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 3453ba51d2SJon Tollefson __initdata LIST_HEAD(huge_boot_pages); 3553ba51d2SJon Tollefson 36e5ff2159SAndi Kleen /* for command line parsing */ 37e5ff2159SAndi Kleen static struct hstate * __initdata parsed_hstate; 38e5ff2159SAndi Kleen static unsigned long __initdata default_hstate_max_huge_pages; 39e11bfbfcSNick Piggin static unsigned long __initdata default_hstate_size; 40e5ff2159SAndi Kleen 41e5ff2159SAndi Kleen #define for_each_hstate(h) \ 42e5ff2159SAndi Kleen for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++) 43396faf03SMel Gorman 443935baa9SDavid Gibson /* 453935baa9SDavid Gibson * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages 463935baa9SDavid Gibson */ 473935baa9SDavid Gibson static DEFINE_SPINLOCK(hugetlb_lock); 480bd0f9fbSEric Paris 49e7c4b0bfSAndy Whitcroft /* 5096822904SAndy Whitcroft * Region tracking -- allows tracking of reservations and instantiated pages 5196822904SAndy Whitcroft * across the pages in a mapping. 5284afd99bSAndy Whitcroft * 5384afd99bSAndy Whitcroft * The region data structures are protected by a combination of the mmap_sem 5484afd99bSAndy Whitcroft * and the hugetlb_instantion_mutex. To access or modify a region the caller 5584afd99bSAndy Whitcroft * must either hold the mmap_sem for write, or the mmap_sem for read and 5684afd99bSAndy Whitcroft * the hugetlb_instantiation mutex: 5784afd99bSAndy Whitcroft * 5884afd99bSAndy Whitcroft * down_write(&mm->mmap_sem); 5984afd99bSAndy Whitcroft * or 6084afd99bSAndy Whitcroft * down_read(&mm->mmap_sem); 6184afd99bSAndy Whitcroft * mutex_lock(&hugetlb_instantiation_mutex); 6296822904SAndy Whitcroft */ 6396822904SAndy Whitcroft struct file_region { 6496822904SAndy Whitcroft struct list_head link; 6596822904SAndy Whitcroft long from; 6696822904SAndy Whitcroft long to; 6796822904SAndy Whitcroft }; 6896822904SAndy Whitcroft 6996822904SAndy Whitcroft static long region_add(struct list_head *head, long f, long t) 7096822904SAndy Whitcroft { 7196822904SAndy Whitcroft struct file_region *rg, *nrg, *trg; 7296822904SAndy Whitcroft 7396822904SAndy Whitcroft /* Locate the region we are either in or before. */ 7496822904SAndy Whitcroft list_for_each_entry(rg, head, link) 7596822904SAndy Whitcroft if (f <= rg->to) 7696822904SAndy Whitcroft break; 7796822904SAndy Whitcroft 7896822904SAndy Whitcroft /* Round our left edge to the current segment if it encloses us. */ 7996822904SAndy Whitcroft if (f > rg->from) 8096822904SAndy Whitcroft f = rg->from; 8196822904SAndy Whitcroft 8296822904SAndy Whitcroft /* Check for and consume any regions we now overlap with. */ 8396822904SAndy Whitcroft nrg = rg; 8496822904SAndy Whitcroft list_for_each_entry_safe(rg, trg, rg->link.prev, link) { 8596822904SAndy Whitcroft if (&rg->link == head) 8696822904SAndy Whitcroft break; 8796822904SAndy Whitcroft if (rg->from > t) 8896822904SAndy Whitcroft break; 8996822904SAndy Whitcroft 9096822904SAndy Whitcroft /* If this area reaches higher then extend our area to 9196822904SAndy Whitcroft * include it completely. If this is not the first area 9296822904SAndy Whitcroft * which we intend to reuse, free it. */ 9396822904SAndy Whitcroft if (rg->to > t) 9496822904SAndy Whitcroft t = rg->to; 9596822904SAndy Whitcroft if (rg != nrg) { 9696822904SAndy Whitcroft list_del(&rg->link); 9796822904SAndy Whitcroft kfree(rg); 9896822904SAndy Whitcroft } 9996822904SAndy Whitcroft } 10096822904SAndy Whitcroft nrg->from = f; 10196822904SAndy Whitcroft nrg->to = t; 10296822904SAndy Whitcroft return 0; 10396822904SAndy Whitcroft } 10496822904SAndy Whitcroft 10596822904SAndy Whitcroft static long region_chg(struct list_head *head, long f, long t) 10696822904SAndy Whitcroft { 10796822904SAndy Whitcroft struct file_region *rg, *nrg; 10896822904SAndy Whitcroft long chg = 0; 10996822904SAndy Whitcroft 11096822904SAndy Whitcroft /* Locate the region we are before or in. */ 11196822904SAndy Whitcroft list_for_each_entry(rg, head, link) 11296822904SAndy Whitcroft if (f <= rg->to) 11396822904SAndy Whitcroft break; 11496822904SAndy Whitcroft 11596822904SAndy Whitcroft /* If we are below the current region then a new region is required. 11696822904SAndy Whitcroft * Subtle, allocate a new region at the position but make it zero 11796822904SAndy Whitcroft * size such that we can guarantee to record the reservation. */ 11896822904SAndy Whitcroft if (&rg->link == head || t < rg->from) { 11996822904SAndy Whitcroft nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); 12096822904SAndy Whitcroft if (!nrg) 12196822904SAndy Whitcroft return -ENOMEM; 12296822904SAndy Whitcroft nrg->from = f; 12396822904SAndy Whitcroft nrg->to = f; 12496822904SAndy Whitcroft INIT_LIST_HEAD(&nrg->link); 12596822904SAndy Whitcroft list_add(&nrg->link, rg->link.prev); 12696822904SAndy Whitcroft 12796822904SAndy Whitcroft return t - f; 12896822904SAndy Whitcroft } 12996822904SAndy Whitcroft 13096822904SAndy Whitcroft /* Round our left edge to the current segment if it encloses us. */ 13196822904SAndy Whitcroft if (f > rg->from) 13296822904SAndy Whitcroft f = rg->from; 13396822904SAndy Whitcroft chg = t - f; 13496822904SAndy Whitcroft 13596822904SAndy Whitcroft /* Check for and consume any regions we now overlap with. */ 13696822904SAndy Whitcroft list_for_each_entry(rg, rg->link.prev, link) { 13796822904SAndy Whitcroft if (&rg->link == head) 13896822904SAndy Whitcroft break; 13996822904SAndy Whitcroft if (rg->from > t) 14096822904SAndy Whitcroft return chg; 14196822904SAndy Whitcroft 14296822904SAndy Whitcroft /* We overlap with this area, if it extends futher than 14396822904SAndy Whitcroft * us then we must extend ourselves. Account for its 14496822904SAndy Whitcroft * existing reservation. */ 14596822904SAndy Whitcroft if (rg->to > t) { 14696822904SAndy Whitcroft chg += rg->to - t; 14796822904SAndy Whitcroft t = rg->to; 14896822904SAndy Whitcroft } 14996822904SAndy Whitcroft chg -= rg->to - rg->from; 15096822904SAndy Whitcroft } 15196822904SAndy Whitcroft return chg; 15296822904SAndy Whitcroft } 15396822904SAndy Whitcroft 15496822904SAndy Whitcroft static long region_truncate(struct list_head *head, long end) 15596822904SAndy Whitcroft { 15696822904SAndy Whitcroft struct file_region *rg, *trg; 15796822904SAndy Whitcroft long chg = 0; 15896822904SAndy Whitcroft 15996822904SAndy Whitcroft /* Locate the region we are either in or before. */ 16096822904SAndy Whitcroft list_for_each_entry(rg, head, link) 16196822904SAndy Whitcroft if (end <= rg->to) 16296822904SAndy Whitcroft break; 16396822904SAndy Whitcroft if (&rg->link == head) 16496822904SAndy Whitcroft return 0; 16596822904SAndy Whitcroft 16696822904SAndy Whitcroft /* If we are in the middle of a region then adjust it. */ 16796822904SAndy Whitcroft if (end > rg->from) { 16896822904SAndy Whitcroft chg = rg->to - end; 16996822904SAndy Whitcroft rg->to = end; 17096822904SAndy Whitcroft rg = list_entry(rg->link.next, typeof(*rg), link); 17196822904SAndy Whitcroft } 17296822904SAndy Whitcroft 17396822904SAndy Whitcroft /* Drop any remaining regions. */ 17496822904SAndy Whitcroft list_for_each_entry_safe(rg, trg, rg->link.prev, link) { 17596822904SAndy Whitcroft if (&rg->link == head) 17696822904SAndy Whitcroft break; 17796822904SAndy Whitcroft chg += rg->to - rg->from; 17896822904SAndy Whitcroft list_del(&rg->link); 17996822904SAndy Whitcroft kfree(rg); 18096822904SAndy Whitcroft } 18196822904SAndy Whitcroft return chg; 18296822904SAndy Whitcroft } 18396822904SAndy Whitcroft 18484afd99bSAndy Whitcroft static long region_count(struct list_head *head, long f, long t) 18584afd99bSAndy Whitcroft { 18684afd99bSAndy Whitcroft struct file_region *rg; 18784afd99bSAndy Whitcroft long chg = 0; 18884afd99bSAndy Whitcroft 18984afd99bSAndy Whitcroft /* Locate each segment we overlap with, and count that overlap. */ 19084afd99bSAndy Whitcroft list_for_each_entry(rg, head, link) { 19184afd99bSAndy Whitcroft int seg_from; 19284afd99bSAndy Whitcroft int seg_to; 19384afd99bSAndy Whitcroft 19484afd99bSAndy Whitcroft if (rg->to <= f) 19584afd99bSAndy Whitcroft continue; 19684afd99bSAndy Whitcroft if (rg->from >= t) 19784afd99bSAndy Whitcroft break; 19884afd99bSAndy Whitcroft 19984afd99bSAndy Whitcroft seg_from = max(rg->from, f); 20084afd99bSAndy Whitcroft seg_to = min(rg->to, t); 20184afd99bSAndy Whitcroft 20284afd99bSAndy Whitcroft chg += seg_to - seg_from; 20384afd99bSAndy Whitcroft } 20484afd99bSAndy Whitcroft 20584afd99bSAndy Whitcroft return chg; 20684afd99bSAndy Whitcroft } 20784afd99bSAndy Whitcroft 20896822904SAndy Whitcroft /* 209e7c4b0bfSAndy Whitcroft * Convert the address within this vma to the page offset within 210e7c4b0bfSAndy Whitcroft * the mapping, in pagecache page units; huge pages here. 211e7c4b0bfSAndy Whitcroft */ 212a5516438SAndi Kleen static pgoff_t vma_hugecache_offset(struct hstate *h, 213a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 214e7c4b0bfSAndy Whitcroft { 215a5516438SAndi Kleen return ((address - vma->vm_start) >> huge_page_shift(h)) + 216a5516438SAndi Kleen (vma->vm_pgoff >> huge_page_order(h)); 217e7c4b0bfSAndy Whitcroft } 218e7c4b0bfSAndy Whitcroft 21984afd99bSAndy Whitcroft /* 22084afd99bSAndy Whitcroft * Flags for MAP_PRIVATE reservations. These are stored in the bottom 22184afd99bSAndy Whitcroft * bits of the reservation map pointer, which are always clear due to 22284afd99bSAndy Whitcroft * alignment. 22384afd99bSAndy Whitcroft */ 22484afd99bSAndy Whitcroft #define HPAGE_RESV_OWNER (1UL << 0) 22584afd99bSAndy Whitcroft #define HPAGE_RESV_UNMAPPED (1UL << 1) 22604f2cbe3SMel Gorman #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) 22784afd99bSAndy Whitcroft 228a1e78772SMel Gorman /* 229a1e78772SMel Gorman * These helpers are used to track how many pages are reserved for 230a1e78772SMel Gorman * faults in a MAP_PRIVATE mapping. Only the process that called mmap() 231a1e78772SMel Gorman * is guaranteed to have their future faults succeed. 232a1e78772SMel Gorman * 233a1e78772SMel Gorman * With the exception of reset_vma_resv_huge_pages() which is called at fork(), 234a1e78772SMel Gorman * the reserve counters are updated with the hugetlb_lock held. It is safe 235a1e78772SMel Gorman * to reset the VMA at fork() time as it is not in use yet and there is no 236a1e78772SMel Gorman * chance of the global counters getting corrupted as a result of the values. 23784afd99bSAndy Whitcroft * 23884afd99bSAndy Whitcroft * The private mapping reservation is represented in a subtly different 23984afd99bSAndy Whitcroft * manner to a shared mapping. A shared mapping has a region map associated 24084afd99bSAndy Whitcroft * with the underlying file, this region map represents the backing file 24184afd99bSAndy Whitcroft * pages which have ever had a reservation assigned which this persists even 24284afd99bSAndy Whitcroft * after the page is instantiated. A private mapping has a region map 24384afd99bSAndy Whitcroft * associated with the original mmap which is attached to all VMAs which 24484afd99bSAndy Whitcroft * reference it, this region map represents those offsets which have consumed 24584afd99bSAndy Whitcroft * reservation ie. where pages have been instantiated. 246a1e78772SMel Gorman */ 247e7c4b0bfSAndy Whitcroft static unsigned long get_vma_private_data(struct vm_area_struct *vma) 248e7c4b0bfSAndy Whitcroft { 249e7c4b0bfSAndy Whitcroft return (unsigned long)vma->vm_private_data; 250e7c4b0bfSAndy Whitcroft } 251e7c4b0bfSAndy Whitcroft 252e7c4b0bfSAndy Whitcroft static void set_vma_private_data(struct vm_area_struct *vma, 253e7c4b0bfSAndy Whitcroft unsigned long value) 254e7c4b0bfSAndy Whitcroft { 255e7c4b0bfSAndy Whitcroft vma->vm_private_data = (void *)value; 256e7c4b0bfSAndy Whitcroft } 257e7c4b0bfSAndy Whitcroft 25884afd99bSAndy Whitcroft struct resv_map { 25984afd99bSAndy Whitcroft struct kref refs; 26084afd99bSAndy Whitcroft struct list_head regions; 26184afd99bSAndy Whitcroft }; 26284afd99bSAndy Whitcroft 26384afd99bSAndy Whitcroft struct resv_map *resv_map_alloc(void) 26484afd99bSAndy Whitcroft { 26584afd99bSAndy Whitcroft struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); 26684afd99bSAndy Whitcroft if (!resv_map) 26784afd99bSAndy Whitcroft return NULL; 26884afd99bSAndy Whitcroft 26984afd99bSAndy Whitcroft kref_init(&resv_map->refs); 27084afd99bSAndy Whitcroft INIT_LIST_HEAD(&resv_map->regions); 27184afd99bSAndy Whitcroft 27284afd99bSAndy Whitcroft return resv_map; 27384afd99bSAndy Whitcroft } 27484afd99bSAndy Whitcroft 27584afd99bSAndy Whitcroft void resv_map_release(struct kref *ref) 27684afd99bSAndy Whitcroft { 27784afd99bSAndy Whitcroft struct resv_map *resv_map = container_of(ref, struct resv_map, refs); 27884afd99bSAndy Whitcroft 27984afd99bSAndy Whitcroft /* Clear out any active regions before we release the map. */ 28084afd99bSAndy Whitcroft region_truncate(&resv_map->regions, 0); 28184afd99bSAndy Whitcroft kfree(resv_map); 28284afd99bSAndy Whitcroft } 28384afd99bSAndy Whitcroft 28484afd99bSAndy Whitcroft static struct resv_map *vma_resv_map(struct vm_area_struct *vma) 285a1e78772SMel Gorman { 286a1e78772SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 287a1e78772SMel Gorman if (!