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 8590481622SDavid Gibson static inline void unlock_or_release_subpool(struct hugepage_subpool *spool) 8690481622SDavid Gibson { 8790481622SDavid Gibson bool free = (spool->count == 0) && (spool->used_hpages == 0); 8890481622SDavid Gibson 8990481622SDavid Gibson spin_unlock(&spool->lock); 9090481622SDavid Gibson 9190481622SDavid Gibson /* If no pages are used, and no other handles to the subpool 927c8de358SEthon Paul * remain, give up any reservations based on minimum size and 937ca02d0aSMike Kravetz * free the subpool */ 947ca02d0aSMike Kravetz if (free) { 957ca02d0aSMike Kravetz if (spool->min_hpages != -1) 967ca02d0aSMike Kravetz hugetlb_acct_memory(spool->hstate, 977ca02d0aSMike Kravetz -spool->min_hpages); 9890481622SDavid Gibson kfree(spool); 9990481622SDavid Gibson } 1007ca02d0aSMike Kravetz } 10190481622SDavid Gibson 1027ca02d0aSMike Kravetz struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, 1037ca02d0aSMike Kravetz long min_hpages) 10490481622SDavid Gibson { 10590481622SDavid Gibson struct hugepage_subpool *spool; 10690481622SDavid Gibson 107c6a91820SMike Kravetz spool = kzalloc(sizeof(*spool), GFP_KERNEL); 10890481622SDavid Gibson if (!spool) 10990481622SDavid Gibson return NULL; 11090481622SDavid Gibson 11190481622SDavid Gibson spin_lock_init(&spool->lock); 11290481622SDavid Gibson spool->count = 1; 1137ca02d0aSMike Kravetz spool->max_hpages = max_hpages; 1147ca02d0aSMike Kravetz spool->hstate = h; 1157ca02d0aSMike Kravetz spool->min_hpages = min_hpages; 1167ca02d0aSMike Kravetz 1177ca02d0aSMike Kravetz if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { 1187ca02d0aSMike Kravetz kfree(spool); 1197ca02d0aSMike Kravetz return NULL; 1207ca02d0aSMike Kravetz } 1217ca02d0aSMike Kravetz spool->rsv_hpages = min_hpages; 12290481622SDavid Gibson 12390481622SDavid Gibson return spool; 12490481622SDavid Gibson } 12590481622SDavid Gibson 12690481622SDavid Gibson void hugepage_put_subpool(struct hugepage_subpool *spool) 12790481622SDavid Gibson { 12890481622SDavid Gibson spin_lock(&spool->lock); 12990481622SDavid Gibson BUG_ON(!spool->count); 13090481622SDavid Gibson spool->count--; 13190481622SDavid Gibson unlock_or_release_subpool(spool); 13290481622SDavid Gibson } 13390481622SDavid Gibson 1341c5ecae3SMike Kravetz /* 1351c5ecae3SMike Kravetz * Subpool accounting for allocating and reserving pages. 1361c5ecae3SMike Kravetz * Return -ENOMEM if there are not enough resources to satisfy the 1379e7ee400SRandy Dunlap * request. Otherwise, return the number of pages by which the 1381c5ecae3SMike Kravetz * global pools must be adjusted (upward). The returned value may 1391c5ecae3SMike Kravetz * only be different than the passed value (delta) in the case where 1407c8de358SEthon Paul * a subpool minimum size must be maintained. 1411c5ecae3SMike Kravetz */ 1421c5ecae3SMike Kravetz static long hugepage_subpool_get_pages(struct hugepage_subpool *spool, 14390481622SDavid Gibson long delta) 14490481622SDavid Gibson { 1451c5ecae3SMike Kravetz long ret = delta; 14690481622SDavid Gibson 14790481622SDavid Gibson if (!spool) 1481c5ecae3SMike Kravetz return ret; 14990481622SDavid Gibson 15090481622SDavid Gibson spin_lock(&spool->lock); 15190481622SDavid Gibson 1521c5ecae3SMike Kravetz if (spool->max_hpages != -1) { /* maximum size accounting */ 1531c5ecae3SMike Kravetz if ((spool->used_hpages + delta) <= spool->max_hpages) 1541c5ecae3SMike Kravetz spool->used_hpages += delta; 1551c5ecae3SMike Kravetz else { 1561c5ecae3SMike Kravetz ret = -ENOMEM; 1571c5ecae3SMike Kravetz goto unlock_ret; 1581c5ecae3SMike Kravetz } 1591c5ecae3SMike Kravetz } 1601c5ecae3SMike Kravetz 16109a95e29SMike Kravetz /* minimum size accounting */ 16209a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->rsv_hpages) { 1631c5ecae3SMike Kravetz if (delta > spool->rsv_hpages) { 1641c5ecae3SMike Kravetz /* 1651c5ecae3SMike Kravetz * Asking for more reserves than those already taken on 1661c5ecae3SMike Kravetz * behalf of subpool. Return difference. 1671c5ecae3SMike Kravetz */ 1681c5ecae3SMike Kravetz ret = delta - spool->rsv_hpages; 1691c5ecae3SMike Kravetz spool->rsv_hpages = 0; 1701c5ecae3SMike Kravetz } else { 1711c5ecae3SMike Kravetz ret = 0; /* reserves already accounted for */ 1721c5ecae3SMike Kravetz spool->rsv_hpages -= delta; 1731c5ecae3SMike Kravetz } 1741c5ecae3SMike Kravetz } 1751c5ecae3SMike Kravetz 1761c5ecae3SMike Kravetz unlock_ret: 1771c5ecae3SMike Kravetz spin_unlock(&spool->lock); 17890481622SDavid Gibson return ret; 17990481622SDavid Gibson } 18090481622SDavid Gibson 1811c5ecae3SMike Kravetz /* 1821c5ecae3SMike Kravetz * Subpool accounting for freeing and unreserving pages. 1831c5ecae3SMike Kravetz * Return the number of global page reservations that must be dropped. 1841c5ecae3SMike Kravetz * The return value may only be different than the passed value (delta) 1851c5ecae3SMike Kravetz * in the case where a subpool minimum size must be maintained. 1861c5ecae3SMike Kravetz */ 1871c5ecae3SMike Kravetz static long hugepage_subpool_put_pages(struct hugepage_subpool *spool, 18890481622SDavid Gibson long delta) 18990481622SDavid Gibson { 1901c5ecae3SMike Kravetz long ret = delta; 1911c5ecae3SMike Kravetz 19290481622SDavid Gibson if (!spool) 1931c5ecae3SMike Kravetz return delta; 19490481622SDavid Gibson 19590481622SDavid Gibson spin_lock(&spool->lock); 1961c5ecae3SMike Kravetz 1971c5ecae3SMike Kravetz if (spool->max_hpages != -1) /* maximum size accounting */ 19890481622SDavid Gibson spool->used_hpages -= delta; 1991c5ecae3SMike Kravetz 20009a95e29SMike Kravetz /* minimum size accounting */ 20109a95e29SMike Kravetz if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { 2021c5ecae3SMike Kravetz if (spool->rsv_hpages + delta <= spool->min_hpages) 2031c5ecae3SMike Kravetz ret = 0; 2041c5ecae3SMike Kravetz else 2051c5ecae3SMike Kravetz ret = spool->rsv_hpages + delta - spool->min_hpages; 2061c5ecae3SMike Kravetz 2071c5ecae3SMike Kravetz spool->rsv_hpages += delta; 2081c5ecae3SMike Kravetz if (spool->rsv_hpages > spool->min_hpages) 2091c5ecae3SMike Kravetz spool->rsv_hpages = spool->min_hpages; 2101c5ecae3SMike Kravetz } 2111c5ecae3SMike Kravetz 2121c5ecae3SMike Kravetz /* 2131c5ecae3SMike Kravetz * If hugetlbfs_put_super couldn't free spool due to an outstanding 2141c5ecae3SMike Kravetz * quota reference, free it now. 2151c5ecae3SMike Kravetz */ 21690481622SDavid Gibson unlock_or_release_subpool(spool); 2171c5ecae3SMike Kravetz 2181c5ecae3SMike Kravetz return ret; 21990481622SDavid Gibson } 22090481622SDavid Gibson 22190481622SDavid Gibson static inline struct hugepage_subpool *subpool_inode(struct inode *inode) 22290481622SDavid Gibson { 22390481622SDavid Gibson return HUGETLBFS_SB(inode->i_sb)->spool; 22490481622SDavid Gibson } 22590481622SDavid Gibson 22690481622SDavid Gibson static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) 22790481622SDavid Gibson { 228496ad9aaSAl Viro return subpool_inode(file_inode(vma->vm_file)); 22990481622SDavid Gibson } 23090481622SDavid Gibson 2310db9d74eSMina Almasry /* Helper that removes a struct file_region from the resv_map cache and returns 2320db9d74eSMina Almasry * it for use. 2330db9d74eSMina Almasry */ 2340db9d74eSMina Almasry static struct file_region * 2350db9d74eSMina Almasry get_file_region_entry_from_cache(struct resv_map *resv, long from, long to) 2360db9d74eSMina Almasry { 2370db9d74eSMina Almasry struct file_region *nrg = NULL; 2380db9d74eSMina Almasry 2390db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count <= 0); 2400db9d74eSMina Almasry 2410db9d74eSMina Almasry resv->region_cache_count--; 2420db9d74eSMina Almasry nrg = list_first_entry(&resv->region_cache, struct file_region, link); 2430db9d74eSMina Almasry VM_BUG_ON(!nrg); 2440db9d74eSMina Almasry list_del(&nrg->link); 2450db9d74eSMina Almasry 2460db9d74eSMina Almasry nrg->from = from; 2470db9d74eSMina Almasry nrg->to = to; 2480db9d74eSMina Almasry 2490db9d74eSMina Almasry return nrg; 2500db9d74eSMina Almasry } 2510db9d74eSMina Almasry 252075a61d0SMina Almasry static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg, 253075a61d0SMina Almasry struct file_region *rg) 254075a61d0SMina Almasry { 255075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 256075a61d0SMina Almasry nrg->reservation_counter = rg->reservation_counter; 257075a61d0SMina Almasry nrg->css = rg->css; 258075a61d0SMina Almasry if (rg->css) 259075a61d0SMina Almasry css_get(rg->css); 260075a61d0SMina Almasry #endif 261075a61d0SMina Almasry } 262075a61d0SMina Almasry 263075a61d0SMina Almasry /* Helper that records hugetlb_cgroup uncharge info. */ 264075a61d0SMina Almasry static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg, 265075a61d0SMina Almasry struct hstate *h, 266075a61d0SMina Almasry struct resv_map *resv, 267075a61d0SMina Almasry struct file_region *nrg) 268075a61d0SMina Almasry { 269075a61d0SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 270075a61d0SMina Almasry if (h_cg) { 271075a61d0SMina Almasry nrg->reservation_counter = 272075a61d0SMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 273075a61d0SMina Almasry nrg->css = &h_cg->css; 274075a61d0SMina Almasry if (!resv->pages_per_hpage) 275075a61d0SMina Almasry resv->pages_per_hpage = pages_per_huge_page(h); 276075a61d0SMina Almasry /* pages_per_hpage should be the same for all entries in 277075a61d0SMina Almasry * a resv_map. 278075a61d0SMina Almasry */ 279075a61d0SMina Almasry VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h)); 280075a61d0SMina Almasry } else { 281075a61d0SMina Almasry nrg->reservation_counter = NULL; 282075a61d0SMina Almasry nrg->css = NULL; 283075a61d0SMina Almasry } 284075a61d0SMina Almasry #endif 285075a61d0SMina Almasry } 286075a61d0SMina Almasry 287a9b3f867SMina Almasry static bool has_same_uncharge_info(struct file_region *rg, 288a9b3f867SMina Almasry struct file_region *org) 289a9b3f867SMina Almasry { 290a9b3f867SMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 291a9b3f867SMina Almasry return rg && org && 292a9b3f867SMina Almasry rg->reservation_counter == org->reservation_counter && 293a9b3f867SMina Almasry rg->css == org->css; 294a9b3f867SMina Almasry 295a9b3f867SMina Almasry #else 296a9b3f867SMina Almasry return true; 297a9b3f867SMina Almasry #endif 298a9b3f867SMina Almasry } 299a9b3f867SMina Almasry 300a9b3f867SMina Almasry static void coalesce_file_region(struct resv_map *resv, struct file_region *rg) 301a9b3f867SMina Almasry { 302a9b3f867SMina Almasry struct file_region *nrg = NULL, *prg = NULL; 303a9b3f867SMina Almasry 304a9b3f867SMina Almasry prg = list_prev_entry(rg, link); 305a9b3f867SMina Almasry if (&prg->link != &resv->regions && prg->to == rg->from && 306a9b3f867SMina Almasry has_same_uncharge_info(prg, rg)) { 307a9b3f867SMina Almasry prg->to = rg->to; 308a9b3f867SMina Almasry 309a9b3f867SMina Almasry list_del(&rg->link); 310a9b3f867SMina Almasry kfree(rg); 311a9b3f867SMina Almasry 312a9b3f867SMina Almasry coalesce_file_region(resv, prg); 313a9b3f867SMina Almasry return; 314a9b3f867SMina Almasry } 315a9b3f867SMina Almasry 316a9b3f867SMina Almasry nrg = list_next_entry(rg, link); 317a9b3f867SMina Almasry if (&nrg->link != &resv->regions && nrg->from == rg->to && 318a9b3f867SMina Almasry has_same_uncharge_info(nrg, rg)) { 319a9b3f867SMina Almasry nrg->from = rg->from; 320a9b3f867SMina Almasry 321a9b3f867SMina Almasry list_del(&rg->link); 322a9b3f867SMina Almasry kfree(rg); 323a9b3f867SMina Almasry 324a9b3f867SMina Almasry coalesce_file_region(resv, nrg); 325a9b3f867SMina Almasry return; 326a9b3f867SMina Almasry } 327a9b3f867SMina Almasry } 328a9b3f867SMina Almasry 329d75c6af9SMina Almasry /* Must be called with resv->lock held. Calling this with count_only == true 330d75c6af9SMina Almasry * will count the number of pages to be added but will not modify the linked 3310db9d74eSMina Almasry * list. If regions_needed != NULL and count_only == true, then regions_needed 3320db9d74eSMina Almasry * will indicate the number of file_regions needed in the cache to carry out to 3330db9d74eSMina Almasry * add the regions for this range. 334d75c6af9SMina Almasry */ 335d75c6af9SMina Almasry static long add_reservation_in_range(struct resv_map *resv, long f, long t, 336075a61d0SMina Almasry struct hugetlb_cgroup *h_cg, 337075a61d0SMina Almasry struct hstate *h, long *regions_needed, 338075a61d0SMina Almasry bool count_only) 339d75c6af9SMina Almasry { 3400db9d74eSMina Almasry long add = 0; 341d75c6af9SMina Almasry struct list_head *head = &resv->regions; 3420db9d74eSMina Almasry long last_accounted_offset = f; 343d75c6af9SMina Almasry struct file_region *rg = NULL, *trg = NULL, *nrg = NULL; 344d75c6af9SMina Almasry 3450db9d74eSMina Almasry if (regions_needed) 3460db9d74eSMina Almasry *regions_needed = 0; 347d75c6af9SMina Almasry 3480db9d74eSMina Almasry /* In this loop, we essentially handle an entry for the range 3490db9d74eSMina Almasry * [last_accounted_offset, rg->from), at every iteration, with some 3500db9d74eSMina Almasry * bounds checking. 3510db9d74eSMina Almasry */ 3520db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, head, link) { 3530db9d74eSMina Almasry /* Skip irrelevant regions that start before our range. */ 3540db9d74eSMina Almasry if (rg->from < f) { 3550db9d74eSMina Almasry /* If this region ends after the last accounted offset, 3560db9d74eSMina Almasry * then we need to update last_accounted_offset. 3570db9d74eSMina Almasry */ 3580db9d74eSMina Almasry if (rg->to > last_accounted_offset) 3590db9d74eSMina Almasry last_accounted_offset = rg->to; 3600db9d74eSMina Almasry continue; 3610db9d74eSMina Almasry } 362d75c6af9SMina Almasry 3630db9d74eSMina Almasry /* When we find a region that starts beyond our range, we've 3640db9d74eSMina Almasry * finished. 3650db9d74eSMina Almasry */ 366d75c6af9SMina Almasry if (rg->from > t) 367d75c6af9SMina Almasry break; 368d75c6af9SMina Almasry 3690db9d74eSMina Almasry /* Add an entry for last_accounted_offset -> rg->from, and 3700db9d74eSMina Almasry * update last_accounted_offset. 371d75c6af9SMina Almasry */ 3720db9d74eSMina Almasry if (rg->from > last_accounted_offset) { 3730db9d74eSMina Almasry add += rg->from - last_accounted_offset; 3740db9d74eSMina Almasry if (!count_only) { 3750db9d74eSMina Almasry nrg = get_file_region_entry_from_cache( 3760db9d74eSMina Almasry resv, last_accounted_offset, rg->from); 377075a61d0SMina Almasry record_hugetlb_cgroup_uncharge_info(h_cg, h, 378075a61d0SMina Almasry resv, nrg); 3790db9d74eSMina Almasry list_add(&nrg->link, rg->link.prev); 380a9b3f867SMina Almasry coalesce_file_region(resv, nrg); 3810db9d74eSMina Almasry } else if (regions_needed) 3820db9d74eSMina Almasry *regions_needed += 1; 383d75c6af9SMina Almasry } 384d75c6af9SMina Almasry 3850db9d74eSMina Almasry last_accounted_offset = rg->to; 3860db9d74eSMina Almasry } 3870db9d74eSMina Almasry 3880db9d74eSMina Almasry /* Handle the case where our range extends beyond 3890db9d74eSMina Almasry * last_accounted_offset. 3900db9d74eSMina Almasry */ 3910db9d74eSMina Almasry if (last_accounted_offset < t) { 3920db9d74eSMina Almasry add += t - last_accounted_offset; 3930db9d74eSMina Almasry if (!count_only) { 3940db9d74eSMina Almasry nrg = get_file_region_entry_from_cache( 3950db9d74eSMina Almasry resv, last_accounted_offset, t); 396075a61d0SMina Almasry record_hugetlb_cgroup_uncharge_info(h_cg, h, resv, nrg); 3970db9d74eSMina Almasry list_add(&nrg->link, rg->link.prev); 398a9b3f867SMina Almasry coalesce_file_region(resv, nrg); 3990db9d74eSMina Almasry } else if (regions_needed) 4000db9d74eSMina Almasry *regions_needed += 1; 4010db9d74eSMina Almasry } 4020db9d74eSMina Almasry 4030db9d74eSMina Almasry VM_BUG_ON(add < 0); 4040db9d74eSMina Almasry return add; 4050db9d74eSMina Almasry } 4060db9d74eSMina Almasry 4070db9d74eSMina Almasry /* Must be called with resv->lock acquired. Will drop lock to allocate entries. 4080db9d74eSMina Almasry */ 4090db9d74eSMina Almasry static int allocate_file_region_entries(struct resv_map *resv, 4100db9d74eSMina Almasry int regions_needed) 4110db9d74eSMina Almasry __must_hold(&resv->lock) 4120db9d74eSMina Almasry { 4130db9d74eSMina Almasry struct list_head allocated_regions; 4140db9d74eSMina Almasry int to_allocate = 0, i = 0; 4150db9d74eSMina Almasry struct file_region *trg = NULL, *rg = NULL; 4160db9d74eSMina Almasry 4170db9d74eSMina Almasry VM_BUG_ON(regions_needed < 0); 4180db9d74eSMina Almasry 4190db9d74eSMina Almasry INIT_LIST_HEAD(&allocated_regions); 4200db9d74eSMina Almasry 4210db9d74eSMina Almasry /* 4220db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 4230db9d74eSMina Almasry * the number of in progress add operations plus regions_needed. 4240db9d74eSMina Almasry * 4250db9d74eSMina Almasry * This is a while loop because when we drop the lock, some other call 4260db9d74eSMina Almasry * to region_add or region_del may have consumed some region_entries, 4270db9d74eSMina Almasry * so we keep looping here until we finally have enough entries for 4280db9d74eSMina Almasry * (adds_in_progress + regions_needed). 4290db9d74eSMina Almasry */ 4300db9d74eSMina Almasry while (resv->region_cache_count < 4310db9d74eSMina Almasry (resv->adds_in_progress + regions_needed)) { 4320db9d74eSMina Almasry to_allocate = resv->adds_in_progress + regions_needed - 4330db9d74eSMina Almasry resv->region_cache_count; 4340db9d74eSMina Almasry 4350db9d74eSMina Almasry /* At this point, we should have enough entries in the cache 4360db9d74eSMina Almasry * for all the existings adds_in_progress. We should only be 4370db9d74eSMina Almasry * needing to allocate for regions_needed. 4380db9d74eSMina Almasry */ 4390db9d74eSMina Almasry VM_BUG_ON(resv->region_cache_count < resv->adds_in_progress); 4400db9d74eSMina Almasry 4410db9d74eSMina Almasry spin_unlock(&resv->lock); 4420db9d74eSMina Almasry for (i = 0; i < to_allocate; i++) { 4430db9d74eSMina Almasry trg = kmalloc(sizeof(*trg), GFP_KERNEL); 4440db9d74eSMina Almasry if (!trg) 4450db9d74eSMina Almasry goto out_of_memory; 4460db9d74eSMina Almasry list_add(&trg->link, &allocated_regions); 4470db9d74eSMina Almasry } 4480db9d74eSMina Almasry 4490db9d74eSMina Almasry spin_lock(&resv->lock); 4500db9d74eSMina Almasry 4510db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, &allocated_regions, link) { 4520db9d74eSMina Almasry list_del(&rg->link); 4530db9d74eSMina Almasry list_add(&rg->link, &resv->region_cache); 4540db9d74eSMina Almasry resv->region_cache_count++; 4550db9d74eSMina Almasry } 4560db9d74eSMina Almasry } 4570db9d74eSMina Almasry 4580db9d74eSMina Almasry return 0; 4590db9d74eSMina Almasry 4600db9d74eSMina Almasry out_of_memory: 4610db9d74eSMina Almasry list_for_each_entry_safe(rg, trg, &allocated_regions, link) { 462d75c6af9SMina Almasry list_del(&rg->link); 463d75c6af9SMina Almasry kfree(rg); 464d75c6af9SMina Almasry } 4650db9d74eSMina Almasry return -ENOMEM; 466d75c6af9SMina Almasry } 467d75c6af9SMina Almasry 4681dd308a7SMike Kravetz /* 4691dd308a7SMike Kravetz * Add the huge page range represented by [f, t) to the reserve 4700db9d74eSMina Almasry * map. Regions will be taken from the cache to fill in this range. 4710db9d74eSMina Almasry * Sufficient regions should exist in the cache due to the previous 4720db9d74eSMina Almasry * call to region_chg with the same range, but in some cases the cache will not 4730db9d74eSMina Almasry * have sufficient entries due to races with other code doing region_add or 4740db9d74eSMina Almasry * region_del. The extra needed entries will be allocated. 475cf3ad20bSMike Kravetz * 4760db9d74eSMina Almasry * regions_needed is the out value provided by a previous call to region_chg. 4770db9d74eSMina Almasry * 4780db9d74eSMina Almasry * Return the number of new huge pages added to the map. This number is greater 4790db9d74eSMina Almasry * than or equal to zero. If file_region entries needed to be allocated for 4807c8de358SEthon Paul * this operation and we were not able to allocate, it returns -ENOMEM. 4810db9d74eSMina Almasry * region_add of regions of length 1 never allocate file_regions and cannot 4820db9d74eSMina Almasry * fail; region_chg will always allocate at least 1 entry and a region_add for 4830db9d74eSMina Almasry * 1 page will only require at most 1 entry. 4841dd308a7SMike Kravetz */ 4850db9d74eSMina Almasry static long region_add(struct resv_map *resv, long f, long t, 486075a61d0SMina Almasry long in_regions_needed, struct hstate *h, 487075a61d0SMina Almasry struct hugetlb_cgroup *h_cg) 48896822904SAndy Whitcroft { 4890db9d74eSMina Almasry long add = 0, actual_regions_needed = 0; 49096822904SAndy Whitcroft 4917b24d861SDavidlohr Bueso spin_lock(&resv->lock); 4920db9d74eSMina Almasry retry: 4930db9d74eSMina Almasry 4940db9d74eSMina Almasry /* Count how many regions are actually needed to execute this add. */ 495075a61d0SMina Almasry add_reservation_in_range(resv, f, t, NULL, NULL, &actual_regions_needed, 496075a61d0SMina Almasry true); 49796822904SAndy Whitcroft 4985e911373SMike Kravetz /* 4990db9d74eSMina Almasry * Check for sufficient descriptors in the cache to accommodate 5000db9d74eSMina Almasry * this add operation. Note that actual_regions_needed may be greater 5010db9d74eSMina Almasry * than in_regions_needed, as the resv_map may have been modified since 5020db9d74eSMina Almasry * the region_chg call. In this case, we need to make sure that we 5030db9d74eSMina Almasry * allocate extra entries, such that we have enough for all the 5040db9d74eSMina Almasry * existing adds_in_progress, plus the excess needed for this 5050db9d74eSMina Almasry * operation. 5065e911373SMike Kravetz */ 5070db9d74eSMina Almasry if (actual_regions_needed > in_regions_needed && 5080db9d74eSMina Almasry resv->region_cache_count < 5090db9d74eSMina Almasry resv->adds_in_progress + 5100db9d74eSMina Almasry (actual_regions_needed - in_regions_needed)) { 5110db9d74eSMina Almasry /* region_add operation of range 1 should never need to 5120db9d74eSMina Almasry * allocate file_region entries. 5130db9d74eSMina Almasry */ 5140db9d74eSMina Almasry VM_BUG_ON(t - f <= 1); 5155e911373SMike Kravetz 5160db9d74eSMina Almasry if (allocate_file_region_entries( 5170db9d74eSMina Almasry resv, actual_regions_needed - in_regions_needed)) { 5180db9d74eSMina Almasry return -ENOMEM; 5195e911373SMike Kravetz } 5205e911373SMike Kravetz 5210db9d74eSMina Almasry goto retry; 5220db9d74eSMina Almasry } 523cf3ad20bSMike Kravetz 524075a61d0SMina Almasry add = add_reservation_in_range(resv, f, t, h_cg, h, NULL, false); 5250db9d74eSMina Almasry 5260db9d74eSMina Almasry resv->adds_in_progress -= in_regions_needed; 5270db9d74eSMina Almasry 5287b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 529cf3ad20bSMike Kravetz VM_BUG_ON(add < 0); 530cf3ad20bSMike Kravetz return add; 53196822904SAndy Whitcroft } 53296822904SAndy Whitcroft 5331dd308a7SMike Kravetz /* 5341dd308a7SMike Kravetz * Examine the existing reserve map and determine how many 5351dd308a7SMike Kravetz * huge pages in the specified range [f, t) are NOT currently 5361dd308a7SMike Kravetz * represented. This routine is called before a subsequent 5371dd308a7SMike Kravetz * call to region_add that will actually modify the reserve 5381dd308a7SMike Kravetz * map to add the specified range [f, t). region_chg does 5391dd308a7SMike Kravetz * not change the number of huge pages represented by the 5400db9d74eSMina Almasry * map. A number of new file_region structures is added to the cache as a 5410db9d74eSMina Almasry * placeholder, for the subsequent region_add call to use. At least 1 5420db9d74eSMina Almasry * file_region structure is added. 5430db9d74eSMina Almasry * 5440db9d74eSMina Almasry * out_regions_needed is the number of regions added to the 5450db9d74eSMina Almasry * resv->adds_in_progress. This value needs to be provided to a follow up call 5460db9d74eSMina Almasry * to region_add or region_abort for proper accounting. 5475e911373SMike Kravetz * 5485e911373SMike Kravetz * Returns the number of huge pages that need to be added to the existing 5495e911373SMike Kravetz * reservation map for the range [f, t). This number is greater or equal to 5505e911373SMike Kravetz * zero. -ENOMEM is returned if a new file_region structure or cache entry 5515e911373SMike Kravetz * is needed and can not be allocated. 5521dd308a7SMike Kravetz */ 5530db9d74eSMina Almasry static long region_chg(struct resv_map *resv, long f, long t, 5540db9d74eSMina Almasry long *out_regions_needed) 55596822904SAndy Whitcroft { 55696822904SAndy Whitcroft long chg = 0; 55796822904SAndy Whitcroft 5587b24d861SDavidlohr Bueso spin_lock(&resv->lock); 5595e911373SMike Kravetz 5600db9d74eSMina Almasry /* Count how many hugepages in this range are NOT respresented. */ 561075a61d0SMina Almasry chg = add_reservation_in_range(resv, f, t, NULL, NULL, 562075a61d0SMina Almasry out_regions_needed, true); 5635e911373SMike Kravetz 5640db9d74eSMina Almasry if (*out_regions_needed == 0) 5650db9d74eSMina Almasry *out_regions_needed = 1; 5665e911373SMike Kravetz 5670db9d74eSMina Almasry if (allocate_file_region_entries(resv, *out_regions_needed)) 5685e911373SMike Kravetz return -ENOMEM; 5695e911373SMike Kravetz 5700db9d74eSMina Almasry resv->adds_in_progress += *out_regions_needed; 57196822904SAndy Whitcroft 5727b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 57396822904SAndy Whitcroft return chg; 57496822904SAndy Whitcroft } 57596822904SAndy Whitcroft 5761dd308a7SMike Kravetz /* 5775e911373SMike Kravetz * Abort the in progress add operation. The adds_in_progress field 5785e911373SMike Kravetz * of the resv_map keeps track of the operations in progress between 5795e911373SMike Kravetz * calls to region_chg and region_add. Operations are sometimes 5805e911373SMike Kravetz * aborted after the call to region_chg. In such cases, region_abort 5810db9d74eSMina Almasry * is called to decrement the adds_in_progress counter. regions_needed 5820db9d74eSMina Almasry * is the value returned by the region_chg call, it is used to decrement 5830db9d74eSMina Almasry * the adds_in_progress counter. 5845e911373SMike Kravetz * 5855e911373SMike Kravetz * NOTE: The range arguments [f, t) are not needed or used in this 5865e911373SMike Kravetz * routine. They are kept to make reading the calling code easier as 5875e911373SMike Kravetz * arguments will match the associated region_chg call. 5885e911373SMike Kravetz */ 5890db9d74eSMina Almasry static void region_abort(struct resv_map *resv, long f, long t, 5900db9d74eSMina Almasry long regions_needed) 5915e911373SMike Kravetz { 5925e911373SMike Kravetz spin_lock(&resv->lock); 5935e911373SMike Kravetz VM_BUG_ON(!resv->region_cache_count); 5940db9d74eSMina Almasry resv->adds_in_progress -= regions_needed; 5955e911373SMike Kravetz spin_unlock(&resv->lock); 5965e911373SMike Kravetz } 5975e911373SMike Kravetz 5985e911373SMike Kravetz /* 599feba16e2SMike Kravetz * Delete the specified range [f, t) from the reserve map. If the 600feba16e2SMike Kravetz * t parameter is LONG_MAX, this indicates that ALL regions after f 601feba16e2SMike Kravetz * should be deleted. Locate the regions which intersect [f, t) 602feba16e2SMike Kravetz * and either trim, delete or split the existing regions. 603feba16e2SMike Kravetz * 604feba16e2SMike Kravetz * Returns the number of huge pages deleted from the reserve map. 605feba16e2SMike Kravetz * In the normal case, the return value is zero or more. In the 606feba16e2SMike Kravetz * case where a region must be split, a new region descriptor must 607feba16e2SMike Kravetz * be allocated. If the allocation fails, -ENOMEM will be returned. 608feba16e2SMike Kravetz * NOTE: If the parameter t == LONG_MAX, then we will never split 609feba16e2SMike Kravetz * a region and possibly return -ENOMEM. Callers specifying 610feba16e2SMike Kravetz * t == LONG_MAX do not need to check for -ENOMEM error. 6111dd308a7SMike Kravetz */ 612feba16e2SMike Kravetz static long region_del(struct resv_map *resv, long f, long t) 61396822904SAndy Whitcroft { 6141406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 61596822904SAndy Whitcroft struct file_region *rg, *trg; 616feba16e2SMike Kravetz struct file_region *nrg = NULL; 617feba16e2SMike Kravetz long del = 0; 61896822904SAndy Whitcroft 619feba16e2SMike Kravetz retry: 6207b24d861SDavidlohr Bueso spin_lock(&resv->lock); 621feba16e2SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 622dbe409e4SMike Kravetz /* 623dbe409e4SMike Kravetz * Skip regions before the range to be deleted. file_region 624dbe409e4SMike Kravetz * ranges are normally of the form [from, to). However, there 625dbe409e4SMike Kravetz * may be a "placeholder" entry in the map which is of the form 626dbe409e4SMike Kravetz * (from, to) with from == to. Check for placeholder entries 627dbe409e4SMike Kravetz * at the beginning of the range to be deleted. 628dbe409e4SMike Kravetz */ 629dbe409e4SMike Kravetz if (rg->to <= f && (rg->to != rg->from || rg->to != f)) 630feba16e2SMike Kravetz continue; 631dbe409e4SMike Kravetz 632feba16e2SMike Kravetz if (rg->from >= t) 63396822904SAndy Whitcroft break; 63496822904SAndy Whitcroft 635feba16e2SMike Kravetz if (f > rg->from && t < rg->to) { /* Must split region */ 636feba16e2SMike Kravetz /* 637feba16e2SMike Kravetz * Check for an entry in the cache before dropping 638feba16e2SMike Kravetz * lock and attempting allocation. 639feba16e2SMike Kravetz */ 640feba16e2SMike Kravetz if (!nrg && 641feba16e2SMike Kravetz resv->region_cache_count > resv->adds_in_progress) { 642feba16e2SMike Kravetz nrg = list_first_entry(&resv->region_cache, 643feba16e2SMike Kravetz struct file_region, 644feba16e2SMike Kravetz link); 645feba16e2SMike Kravetz list_del(&nrg->link); 646feba16e2SMike Kravetz resv->region_cache_count--; 64796822904SAndy Whitcroft } 64896822904SAndy Whitcroft 649feba16e2SMike Kravetz if (!nrg) { 650feba16e2SMike Kravetz spin_unlock(&resv->lock); 651feba16e2SMike Kravetz nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); 652feba16e2SMike Kravetz if (!nrg) 653feba16e2SMike Kravetz return -ENOMEM; 654feba16e2SMike Kravetz goto retry; 655feba16e2SMike Kravetz } 656feba16e2SMike Kravetz 657feba16e2SMike Kravetz del += t - f; 658feba16e2SMike Kravetz 659feba16e2SMike Kravetz /* New entry for end of split region */ 660feba16e2SMike Kravetz nrg->from = t; 661feba16e2SMike Kravetz nrg->to = rg->to; 662075a61d0SMina Almasry 663075a61d0SMina Almasry copy_hugetlb_cgroup_uncharge_info(nrg, rg); 664075a61d0SMina Almasry 665feba16e2SMike Kravetz INIT_LIST_HEAD(&nrg->link); 666feba16e2SMike Kravetz 667feba16e2SMike Kravetz /* Original entry is trimmed */ 668feba16e2SMike Kravetz rg->to = f; 669feba16e2SMike Kravetz 670075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region( 671075a61d0SMina Almasry resv, rg, nrg->to - nrg->from); 672075a61d0SMina Almasry 673feba16e2SMike Kravetz list_add(&nrg->link, &rg->link); 674feba16e2SMike Kravetz nrg = NULL; 67596822904SAndy Whitcroft break; 676feba16e2SMike Kravetz } 677feba16e2SMike Kravetz 678feba16e2SMike Kravetz if (f <= rg->from && t >= rg->to) { /* Remove entire region */ 679feba16e2SMike Kravetz del += rg->to - rg->from; 680075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 681075a61d0SMina Almasry rg->to - rg->from); 68296822904SAndy Whitcroft list_del(&rg->link); 68396822904SAndy Whitcroft kfree(rg); 684feba16e2SMike Kravetz continue; 68596822904SAndy Whitcroft } 6867b24d861SDavidlohr Bueso 687feba16e2SMike Kravetz if (f <= rg->from) { /* Trim beginning of region */ 688feba16e2SMike Kravetz del += t - rg->from; 689feba16e2SMike Kravetz rg->from = t; 690075a61d0SMina Almasry 691075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 692075a61d0SMina Almasry t - rg->from); 693feba16e2SMike Kravetz } else { /* Trim end of region */ 694feba16e2SMike Kravetz del += rg->to - f; 695feba16e2SMike Kravetz rg->to = f; 696075a61d0SMina Almasry 697075a61d0SMina Almasry hugetlb_cgroup_uncharge_file_region(resv, rg, 698075a61d0SMina Almasry rg->to - f); 699feba16e2SMike Kravetz } 700feba16e2SMike Kravetz } 701feba16e2SMike Kravetz 7027b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 703feba16e2SMike Kravetz kfree(nrg); 704feba16e2SMike Kravetz return del; 70596822904SAndy Whitcroft } 70696822904SAndy Whitcroft 7071dd308a7SMike Kravetz /* 708b5cec28dSMike Kravetz * A rare out of memory error was encountered which prevented removal of 709b5cec28dSMike Kravetz * the reserve map region for a page. The huge page itself was free'ed 710b5cec28dSMike Kravetz * and removed from the page cache. This routine will adjust the subpool 711b5cec28dSMike Kravetz * usage count, and the global reserve count if needed. By incrementing 712b5cec28dSMike Kravetz * these counts, the reserve map entry which could not be deleted will 713b5cec28dSMike Kravetz * appear as a "reserved" entry instead of simply dangling with incorrect 714b5cec28dSMike Kravetz * counts. 715b5cec28dSMike Kravetz */ 71672e2936cSzhong jiang void hugetlb_fix_reserve_counts(struct inode *inode) 717b5cec28dSMike Kravetz { 718b5cec28dSMike Kravetz struct hugepage_subpool *spool = subpool_inode(inode); 719b5cec28dSMike Kravetz long rsv_adjust; 720b5cec28dSMike Kravetz 721b5cec28dSMike Kravetz rsv_adjust = hugepage_subpool_get_pages(spool, 1); 72272e2936cSzhong jiang if (rsv_adjust) { 723b5cec28dSMike Kravetz struct hstate *h = hstate_inode(inode); 724b5cec28dSMike Kravetz 725b5cec28dSMike Kravetz hugetlb_acct_memory(h, 1); 726b5cec28dSMike Kravetz } 727b5cec28dSMike Kravetz } 728b5cec28dSMike Kravetz 729b5cec28dSMike Kravetz /* 7301dd308a7SMike Kravetz * Count and return the number of huge pages in the reserve map 7311dd308a7SMike Kravetz * that intersect with the range [f, t). 7321dd308a7SMike Kravetz */ 7331406ec9bSJoonsoo Kim static long region_count(struct resv_map *resv, long f, long t) 73484afd99bSAndy Whitcroft { 7351406ec9bSJoonsoo Kim struct list_head *head = &resv->regions; 73684afd99bSAndy Whitcroft struct file_region *rg; 73784afd99bSAndy Whitcroft long chg = 0; 73884afd99bSAndy Whitcroft 7397b24d861SDavidlohr Bueso spin_lock(&resv->lock); 74084afd99bSAndy Whitcroft /* Locate each segment we overlap with, and count that overlap. */ 74184afd99bSAndy Whitcroft list_for_each_entry(rg, head, link) { 742f2135a4aSWang Sheng-Hui long seg_from; 743f2135a4aSWang Sheng-Hui long seg_to; 74484afd99bSAndy Whitcroft 74584afd99bSAndy Whitcroft if (rg->to <= f) 74684afd99bSAndy Whitcroft continue; 74784afd99bSAndy Whitcroft if (rg->from >= t) 74884afd99bSAndy Whitcroft break; 74984afd99bSAndy Whitcroft 75084afd99bSAndy Whitcroft seg_from = max(rg->from, f); 75184afd99bSAndy Whitcroft seg_to = min(rg->to, t); 75284afd99bSAndy Whitcroft 75384afd99bSAndy Whitcroft chg += seg_to - seg_from; 75484afd99bSAndy Whitcroft } 7557b24d861SDavidlohr Bueso spin_unlock(&resv->lock); 75684afd99bSAndy Whitcroft 75784afd99bSAndy Whitcroft return chg; 75884afd99bSAndy Whitcroft } 75984afd99bSAndy Whitcroft 76096822904SAndy Whitcroft /* 761e7c4b0bfSAndy Whitcroft * Convert the address within this vma to the page offset within 762e7c4b0bfSAndy Whitcroft * the mapping, in pagecache page units; huge pages here. 763e7c4b0bfSAndy Whitcroft */ 764a5516438SAndi Kleen static pgoff_t vma_hugecache_offset(struct hstate *h, 765a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 766e7c4b0bfSAndy Whitcroft { 767a5516438SAndi Kleen return ((address - vma->vm_start) >> huge_page_shift(h)) + 768a5516438SAndi Kleen (vma->vm_pgoff >> huge_page_order(h)); 769e7c4b0bfSAndy Whitcroft } 770e7c4b0bfSAndy Whitcroft 7710fe6e20bSNaoya Horiguchi pgoff_t linear_hugepage_index(struct vm_area_struct *vma, 7720fe6e20bSNaoya Horiguchi unsigned long address) 7730fe6e20bSNaoya Horiguchi { 7740fe6e20bSNaoya Horiguchi return vma_hugecache_offset(hstate_vma(vma), vma, address); 7750fe6e20bSNaoya Horiguchi } 776dee41079SDan Williams EXPORT_SYMBOL_GPL(linear_hugepage_index); 7770fe6e20bSNaoya Horiguchi 77884afd99bSAndy Whitcroft /* 77908fba699SMel Gorman * Return the size of the pages allocated when backing a VMA. In the majority 78008fba699SMel Gorman * cases this will be same size as used by the page table entries. 78108fba699SMel Gorman */ 78208fba699SMel Gorman unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) 78308fba699SMel Gorman { 78405ea8860SDan Williams if (vma->vm_ops && vma->vm_ops->pagesize) 78505ea8860SDan Williams return vma->vm_ops->pagesize(vma); 78608fba699SMel Gorman return PAGE_SIZE; 78708fba699SMel Gorman } 788f340ca0fSJoerg Roedel EXPORT_SYMBOL_GPL(vma_kernel_pagesize); 78908fba699SMel Gorman 79008fba699SMel Gorman /* 7913340289dSMel Gorman * Return the page size being used by the MMU to back a VMA. In the majority 7923340289dSMel Gorman * of cases, the page size used by the kernel matches the MMU size. On 79309135cc5SDan Williams * architectures where it differs, an architecture-specific 'strong' 79409135cc5SDan Williams * version of this symbol is required. 