguchi page = pte_page(entry); 46270f792cf9SNaoya Horiguchi if (page != pagecache_page) 46280f792cf9SNaoya Horiguchi if (!trylock_page(page)) { 46290f792cf9SNaoya Horiguchi need_wait_lock = 1; 46300f792cf9SNaoya Horiguchi goto out_ptl; 46310f792cf9SNaoya Horiguchi } 46320f792cf9SNaoya Horiguchi 46330f792cf9SNaoya Horiguchi get_page(page); 4634b4d1d99fSDavid Gibson 4635788c7df4SHugh Dickins if (flags & FAULT_FLAG_WRITE) { 4636106c992aSGerald Schaefer if (!huge_pte_write(entry)) { 4637974e6d66SHuang Ying ret = hugetlb_cow(mm, vma, address, ptep, 4638cb900f41SKirill A. Shutemov pagecache_page, ptl); 46390f792cf9SNaoya Horiguchi goto out_put_page; 4640b4d1d99fSDavid Gibson } 4641106c992aSGerald Schaefer entry = huge_pte_mkdirty(entry); 4642b4d1d99fSDavid Gibson } 4643b4d1d99fSDavid Gibson entry = pte_mkyoung(entry); 4644285b8dcaSHuang Ying if (huge_ptep_set_access_flags(vma, haddr, ptep, entry, 4645788c7df4SHugh Dickins flags & FAULT_FLAG_WRITE)) 4646285b8dcaSHuang Ying update_mmu_cache(vma, haddr, ptep); 46470f792cf9SNaoya Horiguchi out_put_page: 46480f792cf9SNaoya Horiguchi if (page != pagecache_page) 46490f792cf9SNaoya Horiguchi unlock_page(page); 46500f792cf9SNaoya Horiguchi put_page(page); 4651cb900f41SKirill A. Shutemov out_ptl: 4652cb900f41SKirill A. Shutemov spin_unlock(ptl); 465357303d80SAndy Whitcroft 465457303d80SAndy Whitcroft if (pagecache_page) { 465557303d80SAndy Whitcroft unlock_page(pagecache_page); 465657303d80SAndy Whitcroft put_page(pagecache_page); 465757303d80SAndy Whitcroft } 4658b4d1d99fSDavid Gibson out_mutex: 4659c672c7f2SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 4660c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 46610f792cf9SNaoya Horiguchi /* 46620f792cf9SNaoya Horiguchi * Generally it's safe to hold refcount during waiting page lock. But 46630f792cf9SNaoya Horiguchi * here we just wait to defer the next page fault to avoid busy loop and 46640f792cf9SNaoya Horiguchi * the page is not used after unlocked before returning from the current 46650f792cf9SNaoya Horiguchi * page fault. So we are safe from accessing freed page, even if we wait 46660f792cf9SNaoya Horiguchi * here without taking refcount. 46670f792cf9SNaoya Horiguchi */ 46680f792cf9SNaoya Horiguchi if (need_wait_lock) 46690f792cf9SNaoya Horiguchi wait_on_page_locked(page); 46701e8f889bSDavid Gibson return ret; 467186e5216fSAdam Litke } 467286e5216fSAdam Litke 46738fb5debcSMike Kravetz /* 46748fb5debcSMike Kravetz * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with 46758fb5debcSMike Kravetz * modifications for huge pages. 46768fb5debcSMike Kravetz */ 46778fb5debcSMike Kravetz int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, 46788fb5debcSMike Kravetz pte_t *dst_pte, 46798fb5debcSMike Kravetz struct vm_area_struct *dst_vma, 46808fb5debcSMike Kravetz unsigned long dst_addr, 46818fb5debcSMike Kravetz unsigned long src_addr, 46828fb5debcSMike Kravetz struct page **pagep) 46838fb5debcSMike Kravetz { 46841e392147SAndrea Arcangeli struct address_space *mapping; 46851e392147SAndrea Arcangeli pgoff_t idx; 46861e392147SAndrea Arcangeli unsigned long size; 46871c9e8defSMike Kravetz int vm_shared = dst_vma->vm_flags & VM_SHARED; 46888fb5debcSMike Kravetz struct hstate *h = hstate_vma(dst_vma); 46898fb5debcSMike Kravetz pte_t _dst_pte; 46908fb5debcSMike Kravetz spinlock_t *ptl; 46918fb5debcSMike Kravetz int ret; 46928fb5debcSMike Kravetz struct page *page; 46938fb5debcSMike Kravetz 46948fb5debcSMike Kravetz if (!*pagep) { 46958fb5debcSMike Kravetz ret = -ENOMEM; 46968fb5debcSMike Kravetz page = alloc_huge_page(dst_vma, dst_addr, 0); 46978fb5debcSMike Kravetz if (IS_ERR(page)) 46988fb5debcSMike Kravetz goto out; 46998fb5debcSMike Kravetz 47008fb5debcSMike Kravetz ret = copy_huge_page_from_user(page, 47018fb5debcSMike Kravetz (const void __user *) src_addr, 4702810a56b9SMike Kravetz pages_per_huge_page(h), false); 47038fb5debcSMike Kravetz 4704c1e8d7c6SMichel Lespinasse /* fallback to copy_from_user outside mmap_lock */ 47058fb5debcSMike Kravetz if (unlikely(ret)) { 47069e368259SAndrea Arcangeli ret = -ENOENT; 47078fb5debcSMike Kravetz *pagep = page; 47088fb5debcSMike Kravetz /* don't free the page */ 47098fb5debcSMike Kravetz goto out; 47108fb5debcSMike Kravetz } 47118fb5debcSMike Kravetz } else { 47128fb5debcSMike Kravetz page = *pagep; 47138fb5debcSMike Kravetz *pagep = NULL; 47148fb5debcSMike Kravetz } 47158fb5debcSMike Kravetz 47168fb5debcSMike Kravetz /* 47178fb5debcSMike Kravetz * The memory barrier inside __SetPageUptodate makes sure that 47188fb5debcSMike Kravetz * preceding stores to the page contents become visible before 47198fb5debcSMike Kravetz * the set_pte_at() write. 47208fb5debcSMike Kravetz */ 47218fb5debcSMike Kravetz __SetPageUptodate(page); 47228fb5debcSMike Kravetz 47231e392147SAndrea Arcangeli mapping = dst_vma->vm_file->f_mapping; 47241e392147SAndrea Arcangeli idx = vma_hugecache_offset(h, dst_vma, dst_addr); 47251e392147SAndrea Arcangeli 47261c9e8defSMike Kravetz /* 47271c9e8defSMike Kravetz * If shared, add to page cache 47281c9e8defSMike Kravetz */ 47291c9e8defSMike Kravetz if (vm_shared) { 47301e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 47311e392147SAndrea Arcangeli ret = -EFAULT; 47321e392147SAndrea Arcangeli if (idx >= size) 47331e392147SAndrea Arcangeli goto out_release_nounlock; 47341c9e8defSMike Kravetz 47351e392147SAndrea Arcangeli /* 47361e392147SAndrea Arcangeli * Serialization between remove_inode_hugepages() and 47371e392147SAndrea Arcangeli * huge_add_to_page_cache() below happens through the 47381e392147SAndrea Arcangeli * hugetlb_fault_mutex_table that here must be hold by 47391e392147SAndrea Arcangeli * the caller. 47401e392147SAndrea Arcangeli */ 47411c9e8defSMike Kravetz ret = huge_add_to_page_cache(page, mapping, idx); 47421c9e8defSMike Kravetz if (ret) 47431c9e8defSMike Kravetz goto out_release_nounlock; 47441c9e8defSMike Kravetz } 47451c9e8defSMike Kravetz 47468fb5debcSMike Kravetz ptl = huge_pte_lockptr(h, dst_mm, dst_pte); 47478fb5debcSMike Kravetz spin_lock(ptl); 47488fb5debcSMike Kravetz 47491e392147SAndrea Arcangeli /* 47501e392147SAndrea Arcangeli * Recheck the i_size after holding PT lock to make sure not 47511e392147SAndrea Arcangeli * to leave any page mapped (as page_mapped()) beyond the end 47521e392147SAndrea Arcangeli * of the i_size (remove_inode_hugepages() is strict about 47531e392147SAndrea Arcangeli * enforcing that). If we bail out here, we'll also leave a 47541e392147SAndrea Arcangeli * page in the radix tree in the vm_shared case beyond the end 47551e392147SAndrea Arcangeli * of the i_size, but remove_inode_hugepages() will take care 47561e392147SAndrea Arcangeli * of it as soon as we drop the hugetlb_fault_mutex_table. 