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> 17aa888a74SAndi Kleen #include <linux/bootmem.h> 18a3437870SNishanth Aravamudan #include <linux/sysfs.h> 195da7ca86SChristoph Lameter 2063551ae0SDavid Gibson #include <asm/page.h> 2163551ae0SDavid Gibson #include <asm/pgtable.h> 2263551ae0SDavid Gibson 2363551ae0SDavid Gibson #include <linux/hugetlb.h> 247835e98bSNick Piggin #include "internal.h" 251da177e4SLinus Torvalds 261da177e4SLinus Torvalds const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; 27396faf03SMel Gorman static gfp_t htlb_alloc_mask = GFP_HIGHUSER; 28396faf03SMel Gorman unsigned long hugepages_treat_as_movable; 29a5516438SAndi Kleen 30e5ff2159SAndi Kleen static int max_hstate; 31e5ff2159SAndi Kleen unsigned int default_hstate_idx; 32e5ff2159SAndi Kleen struct hstate hstates[HUGE_MAX_HSTATE]; 33e5ff2159SAndi Kleen 34e5ff2159SAndi Kleen /* for command line parsing */ 35e5ff2159SAndi Kleen static struct hstate * __initdata parsed_hstate; 36e5ff2159SAndi Kleen static unsigned long __initdata default_hstate_max_huge_pages; 37e5ff2159SAndi Kleen 38e5ff2159SAndi Kleen #define for_each_hstate(h) \ 39e5ff2159SAndi Kleen for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++) 40396faf03SMel Gorman 413935baa9SDavid Gibson /* 423935baa9SDavid Gibson * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages 433935baa9SDavid Gibson */ 443935baa9SDavid Gibson static DEFINE_SPINLOCK(hugetlb_lock); 450bd0f9fbSEric Paris 46e7c4b0bfSAndy Whitcroft /* 4796822904SAndy Whitcroft * Region tracking -- allows tracking of reservations and instantiated pages 4896822904SAndy Whitcroft * across the pages in a mapping. 4984afd99bSAndy Whitcroft * 5084afd99bSAndy Whitcroft * The region data structures are protected by a combination of the mmap_sem 5184afd99bSAndy Whitcroft * and the hugetlb_instantion_mutex. To access or modify a region the caller 5284afd99bSAndy Whitcroft * must either hold the mmap_sem for write, or the mmap_sem for read and 5384afd99bSAndy Whitcroft * the hugetlb_instantiation mutex: 5484afd99bSAndy Whitcroft * 5584afd99bSAndy Whitcroft * down_write(&mm->mmap_sem); 5684afd99bSAndy Whitcroft * or 5784afd99bSAndy Whitcroft * down_read(&mm->mmap_sem); 5884afd99bSAndy Whitcroft * mutex_lock(&hugetlb_instantiation_mutex); 5996822904SAndy Whitcroft */ 6096822904SAndy Whitcroft struct file_region { 6196822904SAndy Whitcroft struct list_head link; 6296822904SAndy Whitcroft long from; 6396822904SAndy Whitcroft long to; 6496822904SAndy Whitcroft }; 6596822904SAndy Whitcroft 6696822904SAndy Whitcroft static long region_add(struct list_head *head, long f, long t) 6796822904SAndy Whitcroft { 6896822904SAndy Whitcroft struct file_region *rg, *nrg, *trg; 6996822904SAndy Whitcroft 7096822904SAndy Whitcroft /* Locate the region we are either in or before. */ 7196822904SAndy Whitcroft list_for_each_entry(rg, head, link) 7296822904SAndy Whitcroft if (f <= rg->to) 7396822904SAndy Whitcroft break; 7496822904SAndy Whitcroft 7596822904SAndy Whitcroft /* Round our left edge to the current segment if it encloses us. */ 7696822904SAndy Whitcroft if (f > rg->from) 7796822904SAndy Whitcroft f = rg->from; 7896822904SAndy Whitcroft 7996822904SAndy Whitcroft /* Check for and consume any regions we now overlap with. */ 8096822904SAndy Whitcroft nrg = rg; 8196822904SAndy Whitcroft list_for_each_entry_safe(rg, trg, rg->link.prev, link) { 8296822904SAndy Whitcroft if (&rg->link == head) 8396822904SAndy Whitcroft break; 8496822904SAndy Whitcroft if (rg->from > t) 8596822904SAndy Whitcroft break; 8696822904SAndy Whitcroft 8796822904SAndy Whitcroft /* If this area reaches higher then extend our area to 8896822904SAndy Whitcroft * include it completely. If this is not the first area 8996822904SAndy Whitcroft * which we intend to reuse, free it. */ 9096822904SAndy Whitcroft if (rg->to > t) 9196822904SAndy Whitcroft t = rg->to; 9296822904SAndy Whitcroft if (rg != nrg) { 9396822904SAndy Whitcroft list_del(&rg->link); 9496822904SAndy Whitcroft kfree(rg); 9596822904SAndy Whitcroft } 9696822904SAndy Whitcroft } 9796822904SAndy Whitcroft nrg->from = f; 9896822904SAndy Whitcroft nrg->to = t; 9996822904SAndy Whitcroft return 0; 10096822904SAndy Whitcroft } 10196822904SAndy Whitcroft 10296822904SAndy Whitcroft static long region_chg(struct list_head *head, long f, long t) 10396822904SAndy Whitcroft { 10496822904SAndy Whitcroft struct file_region *rg, *nrg; 10596822904SAndy Whitcroft long chg = 0; 10696822904SAndy Whitcroft 10796822904SAndy Whitcroft /* Locate the region we are before or in. */ 10896822904SAndy Whitcroft list_for_each_entry(rg, head, link) 10996822904SAndy Whitcroft if (f <= rg->to) 11096822904SAndy Whitcroft break; 11196822904SAndy Whitcroft 11296822904SAndy Whitcroft /* If we are below the current region then a new region is required. 11396822904SAndy Whitcroft * Subtle, allocate a new region at the position but make it zero 11496822904SAndy Whitcroft * size such that we can guarantee to record the reservation. */ 11596822904SAndy Whitcroft if (&rg->link == head || t < rg->from) { 11696822904SAndy Whitcroft nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); 11796822904SAndy Whitcroft if (!nrg) 11896822904SAndy Whitcroft return -ENOMEM; 11996822904SAndy Whitcroft nrg->from = f; 12096822904SAndy Whitcroft nrg->to = f; 12196822904SAndy Whitcroft INIT_LIST_HEAD(&nrg->link); 12296822904SAndy Whitcroft list_add(&nrg->link, rg->link.prev); 12396822904SAndy Whitcroft 12496822904SAndy Whitcroft return t - f; 12596822904SAndy Whitcroft } 12696822904SAndy Whitcroft 12796822904SAndy Whitcroft /* Round our left edge to the current segment if it encloses us. */ 12896822904SAndy Whitcroft if (f > rg->from) 12996822904SAndy Whitcroft f = rg->from; 13096822904SAndy Whitcroft chg = t - f; 13196822904SAndy Whitcroft 13296822904SAndy Whitcroft /* Check for and consume any regions we now overlap with. */ 13396822904SAndy Whitcroft list_for_each_entry(rg, rg->link.prev, link) { 13496822904SAndy Whitcroft if (&rg->link == head) 13596822904SAndy Whitcroft break; 13696822904SAndy Whitcroft if (rg->from > t) 13796822904SAndy Whitcroft return chg; 13896822904SAndy Whitcroft 13996822904SAndy Whitcroft /* We overlap with this area, if it extends futher than 14096822904SAndy Whitcroft * us then we must extend ourselves. Account for its 14196822904SAndy Whitcroft * existing reservation. */ 14296822904SAndy Whitcroft if (rg->to > t) { 14396822904SAndy Whitcroft chg += rg->to - t; 14496822904SAndy Whitcroft t = rg->to; 14596822904SAndy Whitcroft } 14696822904SAndy Whitcroft chg -= rg->to - rg->from; 14796822904SAndy Whitcroft } 14896822904SAndy Whitcroft return chg; 14996822904SAndy Whitcroft } 15096822904SAndy Whitcroft 15196822904SAndy Whitcroft static long region_truncate(struct list_head *head, long end) 15296822904SAndy Whitcroft { 15396822904SAndy Whitcroft struct file_region *rg, *trg; 15496822904SAndy Whitcroft long chg = 0; 15596822904SAndy Whitcroft 15696822904SAndy Whitcroft /* Locate the region we are either in or before. */ 15796822904SAndy Whitcroft list_for_each_entry(rg, head, link) 15896822904SAndy Whitcroft if (end <= rg->to) 15996822904SAndy Whitcroft break; 16096822904SAndy Whitcroft if (&rg->link == head) 16196822904SAndy Whitcroft return 0; 16296822904SAndy Whitcroft 16396822904SAndy Whitcroft /* If we are in the middle of a region then adjust it. */ 16496822904SAndy Whitcroft if (end > rg->from) { 16596822904SAndy Whitcroft chg = rg->to - end; 16696822904SAndy Whitcroft rg->to = end; 16796822904SAndy Whitcroft rg = list_entry(rg->link.next, typeof(*rg), link); 16896822904SAndy Whitcroft } 16996822904SAndy Whitcroft 17096822904SAndy Whitcroft /* Drop any remaining regions. */ 17196822904SAndy Whitcroft list_for_each_entry_safe(rg, trg, rg->link.prev, link) { 17296822904SAndy Whitcroft if (&rg->link == head) 17396822904SAndy Whitcroft break; 17496822904SAndy Whitcroft chg += rg->to - rg->from; 17596822904SAndy Whitcroft list_del(&rg->link); 17696822904SAndy Whitcroft kfree(rg); 17796822904SAndy Whitcroft } 17896822904SAndy Whitcroft return chg; 17996822904SAndy Whitcroft } 18096822904SAndy Whitcroft 18184afd99bSAndy Whitcroft static long region_count(struct list_head *head, long f, long t) 18284afd99bSAndy Whitcroft { 18384afd99bSAndy Whitcroft struct file_region *rg; 18484afd99bSAndy Whitcroft long chg = 0; 18584afd99bSAndy Whitcroft 18684afd99bSAndy Whitcroft /* Locate each segment we overlap with, and count that overlap. */ 18784afd99bSAndy Whitcroft list_for_each_entry(rg, head, link) { 18884afd99bSAndy Whitcroft int seg_from; 18984afd99bSAndy Whitcroft int seg_to; 19084afd99bSAndy Whitcroft 19184afd99bSAndy Whitcroft if (rg->to <= f) 19284afd99bSAndy Whitcroft continue; 19384afd99bSAndy Whitcroft if (rg->from >= t) 19484afd99bSAndy Whitcroft break; 19584afd99bSAndy Whitcroft 19684afd99bSAndy Whitcroft seg_from = max(rg->from, f); 19784afd99bSAndy Whitcroft seg_to = min(rg->to, t); 19884afd99bSAndy Whitcroft 19984afd99bSAndy Whitcroft chg += seg_to - seg_from; 20084afd99bSAndy Whitcroft } 20184afd99bSAndy Whitcroft 20284afd99bSAndy Whitcroft return chg; 20384afd99bSAndy Whitcroft } 20484afd99bSAndy Whitcroft 20596822904SAndy Whitcroft /* 206e7c4b0bfSAndy Whitcroft * Convert the address within this vma to the page offset within 207e7c4b0bfSAndy Whitcroft * the mapping, in pagecache page units; huge pages here. 208e7c4b0bfSAndy Whitcroft */ 209a5516438SAndi Kleen static pgoff_t vma_hugecache_offset(struct hstate *h, 210a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 211e7c4b0bfSAndy Whitcroft { 212a5516438SAndi Kleen return ((address - vma->vm_start) >> huge_page_shift(h)) + 213a5516438SAndi Kleen (vma->vm_pgoff >> huge_page_order(h)); 214e7c4b0bfSAndy Whitcroft } 215e7c4b0bfSAndy Whitcroft 21684afd99bSAndy Whitcroft /* 21784afd99bSAndy Whitcroft * Flags for MAP_PRIVATE reservations. These are stored in the bottom 21884afd99bSAndy Whitcroft * bits of the reservation map pointer, which are always clear due to 21984afd99bSAndy Whitcroft * alignment. 22084afd99bSAndy Whitcroft */ 22184afd99bSAndy Whitcroft #define HPAGE_RESV_OWNER (1UL << 0) 22284afd99bSAndy Whitcroft #define HPAGE_RESV_UNMAPPED (1UL << 1) 22304f2cbe3SMel Gorman #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) 22484afd99bSAndy Whitcroft 225a1e78772SMel Gorman /* 226a1e78772SMel Gorman * These helpers are used to track how many pages are reserved for 227a1e78772SMel Gorman * faults in a MAP_PRIVATE mapping. Only the process that called mmap() 228a1e78772SMel Gorman * is guaranteed to have their future faults succeed. 229a1e78772SMel Gorman * 230a1e78772SMel Gorman * With the exception of reset_vma_resv_huge_pages() which is called at fork(), 231a1e78772SMel Gorman * the reserve counters are updated with the hugetlb_lock held. It is safe 232a1e78772SMel Gorman * to reset the VMA at fork() time as it is not in use yet and there is no 233a1e78772SMel Gorman * chance of the global counters getting corrupted as a result of the values. 23484afd99bSAndy Whitcroft * 23584afd99bSAndy Whitcroft * The private mapping reservation is represented in a subtly different 23684afd99bSAndy Whitcroft * manner to a shared mapping. A shared mapping has a region map associated 23784afd99bSAndy Whitcroft * with the underlying file, this region map represents the backing file 23884afd99bSAndy Whitcroft * pages which have ever had a reservation assigned which this persists even 23984afd99bSAndy Whitcroft * after the page is instantiated. A private mapping has a region map 24084afd99bSAndy Whitcroft * associated with the original mmap which is attached to all VMAs which 24184afd99bSAndy Whitcroft * reference it, this region map represents those offsets which have consumed 24284afd99bSAndy Whitcroft * reservation ie. where pages have been instantiated. 243a1e78772SMel Gorman */ 244e7c4b0bfSAndy Whitcroft static unsigned long get_vma_private_data(struct vm_area_struct *vma) 245e7c4b0bfSAndy Whitcroft { 246e7c4b0bfSAndy Whitcroft return (unsigned long)vma->vm_private_data; 247e7c4b0bfSAndy Whitcroft } 248e7c4b0bfSAndy Whitcroft 249e7c4b0bfSAndy Whitcroft static void set_vma_private_data(struct vm_area_struct *vma, 250e7c4b0bfSAndy Whitcroft unsigned long value) 251e7c4b0bfSAndy Whitcroft { 252e7c4b0bfSAndy Whitcroft vma->vm_private_data = (void *)value; 253e7c4b0bfSAndy Whitcroft } 254e7c4b0bfSAndy Whitcroft 25584afd99bSAndy Whitcroft struct resv_map { 25684afd99bSAndy Whitcroft struct kref refs; 25784afd99bSAndy Whitcroft struct list_head regions; 25884afd99bSAndy Whitcroft }; 25984afd99bSAndy Whitcroft 26084afd99bSAndy Whitcroft struct resv_map *resv_map_alloc(void) 26184afd99bSAndy Whitcroft { 26284afd99bSAndy Whitcroft struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); 26384afd99bSAndy Whitcroft if (!resv_map) 26484afd99bSAndy Whitcroft return NULL; 26584afd99bSAndy Whitcroft 26684afd99bSAndy Whitcroft kref_init(&resv_map->refs); 26784afd99bSAndy Whitcroft INIT_LIST_HEAD(&resv_map->regions); 26884afd99bSAndy Whitcroft 26984afd99bSAndy Whitcroft return resv_map; 27084afd99bSAndy Whitcroft } 27184afd99bSAndy Whitcroft 27284afd99bSAndy Whitcroft void resv_map_release(struct kref *ref) 27384afd99bSAndy Whitcroft { 27484afd99bSAndy Whitcroft struct resv_map *resv_map = container_of(ref, struct resv_map, refs); 27584afd99bSAndy Whitcroft 27684afd99bSAndy Whitcroft /* Clear out any active regions before we release the map. */ 27784afd99bSAndy Whitcroft region_truncate(&resv_map->regions, 0); 27884afd99bSAndy Whitcroft kfree(resv_map); 27984afd99bSAndy Whitcroft } 28084afd99bSAndy Whitcroft 28184afd99bSAndy Whitcroft static struct resv_map *vma_resv_map(struct vm_area_struct *vma) 282a1e78772SMel Gorman { 283a1e78772SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 284a1e78772SMel Gorman if (!