11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * Generic hugetlb support. 31da177e4SLinus Torvalds * (C) William Irwin, April 2004 41da177e4SLinus Torvalds */ 51da177e4SLinus Torvalds #include <linux/gfp.h> 61da177e4SLinus Torvalds #include <linux/list.h> 71da177e4SLinus Torvalds #include <linux/init.h> 81da177e4SLinus Torvalds #include <linux/module.h> 91da177e4SLinus Torvalds #include <linux/mm.h> 101da177e4SLinus Torvalds #include <linux/sysctl.h> 111da177e4SLinus Torvalds #include <linux/highmem.h> 121da177e4SLinus Torvalds #include <linux/nodemask.h> 1363551ae0SDavid Gibson #include <linux/pagemap.h> 145da7ca86SChristoph Lameter #include <linux/mempolicy.h> 15aea47ff3SChristoph Lameter #include <linux/cpuset.h> 163935baa9SDavid Gibson #include <linux/mutex.h> 17a3437870SNishanth Aravamudan #include <linux/sysfs.h> 185da7ca86SChristoph Lameter 1963551ae0SDavid Gibson #include <asm/page.h> 2063551ae0SDavid Gibson #include <asm/pgtable.h> 2163551ae0SDavid Gibson 2263551ae0SDavid Gibson #include <linux/hugetlb.h> 237835e98bSNick Piggin #include "internal.h" 241da177e4SLinus Torvalds 251da177e4SLinus Torvalds const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; 26396faf03SMel Gorman static gfp_t htlb_alloc_mask = GFP_HIGHUSER; 27396faf03SMel Gorman unsigned long hugepages_treat_as_movable; 28a5516438SAndi Kleen 29e5ff2159SAndi Kleen static int max_hstate; 30e5ff2159SAndi Kleen unsigned int default_hstate_idx; 31e5ff2159SAndi Kleen struct hstate hstates[HUGE_MAX_HSTATE]; 32e5ff2159SAndi Kleen 33e5ff2159SAndi Kleen /* for command line parsing */ 34e5ff2159SAndi Kleen static struct hstate * __initdata parsed_hstate; 35e5ff2159SAndi Kleen static unsigned long __initdata default_hstate_max_huge_pages; 36e5ff2159SAndi Kleen 37e5ff2159SAndi Kleen #define for_each_hstate(h) \ 38e5ff2159SAndi Kleen for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++) 39396faf03SMel Gorman 403935baa9SDavid Gibson /* 413935baa9SDavid Gibson * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages 423935baa9SDavid Gibson */ 433935baa9SDavid Gibson static DEFINE_SPINLOCK(hugetlb_lock); 440bd0f9fbSEric Paris 45e7c4b0bfSAndy Whitcroft /* 4696822904SAndy Whitcroft * Region tracking -- allows tracking of reservations and instantiated pages 4796822904SAndy Whitcroft * across the pages in a mapping. 4884afd99bSAndy Whitcroft * 4984afd99bSAndy Whitcroft * The region data structures are protected by a combination of the mmap_sem 5084afd99bSAndy Whitcroft * and the hugetlb_instantion_mutex. To access or modify a region the caller 5184afd99bSAndy Whitcroft * must either hold the mmap_sem for write, or the mmap_sem for read and 5284afd99bSAndy Whitcroft * the hugetlb_instantiation mutex: 5384afd99bSAndy Whitcroft * 5484afd99bSAndy Whitcroft * down_write(&mm->mmap_sem); 5584afd99bSAndy Whitcroft * or 5684afd99bSAndy Whitcroft * down_read(&mm->mmap_sem); 5784afd99bSAndy Whitcroft * mutex_lock(&hugetlb_instantiation_mutex); 5896822904SAndy Whitcroft */ 5996822904SAndy Whitcroft struct file_region { 6096822904SAndy Whitcroft struct list_head link; 6196822904SAndy Whitcroft long from; 6296822904SAndy Whitcroft long to; 6396822904SAndy Whitcroft }; 6496822904SAndy Whitcroft 6596822904SAndy Whitcroft static long region_add(struct list_head *head, long f, long t) 6696822904SAndy Whitcroft { 6796822904SAndy Whitcroft struct file_region *rg, *nrg, *trg; 6896822904SAndy Whitcroft 6996822904SAndy Whitcroft /* Locate the region we are either in or before. */ 7096822904SAndy Whitcroft list_for_each_entry(rg, head, link) 7196822904SAndy Whitcroft if (f <= rg->to) 7296822904SAndy Whitcroft break; 7396822904SAndy Whitcroft 7496822904SAndy Whitcroft /* Round our left edge to the current segment if it encloses us. */ 7596822904SAndy Whitcroft if (f > rg->from) 7696822904SAndy Whitcroft f = rg->from; 7796822904SAndy Whitcroft 7896822904SAndy Whitcroft /* Check for and consume any regions we now overlap with. */ 7996822904SAndy Whitcroft nrg = rg; 8096822904SAndy Whitcroft list_for_each_entry_safe(rg, trg, rg->link.prev, link) { 8196822904SAndy Whitcroft if (&rg->link == head) 8296822904SAndy Whitcroft break; 8396822904SAndy Whitcroft if (rg->from > t) 8496822904SAndy Whitcroft break; 8596822904SAndy Whitcroft 8696822904SAndy Whitcroft /* If this area reaches higher then extend our area to 8796822904SAndy Whitcroft * include it completely. If this is not the first area 8896822904SAndy Whitcroft * which we intend to reuse, free it. */ 8996822904SAndy Whitcroft if (rg->to > t) 9096822904SAndy Whitcroft t = rg->to; 9196822904SAndy Whitcroft if (rg != nrg) { 9296822904SAndy Whitcroft list_del(&rg->link); 9396822904SAndy Whitcroft kfree(rg); 9496822904SAndy Whitcroft } 9596822904SAndy Whitcroft } 9696822904SAndy Whitcroft nrg->from = f; 9796822904SAndy Whitcroft nrg->to = t; 9896822904SAndy Whitcroft return 0; 9996822904SAndy Whitcroft } 10096822904SAndy Whitcroft 10196822904SAndy Whitcroft static long region_chg(struct list_head *head, long f, long t) 10296822904SAndy Whitcroft { 10396822904SAndy Whitcroft struct file_region *rg, *nrg; 10496822904SAndy Whitcroft long chg = 0; 10596822904SAndy Whitcroft 10696822904SAndy Whitcroft /* Locate the region we are before or in. */ 10796822904SAndy Whitcroft list_for_each_entry(rg, head, link) 10896822904SAndy Whitcroft if (f <= rg->to) 10996822904SAndy Whitcroft break; 11096822904SAndy Whitcroft 11196822904SAndy Whitcroft /* If we are below the current region then a new region is required. 11296822904SAndy Whitcroft * Subtle, allocate a new region at the position but make it zero 11396822904SAndy Whitcroft * size such that we can guarantee to record the reservation. */ 11496822904SAndy Whitcroft if (&rg->link == head || t < rg->from) { 11596822904SAndy Whitcroft nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); 11696822904SAndy Whitcroft if (!nrg) 11796822904SAndy Whitcroft return -ENOMEM; 11896822904SAndy Whitcroft nrg->from = f; 11996822904SAndy Whitcroft nrg->to = f; 12096822904SAndy Whitcroft INIT_LIST_HEAD(&nrg->link); 12196822904SAndy Whitcroft list_add(&nrg->link, rg->link.prev); 12296822904SAndy Whitcroft 12396822904SAndy Whitcroft return t - f; 12496822904SAndy Whitcroft } 12596822904SAndy Whitcroft 12696822904SAndy Whitcroft /* Round our left edge to the current segment if it encloses us. */ 12796822904SAndy Whitcroft if (f > rg->from) 12896822904SAndy Whitcroft f = rg->from; 12996822904SAndy Whitcroft chg = t - f; 13096822904SAndy Whitcroft 13196822904SAndy Whitcroft /* Check for and consume any regions we now overlap with. */ 13296822904SAndy Whitcroft list_for_each_entry(rg, rg->link.prev, link) { 13396822904SAndy Whitcroft if (&rg->link == head) 13496822904SAndy Whitcroft break; 13596822904SAndy Whitcroft if (rg->from > t) 13696822904SAndy Whitcroft return chg; 13796822904SAndy Whitcroft 13896822904SAndy Whitcroft /* We overlap with this area, if it extends futher than 13996822904SAndy Whitcroft * us then we must extend ourselves. Account for its 14096822904SAndy Whitcroft * existing reservation. */ 14196822904SAndy Whitcroft if (rg->to > t) { 14296822904SAndy Whitcroft chg += rg->to - t; 14396822904SAndy Whitcroft t = rg->to; 14496822904SAndy Whitcroft } 14596822904SAndy Whitcroft chg -= rg->to - rg->from; 14696822904SAndy Whitcroft } 14796822904SAndy Whitcroft return chg; 14896822904SAndy Whitcroft } 14996822904SAndy Whitcroft 15096822904SAndy Whitcroft static long region_truncate(struct list_head *head, long end) 15196822904SAndy Whitcroft { 15296822904SAndy Whitcroft struct file_region *rg, *trg; 15396822904SAndy Whitcroft long chg = 0; 15496822904SAndy Whitcroft 15596822904SAndy Whitcroft /* Locate the region we are either in or before. */ 15696822904SAndy Whitcroft list_for_each_entry(rg, head, link) 15796822904SAndy Whitcroft if (end <= rg->to) 15896822904SAndy Whitcroft break; 15996822904SAndy Whitcroft if (&rg->link == head) 16096822904SAndy Whitcroft return 0; 16196822904SAndy Whitcroft 16296822904SAndy Whitcroft /* If we are in the middle of a region then adjust it. */ 16396822904SAndy Whitcroft if (end > rg->from) { 16496822904SAndy Whitcroft chg = rg->to - end; 16596822904SAndy Whitcroft rg->to = end; 16696822904SAndy Whitcroft rg = list_entry(rg->link.next, typeof(*rg), link); 16796822904SAndy Whitcroft } 16896822904SAndy Whitcroft 16996822904SAndy Whitcroft /* Drop any remaining regions. */ 17096822904SAndy Whitcroft list_for_each_entry_safe(rg, trg, rg->link.prev, link) { 17196822904SAndy Whitcroft if (&rg->link == head) 17296822904SAndy Whitcroft break; 17396822904SAndy Whitcroft chg += rg->to - rg->from; 17496822904SAndy Whitcroft list_del(&rg->link); 17596822904SAndy Whitcroft kfree(rg); 17696822904SAndy Whitcroft } 17796822904SAndy Whitcroft return chg; 17896822904SAndy Whitcroft } 17996822904SAndy Whitcroft 18084afd99bSAndy Whitcroft static long region_count(struct list_head *head, long f, long t) 18184afd99bSAndy Whitcroft { 18284afd99bSAndy Whitcroft struct file_region *rg; 18384afd99bSAndy Whitcroft long chg = 0; 18484afd99bSAndy Whitcroft 18584afd99bSAndy Whitcroft /* Locate each segment we overlap with, and count that overlap. */ 18684afd99bSAndy Whitcroft list_for_each_entry(rg, head, link) { 18784afd99bSAndy Whitcroft int seg_from; 18884afd99bSAndy Whitcroft int seg_to; 18984afd99bSAndy Whitcroft 19084afd99bSAndy Whitcroft if (rg->to <= f) 19184afd99bSAndy Whitcroft continue; 19284afd99bSAndy Whitcroft if (rg->from >= t) 19384afd99bSAndy Whitcroft break; 19484afd99bSAndy Whitcroft 19584afd99bSAndy Whitcroft seg_from = max(rg->from, f); 19684afd99bSAndy Whitcroft seg_to = min(rg->to, t); 19784afd99bSAndy Whitcroft 19884afd99bSAndy Whitcroft chg += seg_to - seg_from; 19984afd99bSAndy Whitcroft } 20084afd99bSAndy Whitcroft 20184afd99bSAndy Whitcroft return chg; 20284afd99bSAndy Whitcroft } 20384afd99bSAndy Whitcroft 20496822904SAndy Whitcroft /* 205e7c4b0bfSAndy Whitcroft * Convert the address within this vma to the page offset within 206e7c4b0bfSAndy Whitcroft * the mapping, in pagecache page units; huge pages here. 207e7c4b0bfSAndy Whitcroft */ 208a5516438SAndi Kleen static pgoff_t vma_hugecache_offset(struct hstate *h, 209a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 210e7c4b0bfSAndy Whitcroft { 211a5516438SAndi Kleen return ((address - vma->vm_start) >> huge_page_shift(h)) + 212a5516438SAndi Kleen (vma->vm_pgoff >> huge_page_order(h)); 213e7c4b0bfSAndy Whitcroft } 214e7c4b0bfSAndy Whitcroft 21584afd99bSAndy Whitcroft /* 21684afd99bSAndy Whitcroft * Flags for MAP_PRIVATE reservations. These are stored in the bottom 21784afd99bSAndy Whitcroft * bits of the reservation map pointer, which are always clear due to 21884afd99bSAndy Whitcroft * alignment. 21984afd99bSAndy Whitcroft */ 22084afd99bSAndy Whitcroft #define HPAGE_RESV_OWNER (1UL << 0) 22184afd99bSAndy Whitcroft #define HPAGE_RESV_UNMAPPED (1UL << 1) 22204f2cbe3SMel Gorman #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) 22384afd99bSAndy Whitcroft 224a1e78772SMel Gorman /* 225a1e78772SMel Gorman * These helpers are used to track how many pages are reserved for 226a1e78772SMel Gorman * faults in a MAP_PRIVATE mapping. Only the process that called mmap() 227a1e78772SMel Gorman * is guaranteed to have their future faults succeed. 228a1e78772SMel Gorman * 229a1e78772SMel Gorman * With the exception of reset_vma_resv_huge_pages() which is called at fork(), 230a1e78772SMel Gorman * the reserve counters are updated with the hugetlb_lock held. It is safe 231a1e78772SMel Gorman * to reset the VMA at fork() time as it is not in use yet and there is no 232a1e78772SMel Gorman * chance of the global counters getting corrupted as a result of the values. 23384afd99bSAndy Whitcroft * 23484afd99bSAndy Whitcroft * The private mapping reservation is represented in a subtly different 23584afd99bSAndy Whitcroft * manner to a shared mapping. A shared mapping has a region map associated 23684afd99bSAndy Whitcroft * with the underlying file, this region map represents the backing file 23784afd99bSAndy Whitcroft * pages which have ever had a reservation assigned which this persists even 23884afd99bSAndy Whitcroft * after the page is instantiated. A private mapping has a region map 23984afd99bSAndy Whitcroft * associated with the original mmap which is attached to all VMAs which 24084afd99bSAndy Whitcroft * reference it, this region map represents those offsets which have consumed 24184afd99bSAndy Whitcroft * reservation ie. where pages have been instantiated. 