47571e392147SAndrea Arcangeli */ 47581e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 47591e392147SAndrea Arcangeli ret = -EFAULT; 47601e392147SAndrea Arcangeli if (idx >= size) 47611e392147SAndrea Arcangeli goto out_release_unlock; 47621e392147SAndrea Arcangeli 47638fb5debcSMike Kravetz ret = -EEXIST; 47648fb5debcSMike Kravetz if (!huge_pte_none(huge_ptep_get(dst_pte))) 47658fb5debcSMike Kravetz goto out_release_unlock; 47668fb5debcSMike Kravetz 47671c9e8defSMike Kravetz if (vm_shared) { 47681c9e8defSMike Kravetz page_dup_rmap(page, true); 47691c9e8defSMike Kravetz } else { 4770d6995da3SMike Kravetz ClearHPageRestoreReserve(page); 47718fb5debcSMike Kravetz hugepage_add_new_anon_rmap(page, dst_vma, dst_addr); 47721c9e8defSMike Kravetz } 47738fb5debcSMike Kravetz 47748fb5debcSMike Kravetz _dst_pte = make_huge_pte(dst_vma, page, dst_vma->vm_flags & VM_WRITE); 47758fb5debcSMike Kravetz if (dst_vma->vm_flags & VM_WRITE) 47768fb5debcSMike Kravetz _dst_pte = huge_pte_mkdirty(_dst_pte); 47778fb5debcSMike Kravetz _dst_pte = pte_mkyoung(_dst_pte); 47788fb5debcSMike Kravetz 47798fb5debcSMike Kravetz set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); 47808fb5debcSMike Kravetz 47818fb5debcSMike Kravetz (void)huge_ptep_set_access_flags(dst_vma, dst_addr, dst_pte, _dst_pte, 47828fb5debcSMike Kravetz dst_vma->vm_flags & VM_WRITE); 47838fb5debcSMike Kravetz hugetlb_count_add(pages_per_huge_page(h), dst_mm); 47848fb5debcSMike Kravetz 47858fb5debcSMike Kravetz /* No need to invalidate - it was non-present before */ 47868fb5debcSMike Kravetz update_mmu_cache(dst_vma, dst_addr, dst_pte); 47878fb5debcSMike Kravetz 47888fb5debcSMike Kravetz spin_unlock(ptl); 47898f251a3dSMike Kravetz SetHPageMigratable(page); 47901c9e8defSMike Kravetz if (vm_shared) 47911c9e8defSMike Kravetz unlock_page(page); 47928fb5debcSMike Kravetz ret = 0; 47938fb5debcSMike Kravetz out: 47948fb5debcSMike Kravetz return ret; 47958fb5debcSMike Kravetz out_release_unlock: 47968fb5debcSMike Kravetz spin_unlock(ptl); 47971c9e8defSMike Kravetz if (vm_shared) 47981c9e8defSMike Kravetz unlock_page(page); 47995af10dfdSAndrea Arcangeli out_release_nounlock: 48008fb5debcSMike Kravetz put_page(page); 48018fb5debcSMike Kravetz goto out; 48028fb5debcSMike Kravetz } 48038fb5debcSMike Kravetz 480482e5d378SJoao Martins static void record_subpages_vmas(struct page *page, struct vm_area_struct *vma, 480582e5d378SJoao Martins int refs, struct page **pages, 480682e5d378SJoao Martins struct vm_area_struct **vmas) 480782e5d378SJoao Martins { 480882e5d378SJoao Martins int nr; 480982e5d378SJoao Martins 481082e5d378SJoao Martins for (nr = 0; nr < refs; nr++) { 481182e5d378SJoao Martins if (likely(pages)) 481282e5d378SJoao Martins pages[nr] = mem_map_offset(page, nr); 481382e5d378SJoao Martins if (vmas) 481482e5d378SJoao Martins vmas[nr] = vma; 481582e5d378SJoao Martins } 481682e5d378SJoao Martins } 481782e5d378SJoao Martins 481828a35716SMichel Lespinasse long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 481963551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 482028a35716SMichel Lespinasse unsigned long *position, unsigned long *nr_pages, 48214f6da934SPeter Xu long i, unsigned int flags, int *locked) 482263551ae0SDavid Gibson { 4823d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 4824d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 482528a35716SMichel Lespinasse unsigned long remainder = *nr_pages; 4826a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 48270fa5bc40SJoao Martins int err = -EFAULT, refs; 482863551ae0SDavid Gibson 482963551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 483063551ae0SDavid Gibson pte_t *pte; 4831cb900f41SKirill A. Shutemov spinlock_t *ptl = NULL; 48322a15efc9SHugh Dickins int absent; 483363551ae0SDavid Gibson struct page *page; 483463551ae0SDavid Gibson 48354c887265SAdam Litke /* 483602057967SDavid Rientjes * If we have a pending SIGKILL, don't keep faulting pages and 483702057967SDavid Rientjes * potentially allocating memory. 483802057967SDavid Rientjes */ 4839fa45f116SDavidlohr Bueso if (fatal_signal_pending(current)) { 484002057967SDavid Rientjes remainder = 0; 484102057967SDavid Rientjes break; 484202057967SDavid Rientjes } 484302057967SDavid Rientjes 484402057967SDavid Rientjes /* 48454c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 48462a15efc9SHugh Dickins * each hugepage. We have to make sure we get the 48474c887265SAdam Litke * first, for the page indexing below to work. 4848cb900f41SKirill A. Shutemov * 4849cb900f41SKirill A. Shutemov * Note that page table lock is not held when pte is null. 48504c887265SAdam Litke */ 48517868a208SPunit Agrawal pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), 48527868a208SPunit Agrawal huge_page_size(h)); 4853cb900f41SKirill A. Shutemov if (pte) 4854cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, pte); 48552a15efc9SHugh Dickins absent = !pte || huge_pte_none(huge_ptep_get(pte)); 485663551ae0SDavid Gibson 48572a15efc9SHugh Dickins /* 48582a15efc9SHugh Dickins * When coredumping, it suits get_dump_page if we just return 48593ae77f43SHugh Dickins * an error where there's an empty slot with no huge pagecache 48603ae77f43SHugh Dickins * to back it. This way, we avoid allocating a hugepage, and 48613ae77f43SHugh Dickins * the sparse dumpfile avoids allocating disk blocks, but its 48623ae77f43SHugh Dickins * huge holes still show up with zeroes where they need to be. 48632a15efc9SHugh Dickins */ 48643ae77f43SHugh Dickins if (absent && (flags & FOLL_DUMP) && 48653ae77f43SHugh Dickins !hugetlbfs_pagecache_present(h, vma, vaddr)) { 4866cb900f41SKirill A. Shutemov if (pte) 4867cb900f41SKirill A. Shutemov spin_unlock(ptl); 48682a15efc9SHugh Dickins remainder = 0; 48692a15efc9SHugh Dickins break; 48702a15efc9SHugh Dickins } 48712a15efc9SHugh Dickins 48729cc3a5bdSNaoya Horiguchi /* 48739cc3a5bdSNaoya Horiguchi * We need call hugetlb_fault for both hugepages under migration 48749cc3a5bdSNaoya Horiguchi * (in which case hugetlb_fault waits for the migration,) and 48759cc3a5bdSNaoya Horiguchi * hwpoisoned hugepages (in which case we need to prevent the 48769cc3a5bdSNaoya Horiguchi * caller from accessing to them.) In order to do this, we use 48779cc3a5bdSNaoya Horiguchi * here is_swap_pte instead of is_hugetlb_entry_migration and 48789cc3a5bdSNaoya Horiguchi * is_hugetlb_entry_hwpoisoned. This is because it simply covers 48799cc3a5bdSNaoya Horiguchi * both cases, and because we can't follow correct pages 48809cc3a5bdSNaoya Horiguchi * directly from any kind of swap entries. 48819cc3a5bdSNaoya Horiguchi */ 48829cc3a5bdSNaoya Horiguchi if (absent || is_swap_pte(huge_ptep_get(pte)) || 4883106c992aSGerald Schaefer ((flags & FOLL_WRITE) && 4884106c992aSGerald Schaefer !huge_pte_write(huge_ptep_get(pte)))) { 48852b740303SSouptick Joarder vm_fault_t ret; 488687ffc118SAndrea Arcangeli unsigned int fault_flags = 0; 48874c887265SAdam Litke 4888cb900f41SKirill A. Shutemov if (pte) 4889cb900f41SKirill A. Shutemov spin_unlock(ptl); 489087ffc118SAndrea Arcangeli if (flags & FOLL_WRITE) 489187ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_WRITE; 48924f6da934SPeter Xu if (locked) 489371335f37SPeter Xu fault_flags |= FAULT_FLAG_ALLOW_RETRY | 489471335f37SPeter Xu FAULT_FLAG_KILLABLE; 489587ffc118SAndrea Arcangeli if (flags & FOLL_NOWAIT) 489687ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_ALLOW_RETRY | 489787ffc118SAndrea Arcangeli FAULT_FLAG_RETRY_NOWAIT; 489887ffc118SAndrea Arcangeli if (flags & FOLL_TRIED) { 48994426e945SPeter Xu /* 49004426e945SPeter Xu * Note: FAULT_FLAG_ALLOW_RETRY and 49014426e945SPeter Xu * FAULT_FLAG_TRIED can co-exist 49024426e945SPeter Xu */ 490387ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_TRIED; 490487ffc118SAndrea Arcangeli } 490587ffc118SAndrea Arcangeli ret = hugetlb_fault(mm, vma, vaddr, fault_flags); 490687ffc118SAndrea Arcangeli if (ret & VM_FAULT_ERROR) { 49072be7cfedSDaniel Jordan err = vm_fault_to_errno(ret, flags); 49081c59827dSHugh Dickins remainder = 0; 49091c59827dSHugh Dickins break; 49101c59827dSHugh Dickins } 491187ffc118SAndrea Arcangeli if (ret & VM_FAULT_RETRY) { 49124f6da934SPeter Xu if (locked && 49131ac25013SAndrea Arcangeli !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) 49144f6da934SPeter Xu *locked = 0; 491587ffc118SAndrea Arcangeli *nr_pages = 0; 491687ffc118SAndrea Arcangeli /* 491787ffc118SAndrea Arcangeli * VM_FAULT_RETRY must not return an 491887ffc118SAndrea Arcangeli * error, it will return zero 491987ffc118SAndrea Arcangeli * instead. 