(vma->vm_flags & VM_SHARED)) 28584afd99bSAndy Whitcroft return (struct resv_map *)(get_vma_private_data(vma) & 28684afd99bSAndy Whitcroft ~HPAGE_RESV_MASK); 287a1e78772SMel Gorman return 0; 288a1e78772SMel Gorman } 289a1e78772SMel Gorman 29084afd99bSAndy Whitcroft static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) 291a1e78772SMel Gorman { 292a1e78772SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 293a1e78772SMel Gorman VM_BUG_ON(vma->vm_flags & VM_SHARED); 294a1e78772SMel Gorman 29584afd99bSAndy Whitcroft set_vma_private_data(vma, (get_vma_private_data(vma) & 29684afd99bSAndy Whitcroft HPAGE_RESV_MASK) | (unsigned long)map); 29704f2cbe3SMel Gorman } 29804f2cbe3SMel Gorman 29904f2cbe3SMel Gorman static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) 30004f2cbe3SMel Gorman { 30104f2cbe3SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 302e7c4b0bfSAndy Whitcroft VM_BUG_ON(vma->vm_flags & VM_SHARED); 303e7c4b0bfSAndy Whitcroft 304e7c4b0bfSAndy Whitcroft set_vma_private_data(vma, get_vma_private_data(vma) | flags); 30504f2cbe3SMel Gorman } 30604f2cbe3SMel Gorman 30704f2cbe3SMel Gorman static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) 30804f2cbe3SMel Gorman { 30904f2cbe3SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 310e7c4b0bfSAndy Whitcroft 311e7c4b0bfSAndy Whitcroft return (get_vma_private_data(vma) & flag) != 0; 312a1e78772SMel Gorman } 313a1e78772SMel Gorman 314a1e78772SMel Gorman /* Decrement the reserved pages in the hugepage pool by one */ 315a5516438SAndi Kleen static void decrement_hugepage_resv_vma(struct hstate *h, 316a5516438SAndi Kleen struct vm_area_struct *vma) 317a1e78772SMel Gorman { 318c37f9fb1SAndy Whitcroft if (vma->vm_flags & VM_NORESERVE) 319c37f9fb1SAndy Whitcroft return; 320c37f9fb1SAndy Whitcroft 321a1e78772SMel Gorman if (vma->vm_flags & VM_SHARED) { 322a1e78772SMel Gorman /* Shared mappings always use reserves */ 323a5516438SAndi Kleen h->resv_huge_pages--; 32484afd99bSAndy Whitcroft } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 325a1e78772SMel Gorman /* 326a1e78772SMel Gorman * Only the process that called mmap() has reserves for 327a1e78772SMel Gorman * private mappings. 328a1e78772SMel Gorman */ 329a5516438SAndi Kleen h->resv_huge_pages--; 330a1e78772SMel Gorman } 331a1e78772SMel Gorman } 332a1e78772SMel Gorman 33304f2cbe3SMel Gorman /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ 334a1e78772SMel Gorman void reset_vma_resv_huge_pages(struct vm_area_struct *vma) 335a1e78772SMel Gorman { 336a1e78772SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 337a1e78772SMel Gorman if (!(vma->vm_flags & VM_SHARED)) 338a1e78772SMel Gorman vma->vm_private_data = (void *)0; 339a1e78772SMel Gorman } 340a1e78772SMel Gorman 341a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 342a1e78772SMel Gorman static int vma_has_private_reserves(struct vm_area_struct *vma) 343a1e78772SMel Gorman { 344a1e78772SMel Gorman if (vma->vm_flags & VM_SHARED) 345a1e78772SMel Gorman return 0; 34684afd99bSAndy Whitcroft if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 347a1e78772SMel Gorman return 0; 348a1e78772SMel Gorman return 1; 349a1e78772SMel Gorman } 350a1e78772SMel Gorman 351a5516438SAndi Kleen static void clear_huge_page(struct page *page, 352a5516438SAndi Kleen unsigned long addr, unsigned long sz) 35379ac6ba4SDavid Gibson { 35479ac6ba4SDavid Gibson int i; 35579ac6ba4SDavid Gibson 35679ac6ba4SDavid Gibson might_sleep(); 357a5516438SAndi Kleen for (i = 0; i < sz/PAGE_SIZE; i++) { 35879ac6ba4SDavid Gibson cond_resched(); 359281e0e3bSRalf Baechle clear_user_highpage(page + i, addr + i * PAGE_SIZE); 36079ac6ba4SDavid Gibson } 36179ac6ba4SDavid Gibson } 36279ac6ba4SDavid Gibson 36379ac6ba4SDavid Gibson static void copy_huge_page(struct page *dst, struct page *src, 3649de455b2SAtsushi Nemoto unsigned long addr, struct vm_area_struct *vma) 36579ac6ba4SDavid Gibson { 36679ac6ba4SDavid Gibson int i; 367a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 36879ac6ba4SDavid Gibson 36979ac6ba4SDavid Gibson might_sleep(); 370a5516438SAndi Kleen for (i = 0; i < pages_per_huge_page(h); i++) { 37179ac6ba4SDavid Gibson cond_resched(); 3729de455b2SAtsushi Nemoto copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); 37379ac6ba4SDavid Gibson } 37479ac6ba4SDavid Gibson } 37579ac6ba4SDavid Gibson 376a5516438SAndi Kleen static void enqueue_huge_page(struct hstate *h, struct page *page) 3771da177e4SLinus Torvalds { 3781da177e4SLinus Torvalds int nid = page_to_nid(page); 379a5516438SAndi Kleen list_add(&page->lru, &h->hugepage_freelists[nid]); 380a5516438SAndi Kleen h->free_huge_pages++; 381a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 3821da177e4SLinus Torvalds } 3831da177e4SLinus Torvalds 384a5516438SAndi Kleen static struct page *dequeue_huge_page(struct hstate *h) 385348e1e04SNishanth Aravamudan { 386348e1e04SNishanth Aravamudan int nid; 387348e1e04SNishanth Aravamudan struct page *page = NULL; 388348e1e04SNishanth Aravamudan 389348e1e04SNishanth Aravamudan for (nid = 0; nid < MAX_NUMNODES; ++nid) { 390a5516438SAndi Kleen if (!list_empty(&h->hugepage_freelists[nid])) { 391a5516438SAndi Kleen page = list_entry(h->hugepage_freelists[nid].next, 392348e1e04SNishanth Aravamudan struct page, lru); 393348e1e04SNishanth Aravamudan list_del(&page->lru); 394a5516438SAndi Kleen h->free_huge_pages--; 395a5516438SAndi Kleen h->free_huge_pages_node[nid]--; 396348e1e04SNishanth Aravamudan break; 397348e1e04SNishanth Aravamudan } 398348e1e04SNishanth Aravamudan } 399348e1e04SNishanth Aravamudan return page; 400348e1e04SNishanth Aravamudan } 401348e1e04SNishanth Aravamudan 402a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 403a5516438SAndi Kleen struct vm_area_struct *vma, 40404f2cbe3SMel Gorman unsigned long address, int avoid_reserve) 4051da177e4SLinus Torvalds { 40631a5c6e4SNishanth Aravamudan int nid; 4071da177e4SLinus Torvalds struct page *page = NULL; 408480eccf9SLee Schermerhorn struct mempolicy *mpol; 40919770b32SMel Gorman nodemask_t *nodemask; 410396faf03SMel Gorman struct zonelist *zonelist = huge_zonelist(vma, address, 41119770b32SMel Gorman htlb_alloc_mask, &mpol, &nodemask); 412dd1a239fSMel Gorman struct zone *zone; 413dd1a239fSMel Gorman struct zoneref *z; 4141da177e4SLinus Torvalds 415a1e78772SMel Gorman /* 416a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 417a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 418a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 419a1e78772SMel Gorman */ 420a1e78772SMel Gorman if (!vma_has_private_reserves(vma) && 421a5516438SAndi Kleen h->free_huge_pages - h->resv_huge_pages == 0) 422a1e78772SMel Gorman return NULL; 423a1e78772SMel Gorman 42404f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 425a5516438SAndi Kleen if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) 42604f2cbe3SMel Gorman return NULL; 42704f2cbe3SMel Gorman 42819770b32SMel Gorman for_each_zone_zonelist_nodemask(zone, z, zonelist, 42919770b32SMel Gorman MAX_NR_ZONES - 1, nodemask) { 43054a6eb5cSMel Gorman nid = zone_to_nid(zone); 43154a6eb5cSMel Gorman if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && 432a5516438SAndi Kleen !list_empty(&h->hugepage_freelists[nid])) { 433a5516438SAndi Kleen page = list_entry(h->hugepage_freelists[nid].next, 4341da177e4SLinus Torvalds struct page, lru); 4351da177e4SLinus Torvalds list_del(&page->lru); 436a5516438SAndi Kleen h->free_huge_pages--; 437a5516438SAndi Kleen h->free_huge_pages_node[nid]--; 43804f2cbe3SMel Gorman 43904f2cbe3SMel Gorman if (!avoid_reserve) 440a5516438SAndi Kleen decrement_hugepage_resv_vma(h, vma); 441a1e78772SMel Gorman 4425ab3ee7bSKen Chen break; 4431da177e4SLinus Torvalds } 4443abf7afdSAndrew Morton } 44552cd3b07SLee Schermerhorn mpol_cond_put(mpol); 4461da177e4SLinus Torvalds return page; 4471da177e4SLinus Torvalds } 4481da177e4SLinus Torvalds 449a5516438SAndi Kleen static void update_and_free_page(struct hstate *h, struct page *page) 4506af2acb6SAdam Litke { 4516af2acb6SAdam Litke int i; 452a5516438SAndi Kleen 453a5516438SAndi Kleen h->nr_huge_pages--; 454a5516438SAndi Kleen h->nr_huge_pages_node[page_to_nid(page)]--; 455a5516438SAndi Kleen for (i = 0; i < pages_per_huge_page(h); i++) { 4566af2acb6SAdam Litke page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | 4576af2acb6SAdam Litke 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | 4586af2acb6SAdam Litke 1 << PG_private | 1<< PG_writeback); 4596af2acb6SAdam Litke } 4606af2acb6SAdam Litke set_compound_page_dtor(page, NULL); 4616af2acb6SAdam Litke set_page_refcounted(page); 4627f2e9525SGerald Schaefer arch_release_hugepage(page); 463a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 4646af2acb6SAdam Litke } 4656af2acb6SAdam Litke 466e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 467e5ff2159SAndi Kleen { 468e5ff2159SAndi Kleen struct hstate *h; 469e5ff2159SAndi Kleen 470e5ff2159SAndi Kleen for_each_hstate(h) { 471e5ff2159SAndi Kleen if (huge_page_size(h) == size) 472e5ff2159SAndi Kleen return h; 473e5ff2159SAndi Kleen } 474e5ff2159SAndi Kleen return NULL; 475e5ff2159SAndi Kleen } 476e5ff2159SAndi Kleen 47727a85ef1SDavid Gibson static void free_huge_page(struct page *page) 47827a85ef1SDavid Gibson { 479a5516438SAndi Kleen /* 480a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 481a5516438SAndi Kleen * compound page destructor. 482a5516438SAndi Kleen */ 483e5ff2159SAndi Kleen struct hstate *h = page_hstate(page); 4847893d1d5SAdam Litke int nid = page_to_nid(page); 485c79fb75eSAdam Litke struct address_space *mapping; 48627a85ef1SDavid Gibson 487c79fb75eSAdam Litke mapping = (struct address_space *) page_private(page); 488e5df70abSAndy Whitcroft set_page_private(page, 0); 4897893d1d5SAdam Litke BUG_ON(page_count(page)); 49027a85ef1SDavid Gibson INIT_LIST_HEAD(&page->lru); 49127a85ef1SDavid Gibson 49227a85ef1SDavid Gibson spin_lock(&hugetlb_lock); 493aa888a74SAndi Kleen if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) { 494a5516438SAndi Kleen update_and_free_page(h, page); 495a5516438SAndi Kleen h->surplus_huge_pages--; 496a5516438SAndi Kleen h->surplus_huge_pages_node[nid]--; 4977893d1d5SAdam Litke } else { 498a5516438SAndi Kleen enqueue_huge_page(h, page); 4997893d1d5SAdam Litke } 50027a85ef1SDavid Gibson spin_unlock(&hugetlb_lock); 501c79fb75eSAdam Litke if (mapping) 5029a119c05SAdam Litke hugetlb_put_quota(mapping, 1); 50327a85ef1SDavid Gibson } 50427a85ef1SDavid Gibson 5057893d1d5SAdam Litke /* 5067893d1d5SAdam Litke * Increment or decrement surplus_huge_pages. Keep node-specific counters 5077893d1d5SAdam Litke * balanced by operating on them in a round-robin fashion. 