7953340289dSMel Gorman */ 79609135cc5SDan Williams __weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) 7973340289dSMel Gorman { 7983340289dSMel Gorman return vma_kernel_pagesize(vma); 7993340289dSMel Gorman } 8003340289dSMel Gorman 8013340289dSMel Gorman /* 80284afd99bSAndy Whitcroft * Flags for MAP_PRIVATE reservations. These are stored in the bottom 80384afd99bSAndy Whitcroft * bits of the reservation map pointer, which are always clear due to 80484afd99bSAndy Whitcroft * alignment. 80584afd99bSAndy Whitcroft */ 80684afd99bSAndy Whitcroft #define HPAGE_RESV_OWNER (1UL << 0) 80784afd99bSAndy Whitcroft #define HPAGE_RESV_UNMAPPED (1UL << 1) 80804f2cbe3SMel Gorman #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) 80984afd99bSAndy Whitcroft 810a1e78772SMel Gorman /* 811a1e78772SMel Gorman * These helpers are used to track how many pages are reserved for 812a1e78772SMel Gorman * faults in a MAP_PRIVATE mapping. Only the process that called mmap() 813a1e78772SMel Gorman * is guaranteed to have their future faults succeed. 814a1e78772SMel Gorman * 815a1e78772SMel Gorman * With the exception of reset_vma_resv_huge_pages() which is called at fork(), 816a1e78772SMel Gorman * the reserve counters are updated with the hugetlb_lock held. It is safe 817a1e78772SMel Gorman * to reset the VMA at fork() time as it is not in use yet and there is no 818a1e78772SMel Gorman * chance of the global counters getting corrupted as a result of the values. 81984afd99bSAndy Whitcroft * 82084afd99bSAndy Whitcroft * The private mapping reservation is represented in a subtly different 82184afd99bSAndy Whitcroft * manner to a shared mapping. A shared mapping has a region map associated 82284afd99bSAndy Whitcroft * with the underlying file, this region map represents the backing file 82384afd99bSAndy Whitcroft * pages which have ever had a reservation assigned which this persists even 82484afd99bSAndy Whitcroft * after the page is instantiated. A private mapping has a region map 82584afd99bSAndy Whitcroft * associated with the original mmap which is attached to all VMAs which 82684afd99bSAndy Whitcroft * reference it, this region map represents those offsets which have consumed 82784afd99bSAndy Whitcroft * reservation ie. where pages have been instantiated. 828a1e78772SMel Gorman */ 829e7c4b0bfSAndy Whitcroft static unsigned long get_vma_private_data(struct vm_area_struct *vma) 830e7c4b0bfSAndy Whitcroft { 831e7c4b0bfSAndy Whitcroft return (unsigned long)vma->vm_private_data; 832e7c4b0bfSAndy Whitcroft } 833e7c4b0bfSAndy Whitcroft 834e7c4b0bfSAndy Whitcroft static void set_vma_private_data(struct vm_area_struct *vma, 835e7c4b0bfSAndy Whitcroft unsigned long value) 836e7c4b0bfSAndy Whitcroft { 837e7c4b0bfSAndy Whitcroft vma->vm_private_data = (void *)value; 838e7c4b0bfSAndy Whitcroft } 839e7c4b0bfSAndy Whitcroft 840e9fe92aeSMina Almasry static void 841e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(struct resv_map *resv_map, 842e9fe92aeSMina Almasry struct hugetlb_cgroup *h_cg, 843e9fe92aeSMina Almasry struct hstate *h) 844e9fe92aeSMina Almasry { 845e9fe92aeSMina Almasry #ifdef CONFIG_CGROUP_HUGETLB 846e9fe92aeSMina Almasry if (!h_cg || !h) { 847e9fe92aeSMina Almasry resv_map->reservation_counter = NULL; 848e9fe92aeSMina Almasry resv_map->pages_per_hpage = 0; 849e9fe92aeSMina Almasry resv_map->css = NULL; 850e9fe92aeSMina Almasry } else { 851e9fe92aeSMina Almasry resv_map->reservation_counter = 852e9fe92aeSMina Almasry &h_cg->rsvd_hugepage[hstate_index(h)]; 853e9fe92aeSMina Almasry resv_map->pages_per_hpage = pages_per_huge_page(h); 854e9fe92aeSMina Almasry resv_map->css = &h_cg->css; 855e9fe92aeSMina Almasry } 856e9fe92aeSMina Almasry #endif 857e9fe92aeSMina Almasry } 858e9fe92aeSMina Almasry 8599119a41eSJoonsoo Kim struct resv_map *resv_map_alloc(void) 86084afd99bSAndy Whitcroft { 86184afd99bSAndy Whitcroft struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); 8625e911373SMike Kravetz struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL); 8635e911373SMike Kravetz 8645e911373SMike Kravetz if (!resv_map || !rg) { 8655e911373SMike Kravetz kfree(resv_map); 8665e911373SMike Kravetz kfree(rg); 86784afd99bSAndy Whitcroft return NULL; 8685e911373SMike Kravetz } 86984afd99bSAndy Whitcroft 87084afd99bSAndy Whitcroft kref_init(&resv_map->refs); 8717b24d861SDavidlohr Bueso spin_lock_init(&resv_map->lock); 87284afd99bSAndy Whitcroft INIT_LIST_HEAD(&resv_map->regions); 87384afd99bSAndy Whitcroft 8745e911373SMike Kravetz resv_map->adds_in_progress = 0; 875e9fe92aeSMina Almasry /* 876e9fe92aeSMina Almasry * Initialize these to 0. On shared mappings, 0's here indicate these 877e9fe92aeSMina Almasry * fields don't do cgroup accounting. On private mappings, these will be 878e9fe92aeSMina Almasry * re-initialized to the proper values, to indicate that hugetlb cgroup 879e9fe92aeSMina Almasry * reservations are to be un-charged from here. 880e9fe92aeSMina Almasry */ 881e9fe92aeSMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, NULL, NULL); 8825e911373SMike Kravetz 8835e911373SMike Kravetz INIT_LIST_HEAD(&resv_map->region_cache); 8845e911373SMike Kravetz list_add(&rg->link, &resv_map->region_cache); 8855e911373SMike Kravetz resv_map->region_cache_count = 1; 8865e911373SMike Kravetz 88784afd99bSAndy Whitcroft return resv_map; 88884afd99bSAndy Whitcroft } 88984afd99bSAndy Whitcroft 8909119a41eSJoonsoo Kim void resv_map_release(struct kref *ref) 89184afd99bSAndy Whitcroft { 89284afd99bSAndy Whitcroft struct resv_map *resv_map = container_of(ref, struct resv_map, refs); 8935e911373SMike Kravetz struct list_head *head = &resv_map->region_cache; 8945e911373SMike Kravetz struct file_region *rg, *trg; 89584afd99bSAndy Whitcroft 89684afd99bSAndy Whitcroft /* Clear out any active regions before we release the map. */ 897feba16e2SMike Kravetz region_del(resv_map, 0, LONG_MAX); 8985e911373SMike Kravetz 8995e911373SMike Kravetz /* ... and any entries left in the cache */ 9005e911373SMike Kravetz list_for_each_entry_safe(rg, trg, head, link) { 9015e911373SMike Kravetz list_del(&rg->link); 9025e911373SMike Kravetz kfree(rg); 9035e911373SMike Kravetz } 9045e911373SMike Kravetz 9055e911373SMike Kravetz VM_BUG_ON(resv_map->adds_in_progress); 9065e911373SMike Kravetz 90784afd99bSAndy Whitcroft kfree(resv_map); 90884afd99bSAndy Whitcroft } 90984afd99bSAndy Whitcroft 9104e35f483SJoonsoo Kim static inline struct resv_map *inode_resv_map(struct inode *inode) 9114e35f483SJoonsoo Kim { 912f27a5136SMike Kravetz /* 913f27a5136SMike Kravetz * At inode evict time, i_mapping may not point to the original 914f27a5136SMike Kravetz * address space within the inode. This original address space 915f27a5136SMike Kravetz * contains the pointer to the resv_map. So, always use the 916f27a5136SMike Kravetz * address space embedded within the inode. 917f27a5136SMike Kravetz * The VERY common case is inode->mapping == &inode->i_data but, 918f27a5136SMike Kravetz * this may not be true for device special inodes. 919f27a5136SMike Kravetz */ 920f27a5136SMike Kravetz return (struct resv_map *)(&inode->i_data)->private_data; 9214e35f483SJoonsoo Kim } 9224e35f483SJoonsoo Kim 92384afd99bSAndy Whitcroft static struct resv_map *vma_resv_map(struct vm_area_struct *vma) 924a1e78772SMel Gorman { 92581d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 9264e35f483SJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE) { 9274e35f483SJoonsoo Kim struct address_space *mapping = vma->vm_file->f_mapping; 9284e35f483SJoonsoo Kim struct inode *inode = mapping->host; 9294e35f483SJoonsoo Kim 9304e35f483SJoonsoo Kim return inode_resv_map(inode); 9314e35f483SJoonsoo Kim 9324e35f483SJoonsoo Kim } else { 93384afd99bSAndy Whitcroft return (struct resv_map *)(get_vma_private_data(vma) & 93484afd99bSAndy Whitcroft ~HPAGE_RESV_MASK); 9354e35f483SJoonsoo Kim } 936a1e78772SMel Gorman } 937a1e78772SMel Gorman 93884afd99bSAndy Whitcroft static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) 939a1e78772SMel Gorman { 94081d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 94181d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 942a1e78772SMel Gorman 94384afd99bSAndy Whitcroft set_vma_private_data(vma, (get_vma_private_data(vma) & 94484afd99bSAndy Whitcroft HPAGE_RESV_MASK) | (unsigned long)map); 94504f2cbe3SMel Gorman } 94604f2cbe3SMel Gorman 94704f2cbe3SMel Gorman static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) 94804f2cbe3SMel Gorman { 94981d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 95081d1b09cSSasha Levin VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); 951e7c4b0bfSAndy Whitcroft 952e7c4b0bfSAndy Whitcroft set_vma_private_data(vma, get_vma_private_data(vma) | flags); 95304f2cbe3SMel Gorman } 95404f2cbe3SMel Gorman 95504f2cbe3SMel Gorman static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) 95604f2cbe3SMel Gorman { 95781d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 958e7c4b0bfSAndy Whitcroft 959e7c4b0bfSAndy Whitcroft return (get_vma_private_data(vma) & flag) != 0; 960a1e78772SMel Gorman } 961a1e78772SMel Gorman 96204f2cbe3SMel Gorman /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ 963a1e78772SMel Gorman void reset_vma_resv_huge_pages(struct vm_area_struct *vma) 964a1e78772SMel Gorman { 96581d1b09cSSasha Levin VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); 966f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 967a1e78772SMel Gorman vma->vm_private_data = (void *)0; 968a1e78772SMel Gorman } 969a1e78772SMel Gorman 970a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 971559ec2f8SNicholas Krause static bool vma_has_reserves(struct vm_area_struct *vma, long chg) 972a1e78772SMel Gorman { 973af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_NORESERVE) { 974af0ed73eSJoonsoo Kim /* 975af0ed73eSJoonsoo Kim * This address is already reserved by other process(chg == 0), 976af0ed73eSJoonsoo Kim * so, we should decrement reserved count. Without decrementing, 977af0ed73eSJoonsoo Kim * reserve count remains after releasing inode, because this 978af0ed73eSJoonsoo Kim * allocated page will go into page cache and is regarded as 979af0ed73eSJoonsoo Kim * coming from reserved pool in releasing step. Currently, we 980af0ed73eSJoonsoo Kim * don't have any other solution to deal with this situation 981af0ed73eSJoonsoo Kim * properly, so add work-around here. 982af0ed73eSJoonsoo Kim */ 983af0ed73eSJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE && chg == 0) 984559ec2f8SNicholas Krause return true; 985af0ed73eSJoonsoo Kim else 986559ec2f8SNicholas Krause return false; 987af0ed73eSJoonsoo Kim } 988a63884e9SJoonsoo Kim 989a63884e9SJoonsoo Kim /* Shared mappings always use reserves */ 9901fb1b0e9SMike Kravetz if (vma->vm_flags & VM_MAYSHARE) { 9911fb1b0e9SMike Kravetz /* 9921fb1b0e9SMike Kravetz * We know VM_NORESERVE is not set. Therefore, there SHOULD 9931fb1b0e9SMike Kravetz * be a region map for all pages. The only situation where 9941fb1b0e9SMike Kravetz * there is no region map is if a hole was punched via 9957c8de358SEthon Paul * fallocate. In this case, there really are no reserves to 9961fb1b0e9SMike Kravetz * use. This situation is indicated if chg != 0. 9971fb1b0e9SMike Kravetz */ 9981fb1b0e9SMike Kravetz if (chg) 9991fb1b0e9SMike Kravetz return false; 10001fb1b0e9SMike Kravetz else 1001559ec2f8SNicholas Krause return true; 10021fb1b0e9SMike Kravetz } 1003a63884e9SJoonsoo Kim 1004a63884e9SJoonsoo Kim /* 1005a63884e9SJoonsoo Kim * Only the process that called mmap() has reserves for 1006a63884e9SJoonsoo Kim * private mappings. 1007a63884e9SJoonsoo Kim */ 100867961f9dSMike Kravetz if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 100967961f9dSMike Kravetz /* 101067961f9dSMike Kravetz * Like the shared case above, a hole punch or truncate 101167961f9dSMike Kravetz * could have been performed on the private mapping. 101267961f9dSMike Kravetz * Examine the value of chg to determine if reserves 101367961f9dSMike Kravetz * actually exist or were previously consumed. 101467961f9dSMike Kravetz * Very Subtle - The value of chg comes from a previous 101567961f9dSMike Kravetz * call to vma_needs_reserves(). The reserve map for 101667961f9dSMike Kravetz * private mappings has different (opposite) semantics 101767961f9dSMike Kravetz * than that of shared mappings. vma_needs_reserves() 101867961f9dSMike Kravetz * has already taken this difference in semantics into 101967961f9dSMike Kravetz * account. Therefore, the meaning of chg is the same 102067961f9dSMike Kravetz * as in the shared case above. Code could easily be 102167961f9dSMike Kravetz * combined, but keeping it separate draws attention to 102267961f9dSMike Kravetz * subtle differences. 102367961f9dSMike Kravetz */ 102467961f9dSMike Kravetz if (chg) 102567961f9dSMike Kravetz return false; 102667961f9dSMike Kravetz else 1027559ec2f8SNicholas Krause return true; 102867961f9dSMike Kravetz } 1029a63884e9SJoonsoo Kim 1030559ec2f8SNicholas Krause return false; 1031a1e78772SMel Gorman } 1032a1e78772SMel Gorman 1033a5516438SAndi Kleen static void enqueue_huge_page(struct hstate *h, struct page *page) 10341da177e4SLinus Torvalds { 10351da177e4SLinus Torvalds int nid = page_to_nid(page); 10360edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_freelists[nid]); 1037a5516438SAndi Kleen h->free_huge_pages++; 1038a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 10391da177e4SLinus Torvalds } 10401da177e4SLinus Torvalds 104194310cbcSAnshuman Khandual static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid) 1042bf50bab2SNaoya Horiguchi { 1043bf50bab2SNaoya Horiguchi struct page *page; 1044bbe88753SJoonsoo Kim bool nocma = !!(current->flags & PF_MEMALLOC_NOCMA); 1045bf50bab2SNaoya Horiguchi 1046bbe88753SJoonsoo Kim list_for_each_entry(page, &h->hugepage_freelists[nid], lru) { 1047bbe88753SJoonsoo Kim if (nocma && is_migrate_cma_page(page)) 1048bbe88753SJoonsoo Kim continue; 1049bbe88753SJoonsoo Kim 1050243abd5bSNaoya Horiguchi if (!PageHWPoison(page)) 1051c8721bbbSNaoya Horiguchi break; 1052bbe88753SJoonsoo Kim } 1053bbe88753SJoonsoo Kim 1054c8721bbbSNaoya Horiguchi /* 1055c8721bbbSNaoya Horiguchi * if 'non-isolated free hugepage' not found on the list, 1056c8721bbbSNaoya Horiguchi * the allocation fails. 1057c8721bbbSNaoya Horiguchi */ 1058c8721bbbSNaoya Horiguchi if (&h->hugepage_freelists[nid] == &page->lru) 1059bf50bab2SNaoya Horiguchi return NULL; 10600edaecfaSAneesh Kumar K.V list_move(&page->lru, &h->hugepage_activelist); 1061a9869b83SNaoya Horiguchi set_page_refcounted(page); 1062bf50bab2SNaoya Horiguchi h->free_huge_pages--; 1063bf50bab2SNaoya Horiguchi h->free_huge_pages_node[nid]--; 1064bf50bab2SNaoya Horiguchi return page; 1065bf50bab2SNaoya Horiguchi } 1066bf50bab2SNaoya Horiguchi 10673e59fcb0SMichal Hocko static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid, 10683e59fcb0SMichal Hocko nodemask_t *nmask) 106994310cbcSAnshuman Khandual { 10703e59fcb0SMichal Hocko unsigned int cpuset_mems_cookie; 10713e59fcb0SMichal Hocko struct zonelist *zonelist; 10723e59fcb0SMichal Hocko struct zone *zone; 10733e59fcb0SMichal Hocko struct zoneref *z; 107498fa15f3SAnshuman Khandual int node = NUMA_NO_NODE; 10753e59fcb0SMichal Hocko 10763e59fcb0SMichal Hocko zonelist = node_zonelist(nid, gfp_mask); 10773e59fcb0SMichal Hocko 10783e59fcb0SMichal Hocko retry_cpuset: 10793e59fcb0SMichal Hocko cpuset_mems_cookie = read_mems_allowed_begin(); 10803e59fcb0SMichal Hocko for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) { 108194310cbcSAnshuman Khandual struct page *page; 108294310cbcSAnshuman Khandual 10833e59fcb0SMichal Hocko if (!cpuset_zone_allowed(zone, gfp_mask)) 10843e59fcb0SMichal Hocko continue; 10853e59fcb0SMichal Hocko /* 10863e59fcb0SMichal Hocko * no need to ask again on the same node. Pool is node rather than 10873e59fcb0SMichal Hocko * zone aware 10883e59fcb0SMichal Hocko */ 10893e59fcb0SMichal Hocko if (zone_to_nid(zone) == node) 10903e59fcb0SMichal Hocko continue; 10913e59fcb0SMichal Hocko node = zone_to_nid(zone); 109294310cbcSAnshuman Khandual 109394310cbcSAnshuman Khandual page = dequeue_huge_page_node_exact(h, node); 109494310cbcSAnshuman Khandual if (page) 109594310cbcSAnshuman Khandual return page; 109694310cbcSAnshuman Khandual } 10973e59fcb0SMichal Hocko if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie))) 10983e59fcb0SMichal Hocko goto retry_cpuset; 10993e59fcb0SMichal Hocko 110094310cbcSAnshuman Khandual return NULL; 110194310cbcSAnshuman Khandual } 110294310cbcSAnshuman Khandual 1103a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 1104a5516438SAndi Kleen struct vm_area_struct *vma, 1105af0ed73eSJoonsoo Kim unsigned long address, int avoid_reserve, 1106af0ed73eSJoonsoo Kim long chg) 11071da177e4SLinus Torvalds { 11083e59fcb0SMichal Hocko struct page *page; 1109480eccf9SLee Schermerhorn struct mempolicy *mpol; 111004ec6264SVlastimil Babka gfp_t gfp_mask; 11113e59fcb0SMichal Hocko nodemask_t *nodemask; 111204ec6264SVlastimil Babka int nid; 11131da177e4SLinus Torvalds 1114a1e78772SMel Gorman /* 1115a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 1116a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 1117a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 1118a1e78772SMel Gorman */ 1119af0ed73eSJoonsoo Kim if (!vma_has_reserves(vma, chg) && 1120a5516438SAndi Kleen h->free_huge_pages - h->resv_huge_pages == 0) 1121c0ff7453SMiao Xie goto err; 1122a1e78772SMel Gorman 112304f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 1124a5516438SAndi Kleen if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) 11256eab04a8SJustin P. Mattock goto err; 112604f2cbe3SMel Gorman 112704ec6264SVlastimil Babka gfp_mask = htlb_alloc_mask(h); 112804ec6264SVlastimil Babka nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 11293e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask); 11303e59fcb0SMichal Hocko if (page && !avoid_reserve && vma_has_reserves(vma, chg)) { 113107443a85SJoonsoo Kim SetPagePrivate(page); 1132a63884e9SJoonsoo Kim h->resv_huge_pages--; 1133bf50bab2SNaoya Horiguchi } 1134cc9a6c87SMel Gorman 1135cc9a6c87SMel Gorman mpol_cond_put(mpol); 1136cc9a6c87SMel Gorman return page; 1137cc9a6c87SMel Gorman 1138c0ff7453SMiao Xie err: 1139cc9a6c87SMel Gorman return NULL; 11401da177e4SLinus Torvalds } 11411da177e4SLinus Torvalds 11421cac6f2cSLuiz Capitulino /* 11431cac6f2cSLuiz Capitulino * common helper functions for hstate_next_node_to_{alloc|free}. 11441cac6f2cSLuiz Capitulino * We may have allocated or freed a huge page based on a different 11451cac6f2cSLuiz Capitulino * nodes_allowed previously, so h->next_node_to_{alloc|free} might 11461cac6f2cSLuiz Capitulino * be outside of *nodes_allowed. Ensure that we use an allowed 11471cac6f2cSLuiz Capitulino * node for alloc or free. 11481cac6f2cSLuiz Capitulino */ 11491cac6f2cSLuiz Capitulino static int next_node_allowed(int nid, nodemask_t *nodes_allowed) 11501cac6f2cSLuiz Capitulino { 11510edaf86cSAndrew Morton nid = next_node_in(nid, *nodes_allowed); 11521cac6f2cSLuiz Capitulino VM_BUG_ON(nid >= MAX_NUMNODES); 11531cac6f2cSLuiz Capitulino 11541cac6f2cSLuiz Capitulino return nid; 11551cac6f2cSLuiz Capitulino } 11561cac6f2cSLuiz Capitulino 11571cac6f2cSLuiz Capitulino static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) 11581cac6f2cSLuiz Capitulino { 11591cac6f2cSLuiz Capitulino if (!node_isset(nid, *nodes_allowed)) 11601cac6f2cSLuiz Capitulino nid = next_node_allowed(nid, nodes_allowed); 11611cac6f2cSLuiz Capitulino return nid; 11621cac6f2cSLuiz Capitulino } 11631cac6f2cSLuiz Capitulino 11641cac6f2cSLuiz Capitulino /* 11651cac6f2cSLuiz Capitulino * returns the previously saved node ["this node"] from which to 11661cac6f2cSLuiz Capitulino * allocate a persistent huge page for the pool and advance the 11671cac6f2cSLuiz Capitulino * next node from which to allocate, handling wrap at end of node 11681cac6f2cSLuiz Capitulino * mask. 11691cac6f2cSLuiz Capitulino */ 11701cac6f2cSLuiz Capitulino static int hstate_next_node_to_alloc(struct hstate *h, 11711cac6f2cSLuiz Capitulino nodemask_t *nodes_allowed) 11721cac6f2cSLuiz Capitulino { 11731cac6f2cSLuiz Capitulino int nid; 11741cac6f2cSLuiz Capitulino 11751cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 11761cac6f2cSLuiz Capitulino 11771cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); 11781cac6f2cSLuiz Capitulino h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); 11791cac6f2cSLuiz Capitulino 11801cac6f2cSLuiz Capitulino return nid; 11811cac6f2cSLuiz Capitulino } 11821cac6f2cSLuiz Capitulino 11831cac6f2cSLuiz Capitulino /* 11841cac6f2cSLuiz Capitulino * helper for free_pool_huge_page() - return the previously saved 11851cac6f2cSLuiz Capitulino * node ["this node"] from which to free a huge page. Advance the 11861cac6f2cSLuiz Capitulino * next node id whether or not we find a free huge page to free so 11871cac6f2cSLuiz Capitulino * that the next attempt to free addresses the next node. 11881cac6f2cSLuiz Capitulino */ 11891cac6f2cSLuiz Capitulino static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) 11901cac6f2cSLuiz Capitulino { 11911cac6f2cSLuiz Capitulino int nid; 11921cac6f2cSLuiz Capitulino 11931cac6f2cSLuiz Capitulino VM_BUG_ON(!nodes_allowed); 11941cac6f2cSLuiz Capitulino 11951cac6f2cSLuiz Capitulino nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); 11961cac6f2cSLuiz Capitulino h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); 11971cac6f2cSLuiz Capitulino 11981cac6f2cSLuiz Capitulino return nid; 11991cac6f2cSLuiz Capitulino } 12001cac6f2cSLuiz Capitulino 12011cac6f2cSLuiz Capitulino #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ 12021cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 12031cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 12041cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ 12051cac6f2cSLuiz Capitulino nr_nodes--) 12061cac6f2cSLuiz Capitulino 12071cac6f2cSLuiz Capitulino #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ 12081cac6f2cSLuiz Capitulino for (nr_nodes = nodes_weight(*mask); \ 12091cac6f2cSLuiz Capitulino nr_nodes > 0 && \ 12101cac6f2cSLuiz Capitulino ((node = hstate_next_node_to_free(hs, mask)) || 1); \ 12111cac6f2cSLuiz Capitulino nr_nodes--) 12121cac6f2cSLuiz Capitulino 1213e1073d1eSAneesh Kumar K.V #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE 1214944d9fecSLuiz Capitulino static void destroy_compound_gigantic_page(struct page *page, 1215d00181b9SKirill A. Shutemov unsigned int order) 1216944d9fecSLuiz Capitulino { 1217944d9fecSLuiz Capitulino int i; 1218944d9fecSLuiz Capitulino int nr_pages = 1 << order; 1219944d9fecSLuiz Capitulino struct page *p = page + 1; 1220944d9fecSLuiz Capitulino 1221c8cc708aSGerald Schaefer atomic_set(compound_mapcount_ptr(page), 0); 122247e29d32SJohn Hubbard if (hpage_pincount_available(page)) 122347e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 122447e29d32SJohn Hubbard 1225944d9fecSLuiz Capitulino for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 12261d798ca3SKirill A. Shutemov clear_compound_head(p); 1227944d9fecSLuiz Capitulino set_page_refcounted(p); 1228944d9fecSLuiz Capitulino } 1229944d9fecSLuiz Capitulino 1230944d9fecSLuiz Capitulino set_compound_order(page, 0); 1231944d9fecSLuiz Capitulino __ClearPageHead(page); 1232944d9fecSLuiz Capitulino } 1233944d9fecSLuiz Capitulino 1234d00181b9SKirill A. Shutemov static void free_gigantic_page(struct page *page, unsigned int order) 1235944d9fecSLuiz Capitulino { 1236cf11e85fSRoman Gushchin /* 1237cf11e85fSRoman Gushchin * If the page isn't allocated using the cma allocator, 1238cf11e85fSRoman Gushchin * cma_release() returns false. 1239cf11e85fSRoman Gushchin */ 1240dbda8feaSBarry Song #ifdef CONFIG_CMA 1241dbda8feaSBarry Song if (cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order)) 1242cf11e85fSRoman Gushchin return; 1243dbda8feaSBarry Song #endif 1244cf11e85fSRoman Gushchin 1245944d9fecSLuiz Capitulino free_contig_range(page_to_pfn(page), 1 << order); 1246944d9fecSLuiz Capitulino } 1247944d9fecSLuiz Capitulino 12484eb0716eSAlexandre Ghiti #ifdef CONFIG_CONTIG_ALLOC 1249d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 1250d9cc948fSMichal Hocko int nid, nodemask_t *nodemask) 1251944d9fecSLuiz Capitulino { 12525e27a2dfSAnshuman Khandual unsigned long nr_pages = 1UL << huge_page_order(h); 1253953f064aSLi Xinhai if (nid == NUMA_NO_NODE) 1254953f064aSLi Xinhai nid = numa_mem_id(); 1255944d9fecSLuiz Capitulino 1256dbda8feaSBarry Song #ifdef CONFIG_CMA 1257dbda8feaSBarry Song { 1258cf11e85fSRoman Gushchin struct page *page; 1259cf11e85fSRoman Gushchin int node; 1260cf11e85fSRoman Gushchin 1261953f064aSLi Xinhai if (hugetlb_cma[nid]) { 1262953f064aSLi Xinhai page = cma_alloc(hugetlb_cma[nid], nr_pages, 1263953f064aSLi Xinhai huge_page_order(h), true); 1264953f064aSLi Xinhai if (page) 1265953f064aSLi Xinhai return page; 1266953f064aSLi Xinhai } 1267953f064aSLi Xinhai 1268953f064aSLi Xinhai if (!(gfp_mask & __GFP_THISNODE)) { 1269cf11e85fSRoman Gushchin for_each_node_mask(node, *nodemask) { 1270953f064aSLi Xinhai if (node == nid || !hugetlb_cma[node]) 1271cf11e85fSRoman Gushchin continue; 1272cf11e85fSRoman Gushchin 1273cf11e85fSRoman Gushchin page = cma_alloc(hugetlb_cma[node], nr_pages, 1274cf11e85fSRoman Gushchin huge_page_order(h), true); 1275cf11e85fSRoman Gushchin if (page) 1276cf11e85fSRoman Gushchin return page; 1277cf11e85fSRoman Gushchin } 1278cf11e85fSRoman Gushchin } 1279953f064aSLi Xinhai } 1280dbda8feaSBarry Song #endif 1281cf11e85fSRoman Gushchin 12825e27a2dfSAnshuman Khandual return alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask); 1283944d9fecSLuiz Capitulino } 1284944d9fecSLuiz Capitulino 1285944d9fecSLuiz Capitulino static void prep_new_huge_page(struct hstate *h, struct page *page, int nid); 1286d00181b9SKirill A. Shutemov static void prep_compound_gigantic_page(struct page *page, unsigned int order); 12874eb0716eSAlexandre Ghiti #else /* !CONFIG_CONTIG_ALLOC */ 12884eb0716eSAlexandre Ghiti static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 12894eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 12904eb0716eSAlexandre Ghiti { 12914eb0716eSAlexandre Ghiti return NULL; 12924eb0716eSAlexandre Ghiti } 12934eb0716eSAlexandre Ghiti #endif /* CONFIG_CONTIG_ALLOC */ 1294944d9fecSLuiz Capitulino 1295e1073d1eSAneesh Kumar K.V #else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ 1296d9cc948fSMichal Hocko static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, 12974eb0716eSAlexandre Ghiti int nid, nodemask_t *nodemask) 12984eb0716eSAlexandre Ghiti { 12994eb0716eSAlexandre Ghiti return NULL; 13004eb0716eSAlexandre Ghiti } 1301d00181b9SKirill A. Shutemov static inline void free_gigantic_page(struct page *page, unsigned int order) { } 1302944d9fecSLuiz Capitulino static inline void destroy_compound_gigantic_page(struct page *page, 1303d00181b9SKirill A. Shutemov unsigned int order) { } 1304944d9fecSLuiz Capitulino #endif 1305944d9fecSLuiz Capitulino 1306a5516438SAndi Kleen static void update_and_free_page(struct hstate *h, struct page *page) 13076af2acb6SAdam Litke { 13086af2acb6SAdam Litke int i; 1309a5516438SAndi Kleen 13104eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 1311944d9fecSLuiz Capitulino return; 131218229df5SAndy Whitcroft 1313a5516438SAndi Kleen h->nr_huge_pages--; 1314a5516438SAndi Kleen h->nr_huge_pages_node[page_to_nid(page)]--; 1315a5516438SAndi Kleen for (i = 0; i < pages_per_huge_page(h); i++) { 131632f84528SChris Forbes page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 131732f84528SChris Forbes 1 << PG_referenced | 1 << PG_dirty | 1318a7407a27SLuiz Capitulino 1 << PG_active | 1 << PG_private | 1319a7407a27SLuiz Capitulino 1 << PG_writeback); 13206af2acb6SAdam Litke } 1321309381feSSasha Levin VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); 13221adc4d41SMina Almasry VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page); 1323f1e61557SKirill A. Shutemov set_compound_page_dtor(page, NULL_COMPOUND_DTOR); 13246af2acb6SAdam Litke set_page_refcounted(page); 1325944d9fecSLuiz Capitulino if (hstate_is_gigantic(h)) { 1326cf11e85fSRoman Gushchin /* 1327cf11e85fSRoman Gushchin * Temporarily drop the hugetlb_lock, because 1328cf11e85fSRoman Gushchin * we might block in free_gigantic_page(). 1329cf11e85fSRoman Gushchin */ 1330cf11e85fSRoman Gushchin spin_unlock(&hugetlb_lock); 1331944d9fecSLuiz Capitulino destroy_compound_gigantic_page(page, huge_page_order(h)); 1332944d9fecSLuiz Capitulino free_gigantic_page(page, huge_page_order(h)); 1333cf11e85fSRoman Gushchin spin_lock(&hugetlb_lock); 1334944d9fecSLuiz Capitulino } else { 1335a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 13366af2acb6SAdam Litke } 1337944d9fecSLuiz Capitulino } 13386af2acb6SAdam Litke 1339e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 1340e5ff2159SAndi Kleen { 1341e5ff2159SAndi Kleen struct hstate *h; 1342e5ff2159SAndi Kleen 1343e5ff2159SAndi Kleen for_each_hstate(h) { 1344e5ff2159SAndi Kleen if (huge_page_size(h) == size) 1345e5ff2159SAndi Kleen return h; 1346e5ff2159SAndi Kleen } 1347e5ff2159SAndi Kleen return NULL; 1348e5ff2159SAndi Kleen } 1349e5ff2159SAndi Kleen 1350bcc54222SNaoya Horiguchi /* 1351bcc54222SNaoya Horiguchi * Test to determine whether the hugepage is "active/in-use" (i.e. being linked 1352bcc54222SNaoya Horiguchi * to hstate->hugepage_activelist.) 1353bcc54222SNaoya Horiguchi * 1354bcc54222SNaoya Horiguchi * This function can be called for tail pages, but never returns true for them. 1355bcc54222SNaoya Horiguchi */ 1356bcc54222SNaoya Horiguchi bool page_huge_active(struct page *page) 1357bcc54222SNaoya Horiguchi { 1358bcc54222SNaoya Horiguchi VM_BUG_ON_PAGE(!PageHuge(page), page); 1359bcc54222SNaoya Horiguchi return PageHead(page) && PagePrivate(&page[1]); 1360bcc54222SNaoya Horiguchi } 1361bcc54222SNaoya Horiguchi 1362bcc54222SNaoya Horiguchi /* never called for tail page */ 1363bcc54222SNaoya Horiguchi static void set_page_huge_active(struct page *page) 1364bcc54222SNaoya Horiguchi { 1365bcc54222SNaoya Horiguchi VM_BUG_ON_PAGE(!PageHeadHuge(page), page); 1366bcc54222SNaoya Horiguchi SetPagePrivate(&page[1]); 1367bcc54222SNaoya Horiguchi } 1368bcc54222SNaoya Horiguchi 1369bcc54222SNaoya Horiguchi static void clear_page_huge_active(struct page *page) 1370bcc54222SNaoya Horiguchi { 1371bcc54222SNaoya Horiguchi VM_BUG_ON_PAGE(!PageHeadHuge(page), page); 1372bcc54222SNaoya Horiguchi ClearPagePrivate(&page[1]); 1373bcc54222SNaoya Horiguchi } 1374bcc54222SNaoya Horiguchi 1375ab5ac90aSMichal Hocko /* 1376ab5ac90aSMichal Hocko * Internal hugetlb specific page flag. Do not use outside of the hugetlb 1377ab5ac90aSMichal Hocko * code 1378ab5ac90aSMichal Hocko */ 1379ab5ac90aSMichal Hocko static inline bool PageHugeTemporary(struct page *page) 1380ab5ac90aSMichal Hocko { 1381ab5ac90aSMichal Hocko if (!PageHuge(page)) 1382ab5ac90aSMichal Hocko return false; 1383ab5ac90aSMichal Hocko 1384ab5ac90aSMichal Hocko return (unsigned long)page[2].mapping == -1U; 1385ab5ac90aSMichal Hocko } 1386ab5ac90aSMichal Hocko 1387ab5ac90aSMichal Hocko static inline void SetPageHugeTemporary(struct page *page) 1388ab5ac90aSMichal Hocko { 1389ab5ac90aSMichal Hocko page[2].mapping = (void *)-1U; 1390ab5ac90aSMichal Hocko } 1391ab5ac90aSMichal Hocko 1392ab5ac90aSMichal Hocko static inline void ClearPageHugeTemporary(struct page *page) 1393ab5ac90aSMichal Hocko { 1394ab5ac90aSMichal Hocko page[2].mapping = NULL; 1395ab5ac90aSMichal Hocko } 1396ab5ac90aSMichal Hocko 1397c77c0a8aSWaiman Long static void __free_huge_page(struct page *page) 139827a85ef1SDavid Gibson { 1399a5516438SAndi Kleen /* 1400a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 1401a5516438SAndi Kleen * compound page destructor. 1402a5516438SAndi Kleen */ 1403e5ff2159SAndi Kleen struct hstate *h = page_hstate(page); 14047893d1d5SAdam Litke int nid = page_to_nid(page); 140590481622SDavid Gibson struct hugepage_subpool *spool = 140690481622SDavid Gibson (struct hugepage_subpool *)page_private(page); 140707443a85SJoonsoo Kim bool restore_reserve; 140827a85ef1SDavid Gibson 1409b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_count(page), page); 1410b4330afbSMike Kravetz VM_BUG_ON_PAGE(page_mapcount(page), page); 14118ace22bcSYongkai Wu 14128ace22bcSYongkai Wu set_page_private(page, 0); 14138ace22bcSYongkai Wu page->mapping = NULL; 141407443a85SJoonsoo Kim restore_reserve = PagePrivate(page); 141516c794b4SJoonsoo Kim ClearPagePrivate(page); 141627a85ef1SDavid Gibson 14171c5ecae3SMike Kravetz /* 14180919e1b6SMike Kravetz * If PagePrivate() was set on page, page allocation consumed a 14190919e1b6SMike Kravetz * reservation. If the page was associated with a subpool, there 14200919e1b6SMike Kravetz * would have been a page reserved in the subpool before allocation 14210919e1b6SMike Kravetz * via hugepage_subpool_get_pages(). Since we are 'restoring' the 14220919e1b6SMike Kravetz * reservtion, do not call hugepage_subpool_put_pages() as this will 14230919e1b6SMike Kravetz * remove the reserved page from the subpool. 14240919e1b6SMike Kravetz */ 14250919e1b6SMike Kravetz if (!restore_reserve) { 14260919e1b6SMike Kravetz /* 14270919e1b6SMike Kravetz * A return code of zero implies that the subpool will be 14280919e1b6SMike Kravetz * under its minimum size if the reservation is not restored 14290919e1b6SMike Kravetz * after page is free. Therefore, force restore_reserve 14300919e1b6SMike Kravetz * operation. 14311c5ecae3SMike Kravetz */ 14321c5ecae3SMike Kravetz if (hugepage_subpool_put_pages(spool, 1) == 0) 14331c5ecae3SMike Kravetz restore_reserve = true; 14340919e1b6SMike Kravetz } 14351c5ecae3SMike Kravetz 143627a85ef1SDavid Gibson spin_lock(&hugetlb_lock); 1437bcc54222SNaoya Horiguchi clear_page_huge_active(page); 14386d76dcf4SAneesh Kumar K.V hugetlb_cgroup_uncharge_page(hstate_index(h), 14396d76dcf4SAneesh Kumar K.V pages_per_huge_page(h), page); 144008cf9fafSMina Almasry hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), 144108cf9fafSMina Almasry pages_per_huge_page(h), page); 144207443a85SJoonsoo Kim if (restore_reserve) 144307443a85SJoonsoo Kim h->resv_huge_pages++; 144407443a85SJoonsoo Kim 1445ab5ac90aSMichal Hocko if (PageHugeTemporary(page)) { 1446ab5ac90aSMichal Hocko list_del(&page->lru); 1447ab5ac90aSMichal Hocko ClearPageHugeTemporary(page); 1448ab5ac90aSMichal Hocko update_and_free_page(h, page); 1449ab5ac90aSMichal Hocko } else if (h->surplus_huge_pages_node[nid]) { 14500edaecfaSAneesh Kumar K.V /* remove the page from active list */ 14510edaecfaSAneesh Kumar K.V list_del(&page->lru); 1452a5516438SAndi Kleen update_and_free_page(h, page); 1453a5516438SAndi Kleen h->surplus_huge_pages--; 1454a5516438SAndi Kleen h->surplus_huge_pages_node[nid]--; 14557893d1d5SAdam Litke } else { 14565d3a551cSWill Deacon arch_clear_hugepage_flags(page); 1457a5516438SAndi Kleen enqueue_huge_page(h, page); 14587893d1d5SAdam Litke } 145927a85ef1SDavid Gibson spin_unlock(&hugetlb_lock); 146027a85ef1SDavid Gibson } 146127a85ef1SDavid Gibson 1462c77c0a8aSWaiman Long /* 1463c77c0a8aSWaiman Long * As free_huge_page() can be called from a non-task context, we have 1464c77c0a8aSWaiman Long * to defer the actual freeing in a workqueue to prevent potential 1465c77c0a8aSWaiman Long * hugetlb_lock deadlock. 1466c77c0a8aSWaiman Long * 1467c77c0a8aSWaiman Long * free_hpage_workfn() locklessly retrieves the linked list of pages to 1468c77c0a8aSWaiman Long * be freed and frees them one-by-one. As the page->mapping pointer is 1469c77c0a8aSWaiman Long * going to be cleared in __free_huge_page() anyway, it is reused as the 1470c77c0a8aSWaiman Long * llist_node structure of a lockless linked list of huge pages to be freed. 1471c77c0a8aSWaiman Long */ 1472c77c0a8aSWaiman Long static LLIST_HEAD(hpage_freelist); 1473c77c0a8aSWaiman Long 1474c77c0a8aSWaiman Long static void free_hpage_workfn(struct work_struct *work) 1475c77c0a8aSWaiman Long { 1476c77c0a8aSWaiman Long struct llist_node *node; 1477c77c0a8aSWaiman Long struct page *page; 1478c77c0a8aSWaiman Long 1479c77c0a8aSWaiman Long node = llist_del_all(&hpage_freelist); 1480c77c0a8aSWaiman Long 1481c77c0a8aSWaiman Long while (node) { 1482c77c0a8aSWaiman Long page = container_of((struct address_space **)node, 1483c77c0a8aSWaiman Long struct page, mapping); 1484c77c0a8aSWaiman Long node = node->next; 1485c77c0a8aSWaiman Long __free_huge_page(page); 1486c77c0a8aSWaiman Long } 1487c77c0a8aSWaiman Long } 1488c77c0a8aSWaiman Long static DECLARE_WORK(free_hpage_work, free_hpage_workfn); 1489c77c0a8aSWaiman Long 1490c77c0a8aSWaiman Long void free_huge_page(struct page *page) 1491c77c0a8aSWaiman Long { 1492c77c0a8aSWaiman Long /* 1493c77c0a8aSWaiman Long * Defer freeing if in non-task context to avoid hugetlb_lock deadlock. 