Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Generic hugetlb support. |
| 3 | * (C) William Irwin, April 2004 |
| 4 | */ |
| 5 | #include <linux/gfp.h> |
| 6 | #include <linux/list.h> |
| 7 | #include <linux/init.h> |
| 8 | #include <linux/module.h> |
| 9 | #include <linux/mm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | #include <linux/sysctl.h> |
| 11 | #include <linux/highmem.h> |
| 12 | #include <linux/nodemask.h> |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 13 | #include <linux/pagemap.h> |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 14 | #include <linux/mempolicy.h> |
Christoph Lameter | aea47ff | 2006-01-08 01:00:57 -0800 | [diff] [blame] | 15 | #include <linux/cpuset.h> |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 16 | #include <linux/mutex.h> |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 17 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 18 | #include <asm/page.h> |
| 19 | #include <asm/pgtable.h> |
| 20 | |
| 21 | #include <linux/hugetlb.h> |
Nick Piggin | 7835e98 | 2006-03-22 00:08:40 -0800 | [diff] [blame] | 22 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | |
| 24 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | unsigned long max_huge_pages; |
Nishanth Aravamudan | 064d9ef | 2008-02-13 15:03:19 -0800 | [diff] [blame] | 26 | unsigned long sysctl_overcommit_huge_pages; |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 27 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
| 28 | unsigned long hugepages_treat_as_movable; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 29 | |
| 30 | struct hstate default_hstate; |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 31 | |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 32 | /* |
| 33 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages |
| 34 | */ |
| 35 | static DEFINE_SPINLOCK(hugetlb_lock); |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 36 | |
Andy Whitcroft | e7c4b0b | 2008-07-23 21:27:26 -0700 | [diff] [blame] | 37 | /* |
Andy Whitcroft | 9682290 | 2008-07-23 21:27:29 -0700 | [diff] [blame] | 38 | * Region tracking -- allows tracking of reservations and instantiated pages |
| 39 | * across the pages in a mapping. |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 40 | * |
| 41 | * The region data structures are protected by a combination of the mmap_sem |
| 42 | * and the hugetlb_instantion_mutex. To access or modify a region the caller |
| 43 | * must either hold the mmap_sem for write, or the mmap_sem for read and |
| 44 | * the hugetlb_instantiation mutex: |
| 45 | * |
| 46 | * down_write(&mm->mmap_sem); |
| 47 | * or |
| 48 | * down_read(&mm->mmap_sem); |
| 49 | * mutex_lock(&hugetlb_instantiation_mutex); |
Andy Whitcroft | 9682290 | 2008-07-23 21:27:29 -0700 | [diff] [blame] | 50 | */ |
| 51 | struct file_region { |
| 52 | struct list_head link; |
| 53 | long from; |
| 54 | long to; |
| 55 | }; |
| 56 | |
| 57 | static long region_add(struct list_head *head, long f, long t) |
| 58 | { |
| 59 | struct file_region *rg, *nrg, *trg; |
| 60 | |
| 61 | /* Locate the region we are either in or before. */ |
| 62 | list_for_each_entry(rg, head, link) |
| 63 | if (f <= rg->to) |
| 64 | break; |
| 65 | |
| 66 | /* Round our left edge to the current segment if it encloses us. */ |
| 67 | if (f > rg->from) |
| 68 | f = rg->from; |
| 69 | |
| 70 | /* Check for and consume any regions we now overlap with. */ |
| 71 | nrg = rg; |
| 72 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
| 73 | if (&rg->link == head) |
| 74 | break; |
| 75 | if (rg->from > t) |
| 76 | break; |
| 77 | |
| 78 | /* If this area reaches higher then extend our area to |
| 79 | * include it completely. If this is not the first area |
| 80 | * which we intend to reuse, free it. */ |
| 81 | if (rg->to > t) |
| 82 | t = rg->to; |
| 83 | if (rg != nrg) { |
| 84 | list_del(&rg->link); |
| 85 | kfree(rg); |
| 86 | } |
| 87 | } |
| 88 | nrg->from = f; |
| 89 | nrg->to = t; |
| 90 | return 0; |
| 91 | } |
| 92 | |
| 93 | static long region_chg(struct list_head *head, long f, long t) |
| 94 | { |
| 95 | struct file_region *rg, *nrg; |
| 96 | long chg = 0; |
| 97 | |
| 98 | /* Locate the region we are before or in. */ |
| 99 | list_for_each_entry(rg, head, link) |
| 100 | if (f <= rg->to) |
| 101 | break; |
| 102 | |
| 103 | /* If we are below the current region then a new region is required. |
| 104 | * Subtle, allocate a new region at the position but make it zero |
| 105 | * size such that we can guarantee to record the reservation. */ |
| 106 | if (&rg->link == head || t < rg->from) { |
| 107 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); |
| 108 | if (!nrg) |
| 109 | return -ENOMEM; |
| 110 | nrg->from = f; |
| 111 | nrg->to = f; |