5087893d1d5SAdam Litke * Returns 1 if an adjustment was made. 5097893d1d5SAdam Litke */ 510a5516438SAndi Kleen static int adjust_pool_surplus(struct hstate *h, int delta) 5117893d1d5SAdam Litke { 5127893d1d5SAdam Litke static int prev_nid; 5137893d1d5SAdam Litke int nid = prev_nid; 5147893d1d5SAdam Litke int ret = 0; 5157893d1d5SAdam Litke 5167893d1d5SAdam Litke VM_BUG_ON(delta != -1 && delta != 1); 5177893d1d5SAdam Litke do { 5187893d1d5SAdam Litke nid = next_node(nid, node_online_map); 5197893d1d5SAdam Litke if (nid == MAX_NUMNODES) 5207893d1d5SAdam Litke nid = first_node(node_online_map); 5217893d1d5SAdam Litke 5227893d1d5SAdam Litke /* To shrink on this node, there must be a surplus page */ 523a5516438SAndi Kleen if (delta < 0 && !h->surplus_huge_pages_node[nid]) 5247893d1d5SAdam Litke continue; 5257893d1d5SAdam Litke /* Surplus cannot exceed the total number of pages */ 526a5516438SAndi Kleen if (delta > 0 && h->surplus_huge_pages_node[nid] >= 527a5516438SAndi Kleen h->nr_huge_pages_node[nid]) 5287893d1d5SAdam Litke continue; 5297893d1d5SAdam Litke 530a5516438SAndi Kleen h->surplus_huge_pages += delta; 531a5516438SAndi Kleen h->surplus_huge_pages_node[nid] += delta; 5327893d1d5SAdam Litke ret = 1; 5337893d1d5SAdam Litke break; 5347893d1d5SAdam Litke } while (nid != prev_nid); 5357893d1d5SAdam Litke 5367893d1d5SAdam Litke prev_nid = nid; 5377893d1d5SAdam Litke return ret; 5387893d1d5SAdam Litke } 5397893d1d5SAdam Litke 540a5516438SAndi Kleen static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) 541b7ba30c6SAndi Kleen { 542b7ba30c6SAndi Kleen set_compound_page_dtor(page, free_huge_page); 543b7ba30c6SAndi Kleen spin_lock(&hugetlb_lock); 544a5516438SAndi Kleen h->nr_huge_pages++; 545a5516438SAndi Kleen h->nr_huge_pages_node[nid]++; 546b7ba30c6SAndi Kleen spin_unlock(&hugetlb_lock); 547b7ba30c6SAndi Kleen put_page(page); /* free it into the hugepage allocator */ 548b7ba30c6SAndi Kleen } 549b7ba30c6SAndi Kleen 550a5516438SAndi Kleen static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) 5511da177e4SLinus Torvalds { 5521da177e4SLinus Torvalds struct page *page; 553f96efd58SJoe Jin 554aa888a74SAndi Kleen if (h->order >= MAX_ORDER) 555aa888a74SAndi Kleen return NULL; 556aa888a74SAndi Kleen 55763b4613cSNishanth Aravamudan page = alloc_pages_node(nid, 558551883aeSNishanth Aravamudan htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| 559551883aeSNishanth Aravamudan __GFP_REPEAT|__GFP_NOWARN, 560a5516438SAndi Kleen huge_page_order(h)); 5611da177e4SLinus Torvalds if (page) { 5627f2e9525SGerald Schaefer if (arch_prepare_hugepage(page)) { 5637f2e9525SGerald Schaefer __free_pages(page, HUGETLB_PAGE_ORDER); 5647b8ee84dSHarvey Harrison return NULL; 5657f2e9525SGerald Schaefer } 566a5516438SAndi Kleen prep_new_huge_page(h, page, nid); 5671da177e4SLinus Torvalds } 56863b4613cSNishanth Aravamudan 56963b4613cSNishanth Aravamudan return page; 57063b4613cSNishanth Aravamudan } 57163b4613cSNishanth Aravamudan 5725ced66c9SAndi Kleen /* 5735ced66c9SAndi Kleen * Use a helper variable to find the next node and then 5745ced66c9SAndi Kleen * copy it back to hugetlb_next_nid afterwards: 5755ced66c9SAndi Kleen * otherwise there's a window in which a racer might 5765ced66c9SAndi Kleen * pass invalid nid MAX_NUMNODES to alloc_pages_node. 5775ced66c9SAndi Kleen * But we don't need to use a spin_lock here: it really 5785ced66c9SAndi Kleen * doesn't matter if occasionally a racer chooses the 5795ced66c9SAndi Kleen * same nid as we do. Move nid forward in the mask even 5805ced66c9SAndi Kleen * if we just successfully allocated a hugepage so that 5815ced66c9SAndi Kleen * the next caller gets hugepages on the next node. 5825ced66c9SAndi Kleen */ 5835ced66c9SAndi Kleen static int hstate_next_node(struct hstate *h) 5845ced66c9SAndi Kleen { 5855ced66c9SAndi Kleen int next_nid; 5865ced66c9SAndi Kleen next_nid = next_node(h->hugetlb_next_nid, node_online_map); 5875ced66c9SAndi Kleen if (next_nid == MAX_NUMNODES) 5885ced66c9SAndi Kleen next_nid = first_node(node_online_map); 5895ced66c9SAndi Kleen h->hugetlb_next_nid = next_nid; 5905ced66c9SAndi Kleen return next_nid; 5915ced66c9SAndi Kleen } 5925ced66c9SAndi Kleen 593a5516438SAndi Kleen static int alloc_fresh_huge_page(struct hstate *h) 59463b4613cSNishanth Aravamudan { 59563b4613cSNishanth Aravamudan struct page *page; 59663b4613cSNishanth Aravamudan int start_nid; 59763b4613cSNishanth Aravamudan int next_nid; 59863b4613cSNishanth Aravamudan int ret = 0; 59963b4613cSNishanth Aravamudan 600a5516438SAndi Kleen start_nid = h->hugetlb_next_nid; 60163b4613cSNishanth Aravamudan 60263b4613cSNishanth Aravamudan do { 603a5516438SAndi Kleen page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid); 60463b4613cSNishanth Aravamudan if (page) 60563b4613cSNishanth Aravamudan ret = 1; 6065ced66c9SAndi Kleen next_nid = hstate_next_node(h); 607a5516438SAndi Kleen } while (!page && h->hugetlb_next_nid != start_nid); 60863b4613cSNishanth Aravamudan 6093b116300SAdam Litke if (ret) 6103b116300SAdam Litke count_vm_event(HTLB_BUDDY_PGALLOC); 6113b116300SAdam Litke else 6123b116300SAdam Litke count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 6133b116300SAdam Litke 61463b4613cSNishanth Aravamudan return ret; 6151da177e4SLinus Torvalds } 6161da177e4SLinus Torvalds 617a5516438SAndi Kleen static struct page *alloc_buddy_huge_page(struct hstate *h, 618a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 6197893d1d5SAdam Litke { 6207893d1d5SAdam Litke struct page *page; 621d1c3fb1fSNishanth Aravamudan unsigned int nid; 6227893d1d5SAdam Litke 623aa888a74SAndi Kleen if (h->order >= MAX_ORDER) 624aa888a74SAndi Kleen return NULL; 625aa888a74SAndi Kleen 626d1c3fb1fSNishanth Aravamudan /* 627d1c3fb1fSNishanth Aravamudan * Assume we will successfully allocate the surplus page to 628d1c3fb1fSNishanth Aravamudan * prevent racing processes from causing the surplus to exceed 629d1c3fb1fSNishanth Aravamudan * overcommit 630d1c3fb1fSNishanth Aravamudan * 631d1c3fb1fSNishanth Aravamudan * This however introduces a different race, where a process B 632d1c3fb1fSNishanth Aravamudan * tries to grow the static hugepage pool while alloc_pages() is 633d1c3fb1fSNishanth Aravamudan * called by process A. B will only examine the per-node 634d1c3fb1fSNishanth Aravamudan * counters in determining if surplus huge pages can be 635d1c3fb1fSNishanth Aravamudan * converted to normal huge pages in adjust_pool_surplus(). A 636d1c3fb1fSNishanth Aravamudan * won't be able to increment the per-node counter, until the 637d1c3fb1fSNishanth Aravamudan * lock is dropped by B, but B doesn't drop hugetlb_lock until 638d1c3fb1fSNishanth Aravamudan * no more huge pages can be converted from surplus to normal 639d1c3fb1fSNishanth Aravamudan * state (and doesn't try to convert again). Thus, we have a 640d1c3fb1fSNishanth Aravamudan * case where a surplus huge page exists, the pool is grown, and 641d1c3fb1fSNishanth Aravamudan * the surplus huge page still exists after, even though it 642d1c3fb1fSNishanth Aravamudan * should just have been converted to a normal huge page. This 643d1c3fb1fSNishanth Aravamudan * does not leak memory, though, as the hugepage will be freed 644d1c3fb1fSNishanth Aravamudan * once it is out of use. It also does not allow the counters to 645d1c3fb1fSNishanth Aravamudan * go out of whack in adjust_pool_surplus() as we don't modify 646d1c3fb1fSNishanth Aravamudan * the node values until we've gotten the hugepage and only the 647d1c3fb1fSNishanth Aravamudan * per-node value is checked there. 648d1c3fb1fSNishanth Aravamudan */ 649d1c3fb1fSNishanth Aravamudan spin_lock(&hugetlb_lock); 650a5516438SAndi Kleen if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 651d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 652d1c3fb1fSNishanth Aravamudan return NULL; 653d1c3fb1fSNishanth Aravamudan } else { 654a5516438SAndi Kleen h->nr_huge_pages++; 655a5516438SAndi Kleen h->surplus_huge_pages++; 656d1c3fb1fSNishanth Aravamudan } 657d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 658d1c3fb1fSNishanth Aravamudan 659551883aeSNishanth Aravamudan page = alloc_pages(htlb_alloc_mask|__GFP_COMP| 660551883aeSNishanth Aravamudan __GFP_REPEAT|__GFP_NOWARN, 661a5516438SAndi Kleen huge_page_order(h)); 662d1c3fb1fSNishanth Aravamudan 6637893d1d5SAdam Litke spin_lock(&hugetlb_lock); 664d1c3fb1fSNishanth Aravamudan if (page) { 6652668db91SAdam Litke /* 6662668db91SAdam Litke * This page is now managed by the hugetlb allocator and has 6672668db91SAdam Litke * no users -- drop the buddy allocator's reference. 6682668db91SAdam Litke */ 6692668db91SAdam Litke put_page_testzero(page); 6702668db91SAdam Litke VM_BUG_ON(page_count(page)); 671d1c3fb1fSNishanth Aravamudan nid = page_to_nid(page); 672d1c3fb1fSNishanth Aravamudan set_compound_page_dtor(page, free_huge_page); 673d1c3fb1fSNishanth Aravamudan /* 674d1c3fb1fSNishanth Aravamudan * We incremented the global counters already 675d1c3fb1fSNishanth Aravamudan */ 676a5516438SAndi Kleen h->nr_huge_pages_node[nid]++; 677a5516438SAndi Kleen h->surplus_huge_pages_node[nid]++; 6783b116300SAdam Litke __count_vm_event(HTLB_BUDDY_PGALLOC); 679d1c3fb1fSNishanth Aravamudan } else { 680a5516438SAndi Kleen h->nr_huge_pages--; 681a5516438SAndi Kleen h->surplus_huge_pages--; 6823b116300SAdam Litke __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 6837893d1d5SAdam Litke } 684d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 6857893d1d5SAdam Litke 6867893d1d5SAdam Litke return page; 6877893d1d5SAdam Litke } 6887893d1d5SAdam Litke 689e4e574b7SAdam Litke /* 690e4e574b7SAdam Litke * Increase the hugetlb pool such that it can accomodate a reservation 691e4e574b7SAdam Litke * of size 'delta'. 692e4e574b7SAdam Litke */ 693a5516438SAndi Kleen static int gather_surplus_pages(struct hstate *h, int delta) 694e4e574b7SAdam Litke { 695e4e574b7SAdam Litke struct list_head surplus_list; 696e4e574b7SAdam Litke struct page *page, *tmp; 697e4e574b7SAdam Litke int ret, i; 698e4e574b7SAdam Litke int needed, allocated; 699e4e574b7SAdam Litke 700a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 701ac09b3a1SAdam Litke if (needed <= 0) { 702a5516438SAndi Kleen h->resv_huge_pages += delta; 703e4e574b7SAdam Litke return 0; 704ac09b3a1SAdam Litke } 705e4e574b7SAdam Litke 706e4e574b7SAdam Litke allocated = 0; 707e4e574b7SAdam Litke INIT_LIST_HEAD(&surplus_list); 708e4e574b7SAdam Litke 709e4e574b7SAdam Litke ret = -ENOMEM; 710e4e574b7SAdam Litke retry: 711e4e574b7SAdam Litke spin_unlock(&hugetlb_lock); 712e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 713a5516438SAndi Kleen page = alloc_buddy_huge_page(h, NULL, 0); 714e4e574b7SAdam Litke if (!page) { 715e4e574b7SAdam Litke /* 716e4e574b7SAdam Litke * We were not able to allocate enough pages to 717e4e574b7SAdam Litke * satisfy the entire reservation so we free what 718e4e574b7SAdam Litke * we've allocated so far. 719e4e574b7SAdam Litke */ 720e4e574b7SAdam Litke spin_lock(&hugetlb_lock); 721e4e574b7SAdam Litke needed = 0; 722e4e574b7SAdam Litke goto free; 723e4e574b7SAdam Litke } 724e4e574b7SAdam Litke 725e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 726e4e574b7SAdam Litke } 727e4e574b7SAdam Litke allocated += needed; 728e4e574b7SAdam Litke 729e4e574b7SAdam Litke /* 730e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 731e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 732e4e574b7SAdam Litke */ 733e4e574b7SAdam Litke spin_lock(&hugetlb_lock); 734a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 735a5516438SAndi Kleen (h->free_huge_pages + allocated); 736e4e574b7SAdam Litke if (needed > 0) 737e4e574b7SAdam Litke goto retry; 738e4e574b7SAdam Litke 739e4e574b7SAdam Litke /* 740e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 741e4e574b7SAdam Litke * needed to accomodate the reservation. Add the appropriate number 742e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 743ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 744ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 745ac09b3a1SAdam Litke * before they are reserved. 746e4e574b7SAdam Litke */ 747e4e574b7SAdam Litke needed += allocated; 748a5516438SAndi Kleen h->resv_huge_pages += delta; 749e4e574b7SAdam Litke ret = 0; 750e4e574b7SAdam Litke free: 75119fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 75219fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 75319fc3f0aSAdam Litke if ((--needed) < 0) 75419fc3f0aSAdam Litke break; 75519fc3f0aSAdam Litke list_del(&page->lru); 756a5516438SAndi Kleen enqueue_huge_page(h, page); 75719fc3f0aSAdam Litke } 75819fc3f0aSAdam Litke 75919fc3f0aSAdam Litke /* Free unnecessary surplus pages to the buddy allocator */ 76019fc3f0aSAdam Litke if (!list_empty(&surplus_list)) { 76119fc3f0aSAdam Litke spin_unlock(&hugetlb_lock); 762e4e574b7SAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 763e4e574b7SAdam Litke list_del(&page->lru); 764af767cbdSAdam Litke /* 7652668db91SAdam Litke * The page has a reference count of zero already, so 7662668db91SAdam Litke * call free_huge_page directly instead of using 7672668db91SAdam Litke * put_page. This must be done with hugetlb_lock 768af767cbdSAdam Litke * unlocked which is safe because free_huge_page takes 769af767cbdSAdam Litke * hugetlb_lock before deciding how to free the page. 770af767cbdSAdam Litke */ 7712668db91SAdam Litke free_huge_page(page); 772af767cbdSAdam Litke } 77319fc3f0aSAdam Litke spin_lock(&hugetlb_lock); 774e4e574b7SAdam Litke } 775e4e574b7SAdam Litke 776e4e574b7SAdam Litke return ret; 777e4e574b7SAdam Litke } 778e4e574b7SAdam Litke 779e4e574b7SAdam Litke /* 780e4e574b7SAdam Litke * When releasing a hugetlb pool reservation, any surplus pages that were 781e4e574b7SAdam Litke * allocated to satisfy the reservation must be explicitly freed if they were 782e4e574b7SAdam Litke * never used. 783e4e574b7SAdam Litke */ 784a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 785a5516438SAndi Kleen unsigned long unused_resv_pages) 786e4e574b7SAdam Litke { 787e4e574b7SAdam Litke static int nid = -1; 788e4e574b7SAdam Litke struct page *page; 789e4e574b7SAdam Litke unsigned long nr_pages; 790e4e574b7SAdam Litke 79111320d17SNishanth Aravamudan /* 79211320d17SNishanth Aravamudan * We want to release as many surplus pages as possible, spread 79311320d17SNishanth Aravamudan * evenly across all nodes. Iterate across all nodes until we 79411320d17SNishanth Aravamudan * can no longer free unreserved surplus pages. This occurs when 79511320d17SNishanth Aravamudan * the nodes with surplus pages have no free pages. 