1494c77c0a8aSWaiman Long */ 1495c77c0a8aSWaiman Long if (!in_task()) { 1496c77c0a8aSWaiman Long /* 1497c77c0a8aSWaiman Long * Only call schedule_work() if hpage_freelist is previously 1498c77c0a8aSWaiman Long * empty. Otherwise, schedule_work() had been called but the 1499c77c0a8aSWaiman Long * workfn hasn't retrieved the list yet. 1500c77c0a8aSWaiman Long */ 1501c77c0a8aSWaiman Long if (llist_add((struct llist_node *)&page->mapping, 1502c77c0a8aSWaiman Long &hpage_freelist)) 1503c77c0a8aSWaiman Long schedule_work(&free_hpage_work); 1504c77c0a8aSWaiman Long return; 1505c77c0a8aSWaiman Long } 1506c77c0a8aSWaiman Long 1507c77c0a8aSWaiman Long __free_huge_page(page); 1508c77c0a8aSWaiman Long } 1509c77c0a8aSWaiman Long 1510a5516438SAndi Kleen static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) 1511b7ba30c6SAndi Kleen { 15120edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&page->lru); 1513f1e61557SKirill A. Shutemov set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); 1514b7ba30c6SAndi Kleen spin_lock(&hugetlb_lock); 15159dd540e2SAneesh Kumar K.V set_hugetlb_cgroup(page, NULL); 15161adc4d41SMina Almasry set_hugetlb_cgroup_rsvd(page, NULL); 1517a5516438SAndi Kleen h->nr_huge_pages++; 1518a5516438SAndi Kleen h->nr_huge_pages_node[nid]++; 1519b7ba30c6SAndi Kleen spin_unlock(&hugetlb_lock); 1520b7ba30c6SAndi Kleen } 1521b7ba30c6SAndi Kleen 1522d00181b9SKirill A. Shutemov static void prep_compound_gigantic_page(struct page *page, unsigned int order) 152320a0307cSWu Fengguang { 152420a0307cSWu Fengguang int i; 152520a0307cSWu Fengguang int nr_pages = 1 << order; 152620a0307cSWu Fengguang struct page *p = page + 1; 152720a0307cSWu Fengguang 152820a0307cSWu Fengguang /* we rely on prep_new_huge_page to set the destructor */ 152920a0307cSWu Fengguang set_compound_order(page, order); 1530ef5a22beSAndrea Arcangeli __ClearPageReserved(page); 1531de09d31dSKirill A. Shutemov __SetPageHead(page); 153220a0307cSWu Fengguang for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 1533ef5a22beSAndrea Arcangeli /* 1534ef5a22beSAndrea Arcangeli * For gigantic hugepages allocated through bootmem at 1535ef5a22beSAndrea Arcangeli * boot, it's safer to be consistent with the not-gigantic 1536ef5a22beSAndrea Arcangeli * hugepages and clear the PG_reserved bit from all tail pages 15377c8de358SEthon Paul * too. Otherwise drivers using get_user_pages() to access tail 1538ef5a22beSAndrea Arcangeli * pages may get the reference counting wrong if they see 1539ef5a22beSAndrea Arcangeli * PG_reserved set on a tail page (despite the head page not 1540ef5a22beSAndrea Arcangeli * having PG_reserved set). Enforcing this consistency between 1541ef5a22beSAndrea Arcangeli * head and tail pages allows drivers to optimize away a check 1542ef5a22beSAndrea Arcangeli * on the head page when they need know if put_page() is needed 1543ef5a22beSAndrea Arcangeli * after get_user_pages(). 1544ef5a22beSAndrea Arcangeli */ 1545ef5a22beSAndrea Arcangeli __ClearPageReserved(p); 154658a84aa9SYouquan Song set_page_count(p, 0); 15471d798ca3SKirill A. Shutemov set_compound_head(p, page); 154820a0307cSWu Fengguang } 1549b4330afbSMike Kravetz atomic_set(compound_mapcount_ptr(page), -1); 155047e29d32SJohn Hubbard 155147e29d32SJohn Hubbard if (hpage_pincount_available(page)) 155247e29d32SJohn Hubbard atomic_set(compound_pincount_ptr(page), 0); 155320a0307cSWu Fengguang } 155420a0307cSWu Fengguang 15557795912cSAndrew Morton /* 15567795912cSAndrew Morton * PageHuge() only returns true for hugetlbfs pages, but not for normal or 15577795912cSAndrew Morton * transparent huge pages. See the PageTransHuge() documentation for more 15587795912cSAndrew Morton * details. 15597795912cSAndrew Morton */ 156020a0307cSWu Fengguang int PageHuge(struct page *page) 156120a0307cSWu Fengguang { 156220a0307cSWu Fengguang if (!PageCompound(page)) 156320a0307cSWu Fengguang return 0; 156420a0307cSWu Fengguang 156520a0307cSWu Fengguang page = compound_head(page); 1566f1e61557SKirill A. Shutemov return page[1].compound_dtor == HUGETLB_PAGE_DTOR; 156720a0307cSWu Fengguang } 156843131e14SNaoya Horiguchi EXPORT_SYMBOL_GPL(PageHuge); 156943131e14SNaoya Horiguchi 157027c73ae7SAndrea Arcangeli /* 157127c73ae7SAndrea Arcangeli * PageHeadHuge() only returns true for hugetlbfs head page, but not for 157227c73ae7SAndrea Arcangeli * normal or transparent huge pages. 157327c73ae7SAndrea Arcangeli */ 157427c73ae7SAndrea Arcangeli int PageHeadHuge(struct page *page_head) 157527c73ae7SAndrea Arcangeli { 157627c73ae7SAndrea Arcangeli if (!PageHead(page_head)) 157727c73ae7SAndrea Arcangeli return 0; 157827c73ae7SAndrea Arcangeli 1579d4af73e3SVlastimil Babka return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR; 158027c73ae7SAndrea Arcangeli } 158127c73ae7SAndrea Arcangeli 1582c0d0381aSMike Kravetz /* 1583c0d0381aSMike Kravetz * Find address_space associated with hugetlbfs page. 1584c0d0381aSMike Kravetz * Upon entry page is locked and page 'was' mapped although mapped state 1585c0d0381aSMike Kravetz * could change. If necessary, use anon_vma to find vma and associated 1586c0d0381aSMike Kravetz * address space. The returned mapping may be stale, but it can not be 1587c0d0381aSMike Kravetz * invalid as page lock (which is held) is required to destroy mapping. 1588c0d0381aSMike Kravetz */ 1589c0d0381aSMike Kravetz static struct address_space *_get_hugetlb_page_mapping(struct page *hpage) 1590c0d0381aSMike Kravetz { 1591c0d0381aSMike Kravetz struct anon_vma *anon_vma; 1592c0d0381aSMike Kravetz pgoff_t pgoff_start, pgoff_end; 1593c0d0381aSMike Kravetz struct anon_vma_chain *avc; 1594c0d0381aSMike Kravetz struct address_space *mapping = page_mapping(hpage); 1595c0d0381aSMike Kravetz 1596c0d0381aSMike Kravetz /* Simple file based mapping */ 1597c0d0381aSMike Kravetz if (mapping) 1598c0d0381aSMike Kravetz return mapping; 1599c0d0381aSMike Kravetz 1600c0d0381aSMike Kravetz /* 1601c0d0381aSMike Kravetz * Even anonymous hugetlbfs mappings are associated with an 1602c0d0381aSMike Kravetz * underlying hugetlbfs file (see hugetlb_file_setup in mmap 1603c0d0381aSMike Kravetz * code). Find a vma associated with the anonymous vma, and 1604c0d0381aSMike Kravetz * use the file pointer to get address_space. 1605c0d0381aSMike Kravetz */ 1606c0d0381aSMike Kravetz anon_vma = page_lock_anon_vma_read(hpage); 1607c0d0381aSMike Kravetz if (!anon_vma) 1608c0d0381aSMike Kravetz return mapping; /* NULL */ 1609c0d0381aSMike Kravetz 1610c0d0381aSMike Kravetz /* Use first found vma */ 1611c0d0381aSMike Kravetz pgoff_start = page_to_pgoff(hpage); 16121139d336SMike Kravetz pgoff_end = pgoff_start + pages_per_huge_page(page_hstate(hpage)) - 1; 1613c0d0381aSMike Kravetz anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, 1614c0d0381aSMike Kravetz pgoff_start, pgoff_end) { 1615c0d0381aSMike Kravetz struct vm_area_struct *vma = avc->vma; 1616c0d0381aSMike Kravetz 1617c0d0381aSMike Kravetz mapping = vma->vm_file->f_mapping; 1618c0d0381aSMike Kravetz break; 1619c0d0381aSMike Kravetz } 1620c0d0381aSMike Kravetz 1621c0d0381aSMike Kravetz anon_vma_unlock_read(anon_vma); 1622c0d0381aSMike Kravetz return mapping; 1623c0d0381aSMike Kravetz } 1624c0d0381aSMike Kravetz 1625c0d0381aSMike Kravetz /* 1626c0d0381aSMike Kravetz * Find and lock address space (mapping) in write mode. 1627c0d0381aSMike Kravetz * 1628c0d0381aSMike Kravetz * Upon entry, the page is locked which allows us to find the mapping 1629c0d0381aSMike Kravetz * even in the case of an anon page. However, locking order dictates 1630c0d0381aSMike Kravetz * the i_mmap_rwsem be acquired BEFORE the page lock. This is hugetlbfs 1631c0d0381aSMike Kravetz * specific. So, we first try to lock the sema while still holding the 1632c0d0381aSMike Kravetz * page lock. If this works, great! If not, then we need to drop the 1633c0d0381aSMike Kravetz * page lock and then acquire i_mmap_rwsem and reacquire page lock. Of 1634c0d0381aSMike Kravetz * course, need to revalidate state along the way. 1635c0d0381aSMike Kravetz */ 1636c0d0381aSMike Kravetz struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage) 1637c0d0381aSMike Kravetz { 1638c0d0381aSMike Kravetz struct address_space *mapping, *mapping2; 1639c0d0381aSMike Kravetz 1640c0d0381aSMike Kravetz mapping = _get_hugetlb_page_mapping(hpage); 1641c0d0381aSMike Kravetz retry: 1642c0d0381aSMike Kravetz if (!mapping) 1643c0d0381aSMike Kravetz return mapping; 1644c0d0381aSMike Kravetz 1645c0d0381aSMike Kravetz /* 1646c0d0381aSMike Kravetz * If no contention, take lock and return 1647c0d0381aSMike Kravetz */ 1648c0d0381aSMike Kravetz if (i_mmap_trylock_write(mapping)) 1649c0d0381aSMike Kravetz return mapping; 1650c0d0381aSMike Kravetz 1651c0d0381aSMike Kravetz /* 1652c0d0381aSMike Kravetz * Must drop page lock and wait on mapping sema. 1653c0d0381aSMike Kravetz * Note: Once page lock is dropped, mapping could become invalid. 1654c0d0381aSMike Kravetz * As a hack, increase map count until we lock page again. 1655c0d0381aSMike Kravetz */ 1656c0d0381aSMike Kravetz atomic_inc(&hpage->_mapcount); 1657c0d0381aSMike Kravetz unlock_page(hpage); 1658c0d0381aSMike Kravetz i_mmap_lock_write(mapping); 1659c0d0381aSMike Kravetz lock_page(hpage); 1660c0d0381aSMike Kravetz atomic_add_negative(-1, &hpage->_mapcount); 1661c0d0381aSMike Kravetz 1662c0d0381aSMike Kravetz /* verify page is still mapped */ 1663c0d0381aSMike Kravetz if (!page_mapped(hpage)) { 1664c0d0381aSMike Kravetz i_mmap_unlock_write(mapping); 1665c0d0381aSMike Kravetz return NULL; 1666c0d0381aSMike Kravetz } 1667c0d0381aSMike Kravetz 1668c0d0381aSMike Kravetz /* 1669c0d0381aSMike Kravetz * Get address space again and verify it is the same one 1670c0d0381aSMike Kravetz * we locked. If not, drop lock and retry. 1671c0d0381aSMike Kravetz */ 1672c0d0381aSMike Kravetz mapping2 = _get_hugetlb_page_mapping(hpage); 1673c0d0381aSMike Kravetz if (mapping2 != mapping) { 1674c0d0381aSMike Kravetz i_mmap_unlock_write(mapping); 1675c0d0381aSMike Kravetz mapping = mapping2; 1676c0d0381aSMike Kravetz goto retry; 1677c0d0381aSMike Kravetz } 1678c0d0381aSMike Kravetz 1679c0d0381aSMike Kravetz return mapping; 1680c0d0381aSMike Kravetz } 1681c0d0381aSMike Kravetz 168213d60f4bSZhang Yi pgoff_t __basepage_index(struct page *page) 168313d60f4bSZhang Yi { 168413d60f4bSZhang Yi struct page *page_head = compound_head(page); 168513d60f4bSZhang Yi pgoff_t index = page_index(page_head); 168613d60f4bSZhang Yi unsigned long compound_idx; 168713d60f4bSZhang Yi 168813d60f4bSZhang Yi if (!PageHuge(page_head)) 168913d60f4bSZhang Yi return page_index(page); 169013d60f4bSZhang Yi 169113d60f4bSZhang Yi if (compound_order(page_head) >= MAX_ORDER) 169213d60f4bSZhang Yi compound_idx = page_to_pfn(page) - page_to_pfn(page_head); 169313d60f4bSZhang Yi else 169413d60f4bSZhang Yi compound_idx = page - page_head; 169513d60f4bSZhang Yi 169613d60f4bSZhang Yi return (index << compound_order(page_head)) + compound_idx; 169713d60f4bSZhang Yi } 169813d60f4bSZhang Yi 16990c397daeSMichal Hocko static struct page *alloc_buddy_huge_page(struct hstate *h, 1700f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1701f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 17021da177e4SLinus Torvalds { 1703af0fb9dfSMichal Hocko int order = huge_page_order(h); 17041da177e4SLinus Torvalds struct page *page; 1705f60858f9SMike Kravetz bool alloc_try_hard = true; 1706f96efd58SJoe Jin 1707f60858f9SMike Kravetz /* 1708f60858f9SMike Kravetz * By default we always try hard to allocate the page with 1709f60858f9SMike Kravetz * __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in 1710f60858f9SMike Kravetz * a loop (to adjust global huge page counts) and previous allocation 1711f60858f9SMike Kravetz * failed, do not continue to try hard on the same node. Use the 1712f60858f9SMike Kravetz * node_alloc_noretry bitmap to manage this state information. 1713f60858f9SMike Kravetz */ 1714f60858f9SMike Kravetz if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry)) 1715f60858f9SMike Kravetz alloc_try_hard = false; 1716f60858f9SMike Kravetz gfp_mask |= __GFP_COMP|__GFP_NOWARN; 1717f60858f9SMike Kravetz if (alloc_try_hard) 1718f60858f9SMike Kravetz gfp_mask |= __GFP_RETRY_MAYFAIL; 1719af0fb9dfSMichal Hocko if (nid == NUMA_NO_NODE) 1720af0fb9dfSMichal Hocko nid = numa_mem_id(); 1721af0fb9dfSMichal Hocko page = __alloc_pages_nodemask(gfp_mask, order, nid, nmask); 1722af0fb9dfSMichal Hocko if (page) 1723af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC); 1724af0fb9dfSMichal Hocko else 1725af0fb9dfSMichal Hocko __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 172663b4613cSNishanth Aravamudan 1727f60858f9SMike Kravetz /* 1728f60858f9SMike Kravetz * If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this 1729f60858f9SMike Kravetz * indicates an overall state change. Clear bit so that we resume 1730f60858f9SMike Kravetz * normal 'try hard' allocations. 1731f60858f9SMike Kravetz */ 1732f60858f9SMike Kravetz if (node_alloc_noretry && page && !alloc_try_hard) 1733f60858f9SMike Kravetz node_clear(nid, *node_alloc_noretry); 1734f60858f9SMike Kravetz 1735f60858f9SMike Kravetz /* 1736f60858f9SMike Kravetz * If we tried hard to get a page but failed, set bit so that 1737f60858f9SMike Kravetz * subsequent attempts will not try as hard until there is an 1738f60858f9SMike Kravetz * overall state change. 1739f60858f9SMike Kravetz */ 1740f60858f9SMike Kravetz if (node_alloc_noretry && !page && alloc_try_hard) 1741f60858f9SMike Kravetz node_set(nid, *node_alloc_noretry); 1742f60858f9SMike Kravetz 174363b4613cSNishanth Aravamudan return page; 174463b4613cSNishanth Aravamudan } 174563b4613cSNishanth Aravamudan 1746af0fb9dfSMichal Hocko /* 17470c397daeSMichal Hocko * Common helper to allocate a fresh hugetlb page. All specific allocators 17480c397daeSMichal Hocko * should use this function to get new hugetlb pages 17490c397daeSMichal Hocko */ 17500c397daeSMichal Hocko static struct page *alloc_fresh_huge_page(struct hstate *h, 1751f60858f9SMike Kravetz gfp_t gfp_mask, int nid, nodemask_t *nmask, 1752f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 17530c397daeSMichal Hocko { 17540c397daeSMichal Hocko struct page *page; 17550c397daeSMichal Hocko 17560c397daeSMichal Hocko if (hstate_is_gigantic(h)) 17570c397daeSMichal Hocko page = alloc_gigantic_page(h, gfp_mask, nid, nmask); 17580c397daeSMichal Hocko else 17590c397daeSMichal Hocko page = alloc_buddy_huge_page(h, gfp_mask, 1760f60858f9SMike Kravetz nid, nmask, node_alloc_noretry); 17610c397daeSMichal Hocko if (!page) 17620c397daeSMichal Hocko return NULL; 17630c397daeSMichal Hocko 17640c397daeSMichal Hocko if (hstate_is_gigantic(h)) 17650c397daeSMichal Hocko prep_compound_gigantic_page(page, huge_page_order(h)); 17660c397daeSMichal Hocko prep_new_huge_page(h, page, page_to_nid(page)); 17670c397daeSMichal Hocko 17680c397daeSMichal Hocko return page; 17690c397daeSMichal Hocko } 17700c397daeSMichal Hocko 17710c397daeSMichal Hocko /* 1772af0fb9dfSMichal Hocko * Allocates a fresh page to the hugetlb allocator pool in the node interleaved 1773af0fb9dfSMichal Hocko * manner. 1774af0fb9dfSMichal Hocko */ 1775f60858f9SMike Kravetz static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 1776f60858f9SMike Kravetz nodemask_t *node_alloc_noretry) 1777b2261026SJoonsoo Kim { 1778b2261026SJoonsoo Kim struct page *page; 1779b2261026SJoonsoo Kim int nr_nodes, node; 1780af0fb9dfSMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; 1781b2261026SJoonsoo Kim 1782b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 1783f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed, 1784f60858f9SMike Kravetz node_alloc_noretry); 1785af0fb9dfSMichal Hocko if (page) 1786b2261026SJoonsoo Kim break; 1787b2261026SJoonsoo Kim } 1788b2261026SJoonsoo Kim 1789af0fb9dfSMichal Hocko if (!page) 1790af0fb9dfSMichal Hocko return 0; 1791b2261026SJoonsoo Kim 1792af0fb9dfSMichal Hocko put_page(page); /* free it into the hugepage allocator */ 1793af0fb9dfSMichal Hocko 1794af0fb9dfSMichal Hocko return 1; 1795b2261026SJoonsoo Kim } 1796b2261026SJoonsoo Kim 1797e8c5c824SLee Schermerhorn /* 1798e8c5c824SLee Schermerhorn * Free huge page from pool from next node to free. 1799e8c5c824SLee Schermerhorn * Attempt to keep persistent huge pages more or less 1800e8c5c824SLee Schermerhorn * balanced over allowed nodes. 1801e8c5c824SLee Schermerhorn * Called with hugetlb_lock locked. 1802e8c5c824SLee Schermerhorn */ 18036ae11b27SLee Schermerhorn static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, 18046ae11b27SLee Schermerhorn bool acct_surplus) 1805e8c5c824SLee Schermerhorn { 1806b2261026SJoonsoo Kim int nr_nodes, node; 1807e8c5c824SLee Schermerhorn int ret = 0; 1808e8c5c824SLee Schermerhorn 1809b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 1810685f3457SLee Schermerhorn /* 1811685f3457SLee Schermerhorn * If we're returning unused surplus pages, only examine 1812685f3457SLee Schermerhorn * nodes with surplus pages. 1813685f3457SLee Schermerhorn */ 1814b2261026SJoonsoo Kim if ((!acct_surplus || h->surplus_huge_pages_node[node]) && 1815b2261026SJoonsoo Kim !list_empty(&h->hugepage_freelists[node])) { 1816e8c5c824SLee Schermerhorn struct page *page = 1817b2261026SJoonsoo Kim list_entry(h->hugepage_freelists[node].next, 1818e8c5c824SLee Schermerhorn struct page, lru); 1819e8c5c824SLee Schermerhorn list_del(&page->lru); 1820e8c5c824SLee Schermerhorn h->free_huge_pages--; 1821b2261026SJoonsoo Kim h->free_huge_pages_node[node]--; 1822685f3457SLee Schermerhorn if (acct_surplus) { 1823685f3457SLee Schermerhorn h->surplus_huge_pages--; 1824b2261026SJoonsoo Kim h->surplus_huge_pages_node[node]--; 1825685f3457SLee Schermerhorn } 1826e8c5c824SLee Schermerhorn update_and_free_page(h, page); 1827e8c5c824SLee Schermerhorn ret = 1; 18289a76db09SLee Schermerhorn break; 1829e8c5c824SLee Schermerhorn } 1830b2261026SJoonsoo Kim } 1831e8c5c824SLee Schermerhorn 1832e8c5c824SLee Schermerhorn return ret; 1833e8c5c824SLee Schermerhorn } 1834e8c5c824SLee Schermerhorn 1835c8721bbbSNaoya Horiguchi /* 1836c8721bbbSNaoya Horiguchi * Dissolve a given free hugepage into free buddy pages. This function does 1837faf53defSNaoya Horiguchi * nothing for in-use hugepages and non-hugepages. 1838faf53defSNaoya Horiguchi * This function returns values like below: 1839faf53defSNaoya Horiguchi * 1840faf53defSNaoya Horiguchi * -EBUSY: failed to dissolved free hugepages or the hugepage is in-use 1841faf53defSNaoya Horiguchi * (allocated or reserved.) 1842faf53defSNaoya Horiguchi * 0: successfully dissolved free hugepages or the page is not a 1843faf53defSNaoya Horiguchi * hugepage (considered as already dissolved) 1844c8721bbbSNaoya Horiguchi */ 1845c3114a84SAnshuman Khandual int dissolve_free_huge_page(struct page *page) 1846c8721bbbSNaoya Horiguchi { 18476bc9b564SNaoya Horiguchi int rc = -EBUSY; 1848082d5b6bSGerald Schaefer 1849faf53defSNaoya Horiguchi /* Not to disrupt normal path by vainly holding hugetlb_lock */ 1850faf53defSNaoya Horiguchi if (!PageHuge(page)) 1851faf53defSNaoya Horiguchi return 0; 1852faf53defSNaoya Horiguchi 1853c8721bbbSNaoya Horiguchi spin_lock(&hugetlb_lock); 1854faf53defSNaoya Horiguchi if (!PageHuge(page)) { 1855faf53defSNaoya Horiguchi rc = 0; 1856faf53defSNaoya Horiguchi goto out; 1857faf53defSNaoya Horiguchi } 1858faf53defSNaoya Horiguchi 1859faf53defSNaoya Horiguchi if (!page_count(page)) { 18602247bb33SGerald Schaefer struct page *head = compound_head(page); 18612247bb33SGerald Schaefer struct hstate *h = page_hstate(head); 18622247bb33SGerald Schaefer int nid = page_to_nid(head); 18636bc9b564SNaoya Horiguchi if (h->free_huge_pages - h->resv_huge_pages == 0) 1864082d5b6bSGerald Schaefer goto out; 1865c3114a84SAnshuman Khandual /* 1866c3114a84SAnshuman Khandual * Move PageHWPoison flag from head page to the raw error page, 1867c3114a84SAnshuman Khandual * which makes any subpages rather than the error page reusable. 1868c3114a84SAnshuman Khandual */ 1869c3114a84SAnshuman Khandual if (PageHWPoison(head) && page != head) { 1870c3114a84SAnshuman Khandual SetPageHWPoison(page); 1871c3114a84SAnshuman Khandual ClearPageHWPoison(head); 1872c3114a84SAnshuman Khandual } 18732247bb33SGerald Schaefer list_del(&head->lru); 1874c8721bbbSNaoya Horiguchi h->free_huge_pages--; 1875c8721bbbSNaoya Horiguchi h->free_huge_pages_node[nid]--; 1876c1470b33Szhong jiang h->max_huge_pages--; 18772247bb33SGerald Schaefer update_and_free_page(h, head); 18786bc9b564SNaoya Horiguchi rc = 0; 1879c8721bbbSNaoya Horiguchi } 1880082d5b6bSGerald Schaefer out: 1881c8721bbbSNaoya Horiguchi spin_unlock(&hugetlb_lock); 1882082d5b6bSGerald Schaefer return rc; 1883c8721bbbSNaoya Horiguchi } 1884c8721bbbSNaoya Horiguchi 1885c8721bbbSNaoya Horiguchi /* 1886c8721bbbSNaoya Horiguchi * Dissolve free hugepages in a given pfn range. Used by memory hotplug to 1887c8721bbbSNaoya Horiguchi * make specified memory blocks removable from the system. 18882247bb33SGerald Schaefer * Note that this will dissolve a free gigantic hugepage completely, if any 18892247bb33SGerald Schaefer * part of it lies within the given range. 1890082d5b6bSGerald Schaefer * Also note that if dissolve_free_huge_page() returns with an error, all 1891082d5b6bSGerald Schaefer * free hugepages that were dissolved before that error are lost. 1892c8721bbbSNaoya Horiguchi */ 1893082d5b6bSGerald Schaefer int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) 1894c8721bbbSNaoya Horiguchi { 1895c8721bbbSNaoya Horiguchi unsigned long pfn; 1896eb03aa00SGerald Schaefer struct page *page; 1897082d5b6bSGerald Schaefer int rc = 0; 1898c8721bbbSNaoya Horiguchi 1899d0177639SLi Zhong if (!hugepages_supported()) 1900082d5b6bSGerald Schaefer return rc; 1901d0177639SLi Zhong 1902eb03aa00SGerald Schaefer for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) { 1903eb03aa00SGerald Schaefer page = pfn_to_page(pfn); 1904eb03aa00SGerald Schaefer rc = dissolve_free_huge_page(page); 1905eb03aa00SGerald Schaefer if (rc) 1906082d5b6bSGerald Schaefer break; 1907eb03aa00SGerald Schaefer } 1908082d5b6bSGerald Schaefer 1909082d5b6bSGerald Schaefer return rc; 1910c8721bbbSNaoya Horiguchi } 1911c8721bbbSNaoya Horiguchi 1912ab5ac90aSMichal Hocko /* 1913ab5ac90aSMichal Hocko * Allocates a fresh surplus page from the page allocator. 1914ab5ac90aSMichal Hocko */ 19150c397daeSMichal Hocko static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, 1916aaf14e40SMichal Hocko int nid, nodemask_t *nmask) 19177893d1d5SAdam Litke { 19189980d744SMichal Hocko struct page *page = NULL; 19197893d1d5SAdam Litke 1920bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 1921aa888a74SAndi Kleen return NULL; 1922aa888a74SAndi Kleen 1923d1c3fb1fSNishanth Aravamudan spin_lock(&hugetlb_lock); 19249980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) 19259980d744SMichal Hocko goto out_unlock; 1926d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 1927d1c3fb1fSNishanth Aravamudan 1928f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 19299980d744SMichal Hocko if (!page) 19300c397daeSMichal Hocko return NULL; 1931d1c3fb1fSNishanth Aravamudan 19327893d1d5SAdam Litke spin_lock(&hugetlb_lock); 19339980d744SMichal Hocko /* 19349980d744SMichal Hocko * We could have raced with the pool size change. 19359980d744SMichal Hocko * Double check that and simply deallocate the new page 19369980d744SMichal Hocko * if we would end up overcommiting the surpluses. Abuse 19379980d744SMichal Hocko * temporary page to workaround the nasty free_huge_page 19389980d744SMichal Hocko * codeflow 19399980d744SMichal Hocko */ 19409980d744SMichal Hocko if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 19419980d744SMichal Hocko SetPageHugeTemporary(page); 19422bf753e6SKai Shen spin_unlock(&hugetlb_lock); 19439980d744SMichal Hocko put_page(page); 19442bf753e6SKai Shen return NULL; 19459980d744SMichal Hocko } else { 19469980d744SMichal Hocko h->surplus_huge_pages++; 19474704dea3SMichal Hocko h->surplus_huge_pages_node[page_to_nid(page)]++; 19487893d1d5SAdam Litke } 19499980d744SMichal Hocko 19509980d744SMichal Hocko out_unlock: 1951d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 19527893d1d5SAdam Litke 19537893d1d5SAdam Litke return page; 19547893d1d5SAdam Litke } 19557893d1d5SAdam Litke 1956bbe88753SJoonsoo Kim static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask, 1957ab5ac90aSMichal Hocko int nid, nodemask_t *nmask) 1958ab5ac90aSMichal Hocko { 1959ab5ac90aSMichal Hocko struct page *page; 1960ab5ac90aSMichal Hocko 1961ab5ac90aSMichal Hocko if (hstate_is_gigantic(h)) 1962ab5ac90aSMichal Hocko return NULL; 1963ab5ac90aSMichal Hocko 1964f60858f9SMike Kravetz page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL); 1965ab5ac90aSMichal Hocko if (!page) 1966ab5ac90aSMichal Hocko return NULL; 1967ab5ac90aSMichal Hocko 1968ab5ac90aSMichal Hocko /* 1969ab5ac90aSMichal Hocko * We do not account these pages as surplus because they are only 1970ab5ac90aSMichal Hocko * temporary and will be released properly on the last reference 1971ab5ac90aSMichal Hocko */ 1972ab5ac90aSMichal Hocko SetPageHugeTemporary(page); 1973ab5ac90aSMichal Hocko 1974ab5ac90aSMichal Hocko return page; 1975ab5ac90aSMichal Hocko } 1976ab5ac90aSMichal Hocko 1977e4e574b7SAdam Litke /* 1978099730d6SDave Hansen * Use the VMA's mpolicy to allocate a huge page from the buddy. 1979099730d6SDave Hansen */ 1980e0ec90eeSDave Hansen static 19810c397daeSMichal Hocko struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h, 1982099730d6SDave Hansen struct vm_area_struct *vma, unsigned long addr) 1983099730d6SDave Hansen { 1984aaf14e40SMichal Hocko struct page *page; 1985aaf14e40SMichal Hocko struct mempolicy *mpol; 1986aaf14e40SMichal Hocko gfp_t gfp_mask = htlb_alloc_mask(h); 1987aaf14e40SMichal Hocko int nid; 1988aaf14e40SMichal Hocko nodemask_t *nodemask; 1989aaf14e40SMichal Hocko 1990aaf14e40SMichal Hocko nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); 19910c397daeSMichal Hocko page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask); 1992aaf14e40SMichal Hocko mpol_cond_put(mpol); 1993aaf14e40SMichal Hocko 1994aaf14e40SMichal Hocko return page; 1995099730d6SDave Hansen } 1996099730d6SDave Hansen 1997ab5ac90aSMichal Hocko /* page migration callback function */ 19983e59fcb0SMichal Hocko struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid, 1999d92bbc27SJoonsoo Kim nodemask_t *nmask, gfp_t gfp_mask) 20004db9b2efSMichal Hocko { 20014db9b2efSMichal Hocko spin_lock(&hugetlb_lock); 20024db9b2efSMichal Hocko if (h->free_huge_pages - h->resv_huge_pages > 0) { 20033e59fcb0SMichal Hocko struct page *page; 20043e59fcb0SMichal Hocko 20053e59fcb0SMichal Hocko page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask); 20063e59fcb0SMichal Hocko if (page) { 20073e59fcb0SMichal Hocko spin_unlock(&hugetlb_lock); 20083e59fcb0SMichal Hocko return page; 20094db9b2efSMichal Hocko } 20104db9b2efSMichal Hocko } 20114db9b2efSMichal Hocko spin_unlock(&hugetlb_lock); 20124db9b2efSMichal Hocko 20130c397daeSMichal Hocko return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask); 20144db9b2efSMichal Hocko } 20154db9b2efSMichal Hocko 2016ebd63723SMichal Hocko /* mempolicy aware migration callback */ 2017389c8178SMichal Hocko struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma, 2018389c8178SMichal Hocko unsigned long address) 2019ebd63723SMichal Hocko { 2020ebd63723SMichal Hocko struct mempolicy *mpol; 2021ebd63723SMichal Hocko nodemask_t *nodemask; 2022ebd63723SMichal Hocko struct page *page; 2023ebd63723SMichal Hocko gfp_t gfp_mask; 2024ebd63723SMichal Hocko int node; 2025ebd63723SMichal Hocko 2026ebd63723SMichal Hocko gfp_mask = htlb_alloc_mask(h); 2027ebd63723SMichal Hocko node = huge_node(vma, address, gfp_mask, &mpol, &nodemask); 2028d92bbc27SJoonsoo Kim page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask); 2029ebd63723SMichal Hocko mpol_cond_put(mpol); 2030ebd63723SMichal Hocko 2031ebd63723SMichal Hocko return page; 2032ebd63723SMichal Hocko } 2033ebd63723SMichal Hocko 2034bf50bab2SNaoya Horiguchi /* 203525985edcSLucas De Marchi * Increase the hugetlb pool such that it can accommodate a reservation 2036e4e574b7SAdam Litke * of size 'delta'. 2037e4e574b7SAdam Litke */ 2038a5516438SAndi Kleen static int gather_surplus_pages(struct hstate *h, int delta) 20391b2a1e7bSJules Irenge __must_hold(&hugetlb_lock) 2040e4e574b7SAdam Litke { 2041e4e574b7SAdam Litke struct list_head surplus_list; 2042e4e574b7SAdam Litke struct page *page, *tmp; 2043e4e574b7SAdam Litke int ret, i; 2044e4e574b7SAdam Litke int needed, allocated; 204528073b02SHillf Danton bool alloc_ok = true; 2046e4e574b7SAdam Litke 2047a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 2048ac09b3a1SAdam Litke if (needed <= 0) { 2049a5516438SAndi Kleen h->resv_huge_pages += delta; 2050e4e574b7SAdam Litke return 0; 2051ac09b3a1SAdam Litke } 2052e4e574b7SAdam Litke 2053e4e574b7SAdam Litke allocated = 0; 2054e4e574b7SAdam Litke INIT_LIST_HEAD(&surplus_list); 2055e4e574b7SAdam Litke 2056e4e574b7SAdam Litke ret = -ENOMEM; 2057e4e574b7SAdam Litke retry: 2058e4e574b7SAdam Litke spin_unlock(&hugetlb_lock); 2059e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 20600c397daeSMichal Hocko page = alloc_surplus_huge_page(h, htlb_alloc_mask(h), 2061aaf14e40SMichal Hocko NUMA_NO_NODE, NULL); 206228073b02SHillf Danton if (!page) { 206328073b02SHillf Danton alloc_ok = false; 206428073b02SHillf Danton break; 206528073b02SHillf Danton } 2066e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 206769ed779aSDavid Rientjes cond_resched(); 2068e4e574b7SAdam Litke } 206928073b02SHillf Danton allocated += i; 2070e4e574b7SAdam Litke 2071e4e574b7SAdam Litke /* 2072e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 2073e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 2074e4e574b7SAdam Litke */ 2075e4e574b7SAdam Litke spin_lock(&hugetlb_lock); 2076a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 2077a5516438SAndi Kleen (h->free_huge_pages + allocated); 207828073b02SHillf Danton if (needed > 0) { 207928073b02SHillf Danton if (alloc_ok) 2080e4e574b7SAdam Litke goto retry; 208128073b02SHillf Danton /* 208228073b02SHillf Danton * We were not able to allocate enough pages to 208328073b02SHillf Danton * satisfy the entire reservation so we free what 208428073b02SHillf Danton * we've allocated so far. 208528073b02SHillf Danton */ 208628073b02SHillf Danton goto free; 208728073b02SHillf Danton } 2088e4e574b7SAdam Litke /* 2089e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 209025985edcSLucas De Marchi * needed to accommodate the reservation. Add the appropriate number 2091e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 2092ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 2093ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 2094ac09b3a1SAdam Litke * before they are reserved. 2095e4e574b7SAdam Litke */ 2096e4e574b7SAdam Litke needed += allocated; 2097a5516438SAndi Kleen h->resv_huge_pages += delta; 2098e4e574b7SAdam Litke ret = 0; 2099a9869b83SNaoya Horiguchi 210019fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 210119fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 210219fc3f0aSAdam Litke if ((--needed) < 0) 210319fc3f0aSAdam Litke break; 2104a9869b83SNaoya Horiguchi /* 2105a9869b83SNaoya Horiguchi * This page is now managed by the hugetlb allocator and has 2106a9869b83SNaoya Horiguchi * no users -- drop the buddy allocator's reference. 2107a9869b83SNaoya Horiguchi */ 2108a9869b83SNaoya Horiguchi put_page_testzero(page); 2109309381feSSasha Levin VM_BUG_ON_PAGE(page_count(page), page); 2110a5516438SAndi Kleen enqueue_huge_page(h, page); 211119fc3f0aSAdam Litke } 211228073b02SHillf Danton free: 2113b0365c8dSHillf Danton spin_unlock(&hugetlb_lock); 211419fc3f0aSAdam Litke 211519fc3f0aSAdam Litke /* Free unnecessary surplus pages to the buddy allocator */ 2116c0d934baSJoonsoo Kim list_for_each_entry_safe(page, tmp, &surplus_list, lru) 2117a9869b83SNaoya Horiguchi put_page(page); 211819fc3f0aSAdam Litke spin_lock(&hugetlb_lock); 2119e4e574b7SAdam Litke 2120e4e574b7SAdam Litke return ret; 2121e4e574b7SAdam Litke } 2122e4e574b7SAdam Litke 2123e4e574b7SAdam Litke /* 2124e5bbc8a6SMike Kravetz * This routine has two main purposes: 2125e5bbc8a6SMike Kravetz * 1) Decrement the reservation count (resv_huge_pages) by the value passed 2126e5bbc8a6SMike Kravetz * in unused_resv_pages. This corresponds to the prior adjustments made 2127e5bbc8a6SMike Kravetz * to the associated reservation map. 2128e5bbc8a6SMike Kravetz * 2) Free any unused surplus pages that may have been allocated to satisfy 2129e5bbc8a6SMike Kravetz * the reservation. As many as unused_resv_pages may be freed. 2130e5bbc8a6SMike Kravetz * 2131e5bbc8a6SMike Kravetz * Called with hugetlb_lock held. However, the lock could be dropped (and 2132e5bbc8a6SMike Kravetz * reacquired) during calls to cond_resched_lock. Whenever dropping the lock, 2133e5bbc8a6SMike Kravetz * we must make sure nobody else can claim pages we are in the process of 2134e5bbc8a6SMike Kravetz * freeing. Do this by ensuring resv_huge_page always is greater than the 2135e5bbc8a6SMike Kravetz * number of huge pages we plan to free when dropping the lock. 2136e4e574b7SAdam Litke */ 2137a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 2138a5516438SAndi Kleen unsigned long unused_resv_pages) 2139e4e574b7SAdam Litke { 2140e4e574b7SAdam Litke unsigned long nr_pages; 2141e4e574b7SAdam Litke 2142aa888a74SAndi Kleen /* Cannot return gigantic pages currently */ 2143bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2144e5bbc8a6SMike Kravetz goto out; 2145aa888a74SAndi Kleen 2146e5bbc8a6SMike Kravetz /* 2147e5bbc8a6SMike Kravetz * Part (or even all) of the reservation could have been backed 2148e5bbc8a6SMike Kravetz * by pre-allocated pages. Only free surplus pages. 2149e5bbc8a6SMike Kravetz */ 2150a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 2151e4e574b7SAdam Litke 2152685f3457SLee Schermerhorn /* 2153685f3457SLee Schermerhorn * We want to release as many surplus pages as possible, spread 21549b5e5d0fSLee Schermerhorn * evenly across all nodes with memory. Iterate across these nodes 21559b5e5d0fSLee Schermerhorn * until we can no longer free unreserved surplus pages. This occurs 21569b5e5d0fSLee Schermerhorn * when the nodes with surplus pages have no free pages. 21579e7ee400SRandy Dunlap * free_pool_huge_page() will balance the freed pages across the 21589b5e5d0fSLee Schermerhorn * on-line nodes with memory and will handle the hstate accounting. 2159e5bbc8a6SMike Kravetz * 2160e5bbc8a6SMike Kravetz * Note that we decrement resv_huge_pages as we free the pages. If 2161e5bbc8a6SMike Kravetz * we drop the lock, resv_huge_pages will still be sufficiently large 2162e5bbc8a6SMike Kravetz * to cover subsequent pages we may free. 2163685f3457SLee Schermerhorn */ 2164685f3457SLee Schermerhorn while (nr_pages--) { 2165e5bbc8a6SMike Kravetz h->resv_huge_pages--; 2166e5bbc8a6SMike Kravetz unused_resv_pages--; 21678cebfcd0SLai Jiangshan if (!free_pool_huge_page(h, &node_states[N_MEMORY], 1)) 2168e5bbc8a6SMike Kravetz goto out; 21697848a4bfSMizuma, Masayoshi cond_resched_lock(&hugetlb_lock); 2170e4e574b7SAdam Litke } 2171e5bbc8a6SMike Kravetz 2172e5bbc8a6SMike Kravetz out: 2173e5bbc8a6SMike Kravetz /* Fully uncommit the reservation */ 2174e5bbc8a6SMike Kravetz h->resv_huge_pages -= unused_resv_pages; 2175e4e574b7SAdam Litke } 2176e4e574b7SAdam Litke 21775e911373SMike Kravetz 2178c37f9fb1SAndy Whitcroft /* 2179feba16e2SMike Kravetz * vma_needs_reservation, vma_commit_reservation and vma_end_reservation 21805e911373SMike Kravetz * are used by the huge page allocation routines to manage reservations. 2181cf3ad20bSMike Kravetz * 2182cf3ad20bSMike Kravetz * vma_needs_reservation is called to determine if the huge page at addr 2183cf3ad20bSMike Kravetz * within the vma has an associated reservation. If a reservation is 2184cf3ad20bSMike Kravetz * needed, the value 1 is returned. The caller is then responsible for 2185cf3ad20bSMike Kravetz * managing the global reservation and subpool usage counts. After 2186cf3ad20bSMike Kravetz * the huge page has been allocated, vma_commit_reservation is called 2187feba16e2SMike Kravetz * to add the page to the reservation map. If the page allocation fails, 2188feba16e2SMike Kravetz * the reservation must be ended instead of committed. vma_end_reservation 2189feba16e2SMike Kravetz * is called in such cases. 