| 112 | INIT_LIST_HEAD(&nrg->link); |
| 113 | list_add(&nrg->link, rg->link.prev); |
| 114 | |
| 115 | return t - f; |
| 116 | } |
| 117 | |
| 118 | /* Round our left edge to the current segment if it encloses us. */ |
| 119 | if (f > rg->from) |
| 120 | f = rg->from; |
| 121 | chg = t - f; |
| 122 | |
| 123 | /* Check for and consume any regions we now overlap with. */ |
| 124 | list_for_each_entry(rg, rg->link.prev, link) { |
| 125 | if (&rg->link == head) |
| 126 | break; |
| 127 | if (rg->from > t) |
| 128 | return chg; |
| 129 | |
| 130 | /* We overlap with this area, if it extends futher than |
| 131 | * us then we must extend ourselves. Account for its |
| 132 | * existing reservation. */ |
| 133 | if (rg->to > t) { |
| 134 | chg += rg->to - t; |
| 135 | t = rg->to; |
| 136 | } |
| 137 | chg -= rg->to - rg->from; |
| 138 | } |
| 139 | return chg; |
| 140 | } |
| 141 | |
| 142 | static long region_truncate(struct list_head *head, long end) |
| 143 | { |
| 144 | struct file_region *rg, *trg; |
| 145 | long chg = 0; |
| 146 | |
| 147 | /* Locate the region we are either in or before. */ |
| 148 | list_for_each_entry(rg, head, link) |
| 149 | if (end <= rg->to) |
| 150 | break; |
| 151 | if (&rg->link == head) |
| 152 | return 0; |
| 153 | |
| 154 | /* If we are in the middle of a region then adjust it. */ |
| 155 | if (end > rg->from) { |
| 156 | chg = rg->to - end; |
| 157 | rg->to = end; |
| 158 | rg = list_entry(rg->link.next, typeof(*rg), link); |
| 159 | } |
| 160 | |
| 161 | /* Drop any remaining regions. */ |
| 162 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
| 163 | if (&rg->link == head) |
| 164 | break; |
| 165 | chg += rg->to - rg->from; |
| 166 | list_del(&rg->link); |
| 167 | kfree(rg); |
| 168 | } |
| 169 | return chg; |
| 170 | } |
| 171 | |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 172 | static long region_count(struct list_head *head, long f, long t) |
| 173 | { |
| 174 | struct file_region *rg; |
| 175 | long chg = 0; |
| 176 | |
| 177 | /* Locate each segment we overlap with, and count that overlap. */ |
| 178 | list_for_each_entry(rg, head, link) { |
| 179 | int seg_from; |
| 180 | int seg_to; |
| 181 | |
| 182 | if (rg->to <= f) |
| 183 | continue; |
| 184 | if (rg->from >= t) |
| 185 | break; |
| 186 | |
| 187 | seg_from = max(rg->from, f); |
| 188 | seg_to = min(rg->to, t); |
| 189 | |
| 190 | chg += seg_to - seg_from; |
| 191 | } |
| 192 | |
| 193 | return chg; |
| 194 | } |
| 195 | |
Andy Whitcroft | 9682290 | 2008-07-23 21:27:29 -0700 | [diff] [blame] | 196 | /* |
Andy Whitcroft | e7c4b0b | 2008-07-23 21:27:26 -0700 | [diff] [blame] | 197 | * Convert the address within this vma to the page offset within |
Andy Whitcroft | e7c4b0b | 2008-07-23 21:27:26 -0700 | [diff] [blame] | 198 | * the mapping, in pagecache page units; huge pages here. |
| 199 | */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 200 | static pgoff_t vma_hugecache_offset(struct hstate *h, |
| 201 | struct vm_area_struct *vma, unsigned long address) |
Andy Whitcroft | e7c4b0b | 2008-07-23 21:27:26 -0700 | [diff] [blame] | 202 | { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 203 | return ((address - vma->vm_start) >> huge_page_shift(h)) + |
| 204 | (vma->vm_pgoff >> huge_page_order(h)); |
Andy Whitcroft | e7c4b0b | 2008-07-23 21:27:26 -0700 | [diff] [blame] | 205 | } |
| 206 | |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 207 | /* |
| 208 | * Flags for MAP_PRIVATE reservations. These are stored in the bottom |
| 209 | * bits of the reservation map pointer, which are always clear due to |
| 210 | * alignment. |
| 211 | */ |
| 212 | #define HPAGE_RESV_OWNER (1UL << 0) |
| 213 | #define HPAGE_RESV_UNMAPPED (1UL << 1) |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 214 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 215 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 216 | /* |
| 217 | * These helpers are used to track how many pages are reserved for |
| 218 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() |
| 219 | * is guaranteed to have their future faults succeed. |
| 220 | * |
| 221 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), |
| 222 | * the reserve counters are updated with the hugetlb_lock held. It is safe |
| 223 | * to reset the VMA at fork() time as it is not in use yet and there is no |
| 224 | * chance of the global counters getting corrupted as a result of the values. |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 225 | * |
| 226 | * The private mapping reservation is represented in a subtly different |
| 227 | * manner to a shared mapping. A shared mapping has a region map associated |
| 228 | * with the underlying file, this region map represents the backing file |