492087ffc118SAndrea Arcangeli * 492187ffc118SAndrea Arcangeli * No need to update "position" as the 492287ffc118SAndrea Arcangeli * caller will not check it after 492387ffc118SAndrea Arcangeli * *nr_pages is set to 0. 492487ffc118SAndrea Arcangeli */ 492587ffc118SAndrea Arcangeli return i; 492687ffc118SAndrea Arcangeli } 492787ffc118SAndrea Arcangeli continue; 492887ffc118SAndrea Arcangeli } 492963551ae0SDavid Gibson 4930a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 49317f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 49328fde12caSLinus Torvalds 49338fde12caSLinus Torvalds /* 4934acbfb087SZhigang Lu * If subpage information not requested, update counters 4935acbfb087SZhigang Lu * and skip the same_page loop below. 4936acbfb087SZhigang Lu */ 4937acbfb087SZhigang Lu if (!pages && !vmas && !pfn_offset && 4938acbfb087SZhigang Lu (vaddr + huge_page_size(h) < vma->vm_end) && 4939acbfb087SZhigang Lu (remainder >= pages_per_huge_page(h))) { 4940acbfb087SZhigang Lu vaddr += huge_page_size(h); 4941acbfb087SZhigang Lu remainder -= pages_per_huge_page(h); 4942acbfb087SZhigang Lu i += pages_per_huge_page(h); 4943acbfb087SZhigang Lu spin_unlock(ptl); 4944acbfb087SZhigang Lu continue; 4945acbfb087SZhigang Lu } 4946acbfb087SZhigang Lu 494782e5d378SJoao Martins refs = min3(pages_per_huge_page(h) - pfn_offset, 494882e5d378SJoao Martins (vma->vm_end - vaddr) >> PAGE_SHIFT, remainder); 49490fa5bc40SJoao Martins 495082e5d378SJoao Martins if (pages || vmas) 495182e5d378SJoao Martins record_subpages_vmas(mem_map_offset(page, pfn_offset), 495282e5d378SJoao Martins vma, refs, 495382e5d378SJoao Martins likely(pages) ? pages + i : NULL, 495482e5d378SJoao Martins vmas ? vmas + i : NULL); 495563551ae0SDavid Gibson 495682e5d378SJoao Martins if (pages) { 49570fa5bc40SJoao Martins /* 49580fa5bc40SJoao Martins * try_grab_compound_head() should always succeed here, 49590fa5bc40SJoao Martins * because: a) we hold the ptl lock, and b) we've just 49600fa5bc40SJoao Martins * checked that the huge page is present in the page 49610fa5bc40SJoao Martins * tables. If the huge page is present, then the tail 49620fa5bc40SJoao Martins * pages must also be present. The ptl prevents the 49630fa5bc40SJoao Martins * head page and tail pages from being rearranged in 49640fa5bc40SJoao Martins * any way. So this page must be available at this 49650fa5bc40SJoao Martins * point, unless the page refcount overflowed: 49660fa5bc40SJoao Martins */ 496782e5d378SJoao Martins if (WARN_ON_ONCE(!try_grab_compound_head(pages[i], 49680fa5bc40SJoao Martins refs, 49690fa5bc40SJoao Martins flags))) { 49700fa5bc40SJoao Martins spin_unlock(ptl); 49710fa5bc40SJoao Martins remainder = 0; 49720fa5bc40SJoao Martins err = -ENOMEM; 49730fa5bc40SJoao Martins break; 49740fa5bc40SJoao Martins } 4975d5d4b0aaSChen, Kenneth W } 497682e5d378SJoao Martins 497782e5d378SJoao Martins vaddr += (refs << PAGE_SHIFT); 497882e5d378SJoao Martins remainder -= refs; 497982e5d378SJoao Martins i += refs; 498082e5d378SJoao Martins 4981cb900f41SKirill A. Shutemov spin_unlock(ptl); 498263551ae0SDavid Gibson } 498328a35716SMichel Lespinasse *nr_pages = remainder; 498487ffc118SAndrea Arcangeli /* 498587ffc118SAndrea Arcangeli * setting position is actually required only if remainder is 498687ffc118SAndrea Arcangeli * not zero but it's faster not to add a "if (remainder)" 498787ffc118SAndrea Arcangeli * branch. 498887ffc118SAndrea Arcangeli */ 498963551ae0SDavid Gibson *position = vaddr; 499063551ae0SDavid Gibson 49912be7cfedSDaniel Jordan return i ? i : err; 499263551ae0SDavid Gibson } 49938f860591SZhang, Yanmin 49947da4d641SPeter Zijlstra unsigned long hugetlb_change_protection(struct vm_area_struct *vma, 49958f860591SZhang, Yanmin unsigned long address, unsigned long end, pgprot_t newprot) 49968f860591SZhang, Yanmin { 49978f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 49988f860591SZhang, Yanmin unsigned long start = address; 49998f860591SZhang, Yanmin pte_t *ptep; 50008f860591SZhang, Yanmin pte_t pte; 5001a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 50027da4d641SPeter Zijlstra unsigned long pages = 0; 5003dff11abeSMike Kravetz bool shared_pmd = false; 5004ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 5005dff11abeSMike Kravetz 5006dff11abeSMike Kravetz /* 5007dff11abeSMike Kravetz * In the case of shared PMDs, the area to flush could be beyond 5008ac46d4f3SJérôme Glisse * start/end. Set range.start/range.end to cover the maximum possible 5009dff11abeSMike Kravetz * range if PMD sharing is possible. 5010dff11abeSMike Kravetz */ 50117269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 50127269f999SJérôme Glisse 0, vma, mm, start, end); 5013ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 50148f860591SZhang, Yanmin 50158f860591SZhang, Yanmin BUG_ON(address >= end); 5016ac46d4f3SJérôme Glisse flush_cache_range(vma, range.start, range.end); 50178f860591SZhang, Yanmin 5018ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 501983cde9e8SDavidlohr Bueso i_mmap_lock_write(vma->vm_file->f_mapping); 5020a5516438SAndi Kleen for (; address < end; address += huge_page_size(h)) { 5021cb900f41SKirill A. Shutemov spinlock_t *ptl; 50227868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, huge_page_size(h)); 50238f860591SZhang, Yanmin if (!ptep) 50248f860591SZhang, Yanmin continue; 5025cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 502634ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 50277da4d641SPeter Zijlstra pages++; 5028cb900f41SKirill A. Shutemov spin_unlock(ptl); 5029dff11abeSMike Kravetz shared_pmd = true; 503039dde65cSChen, Kenneth W continue; 50317da4d641SPeter Zijlstra } 5032a8bda28dSNaoya Horiguchi pte = huge_ptep_get(ptep); 5033a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { 5034a8bda28dSNaoya Horiguchi spin_unlock(ptl); 5035a8bda28dSNaoya Horiguchi continue; 5036a8bda28dSNaoya Horiguchi } 5037a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(pte))) { 5038a8bda28dSNaoya Horiguchi swp_entry_t entry = pte_to_swp_entry(pte); 5039a8bda28dSNaoya Horiguchi 5040a8bda28dSNaoya Horiguchi if (is_write_migration_entry(entry)) { 5041a8bda28dSNaoya Horiguchi pte_t newpte; 5042a8bda28dSNaoya Horiguchi 5043a8bda28dSNaoya Horiguchi make_migration_entry_read(&entry); 5044a8bda28dSNaoya Horiguchi newpte = swp_entry_to_pte(entry); 5045e5251fd4SPunit Agrawal set_huge_swap_pte_at(mm, address, ptep, 5046e5251fd4SPunit Agrawal newpte, huge_page_size(h)); 5047a8bda28dSNaoya Horiguchi pages++; 5048a8bda28dSNaoya Horiguchi } 5049a8bda28dSNaoya Horiguchi spin_unlock(ptl); 5050a8bda28dSNaoya Horiguchi continue; 5051a8bda28dSNaoya Horiguchi } 5052a8bda28dSNaoya Horiguchi if (!huge_pte_none(pte)) { 5053023bdd00SAneesh Kumar K.V pte_t old_pte; 5054023bdd00SAneesh Kumar K.V 5055023bdd00SAneesh Kumar K.V old_pte = huge_ptep_modify_prot_start(vma, address, ptep); 5056023bdd00SAneesh Kumar K.V pte = pte_mkhuge(huge_pte_modify(old_pte, newprot)); 5057be7517d6STony Lu pte = arch_make_huge_pte(pte, vma, NULL, 0); 5058023bdd00SAneesh Kumar K.V huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); 50597da4d641SPeter Zijlstra pages++; 50608f860591SZhang, Yanmin } 5061cb900f41SKirill A. Shutemov spin_unlock(ptl); 50628f860591SZhang, Yanmin } 5063d833352aSMel Gorman /* 5064c8c06efaSDavidlohr Bueso * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare 5065d833352aSMel Gorman * may have cleared our pud entry and done put_page on the page table: 5066c8c06efaSDavidlohr Bueso * once we release i_mmap_rwsem, another task can do the final put_page 5067dff11abeSMike Kravetz * and that page table be reused and filled with junk. If we actually 5068dff11abeSMike Kravetz * did unshare a page of pmds, flush the range corresponding to the pud. 5069d833352aSMel Gorman */ 5070dff11abeSMike Kravetz if (shared_pmd) 