2190cf3ad20bSMike Kravetz * 2191cf3ad20bSMike Kravetz * In the normal case, vma_commit_reservation returns the same value 2192cf3ad20bSMike Kravetz * as the preceding vma_needs_reservation call. The only time this 2193cf3ad20bSMike Kravetz * is not the case is if a reserve map was changed between calls. It 2194cf3ad20bSMike Kravetz * is the responsibility of the caller to notice the difference and 2195cf3ad20bSMike Kravetz * take appropriate action. 219696b96a96SMike Kravetz * 219796b96a96SMike Kravetz * vma_add_reservation is used in error paths where a reservation must 219896b96a96SMike Kravetz * be restored when a newly allocated huge page must be freed. It is 219996b96a96SMike Kravetz * to be called after calling vma_needs_reservation to determine if a 220096b96a96SMike Kravetz * reservation exists. 2201c37f9fb1SAndy Whitcroft */ 22025e911373SMike Kravetz enum vma_resv_mode { 22035e911373SMike Kravetz VMA_NEEDS_RESV, 22045e911373SMike Kravetz VMA_COMMIT_RESV, 2205feba16e2SMike Kravetz VMA_END_RESV, 220696b96a96SMike Kravetz VMA_ADD_RESV, 22075e911373SMike Kravetz }; 2208cf3ad20bSMike Kravetz static long __vma_reservation_common(struct hstate *h, 2209cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr, 22105e911373SMike Kravetz enum vma_resv_mode mode) 2211c37f9fb1SAndy Whitcroft { 22124e35f483SJoonsoo Kim struct resv_map *resv; 22134e35f483SJoonsoo Kim pgoff_t idx; 2214cf3ad20bSMike Kravetz long ret; 22150db9d74eSMina Almasry long dummy_out_regions_needed; 2216c37f9fb1SAndy Whitcroft 22174e35f483SJoonsoo Kim resv = vma_resv_map(vma); 22184e35f483SJoonsoo Kim if (!resv) 2219c37f9fb1SAndy Whitcroft return 1; 2220c37f9fb1SAndy Whitcroft 22214e35f483SJoonsoo Kim idx = vma_hugecache_offset(h, vma, addr); 22225e911373SMike Kravetz switch (mode) { 22235e911373SMike Kravetz case VMA_NEEDS_RESV: 22240db9d74eSMina Almasry ret = region_chg(resv, idx, idx + 1, &dummy_out_regions_needed); 22250db9d74eSMina Almasry /* We assume that vma_reservation_* routines always operate on 22260db9d74eSMina Almasry * 1 page, and that adding to resv map a 1 page entry can only 22270db9d74eSMina Almasry * ever require 1 region. 22280db9d74eSMina Almasry */ 22290db9d74eSMina Almasry VM_BUG_ON(dummy_out_regions_needed != 1); 22305e911373SMike Kravetz break; 22315e911373SMike Kravetz case VMA_COMMIT_RESV: 2232075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 22330db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 22340db9d74eSMina Almasry VM_BUG_ON(ret < 0); 22355e911373SMike Kravetz break; 2236feba16e2SMike Kravetz case VMA_END_RESV: 22370db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 22385e911373SMike Kravetz ret = 0; 22395e911373SMike Kravetz break; 224096b96a96SMike Kravetz case VMA_ADD_RESV: 22410db9d74eSMina Almasry if (vma->vm_flags & VM_MAYSHARE) { 2242075a61d0SMina Almasry ret = region_add(resv, idx, idx + 1, 1, NULL, NULL); 22430db9d74eSMina Almasry /* region_add calls of range 1 should never fail. */ 22440db9d74eSMina Almasry VM_BUG_ON(ret < 0); 22450db9d74eSMina Almasry } else { 22460db9d74eSMina Almasry region_abort(resv, idx, idx + 1, 1); 224796b96a96SMike Kravetz ret = region_del(resv, idx, idx + 1); 224896b96a96SMike Kravetz } 224996b96a96SMike Kravetz break; 22505e911373SMike Kravetz default: 22515e911373SMike Kravetz BUG(); 22525e911373SMike Kravetz } 225384afd99bSAndy Whitcroft 22544e35f483SJoonsoo Kim if (vma->vm_flags & VM_MAYSHARE) 2255cf3ad20bSMike Kravetz return ret; 225667961f9dSMike Kravetz else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && ret >= 0) { 225767961f9dSMike Kravetz /* 225867961f9dSMike Kravetz * In most cases, reserves always exist for private mappings. 225967961f9dSMike Kravetz * However, a file associated with mapping could have been 226067961f9dSMike Kravetz * hole punched or truncated after reserves were consumed. 226167961f9dSMike Kravetz * As subsequent fault on such a range will not use reserves. 226267961f9dSMike Kravetz * Subtle - The reserve map for private mappings has the 226367961f9dSMike Kravetz * opposite meaning than that of shared mappings. If NO 226467961f9dSMike Kravetz * entry is in the reserve map, it means a reservation exists. 226567961f9dSMike Kravetz * If an entry exists in the reserve map, it means the 226667961f9dSMike Kravetz * reservation has already been consumed. As a result, the 226767961f9dSMike Kravetz * return value of this routine is the opposite of the 226867961f9dSMike Kravetz * value returned from reserve map manipulation routines above. 226967961f9dSMike Kravetz */ 227067961f9dSMike Kravetz if (ret) 227167961f9dSMike Kravetz return 0; 227267961f9dSMike Kravetz else 227367961f9dSMike Kravetz return 1; 227467961f9dSMike Kravetz } 22754e35f483SJoonsoo Kim else 2276cf3ad20bSMike Kravetz return ret < 0 ? ret : 0; 227784afd99bSAndy Whitcroft } 2278cf3ad20bSMike Kravetz 2279cf3ad20bSMike Kravetz static long vma_needs_reservation(struct hstate *h, 2280a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 2281c37f9fb1SAndy Whitcroft { 22825e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV); 2283cf3ad20bSMike Kravetz } 2284c37f9fb1SAndy Whitcroft 2285cf3ad20bSMike Kravetz static long vma_commit_reservation(struct hstate *h, 2286cf3ad20bSMike Kravetz struct vm_area_struct *vma, unsigned long addr) 2287cf3ad20bSMike Kravetz { 22885e911373SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV); 22895e911373SMike Kravetz } 22905e911373SMike Kravetz 2291feba16e2SMike Kravetz static void vma_end_reservation(struct hstate *h, 22925e911373SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 22935e911373SMike Kravetz { 2294feba16e2SMike Kravetz (void)__vma_reservation_common(h, vma, addr, VMA_END_RESV); 2295c37f9fb1SAndy Whitcroft } 2296c37f9fb1SAndy Whitcroft 229796b96a96SMike Kravetz static long vma_add_reservation(struct hstate *h, 229896b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long addr) 229996b96a96SMike Kravetz { 230096b96a96SMike Kravetz return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV); 230196b96a96SMike Kravetz } 230296b96a96SMike Kravetz 230396b96a96SMike Kravetz /* 230496b96a96SMike Kravetz * This routine is called to restore a reservation on error paths. In the 230596b96a96SMike Kravetz * specific error paths, a huge page was allocated (via alloc_huge_page) 230696b96a96SMike Kravetz * and is about to be freed. If a reservation for the page existed, 230796b96a96SMike Kravetz * alloc_huge_page would have consumed the reservation and set PagePrivate 230896b96a96SMike Kravetz * in the newly allocated page. When the page is freed via free_huge_page, 230996b96a96SMike Kravetz * the global reservation count will be incremented if PagePrivate is set. 231096b96a96SMike Kravetz * However, free_huge_page can not adjust the reserve map. Adjust the 231196b96a96SMike Kravetz * reserve map here to be consistent with global reserve count adjustments 231296b96a96SMike Kravetz * to be made by free_huge_page. 231396b96a96SMike Kravetz */ 231496b96a96SMike Kravetz static void restore_reserve_on_error(struct hstate *h, 231596b96a96SMike Kravetz struct vm_area_struct *vma, unsigned long address, 231696b96a96SMike Kravetz struct page *page) 231796b96a96SMike Kravetz { 231896b96a96SMike Kravetz if (unlikely(PagePrivate(page))) { 231996b96a96SMike Kravetz long rc = vma_needs_reservation(h, vma, address); 232096b96a96SMike Kravetz 232196b96a96SMike Kravetz if (unlikely(rc < 0)) { 232296b96a96SMike Kravetz /* 232396b96a96SMike Kravetz * Rare out of memory condition in reserve map 232496b96a96SMike Kravetz * manipulation. Clear PagePrivate so that 232596b96a96SMike Kravetz * global reserve count will not be incremented 232696b96a96SMike Kravetz * by free_huge_page. This will make it appear 232796b96a96SMike Kravetz * as though the reservation for this page was 232896b96a96SMike Kravetz * consumed. This may prevent the task from 232996b96a96SMike Kravetz * faulting in the page at a later time. This 233096b96a96SMike Kravetz * is better than inconsistent global huge page 233196b96a96SMike Kravetz * accounting of reserve counts. 233296b96a96SMike Kravetz */ 233396b96a96SMike Kravetz ClearPagePrivate(page); 233496b96a96SMike Kravetz } else if (rc) { 233596b96a96SMike Kravetz rc = vma_add_reservation(h, vma, address); 233696b96a96SMike Kravetz if (unlikely(rc < 0)) 233796b96a96SMike Kravetz /* 233896b96a96SMike Kravetz * See above comment about rare out of 233996b96a96SMike Kravetz * memory condition. 234096b96a96SMike Kravetz */ 234196b96a96SMike Kravetz ClearPagePrivate(page); 234296b96a96SMike Kravetz } else 234396b96a96SMike Kravetz vma_end_reservation(h, vma, address); 234496b96a96SMike Kravetz } 234596b96a96SMike Kravetz } 234696b96a96SMike Kravetz 234770c3547eSMike Kravetz struct page *alloc_huge_page(struct vm_area_struct *vma, 234804f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 2349348ea204SAdam Litke { 235090481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 2351a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 2352348ea204SAdam Litke struct page *page; 2353d85f69b0SMike Kravetz long map_chg, map_commit; 2354d85f69b0SMike Kravetz long gbl_chg; 23556d76dcf4SAneesh Kumar K.V int ret, idx; 23566d76dcf4SAneesh Kumar K.V struct hugetlb_cgroup *h_cg; 235708cf9fafSMina Almasry bool deferred_reserve; 23582fc39cecSAdam Litke 23596d76dcf4SAneesh Kumar K.V idx = hstate_index(h); 2360a1e78772SMel Gorman /* 2361d85f69b0SMike Kravetz * Examine the region/reserve map to determine if the process 2362d85f69b0SMike Kravetz * has a reservation for the page to be allocated. A return 2363d85f69b0SMike Kravetz * code of zero indicates a reservation exists (no change). 2364a1e78772SMel Gorman */ 2365d85f69b0SMike Kravetz map_chg = gbl_chg = vma_needs_reservation(h, vma, addr); 2366d85f69b0SMike Kravetz if (map_chg < 0) 236776dcee75SAneesh Kumar K.V return ERR_PTR(-ENOMEM); 2368d85f69b0SMike Kravetz 2369d85f69b0SMike Kravetz /* 2370d85f69b0SMike Kravetz * Processes that did not create the mapping will have no 2371d85f69b0SMike Kravetz * reserves as indicated by the region/reserve map. Check 2372d85f69b0SMike Kravetz * that the allocation will not exceed the subpool limit. 2373d85f69b0SMike Kravetz * Allocations for MAP_NORESERVE mappings also need to be 2374d85f69b0SMike Kravetz * checked against any subpool limit. 2375d85f69b0SMike Kravetz */ 2376d85f69b0SMike Kravetz if (map_chg || avoid_reserve) { 2377d85f69b0SMike Kravetz gbl_chg = hugepage_subpool_get_pages(spool, 1); 2378d85f69b0SMike Kravetz if (gbl_chg < 0) { 2379feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 238076dcee75SAneesh Kumar K.V return ERR_PTR(-ENOSPC); 23815e911373SMike Kravetz } 238290d8b7e6SAdam Litke 2383d85f69b0SMike Kravetz /* 2384d85f69b0SMike Kravetz * Even though there was no reservation in the region/reserve 2385d85f69b0SMike Kravetz * map, there could be reservations associated with the 2386d85f69b0SMike Kravetz * subpool that can be used. This would be indicated if the 2387d85f69b0SMike Kravetz * return value of hugepage_subpool_get_pages() is zero. 2388d85f69b0SMike Kravetz * However, if avoid_reserve is specified we still avoid even 2389d85f69b0SMike Kravetz * the subpool reservations. 2390d85f69b0SMike Kravetz */ 2391d85f69b0SMike Kravetz if (avoid_reserve) 2392d85f69b0SMike Kravetz gbl_chg = 1; 2393d85f69b0SMike Kravetz } 2394d85f69b0SMike Kravetz 239508cf9fafSMina Almasry /* If this allocation is not consuming a reservation, charge it now. 239608cf9fafSMina Almasry */ 239708cf9fafSMina Almasry deferred_reserve = map_chg || avoid_reserve || !vma_resv_map(vma); 239808cf9fafSMina Almasry if (deferred_reserve) { 239908cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup_rsvd( 240008cf9fafSMina Almasry idx, pages_per_huge_page(h), &h_cg); 24018f34af6fSJianyu Zhan if (ret) 24028f34af6fSJianyu Zhan goto out_subpool_put; 240308cf9fafSMina Almasry } 240408cf9fafSMina Almasry 240508cf9fafSMina Almasry ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); 240608cf9fafSMina Almasry if (ret) 240708cf9fafSMina Almasry goto out_uncharge_cgroup_reservation; 24088f34af6fSJianyu Zhan 2409a1e78772SMel Gorman spin_lock(&hugetlb_lock); 2410d85f69b0SMike Kravetz /* 2411d85f69b0SMike Kravetz * glb_chg is passed to indicate whether or not a page must be taken 2412d85f69b0SMike Kravetz * from the global free pool (global change). gbl_chg == 0 indicates 2413d85f69b0SMike Kravetz * a reservation exists for the allocation. 2414d85f69b0SMike Kravetz */ 2415d85f69b0SMike Kravetz page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg); 241681a6fcaeSJoonsoo Kim if (!page) { 241794ae8ba7SAneesh Kumar K.V spin_unlock(&hugetlb_lock); 24180c397daeSMichal Hocko page = alloc_buddy_huge_page_with_mpol(h, vma, addr); 24198f34af6fSJianyu Zhan if (!page) 24208f34af6fSJianyu Zhan goto out_uncharge_cgroup; 2421a88c7695SNaoya Horiguchi if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) { 2422a88c7695SNaoya Horiguchi SetPagePrivate(page); 2423a88c7695SNaoya Horiguchi h->resv_huge_pages--; 2424a88c7695SNaoya Horiguchi } 242579dbb236SAneesh Kumar K.V spin_lock(&hugetlb_lock); 242679dbb236SAneesh Kumar K.V list_move(&page->lru, &h->hugepage_activelist); 242781a6fcaeSJoonsoo Kim /* Fall through */ 2428a1e78772SMel Gorman } 242981a6fcaeSJoonsoo Kim hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); 243008cf9fafSMina Almasry /* If allocation is not consuming a reservation, also store the 243108cf9fafSMina Almasry * hugetlb_cgroup pointer on the page. 243208cf9fafSMina Almasry */ 243308cf9fafSMina Almasry if (deferred_reserve) { 243408cf9fafSMina Almasry hugetlb_cgroup_commit_charge_rsvd(idx, pages_per_huge_page(h), 243508cf9fafSMina Almasry h_cg, page); 243608cf9fafSMina Almasry } 243708cf9fafSMina Almasry 243881a6fcaeSJoonsoo Kim spin_unlock(&hugetlb_lock); 2439a1e78772SMel Gorman 244090481622SDavid Gibson set_page_private(page, (unsigned long)spool); 2441a1e78772SMel Gorman 2442d85f69b0SMike Kravetz map_commit = vma_commit_reservation(h, vma, addr); 2443d85f69b0SMike Kravetz if (unlikely(map_chg > map_commit)) { 244433039678SMike Kravetz /* 244533039678SMike Kravetz * The page was added to the reservation map between 244633039678SMike Kravetz * vma_needs_reservation and vma_commit_reservation. 244733039678SMike Kravetz * This indicates a race with hugetlb_reserve_pages. 244833039678SMike Kravetz * Adjust for the subpool count incremented above AND 244933039678SMike Kravetz * in hugetlb_reserve_pages for the same page. Also, 245033039678SMike Kravetz * the reservation count added in hugetlb_reserve_pages 245133039678SMike Kravetz * no longer applies. 245233039678SMike Kravetz */ 245333039678SMike Kravetz long rsv_adjust; 245433039678SMike Kravetz 245533039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 1); 245633039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 245733039678SMike Kravetz } 24587893d1d5SAdam Litke return page; 24598f34af6fSJianyu Zhan 24608f34af6fSJianyu Zhan out_uncharge_cgroup: 24618f34af6fSJianyu Zhan hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); 246208cf9fafSMina Almasry out_uncharge_cgroup_reservation: 246308cf9fafSMina Almasry if (deferred_reserve) 246408cf9fafSMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h), 246508cf9fafSMina Almasry h_cg); 24668f34af6fSJianyu Zhan out_subpool_put: 2467d85f69b0SMike Kravetz if (map_chg || avoid_reserve) 24688f34af6fSJianyu Zhan hugepage_subpool_put_pages(spool, 1); 2469feba16e2SMike Kravetz vma_end_reservation(h, vma, addr); 24708f34af6fSJianyu Zhan return ERR_PTR(-ENOSPC); 2471b45b5bd6SDavid Gibson } 2472b45b5bd6SDavid Gibson 2473e24a1307SAneesh Kumar K.V int alloc_bootmem_huge_page(struct hstate *h) 2474e24a1307SAneesh Kumar K.V __attribute__ ((weak, alias("__alloc_bootmem_huge_page"))); 2475e24a1307SAneesh Kumar K.V int __alloc_bootmem_huge_page(struct hstate *h) 2476aa888a74SAndi Kleen { 2477aa888a74SAndi Kleen struct huge_bootmem_page *m; 2478b2261026SJoonsoo Kim int nr_nodes, node; 2479aa888a74SAndi Kleen 2480b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { 2481aa888a74SAndi Kleen void *addr; 2482aa888a74SAndi Kleen 2483eb31d559SMike Rapoport addr = memblock_alloc_try_nid_raw( 24848b89a116SGrygorii Strashko huge_page_size(h), huge_page_size(h), 248597ad1087SMike Rapoport 0, MEMBLOCK_ALLOC_ACCESSIBLE, node); 2486aa888a74SAndi Kleen if (addr) { 2487aa888a74SAndi Kleen /* 2488aa888a74SAndi Kleen * Use the beginning of the huge page to store the 2489aa888a74SAndi Kleen * huge_bootmem_page struct (until gather_bootmem 2490aa888a74SAndi Kleen * puts them into the mem_map). 2491aa888a74SAndi Kleen */ 2492aa888a74SAndi Kleen m = addr; 2493aa888a74SAndi Kleen goto found; 2494aa888a74SAndi Kleen } 2495aa888a74SAndi Kleen } 2496aa888a74SAndi Kleen return 0; 2497aa888a74SAndi Kleen 2498aa888a74SAndi Kleen found: 2499df994eadSLuiz Capitulino BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h))); 2500aa888a74SAndi Kleen /* Put them into a private list first because mem_map is not up yet */ 2501330d6e48SCannon Matthews INIT_LIST_HEAD(&m->list); 2502aa888a74SAndi Kleen list_add(&m->list, &huge_boot_pages); 2503aa888a74SAndi Kleen m->hstate = h; 2504aa888a74SAndi Kleen return 1; 2505aa888a74SAndi Kleen } 2506aa888a74SAndi Kleen 2507d00181b9SKirill A. Shutemov static void __init prep_compound_huge_page(struct page *page, 2508d00181b9SKirill A. Shutemov unsigned int order) 250918229df5SAndy Whitcroft { 251018229df5SAndy Whitcroft if (unlikely(order > (MAX_ORDER - 1))) 251118229df5SAndy Whitcroft prep_compound_gigantic_page(page, order); 251218229df5SAndy Whitcroft else 251318229df5SAndy Whitcroft prep_compound_page(page, order); 251418229df5SAndy Whitcroft } 251518229df5SAndy Whitcroft 2516aa888a74SAndi Kleen /* Put bootmem huge pages into the standard lists after mem_map is up */ 2517aa888a74SAndi Kleen static void __init gather_bootmem_prealloc(void) 2518aa888a74SAndi Kleen { 2519aa888a74SAndi Kleen struct huge_bootmem_page *m; 2520aa888a74SAndi Kleen 2521aa888a74SAndi Kleen list_for_each_entry(m, &huge_boot_pages, list) { 252240d18ebfSMike Kravetz struct page *page = virt_to_page(m); 2523aa888a74SAndi Kleen struct hstate *h = m->hstate; 2524ee8f248dSBecky Bruce 2525aa888a74SAndi Kleen WARN_ON(page_count(page) != 1); 252618229df5SAndy Whitcroft prep_compound_huge_page(page, h->order); 2527ef5a22beSAndrea Arcangeli WARN_ON(PageReserved(page)); 2528aa888a74SAndi Kleen prep_new_huge_page(h, page, page_to_nid(page)); 2529af0fb9dfSMichal Hocko put_page(page); /* free it into the hugepage allocator */ 2530af0fb9dfSMichal Hocko 2531b0320c7bSRafael Aquini /* 2532b0320c7bSRafael Aquini * If we had gigantic hugepages allocated at boot time, we need 2533b0320c7bSRafael Aquini * to restore the 'stolen' pages to totalram_pages in order to 2534b0320c7bSRafael Aquini * fix confusing memory reports from free(1) and another 2535b0320c7bSRafael Aquini * side-effects, like CommitLimit going negative. 2536b0320c7bSRafael Aquini */ 2537bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 25383dcc0571SJiang Liu adjust_managed_page_count(page, 1 << h->order); 2539520495feSCannon Matthews cond_resched(); 2540aa888a74SAndi Kleen } 2541aa888a74SAndi Kleen } 2542aa888a74SAndi Kleen 25438faa8b07SAndi Kleen static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 25441da177e4SLinus Torvalds { 25451da177e4SLinus Torvalds unsigned long i; 2546f60858f9SMike Kravetz nodemask_t *node_alloc_noretry; 2547f60858f9SMike Kravetz 2548f60858f9SMike Kravetz if (!hstate_is_gigantic(h)) { 2549f60858f9SMike Kravetz /* 2550f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 2551f60858f9SMike Kravetz * Ignore errors as lower level routines can deal with 2552f60858f9SMike Kravetz * node_alloc_noretry == NULL. If this kmalloc fails at boot 2553f60858f9SMike Kravetz * time, we are likely in bigger trouble. 2554f60858f9SMike Kravetz */ 2555f60858f9SMike Kravetz node_alloc_noretry = kmalloc(sizeof(*node_alloc_noretry), 2556f60858f9SMike Kravetz GFP_KERNEL); 2557f60858f9SMike Kravetz } else { 2558f60858f9SMike Kravetz /* allocations done at boot time */ 2559f60858f9SMike Kravetz node_alloc_noretry = NULL; 2560f60858f9SMike Kravetz } 2561f60858f9SMike Kravetz 2562f60858f9SMike Kravetz /* bit mask controlling how hard we retry per-node allocations */ 2563f60858f9SMike Kravetz if (node_alloc_noretry) 2564f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 25651da177e4SLinus Torvalds 2566e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 2567bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) { 2568dbda8feaSBarry Song if (hugetlb_cma_size) { 2569cf11e85fSRoman Gushchin pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n"); 2570cf11e85fSRoman Gushchin break; 2571cf11e85fSRoman Gushchin } 2572aa888a74SAndi Kleen if (!alloc_bootmem_huge_page(h)) 2573aa888a74SAndi Kleen break; 25740c397daeSMichal Hocko } else if (!alloc_pool_huge_page(h, 2575f60858f9SMike Kravetz &node_states[N_MEMORY], 2576f60858f9SMike Kravetz node_alloc_noretry)) 25771da177e4SLinus Torvalds break; 257869ed779aSDavid Rientjes cond_resched(); 25791da177e4SLinus Torvalds } 2580d715cf80SLiam R. Howlett if (i < h->max_huge_pages) { 2581d715cf80SLiam R. Howlett char buf[32]; 2582d715cf80SLiam R. Howlett 2583c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 2584d715cf80SLiam R. Howlett pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n", 2585d715cf80SLiam R. Howlett h->max_huge_pages, buf, i); 25868faa8b07SAndi Kleen h->max_huge_pages = i; 2587e5ff2159SAndi Kleen } 2588f60858f9SMike Kravetz 2589f60858f9SMike Kravetz kfree(node_alloc_noretry); 2590d715cf80SLiam R. Howlett } 2591e5ff2159SAndi Kleen 2592e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 2593e5ff2159SAndi Kleen { 2594e5ff2159SAndi Kleen struct hstate *h; 2595e5ff2159SAndi Kleen 2596e5ff2159SAndi Kleen for_each_hstate(h) { 2597641844f5SNaoya Horiguchi if (minimum_order > huge_page_order(h)) 2598641844f5SNaoya Horiguchi minimum_order = huge_page_order(h); 2599641844f5SNaoya Horiguchi 26008faa8b07SAndi Kleen /* oversize hugepages were init'ed in early boot */ 2601bae7f4aeSLuiz Capitulino if (!hstate_is_gigantic(h)) 26028faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(h); 2603e5ff2159SAndi Kleen } 2604641844f5SNaoya Horiguchi VM_BUG_ON(minimum_order == UINT_MAX); 2605e5ff2159SAndi Kleen } 2606e5ff2159SAndi Kleen 2607e5ff2159SAndi Kleen static void __init report_hugepages(void) 2608e5ff2159SAndi Kleen { 2609e5ff2159SAndi Kleen struct hstate *h; 2610e5ff2159SAndi Kleen 2611e5ff2159SAndi Kleen for_each_hstate(h) { 26124abd32dbSAndi Kleen char buf[32]; 2613c6247f72SMatthew Wilcox 2614c6247f72SMatthew Wilcox string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); 2615ffb22af5SAndrew Morton pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n", 2616c6247f72SMatthew Wilcox buf, h->free_huge_pages); 2617e5ff2159SAndi Kleen } 2618e5ff2159SAndi Kleen } 2619e5ff2159SAndi Kleen 26201da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 26216ae11b27SLee Schermerhorn static void try_to_free_low(struct hstate *h, unsigned long count, 26226ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 26231da177e4SLinus Torvalds { 26244415cc8dSChristoph Lameter int i; 26254415cc8dSChristoph Lameter 2626bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2627aa888a74SAndi Kleen return; 2628aa888a74SAndi Kleen 26296ae11b27SLee Schermerhorn for_each_node_mask(i, *nodes_allowed) { 26301da177e4SLinus Torvalds struct page *page, *next; 2631a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 2632a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 2633a5516438SAndi Kleen if (count >= h->nr_huge_pages) 26346b0c880dSAdam Litke return; 26351da177e4SLinus Torvalds if (PageHighMem(page)) 26361da177e4SLinus Torvalds continue; 26371da177e4SLinus Torvalds list_del(&page->lru); 2638e5ff2159SAndi Kleen update_and_free_page(h, page); 2639a5516438SAndi Kleen h->free_huge_pages--; 2640a5516438SAndi Kleen h->free_huge_pages_node[page_to_nid(page)]--; 26411da177e4SLinus Torvalds } 26421da177e4SLinus Torvalds } 26431da177e4SLinus Torvalds } 26441da177e4SLinus Torvalds #else 26456ae11b27SLee Schermerhorn static inline void try_to_free_low(struct hstate *h, unsigned long count, 26466ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 26471da177e4SLinus Torvalds { 26481da177e4SLinus Torvalds } 26491da177e4SLinus Torvalds #endif 26501da177e4SLinus Torvalds 265120a0307cSWu Fengguang /* 265220a0307cSWu Fengguang * Increment or decrement surplus_huge_pages. Keep node-specific counters 265320a0307cSWu Fengguang * balanced by operating on them in a round-robin fashion. 265420a0307cSWu Fengguang * Returns 1 if an adjustment was made. 265520a0307cSWu Fengguang */ 26566ae11b27SLee Schermerhorn static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, 26576ae11b27SLee Schermerhorn int delta) 265820a0307cSWu Fengguang { 2659b2261026SJoonsoo Kim int nr_nodes, node; 266020a0307cSWu Fengguang 266120a0307cSWu Fengguang VM_BUG_ON(delta != -1 && delta != 1); 266220a0307cSWu Fengguang 2663e8c5c824SLee Schermerhorn if (delta < 0) { 2664b2261026SJoonsoo Kim for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { 2665b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node]) 2666b2261026SJoonsoo Kim goto found; 2667b2261026SJoonsoo Kim } 2668b2261026SJoonsoo Kim } else { 2669b2261026SJoonsoo Kim for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 2670b2261026SJoonsoo Kim if (h->surplus_huge_pages_node[node] < 2671b2261026SJoonsoo Kim h->nr_huge_pages_node[node]) 2672b2261026SJoonsoo Kim goto found; 2673e8c5c824SLee Schermerhorn } 26749a76db09SLee Schermerhorn } 2675b2261026SJoonsoo Kim return 0; 267620a0307cSWu Fengguang 2677b2261026SJoonsoo Kim found: 267820a0307cSWu Fengguang h->surplus_huge_pages += delta; 2679b2261026SJoonsoo Kim h->surplus_huge_pages_node[node] += delta; 2680b2261026SJoonsoo Kim return 1; 268120a0307cSWu Fengguang } 268220a0307cSWu Fengguang 2683a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 2684fd875dcaSMike Kravetz static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, 26856ae11b27SLee Schermerhorn nodemask_t *nodes_allowed) 26861da177e4SLinus Torvalds { 26877893d1d5SAdam Litke unsigned long min_count, ret; 2688f60858f9SMike Kravetz NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL); 2689f60858f9SMike Kravetz 2690f60858f9SMike Kravetz /* 2691f60858f9SMike Kravetz * Bit mask controlling how hard we retry per-node allocations. 2692f60858f9SMike Kravetz * If we can not allocate the bit mask, do not attempt to allocate 2693f60858f9SMike Kravetz * the requested huge pages. 2694f60858f9SMike Kravetz */ 2695f60858f9SMike Kravetz if (node_alloc_noretry) 2696f60858f9SMike Kravetz nodes_clear(*node_alloc_noretry); 2697f60858f9SMike Kravetz else 2698f60858f9SMike Kravetz return -ENOMEM; 26991da177e4SLinus Torvalds 27004eb0716eSAlexandre Ghiti spin_lock(&hugetlb_lock); 27014eb0716eSAlexandre Ghiti 27024eb0716eSAlexandre Ghiti /* 2703fd875dcaSMike Kravetz * Check for a node specific request. 2704fd875dcaSMike Kravetz * Changing node specific huge page count may require a corresponding 2705fd875dcaSMike Kravetz * change to the global count. In any case, the passed node mask 2706fd875dcaSMike Kravetz * (nodes_allowed) will restrict alloc/free to the specified node. 2707fd875dcaSMike Kravetz */ 2708fd875dcaSMike Kravetz if (nid != NUMA_NO_NODE) { 2709fd875dcaSMike Kravetz unsigned long old_count = count; 2710fd875dcaSMike Kravetz 2711fd875dcaSMike Kravetz count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; 2712fd875dcaSMike Kravetz /* 2713fd875dcaSMike Kravetz * User may have specified a large count value which caused the 2714fd875dcaSMike Kravetz * above calculation to overflow. In this case, they wanted 2715fd875dcaSMike Kravetz * to allocate as many huge pages as possible. Set count to 2716fd875dcaSMike Kravetz * largest possible value to align with their intention. 2717fd875dcaSMike Kravetz */ 2718fd875dcaSMike Kravetz if (count < old_count) 2719fd875dcaSMike Kravetz count = ULONG_MAX; 2720fd875dcaSMike Kravetz } 2721fd875dcaSMike Kravetz 2722fd875dcaSMike Kravetz /* 27234eb0716eSAlexandre Ghiti * Gigantic pages runtime allocation depend on the capability for large 27244eb0716eSAlexandre Ghiti * page range allocation. 27254eb0716eSAlexandre Ghiti * If the system does not provide this feature, return an error when 27264eb0716eSAlexandre Ghiti * the user tries to allocate gigantic pages but let the user free the 27274eb0716eSAlexandre Ghiti * boottime allocated gigantic pages. 27284eb0716eSAlexandre Ghiti */ 27294eb0716eSAlexandre Ghiti if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) { 27304eb0716eSAlexandre Ghiti if (count > persistent_huge_pages(h)) { 27314eb0716eSAlexandre Ghiti spin_unlock(&hugetlb_lock); 2732f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 27334eb0716eSAlexandre Ghiti return -EINVAL; 27344eb0716eSAlexandre Ghiti } 27354eb0716eSAlexandre Ghiti /* Fall through to decrease pool */ 27364eb0716eSAlexandre Ghiti } 2737aa888a74SAndi Kleen 27387893d1d5SAdam Litke /* 27397893d1d5SAdam Litke * Increase the pool size 27407893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 27417893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 2742d1c3fb1fSNishanth Aravamudan * 27430c397daeSMichal Hocko * We might race with alloc_surplus_huge_page() here and be unable 2744d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 2745d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 2746d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 2747d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 27487893d1d5SAdam Litke */ 2749a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 27506ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, -1)) 27517893d1d5SAdam Litke break; 27527893d1d5SAdam Litke } 27537893d1d5SAdam Litke 2754a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 27557893d1d5SAdam Litke /* 27567893d1d5SAdam Litke * If this allocation races such that we no longer need the 27577893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 27587893d1d5SAdam Litke * and reducing the surplus. 27597893d1d5SAdam Litke */ 27607893d1d5SAdam Litke spin_unlock(&hugetlb_lock); 2761649920c6SJia He 2762649920c6SJia He /* yield cpu to avoid soft lockup */ 2763649920c6SJia He cond_resched(); 2764649920c6SJia He 2765f60858f9SMike Kravetz ret = alloc_pool_huge_page(h, nodes_allowed, 2766f60858f9SMike Kravetz node_alloc_noretry); 27677893d1d5SAdam Litke spin_lock(&hugetlb_lock); 27687893d1d5SAdam Litke if (!ret) 27697893d1d5SAdam Litke goto out; 27707893d1d5SAdam Litke 2771536240f2SMel Gorman /* Bail for signals. Probably ctrl-c from user */ 2772536240f2SMel Gorman if (signal_pending(current)) 2773536240f2SMel Gorman goto out; 27747893d1d5SAdam Litke } 27757893d1d5SAdam Litke 27767893d1d5SAdam Litke /* 27777893d1d5SAdam Litke * Decrease the pool size 27787893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 27797893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 27807893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 27817893d1d5SAdam Litke * to the desired size as pages become free. 2782d1c3fb1fSNishanth Aravamudan * 2783d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 2784d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 2785d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 27860c397daeSMichal Hocko * alloc_surplus_huge_page() is checking the global counter, 2787d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 2788d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 2789d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 27907893d1d5SAdam Litke */ 2791a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 27926b0c880dSAdam Litke min_count = max(count, min_count); 27936ae11b27SLee Schermerhorn try_to_free_low(h, min_count, nodes_allowed); 2794a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 27956ae11b27SLee Schermerhorn if (!free_pool_huge_page(h, nodes_allowed, 0)) 27961da177e4SLinus Torvalds break; 279755f67141SMizuma, Masayoshi cond_resched_lock(&hugetlb_lock); 27981da177e4SLinus Torvalds } 2799a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 28006ae11b27SLee Schermerhorn if (!adjust_pool_surplus(h, nodes_allowed, 1)) 28017893d1d5SAdam Litke break; 28027893d1d5SAdam Litke } 28037893d1d5SAdam Litke out: 28044eb0716eSAlexandre Ghiti h->max_huge_pages = persistent_huge_pages(h); 28051da177e4SLinus Torvalds spin_unlock(&hugetlb_lock); 28064eb0716eSAlexandre Ghiti 2807f60858f9SMike Kravetz NODEMASK_FREE(node_alloc_noretry); 2808f60858f9SMike Kravetz 28094eb0716eSAlexandre Ghiti return 0; 28101da177e4SLinus Torvalds } 28111da177e4SLinus Torvalds 2812a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 2813a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 2814a3437870SNishanth Aravamudan 2815a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 2816a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = \ 2817a3437870SNishanth Aravamudan __ATTR(_name, 0644, _name##_show, _name##_store) 2818a3437870SNishanth Aravamudan 2819a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 2820a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 2821a3437870SNishanth Aravamudan 28229a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); 28239a305230SLee Schermerhorn 28249a305230SLee Schermerhorn static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) 2825a3437870SNishanth Aravamudan { 2826a3437870SNishanth Aravamudan int i; 28279a305230SLee Schermerhorn 2828a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 28299a305230SLee Schermerhorn if (hstate_kobjs[i] == kobj) { 28309a305230SLee Schermerhorn if (nidp) 28319a305230SLee Schermerhorn *nidp = NUMA_NO_NODE; 2832a3437870SNishanth Aravamudan return &hstates[i]; 28339a305230SLee Schermerhorn } 28349a305230SLee Schermerhorn 28359a305230SLee Schermerhorn return kobj_to_node_hstate(kobj, nidp); 2836a3437870SNishanth Aravamudan } 2837a3437870SNishanth Aravamudan 283806808b08SLee Schermerhorn static ssize_t nr_hugepages_show_common(struct kobject *kobj, 2839a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2840a3437870SNishanth Aravamudan { 28419a305230SLee Schermerhorn struct hstate *h; 28429a305230SLee Schermerhorn unsigned long nr_huge_pages; 28439a305230SLee Schermerhorn int nid; 28449a305230SLee Schermerhorn 28459a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 28469a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 28479a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages; 28489a305230SLee Schermerhorn else 28499a305230SLee Schermerhorn nr_huge_pages = h->nr_huge_pages_node[nid]; 28509a305230SLee Schermerhorn 28519a305230SLee Schermerhorn return sprintf(buf, "%lu\n", nr_huge_pages); 2852a3437870SNishanth Aravamudan } 2853adbe8726SEric B Munson 2854238d3c13SDavid Rientjes static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, 2855238d3c13SDavid Rientjes struct hstate *h, int nid, 2856238d3c13SDavid Rientjes unsigned long count, size_t len) 2857a3437870SNishanth Aravamudan { 2858a3437870SNishanth Aravamudan int err; 28592d0adf7eSOscar Salvador nodemask_t nodes_allowed, *n_mask; 2860a3437870SNishanth Aravamudan 28612d0adf7eSOscar Salvador if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported()) 28622d0adf7eSOscar Salvador return -EINVAL; 2863adbe8726SEric B Munson 28649a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) { 28659a305230SLee Schermerhorn /* 28669a305230SLee Schermerhorn * global hstate attribute 28679a305230SLee Schermerhorn */ 28689a305230SLee Schermerhorn if (!