242a1e78772SMel Gorman */ 243e7c4b0bfSAndy Whitcroft static unsigned long get_vma_private_data(struct vm_area_struct *vma) 244e7c4b0bfSAndy Whitcroft { 245e7c4b0bfSAndy Whitcroft return (unsigned long)vma->vm_private_data; 246e7c4b0bfSAndy Whitcroft } 247e7c4b0bfSAndy Whitcroft 248e7c4b0bfSAndy Whitcroft static void set_vma_private_data(struct vm_area_struct *vma, 249e7c4b0bfSAndy Whitcroft unsigned long value) 250e7c4b0bfSAndy Whitcroft { 251e7c4b0bfSAndy Whitcroft vma->vm_private_data = (void *)value; 252e7c4b0bfSAndy Whitcroft } 253e7c4b0bfSAndy Whitcroft 25484afd99bSAndy Whitcroft struct resv_map { 25584afd99bSAndy Whitcroft struct kref refs; 25684afd99bSAndy Whitcroft struct list_head regions; 25784afd99bSAndy Whitcroft }; 25884afd99bSAndy Whitcroft 25984afd99bSAndy Whitcroft struct resv_map *resv_map_alloc(void) 26084afd99bSAndy Whitcroft { 26184afd99bSAndy Whitcroft struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); 26284afd99bSAndy Whitcroft if (!resv_map) 26384afd99bSAndy Whitcroft return NULL; 26484afd99bSAndy Whitcroft 26584afd99bSAndy Whitcroft kref_init(&resv_map->refs); 26684afd99bSAndy Whitcroft INIT_LIST_HEAD(&resv_map->regions); 26784afd99bSAndy Whitcroft 26884afd99bSAndy Whitcroft return resv_map; 26984afd99bSAndy Whitcroft } 27084afd99bSAndy Whitcroft 27184afd99bSAndy Whitcroft void resv_map_release(struct kref *ref) 27284afd99bSAndy Whitcroft { 27384afd99bSAndy Whitcroft struct resv_map *resv_map = container_of(ref, struct resv_map, refs); 27484afd99bSAndy Whitcroft 27584afd99bSAndy Whitcroft /* Clear out any active regions before we release the map. */ 27684afd99bSAndy Whitcroft region_truncate(&resv_map->regions, 0); 27784afd99bSAndy Whitcroft kfree(resv_map); 27884afd99bSAndy Whitcroft } 27984afd99bSAndy Whitcroft 28084afd99bSAndy Whitcroft static struct resv_map *vma_resv_map(struct vm_area_struct *vma) 281a1e78772SMel Gorman { 282a1e78772SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 283a1e78772SMel Gorman if (!(vma->vm_flags & VM_SHARED)) 28484afd99bSAndy Whitcroft return (struct resv_map *)(get_vma_private_data(vma) & 28584afd99bSAndy Whitcroft ~HPAGE_RESV_MASK); 286a1e78772SMel Gorman return 0; 287a1e78772SMel Gorman } 288a1e78772SMel Gorman 28984afd99bSAndy Whitcroft static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) 290a1e78772SMel Gorman { 291a1e78772SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 292a1e78772SMel Gorman VM_BUG_ON(vma->vm_flags & VM_SHARED); 293a1e78772SMel Gorman 29484afd99bSAndy Whitcroft set_vma_private_data(vma, (get_vma_private_data(vma) & 29584afd99bSAndy Whitcroft HPAGE_RESV_MASK) | (unsigned long)map); 29604f2cbe3SMel Gorman } 29704f2cbe3SMel Gorman 29804f2cbe3SMel Gorman static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) 29904f2cbe3SMel Gorman { 30004f2cbe3SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 301e7c4b0bfSAndy Whitcroft VM_BUG_ON(vma->vm_flags & VM_SHARED); 302e7c4b0bfSAndy Whitcroft 303e7c4b0bfSAndy Whitcroft set_vma_private_data(vma, get_vma_private_data(vma) | flags); 30404f2cbe3SMel Gorman } 30504f2cbe3SMel Gorman 30604f2cbe3SMel Gorman static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) 30704f2cbe3SMel Gorman { 30804f2cbe3SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 309e7c4b0bfSAndy Whitcroft 310e7c4b0bfSAndy Whitcroft return (get_vma_private_data(vma) & flag) != 0; 311a1e78772SMel Gorman } 312a1e78772SMel Gorman 313a1e78772SMel Gorman /* Decrement the reserved pages in the hugepage pool by one */ 314a5516438SAndi Kleen static void decrement_hugepage_resv_vma(struct hstate *h, 315a5516438SAndi Kleen struct vm_area_struct *vma) 316a1e78772SMel Gorman { 317c37f9fb1SAndy Whitcroft if (vma->vm_flags & VM_NORESERVE) 318c37f9fb1SAndy Whitcroft return; 319c37f9fb1SAndy Whitcroft 320a1e78772SMel Gorman if (vma->vm_flags & VM_SHARED) { 321a1e78772SMel Gorman /* Shared mappings always use reserves */ 322a5516438SAndi Kleen h->resv_huge_pages--; 32384afd99bSAndy Whitcroft } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 324a1e78772SMel Gorman /* 325a1e78772SMel Gorman * Only the process that called mmap() has reserves for 326a1e78772SMel Gorman * private mappings. 327a1e78772SMel Gorman */ 328a5516438SAndi Kleen h->resv_huge_pages--; 329a1e78772SMel Gorman } 330a1e78772SMel Gorman } 331a1e78772SMel Gorman 33204f2cbe3SMel Gorman /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ 333a1e78772SMel Gorman void reset_vma_resv_huge_pages(struct vm_area_struct *vma) 334a1e78772SMel Gorman { 335a1e78772SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 336a1e78772SMel Gorman if (!(vma->vm_flags & VM_SHARED)) 337a1e78772SMel Gorman vma->vm_private_data = (void *)0; 338a1e78772SMel Gorman } 339a1e78772SMel Gorman 340a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 341a1e78772SMel Gorman static int vma_has_private_reserves(struct vm_area_struct *vma) 342a1e78772SMel Gorman { 343a1e78772SMel Gorman if (vma->vm_flags & VM_SHARED) 344a1e78772SMel Gorman return 0; 34584afd99bSAndy Whitcroft if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 346a1e78772SMel Gorman return 0; 347a1e78772SMel Gorman return 1; 348a1e78772SMel Gorman } 349a1e78772SMel Gorman 350a5516438SAndi Kleen static void clear_huge_page(struct page *page, 351a5516438SAndi Kleen unsigned long addr, unsigned long sz) 35279ac6ba4SDavid Gibson { 35379ac6ba4SDavid Gibson int i; 35479ac6ba4SDavid Gibson 35579ac6ba4SDavid Gibson might_sleep(); 356a5516438SAndi Kleen for (i = 0; i < sz/PAGE_SIZE; i++) { 35779ac6ba4SDavid Gibson cond_resched(); 358281e0e3bSRalf Baechle clear_user_highpage(page + i, addr + i * PAGE_SIZE); 35979ac6ba4SDavid Gibson } 36079ac6ba4SDavid Gibson } 36179ac6ba4SDavid Gibson 36279ac6ba4SDavid Gibson static void copy_huge_page(struct page *dst, struct page *src, 3639de455b2SAtsushi Nemoto unsigned long addr, struct vm_area_struct *vma) 36479ac6ba4SDavid Gibson { 36579ac6ba4SDavid Gibson int i; 366a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 36779ac6ba4SDavid Gibson 36879ac6ba4SDavid Gibson might_sleep(); 369a5516438SAndi Kleen for (i = 0; i < pages_per_huge_page(h); i++) { 37079ac6ba4SDavid Gibson cond_resched(); 3719de455b2SAtsushi Nemoto copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); 37279ac6ba4SDavid Gibson } 37379ac6ba4SDavid Gibson } 37479ac6ba4SDavid Gibson 375a5516438SAndi Kleen static void enqueue_huge_page(struct hstate *h, struct page *page) 3761da177e4SLinus Torvalds { 3771da177e4SLinus Torvalds int nid = page_to_nid(page); 378a5516438SAndi Kleen list_add(&page->lru, &h->hugepage_freelists[nid]); 379a5516438SAndi Kleen h->free_huge_pages++; 380a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 3811da177e4SLinus Torvalds } 3821da177e4SLinus Torvalds 383a5516438SAndi Kleen static struct page *dequeue_huge_page(struct hstate *h) 384348e1e04SNishanth Aravamudan { 385348e1e04SNishanth Aravamudan int nid; 386348e1e04SNishanth Aravamudan struct page *page = NULL; 387348e1e04SNishanth Aravamudan 388348e1e04SNishanth Aravamudan for (nid = 0; nid < MAX_NUMNODES; ++nid) { 389a5516438SAndi Kleen if (!list_empty(&h->hugepage_freelists[nid])) { 390a5516438SAndi Kleen page = list_entry(h->hugepage_freelists[nid].next, 391348e1e04SNishanth Aravamudan struct page, lru); 392348e1e04SNishanth Aravamudan list_del(&page->lru); 393a5516438SAndi Kleen h->free_huge_pages--; 394a5516438SAndi Kleen h->free_huge_pages_node[nid]--; 395348e1e04SNishanth Aravamudan break; 396348e1e04SNishanth Aravamudan } 397348e1e04SNishanth Aravamudan } 398348e1e04SNishanth Aravamudan return page; 399348e1e04SNishanth Aravamudan } 400348e1e04SNishanth Aravamudan 401a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 402a5516438SAndi Kleen struct vm_area_struct *vma, 40304f2cbe3SMel Gorman unsigned long address, int avoid_reserve) 4041da177e4SLinus Torvalds { 40531a5c6e4SNishanth Aravamudan int nid; 4061da177e4SLinus Torvalds struct page *page = NULL; 407480eccf9SLee Schermerhorn struct mempolicy *mpol; 40819770b32SMel Gorman nodemask_t *nodemask; 409396faf03SMel Gorman struct zonelist *zonelist = huge_zonelist(vma, address, 41019770b32SMel Gorman htlb_alloc_mask, &mpol, &nodemask); 411dd1a239fSMel Gorman struct zone *zone; 412dd1a239fSMel Gorman struct zoneref *z; 4131da177e4SLinus Torvalds 414a1e78772SMel Gorman /* 415a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 416a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 417a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 418a1e78772SMel Gorman */ 419a1e78772SMel Gorman if (!vma_has_private_reserves(vma) && 420a5516438SAndi Kleen h->free_huge_pages - h->resv_huge_pages == 0) 421a1e78772SMel Gorman return NULL; 422a1e78772SMel Gorman 42304f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 424a5516438SAndi Kleen if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) 42504f2cbe3SMel Gorman return NULL; 42604f2cbe3SMel Gorman 42719770b32SMel Gorman for_each_zone_zonelist_nodemask(zone, z, zonelist, 42819770b32SMel Gorman MAX_NR_ZONES - 1, nodemask) { 42954a6eb5cSMel Gorman nid = zone_to_nid(zone); 43054a6eb5cSMel Gorman if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && 431a5516438SAndi Kleen !list_empty(&h->hugepage_freelists[nid])) { 432a5516438SAndi Kleen page = list_entry(h->hugepage_freelists[nid].next, 4331da177e4SLinus Torvalds struct page, lru); 4341da177e4SLinus Torvalds list_del(&page->lru); 435a5516438SAndi Kleen h->free_huge_pages--; 436a5516438SAndi Kleen h->free_huge_pages_node[nid]--; 43704f2cbe3SMel Gorman 43804f2cbe3SMel Gorman if (!avoid_reserve) 439a5516438SAndi Kleen decrement_hugepage_resv_vma(h, vma); 440a1e78772SMel Gorman 4415ab3ee7bSKen Chen break; 4421da177e4SLinus Torvalds } 4433abf7afdSAndrew Morton } 44452cd3b07SLee Schermerhorn mpol_cond_put(mpol); 4451da177e4SLinus Torvalds return page; 4461da177e4SLinus Torvalds } 4471da177e4SLinus Torvalds 448a5516438SAndi Kleen static void update_and_free_page(struct hstate *h, struct page *page) 4496af2acb6SAdam Litke { 4506af2acb6SAdam Litke int i; 451a5516438SAndi Kleen 452a5516438SAndi Kleen h->nr_huge_pages--; 453a5516438SAndi Kleen h->nr_huge_pages_node[page_to_nid(page)]--; 454a5516438SAndi Kleen for (i = 0; i < pages_per_huge_page(h); i++) { 4556af2acb6SAdam Litke page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | 4566af2acb6SAdam Litke 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | 4576af2acb6SAdam Litke 1 << PG_private | 1<< PG_writeback); 4586af2acb6SAdam Litke } 4596af2acb6SAdam Litke set_compound_page_dtor(page, NULL); 4606af2acb6SAdam Litke set_page_refcounted(page); 4617f2e9525SGerald Schaefer arch_release_hugepage(page); 462a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 4636af2acb6SAdam Litke } 4646af2acb6SAdam Litke 465e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 466e5ff2159SAndi Kleen { 467e5ff2159SAndi Kleen struct hstate *h; 468e5ff2159SAndi Kleen 469e5ff2159SAndi Kleen for_each_hstate(h) { 470e5ff2159SAndi Kleen if (huge_page_size(h) == size) 471e5ff2159SAndi Kleen return h; 472e5ff2159SAndi Kleen } 473e5ff2159SAndi Kleen return NULL; 474e5ff2159SAndi Kleen } 475e5ff2159SAndi Kleen 47627a85ef1SDavid Gibson static void free_huge_page(struct page *page) 47727a85ef1SDavid Gibson { 478a5516438SAndi Kleen /* 479a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 480a5516438SAndi Kleen * compound page destructor. 481a5516438SAndi Kleen */ 482e5ff2159SAndi Kleen struct hstate *h = page_hstate(page); 4837893d1d5SAdam Litke int nid = page_to_nid(page); 484c79fb75eSAdam Litke struct address_space *mapping; 48527a85ef1SDavid Gibson 486c79fb75eSAdam Litke mapping = (struct address_space *) page_private(page); 487e5df70abSAndy Whitcroft set_page_private(page, 0); 4887893d1d5SAdam Litke BUG_ON(page_count(page)); 48927a85ef1SDavid Gibson INIT_LIST_HEAD(&page->lru); 49027a85ef1SDavid Gibson 49127a85ef1SDavid Gibson spin_lock(&hugetlb_lock); 492a5516438SAndi Kleen if (h->surplus_huge_pages_node[nid]) { 493a5516438SAndi Kleen update_and_free_page(h, page); 494a5516438SAndi Kleen h->surplus_huge_pages--; 495a5516438SAndi Kleen h->surplus_huge_pages_node[nid]--; 4967893d1d5SAdam Litke } else { 497a5516438SAndi Kleen enqueue_huge_page(h, page); 4987893d1d5SAdam Litke } 49927a85ef1SDavid Gibson spin_unlock(&hugetlb_lock); 500c79fb75eSAdam Litke if (mapping) 5019a119c05SAdam Litke hugetlb_put_quota(mapping, 1); 50227a85ef1SDavid Gibson } 50327a85ef1SDavid Gibson 5047893d1d5SAdam Litke /* 5057893d1d5SAdam Litke * Increment or decrement surplus_huge_pages. Keep node-specific counters 5067893d1d5SAdam Litke * balanced by operating on them in a round-robin fashion. 