5071ac46d4f3SJérôme Glisse flush_hugetlb_tlb_range(vma, range.start, range.end); 5072dff11abeSMike Kravetz else 50735491ae7bSAneesh Kumar K.V flush_hugetlb_tlb_range(vma, start, end); 50740f10851eSJérôme Glisse /* 50750f10851eSJérôme Glisse * No need to call mmu_notifier_invalidate_range() we are downgrading 50760f10851eSJérôme Glisse * page table protection not changing it to point to a new page. 50770f10851eSJérôme Glisse * 5078ad56b738SMike Rapoport * See Documentation/vm/mmu_notifier.rst 50790f10851eSJérôme Glisse */ 508083cde9e8SDavidlohr Bueso i_mmap_unlock_write(vma->vm_file->f_mapping); 5081ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 50827da4d641SPeter Zijlstra 50837da4d641SPeter Zijlstra return pages << h->order; 50848f860591SZhang, Yanmin } 50858f860591SZhang, Yanmin 508633b8f84aSMike Kravetz /* Return true if reservation was successful, false otherwise. */ 508733b8f84aSMike Kravetz bool hugetlb_reserve_pages(struct inode *inode, 5088a1e78772SMel Gorman long from, long to, 50895a6fe125SMel Gorman struct vm_area_struct *vma, 5090ca16d140SKOSAKI Motohiro vm_flags_t vm_flags) 5091e4e574b7SAdam Litke { 509233b8f84aSMike Kravetz long chg, add = -1; 5093a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 509490481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 50959119a41eSJoonsoo Kim struct resv_map *resv_map; 5096075a61d0SMina Almasry struct hugetlb_cgroup *h_cg = NULL; 50970db9d74eSMina Almasry long gbl_reserve, regions_needed = 0; 5098e4e574b7SAdam Litke 509963489f8eSMike Kravetz /* This should never happen */ 510063489f8eSMike Kravetz if (from > to) { 510163489f8eSMike Kravetz VM_WARN(1, "%s called with a negative range\n", __func__); 510233b8f84aSMike Kravetz return false; 510363489f8eSMike Kravetz } 510463489f8eSMike Kravetz 5105a1e78772SMel Gorman /* 510617c9d12eSMel Gorman * Only apply hugepage reservation if asked. At fault time, an 510717c9d12eSMel Gorman * attempt will be made for VM_NORESERVE to allocate a page 510890481622SDavid Gibson * without using reserves 510917c9d12eSMel Gorman */ 5110ca16d140SKOSAKI Motohiro if (vm_flags & VM_NORESERVE) 511133b8f84aSMike Kravetz return true; 511217c9d12eSMel Gorman 511317c9d12eSMel Gorman /* 5114a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 5115a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 5116a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 5117a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 5118a1e78772SMel Gorman */ 51199119a41eSJoonsoo Kim if (!vma || vma->vm_flags & VM_MAYSHARE) { 5120f27a5136SMike Kravetz /* 5121f27a5136SMike Kravetz * resv_map can not be NULL as hugetlb_reserve_pages is only 5122f27a5136SMike Kravetz * called for inodes for which resv_maps were created (see 5123f27a5136SMike Kravetz * hugetlbfs_get_inode). 5124f27a5136SMike Kravetz */ 51254e35f483SJoonsoo Kim resv_map = inode_resv_map(inode); 51269119a41eSJoonsoo Kim 51270db9d74eSMina Almasry chg = region_chg(resv_map, from, to, ®ions_needed); 51289119a41eSJoonsoo Kim 51299119a41eSJoonsoo Kim } else { 5130e9fe92aeSMina Almasry /* Private mapping. */ 51319119a41eSJoonsoo Kim resv_map = resv_map_alloc(); 51325a6fe125SMel Gorman if (!resv_map) 513333b8f84aSMike Kravetz return false; 51345a6fe125SMel Gorman 513517c9d12eSMel Gorman chg = to - from; 513617c9d12eSMel Gorman 51375a6fe125SMel Gorman set_vma_resv_map(vma, resv_map); 51385a6fe125SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 51395a6fe125SMel Gorman } 51405a6fe125SMel Gorman 514133b8f84aSMike Kravetz if (chg < 0) 5142c50ac050SDave Hansen goto out_err; 514317c9d12eSMel Gorman 514433b8f84aSMike Kravetz if (hugetlb_cgroup_charge_cgroup_rsvd(hstate_index(h), 514533b8f84aSMike Kravetz chg * pages_per_huge_page(h), &h_cg) < 0) 5146075a61d0SMina Almasry goto out_err; 5147075a61d0SMina Almasry 5148075a61d0SMina Almasry if (vma && !(vma->vm_flags & VM_MAYSHARE) && h_cg) { 5149075a61d0SMina Almasry /* For private mappings, the hugetlb_cgroup uncharge info hangs 5150075a61d0SMina Almasry * of the resv_map. 5151075a61d0SMina Almasry */ 5152075a61d0SMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h); 5153075a61d0SMina Almasry } 5154075a61d0SMina Almasry 51551c5ecae3SMike Kravetz /* 51561c5ecae3SMike Kravetz * There must be enough pages in the subpool for the mapping. If 51571c5ecae3SMike Kravetz * the subpool has a minimum size, there may be some global 51581c5ecae3SMike Kravetz * reservations already in place (gbl_reserve). 51591c5ecae3SMike Kravetz */ 51601c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_get_pages(spool, chg); 516133b8f84aSMike Kravetz if (gbl_reserve < 0) 5162075a61d0SMina Almasry goto out_uncharge_cgroup; 516317c9d12eSMel Gorman 516417c9d12eSMel Gorman /* 516517c9d12eSMel Gorman * Check enough hugepages are available for the reservation. 516690481622SDavid Gibson * Hand the pages back to the subpool if there are not 516717c9d12eSMel Gorman */ 516833b8f84aSMike Kravetz if (hugetlb_acct_memory(h, gbl_reserve) < 0) 5169075a61d0SMina Almasry goto out_put_pages; 517017c9d12eSMel Gorman 517117c9d12eSMel Gorman /* 517217c9d12eSMel Gorman * Account for the reservations made. Shared mappings record regions 517317c9d12eSMel Gorman * that have reservations as they are shared by multiple VMAs. 517417c9d12eSMel Gorman * When the last VMA disappears, the region map says how much 517517c9d12eSMel Gorman * the reservation was and the page cache tells how much of 517617c9d12eSMel Gorman * the reservation was consumed. Private mappings are per-VMA and 517717c9d12eSMel Gorman * only the consumed reservations are tracked. When the VMA 517817c9d12eSMel Gorman * disappears, the original reservation is the VMA size and the 517917c9d12eSMel Gorman * consumed reservations are stored in the map. Hence, nothing 518017c9d12eSMel Gorman * else has to be done for private mappings here 518117c9d12eSMel Gorman */ 518233039678SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) { 5183075a61d0SMina Almasry add = region_add(resv_map, from, to, regions_needed, h, h_cg); 518433039678SMike Kravetz 51850db9d74eSMina Almasry if (unlikely(add < 0)) { 51860db9d74eSMina Almasry hugetlb_acct_memory(h, -gbl_reserve); 5187075a61d0SMina Almasry goto out_put_pages; 51880db9d74eSMina Almasry } else if (unlikely(chg > add)) { 518933039678SMike Kravetz /* 519033039678SMike Kravetz * pages in this range were added to the reserve 519133039678SMike Kravetz * map between region_chg and region_add. This 519233039678SMike Kravetz * indicates a race with alloc_huge_page. Adjust 519333039678SMike Kravetz * the subpool and reserve counts modified above 519433039678SMike Kravetz * based on the difference. 519533039678SMike Kravetz */ 519633039678SMike Kravetz long rsv_adjust; 519733039678SMike Kravetz 5198d85aecf2SMiaohe Lin /* 5199d85aecf2SMiaohe Lin * hugetlb_cgroup_uncharge_cgroup_rsvd() will put the 5200d85aecf2SMiaohe Lin * reference to h_cg->css. See comment below for detail. 