| 229 | * pages which have ever had a reservation assigned which this persists even |
| 230 | * after the page is instantiated. A private mapping has a region map |
| 231 | * associated with the original mmap which is attached to all VMAs which |
| 232 | * reference it, this region map represents those offsets which have consumed |
| 233 | * reservation ie. where pages have been instantiated. |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 234 | */ |
Andy Whitcroft | e7c4b0b | 2008-07-23 21:27:26 -0700 | [diff] [blame] | 235 | static unsigned long get_vma_private_data(struct vm_area_struct *vma) |
| 236 | { |
| 237 | return (unsigned long)vma->vm_private_data; |
| 238 | } |
| 239 | |
| 240 | static void set_vma_private_data(struct vm_area_struct *vma, |
| 241 | unsigned long value) |
| 242 | { |
| 243 | vma->vm_private_data = (void *)value; |
| 244 | } |
| 245 | |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 246 | struct resv_map { |
| 247 | struct kref refs; |
| 248 | struct list_head regions; |
| 249 | }; |
| 250 | |
| 251 | struct resv_map *resv_map_alloc(void) |
| 252 | { |
| 253 | struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); |
| 254 | if (!resv_map) |
| 255 | return NULL; |
| 256 | |
| 257 | kref_init(&resv_map->refs); |
| 258 | INIT_LIST_HEAD(&resv_map->regions); |
| 259 | |
| 260 | return resv_map; |
| 261 | } |
| 262 | |
| 263 | void resv_map_release(struct kref *ref) |
| 264 | { |
| 265 | struct resv_map *resv_map = container_of(ref, struct resv_map, refs); |
| 266 | |
| 267 | /* Clear out any active regions before we release the map. */ |
| 268 | region_truncate(&resv_map->regions, 0); |
| 269 | kfree(resv_map); |
| 270 | } |
| 271 | |
| 272 | static struct resv_map *vma_resv_map(struct vm_area_struct *vma) |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 273 | { |
| 274 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
| 275 | if (!(vma->vm_flags & VM_SHARED)) |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 276 | return (struct resv_map *)(get_vma_private_data(vma) & |
| 277 | ~HPAGE_RESV_MASK); |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 278 | return 0; |
| 279 | } |
| 280 | |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 281 | static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 282 | { |
| 283 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
| 284 | VM_BUG_ON(vma->vm_flags & VM_SHARED); |
| 285 | |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 286 | set_vma_private_data(vma, (get_vma_private_data(vma) & |
| 287 | HPAGE_RESV_MASK) | (unsigned long)map); |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 288 | } |
| 289 | |
| 290 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) |
| 291 | { |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 292 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
Andy Whitcroft | e7c4b0b | 2008-07-23 21:27:26 -0700 | [diff] [blame] | 293 | VM_BUG_ON(vma->vm_flags & VM_SHARED); |
| 294 | |
| 295 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 296 | } |
| 297 | |
| 298 | static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) |
| 299 | { |
| 300 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
Andy Whitcroft | e7c4b0b | 2008-07-23 21:27:26 -0700 | [diff] [blame] | 301 | |
| 302 | return (get_vma_private_data(vma) & flag) != 0; |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 303 | } |
| 304 | |
| 305 | /* Decrement the reserved pages in the hugepage pool by one */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 306 | static void decrement_hugepage_resv_vma(struct hstate *h, |
| 307 | struct vm_area_struct *vma) |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 308 | { |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 309 | if (vma->vm_flags & VM_NORESERVE) |
| 310 | return; |
| 311 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 312 | if (vma->vm_flags & VM_SHARED) { |
| 313 | /* Shared mappings always use reserves */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 314 | h->resv_huge_pages--; |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 315 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 316 | /* |
| 317 | * Only the process that called mmap() has reserves for |
| 318 | * private mappings. |
| 319 | */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 320 | h->resv_huge_pages--; |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 321 | } |
| 322 | } |
| 323 | |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 324 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 325 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
| 326 | { |
| 327 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
| 328 | if (!(vma->vm_flags & VM_SHARED)) |
| 329 | vma->vm_private_data = (void *)0; |