5077893d1d5SAdam Litke * Returns 1 if an adjustment was made. 5087893d1d5SAdam Litke */ 509a5516438SAndi Kleen static int adjust_pool_surplus(struct hstate *h, int delta) 5107893d1d5SAdam Litke { 5117893d1d5SAdam Litke static int prev_nid; 5127893d1d5SAdam Litke int nid = prev_nid; 5137893d1d5SAdam Litke int ret = 0; 5147893d1d5SAdam Litke 5157893d1d5SAdam Litke VM_BUG_ON(delta != -1 && delta != 1); 5167893d1d5SAdam Litke do { 5177893d1d5SAdam Litke nid = next_node(nid, node_online_map); 5187893d1d5SAdam Litke if (nid == MAX_NUMNODES) 5197893d1d5SAdam Litke nid = first_node(node_online_map); 5207893d1d5SAdam Litke 5217893d1d5SAdam Litke /* To shrink on this node, there must be a surplus page */ 522a5516438SAndi Kleen if (delta < 0 && !h->surplus_huge_pages_node[nid]) 5237893d1d5SAdam Litke continue; 5247893d1d5SAdam Litke /* Surplus cannot exceed the total number of pages */ 525a5516438SAndi Kleen if (delta > 0 && h->surplus_huge_pages_node[nid] >= 526a5516438SAndi Kleen h->nr_huge_pages_node[nid]) 5277893d1d5SAdam Litke continue; 5287893d1d5SAdam Litke 529a5516438SAndi Kleen h->surplus_huge_pages += delta; 530a5516438SAndi Kleen h->surplus_huge_pages_node[nid] += delta; 5317893d1d5SAdam Litke ret = 1; 5327893d1d5SAdam Litke break; 5337893d1d5SAdam Litke } while (nid != prev_nid); 5347893d1d5SAdam Litke 5357893d1d5SAdam Litke prev_nid = nid; 5367893d1d5SAdam Litke return ret; 5377893d1d5SAdam Litke } 5387893d1d5SAdam Litke 539a5516438SAndi Kleen static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) 540b7ba30c6SAndi Kleen { 541b7ba30c6SAndi Kleen set_compound_page_dtor(page, free_huge_page); 542b7ba30c6SAndi Kleen spin_lock(&hugetlb_lock); 543a5516438SAndi Kleen h->nr_huge_pages++; 544a5516438SAndi Kleen h->nr_huge_pages_node[nid]++; 545b7ba30c6SAndi Kleen spin_unlock(&hugetlb_lock); 546b7ba30c6SAndi Kleen put_page(page); /* free it into the hugepage allocator */ 547b7ba30c6SAndi Kleen } 548b7ba30c6SAndi Kleen 549a5516438SAndi Kleen static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) 5501da177e4SLinus Torvalds { 5511da177e4SLinus Torvalds struct page *page; 552f96efd58SJoe Jin 55363b4613cSNishanth Aravamudan page = alloc_pages_node(nid, 554551883aeSNishanth Aravamudan htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| 555551883aeSNishanth Aravamudan __GFP_REPEAT|__GFP_NOWARN, 556a5516438SAndi Kleen huge_page_order(h)); 5571da177e4SLinus Torvalds if (page) { 5587f2e9525SGerald Schaefer if (arch_prepare_hugepage(page)) { 5597f2e9525SGerald Schaefer __free_pages(page, HUGETLB_PAGE_ORDER); 5607b8ee84dSHarvey Harrison return NULL; 5617f2e9525SGerald Schaefer } 562a5516438SAndi Kleen prep_new_huge_page(h, page, nid); 5631da177e4SLinus Torvalds } 56463b4613cSNishanth Aravamudan 56563b4613cSNishanth Aravamudan return page; 56663b4613cSNishanth Aravamudan } 56763b4613cSNishanth Aravamudan 568a5516438SAndi Kleen static int alloc_fresh_huge_page(struct hstate *h) 56963b4613cSNishanth Aravamudan { 57063b4613cSNishanth Aravamudan struct page *page; 57163b4613cSNishanth Aravamudan int start_nid; 57263b4613cSNishanth Aravamudan int next_nid; 57363b4613cSNishanth Aravamudan int ret = 0; 57463b4613cSNishanth Aravamudan 575a5516438SAndi Kleen start_nid = h->hugetlb_next_nid; 57663b4613cSNishanth Aravamudan 57763b4613cSNishanth Aravamudan do { 578a5516438SAndi Kleen page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid); 57963b4613cSNishanth Aravamudan if (page) 58063b4613cSNishanth Aravamudan ret = 1; 58163b4613cSNishanth Aravamudan /* 58263b4613cSNishanth Aravamudan * Use a helper variable to find the next node and then 58363b4613cSNishanth Aravamudan * copy it back to hugetlb_next_nid afterwards: 58463b4613cSNishanth Aravamudan * otherwise there's a window in which a racer might 58563b4613cSNishanth Aravamudan * pass invalid nid MAX_NUMNODES to alloc_pages_node. 58663b4613cSNishanth Aravamudan * But we don't need to use a spin_lock here: it really 58763b4613cSNishanth Aravamudan * doesn't matter if occasionally a racer chooses the 58863b4613cSNishanth Aravamudan * same nid as we do. Move nid forward in the mask even 58963b4613cSNishanth Aravamudan * if we just successfully allocated a hugepage so that 59063b4613cSNishanth Aravamudan * the next caller gets hugepages on the next node. 59163b4613cSNishanth Aravamudan */ 592a5516438SAndi Kleen next_nid = next_node(h->hugetlb_next_nid, node_online_map); 59363b4613cSNishanth Aravamudan if (next_nid == MAX_NUMNODES) 59463b4613cSNishanth Aravamudan next_nid = first_node(node_online_map); 595a5516438SAndi Kleen h->hugetlb_next_nid = next_nid; 596a5516438SAndi Kleen } while (!page && h->hugetlb_next_nid != start_nid); 59763b4613cSNishanth Aravamudan 5983b116300SAdam Litke if (ret) 5993b116300SAdam Litke count_vm_event(HTLB_BUDDY_PGALLOC); 6003b116300SAdam Litke else 6013b116300SAdam Litke count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 6023b116300SAdam Litke 60363b4613cSNishanth Aravamudan return ret; 6041da177e4SLinus Torvalds } 6051da177e4SLinus Torvalds 606a5516438SAndi Kleen static struct page *alloc_buddy_huge_page(struct hstate *h, 607a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 6087893d1d5SAdam Litke { 6097893d1d5SAdam Litke struct page *page; 610d1c3fb1fSNishanth Aravamudan unsigned int nid; 6117893d1d5SAdam Litke 612d1c3fb1fSNishanth Aravamudan /* 613d1c3fb1fSNishanth Aravamudan * Assume we will successfully allocate the surplus page to 614d1c3fb1fSNishanth Aravamudan * prevent racing processes from causing the surplus to exceed 615d1c3fb1fSNishanth Aravamudan * overcommit 616d1c3fb1fSNishanth Aravamudan * 617d1c3fb1fSNishanth Aravamudan * This however introduces a different race, where a process B 618d1c3fb1fSNishanth Aravamudan * tries to grow the static hugepage pool while alloc_pages() is 619d1c3fb1fSNishanth Aravamudan * called by process A. B will only examine the per-node 620d1c3fb1fSNishanth Aravamudan * counters in determining if surplus huge pages can be 621d1c3fb1fSNishanth Aravamudan * converted to normal huge pages in adjust_pool_surplus(). A 622d1c3fb1fSNishanth Aravamudan * won't be able to increment the per-node counter, until the 623d1c3fb1fSNishanth Aravamudan * lock is dropped by B, but B doesn't drop hugetlb_lock until 624d1c3fb1fSNishanth Aravamudan * no more huge pages can be converted from surplus to normal 625d1c3fb1fSNishanth Aravamudan * state (and doesn't try to convert again). Thus, we have a 626d1c3fb1fSNishanth Aravamudan * case where a surplus huge page exists, the pool is grown, and 627d1c3fb1fSNishanth Aravamudan * the surplus huge page still exists after, even though it 628d1c3fb1fSNishanth Aravamudan * should just have been converted to a normal huge page. This 629d1c3fb1fSNishanth Aravamudan * does not leak memory, though, as the hugepage will be freed 630d1c3fb1fSNishanth Aravamudan * once it is out of use. It also does not allow the counters to 631d1c3fb1fSNishanth Aravamudan * go out of whack in adjust_pool_surplus() as we don't modify 632d1c3fb1fSNishanth Aravamudan * the node values until we've gotten the hugepage and only the 633d1c3fb1fSNishanth Aravamudan * per-node value is checked there. 634d1c3fb1fSNishanth Aravamudan */ 635d1c3fb1fSNishanth Aravamudan spin_lock(&hugetlb_lock); 636a5516438SAndi Kleen if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 637d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 638d1c3fb1fSNishanth Aravamudan return NULL; 639d1c3fb1fSNishanth Aravamudan } else { 640a5516438SAndi Kleen h->nr_huge_pages++; 641a5516438SAndi Kleen h->surplus_huge_pages++; 642d1c3fb1fSNishanth Aravamudan } 643d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 644d1c3fb1fSNishanth Aravamudan 645551883aeSNishanth Aravamudan page = alloc_pages(htlb_alloc_mask|__GFP_COMP| 646551883aeSNishanth Aravamudan __GFP_REPEAT|__GFP_NOWARN, 647a5516438SAndi Kleen huge_page_order(h)); 648d1c3fb1fSNishanth Aravamudan 6497893d1d5SAdam Litke spin_lock(&hugetlb_lock); 650d1c3fb1fSNishanth Aravamudan if (page) { 6512668db91SAdam Litke /* 6522668db91SAdam Litke * This page is now managed by the hugetlb allocator and has 6532668db91SAdam Litke * no users -- drop the buddy allocator's reference. 6542668db91SAdam Litke */ 6552668db91SAdam Litke put_page_testzero(page); 6562668db91SAdam Litke VM_BUG_ON(page_count(page)); 657d1c3fb1fSNishanth Aravamudan nid = page_to_nid(page); 658d1c3fb1fSNishanth Aravamudan set_compound_page_dtor(page, free_huge_page); 659d1c3fb1fSNishanth Aravamudan /* 660d1c3fb1fSNishanth Aravamudan * We incremented the global counters already 661d1c3fb1fSNishanth Aravamudan */ 662a5516438SAndi Kleen h->nr_huge_pages_node[nid]++; 663a5516438SAndi Kleen h->surplus_huge_pages_node[nid]++; 6643b116300SAdam Litke __count_vm_event(HTLB_BUDDY_PGALLOC); 665d1c3fb1fSNishanth Aravamudan } else { 666a5516438SAndi Kleen h->nr_huge_pages--; 667a5516438SAndi Kleen h->surplus_huge_pages--; 6683b116300SAdam Litke __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 6697893d1d5SAdam Litke } 670d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 6717893d1d5SAdam Litke 6727893d1d5SAdam Litke return page; 6737893d1d5SAdam Litke } 6747893d1d5SAdam Litke 675e4e574b7SAdam Litke /* 676e4e574b7SAdam Litke * Increase the hugetlb pool such that it can accomodate a reservation 677e4e574b7SAdam Litke * of size 'delta'. 678e4e574b7SAdam Litke */ 679a5516438SAndi Kleen static int gather_surplus_pages(struct hstate *h, int delta) 680e4e574b7SAdam Litke { 681e4e574b7SAdam Litke struct list_head surplus_list; 682e4e574b7SAdam Litke struct page *page, *tmp; 683e4e574b7SAdam Litke int ret, i; 684e4e574b7SAdam Litke int needed, allocated; 685e4e574b7SAdam Litke 686a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 687ac09b3a1SAdam Litke if (needed <= 0) { 688a5516438SAndi Kleen h->resv_huge_pages += delta; 689e4e574b7SAdam Litke return 0; 690ac09b3a1SAdam Litke } 691e4e574b7SAdam Litke 692e4e574b7SAdam Litke allocated = 0; 693e4e574b7SAdam Litke INIT_LIST_HEAD(&surplus_list); 694e4e574b7SAdam Litke 695e4e574b7SAdam Litke ret = -ENOMEM; 696e4e574b7SAdam Litke retry: 697e4e574b7SAdam Litke spin_unlock(&hugetlb_lock); 698e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 699a5516438SAndi Kleen page = alloc_buddy_huge_page(h, NULL, 0); 700e4e574b7SAdam Litke if (!page) { 701e4e574b7SAdam Litke /* 702e4e574b7SAdam Litke * We were not able to allocate enough pages to 703e4e574b7SAdam Litke * satisfy the entire reservation so we free what 704e4e574b7SAdam Litke * we've allocated so far. 705e4e574b7SAdam Litke */ 706e4e574b7SAdam Litke spin_lock(&hugetlb_lock); 707e4e574b7SAdam Litke needed = 0; 708e4e574b7SAdam Litke goto free; 709e4e574b7SAdam Litke } 710e4e574b7SAdam Litke 711e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 712e4e574b7SAdam Litke } 713e4e574b7SAdam Litke allocated += needed; 714e4e574b7SAdam Litke 715e4e574b7SAdam Litke /* 716e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 717e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 718e4e574b7SAdam Litke */ 719e4e574b7SAdam Litke spin_lock(&hugetlb_lock); 720a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 721a5516438SAndi Kleen (h->free_huge_pages + allocated); 722e4e574b7SAdam Litke if (needed > 0) 723e4e574b7SAdam Litke goto retry; 724e4e574b7SAdam Litke 725e4e574b7SAdam Litke /* 726e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 727e4e574b7SAdam Litke * needed to accomodate the reservation. Add the appropriate number 728e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 729ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 730ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 731ac09b3a1SAdam Litke * before they are reserved. 