5201d85aecf2SMiaohe Lin */ 5202075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd( 5203075a61d0SMina Almasry hstate_index(h), 5204075a61d0SMina Almasry (chg - add) * pages_per_huge_page(h), h_cg); 5205075a61d0SMina Almasry 520633039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 520733039678SMike Kravetz chg - add); 520833039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 5209d85aecf2SMiaohe Lin } else if (h_cg) { 5210d85aecf2SMiaohe Lin /* 5211d85aecf2SMiaohe Lin * The file_regions will hold their own reference to 5212d85aecf2SMiaohe Lin * h_cg->css. So we should release the reference held 5213d85aecf2SMiaohe Lin * via hugetlb_cgroup_charge_cgroup_rsvd() when we are 5214d85aecf2SMiaohe Lin * done. 5215d85aecf2SMiaohe Lin */ 5216d85aecf2SMiaohe Lin hugetlb_cgroup_put_rsvd_cgroup(h_cg); 521733039678SMike Kravetz } 521833039678SMike Kravetz } 521933b8f84aSMike Kravetz return true; 522033b8f84aSMike Kravetz 5221075a61d0SMina Almasry out_put_pages: 5222075a61d0SMina Almasry /* put back original number of pages, chg */ 5223075a61d0SMina Almasry (void)hugepage_subpool_put_pages(spool, chg); 5224075a61d0SMina Almasry out_uncharge_cgroup: 5225075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h), 5226075a61d0SMina Almasry chg * pages_per_huge_page(h), h_cg); 5227c50ac050SDave Hansen out_err: 52285e911373SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) 52290db9d74eSMina Almasry /* Only call region_abort if the region_chg succeeded but the 52300db9d74eSMina Almasry * region_add failed or didn't run. 52310db9d74eSMina Almasry */ 52320db9d74eSMina Almasry if (chg >= 0 && add < 0) 52330db9d74eSMina Almasry region_abort(resv_map, from, to, regions_needed); 5234f031dd27SJoonsoo Kim if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 5235f031dd27SJoonsoo Kim kref_put(&resv_map->refs, resv_map_release); 523633b8f84aSMike Kravetz return false; 5237a43a8c39SChen, Kenneth W } 5238a43a8c39SChen, Kenneth W 5239b5cec28dSMike Kravetz long hugetlb_unreserve_pages(struct inode *inode, long start, long end, 5240b5cec28dSMike Kravetz long freed) 5241a43a8c39SChen, Kenneth W { 5242a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 52434e35f483SJoonsoo Kim struct resv_map *resv_map = inode_resv_map(inode); 52449119a41eSJoonsoo Kim long chg = 0; 524590481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 52461c5ecae3SMike Kravetz long gbl_reserve; 524745c682a6SKen Chen 5248f27a5136SMike Kravetz /* 5249f27a5136SMike Kravetz * Since this routine can be called in the evict inode path for all 5250f27a5136SMike Kravetz * hugetlbfs inodes, resv_map could be NULL. 5251f27a5136SMike Kravetz */ 5252b5cec28dSMike Kravetz if (resv_map) { 5253b5cec28dSMike Kravetz chg = region_del(resv_map, start, end); 5254b5cec28dSMike Kravetz /* 5255b5cec28dSMike Kravetz * region_del() can fail in the rare case where a region 5256b5cec28dSMike Kravetz * must be split and another region descriptor can not be 5257b5cec28dSMike Kravetz * allocated. If end == LONG_MAX, it will not fail. 5258b5cec28dSMike Kravetz */ 5259b5cec28dSMike Kravetz if (chg < 0) 5260b5cec28dSMike Kravetz return chg; 5261b5cec28dSMike Kravetz } 5262b5cec28dSMike Kravetz 526345c682a6SKen Chen spin_lock(&inode->i_lock); 5264e4c6f8beSEric Sandeen inode->i_blocks -= (blocks_per_huge_page(h) * freed); 526545c682a6SKen Chen spin_unlock(&inode->i_lock); 526645c682a6SKen Chen 52671c5ecae3SMike Kravetz /* 52681c5ecae3SMike Kravetz * If the subpool has a minimum size, the number of global 52691c5ecae3SMike Kravetz * reservations to be released may be adjusted. 5270*dddf31a4SMiaohe Lin * 5271*dddf31a4SMiaohe Lin * Note that !resv_map implies freed == 0. So (chg - freed) 5272*dddf31a4SMiaohe Lin * won't go negative. 52731c5ecae3SMike Kravetz */ 52741c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed)); 52751c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 5276b5cec28dSMike Kravetz 5277b5cec28dSMike Kravetz return 0; 5278a43a8c39SChen, Kenneth W } 527993f70f90SNaoya Horiguchi 52803212b535SSteve Capper #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 52813212b535SSteve Capper static unsigned long page_table_shareable(struct vm_area_struct *svma, 52823212b535SSteve Capper struct vm_area_struct *vma, 52833212b535SSteve Capper unsigned long addr, pgoff_t idx) 52843212b535SSteve Capper { 52853212b535SSteve Capper unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + 52863212b535SSteve Capper svma->vm_start; 52873212b535SSteve Capper unsigned long sbase = saddr & PUD_MASK; 52883212b535SSteve Capper unsigned long s_end = sbase + PUD_SIZE; 52893212b535SSteve Capper 52903212b535SSteve Capper /* Allow segments to share if only one is marked locked */ 5291de60f5f1SEric B Munson unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; 5292de60f5f1SEric B Munson unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK; 52933212b535SSteve Capper 52943212b535SSteve Capper /* 52953212b535SSteve Capper * match the virtual addresses, permission and the alignment of the 52963212b535SSteve Capper * page table page. 52973212b535SSteve Capper */ 52983212b535SSteve Capper if (pmd_index(addr) != pmd_index(saddr) || 52993212b535SSteve Capper vm_flags != svm_flags || 530007e51edfSMiaohe Lin !range_in_vma(svma, sbase, s_end)) 53013212b535SSteve Capper return 0; 53023212b535SSteve Capper 53033212b535SSteve Capper return saddr; 53043212b535SSteve Capper } 53053212b535SSteve Capper 530631aafb45SNicholas Krause static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr) 53073212b535SSteve Capper { 53083212b535SSteve Capper unsigned long base = addr & PUD_MASK; 53093212b535SSteve Capper unsigned long end = base + PUD_SIZE; 53103212b535SSteve Capper 53113212b535SSteve Capper /* 53123212b535SSteve Capper * check on proper vm_flags and page table alignment 53133212b535SSteve Capper */ 5314017b1660SMike Kravetz if (vma->vm_flags & VM_MAYSHARE && range_in_vma(vma, base, end)) 531531aafb45SNicholas Krause return true; 531631aafb45SNicholas Krause return false; 53173212b535SSteve Capper } 53183212b535SSteve Capper 5319c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 5320c1991e07SPeter Xu { 5321c1991e07SPeter Xu #ifdef CONFIG_USERFAULTFD 5322c1991e07SPeter Xu if (uffd_disable_huge_pmd_share(vma)) 5323c1991e07SPeter Xu return false; 5324c1991e07SPeter Xu #endif 5325c1991e07SPeter Xu return vma_shareable(vma, addr); 5326c1991e07SPeter Xu } 5327c1991e07SPeter Xu 53283212b535SSteve Capper /* 5329017b1660SMike Kravetz * Determine if start,end range within vma could be mapped by shared pmd. 5330017b1660SMike Kravetz * If yes, adjust start and end to cover range associated with possible 5331017b1660SMike Kravetz * shared pmd mappings. 5332017b1660SMike Kravetz */ 5333017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 5334017b1660SMike Kravetz unsigned long *start, unsigned long *end) 5335017b1660SMike Kravetz { 5336a1ba9da8SLi Xinhai unsigned long v_start = ALIGN(vma->vm_start, PUD_SIZE), 5337a1ba9da8SLi Xinhai v_end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 5338017b1660SMike Kravetz 5339a1ba9da8SLi Xinhai /* 5340a1ba9da8SLi Xinhai * vma need span at least one aligned PUD size and the start,end range 5341a1ba9da8SLi Xinhai * must at least partialy within it. 5342a1ba9da8SLi Xinhai */ 5343a1ba9da8SLi Xinhai if (!(vma->vm_flags & VM_MAYSHARE) || !(v_end > v_start) || 5344a1ba9da8SLi Xinhai (*end <= v_start) || (*start >= v_end)) 5345017b1660SMike Kravetz return; 5346017b1660SMike Kravetz 534775802ca6SPeter Xu /* Extend the range to be PUD aligned for a worst case scenario */ 5348a1ba9da8SLi Xinhai if (*start > v_start) 5349a1ba9da8SLi Xinhai *start = ALIGN_DOWN(*start, PUD_SIZE); 5350017b1660SMike Kravetz 5351a1ba9da8SLi Xinhai if (*end < v_end) 5352a1ba9da8SLi Xinhai *end = ALIGN(*end, PUD_SIZE); 5353017b1660SMike Kravetz } 5354017b1660SMike Kravetz 5355017b1660SMike Kravetz /* 53563212b535SSteve Capper * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() 53573212b535SSteve Capper * and returns the corresponding pte. While this is not necessary for the 53583212b535SSteve Capper * !shared pmd case because we can allocate the pmd later as well, it makes the 5359c0d0381aSMike Kravetz * code much cleaner. 5360c0d0381aSMike Kravetz * 53610bf7b64eSMike Kravetz * This routine must be called with i_mmap_rwsem held in at least read mode if 53620bf7b64eSMike Kravetz * sharing is possible. For hugetlbfs, this prevents removal of any page 53630bf7b64eSMike Kravetz * table entries associated with the address space. This is important as we 53640bf7b64eSMike Kravetz * are setting up sharing based on existing page table entries (mappings). 