(vma->vm_flags & VM_SHARED)) 28884afd99bSAndy Whitcroft return (struct resv_map *)(get_vma_private_data(vma) & 28984afd99bSAndy Whitcroft ~HPAGE_RESV_MASK); 290a1e78772SMel Gorman return 0; 291a1e78772SMel Gorman } 292a1e78772SMel Gorman 29384afd99bSAndy Whitcroft static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) 294a1e78772SMel Gorman { 295a1e78772SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 296a1e78772SMel Gorman VM_BUG_ON(vma->vm_flags & VM_SHARED); 297a1e78772SMel Gorman 29884afd99bSAndy Whitcroft set_vma_private_data(vma, (get_vma_private_data(vma) & 29984afd99bSAndy Whitcroft HPAGE_RESV_MASK) | (unsigned long)map); 30004f2cbe3SMel Gorman } 30104f2cbe3SMel Gorman 30204f2cbe3SMel Gorman static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) 30304f2cbe3SMel Gorman { 30404f2cbe3SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 305e7c4b0bfSAndy Whitcroft VM_BUG_ON(vma->vm_flags & VM_SHARED); 306e7c4b0bfSAndy Whitcroft 307e7c4b0bfSAndy Whitcroft set_vma_private_data(vma, get_vma_private_data(vma) | flags); 30804f2cbe3SMel Gorman } 30904f2cbe3SMel Gorman 31004f2cbe3SMel Gorman static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) 31104f2cbe3SMel Gorman { 31204f2cbe3SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 313e7c4b0bfSAndy Whitcroft 314e7c4b0bfSAndy Whitcroft return (get_vma_private_data(vma) & flag) != 0; 315a1e78772SMel Gorman } 316a1e78772SMel Gorman 317a1e78772SMel Gorman /* Decrement the reserved pages in the hugepage pool by one */ 318a5516438SAndi Kleen static void decrement_hugepage_resv_vma(struct hstate *h, 319a5516438SAndi Kleen struct vm_area_struct *vma) 320a1e78772SMel Gorman { 321c37f9fb1SAndy Whitcroft if (vma->vm_flags & VM_NORESERVE) 322c37f9fb1SAndy Whitcroft return; 323c37f9fb1SAndy Whitcroft 324a1e78772SMel Gorman if (vma->vm_flags & VM_SHARED) { 325a1e78772SMel Gorman /* Shared mappings always use reserves */ 326a5516438SAndi Kleen h->resv_huge_pages--; 32784afd99bSAndy Whitcroft } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 328a1e78772SMel Gorman /* 329a1e78772SMel Gorman * Only the process that called mmap() has reserves for 330a1e78772SMel Gorman * private mappings. 331a1e78772SMel Gorman */ 332a5516438SAndi Kleen h->resv_huge_pages--; 333a1e78772SMel Gorman } 334a1e78772SMel Gorman } 335a1e78772SMel Gorman 33604f2cbe3SMel Gorman /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ 337a1e78772SMel Gorman void reset_vma_resv_huge_pages(struct vm_area_struct *vma) 338a1e78772SMel Gorman { 339a1e78772SMel Gorman VM_BUG_ON(!is_vm_hugetlb_page(vma)); 340a1e78772SMel Gorman if (!(vma->vm_flags & VM_SHARED)) 341a1e78772SMel Gorman vma->vm_private_data = (void *)0; 342a1e78772SMel Gorman } 343a1e78772SMel Gorman 344a1e78772SMel Gorman /* Returns true if the VMA has associated reserve pages */ 345a1e78772SMel Gorman static int vma_has_private_reserves(struct vm_area_struct *vma) 346a1e78772SMel Gorman { 347a1e78772SMel Gorman if (vma->vm_flags & VM_SHARED) 348a1e78772SMel Gorman return 0; 34984afd99bSAndy Whitcroft if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) 350a1e78772SMel Gorman return 0; 351a1e78772SMel Gorman return 1; 352a1e78772SMel Gorman } 353a1e78772SMel Gorman 354a5516438SAndi Kleen static void clear_huge_page(struct page *page, 355a5516438SAndi Kleen unsigned long addr, unsigned long sz) 35679ac6ba4SDavid Gibson { 35779ac6ba4SDavid Gibson int i; 35879ac6ba4SDavid Gibson 35979ac6ba4SDavid Gibson might_sleep(); 360a5516438SAndi Kleen for (i = 0; i < sz/PAGE_SIZE; i++) { 36179ac6ba4SDavid Gibson cond_resched(); 362281e0e3bSRalf Baechle clear_user_highpage(page + i, addr + i * PAGE_SIZE); 36379ac6ba4SDavid Gibson } 36479ac6ba4SDavid Gibson } 36579ac6ba4SDavid Gibson 36679ac6ba4SDavid Gibson static void copy_huge_page(struct page *dst, struct page *src, 3679de455b2SAtsushi Nemoto unsigned long addr, struct vm_area_struct *vma) 36879ac6ba4SDavid Gibson { 36979ac6ba4SDavid Gibson int i; 370a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 37179ac6ba4SDavid Gibson 37279ac6ba4SDavid Gibson might_sleep(); 373a5516438SAndi Kleen for (i = 0; i < pages_per_huge_page(h); i++) { 37479ac6ba4SDavid Gibson cond_resched(); 3759de455b2SAtsushi Nemoto copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); 37679ac6ba4SDavid Gibson } 37779ac6ba4SDavid Gibson } 37879ac6ba4SDavid Gibson 379a5516438SAndi Kleen static void enqueue_huge_page(struct hstate *h, struct page *page) 3801da177e4SLinus Torvalds { 3811da177e4SLinus Torvalds int nid = page_to_nid(page); 382a5516438SAndi Kleen list_add(&page->lru, &h->hugepage_freelists[nid]); 383a5516438SAndi Kleen h->free_huge_pages++; 384a5516438SAndi Kleen h->free_huge_pages_node[nid]++; 3851da177e4SLinus Torvalds } 3861da177e4SLinus Torvalds 387a5516438SAndi Kleen static struct page *dequeue_huge_page(struct hstate *h) 388348e1e04SNishanth Aravamudan { 389348e1e04SNishanth Aravamudan int nid; 390348e1e04SNishanth Aravamudan struct page *page = NULL; 391348e1e04SNishanth Aravamudan 392348e1e04SNishanth Aravamudan for (nid = 0; nid < MAX_NUMNODES; ++nid) { 393a5516438SAndi Kleen if (!list_empty(&h->hugepage_freelists[nid])) { 394a5516438SAndi Kleen page = list_entry(h->hugepage_freelists[nid].next, 395348e1e04SNishanth Aravamudan struct page, lru); 396348e1e04SNishanth Aravamudan list_del(&page->lru); 397a5516438SAndi Kleen h->free_huge_pages--; 398a5516438SAndi Kleen h->free_huge_pages_node[nid]--; 399348e1e04SNishanth Aravamudan break; 400348e1e04SNishanth Aravamudan } 401348e1e04SNishanth Aravamudan } 402348e1e04SNishanth Aravamudan return page; 403348e1e04SNishanth Aravamudan } 404348e1e04SNishanth Aravamudan 405a5516438SAndi Kleen static struct page *dequeue_huge_page_vma(struct hstate *h, 406a5516438SAndi Kleen struct vm_area_struct *vma, 40704f2cbe3SMel Gorman unsigned long address, int avoid_reserve) 4081da177e4SLinus Torvalds { 40931a5c6e4SNishanth Aravamudan int nid; 4101da177e4SLinus Torvalds struct page *page = NULL; 411480eccf9SLee Schermerhorn struct mempolicy *mpol; 41219770b32SMel Gorman nodemask_t *nodemask; 413396faf03SMel Gorman struct zonelist *zonelist = huge_zonelist(vma, address, 41419770b32SMel Gorman htlb_alloc_mask, &mpol, &nodemask); 415dd1a239fSMel Gorman struct zone *zone; 416dd1a239fSMel Gorman struct zoneref *z; 4171da177e4SLinus Torvalds 418a1e78772SMel Gorman /* 419a1e78772SMel Gorman * A child process with MAP_PRIVATE mappings created by their parent 420a1e78772SMel Gorman * have no page reserves. This check ensures that reservations are 421a1e78772SMel Gorman * not "stolen". The child may still get SIGKILLed 422a1e78772SMel Gorman */ 423a1e78772SMel Gorman if (!vma_has_private_reserves(vma) && 424a5516438SAndi Kleen h->free_huge_pages - h->resv_huge_pages == 0) 425a1e78772SMel Gorman return NULL; 426a1e78772SMel Gorman 42704f2cbe3SMel Gorman /* If reserves cannot be used, ensure enough pages are in the pool */ 428a5516438SAndi Kleen if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) 42904f2cbe3SMel Gorman return NULL; 43004f2cbe3SMel Gorman 43119770b32SMel Gorman for_each_zone_zonelist_nodemask(zone, z, zonelist, 43219770b32SMel Gorman MAX_NR_ZONES - 1, nodemask) { 43354a6eb5cSMel Gorman nid = zone_to_nid(zone); 43454a6eb5cSMel Gorman if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && 435a5516438SAndi Kleen !list_empty(&h->hugepage_freelists[nid])) { 436a5516438SAndi Kleen page = list_entry(h->hugepage_freelists[nid].next, 4371da177e4SLinus Torvalds struct page, lru); 4381da177e4SLinus Torvalds list_del(&page->lru); 439a5516438SAndi Kleen h->free_huge_pages--; 440a5516438SAndi Kleen h->free_huge_pages_node[nid]--; 44104f2cbe3SMel Gorman 44204f2cbe3SMel Gorman if (!avoid_reserve) 443a5516438SAndi Kleen decrement_hugepage_resv_vma(h, vma); 444a1e78772SMel Gorman 4455ab3ee7bSKen Chen break; 4461da177e4SLinus Torvalds } 4473abf7afdSAndrew Morton } 44852cd3b07SLee Schermerhorn mpol_cond_put(mpol); 4491da177e4SLinus Torvalds return page; 4501da177e4SLinus Torvalds } 4511da177e4SLinus Torvalds 452a5516438SAndi Kleen static void update_and_free_page(struct hstate *h, struct page *page) 4536af2acb6SAdam Litke { 4546af2acb6SAdam Litke int i; 455a5516438SAndi Kleen 456a5516438SAndi Kleen h->nr_huge_pages--; 457a5516438SAndi Kleen h->nr_huge_pages_node[page_to_nid(page)]--; 458a5516438SAndi Kleen for (i = 0; i < pages_per_huge_page(h); i++) { 4596af2acb6SAdam Litke page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | 4606af2acb6SAdam Litke 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | 4616af2acb6SAdam Litke 1 << PG_private | 1<< PG_writeback); 4626af2acb6SAdam Litke } 4636af2acb6SAdam Litke set_compound_page_dtor(page, NULL); 4646af2acb6SAdam Litke set_page_refcounted(page); 4657f2e9525SGerald Schaefer arch_release_hugepage(page); 466a5516438SAndi Kleen __free_pages(page, huge_page_order(h)); 4676af2acb6SAdam Litke } 4686af2acb6SAdam Litke 469e5ff2159SAndi Kleen struct hstate *size_to_hstate(unsigned long size) 470e5ff2159SAndi Kleen { 471e5ff2159SAndi Kleen struct hstate *h; 472e5ff2159SAndi Kleen 473e5ff2159SAndi Kleen for_each_hstate(h) { 474e5ff2159SAndi Kleen if (huge_page_size(h) == size) 475e5ff2159SAndi Kleen return h; 476e5ff2159SAndi Kleen } 477e5ff2159SAndi Kleen return NULL; 478e5ff2159SAndi Kleen } 479e5ff2159SAndi Kleen 48027a85ef1SDavid Gibson static void free_huge_page(struct page *page) 48127a85ef1SDavid Gibson { 482a5516438SAndi Kleen /* 483a5516438SAndi Kleen * Can't pass hstate in here because it is called from the 484a5516438SAndi Kleen * compound page destructor. 485a5516438SAndi Kleen */ 486e5ff2159SAndi Kleen struct hstate *h = page_hstate(page); 4877893d1d5SAdam Litke int nid = page_to_nid(page); 488c79fb75eSAdam Litke struct address_space *mapping; 48927a85ef1SDavid Gibson 490c79fb75eSAdam Litke mapping = (struct address_space *) page_private(page); 491e5df70abSAndy Whitcroft set_page_private(page, 0); 4927893d1d5SAdam Litke BUG_ON(page_count(page)); 49327a85ef1SDavid Gibson INIT_LIST_HEAD(&page->lru); 49427a85ef1SDavid Gibson 49527a85ef1SDavid Gibson spin_lock(&hugetlb_lock); 496aa888a74SAndi Kleen if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) { 497a5516438SAndi Kleen update_and_free_page(h, page); 498a5516438SAndi Kleen h->surplus_huge_pages--; 499a5516438SAndi Kleen h->surplus_huge_pages_node[nid]--; 5007893d1d5SAdam Litke } else { 501a5516438SAndi Kleen enqueue_huge_page(h, page); 5027893d1d5SAdam Litke } 50327a85ef1SDavid Gibson spin_unlock(&hugetlb_lock); 504c79fb75eSAdam Litke if (mapping) 5059a119c05SAdam Litke hugetlb_put_quota(mapping, 1); 50627a85ef1SDavid Gibson } 50727a85ef1SDavid Gibson 5087893d1d5SAdam Litke /* 5097893d1d5SAdam Litke * Increment or decrement surplus_huge_pages. Keep node-specific counters 5107893d1d5SAdam Litke * balanced by operating on them in a round-robin fashion. 5117893d1d5SAdam Litke * Returns 1 if an adjustment was made. 5127893d1d5SAdam Litke */ 513a5516438SAndi Kleen static int adjust_pool_surplus(struct hstate *h, int delta) 5147893d1d5SAdam Litke { 5157893d1d5SAdam Litke static int prev_nid; 5167893d1d5SAdam Litke int nid = prev_nid; 5177893d1d5SAdam Litke int ret = 0; 5187893d1d5SAdam Litke 5197893d1d5SAdam Litke VM_BUG_ON(delta != -1 && delta != 1); 5207893d1d5SAdam Litke do { 5217893d1d5SAdam Litke nid = next_node(nid, node_online_map); 5227893d1d5SAdam Litke if (nid == MAX_NUMNODES) 5237893d1d5SAdam Litke nid = first_node(node_online_map); 5247893d1d5SAdam Litke 5257893d1d5SAdam Litke /* To shrink on this node, there must be a surplus page */ 526a5516438SAndi Kleen if (delta < 0 && !h->surplus_huge_pages_node[nid]) 5277893d1d5SAdam Litke continue; 5287893d1d5SAdam Litke /* Surplus cannot exceed the total number of pages */ 529a5516438SAndi Kleen if (delta > 0 && h->surplus_huge_pages_node[nid] >= 530a5516438SAndi Kleen h->nr_huge_pages_node[nid]) 5317893d1d5SAdam Litke continue; 5327893d1d5SAdam Litke 533a5516438SAndi Kleen h->surplus_huge_pages += delta; 534a5516438SAndi Kleen h->surplus_huge_pages_node[nid] += delta; 5357893d1d5SAdam Litke ret = 1; 5367893d1d5SAdam Litke break; 5377893d1d5SAdam Litke } while (nid != prev_nid); 5387893d1d5SAdam Litke 5397893d1d5SAdam Litke prev_nid = nid; 5407893d1d5SAdam Litke return ret; 5417893d1d5SAdam Litke } 5427893d1d5SAdam Litke 543a5516438SAndi Kleen static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) 544b7ba30c6SAndi Kleen { 545b7ba30c6SAndi Kleen set_compound_page_dtor(page, free_huge_page); 546b7ba30c6SAndi Kleen spin_lock(&hugetlb_lock); 547a5516438SAndi Kleen h->nr_huge_pages++; 548a5516438SAndi Kleen h->nr_huge_pages_node[nid]++; 549b7ba30c6SAndi Kleen spin_unlock(&hugetlb_lock); 550b7ba30c6SAndi Kleen put_page(page); /* free it into the hugepage allocator */ 551b7ba30c6SAndi Kleen } 552b7ba30c6SAndi Kleen 553a5516438SAndi Kleen static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) 5541da177e4SLinus Torvalds { 5551da177e4SLinus Torvalds struct page *page; 556f96efd58SJoe Jin 557aa888a74SAndi Kleen if (h->order >= MAX_ORDER) 558aa888a74SAndi Kleen return NULL; 559aa888a74SAndi Kleen 56063b4613cSNishanth Aravamudan page = alloc_pages_node(nid, 561551883aeSNishanth Aravamudan htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| 562551883aeSNishanth Aravamudan __GFP_REPEAT|__GFP_NOWARN, 563a5516438SAndi Kleen huge_page_order(h)); 5641da177e4SLinus Torvalds if (page) { 5657f2e9525SGerald Schaefer if (arch_prepare_hugepage(page)) { 5667f2e9525SGerald Schaefer __free_pages(page, HUGETLB_PAGE_ORDER); 5677b8ee84dSHarvey Harrison return NULL; 5687f2e9525SGerald Schaefer } 569a5516438SAndi Kleen prep_new_huge_page(h, page, nid); 5701da177e4SLinus Torvalds } 57163b4613cSNishanth Aravamudan 57263b4613cSNishanth Aravamudan return page; 57363b4613cSNishanth Aravamudan } 57463b4613cSNishanth Aravamudan 5755ced66c9SAndi Kleen /* 5765ced66c9SAndi Kleen * Use a helper variable to find the next node and then 5775ced66c9SAndi Kleen * copy it back to hugetlb_next_nid afterwards: 5785ced66c9SAndi Kleen * otherwise there's a window in which a racer might 