| 330 | } |
| 331 | |
| 332 | /* Returns true if the VMA has associated reserve pages */ |
| 333 | static int vma_has_private_reserves(struct vm_area_struct *vma) |
| 334 | { |
| 335 | if (vma->vm_flags & VM_SHARED) |
| 336 | return 0; |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 337 | if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 338 | return 0; |
| 339 | return 1; |
| 340 | } |
| 341 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 342 | static void clear_huge_page(struct page *page, |
| 343 | unsigned long addr, unsigned long sz) |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 344 | { |
| 345 | int i; |
| 346 | |
| 347 | might_sleep(); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 348 | for (i = 0; i < sz/PAGE_SIZE; i++) { |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 349 | cond_resched(); |
Ralf Baechle | 281e0e3 | 2007-10-01 01:20:10 -0700 | [diff] [blame] | 350 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 351 | } |
| 352 | } |
| 353 | |
| 354 | static void copy_huge_page(struct page *dst, struct page *src, |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 355 | unsigned long addr, struct vm_area_struct *vma) |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 356 | { |
| 357 | int i; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 358 | struct hstate *h = hstate_vma(vma); |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 359 | |
| 360 | might_sleep(); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 361 | for (i = 0; i < pages_per_huge_page(h); i++) { |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 362 | cond_resched(); |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 363 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 364 | } |
| 365 | } |
| 366 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 367 | static void enqueue_huge_page(struct hstate *h, struct page *page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 368 | { |
| 369 | int nid = page_to_nid(page); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 370 | list_add(&page->lru, &h->hugepage_freelists[nid]); |
| 371 | h->free_huge_pages++; |
| 372 | h->free_huge_pages_node[nid]++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | } |
| 374 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 375 | static struct page *dequeue_huge_page(struct hstate *h) |
Nishanth Aravamudan | 348e1e0 | 2008-03-04 14:29:42 -0800 | [diff] [blame] | 376 | { |
| 377 | int nid; |
| 378 | struct page *page = NULL; |
| 379 | |
| 380 | for (nid = 0; nid < MAX_NUMNODES; ++nid) { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 381 | if (!list_empty(&h->hugepage_freelists[nid])) { |
| 382 | page = list_entry(h->hugepage_freelists[nid].next, |
Nishanth Aravamudan | 348e1e0 | 2008-03-04 14:29:42 -0800 | [diff] [blame] | 383 | struct page, lru); |
| 384 | list_del(&page->lru); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 385 | h->free_huge_pages--; |
| 386 | h->free_huge_pages_node[nid]--; |
Nishanth Aravamudan | 348e1e0 | 2008-03-04 14:29:42 -0800 | [diff] [blame] | 387 | break; |
| 388 | } |
| 389 | } |
| 390 | return page; |
| 391 | } |
| 392 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 393 | static struct page *dequeue_huge_page_vma(struct hstate *h, |
| 394 | struct vm_area_struct *vma, |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 395 | unsigned long address, int avoid_reserve) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | { |
Nishanth Aravamudan | 31a5c6e | 2007-07-15 23:38:02 -0700 | [diff] [blame] | 397 | int nid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | struct page *page = NULL; |
Lee Schermerhorn | 480eccf | 2007-09-18 22:46:47 -0700 | [diff] [blame] | 399 | struct mempolicy *mpol; |
Mel Gorman | 19770b3 | 2008-04-28 02:12:18 -0700 | [diff] [blame] | 400 | nodemask_t *nodemask; |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 401 | struct zonelist *zonelist = huge_zonelist(vma, address, |
Mel Gorman | 19770b3 | 2008-04-28 02:12:18 -0700 | [diff] [blame] | 402 | htlb_alloc_mask, &mpol, &nodemask); |
Mel Gorman | dd1a239 | 2008-04-28 02:12:17 -0700 | [diff] [blame] | 403 | struct zone *zone; |
| 404 | struct zoneref *z; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 406 | /* |
| 407 | * A child process with MAP_PRIVATE mappings created by their parent |
| 408 | * have no page reserves. This check ensures that reservations are |
| 409 | * not "stolen". The child may still get SIGKILLed |
| 410 | */ |
| 411 | if (!vma_has_private_reserves(vma) && |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 412 | h->free_huge_pages - h->resv_huge_pages == 0) |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 413 | return NULL; |