79611320d17SNishanth Aravamudan */ 79711320d17SNishanth Aravamudan unsigned long remaining_iterations = num_online_nodes(); 79811320d17SNishanth Aravamudan 799ac09b3a1SAdam Litke /* Uncommit the reservation */ 800a5516438SAndi Kleen h->resv_huge_pages -= unused_resv_pages; 801ac09b3a1SAdam Litke 802aa888a74SAndi Kleen /* Cannot return gigantic pages currently */ 803aa888a74SAndi Kleen if (h->order >= MAX_ORDER) 804aa888a74SAndi Kleen return; 805aa888a74SAndi Kleen 806a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 807e4e574b7SAdam Litke 80811320d17SNishanth Aravamudan while (remaining_iterations-- && nr_pages) { 809e4e574b7SAdam Litke nid = next_node(nid, node_online_map); 810e4e574b7SAdam Litke if (nid == MAX_NUMNODES) 811e4e574b7SAdam Litke nid = first_node(node_online_map); 812e4e574b7SAdam Litke 813a5516438SAndi Kleen if (!h->surplus_huge_pages_node[nid]) 814e4e574b7SAdam Litke continue; 815e4e574b7SAdam Litke 816a5516438SAndi Kleen if (!list_empty(&h->hugepage_freelists[nid])) { 817a5516438SAndi Kleen page = list_entry(h->hugepage_freelists[nid].next, 818e4e574b7SAdam Litke struct page, lru); 819e4e574b7SAdam Litke list_del(&page->lru); 820a5516438SAndi Kleen update_and_free_page(h, page); 821a5516438SAndi Kleen h->free_huge_pages--; 822a5516438SAndi Kleen h->free_huge_pages_node[nid]--; 823a5516438SAndi Kleen h->surplus_huge_pages--; 824a5516438SAndi Kleen h->surplus_huge_pages_node[nid]--; 825e4e574b7SAdam Litke nr_pages--; 82611320d17SNishanth Aravamudan remaining_iterations = num_online_nodes(); 827e4e574b7SAdam Litke } 828e4e574b7SAdam Litke } 829e4e574b7SAdam Litke } 830e4e574b7SAdam Litke 831c37f9fb1SAndy Whitcroft /* 832c37f9fb1SAndy Whitcroft * Determine if the huge page at addr within the vma has an associated 833c37f9fb1SAndy Whitcroft * reservation. Where it does not we will need to logically increase 834c37f9fb1SAndy Whitcroft * reservation and actually increase quota before an allocation can occur. 835c37f9fb1SAndy Whitcroft * Where any new reservation would be required the reservation change is 836c37f9fb1SAndy Whitcroft * prepared, but not committed. Once the page has been quota'd allocated 837c37f9fb1SAndy Whitcroft * an instantiated the change should be committed via vma_commit_reservation. 838c37f9fb1SAndy Whitcroft * No action is required on failure. 839c37f9fb1SAndy Whitcroft */ 840a5516438SAndi Kleen static int vma_needs_reservation(struct hstate *h, 841a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 842c37f9fb1SAndy Whitcroft { 843c37f9fb1SAndy Whitcroft struct address_space *mapping = vma->vm_file->f_mapping; 844c37f9fb1SAndy Whitcroft struct inode *inode = mapping->host; 845c37f9fb1SAndy Whitcroft 846c37f9fb1SAndy Whitcroft if (vma->vm_flags & VM_SHARED) { 847a5516438SAndi Kleen pgoff_t idx = vma_hugecache_offset(h, vma, addr); 848c37f9fb1SAndy Whitcroft return region_chg(&inode->i_mapping->private_list, 849c37f9fb1SAndy Whitcroft idx, idx + 1); 850c37f9fb1SAndy Whitcroft 85184afd99bSAndy Whitcroft } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 852c37f9fb1SAndy Whitcroft return 1; 853c37f9fb1SAndy Whitcroft 85484afd99bSAndy Whitcroft } else { 85584afd99bSAndy Whitcroft int err; 856a5516438SAndi Kleen pgoff_t idx = vma_hugecache_offset(h, vma, addr); 85784afd99bSAndy Whitcroft struct resv_map *reservations = vma_resv_map(vma); 85884afd99bSAndy Whitcroft 85984afd99bSAndy Whitcroft err = region_chg(&reservations->regions, idx, idx + 1); 86084afd99bSAndy Whitcroft if (err < 0) 86184afd99bSAndy Whitcroft return err; 862c37f9fb1SAndy Whitcroft return 0; 863c37f9fb1SAndy Whitcroft } 86484afd99bSAndy Whitcroft } 865a5516438SAndi Kleen static void vma_commit_reservation(struct hstate *h, 866a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 867c37f9fb1SAndy Whitcroft { 868c37f9fb1SAndy Whitcroft struct address_space *mapping = vma->vm_file->f_mapping; 869c37f9fb1SAndy Whitcroft struct inode *inode = mapping->host; 870c37f9fb1SAndy Whitcroft 871c37f9fb1SAndy Whitcroft if (vma->vm_flags & VM_SHARED) { 872a5516438SAndi Kleen pgoff_t idx = vma_hugecache_offset(h, vma, addr); 873c37f9fb1SAndy Whitcroft region_add(&inode->i_mapping->private_list, idx, idx + 1); 87484afd99bSAndy Whitcroft 87584afd99bSAndy Whitcroft } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 876a5516438SAndi Kleen pgoff_t idx = vma_hugecache_offset(h, vma, addr); 87784afd99bSAndy Whitcroft struct resv_map *reservations = vma_resv_map(vma); 87884afd99bSAndy Whitcroft 87984afd99bSAndy Whitcroft /* Mark this page used in the map. */ 88084afd99bSAndy Whitcroft region_add(&reservations->regions, idx, idx + 1); 881c37f9fb1SAndy Whitcroft } 882c37f9fb1SAndy Whitcroft } 883c37f9fb1SAndy Whitcroft 884348ea204SAdam Litke static struct page *alloc_huge_page(struct vm_area_struct *vma, 88504f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 886348ea204SAdam Litke { 887a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 888348ea204SAdam Litke struct page *page; 8892fc39cecSAdam Litke struct address_space *mapping = vma->vm_file->f_mapping; 890a1e78772SMel Gorman struct inode *inode = mapping->host; 891c37f9fb1SAndy Whitcroft unsigned int chg; 8922fc39cecSAdam Litke 893a1e78772SMel Gorman /* 894a1e78772SMel Gorman * Processes that did not create the mapping will have no reserves and 895a1e78772SMel Gorman * will not have accounted against quota. Check that the quota can be 896a1e78772SMel Gorman * made before satisfying the allocation 897c37f9fb1SAndy Whitcroft * MAP_NORESERVE mappings may also need pages and quota allocated 898c37f9fb1SAndy Whitcroft * if no reserve mapping overlaps. 899a1e78772SMel Gorman */ 900a5516438SAndi Kleen chg = vma_needs_reservation(h, vma, addr); 901c37f9fb1SAndy Whitcroft if (chg < 0) 902c37f9fb1SAndy Whitcroft return ERR_PTR(chg); 903c37f9fb1SAndy Whitcroft if (chg) 904a1e78772SMel Gorman if (hugetlb_get_quota(inode->i_mapping, chg)) 905a1e78772SMel Gorman return ERR_PTR(-ENOSPC); 90690d8b7e6SAdam Litke 907a1e78772SMel Gorman spin_lock(&hugetlb_lock); 908a5516438SAndi Kleen page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve); 909a1e78772SMel Gorman spin_unlock(&hugetlb_lock); 910a1e78772SMel Gorman 911a1e78772SMel Gorman if (!page) { 912a5516438SAndi Kleen page = alloc_buddy_huge_page(h, vma, addr); 913a1e78772SMel Gorman if (!page) { 914a1e78772SMel Gorman hugetlb_put_quota(inode->i_mapping, chg); 915a1e78772SMel Gorman return ERR_PTR(-VM_FAULT_OOM); 916a1e78772SMel Gorman } 917a1e78772SMel Gorman } 918a1e78772SMel Gorman 919348ea204SAdam Litke set_page_refcounted(page); 9202fc39cecSAdam Litke set_page_private(page, (unsigned long) mapping); 921a1e78772SMel Gorman 922a5516438SAndi Kleen vma_commit_reservation(h, vma, addr); 923c37f9fb1SAndy Whitcroft 9247893d1d5SAdam Litke return page; 925b45b5bd6SDavid Gibson } 926b45b5bd6SDavid Gibson 927aa888a74SAndi Kleen static __initdata LIST_HEAD(huge_boot_pages); 928aa888a74SAndi Kleen 929aa888a74SAndi Kleen struct huge_bootmem_page { 930aa888a74SAndi Kleen struct list_head list; 931aa888a74SAndi Kleen struct hstate *hstate; 932aa888a74SAndi Kleen }; 933aa888a74SAndi Kleen 934aa888a74SAndi Kleen static int __init alloc_bootmem_huge_page(struct hstate *h) 935aa888a74SAndi Kleen { 936aa888a74SAndi Kleen struct huge_bootmem_page *m; 937aa888a74SAndi Kleen int nr_nodes = nodes_weight(node_online_map); 938aa888a74SAndi Kleen 939aa888a74SAndi Kleen while (nr_nodes) { 940aa888a74SAndi Kleen void *addr; 941aa888a74SAndi Kleen 942aa888a74SAndi Kleen addr = __alloc_bootmem_node_nopanic( 943aa888a74SAndi Kleen NODE_DATA(h->hugetlb_next_nid), 944aa888a74SAndi Kleen huge_page_size(h), huge_page_size(h), 0); 945aa888a74SAndi Kleen 946aa888a74SAndi Kleen if (addr) { 947aa888a74SAndi Kleen /* 948aa888a74SAndi Kleen * Use the beginning of the huge page to store the 949aa888a74SAndi Kleen * huge_bootmem_page struct (until gather_bootmem 950aa888a74SAndi Kleen * puts them into the mem_map). 951aa888a74SAndi Kleen */ 952aa888a74SAndi Kleen m = addr; 953aa888a74SAndi Kleen if (m) 954aa888a74SAndi Kleen goto found; 955aa888a74SAndi Kleen } 956aa888a74SAndi Kleen hstate_next_node(h); 957aa888a74SAndi Kleen nr_nodes--; 958aa888a74SAndi Kleen } 959aa888a74SAndi Kleen return 0; 960aa888a74SAndi Kleen 961aa888a74SAndi Kleen found: 962aa888a74SAndi Kleen BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1)); 963aa888a74SAndi Kleen /* Put them into a private list first because mem_map is not up yet */ 964aa888a74SAndi Kleen list_add(&m->list, &huge_boot_pages); 965aa888a74SAndi Kleen m->hstate = h; 966aa888a74SAndi Kleen return 1; 967aa888a74SAndi Kleen } 968aa888a74SAndi Kleen 969aa888a74SAndi Kleen /* Put bootmem huge pages into the standard lists after mem_map is up */ 970aa888a74SAndi Kleen static void __init gather_bootmem_prealloc(void) 971aa888a74SAndi Kleen { 972aa888a74SAndi Kleen struct huge_bootmem_page *m; 973aa888a74SAndi Kleen 974aa888a74SAndi Kleen list_for_each_entry(m, &huge_boot_pages, list) { 975aa888a74SAndi Kleen struct page *page = virt_to_page(m); 976aa888a74SAndi Kleen struct hstate *h = m->hstate; 977aa888a74SAndi Kleen __ClearPageReserved(page); 978aa888a74SAndi Kleen WARN_ON(page_count(page) != 1); 979aa888a74SAndi Kleen prep_compound_page(page, h->order); 980aa888a74SAndi Kleen prep_new_huge_page(h, page, page_to_nid(page)); 981aa888a74SAndi Kleen } 982aa888a74SAndi Kleen } 983aa888a74SAndi Kleen 9848faa8b07SAndi Kleen static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 9851da177e4SLinus Torvalds { 9861da177e4SLinus Torvalds unsigned long i; 9871da177e4SLinus Torvalds 988e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 989aa888a74SAndi Kleen if (h->order >= MAX_ORDER) { 990aa888a74SAndi Kleen if (!alloc_bootmem_huge_page(h)) 991aa888a74SAndi Kleen break; 992aa888a74SAndi Kleen } else if (!alloc_fresh_huge_page(h)) 9931da177e4SLinus Torvalds break; 9941da177e4SLinus Torvalds } 9958faa8b07SAndi Kleen h->max_huge_pages = i; 996e5ff2159SAndi Kleen } 997e5ff2159SAndi Kleen 998e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 999e5ff2159SAndi Kleen { 1000e5ff2159SAndi Kleen struct hstate *h; 1001e5ff2159SAndi Kleen 1002e5ff2159SAndi Kleen for_each_hstate(h) { 10038faa8b07SAndi Kleen /* oversize hugepages were init'ed in early boot */ 10048faa8b07SAndi Kleen if (h->order < MAX_ORDER) 10058faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(h); 1006e5ff2159SAndi Kleen } 1007e5ff2159SAndi Kleen } 1008e5ff2159SAndi Kleen 10094abd32dbSAndi Kleen static char * __init memfmt(char *buf, unsigned long n) 10104abd32dbSAndi Kleen { 10114abd32dbSAndi Kleen if (n >= (1UL << 30)) 10124abd32dbSAndi Kleen sprintf(buf, "%lu GB", n >> 30); 10134abd32dbSAndi Kleen else if (n >= (1UL << 20)) 10144abd32dbSAndi Kleen sprintf(buf, "%lu MB", n >> 20); 10154abd32dbSAndi Kleen else 10164abd32dbSAndi Kleen sprintf(buf, "%lu KB", n >> 10); 10174abd32dbSAndi Kleen return buf; 10184abd32dbSAndi Kleen } 10194abd32dbSAndi Kleen 1020e5ff2159SAndi Kleen static void __init report_hugepages(void) 1021e5ff2159SAndi Kleen { 1022e5ff2159SAndi Kleen struct hstate *h; 1023e5ff2159SAndi Kleen 1024e5ff2159SAndi Kleen for_each_hstate(h) { 10254abd32dbSAndi Kleen char buf[32]; 10264abd32dbSAndi Kleen printk(KERN_INFO "HugeTLB registered %s page size, " 10274abd32dbSAndi Kleen "pre-allocated %ld pages\n", 10284abd32dbSAndi Kleen memfmt(buf, huge_page_size(h)), 10294abd32dbSAndi Kleen h->free_huge_pages); 1030e5ff2159SAndi Kleen } 1031e5ff2159SAndi Kleen } 1032e5ff2159SAndi Kleen 10331da177e4SLinus Torvalds #ifdef CONFIG_SYSCTL 10341da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 1035a5516438SAndi Kleen static void try_to_free_low(struct hstate *h, unsigned long count) 10361da177e4SLinus Torvalds { 10374415cc8dSChristoph Lameter int i; 10384415cc8dSChristoph Lameter 1039aa888a74SAndi Kleen if (h->order >= MAX_ORDER) 1040aa888a74SAndi Kleen return; 1041aa888a74SAndi Kleen 10421da177e4SLinus Torvalds for (i = 0; i < MAX_NUMNODES; ++i) { 10431da177e4SLinus Torvalds struct page *page, *next; 1044a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 1045a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 1046a5516438SAndi Kleen if (count >= h->nr_huge_pages) 10476b0c880dSAdam Litke return; 10481da177e4SLinus Torvalds if (PageHighMem(page)) 10491da177e4SLinus Torvalds continue; 10501da177e4SLinus Torvalds list_del(&page->lru); 1051e5ff2159SAndi Kleen update_and_free_page(h, page); 1052a5516438SAndi Kleen h->free_huge_pages--; 1053a5516438SAndi Kleen h->free_huge_pages_node[page_to_nid(page)]--; 10541da177e4SLinus Torvalds } 10551da177e4SLinus Torvalds } 10561da177e4SLinus Torvalds } 10571da177e4SLinus Torvalds #else 1058a5516438SAndi Kleen static inline void try_to_free_low(struct hstate *h, unsigned long count) 10591da177e4SLinus Torvalds { 10601da177e4SLinus Torvalds } 10611da177e4SLinus Torvalds #endif 10621da177e4SLinus Torvalds 1063a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 1064e5ff2159SAndi Kleen static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count) 10651da177e4SLinus Torvalds { 10667893d1d5SAdam Litke unsigned long min_count, ret; 10671da177e4SLinus Torvalds 1068aa888a74SAndi Kleen if (h->order >= MAX_ORDER) 1069aa888a74SAndi Kleen return h->max_huge_pages; 1070aa888a74SAndi Kleen 10717893d1d5SAdam Litke /* 10727893d1d5SAdam Litke * Increase the pool size 10737893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 10747893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 1075d1c3fb1fSNishanth Aravamudan * 1076d1c3fb1fSNishanth Aravamudan * We might race with alloc_buddy_huge_page() here and be unable 1077d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 1078d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 1079d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 1080d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 10817893d1d5SAdam Litke */ 10821da177e4SLinus Torvalds spin_lock(&hugetlb_lock); 1083a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 1084a5516438SAndi Kleen if (!adjust_pool_surplus(h, -1)) 10857893d1d5SAdam Litke break; 10867893d1d5SAdam Litke } 10877893d1d5SAdam Litke 1088a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 10897893d1d5SAdam Litke /* 10907893d1d5SAdam Litke * If this allocation races such that we no longer need the 10917893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 10927893d1d5SAdam Litke * and reducing the surplus. 