(obey_mempolicy && 28692d0adf7eSOscar Salvador init_nodemask_of_mempolicy(&nodes_allowed))) 28702d0adf7eSOscar Salvador n_mask = &node_states[N_MEMORY]; 28712d0adf7eSOscar Salvador else 28722d0adf7eSOscar Salvador n_mask = &nodes_allowed; 28732d0adf7eSOscar Salvador } else { 28749a305230SLee Schermerhorn /* 2875fd875dcaSMike Kravetz * Node specific request. count adjustment happens in 2876fd875dcaSMike Kravetz * set_max_huge_pages() after acquiring hugetlb_lock. 28779a305230SLee Schermerhorn */ 28782d0adf7eSOscar Salvador init_nodemask_of_node(&nodes_allowed, nid); 28792d0adf7eSOscar Salvador n_mask = &nodes_allowed; 2880fd875dcaSMike Kravetz } 28819a305230SLee Schermerhorn 28822d0adf7eSOscar Salvador err = set_max_huge_pages(h, count, nid, n_mask); 288306808b08SLee Schermerhorn 28844eb0716eSAlexandre Ghiti return err ? err : len; 288506808b08SLee Schermerhorn } 288606808b08SLee Schermerhorn 2887238d3c13SDavid Rientjes static ssize_t nr_hugepages_store_common(bool obey_mempolicy, 2888238d3c13SDavid Rientjes struct kobject *kobj, const char *buf, 2889238d3c13SDavid Rientjes size_t len) 2890238d3c13SDavid Rientjes { 2891238d3c13SDavid Rientjes struct hstate *h; 2892238d3c13SDavid Rientjes unsigned long count; 2893238d3c13SDavid Rientjes int nid; 2894238d3c13SDavid Rientjes int err; 2895238d3c13SDavid Rientjes 2896238d3c13SDavid Rientjes err = kstrtoul(buf, 10, &count); 2897238d3c13SDavid Rientjes if (err) 2898238d3c13SDavid Rientjes return err; 2899238d3c13SDavid Rientjes 2900238d3c13SDavid Rientjes h = kobj_to_hstate(kobj, &nid); 2901238d3c13SDavid Rientjes return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); 2902238d3c13SDavid Rientjes } 2903238d3c13SDavid Rientjes 290406808b08SLee Schermerhorn static ssize_t nr_hugepages_show(struct kobject *kobj, 290506808b08SLee Schermerhorn struct kobj_attribute *attr, char *buf) 290606808b08SLee Schermerhorn { 290706808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 290806808b08SLee Schermerhorn } 290906808b08SLee Schermerhorn 291006808b08SLee Schermerhorn static ssize_t nr_hugepages_store(struct kobject *kobj, 291106808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 291206808b08SLee Schermerhorn { 2913238d3c13SDavid Rientjes return nr_hugepages_store_common(false, kobj, buf, len); 2914a3437870SNishanth Aravamudan } 2915a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 2916a3437870SNishanth Aravamudan 291706808b08SLee Schermerhorn #ifdef CONFIG_NUMA 291806808b08SLee Schermerhorn 291906808b08SLee Schermerhorn /* 292006808b08SLee Schermerhorn * hstate attribute for optionally mempolicy-based constraint on persistent 292106808b08SLee Schermerhorn * huge page alloc/free. 292206808b08SLee Schermerhorn */ 292306808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, 292406808b08SLee Schermerhorn struct kobj_attribute *attr, char *buf) 292506808b08SLee Schermerhorn { 292606808b08SLee Schermerhorn return nr_hugepages_show_common(kobj, attr, buf); 292706808b08SLee Schermerhorn } 292806808b08SLee Schermerhorn 292906808b08SLee Schermerhorn static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, 293006808b08SLee Schermerhorn struct kobj_attribute *attr, const char *buf, size_t len) 293106808b08SLee Schermerhorn { 2932238d3c13SDavid Rientjes return nr_hugepages_store_common(true, kobj, buf, len); 293306808b08SLee Schermerhorn } 293406808b08SLee Schermerhorn HSTATE_ATTR(nr_hugepages_mempolicy); 293506808b08SLee Schermerhorn #endif 293606808b08SLee Schermerhorn 293706808b08SLee Schermerhorn 2938a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 2939a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2940a3437870SNishanth Aravamudan { 29419a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 2942a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); 2943a3437870SNishanth Aravamudan } 2944adbe8726SEric B Munson 2945a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 2946a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 2947a3437870SNishanth Aravamudan { 2948a3437870SNishanth Aravamudan int err; 2949a3437870SNishanth Aravamudan unsigned long input; 29509a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 2951a3437870SNishanth Aravamudan 2952bae7f4aeSLuiz Capitulino if (hstate_is_gigantic(h)) 2953adbe8726SEric B Munson return -EINVAL; 2954adbe8726SEric B Munson 29553dbb95f7SJingoo Han err = kstrtoul(buf, 10, &input); 2956a3437870SNishanth Aravamudan if (err) 295773ae31e5SEric B Munson return err; 2958a3437870SNishanth Aravamudan 2959a3437870SNishanth Aravamudan spin_lock(&hugetlb_lock); 2960a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 2961a3437870SNishanth Aravamudan spin_unlock(&hugetlb_lock); 2962a3437870SNishanth Aravamudan 2963a3437870SNishanth Aravamudan return count; 2964a3437870SNishanth Aravamudan } 2965a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 2966a3437870SNishanth Aravamudan 2967a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 2968a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2969a3437870SNishanth Aravamudan { 29709a305230SLee Schermerhorn struct hstate *h; 29719a305230SLee Schermerhorn unsigned long free_huge_pages; 29729a305230SLee Schermerhorn int nid; 29739a305230SLee Schermerhorn 29749a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 29759a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 29769a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages; 29779a305230SLee Schermerhorn else 29789a305230SLee Schermerhorn free_huge_pages = h->free_huge_pages_node[nid]; 29799a305230SLee Schermerhorn 29809a305230SLee Schermerhorn return sprintf(buf, "%lu\n", free_huge_pages); 2981a3437870SNishanth Aravamudan } 2982a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 2983a3437870SNishanth Aravamudan 2984a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 2985a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2986a3437870SNishanth Aravamudan { 29879a305230SLee Schermerhorn struct hstate *h = kobj_to_hstate(kobj, NULL); 2988a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->resv_huge_pages); 2989a3437870SNishanth Aravamudan } 2990a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 2991a3437870SNishanth Aravamudan 2992a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 2993a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 2994a3437870SNishanth Aravamudan { 29959a305230SLee Schermerhorn struct hstate *h; 29969a305230SLee Schermerhorn unsigned long surplus_huge_pages; 29979a305230SLee Schermerhorn int nid; 29989a305230SLee Schermerhorn 29999a305230SLee Schermerhorn h = kobj_to_hstate(kobj, &nid); 30009a305230SLee Schermerhorn if (nid == NUMA_NO_NODE) 30019a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages; 30029a305230SLee Schermerhorn else 30039a305230SLee Schermerhorn surplus_huge_pages = h->surplus_huge_pages_node[nid]; 30049a305230SLee Schermerhorn 30059a305230SLee Schermerhorn return sprintf(buf, "%lu\n", surplus_huge_pages); 3006a3437870SNishanth Aravamudan } 3007a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 3008a3437870SNishanth Aravamudan 3009a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 3010a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 3011a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 3012a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 3013a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 3014a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 301506808b08SLee Schermerhorn #ifdef CONFIG_NUMA 301606808b08SLee Schermerhorn &nr_hugepages_mempolicy_attr.attr, 301706808b08SLee Schermerhorn #endif 3018a3437870SNishanth Aravamudan NULL, 3019a3437870SNishanth Aravamudan }; 3020a3437870SNishanth Aravamudan 302167e5ed96SArvind Yadav static const struct attribute_group hstate_attr_group = { 3022a3437870SNishanth Aravamudan .attrs = hstate_attrs, 3023a3437870SNishanth Aravamudan }; 3024a3437870SNishanth Aravamudan 3025094e9539SJeff Mahoney static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, 30269a305230SLee Schermerhorn struct kobject **hstate_kobjs, 302767e5ed96SArvind Yadav const struct attribute_group *hstate_attr_group) 3028a3437870SNishanth Aravamudan { 3029a3437870SNishanth Aravamudan int retval; 3030972dc4deSAneesh Kumar K.V int hi = hstate_index(h); 3031a3437870SNishanth Aravamudan 30329a305230SLee Schermerhorn hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); 30339a305230SLee Schermerhorn if (!hstate_kobjs[hi]) 3034a3437870SNishanth Aravamudan return -ENOMEM; 3035a3437870SNishanth Aravamudan 30369a305230SLee Schermerhorn retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); 3037a3437870SNishanth Aravamudan if (retval) 30389a305230SLee Schermerhorn kobject_put(hstate_kobjs[hi]); 3039a3437870SNishanth Aravamudan 3040a3437870SNishanth Aravamudan return retval; 3041a3437870SNishanth Aravamudan } 3042a3437870SNishanth Aravamudan 3043a3437870SNishanth Aravamudan static void __init hugetlb_sysfs_init(void) 3044a3437870SNishanth Aravamudan { 3045a3437870SNishanth Aravamudan struct hstate *h; 3046a3437870SNishanth Aravamudan int err; 3047a3437870SNishanth Aravamudan 3048a3437870SNishanth Aravamudan hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 3049a3437870SNishanth Aravamudan if (!hugepages_kobj) 3050a3437870SNishanth Aravamudan return; 3051a3437870SNishanth Aravamudan 3052a3437870SNishanth Aravamudan for_each_hstate(h) { 30539a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, 30549a305230SLee Schermerhorn hstate_kobjs, &hstate_attr_group); 3055a3437870SNishanth Aravamudan if (err) 3056282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s", h->name); 3057a3437870SNishanth Aravamudan } 3058a3437870SNishanth Aravamudan } 3059a3437870SNishanth Aravamudan 30609a305230SLee Schermerhorn #ifdef CONFIG_NUMA 30619a305230SLee Schermerhorn 30629a305230SLee Schermerhorn /* 30639a305230SLee Schermerhorn * node_hstate/s - associate per node hstate attributes, via their kobjects, 306410fbcf4cSKay Sievers * with node devices in node_devices[] using a parallel array. The array 306510fbcf4cSKay Sievers * index of a node device or _hstate == node id. 306610fbcf4cSKay Sievers * This is here to avoid any static dependency of the node device driver, in 30679a305230SLee Schermerhorn * the base kernel, on the hugetlb module. 30689a305230SLee Schermerhorn */ 30699a305230SLee Schermerhorn struct node_hstate { 30709a305230SLee Schermerhorn struct kobject *hugepages_kobj; 30719a305230SLee Schermerhorn struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 30729a305230SLee Schermerhorn }; 3073b4e289a6SAlexander Kuleshov static struct node_hstate node_hstates[MAX_NUMNODES]; 30749a305230SLee Schermerhorn 30759a305230SLee Schermerhorn /* 307610fbcf4cSKay Sievers * A subset of global hstate attributes for node devices 30779a305230SLee Schermerhorn */ 30789a305230SLee Schermerhorn static struct attribute *per_node_hstate_attrs[] = { 30799a305230SLee Schermerhorn &nr_hugepages_attr.attr, 30809a305230SLee Schermerhorn &free_hugepages_attr.attr, 30819a305230SLee Schermerhorn &surplus_hugepages_attr.attr, 30829a305230SLee Schermerhorn NULL, 30839a305230SLee Schermerhorn }; 30849a305230SLee Schermerhorn 308567e5ed96SArvind Yadav static const struct attribute_group per_node_hstate_attr_group = { 30869a305230SLee Schermerhorn .attrs = per_node_hstate_attrs, 30879a305230SLee Schermerhorn }; 30889a305230SLee Schermerhorn 30899a305230SLee Schermerhorn /* 309010fbcf4cSKay Sievers * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. 30919a305230SLee Schermerhorn * Returns node id via non-NULL nidp. 30929a305230SLee Schermerhorn */ 30939a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 30949a305230SLee Schermerhorn { 30959a305230SLee Schermerhorn int nid; 30969a305230SLee Schermerhorn 30979a305230SLee Schermerhorn for (nid = 0; nid < nr_node_ids; nid++) { 30989a305230SLee Schermerhorn struct node_hstate *nhs = &node_hstates[nid]; 30999a305230SLee Schermerhorn int i; 31009a305230SLee Schermerhorn for (i = 0; i < HUGE_MAX_HSTATE; i++) 31019a305230SLee Schermerhorn if (nhs->hstate_kobjs[i] == kobj) { 31029a305230SLee Schermerhorn if (nidp) 31039a305230SLee Schermerhorn *nidp = nid; 31049a305230SLee Schermerhorn return &hstates[i]; 31059a305230SLee Schermerhorn } 31069a305230SLee Schermerhorn } 31079a305230SLee Schermerhorn 31089a305230SLee Schermerhorn BUG(); 31099a305230SLee Schermerhorn return NULL; 31109a305230SLee Schermerhorn } 31119a305230SLee Schermerhorn 31129a305230SLee Schermerhorn /* 311310fbcf4cSKay Sievers * Unregister hstate attributes from a single node device. 31149a305230SLee Schermerhorn * No-op if no hstate attributes attached. 31159a305230SLee Schermerhorn */ 31163cd8b44fSClaudiu Ghioc static void hugetlb_unregister_node(struct node *node) 31179a305230SLee Schermerhorn { 31189a305230SLee Schermerhorn struct hstate *h; 311910fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 31209a305230SLee Schermerhorn 31219a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 31229b5e5d0fSLee Schermerhorn return; /* no hstate attributes */ 31239a305230SLee Schermerhorn 3124972dc4deSAneesh Kumar K.V for_each_hstate(h) { 3125972dc4deSAneesh Kumar K.V int idx = hstate_index(h); 3126972dc4deSAneesh Kumar K.V if (nhs->hstate_kobjs[idx]) { 3127972dc4deSAneesh Kumar K.V kobject_put(nhs->hstate_kobjs[idx]); 3128972dc4deSAneesh Kumar K.V nhs->hstate_kobjs[idx] = NULL; 3129972dc4deSAneesh Kumar K.V } 31309a305230SLee Schermerhorn } 31319a305230SLee Schermerhorn 31329a305230SLee Schermerhorn kobject_put(nhs->hugepages_kobj); 31339a305230SLee Schermerhorn nhs->hugepages_kobj = NULL; 31349a305230SLee Schermerhorn } 31359a305230SLee Schermerhorn 31369a305230SLee Schermerhorn 31379a305230SLee Schermerhorn /* 313810fbcf4cSKay Sievers * Register hstate attributes for a single node device. 31399a305230SLee Schermerhorn * No-op if attributes already registered. 31409a305230SLee Schermerhorn */ 31413cd8b44fSClaudiu Ghioc static void hugetlb_register_node(struct node *node) 31429a305230SLee Schermerhorn { 31439a305230SLee Schermerhorn struct hstate *h; 314410fbcf4cSKay Sievers struct node_hstate *nhs = &node_hstates[node->dev.id]; 31459a305230SLee Schermerhorn int err; 31469a305230SLee Schermerhorn 31479a305230SLee Schermerhorn if (nhs->hugepages_kobj) 31489a305230SLee Schermerhorn return; /* already allocated */ 31499a305230SLee Schermerhorn 31509a305230SLee Schermerhorn nhs->hugepages_kobj = kobject_create_and_add("hugepages", 315110fbcf4cSKay Sievers &node->dev.kobj); 31529a305230SLee Schermerhorn if (!nhs->hugepages_kobj) 31539a305230SLee Schermerhorn return; 31549a305230SLee Schermerhorn 31559a305230SLee Schermerhorn for_each_hstate(h) { 31569a305230SLee Schermerhorn err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, 31579a305230SLee Schermerhorn nhs->hstate_kobjs, 31589a305230SLee Schermerhorn &per_node_hstate_attr_group); 31599a305230SLee Schermerhorn if (err) { 3160282f4214SMike Kravetz pr_err("HugeTLB: Unable to add hstate %s for node %d\n", 316110fbcf4cSKay Sievers h->name, node->dev.id); 31629a305230SLee Schermerhorn hugetlb_unregister_node(node); 31639a305230SLee Schermerhorn break; 31649a305230SLee Schermerhorn } 31659a305230SLee Schermerhorn } 31669a305230SLee Schermerhorn } 31679a305230SLee Schermerhorn 31689a305230SLee Schermerhorn /* 31699b5e5d0fSLee Schermerhorn * hugetlb init time: register hstate attributes for all registered node 317010fbcf4cSKay Sievers * devices of nodes that have memory. All on-line nodes should have 317110fbcf4cSKay Sievers * registered their associated device by this time. 31729a305230SLee Schermerhorn */ 31737d9ca000SLuiz Capitulino static void __init hugetlb_register_all_nodes(void) 31749a305230SLee Schermerhorn { 31759a305230SLee Schermerhorn int nid; 31769a305230SLee Schermerhorn 31778cebfcd0SLai Jiangshan for_each_node_state(nid, N_MEMORY) { 31788732794bSWen Congyang struct node *node = node_devices[nid]; 317910fbcf4cSKay Sievers if (node->dev.id == nid) 31809a305230SLee Schermerhorn hugetlb_register_node(node); 31819a305230SLee Schermerhorn } 31829a305230SLee Schermerhorn 31839a305230SLee Schermerhorn /* 318410fbcf4cSKay Sievers * Let the node device driver know we're here so it can 31859a305230SLee Schermerhorn * [un]register hstate attributes on node hotplug. 31869a305230SLee Schermerhorn */ 31879a305230SLee Schermerhorn register_hugetlbfs_with_node(hugetlb_register_node, 31889a305230SLee Schermerhorn hugetlb_unregister_node); 31899a305230SLee Schermerhorn } 31909a305230SLee Schermerhorn #else /* !CONFIG_NUMA */ 31919a305230SLee Schermerhorn 31929a305230SLee Schermerhorn static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) 31939a305230SLee Schermerhorn { 31949a305230SLee Schermerhorn BUG(); 31959a305230SLee Schermerhorn if (nidp) 31969a305230SLee Schermerhorn *nidp = -1; 31979a305230SLee Schermerhorn return NULL; 31989a305230SLee Schermerhorn } 31999a305230SLee Schermerhorn 32009a305230SLee Schermerhorn static void hugetlb_register_all_nodes(void) { } 32019a305230SLee Schermerhorn 32029a305230SLee Schermerhorn #endif 32039a305230SLee Schermerhorn 3204a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 3205a3437870SNishanth Aravamudan { 32068382d914SDavidlohr Bueso int i; 32078382d914SDavidlohr Bueso 3208c2833a5bSMike Kravetz if (!hugepages_supported()) { 3209c2833a5bSMike Kravetz if (hugetlb_max_hstate || default_hstate_max_huge_pages) 3210c2833a5bSMike Kravetz pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n"); 32110ef89d25SBenjamin Herrenschmidt return 0; 3212d715cf80SLiam R. Howlett } 3213d715cf80SLiam R. Howlett 3214282f4214SMike Kravetz /* 3215282f4214SMike Kravetz * Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some 3216282f4214SMike Kravetz * architectures depend on setup being done here. 3217282f4214SMike Kravetz */ 3218a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 3219282f4214SMike Kravetz if (!parsed_default_hugepagesz) { 3220282f4214SMike Kravetz /* 3221282f4214SMike Kravetz * If we did not parse a default huge page size, set 3222282f4214SMike Kravetz * default_hstate_idx to HPAGE_SIZE hstate. And, if the 3223282f4214SMike Kravetz * number of huge pages for this default size was implicitly 3224282f4214SMike Kravetz * specified, set that here as well. 3225282f4214SMike Kravetz * Note that the implicit setting will overwrite an explicit 3226282f4214SMike Kravetz * setting. A warning will be printed in this case. 3227282f4214SMike Kravetz */ 3228282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(HPAGE_SIZE)); 3229f8b74815SVaishali Thakkar if (default_hstate_max_huge_pages) { 3230282f4214SMike Kravetz if (default_hstate.max_huge_pages) { 3231282f4214SMike Kravetz char buf[32]; 3232282f4214SMike Kravetz 3233282f4214SMike Kravetz string_get_size(huge_page_size(&default_hstate), 3234282f4214SMike Kravetz 1, STRING_UNITS_2, buf, 32); 3235282f4214SMike Kravetz pr_warn("HugeTLB: Ignoring hugepages=%lu associated with %s page size\n", 3236282f4214SMike Kravetz default_hstate.max_huge_pages, buf); 3237282f4214SMike Kravetz pr_warn("HugeTLB: Using hugepages=%lu for number of default huge pages\n", 3238282f4214SMike Kravetz default_hstate_max_huge_pages); 3239282f4214SMike Kravetz } 3240282f4214SMike Kravetz default_hstate.max_huge_pages = 3241282f4214SMike Kravetz default_hstate_max_huge_pages; 3242282f4214SMike Kravetz } 3243f8b74815SVaishali Thakkar } 3244a3437870SNishanth Aravamudan 3245cf11e85fSRoman Gushchin hugetlb_cma_check(); 3246a3437870SNishanth Aravamudan hugetlb_init_hstates(); 3247aa888a74SAndi Kleen gather_bootmem_prealloc(); 3248a3437870SNishanth Aravamudan report_hugepages(); 3249a3437870SNishanth Aravamudan 3250a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 32519a305230SLee Schermerhorn hugetlb_register_all_nodes(); 32527179e7bfSJianguo Wu hugetlb_cgroup_file_init(); 32539a305230SLee Schermerhorn 32548382d914SDavidlohr Bueso #ifdef CONFIG_SMP 32558382d914SDavidlohr Bueso num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); 32568382d914SDavidlohr Bueso #else 32578382d914SDavidlohr Bueso num_fault_mutexes = 1; 32588382d914SDavidlohr Bueso #endif 3259c672c7f2SMike Kravetz hugetlb_fault_mutex_table = 32606da2ec56SKees Cook kmalloc_array(num_fault_mutexes, sizeof(struct mutex), 32616da2ec56SKees Cook GFP_KERNEL); 3262c672c7f2SMike Kravetz BUG_ON(!hugetlb_fault_mutex_table); 32638382d914SDavidlohr Bueso 32648382d914SDavidlohr Bueso for (i = 0; i < num_fault_mutexes; i++) 3265c672c7f2SMike Kravetz mutex_init(&hugetlb_fault_mutex_table[i]); 3266a3437870SNishanth Aravamudan return 0; 3267a3437870SNishanth Aravamudan } 32683e89e1c5SPaul Gortmaker subsys_initcall(hugetlb_init); 3269a3437870SNishanth Aravamudan 3270ae94da89SMike Kravetz /* Overwritten by architectures with more huge page sizes */ 3271ae94da89SMike Kravetz bool __init __attribute((weak)) arch_hugetlb_valid_size(unsigned long size) 32729fee021dSVaishali Thakkar { 3273ae94da89SMike Kravetz return size == HPAGE_SIZE; 32749fee021dSVaishali Thakkar } 32759fee021dSVaishali Thakkar 3276d00181b9SKirill A. Shutemov void __init hugetlb_add_hstate(unsigned int order) 3277a3437870SNishanth Aravamudan { 3278a3437870SNishanth Aravamudan struct hstate *h; 32798faa8b07SAndi Kleen unsigned long i; 32808faa8b07SAndi Kleen 3281a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 3282a3437870SNishanth Aravamudan return; 3283a3437870SNishanth Aravamudan } 328447d38344SAneesh Kumar K.V BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); 3285a3437870SNishanth Aravamudan BUG_ON(order == 0); 328647d38344SAneesh Kumar K.V h = &hstates[hugetlb_max_hstate++]; 3287a3437870SNishanth Aravamudan h->order = order; 3288a3437870SNishanth Aravamudan h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); 32898faa8b07SAndi Kleen h->nr_huge_pages = 0; 32908faa8b07SAndi Kleen h->free_huge_pages = 0; 32918faa8b07SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 32928faa8b07SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 32930edaecfaSAneesh Kumar K.V INIT_LIST_HEAD(&h->hugepage_activelist); 329454f18d35SAndrew Morton h->next_nid_to_alloc = first_memory_node; 329554f18d35SAndrew Morton h->next_nid_to_free = first_memory_node; 3296a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 3297a3437870SNishanth Aravamudan huge_page_size(h)/1024); 32988faa8b07SAndi Kleen 3299a3437870SNishanth Aravamudan parsed_hstate = h; 3300a3437870SNishanth Aravamudan } 3301a3437870SNishanth Aravamudan 3302282f4214SMike Kravetz /* 3303282f4214SMike Kravetz * hugepages command line processing 3304282f4214SMike Kravetz * hugepages normally follows a valid hugepagsz or default_hugepagsz 3305282f4214SMike Kravetz * specification. If not, ignore the hugepages value. hugepages can also 3306282f4214SMike Kravetz * be the first huge page command line option in which case it implicitly 3307282f4214SMike Kravetz * specifies the number of huge pages for the default size. 3308282f4214SMike Kravetz */ 3309282f4214SMike Kravetz static int __init hugepages_setup(char *s) 3310a3437870SNishanth Aravamudan { 3311a3437870SNishanth Aravamudan unsigned long *mhp; 33128faa8b07SAndi Kleen static unsigned long *last_mhp; 3313a3437870SNishanth Aravamudan 33149fee021dSVaishali Thakkar if (!parsed_valid_hugepagesz) { 3315282f4214SMike Kravetz pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s); 33169fee021dSVaishali Thakkar parsed_valid_hugepagesz = true; 3317282f4214SMike Kravetz return 0; 33189fee021dSVaishali Thakkar } 3319282f4214SMike Kravetz 3320a3437870SNishanth Aravamudan /* 3321282f4214SMike Kravetz * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter 3322282f4214SMike Kravetz * yet, so this hugepages= parameter goes to the "default hstate". 3323282f4214SMike Kravetz * Otherwise, it goes with the previously parsed hugepagesz or 3324282f4214SMike Kravetz * default_hugepagesz. 3325a3437870SNishanth Aravamudan */ 33269fee021dSVaishali Thakkar else if (!hugetlb_max_hstate) 3327a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 3328a3437870SNishanth Aravamudan else 3329a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 3330a3437870SNishanth Aravamudan 33318faa8b07SAndi Kleen if (mhp == last_mhp) { 3332282f4214SMike Kravetz pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s); 3333282f4214SMike Kravetz return 0; 33348faa8b07SAndi Kleen } 33358faa8b07SAndi Kleen 3336a3437870SNishanth Aravamudan if (sscanf(s, "%lu", mhp) <= 0) 3337a3437870SNishanth Aravamudan *mhp = 0; 3338a3437870SNishanth Aravamudan 33398faa8b07SAndi Kleen /* 33408faa8b07SAndi Kleen * Global state is always initialized later in hugetlb_init. 33418faa8b07SAndi Kleen * But we need to allocate >= MAX_ORDER hstates here early to still 33428faa8b07SAndi Kleen * use the bootmem allocator. 33438faa8b07SAndi Kleen */ 334447d38344SAneesh Kumar K.V if (hugetlb_max_hstate && parsed_hstate->order >= MAX_ORDER) 33458faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(parsed_hstate); 33468faa8b07SAndi Kleen 33478faa8b07SAndi Kleen last_mhp = mhp; 33488faa8b07SAndi Kleen 3349a3437870SNishanth Aravamudan return 1; 3350a3437870SNishanth Aravamudan } 3351282f4214SMike Kravetz __setup("hugepages=", hugepages_setup); 3352e11bfbfcSNick Piggin 3353282f4214SMike Kravetz /* 3354282f4214SMike Kravetz * hugepagesz command line processing 3355282f4214SMike Kravetz * A specific huge page size can only be specified once with hugepagesz. 3356282f4214SMike Kravetz * hugepagesz is followed by hugepages on the command line. The global 3357282f4214SMike Kravetz * variable 'parsed_valid_hugepagesz' is used to determine if prior 3358282f4214SMike Kravetz * hugepagesz argument was valid. 3359282f4214SMike Kravetz */ 3360359f2544SMike Kravetz static int __init hugepagesz_setup(char *s) 3361e11bfbfcSNick Piggin { 3362359f2544SMike Kravetz unsigned long size; 3363282f4214SMike Kravetz struct hstate *h; 3364282f4214SMike Kravetz 3365282f4214SMike Kravetz parsed_valid_hugepagesz = false; 3366359f2544SMike Kravetz size = (unsigned long)memparse(s, NULL); 3367359f2544SMike Kravetz 3368359f2544SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 3369282f4214SMike Kravetz pr_err("HugeTLB: unsupported hugepagesz=%s\n", s); 3370359f2544SMike Kravetz return 0; 3371359f2544SMike Kravetz } 3372359f2544SMike Kravetz 3373282f4214SMike Kravetz h = size_to_hstate(size); 3374282f4214SMike Kravetz if (h) { 3375282f4214SMike Kravetz /* 3376282f4214SMike Kravetz * hstate for this size already exists. This is normally 3377282f4214SMike Kravetz * an error, but is allowed if the existing hstate is the 3378282f4214SMike Kravetz * default hstate. More specifically, it is only allowed if 3379282f4214SMike Kravetz * the number of huge pages for the default hstate was not 3380282f4214SMike Kravetz * previously specified. 3381282f4214SMike Kravetz */ 3382282f4214SMike Kravetz if (!parsed_default_hugepagesz || h != &default_hstate || 3383282f4214SMike Kravetz default_hstate.max_huge_pages) { 3384282f4214SMike Kravetz pr_warn("HugeTLB: hugepagesz=%s specified twice, ignoring\n", s); 338538237830SMike Kravetz return 0; 338638237830SMike Kravetz } 338738237830SMike Kravetz 3388282f4214SMike Kravetz /* 3389282f4214SMike Kravetz * No need to call hugetlb_add_hstate() as hstate already 3390282f4214SMike Kravetz * exists. But, do set parsed_hstate so that a following 3391282f4214SMike Kravetz * hugepages= parameter will be applied to this hstate. 3392282f4214SMike Kravetz */ 3393282f4214SMike Kravetz parsed_hstate = h; 3394282f4214SMike Kravetz parsed_valid_hugepagesz = true; 3395e11bfbfcSNick Piggin return 1; 3396e11bfbfcSNick Piggin } 3397282f4214SMike Kravetz 3398359f2544SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 3399282f4214SMike Kravetz parsed_valid_hugepagesz = true; 3400359f2544SMike Kravetz return 1; 3401359f2544SMike Kravetz } 3402359f2544SMike Kravetz __setup("hugepagesz=", hugepagesz_setup); 3403359f2544SMike Kravetz 3404282f4214SMike Kravetz /* 3405282f4214SMike Kravetz * default_hugepagesz command line input 3406282f4214SMike Kravetz * Only one instance of default_hugepagesz allowed on command line. 3407282f4214SMike Kravetz */ 3408ae94da89SMike Kravetz static int __init default_hugepagesz_setup(char *s) 3409e11bfbfcSNick Piggin { 3410ae94da89SMike Kravetz unsigned long size; 3411ae94da89SMike Kravetz 3412282f4214SMike Kravetz parsed_valid_hugepagesz = false; 3413282f4214SMike Kravetz if (parsed_default_hugepagesz) { 3414282f4214SMike Kravetz pr_err("HugeTLB: default_hugepagesz previously specified, ignoring %s\n", s); 3415282f4214SMike Kravetz return 0; 3416282f4214SMike Kravetz } 3417282f4214SMike Kravetz 3418282f4214SMike Kravetz size = (unsigned long)memparse(s, NULL); 3419282f4214SMike Kravetz 3420282f4214SMike Kravetz if (!arch_hugetlb_valid_size(size)) { 3421282f4214SMike Kravetz pr_err("HugeTLB: unsupported default_hugepagesz=%s\n", s); 3422282f4214SMike Kravetz return 0; 3423282f4214SMike Kravetz } 3424282f4214SMike Kravetz 3425282f4214SMike Kravetz hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT); 3426282f4214SMike Kravetz parsed_valid_hugepagesz = true; 3427282f4214SMike Kravetz parsed_default_hugepagesz = true; 3428282f4214SMike Kravetz default_hstate_idx = hstate_index(size_to_hstate(size)); 3429282f4214SMike Kravetz 3430282f4214SMike Kravetz /* 3431282f4214SMike Kravetz * The number of default huge pages (for this size) could have been 3432282f4214SMike Kravetz * specified as the first hugetlb parameter: hugepages=X. If so, 3433282f4214SMike Kravetz * then default_hstate_max_huge_pages is set. If the default huge 3434282f4214SMike Kravetz * page size is gigantic (>= MAX_ORDER), then the pages must be 3435282f4214SMike Kravetz * allocated here from bootmem allocator. 3436282f4214SMike Kravetz */ 3437282f4214SMike Kravetz if (default_hstate_max_huge_pages) { 3438282f4214SMike Kravetz default_hstate.max_huge_pages = default_hstate_max_huge_pages; 3439282f4214SMike Kravetz if (hstate_is_gigantic(&default_hstate)) 3440282f4214SMike Kravetz hugetlb_hstate_alloc_pages(&default_hstate); 3441282f4214SMike Kravetz default_hstate_max_huge_pages = 0; 3442282f4214SMike Kravetz } 3443282f4214SMike Kravetz 3444e11bfbfcSNick Piggin return 1; 3445e11bfbfcSNick Piggin } 3446ae94da89SMike Kravetz __setup("default_hugepagesz=", default_hugepagesz_setup); 3447a3437870SNishanth Aravamudan 34488ca39e68SMuchun Song static unsigned int allowed_mems_nr(struct hstate *h) 34498a213460SNishanth Aravamudan { 34508a213460SNishanth Aravamudan int node; 34518a213460SNishanth Aravamudan unsigned int nr = 0; 34528ca39e68SMuchun Song nodemask_t *mpol_allowed; 34538ca39e68SMuchun Song unsigned int *array = h->free_huge_pages_node; 34548ca39e68SMuchun Song gfp_t gfp_mask = htlb_alloc_mask(h); 34558a213460SNishanth Aravamudan 34568ca39e68SMuchun Song mpol_allowed = policy_nodemask_current(gfp_mask); 34578ca39e68SMuchun Song 34588ca39e68SMuchun Song for_each_node_mask(node, cpuset_current_mems_allowed) { 34598ca39e68SMuchun Song if (!mpol_allowed || 34608ca39e68SMuchun Song (mpol_allowed && node_isset(node, *mpol_allowed))) 34618a213460SNishanth Aravamudan nr += array[node]; 34628ca39e68SMuchun Song } 34638a213460SNishanth Aravamudan 34648a213460SNishanth Aravamudan return nr; 34658a213460SNishanth Aravamudan } 34668a213460SNishanth Aravamudan 34678a213460SNishanth Aravamudan #ifdef CONFIG_SYSCTL 346817743798SMuchun Song static int proc_hugetlb_doulongvec_minmax(struct ctl_table *table, int write, 346917743798SMuchun Song void *buffer, size_t *length, 347017743798SMuchun Song loff_t *ppos, unsigned long *out) 347117743798SMuchun Song { 347217743798SMuchun Song struct ctl_table dup_table; 347317743798SMuchun Song 347417743798SMuchun Song /* 347517743798SMuchun Song * In order to avoid races with __do_proc_doulongvec_minmax(), we 347617743798SMuchun Song * can duplicate the @table and alter the duplicate of it. 347717743798SMuchun Song */ 347817743798SMuchun Song dup_table = *table; 347917743798SMuchun Song dup_table.data = out; 348017743798SMuchun Song 348117743798SMuchun Song return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos); 348217743798SMuchun Song } 348317743798SMuchun Song 348406808b08SLee Schermerhorn static int hugetlb_sysctl_handler_common(bool obey_mempolicy, 348506808b08SLee Schermerhorn struct ctl_table *table, int write, 348632927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 34871da177e4SLinus Torvalds { 3488e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 3489238d3c13SDavid Rientjes unsigned long tmp = h->max_huge_pages; 349008d4a246SMichal Hocko int ret; 3491e5ff2159SAndi Kleen 3492457c1b27SNishanth Aravamudan if (!hugepages_supported()) 349386613628SJan Stancek return -EOPNOTSUPP; 3494457c1b27SNishanth Aravamudan 349517743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 349617743798SMuchun Song &tmp); 349708d4a246SMichal Hocko if (ret) 349808d4a246SMichal Hocko goto out; 3499e5ff2159SAndi Kleen 3500238d3c13SDavid Rientjes if (write) 3501238d3c13SDavid Rientjes ret = __nr_hugepages_store_common(obey_mempolicy, h, 3502238d3c13SDavid Rientjes NUMA_NO_NODE, tmp, *length); 350308d4a246SMichal Hocko out: 350408d4a246SMichal Hocko return ret; 35051da177e4SLinus Torvalds } 3506396faf03SMel Gorman 350706808b08SLee Schermerhorn int hugetlb_sysctl_handler(struct ctl_table *table, int write, 350832927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 350906808b08SLee Schermerhorn { 351006808b08SLee Schermerhorn 351106808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(false, table, write, 351206808b08SLee Schermerhorn buffer, length, ppos); 351306808b08SLee Schermerhorn } 351406808b08SLee Schermerhorn 351506808b08SLee Schermerhorn #ifdef CONFIG_NUMA 351606808b08SLee Schermerhorn int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, 351732927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 351806808b08SLee Schermerhorn { 351906808b08SLee Schermerhorn return hugetlb_sysctl_handler_common(true, table, write, 352006808b08SLee Schermerhorn buffer, length, ppos); 352106808b08SLee Schermerhorn } 352206808b08SLee Schermerhorn #endif /* CONFIG_NUMA */ 352306808b08SLee Schermerhorn 3524a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 352532927393SChristoph Hellwig void *buffer, size_t *length, loff_t *ppos) 3526a3d0c6aaSNishanth Aravamudan { 3527a5516438SAndi Kleen struct hstate *h = &default_hstate; 3528e5ff2159SAndi Kleen unsigned long tmp; 352908d4a246SMichal Hocko int ret; 3530e5ff2159SAndi Kleen 3531457c1b27SNishanth Aravamudan if (!hugepages_supported()) 353286613628SJan Stancek return -EOPNOTSUPP; 3533457c1b27SNishanth Aravamudan 3534e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 3535e5ff2159SAndi Kleen 3536bae7f4aeSLuiz Capitulino if (write && hstate_is_gigantic(h)) 3537adbe8726SEric B Munson return -EINVAL; 3538adbe8726SEric B Munson 353917743798SMuchun Song ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos, 354017743798SMuchun Song &tmp); 354108d4a246SMichal Hocko if (ret) 354208d4a246SMichal Hocko goto out; 3543e5ff2159SAndi Kleen 3544e5ff2159SAndi Kleen if (write) { 3545064d9efeSNishanth Aravamudan spin_lock(&hugetlb_lock); 3546e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 3547a3d0c6aaSNishanth Aravamudan spin_unlock(&hugetlb_lock); 3548e5ff2159SAndi Kleen } 354908d4a246SMichal Hocko out: 355008d4a246SMichal Hocko return ret; 3551a3d0c6aaSNishanth Aravamudan } 3552a3d0c6aaSNishanth Aravamudan 35531da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 35541da177e4SLinus Torvalds 3555e1759c21SAlexey Dobriyan void hugetlb_report_meminfo(struct seq_file *m) 35561da177e4SLinus Torvalds { 3557fcb2b0c5SRoman Gushchin struct hstate *h; 3558fcb2b0c5SRoman Gushchin unsigned long total = 0; 3559fcb2b0c5SRoman Gushchin 3560457c1b27SNishanth Aravamudan if (!hugepages_supported()) 3561457c1b27SNishanth Aravamudan return; 3562fcb2b0c5SRoman Gushchin 3563fcb2b0c5SRoman Gushchin for_each_hstate(h) { 3564fcb2b0c5SRoman Gushchin unsigned long count = h->nr_huge_pages; 3565fcb2b0c5SRoman Gushchin 3566fcb2b0c5SRoman Gushchin total += (PAGE_SIZE << huge_page_order(h)) * count; 3567fcb2b0c5SRoman Gushchin 3568fcb2b0c5SRoman Gushchin if (h == &default_hstate) 3569e1759c21SAlexey Dobriyan seq_printf(m, 35701da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 35711da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 3572b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 35737893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 35744f98a2feSRik van Riel "Hugepagesize: %8lu kB\n", 3575fcb2b0c5SRoman Gushchin count, 3576a5516438SAndi Kleen h->free_huge_pages, 3577a5516438SAndi Kleen h->resv_huge_pages, 3578a5516438SAndi Kleen h->surplus_huge_pages, 3579fcb2b0c5SRoman Gushchin (PAGE_SIZE << huge_page_order(h)) / 1024); 3580fcb2b0c5SRoman Gushchin } 3581fcb2b0c5SRoman Gushchin 3582fcb2b0c5SRoman Gushchin seq_printf(m, "Hugetlb: %8lu kB\n", total / 1024); 35831da177e4SLinus Torvalds } 35841da177e4SLinus Torvalds 35851da177e4SLinus Torvalds int hugetlb_report_node_meminfo(int nid, char *buf) 35861da177e4SLinus Torvalds { 3587a5516438SAndi Kleen struct hstate *h = &default_hstate; 3588457c1b27SNishanth Aravamudan if (!hugepages_supported()) 3589457c1b27SNishanth Aravamudan return 0; 35901da177e4SLinus Torvalds return sprintf(buf, 35911da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 3592a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 3593a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 3594a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 3595a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 3596a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 35971da177e4SLinus Torvalds } 35981da177e4SLinus Torvalds 3599949f7ec5SDavid Rientjes void hugetlb_show_meminfo(void) 3600949f7ec5SDavid Rientjes { 3601949f7ec5SDavid Rientjes struct hstate *h; 3602949f7ec5SDavid Rientjes int nid; 3603949f7ec5SDavid Rientjes 3604457c1b27SNishanth Aravamudan if (!hugepages_supported()) 3605457c1b27SNishanth Aravamudan return; 3606457c1b27SNishanth Aravamudan 3607949f7ec5SDavid Rientjes for_each_node_state(nid, N_MEMORY) 3608949f7ec5SDavid Rientjes for_each_hstate(h) 3609949f7ec5SDavid Rientjes pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", 3610949f7ec5SDavid Rientjes nid, 3611949f7ec5SDavid Rientjes h->nr_huge_pages_node[nid], 3612949f7ec5SDavid Rientjes h->free_huge_pages_node[nid], 3613949f7ec5SDavid Rientjes h->surplus_huge_pages_node[nid], 3614949f7ec5SDavid Rientjes 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); 3615949f7ec5SDavid Rientjes } 3616949f7ec5SDavid Rientjes 36175d317b2bSNaoya Horiguchi void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm) 36185d317b2bSNaoya Horiguchi { 36195d317b2bSNaoya Horiguchi seq_printf(m, "HugetlbPages:\t%8lu kB\n", 36205d317b2bSNaoya Horiguchi atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10)); 36215d317b2bSNaoya Horiguchi } 36225d317b2bSNaoya Horiguchi 36231da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 36241da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 36251da177e4SLinus Torvalds { 3626d0028588SWanpeng Li struct hstate *h; 3627d0028588SWanpeng Li unsigned long nr_total_pages = 0; 3628d0028588SWanpeng Li 3629d0028588SWanpeng Li for_each_hstate(h) 3630d0028588SWanpeng Li nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); 3631d0028588SWanpeng Li return nr_total_pages; 36321da177e4SLinus Torvalds } 36331da177e4SLinus Torvalds 3634a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 3635fc1b8a73SMel Gorman { 3636fc1b8a73SMel Gorman int ret = -ENOMEM; 3637fc1b8a73SMel Gorman 3638fc1b8a73SMel Gorman spin_lock(&hugetlb_lock); 3639fc1b8a73SMel Gorman /* 3640fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 3641fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 3642fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 3643fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 3644fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 3645fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 3646fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 3647fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 3648fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 3649fc1b8a73SMel Gorman * 3650fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 3651fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 3652fc1b8a73SMel Gorman * we fall back to check against current free page availability as 3653fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 3654fc1b8a73SMel Gorman * semantics that cpuset has. 36558ca39e68SMuchun Song * 36568ca39e68SMuchun Song * Apart from cpuset, we also have memory policy mechanism that 36578ca39e68SMuchun Song * also determines from which node the kernel will allocate memory 36588ca39e68SMuchun Song * in a NUMA system. So similar to cpuset, we also should consider 36598ca39e68SMuchun Song * the memory policy of the current task. Similar to the description 36608ca39e68SMuchun Song * above. 