732e4e574b7SAdam Litke */ 733e4e574b7SAdam Litke needed += allocated; 734a5516438SAndi Kleen h->resv_huge_pages += delta; 735e4e574b7SAdam Litke ret = 0; 736e4e574b7SAdam Litke free: 73719fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 73819fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 73919fc3f0aSAdam Litke if ((--needed) < 0) 74019fc3f0aSAdam Litke break; 74119fc3f0aSAdam Litke list_del(&page->lru); 742a5516438SAndi Kleen enqueue_huge_page(h, page); 74319fc3f0aSAdam Litke } 74419fc3f0aSAdam Litke 74519fc3f0aSAdam Litke /* Free unnecessary surplus pages to the buddy allocator */ 74619fc3f0aSAdam Litke if (!list_empty(&surplus_list)) { 74719fc3f0aSAdam Litke spin_unlock(&hugetlb_lock); 748e4e574b7SAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 749e4e574b7SAdam Litke list_del(&page->lru); 750af767cbdSAdam Litke /* 7512668db91SAdam Litke * The page has a reference count of zero already, so 7522668db91SAdam Litke * call free_huge_page directly instead of using 7532668db91SAdam Litke * put_page. This must be done with hugetlb_lock 754af767cbdSAdam Litke * unlocked which is safe because free_huge_page takes 755af767cbdSAdam Litke * hugetlb_lock before deciding how to free the page. 756af767cbdSAdam Litke */ 7572668db91SAdam Litke free_huge_page(page); 758af767cbdSAdam Litke } 75919fc3f0aSAdam Litke spin_lock(&hugetlb_lock); 760e4e574b7SAdam Litke } 761e4e574b7SAdam Litke 762e4e574b7SAdam Litke return ret; 763e4e574b7SAdam Litke } 764e4e574b7SAdam Litke 765e4e574b7SAdam Litke /* 766e4e574b7SAdam Litke * When releasing a hugetlb pool reservation, any surplus pages that were 767e4e574b7SAdam Litke * allocated to satisfy the reservation must be explicitly freed if they were 768e4e574b7SAdam Litke * never used. 769e4e574b7SAdam Litke */ 770a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 771a5516438SAndi Kleen unsigned long unused_resv_pages) 772e4e574b7SAdam Litke { 773e4e574b7SAdam Litke static int nid = -1; 774e4e574b7SAdam Litke struct page *page; 775e4e574b7SAdam Litke unsigned long nr_pages; 776e4e574b7SAdam Litke 77711320d17SNishanth Aravamudan /* 77811320d17SNishanth Aravamudan * We want to release as many surplus pages as possible, spread 77911320d17SNishanth Aravamudan * evenly across all nodes. Iterate across all nodes until we 78011320d17SNishanth Aravamudan * can no longer free unreserved surplus pages. This occurs when 78111320d17SNishanth Aravamudan * the nodes with surplus pages have no free pages. 78211320d17SNishanth Aravamudan */ 78311320d17SNishanth Aravamudan unsigned long remaining_iterations = num_online_nodes(); 78411320d17SNishanth Aravamudan 785ac09b3a1SAdam Litke /* Uncommit the reservation */ 786a5516438SAndi Kleen h->resv_huge_pages -= unused_resv_pages; 787ac09b3a1SAdam Litke 788a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 789e4e574b7SAdam Litke 79011320d17SNishanth Aravamudan while (remaining_iterations-- && nr_pages) { 791e4e574b7SAdam Litke nid = next_node(nid, node_online_map); 792e4e574b7SAdam Litke if (nid == MAX_NUMNODES) 793e4e574b7SAdam Litke nid = first_node(node_online_map); 794e4e574b7SAdam Litke 795a5516438SAndi Kleen if (!h->surplus_huge_pages_node[nid]) 796e4e574b7SAdam Litke continue; 797e4e574b7SAdam Litke 798a5516438SAndi Kleen if (!list_empty(&h->hugepage_freelists[nid])) { 799a5516438SAndi Kleen page = list_entry(h->hugepage_freelists[nid].next, 800e4e574b7SAdam Litke struct page, lru); 801e4e574b7SAdam Litke list_del(&page->lru); 802a5516438SAndi Kleen update_and_free_page(h, page); 803a5516438SAndi Kleen h->free_huge_pages--; 804a5516438SAndi Kleen h->free_huge_pages_node[nid]--; 805a5516438SAndi Kleen h->surplus_huge_pages--; 806a5516438SAndi Kleen h->surplus_huge_pages_node[nid]--; 807e4e574b7SAdam Litke nr_pages--; 80811320d17SNishanth Aravamudan remaining_iterations = num_online_nodes(); 809e4e574b7SAdam Litke } 810e4e574b7SAdam Litke } 811e4e574b7SAdam Litke } 812e4e574b7SAdam Litke 813c37f9fb1SAndy Whitcroft /* 814c37f9fb1SAndy Whitcroft * Determine if the huge page at addr within the vma has an associated 815c37f9fb1SAndy Whitcroft * reservation. Where it does not we will need to logically increase 816c37f9fb1SAndy Whitcroft * reservation and actually increase quota before an allocation can occur. 817c37f9fb1SAndy Whitcroft * Where any new reservation would be required the reservation change is 818c37f9fb1SAndy Whitcroft * prepared, but not committed. Once the page has been quota'd allocated 819c37f9fb1SAndy Whitcroft * an instantiated the change should be committed via vma_commit_reservation. 820c37f9fb1SAndy Whitcroft * No action is required on failure. 821c37f9fb1SAndy Whitcroft */ 822a5516438SAndi Kleen static int vma_needs_reservation(struct hstate *h, 823a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 824c37f9fb1SAndy Whitcroft { 825c37f9fb1SAndy Whitcroft struct address_space *mapping = vma->vm_file->f_mapping; 826c37f9fb1SAndy Whitcroft struct inode *inode = mapping->host; 827c37f9fb1SAndy Whitcroft 828c37f9fb1SAndy Whitcroft if (vma->vm_flags & VM_SHARED) { 829a5516438SAndi Kleen pgoff_t idx = vma_hugecache_offset(h, vma, addr); 830c37f9fb1SAndy Whitcroft return region_chg(&inode->i_mapping->private_list, 831c37f9fb1SAndy Whitcroft idx, idx + 1); 832c37f9fb1SAndy Whitcroft 83384afd99bSAndy Whitcroft } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 834c37f9fb1SAndy Whitcroft return 1; 835c37f9fb1SAndy Whitcroft 83684afd99bSAndy Whitcroft } else { 83784afd99bSAndy Whitcroft int err; 838a5516438SAndi Kleen pgoff_t idx = vma_hugecache_offset(h, vma, addr); 83984afd99bSAndy Whitcroft struct resv_map *reservations = vma_resv_map(vma); 84084afd99bSAndy Whitcroft 84184afd99bSAndy Whitcroft err = region_chg(&reservations->regions, idx, idx + 1); 84284afd99bSAndy Whitcroft if (err < 0) 84384afd99bSAndy Whitcroft return err; 844c37f9fb1SAndy Whitcroft return 0; 845c37f9fb1SAndy Whitcroft } 84684afd99bSAndy Whitcroft } 847a5516438SAndi Kleen static void vma_commit_reservation(struct hstate *h, 848a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 849c37f9fb1SAndy Whitcroft { 850c37f9fb1SAndy Whitcroft struct address_space *mapping = vma->vm_file->f_mapping; 851c37f9fb1SAndy Whitcroft struct inode *inode = mapping->host; 852c37f9fb1SAndy Whitcroft 853c37f9fb1SAndy Whitcroft if (vma->vm_flags & VM_SHARED) { 854a5516438SAndi Kleen pgoff_t idx = vma_hugecache_offset(h, vma, addr); 855c37f9fb1SAndy Whitcroft region_add(&inode->i_mapping->private_list, idx, idx + 1); 85684afd99bSAndy Whitcroft 85784afd99bSAndy Whitcroft } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 858a5516438SAndi Kleen pgoff_t idx = vma_hugecache_offset(h, vma, addr); 85984afd99bSAndy Whitcroft struct resv_map *reservations = vma_resv_map(vma); 86084afd99bSAndy Whitcroft 86184afd99bSAndy Whitcroft /* Mark this page used in the map. */ 86284afd99bSAndy Whitcroft region_add(&reservations->regions, idx, idx + 1); 863c37f9fb1SAndy Whitcroft } 864c37f9fb1SAndy Whitcroft } 865c37f9fb1SAndy Whitcroft 866348ea204SAdam Litke static struct page *alloc_huge_page(struct vm_area_struct *vma, 86704f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 868348ea204SAdam Litke { 869a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 870348ea204SAdam Litke struct page *page; 8712fc39cecSAdam Litke struct address_space *mapping = vma->vm_file->f_mapping; 872a1e78772SMel Gorman struct inode *inode = mapping->host; 873c37f9fb1SAndy Whitcroft unsigned int chg; 8742fc39cecSAdam Litke 875a1e78772SMel Gorman /* 876a1e78772SMel Gorman * Processes that did not create the mapping will have no reserves and 877a1e78772SMel Gorman * will not have accounted against quota. Check that the quota can be 878a1e78772SMel Gorman * made before satisfying the allocation 879c37f9fb1SAndy Whitcroft * MAP_NORESERVE mappings may also need pages and quota allocated 880c37f9fb1SAndy Whitcroft * if no reserve mapping overlaps. 881a1e78772SMel Gorman */ 882a5516438SAndi Kleen chg = vma_needs_reservation(h, vma, addr); 883c37f9fb1SAndy Whitcroft if (chg < 0) 884c37f9fb1SAndy Whitcroft return ERR_PTR(chg); 885c37f9fb1SAndy Whitcroft if (chg) 886a1e78772SMel Gorman if (hugetlb_get_quota(inode->i_mapping, chg)) 887a1e78772SMel Gorman return ERR_PTR(-ENOSPC); 88890d8b7e6SAdam Litke 889a1e78772SMel Gorman spin_lock(&hugetlb_lock); 890a5516438SAndi Kleen page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve); 891a1e78772SMel Gorman spin_unlock(&hugetlb_lock); 892a1e78772SMel Gorman 893a1e78772SMel Gorman if (!page) { 894a5516438SAndi Kleen page = alloc_buddy_huge_page(h, vma, addr); 895a1e78772SMel Gorman if (!page) { 896a1e78772SMel Gorman hugetlb_put_quota(inode->i_mapping, chg); 897a1e78772SMel Gorman return ERR_PTR(-VM_FAULT_OOM); 898a1e78772SMel Gorman } 899a1e78772SMel Gorman } 900a1e78772SMel Gorman 901348ea204SAdam Litke set_page_refcounted(page); 9022fc39cecSAdam Litke set_page_private(page, (unsigned long) mapping); 903a1e78772SMel Gorman 904a5516438SAndi Kleen vma_commit_reservation(h, vma, addr); 905c37f9fb1SAndy Whitcroft 9067893d1d5SAdam Litke return page; 907b45b5bd6SDavid Gibson } 908b45b5bd6SDavid Gibson 909e5ff2159SAndi Kleen static void __init hugetlb_init_one_hstate(struct hstate *h) 9101da177e4SLinus Torvalds { 9111da177e4SLinus Torvalds unsigned long i; 9121da177e4SLinus Torvalds 913a5516438SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 914a5516438SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 915a5516438SAndi Kleen 916a5516438SAndi Kleen h->hugetlb_next_nid = first_node(node_online_map); 91763b4613cSNishanth Aravamudan 918e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 919a5516438SAndi Kleen if (!alloc_fresh_huge_page(h)) 9201da177e4SLinus Torvalds break; 9211da177e4SLinus Torvalds } 922e5ff2159SAndi Kleen h->max_huge_pages = h->free_huge_pages = h->nr_huge_pages = i; 923e5ff2159SAndi Kleen } 924e5ff2159SAndi Kleen 925e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 926e5ff2159SAndi Kleen { 927e5ff2159SAndi Kleen struct hstate *h; 928e5ff2159SAndi Kleen 929e5ff2159SAndi Kleen for_each_hstate(h) { 930e5ff2159SAndi Kleen hugetlb_init_one_hstate(h); 931e5ff2159SAndi Kleen } 932e5ff2159SAndi Kleen } 933e5ff2159SAndi Kleen 934e5ff2159SAndi Kleen static void __init report_hugepages(void) 935e5ff2159SAndi Kleen { 936e5ff2159SAndi Kleen struct hstate *h; 937e5ff2159SAndi Kleen 938e5ff2159SAndi Kleen for_each_hstate(h) { 939e5ff2159SAndi Kleen printk(KERN_INFO "Total HugeTLB memory allocated, " 940e5ff2159SAndi Kleen "%ld %dMB pages\n", 941e5ff2159SAndi Kleen h->free_huge_pages, 942e5ff2159SAndi Kleen 1 << (h->order + PAGE_SHIFT - 20)); 943e5ff2159SAndi Kleen } 944e5ff2159SAndi Kleen } 945e5ff2159SAndi Kleen 9461da177e4SLinus Torvalds #ifdef CONFIG_SYSCTL 9471da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 948a5516438SAndi Kleen static void try_to_free_low(struct hstate *h, unsigned long count) 9491da177e4SLinus Torvalds { 9504415cc8dSChristoph Lameter int i; 9514415cc8dSChristoph Lameter 9521da177e4SLinus Torvalds for (i = 0; i < MAX_NUMNODES; ++i) { 9531da177e4SLinus Torvalds struct page *page, *next; 954a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 955a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 956a5516438SAndi Kleen if (count >= h->nr_huge_pages) 9576b0c880dSAdam Litke return; 9581da177e4SLinus Torvalds if (PageHighMem(page)) 9591da177e4SLinus Torvalds continue; 9601da177e4SLinus Torvalds list_del(&page->lru); 961e5ff2159SAndi Kleen update_and_free_page(h, page); 962a5516438SAndi Kleen h->free_huge_pages--; 963a5516438SAndi Kleen h->free_huge_pages_node[page_to_nid(page)]--; 9641da177e4SLinus Torvalds } 9651da177e4SLinus Torvalds } 9661da177e4SLinus Torvalds } 9671da177e4SLinus Torvalds #else 968a5516438SAndi Kleen static inline void try_to_free_low(struct hstate *h, unsigned long count) 9691da177e4SLinus Torvalds { 9701da177e4SLinus Torvalds } 9711da177e4SLinus Torvalds #endif 9721da177e4SLinus Torvalds 973a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 974e5ff2159SAndi Kleen static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count) 9751da177e4SLinus Torvalds { 9767893d1d5SAdam Litke unsigned long min_count, ret; 9771da177e4SLinus Torvalds 9787893d1d5SAdam Litke /* 9797893d1d5SAdam Litke * Increase the pool size 9807893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 9817893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 982d1c3fb1fSNishanth Aravamudan * 983d1c3fb1fSNishanth Aravamudan * We might race with alloc_buddy_huge_page() here and be unable 984d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 985d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 986d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 987d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 9887893d1d5SAdam Litke */ 9891da177e4SLinus Torvalds spin_lock(&hugetlb_lock); 990a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 991a5516438SAndi Kleen if (!adjust_pool_surplus(h, -1)) 9927893d1d5SAdam Litke break; 9937893d1d5SAdam Litke } 9947893d1d5SAdam Litke 995a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 9967893d1d5SAdam Litke /* 9977893d1d5SAdam Litke * If this allocation races such that we no longer need the 9987893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 9997893d1d5SAdam Litke * and reducing the surplus. 