10937893d1d5SAdam Litke */ 10947893d1d5SAdam Litke spin_unlock(&hugetlb_lock); 1095a5516438SAndi Kleen ret = alloc_fresh_huge_page(h); 10967893d1d5SAdam Litke spin_lock(&hugetlb_lock); 10977893d1d5SAdam Litke if (!ret) 10987893d1d5SAdam Litke goto out; 10997893d1d5SAdam Litke 11007893d1d5SAdam Litke } 11017893d1d5SAdam Litke 11027893d1d5SAdam Litke /* 11037893d1d5SAdam Litke * Decrease the pool size 11047893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 11057893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 11067893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 11077893d1d5SAdam Litke * to the desired size as pages become free. 1108d1c3fb1fSNishanth Aravamudan * 1109d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 1110d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 1111d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 1112d1c3fb1fSNishanth Aravamudan * alloc_buddy_huge_page() is checking the global counter, 1113d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 1114d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 1115d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 11167893d1d5SAdam Litke */ 1117a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 11186b0c880dSAdam Litke min_count = max(count, min_count); 1119a5516438SAndi Kleen try_to_free_low(h, min_count); 1120a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 1121a5516438SAndi Kleen struct page *page = dequeue_huge_page(h); 11221da177e4SLinus Torvalds if (!page) 11231da177e4SLinus Torvalds break; 1124a5516438SAndi Kleen update_and_free_page(h, page); 11251da177e4SLinus Torvalds } 1126a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 1127a5516438SAndi Kleen if (!adjust_pool_surplus(h, 1)) 11287893d1d5SAdam Litke break; 11297893d1d5SAdam Litke } 11307893d1d5SAdam Litke out: 1131a5516438SAndi Kleen ret = persistent_huge_pages(h); 11321da177e4SLinus Torvalds spin_unlock(&hugetlb_lock); 11337893d1d5SAdam Litke return ret; 11341da177e4SLinus Torvalds } 11351da177e4SLinus Torvalds 1136a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 1137a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 1138a3437870SNishanth Aravamudan 1139a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 1140a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = \ 1141a3437870SNishanth Aravamudan __ATTR(_name, 0644, _name##_show, _name##_store) 1142a3437870SNishanth Aravamudan 1143a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 1144a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 1145a3437870SNishanth Aravamudan 1146a3437870SNishanth Aravamudan static struct hstate *kobj_to_hstate(struct kobject *kobj) 1147a3437870SNishanth Aravamudan { 1148a3437870SNishanth Aravamudan int i; 1149a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 1150a3437870SNishanth Aravamudan if (hstate_kobjs[i] == kobj) 1151a3437870SNishanth Aravamudan return &hstates[i]; 1152a3437870SNishanth Aravamudan BUG(); 1153a3437870SNishanth Aravamudan return NULL; 1154a3437870SNishanth Aravamudan } 1155a3437870SNishanth Aravamudan 1156a3437870SNishanth Aravamudan static ssize_t nr_hugepages_show(struct kobject *kobj, 1157a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1158a3437870SNishanth Aravamudan { 1159a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1160a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->nr_huge_pages); 1161a3437870SNishanth Aravamudan } 1162a3437870SNishanth Aravamudan static ssize_t nr_hugepages_store(struct kobject *kobj, 1163a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 1164a3437870SNishanth Aravamudan { 1165a3437870SNishanth Aravamudan int err; 1166a3437870SNishanth Aravamudan unsigned long input; 1167a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1168a3437870SNishanth Aravamudan 1169a3437870SNishanth Aravamudan err = strict_strtoul(buf, 10, &input); 1170a3437870SNishanth Aravamudan if (err) 1171a3437870SNishanth Aravamudan return 0; 1172a3437870SNishanth Aravamudan 1173a3437870SNishanth Aravamudan h->max_huge_pages = set_max_huge_pages(h, input); 1174a3437870SNishanth Aravamudan 1175a3437870SNishanth Aravamudan return count; 1176a3437870SNishanth Aravamudan } 1177a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 1178a3437870SNishanth Aravamudan 1179a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 1180a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1181a3437870SNishanth Aravamudan { 1182a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1183a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); 1184a3437870SNishanth Aravamudan } 1185a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 1186a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 1187a3437870SNishanth Aravamudan { 1188a3437870SNishanth Aravamudan int err; 1189a3437870SNishanth Aravamudan unsigned long input; 1190a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1191a3437870SNishanth Aravamudan 1192a3437870SNishanth Aravamudan err = strict_strtoul(buf, 10, &input); 1193a3437870SNishanth Aravamudan if (err) 1194a3437870SNishanth Aravamudan return 0; 1195a3437870SNishanth Aravamudan 1196a3437870SNishanth Aravamudan spin_lock(&hugetlb_lock); 1197a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 1198a3437870SNishanth Aravamudan spin_unlock(&hugetlb_lock); 1199a3437870SNishanth Aravamudan 1200a3437870SNishanth Aravamudan return count; 1201a3437870SNishanth Aravamudan } 1202a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 1203a3437870SNishanth Aravamudan 1204a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 1205a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1206a3437870SNishanth Aravamudan { 1207a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1208a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->free_huge_pages); 1209a3437870SNishanth Aravamudan } 1210a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 1211a3437870SNishanth Aravamudan 1212a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 1213a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1214a3437870SNishanth Aravamudan { 1215a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1216a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->resv_huge_pages); 1217a3437870SNishanth Aravamudan } 1218a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 1219a3437870SNishanth Aravamudan 1220a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 1221a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1222a3437870SNishanth Aravamudan { 1223a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1224a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->surplus_huge_pages); 1225a3437870SNishanth Aravamudan } 1226a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 1227a3437870SNishanth Aravamudan 1228a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 1229a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 1230a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 1231a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 1232a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 1233a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 1234a3437870SNishanth Aravamudan NULL, 1235a3437870SNishanth Aravamudan }; 1236a3437870SNishanth Aravamudan 1237a3437870SNishanth Aravamudan static struct attribute_group hstate_attr_group = { 1238a3437870SNishanth Aravamudan .attrs = hstate_attrs, 1239a3437870SNishanth Aravamudan }; 1240a3437870SNishanth Aravamudan 1241a3437870SNishanth Aravamudan static int __init hugetlb_sysfs_add_hstate(struct hstate *h) 1242a3437870SNishanth Aravamudan { 1243a3437870SNishanth Aravamudan int retval; 1244a3437870SNishanth Aravamudan 1245a3437870SNishanth Aravamudan hstate_kobjs[h - hstates] = kobject_create_and_add(h->name, 1246a3437870SNishanth Aravamudan hugepages_kobj); 1247a3437870SNishanth Aravamudan if (!hstate_kobjs[h - hstates]) 1248a3437870SNishanth Aravamudan return -ENOMEM; 1249a3437870SNishanth Aravamudan 1250a3437870SNishanth Aravamudan retval = sysfs_create_group(hstate_kobjs[h - hstates], 1251a3437870SNishanth Aravamudan &hstate_attr_group); 1252a3437870SNishanth Aravamudan if (retval) 1253a3437870SNishanth Aravamudan kobject_put(hstate_kobjs[h - hstates]); 1254a3437870SNishanth Aravamudan 1255a3437870SNishanth Aravamudan return retval; 1256a3437870SNishanth Aravamudan } 1257a3437870SNishanth Aravamudan 1258a3437870SNishanth Aravamudan static void __init hugetlb_sysfs_init(void) 1259a3437870SNishanth Aravamudan { 1260a3437870SNishanth Aravamudan struct hstate *h; 1261a3437870SNishanth Aravamudan int err; 1262a3437870SNishanth Aravamudan 1263a3437870SNishanth Aravamudan hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 1264a3437870SNishanth Aravamudan if (!hugepages_kobj) 1265a3437870SNishanth Aravamudan return; 1266a3437870SNishanth Aravamudan 1267a3437870SNishanth Aravamudan for_each_hstate(h) { 1268a3437870SNishanth Aravamudan err = hugetlb_sysfs_add_hstate(h); 1269a3437870SNishanth Aravamudan if (err) 1270a3437870SNishanth Aravamudan printk(KERN_ERR "Hugetlb: Unable to add hstate %s", 1271a3437870SNishanth Aravamudan h->name); 1272a3437870SNishanth Aravamudan } 1273a3437870SNishanth Aravamudan } 1274a3437870SNishanth Aravamudan 1275a3437870SNishanth Aravamudan static void __exit hugetlb_exit(void) 1276a3437870SNishanth Aravamudan { 1277a3437870SNishanth Aravamudan struct hstate *h; 1278a3437870SNishanth Aravamudan 1279a3437870SNishanth Aravamudan for_each_hstate(h) { 1280a3437870SNishanth Aravamudan kobject_put(hstate_kobjs[h - hstates]); 1281a3437870SNishanth Aravamudan } 1282a3437870SNishanth Aravamudan 1283a3437870SNishanth Aravamudan kobject_put(hugepages_kobj); 1284a3437870SNishanth Aravamudan } 1285a3437870SNishanth Aravamudan module_exit(hugetlb_exit); 1286a3437870SNishanth Aravamudan 1287a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 1288a3437870SNishanth Aravamudan { 1289a3437870SNishanth Aravamudan BUILD_BUG_ON(HPAGE_SHIFT == 0); 1290a3437870SNishanth Aravamudan 1291a3437870SNishanth Aravamudan if (!size_to_hstate(HPAGE_SIZE)) { 1292a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 1293a3437870SNishanth Aravamudan parsed_hstate->max_huge_pages = default_hstate_max_huge_pages; 1294a3437870SNishanth Aravamudan } 1295a3437870SNishanth Aravamudan default_hstate_idx = size_to_hstate(HPAGE_SIZE) - hstates; 1296a3437870SNishanth Aravamudan 1297a3437870SNishanth Aravamudan hugetlb_init_hstates(); 1298a3437870SNishanth Aravamudan 1299aa888a74SAndi Kleen gather_bootmem_prealloc(); 1300aa888a74SAndi Kleen 1301a3437870SNishanth Aravamudan report_hugepages(); 1302a3437870SNishanth Aravamudan 1303a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 1304a3437870SNishanth Aravamudan 1305a3437870SNishanth Aravamudan return 0; 1306a3437870SNishanth Aravamudan } 1307a3437870SNishanth Aravamudan module_init(hugetlb_init); 1308a3437870SNishanth Aravamudan 1309a3437870SNishanth Aravamudan /* Should be called on processing a hugepagesz=... option */ 1310a3437870SNishanth Aravamudan void __init hugetlb_add_hstate(unsigned order) 1311a3437870SNishanth Aravamudan { 1312a3437870SNishanth Aravamudan struct hstate *h; 13138faa8b07SAndi Kleen unsigned long i; 13148faa8b07SAndi Kleen 1315a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 1316a3437870SNishanth Aravamudan printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n"); 1317a3437870SNishanth Aravamudan return; 1318a3437870SNishanth Aravamudan } 1319a3437870SNishanth Aravamudan BUG_ON(max_hstate >= HUGE_MAX_HSTATE); 1320a3437870SNishanth Aravamudan BUG_ON(order == 0); 1321a3437870SNishanth Aravamudan h = &hstates[max_hstate++]; 1322a3437870SNishanth Aravamudan h->order = order; 1323a3437870SNishanth Aravamudan h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); 13248faa8b07SAndi Kleen h->nr_huge_pages = 0; 13258faa8b07SAndi Kleen h->free_huge_pages = 0; 13268faa8b07SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 13278faa8b07SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 13288faa8b07SAndi Kleen h->hugetlb_next_nid = first_node(node_online_map); 1329a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 1330a3437870SNishanth Aravamudan huge_page_size(h)/1024); 13318faa8b07SAndi Kleen 1332a3437870SNishanth Aravamudan parsed_hstate = h; 1333a3437870SNishanth Aravamudan } 1334a3437870SNishanth Aravamudan 1335a3437870SNishanth Aravamudan static int __init hugetlb_setup(char *s) 1336a3437870SNishanth Aravamudan { 1337a3437870SNishanth Aravamudan unsigned long *mhp; 13388faa8b07SAndi Kleen static unsigned long *last_mhp; 1339a3437870SNishanth Aravamudan 1340a3437870SNishanth Aravamudan /* 1341a3437870SNishanth Aravamudan * !max_hstate means we haven't parsed a hugepagesz= parameter yet, 1342a3437870SNishanth Aravamudan * so this hugepages= parameter goes to the "default hstate". 