| 414 | |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 415 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 416 | if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 417 | return NULL; |
| 418 | |
Mel Gorman | 19770b3 | 2008-04-28 02:12:18 -0700 | [diff] [blame] | 419 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
| 420 | MAX_NR_ZONES - 1, nodemask) { |
Mel Gorman | 54a6eb5 | 2008-04-28 02:12:16 -0700 | [diff] [blame] | 421 | nid = zone_to_nid(zone); |
| 422 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 423 | !list_empty(&h->hugepage_freelists[nid])) { |
| 424 | page = list_entry(h->hugepage_freelists[nid].next, |
Andrew Morton | 3abf7af | 2007-07-19 01:49:08 -0700 | [diff] [blame] | 425 | struct page, lru); |
| 426 | list_del(&page->lru); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 427 | h->free_huge_pages--; |
| 428 | h->free_huge_pages_node[nid]--; |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 429 | |
| 430 | if (!avoid_reserve) |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 431 | decrement_hugepage_resv_vma(h, vma); |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 432 | |
Ken Chen | 5ab3ee7 | 2007-07-23 18:44:00 -0700 | [diff] [blame] | 433 | break; |
Andrew Morton | 3abf7af | 2007-07-19 01:49:08 -0700 | [diff] [blame] | 434 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | } |
Lee Schermerhorn | 52cd3b0 | 2008-04-28 02:13:16 -0700 | [diff] [blame] | 436 | mpol_cond_put(mpol); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | return page; |
| 438 | } |
| 439 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 440 | static void update_and_free_page(struct hstate *h, struct page *page) |
Adam Litke | 6af2acb | 2007-10-16 01:26:16 -0700 | [diff] [blame] | 441 | { |
| 442 | int i; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 443 | |
| 444 | h->nr_huge_pages--; |
| 445 | h->nr_huge_pages_node[page_to_nid(page)]--; |
| 446 | for (i = 0; i < pages_per_huge_page(h); i++) { |
Adam Litke | 6af2acb | 2007-10-16 01:26:16 -0700 | [diff] [blame] | 447 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | |
| 448 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | |
| 449 | 1 << PG_private | 1<< PG_writeback); |
| 450 | } |
| 451 | set_compound_page_dtor(page, NULL); |
| 452 | set_page_refcounted(page); |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 453 | arch_release_hugepage(page); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 454 | __free_pages(page, huge_page_order(h)); |
Adam Litke | 6af2acb | 2007-10-16 01:26:16 -0700 | [diff] [blame] | 455 | } |
| 456 | |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 457 | static void free_huge_page(struct page *page) |
| 458 | { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 459 | /* |
| 460 | * Can't pass hstate in here because it is called from the |
| 461 | * compound page destructor. |
| 462 | */ |
| 463 | struct hstate *h = &default_hstate; |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 464 | int nid = page_to_nid(page); |
Adam Litke | c79fb75 | 2007-11-14 16:59:38 -0800 | [diff] [blame] | 465 | struct address_space *mapping; |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 466 | |
Adam Litke | c79fb75 | 2007-11-14 16:59:38 -0800 | [diff] [blame] | 467 | mapping = (struct address_space *) page_private(page); |
Andy Whitcroft | e5df70a | 2008-02-23 15:23:32 -0800 | [diff] [blame] | 468 | set_page_private(page, 0); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 469 | BUG_ON(page_count(page)); |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 470 | INIT_LIST_HEAD(&page->lru); |
| 471 | |
| 472 | spin_lock(&hugetlb_lock); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 473 | if (h->surplus_huge_pages_node[nid]) { |
| 474 | update_and_free_page(h, page); |
| 475 | h->surplus_huge_pages--; |
| 476 | h->surplus_huge_pages_node[nid]--; |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 477 | } else { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 478 | enqueue_huge_page(h, page); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 479 | } |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 480 | spin_unlock(&hugetlb_lock); |
Adam Litke | c79fb75 | 2007-11-14 16:59:38 -0800 | [diff] [blame] | 481 | if (mapping) |
Adam Litke | 9a119c0 | 2007-11-14 16:59:41 -0800 | [diff] [blame] | 482 | hugetlb_put_quota(mapping, 1); |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 483 | } |
| 484 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 485 | /* |
| 486 | * Increment or decrement surplus_huge_pages. Keep node-specific counters |
| 487 | * balanced by operating on them in a round-robin fashion. |
| 488 | * Returns 1 if an adjustment was made. |