5795ced66c9SAndi Kleen * pass invalid nid MAX_NUMNODES to alloc_pages_node. 5805ced66c9SAndi Kleen * But we don't need to use a spin_lock here: it really 5815ced66c9SAndi Kleen * doesn't matter if occasionally a racer chooses the 5825ced66c9SAndi Kleen * same nid as we do. Move nid forward in the mask even 5835ced66c9SAndi Kleen * if we just successfully allocated a hugepage so that 5845ced66c9SAndi Kleen * the next caller gets hugepages on the next node. 5855ced66c9SAndi Kleen */ 5865ced66c9SAndi Kleen static int hstate_next_node(struct hstate *h) 5875ced66c9SAndi Kleen { 5885ced66c9SAndi Kleen int next_nid; 5895ced66c9SAndi Kleen next_nid = next_node(h->hugetlb_next_nid, node_online_map); 5905ced66c9SAndi Kleen if (next_nid == MAX_NUMNODES) 5915ced66c9SAndi Kleen next_nid = first_node(node_online_map); 5925ced66c9SAndi Kleen h->hugetlb_next_nid = next_nid; 5935ced66c9SAndi Kleen return next_nid; 5945ced66c9SAndi Kleen } 5955ced66c9SAndi Kleen 596a5516438SAndi Kleen static int alloc_fresh_huge_page(struct hstate *h) 59763b4613cSNishanth Aravamudan { 59863b4613cSNishanth Aravamudan struct page *page; 59963b4613cSNishanth Aravamudan int start_nid; 60063b4613cSNishanth Aravamudan int next_nid; 60163b4613cSNishanth Aravamudan int ret = 0; 60263b4613cSNishanth Aravamudan 603a5516438SAndi Kleen start_nid = h->hugetlb_next_nid; 60463b4613cSNishanth Aravamudan 60563b4613cSNishanth Aravamudan do { 606a5516438SAndi Kleen page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid); 60763b4613cSNishanth Aravamudan if (page) 60863b4613cSNishanth Aravamudan ret = 1; 6095ced66c9SAndi Kleen next_nid = hstate_next_node(h); 610a5516438SAndi Kleen } while (!page && h->hugetlb_next_nid != start_nid); 61163b4613cSNishanth Aravamudan 6123b116300SAdam Litke if (ret) 6133b116300SAdam Litke count_vm_event(HTLB_BUDDY_PGALLOC); 6143b116300SAdam Litke else 6153b116300SAdam Litke count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 6163b116300SAdam Litke 61763b4613cSNishanth Aravamudan return ret; 6181da177e4SLinus Torvalds } 6191da177e4SLinus Torvalds 620a5516438SAndi Kleen static struct page *alloc_buddy_huge_page(struct hstate *h, 621a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 6227893d1d5SAdam Litke { 6237893d1d5SAdam Litke struct page *page; 624d1c3fb1fSNishanth Aravamudan unsigned int nid; 6257893d1d5SAdam Litke 626aa888a74SAndi Kleen if (h->order >= MAX_ORDER) 627aa888a74SAndi Kleen return NULL; 628aa888a74SAndi Kleen 629d1c3fb1fSNishanth Aravamudan /* 630d1c3fb1fSNishanth Aravamudan * Assume we will successfully allocate the surplus page to 631d1c3fb1fSNishanth Aravamudan * prevent racing processes from causing the surplus to exceed 632d1c3fb1fSNishanth Aravamudan * overcommit 633d1c3fb1fSNishanth Aravamudan * 634d1c3fb1fSNishanth Aravamudan * This however introduces a different race, where a process B 635d1c3fb1fSNishanth Aravamudan * tries to grow the static hugepage pool while alloc_pages() is 636d1c3fb1fSNishanth Aravamudan * called by process A. B will only examine the per-node 637d1c3fb1fSNishanth Aravamudan * counters in determining if surplus huge pages can be 638d1c3fb1fSNishanth Aravamudan * converted to normal huge pages in adjust_pool_surplus(). A 639d1c3fb1fSNishanth Aravamudan * won't be able to increment the per-node counter, until the 640d1c3fb1fSNishanth Aravamudan * lock is dropped by B, but B doesn't drop hugetlb_lock until 641d1c3fb1fSNishanth Aravamudan * no more huge pages can be converted from surplus to normal 642d1c3fb1fSNishanth Aravamudan * state (and doesn't try to convert again). Thus, we have a 643d1c3fb1fSNishanth Aravamudan * case where a surplus huge page exists, the pool is grown, and 644d1c3fb1fSNishanth Aravamudan * the surplus huge page still exists after, even though it 645d1c3fb1fSNishanth Aravamudan * should just have been converted to a normal huge page. This 646d1c3fb1fSNishanth Aravamudan * does not leak memory, though, as the hugepage will be freed 647d1c3fb1fSNishanth Aravamudan * once it is out of use. It also does not allow the counters to 648d1c3fb1fSNishanth Aravamudan * go out of whack in adjust_pool_surplus() as we don't modify 649d1c3fb1fSNishanth Aravamudan * the node values until we've gotten the hugepage and only the 650d1c3fb1fSNishanth Aravamudan * per-node value is checked there. 651d1c3fb1fSNishanth Aravamudan */ 652d1c3fb1fSNishanth Aravamudan spin_lock(&hugetlb_lock); 653a5516438SAndi Kleen if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { 654d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 655d1c3fb1fSNishanth Aravamudan return NULL; 656d1c3fb1fSNishanth Aravamudan } else { 657a5516438SAndi Kleen h->nr_huge_pages++; 658a5516438SAndi Kleen h->surplus_huge_pages++; 659d1c3fb1fSNishanth Aravamudan } 660d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 661d1c3fb1fSNishanth Aravamudan 662551883aeSNishanth Aravamudan page = alloc_pages(htlb_alloc_mask|__GFP_COMP| 663551883aeSNishanth Aravamudan __GFP_REPEAT|__GFP_NOWARN, 664a5516438SAndi Kleen huge_page_order(h)); 665d1c3fb1fSNishanth Aravamudan 6667893d1d5SAdam Litke spin_lock(&hugetlb_lock); 667d1c3fb1fSNishanth Aravamudan if (page) { 6682668db91SAdam Litke /* 6692668db91SAdam Litke * This page is now managed by the hugetlb allocator and has 6702668db91SAdam Litke * no users -- drop the buddy allocator's reference. 6712668db91SAdam Litke */ 6722668db91SAdam Litke put_page_testzero(page); 6732668db91SAdam Litke VM_BUG_ON(page_count(page)); 674d1c3fb1fSNishanth Aravamudan nid = page_to_nid(page); 675d1c3fb1fSNishanth Aravamudan set_compound_page_dtor(page, free_huge_page); 676d1c3fb1fSNishanth Aravamudan /* 677d1c3fb1fSNishanth Aravamudan * We incremented the global counters already 678d1c3fb1fSNishanth Aravamudan */ 679a5516438SAndi Kleen h->nr_huge_pages_node[nid]++; 680a5516438SAndi Kleen h->surplus_huge_pages_node[nid]++; 6813b116300SAdam Litke __count_vm_event(HTLB_BUDDY_PGALLOC); 682d1c3fb1fSNishanth Aravamudan } else { 683a5516438SAndi Kleen h->nr_huge_pages--; 684a5516438SAndi Kleen h->surplus_huge_pages--; 6853b116300SAdam Litke __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); 6867893d1d5SAdam Litke } 687d1c3fb1fSNishanth Aravamudan spin_unlock(&hugetlb_lock); 6887893d1d5SAdam Litke 6897893d1d5SAdam Litke return page; 6907893d1d5SAdam Litke } 6917893d1d5SAdam Litke 692e4e574b7SAdam Litke /* 693e4e574b7SAdam Litke * Increase the hugetlb pool such that it can accomodate a reservation 694e4e574b7SAdam Litke * of size 'delta'. 695e4e574b7SAdam Litke */ 696a5516438SAndi Kleen static int gather_surplus_pages(struct hstate *h, int delta) 697e4e574b7SAdam Litke { 698e4e574b7SAdam Litke struct list_head surplus_list; 699e4e574b7SAdam Litke struct page *page, *tmp; 700e4e574b7SAdam Litke int ret, i; 701e4e574b7SAdam Litke int needed, allocated; 702e4e574b7SAdam Litke 703a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - h->free_huge_pages; 704ac09b3a1SAdam Litke if (needed <= 0) { 705a5516438SAndi Kleen h->resv_huge_pages += delta; 706e4e574b7SAdam Litke return 0; 707ac09b3a1SAdam Litke } 708e4e574b7SAdam Litke 709e4e574b7SAdam Litke allocated = 0; 710e4e574b7SAdam Litke INIT_LIST_HEAD(&surplus_list); 711e4e574b7SAdam Litke 712e4e574b7SAdam Litke ret = -ENOMEM; 713e4e574b7SAdam Litke retry: 714e4e574b7SAdam Litke spin_unlock(&hugetlb_lock); 715e4e574b7SAdam Litke for (i = 0; i < needed; i++) { 716a5516438SAndi Kleen page = alloc_buddy_huge_page(h, NULL, 0); 717e4e574b7SAdam Litke if (!page) { 718e4e574b7SAdam Litke /* 719e4e574b7SAdam Litke * We were not able to allocate enough pages to 720e4e574b7SAdam Litke * satisfy the entire reservation so we free what 721e4e574b7SAdam Litke * we've allocated so far. 722e4e574b7SAdam Litke */ 723e4e574b7SAdam Litke spin_lock(&hugetlb_lock); 724e4e574b7SAdam Litke needed = 0; 725e4e574b7SAdam Litke goto free; 726e4e574b7SAdam Litke } 727e4e574b7SAdam Litke 728e4e574b7SAdam Litke list_add(&page->lru, &surplus_list); 729e4e574b7SAdam Litke } 730e4e574b7SAdam Litke allocated += needed; 731e4e574b7SAdam Litke 732e4e574b7SAdam Litke /* 733e4e574b7SAdam Litke * After retaking hugetlb_lock, we need to recalculate 'needed' 734e4e574b7SAdam Litke * because either resv_huge_pages or free_huge_pages may have changed. 735e4e574b7SAdam Litke */ 736e4e574b7SAdam Litke spin_lock(&hugetlb_lock); 737a5516438SAndi Kleen needed = (h->resv_huge_pages + delta) - 738a5516438SAndi Kleen (h->free_huge_pages + allocated); 739e4e574b7SAdam Litke if (needed > 0) 740e4e574b7SAdam Litke goto retry; 741e4e574b7SAdam Litke 742e4e574b7SAdam Litke /* 743e4e574b7SAdam Litke * The surplus_list now contains _at_least_ the number of extra pages 744e4e574b7SAdam Litke * needed to accomodate the reservation. Add the appropriate number 745e4e574b7SAdam Litke * of pages to the hugetlb pool and free the extras back to the buddy 746ac09b3a1SAdam Litke * allocator. Commit the entire reservation here to prevent another 747ac09b3a1SAdam Litke * process from stealing the pages as they are added to the pool but 748ac09b3a1SAdam Litke * before they are reserved. 749e4e574b7SAdam Litke */ 750e4e574b7SAdam Litke needed += allocated; 751a5516438SAndi Kleen h->resv_huge_pages += delta; 752e4e574b7SAdam Litke ret = 0; 753e4e574b7SAdam Litke free: 75419fc3f0aSAdam Litke /* Free the needed pages to the hugetlb pool */ 75519fc3f0aSAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 75619fc3f0aSAdam Litke if ((--needed) < 0) 75719fc3f0aSAdam Litke break; 75819fc3f0aSAdam Litke list_del(&page->lru); 759a5516438SAndi Kleen enqueue_huge_page(h, page); 76019fc3f0aSAdam Litke } 76119fc3f0aSAdam Litke 76219fc3f0aSAdam Litke /* Free unnecessary surplus pages to the buddy allocator */ 76319fc3f0aSAdam Litke if (!list_empty(&surplus_list)) { 76419fc3f0aSAdam Litke spin_unlock(&hugetlb_lock); 765e4e574b7SAdam Litke list_for_each_entry_safe(page, tmp, &surplus_list, lru) { 766e4e574b7SAdam Litke list_del(&page->lru); 767af767cbdSAdam Litke /* 7682668db91SAdam Litke * The page has a reference count of zero already, so 7692668db91SAdam Litke * call free_huge_page directly instead of using 7702668db91SAdam Litke * put_page. This must be done with hugetlb_lock 771af767cbdSAdam Litke * unlocked which is safe because free_huge_page takes 772af767cbdSAdam Litke * hugetlb_lock before deciding how to free the page. 773af767cbdSAdam Litke */ 7742668db91SAdam Litke free_huge_page(page); 775af767cbdSAdam Litke } 77619fc3f0aSAdam Litke spin_lock(&hugetlb_lock); 777e4e574b7SAdam Litke } 778e4e574b7SAdam Litke 779e4e574b7SAdam Litke return ret; 780e4e574b7SAdam Litke } 781e4e574b7SAdam Litke 782e4e574b7SAdam Litke /* 783e4e574b7SAdam Litke * When releasing a hugetlb pool reservation, any surplus pages that were 784e4e574b7SAdam Litke * allocated to satisfy the reservation must be explicitly freed if they were 785e4e574b7SAdam Litke * never used. 786e4e574b7SAdam Litke */ 787a5516438SAndi Kleen static void return_unused_surplus_pages(struct hstate *h, 788a5516438SAndi Kleen unsigned long unused_resv_pages) 789e4e574b7SAdam Litke { 790e4e574b7SAdam Litke static int nid = -1; 791e4e574b7SAdam Litke struct page *page; 792e4e574b7SAdam Litke unsigned long nr_pages; 793e4e574b7SAdam Litke 79411320d17SNishanth Aravamudan /* 79511320d17SNishanth Aravamudan * We want to release as many surplus pages as possible, spread 79611320d17SNishanth Aravamudan * evenly across all nodes. Iterate across all nodes until we 79711320d17SNishanth Aravamudan * can no longer free unreserved surplus pages. This occurs when 79811320d17SNishanth Aravamudan * the nodes with surplus pages have no free pages. 79911320d17SNishanth Aravamudan */ 80011320d17SNishanth Aravamudan unsigned long remaining_iterations = num_online_nodes(); 80111320d17SNishanth Aravamudan 802ac09b3a1SAdam Litke /* Uncommit the reservation */ 803a5516438SAndi Kleen h->resv_huge_pages -= unused_resv_pages; 804ac09b3a1SAdam Litke 805aa888a74SAndi Kleen /* Cannot return gigantic pages currently */ 806aa888a74SAndi Kleen if (h->order >= MAX_ORDER) 807aa888a74SAndi Kleen return; 808aa888a74SAndi Kleen 809a5516438SAndi Kleen nr_pages = min(unused_resv_pages, h->surplus_huge_pages); 810e4e574b7SAdam Litke 81111320d17SNishanth Aravamudan while (remaining_iterations-- && nr_pages) { 812e4e574b7SAdam Litke nid = next_node(nid, node_online_map); 813e4e574b7SAdam Litke if (nid == MAX_NUMNODES) 814e4e574b7SAdam Litke nid = first_node(node_online_map); 815e4e574b7SAdam Litke 816a5516438SAndi Kleen if (!h->surplus_huge_pages_node[nid]) 817e4e574b7SAdam Litke continue; 818e4e574b7SAdam Litke 819a5516438SAndi Kleen if (!list_empty(&h->hugepage_freelists[nid])) { 820a5516438SAndi Kleen page = list_entry(h->hugepage_freelists[nid].next, 821e4e574b7SAdam Litke struct page, lru); 822e4e574b7SAdam Litke list_del(&page->lru); 823a5516438SAndi Kleen update_and_free_page(h, page); 824a5516438SAndi Kleen h->free_huge_pages--; 825a5516438SAndi Kleen h->free_huge_pages_node[nid]--; 826a5516438SAndi Kleen h->surplus_huge_pages--; 827a5516438SAndi Kleen h->surplus_huge_pages_node[nid]--; 828e4e574b7SAdam Litke nr_pages--; 82911320d17SNishanth Aravamudan remaining_iterations = num_online_nodes(); 830e4e574b7SAdam Litke } 831e4e574b7SAdam Litke } 832e4e574b7SAdam Litke } 833e4e574b7SAdam Litke 834c37f9fb1SAndy Whitcroft /* 835c37f9fb1SAndy Whitcroft * Determine if the huge page at addr within the vma has an associated 836c37f9fb1SAndy Whitcroft * reservation. Where it does not we will need to logically increase 837c37f9fb1SAndy Whitcroft * reservation and actually increase quota before an allocation can occur. 