10007893d1d5SAdam Litke */ 10017893d1d5SAdam Litke spin_unlock(&hugetlb_lock); 1002a5516438SAndi Kleen ret = alloc_fresh_huge_page(h); 10037893d1d5SAdam Litke spin_lock(&hugetlb_lock); 10047893d1d5SAdam Litke if (!ret) 10057893d1d5SAdam Litke goto out; 10067893d1d5SAdam Litke 10077893d1d5SAdam Litke } 10087893d1d5SAdam Litke 10097893d1d5SAdam Litke /* 10107893d1d5SAdam Litke * Decrease the pool size 10117893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 10127893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 10137893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 10147893d1d5SAdam Litke * to the desired size as pages become free. 1015d1c3fb1fSNishanth Aravamudan * 1016d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 1017d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 1018d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 1019d1c3fb1fSNishanth Aravamudan * alloc_buddy_huge_page() is checking the global counter, 1020d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 1021d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 1022d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 10237893d1d5SAdam Litke */ 1024a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 10256b0c880dSAdam Litke min_count = max(count, min_count); 1026a5516438SAndi Kleen try_to_free_low(h, min_count); 1027a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 1028a5516438SAndi Kleen struct page *page = dequeue_huge_page(h); 10291da177e4SLinus Torvalds if (!page) 10301da177e4SLinus Torvalds break; 1031a5516438SAndi Kleen update_and_free_page(h, page); 10321da177e4SLinus Torvalds } 1033a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 1034a5516438SAndi Kleen if (!adjust_pool_surplus(h, 1)) 10357893d1d5SAdam Litke break; 10367893d1d5SAdam Litke } 10377893d1d5SAdam Litke out: 1038a5516438SAndi Kleen ret = persistent_huge_pages(h); 10391da177e4SLinus Torvalds spin_unlock(&hugetlb_lock); 10407893d1d5SAdam Litke return ret; 10411da177e4SLinus Torvalds } 10421da177e4SLinus Torvalds 1043a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 1044a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 1045a3437870SNishanth Aravamudan 1046a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 1047a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = \ 1048a3437870SNishanth Aravamudan __ATTR(_name, 0644, _name##_show, _name##_store) 1049a3437870SNishanth Aravamudan 1050a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 1051a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 1052a3437870SNishanth Aravamudan 1053a3437870SNishanth Aravamudan static struct hstate *kobj_to_hstate(struct kobject *kobj) 1054a3437870SNishanth Aravamudan { 1055a3437870SNishanth Aravamudan int i; 1056a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 1057a3437870SNishanth Aravamudan if (hstate_kobjs[i] == kobj) 1058a3437870SNishanth Aravamudan return &hstates[i]; 1059a3437870SNishanth Aravamudan BUG(); 1060a3437870SNishanth Aravamudan return NULL; 1061a3437870SNishanth Aravamudan } 1062a3437870SNishanth Aravamudan 1063a3437870SNishanth Aravamudan static ssize_t nr_hugepages_show(struct kobject *kobj, 1064a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1065a3437870SNishanth Aravamudan { 1066a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1067a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->nr_huge_pages); 1068a3437870SNishanth Aravamudan } 1069a3437870SNishanth Aravamudan static ssize_t nr_hugepages_store(struct kobject *kobj, 1070a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 1071a3437870SNishanth Aravamudan { 1072a3437870SNishanth Aravamudan int err; 1073a3437870SNishanth Aravamudan unsigned long input; 1074a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1075a3437870SNishanth Aravamudan 1076a3437870SNishanth Aravamudan err = strict_strtoul(buf, 10, &input); 1077a3437870SNishanth Aravamudan if (err) 1078a3437870SNishanth Aravamudan return 0; 1079a3437870SNishanth Aravamudan 1080a3437870SNishanth Aravamudan h->max_huge_pages = set_max_huge_pages(h, input); 1081a3437870SNishanth Aravamudan 1082a3437870SNishanth Aravamudan return count; 1083a3437870SNishanth Aravamudan } 1084a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 1085a3437870SNishanth Aravamudan 1086a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 1087a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1088a3437870SNishanth Aravamudan { 1089a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1090a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); 1091a3437870SNishanth Aravamudan } 1092a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 1093a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 1094a3437870SNishanth Aravamudan { 1095a3437870SNishanth Aravamudan int err; 1096a3437870SNishanth Aravamudan unsigned long input; 1097a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1098a3437870SNishanth Aravamudan 1099a3437870SNishanth Aravamudan err = strict_strtoul(buf, 10, &input); 1100a3437870SNishanth Aravamudan if (err) 1101a3437870SNishanth Aravamudan return 0; 1102a3437870SNishanth Aravamudan 1103a3437870SNishanth Aravamudan spin_lock(&hugetlb_lock); 1104a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 1105a3437870SNishanth Aravamudan spin_unlock(&hugetlb_lock); 1106a3437870SNishanth Aravamudan 1107a3437870SNishanth Aravamudan return count; 1108a3437870SNishanth Aravamudan } 1109a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 1110a3437870SNishanth Aravamudan 1111a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 1112a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1113a3437870SNishanth Aravamudan { 1114a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1115a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->free_huge_pages); 1116a3437870SNishanth Aravamudan } 1117a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 1118a3437870SNishanth Aravamudan 1119a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 1120a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1121a3437870SNishanth Aravamudan { 1122a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1123a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->resv_huge_pages); 1124a3437870SNishanth Aravamudan } 1125a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 1126a3437870SNishanth Aravamudan 1127a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 1128a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1129a3437870SNishanth Aravamudan { 1130a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1131a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->surplus_huge_pages); 1132a3437870SNishanth Aravamudan } 1133a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 1134a3437870SNishanth Aravamudan 1135a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 1136a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 1137a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 1138a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 1139a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 1140a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 1141a3437870SNishanth Aravamudan NULL, 1142a3437870SNishanth Aravamudan }; 1143a3437870SNishanth Aravamudan 1144a3437870SNishanth Aravamudan static struct attribute_group hstate_attr_group = { 1145a3437870SNishanth Aravamudan .attrs = hstate_attrs, 1146a3437870SNishanth Aravamudan }; 1147a3437870SNishanth Aravamudan 1148a3437870SNishanth Aravamudan static int __init hugetlb_sysfs_add_hstate(struct hstate *h) 1149a3437870SNishanth Aravamudan { 1150a3437870SNishanth Aravamudan int retval; 1151a3437870SNishanth Aravamudan 1152a3437870SNishanth Aravamudan hstate_kobjs[h - hstates] = kobject_create_and_add(h->name, 1153a3437870SNishanth Aravamudan hugepages_kobj); 1154a3437870SNishanth Aravamudan if (!hstate_kobjs[h - hstates]) 1155a3437870SNishanth Aravamudan return -ENOMEM; 1156a3437870SNishanth Aravamudan 1157a3437870SNishanth Aravamudan retval = sysfs_create_group(hstate_kobjs[h - hstates], 1158a3437870SNishanth Aravamudan &hstate_attr_group); 1159a3437870SNishanth Aravamudan if (retval) 1160a3437870SNishanth Aravamudan kobject_put(hstate_kobjs[h - hstates]); 1161a3437870SNishanth Aravamudan 1162a3437870SNishanth Aravamudan return retval; 1163a3437870SNishanth Aravamudan } 1164a3437870SNishanth Aravamudan 1165a3437870SNishanth Aravamudan static void __init hugetlb_sysfs_init(void) 1166a3437870SNishanth Aravamudan { 1167a3437870SNishanth Aravamudan struct hstate *h; 1168a3437870SNishanth Aravamudan int err; 1169a3437870SNishanth Aravamudan 1170a3437870SNishanth Aravamudan hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 1171a3437870SNishanth Aravamudan if (!hugepages_kobj) 1172a3437870SNishanth Aravamudan return; 1173a3437870SNishanth Aravamudan 1174a3437870SNishanth Aravamudan for_each_hstate(h) { 1175a3437870SNishanth Aravamudan err = hugetlb_sysfs_add_hstate(h); 1176a3437870SNishanth Aravamudan if (err) 1177a3437870SNishanth Aravamudan printk(KERN_ERR "Hugetlb: Unable to add hstate %s", 1178a3437870SNishanth Aravamudan h->name); 1179a3437870SNishanth Aravamudan } 1180a3437870SNishanth Aravamudan } 1181a3437870SNishanth Aravamudan 1182a3437870SNishanth Aravamudan static void __exit hugetlb_exit(void) 1183a3437870SNishanth Aravamudan { 1184a3437870SNishanth Aravamudan struct hstate *h; 1185a3437870SNishanth Aravamudan 1186a3437870SNishanth Aravamudan for_each_hstate(h) { 1187a3437870SNishanth Aravamudan kobject_put(hstate_kobjs[h - hstates]); 1188a3437870SNishanth Aravamudan } 1189a3437870SNishanth Aravamudan 1190a3437870SNishanth Aravamudan kobject_put(hugepages_kobj); 1191a3437870SNishanth Aravamudan } 1192a3437870SNishanth Aravamudan module_exit(hugetlb_exit); 1193a3437870SNishanth Aravamudan 1194a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 1195a3437870SNishanth Aravamudan { 1196a3437870SNishanth Aravamudan BUILD_BUG_ON(HPAGE_SHIFT == 0); 1197a3437870SNishanth Aravamudan 1198a3437870SNishanth Aravamudan if (!size_to_hstate(HPAGE_SIZE)) { 1199a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 1200a3437870SNishanth Aravamudan parsed_hstate->max_huge_pages = default_hstate_max_huge_pages; 1201a3437870SNishanth Aravamudan } 1202a3437870SNishanth Aravamudan default_hstate_idx = size_to_hstate(HPAGE_SIZE) - hstates; 1203a3437870SNishanth Aravamudan 1204a3437870SNishanth Aravamudan hugetlb_init_hstates(); 1205a3437870SNishanth Aravamudan 1206a3437870SNishanth Aravamudan report_hugepages(); 1207a3437870SNishanth Aravamudan 1208a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 1209a3437870SNishanth Aravamudan 1210a3437870SNishanth Aravamudan return 0; 1211a3437870SNishanth Aravamudan } 1212a3437870SNishanth Aravamudan module_init(hugetlb_init); 1213a3437870SNishanth Aravamudan 1214a3437870SNishanth Aravamudan /* Should be called on processing a hugepagesz=... option */ 1215a3437870SNishanth Aravamudan void __init hugetlb_add_hstate(unsigned order) 1216a3437870SNishanth Aravamudan { 1217a3437870SNishanth Aravamudan struct hstate *h; 1218a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 1219a3437870SNishanth Aravamudan printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n"); 1220a3437870SNishanth Aravamudan return; 1221a3437870SNishanth Aravamudan } 1222a3437870SNishanth Aravamudan BUG_ON(max_hstate >= HUGE_MAX_HSTATE); 1223a3437870SNishanth Aravamudan BUG_ON(order == 0); 1224a3437870SNishanth Aravamudan h = &hstates[max_hstate++]; 1225a3437870SNishanth Aravamudan h->order = order; 1226a3437870SNishanth Aravamudan h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); 1227a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 1228a3437870SNishanth Aravamudan huge_page_size(h)/1024); 1229a3437870SNishanth Aravamudan hugetlb_init_one_hstate(h); 1230a3437870SNishanth Aravamudan parsed_hstate = h; 1231a3437870SNishanth Aravamudan } 1232a3437870SNishanth Aravamudan 1233a3437870SNishanth Aravamudan static int __init hugetlb_setup(char *s) 1234a3437870SNishanth Aravamudan { 1235a3437870SNishanth Aravamudan unsigned long *mhp; 1236a3437870SNishanth Aravamudan 1237a3437870SNishanth Aravamudan /* 1238a3437870SNishanth Aravamudan * !max_hstate means we haven't parsed a hugepagesz= parameter yet, 1239a3437870SNishanth Aravamudan * so this hugepages= parameter goes to the "default hstate". 