| 489 | */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 490 | static int adjust_pool_surplus(struct hstate *h, int delta) |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 491 | { |
| 492 | static int prev_nid; |
| 493 | int nid = prev_nid; |
| 494 | int ret = 0; |
| 495 | |
| 496 | VM_BUG_ON(delta != -1 && delta != 1); |
| 497 | do { |
| 498 | nid = next_node(nid, node_online_map); |
| 499 | if (nid == MAX_NUMNODES) |
| 500 | nid = first_node(node_online_map); |
| 501 | |
| 502 | /* To shrink on this node, there must be a surplus page */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 503 | if (delta < 0 && !h->surplus_huge_pages_node[nid]) |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 504 | continue; |
| 505 | /* Surplus cannot exceed the total number of pages */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 506 | if (delta > 0 && h->surplus_huge_pages_node[nid] >= |
| 507 | h->nr_huge_pages_node[nid]) |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 508 | continue; |
| 509 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 510 | h->surplus_huge_pages += delta; |
| 511 | h->surplus_huge_pages_node[nid] += delta; |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 512 | ret = 1; |
| 513 | break; |
| 514 | } while (nid != prev_nid); |
| 515 | |
| 516 | prev_nid = nid; |
| 517 | return ret; |
| 518 | } |
| 519 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 520 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) |
Andi Kleen | b7ba30c | 2008-07-23 21:27:40 -0700 | [diff] [blame] | 521 | { |
| 522 | set_compound_page_dtor(page, free_huge_page); |
| 523 | spin_lock(&hugetlb_lock); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 524 | h->nr_huge_pages++; |
| 525 | h->nr_huge_pages_node[nid]++; |
Andi Kleen | b7ba30c | 2008-07-23 21:27:40 -0700 | [diff] [blame] | 526 | spin_unlock(&hugetlb_lock); |
| 527 | put_page(page); /* free it into the hugepage allocator */ |
| 528 | } |
| 529 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 530 | static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | struct page *page; |
Joe Jin | f96efd5 | 2007-07-15 23:38:12 -0700 | [diff] [blame] | 533 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 534 | page = alloc_pages_node(nid, |
Nishanth Aravamudan | 551883a | 2008-04-29 00:58:26 -0700 | [diff] [blame] | 535 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| |
| 536 | __GFP_REPEAT|__GFP_NOWARN, |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 537 | huge_page_order(h)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | if (page) { |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 539 | if (arch_prepare_hugepage(page)) { |
| 540 | __free_pages(page, HUGETLB_PAGE_ORDER); |
Harvey Harrison | 7b8ee84 | 2008-04-28 14:13:19 -0700 | [diff] [blame] | 541 | return NULL; |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 542 | } |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 543 | prep_new_huge_page(h, page, nid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | } |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 545 | |
| 546 | return page; |
| 547 | } |
| 548 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 549 | static int alloc_fresh_huge_page(struct hstate *h) |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 550 | { |
| 551 | struct page *page; |
| 552 | int start_nid; |
| 553 | int next_nid; |
| 554 | int ret = 0; |
| 555 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 556 | start_nid = h->hugetlb_next_nid; |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 557 | |
| 558 | do { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 559 | page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid); |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 560 | if (page) |
| 561 | ret = 1; |
| 562 | /* |
| 563 | * Use a helper variable to find the next node and then |
| 564 | * copy it back to hugetlb_next_nid afterwards: |
| 565 | * otherwise there's a window in which a racer might |
| 566 | * pass invalid nid MAX_NUMNODES to alloc_pages_node. |
| 567 | * But we don't need to use a spin_lock here: it really |
| 568 | * doesn't matter if occasionally a racer chooses the |
| 569 | * same nid as we do. Move nid forward in the mask even |
| 570 | * if we just successfully allocated a hugepage so that |
| 571 | * the next caller gets hugepages on the next node. |
| 572 | */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 573 | next_nid = next_node(h->hugetlb_next_nid, node_online_map); |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 574 | if (next_nid == MAX_NUMNODES) |
| 575 | next_nid = first_node(node_online_map); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 576 | h->hugetlb_next_nid = next_nid; |