3661fc1b8a73SMel Gorman */ 3662fc1b8a73SMel Gorman if (delta > 0) { 3663a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 3664fc1b8a73SMel Gorman goto out; 3665fc1b8a73SMel Gorman 36668ca39e68SMuchun Song if (delta > allowed_mems_nr(h)) { 3667a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 3668fc1b8a73SMel Gorman goto out; 3669fc1b8a73SMel Gorman } 3670fc1b8a73SMel Gorman } 3671fc1b8a73SMel Gorman 3672fc1b8a73SMel Gorman ret = 0; 3673fc1b8a73SMel Gorman if (delta < 0) 3674a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 3675fc1b8a73SMel Gorman 3676fc1b8a73SMel Gorman out: 3677fc1b8a73SMel Gorman spin_unlock(&hugetlb_lock); 3678fc1b8a73SMel Gorman return ret; 3679fc1b8a73SMel Gorman } 3680fc1b8a73SMel Gorman 368184afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 368284afd99bSAndy Whitcroft { 3683f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 368484afd99bSAndy Whitcroft 368584afd99bSAndy Whitcroft /* 368684afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 368784afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 368884afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 368925985edcSLucas De Marchi * has a reference to the reservation map it cannot disappear until 369084afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 369184afd99bSAndy Whitcroft * new reference here without additional locking. 369284afd99bSAndy Whitcroft */ 36934e35f483SJoonsoo Kim if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 3694f522c3acSJoonsoo Kim kref_get(&resv->refs); 369584afd99bSAndy Whitcroft } 369684afd99bSAndy Whitcroft 3697a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 3698a1e78772SMel Gorman { 3699a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 3700f522c3acSJoonsoo Kim struct resv_map *resv = vma_resv_map(vma); 370190481622SDavid Gibson struct hugepage_subpool *spool = subpool_vma(vma); 37024e35f483SJoonsoo Kim unsigned long reserve, start, end; 37031c5ecae3SMike Kravetz long gbl_reserve; 370484afd99bSAndy Whitcroft 37054e35f483SJoonsoo Kim if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 37064e35f483SJoonsoo Kim return; 37074e35f483SJoonsoo Kim 3708a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 3709a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 371084afd99bSAndy Whitcroft 37114e35f483SJoonsoo Kim reserve = (end - start) - region_count(resv, start, end); 3712e9fe92aeSMina Almasry hugetlb_cgroup_uncharge_counter(resv, start, end); 37137251ff78SAdam Litke if (reserve) { 37141c5ecae3SMike Kravetz /* 37151c5ecae3SMike Kravetz * Decrement reserve counts. The global reserve count may be 37161c5ecae3SMike Kravetz * adjusted if the subpool has a minimum size. 37171c5ecae3SMike Kravetz */ 37181c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, reserve); 37191c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 37207251ff78SAdam Litke } 3721e9fe92aeSMina Almasry 3722e9fe92aeSMina Almasry kref_put(&resv->refs, resv_map_release); 3723a1e78772SMel Gorman } 3724a1e78772SMel Gorman 372531383c68SDan Williams static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr) 372631383c68SDan Williams { 372731383c68SDan Williams if (addr & ~(huge_page_mask(hstate_vma(vma)))) 372831383c68SDan Williams return -EINVAL; 372931383c68SDan Williams return 0; 373031383c68SDan Williams } 373131383c68SDan Williams 373205ea8860SDan Williams static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma) 373305ea8860SDan Williams { 373405ea8860SDan Williams struct hstate *hstate = hstate_vma(vma); 373505ea8860SDan Williams 373605ea8860SDan Williams return 1UL << huge_page_shift(hstate); 373705ea8860SDan Williams } 373805ea8860SDan Williams 37391da177e4SLinus Torvalds /* 37401da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 37411da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 37421da177e4SLinus Torvalds * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get 37431da177e4SLinus Torvalds * this far. 37441da177e4SLinus Torvalds */ 3745b3ec9f33SSouptick Joarder static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf) 37461da177e4SLinus Torvalds { 37471da177e4SLinus Torvalds BUG(); 3748d0217ac0SNick Piggin return 0; 37491da177e4SLinus Torvalds } 37501da177e4SLinus Torvalds 3751eec3636aSJane Chu /* 3752eec3636aSJane Chu * When a new function is introduced to vm_operations_struct and added 3753eec3636aSJane Chu * to hugetlb_vm_ops, please consider adding the function to shm_vm_ops. 3754eec3636aSJane Chu * This is because under System V memory model, mappings created via 3755eec3636aSJane Chu * shmget/shmat with "huge page" specified are backed by hugetlbfs files, 3756eec3636aSJane Chu * their original vm_ops are overwritten with shm_vm_ops. 3757eec3636aSJane Chu */ 3758f0f37e2fSAlexey Dobriyan const struct vm_operations_struct hugetlb_vm_ops = { 3759d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 376084afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 3761a1e78772SMel Gorman .close = hugetlb_vm_op_close, 376231383c68SDan Williams .split = hugetlb_vm_op_split, 376305ea8860SDan Williams .pagesize = hugetlb_vm_op_pagesize, 37641da177e4SLinus Torvalds }; 37651da177e4SLinus Torvalds 37661e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 37671e8f889bSDavid Gibson int writable) 376863551ae0SDavid Gibson { 376963551ae0SDavid Gibson pte_t entry; 377063551ae0SDavid Gibson 37711e8f889bSDavid Gibson if (writable) { 3772106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, 3773106c992aSGerald Schaefer vma->vm_page_prot))); 377463551ae0SDavid Gibson } else { 3775106c992aSGerald Schaefer entry = huge_pte_wrprotect(mk_huge_pte(page, 3776106c992aSGerald Schaefer vma->vm_page_prot)); 377763551ae0SDavid Gibson } 377863551ae0SDavid Gibson entry = pte_mkyoung(entry); 377963551ae0SDavid Gibson entry = pte_mkhuge(entry); 3780d9ed9faaSChris Metcalf entry = arch_make_huge_pte(entry, vma, page, writable); 378163551ae0SDavid Gibson 378263551ae0SDavid Gibson return entry; 378363551ae0SDavid Gibson } 378463551ae0SDavid Gibson 37851e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 37861e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 37871e8f889bSDavid Gibson { 37881e8f889bSDavid Gibson pte_t entry; 37891e8f889bSDavid Gibson 3790106c992aSGerald Schaefer entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); 379132f84528SChris Forbes if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) 37924b3073e1SRussell King update_mmu_cache(vma, address, ptep); 37931e8f889bSDavid Gibson } 37941e8f889bSDavid Gibson 3795d5ed7444SAneesh Kumar K.V bool is_hugetlb_entry_migration(pte_t pte) 37964a705fefSNaoya Horiguchi { 37974a705fefSNaoya Horiguchi swp_entry_t swp; 37984a705fefSNaoya Horiguchi 37994a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 3800d5ed7444SAneesh Kumar K.V return false; 38014a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 3802d79d176aSBaoquan He if (is_migration_entry(swp)) 3803d5ed7444SAneesh Kumar K.V return true; 38044a705fefSNaoya Horiguchi else 3805d5ed7444SAneesh Kumar K.V return false; 38064a705fefSNaoya Horiguchi } 38074a705fefSNaoya Horiguchi 38083e5c3600SBaoquan He static bool is_hugetlb_entry_hwpoisoned(pte_t pte) 38094a705fefSNaoya Horiguchi { 38104a705fefSNaoya Horiguchi swp_entry_t swp; 38114a705fefSNaoya Horiguchi 38124a705fefSNaoya Horiguchi if (huge_pte_none(pte) || pte_present(pte)) 38133e5c3600SBaoquan He return false; 38144a705fefSNaoya Horiguchi swp = pte_to_swp_entry(pte); 3815d79d176aSBaoquan He if (is_hwpoison_entry(swp)) 38163e5c3600SBaoquan He return true; 38174a705fefSNaoya Horiguchi else 38183e5c3600SBaoquan He return false; 38194a705fefSNaoya Horiguchi } 38201e8f889bSDavid Gibson 382163551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 382263551ae0SDavid Gibson struct vm_area_struct *vma) 382363551ae0SDavid Gibson { 38245e41540cSMike Kravetz pte_t *src_pte, *dst_pte, entry, dst_entry; 382563551ae0SDavid Gibson struct page *ptepage; 38261c59827dSHugh Dickins unsigned long addr; 38271e8f889bSDavid Gibson int cow; 3828a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 3829a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 3830c0d0381aSMike Kravetz struct address_space *mapping = vma->vm_file->f_mapping; 3831ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 3832e8569dd2SAndreas Sandberg int ret = 0; 38331e8f889bSDavid Gibson 38341e8f889bSDavid Gibson cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; 383563551ae0SDavid Gibson 3836ac46d4f3SJérôme Glisse if (cow) { 38377269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, src, 38386f4f13e8SJérôme Glisse vma->vm_start, 3839ac46d4f3SJérôme Glisse vma->vm_end); 3840ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 3841c0d0381aSMike Kravetz } else { 3842c0d0381aSMike Kravetz /* 3843c0d0381aSMike Kravetz * For shared mappings i_mmap_rwsem must be held to call 3844c0d0381aSMike Kravetz * huge_pte_alloc, otherwise the returned ptep could go 3845c0d0381aSMike Kravetz * away if part of a shared pmd and another thread calls 3846c0d0381aSMike Kravetz * huge_pmd_unshare. 3847c0d0381aSMike Kravetz */ 3848c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 3849ac46d4f3SJérôme Glisse } 3850e8569dd2SAndreas Sandberg 3851a5516438SAndi Kleen for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { 3852cb900f41SKirill A. Shutemov spinlock_t *src_ptl, *dst_ptl; 38537868a208SPunit Agrawal src_pte = huge_pte_offset(src, addr, sz); 3854c74df32cSHugh Dickins if (!src_pte) 3855c74df32cSHugh Dickins continue; 3856a5516438SAndi Kleen dst_pte = huge_pte_alloc(dst, addr, sz); 3857e8569dd2SAndreas Sandberg if (!dst_pte) { 3858e8569dd2SAndreas Sandberg ret = -ENOMEM; 3859e8569dd2SAndreas Sandberg break; 3860e8569dd2SAndreas Sandberg } 3861c5c99429SLarry Woodman 38625e41540cSMike Kravetz /* 38635e41540cSMike Kravetz * If the pagetables are shared don't copy or take references. 38645e41540cSMike Kravetz * dst_pte == src_pte is the common case of src/dest sharing. 38655e41540cSMike Kravetz * 38665e41540cSMike Kravetz * However, src could have 'unshared' and dst shares with 38675e41540cSMike Kravetz * another vma. If dst_pte !none, this implies sharing. 38685e41540cSMike Kravetz * Check here before taking page table lock, and once again 38695e41540cSMike Kravetz * after taking the lock below. 38705e41540cSMike Kravetz */ 38715e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 38725e41540cSMike Kravetz if ((dst_pte == src_pte) || !huge_pte_none(dst_entry)) 3873c5c99429SLarry Woodman continue; 3874c5c99429SLarry Woodman 3875cb900f41SKirill A. Shutemov dst_ptl = huge_pte_lock(h, dst, dst_pte); 3876cb900f41SKirill A. Shutemov src_ptl = huge_pte_lockptr(h, src, src_pte); 3877cb900f41SKirill A. Shutemov spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 38784a705fefSNaoya Horiguchi entry = huge_ptep_get(src_pte); 38795e41540cSMike Kravetz dst_entry = huge_ptep_get(dst_pte); 38805e41540cSMike Kravetz if (huge_pte_none(entry) || !huge_pte_none(dst_entry)) { 38815e41540cSMike Kravetz /* 38825e41540cSMike Kravetz * Skip if src entry none. Also, skip in the 38835e41540cSMike Kravetz * unlikely case dst entry !none as this implies 38845e41540cSMike Kravetz * sharing with another vma. 38855e41540cSMike Kravetz */ 38864a705fefSNaoya Horiguchi ; 38874a705fefSNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_migration(entry) || 38884a705fefSNaoya Horiguchi is_hugetlb_entry_hwpoisoned(entry))) { 38894a705fefSNaoya Horiguchi swp_entry_t swp_entry = pte_to_swp_entry(entry); 38904a705fefSNaoya Horiguchi 38914a705fefSNaoya Horiguchi if (is_write_migration_entry(swp_entry) && cow) { 38924a705fefSNaoya Horiguchi /* 38934a705fefSNaoya Horiguchi * COW mappings require pages in both 38944a705fefSNaoya Horiguchi * parent and child to be set to read. 38954a705fefSNaoya Horiguchi */ 38964a705fefSNaoya Horiguchi make_migration_entry_read(&swp_entry); 38974a705fefSNaoya Horiguchi entry = swp_entry_to_pte(swp_entry); 3898e5251fd4SPunit Agrawal set_huge_swap_pte_at(src, addr, src_pte, 3899e5251fd4SPunit Agrawal entry, sz); 39004a705fefSNaoya Horiguchi } 3901e5251fd4SPunit Agrawal set_huge_swap_pte_at(dst, addr, dst_pte, entry, sz); 39024a705fefSNaoya Horiguchi } else { 390334ee645eSJoerg Roedel if (cow) { 39040f10851eSJérôme Glisse /* 39050f10851eSJérôme Glisse * No need to notify as we are downgrading page 39060f10851eSJérôme Glisse * table protection not changing it to point 39070f10851eSJérôme Glisse * to a new page. 39080f10851eSJérôme Glisse * 3909ad56b738SMike Rapoport * See Documentation/vm/mmu_notifier.rst 39100f10851eSJérôme Glisse */ 39117f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 391234ee645eSJoerg Roedel } 39130253d634SNaoya Horiguchi entry = huge_ptep_get(src_pte); 391463551ae0SDavid Gibson ptepage = pte_page(entry); 391563551ae0SDavid Gibson get_page(ptepage); 391653f9263bSKirill A. Shutemov page_dup_rmap(ptepage, true); 391763551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 39185d317b2bSNaoya Horiguchi hugetlb_count_add(pages_per_huge_page(h), dst); 39191c59827dSHugh Dickins } 3920cb900f41SKirill A. Shutemov spin_unlock(src_ptl); 3921cb900f41SKirill A. Shutemov spin_unlock(dst_ptl); 392263551ae0SDavid Gibson } 392363551ae0SDavid Gibson 3924e8569dd2SAndreas Sandberg if (cow) 3925ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 3926c0d0381aSMike Kravetz else 3927c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 3928e8569dd2SAndreas Sandberg 3929e8569dd2SAndreas Sandberg return ret; 393063551ae0SDavid Gibson } 393163551ae0SDavid Gibson 393224669e58SAneesh Kumar K.V void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, 393324669e58SAneesh Kumar K.V unsigned long start, unsigned long end, 393424669e58SAneesh Kumar K.V struct page *ref_page) 393563551ae0SDavid Gibson { 393663551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 393763551ae0SDavid Gibson unsigned long address; 3938c7546f8fSDavid Gibson pte_t *ptep; 393963551ae0SDavid Gibson pte_t pte; 3940cb900f41SKirill A. Shutemov spinlock_t *ptl; 394163551ae0SDavid Gibson struct page *page; 3942a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 3943a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 3944ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 3945a5516438SAndi Kleen 394663551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 3947a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 3948a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 394963551ae0SDavid Gibson 395007e32661SAneesh Kumar K.V /* 395107e32661SAneesh Kumar K.V * This is a hugetlb vma, all the pte entries should point 395207e32661SAneesh Kumar K.V * to huge page. 395307e32661SAneesh Kumar K.V */ 3954ed6a7935SPeter Zijlstra tlb_change_page_size(tlb, sz); 395524669e58SAneesh Kumar K.V tlb_start_vma(tlb, vma); 3956dff11abeSMike Kravetz 3957dff11abeSMike Kravetz /* 3958dff11abeSMike Kravetz * If sharing possible, alert mmu notifiers of worst case. 3959dff11abeSMike Kravetz */ 39606f4f13e8SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, mm, start, 39616f4f13e8SJérôme Glisse end); 3962ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 3963ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 3964569f48b8SHillf Danton address = start; 3965569f48b8SHillf Danton for (; address < end; address += sz) { 39667868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, sz); 3967c7546f8fSDavid Gibson if (!ptep) 3968c7546f8fSDavid Gibson continue; 3969c7546f8fSDavid Gibson 3970cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 397134ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 397231d49da5SAneesh Kumar K.V spin_unlock(ptl); 3973dff11abeSMike Kravetz /* 3974dff11abeSMike Kravetz * We just unmapped a page of PMDs by clearing a PUD. 3975dff11abeSMike Kravetz * The caller's TLB flush range should cover this area. 3976dff11abeSMike Kravetz */ 397731d49da5SAneesh Kumar K.V continue; 397831d49da5SAneesh Kumar K.V } 397939dde65cSChen, Kenneth W 39806629326bSHillf Danton pte = huge_ptep_get(ptep); 398131d49da5SAneesh Kumar K.V if (huge_pte_none(pte)) { 398231d49da5SAneesh Kumar K.V spin_unlock(ptl); 398331d49da5SAneesh Kumar K.V continue; 398431d49da5SAneesh Kumar K.V } 39856629326bSHillf Danton 39866629326bSHillf Danton /* 39879fbc1f63SNaoya Horiguchi * Migrating hugepage or HWPoisoned hugepage is already 39889fbc1f63SNaoya Horiguchi * unmapped and its refcount is dropped, so just clear pte here. 39896629326bSHillf Danton */ 39909fbc1f63SNaoya Horiguchi if (unlikely(!pte_present(pte))) { 39919386fac3SPunit Agrawal huge_pte_clear(mm, address, ptep, sz); 399231d49da5SAneesh Kumar K.V spin_unlock(ptl); 399331d49da5SAneesh Kumar K.V continue; 39948c4894c6SNaoya Horiguchi } 39956629326bSHillf Danton 39966629326bSHillf Danton page = pte_page(pte); 399704f2cbe3SMel Gorman /* 399804f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 399904f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 400004f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 400104f2cbe3SMel Gorman */ 400204f2cbe3SMel Gorman if (ref_page) { 400331d49da5SAneesh Kumar K.V if (page != ref_page) { 400431d49da5SAneesh Kumar K.V spin_unlock(ptl); 400531d49da5SAneesh Kumar K.V continue; 400631d49da5SAneesh Kumar K.V } 400704f2cbe3SMel Gorman /* 400804f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 400904f2cbe3SMel Gorman * future faults in this VMA will fail rather than 401004f2cbe3SMel Gorman * looking like data was lost 401104f2cbe3SMel Gorman */ 401204f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 401304f2cbe3SMel Gorman } 401404f2cbe3SMel Gorman 4015c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 4016b528e4b6SAneesh Kumar K.V tlb_remove_huge_tlb_entry(h, tlb, ptep, address); 4017106c992aSGerald Schaefer if (huge_pte_dirty(pte)) 40186649a386SKen Chen set_page_dirty(page); 40199e81130bSHillf Danton 40205d317b2bSNaoya Horiguchi hugetlb_count_sub(pages_per_huge_page(h), mm); 4021d281ee61SKirill A. Shutemov page_remove_rmap(page, true); 402231d49da5SAneesh Kumar K.V 4023cb900f41SKirill A. Shutemov spin_unlock(ptl); 4024e77b0852SAneesh Kumar K.V tlb_remove_page_size(tlb, page, huge_page_size(h)); 402524669e58SAneesh Kumar K.V /* 402631d49da5SAneesh Kumar K.V * Bail out after unmapping reference page if supplied 402724669e58SAneesh Kumar K.V */ 402831d49da5SAneesh Kumar K.V if (ref_page) 402931d49da5SAneesh Kumar K.V break; 4030fe1668aeSChen, Kenneth W } 4031ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 403224669e58SAneesh Kumar K.V tlb_end_vma(tlb, vma); 40331da177e4SLinus Torvalds } 403463551ae0SDavid Gibson 4035d833352aSMel Gorman void __unmap_hugepage_range_final(struct mmu_gather *tlb, 4036d833352aSMel Gorman struct vm_area_struct *vma, unsigned long start, 4037d833352aSMel Gorman unsigned long end, struct page *ref_page) 4038d833352aSMel Gorman { 4039d833352aSMel Gorman __unmap_hugepage_range(tlb, vma, start, end, ref_page); 4040d833352aSMel Gorman 4041d833352aSMel Gorman /* 4042d833352aSMel Gorman * Clear this flag so that x86's huge_pmd_share page_table_shareable 4043d833352aSMel Gorman * test will fail on a vma being torn down, and not grab a page table 4044d833352aSMel Gorman * on its way out. We're lucky that the flag has such an appropriate 4045d833352aSMel Gorman * name, and can in fact be safely cleared here. We could clear it 4046d833352aSMel Gorman * before the __unmap_hugepage_range above, but all that's necessary 4047c8c06efaSDavidlohr Bueso * is to clear it before releasing the i_mmap_rwsem. This works 4048d833352aSMel Gorman * because in the context this is called, the VMA is about to be 4049c8c06efaSDavidlohr Bueso * destroyed and the i_mmap_rwsem is held. 4050d833352aSMel Gorman */ 4051d833352aSMel Gorman vma->vm_flags &= ~VM_MAYSHARE; 4052d833352aSMel Gorman } 4053d833352aSMel Gorman 4054502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 405504f2cbe3SMel Gorman unsigned long end, struct page *ref_page) 4056502717f4SChen, Kenneth W { 405724669e58SAneesh Kumar K.V struct mm_struct *mm; 405824669e58SAneesh Kumar K.V struct mmu_gather tlb; 4059dff11abeSMike Kravetz unsigned long tlb_start = start; 4060dff11abeSMike Kravetz unsigned long tlb_end = end; 4061dff11abeSMike Kravetz 4062dff11abeSMike Kravetz /* 4063dff11abeSMike Kravetz * If shared PMDs were possibly used within this vma range, adjust 4064dff11abeSMike Kravetz * start/end for worst case tlb flushing. 4065dff11abeSMike Kravetz * Note that we can not be sure if PMDs are shared until we try to 4066dff11abeSMike Kravetz * unmap pages. However, we want to make sure TLB flushing covers 4067dff11abeSMike Kravetz * the largest possible range. 4068dff11abeSMike Kravetz */ 4069dff11abeSMike Kravetz adjust_range_if_pmd_sharing_possible(vma, &tlb_start, &tlb_end); 407024669e58SAneesh Kumar K.V 407124669e58SAneesh Kumar K.V mm = vma->vm_mm; 407224669e58SAneesh Kumar K.V 4073dff11abeSMike Kravetz tlb_gather_mmu(&tlb, mm, tlb_start, tlb_end); 407424669e58SAneesh Kumar K.V __unmap_hugepage_range(&tlb, vma, start, end, ref_page); 4075dff11abeSMike Kravetz tlb_finish_mmu(&tlb, tlb_start, tlb_end); 4076502717f4SChen, Kenneth W } 4077502717f4SChen, Kenneth W 407804f2cbe3SMel Gorman /* 407904f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 408004f2cbe3SMel Gorman * mappping it owns the reserve page for. The intention is to unmap the page 408104f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 408204f2cbe3SMel Gorman * same region. 408304f2cbe3SMel Gorman */ 40842f4612afSDavidlohr Bueso static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, 40852a4b3dedSHarvey Harrison struct page *page, unsigned long address) 408604f2cbe3SMel Gorman { 40877526674dSAdam Litke struct hstate *h = hstate_vma(vma); 408804f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 408904f2cbe3SMel Gorman struct address_space *mapping; 409004f2cbe3SMel Gorman pgoff_t pgoff; 409104f2cbe3SMel Gorman 409204f2cbe3SMel Gorman /* 409304f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 409404f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 409504f2cbe3SMel Gorman */ 40967526674dSAdam Litke address = address & huge_page_mask(h); 409736e4f20aSMichal Hocko pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + 409836e4f20aSMichal Hocko vma->vm_pgoff; 409993c76a3dSAl Viro mapping = vma->vm_file->f_mapping; 410004f2cbe3SMel Gorman 41014eb2b1dcSMel Gorman /* 41024eb2b1dcSMel Gorman * Take the mapping lock for the duration of the table walk. As 41034eb2b1dcSMel Gorman * this mapping should be shared between all the VMAs, 41044eb2b1dcSMel Gorman * __unmap_hugepage_range() is called as the lock is already held 41054eb2b1dcSMel Gorman */ 410683cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 41076b2dbba8SMichel Lespinasse vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { 410804f2cbe3SMel Gorman /* Do not unmap the current VMA */ 410904f2cbe3SMel Gorman if (iter_vma == vma) 411004f2cbe3SMel Gorman continue; 411104f2cbe3SMel Gorman 411204f2cbe3SMel Gorman /* 41132f84a899SMel Gorman * Shared VMAs have their own reserves and do not affect 41142f84a899SMel Gorman * MAP_PRIVATE accounting but it is possible that a shared 41152f84a899SMel Gorman * VMA is using the same page so check and skip such VMAs. 41162f84a899SMel Gorman */ 41172f84a899SMel Gorman if (iter_vma->vm_flags & VM_MAYSHARE) 41182f84a899SMel Gorman continue; 41192f84a899SMel Gorman 41202f84a899SMel Gorman /* 412104f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 412204f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 412304f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 412404f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 412504f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 412604f2cbe3SMel Gorman */ 412704f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 412824669e58SAneesh Kumar K.V unmap_hugepage_range(iter_vma, address, 412924669e58SAneesh Kumar K.V address + huge_page_size(h), page); 413004f2cbe3SMel Gorman } 413183cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 413204f2cbe3SMel Gorman } 413304f2cbe3SMel Gorman 41340fe6e20bSNaoya Horiguchi /* 41350fe6e20bSNaoya Horiguchi * Hugetlb_cow() should be called with page lock of the original hugepage held. 4136ef009b25SMichal Hocko * Called with hugetlb_instantiation_mutex held and pte_page locked so we 4137ef009b25SMichal Hocko * cannot race with other handlers or page migration. 4138ef009b25SMichal Hocko * Keep the pte_same checks anyway to make transition from the mutex easier. 41390fe6e20bSNaoya Horiguchi */ 41402b740303SSouptick Joarder static vm_fault_t hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, 4141974e6d66SHuang Ying unsigned long address, pte_t *ptep, 4142cb900f41SKirill A. Shutemov struct page *pagecache_page, spinlock_t *ptl) 41431e8f889bSDavid Gibson { 41443999f52eSAneesh Kumar K.V pte_t pte; 4145a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 41461e8f889bSDavid Gibson struct page *old_page, *new_page; 41472b740303SSouptick Joarder int outside_reserve = 0; 41482b740303SSouptick Joarder vm_fault_t ret = 0; 4149974e6d66SHuang Ying unsigned long haddr = address & huge_page_mask(h); 4150ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 41511e8f889bSDavid Gibson 41523999f52eSAneesh Kumar K.V pte = huge_ptep_get(ptep); 41531e8f889bSDavid Gibson old_page = pte_page(pte); 41541e8f889bSDavid Gibson 415504f2cbe3SMel Gorman retry_avoidcopy: 41561e8f889bSDavid Gibson /* If no-one else is actually using this page, avoid the copy 41571e8f889bSDavid Gibson * and just make the page writable */ 415837a2140dSJoonsoo Kim if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { 41595a49973dSHugh Dickins page_move_anon_rmap(old_page, vma); 41605b7a1d40SHuang Ying set_huge_ptep_writable(vma, haddr, ptep); 416183c54070SNick Piggin return 0; 41621e8f889bSDavid Gibson } 41631e8f889bSDavid Gibson 416404f2cbe3SMel Gorman /* 416504f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 416604f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 416704f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 416804f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 416904f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 417004f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 417104f2cbe3SMel Gorman * of the full address range. 417204f2cbe3SMel Gorman */ 41735944d011SJoonsoo Kim if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 417404f2cbe3SMel Gorman old_page != pagecache_page) 417504f2cbe3SMel Gorman outside_reserve = 1; 417604f2cbe3SMel Gorman 417709cbfeafSKirill A. Shutemov get_page(old_page); 4178b76c8cfbSLarry Woodman 4179ad4404a2SDavidlohr Bueso /* 4180ad4404a2SDavidlohr Bueso * Drop page table lock as buddy allocator may be called. It will 4181ad4404a2SDavidlohr Bueso * be acquired again before returning to the caller, as expected. 4182ad4404a2SDavidlohr Bueso */ 4183cb900f41SKirill A. Shutemov spin_unlock(ptl); 41845b7a1d40SHuang Ying new_page = alloc_huge_page(vma, haddr, outside_reserve); 41851e8f889bSDavid Gibson 41862fc39cecSAdam Litke if (IS_ERR(new_page)) { 418704f2cbe3SMel Gorman /* 418804f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 418904f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 419004f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 419104f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 419204f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 419304f2cbe3SMel Gorman */ 419404f2cbe3SMel Gorman if (outside_reserve) { 419509cbfeafSKirill A. Shutemov put_page(old_page); 419604f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 41975b7a1d40SHuang Ying unmap_ref_private(mm, vma, old_page, haddr); 419804f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 4199cb900f41SKirill A. Shutemov spin_lock(ptl); 42005b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 4201a9af0c5dSNaoya Horiguchi if (likely(ptep && 4202a9af0c5dSNaoya Horiguchi pte_same(huge_ptep_get(ptep), pte))) 420304f2cbe3SMel Gorman goto retry_avoidcopy; 4204a734bcc8SHillf Danton /* 4205cb900f41SKirill A. Shutemov * race occurs while re-acquiring page table 4206cb900f41SKirill A. Shutemov * lock, and our job is done. 4207a734bcc8SHillf Danton */ 4208a734bcc8SHillf Danton return 0; 420904f2cbe3SMel Gorman } 421004f2cbe3SMel Gorman 42112b740303SSouptick Joarder ret = vmf_error(PTR_ERR(new_page)); 4212ad4404a2SDavidlohr Bueso goto out_release_old; 42131e8f889bSDavid Gibson } 42141e8f889bSDavid Gibson 42150fe6e20bSNaoya Horiguchi /* 42160fe6e20bSNaoya Horiguchi * When the original hugepage is shared one, it does not have 42170fe6e20bSNaoya Horiguchi * anon_vma prepared. 42180fe6e20bSNaoya Horiguchi */ 421944e2aa93SDean Nelson if (unlikely(anon_vma_prepare(vma))) { 4220ad4404a2SDavidlohr Bueso ret = VM_FAULT_OOM; 4221ad4404a2SDavidlohr Bueso goto out_release_all; 422244e2aa93SDean Nelson } 42230fe6e20bSNaoya Horiguchi 4224974e6d66SHuang Ying copy_user_huge_page(new_page, old_page, address, vma, 422547ad8475SAndrea Arcangeli pages_per_huge_page(h)); 42260ed361deSNick Piggin __SetPageUptodate(new_page); 42271e8f889bSDavid Gibson 42287269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr, 42296f4f13e8SJérôme Glisse haddr + huge_page_size(h)); 4230ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 4231ad4404a2SDavidlohr Bueso 4232b76c8cfbSLarry Woodman /* 4233cb900f41SKirill A. Shutemov * Retake the page table lock to check for racing updates 4234b76c8cfbSLarry Woodman * before the page tables are altered 4235b76c8cfbSLarry Woodman */ 4236cb900f41SKirill A. Shutemov spin_lock(ptl); 42375b7a1d40SHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 4238a9af0c5dSNaoya Horiguchi if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { 423907443a85SJoonsoo Kim ClearPagePrivate(new_page); 424007443a85SJoonsoo Kim 42411e8f889bSDavid Gibson /* Break COW */ 42425b7a1d40SHuang Ying huge_ptep_clear_flush(vma, haddr, ptep); 4243ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range(mm, range.start, range.end); 42445b7a1d40SHuang Ying set_huge_pte_at(mm, haddr, ptep, 42451e8f889bSDavid Gibson make_huge_pte(vma, new_page, 1)); 4246d281ee61SKirill A. Shutemov page_remove_rmap(old_page, true); 42475b7a1d40SHuang Ying hugepage_add_new_anon_rmap(new_page, vma, haddr); 4248cb6acd01SMike Kravetz set_page_huge_active(new_page); 42491e8f889bSDavid Gibson /* Make the old page be freed below */ 42501e8f889bSDavid Gibson new_page = old_page; 42511e8f889bSDavid Gibson } 4252cb900f41SKirill A. Shutemov spin_unlock(ptl); 4253ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 4254ad4404a2SDavidlohr Bueso out_release_all: 42555b7a1d40SHuang Ying restore_reserve_on_error(h, vma, haddr, new_page); 425609cbfeafSKirill A. Shutemov put_page(new_page); 4257ad4404a2SDavidlohr Bueso out_release_old: 425809cbfeafSKirill A. Shutemov put_page(old_page); 42598312034fSJoonsoo Kim 4260ad4404a2SDavidlohr Bueso spin_lock(ptl); /* Caller expects lock to be held */ 4261ad4404a2SDavidlohr Bueso return ret; 42621e8f889bSDavid Gibson } 42631e8f889bSDavid Gibson 426404f2cbe3SMel Gorman /* Return the pagecache page at a given address within a VMA */ 4265a5516438SAndi Kleen static struct page *hugetlbfs_pagecache_page(struct hstate *h, 4266a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 426704f2cbe3SMel Gorman { 426804f2cbe3SMel Gorman struct address_space *mapping; 4269e7c4b0bfSAndy Whitcroft pgoff_t idx; 427004f2cbe3SMel Gorman 427104f2cbe3SMel Gorman mapping = vma->vm_file->f_mapping; 4272a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 427304f2cbe3SMel Gorman 427404f2cbe3SMel Gorman return find_lock_page(mapping, idx); 427504f2cbe3SMel Gorman } 427604f2cbe3SMel Gorman 42773ae77f43SHugh Dickins /* 42783ae77f43SHugh Dickins * Return whether there is a pagecache page to back given address within VMA. 42793ae77f43SHugh Dickins * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. 42803ae77f43SHugh Dickins */ 42813ae77f43SHugh Dickins static bool hugetlbfs_pagecache_present(struct hstate *h, 42822a15efc9SHugh Dickins struct vm_area_struct *vma, unsigned long address) 42832a15efc9SHugh Dickins { 42842a15efc9SHugh Dickins struct address_space *mapping; 42852a15efc9SHugh Dickins pgoff_t idx; 42862a15efc9SHugh Dickins struct page *page; 42872a15efc9SHugh Dickins 42882a15efc9SHugh Dickins mapping = vma->vm_file->f_mapping; 42892a15efc9SHugh Dickins idx = vma_hugecache_offset(h, vma, address); 42902a15efc9SHugh Dickins 42912a15efc9SHugh Dickins page = find_get_page(mapping, idx); 42922a15efc9SHugh Dickins if (page) 42932a15efc9SHugh Dickins put_page(page); 42942a15efc9SHugh Dickins return page != NULL; 42952a15efc9SHugh Dickins } 42962a15efc9SHugh Dickins 4297ab76ad54SMike Kravetz int huge_add_to_page_cache(struct page *page, struct address_space *mapping, 4298ab76ad54SMike Kravetz pgoff_t idx) 4299ab76ad54SMike Kravetz { 4300ab76ad54SMike Kravetz struct inode *inode = mapping->host; 4301ab76ad54SMike Kravetz struct hstate *h = hstate_inode(inode); 4302ab76ad54SMike Kravetz int err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); 4303ab76ad54SMike Kravetz 4304ab76ad54SMike Kravetz if (err) 4305ab76ad54SMike Kravetz return err; 4306ab76ad54SMike Kravetz ClearPagePrivate(page); 4307ab76ad54SMike Kravetz 430822146c3cSMike Kravetz /* 430922146c3cSMike Kravetz * set page dirty so that it will not be removed from cache/file 431022146c3cSMike Kravetz * by non-hugetlbfs specific code paths. 