1240a3437870SNishanth Aravamudan */ 1241a3437870SNishanth Aravamudan if (!max_hstate) 1242a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 1243a3437870SNishanth Aravamudan else 1244a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 1245a3437870SNishanth Aravamudan 1246a3437870SNishanth Aravamudan if (sscanf(s, "%lu", mhp) <= 0) 1247a3437870SNishanth Aravamudan *mhp = 0; 1248a3437870SNishanth Aravamudan 1249a3437870SNishanth Aravamudan return 1; 1250a3437870SNishanth Aravamudan } 1251a3437870SNishanth Aravamudan __setup("hugepages=", hugetlb_setup); 1252a3437870SNishanth Aravamudan 1253a3437870SNishanth Aravamudan static unsigned int cpuset_mems_nr(unsigned int *array) 1254a3437870SNishanth Aravamudan { 1255a3437870SNishanth Aravamudan int node; 1256a3437870SNishanth Aravamudan unsigned int nr = 0; 1257a3437870SNishanth Aravamudan 1258a3437870SNishanth Aravamudan for_each_node_mask(node, cpuset_current_mems_allowed) 1259a3437870SNishanth Aravamudan nr += array[node]; 1260a3437870SNishanth Aravamudan 1261a3437870SNishanth Aravamudan return nr; 1262a3437870SNishanth Aravamudan } 1263a3437870SNishanth Aravamudan 12641da177e4SLinus Torvalds int hugetlb_sysctl_handler(struct ctl_table *table, int write, 12651da177e4SLinus Torvalds struct file *file, void __user *buffer, 12661da177e4SLinus Torvalds size_t *length, loff_t *ppos) 12671da177e4SLinus Torvalds { 1268e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 1269e5ff2159SAndi Kleen unsigned long tmp; 1270e5ff2159SAndi Kleen 1271e5ff2159SAndi Kleen if (!write) 1272e5ff2159SAndi Kleen tmp = h->max_huge_pages; 1273e5ff2159SAndi Kleen 1274e5ff2159SAndi Kleen table->data = &tmp; 1275e5ff2159SAndi Kleen table->maxlen = sizeof(unsigned long); 12761da177e4SLinus Torvalds proc_doulongvec_minmax(table, write, file, buffer, length, ppos); 1277e5ff2159SAndi Kleen 1278e5ff2159SAndi Kleen if (write) 1279e5ff2159SAndi Kleen h->max_huge_pages = set_max_huge_pages(h, tmp); 1280e5ff2159SAndi Kleen 12811da177e4SLinus Torvalds return 0; 12821da177e4SLinus Torvalds } 1283396faf03SMel Gorman 1284396faf03SMel Gorman int hugetlb_treat_movable_handler(struct ctl_table *table, int write, 1285396faf03SMel Gorman struct file *file, void __user *buffer, 1286396faf03SMel Gorman size_t *length, loff_t *ppos) 1287396faf03SMel Gorman { 1288396faf03SMel Gorman proc_dointvec(table, write, file, buffer, length, ppos); 1289396faf03SMel Gorman if (hugepages_treat_as_movable) 1290396faf03SMel Gorman htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; 1291396faf03SMel Gorman else 1292396faf03SMel Gorman htlb_alloc_mask = GFP_HIGHUSER; 1293396faf03SMel Gorman return 0; 1294396faf03SMel Gorman } 1295396faf03SMel Gorman 1296a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 1297a3d0c6aaSNishanth Aravamudan struct file *file, void __user *buffer, 1298a3d0c6aaSNishanth Aravamudan size_t *length, loff_t *ppos) 1299a3d0c6aaSNishanth Aravamudan { 1300a5516438SAndi Kleen struct hstate *h = &default_hstate; 1301e5ff2159SAndi Kleen unsigned long tmp; 1302e5ff2159SAndi Kleen 1303e5ff2159SAndi Kleen if (!write) 1304e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 1305e5ff2159SAndi Kleen 1306e5ff2159SAndi Kleen table->data = &tmp; 1307e5ff2159SAndi Kleen table->maxlen = sizeof(unsigned long); 1308a3d0c6aaSNishanth Aravamudan proc_doulongvec_minmax(table, write, file, buffer, length, ppos); 1309e5ff2159SAndi Kleen 1310e5ff2159SAndi Kleen if (write) { 1311064d9efeSNishanth Aravamudan spin_lock(&hugetlb_lock); 1312e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 1313a3d0c6aaSNishanth Aravamudan spin_unlock(&hugetlb_lock); 1314e5ff2159SAndi Kleen } 1315e5ff2159SAndi Kleen 1316a3d0c6aaSNishanth Aravamudan return 0; 1317a3d0c6aaSNishanth Aravamudan } 1318a3d0c6aaSNishanth Aravamudan 13191da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 13201da177e4SLinus Torvalds 13211da177e4SLinus Torvalds int hugetlb_report_meminfo(char *buf) 13221da177e4SLinus Torvalds { 1323a5516438SAndi Kleen struct hstate *h = &default_hstate; 13241da177e4SLinus Torvalds return sprintf(buf, 13251da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 13261da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 1327b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 13287893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 13291da177e4SLinus Torvalds "Hugepagesize: %5lu kB\n", 1330a5516438SAndi Kleen h->nr_huge_pages, 1331a5516438SAndi Kleen h->free_huge_pages, 1332a5516438SAndi Kleen h->resv_huge_pages, 1333a5516438SAndi Kleen h->surplus_huge_pages, 1334a5516438SAndi Kleen 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); 13351da177e4SLinus Torvalds } 13361da177e4SLinus Torvalds 13371da177e4SLinus Torvalds int hugetlb_report_node_meminfo(int nid, char *buf) 13381da177e4SLinus Torvalds { 1339a5516438SAndi Kleen struct hstate *h = &default_hstate; 13401da177e4SLinus Torvalds return sprintf(buf, 13411da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 1342a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 1343a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 1344a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 1345a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 1346a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 13471da177e4SLinus Torvalds } 13481da177e4SLinus Torvalds 13491da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 13501da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 13511da177e4SLinus Torvalds { 1352a5516438SAndi Kleen struct hstate *h = &default_hstate; 1353a5516438SAndi Kleen return h->nr_huge_pages * pages_per_huge_page(h); 13541da177e4SLinus Torvalds } 13551da177e4SLinus Torvalds 1356a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 1357fc1b8a73SMel Gorman { 1358fc1b8a73SMel Gorman int ret = -ENOMEM; 1359fc1b8a73SMel Gorman 1360fc1b8a73SMel Gorman spin_lock(&hugetlb_lock); 1361fc1b8a73SMel Gorman /* 1362fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 1363fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 1364fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 1365fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 1366fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 1367fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 1368fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 1369fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 1370fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 1371fc1b8a73SMel Gorman * 1372fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 1373fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 1374fc1b8a73SMel Gorman * we fall back to check against current free page availability as 1375fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 1376fc1b8a73SMel Gorman * semantics that cpuset has. 1377fc1b8a73SMel Gorman */ 1378fc1b8a73SMel Gorman if (delta > 0) { 1379a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 1380fc1b8a73SMel Gorman goto out; 1381fc1b8a73SMel Gorman 1382a5516438SAndi Kleen if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { 1383a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 1384fc1b8a73SMel Gorman goto out; 1385fc1b8a73SMel Gorman } 1386fc1b8a73SMel Gorman } 1387fc1b8a73SMel Gorman 1388fc1b8a73SMel Gorman ret = 0; 1389fc1b8a73SMel Gorman if (delta < 0) 1390a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 1391fc1b8a73SMel Gorman 1392fc1b8a73SMel Gorman out: 1393fc1b8a73SMel Gorman spin_unlock(&hugetlb_lock); 1394fc1b8a73SMel Gorman return ret; 1395fc1b8a73SMel Gorman } 1396fc1b8a73SMel Gorman 139784afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 139884afd99bSAndy Whitcroft { 139984afd99bSAndy Whitcroft struct resv_map *reservations = vma_resv_map(vma); 140084afd99bSAndy Whitcroft 140184afd99bSAndy Whitcroft /* 140284afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 140384afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 140484afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 140584afd99bSAndy Whitcroft * has a reference to the reservation map it cannot dissappear until 140684afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 140784afd99bSAndy Whitcroft * new reference here without additional locking. 140884afd99bSAndy Whitcroft */ 140984afd99bSAndy Whitcroft if (reservations) 141084afd99bSAndy Whitcroft kref_get(&reservations->refs); 141184afd99bSAndy Whitcroft } 141284afd99bSAndy Whitcroft 1413a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 1414a1e78772SMel Gorman { 1415a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 141684afd99bSAndy Whitcroft struct resv_map *reservations = vma_resv_map(vma); 141784afd99bSAndy Whitcroft unsigned long reserve; 141884afd99bSAndy Whitcroft unsigned long start; 141984afd99bSAndy Whitcroft unsigned long end; 142084afd99bSAndy Whitcroft 142184afd99bSAndy Whitcroft if (reservations) { 1422a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 1423a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 142484afd99bSAndy Whitcroft 142584afd99bSAndy Whitcroft reserve = (end - start) - 142684afd99bSAndy Whitcroft region_count(&reservations->regions, start, end); 142784afd99bSAndy Whitcroft 142884afd99bSAndy Whitcroft kref_put(&reservations->refs, resv_map_release); 142984afd99bSAndy Whitcroft 1430a1e78772SMel Gorman if (reserve) 1431a5516438SAndi Kleen hugetlb_acct_memory(h, -reserve); 1432a1e78772SMel Gorman } 143384afd99bSAndy Whitcroft } 1434a1e78772SMel Gorman 14351da177e4SLinus Torvalds /* 14361da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 14371da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 14381da177e4SLinus Torvalds * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get 14391da177e4SLinus Torvalds * this far. 14401da177e4SLinus Torvalds */ 1441d0217ac0SNick Piggin static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 14421da177e4SLinus Torvalds { 14431da177e4SLinus Torvalds BUG(); 1444d0217ac0SNick Piggin return 0; 14451da177e4SLinus Torvalds } 14461da177e4SLinus Torvalds 14471da177e4SLinus Torvalds struct vm_operations_struct hugetlb_vm_ops = { 1448d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 144984afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 1450a1e78772SMel Gorman .close = hugetlb_vm_op_close, 14511da177e4SLinus Torvalds }; 14521da177e4SLinus Torvalds 14531e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 14541e8f889bSDavid Gibson int writable) 145563551ae0SDavid Gibson { 145663551ae0SDavid Gibson pte_t entry; 145763551ae0SDavid Gibson 14581e8f889bSDavid Gibson if (writable) { 145963551ae0SDavid Gibson entry = 146063551ae0SDavid Gibson pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); 146163551ae0SDavid Gibson } else { 14627f2e9525SGerald Schaefer entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); 146363551ae0SDavid Gibson } 146463551ae0SDavid Gibson entry = pte_mkyoung(entry); 146563551ae0SDavid Gibson entry = pte_mkhuge(entry); 146663551ae0SDavid Gibson 146763551ae0SDavid Gibson return entry; 146863551ae0SDavid Gibson } 146963551ae0SDavid Gibson 14701e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 14711e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 14721e8f889bSDavid Gibson { 14731e8f889bSDavid Gibson pte_t entry; 14741e8f889bSDavid Gibson 14757f2e9525SGerald Schaefer entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); 14767f2e9525SGerald Schaefer if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { 14771e8f889bSDavid Gibson update_mmu_cache(vma, address, entry); 14781e8f889bSDavid Gibson } 14798dab5241SBenjamin Herrenschmidt } 14801e8f889bSDavid Gibson 14811e8f889bSDavid Gibson 148263551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 148363551ae0SDavid Gibson struct vm_area_struct *vma) 148463551ae0SDavid Gibson { 148563551ae0SDavid Gibson pte_t *src_pte, *dst_pte, entry; 148663551ae0SDavid Gibson struct page *ptepage; 14871c59827dSHugh Dickins unsigned long addr; 14881e8f889bSDavid Gibson int cow; 1489a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 1490a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 14911e8f889bSDavid Gibson 14921e8f889bSDavid Gibson cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; 149363551ae0SDavid Gibson 1494a5516438SAndi Kleen for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { 1495c74df32cSHugh Dickins src_pte = huge_pte_offset(src, addr); 1496c74df32cSHugh Dickins if (!src_pte) 1497c74df32cSHugh Dickins continue; 1498a5516438SAndi Kleen dst_pte = huge_pte_alloc(dst, addr, sz); 149963551ae0SDavid Gibson if (!dst_pte) 150063551ae0SDavid Gibson goto nomem; 1501c5c99429SLarry Woodman 1502c5c99429SLarry Woodman /* If the pagetables are shared don't copy or take references */ 1503c5c99429SLarry Woodman if (dst_pte == src_pte) 1504c5c99429SLarry Woodman continue; 1505c5c99429SLarry Woodman 1506c74df32cSHugh Dickins spin_lock(&dst->page_table_lock); 150746478758SNick Piggin spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); 15087f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(src_pte))) { 15091e8f889bSDavid Gibson if (cow) 15107f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 15117f2e9525SGerald Schaefer entry = huge_ptep_get(src_pte); 151263551ae0SDavid Gibson ptepage = pte_page(entry); 151363551ae0SDavid Gibson get_page(ptepage); 151463551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 