1343a3437870SNishanth Aravamudan */ 1344a3437870SNishanth Aravamudan if (!max_hstate) 1345a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 1346a3437870SNishanth Aravamudan else 1347a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 1348a3437870SNishanth Aravamudan 13498faa8b07SAndi Kleen if (mhp == last_mhp) { 13508faa8b07SAndi Kleen printk(KERN_WARNING "hugepages= specified twice without " 13518faa8b07SAndi Kleen "interleaving hugepagesz=, ignoring\n"); 13528faa8b07SAndi Kleen return 1; 13538faa8b07SAndi Kleen } 13548faa8b07SAndi Kleen 1355a3437870SNishanth Aravamudan if (sscanf(s, "%lu", mhp) <= 0) 1356a3437870SNishanth Aravamudan *mhp = 0; 1357a3437870SNishanth Aravamudan 13588faa8b07SAndi Kleen /* 13598faa8b07SAndi Kleen * Global state is always initialized later in hugetlb_init. 13608faa8b07SAndi Kleen * But we need to allocate >= MAX_ORDER hstates here early to still 13618faa8b07SAndi Kleen * use the bootmem allocator. 13628faa8b07SAndi Kleen */ 13638faa8b07SAndi Kleen if (max_hstate && parsed_hstate->order >= MAX_ORDER) 13648faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(parsed_hstate); 13658faa8b07SAndi Kleen 13668faa8b07SAndi Kleen last_mhp = mhp; 13678faa8b07SAndi Kleen 1368a3437870SNishanth Aravamudan return 1; 1369a3437870SNishanth Aravamudan } 1370a3437870SNishanth Aravamudan __setup("hugepages=", hugetlb_setup); 1371a3437870SNishanth Aravamudan 1372a3437870SNishanth Aravamudan static unsigned int cpuset_mems_nr(unsigned int *array) 1373a3437870SNishanth Aravamudan { 1374a3437870SNishanth Aravamudan int node; 1375a3437870SNishanth Aravamudan unsigned int nr = 0; 1376a3437870SNishanth Aravamudan 1377a3437870SNishanth Aravamudan for_each_node_mask(node, cpuset_current_mems_allowed) 1378a3437870SNishanth Aravamudan nr += array[node]; 1379a3437870SNishanth Aravamudan 1380a3437870SNishanth Aravamudan return nr; 1381a3437870SNishanth Aravamudan } 1382a3437870SNishanth Aravamudan 13831da177e4SLinus Torvalds int hugetlb_sysctl_handler(struct ctl_table *table, int write, 13841da177e4SLinus Torvalds struct file *file, void __user *buffer, 13851da177e4SLinus Torvalds size_t *length, loff_t *ppos) 13861da177e4SLinus Torvalds { 1387e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 1388e5ff2159SAndi Kleen unsigned long tmp; 1389e5ff2159SAndi Kleen 1390e5ff2159SAndi Kleen if (!write) 1391e5ff2159SAndi Kleen tmp = h->max_huge_pages; 1392e5ff2159SAndi Kleen 1393e5ff2159SAndi Kleen table->data = &tmp; 1394e5ff2159SAndi Kleen table->maxlen = sizeof(unsigned long); 13951da177e4SLinus Torvalds proc_doulongvec_minmax(table, write, file, buffer, length, ppos); 1396e5ff2159SAndi Kleen 1397e5ff2159SAndi Kleen if (write) 1398e5ff2159SAndi Kleen h->max_huge_pages = set_max_huge_pages(h, tmp); 1399e5ff2159SAndi Kleen 14001da177e4SLinus Torvalds return 0; 14011da177e4SLinus Torvalds } 1402396faf03SMel Gorman 1403396faf03SMel Gorman int hugetlb_treat_movable_handler(struct ctl_table *table, int write, 1404396faf03SMel Gorman struct file *file, void __user *buffer, 1405396faf03SMel Gorman size_t *length, loff_t *ppos) 1406396faf03SMel Gorman { 1407396faf03SMel Gorman proc_dointvec(table, write, file, buffer, length, ppos); 1408396faf03SMel Gorman if (hugepages_treat_as_movable) 1409396faf03SMel Gorman htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; 1410396faf03SMel Gorman else 1411396faf03SMel Gorman htlb_alloc_mask = GFP_HIGHUSER; 1412396faf03SMel Gorman return 0; 1413396faf03SMel Gorman } 1414396faf03SMel Gorman 1415a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 1416a3d0c6aaSNishanth Aravamudan struct file *file, void __user *buffer, 1417a3d0c6aaSNishanth Aravamudan size_t *length, loff_t *ppos) 1418a3d0c6aaSNishanth Aravamudan { 1419a5516438SAndi Kleen struct hstate *h = &default_hstate; 1420e5ff2159SAndi Kleen unsigned long tmp; 1421e5ff2159SAndi Kleen 1422e5ff2159SAndi Kleen if (!write) 1423e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 1424e5ff2159SAndi Kleen 1425e5ff2159SAndi Kleen table->data = &tmp; 1426e5ff2159SAndi Kleen table->maxlen = sizeof(unsigned long); 1427a3d0c6aaSNishanth Aravamudan proc_doulongvec_minmax(table, write, file, buffer, length, ppos); 1428e5ff2159SAndi Kleen 1429e5ff2159SAndi Kleen if (write) { 1430064d9efeSNishanth Aravamudan spin_lock(&hugetlb_lock); 1431e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 1432a3d0c6aaSNishanth Aravamudan spin_unlock(&hugetlb_lock); 1433e5ff2159SAndi Kleen } 1434e5ff2159SAndi Kleen 1435a3d0c6aaSNishanth Aravamudan return 0; 1436a3d0c6aaSNishanth Aravamudan } 1437a3d0c6aaSNishanth Aravamudan 14381da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 14391da177e4SLinus Torvalds 14401da177e4SLinus Torvalds int hugetlb_report_meminfo(char *buf) 14411da177e4SLinus Torvalds { 1442a5516438SAndi Kleen struct hstate *h = &default_hstate; 14431da177e4SLinus Torvalds return sprintf(buf, 14441da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 14451da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 1446b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 14477893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 14481da177e4SLinus Torvalds "Hugepagesize: %5lu kB\n", 1449a5516438SAndi Kleen h->nr_huge_pages, 1450a5516438SAndi Kleen h->free_huge_pages, 1451a5516438SAndi Kleen h->resv_huge_pages, 1452a5516438SAndi Kleen h->surplus_huge_pages, 1453a5516438SAndi Kleen 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); 14541da177e4SLinus Torvalds } 14551da177e4SLinus Torvalds 14561da177e4SLinus Torvalds int hugetlb_report_node_meminfo(int nid, char *buf) 14571da177e4SLinus Torvalds { 1458a5516438SAndi Kleen struct hstate *h = &default_hstate; 14591da177e4SLinus Torvalds return sprintf(buf, 14601da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 1461a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 1462a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 1463a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 1464a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 1465a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 14661da177e4SLinus Torvalds } 14671da177e4SLinus Torvalds 14681da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 14691da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 14701da177e4SLinus Torvalds { 1471a5516438SAndi Kleen struct hstate *h = &default_hstate; 1472a5516438SAndi Kleen return h->nr_huge_pages * pages_per_huge_page(h); 14731da177e4SLinus Torvalds } 14741da177e4SLinus Torvalds 1475a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 1476fc1b8a73SMel Gorman { 1477fc1b8a73SMel Gorman int ret = -ENOMEM; 1478fc1b8a73SMel Gorman 1479fc1b8a73SMel Gorman spin_lock(&hugetlb_lock); 1480fc1b8a73SMel Gorman /* 1481fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 1482fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 1483fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 1484fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 1485fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 1486fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 1487fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 1488fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 1489fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 1490fc1b8a73SMel Gorman * 1491fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 1492fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 1493fc1b8a73SMel Gorman * we fall back to check against current free page availability as 1494fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 1495fc1b8a73SMel Gorman * semantics that cpuset has. 1496fc1b8a73SMel Gorman */ 1497fc1b8a73SMel Gorman if (delta > 0) { 1498a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 1499fc1b8a73SMel Gorman goto out; 1500fc1b8a73SMel Gorman 1501a5516438SAndi Kleen if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { 1502a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 1503fc1b8a73SMel Gorman goto out; 1504fc1b8a73SMel Gorman } 1505fc1b8a73SMel Gorman } 1506fc1b8a73SMel Gorman 1507fc1b8a73SMel Gorman ret = 0; 1508fc1b8a73SMel Gorman if (delta < 0) 1509a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 1510fc1b8a73SMel Gorman 1511fc1b8a73SMel Gorman out: 1512fc1b8a73SMel Gorman spin_unlock(&hugetlb_lock); 1513fc1b8a73SMel Gorman return ret; 1514fc1b8a73SMel Gorman } 1515fc1b8a73SMel Gorman 151684afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 151784afd99bSAndy Whitcroft { 151884afd99bSAndy Whitcroft struct resv_map *reservations = vma_resv_map(vma); 151984afd99bSAndy Whitcroft 152084afd99bSAndy Whitcroft /* 152184afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 152284afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 152384afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 152484afd99bSAndy Whitcroft * has a reference to the reservation map it cannot dissappear until 152584afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 152684afd99bSAndy Whitcroft * new reference here without additional locking. 152784afd99bSAndy Whitcroft */ 152884afd99bSAndy Whitcroft if (reservations) 152984afd99bSAndy Whitcroft kref_get(&reservations->refs); 153084afd99bSAndy Whitcroft } 153184afd99bSAndy Whitcroft 1532a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 1533a1e78772SMel Gorman { 1534a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 153584afd99bSAndy Whitcroft struct resv_map *reservations = vma_resv_map(vma); 153684afd99bSAndy Whitcroft unsigned long reserve; 153784afd99bSAndy Whitcroft unsigned long start; 153884afd99bSAndy Whitcroft unsigned long end; 153984afd99bSAndy Whitcroft 154084afd99bSAndy Whitcroft if (reservations) { 1541a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 1542a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 154384afd99bSAndy Whitcroft 154484afd99bSAndy Whitcroft reserve = (end - start) - 154584afd99bSAndy Whitcroft region_count(&reservations->regions, start, end); 154684afd99bSAndy Whitcroft 154784afd99bSAndy Whitcroft kref_put(&reservations->refs, resv_map_release); 154884afd99bSAndy Whitcroft 1549a1e78772SMel Gorman if (reserve) 1550a5516438SAndi Kleen hugetlb_acct_memory(h, -reserve); 1551a1e78772SMel Gorman } 155284afd99bSAndy Whitcroft } 1553a1e78772SMel Gorman 15541da177e4SLinus Torvalds /* 15551da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 15561da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 15571da177e4SLinus Torvalds * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get 15581da177e4SLinus Torvalds * this far. 15591da177e4SLinus Torvalds */ 1560d0217ac0SNick Piggin static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 15611da177e4SLinus Torvalds { 15621da177e4SLinus Torvalds BUG(); 1563d0217ac0SNick Piggin return 0; 15641da177e4SLinus Torvalds } 15651da177e4SLinus Torvalds 15661da177e4SLinus Torvalds struct vm_operations_struct hugetlb_vm_ops = { 1567d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 156884afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 1569a1e78772SMel Gorman .close = hugetlb_vm_op_close, 15701da177e4SLinus Torvalds }; 15711da177e4SLinus Torvalds 15721e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 15731e8f889bSDavid Gibson int writable) 157463551ae0SDavid Gibson { 157563551ae0SDavid Gibson pte_t entry; 157663551ae0SDavid Gibson 15771e8f889bSDavid Gibson if (writable) { 157863551ae0SDavid Gibson entry = 157963551ae0SDavid Gibson pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); 158063551ae0SDavid Gibson } else { 15817f2e9525SGerald Schaefer entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); 158263551ae0SDavid Gibson } 158363551ae0SDavid Gibson entry = pte_mkyoung(entry); 158463551ae0SDavid Gibson entry = pte_mkhuge(entry); 158563551ae0SDavid Gibson 158663551ae0SDavid Gibson return entry; 158763551ae0SDavid Gibson } 158863551ae0SDavid Gibson 15891e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 15901e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 15911e8f889bSDavid Gibson { 15921e8f889bSDavid Gibson pte_t entry; 15931e8f889bSDavid Gibson 15947f2e9525SGerald Schaefer entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); 15957f2e9525SGerald Schaefer if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { 15961e8f889bSDavid Gibson update_mmu_cache(vma, address, entry); 15971e8f889bSDavid Gibson } 15988dab5241SBenjamin Herrenschmidt } 15991e8f889bSDavid Gibson 16001e8f889bSDavid Gibson 160163551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 160263551ae0SDavid Gibson struct vm_area_struct *vma) 160363551ae0SDavid Gibson { 160463551ae0SDavid Gibson pte_t *src_pte, *dst_pte, entry; 160563551ae0SDavid Gibson struct page *ptepage; 16061c59827dSHugh Dickins unsigned long addr; 16071e8f889bSDavid Gibson int cow; 1608a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 1609a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 16101e8f889bSDavid Gibson 16111e8f889bSDavid Gibson cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; 161263551ae0SDavid Gibson 