838c37f9fb1SAndy Whitcroft * Where any new reservation would be required the reservation change is 839c37f9fb1SAndy Whitcroft * prepared, but not committed. Once the page has been quota'd allocated 840c37f9fb1SAndy Whitcroft * an instantiated the change should be committed via vma_commit_reservation. 841c37f9fb1SAndy Whitcroft * No action is required on failure. 842c37f9fb1SAndy Whitcroft */ 843a5516438SAndi Kleen static int vma_needs_reservation(struct hstate *h, 844a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 845c37f9fb1SAndy Whitcroft { 846c37f9fb1SAndy Whitcroft struct address_space *mapping = vma->vm_file->f_mapping; 847c37f9fb1SAndy Whitcroft struct inode *inode = mapping->host; 848c37f9fb1SAndy Whitcroft 849c37f9fb1SAndy Whitcroft if (vma->vm_flags & VM_SHARED) { 850a5516438SAndi Kleen pgoff_t idx = vma_hugecache_offset(h, vma, addr); 851c37f9fb1SAndy Whitcroft return region_chg(&inode->i_mapping->private_list, 852c37f9fb1SAndy Whitcroft idx, idx + 1); 853c37f9fb1SAndy Whitcroft 85484afd99bSAndy Whitcroft } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 855c37f9fb1SAndy Whitcroft return 1; 856c37f9fb1SAndy Whitcroft 85784afd99bSAndy Whitcroft } else { 85884afd99bSAndy Whitcroft int err; 859a5516438SAndi Kleen pgoff_t idx = vma_hugecache_offset(h, vma, addr); 86084afd99bSAndy Whitcroft struct resv_map *reservations = vma_resv_map(vma); 86184afd99bSAndy Whitcroft 86284afd99bSAndy Whitcroft err = region_chg(&reservations->regions, idx, idx + 1); 86384afd99bSAndy Whitcroft if (err < 0) 86484afd99bSAndy Whitcroft return err; 865c37f9fb1SAndy Whitcroft return 0; 866c37f9fb1SAndy Whitcroft } 86784afd99bSAndy Whitcroft } 868a5516438SAndi Kleen static void vma_commit_reservation(struct hstate *h, 869a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long addr) 870c37f9fb1SAndy Whitcroft { 871c37f9fb1SAndy Whitcroft struct address_space *mapping = vma->vm_file->f_mapping; 872c37f9fb1SAndy Whitcroft struct inode *inode = mapping->host; 873c37f9fb1SAndy Whitcroft 874c37f9fb1SAndy Whitcroft if (vma->vm_flags & VM_SHARED) { 875a5516438SAndi Kleen pgoff_t idx = vma_hugecache_offset(h, vma, addr); 876c37f9fb1SAndy Whitcroft region_add(&inode->i_mapping->private_list, idx, idx + 1); 87784afd99bSAndy Whitcroft 87884afd99bSAndy Whitcroft } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { 879a5516438SAndi Kleen pgoff_t idx = vma_hugecache_offset(h, vma, addr); 88084afd99bSAndy Whitcroft struct resv_map *reservations = vma_resv_map(vma); 88184afd99bSAndy Whitcroft 88284afd99bSAndy Whitcroft /* Mark this page used in the map. */ 88384afd99bSAndy Whitcroft region_add(&reservations->regions, idx, idx + 1); 884c37f9fb1SAndy Whitcroft } 885c37f9fb1SAndy Whitcroft } 886c37f9fb1SAndy Whitcroft 887348ea204SAdam Litke static struct page *alloc_huge_page(struct vm_area_struct *vma, 88804f2cbe3SMel Gorman unsigned long addr, int avoid_reserve) 889348ea204SAdam Litke { 890a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 891348ea204SAdam Litke struct page *page; 8922fc39cecSAdam Litke struct address_space *mapping = vma->vm_file->f_mapping; 893a1e78772SMel Gorman struct inode *inode = mapping->host; 894c37f9fb1SAndy Whitcroft unsigned int chg; 8952fc39cecSAdam Litke 896a1e78772SMel Gorman /* 897a1e78772SMel Gorman * Processes that did not create the mapping will have no reserves and 898a1e78772SMel Gorman * will not have accounted against quota. Check that the quota can be 899a1e78772SMel Gorman * made before satisfying the allocation 900c37f9fb1SAndy Whitcroft * MAP_NORESERVE mappings may also need pages and quota allocated 901c37f9fb1SAndy Whitcroft * if no reserve mapping overlaps. 902a1e78772SMel Gorman */ 903a5516438SAndi Kleen chg = vma_needs_reservation(h, vma, addr); 904c37f9fb1SAndy Whitcroft if (chg < 0) 905c37f9fb1SAndy Whitcroft return ERR_PTR(chg); 906c37f9fb1SAndy Whitcroft if (chg) 907a1e78772SMel Gorman if (hugetlb_get_quota(inode->i_mapping, chg)) 908a1e78772SMel Gorman return ERR_PTR(-ENOSPC); 90990d8b7e6SAdam Litke 910a1e78772SMel Gorman spin_lock(&hugetlb_lock); 911a5516438SAndi Kleen page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve); 912a1e78772SMel Gorman spin_unlock(&hugetlb_lock); 913a1e78772SMel Gorman 914a1e78772SMel Gorman if (!page) { 915a5516438SAndi Kleen page = alloc_buddy_huge_page(h, vma, addr); 916a1e78772SMel Gorman if (!page) { 917a1e78772SMel Gorman hugetlb_put_quota(inode->i_mapping, chg); 918a1e78772SMel Gorman return ERR_PTR(-VM_FAULT_OOM); 919a1e78772SMel Gorman } 920a1e78772SMel Gorman } 921a1e78772SMel Gorman 922348ea204SAdam Litke set_page_refcounted(page); 9232fc39cecSAdam Litke set_page_private(page, (unsigned long) mapping); 924a1e78772SMel Gorman 925a5516438SAndi Kleen vma_commit_reservation(h, vma, addr); 926c37f9fb1SAndy Whitcroft 9277893d1d5SAdam Litke return page; 928b45b5bd6SDavid Gibson } 929b45b5bd6SDavid Gibson 93053ba51d2SJon Tollefson __attribute__((weak)) int alloc_bootmem_huge_page(struct hstate *h) 931aa888a74SAndi Kleen { 932aa888a74SAndi Kleen struct huge_bootmem_page *m; 933aa888a74SAndi Kleen int nr_nodes = nodes_weight(node_online_map); 934aa888a74SAndi Kleen 935aa888a74SAndi Kleen while (nr_nodes) { 936aa888a74SAndi Kleen void *addr; 937aa888a74SAndi Kleen 938aa888a74SAndi Kleen addr = __alloc_bootmem_node_nopanic( 939aa888a74SAndi Kleen NODE_DATA(h->hugetlb_next_nid), 940aa888a74SAndi Kleen huge_page_size(h), huge_page_size(h), 0); 941aa888a74SAndi Kleen 942aa888a74SAndi Kleen if (addr) { 943aa888a74SAndi Kleen /* 944aa888a74SAndi Kleen * Use the beginning of the huge page to store the 945aa888a74SAndi Kleen * huge_bootmem_page struct (until gather_bootmem 946aa888a74SAndi Kleen * puts them into the mem_map). 947aa888a74SAndi Kleen */ 948aa888a74SAndi Kleen m = addr; 949aa888a74SAndi Kleen if (m) 950aa888a74SAndi Kleen goto found; 951aa888a74SAndi Kleen } 952aa888a74SAndi Kleen hstate_next_node(h); 953aa888a74SAndi Kleen nr_nodes--; 954aa888a74SAndi Kleen } 955aa888a74SAndi Kleen return 0; 956aa888a74SAndi Kleen 957aa888a74SAndi Kleen found: 958aa888a74SAndi Kleen BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1)); 959aa888a74SAndi Kleen /* Put them into a private list first because mem_map is not up yet */ 960aa888a74SAndi Kleen list_add(&m->list, &huge_boot_pages); 961aa888a74SAndi Kleen m->hstate = h; 962aa888a74SAndi Kleen return 1; 963aa888a74SAndi Kleen } 964aa888a74SAndi Kleen 965aa888a74SAndi Kleen /* Put bootmem huge pages into the standard lists after mem_map is up */ 966aa888a74SAndi Kleen static void __init gather_bootmem_prealloc(void) 967aa888a74SAndi Kleen { 968aa888a74SAndi Kleen struct huge_bootmem_page *m; 969aa888a74SAndi Kleen 970aa888a74SAndi Kleen list_for_each_entry(m, &huge_boot_pages, list) { 971aa888a74SAndi Kleen struct page *page = virt_to_page(m); 972aa888a74SAndi Kleen struct hstate *h = m->hstate; 973aa888a74SAndi Kleen __ClearPageReserved(page); 974aa888a74SAndi Kleen WARN_ON(page_count(page) != 1); 975aa888a74SAndi Kleen prep_compound_page(page, h->order); 976aa888a74SAndi Kleen prep_new_huge_page(h, page, page_to_nid(page)); 977aa888a74SAndi Kleen } 978aa888a74SAndi Kleen } 979aa888a74SAndi Kleen 9808faa8b07SAndi Kleen static void __init hugetlb_hstate_alloc_pages(struct hstate *h) 9811da177e4SLinus Torvalds { 9821da177e4SLinus Torvalds unsigned long i; 9831da177e4SLinus Torvalds 984e5ff2159SAndi Kleen for (i = 0; i < h->max_huge_pages; ++i) { 985aa888a74SAndi Kleen if (h->order >= MAX_ORDER) { 986aa888a74SAndi Kleen if (!alloc_bootmem_huge_page(h)) 987aa888a74SAndi Kleen break; 988aa888a74SAndi Kleen } else if (!alloc_fresh_huge_page(h)) 9891da177e4SLinus Torvalds break; 9901da177e4SLinus Torvalds } 9918faa8b07SAndi Kleen h->max_huge_pages = i; 992e5ff2159SAndi Kleen } 993e5ff2159SAndi Kleen 994e5ff2159SAndi Kleen static void __init hugetlb_init_hstates(void) 995e5ff2159SAndi Kleen { 996e5ff2159SAndi Kleen struct hstate *h; 997e5ff2159SAndi Kleen 998e5ff2159SAndi Kleen for_each_hstate(h) { 9998faa8b07SAndi Kleen /* oversize hugepages were init'ed in early boot */ 10008faa8b07SAndi Kleen if (h->order < MAX_ORDER) 10018faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(h); 1002e5ff2159SAndi Kleen } 1003e5ff2159SAndi Kleen } 1004e5ff2159SAndi Kleen 10054abd32dbSAndi Kleen static char * __init memfmt(char *buf, unsigned long n) 10064abd32dbSAndi Kleen { 10074abd32dbSAndi Kleen if (n >= (1UL << 30)) 10084abd32dbSAndi Kleen sprintf(buf, "%lu GB", n >> 30); 10094abd32dbSAndi Kleen else if (n >= (1UL << 20)) 10104abd32dbSAndi Kleen sprintf(buf, "%lu MB", n >> 20); 10114abd32dbSAndi Kleen else 10124abd32dbSAndi Kleen sprintf(buf, "%lu KB", n >> 10); 10134abd32dbSAndi Kleen return buf; 10144abd32dbSAndi Kleen } 10154abd32dbSAndi Kleen 1016e5ff2159SAndi Kleen static void __init report_hugepages(void) 1017e5ff2159SAndi Kleen { 1018e5ff2159SAndi Kleen struct hstate *h; 1019e5ff2159SAndi Kleen 1020e5ff2159SAndi Kleen for_each_hstate(h) { 10214abd32dbSAndi Kleen char buf[32]; 10224abd32dbSAndi Kleen printk(KERN_INFO "HugeTLB registered %s page size, " 10234abd32dbSAndi Kleen "pre-allocated %ld pages\n", 10244abd32dbSAndi Kleen memfmt(buf, huge_page_size(h)), 10254abd32dbSAndi Kleen h->free_huge_pages); 1026e5ff2159SAndi Kleen } 1027e5ff2159SAndi Kleen } 1028e5ff2159SAndi Kleen 10291da177e4SLinus Torvalds #ifdef CONFIG_SYSCTL 10301da177e4SLinus Torvalds #ifdef CONFIG_HIGHMEM 1031a5516438SAndi Kleen static void try_to_free_low(struct hstate *h, unsigned long count) 10321da177e4SLinus Torvalds { 10334415cc8dSChristoph Lameter int i; 10344415cc8dSChristoph Lameter 1035aa888a74SAndi Kleen if (h->order >= MAX_ORDER) 1036aa888a74SAndi Kleen return; 1037aa888a74SAndi Kleen 10381da177e4SLinus Torvalds for (i = 0; i < MAX_NUMNODES; ++i) { 10391da177e4SLinus Torvalds struct page *page, *next; 1040a5516438SAndi Kleen struct list_head *freel = &h->hugepage_freelists[i]; 1041a5516438SAndi Kleen list_for_each_entry_safe(page, next, freel, lru) { 1042a5516438SAndi Kleen if (count >= h->nr_huge_pages) 10436b0c880dSAdam Litke return; 10441da177e4SLinus Torvalds if (PageHighMem(page)) 10451da177e4SLinus Torvalds continue; 10461da177e4SLinus Torvalds list_del(&page->lru); 1047e5ff2159SAndi Kleen update_and_free_page(h, page); 1048a5516438SAndi Kleen h->free_huge_pages--; 1049a5516438SAndi Kleen h->free_huge_pages_node[page_to_nid(page)]--; 10501da177e4SLinus Torvalds } 10511da177e4SLinus Torvalds } 10521da177e4SLinus Torvalds } 10531da177e4SLinus Torvalds #else 1054a5516438SAndi Kleen static inline void try_to_free_low(struct hstate *h, unsigned long count) 10551da177e4SLinus Torvalds { 10561da177e4SLinus Torvalds } 10571da177e4SLinus Torvalds #endif 10581da177e4SLinus Torvalds 1059a5516438SAndi Kleen #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) 1060e5ff2159SAndi Kleen static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count) 10611da177e4SLinus Torvalds { 10627893d1d5SAdam Litke unsigned long min_count, ret; 10631da177e4SLinus Torvalds 1064aa888a74SAndi Kleen if (h->order >= MAX_ORDER) 1065aa888a74SAndi Kleen return h->max_huge_pages; 1066aa888a74SAndi Kleen 10677893d1d5SAdam Litke /* 10687893d1d5SAdam Litke * Increase the pool size 10697893d1d5SAdam Litke * First take pages out of surplus state. Then make up the 10707893d1d5SAdam Litke * remaining difference by allocating fresh huge pages. 1071d1c3fb1fSNishanth Aravamudan * 1072d1c3fb1fSNishanth Aravamudan * We might race with alloc_buddy_huge_page() here and be unable 1073d1c3fb1fSNishanth Aravamudan * to convert a surplus huge page to a normal huge page. That is 1074d1c3fb1fSNishanth Aravamudan * not critical, though, it just means the overall size of the 1075d1c3fb1fSNishanth Aravamudan * pool might be one hugepage larger than it needs to be, but 1076d1c3fb1fSNishanth Aravamudan * within all the constraints specified by the sysctls. 10777893d1d5SAdam Litke */ 10781da177e4SLinus Torvalds spin_lock(&hugetlb_lock); 1079a5516438SAndi Kleen while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { 1080a5516438SAndi Kleen if (!adjust_pool_surplus(h, -1)) 10817893d1d5SAdam Litke break; 10827893d1d5SAdam Litke } 10837893d1d5SAdam Litke 1084a5516438SAndi Kleen while (count > persistent_huge_pages(h)) { 10857893d1d5SAdam Litke /* 10867893d1d5SAdam Litke * If this allocation races such that we no longer need the 10877893d1d5SAdam Litke * page, free_huge_page will handle it by freeing the page 10887893d1d5SAdam Litke * and reducing the surplus. 