15151c59827dSHugh Dickins } 15161c59827dSHugh Dickins spin_unlock(&src->page_table_lock); 1517c74df32cSHugh Dickins spin_unlock(&dst->page_table_lock); 151863551ae0SDavid Gibson } 151963551ae0SDavid Gibson return 0; 152063551ae0SDavid Gibson 152163551ae0SDavid Gibson nomem: 152263551ae0SDavid Gibson return -ENOMEM; 152363551ae0SDavid Gibson } 152463551ae0SDavid Gibson 1525502717f4SChen, Kenneth W void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 152604f2cbe3SMel Gorman unsigned long end, struct page *ref_page) 152763551ae0SDavid Gibson { 152863551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 152963551ae0SDavid Gibson unsigned long address; 1530c7546f8fSDavid Gibson pte_t *ptep; 153163551ae0SDavid Gibson pte_t pte; 153263551ae0SDavid Gibson struct page *page; 1533fe1668aeSChen, Kenneth W struct page *tmp; 1534a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 1535a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 1536a5516438SAndi Kleen 1537c0a499c2SChen, Kenneth W /* 1538c0a499c2SChen, Kenneth W * A page gathering list, protected by per file i_mmap_lock. The 1539c0a499c2SChen, Kenneth W * lock is used to avoid list corruption from multiple unmapping 1540c0a499c2SChen, Kenneth W * of the same page since we are using page->lru. 1541c0a499c2SChen, Kenneth W */ 1542fe1668aeSChen, Kenneth W LIST_HEAD(page_list); 154363551ae0SDavid Gibson 154463551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 1545a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 1546a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 154763551ae0SDavid Gibson 1548508034a3SHugh Dickins spin_lock(&mm->page_table_lock); 1549a5516438SAndi Kleen for (address = start; address < end; address += sz) { 1550c7546f8fSDavid Gibson ptep = huge_pte_offset(mm, address); 1551c7546f8fSDavid Gibson if (!ptep) 1552c7546f8fSDavid Gibson continue; 1553c7546f8fSDavid Gibson 155439dde65cSChen, Kenneth W if (huge_pmd_unshare(mm, &address, ptep)) 155539dde65cSChen, Kenneth W continue; 155639dde65cSChen, Kenneth W 155704f2cbe3SMel Gorman /* 155804f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 155904f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 156004f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 156104f2cbe3SMel Gorman */ 156204f2cbe3SMel Gorman if (ref_page) { 156304f2cbe3SMel Gorman pte = huge_ptep_get(ptep); 156404f2cbe3SMel Gorman if (huge_pte_none(pte)) 156504f2cbe3SMel Gorman continue; 156604f2cbe3SMel Gorman page = pte_page(pte); 156704f2cbe3SMel Gorman if (page != ref_page) 156804f2cbe3SMel Gorman continue; 156904f2cbe3SMel Gorman 157004f2cbe3SMel Gorman /* 157104f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 157204f2cbe3SMel Gorman * future faults in this VMA will fail rather than 157304f2cbe3SMel Gorman * looking like data was lost 157404f2cbe3SMel Gorman */ 157504f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 157604f2cbe3SMel Gorman } 157704f2cbe3SMel Gorman 1578c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 15797f2e9525SGerald Schaefer if (huge_pte_none(pte)) 158063551ae0SDavid Gibson continue; 1581c7546f8fSDavid Gibson 158263551ae0SDavid Gibson page = pte_page(pte); 15836649a386SKen Chen if (pte_dirty(pte)) 15846649a386SKen Chen set_page_dirty(page); 1585fe1668aeSChen, Kenneth W list_add(&page->lru, &page_list); 158663551ae0SDavid Gibson } 15871da177e4SLinus Torvalds spin_unlock(&mm->page_table_lock); 1588508034a3SHugh Dickins flush_tlb_range(vma, start, end); 1589fe1668aeSChen, Kenneth W list_for_each_entry_safe(page, tmp, &page_list, lru) { 1590fe1668aeSChen, Kenneth W list_del(&page->lru); 1591fe1668aeSChen, Kenneth W put_page(page); 1592fe1668aeSChen, Kenneth W } 15931da177e4SLinus Torvalds } 159463551ae0SDavid Gibson 1595502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 159604f2cbe3SMel Gorman unsigned long end, struct page *ref_page) 1597502717f4SChen, Kenneth W { 1598502717f4SChen, Kenneth W spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); 159904f2cbe3SMel Gorman __unmap_hugepage_range(vma, start, end, ref_page); 1600502717f4SChen, Kenneth W spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); 1601502717f4SChen, Kenneth W } 1602502717f4SChen, Kenneth W 160304f2cbe3SMel Gorman /* 160404f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 160504f2cbe3SMel Gorman * mappping it owns the reserve page for. The intention is to unmap the page 160604f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 160704f2cbe3SMel Gorman * same region. 160804f2cbe3SMel Gorman */ 160904f2cbe3SMel Gorman int unmap_ref_private(struct mm_struct *mm, 161004f2cbe3SMel Gorman struct vm_area_struct *vma, 161104f2cbe3SMel Gorman struct page *page, 161204f2cbe3SMel Gorman unsigned long address) 161304f2cbe3SMel Gorman { 161404f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 161504f2cbe3SMel Gorman struct address_space *mapping; 161604f2cbe3SMel Gorman struct prio_tree_iter iter; 161704f2cbe3SMel Gorman pgoff_t pgoff; 161804f2cbe3SMel Gorman 161904f2cbe3SMel Gorman /* 162004f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 162104f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 162204f2cbe3SMel Gorman */ 162304f2cbe3SMel Gorman address = address & huge_page_mask(hstate_vma(vma)); 162404f2cbe3SMel Gorman pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) 162504f2cbe3SMel Gorman + (vma->vm_pgoff >> PAGE_SHIFT); 162604f2cbe3SMel Gorman mapping = (struct address_space *)page_private(page); 162704f2cbe3SMel Gorman 162804f2cbe3SMel Gorman vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { 162904f2cbe3SMel Gorman /* Do not unmap the current VMA */ 163004f2cbe3SMel Gorman if (iter_vma == vma) 163104f2cbe3SMel Gorman continue; 163204f2cbe3SMel Gorman 163304f2cbe3SMel Gorman /* 163404f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 163504f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 163604f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 163704f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 163804f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 163904f2cbe3SMel Gorman */ 164004f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 164104f2cbe3SMel Gorman unmap_hugepage_range(iter_vma, 164204f2cbe3SMel Gorman address, address + HPAGE_SIZE, 164304f2cbe3SMel Gorman page); 164404f2cbe3SMel Gorman } 164504f2cbe3SMel Gorman 164604f2cbe3SMel Gorman return 1; 164704f2cbe3SMel Gorman } 164804f2cbe3SMel Gorman 16491e8f889bSDavid Gibson static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, 165004f2cbe3SMel Gorman unsigned long address, pte_t *ptep, pte_t pte, 165104f2cbe3SMel Gorman struct page *pagecache_page) 16521e8f889bSDavid Gibson { 1653a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 16541e8f889bSDavid Gibson struct page *old_page, *new_page; 165579ac6ba4SDavid Gibson int avoidcopy; 165604f2cbe3SMel Gorman int outside_reserve = 0; 16571e8f889bSDavid Gibson 16581e8f889bSDavid Gibson old_page = pte_page(pte); 16591e8f889bSDavid Gibson 166004f2cbe3SMel Gorman retry_avoidcopy: 16611e8f889bSDavid Gibson /* If no-one else is actually using this page, avoid the copy 16621e8f889bSDavid Gibson * and just make the page writable */ 16631e8f889bSDavid Gibson avoidcopy = (page_count(old_page) == 1); 16641e8f889bSDavid Gibson if (avoidcopy) { 16651e8f889bSDavid Gibson set_huge_ptep_writable(vma, address, ptep); 166683c54070SNick Piggin return 0; 16671e8f889bSDavid Gibson } 16681e8f889bSDavid Gibson 166904f2cbe3SMel Gorman /* 167004f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 167104f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 167204f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 167304f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 167404f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 167504f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 167604f2cbe3SMel Gorman * of the full address range. 167704f2cbe3SMel Gorman */ 167804f2cbe3SMel Gorman if (!(vma->vm_flags & VM_SHARED) && 167904f2cbe3SMel Gorman is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 168004f2cbe3SMel Gorman old_page != pagecache_page) 168104f2cbe3SMel Gorman outside_reserve = 1; 168204f2cbe3SMel Gorman 16831e8f889bSDavid Gibson page_cache_get(old_page); 168404f2cbe3SMel Gorman new_page = alloc_huge_page(vma, address, outside_reserve); 16851e8f889bSDavid Gibson 16862fc39cecSAdam Litke if (IS_ERR(new_page)) { 16871e8f889bSDavid Gibson page_cache_release(old_page); 168804f2cbe3SMel Gorman 168904f2cbe3SMel Gorman /* 169004f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 169104f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 169204f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 169304f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 169404f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 169504f2cbe3SMel Gorman */ 169604f2cbe3SMel Gorman if (outside_reserve) { 169704f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 169804f2cbe3SMel Gorman if (unmap_ref_private(mm, vma, old_page, address)) { 169904f2cbe3SMel Gorman BUG_ON(page_count(old_page) != 1); 170004f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 170104f2cbe3SMel Gorman goto retry_avoidcopy; 170204f2cbe3SMel Gorman } 170304f2cbe3SMel Gorman WARN_ON_ONCE(1); 170404f2cbe3SMel Gorman } 170504f2cbe3SMel Gorman 17062fc39cecSAdam Litke return -PTR_ERR(new_page); 17071e8f889bSDavid Gibson } 17081e8f889bSDavid Gibson 17091e8f889bSDavid Gibson spin_unlock(&mm->page_table_lock); 17109de455b2SAtsushi Nemoto copy_huge_page(new_page, old_page, address, vma); 17110ed361deSNick Piggin __SetPageUptodate(new_page); 17121e8f889bSDavid Gibson spin_lock(&mm->page_table_lock); 17131e8f889bSDavid Gibson 1714a5516438SAndi Kleen ptep = huge_pte_offset(mm, address & huge_page_mask(h)); 17157f2e9525SGerald Schaefer if (likely(pte_same(huge_ptep_get(ptep), pte))) { 17161e8f889bSDavid Gibson /* Break COW */ 17178fe627ecSGerald Schaefer huge_ptep_clear_flush(vma, address, ptep); 17181e8f889bSDavid Gibson set_huge_pte_at(mm, address, ptep, 17191e8f889bSDavid Gibson make_huge_pte(vma, new_page, 1)); 17201e8f889bSDavid Gibson /* Make the old page be freed below */ 17211e8f889bSDavid Gibson new_page = old_page; 17221e8f889bSDavid Gibson } 17231e8f889bSDavid Gibson page_cache_release(new_page); 17241e8f889bSDavid Gibson page_cache_release(old_page); 172583c54070SNick Piggin return 0; 17261e8f889bSDavid Gibson } 17271e8f889bSDavid Gibson 172804f2cbe3SMel Gorman /* Return the pagecache page at a given address within a VMA */ 1729a5516438SAndi Kleen static struct page *hugetlbfs_pagecache_page(struct hstate *h, 1730a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 173104f2cbe3SMel Gorman { 173204f2cbe3SMel Gorman struct address_space *mapping; 1733e7c4b0bfSAndy Whitcroft pgoff_t idx; 173404f2cbe3SMel Gorman 173504f2cbe3SMel Gorman mapping = vma->vm_file->f_mapping; 1736a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 173704f2cbe3SMel Gorman 173804f2cbe3SMel Gorman return find_lock_page(mapping, idx); 173904f2cbe3SMel Gorman } 174004f2cbe3SMel Gorman 1741a1ed3ddaSRobert P. J. Day static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, 17421e8f889bSDavid Gibson unsigned long address, pte_t *ptep, int write_access) 1743ac9b9c66SHugh Dickins { 1744a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 1745ac9b9c66SHugh Dickins int ret = VM_FAULT_SIGBUS; 1746e7c4b0bfSAndy Whitcroft pgoff_t idx; 17474c887265SAdam Litke unsigned long size; 17484c887265SAdam Litke struct page *page; 17494c887265SAdam Litke struct address_space *mapping; 17501e8f889bSDavid Gibson pte_t new_pte; 17514c887265SAdam Litke 175204f2cbe3SMel Gorman /* 175304f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 175404f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 175504f2cbe3SMel Gorman * COW. Warn that such a situation has occured as it may not be obvious 175604f2cbe3SMel Gorman */ 175704f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 175804f2cbe3SMel Gorman printk(KERN_WARNING 175904f2cbe3SMel Gorman "PID %d killed due to inadequate hugepage pool\n", 176004f2cbe3SMel Gorman current->pid); 176104f2cbe3SMel Gorman return ret; 176204f2cbe3SMel Gorman } 176304f2cbe3SMel Gorman 17644c887265SAdam Litke mapping = vma->vm_file->f_mapping; 1765a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 17664c887265SAdam Litke 17674c887265SAdam Litke /* 17684c887265SAdam Litke * Use page lock to guard against racing truncation 17694c887265SAdam Litke * before we get page_table_lock. 17704c887265SAdam Litke */ 17716bda666aSChristoph Lameter retry: 17726bda666aSChristoph Lameter page = find_lock_page(mapping, idx); 17736bda666aSChristoph