431122146c3cSMike Kravetz */ 431222146c3cSMike Kravetz set_page_dirty(page); 431322146c3cSMike Kravetz 4314ab76ad54SMike Kravetz spin_lock(&inode->i_lock); 4315ab76ad54SMike Kravetz inode->i_blocks += blocks_per_huge_page(h); 4316ab76ad54SMike Kravetz spin_unlock(&inode->i_lock); 4317ab76ad54SMike Kravetz return 0; 4318ab76ad54SMike Kravetz } 4319ab76ad54SMike Kravetz 43202b740303SSouptick Joarder static vm_fault_t hugetlb_no_page(struct mm_struct *mm, 43212b740303SSouptick Joarder struct vm_area_struct *vma, 43228382d914SDavidlohr Bueso struct address_space *mapping, pgoff_t idx, 4323788c7df4SHugh Dickins unsigned long address, pte_t *ptep, unsigned int flags) 4324ac9b9c66SHugh Dickins { 4325a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 43262b740303SSouptick Joarder vm_fault_t ret = VM_FAULT_SIGBUS; 4327409eb8c2SHillf Danton int anon_rmap = 0; 43284c887265SAdam Litke unsigned long size; 43294c887265SAdam Litke struct page *page; 43301e8f889bSDavid Gibson pte_t new_pte; 4331cb900f41SKirill A. Shutemov spinlock_t *ptl; 4332285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 4333cb6acd01SMike Kravetz bool new_page = false; 43344c887265SAdam Litke 433504f2cbe3SMel Gorman /* 433604f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 433704f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 433825985edcSLucas De Marchi * COW. Warn that such a situation has occurred as it may not be obvious 433904f2cbe3SMel Gorman */ 434004f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 4341910154d5SGeoffrey Thomas pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n", 434204f2cbe3SMel Gorman current->pid); 434304f2cbe3SMel Gorman return ret; 434404f2cbe3SMel Gorman } 434504f2cbe3SMel Gorman 43464c887265SAdam Litke /* 434787bf91d3SMike Kravetz * We can not race with truncation due to holding i_mmap_rwsem. 434887bf91d3SMike Kravetz * i_size is modified when holding i_mmap_rwsem, so check here 434987bf91d3SMike Kravetz * once for faults beyond end of file. 43504c887265SAdam Litke */ 4351a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 4352ebed4bfcSHugh Dickins if (idx >= size) 4353ebed4bfcSHugh Dickins goto out; 43541a1aad8aSMike Kravetz 435587bf91d3SMike Kravetz retry: 435687bf91d3SMike Kravetz page = find_lock_page(mapping, idx); 435787bf91d3SMike Kravetz if (!page) { 43581a1aad8aSMike Kravetz /* 43591a1aad8aSMike Kravetz * Check for page in userfault range 43601a1aad8aSMike Kravetz */ 43611a1aad8aSMike Kravetz if (userfaultfd_missing(vma)) { 43621a1aad8aSMike Kravetz u32 hash; 43631a1aad8aSMike Kravetz struct vm_fault vmf = { 43641a1aad8aSMike Kravetz .vma = vma, 4365285b8dcaSHuang Ying .address = haddr, 43661a1aad8aSMike Kravetz .flags = flags, 43671a1aad8aSMike Kravetz /* 43681a1aad8aSMike Kravetz * Hard to debug if it ends up being 43691a1aad8aSMike Kravetz * used by a callee that assumes 43701a1aad8aSMike Kravetz * something about the other 43711a1aad8aSMike Kravetz * uninitialized fields... same as in 43721a1aad8aSMike Kravetz * memory.c 43731a1aad8aSMike Kravetz */ 43741a1aad8aSMike Kravetz }; 43751a1aad8aSMike Kravetz 43761a1aad8aSMike Kravetz /* 4377c0d0381aSMike Kravetz * hugetlb_fault_mutex and i_mmap_rwsem must be 4378c0d0381aSMike Kravetz * dropped before handling userfault. Reacquire 4379c0d0381aSMike Kravetz * after handling fault to make calling code simpler. 43801a1aad8aSMike Kravetz */ 4381188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 43821a1aad8aSMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 4383c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 43841a1aad8aSMike Kravetz ret = handle_userfault(&vmf, VM_UFFD_MISSING); 4385c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 43861a1aad8aSMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 43871a1aad8aSMike Kravetz goto out; 43881a1aad8aSMike Kravetz } 43891a1aad8aSMike Kravetz 4390285b8dcaSHuang Ying page = alloc_huge_page(vma, haddr, 0); 43912fc39cecSAdam Litke if (IS_ERR(page)) { 43924643d67eSMike Kravetz /* 43934643d67eSMike Kravetz * Returning error will result in faulting task being 43944643d67eSMike Kravetz * sent SIGBUS. The hugetlb fault mutex prevents two 43954643d67eSMike Kravetz * tasks from racing to fault in the same page which 43964643d67eSMike Kravetz * could result in false unable to allocate errors. 43974643d67eSMike Kravetz * Page migration does not take the fault mutex, but 43984643d67eSMike Kravetz * does a clear then write of pte's under page table 43994643d67eSMike Kravetz * lock. Page fault code could race with migration, 44004643d67eSMike Kravetz * notice the clear pte and try to allocate a page 44014643d67eSMike Kravetz * here. Before returning error, get ptl and make 44024643d67eSMike Kravetz * sure there really is no pte entry. 44034643d67eSMike Kravetz */ 44044643d67eSMike Kravetz ptl = huge_pte_lock(h, mm, ptep); 44054643d67eSMike Kravetz if (!huge_pte_none(huge_ptep_get(ptep))) { 44064643d67eSMike Kravetz ret = 0; 44074643d67eSMike Kravetz spin_unlock(ptl); 44084643d67eSMike Kravetz goto out; 44094643d67eSMike Kravetz } 44104643d67eSMike Kravetz spin_unlock(ptl); 44112b740303SSouptick Joarder ret = vmf_error(PTR_ERR(page)); 44126bda666aSChristoph Lameter goto out; 44136bda666aSChristoph Lameter } 441447ad8475SAndrea Arcangeli clear_huge_page(page, address, pages_per_huge_page(h)); 44150ed361deSNick Piggin __SetPageUptodate(page); 4416cb6acd01SMike Kravetz new_page = true; 4417ac9b9c66SHugh Dickins 4418f83a275dSMel Gorman if (vma->vm_flags & VM_MAYSHARE) { 4419ab76ad54SMike Kravetz int err = huge_add_to_page_cache(page, mapping, idx); 44206bda666aSChristoph Lameter if (err) { 44216bda666aSChristoph Lameter put_page(page); 44226bda666aSChristoph Lameter if (err == -EEXIST) 44236bda666aSChristoph Lameter goto retry; 44246bda666aSChristoph Lameter goto out; 44256bda666aSChristoph Lameter } 442623be7468SMel Gorman } else { 44276bda666aSChristoph Lameter lock_page(page); 44280fe6e20bSNaoya Horiguchi if (unlikely(anon_vma_prepare(vma))) { 44290fe6e20bSNaoya Horiguchi ret = VM_FAULT_OOM; 44300fe6e20bSNaoya Horiguchi goto backout_unlocked; 443123be7468SMel Gorman } 4432409eb8c2SHillf Danton anon_rmap = 1; 44330fe6e20bSNaoya Horiguchi } 44340fe6e20bSNaoya Horiguchi } else { 443557303d80SAndy Whitcroft /* 4436998b4382SNaoya Horiguchi * If memory error occurs between mmap() and fault, some process 4437998b4382SNaoya Horiguchi * don't have hwpoisoned swap entry for errored virtual address. 4438998b4382SNaoya Horiguchi * So we need to block hugepage fault by PG_hwpoison bit check. 4439fd6a03edSNaoya Horiguchi */ 4440fd6a03edSNaoya Horiguchi if (unlikely(PageHWPoison(page))) { 4441aa50d3a7SAndi Kleen ret = VM_FAULT_HWPOISON | 4442972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 4443fd6a03edSNaoya Horiguchi goto backout_unlocked; 44446bda666aSChristoph Lameter } 4445998b4382SNaoya Horiguchi } 44461e8f889bSDavid Gibson 444757303d80SAndy Whitcroft /* 444857303d80SAndy Whitcroft * If we are going to COW a private mapping later, we examine the 444957303d80SAndy Whitcroft * pending reservations for this page now. This will ensure that 445057303d80SAndy Whitcroft * any allocations necessary to record that reservation occur outside 445157303d80SAndy Whitcroft * the spinlock. 445257303d80SAndy Whitcroft */ 44535e911373SMike Kravetz if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 4454285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 44552b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 44562b26736cSAndy Whitcroft goto backout_unlocked; 44572b26736cSAndy Whitcroft } 44585e911373SMike Kravetz /* Just decrements count, does not deallocate */ 4459285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 44605e911373SMike Kravetz } 446157303d80SAndy Whitcroft 44628bea8052SAneesh Kumar K.V ptl = huge_pte_lock(h, mm, ptep); 446383c54070SNick Piggin ret = 0; 44647f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(ptep))) 44654c887265SAdam Litke goto backout; 44664c887265SAdam Litke 446707443a85SJoonsoo Kim if (anon_rmap) { 446807443a85SJoonsoo Kim ClearPagePrivate(page); 4469285b8dcaSHuang Ying hugepage_add_new_anon_rmap(page, vma, haddr); 4470ac714904SChoi Gi-yong } else 447153f9263bSKirill A. Shutemov page_dup_rmap(page, true); 44721e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 44731e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 4474285b8dcaSHuang Ying set_huge_pte_at(mm, haddr, ptep, new_pte); 44751e8f889bSDavid Gibson 44765d317b2bSNaoya Horiguchi hugetlb_count_add(pages_per_huge_page(h), mm); 4477788c7df4SHugh Dickins if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { 44781e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 4479974e6d66SHuang Ying ret = hugetlb_cow(mm, vma, address, ptep, page, ptl); 44801e8f889bSDavid Gibson } 44811e8f889bSDavid Gibson 4482cb900f41SKirill A. Shutemov spin_unlock(ptl); 4483cb6acd01SMike Kravetz 4484cb6acd01SMike Kravetz /* 4485cb6acd01SMike Kravetz * Only make newly allocated pages active. Existing pages found 4486cb6acd01SMike Kravetz * in the pagecache could be !page_huge_active() if they have been 4487cb6acd01SMike Kravetz * isolated for migration. 4488cb6acd01SMike Kravetz */ 4489cb6acd01SMike Kravetz if (new_page) 4490cb6acd01SMike Kravetz set_page_huge_active(page); 4491cb6acd01SMike Kravetz 44924c887265SAdam Litke unlock_page(page); 44934c887265SAdam Litke out: 4494ac9b9c66SHugh Dickins return ret; 44954c887265SAdam Litke 44964c887265SAdam Litke backout: 4497cb900f41SKirill A. Shutemov spin_unlock(ptl); 44982b26736cSAndy Whitcroft backout_unlocked: 44994c887265SAdam Litke unlock_page(page); 4500285b8dcaSHuang Ying restore_reserve_on_error(h, vma, haddr, page); 45014c887265SAdam Litke put_page(page); 45024c887265SAdam Litke goto out; 4503ac9b9c66SHugh Dickins } 4504ac9b9c66SHugh Dickins 45058382d914SDavidlohr Bueso #ifdef CONFIG_SMP 4506188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 45078382d914SDavidlohr Bueso { 45088382d914SDavidlohr Bueso unsigned long key[2]; 45098382d914SDavidlohr Bueso u32 hash; 45108382d914SDavidlohr Bueso 45118382d914SDavidlohr Bueso key[0] = (unsigned long) mapping; 45128382d914SDavidlohr Bueso key[1] = idx; 45138382d914SDavidlohr Bueso 451455254636SMike Kravetz hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0); 45158382d914SDavidlohr Bueso 45168382d914SDavidlohr Bueso return hash & (num_fault_mutexes - 1); 45178382d914SDavidlohr Bueso } 45188382d914SDavidlohr Bueso #else 45198382d914SDavidlohr Bueso /* 45208382d914SDavidlohr Bueso * For uniprocesor systems we always use a single mutex, so just 45218382d914SDavidlohr Bueso * return 0 and avoid the hashing overhead. 45228382d914SDavidlohr Bueso */ 4523188b04a7SWei Yang u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx) 45248382d914SDavidlohr Bueso { 45258382d914SDavidlohr Bueso return 0; 45268382d914SDavidlohr Bueso } 45278382d914SDavidlohr Bueso #endif 45288382d914SDavidlohr Bueso 45292b740303SSouptick Joarder vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 4530788c7df4SHugh Dickins unsigned long address, unsigned int flags) 453186e5216fSAdam Litke { 45328382d914SDavidlohr Bueso pte_t *ptep, entry; 4533cb900f41SKirill A. Shutemov spinlock_t *ptl; 45342b740303SSouptick Joarder vm_fault_t ret; 45358382d914SDavidlohr Bueso u32 hash; 45368382d914SDavidlohr Bueso pgoff_t idx; 45370fe6e20bSNaoya Horiguchi struct page *page = NULL; 453857303d80SAndy Whitcroft struct page *pagecache_page = NULL; 4539a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 45408382d914SDavidlohr Bueso struct address_space *mapping; 45410f792cf9SNaoya Horiguchi int need_wait_lock = 0; 4542285b8dcaSHuang Ying unsigned long haddr = address & huge_page_mask(h); 454386e5216fSAdam Litke 4544285b8dcaSHuang Ying ptep = huge_pte_offset(mm, haddr, huge_page_size(h)); 4545fd6a03edSNaoya Horiguchi if (ptep) { 4546c0d0381aSMike Kravetz /* 4547c0d0381aSMike Kravetz * Since we hold no locks, ptep could be stale. That is 4548c0d0381aSMike Kravetz * OK as we are only making decisions based on content and 4549c0d0381aSMike Kravetz * not actually modifying content here. 4550c0d0381aSMike Kravetz */ 4551fd6a03edSNaoya Horiguchi entry = huge_ptep_get(ptep); 4552290408d4SNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(entry))) { 4553cb900f41SKirill A. Shutemov migration_entry_wait_huge(vma, mm, ptep); 4554290408d4SNaoya Horiguchi return 0; 4555290408d4SNaoya Horiguchi } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) 4556aa50d3a7SAndi Kleen return VM_FAULT_HWPOISON_LARGE | 4557972dc4deSAneesh Kumar K.V VM_FAULT_SET_HINDEX(hstate_index(h)); 4558b43a9990SMike Kravetz } 45598382d914SDavidlohr Bueso 4560c0d0381aSMike Kravetz /* 4561c0d0381aSMike Kravetz * Acquire i_mmap_rwsem before calling huge_pte_alloc and hold 456287bf91d3SMike Kravetz * until finished with ptep. This serves two purposes: 456387bf91d3SMike Kravetz * 1) It prevents huge_pmd_unshare from being called elsewhere 456487bf91d3SMike Kravetz * and making the ptep no longer valid. 456587bf91d3SMike Kravetz * 2) It synchronizes us with i_size modifications during truncation. 4566c0d0381aSMike Kravetz * 4567c0d0381aSMike Kravetz * ptep could have already be assigned via huge_pte_offset. That 4568c0d0381aSMike Kravetz * is OK, as huge_pte_alloc will return the same value unless 4569c0d0381aSMike Kravetz * something has changed. 4570c0d0381aSMike Kravetz */ 4571ddeaab32SMike Kravetz mapping = vma->vm_file->f_mapping; 4572c0d0381aSMike Kravetz i_mmap_lock_read(mapping); 4573c0d0381aSMike Kravetz ptep = huge_pte_alloc(mm, haddr, huge_page_size(h)); 4574c0d0381aSMike Kravetz if (!ptep) { 4575c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 4576c0d0381aSMike Kravetz return VM_FAULT_OOM; 4577c0d0381aSMike Kravetz } 4578ddeaab32SMike Kravetz 45793935baa9SDavid Gibson /* 45803935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 45813935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 45823935baa9SDavid Gibson * the same page in the page cache. 45833935baa9SDavid Gibson */ 4584c0d0381aSMike Kravetz idx = vma_hugecache_offset(h, vma, haddr); 4585188b04a7SWei Yang hash = hugetlb_fault_mutex_hash(mapping, idx); 4586c672c7f2SMike Kravetz mutex_lock(&hugetlb_fault_mutex_table[hash]); 45878382d914SDavidlohr Bueso 45887f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 45897f2e9525SGerald Schaefer if (huge_pte_none(entry)) { 45908382d914SDavidlohr Bueso ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, flags); 4591b4d1d99fSDavid Gibson goto out_mutex; 45923935baa9SDavid Gibson } 459386e5216fSAdam Litke 459483c54070SNick Piggin ret = 0; 45951e8f889bSDavid Gibson 459657303d80SAndy Whitcroft /* 45970f792cf9SNaoya Horiguchi * entry could be a migration/hwpoison entry at this point, so this 45980f792cf9SNaoya Horiguchi * check prevents the kernel from going below assuming that we have 45997c8de358SEthon Paul * an active hugepage in pagecache. This goto expects the 2nd page 46007c8de358SEthon Paul * fault, and is_hugetlb_entry_(migration|hwpoisoned) check will 46017c8de358SEthon Paul * properly handle it. 46020f792cf9SNaoya Horiguchi */ 46030f792cf9SNaoya Horiguchi if (!pte_present(entry)) 46040f792cf9SNaoya Horiguchi goto out_mutex; 46050f792cf9SNaoya Horiguchi 46060f792cf9SNaoya Horiguchi /* 460757303d80SAndy Whitcroft * If we are going to COW the mapping later, we examine the pending 460857303d80SAndy Whitcroft * reservations for this page now. This will ensure that any 460957303d80SAndy Whitcroft * allocations necessary to record that reservation occur outside the 461057303d80SAndy Whitcroft * spinlock. For private mappings, we also lookup the pagecache 461157303d80SAndy Whitcroft * page now as it is used to determine if a reservation has been 461257303d80SAndy Whitcroft * consumed. 461357303d80SAndy Whitcroft */ 4614106c992aSGerald Schaefer if ((flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { 4615285b8dcaSHuang Ying if (vma_needs_reservation(h, vma, haddr) < 0) { 46162b26736cSAndy Whitcroft ret = VM_FAULT_OOM; 4617b4d1d99fSDavid Gibson goto out_mutex; 46182b26736cSAndy Whitcroft } 46195e911373SMike Kravetz /* Just decrements count, does not deallocate */ 4620285b8dcaSHuang Ying vma_end_reservation(h, vma, haddr); 462157303d80SAndy Whitcroft 4622f83a275dSMel Gorman if (!(vma->vm_flags & VM_MAYSHARE)) 462357303d80SAndy Whitcroft pagecache_page = hugetlbfs_pagecache_page(h, 4624285b8dcaSHuang Ying vma, haddr); 462557303d80SAndy Whitcroft } 462657303d80SAndy Whitcroft 46270f792cf9SNaoya Horiguchi ptl = huge_pte_lock(h, mm, ptep); 46280fe6e20bSNaoya Horiguchi 46291e8f889bSDavid Gibson /* Check for a racing update before calling hugetlb_cow */ 4630b4d1d99fSDavid Gibson if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) 4631cb900f41SKirill A. Shutemov goto out_ptl; 4632b4d1d99fSDavid Gibson 46330f792cf9SNaoya Horiguchi /* 46340f792cf9SNaoya Horiguchi * hugetlb_cow() requires page locks of pte_page(entry) and 46350f792cf9SNaoya Horiguchi * pagecache_page, so here we need take the former one 46360f792cf9SNaoya Horiguchi * when page != pagecache_page or !pagecache_page. 46370f792cf9SNaoya Horiguchi */ 46380f792cf9SNaoya Horiguchi page = pte_page(entry); 46390f792cf9SNaoya Horiguchi if (page != pagecache_page) 46400f792cf9SNaoya Horiguchi if (!trylock_page(page)) { 46410f792cf9SNaoya Horiguchi need_wait_lock = 1; 46420f792cf9SNaoya Horiguchi goto out_ptl; 46430f792cf9SNaoya Horiguchi } 46440f792cf9SNaoya Horiguchi 46450f792cf9SNaoya Horiguchi get_page(page); 4646b4d1d99fSDavid Gibson 4647788c7df4SHugh Dickins if (flags & FAULT_FLAG_WRITE) { 4648106c992aSGerald Schaefer if (!huge_pte_write(entry)) { 4649974e6d66SHuang Ying ret = hugetlb_cow(mm, vma, address, ptep, 4650cb900f41SKirill A. Shutemov pagecache_page, ptl); 46510f792cf9SNaoya Horiguchi goto out_put_page; 4652b4d1d99fSDavid Gibson } 4653106c992aSGerald Schaefer entry = huge_pte_mkdirty(entry); 4654b4d1d99fSDavid Gibson } 4655b4d1d99fSDavid Gibson entry = pte_mkyoung(entry); 4656285b8dcaSHuang Ying if (huge_ptep_set_access_flags(vma, haddr, ptep, entry, 4657788c7df4SHugh Dickins flags & FAULT_FLAG_WRITE)) 4658285b8dcaSHuang Ying update_mmu_cache(vma, haddr, ptep); 46590f792cf9SNaoya Horiguchi out_put_page: 46600f792cf9SNaoya Horiguchi if (page != pagecache_page) 46610f792cf9SNaoya Horiguchi unlock_page(page); 46620f792cf9SNaoya Horiguchi put_page(page); 4663cb900f41SKirill A. Shutemov out_ptl: 4664cb900f41SKirill A. Shutemov spin_unlock(ptl); 466557303d80SAndy Whitcroft 466657303d80SAndy Whitcroft if (pagecache_page) { 466757303d80SAndy Whitcroft unlock_page(pagecache_page); 466857303d80SAndy Whitcroft put_page(pagecache_page); 466957303d80SAndy Whitcroft } 4670b4d1d99fSDavid Gibson out_mutex: 4671c672c7f2SMike Kravetz mutex_unlock(&hugetlb_fault_mutex_table[hash]); 4672c0d0381aSMike Kravetz i_mmap_unlock_read(mapping); 46730f792cf9SNaoya Horiguchi /* 46740f792cf9SNaoya Horiguchi * Generally it's safe to hold refcount during waiting page lock. But 46750f792cf9SNaoya Horiguchi * here we just wait to defer the next page fault to avoid busy loop and 46760f792cf9SNaoya Horiguchi * the page is not used after unlocked before returning from the current 46770f792cf9SNaoya Horiguchi * page fault. So we are safe from accessing freed page, even if we wait 46780f792cf9SNaoya Horiguchi * here without taking refcount. 46790f792cf9SNaoya Horiguchi */ 46800f792cf9SNaoya Horiguchi if (need_wait_lock) 46810f792cf9SNaoya Horiguchi wait_on_page_locked(page); 46821e8f889bSDavid Gibson return ret; 468386e5216fSAdam Litke } 468486e5216fSAdam Litke 46858fb5debcSMike Kravetz /* 46868fb5debcSMike Kravetz * Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with 46878fb5debcSMike Kravetz * modifications for huge pages. 46888fb5debcSMike Kravetz */ 46898fb5debcSMike Kravetz int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, 46908fb5debcSMike Kravetz pte_t *dst_pte, 46918fb5debcSMike Kravetz struct vm_area_struct *dst_vma, 46928fb5debcSMike Kravetz unsigned long dst_addr, 46938fb5debcSMike Kravetz unsigned long src_addr, 46948fb5debcSMike Kravetz struct page **pagep) 46958fb5debcSMike Kravetz { 46961e392147SAndrea Arcangeli struct address_space *mapping; 46971e392147SAndrea Arcangeli pgoff_t idx; 46981e392147SAndrea Arcangeli unsigned long size; 46991c9e8defSMike Kravetz int vm_shared = dst_vma->vm_flags & VM_SHARED; 47008fb5debcSMike Kravetz struct hstate *h = hstate_vma(dst_vma); 47018fb5debcSMike Kravetz pte_t _dst_pte; 47028fb5debcSMike Kravetz spinlock_t *ptl; 47038fb5debcSMike Kravetz int ret; 47048fb5debcSMike Kravetz struct page *page; 47058fb5debcSMike Kravetz 47068fb5debcSMike Kravetz if (!*pagep) { 47078fb5debcSMike Kravetz ret = -ENOMEM; 47088fb5debcSMike Kravetz page = alloc_huge_page(dst_vma, dst_addr, 0); 47098fb5debcSMike Kravetz if (IS_ERR(page)) 47108fb5debcSMike Kravetz goto out; 47118fb5debcSMike Kravetz 47128fb5debcSMike Kravetz ret = copy_huge_page_from_user(page, 47138fb5debcSMike Kravetz (const void __user *) src_addr, 4714810a56b9SMike Kravetz pages_per_huge_page(h), false); 47158fb5debcSMike Kravetz 4716c1e8d7c6SMichel Lespinasse /* fallback to copy_from_user outside mmap_lock */ 47178fb5debcSMike Kravetz if (unlikely(ret)) { 47189e368259SAndrea Arcangeli ret = -ENOENT; 47198fb5debcSMike Kravetz *pagep = page; 47208fb5debcSMike Kravetz /* don't free the page */ 47218fb5debcSMike Kravetz goto out; 47228fb5debcSMike Kravetz } 47238fb5debcSMike Kravetz } else { 47248fb5debcSMike Kravetz page = *pagep; 47258fb5debcSMike Kravetz *pagep = NULL; 47268fb5debcSMike Kravetz } 47278fb5debcSMike Kravetz 47288fb5debcSMike Kravetz /* 47298fb5debcSMike Kravetz * The memory barrier inside __SetPageUptodate makes sure that 47308fb5debcSMike Kravetz * preceding stores to the page contents become visible before 47318fb5debcSMike Kravetz * the set_pte_at() write. 47328fb5debcSMike Kravetz */ 47338fb5debcSMike Kravetz __SetPageUptodate(page); 47348fb5debcSMike Kravetz 47351e392147SAndrea Arcangeli mapping = dst_vma->vm_file->f_mapping; 47361e392147SAndrea Arcangeli idx = vma_hugecache_offset(h, dst_vma, dst_addr); 47371e392147SAndrea Arcangeli 47381c9e8defSMike Kravetz /* 47391c9e8defSMike Kravetz * If shared, add to page cache 47401c9e8defSMike Kravetz */ 47411c9e8defSMike Kravetz if (vm_shared) { 47421e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 47431e392147SAndrea Arcangeli ret = -EFAULT; 47441e392147SAndrea Arcangeli if (idx >= size) 47451e392147SAndrea Arcangeli goto out_release_nounlock; 47461c9e8defSMike Kravetz 47471e392147SAndrea Arcangeli /* 47481e392147SAndrea Arcangeli * Serialization between remove_inode_hugepages() and 47491e392147SAndrea Arcangeli * huge_add_to_page_cache() below happens through the 47501e392147SAndrea Arcangeli * hugetlb_fault_mutex_table that here must be hold by 47511e392147SAndrea Arcangeli * the caller. 47521e392147SAndrea Arcangeli */ 47531c9e8defSMike Kravetz ret = huge_add_to_page_cache(page, mapping, idx); 47541c9e8defSMike Kravetz if (ret) 47551c9e8defSMike Kravetz goto out_release_nounlock; 47561c9e8defSMike Kravetz } 47571c9e8defSMike Kravetz 47588fb5debcSMike Kravetz ptl = huge_pte_lockptr(h, dst_mm, dst_pte); 47598fb5debcSMike Kravetz spin_lock(ptl); 47608fb5debcSMike Kravetz 47611e392147SAndrea Arcangeli /* 47621e392147SAndrea Arcangeli * Recheck the i_size after holding PT lock to make sure not 47631e392147SAndrea Arcangeli * to leave any page mapped (as page_mapped()) beyond the end 47641e392147SAndrea Arcangeli * of the i_size (remove_inode_hugepages() is strict about 47651e392147SAndrea Arcangeli * enforcing that). If we bail out here, we'll also leave a 47661e392147SAndrea Arcangeli * page in the radix tree in the vm_shared case beyond the end 47671e392147SAndrea Arcangeli * of the i_size, but remove_inode_hugepages() will take care 47681e392147SAndrea Arcangeli * of it as soon as we drop the hugetlb_fault_mutex_table. 47691e392147SAndrea Arcangeli */ 47701e392147SAndrea Arcangeli size = i_size_read(mapping->host) >> huge_page_shift(h); 47711e392147SAndrea Arcangeli ret = -EFAULT; 47721e392147SAndrea Arcangeli if (idx >= size) 47731e392147SAndrea Arcangeli goto out_release_unlock; 47741e392147SAndrea Arcangeli 47758fb5debcSMike Kravetz ret = -EEXIST; 47768fb5debcSMike Kravetz if (!huge_pte_none(huge_ptep_get(dst_pte))) 47778fb5debcSMike Kravetz goto out_release_unlock; 47788fb5debcSMike Kravetz 47791c9e8defSMike Kravetz if (vm_shared) { 47801c9e8defSMike Kravetz page_dup_rmap(page, true); 47811c9e8defSMike Kravetz } else { 47828fb5debcSMike Kravetz ClearPagePrivate(page); 47838fb5debcSMike Kravetz hugepage_add_new_anon_rmap(page, dst_vma, dst_addr); 47841c9e8defSMike Kravetz } 47858fb5debcSMike Kravetz 47868fb5debcSMike Kravetz _dst_pte = make_huge_pte(dst_vma, page, dst_vma->vm_flags & VM_WRITE); 47878fb5debcSMike Kravetz if (dst_vma->vm_flags & VM_WRITE) 47888fb5debcSMike Kravetz _dst_pte = huge_pte_mkdirty(_dst_pte); 47898fb5debcSMike Kravetz _dst_pte = pte_mkyoung(_dst_pte); 47908fb5debcSMike Kravetz 47918fb5debcSMike Kravetz set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); 47928fb5debcSMike Kravetz 47938fb5debcSMike Kravetz (void)huge_ptep_set_access_flags(dst_vma, dst_addr, dst_pte, _dst_pte, 47948fb5debcSMike Kravetz dst_vma->vm_flags & VM_WRITE); 47958fb5debcSMike Kravetz hugetlb_count_add(pages_per_huge_page(h), dst_mm); 47968fb5debcSMike Kravetz 47978fb5debcSMike Kravetz /* No need to invalidate - it was non-present before */ 47988fb5debcSMike Kravetz update_mmu_cache(dst_vma, dst_addr, dst_pte); 47998fb5debcSMike Kravetz 48008fb5debcSMike Kravetz spin_unlock(ptl); 4801cb6acd01SMike Kravetz set_page_huge_active(page); 48021c9e8defSMike Kravetz if (vm_shared) 48031c9e8defSMike Kravetz unlock_page(page); 48048fb5debcSMike Kravetz ret = 0; 48058fb5debcSMike Kravetz out: 48068fb5debcSMike Kravetz return ret; 48078fb5debcSMike Kravetz out_release_unlock: 48088fb5debcSMike Kravetz spin_unlock(ptl); 48091c9e8defSMike Kravetz if (vm_shared) 48101c9e8defSMike Kravetz unlock_page(page); 48115af10dfdSAndrea Arcangeli out_release_nounlock: 48128fb5debcSMike Kravetz put_page(page); 48138fb5debcSMike Kravetz goto out; 48148fb5debcSMike Kravetz } 48158fb5debcSMike Kravetz 481628a35716SMichel Lespinasse long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 481763551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 481828a35716SMichel Lespinasse unsigned long *position, unsigned long *nr_pages, 48194f6da934SPeter Xu long i, unsigned int flags, int *locked) 482063551ae0SDavid Gibson { 4821d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 4822d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 482328a35716SMichel Lespinasse unsigned long remainder = *nr_pages; 4824a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 48252be7cfedSDaniel Jordan int err = -EFAULT; 482663551ae0SDavid Gibson 482763551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 482863551ae0SDavid Gibson pte_t *pte; 4829cb900f41SKirill A. Shutemov spinlock_t *ptl = NULL; 48302a15efc9SHugh Dickins int absent; 483163551ae0SDavid Gibson struct page *page; 483263551ae0SDavid Gibson 48334c887265SAdam Litke /* 483402057967SDavid Rientjes * If we have a pending SIGKILL, don't keep faulting pages and 483502057967SDavid Rientjes * potentially allocating memory. 483602057967SDavid Rientjes */ 4837fa45f116SDavidlohr Bueso if (fatal_signal_pending(current)) { 483802057967SDavid Rientjes remainder = 0; 483902057967SDavid Rientjes break; 484002057967SDavid Rientjes } 484102057967SDavid Rientjes 484202057967SDavid Rientjes /* 48434c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 48442a15efc9SHugh Dickins * each hugepage. We have to make sure we get the 48454c887265SAdam Litke * first, for the page indexing below to work. 4846cb900f41SKirill A. Shutemov * 4847cb900f41SKirill A. Shutemov * Note that page table lock is not held when pte is null. 48484c887265SAdam Litke */ 48497868a208SPunit Agrawal pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), 48507868a208SPunit Agrawal huge_page_size(h)); 4851cb900f41SKirill A. Shutemov if (pte) 4852cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, pte); 48532a15efc9SHugh Dickins absent = !pte || huge_pte_none(huge_ptep_get(pte)); 485463551ae0SDavid Gibson 48552a15efc9SHugh Dickins /* 48562a15efc9SHugh Dickins * When coredumping, it suits get_dump_page if we just return 48573ae77f43SHugh Dickins * an error where there's an empty slot with no huge pagecache 48583ae77f43SHugh Dickins * to back it. This way, we avoid allocating a hugepage, and 48593ae77f43SHugh Dickins * the sparse dumpfile avoids allocating disk blocks, but its 48603ae77f43SHugh Dickins * huge holes still show up with zeroes where they need to be. 48612a15efc9SHugh Dickins */ 48623ae77f43SHugh Dickins if (absent && (flags & FOLL_DUMP) && 48633ae77f43SHugh Dickins !hugetlbfs_pagecache_present(h, vma, vaddr)) { 4864cb900f41SKirill A. Shutemov if (pte) 4865cb900f41SKirill A. Shutemov spin_unlock(ptl); 48662a15efc9SHugh Dickins remainder = 0; 48672a15efc9SHugh Dickins break; 48682a15efc9SHugh Dickins } 48692a15efc9SHugh Dickins 48709cc3a5bdSNaoya Horiguchi /* 48719cc3a5bdSNaoya Horiguchi * We need call hugetlb_fault for both hugepages under migration 48729cc3a5bdSNaoya Horiguchi * (in which case hugetlb_fault waits for the migration,) and 48739cc3a5bdSNaoya Horiguchi * hwpoisoned hugepages (in which case we need to prevent the 48749cc3a5bdSNaoya Horiguchi * caller from accessing to them.) In order to do this, we use 48759cc3a5bdSNaoya Horiguchi * here is_swap_pte instead of is_hugetlb_entry_migration and 48769cc3a5bdSNaoya Horiguchi * is_hugetlb_entry_hwpoisoned. This is because it simply covers 48779cc3a5bdSNaoya Horiguchi * both cases, and because we can't follow correct pages 48789cc3a5bdSNaoya Horiguchi * directly from any kind of swap entries. 48799cc3a5bdSNaoya Horiguchi */ 48809cc3a5bdSNaoya Horiguchi if (absent || is_swap_pte(huge_ptep_get(pte)) || 4881106c992aSGerald Schaefer ((flags & FOLL_WRITE) && 4882106c992aSGerald Schaefer !huge_pte_write(huge_ptep_get(pte)))) { 48832b740303SSouptick Joarder vm_fault_t ret; 488487ffc118SAndrea Arcangeli unsigned int fault_flags = 0; 48854c887265SAdam Litke 4886cb900f41SKirill A. Shutemov if (pte) 4887cb900f41SKirill A. Shutemov spin_unlock(ptl); 488887ffc118SAndrea Arcangeli if (flags & FOLL_WRITE) 488987ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_WRITE; 48904f6da934SPeter Xu if (locked) 489171335f37SPeter Xu fault_flags |= FAULT_FLAG_ALLOW_RETRY | 489271335f37SPeter Xu FAULT_FLAG_KILLABLE; 489387ffc118SAndrea Arcangeli if (flags & FOLL_NOWAIT) 489487ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_ALLOW_RETRY | 489587ffc118SAndrea Arcangeli FAULT_FLAG_RETRY_NOWAIT; 489687ffc118SAndrea Arcangeli if (flags & FOLL_TRIED) { 48974426e945SPeter Xu /* 48984426e945SPeter Xu * Note: FAULT_FLAG_ALLOW_RETRY and 48994426e945SPeter Xu * FAULT_FLAG_TRIED can co-exist 49004426e945SPeter Xu */ 490187ffc118SAndrea Arcangeli fault_flags |= FAULT_FLAG_TRIED; 490287ffc118SAndrea Arcangeli } 490387ffc118SAndrea Arcangeli ret = hugetlb_fault(mm, vma, vaddr, fault_flags); 490487ffc118SAndrea Arcangeli if (ret & VM_FAULT_ERROR) { 49052be7cfedSDaniel Jordan err = vm_fault_to_errno(ret, flags); 49061c59827dSHugh Dickins remainder = 0; 49071c59827dSHugh Dickins break; 49081c59827dSHugh Dickins } 490987ffc118SAndrea Arcangeli if (ret & VM_FAULT_RETRY) { 49104f6da934SPeter Xu if (locked && 49111ac25013SAndrea Arcangeli !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) 49124f6da934SPeter Xu *locked = 0; 491387ffc118SAndrea Arcangeli *nr_pages = 0; 491487ffc118SAndrea Arcangeli /* 491587ffc118SAndrea Arcangeli * VM_FAULT_RETRY must not return an 491687ffc118SAndrea Arcangeli * error, it will return zero 491787ffc118SAndrea Arcangeli * instead. 491887ffc118SAndrea Arcangeli * 491987ffc118SAndrea Arcangeli * No need to update "position" as the 492087ffc118SAndrea Arcangeli * caller will not check it after 492187ffc118SAndrea Arcangeli * *nr_pages is set to 0. 492287ffc118SAndrea Arcangeli */ 492387ffc118SAndrea Arcangeli return i; 492487ffc118SAndrea Arcangeli } 492587ffc118SAndrea Arcangeli continue; 492687ffc118SAndrea Arcangeli } 492763551ae0SDavid Gibson 4928a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 49297f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 49308fde12caSLinus Torvalds 49318fde12caSLinus Torvalds /* 4932acbfb087SZhigang Lu * If subpage information not requested, update counters 4933acbfb087SZhigang Lu * and skip the same_page loop below. 4934acbfb087SZhigang Lu */ 4935acbfb087SZhigang Lu if (!pages && !vmas && !pfn_offset && 4936acbfb087SZhigang Lu (vaddr + huge_page_size(h) < vma->vm_end) && 4937acbfb087SZhigang Lu (remainder >= pages_per_huge_page(h))) { 4938acbfb087SZhigang Lu vaddr += huge_page_size(h); 4939acbfb087SZhigang Lu remainder -= pages_per_huge_page(h); 4940acbfb087SZhigang Lu i += pages_per_huge_page(h); 4941acbfb087SZhigang Lu spin_unlock(ptl); 4942acbfb087SZhigang Lu continue; 4943acbfb087SZhigang Lu } 4944acbfb087SZhigang Lu 4945d5d4b0aaSChen, Kenneth W same_page: 4946d6692183SChen, Kenneth W if (pages) { 494769d177c2SAndy Whitcroft pages[i] = mem_map_offset(page, pfn_offset); 49483faa52c0SJohn Hubbard /* 49493faa52c0SJohn Hubbard * try_grab_page() should always succeed here, because: 49503faa52c0SJohn Hubbard * a) we hold the ptl lock, and b) we've just checked 49513faa52c0SJohn Hubbard * that the huge page is present in the page tables. If 49523faa52c0SJohn Hubbard * the huge page is present, then the tail pages must 49533faa52c0SJohn Hubbard * also be present. The ptl prevents the head page and 49543faa52c0SJohn Hubbard * tail pages from being rearranged in any way. So this 49553faa52c0SJohn Hubbard * page must be available at this point, unless the page 49563faa52c0SJohn Hubbard * refcount overflowed: 49573faa52c0SJohn Hubbard */ 49583faa52c0SJohn Hubbard if (WARN_ON_ONCE(!try_grab_page(pages[i], flags))) { 49593faa52c0SJohn Hubbard spin_unlock(ptl); 49603faa52c0SJohn Hubbard remainder = 0; 49613faa52c0SJohn Hubbard err = -ENOMEM; 49623faa52c0SJohn Hubbard break; 49633faa52c0SJohn Hubbard } 4964d6692183SChen, Kenneth W } 496563551ae0SDavid Gibson 496663551ae0SDavid Gibson if (vmas) 496763551ae0SDavid Gibson vmas[i] = vma; 496863551ae0SDavid Gibson 496963551ae0SDavid Gibson vaddr += PAGE_SIZE; 4970d5d4b0aaSChen, Kenneth W ++pfn_offset; 497163551ae0SDavid Gibson --remainder; 497263551ae0SDavid Gibson ++i; 4973d5d4b0aaSChen, Kenneth W if (vaddr < vma->vm_end && remainder && 4974a5516438SAndi Kleen pfn_offset < pages_per_huge_page(h)) { 4975d5d4b0aaSChen, Kenneth W /* 4976d5d4b0aaSChen, Kenneth W * We use pfn_offset to avoid touching the pageframes 4977d5d4b0aaSChen, Kenneth W * of this compound page. 4978d5d4b0aaSChen, Kenneth W */ 4979d5d4b0aaSChen, Kenneth W goto same_page; 4980d5d4b0aaSChen, Kenneth W } 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 49945491ae7bSAneesh Kumar K.V #ifndef __HAVE_ARCH_FLUSH_HUGETLB_TLB_RANGE 49955491ae7bSAneesh Kumar K.V /* 49965491ae7bSAneesh Kumar K.V * ARCHes with special requirements for evicting HUGETLB backing TLB entries can 49975491ae7bSAneesh Kumar K.V * implement this. 49985491ae7bSAneesh Kumar K.V */ 49995491ae7bSAneesh Kumar K.V #define flush_hugetlb_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end) 50005491ae7bSAneesh Kumar K.V #endif 50015491ae7bSAneesh Kumar K.V 50027da4d641SPeter Zijlstra unsigned long hugetlb_change_protection(struct vm_area_struct *vma, 50038f860591SZhang, Yanmin unsigned long address, unsigned long end, pgprot_t newprot) 50048f860591SZhang, Yanmin { 50058f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 50068f860591SZhang, Yanmin unsigned long start = address; 50078f860591SZhang, Yanmin pte_t *ptep; 50088f860591SZhang, Yanmin pte_t pte; 5009a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 50107da4d641SPeter Zijlstra unsigned long pages = 0; 5011dff11abeSMike Kravetz bool shared_pmd = false; 5012ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 5013dff11abeSMike Kravetz 5014dff11abeSMike Kravetz /* 5015dff11abeSMike Kravetz * In the case of shared PMDs, the area to flush could be beyond 5016ac46d4f3SJérôme Glisse * start/end. Set range.start/range.end to cover the maximum possible 5017dff11abeSMike Kravetz * range if PMD sharing is possible. 