1613a5516438SAndi Kleen for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { 1614c74df32cSHugh Dickins src_pte = huge_pte_offset(src, addr); 1615c74df32cSHugh Dickins if (!src_pte) 1616c74df32cSHugh Dickins continue; 1617a5516438SAndi Kleen dst_pte = huge_pte_alloc(dst, addr, sz); 161863551ae0SDavid Gibson if (!dst_pte) 161963551ae0SDavid Gibson goto nomem; 1620c5c99429SLarry Woodman 1621c5c99429SLarry Woodman /* If the pagetables are shared don't copy or take references */ 1622c5c99429SLarry Woodman if (dst_pte == src_pte) 1623c5c99429SLarry Woodman continue; 1624c5c99429SLarry Woodman 1625c74df32cSHugh Dickins spin_lock(&dst->page_table_lock); 162646478758SNick Piggin spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); 16277f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(src_pte))) { 16281e8f889bSDavid Gibson if (cow) 16297f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 16307f2e9525SGerald Schaefer entry = huge_ptep_get(src_pte); 163163551ae0SDavid Gibson ptepage = pte_page(entry); 163263551ae0SDavid Gibson get_page(ptepage); 163363551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 16341c59827dSHugh Dickins } 16351c59827dSHugh Dickins spin_unlock(&src->page_table_lock); 1636c74df32cSHugh Dickins spin_unlock(&dst->page_table_lock); 163763551ae0SDavid Gibson } 163863551ae0SDavid Gibson return 0; 163963551ae0SDavid Gibson 164063551ae0SDavid Gibson nomem: 164163551ae0SDavid Gibson return -ENOMEM; 164263551ae0SDavid Gibson } 164363551ae0SDavid Gibson 1644502717f4SChen, Kenneth W void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 164504f2cbe3SMel Gorman unsigned long end, struct page *ref_page) 164663551ae0SDavid Gibson { 164763551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 164863551ae0SDavid Gibson unsigned long address; 1649c7546f8fSDavid Gibson pte_t *ptep; 165063551ae0SDavid Gibson pte_t pte; 165163551ae0SDavid Gibson struct page *page; 1652fe1668aeSChen, Kenneth W struct page *tmp; 1653a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 1654a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 1655a5516438SAndi Kleen 1656c0a499c2SChen, Kenneth W /* 1657c0a499c2SChen, Kenneth W * A page gathering list, protected by per file i_mmap_lock. The 1658c0a499c2SChen, Kenneth W * lock is used to avoid list corruption from multiple unmapping 1659c0a499c2SChen, Kenneth W * of the same page since we are using page->lru. 1660c0a499c2SChen, Kenneth W */ 1661fe1668aeSChen, Kenneth W LIST_HEAD(page_list); 166263551ae0SDavid Gibson 166363551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 1664a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 1665a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 166663551ae0SDavid Gibson 1667508034a3SHugh Dickins spin_lock(&mm->page_table_lock); 1668a5516438SAndi Kleen for (address = start; address < end; address += sz) { 1669c7546f8fSDavid Gibson ptep = huge_pte_offset(mm, address); 1670c7546f8fSDavid Gibson if (!ptep) 1671c7546f8fSDavid Gibson continue; 1672c7546f8fSDavid Gibson 167339dde65cSChen, Kenneth W if (huge_pmd_unshare(mm, &address, ptep)) 167439dde65cSChen, Kenneth W continue; 167539dde65cSChen, Kenneth W 167604f2cbe3SMel Gorman /* 167704f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 167804f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 167904f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 168004f2cbe3SMel Gorman */ 168104f2cbe3SMel Gorman if (ref_page) { 168204f2cbe3SMel Gorman pte = huge_ptep_get(ptep); 168304f2cbe3SMel Gorman if (huge_pte_none(pte)) 168404f2cbe3SMel Gorman continue; 168504f2cbe3SMel Gorman page = pte_page(pte); 168604f2cbe3SMel Gorman if (page != ref_page) 168704f2cbe3SMel Gorman continue; 168804f2cbe3SMel Gorman 168904f2cbe3SMel Gorman /* 169004f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 169104f2cbe3SMel Gorman * future faults in this VMA will fail rather than 169204f2cbe3SMel Gorman * looking like data was lost 169304f2cbe3SMel Gorman */ 169404f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 169504f2cbe3SMel Gorman } 169604f2cbe3SMel Gorman 1697c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 16987f2e9525SGerald Schaefer if (huge_pte_none(pte)) 169963551ae0SDavid Gibson continue; 1700c7546f8fSDavid Gibson 170163551ae0SDavid Gibson page = pte_page(pte); 17026649a386SKen Chen if (pte_dirty(pte)) 17036649a386SKen Chen set_page_dirty(page); 1704fe1668aeSChen, Kenneth W list_add(&page->lru, &page_list); 170563551ae0SDavid Gibson } 17061da177e4SLinus Torvalds spin_unlock(&mm->page_table_lock); 1707508034a3SHugh Dickins flush_tlb_range(vma, start, end); 1708fe1668aeSChen, Kenneth W list_for_each_entry_safe(page, tmp, &page_list, lru) { 1709fe1668aeSChen, Kenneth W list_del(&page->lru); 1710fe1668aeSChen, Kenneth W put_page(page); 1711fe1668aeSChen, Kenneth W } 17121da177e4SLinus Torvalds } 171363551ae0SDavid Gibson 1714502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 171504f2cbe3SMel Gorman unsigned long end, struct page *ref_page) 1716502717f4SChen, Kenneth W { 1717502717f4SChen, Kenneth W spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); 171804f2cbe3SMel Gorman __unmap_hugepage_range(vma, start, end, ref_page); 1719502717f4SChen, Kenneth W spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); 1720502717f4SChen, Kenneth W } 1721502717f4SChen, Kenneth W 172204f2cbe3SMel Gorman /* 172304f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 172404f2cbe3SMel Gorman * mappping it owns the reserve page for. The intention is to unmap the page 172504f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 172604f2cbe3SMel Gorman * same region. 172704f2cbe3SMel Gorman */ 172804f2cbe3SMel Gorman int unmap_ref_private(struct mm_struct *mm, 172904f2cbe3SMel Gorman struct vm_area_struct *vma, 173004f2cbe3SMel Gorman struct page *page, 173104f2cbe3SMel Gorman unsigned long address) 173204f2cbe3SMel Gorman { 173304f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 173404f2cbe3SMel Gorman struct address_space *mapping; 173504f2cbe3SMel Gorman struct prio_tree_iter iter; 173604f2cbe3SMel Gorman pgoff_t pgoff; 173704f2cbe3SMel Gorman 173804f2cbe3SMel Gorman /* 173904f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 174004f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 174104f2cbe3SMel Gorman */ 174204f2cbe3SMel Gorman address = address & huge_page_mask(hstate_vma(vma)); 174304f2cbe3SMel Gorman pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) 174404f2cbe3SMel Gorman + (vma->vm_pgoff >> PAGE_SHIFT); 174504f2cbe3SMel Gorman mapping = (struct address_space *)page_private(page); 174604f2cbe3SMel Gorman 174704f2cbe3SMel Gorman vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { 174804f2cbe3SMel Gorman /* Do not unmap the current VMA */ 174904f2cbe3SMel Gorman if (iter_vma == vma) 175004f2cbe3SMel Gorman continue; 175104f2cbe3SMel Gorman 175204f2cbe3SMel Gorman /* 175304f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 175404f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 175504f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 175604f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 175704f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 175804f2cbe3SMel Gorman */ 175904f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 176004f2cbe3SMel Gorman unmap_hugepage_range(iter_vma, 176104f2cbe3SMel Gorman address, address + HPAGE_SIZE, 176204f2cbe3SMel Gorman page); 176304f2cbe3SMel Gorman } 176404f2cbe3SMel Gorman 176504f2cbe3SMel Gorman return 1; 176604f2cbe3SMel Gorman } 176704f2cbe3SMel Gorman 17681e8f889bSDavid Gibson static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, 176904f2cbe3SMel Gorman unsigned long address, pte_t *ptep, pte_t pte, 177004f2cbe3SMel Gorman struct page *pagecache_page) 17711e8f889bSDavid Gibson { 1772a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 17731e8f889bSDavid Gibson struct page *old_page, *new_page; 177479ac6ba4SDavid Gibson int avoidcopy; 177504f2cbe3SMel Gorman int outside_reserve = 0; 17761e8f889bSDavid Gibson 17771e8f889bSDavid Gibson old_page = pte_page(pte); 17781e8f889bSDavid Gibson 177904f2cbe3SMel Gorman retry_avoidcopy: 17801e8f889bSDavid Gibson /* If no-one else is actually using this page, avoid the copy 17811e8f889bSDavid Gibson * and just make the page writable */ 17821e8f889bSDavid Gibson avoidcopy = (page_count(old_page) == 1); 17831e8f889bSDavid Gibson if (avoidcopy) { 17841e8f889bSDavid Gibson set_huge_ptep_writable(vma, address, ptep); 178583c54070SNick Piggin return 0; 17861e8f889bSDavid Gibson } 17871e8f889bSDavid Gibson 178804f2cbe3SMel Gorman /* 178904f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 179004f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 179104f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 179204f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 179304f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 179404f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 179504f2cbe3SMel Gorman * of the full address range. 179604f2cbe3SMel Gorman */ 179704f2cbe3SMel Gorman if (!(vma->vm_flags & VM_SHARED) && 179804f2cbe3SMel Gorman is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 179904f2cbe3SMel Gorman old_page != pagecache_page) 180004f2cbe3SMel Gorman outside_reserve = 1; 180104f2cbe3SMel Gorman 18021e8f889bSDavid Gibson page_cache_get(old_page); 180304f2cbe3SMel Gorman new_page = alloc_huge_page(vma, address, outside_reserve); 18041e8f889bSDavid Gibson 18052fc39cecSAdam Litke if (IS_ERR(new_page)) { 18061e8f889bSDavid Gibson page_cache_release(old_page); 180704f2cbe3SMel Gorman 180804f2cbe3SMel Gorman /* 180904f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 181004f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 181104f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 181204f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 181304f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 181404f2cbe3SMel Gorman */ 181504f2cbe3SMel Gorman if (outside_reserve) { 181604f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 181704f2cbe3SMel Gorman if (unmap_ref_private(mm, vma, old_page, address)) { 181804f2cbe3SMel Gorman BUG_ON(page_count(old_page) != 1); 181904f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 182004f2cbe3SMel Gorman goto retry_avoidcopy; 182104f2cbe3SMel Gorman } 182204f2cbe3SMel Gorman WARN_ON_ONCE(1); 182304f2cbe3SMel Gorman } 182404f2cbe3SMel Gorman 18252fc39cecSAdam Litke return -PTR_ERR(new_page); 18261e8f889bSDavid Gibson } 18271e8f889bSDavid Gibson 18281e8f889bSDavid Gibson spin_unlock(&mm->page_table_lock); 18299de455b2SAtsushi Nemoto copy_huge_page(new_page, old_page, address, vma); 18300ed361deSNick Piggin __SetPageUptodate(new_page); 18311e8f889bSDavid Gibson spin_lock(&mm->page_table_lock); 18321e8f889bSDavid Gibson 1833a5516438SAndi Kleen ptep = huge_pte_offset(mm, address & huge_page_mask(h)); 18347f2e9525SGerald Schaefer if (likely(pte_same(huge_ptep_get(ptep), pte))) { 18351e8f889bSDavid Gibson /* Break COW */ 18368fe627ecSGerald Schaefer huge_ptep_clear_flush(vma, address, ptep); 18371e8f889bSDavid Gibson set_huge_pte_at(mm, address, ptep, 18381e8f889bSDavid Gibson make_huge_pte(vma, new_page, 1)); 18391e8f889bSDavid Gibson /* Make the old page be freed below */ 18401e8f889bSDavid Gibson new_page = old_page; 18411e8f889bSDavid Gibson } 18421e8f889bSDavid Gibson page_cache_release(new_page); 18431e8f889bSDavid Gibson page_cache_release(old_page); 184483c54070SNick Piggin return 0; 18451e8f889bSDavid Gibson } 18461e8f889bSDavid Gibson 184704f2cbe3SMel Gorman /* Return the pagecache page at a given address within a VMA */ 1848a5516438SAndi Kleen static struct page *hugetlbfs_pagecache_page(struct hstate *h, 1849a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 185004f2cbe3SMel Gorman { 185104f2cbe3SMel Gorman struct address_space *mapping; 1852e7c4b0bfSAndy Whitcroft pgoff_t idx; 185304f2cbe3SMel Gorman 185404f2cbe3SMel Gorman mapping = vma->vm_file->f_mapping; 1855a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 185604f2cbe3SMel Gorman 185704f2cbe3SMel Gorman return find_lock_page(mapping, idx); 185804f2cbe3SMel Gorman } 185904f2cbe3SMel Gorman 1860a1ed3ddaSRobert P. J. Day static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, 18611e8f889bSDavid Gibson unsigned long address, pte_t *ptep, int write_access) 1862ac9b9c66SHugh Dickins { 1863a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 1864ac9b9c66SHugh Dickins int ret = VM_FAULT_SIGBUS; 1865e7c4b0bfSAndy Whitcroft pgoff_t idx; 18664c887265SAdam Litke unsigned long size; 18674c887265SAdam Litke struct page *page; 18684c887265SAdam Litke struct address_space *mapping; 18691e8f889bSDavid Gibson pte_t new_pte; 18704c887265SAdam Litke 187104f2cbe3SMel Gorman /* 187204f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 187304f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 187404f2cbe3SMel Gorman * COW. Warn that such a situation has occured as it may not be obvious 187504f2cbe3SMel Gorman */ 187604f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 187704f2cbe3SMel Gorman printk(KERN_WARNING 187804f2cbe3SMel Gorman "PID %d killed due to inadequate hugepage pool\n", 