10897893d1d5SAdam Litke */ 10907893d1d5SAdam Litke spin_unlock(&hugetlb_lock); 1091a5516438SAndi Kleen ret = alloc_fresh_huge_page(h); 10927893d1d5SAdam Litke spin_lock(&hugetlb_lock); 10937893d1d5SAdam Litke if (!ret) 10947893d1d5SAdam Litke goto out; 10957893d1d5SAdam Litke 10967893d1d5SAdam Litke } 10977893d1d5SAdam Litke 10987893d1d5SAdam Litke /* 10997893d1d5SAdam Litke * Decrease the pool size 11007893d1d5SAdam Litke * First return free pages to the buddy allocator (being careful 11017893d1d5SAdam Litke * to keep enough around to satisfy reservations). Then place 11027893d1d5SAdam Litke * pages into surplus state as needed so the pool will shrink 11037893d1d5SAdam Litke * to the desired size as pages become free. 1104d1c3fb1fSNishanth Aravamudan * 1105d1c3fb1fSNishanth Aravamudan * By placing pages into the surplus state independent of the 1106d1c3fb1fSNishanth Aravamudan * overcommit value, we are allowing the surplus pool size to 1107d1c3fb1fSNishanth Aravamudan * exceed overcommit. There are few sane options here. Since 1108d1c3fb1fSNishanth Aravamudan * alloc_buddy_huge_page() is checking the global counter, 1109d1c3fb1fSNishanth Aravamudan * though, we'll note that we're not allowed to exceed surplus 1110d1c3fb1fSNishanth Aravamudan * and won't grow the pool anywhere else. Not until one of the 1111d1c3fb1fSNishanth Aravamudan * sysctls are changed, or the surplus pages go out of use. 11127893d1d5SAdam Litke */ 1113a5516438SAndi Kleen min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; 11146b0c880dSAdam Litke min_count = max(count, min_count); 1115a5516438SAndi Kleen try_to_free_low(h, min_count); 1116a5516438SAndi Kleen while (min_count < persistent_huge_pages(h)) { 1117a5516438SAndi Kleen struct page *page = dequeue_huge_page(h); 11181da177e4SLinus Torvalds if (!page) 11191da177e4SLinus Torvalds break; 1120a5516438SAndi Kleen update_and_free_page(h, page); 11211da177e4SLinus Torvalds } 1122a5516438SAndi Kleen while (count < persistent_huge_pages(h)) { 1123a5516438SAndi Kleen if (!adjust_pool_surplus(h, 1)) 11247893d1d5SAdam Litke break; 11257893d1d5SAdam Litke } 11267893d1d5SAdam Litke out: 1127a5516438SAndi Kleen ret = persistent_huge_pages(h); 11281da177e4SLinus Torvalds spin_unlock(&hugetlb_lock); 11297893d1d5SAdam Litke return ret; 11301da177e4SLinus Torvalds } 11311da177e4SLinus Torvalds 1132a3437870SNishanth Aravamudan #define HSTATE_ATTR_RO(_name) \ 1133a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = __ATTR_RO(_name) 1134a3437870SNishanth Aravamudan 1135a3437870SNishanth Aravamudan #define HSTATE_ATTR(_name) \ 1136a3437870SNishanth Aravamudan static struct kobj_attribute _name##_attr = \ 1137a3437870SNishanth Aravamudan __ATTR(_name, 0644, _name##_show, _name##_store) 1138a3437870SNishanth Aravamudan 1139a3437870SNishanth Aravamudan static struct kobject *hugepages_kobj; 1140a3437870SNishanth Aravamudan static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; 1141a3437870SNishanth Aravamudan 1142a3437870SNishanth Aravamudan static struct hstate *kobj_to_hstate(struct kobject *kobj) 1143a3437870SNishanth Aravamudan { 1144a3437870SNishanth Aravamudan int i; 1145a3437870SNishanth Aravamudan for (i = 0; i < HUGE_MAX_HSTATE; i++) 1146a3437870SNishanth Aravamudan if (hstate_kobjs[i] == kobj) 1147a3437870SNishanth Aravamudan return &hstates[i]; 1148a3437870SNishanth Aravamudan BUG(); 1149a3437870SNishanth Aravamudan return NULL; 1150a3437870SNishanth Aravamudan } 1151a3437870SNishanth Aravamudan 1152a3437870SNishanth Aravamudan static ssize_t nr_hugepages_show(struct kobject *kobj, 1153a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1154a3437870SNishanth Aravamudan { 1155a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1156a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->nr_huge_pages); 1157a3437870SNishanth Aravamudan } 1158a3437870SNishanth Aravamudan static ssize_t nr_hugepages_store(struct kobject *kobj, 1159a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 1160a3437870SNishanth Aravamudan { 1161a3437870SNishanth Aravamudan int err; 1162a3437870SNishanth Aravamudan unsigned long input; 1163a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1164a3437870SNishanth Aravamudan 1165a3437870SNishanth Aravamudan err = strict_strtoul(buf, 10, &input); 1166a3437870SNishanth Aravamudan if (err) 1167a3437870SNishanth Aravamudan return 0; 1168a3437870SNishanth Aravamudan 1169a3437870SNishanth Aravamudan h->max_huge_pages = set_max_huge_pages(h, input); 1170a3437870SNishanth Aravamudan 1171a3437870SNishanth Aravamudan return count; 1172a3437870SNishanth Aravamudan } 1173a3437870SNishanth Aravamudan HSTATE_ATTR(nr_hugepages); 1174a3437870SNishanth Aravamudan 1175a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, 1176a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1177a3437870SNishanth Aravamudan { 1178a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1179a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); 1180a3437870SNishanth Aravamudan } 1181a3437870SNishanth Aravamudan static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, 1182a3437870SNishanth Aravamudan struct kobj_attribute *attr, const char *buf, size_t count) 1183a3437870SNishanth Aravamudan { 1184a3437870SNishanth Aravamudan int err; 1185a3437870SNishanth Aravamudan unsigned long input; 1186a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1187a3437870SNishanth Aravamudan 1188a3437870SNishanth Aravamudan err = strict_strtoul(buf, 10, &input); 1189a3437870SNishanth Aravamudan if (err) 1190a3437870SNishanth Aravamudan return 0; 1191a3437870SNishanth Aravamudan 1192a3437870SNishanth Aravamudan spin_lock(&hugetlb_lock); 1193a3437870SNishanth Aravamudan h->nr_overcommit_huge_pages = input; 1194a3437870SNishanth Aravamudan spin_unlock(&hugetlb_lock); 1195a3437870SNishanth Aravamudan 1196a3437870SNishanth Aravamudan return count; 1197a3437870SNishanth Aravamudan } 1198a3437870SNishanth Aravamudan HSTATE_ATTR(nr_overcommit_hugepages); 1199a3437870SNishanth Aravamudan 1200a3437870SNishanth Aravamudan static ssize_t free_hugepages_show(struct kobject *kobj, 1201a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1202a3437870SNishanth Aravamudan { 1203a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1204a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->free_huge_pages); 1205a3437870SNishanth Aravamudan } 1206a3437870SNishanth Aravamudan HSTATE_ATTR_RO(free_hugepages); 1207a3437870SNishanth Aravamudan 1208a3437870SNishanth Aravamudan static ssize_t resv_hugepages_show(struct kobject *kobj, 1209a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1210a3437870SNishanth Aravamudan { 1211a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1212a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->resv_huge_pages); 1213a3437870SNishanth Aravamudan } 1214a3437870SNishanth Aravamudan HSTATE_ATTR_RO(resv_hugepages); 1215a3437870SNishanth Aravamudan 1216a3437870SNishanth Aravamudan static ssize_t surplus_hugepages_show(struct kobject *kobj, 1217a3437870SNishanth Aravamudan struct kobj_attribute *attr, char *buf) 1218a3437870SNishanth Aravamudan { 1219a3437870SNishanth Aravamudan struct hstate *h = kobj_to_hstate(kobj); 1220a3437870SNishanth Aravamudan return sprintf(buf, "%lu\n", h->surplus_huge_pages); 1221a3437870SNishanth Aravamudan } 1222a3437870SNishanth Aravamudan HSTATE_ATTR_RO(surplus_hugepages); 1223a3437870SNishanth Aravamudan 1224a3437870SNishanth Aravamudan static struct attribute *hstate_attrs[] = { 1225a3437870SNishanth Aravamudan &nr_hugepages_attr.attr, 1226a3437870SNishanth Aravamudan &nr_overcommit_hugepages_attr.attr, 1227a3437870SNishanth Aravamudan &free_hugepages_attr.attr, 1228a3437870SNishanth Aravamudan &resv_hugepages_attr.attr, 1229a3437870SNishanth Aravamudan &surplus_hugepages_attr.attr, 1230a3437870SNishanth Aravamudan NULL, 1231a3437870SNishanth Aravamudan }; 1232a3437870SNishanth Aravamudan 1233a3437870SNishanth Aravamudan static struct attribute_group hstate_attr_group = { 1234a3437870SNishanth Aravamudan .attrs = hstate_attrs, 1235a3437870SNishanth Aravamudan }; 1236a3437870SNishanth Aravamudan 1237a3437870SNishanth Aravamudan static int __init hugetlb_sysfs_add_hstate(struct hstate *h) 1238a3437870SNishanth Aravamudan { 1239a3437870SNishanth Aravamudan int retval; 1240a3437870SNishanth Aravamudan 1241a3437870SNishanth Aravamudan hstate_kobjs[h - hstates] = kobject_create_and_add(h->name, 1242a3437870SNishanth Aravamudan hugepages_kobj); 1243a3437870SNishanth Aravamudan if (!hstate_kobjs[h - hstates]) 1244a3437870SNishanth Aravamudan return -ENOMEM; 1245a3437870SNishanth Aravamudan 1246a3437870SNishanth Aravamudan retval = sysfs_create_group(hstate_kobjs[h - hstates], 1247a3437870SNishanth Aravamudan &hstate_attr_group); 1248a3437870SNishanth Aravamudan if (retval) 1249a3437870SNishanth Aravamudan kobject_put(hstate_kobjs[h - hstates]); 1250a3437870SNishanth Aravamudan 1251a3437870SNishanth Aravamudan return retval; 1252a3437870SNishanth Aravamudan } 1253a3437870SNishanth Aravamudan 1254a3437870SNishanth Aravamudan static void __init hugetlb_sysfs_init(void) 1255a3437870SNishanth Aravamudan { 1256a3437870SNishanth Aravamudan struct hstate *h; 1257a3437870SNishanth Aravamudan int err; 1258a3437870SNishanth Aravamudan 1259a3437870SNishanth Aravamudan hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); 1260a3437870SNishanth Aravamudan if (!hugepages_kobj) 1261a3437870SNishanth Aravamudan return; 1262a3437870SNishanth Aravamudan 1263a3437870SNishanth Aravamudan for_each_hstate(h) { 1264a3437870SNishanth Aravamudan err = hugetlb_sysfs_add_hstate(h); 1265a3437870SNishanth Aravamudan if (err) 1266a3437870SNishanth Aravamudan printk(KERN_ERR "Hugetlb: Unable to add hstate %s", 1267a3437870SNishanth Aravamudan h->name); 1268a3437870SNishanth Aravamudan } 1269a3437870SNishanth Aravamudan } 1270a3437870SNishanth Aravamudan 1271a3437870SNishanth Aravamudan static void __exit hugetlb_exit(void) 1272a3437870SNishanth Aravamudan { 1273a3437870SNishanth Aravamudan struct hstate *h; 1274a3437870SNishanth Aravamudan 1275a3437870SNishanth Aravamudan for_each_hstate(h) { 1276a3437870SNishanth Aravamudan kobject_put(hstate_kobjs[h - hstates]); 1277a3437870SNishanth Aravamudan } 1278a3437870SNishanth Aravamudan 1279a3437870SNishanth Aravamudan kobject_put(hugepages_kobj); 1280a3437870SNishanth Aravamudan } 1281a3437870SNishanth Aravamudan module_exit(hugetlb_exit); 1282a3437870SNishanth Aravamudan 1283a3437870SNishanth Aravamudan static int __init hugetlb_init(void) 1284a3437870SNishanth Aravamudan { 1285a3437870SNishanth Aravamudan BUILD_BUG_ON(HPAGE_SHIFT == 0); 1286a3437870SNishanth Aravamudan 1287e11bfbfcSNick Piggin if (!size_to_hstate(default_hstate_size)) { 1288e11bfbfcSNick Piggin default_hstate_size = HPAGE_SIZE; 1289e11bfbfcSNick Piggin if (!size_to_hstate(default_hstate_size)) 1290a3437870SNishanth Aravamudan hugetlb_add_hstate(HUGETLB_PAGE_ORDER); 1291a3437870SNishanth Aravamudan } 1292e11bfbfcSNick Piggin default_hstate_idx = size_to_hstate(default_hstate_size) - hstates; 1293e11bfbfcSNick Piggin if (default_hstate_max_huge_pages) 1294e11bfbfcSNick Piggin default_hstate.max_huge_pages = default_hstate_max_huge_pages; 1295a3437870SNishanth Aravamudan 1296a3437870SNishanth Aravamudan hugetlb_init_hstates(); 1297a3437870SNishanth Aravamudan 1298aa888a74SAndi Kleen gather_bootmem_prealloc(); 1299aa888a74SAndi Kleen 1300a3437870SNishanth Aravamudan report_hugepages(); 1301a3437870SNishanth Aravamudan 1302a3437870SNishanth Aravamudan hugetlb_sysfs_init(); 1303a3437870SNishanth Aravamudan 1304a3437870SNishanth Aravamudan return 0; 1305a3437870SNishanth Aravamudan } 1306a3437870SNishanth Aravamudan module_init(hugetlb_init); 1307a3437870SNishanth Aravamudan 1308a3437870SNishanth Aravamudan /* Should be called on processing a hugepagesz=... option */ 1309a3437870SNishanth Aravamudan void __init hugetlb_add_hstate(unsigned order) 1310a3437870SNishanth Aravamudan { 1311a3437870SNishanth Aravamudan struct hstate *h; 13128faa8b07SAndi Kleen unsigned long i; 13138faa8b07SAndi Kleen 1314a3437870SNishanth Aravamudan if (size_to_hstate(PAGE_SIZE << order)) { 1315a3437870SNishanth Aravamudan printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n"); 1316a3437870SNishanth Aravamudan return; 1317a3437870SNishanth Aravamudan } 1318a3437870SNishanth Aravamudan BUG_ON(max_hstate >= HUGE_MAX_HSTATE); 1319a3437870SNishanth Aravamudan BUG_ON(order == 0); 1320a3437870SNishanth Aravamudan h = &hstates[max_hstate++]; 1321a3437870SNishanth Aravamudan h->order = order; 1322a3437870SNishanth Aravamudan h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); 13238faa8b07SAndi Kleen h->nr_huge_pages = 0; 13248faa8b07SAndi Kleen h->free_huge_pages = 0; 13258faa8b07SAndi Kleen for (i = 0; i < MAX_NUMNODES; ++i) 13268faa8b07SAndi Kleen INIT_LIST_HEAD(&h->hugepage_freelists[i]); 13278faa8b07SAndi Kleen h->hugetlb_next_nid = first_node(node_online_map); 1328a3437870SNishanth Aravamudan snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", 1329a3437870SNishanth Aravamudan huge_page_size(h)/1024); 13308faa8b07SAndi Kleen 1331a3437870SNishanth Aravamudan parsed_hstate = h; 1332a3437870SNishanth Aravamudan } 1333a3437870SNishanth Aravamudan 1334e11bfbfcSNick Piggin static int __init hugetlb_nrpages_setup(char *s) 1335a3437870SNishanth Aravamudan { 1336a3437870SNishanth Aravamudan unsigned long *mhp; 13378faa8b07SAndi Kleen static unsigned long *last_mhp; 1338a3437870SNishanth Aravamudan 1339a3437870SNishanth Aravamudan /* 1340a3437870SNishanth Aravamudan * !max_hstate means we haven't parsed a hugepagesz= parameter yet, 1341a3437870SNishanth Aravamudan * so this hugepages= parameter goes to the "default hstate". 1342a3437870SNishanth Aravamudan */ 1343a3437870SNishanth Aravamudan if (!max_hstate) 1344a3437870SNishanth Aravamudan mhp = &default_hstate_max_huge_pages; 1345a3437870SNishanth Aravamudan else 1346a3437870SNishanth Aravamudan mhp = &parsed_hstate->max_huge_pages; 1347a3437870SNishanth Aravamudan 13488faa8b07SAndi Kleen if (mhp == last_mhp) { 13498faa8b07SAndi Kleen printk(KERN_WARNING "hugepages= specified twice without " 13508faa8b07SAndi Kleen "interleaving hugepagesz=, ignoring\n"); 13518faa8b07SAndi Kleen return 1; 13528faa8b07SAndi Kleen } 13538faa8b07SAndi Kleen 1354a3437870SNishanth Aravamudan if (sscanf(s, "%lu", mhp) <= 0) 1355a3437870SNishanth Aravamudan *mhp = 0; 1356a3437870SNishanth Aravamudan 13578faa8b07SAndi Kleen /* 13588faa8b07SAndi Kleen * Global state is always initialized later in hugetlb_init. 13598faa8b07SAndi Kleen * But we need to allocate >= MAX_ORDER hstates here early to still 13608faa8b07SAndi Kleen * use the bootmem allocator. 