5018dff11abeSMike Kravetz */ 50197269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA, 50207269f999SJérôme Glisse 0, vma, mm, start, end); 5021ac46d4f3SJérôme Glisse adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end); 50228f860591SZhang, Yanmin 50238f860591SZhang, Yanmin BUG_ON(address >= end); 5024ac46d4f3SJérôme Glisse flush_cache_range(vma, range.start, range.end); 50258f860591SZhang, Yanmin 5026ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 502783cde9e8SDavidlohr Bueso i_mmap_lock_write(vma->vm_file->f_mapping); 5028a5516438SAndi Kleen for (; address < end; address += huge_page_size(h)) { 5029cb900f41SKirill A. Shutemov spinlock_t *ptl; 50307868a208SPunit Agrawal ptep = huge_pte_offset(mm, address, huge_page_size(h)); 50318f860591SZhang, Yanmin if (!ptep) 50328f860591SZhang, Yanmin continue; 5033cb900f41SKirill A. Shutemov ptl = huge_pte_lock(h, mm, ptep); 503434ae204fSMike Kravetz if (huge_pmd_unshare(mm, vma, &address, ptep)) { 50357da4d641SPeter Zijlstra pages++; 5036cb900f41SKirill A. Shutemov spin_unlock(ptl); 5037dff11abeSMike Kravetz shared_pmd = true; 503839dde65cSChen, Kenneth W continue; 50397da4d641SPeter Zijlstra } 5040a8bda28dSNaoya Horiguchi pte = huge_ptep_get(ptep); 5041a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { 5042a8bda28dSNaoya Horiguchi spin_unlock(ptl); 5043a8bda28dSNaoya Horiguchi continue; 5044a8bda28dSNaoya Horiguchi } 5045a8bda28dSNaoya Horiguchi if (unlikely(is_hugetlb_entry_migration(pte))) { 5046a8bda28dSNaoya Horiguchi swp_entry_t entry = pte_to_swp_entry(pte); 5047a8bda28dSNaoya Horiguchi 5048a8bda28dSNaoya Horiguchi if (is_write_migration_entry(entry)) { 5049a8bda28dSNaoya Horiguchi pte_t newpte; 5050a8bda28dSNaoya Horiguchi 5051a8bda28dSNaoya Horiguchi make_migration_entry_read(&entry); 5052a8bda28dSNaoya Horiguchi newpte = swp_entry_to_pte(entry); 5053e5251fd4SPunit Agrawal set_huge_swap_pte_at(mm, address, ptep, 5054e5251fd4SPunit Agrawal newpte, huge_page_size(h)); 5055a8bda28dSNaoya Horiguchi pages++; 5056a8bda28dSNaoya Horiguchi } 5057a8bda28dSNaoya Horiguchi spin_unlock(ptl); 5058a8bda28dSNaoya Horiguchi continue; 5059a8bda28dSNaoya Horiguchi } 5060a8bda28dSNaoya Horiguchi if (!huge_pte_none(pte)) { 5061023bdd00SAneesh Kumar K.V pte_t old_pte; 5062023bdd00SAneesh Kumar K.V 5063023bdd00SAneesh Kumar K.V old_pte = huge_ptep_modify_prot_start(vma, address, ptep); 5064023bdd00SAneesh Kumar K.V pte = pte_mkhuge(huge_pte_modify(old_pte, newprot)); 5065be7517d6STony Lu pte = arch_make_huge_pte(pte, vma, NULL, 0); 5066023bdd00SAneesh Kumar K.V huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); 50677da4d641SPeter Zijlstra pages++; 50688f860591SZhang, Yanmin } 5069cb900f41SKirill A. Shutemov spin_unlock(ptl); 50708f860591SZhang, Yanmin } 5071d833352aSMel Gorman /* 5072c8c06efaSDavidlohr Bueso * Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare 5073d833352aSMel Gorman * may have cleared our pud entry and done put_page on the page table: 5074c8c06efaSDavidlohr Bueso * once we release i_mmap_rwsem, another task can do the final put_page 5075dff11abeSMike Kravetz * and that page table be reused and filled with junk. If we actually 5076dff11abeSMike Kravetz * did unshare a page of pmds, flush the range corresponding to the pud. 5077d833352aSMel Gorman */ 5078dff11abeSMike Kravetz if (shared_pmd) 5079ac46d4f3SJérôme Glisse flush_hugetlb_tlb_range(vma, range.start, range.end); 5080dff11abeSMike Kravetz else 50815491ae7bSAneesh Kumar K.V flush_hugetlb_tlb_range(vma, start, end); 50820f10851eSJérôme Glisse /* 50830f10851eSJérôme Glisse * No need to call mmu_notifier_invalidate_range() we are downgrading 50840f10851eSJérôme Glisse * page table protection not changing it to point to a new page. 50850f10851eSJérôme Glisse * 5086ad56b738SMike Rapoport * See Documentation/vm/mmu_notifier.rst 50870f10851eSJérôme Glisse */ 508883cde9e8SDavidlohr Bueso i_mmap_unlock_write(vma->vm_file->f_mapping); 5089ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 50907da4d641SPeter Zijlstra 50917da4d641SPeter Zijlstra return pages << h->order; 50928f860591SZhang, Yanmin } 50938f860591SZhang, Yanmin 5094a1e78772SMel Gorman int hugetlb_reserve_pages(struct inode *inode, 5095a1e78772SMel Gorman long from, long to, 50965a6fe125SMel Gorman struct vm_area_struct *vma, 5097ca16d140SKOSAKI Motohiro vm_flags_t vm_flags) 5098e4e574b7SAdam Litke { 50990db9d74eSMina Almasry long ret, chg, add = -1; 5100a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 510190481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 51029119a41eSJoonsoo Kim struct resv_map *resv_map; 5103075a61d0SMina Almasry struct hugetlb_cgroup *h_cg = NULL; 51040db9d74eSMina Almasry long gbl_reserve, regions_needed = 0; 5105e4e574b7SAdam Litke 510663489f8eSMike Kravetz /* This should never happen */ 510763489f8eSMike Kravetz if (from > to) { 510863489f8eSMike Kravetz VM_WARN(1, "%s called with a negative range\n", __func__); 510963489f8eSMike Kravetz return -EINVAL; 511063489f8eSMike Kravetz } 511163489f8eSMike Kravetz 5112a1e78772SMel Gorman /* 511317c9d12eSMel Gorman * Only apply hugepage reservation if asked. At fault time, an 511417c9d12eSMel Gorman * attempt will be made for VM_NORESERVE to allocate a page 511590481622SDavid Gibson * without using reserves 511617c9d12eSMel Gorman */ 5117ca16d140SKOSAKI Motohiro if (vm_flags & VM_NORESERVE) 511817c9d12eSMel Gorman return 0; 511917c9d12eSMel Gorman 512017c9d12eSMel Gorman /* 5121a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 5122a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 5123a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 5124a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 5125a1e78772SMel Gorman */ 51269119a41eSJoonsoo Kim if (!vma || vma->vm_flags & VM_MAYSHARE) { 5127f27a5136SMike Kravetz /* 5128f27a5136SMike Kravetz * resv_map can not be NULL as hugetlb_reserve_pages is only 5129f27a5136SMike Kravetz * called for inodes for which resv_maps were created (see 5130f27a5136SMike Kravetz * hugetlbfs_get_inode). 5131f27a5136SMike Kravetz */ 51324e35f483SJoonsoo Kim resv_map = inode_resv_map(inode); 51339119a41eSJoonsoo Kim 51340db9d74eSMina Almasry chg = region_chg(resv_map, from, to, ®ions_needed); 51359119a41eSJoonsoo Kim 51369119a41eSJoonsoo Kim } else { 5137e9fe92aeSMina Almasry /* Private mapping. */ 51389119a41eSJoonsoo Kim resv_map = resv_map_alloc(); 51395a6fe125SMel Gorman if (!resv_map) 51405a6fe125SMel Gorman return -ENOMEM; 51415a6fe125SMel Gorman 514217c9d12eSMel Gorman chg = to - from; 514317c9d12eSMel Gorman 51445a6fe125SMel Gorman set_vma_resv_map(vma, resv_map); 51455a6fe125SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 51465a6fe125SMel Gorman } 51475a6fe125SMel Gorman 5148c50ac050SDave Hansen if (chg < 0) { 5149c50ac050SDave Hansen ret = chg; 5150c50ac050SDave Hansen goto out_err; 5151c50ac050SDave Hansen } 515217c9d12eSMel Gorman 5153075a61d0SMina Almasry ret = hugetlb_cgroup_charge_cgroup_rsvd( 5154075a61d0SMina Almasry hstate_index(h), chg * pages_per_huge_page(h), &h_cg); 5155075a61d0SMina Almasry 5156075a61d0SMina Almasry if (ret < 0) { 5157075a61d0SMina Almasry ret = -ENOMEM; 5158075a61d0SMina Almasry goto out_err; 5159075a61d0SMina Almasry } 5160075a61d0SMina Almasry 5161075a61d0SMina Almasry if (vma && !(vma->vm_flags & VM_MAYSHARE) && h_cg) { 5162075a61d0SMina Almasry /* For private mappings, the hugetlb_cgroup uncharge info hangs 5163075a61d0SMina Almasry * of the resv_map. 5164075a61d0SMina Almasry */ 5165075a61d0SMina Almasry resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h); 5166075a61d0SMina Almasry } 5167075a61d0SMina Almasry 51681c5ecae3SMike Kravetz /* 51691c5ecae3SMike Kravetz * There must be enough pages in the subpool for the mapping. If 51701c5ecae3SMike Kravetz * the subpool has a minimum size, there may be some global 51711c5ecae3SMike Kravetz * reservations already in place (gbl_reserve). 51721c5ecae3SMike Kravetz */ 51731c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_get_pages(spool, chg); 51741c5ecae3SMike Kravetz if (gbl_reserve < 0) { 5175c50ac050SDave Hansen ret = -ENOSPC; 5176075a61d0SMina Almasry goto out_uncharge_cgroup; 5177c50ac050SDave Hansen } 517817c9d12eSMel Gorman 517917c9d12eSMel Gorman /* 518017c9d12eSMel Gorman * Check enough hugepages are available for the reservation. 518190481622SDavid Gibson * Hand the pages back to the subpool if there are not 518217c9d12eSMel Gorman */ 51831c5ecae3SMike Kravetz ret = hugetlb_acct_memory(h, gbl_reserve); 518417c9d12eSMel Gorman if (ret < 0) { 5185075a61d0SMina Almasry goto out_put_pages; 518617c9d12eSMel Gorman } 518717c9d12eSMel Gorman 518817c9d12eSMel Gorman /* 518917c9d12eSMel Gorman * Account for the reservations made. Shared mappings record regions 519017c9d12eSMel Gorman * that have reservations as they are shared by multiple VMAs. 519117c9d12eSMel Gorman * When the last VMA disappears, the region map says how much 519217c9d12eSMel Gorman * the reservation was and the page cache tells how much of 519317c9d12eSMel Gorman * the reservation was consumed. Private mappings are per-VMA and 519417c9d12eSMel Gorman * only the consumed reservations are tracked. When the VMA 519517c9d12eSMel Gorman * disappears, the original reservation is the VMA size and the 519617c9d12eSMel Gorman * consumed reservations are stored in the map. Hence, nothing 519717c9d12eSMel Gorman * else has to be done for private mappings here 519817c9d12eSMel Gorman */ 519933039678SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) { 5200075a61d0SMina Almasry add = region_add(resv_map, from, to, regions_needed, h, h_cg); 520133039678SMike Kravetz 52020db9d74eSMina Almasry if (unlikely(add < 0)) { 52030db9d74eSMina Almasry hugetlb_acct_memory(h, -gbl_reserve); 5204075a61d0SMina Almasry goto out_put_pages; 52050db9d74eSMina Almasry } else if (unlikely(chg > add)) { 520633039678SMike Kravetz /* 520733039678SMike Kravetz * pages in this range were added to the reserve 520833039678SMike Kravetz * map between region_chg and region_add. This 520933039678SMike Kravetz * indicates a race with alloc_huge_page. Adjust 521033039678SMike Kravetz * the subpool and reserve counts modified above 521133039678SMike Kravetz * based on the difference. 521233039678SMike Kravetz */ 521333039678SMike Kravetz long rsv_adjust; 521433039678SMike Kravetz 5215075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd( 5216075a61d0SMina Almasry hstate_index(h), 5217075a61d0SMina Almasry (chg - add) * pages_per_huge_page(h), h_cg); 5218075a61d0SMina Almasry 521933039678SMike Kravetz rsv_adjust = hugepage_subpool_put_pages(spool, 522033039678SMike Kravetz chg - add); 522133039678SMike Kravetz hugetlb_acct_memory(h, -rsv_adjust); 522233039678SMike Kravetz } 522333039678SMike Kravetz } 5224a43a8c39SChen, Kenneth W return 0; 5225075a61d0SMina Almasry out_put_pages: 5226075a61d0SMina Almasry /* put back original number of pages, chg */ 5227075a61d0SMina Almasry (void)hugepage_subpool_put_pages(spool, chg); 5228075a61d0SMina Almasry out_uncharge_cgroup: 5229075a61d0SMina Almasry hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h), 5230075a61d0SMina Almasry chg * pages_per_huge_page(h), h_cg); 5231c50ac050SDave Hansen out_err: 52325e911373SMike Kravetz if (!vma || vma->vm_flags & VM_MAYSHARE) 52330db9d74eSMina Almasry /* Only call region_abort if the region_chg succeeded but the 52340db9d74eSMina Almasry * region_add failed or didn't run. 52350db9d74eSMina Almasry */ 52360db9d74eSMina Almasry if (chg >= 0 && add < 0) 52370db9d74eSMina Almasry region_abort(resv_map, from, to, regions_needed); 5238f031dd27SJoonsoo Kim if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 5239f031dd27SJoonsoo Kim kref_put(&resv_map->refs, resv_map_release); 5240c50ac050SDave Hansen return ret; 5241a43a8c39SChen, Kenneth W } 5242a43a8c39SChen, Kenneth W 5243b5cec28dSMike Kravetz long hugetlb_unreserve_pages(struct inode *inode, long start, long end, 5244b5cec28dSMike Kravetz long freed) 5245a43a8c39SChen, Kenneth W { 5246a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 52474e35f483SJoonsoo Kim struct resv_map *resv_map = inode_resv_map(inode); 52489119a41eSJoonsoo Kim long chg = 0; 524990481622SDavid Gibson struct hugepage_subpool *spool = subpool_inode(inode); 52501c5ecae3SMike Kravetz long gbl_reserve; 525145c682a6SKen Chen 5252f27a5136SMike Kravetz /* 5253f27a5136SMike Kravetz * Since this routine can be called in the evict inode path for all 5254f27a5136SMike Kravetz * hugetlbfs inodes, resv_map could be NULL. 5255f27a5136SMike Kravetz */ 5256b5cec28dSMike Kravetz if (resv_map) { 5257b5cec28dSMike Kravetz chg = region_del(resv_map, start, end); 5258b5cec28dSMike Kravetz /* 5259b5cec28dSMike Kravetz * region_del() can fail in the rare case where a region 5260b5cec28dSMike Kravetz * must be split and another region descriptor can not be 5261b5cec28dSMike Kravetz * allocated. If end == LONG_MAX, it will not fail. 5262b5cec28dSMike Kravetz */ 5263b5cec28dSMike Kravetz if (chg < 0) 5264b5cec28dSMike Kravetz return chg; 5265b5cec28dSMike Kravetz } 5266b5cec28dSMike Kravetz 526745c682a6SKen Chen spin_lock(&inode->i_lock); 5268e4c6f8beSEric Sandeen inode->i_blocks -= (blocks_per_huge_page(h) * freed); 526945c682a6SKen Chen spin_unlock(&inode->i_lock); 527045c682a6SKen Chen 52711c5ecae3SMike Kravetz /* 52721c5ecae3SMike Kravetz * If the subpool has a minimum size, the number of global 52731c5ecae3SMike Kravetz * reservations to be released may be adjusted. 52741c5ecae3SMike Kravetz */ 52751c5ecae3SMike Kravetz gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed)); 52761c5ecae3SMike Kravetz hugetlb_acct_memory(h, -gbl_reserve); 5277b5cec28dSMike Kravetz 5278b5cec28dSMike Kravetz return 0; 5279a43a8c39SChen, Kenneth W } 528093f70f90SNaoya Horiguchi 52813212b535SSteve Capper #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 52823212b535SSteve Capper static unsigned long page_table_shareable(struct vm_area_struct *svma, 52833212b535SSteve Capper struct vm_area_struct *vma, 52843212b535SSteve Capper unsigned long addr, pgoff_t idx) 52853212b535SSteve Capper { 52863212b535SSteve Capper unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + 52873212b535SSteve Capper svma->vm_start; 52883212b535SSteve Capper unsigned long sbase = saddr & PUD_MASK; 52893212b535SSteve Capper unsigned long s_end = sbase + PUD_SIZE; 52903212b535SSteve Capper 52913212b535SSteve Capper /* Allow segments to share if only one is marked locked */ 5292de60f5f1SEric B Munson unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; 5293de60f5f1SEric B Munson unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK; 52943212b535SSteve Capper 52953212b535SSteve Capper /* 52963212b535SSteve Capper * match the virtual addresses, permission and the alignment of the 52973212b535SSteve Capper * page table page. 52983212b535SSteve Capper */ 52993212b535SSteve Capper if (pmd_index(addr) != pmd_index(saddr) || 53003212b535SSteve Capper vm_flags != svm_flags || 53013212b535SSteve Capper sbase < svma->vm_start || svma->vm_end < s_end) 53023212b535SSteve Capper return 0; 53033212b535SSteve Capper 53043212b535SSteve Capper return saddr; 53053212b535SSteve Capper } 53063212b535SSteve Capper 530731aafb45SNicholas Krause static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr) 53083212b535SSteve Capper { 53093212b535SSteve Capper unsigned long base = addr & PUD_MASK; 53103212b535SSteve Capper unsigned long end = base + PUD_SIZE; 53113212b535SSteve Capper 53123212b535SSteve Capper /* 53133212b535SSteve Capper * check on proper vm_flags and page table alignment 53143212b535SSteve Capper */ 5315017b1660SMike Kravetz if (vma->vm_flags & VM_MAYSHARE && range_in_vma(vma, base, end)) 531631aafb45SNicholas Krause return true; 531731aafb45SNicholas Krause return false; 53183212b535SSteve Capper } 53193212b535SSteve Capper 53203212b535SSteve Capper /* 5321017b1660SMike Kravetz * Determine if start,end range within vma could be mapped by shared pmd. 5322017b1660SMike Kravetz * If yes, adjust start and end to cover range associated with possible 5323017b1660SMike Kravetz * shared pmd mappings. 5324017b1660SMike Kravetz */ 5325017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 5326017b1660SMike Kravetz unsigned long *start, unsigned long *end) 5327017b1660SMike Kravetz { 532875802ca6SPeter Xu unsigned long a_start, a_end; 5329017b1660SMike Kravetz 5330017b1660SMike Kravetz if (!(vma->vm_flags & VM_MAYSHARE)) 5331017b1660SMike Kravetz return; 5332017b1660SMike Kravetz 533375802ca6SPeter Xu /* Extend the range to be PUD aligned for a worst case scenario */ 533475802ca6SPeter Xu a_start = ALIGN_DOWN(*start, PUD_SIZE); 533575802ca6SPeter Xu a_end = ALIGN(*end, PUD_SIZE); 5336017b1660SMike Kravetz 5337017b1660SMike Kravetz /* 533875802ca6SPeter Xu * Intersect the range with the vma range, since pmd sharing won't be 533975802ca6SPeter Xu * across vma after all 5340017b1660SMike Kravetz */ 534175802ca6SPeter Xu *start = max(vma->vm_start, a_start); 534275802ca6SPeter Xu *end = min(vma->vm_end, a_end); 5343017b1660SMike Kravetz } 5344017b1660SMike Kravetz 5345017b1660SMike Kravetz /* 53463212b535SSteve Capper * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() 53473212b535SSteve Capper * and returns the corresponding pte. While this is not necessary for the 53483212b535SSteve Capper * !shared pmd case because we can allocate the pmd later as well, it makes the 5349c0d0381aSMike Kravetz * code much cleaner. 5350c0d0381aSMike Kravetz * 5351c0d0381aSMike Kravetz * This routine must be called with i_mmap_rwsem held in at least read mode. 5352c0d0381aSMike Kravetz * For hugetlbfs, this prevents removal of any page table entries associated 5353c0d0381aSMike Kravetz * with the address space. This is important as we are setting up sharing 5354c0d0381aSMike Kravetz * based on existing page table entries (mappings). 53553212b535SSteve Capper */ 53563212b535SSteve Capper pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) 53573212b535SSteve Capper { 53583212b535SSteve Capper struct vm_area_struct *vma = find_vma(mm, addr); 53593212b535SSteve Capper struct address_space *mapping = vma->vm_file->f_mapping; 53603212b535SSteve Capper pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + 53613212b535SSteve Capper vma->vm_pgoff; 53623212b535SSteve Capper struct vm_area_struct *svma; 53633212b535SSteve Capper unsigned long saddr; 53643212b535SSteve Capper pte_t *spte = NULL; 53653212b535SSteve Capper pte_t *pte; 5366cb900f41SKirill A. Shutemov spinlock_t *ptl; 53673212b535SSteve Capper 53683212b535SSteve Capper if (!vma_shareable(vma, addr)) 53693212b535SSteve Capper return (pte_t *)pmd_alloc(mm, pud, addr); 53703212b535SSteve Capper 53713212b535SSteve Capper vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { 53723212b535SSteve Capper if (svma == vma) 53733212b535SSteve Capper continue; 53743212b535SSteve Capper 53753212b535SSteve Capper saddr = page_table_shareable(svma, vma, addr, idx); 53763212b535SSteve Capper if (saddr) { 53777868a208SPunit Agrawal spte = huge_pte_offset(svma->vm_mm, saddr, 53787868a208SPunit Agrawal vma_mmu_pagesize(svma)); 53793212b535SSteve Capper if (spte) { 53803212b535SSteve Capper get_page(virt_to_page(spte)); 53813212b535SSteve Capper break; 53823212b535SSteve Capper } 53833212b535SSteve Capper } 53843212b535SSteve Capper } 53853212b535SSteve Capper 53863212b535SSteve Capper if (!spte) 53873212b535SSteve Capper goto out; 53883212b535SSteve Capper 53898bea8052SAneesh Kumar K.V ptl = huge_pte_lock(hstate_vma(vma), mm, spte); 5390dc6c9a35SKirill A. Shutemov if (pud_none(*pud)) { 53913212b535SSteve Capper pud_populate(mm, pud, 53923212b535SSteve Capper (pmd_t *)((unsigned long)spte & PAGE_MASK)); 5393c17b1f42SKirill A. Shutemov mm_inc_nr_pmds(mm); 5394dc6c9a35SKirill A. Shutemov } else { 53953212b535SSteve Capper put_page(virt_to_page(spte)); 5396dc6c9a35SKirill A. Shutemov } 5397cb900f41SKirill A. Shutemov spin_unlock(ptl); 53983212b535SSteve Capper out: 53993212b535SSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 54003212b535SSteve Capper return pte; 54013212b535SSteve Capper } 54023212b535SSteve Capper 54033212b535SSteve Capper /* 54043212b535SSteve Capper * unmap huge page backed by shared pte. 54053212b535SSteve Capper * 54063212b535SSteve Capper * Hugetlb pte page is ref counted at the time of mapping. If pte is shared 54073212b535SSteve Capper * indicated by page_count > 1, unmap is achieved by clearing pud and 54083212b535SSteve Capper * decrementing the ref count. If count == 1, the pte page is not shared. 54093212b535SSteve Capper * 5410c0d0381aSMike Kravetz * Called with page table lock held and i_mmap_rwsem held in write mode. 54113212b535SSteve Capper * 54123212b535SSteve Capper * returns: 1 successfully unmapped a shared pte page 54133212b535SSteve Capper * 0 the underlying pte page is not shared, or it is the last user 54143212b535SSteve Capper */ 541534ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 541634ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 54173212b535SSteve Capper { 54183212b535SSteve Capper pgd_t *pgd = pgd_offset(mm, *addr); 5419c2febafcSKirill A. Shutemov p4d_t *p4d = p4d_offset(pgd, *addr); 5420c2febafcSKirill A. Shutemov pud_t *pud = pud_offset(p4d, *addr); 54213212b535SSteve Capper 542234ae204fSMike Kravetz i_mmap_assert_write_locked(vma->vm_file->f_mapping); 54233212b535SSteve Capper BUG_ON(page_count(virt_to_page(ptep)) == 0); 54243212b535SSteve Capper if (page_count(virt_to_page(ptep)) == 1) 54253212b535SSteve Capper return 0; 54263212b535SSteve Capper 54273212b535SSteve Capper pud_clear(pud); 54283212b535SSteve Capper put_page(virt_to_page(ptep)); 5429dc6c9a35SKirill A. Shutemov mm_dec_nr_pmds(mm); 54303212b535SSteve Capper *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE; 54313212b535SSteve Capper return 1; 54323212b535SSteve Capper } 54339e5fc74cSSteve Capper #define want_pmd_share() (1) 54349e5fc74cSSteve Capper #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 54359e5fc74cSSteve Capper pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) 54369e5fc74cSSteve Capper { 54379e5fc74cSSteve Capper return NULL; 54389e5fc74cSSteve Capper } 5439e81f2d22SZhang Zhen 544034ae204fSMike Kravetz int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, 544134ae204fSMike Kravetz unsigned long *addr, pte_t *ptep) 5442e81f2d22SZhang Zhen { 5443e81f2d22SZhang Zhen return 0; 5444e81f2d22SZhang Zhen } 5445017b1660SMike Kravetz 5446017b1660SMike Kravetz void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, 5447017b1660SMike Kravetz unsigned long *start, unsigned long *end) 5448017b1660SMike Kravetz { 5449017b1660SMike Kravetz } 54509e5fc74cSSteve Capper #define want_pmd_share() (0) 54513212b535SSteve Capper #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ 54523212b535SSteve Capper 54539e5fc74cSSteve Capper #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB 54549e5fc74cSSteve Capper pte_t *huge_pte_alloc(struct mm_struct *mm, 54559e5fc74cSSteve Capper unsigned long addr, unsigned long sz) 54569e5fc74cSSteve Capper { 54579e5fc74cSSteve Capper pgd_t *pgd; 5458c2febafcSKirill A. Shutemov p4d_t *p4d; 54599e5fc74cSSteve Capper pud_t *pud; 54609e5fc74cSSteve Capper pte_t *pte = NULL; 54619e5fc74cSSteve Capper 54629e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 5463f4f0a3d8SKirill A. Shutemov p4d = p4d_alloc(mm, pgd, addr); 5464f4f0a3d8SKirill A. Shutemov if (!p4d) 5465f4f0a3d8SKirill A. Shutemov return NULL; 5466c2febafcSKirill A. Shutemov pud = pud_alloc(mm, p4d, addr); 54679e5fc74cSSteve Capper if (pud) { 54689e5fc74cSSteve Capper if (sz == PUD_SIZE) { 54699e5fc74cSSteve Capper pte = (pte_t *)pud; 54709e5fc74cSSteve Capper } else { 54719e5fc74cSSteve Capper BUG_ON(sz != PMD_SIZE); 54729e5fc74cSSteve Capper if (want_pmd_share() && pud_none(*pud)) 54739e5fc74cSSteve Capper pte = huge_pmd_share(mm, addr, pud); 54749e5fc74cSSteve Capper else 54759e5fc74cSSteve Capper pte = (pte_t *)pmd_alloc(mm, pud, addr); 54769e5fc74cSSteve Capper } 54779e5fc74cSSteve Capper } 54784e666314SMichal Hocko BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte)); 54799e5fc74cSSteve Capper 54809e5fc74cSSteve Capper return pte; 54819e5fc74cSSteve Capper } 54829e5fc74cSSteve Capper 54839b19df29SPunit Agrawal /* 54849b19df29SPunit Agrawal * huge_pte_offset() - Walk the page table to resolve the hugepage 54859b19df29SPunit Agrawal * entry at address @addr 54869b19df29SPunit Agrawal * 54878ac0b81aSLi Xinhai * Return: Pointer to page table entry (PUD or PMD) for 54888ac0b81aSLi Xinhai * address @addr, or NULL if a !p*d_present() entry is encountered and the 54899b19df29SPunit Agrawal * size @sz doesn't match the hugepage size at this level of the page 54909b19df29SPunit Agrawal * table. 54919b19df29SPunit Agrawal */ 54927868a208SPunit Agrawal pte_t *huge_pte_offset(struct mm_struct *mm, 54937868a208SPunit Agrawal unsigned long addr, unsigned long sz) 54949e5fc74cSSteve Capper { 54959e5fc74cSSteve Capper pgd_t *pgd; 5496c2febafcSKirill A. Shutemov p4d_t *p4d; 54978ac0b81aSLi Xinhai pud_t *pud; 54988ac0b81aSLi Xinhai pmd_t *pmd; 54999e5fc74cSSteve Capper 55009e5fc74cSSteve Capper pgd = pgd_offset(mm, addr); 5501c2febafcSKirill A. Shutemov if (!pgd_present(*pgd)) 5502c2febafcSKirill A. Shutemov return NULL; 5503c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, addr); 5504c2febafcSKirill A. Shutemov if (!p4d_present(*p4d)) 5505c2febafcSKirill A. Shutemov return NULL; 55069b19df29SPunit Agrawal 5507c2febafcSKirill A. Shutemov pud = pud_offset(p4d, addr); 55088ac0b81aSLi Xinhai if (sz == PUD_SIZE) 55098ac0b81aSLi Xinhai /* must be pud huge, non-present or none */ 55109e5fc74cSSteve Capper return (pte_t *)pud; 55118ac0b81aSLi Xinhai if (!pud_present(*pud)) 55128ac0b81aSLi Xinhai return NULL; 55138ac0b81aSLi Xinhai /* must have a valid entry and size to go further */ 55149b19df29SPunit Agrawal 55159e5fc74cSSteve Capper pmd = pmd_offset(pud, addr); 55168ac0b81aSLi Xinhai /* must be pmd huge, non-present or none */ 55179e5fc74cSSteve Capper return (pte_t *)pmd; 55189e5fc74cSSteve Capper } 55199e5fc74cSSteve Capper 552061f77edaSNaoya Horiguchi #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ 552161f77edaSNaoya Horiguchi 552261f77edaSNaoya Horiguchi /* 552361f77edaSNaoya Horiguchi * These functions are overwritable if your architecture needs its own 552461f77edaSNaoya Horiguchi * behavior. 552561f77edaSNaoya Horiguchi */ 552661f77edaSNaoya Horiguchi struct page * __weak 552761f77edaSNaoya Horiguchi follow_huge_addr(struct mm_struct *mm, unsigned long address, 552861f77edaSNaoya Horiguchi int write) 552961f77edaSNaoya Horiguchi { 553061f77edaSNaoya Horiguchi return ERR_PTR(-EINVAL); 553161f77edaSNaoya Horiguchi } 553261f77edaSNaoya Horiguchi 553361f77edaSNaoya Horiguchi struct page * __weak 55344dc71451SAneesh Kumar K.V follow_huge_pd(struct vm_area_struct *vma, 55354dc71451SAneesh Kumar K.V unsigned long address, hugepd_t hpd, int flags, int pdshift) 55364dc71451SAneesh Kumar K.V { 55374dc71451SAneesh Kumar K.V WARN(1, "hugepd follow called with no support for hugepage directory format\n"); 55384dc71451SAneesh Kumar K.V return NULL; 55394dc71451SAneesh Kumar K.V } 55404dc71451SAneesh Kumar K.V 55414dc71451SAneesh Kumar K.V struct page * __weak 55429e5fc74cSSteve Capper follow_huge_pmd(struct mm_struct *mm, unsigned long address, 5543e66f17ffSNaoya Horiguchi pmd_t *pmd, int flags) 55449e5fc74cSSteve Capper { 5545e66f17ffSNaoya Horiguchi struct page *page = NULL; 5546e66f17ffSNaoya Horiguchi spinlock_t *ptl; 5547c9d398faSNaoya Horiguchi pte_t pte; 55483faa52c0SJohn Hubbard 55493faa52c0SJohn Hubbard /* FOLL_GET and FOLL_PIN are mutually exclusive. */ 55503faa52c0SJohn Hubbard if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == 55513faa52c0SJohn Hubbard (FOLL_PIN | FOLL_GET))) 55523faa52c0SJohn Hubbard return NULL; 55533faa52c0SJohn Hubbard 5554e66f17ffSNaoya Horiguchi retry: 5555e66f17ffSNaoya Horiguchi ptl = pmd_lockptr(mm, pmd); 5556e66f17ffSNaoya Horiguchi spin_lock(ptl); 5557e66f17ffSNaoya Horiguchi /* 5558e66f17ffSNaoya Horiguchi * make sure that the address range covered by this pmd is not 5559e66f17ffSNaoya Horiguchi * unmapped from other threads. 5560e66f17ffSNaoya Horiguchi */ 5561e66f17ffSNaoya Horiguchi if (!pmd_huge(*pmd)) 5562e66f17ffSNaoya Horiguchi goto out; 5563c9d398faSNaoya Horiguchi pte = huge_ptep_get((pte_t *)pmd); 5564c9d398faSNaoya Horiguchi if (pte_present(pte)) { 556597534127SGerald Schaefer page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT); 55663faa52c0SJohn Hubbard /* 55673faa52c0SJohn Hubbard * try_grab_page() should always succeed here, because: a) we 55683faa52c0SJohn Hubbard * hold the pmd (ptl) lock, and b) we've just checked that the 55693faa52c0SJohn Hubbard * huge pmd (head) page is present in the page tables. The ptl 55703faa52c0SJohn Hubbard * prevents the head page and tail pages from being rearranged 55713faa52c0SJohn Hubbard * in any way. So this page must be available at this point, 55723faa52c0SJohn Hubbard * unless the page refcount overflowed: 55733faa52c0SJohn Hubbard */ 55743faa52c0SJohn Hubbard if (WARN_ON_ONCE(!try_grab_page(page, flags))) { 55753faa52c0SJohn Hubbard page = NULL; 55763faa52c0SJohn Hubbard goto out; 55773faa52c0SJohn Hubbard } 5578e66f17ffSNaoya Horiguchi } else { 5579c9d398faSNaoya Horiguchi if (is_hugetlb_entry_migration(pte)) { 5580e66f17ffSNaoya Horiguchi spin_unlock(ptl); 5581e66f17ffSNaoya Horiguchi __migration_entry_wait(mm, (pte_t *)pmd, ptl); 5582e66f17ffSNaoya Horiguchi goto retry; 5583e66f17ffSNaoya Horiguchi } 5584e66f17ffSNaoya Horiguchi /* 5585e66f17ffSNaoya Horiguchi * hwpoisoned entry is treated as no_page_table in 5586e66f17ffSNaoya Horiguchi * follow_page_mask(). 5587e66f17ffSNaoya Horiguchi */ 5588e66f17ffSNaoya Horiguchi } 5589e66f17ffSNaoya Horiguchi out: 5590e66f17ffSNaoya Horiguchi spin_unlock(ptl); 55919e5fc74cSSteve Capper return page; 55929e5fc74cSSteve Capper } 55939e5fc74cSSteve Capper 559461f77edaSNaoya Horiguchi struct page * __weak 55959e5fc74cSSteve Capper follow_huge_pud(struct mm_struct *mm, unsigned long address, 5596e66f17ffSNaoya Horiguchi pud_t *pud, int flags) 55979e5fc74cSSteve Capper { 55983faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 5599e66f17ffSNaoya Horiguchi return NULL; 56009e5fc74cSSteve Capper 5601e66f17ffSNaoya Horiguchi return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); 56029e5fc74cSSteve Capper } 56039e5fc74cSSteve Capper 5604faaa5b62SAnshuman Khandual struct page * __weak 5605faaa5b62SAnshuman Khandual follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) 5606faaa5b62SAnshuman Khandual { 56073faa52c0SJohn Hubbard if (flags & (FOLL_GET | FOLL_PIN)) 5608faaa5b62SAnshuman Khandual return NULL; 5609faaa5b62SAnshuman Khandual 5610faaa5b62SAnshuman Khandual return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); 5611faaa5b62SAnshuman Khandual } 5612faaa5b62SAnshuman Khandual 561331caf665SNaoya Horiguchi bool isolate_huge_page(struct page *page, struct list_head *list) 561431caf665SNaoya Horiguchi { 5615bcc54222SNaoya Horiguchi bool ret = true; 5616bcc54222SNaoya Horiguchi 5617309381feSSasha Levin VM_BUG_ON_PAGE(!PageHead(page), page); 561831caf665SNaoya Horiguchi spin_lock(&hugetlb_lock); 5619bcc54222SNaoya Horiguchi if (!page_huge_active(page) || !get_page_unless_zero(page)) { 5620bcc54222SNaoya Horiguchi ret = false; 5621bcc54222SNaoya Horiguchi goto unlock; 5622bcc54222SNaoya Horiguchi } 5623bcc54222SNaoya Horiguchi clear_page_huge_active(page); 562431caf665SNaoya Horiguchi list_move_tail(&page->lru, list); 5625bcc54222SNaoya Horiguchi unlock: 562631caf665SNaoya Horiguchi spin_unlock(&hugetlb_lock); 5627bcc54222SNaoya Horiguchi return ret; 562831caf665SNaoya Horiguchi } 562931caf665SNaoya Horiguchi 563031caf665SNaoya Horiguchi void putback_active_hugepage(struct page *page) 563131caf665SNaoya Horiguchi { 5632309381feSSasha Levin VM_BUG_ON_PAGE(!PageHead(page), page); 563331caf665SNaoya Horiguchi spin_lock(&hugetlb_lock); 5634bcc54222SNaoya Horiguchi set_page_huge_active(page); 563531caf665SNaoya Horiguchi list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); 563631caf665SNaoya Horiguchi spin_unlock(&hugetlb_lock); 563731caf665SNaoya Horiguchi put_page(page); 563831caf665SNaoya Horiguchi } 5639ab5ac90aSMichal Hocko 5640ab5ac90aSMichal Hocko void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason) 5641ab5ac90aSMichal Hocko { 5642ab5ac90aSMichal Hocko struct hstate *h = page_hstate(oldpage); 5643ab5ac90aSMichal Hocko 5644ab5ac90aSMichal Hocko hugetlb_cgroup_migrate(oldpage, newpage); 5645ab5ac90aSMichal Hocko set_page_owner_migrate_reason(newpage, reason); 5646ab5ac90aSMichal Hocko 5647ab5ac90aSMichal Hocko /* 5648ab5ac90aSMichal Hocko * transfer temporary state of the new huge page. This is 5649ab5ac90aSMichal Hocko * reverse to other transitions because the newpage is going to 5650ab5ac90aSMichal Hocko * be final while the old one will be freed so it takes over 5651ab5ac90aSMichal Hocko * the temporary status. 5652ab5ac90aSMichal Hocko * 5653ab5ac90aSMichal Hocko * Also note that we have to transfer the per-node surplus state 5654ab5ac90aSMichal Hocko * here as well otherwise the global surplus count will not match 5655ab5ac90aSMichal Hocko * the per-node's. 5656ab5ac90aSMichal Hocko */ 5657ab5ac90aSMichal Hocko if (PageHugeTemporary(newpage)) { 5658ab5ac90aSMichal Hocko int old_nid = page_to_nid(oldpage); 5659ab5ac90aSMichal Hocko int new_nid = page_to_nid(newpage); 5660ab5ac90aSMichal Hocko 5661ab5ac90aSMichal Hocko SetPageHugeTemporary(oldpage); 5662ab5ac90aSMichal Hocko ClearPageHugeTemporary(newpage); 5663ab5ac90aSMichal Hocko 5664ab5ac90aSMichal Hocko spin_lock(&hugetlb_lock); 5665ab5ac90aSMichal Hocko if (h->surplus_huge_pages_node[old_nid]) { 5666ab5ac90aSMichal Hocko h->surplus_huge_pages_node[old_nid]--; 5667ab5ac90aSMichal Hocko h->surplus_huge_pages_node[new_nid]++; 5668ab5ac90aSMichal Hocko } 5669ab5ac90aSMichal Hocko spin_unlock(&hugetlb_lock); 5670ab5ac90aSMichal Hocko } 5671ab5ac90aSMichal Hocko } 5672cf11e85fSRoman Gushchin 5673cf11e85fSRoman Gushchin #ifdef CONFIG_CMA 5674cf11e85fSRoman Gushchin static bool cma_reserve_called __initdata; 5675cf11e85fSRoman Gushchin 5676cf11e85fSRoman Gushchin static int __init cmdline_parse_hugetlb_cma(char *p) 5677cf11e85fSRoman Gushchin { 5678cf11e85fSRoman Gushchin hugetlb_cma_size = memparse(p, &p); 5679cf11e85fSRoman Gushchin return 0; 5680cf11e85fSRoman Gushchin } 5681cf11e85fSRoman Gushchin 5682cf11e85fSRoman Gushchin early_param("hugetlb_cma", cmdline_parse_hugetlb_cma); 5683cf11e85fSRoman Gushchin 5684cf11e85fSRoman Gushchin void __init hugetlb_cma_reserve(int order) 5685cf11e85fSRoman Gushchin { 5686cf11e85fSRoman Gushchin unsigned long size, reserved, per_node; 5687cf11e85fSRoman Gushchin int nid; 5688cf11e85fSRoman Gushchin 5689cf11e85fSRoman Gushchin cma_reserve_called = true; 5690cf11e85fSRoman Gushchin 5691cf11e85fSRoman Gushchin if (!hugetlb_cma_size) 5692cf11e85fSRoman Gushchin return; 5693cf11e85fSRoman Gushchin 5694cf11e85fSRoman Gushchin if (hugetlb_cma_size < (PAGE_SIZE << order)) { 5695cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n", 5696cf11e85fSRoman Gushchin (PAGE_SIZE << order) / SZ_1M); 5697cf11e85fSRoman Gushchin return; 5698cf11e85fSRoman Gushchin } 5699cf11e85fSRoman Gushchin 5700cf11e85fSRoman Gushchin /* 5701cf11e85fSRoman Gushchin * If 3 GB area is requested on a machine with 4 numa nodes, 5702cf11e85fSRoman Gushchin * let's allocate 1 GB on first three nodes and ignore the last one. 5703cf11e85fSRoman Gushchin */ 5704cf11e85fSRoman Gushchin per_node = DIV_ROUND_UP(hugetlb_cma_size, nr_online_nodes); 5705cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n", 5706cf11e85fSRoman Gushchin hugetlb_cma_size / SZ_1M, per_node / SZ_1M); 5707cf11e85fSRoman Gushchin 5708cf11e85fSRoman Gushchin reserved = 0; 5709cf11e85fSRoman Gushchin for_each_node_state(nid, N_ONLINE) { 5710cf11e85fSRoman Gushchin int res; 571129d0f41dSBarry Song char name[20]; 5712cf11e85fSRoman Gushchin 5713cf11e85fSRoman Gushchin size = min(per_node, hugetlb_cma_size - reserved); 5714cf11e85fSRoman Gushchin size = round_up(size, PAGE_SIZE << order); 5715cf11e85fSRoman Gushchin 571629d0f41dSBarry Song snprintf(name, 20, "hugetlb%d", nid); 5717cf11e85fSRoman Gushchin res = cma_declare_contiguous_nid(0, size, 0, PAGE_SIZE << order, 571829d0f41dSBarry Song 0, false, name, 5719cf11e85fSRoman Gushchin &hugetlb_cma[nid], nid); 5720cf11e85fSRoman Gushchin if (res) { 5721cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: reservation failed: err %d, node %d", 5722cf11e85fSRoman Gushchin res, nid); 5723cf11e85fSRoman Gushchin continue; 5724cf11e85fSRoman Gushchin } 5725cf11e85fSRoman Gushchin 5726cf11e85fSRoman Gushchin reserved += size; 5727cf11e85fSRoman Gushchin pr_info("hugetlb_cma: reserved %lu MiB on node %d\n", 5728cf11e85fSRoman Gushchin size / SZ_1M, nid); 5729cf11e85fSRoman Gushchin 5730cf11e85fSRoman Gushchin if (reserved >= hugetlb_cma_size) 5731cf11e85fSRoman Gushchin break; 5732cf11e85fSRoman Gushchin } 5733cf11e85fSRoman Gushchin } 5734cf11e85fSRoman Gushchin 5735cf11e85fSRoman Gushchin void __init hugetlb_cma_check(void) 5736cf11e85fSRoman Gushchin { 5737cf11e85fSRoman Gushchin if (!hugetlb_cma_size || cma_reserve_called) 5738cf11e85fSRoman Gushchin return; 5739cf11e85fSRoman Gushchin 5740cf11e85fSRoman Gushchin pr_warn("hugetlb_cma: the option isn't supported by current arch\n"); 5741cf11e85fSRoman Gushchin } 5742cf11e85fSRoman Gushchin 5743cf11e85fSRoman Gushchin #endif /* CONFIG_CMA */ 5744