187904f2cbe3SMel Gorman current->pid); 188004f2cbe3SMel Gorman return ret; 188104f2cbe3SMel Gorman } 188204f2cbe3SMel Gorman 18834c887265SAdam Litke mapping = vma->vm_file->f_mapping; 1884a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 18854c887265SAdam Litke 18864c887265SAdam Litke /* 18874c887265SAdam Litke * Use page lock to guard against racing truncation 18884c887265SAdam Litke * before we get page_table_lock. 18894c887265SAdam Litke */ 18906bda666aSChristoph Lameter retry: 18916bda666aSChristoph Lameter page = find_lock_page(mapping, idx); 18926bda666aSChristoph Lameter if (!page) { 1893a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 1894ebed4bfcSHugh Dickins if (idx >= size) 1895ebed4bfcSHugh Dickins goto out; 189604f2cbe3SMel Gorman page = alloc_huge_page(vma, address, 0); 18972fc39cecSAdam Litke if (IS_ERR(page)) { 18982fc39cecSAdam Litke ret = -PTR_ERR(page); 18996bda666aSChristoph Lameter goto out; 19006bda666aSChristoph Lameter } 1901a5516438SAndi Kleen clear_huge_page(page, address, huge_page_size(h)); 19020ed361deSNick Piggin __SetPageUptodate(page); 1903ac9b9c66SHugh Dickins 19046bda666aSChristoph Lameter if (vma->vm_flags & VM_SHARED) { 19056bda666aSChristoph Lameter int err; 190645c682a6SKen Chen struct inode *inode = mapping->host; 19076bda666aSChristoph Lameter 19086bda666aSChristoph Lameter err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); 19096bda666aSChristoph Lameter if (err) { 19106bda666aSChristoph Lameter put_page(page); 19116bda666aSChristoph Lameter if (err == -EEXIST) 19126bda666aSChristoph Lameter goto retry; 19136bda666aSChristoph Lameter goto out; 19146bda666aSChristoph Lameter } 191545c682a6SKen Chen 191645c682a6SKen Chen spin_lock(&inode->i_lock); 1917a5516438SAndi Kleen inode->i_blocks += blocks_per_huge_page(h); 191845c682a6SKen Chen spin_unlock(&inode->i_lock); 19196bda666aSChristoph Lameter } else 19206bda666aSChristoph Lameter lock_page(page); 19216bda666aSChristoph Lameter } 19221e8f889bSDavid Gibson 1923ac9b9c66SHugh Dickins spin_lock(&mm->page_table_lock); 1924a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 19254c887265SAdam Litke if (idx >= size) 19264c887265SAdam Litke goto backout; 19274c887265SAdam Litke 192883c54070SNick Piggin ret = 0; 19297f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(ptep))) 19304c887265SAdam Litke goto backout; 19314c887265SAdam Litke 19321e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 19331e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 19341e8f889bSDavid Gibson set_huge_pte_at(mm, address, ptep, new_pte); 19351e8f889bSDavid Gibson 19361e8f889bSDavid Gibson if (write_access && !(vma->vm_flags & VM_SHARED)) { 19371e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 193804f2cbe3SMel Gorman ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); 19391e8f889bSDavid Gibson } 19401e8f889bSDavid Gibson 1941ac9b9c66SHugh Dickins spin_unlock(&mm->page_table_lock); 19424c887265SAdam Litke unlock_page(page); 19434c887265SAdam Litke out: 1944ac9b9c66SHugh Dickins return ret; 19454c887265SAdam Litke 19464c887265SAdam Litke backout: 19474c887265SAdam Litke spin_unlock(&mm->page_table_lock); 19484c887265SAdam Litke unlock_page(page); 19494c887265SAdam Litke put_page(page); 19504c887265SAdam Litke goto out; 1951ac9b9c66SHugh Dickins } 1952ac9b9c66SHugh Dickins 195386e5216fSAdam Litke int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 195486e5216fSAdam Litke unsigned long address, int write_access) 195586e5216fSAdam Litke { 195686e5216fSAdam Litke pte_t *ptep; 195786e5216fSAdam Litke pte_t entry; 19581e8f889bSDavid Gibson int ret; 19593935baa9SDavid Gibson static DEFINE_MUTEX(hugetlb_instantiation_mutex); 1960a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 196186e5216fSAdam Litke 1962a5516438SAndi Kleen ptep = huge_pte_alloc(mm, address, huge_page_size(h)); 196386e5216fSAdam Litke if (!ptep) 196486e5216fSAdam Litke return VM_FAULT_OOM; 196586e5216fSAdam Litke 19663935baa9SDavid Gibson /* 19673935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 19683935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 19693935baa9SDavid Gibson * the same page in the page cache. 19703935baa9SDavid Gibson */ 19713935baa9SDavid Gibson mutex_lock(&hugetlb_instantiation_mutex); 19727f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 19737f2e9525SGerald Schaefer if (huge_pte_none(entry)) { 19743935baa9SDavid Gibson ret = hugetlb_no_page(mm, vma, address, ptep, write_access); 19753935baa9SDavid Gibson mutex_unlock(&hugetlb_instantiation_mutex); 19763935baa9SDavid Gibson return ret; 19773935baa9SDavid Gibson } 197886e5216fSAdam Litke 197983c54070SNick Piggin ret = 0; 19801e8f889bSDavid Gibson 19811e8f889bSDavid Gibson spin_lock(&mm->page_table_lock); 19821e8f889bSDavid Gibson /* Check for a racing update before calling hugetlb_cow */ 19837f2e9525SGerald Schaefer if (likely(pte_same(entry, huge_ptep_get(ptep)))) 198404f2cbe3SMel Gorman if (write_access && !pte_write(entry)) { 198504f2cbe3SMel Gorman struct page *page; 1986a5516438SAndi Kleen page = hugetlbfs_pagecache_page(h, vma, address); 198704f2cbe3SMel Gorman ret = hugetlb_cow(mm, vma, address, ptep, entry, page); 198804f2cbe3SMel Gorman if (page) { 198904f2cbe3SMel Gorman unlock_page(page); 199004f2cbe3SMel Gorman put_page(page); 199104f2cbe3SMel Gorman } 199204f2cbe3SMel Gorman } 19931e8f889bSDavid Gibson spin_unlock(&mm->page_table_lock); 19943935baa9SDavid Gibson mutex_unlock(&hugetlb_instantiation_mutex); 19951e8f889bSDavid Gibson 19961e8f889bSDavid Gibson return ret; 199786e5216fSAdam Litke } 199886e5216fSAdam Litke 199963551ae0SDavid Gibson int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 200063551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 20015b23dbe8SAdam Litke unsigned long *position, int *length, int i, 20025b23dbe8SAdam Litke int write) 200363551ae0SDavid Gibson { 2004d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 2005d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 200663551ae0SDavid Gibson int remainder = *length; 2007a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 200863551ae0SDavid Gibson 20091c59827dSHugh Dickins spin_lock(&mm->page_table_lock); 201063551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 201163551ae0SDavid Gibson pte_t *pte; 201263551ae0SDavid Gibson struct page *page; 201363551ae0SDavid Gibson 20144c887265SAdam Litke /* 20154c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 20164c887265SAdam Litke * each hugepage. We have to make * sure we get the 20174c887265SAdam Litke * first, for the page indexing below to work. 20184c887265SAdam Litke */ 2019a5516438SAndi Kleen pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); 202063551ae0SDavid Gibson 20217f2e9525SGerald Schaefer if (!pte || huge_pte_none(huge_ptep_get(pte)) || 20227f2e9525SGerald Schaefer (write && !pte_write(huge_ptep_get(pte)))) { 20234c887265SAdam Litke int ret; 20244c887265SAdam Litke 20254c887265SAdam Litke spin_unlock(&mm->page_table_lock); 20265b23dbe8SAdam Litke ret = hugetlb_fault(mm, vma, vaddr, write); 20274c887265SAdam Litke spin_lock(&mm->page_table_lock); 2028a89182c7SAdam Litke if (!(ret & VM_FAULT_ERROR)) 20294c887265SAdam Litke continue; 20304c887265SAdam Litke 20311c59827dSHugh Dickins remainder = 0; 20321c59827dSHugh Dickins if (!i) 20331c59827dSHugh Dickins i = -EFAULT; 20341c59827dSHugh Dickins break; 20351c59827dSHugh Dickins } 203663551ae0SDavid Gibson 2037a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 20387f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 2039d5d4b0aaSChen, Kenneth W same_page: 2040d6692183SChen, Kenneth W if (pages) { 204163551ae0SDavid Gibson get_page(page); 2042d5d4b0aaSChen, Kenneth W pages[i] = page + pfn_offset; 2043d6692183SChen, Kenneth W } 204463551ae0SDavid Gibson 204563551ae0SDavid Gibson if (vmas) 204663551ae0SDavid Gibson vmas[i] = vma; 204763551ae0SDavid Gibson 204863551ae0SDavid Gibson vaddr += PAGE_SIZE; 2049d5d4b0aaSChen, Kenneth W ++pfn_offset; 205063551ae0SDavid Gibson --remainder; 205163551ae0SDavid Gibson ++i; 2052d5d4b0aaSChen, Kenneth W if (vaddr < vma->vm_end && remainder && 2053a5516438SAndi Kleen pfn_offset < pages_per_huge_page(h)) { 2054d5d4b0aaSChen, Kenneth W /* 2055d5d4b0aaSChen, Kenneth W * We use pfn_offset to avoid touching the pageframes 2056d5d4b0aaSChen, Kenneth W * of this compound page. 2057d5d4b0aaSChen, Kenneth W */ 2058d5d4b0aaSChen, Kenneth W goto same_page; 2059d5d4b0aaSChen, Kenneth W } 206063551ae0SDavid Gibson } 20611c59827dSHugh Dickins spin_unlock(&mm->page_table_lock); 206263551ae0SDavid Gibson *length = remainder; 206363551ae0SDavid Gibson *position = vaddr; 206463551ae0SDavid Gibson 206563551ae0SDavid Gibson return i; 206663551ae0SDavid Gibson } 20678f860591SZhang, Yanmin 20688f860591SZhang, Yanmin void hugetlb_change_protection(struct vm_area_struct *vma, 20698f860591SZhang, Yanmin unsigned long address, unsigned long end, pgprot_t newprot) 20708f860591SZhang, Yanmin { 20718f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 20728f860591SZhang, Yanmin unsigned long start = address; 20738f860591SZhang, Yanmin pte_t *ptep; 20748f860591SZhang, Yanmin pte_t pte; 2075a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 20768f860591SZhang, Yanmin 20778f860591SZhang, Yanmin BUG_ON(address >= end); 20788f860591SZhang, Yanmin flush_cache_range(vma, address, end); 20798f860591SZhang, Yanmin 208039dde65cSChen, Kenneth W spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); 20818f860591SZhang, Yanmin spin_lock(&mm->page_table_lock); 2082a5516438SAndi Kleen for (; address < end; address += huge_page_size(h)) { 20838f860591SZhang, Yanmin ptep = huge_pte_offset(mm, address); 20848f860591SZhang, Yanmin if (!ptep) 20858f860591SZhang, Yanmin continue; 208639dde65cSChen, Kenneth W if (huge_pmd_unshare(mm, &address, ptep)) 208739dde65cSChen, Kenneth W continue; 20887f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(ptep))) { 20898f860591SZhang, Yanmin pte = huge_ptep_get_and_clear(mm, address, ptep); 20908f860591SZhang, Yanmin pte = pte_mkhuge(pte_modify(pte, newprot)); 20918f860591SZhang, Yanmin set_huge_pte_at(mm, address, ptep, pte); 20928f860591SZhang, Yanmin } 20938f860591SZhang, Yanmin } 20948f860591SZhang, Yanmin spin_unlock(&mm->page_table_lock); 209539dde65cSChen, Kenneth W spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); 20968f860591SZhang, Yanmin 20978f860591SZhang, Yanmin flush_tlb_range(vma, start, end); 20988f860591SZhang, Yanmin } 20998f860591SZhang, Yanmin 2100a1e78772SMel Gorman int hugetlb_reserve_pages(struct inode *inode, 2101a1e78772SMel Gorman long from, long to, 2102a1e78772SMel Gorman struct vm_area_struct *vma) 2103e4e574b7SAdam Litke { 2104e4e574b7SAdam Litke long ret, chg; 2105a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 2106e4e574b7SAdam Litke 2107c37f9fb1SAndy Whitcroft if (vma && vma->vm_flags & VM_NORESERVE) 2108c37f9fb1SAndy Whitcroft return 0; 2109c37f9fb1SAndy Whitcroft 2110a1e78772SMel Gorman /* 2111a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 2112a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 2113a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 2114a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 2115a1e78772SMel Gorman */ 2116a1e78772SMel Gorman if (!vma || vma->vm_flags & VM_SHARED) 2117e4e574b7SAdam Litke chg = region_chg(&inode->i_mapping->private_list, from, to); 2118a1e78772SMel Gorman else { 211984afd99bSAndy Whitcroft struct resv_map *resv_map = resv_map_alloc(); 212084afd99bSAndy Whitcroft if (!resv_map) 212184afd99bSAndy Whitcroft return -ENOMEM; 212284afd99bSAndy Whitcroft 2123a1e78772SMel Gorman chg = to - from; 212484afd99bSAndy Whitcroft 212584afd99bSAndy Whitcroft set_vma_resv_map(vma, resv_map); 212604f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 2127a1e78772SMel Gorman } 2128a1e78772SMel Gorman 2129e4e574b7SAdam Litke if (chg < 0) 2130e4e574b7SAdam Litke return chg; 21318a630112SKen Chen 213290d8b7e6SAdam Litke if (hugetlb_get_quota(inode->i_mapping, chg)) 213390d8b7e6SAdam Litke return -ENOSPC; 2134a5516438SAndi Kleen ret = hugetlb_acct_memory(h, chg); 213568842c9bSKen Chen if (ret < 0) { 213668842c9bSKen Chen hugetlb_put_quota(inode->i_mapping, chg); 2137a43a8c39SChen, Kenneth W return ret; 213868842c9bSKen Chen } 2139a1e78772SMel Gorman if (!vma || vma->vm_flags & VM_SHARED) 2140a43a8c39SChen, Kenneth W region_add(&inode->i_mapping->private_list, from, to); 2141a43a8c39SChen, Kenneth W return 0; 2142a43a8c39SChen, Kenneth W } 2143a43a8c39SChen, Kenneth W 2144a43a8c39SChen, Kenneth W void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) 2145a43a8c39SChen, Kenneth W { 2146a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 2147a43a8c39SChen, Kenneth W long chg = region_truncate(&inode->i_mapping->private_list, offset); 214845c682a6SKen Chen 214945c682a6SKen Chen spin_lock(&inode->i_lock); 2150a5516438SAndi Kleen inode->i_blocks -= blocks_per_huge_page(h); 215145c682a6SKen Chen spin_unlock(&inode->i_lock); 215245c682a6SKen Chen 215390d8b7e6SAdam Litke hugetlb_put_quota(inode->i_mapping, (chg - freed)); 2154a5516438SAndi Kleen hugetlb_acct_memory(h, -(chg - freed)); 2155a43a8c39SChen, Kenneth W } 2156