Lameter if (!page) { 1774a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 1775ebed4bfcSHugh Dickins if (idx >= size) 1776ebed4bfcSHugh Dickins goto out; 177704f2cbe3SMel Gorman page = alloc_huge_page(vma, address, 0); 17782fc39cecSAdam Litke if (IS_ERR(page)) { 17792fc39cecSAdam Litke ret = -PTR_ERR(page); 17806bda666aSChristoph Lameter goto out; 17816bda666aSChristoph Lameter } 1782a5516438SAndi Kleen clear_huge_page(page, address, huge_page_size(h)); 17830ed361deSNick Piggin __SetPageUptodate(page); 1784ac9b9c66SHugh Dickins 17856bda666aSChristoph Lameter if (vma->vm_flags & VM_SHARED) { 17866bda666aSChristoph Lameter int err; 178745c682a6SKen Chen struct inode *inode = mapping->host; 17886bda666aSChristoph Lameter 17896bda666aSChristoph Lameter err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); 17906bda666aSChristoph Lameter if (err) { 17916bda666aSChristoph Lameter put_page(page); 17926bda666aSChristoph Lameter if (err == -EEXIST) 17936bda666aSChristoph Lameter goto retry; 17946bda666aSChristoph Lameter goto out; 17956bda666aSChristoph Lameter } 179645c682a6SKen Chen 179745c682a6SKen Chen spin_lock(&inode->i_lock); 1798a5516438SAndi Kleen inode->i_blocks += blocks_per_huge_page(h); 179945c682a6SKen Chen spin_unlock(&inode->i_lock); 18006bda666aSChristoph Lameter } else 18016bda666aSChristoph Lameter lock_page(page); 18026bda666aSChristoph Lameter } 18031e8f889bSDavid Gibson 1804ac9b9c66SHugh Dickins spin_lock(&mm->page_table_lock); 1805a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 18064c887265SAdam Litke if (idx >= size) 18074c887265SAdam Litke goto backout; 18084c887265SAdam Litke 180983c54070SNick Piggin ret = 0; 18107f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(ptep))) 18114c887265SAdam Litke goto backout; 18124c887265SAdam Litke 18131e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 18141e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 18151e8f889bSDavid Gibson set_huge_pte_at(mm, address, ptep, new_pte); 18161e8f889bSDavid Gibson 18171e8f889bSDavid Gibson if (write_access && !(vma->vm_flags & VM_SHARED)) { 18181e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 181904f2cbe3SMel Gorman ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); 18201e8f889bSDavid Gibson } 18211e8f889bSDavid Gibson 1822ac9b9c66SHugh Dickins spin_unlock(&mm->page_table_lock); 18234c887265SAdam Litke unlock_page(page); 18244c887265SAdam Litke out: 1825ac9b9c66SHugh Dickins return ret; 18264c887265SAdam Litke 18274c887265SAdam Litke backout: 18284c887265SAdam Litke spin_unlock(&mm->page_table_lock); 18294c887265SAdam Litke unlock_page(page); 18304c887265SAdam Litke put_page(page); 18314c887265SAdam Litke goto out; 1832ac9b9c66SHugh Dickins } 1833ac9b9c66SHugh Dickins 183486e5216fSAdam Litke int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 183586e5216fSAdam Litke unsigned long address, int write_access) 183686e5216fSAdam Litke { 183786e5216fSAdam Litke pte_t *ptep; 183886e5216fSAdam Litke pte_t entry; 18391e8f889bSDavid Gibson int ret; 18403935baa9SDavid Gibson static DEFINE_MUTEX(hugetlb_instantiation_mutex); 1841a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 184286e5216fSAdam Litke 1843a5516438SAndi Kleen ptep = huge_pte_alloc(mm, address, huge_page_size(h)); 184486e5216fSAdam Litke if (!ptep) 184586e5216fSAdam Litke return VM_FAULT_OOM; 184686e5216fSAdam Litke 18473935baa9SDavid Gibson /* 18483935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 18493935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 18503935baa9SDavid Gibson * the same page in the page cache. 18513935baa9SDavid Gibson */ 18523935baa9SDavid Gibson mutex_lock(&hugetlb_instantiation_mutex); 18537f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 18547f2e9525SGerald Schaefer if (huge_pte_none(entry)) { 18553935baa9SDavid Gibson ret = hugetlb_no_page(mm, vma, address, ptep, write_access); 18563935baa9SDavid Gibson mutex_unlock(&hugetlb_instantiation_mutex); 18573935baa9SDavid Gibson return ret; 18583935baa9SDavid Gibson } 185986e5216fSAdam Litke 186083c54070SNick Piggin ret = 0; 18611e8f889bSDavid Gibson 18621e8f889bSDavid Gibson spin_lock(&mm->page_table_lock); 18631e8f889bSDavid Gibson /* Check for a racing update before calling hugetlb_cow */ 18647f2e9525SGerald Schaefer if (likely(pte_same(entry, huge_ptep_get(ptep)))) 186504f2cbe3SMel Gorman if (write_access && !pte_write(entry)) { 186604f2cbe3SMel Gorman struct page *page; 1867a5516438SAndi Kleen page = hugetlbfs_pagecache_page(h, vma, address); 186804f2cbe3SMel Gorman ret = hugetlb_cow(mm, vma, address, ptep, entry, page); 186904f2cbe3SMel Gorman if (page) { 187004f2cbe3SMel Gorman unlock_page(page); 187104f2cbe3SMel Gorman put_page(page); 187204f2cbe3SMel Gorman } 187304f2cbe3SMel Gorman } 18741e8f889bSDavid Gibson spin_unlock(&mm->page_table_lock); 18753935baa9SDavid Gibson mutex_unlock(&hugetlb_instantiation_mutex); 18761e8f889bSDavid Gibson 18771e8f889bSDavid Gibson return ret; 187886e5216fSAdam Litke } 187986e5216fSAdam Litke 188063551ae0SDavid Gibson int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 188163551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 18825b23dbe8SAdam Litke unsigned long *position, int *length, int i, 18835b23dbe8SAdam Litke int write) 188463551ae0SDavid Gibson { 1885d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 1886d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 188763551ae0SDavid Gibson int remainder = *length; 1888a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 188963551ae0SDavid Gibson 18901c59827dSHugh Dickins spin_lock(&mm->page_table_lock); 189163551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 189263551ae0SDavid Gibson pte_t *pte; 189363551ae0SDavid Gibson struct page *page; 189463551ae0SDavid Gibson 18954c887265SAdam Litke /* 18964c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 18974c887265SAdam Litke * each hugepage. We have to make * sure we get the 18984c887265SAdam Litke * first, for the page indexing below to work. 18994c887265SAdam Litke */ 1900a5516438SAndi Kleen pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); 190163551ae0SDavid Gibson 19027f2e9525SGerald Schaefer if (!pte || huge_pte_none(huge_ptep_get(pte)) || 19037f2e9525SGerald Schaefer (write && !pte_write(huge_ptep_get(pte)))) { 19044c887265SAdam Litke int ret; 19054c887265SAdam Litke 19064c887265SAdam Litke spin_unlock(&mm->page_table_lock); 19075b23dbe8SAdam Litke ret = hugetlb_fault(mm, vma, vaddr, write); 19084c887265SAdam Litke spin_lock(&mm->page_table_lock); 1909a89182c7SAdam Litke if (!(ret & VM_FAULT_ERROR)) 19104c887265SAdam Litke continue; 19114c887265SAdam Litke 19121c59827dSHugh Dickins remainder = 0; 19131c59827dSHugh Dickins if (!i) 19141c59827dSHugh Dickins i = -EFAULT; 19151c59827dSHugh Dickins break; 19161c59827dSHugh Dickins } 191763551ae0SDavid Gibson 1918a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 19197f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 1920d5d4b0aaSChen, Kenneth W same_page: 1921d6692183SChen, Kenneth W if (pages) { 192263551ae0SDavid Gibson get_page(page); 1923d5d4b0aaSChen, Kenneth W pages[i] = page + pfn_offset; 1924d6692183SChen, Kenneth W } 192563551ae0SDavid Gibson 192663551ae0SDavid Gibson if (vmas) 192763551ae0SDavid Gibson vmas[i] = vma; 192863551ae0SDavid Gibson 192963551ae0SDavid Gibson vaddr += PAGE_SIZE; 1930d5d4b0aaSChen, Kenneth W ++pfn_offset; 193163551ae0SDavid Gibson --remainder; 193263551ae0SDavid Gibson ++i; 1933d5d4b0aaSChen, Kenneth W if (vaddr < vma->vm_end && remainder && 1934a5516438SAndi Kleen pfn_offset < pages_per_huge_page(h)) { 1935d5d4b0aaSChen, Kenneth W /* 1936d5d4b0aaSChen, Kenneth W * We use pfn_offset to avoid touching the pageframes 1937d5d4b0aaSChen, Kenneth W * of this compound page. 1938d5d4b0aaSChen, Kenneth W */ 1939d5d4b0aaSChen, Kenneth W goto same_page; 1940d5d4b0aaSChen, Kenneth W } 194163551ae0SDavid Gibson } 19421c59827dSHugh Dickins spin_unlock(&mm->page_table_lock); 194363551ae0SDavid Gibson *length = remainder; 194463551ae0SDavid Gibson *position = vaddr; 194563551ae0SDavid Gibson 194663551ae0SDavid Gibson return i; 194763551ae0SDavid Gibson } 19488f860591SZhang, Yanmin 19498f860591SZhang, Yanmin void hugetlb_change_protection(struct vm_area_struct *vma, 19508f860591SZhang, Yanmin unsigned long address, unsigned long end, pgprot_t newprot) 19518f860591SZhang, Yanmin { 19528f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 19538f860591SZhang, Yanmin unsigned long start = address; 19548f860591SZhang, Yanmin pte_t *ptep; 19558f860591SZhang, Yanmin pte_t pte; 1956a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 19578f860591SZhang, Yanmin 19588f860591SZhang, Yanmin BUG_ON(address >= end); 19598f860591SZhang, Yanmin flush_cache_range(vma, address, end); 19608f860591SZhang, Yanmin 196139dde65cSChen, Kenneth W spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); 19628f860591SZhang, Yanmin spin_lock(&mm->page_table_lock); 1963a5516438SAndi Kleen for (; address < end; address += huge_page_size(h)) { 19648f860591SZhang, Yanmin ptep = huge_pte_offset(mm, address); 19658f860591SZhang, Yanmin if (!ptep) 19668f860591SZhang, Yanmin continue; 196739dde65cSChen, Kenneth W if (huge_pmd_unshare(mm, &address, ptep)) 196839dde65cSChen, Kenneth W continue; 19697f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(ptep))) { 19708f860591SZhang, Yanmin pte = huge_ptep_get_and_clear(mm, address, ptep); 19718f860591SZhang, Yanmin pte = pte_mkhuge(pte_modify(pte, newprot)); 19728f860591SZhang, Yanmin set_huge_pte_at(mm, address, ptep, pte); 19738f860591SZhang, Yanmin } 19748f860591SZhang, Yanmin } 19758f860591SZhang, Yanmin spin_unlock(&mm->page_table_lock); 197639dde65cSChen, Kenneth W spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); 19778f860591SZhang, Yanmin 19788f860591SZhang, Yanmin flush_tlb_range(vma, start, end); 19798f860591SZhang, Yanmin } 19808f860591SZhang, Yanmin 1981a1e78772SMel Gorman int hugetlb_reserve_pages(struct inode *inode, 1982a1e78772SMel Gorman long from, long to, 1983a1e78772SMel Gorman struct vm_area_struct *vma) 1984e4e574b7SAdam Litke { 1985e4e574b7SAdam Litke long ret, chg; 1986a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 1987e4e574b7SAdam Litke 1988c37f9fb1SAndy Whitcroft if (vma && vma->vm_flags & VM_NORESERVE) 1989c37f9fb1SAndy Whitcroft return 0; 1990c37f9fb1SAndy Whitcroft 1991a1e78772SMel Gorman /* 1992a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 1993a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 1994a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 1995a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 1996a1e78772SMel Gorman */ 1997a1e78772SMel Gorman if (!vma || vma->vm_flags & VM_SHARED) 1998e4e574b7SAdam Litke chg = region_chg(&inode->i_mapping->private_list, from, to); 1999a1e78772SMel Gorman else { 200084afd99bSAndy Whitcroft struct resv_map *resv_map = resv_map_alloc(); 200184afd99bSAndy Whitcroft if (!resv_map) 200284afd99bSAndy Whitcroft return -ENOMEM; 200384afd99bSAndy Whitcroft 2004a1e78772SMel Gorman chg = to - from; 200584afd99bSAndy Whitcroft 200684afd99bSAndy Whitcroft set_vma_resv_map(vma, resv_map); 200704f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 2008a1e78772SMel Gorman } 2009a1e78772SMel Gorman 2010e4e574b7SAdam Litke if (chg < 0) 2011e4e574b7SAdam Litke return chg; 20128a630112SKen Chen 201390d8b7e6SAdam Litke if (hugetlb_get_quota(inode->i_mapping, chg)) 201490d8b7e6SAdam Litke return -ENOSPC; 2015a5516438SAndi Kleen ret = hugetlb_acct_memory(h, chg); 201668842c9bSKen Chen if (ret < 0) { 201768842c9bSKen Chen hugetlb_put_quota(inode->i_mapping, chg); 2018a43a8c39SChen, Kenneth W return ret; 201968842c9bSKen Chen } 2020a1e78772SMel Gorman if (!vma || vma->vm_flags & VM_SHARED) 2021a43a8c39SChen, Kenneth W region_add(&inode->i_mapping->private_list, from, to); 2022a43a8c39SChen, Kenneth W return 0; 2023a43a8c39SChen, Kenneth W } 2024a43a8c39SChen, Kenneth W 2025a43a8c39SChen, Kenneth W void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) 2026a43a8c39SChen, Kenneth W { 2027a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 2028a43a8c39SChen, Kenneth W long chg = region_truncate(&inode->i_mapping->private_list, offset); 202945c682a6SKen Chen 203045c682a6SKen Chen spin_lock(&inode->i_lock); 2031a5516438SAndi Kleen inode->i_blocks -= blocks_per_huge_page(h); 203245c682a6SKen Chen spin_unlock(&inode->i_lock); 203345c682a6SKen Chen 203490d8b7e6SAdam Litke hugetlb_put_quota(inode->i_mapping, (chg - freed)); 2035a5516438SAndi Kleen hugetlb_acct_memory(h, -(chg - freed)); 2036a43a8c39SChen, Kenneth W } 2037