13618faa8b07SAndi Kleen */ 13628faa8b07SAndi Kleen if (max_hstate && parsed_hstate->order >= MAX_ORDER) 13638faa8b07SAndi Kleen hugetlb_hstate_alloc_pages(parsed_hstate); 13648faa8b07SAndi Kleen 13658faa8b07SAndi Kleen last_mhp = mhp; 13668faa8b07SAndi Kleen 1367a3437870SNishanth Aravamudan return 1; 1368a3437870SNishanth Aravamudan } 1369e11bfbfcSNick Piggin __setup("hugepages=", hugetlb_nrpages_setup); 1370e11bfbfcSNick Piggin 1371e11bfbfcSNick Piggin static int __init hugetlb_default_setup(char *s) 1372e11bfbfcSNick Piggin { 1373e11bfbfcSNick Piggin default_hstate_size = memparse(s, &s); 1374e11bfbfcSNick Piggin return 1; 1375e11bfbfcSNick Piggin } 1376e11bfbfcSNick Piggin __setup("default_hugepagesz=", hugetlb_default_setup); 1377a3437870SNishanth Aravamudan 1378a3437870SNishanth Aravamudan static unsigned int cpuset_mems_nr(unsigned int *array) 1379a3437870SNishanth Aravamudan { 1380a3437870SNishanth Aravamudan int node; 1381a3437870SNishanth Aravamudan unsigned int nr = 0; 1382a3437870SNishanth Aravamudan 1383a3437870SNishanth Aravamudan for_each_node_mask(node, cpuset_current_mems_allowed) 1384a3437870SNishanth Aravamudan nr += array[node]; 1385a3437870SNishanth Aravamudan 1386a3437870SNishanth Aravamudan return nr; 1387a3437870SNishanth Aravamudan } 1388a3437870SNishanth Aravamudan 13891da177e4SLinus Torvalds int hugetlb_sysctl_handler(struct ctl_table *table, int write, 13901da177e4SLinus Torvalds struct file *file, void __user *buffer, 13911da177e4SLinus Torvalds size_t *length, loff_t *ppos) 13921da177e4SLinus Torvalds { 1393e5ff2159SAndi Kleen struct hstate *h = &default_hstate; 1394e5ff2159SAndi Kleen unsigned long tmp; 1395e5ff2159SAndi Kleen 1396e5ff2159SAndi Kleen if (!write) 1397e5ff2159SAndi Kleen tmp = h->max_huge_pages; 1398e5ff2159SAndi Kleen 1399e5ff2159SAndi Kleen table->data = &tmp; 1400e5ff2159SAndi Kleen table->maxlen = sizeof(unsigned long); 14011da177e4SLinus Torvalds proc_doulongvec_minmax(table, write, file, buffer, length, ppos); 1402e5ff2159SAndi Kleen 1403e5ff2159SAndi Kleen if (write) 1404e5ff2159SAndi Kleen h->max_huge_pages = set_max_huge_pages(h, tmp); 1405e5ff2159SAndi Kleen 14061da177e4SLinus Torvalds return 0; 14071da177e4SLinus Torvalds } 1408396faf03SMel Gorman 1409396faf03SMel Gorman int hugetlb_treat_movable_handler(struct ctl_table *table, int write, 1410396faf03SMel Gorman struct file *file, void __user *buffer, 1411396faf03SMel Gorman size_t *length, loff_t *ppos) 1412396faf03SMel Gorman { 1413396faf03SMel Gorman proc_dointvec(table, write, file, buffer, length, ppos); 1414396faf03SMel Gorman if (hugepages_treat_as_movable) 1415396faf03SMel Gorman htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; 1416396faf03SMel Gorman else 1417396faf03SMel Gorman htlb_alloc_mask = GFP_HIGHUSER; 1418396faf03SMel Gorman return 0; 1419396faf03SMel Gorman } 1420396faf03SMel Gorman 1421a3d0c6aaSNishanth Aravamudan int hugetlb_overcommit_handler(struct ctl_table *table, int write, 1422a3d0c6aaSNishanth Aravamudan struct file *file, void __user *buffer, 1423a3d0c6aaSNishanth Aravamudan size_t *length, loff_t *ppos) 1424a3d0c6aaSNishanth Aravamudan { 1425a5516438SAndi Kleen struct hstate *h = &default_hstate; 1426e5ff2159SAndi Kleen unsigned long tmp; 1427e5ff2159SAndi Kleen 1428e5ff2159SAndi Kleen if (!write) 1429e5ff2159SAndi Kleen tmp = h->nr_overcommit_huge_pages; 1430e5ff2159SAndi Kleen 1431e5ff2159SAndi Kleen table->data = &tmp; 1432e5ff2159SAndi Kleen table->maxlen = sizeof(unsigned long); 1433a3d0c6aaSNishanth Aravamudan proc_doulongvec_minmax(table, write, file, buffer, length, ppos); 1434e5ff2159SAndi Kleen 1435e5ff2159SAndi Kleen if (write) { 1436064d9efeSNishanth Aravamudan spin_lock(&hugetlb_lock); 1437e5ff2159SAndi Kleen h->nr_overcommit_huge_pages = tmp; 1438a3d0c6aaSNishanth Aravamudan spin_unlock(&hugetlb_lock); 1439e5ff2159SAndi Kleen } 1440e5ff2159SAndi Kleen 1441a3d0c6aaSNishanth Aravamudan return 0; 1442a3d0c6aaSNishanth Aravamudan } 1443a3d0c6aaSNishanth Aravamudan 14441da177e4SLinus Torvalds #endif /* CONFIG_SYSCTL */ 14451da177e4SLinus Torvalds 14461da177e4SLinus Torvalds int hugetlb_report_meminfo(char *buf) 14471da177e4SLinus Torvalds { 1448a5516438SAndi Kleen struct hstate *h = &default_hstate; 14491da177e4SLinus Torvalds return sprintf(buf, 14501da177e4SLinus Torvalds "HugePages_Total: %5lu\n" 14511da177e4SLinus Torvalds "HugePages_Free: %5lu\n" 1452b45b5bd6SDavid Gibson "HugePages_Rsvd: %5lu\n" 14537893d1d5SAdam Litke "HugePages_Surp: %5lu\n" 14541da177e4SLinus Torvalds "Hugepagesize: %5lu kB\n", 1455a5516438SAndi Kleen h->nr_huge_pages, 1456a5516438SAndi Kleen h->free_huge_pages, 1457a5516438SAndi Kleen h->resv_huge_pages, 1458a5516438SAndi Kleen h->surplus_huge_pages, 1459a5516438SAndi Kleen 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); 14601da177e4SLinus Torvalds } 14611da177e4SLinus Torvalds 14621da177e4SLinus Torvalds int hugetlb_report_node_meminfo(int nid, char *buf) 14631da177e4SLinus Torvalds { 1464a5516438SAndi Kleen struct hstate *h = &default_hstate; 14651da177e4SLinus Torvalds return sprintf(buf, 14661da177e4SLinus Torvalds "Node %d HugePages_Total: %5u\n" 1467a1de0919SNishanth Aravamudan "Node %d HugePages_Free: %5u\n" 1468a1de0919SNishanth Aravamudan "Node %d HugePages_Surp: %5u\n", 1469a5516438SAndi Kleen nid, h->nr_huge_pages_node[nid], 1470a5516438SAndi Kleen nid, h->free_huge_pages_node[nid], 1471a5516438SAndi Kleen nid, h->surplus_huge_pages_node[nid]); 14721da177e4SLinus Torvalds } 14731da177e4SLinus Torvalds 14741da177e4SLinus Torvalds /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ 14751da177e4SLinus Torvalds unsigned long hugetlb_total_pages(void) 14761da177e4SLinus Torvalds { 1477a5516438SAndi Kleen struct hstate *h = &default_hstate; 1478a5516438SAndi Kleen return h->nr_huge_pages * pages_per_huge_page(h); 14791da177e4SLinus Torvalds } 14801da177e4SLinus Torvalds 1481a5516438SAndi Kleen static int hugetlb_acct_memory(struct hstate *h, long delta) 1482fc1b8a73SMel Gorman { 1483fc1b8a73SMel Gorman int ret = -ENOMEM; 1484fc1b8a73SMel Gorman 1485fc1b8a73SMel Gorman spin_lock(&hugetlb_lock); 1486fc1b8a73SMel Gorman /* 1487fc1b8a73SMel Gorman * When cpuset is configured, it breaks the strict hugetlb page 1488fc1b8a73SMel Gorman * reservation as the accounting is done on a global variable. Such 1489fc1b8a73SMel Gorman * reservation is completely rubbish in the presence of cpuset because 1490fc1b8a73SMel Gorman * the reservation is not checked against page availability for the 1491fc1b8a73SMel Gorman * current cpuset. Application can still potentially OOM'ed by kernel 1492fc1b8a73SMel Gorman * with lack of free htlb page in cpuset that the task is in. 1493fc1b8a73SMel Gorman * Attempt to enforce strict accounting with cpuset is almost 1494fc1b8a73SMel Gorman * impossible (or too ugly) because cpuset is too fluid that 1495fc1b8a73SMel Gorman * task or memory node can be dynamically moved between cpusets. 1496fc1b8a73SMel Gorman * 1497fc1b8a73SMel Gorman * The change of semantics for shared hugetlb mapping with cpuset is 1498fc1b8a73SMel Gorman * undesirable. However, in order to preserve some of the semantics, 1499fc1b8a73SMel Gorman * we fall back to check against current free page availability as 1500fc1b8a73SMel Gorman * a best attempt and hopefully to minimize the impact of changing 1501fc1b8a73SMel Gorman * semantics that cpuset has. 1502fc1b8a73SMel Gorman */ 1503fc1b8a73SMel Gorman if (delta > 0) { 1504a5516438SAndi Kleen if (gather_surplus_pages(h, delta) < 0) 1505fc1b8a73SMel Gorman goto out; 1506fc1b8a73SMel Gorman 1507a5516438SAndi Kleen if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { 1508a5516438SAndi Kleen return_unused_surplus_pages(h, delta); 1509fc1b8a73SMel Gorman goto out; 1510fc1b8a73SMel Gorman } 1511fc1b8a73SMel Gorman } 1512fc1b8a73SMel Gorman 1513fc1b8a73SMel Gorman ret = 0; 1514fc1b8a73SMel Gorman if (delta < 0) 1515a5516438SAndi Kleen return_unused_surplus_pages(h, (unsigned long) -delta); 1516fc1b8a73SMel Gorman 1517fc1b8a73SMel Gorman out: 1518fc1b8a73SMel Gorman spin_unlock(&hugetlb_lock); 1519fc1b8a73SMel Gorman return ret; 1520fc1b8a73SMel Gorman } 1521fc1b8a73SMel Gorman 152284afd99bSAndy Whitcroft static void hugetlb_vm_op_open(struct vm_area_struct *vma) 152384afd99bSAndy Whitcroft { 152484afd99bSAndy Whitcroft struct resv_map *reservations = vma_resv_map(vma); 152584afd99bSAndy Whitcroft 152684afd99bSAndy Whitcroft /* 152784afd99bSAndy Whitcroft * This new VMA should share its siblings reservation map if present. 152884afd99bSAndy Whitcroft * The VMA will only ever have a valid reservation map pointer where 152984afd99bSAndy Whitcroft * it is being copied for another still existing VMA. As that VMA 153084afd99bSAndy Whitcroft * has a reference to the reservation map it cannot dissappear until 153184afd99bSAndy Whitcroft * after this open call completes. It is therefore safe to take a 153284afd99bSAndy Whitcroft * new reference here without additional locking. 153384afd99bSAndy Whitcroft */ 153484afd99bSAndy Whitcroft if (reservations) 153584afd99bSAndy Whitcroft kref_get(&reservations->refs); 153684afd99bSAndy Whitcroft } 153784afd99bSAndy Whitcroft 1538a1e78772SMel Gorman static void hugetlb_vm_op_close(struct vm_area_struct *vma) 1539a1e78772SMel Gorman { 1540a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 154184afd99bSAndy Whitcroft struct resv_map *reservations = vma_resv_map(vma); 154284afd99bSAndy Whitcroft unsigned long reserve; 154384afd99bSAndy Whitcroft unsigned long start; 154484afd99bSAndy Whitcroft unsigned long end; 154584afd99bSAndy Whitcroft 154684afd99bSAndy Whitcroft if (reservations) { 1547a5516438SAndi Kleen start = vma_hugecache_offset(h, vma, vma->vm_start); 1548a5516438SAndi Kleen end = vma_hugecache_offset(h, vma, vma->vm_end); 154984afd99bSAndy Whitcroft 155084afd99bSAndy Whitcroft reserve = (end - start) - 155184afd99bSAndy Whitcroft region_count(&reservations->regions, start, end); 155284afd99bSAndy Whitcroft 155384afd99bSAndy Whitcroft kref_put(&reservations->refs, resv_map_release); 155484afd99bSAndy Whitcroft 1555a1e78772SMel Gorman if (reserve) 1556a5516438SAndi Kleen hugetlb_acct_memory(h, -reserve); 1557a1e78772SMel Gorman } 155884afd99bSAndy Whitcroft } 1559a1e78772SMel Gorman 15601da177e4SLinus Torvalds /* 15611da177e4SLinus Torvalds * We cannot handle pagefaults against hugetlb pages at all. They cause 15621da177e4SLinus Torvalds * handle_mm_fault() to try to instantiate regular-sized pages in the 15631da177e4SLinus Torvalds * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get 15641da177e4SLinus Torvalds * this far. 15651da177e4SLinus Torvalds */ 1566d0217ac0SNick Piggin static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 15671da177e4SLinus Torvalds { 15681da177e4SLinus Torvalds BUG(); 1569d0217ac0SNick Piggin return 0; 15701da177e4SLinus Torvalds } 15711da177e4SLinus Torvalds 15721da177e4SLinus Torvalds struct vm_operations_struct hugetlb_vm_ops = { 1573d0217ac0SNick Piggin .fault = hugetlb_vm_op_fault, 157484afd99bSAndy Whitcroft .open = hugetlb_vm_op_open, 1575a1e78772SMel Gorman .close = hugetlb_vm_op_close, 15761da177e4SLinus Torvalds }; 15771da177e4SLinus Torvalds 15781e8f889bSDavid Gibson static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, 15791e8f889bSDavid Gibson int writable) 158063551ae0SDavid Gibson { 158163551ae0SDavid Gibson pte_t entry; 158263551ae0SDavid Gibson 15831e8f889bSDavid Gibson if (writable) { 158463551ae0SDavid Gibson entry = 158563551ae0SDavid Gibson pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); 158663551ae0SDavid Gibson } else { 15877f2e9525SGerald Schaefer entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); 158863551ae0SDavid Gibson } 158963551ae0SDavid Gibson entry = pte_mkyoung(entry); 159063551ae0SDavid Gibson entry = pte_mkhuge(entry); 159163551ae0SDavid Gibson 159263551ae0SDavid Gibson return entry; 159363551ae0SDavid Gibson } 159463551ae0SDavid Gibson 15951e8f889bSDavid Gibson static void set_huge_ptep_writable(struct vm_area_struct *vma, 15961e8f889bSDavid Gibson unsigned long address, pte_t *ptep) 15971e8f889bSDavid Gibson { 15981e8f889bSDavid Gibson pte_t entry; 15991e8f889bSDavid Gibson 16007f2e9525SGerald Schaefer entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); 16017f2e9525SGerald Schaefer if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { 16021e8f889bSDavid Gibson update_mmu_cache(vma, address, entry); 16031e8f889bSDavid Gibson } 16048dab5241SBenjamin Herrenschmidt } 16051e8f889bSDavid Gibson 16061e8f889bSDavid Gibson 160763551ae0SDavid Gibson int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, 160863551ae0SDavid Gibson struct vm_area_struct *vma) 160963551ae0SDavid Gibson { 161063551ae0SDavid Gibson pte_t *src_pte, *dst_pte, entry; 161163551ae0SDavid Gibson struct page *ptepage; 16121c59827dSHugh Dickins unsigned long addr; 16131e8f889bSDavid Gibson int cow; 1614a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 1615a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 16161e8f889bSDavid Gibson 16171e8f889bSDavid Gibson cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; 161863551ae0SDavid Gibson 1619a5516438SAndi Kleen for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { 1620c74df32cSHugh Dickins src_pte = huge_pte_offset(src, addr); 1621c74df32cSHugh Dickins if (!src_pte) 1622c74df32cSHugh Dickins continue; 1623a5516438SAndi Kleen dst_pte = huge_pte_alloc(dst, addr, sz); 162463551ae0SDavid Gibson if (!dst_pte) 162563551ae0SDavid Gibson goto nomem; 1626c5c99429SLarry Woodman 1627c5c99429SLarry Woodman /* If the pagetables are shared don't copy or take references */ 1628c5c99429SLarry Woodman if (dst_pte == src_pte) 1629c5c99429SLarry Woodman continue; 1630c5c99429SLarry Woodman 