| 577 | } while (!page && h->hugetlb_next_nid != start_nid); |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 578 | |
Adam Litke | 3b11630 | 2008-04-28 02:13:06 -0700 | [diff] [blame] | 579 | if (ret) |
| 580 | count_vm_event(HTLB_BUDDY_PGALLOC); |
| 581 | else |
| 582 | count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
| 583 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 584 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | } |
| 586 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 587 | static struct page *alloc_buddy_huge_page(struct hstate *h, |
| 588 | struct vm_area_struct *vma, unsigned long address) |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 589 | { |
| 590 | struct page *page; |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 591 | unsigned int nid; |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 592 | |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 593 | /* |
| 594 | * Assume we will successfully allocate the surplus page to |
| 595 | * prevent racing processes from causing the surplus to exceed |
| 596 | * overcommit |
| 597 | * |
| 598 | * This however introduces a different race, where a process B |
| 599 | * tries to grow the static hugepage pool while alloc_pages() is |
| 600 | * called by process A. B will only examine the per-node |
| 601 | * counters in determining if surplus huge pages can be |
| 602 | * converted to normal huge pages in adjust_pool_surplus(). A |
| 603 | * won't be able to increment the per-node counter, until the |
| 604 | * lock is dropped by B, but B doesn't drop hugetlb_lock until |
| 605 | * no more huge pages can be converted from surplus to normal |
| 606 | * state (and doesn't try to convert again). Thus, we have a |
| 607 | * case where a surplus huge page exists, the pool is grown, and |
| 608 | * the surplus huge page still exists after, even though it |
| 609 | * should just have been converted to a normal huge page. This |
| 610 | * does not leak memory, though, as the hugepage will be freed |
| 611 | * once it is out of use. It also does not allow the counters to |
| 612 | * go out of whack in adjust_pool_surplus() as we don't modify |
| 613 | * the node values until we've gotten the hugepage and only the |
| 614 | * per-node value is checked there. |
| 615 | */ |
| 616 | spin_lock(&hugetlb_lock); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 617 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 618 | spin_unlock(&hugetlb_lock); |
| 619 | return NULL; |
| 620 | } else { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 621 | h->nr_huge_pages++; |
| 622 | h->surplus_huge_pages++; |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 623 | } |
| 624 | spin_unlock(&hugetlb_lock); |
| 625 | |
Nishanth Aravamudan | 551883a | 2008-04-29 00:58:26 -0700 | [diff] [blame] | 626 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP| |
| 627 | __GFP_REPEAT|__GFP_NOWARN, |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 628 | huge_page_order(h)); |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 629 | |
| 630 | spin_lock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 631 | if (page) { |
Adam Litke | 2668db9 | 2008-03-10 11:43:50 -0700 | [diff] [blame] | 632 | /* |
| 633 | * This page is now managed by the hugetlb allocator and has |
| 634 | * no users -- drop the buddy allocator's reference. |
| 635 | */ |
| 636 | put_page_testzero(page); |
| 637 | VM_BUG_ON(page_count(page)); |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 638 | nid = page_to_nid(page); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 639 | set_compound_page_dtor(page, free_huge_page); |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 640 | /* |
| 641 | * We incremented the global counters already |
| 642 | */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 643 | h->nr_huge_pages_node[nid]++; |
| 644 | h->surplus_huge_pages_node[nid]++; |
Adam Litke | 3b11630 | 2008-04-28 02:13:06 -0700 | [diff] [blame] | 645 | __count_vm_event(HTLB_BUDDY_PGALLOC); |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 646 | } else { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 647 | h->nr_huge_pages--; |
| 648 | h->surplus_huge_pages--; |
Adam Litke | 3b11630 | 2008-04-28 02:13:06 -0700 | [diff] [blame] | 649 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 650 | } |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 651 | spin_unlock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 652 | |
| 653 | return page; |
| 654 | } |
| 655 | |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 656 | /* |
| 657 | * Increase the hugetlb pool such that it can accomodate a reservation |
| 658 | * of size 'delta'. |
| 659 | */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 660 | static int gather_surplus_pages(struct hstate *h, int delta) |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 661 | { |