53650bf7b64eSMike Kravetz * 53660bf7b64eSMike Kravetz * NOTE: This routine is only called from huge_pte_alloc. Some callers of 53670bf7b64eSMike Kravetz * huge_pte_alloc know that sharing is not possible and do not take 53680bf7b64eSMike Kravetz * i_mmap_rwsem as a performance optimization. This is handled by the 53690bf7b64eSMike Kravetz * if !vma_shareable check at the beginning of the routine. i_mmap_rwsem is 53700bf7b64eSMike Kravetz * only required for subsequent processing. 53713212b535SSteve Capper */ 5372aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 5373aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 53743212b535SSteve Capper { 53753212b535SSteve Capper struct address_space *mapping = vma->vm_file->f_mapping; 53763212b535SSteve Capper pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + 53773212b535SSteve Capper vma->vm_pgoff; 53783212b535SSteve Capper struct vm_area_struct *svma; 53793212b535SSteve Capper unsigned long saddr; 53803212b535SSteve Capper pte_t *spte = NULL; 53813212b535SSteve Capper pte_t *pte; 5382cb900f41SKirill A. Shutemov spinlock_t *ptl; 53833212b535SSteve Capper 53840bf7b64eSMike Kravetz i_mmap_assert_locked(mapping); 53853212b535SSteve Capper vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { 53863212b535SSteve Capper if (svma == vma) 53873212b535SSteve Capper continue; 53883212b535SSteve Capper 53893212b535SSteve Capper saddr = page_table_shareable(svma, vma, addr, idx); 53903212b535SSteve Capper if (saddr) { 53917868a208SPunit Agrawal spte = huge_pte_offset(svma->vm_mm, saddr, 53927868a208SPunit Agrawal vma_mmu_pagesize(svma)); 53933212b535SSteve Capper if (spte) { 53943212b535SSteve Capper get_page(virt_to_page(spte)); 53953212b535SSteve Capper break; 53963212b535SSteve Capper } 53973212b535SSteve Capper } 53983212b535SSteve Capper } 53993212b535SSteve Capper 54003212b535SSteve Capper if (!spte) 54013212b535SSteve Capper goto out; 54023212b535SSteve Capper 54038bea8052SAneesh Kumar K.V ptl = huge_pte_lock(hstate_vma(vma), mm, spte); 5404dc6c9a35SKirill A. Shutemov if (pud_none(*pud)) { 54053212b535SSteve Capper pud_populate(mm, pud, 54063212b535SSteve Capper (pmd_t *)((unsigned long)spte & PAGE_MASK)); 5407c17b1f42SKirill A. Shutemov mm_inc_nr_pmds(mm); 5408dc6c9a35SKirill A. Shutemov } else { 54093212b535SSteve Capper put_page(virt_to_page(spte)); 5410dc6c9a35SKirill A. Shutemov } 5411cb900f41SKirill A. Shutemov spin_unlock(ptl); 54123212b535SSteve Capper out: 54133212b535SSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 54143212b535SSteve Capper return pte; 54153212b535SSteve Capper } 54163212b535SSteve Capper 54173212b535SSteve Capper /* 54183212b535SSteve Capper * unmap huge page backed by shared pte. 54193212b535SSteve Capper * 54203212b535SSteve Capper * Hugetlb pte page is ref counted at the time of mapping. If pte is shared 54213212b535SSteve Capper * indicated by page_count > 1, unmap is achieved by clearing pud and 54223212b535SSteve Capper * decrementing the ref count. If count == 1, the pte page is not shared. 54233212b535SSteve Capper * 5424c0d0381aSMike Kravetz * Called with page table lock held and i_mmap_rwsem held in write mode. 54253212b535SSteve Capper * 54263212b535SSteve Capper * returns: 1 successfully unmapped a shared pte page 54273212b535SSteve Capper * 0 the underlying pte page is not shared, or it is the last user 54283212b535SSteve Capper */ 542934ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 543034ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 54313212b535SSteve Capper { 54323212b535SSteve Capper pgd_t *pgd = pgd_offset(mm, *addr); 5433c2febafcSKirill A. Shutemov p4d_t *p4d = p4d_offset(pgd, *addr); 5434c2febafcSKirill A. Shutemov pud_t *pud = pud_offset(p4d, *addr); 54353212b535SSteve Capper 543634ae204fSMike Kravetz i_mmap_assert_write_locked(vma->vm_file->f_mapping); 54373212b535SSteve Capper BUG_ON(page_count(virt_to_page(ptep)) == 0); 54383212b535SSteve Capper if (page_count(virt_to_page(ptep)) == 1) 54393212b535SSteve Capper return 0; 54403212b535SSteve Capper 54413212b535SSteve Capper pud_clear(pud); 54423212b535SSteve Capper put_page(virt_to_page(ptep)); 5443dc6c9a35SKirill A. Shutemov mm_dec_nr_pmds(mm); 54443212b535SSteve Capper *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE; 54453212b535SSteve Capper return 1; 54463212b535SSteve Capper } 5447c1991e07SPeter Xu 54489e5fc74cSSteve Capper #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 5449aec44e0fSPeter Xu pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, 5450aec44e0fSPeter Xu unsigned long addr, pud_t *pud) 54519e5fc74cSSteve Capper { 54529e5fc74cSSteve Capper return NULL; 54539e5fc74cSSteve Capper } 5454e81f2d22SZhang Zhen 545534ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 545634ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 5457e81f2d22SZhang Zhen { 5458e81f2d22SZhang Zhen return 0; 5459e81f2d22SZhang Zhen } 5460017b1660SMike Kravetz 5461017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 5462017b1660SMike Kravetz unsigned long *start, unsigned long *end) 5463017b1660SMike Kravetz { 5464017b1660SMike Kravetz } 5465c1991e07SPeter Xu 5466c1991e07SPeter Xu bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr) 5467c1991e07SPeter Xu { 5468c1991e07SPeter Xu return false; 5469c1991e07SPeter Xu } 54703212b535SSteve Capper #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 54713212b535SSteve Capper 54729e5fc74cSSteve Capper #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB 5473aec44e0fSPeter Xu pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, 54749e5fc74cSSteve Capper unsigned long addr, unsigned long sz) 54759e5fc74cSSteve Capper { 54769e5fc74cSSteve Capper pgd_t *pgd; 5477c2febafcSKirill A. Shutemov p4d_t *p4d; 54789e5fc74cSSteve Capper pud_t *pud; 54799e5fc74cSSteve Capper pte_t *pte = NULL; 54809e5fc74cSSteve Capper 54819e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 5482f4f0a3d8SKirill A. Shutemov p4d = p4d_alloc(mm, pgd, addr); 5483f4f0a3d8SKirill A. Shutemov if (!p4d) 5484f4f0a3d8SKirill A. Shutemov return NULL; 5485c2febafcSKirill A. Shutemov pud = pud_alloc(mm, p4d, addr); 54869e5fc74cSSteve Capper if (pud) { 54879e5fc74cSSteve Capper if (sz == PUD_SIZE) { 54889e5fc74cSSteve Capper pte = (pte_t *)pud; 54899e5fc74cSSteve Capper } else { 54909e5fc74cSSteve Capper BUG_ON(sz != PMD_SIZE); 5491c1991e07SPeter Xu if (want_pmd_share(vma, addr) && pud_none(*pud)) 5492aec44e0fSPeter Xu pte = huge_pmd_share(mm, vma, addr, pud); 54939e5fc74cSSteve Capper else 54949e5fc74cSSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 54959e5fc74cSSteve Capper } 54969e5fc74cSSteve Capper } 54974e666314SMichal Hocko BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte)); 54989e5fc74cSSteve Capper 54999e5fc74cSSteve Capper return pte; 55009e5fc74cSSteve Capper } 55019e5fc74cSSteve Capper 55029b19df29SPunit Agrawal /* 55039b19df29SPunit Agrawal * huge_pte_offset() - Walk the page table to resolve the hugepage 55049b19df29SPunit Agrawal * entry at address @addr 55059b19df29SPunit Agrawal * 55068ac0b81aSLi Xinhai * Return: Pointer to page table entry (PUD or PMD) for 55078ac0b81aSLi Xinhai * address @addr, or NULL if a !p*d_present() entry is encountered and the 55089b19df29SPunit Agrawal * size @sz doesn't match the hugepage size at this level of the page 55099b19df29SPunit Agrawal * table. 