1631c74df32cSHugh Dickins spin_lock(&dst->page_table_lock); 163246478758SNick Piggin spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); 16337f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(src_pte))) { 16341e8f889bSDavid Gibson if (cow) 16357f2e9525SGerald Schaefer huge_ptep_set_wrprotect(src, addr, src_pte); 16367f2e9525SGerald Schaefer entry = huge_ptep_get(src_pte); 163763551ae0SDavid Gibson ptepage = pte_page(entry); 163863551ae0SDavid Gibson get_page(ptepage); 163963551ae0SDavid Gibson set_huge_pte_at(dst, addr, dst_pte, entry); 16401c59827dSHugh Dickins } 16411c59827dSHugh Dickins spin_unlock(&src->page_table_lock); 1642c74df32cSHugh Dickins spin_unlock(&dst->page_table_lock); 164363551ae0SDavid Gibson } 164463551ae0SDavid Gibson return 0; 164563551ae0SDavid Gibson 164663551ae0SDavid Gibson nomem: 164763551ae0SDavid Gibson return -ENOMEM; 164863551ae0SDavid Gibson } 164963551ae0SDavid Gibson 1650502717f4SChen, Kenneth W void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 165104f2cbe3SMel Gorman unsigned long end, struct page *ref_page) 165263551ae0SDavid Gibson { 165363551ae0SDavid Gibson struct mm_struct *mm = vma->vm_mm; 165463551ae0SDavid Gibson unsigned long address; 1655c7546f8fSDavid Gibson pte_t *ptep; 165663551ae0SDavid Gibson pte_t pte; 165763551ae0SDavid Gibson struct page *page; 1658fe1668aeSChen, Kenneth W struct page *tmp; 1659a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 1660a5516438SAndi Kleen unsigned long sz = huge_page_size(h); 1661a5516438SAndi Kleen 1662c0a499c2SChen, Kenneth W /* 1663c0a499c2SChen, Kenneth W * A page gathering list, protected by per file i_mmap_lock. The 1664c0a499c2SChen, Kenneth W * lock is used to avoid list corruption from multiple unmapping 1665c0a499c2SChen, Kenneth W * of the same page since we are using page->lru. 1666c0a499c2SChen, Kenneth W */ 1667fe1668aeSChen, Kenneth W LIST_HEAD(page_list); 166863551ae0SDavid Gibson 166963551ae0SDavid Gibson WARN_ON(!is_vm_hugetlb_page(vma)); 1670a5516438SAndi Kleen BUG_ON(start & ~huge_page_mask(h)); 1671a5516438SAndi Kleen BUG_ON(end & ~huge_page_mask(h)); 167263551ae0SDavid Gibson 1673508034a3SHugh Dickins spin_lock(&mm->page_table_lock); 1674a5516438SAndi Kleen for (address = start; address < end; address += sz) { 1675c7546f8fSDavid Gibson ptep = huge_pte_offset(mm, address); 1676c7546f8fSDavid Gibson if (!ptep) 1677c7546f8fSDavid Gibson continue; 1678c7546f8fSDavid Gibson 167939dde65cSChen, Kenneth W if (huge_pmd_unshare(mm, &address, ptep)) 168039dde65cSChen, Kenneth W continue; 168139dde65cSChen, Kenneth W 168204f2cbe3SMel Gorman /* 168304f2cbe3SMel Gorman * If a reference page is supplied, it is because a specific 168404f2cbe3SMel Gorman * page is being unmapped, not a range. Ensure the page we 168504f2cbe3SMel Gorman * are about to unmap is the actual page of interest. 168604f2cbe3SMel Gorman */ 168704f2cbe3SMel Gorman if (ref_page) { 168804f2cbe3SMel Gorman pte = huge_ptep_get(ptep); 168904f2cbe3SMel Gorman if (huge_pte_none(pte)) 169004f2cbe3SMel Gorman continue; 169104f2cbe3SMel Gorman page = pte_page(pte); 169204f2cbe3SMel Gorman if (page != ref_page) 169304f2cbe3SMel Gorman continue; 169404f2cbe3SMel Gorman 169504f2cbe3SMel Gorman /* 169604f2cbe3SMel Gorman * Mark the VMA as having unmapped its page so that 169704f2cbe3SMel Gorman * future faults in this VMA will fail rather than 169804f2cbe3SMel Gorman * looking like data was lost 169904f2cbe3SMel Gorman */ 170004f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); 170104f2cbe3SMel Gorman } 170204f2cbe3SMel Gorman 1703c7546f8fSDavid Gibson pte = huge_ptep_get_and_clear(mm, address, ptep); 17047f2e9525SGerald Schaefer if (huge_pte_none(pte)) 170563551ae0SDavid Gibson continue; 1706c7546f8fSDavid Gibson 170763551ae0SDavid Gibson page = pte_page(pte); 17086649a386SKen Chen if (pte_dirty(pte)) 17096649a386SKen Chen set_page_dirty(page); 1710fe1668aeSChen, Kenneth W list_add(&page->lru, &page_list); 171163551ae0SDavid Gibson } 17121da177e4SLinus Torvalds spin_unlock(&mm->page_table_lock); 1713508034a3SHugh Dickins flush_tlb_range(vma, start, end); 1714fe1668aeSChen, Kenneth W list_for_each_entry_safe(page, tmp, &page_list, lru) { 1715fe1668aeSChen, Kenneth W list_del(&page->lru); 1716fe1668aeSChen, Kenneth W put_page(page); 1717fe1668aeSChen, Kenneth W } 17181da177e4SLinus Torvalds } 171963551ae0SDavid Gibson 1720502717f4SChen, Kenneth W void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, 172104f2cbe3SMel Gorman unsigned long end, struct page *ref_page) 1722502717f4SChen, Kenneth W { 1723502717f4SChen, Kenneth W spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); 172404f2cbe3SMel Gorman __unmap_hugepage_range(vma, start, end, ref_page); 1725502717f4SChen, Kenneth W spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); 1726502717f4SChen, Kenneth W } 1727502717f4SChen, Kenneth W 172804f2cbe3SMel Gorman /* 172904f2cbe3SMel Gorman * This is called when the original mapper is failing to COW a MAP_PRIVATE 173004f2cbe3SMel Gorman * mappping it owns the reserve page for. The intention is to unmap the page 173104f2cbe3SMel Gorman * from other VMAs and let the children be SIGKILLed if they are faulting the 173204f2cbe3SMel Gorman * same region. 173304f2cbe3SMel Gorman */ 173404f2cbe3SMel Gorman int unmap_ref_private(struct mm_struct *mm, 173504f2cbe3SMel Gorman struct vm_area_struct *vma, 173604f2cbe3SMel Gorman struct page *page, 173704f2cbe3SMel Gorman unsigned long address) 173804f2cbe3SMel Gorman { 173904f2cbe3SMel Gorman struct vm_area_struct *iter_vma; 174004f2cbe3SMel Gorman struct address_space *mapping; 174104f2cbe3SMel Gorman struct prio_tree_iter iter; 174204f2cbe3SMel Gorman pgoff_t pgoff; 174304f2cbe3SMel Gorman 174404f2cbe3SMel Gorman /* 174504f2cbe3SMel Gorman * vm_pgoff is in PAGE_SIZE units, hence the different calculation 174604f2cbe3SMel Gorman * from page cache lookup which is in HPAGE_SIZE units. 174704f2cbe3SMel Gorman */ 174804f2cbe3SMel Gorman address = address & huge_page_mask(hstate_vma(vma)); 174904f2cbe3SMel Gorman pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) 175004f2cbe3SMel Gorman + (vma->vm_pgoff >> PAGE_SHIFT); 175104f2cbe3SMel Gorman mapping = (struct address_space *)page_private(page); 175204f2cbe3SMel Gorman 175304f2cbe3SMel Gorman vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { 175404f2cbe3SMel Gorman /* Do not unmap the current VMA */ 175504f2cbe3SMel Gorman if (iter_vma == vma) 175604f2cbe3SMel Gorman continue; 175704f2cbe3SMel Gorman 175804f2cbe3SMel Gorman /* 175904f2cbe3SMel Gorman * Unmap the page from other VMAs without their own reserves. 176004f2cbe3SMel Gorman * They get marked to be SIGKILLed if they fault in these 176104f2cbe3SMel Gorman * areas. This is because a future no-page fault on this VMA 176204f2cbe3SMel Gorman * could insert a zeroed page instead of the data existing 176304f2cbe3SMel Gorman * from the time of fork. This would look like data corruption 176404f2cbe3SMel Gorman */ 176504f2cbe3SMel Gorman if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) 176604f2cbe3SMel Gorman unmap_hugepage_range(iter_vma, 176704f2cbe3SMel Gorman address, address + HPAGE_SIZE, 176804f2cbe3SMel Gorman page); 176904f2cbe3SMel Gorman } 177004f2cbe3SMel Gorman 177104f2cbe3SMel Gorman return 1; 177204f2cbe3SMel Gorman } 177304f2cbe3SMel Gorman 17741e8f889bSDavid Gibson static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, 177504f2cbe3SMel Gorman unsigned long address, pte_t *ptep, pte_t pte, 177604f2cbe3SMel Gorman struct page *pagecache_page) 17771e8f889bSDavid Gibson { 1778a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 17791e8f889bSDavid Gibson struct page *old_page, *new_page; 178079ac6ba4SDavid Gibson int avoidcopy; 178104f2cbe3SMel Gorman int outside_reserve = 0; 17821e8f889bSDavid Gibson 17831e8f889bSDavid Gibson old_page = pte_page(pte); 17841e8f889bSDavid Gibson 178504f2cbe3SMel Gorman retry_avoidcopy: 17861e8f889bSDavid Gibson /* If no-one else is actually using this page, avoid the copy 17871e8f889bSDavid Gibson * and just make the page writable */ 17881e8f889bSDavid Gibson avoidcopy = (page_count(old_page) == 1); 17891e8f889bSDavid Gibson if (avoidcopy) { 17901e8f889bSDavid Gibson set_huge_ptep_writable(vma, address, ptep); 179183c54070SNick Piggin return 0; 17921e8f889bSDavid Gibson } 17931e8f889bSDavid Gibson 179404f2cbe3SMel Gorman /* 179504f2cbe3SMel Gorman * If the process that created a MAP_PRIVATE mapping is about to 179604f2cbe3SMel Gorman * perform a COW due to a shared page count, attempt to satisfy 179704f2cbe3SMel Gorman * the allocation without using the existing reserves. The pagecache 179804f2cbe3SMel Gorman * page is used to determine if the reserve at this address was 179904f2cbe3SMel Gorman * consumed or not. If reserves were used, a partial faulted mapping 180004f2cbe3SMel Gorman * at the time of fork() could consume its reserves on COW instead 180104f2cbe3SMel Gorman * of the full address range. 180204f2cbe3SMel Gorman */ 180304f2cbe3SMel Gorman if (!(vma->vm_flags & VM_SHARED) && 180404f2cbe3SMel Gorman is_vma_resv_set(vma, HPAGE_RESV_OWNER) && 180504f2cbe3SMel Gorman old_page != pagecache_page) 180604f2cbe3SMel Gorman outside_reserve = 1; 180704f2cbe3SMel Gorman 18081e8f889bSDavid Gibson page_cache_get(old_page); 180904f2cbe3SMel Gorman new_page = alloc_huge_page(vma, address, outside_reserve); 18101e8f889bSDavid Gibson 18112fc39cecSAdam Litke if (IS_ERR(new_page)) { 18121e8f889bSDavid Gibson page_cache_release(old_page); 181304f2cbe3SMel Gorman 181404f2cbe3SMel Gorman /* 181504f2cbe3SMel Gorman * If a process owning a MAP_PRIVATE mapping fails to COW, 181604f2cbe3SMel Gorman * it is due to references held by a child and an insufficient 181704f2cbe3SMel Gorman * huge page pool. To guarantee the original mappers 181804f2cbe3SMel Gorman * reliability, unmap the page from child processes. The child 181904f2cbe3SMel Gorman * may get SIGKILLed if it later faults. 182004f2cbe3SMel Gorman */ 182104f2cbe3SMel Gorman if (outside_reserve) { 182204f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 182304f2cbe3SMel Gorman if (unmap_ref_private(mm, vma, old_page, address)) { 182404f2cbe3SMel Gorman BUG_ON(page_count(old_page) != 1); 182504f2cbe3SMel Gorman BUG_ON(huge_pte_none(pte)); 182604f2cbe3SMel Gorman goto retry_avoidcopy; 182704f2cbe3SMel Gorman } 182804f2cbe3SMel Gorman WARN_ON_ONCE(1); 182904f2cbe3SMel Gorman } 183004f2cbe3SMel Gorman 18312fc39cecSAdam Litke return -PTR_ERR(new_page); 18321e8f889bSDavid Gibson } 18331e8f889bSDavid Gibson 18341e8f889bSDavid Gibson spin_unlock(&mm->page_table_lock); 18359de455b2SAtsushi Nemoto copy_huge_page(new_page, old_page, address, vma); 18360ed361deSNick Piggin __SetPageUptodate(new_page); 18371e8f889bSDavid Gibson spin_lock(&mm->page_table_lock); 18381e8f889bSDavid Gibson 1839a5516438SAndi Kleen ptep = huge_pte_offset(mm, address & huge_page_mask(h)); 18407f2e9525SGerald Schaefer if (likely(pte_same(huge_ptep_get(ptep), pte))) { 18411e8f889bSDavid Gibson /* Break COW */ 18428fe627ecSGerald Schaefer huge_ptep_clear_flush(vma, address, ptep); 18431e8f889bSDavid Gibson set_huge_pte_at(mm, address, ptep, 18441e8f889bSDavid Gibson make_huge_pte(vma, new_page, 1)); 18451e8f889bSDavid Gibson /* Make the old page be freed below */ 18461e8f889bSDavid Gibson new_page = old_page; 18471e8f889bSDavid Gibson } 18481e8f889bSDavid Gibson page_cache_release(new_page); 18491e8f889bSDavid Gibson page_cache_release(old_page); 185083c54070SNick Piggin return 0; 18511e8f889bSDavid Gibson } 18521e8f889bSDavid Gibson 185304f2cbe3SMel Gorman /* Return the pagecache page at a given address within a VMA */ 1854a5516438SAndi Kleen static struct page *hugetlbfs_pagecache_page(struct hstate *h, 1855a5516438SAndi Kleen struct vm_area_struct *vma, unsigned long address) 185604f2cbe3SMel Gorman { 185704f2cbe3SMel Gorman struct address_space *mapping; 1858e7c4b0bfSAndy Whitcroft pgoff_t idx; 185904f2cbe3SMel Gorman 186004f2cbe3SMel Gorman mapping = vma->vm_file->f_mapping; 1861a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 186204f2cbe3SMel Gorman 186304f2cbe3SMel Gorman return find_lock_page(mapping, idx); 186404f2cbe3SMel Gorman } 186504f2cbe3SMel Gorman 1866a1ed3ddaSRobert P. J. Day static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, 18671e8f889bSDavid Gibson unsigned long address, pte_t *ptep, int write_access) 1868ac9b9c66SHugh Dickins { 1869a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 1870ac9b9c66SHugh Dickins int ret = VM_FAULT_SIGBUS; 1871e7c4b0bfSAndy Whitcroft pgoff_t idx; 18724c887265SAdam Litke unsigned long size; 18734c887265SAdam Litke struct page *page; 18744c887265SAdam Litke struct address_space *mapping; 18751e8f889bSDavid Gibson pte_t new_pte; 18764c887265SAdam Litke 187704f2cbe3SMel Gorman /* 187804f2cbe3SMel Gorman * Currently, we are forced to kill the process in the event the 187904f2cbe3SMel Gorman * original mapper has unmapped pages from the child due to a failed 188004f2cbe3SMel Gorman * COW. Warn that such a situation has occured as it may not be obvious 188104f2cbe3SMel Gorman */ 188204f2cbe3SMel Gorman if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { 188304f2cbe3SMel Gorman printk(KERN_WARNING 188404f2cbe3SMel Gorman "PID %d killed due to inadequate hugepage pool\n", 188504f2cbe3SMel Gorman current->pid); 188604f2cbe3SMel Gorman return ret; 188704f2cbe3SMel Gorman } 188804f2cbe3SMel Gorman 18894c887265SAdam Litke mapping = vma->vm_file->f_mapping; 1890a5516438SAndi Kleen idx = vma_hugecache_offset(h, vma, address); 18914c887265SAdam Litke 18924c887265SAdam Litke /* 18934c887265SAdam Litke * Use page lock to guard against racing truncation 18944c887265SAdam Litke * before we get page_table_lock. 18954c887265SAdam Litke */ 18966bda666aSChristoph Lameter retry: 18976bda666aSChristoph Lameter page = find_lock_page(mapping, idx); 18986bda666aSChristoph Lameter if (!page) { 1899a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 1900ebed4bfcSHugh Dickins if (idx >= size) 1901ebed4bfcSHugh Dickins goto out; 190204f2cbe3SMel Gorman page = alloc_huge_page(vma, address, 0); 19032fc39cecSAdam Litke if (IS_ERR(page)) { 19042fc39cecSAdam Litke ret = -PTR_ERR(page); 19056bda666aSChristoph Lameter goto out; 19066bda666aSChristoph Lameter } 1907a5516438SAndi Kleen clear_huge_page(page, address, huge_page_size(h)); 19080ed361deSNick Piggin __SetPageUptodate(page); 1909ac9b9c66SHugh Dickins 19106bda666aSChristoph Lameter if (vma->vm_flags & VM_SHARED) { 19116bda666aSChristoph Lameter int err; 191245c682a6SKen Chen struct inode *inode = mapping->host; 19136bda666aSChristoph Lameter 19146bda666aSChristoph Lameter err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); 19156bda666aSChristoph Lameter if (err) { 19166bda666aSChristoph Lameter put_page(page); 19176bda666aSChristoph Lameter if (err == -EEXIST) 19186bda666aSChristoph Lameter goto retry; 19196bda666aSChristoph Lameter goto out; 19206bda666aSChristoph Lameter } 192145c682a6SKen Chen 192245c682a6SKen Chen spin_lock(&inode->i_lock); 1923a5516438SAndi Kleen inode->i_blocks += blocks_per_huge_page(h); 192445c682a6SKen Chen spin_unlock(&inode->i_lock); 19256bda666aSChristoph Lameter } else 19266bda666aSChristoph Lameter lock_page(page); 19276bda666aSChristoph Lameter } 19281e8f889bSDavid Gibson 1929ac9b9c66SHugh Dickins spin_lock(&mm->page_table_lock); 1930a5516438SAndi Kleen size = i_size_read(mapping->host) >> huge_page_shift(h); 19314c887265SAdam Litke if (idx >= size) 19324c887265SAdam Litke goto backout; 19334c887265SAdam Litke 193483c54070SNick Piggin ret = 0; 19357f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(ptep))) 19364c887265SAdam Litke goto backout; 19374c887265SAdam Litke 19381e8f889bSDavid Gibson new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) 19391e8f889bSDavid Gibson && (vma->vm_flags & VM_SHARED))); 19401e8f889bSDavid Gibson set_huge_pte_at(mm, address, ptep, new_pte); 19411e8f889bSDavid Gibson 19421e8f889bSDavid Gibson if (write_access && !(vma->vm_flags & VM_SHARED)) { 19431e8f889bSDavid Gibson /* Optimization, do the COW without a second fault */ 194404f2cbe3SMel Gorman ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); 19451e8f889bSDavid Gibson } 19461e8f889bSDavid Gibson 1947ac9b9c66SHugh Dickins spin_unlock(&mm->page_table_lock); 19484c887265SAdam Litke unlock_page(page); 19494c887265SAdam Litke out: 1950ac9b9c66SHugh Dickins return ret; 19514c887265SAdam Litke 19524c887265SAdam Litke backout: 19534c887265SAdam Litke spin_unlock(&mm->page_table_lock); 19544c887265SAdam Litke unlock_page(page); 19554c887265SAdam Litke put_page(page); 19564c887265SAdam Litke goto out; 1957ac9b9c66SHugh Dickins } 1958ac9b9c66SHugh Dickins 195986e5216fSAdam Litke int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 196086e5216fSAdam Litke unsigned long address, int write_access) 196186e5216fSAdam Litke { 196286e5216fSAdam Litke pte_t *ptep; 196386e5216fSAdam Litke pte_t entry; 19641e8f889bSDavid Gibson int ret; 19653935baa9SDavid Gibson static DEFINE_MUTEX(hugetlb_instantiation_mutex); 1966a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 196786e5216fSAdam Litke 1968a5516438SAndi Kleen ptep = huge_pte_alloc(mm, address, huge_page_size(h)); 196986e5216fSAdam Litke if (!ptep) 197086e5216fSAdam Litke return VM_FAULT_OOM; 197186e5216fSAdam Litke 19723935baa9SDavid Gibson /* 19733935baa9SDavid Gibson * Serialize hugepage allocation and instantiation, so that we don't 19743935baa9SDavid Gibson * get spurious allocation failures if two CPUs race to instantiate 19753935baa9SDavid Gibson * the same page in the page cache. 19763935baa9SDavid Gibson */ 19773935baa9SDavid Gibson mutex_lock(&hugetlb_instantiation_mutex); 19787f2e9525SGerald Schaefer entry = huge_ptep_get(ptep); 19797f2e9525SGerald Schaefer if (huge_pte_none(entry)) { 19803935baa9SDavid Gibson ret = hugetlb_no_page(mm, vma, address, ptep, write_access); 19813935baa9SDavid Gibson mutex_unlock(&hugetlb_instantiation_mutex); 19823935baa9SDavid Gibson return ret; 19833935baa9SDavid Gibson } 198486e5216fSAdam Litke 198583c54070SNick Piggin ret = 0; 19861e8f889bSDavid Gibson 19871e8f889bSDavid Gibson spin_lock(&mm->page_table_lock); 19881e8f889bSDavid Gibson /* Check for a racing update before calling hugetlb_cow */ 19897f2e9525SGerald Schaefer if (likely(pte_same(entry, huge_ptep_get(ptep)))) 199004f2cbe3SMel Gorman if (write_access && !pte_write(entry)) { 199104f2cbe3SMel Gorman struct page *page; 1992a5516438SAndi Kleen page = hugetlbfs_pagecache_page(h, vma, address); 199304f2cbe3SMel Gorman ret = hugetlb_cow(mm, vma, address, ptep, entry, page); 199404f2cbe3SMel Gorman if (page) { 199504f2cbe3SMel Gorman unlock_page(page); 199604f2cbe3SMel Gorman put_page(page); 199704f2cbe3SMel Gorman } 199804f2cbe3SMel Gorman } 19991e8f889bSDavid Gibson spin_unlock(&mm->page_table_lock); 20003935baa9SDavid Gibson mutex_unlock(&hugetlb_instantiation_mutex); 20011e8f889bSDavid Gibson 20021e8f889bSDavid Gibson return ret; 200386e5216fSAdam Litke } 200486e5216fSAdam Litke 2005ceb86879SAndi Kleen /* Can be overriden by architectures */ 2006ceb86879SAndi Kleen __attribute__((weak)) struct page * 2007ceb86879SAndi Kleen follow_huge_pud(struct mm_struct *mm, unsigned long address, 2008ceb86879SAndi Kleen pud_t *pud, int write) 2009ceb86879SAndi Kleen { 2010ceb86879SAndi Kleen BUG(); 2011ceb86879SAndi Kleen return NULL; 2012ceb86879SAndi Kleen } 2013ceb86879SAndi Kleen 201463551ae0SDavid Gibson int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, 201563551ae0SDavid Gibson struct page **pages, struct vm_area_struct **vmas, 20165b23dbe8SAdam Litke unsigned long *position, int *length, int i, 20175b23dbe8SAdam Litke int write) 201863551ae0SDavid Gibson { 2019d5d4b0aaSChen, Kenneth W unsigned long pfn_offset; 2020d5d4b0aaSChen, Kenneth W unsigned long vaddr = *position; 202163551ae0SDavid Gibson int remainder = *length; 2022a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 202363551ae0SDavid Gibson 20241c59827dSHugh Dickins spin_lock(&mm->page_table_lock); 202563551ae0SDavid Gibson while (vaddr < vma->vm_end && remainder) { 202663551ae0SDavid Gibson pte_t *pte; 202763551ae0SDavid Gibson struct page *page; 202863551ae0SDavid Gibson 20294c887265SAdam Litke /* 20304c887265SAdam Litke * Some archs (sparc64, sh*) have multiple pte_ts to 20314c887265SAdam Litke * each hugepage. We have to make * sure we get the 20324c887265SAdam Litke * first, for the page indexing below to work. 20334c887265SAdam Litke */ 2034a5516438SAndi Kleen pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); 203563551ae0SDavid Gibson 20367f2e9525SGerald Schaefer if (!pte || huge_pte_none(huge_ptep_get(pte)) || 20377f2e9525SGerald Schaefer (write && !pte_write(huge_ptep_get(pte)))) { 20384c887265SAdam Litke int ret; 20394c887265SAdam Litke 20404c887265SAdam Litke spin_unlock(&mm->page_table_lock); 20415b23dbe8SAdam Litke ret = hugetlb_fault(mm, vma, vaddr, write); 20424c887265SAdam Litke spin_lock(&mm->page_table_lock); 2043a89182c7SAdam Litke if (!(ret & VM_FAULT_ERROR)) 20444c887265SAdam Litke continue; 20454c887265SAdam Litke 20461c59827dSHugh Dickins remainder = 0; 20471c59827dSHugh Dickins if (!i) 20481c59827dSHugh Dickins i = -EFAULT; 20491c59827dSHugh Dickins break; 20501c59827dSHugh Dickins } 205163551ae0SDavid Gibson 2052a5516438SAndi Kleen pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; 20537f2e9525SGerald Schaefer page = pte_page(huge_ptep_get(pte)); 2054d5d4b0aaSChen, Kenneth W same_page: 2055d6692183SChen, Kenneth W if (pages) { 205663551ae0SDavid Gibson get_page(page); 2057d5d4b0aaSChen, Kenneth W pages[i] = page + pfn_offset; 2058d6692183SChen, Kenneth W } 205963551ae0SDavid Gibson 206063551ae0SDavid Gibson if (vmas) 206163551ae0SDavid Gibson vmas[i] = vma; 206263551ae0SDavid Gibson 206363551ae0SDavid Gibson vaddr += PAGE_SIZE; 2064d5d4b0aaSChen, Kenneth W ++pfn_offset; 206563551ae0SDavid Gibson --remainder; 206663551ae0SDavid Gibson ++i; 2067d5d4b0aaSChen, Kenneth W if (vaddr < vma->vm_end && remainder && 2068a5516438SAndi Kleen pfn_offset < pages_per_huge_page(h)) { 2069d5d4b0aaSChen, Kenneth W /* 2070d5d4b0aaSChen, Kenneth W * We use pfn_offset to avoid touching the pageframes 2071d5d4b0aaSChen, Kenneth W * of this compound page. 2072d5d4b0aaSChen, Kenneth W */ 2073d5d4b0aaSChen, Kenneth W goto same_page; 2074d5d4b0aaSChen, Kenneth W } 207563551ae0SDavid Gibson } 20761c59827dSHugh Dickins spin_unlock(&mm->page_table_lock); 207763551ae0SDavid Gibson *length = remainder; 207863551ae0SDavid Gibson *position = vaddr; 207963551ae0SDavid Gibson 208063551ae0SDavid Gibson return i; 208163551ae0SDavid Gibson } 20828f860591SZhang, Yanmin 20838f860591SZhang, Yanmin void hugetlb_change_protection(struct vm_area_struct *vma, 20848f860591SZhang, Yanmin unsigned long address, unsigned long end, pgprot_t newprot) 20858f860591SZhang, Yanmin { 20868f860591SZhang, Yanmin struct mm_struct *mm = vma->vm_mm; 20878f860591SZhang, Yanmin unsigned long start = address; 20888f860591SZhang, Yanmin pte_t *ptep; 20898f860591SZhang, Yanmin pte_t pte; 2090a5516438SAndi Kleen struct hstate *h = hstate_vma(vma); 20918f860591SZhang, Yanmin 20928f860591SZhang, Yanmin BUG_ON(address >= end); 20938f860591SZhang, Yanmin flush_cache_range(vma, address, end); 20948f860591SZhang, Yanmin 209539dde65cSChen, Kenneth W spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); 20968f860591SZhang, Yanmin spin_lock(&mm->page_table_lock); 2097a5516438SAndi Kleen for (; address < end; address += huge_page_size(h)) { 20988f860591SZhang, Yanmin ptep = huge_pte_offset(mm, address); 20998f860591SZhang, Yanmin if (!ptep) 21008f860591SZhang, Yanmin continue; 210139dde65cSChen, Kenneth W if (huge_pmd_unshare(mm, &address, ptep)) 210239dde65cSChen, Kenneth W continue; 21037f2e9525SGerald Schaefer if (!huge_pte_none(huge_ptep_get(ptep))) { 21048f860591SZhang, Yanmin pte = huge_ptep_get_and_clear(mm, address, ptep); 21058f860591SZhang, Yanmin pte = pte_mkhuge(pte_modify(pte, newprot)); 21068f860591SZhang, Yanmin set_huge_pte_at(mm, address, ptep, pte); 21078f860591SZhang, Yanmin } 21088f860591SZhang, Yanmin } 21098f860591SZhang, Yanmin spin_unlock(&mm->page_table_lock); 211039dde65cSChen, Kenneth W spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); 21118f860591SZhang, Yanmin 21128f860591SZhang, Yanmin flush_tlb_range(vma, start, end); 21138f860591SZhang, Yanmin } 21148f860591SZhang, Yanmin 2115a1e78772SMel Gorman int hugetlb_reserve_pages(struct inode *inode, 2116a1e78772SMel Gorman long from, long to, 2117a1e78772SMel Gorman struct vm_area_struct *vma) 2118e4e574b7SAdam Litke { 2119e4e574b7SAdam Litke long ret, chg; 2120a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 2121e4e574b7SAdam Litke 2122c37f9fb1SAndy Whitcroft if (vma && vma->vm_flags & VM_NORESERVE) 2123c37f9fb1SAndy Whitcroft return 0; 2124c37f9fb1SAndy Whitcroft 2125a1e78772SMel Gorman /* 2126a1e78772SMel Gorman * Shared mappings base their reservation on the number of pages that 2127a1e78772SMel Gorman * are already allocated on behalf of the file. Private mappings need 2128a1e78772SMel Gorman * to reserve the full area even if read-only as mprotect() may be 2129a1e78772SMel Gorman * called to make the mapping read-write. Assume !vma is a shm mapping 2130a1e78772SMel Gorman */ 2131a1e78772SMel Gorman if (!vma || vma->vm_flags & VM_SHARED) 2132e4e574b7SAdam Litke chg = region_chg(&inode->i_mapping->private_list, from, to); 2133a1e78772SMel Gorman else { 213484afd99bSAndy Whitcroft struct resv_map *resv_map = resv_map_alloc(); 213584afd99bSAndy Whitcroft if (!resv_map) 213684afd99bSAndy Whitcroft return -ENOMEM; 213784afd99bSAndy Whitcroft 2138a1e78772SMel Gorman chg = to - from; 213984afd99bSAndy Whitcroft 214084afd99bSAndy Whitcroft set_vma_resv_map(vma, resv_map); 214104f2cbe3SMel Gorman set_vma_resv_flags(vma, HPAGE_RESV_OWNER); 2142a1e78772SMel Gorman } 2143a1e78772SMel Gorman 2144e4e574b7SAdam Litke if (chg < 0) 2145e4e574b7SAdam Litke return chg; 21468a630112SKen Chen 214790d8b7e6SAdam Litke if (hugetlb_get_quota(inode->i_mapping, chg)) 214890d8b7e6SAdam Litke return -ENOSPC; 2149a5516438SAndi Kleen ret = hugetlb_acct_memory(h, chg); 215068842c9bSKen Chen if (ret < 0) { 215168842c9bSKen Chen hugetlb_put_quota(inode->i_mapping, chg); 2152a43a8c39SChen, Kenneth W return ret; 215368842c9bSKen Chen } 2154a1e78772SMel Gorman if (!vma || vma->vm_flags & VM_SHARED) 2155a43a8c39SChen, Kenneth W region_add(&inode->i_mapping->private_list, from, to); 2156a43a8c39SChen, Kenneth W return 0; 2157a43a8c39SChen, Kenneth W } 2158a43a8c39SChen, Kenneth W 2159a43a8c39SChen, Kenneth W void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) 2160a43a8c39SChen, Kenneth W { 2161a5516438SAndi Kleen struct hstate *h = hstate_inode(inode); 2162a43a8c39SChen, Kenneth W long chg = region_truncate(&inode->i_mapping->private_list, offset); 216345c682a6SKen Chen 216445c682a6SKen Chen spin_lock(&inode->i_lock); 2165a5516438SAndi Kleen inode->i_blocks -= blocks_per_huge_page(h); 216645c682a6SKen Chen spin_unlock(&inode->i_lock); 216745c682a6SKen Chen 216890d8b7e6SAdam Litke hugetlb_put_quota(inode->i_mapping, (chg - freed)); 2169a5516438SAndi Kleen hugetlb_acct_memory(h, -(chg - freed)); 2170a43a8c39SChen, Kenneth W } 2171