55109b19df29SPunit Agrawal */ 55117868a208SPunit Agrawal pte_t *huge_pte_offset(struct mm_struct *mm, 55127868a208SPunit Agrawal unsigned long addr, unsigned long sz) 55139e5fc74cSSteve Capper { 55149e5fc74cSSteve Capper pgd_t *pgd; 5515c2febafcSKirill A. Shutemov p4d_t *p4d; 55168ac0b81aSLi Xinhai pud_t *pud; 55178ac0b81aSLi Xinhai pmd_t *pmd; 55189e5fc74cSSteve Capper 55199e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 5520c2febafcSKirill A. Shutemov if (!pgd_present(*pgd)) 5521c2febafcSKirill A. Shutemov return NULL; 5522c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, addr); 5523c2febafcSKirill A. Shutemov if (!p4d_present(*p4d)) 5524c2febafcSKirill A. Shutemov return NULL; 55259b19df29SPunit Agrawal 5526c2febafcSKirill A. Shutemov pud = pud_offset(p4d, addr); 55278ac0b81aSLi Xinhai if (sz == PUD_SIZE) 55288ac0b81aSLi Xinhai /* must be pud huge, non-present or none */ 55299e5fc74cSSteve Capper return (pte_t *)pud; 55308ac0b81aSLi Xinhai if (!pud_present(*pud)) 55318ac0b81aSLi Xinhai return NULL; 55328ac0b81aSLi Xinhai /* must have a valid entry and size to go further */ 55339b19df29SPunit Agrawal 55349e5fc74cSSteve Capper pmd = pmd_offset(pud, addr); 55358ac0b81aSLi Xinhai /* must be pmd huge, non-present or none */ 55369e5fc74cSSteve Capper return (pte_t *)pmd; 55379e5fc74cSSteve Capper } 55389e5fc74cSSteve Capper 553961f77edaSNaoya Horiguchi #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ 554061f77edaSNaoya Horiguchi 554161f77edaSNaoya Horiguchi /* 554261f77edaSNaoya Horiguchi * These functions are overwritable if your architecture needs its own 554361f77edaSNaoya Horiguchi * behavior. 554461f77edaSNaoya Horiguchi */ 554561f77edaSNaoya Horiguchi struct page * __weak 554661f77edaSNaoya Horiguchi follow_huge_addr(struct mm_struct *mm, unsigned long address, 554761f77edaSNaoya Horiguchi int write) 554861f77edaSNaoya Horiguchi { 554961f77edaSNaoya Horiguchi return ERR_PTR(-EINVAL); 555061f77edaSNaoya Horiguchi } 555161f77edaSNaoya Horiguchi 555261f77edaSNaoya Horiguchi struct page * __weak 55534dc71451SAneesh Kumar K.V follow_huge_pd(struct vm_area_struct *vma, 55544dc71451SAneesh Kumar K.V unsigned long address, hugepd_t hpd, int flags, int pdshift) 55554dc71451SAneesh Kumar K.V { 55564dc71451SAneesh Kumar K.V WARN(1, "hugepd follow called with no support for hugepage directory format\n"); 55574dc71451SAneesh Kumar K.V return NULL; 55584dc71451SAneesh Kumar K.V } 55594dc71451SAneesh Kumar K.V 55604dc71451SAneesh Kumar K.V struct page * __weak 55619e5fc74cSSteve Capper follow_huge_pmd(struct mm_struct *mm, unsigned long address, 5562e66f17ffSNaoya Horiguchi pmd_t *pmd, int flags) 55639e5fc74cSSteve Capper { 5564e66f17ffSNaoya Horiguchi struct page *page = NULL; 5565e66f17ffSNaoya Horiguchi spinlock_t *ptl; 5566c9d398faSNaoya Horiguchi pte_t pte; 55673faa52c0SJohn Hubbard 55683faa52c0SJohn Hubbard /* FOLL_GET and FOLL_PIN are mutually exclusive. */ 55693faa52c0SJohn Hubbard if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == 55703faa52c0SJohn Hubbard (FOLL_PIN | FOLL_GET))) 55713faa52c0SJohn Hubbard return NULL; 55723faa52c0SJohn Hubbard 5573e66f17ffSNaoya Horiguchi retry: 5574e66f17ffSNaoya Horiguchi ptl = pmd_lockptr(mm, pmd); 5575e66f17ffSNaoya Horiguchi spin_lock(ptl); 5576e66f17ffSNaoya Horiguchi /* 5577e66f17ffSNaoya Horiguchi * make sure that the address range covered by this pmd is not 5578e66f17ffSNaoya Horiguchi * unmapped from other threads. 5579e66f17ffSNaoya Horiguchi */ 5580e66f17ffSNaoya Horiguchi if (!pmd_huge(*pmd)) 5581e66f17ffSNaoya Horiguchi goto out; 5582c9d398faSNaoya Horiguchi pte = huge_ptep_get((pte_t *)pmd); 5583c9d398faSNaoya Horiguchi if (pte_present(pte)) { 558497534127SGerald Schaefer page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT); 55853faa52c0SJohn Hubbard /* 55863faa52c0SJohn Hubbard * try_grab_page() should always succeed here, because: a) we 55873faa52c0SJohn Hubbard * hold the pmd (ptl) lock, and b) we've just checked that the 55883faa52c0SJohn Hubbard * huge pmd (head) page is present in the page tables. The ptl 55893faa52c0SJohn Hubbard * prevents the head page and tail pages from being rearranged 55903faa52c0SJohn Hubbard * in any way. So this page must be available at this point, 55913faa52c0SJohn Hubbard * unless the page refcount overflowed: 55923faa52c0SJohn Hubbard */ 55933faa52c0SJohn Hubbard if (WARN_ON_ONCE(!try_grab_page(page, flags))) { 55943faa52c0SJohn Hubbard page = NULL; 55953faa52c0SJohn Hubbard goto out; 55963faa52c0SJohn Hubbard } 5597e66f17ffSNaoya Horiguchi } else { 5598c9d398faSNaoya Horiguchi if (is_hugetlb_entry_migration(pte)) { 5599e66f17ffSNaoya Horiguchi spin_unlock(ptl); 5600e66f17ffSNaoya Horiguchi __migration_entry_wait(mm, (pte_t *)pmd, ptl); 5601e66f17ffSNaoya Horiguchi goto retry; 5602e66f17ffSNaoya Horiguchi } 5603e66f17ffSNaoya Horiguchi /* 5604e66f17ffSNaoya Horiguchi * hwpoisoned entry is treated as no_page_table in 5605e66f17ffSNaoya Horiguchi * follow_page_mask(). 5606e66f17ffSNaoya Horiguchi */ 5607e66f17ffSNaoya Horiguchi } 5608e66f17ffSNaoya Horiguchi out: 5609e66f17ffSNaoya Horiguchi spin_unlock(ptl); 56109e5fc74cSSteve Capper return page; 56119e5fc74cSSteve Capper } 56129e5fc74cSSteve Capper 561361f77edaSNaoya Horiguchi struct page * __weak 56149e5fc74cSSteve Capper follow_huge_pud(struct mm_struct *mm, unsigned long address, 5615e66f17ffSNaoya Horiguchi pud_t *pud, int flags) 56169e5fc74cSSteve Capper { 56173faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 5618e66f17ffSNaoya Horiguchi return NULL; 56199e5fc74cSSteve Capper 5620e66f17ffSNaoya Horiguchi return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); 56219e5fc74cSSteve Capper } 56229e5fc74cSSteve Capper 5623faaa5b62SAnshuman Khandual struct page * __weak 5624faaa5b62SAnshuman Khandual follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) 5625faaa5b62SAnshuman Khandual { 56263faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 5627faaa5b62SAnshuman Khandual return NULL; 5628faaa5b62SAnshuman Khandual 5629faaa5b62SAnshuman Khandual return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); 5630faaa5b62SAnshuman Khandual } 5631faaa5b62SAnshuman Khandual 563231caf665SNaoya Horiguchi bool isolate_huge_page(struct page *page, struct list_head *list) 563331caf665SNaoya Horiguchi { 5634bcc54222SNaoya Horiguchi bool ret = true; 5635bcc54222SNaoya Horiguchi 563631caf665SNaoya Horiguchi spin_lock(&hugetlb_lock); 56378f251a3dSMike Kravetz if (!PageHeadHuge(page) || 56388f251a3dSMike Kravetz !HPageMigratable(page) || 56390eb2df2bSMuchun Song !get_page_unless_zero(page)) { 5640bcc54222SNaoya Horiguchi ret = false; 5641bcc54222SNaoya Horiguchi goto unlock; 5642bcc54222SNaoya Horiguchi } 56438f251a3dSMike Kravetz ClearHPageMigratable(page); 564431caf665SNaoya Horiguchi list_move_tail(&page->lru, list); 5645bcc54222SNaoya Horiguchi unlock: 564631caf665SNaoya Horiguchi spin_unlock(&hugetlb_lock); 5647bcc54222SNaoya Horiguchi return ret; 564831caf665SNaoya Horiguchi } 564931caf665SNaoya Horiguchi 565031caf665SNaoya Horiguchi void putback_active_hugepage(struct page *page) 565131caf665SNaoya Horiguchi { 565231caf665SNaoya Horiguchi spin_lock(&hugetlb_lock); 56538f251a3dSMike Kravetz SetHPageMigratable(page); 565431caf665SNaoya Horiguchi list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); 565531caf665SNaoya Horiguchi spin_unlock(&hugetlb_lock); 565631caf665SNaoya Horiguchi put_page(page); 565731caf665SNaoya Horiguchi } 5658ab5ac90aSMichal Hocko 5659ab5ac90aSMichal Hocko void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason) 5660ab5ac90aSMichal Hocko { 5661ab5ac90aSMichal Hocko struct hstate *h = page_hstate(oldpage); 5662ab5ac90aSMichal Hocko 5663ab5ac90aSMichal Hocko hugetlb_cgroup_migrate(oldpage, newpage); 5664ab5ac90aSMichal Hocko set_page_owner_migrate_reason(newpage, reason); 5665ab5ac90aSMichal Hocko 5666ab5ac90aSMichal Hocko /* 5667ab5ac90aSMichal Hocko * transfer temporary state of the new huge page. This is 5668ab5ac90aSMichal Hocko * reverse to other transitions because the newpage is going to 5669ab5ac90aSMichal Hocko * be final while the old one will be freed so it takes over 5670ab5ac90aSMichal Hocko * the temporary status. 5671ab5ac90aSMichal Hocko * 5672ab5ac90aSMichal Hocko * Also note that we have to transfer the per-node surplus state 5673ab5ac90aSMichal Hocko * here as well otherwise the global surplus count will not match 5674ab5ac90aSMichal Hocko * the per-node's. 5675ab5ac90aSMichal Hocko */ 56769157c311SMike Kravetz if (HPageTemporary(newpage)) { 5677ab5ac90aSMichal Hocko int old_nid = page_to_nid(oldpage); 5678ab5ac90aSMichal Hocko int new_nid = page_to_nid(newpage); 5679ab5ac90aSMichal Hocko 56809157c311SMike Kravetz SetHPageTemporary(oldpage); 56819157c311SMike Kravetz ClearHPageTemporary(newpage); 5682ab5ac90aSMichal Hocko 56835af1ab1dSMiaohe Lin /* 56845af1ab1dSMiaohe Lin * There is no need to transfer the per-node surplus state 56855af1ab1dSMiaohe Lin * when we do not cross the node. 56865af1ab1dSMiaohe Lin */ 56875af1ab1dSMiaohe Lin if (new_nid == old_nid) 56885af1ab1dSMiaohe Lin return; 5689ab5ac90aSMichal Hocko spin_lock(&hugetlb_lock); 5690ab5ac90aSMichal Hocko if (h->surplus_huge_pages_node[old_nid]) { 5691ab5ac90aSMichal Hocko h->surplus_huge_pages_node[old_nid]--; 5692ab5ac90aSMichal Hocko h->surplus_huge_pages_node[new_nid]++; 5693ab5ac90aSMichal Hocko } 5694ab5ac90aSMichal Hocko spin_unlock(&hugetlb_lock); 5695ab5ac90aSMichal Hocko } 5696ab5ac90aSMichal Hocko } 5697cf11e85fSRoman Gushchin 56986dfeaff9SPeter Xu /* 56996dfeaff9SPeter Xu * This function will unconditionally remove all the shared pmd pgtable entries 57006dfeaff9SPeter Xu * within the specific vma for a hugetlbfs memory range. 57016dfeaff9SPeter Xu */ 57026dfeaff9SPeter Xu void hugetlb_unshare_all_pmds(struct vm_area_struct *vma) 57036dfeaff9SPeter Xu { 57046dfeaff9SPeter Xu struct hstate *h = hstate_vma(vma); 57056dfeaff9SPeter Xu unsigned long sz = huge_page_size(h); 57066dfeaff9SPeter Xu struct mm_struct *mm = vma->vm_mm; 57076dfeaff9SPeter Xu struct mmu_notifier_range range; 57086dfeaff9SPeter Xu unsigned long address, start, end; 57096dfeaff9SPeter Xu spinlock_t *ptl; 57106dfeaff9SPeter Xu pte_t *ptep; 57116dfeaff9SPeter Xu 57126dfeaff9SPeter Xu if (!(vma->vm_flags & VM_MAYSHARE)) 57136dfeaff9SPeter Xu return; 57146dfeaff9SPeter Xu 57156dfeaff9SPeter Xu start = ALIGN(vma->vm_start, PUD_SIZE); 57166dfeaff9SPeter Xu end = ALIGN_DOWN(vma->vm_end, PUD_SIZE); 57176dfeaff9SPeter Xu 57186dfeaff9SPeter Xu if (start >= end) 57196dfeaff9SPeter Xu return; 57206dfeaff9SPeter Xu 57216dfeaff9SPeter Xu /* 57226dfeaff9SPeter Xu * No need to call adjust_range_if_pmd_sharing_possible(), because 57236dfeaff9SPeter Xu * we have already done the PUD_SIZE alignment. 57246dfeaff9SPeter Xu */ 57256dfeaff9SPeter Xu mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, 57266dfeaff9SPeter Xu start, end); 57276dfeaff9SPeter Xu mmu_notifier_invalidate_range_start(&range); 57286dfeaff9SPeter Xu i_mmap_lock_write(vma->vm_file->f_mapping); 57296dfeaff9SPeter Xu for (address = start; address < end; address += PUD_SIZE) { 57306dfeaff9SPeter Xu unsigned long tmp = address; 57316dfeaff9SPeter Xu 57326dfeaff9SPeter Xu ptep = huge_pte_offset(mm, address, sz); 57336dfeaff9SPeter Xu if (!ptep) 57346dfeaff9SPeter Xu continue; 57356dfeaff9SPeter Xu ptl = huge_pte_lock(h, mm, ptep); 57366dfeaff9SPeter Xu /* We don't want 'address' to be changed */ 57376dfeaff9SPeter Xu huge_pmd_unshare(mm, vma, &tmp, ptep); 57386dfeaff9SPeter Xu spin_unlock(ptl); 57396dfeaff9SPeter Xu } 57406dfeaff9SPeter Xu flush_hugetlb_tlb_range(vma, start, end); 57416dfeaff9SPeter Xu i_mmap_unlock_write(vma->vm_file->f_mapping); 57426dfeaff9SPeter Xu /* 57436dfeaff9SPeter Xu * No need to call mmu_notifier_invalidate_range(), see 57446dfeaff9SPeter Xu * Documentation/vm/mmu_notifier.rst. 57456dfeaff9SPeter Xu */ 57466dfeaff9SPeter Xu mmu_notifier_invalidate_range_end(&range); 57476dfeaff9SPeter Xu } 57486dfeaff9SPeter Xu 5749cf11e85fSRoman Gushchin #ifdef CONFIG_CMA 5750cf11e85fSRoman Gushchin static bool cma_reserve_called __initdata; 5751cf11e85fSRoman Gushchin 5752cf11e85fSRoman Gushchin static int __init cmdline_parse_hugetlb_cma(char *p) 5753cf11e85fSRoman Gushchin { 5754cf11e85fSRoman Gushchin hugetlb_cma_size = memparse(p, &p); 5755cf11e85fSRoman Gushchin return 0; 5756cf11e85fSRoman Gushchin } 5757cf11e85fSRoman Gushchin 5758cf11e85fSRoman Gushchin early_param("hugetlb_cma", cmdline_parse_hugetlb_cma); 5759cf11e85fSRoman Gushchin 5760cf11e85fSRoman Gushchin void __init hugetlb_cma_reserve(int order) 5761cf11e85fSRoman Gushchin { 5762cf11e85fSRoman Gushchin unsigned long size, reserved, per_node; 5763cf11e85fSRoman Gushchin int nid; 5764cf11e85fSRoman Gushchin 5765cf11e85fSRoman Gushchin cma_reserve_called = true; 5766cf11e85fSRoman Gushchin 5767cf11e85fSRoman Gushchin if (!hugetlb_cma_size) 5768cf11e85fSRoman Gushchin return; 5769cf11e85fSRoman Gushchin 5770cf11e85fSRoman Gushchin if (hugetlb_cma_size < (PAGE_SIZE << order)) { 5771cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n", 5772cf11e85fSRoman Gushchin (PAGE_SIZE << order) / SZ_1M); 5773cf11e85fSRoman Gushchin return; 5774cf11e85fSRoman Gushchin } 5775cf11e85fSRoman Gushchin 5776cf11e85fSRoman Gushchin /* 5777cf11e85fSRoman Gushchin * If 3 GB area is requested on a machine with 4 numa nodes, 5778cf11e85fSRoman Gushchin * let's allocate 1 GB on first three nodes and ignore the last one. 5779cf11e85fSRoman Gushchin */ 5780cf11e85fSRoman Gushchin per_node = DIV_ROUND_UP(hugetlb_cma_size, nr_online_nodes); 5781cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n", 5782cf11e85fSRoman Gushchin hugetlb_cma_size / SZ_1M, per_node / SZ_1M); 5783cf11e85fSRoman Gushchin 5784cf11e85fSRoman Gushchin reserved = 0; 5785cf11e85fSRoman Gushchin for_each_node_state(nid, N_ONLINE) { 5786cf11e85fSRoman Gushchin int res; 57872281f797SBarry Song char name[CMA_MAX_NAME]; 5788cf11e85fSRoman Gushchin 5789cf11e85fSRoman Gushchin size = min(per_node, hugetlb_cma_size - reserved); 5790cf11e85fSRoman Gushchin size = round_up(size, PAGE_SIZE << order); 5791cf11e85fSRoman Gushchin 57922281f797SBarry Song snprintf(name, sizeof(name), "hugetlb%d", nid); 5793cf11e85fSRoman Gushchin res = cma_declare_contiguous_nid(0, size, 0, PAGE_SIZE << order, 579429d0f41dSBarry Song 0, false, name, 5795cf11e85fSRoman Gushchin &hugetlb_cma[nid], nid); 5796cf11e85fSRoman Gushchin if (res) { 5797cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: reservation failed: err %d, node %d", 5798cf11e85fSRoman Gushchin res, nid); 5799cf11e85fSRoman Gushchin continue; 5800cf11e85fSRoman Gushchin } 5801cf11e85fSRoman Gushchin 5802cf11e85fSRoman Gushchin reserved += size; 5803cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserved %lu MiB on node %d\n", 5804cf11e85fSRoman Gushchin size / SZ_1M, nid); 5805cf11e85fSRoman Gushchin 5806cf11e85fSRoman Gushchin if (reserved >= hugetlb_cma_size) 5807cf11e85fSRoman Gushchin break; 5808cf11e85fSRoman Gushchin } 5809cf11e85fSRoman Gushchin } 5810cf11e85fSRoman Gushchin 5811cf11e85fSRoman Gushchin void __init hugetlb_cma_check(void) 5812cf11e85fSRoman Gushchin { 5813cf11e85fSRoman Gushchin if (!hugetlb_cma_size || cma_reserve_called) 5814cf11e85fSRoman Gushchin return; 5815cf11e85fSRoman Gushchin 5816cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: the option isn't supported by current arch\n"); 5817cf11e85fSRoman Gushchin } 5818cf11e85fSRoman Gushchin 5819cf11e85fSRoman Gushchin #endif /* CONFIG_CMA */ 5820