| 662 | struct list_head surplus_list; |
| 663 | struct page *page, *tmp; |
| 664 | int ret, i; |
| 665 | int needed, allocated; |
| 666 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 667 | needed = (h->resv_huge_pages + delta) - h->free_huge_pages; |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 668 | if (needed <= 0) { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 669 | h->resv_huge_pages += delta; |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 670 | return 0; |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 671 | } |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 672 | |
| 673 | allocated = 0; |
| 674 | INIT_LIST_HEAD(&surplus_list); |
| 675 | |
| 676 | ret = -ENOMEM; |
| 677 | retry: |
| 678 | spin_unlock(&hugetlb_lock); |
| 679 | for (i = 0; i < needed; i++) { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 680 | page = alloc_buddy_huge_page(h, NULL, 0); |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 681 | if (!page) { |
| 682 | /* |
| 683 | * We were not able to allocate enough pages to |
| 684 | * satisfy the entire reservation so we free what |
| 685 | * we've allocated so far. |
| 686 | */ |
| 687 | spin_lock(&hugetlb_lock); |
| 688 | needed = 0; |
| 689 | goto free; |
| 690 | } |
| 691 | |
| 692 | list_add(&page->lru, &surplus_list); |
| 693 | } |
| 694 | allocated += needed; |
| 695 | |
| 696 | /* |
| 697 | * After retaking hugetlb_lock, we need to recalculate 'needed' |
| 698 | * because either resv_huge_pages or free_huge_pages may have changed. |
| 699 | */ |
| 700 | spin_lock(&hugetlb_lock); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 701 | needed = (h->resv_huge_pages + delta) - |
| 702 | (h->free_huge_pages + allocated); |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 703 | if (needed > 0) |
| 704 | goto retry; |
| 705 | |
| 706 | /* |
| 707 | * The surplus_list now contains _at_least_ the number of extra pages |
| 708 | * needed to accomodate the reservation. Add the appropriate number |
| 709 | * of pages to the hugetlb pool and free the extras back to the buddy |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 710 | * allocator. Commit the entire reservation here to prevent another |
| 711 | * process from stealing the pages as they are added to the pool but |
| 712 | * before they are reserved. |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 713 | */ |
| 714 | needed += allocated; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 715 | h->resv_huge_pages += delta; |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 716 | ret = 0; |
| 717 | free: |
Adam Litke | 19fc3f0 | 2008-04-28 02:12:20 -0700 | [diff] [blame] | 718 | /* Free the needed pages to the hugetlb pool */ |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 719 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
Adam Litke | 19fc3f0 | 2008-04-28 02:12:20 -0700 | [diff] [blame] | 720 | if ((--needed) < 0) |
| 721 | break; |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 722 | list_del(&page->lru); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 723 | enqueue_huge_page(h, page); |
Adam Litke | 19fc3f0 | 2008-04-28 02:12:20 -0700 | [diff] [blame] | 724 | } |
| 725 | |
| 726 | /* Free unnecessary surplus pages to the buddy allocator */ |
| 727 | if (!list_empty(&surplus_list)) { |
| 728 | spin_unlock(&hugetlb_lock); |
| 729 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
| 730 | list_del(&page->lru); |
Adam Litke | af767cb | 2007-10-16 01:26:25 -0700 | [diff] [blame] | 731 | /* |
Adam Litke | 2668db9 | 2008-03-10 11:43:50 -0700 | [diff] [blame] | 732 | * The page has a reference count of zero already, so |
| 733 | * call free_huge_page directly instead of using |
| 734 | * put_page. This must be done with hugetlb_lock |
Adam Litke | af767cb | 2007-10-16 01:26:25 -0700 | [diff] [blame] | 735 | * unlocked which is safe because free_huge_page takes |
| 736 | * hugetlb_lock before deciding how to free the page. |
| 737 | */ |
Adam Litke | 2668db9 | 2008-03-10 11:43:50 -0700 | [diff] [blame] | 738 | free_huge_page(page); |
Adam Litke | af767cb | 2007-10-16 01:26:25 -0700 | [diff] [blame] | 739 | } |
Adam Litke | 19fc3f0 | 2008-04-28 02:12:20 -0700 | [diff] [blame] | 740 | spin_lock(&hugetlb_lock); |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 741 | } |
| 742 | |
| 743 | return ret; |
| 744 | } |
| 745 | |
| 746 | /* |
| 747 | * When releasing a hugetlb pool reservation, any surplus pages that were |
| 748 | * allocated to satisfy the reservation must be explicitly freed if they were |
| 749 | * never used. |
| 750 | */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 751 | static void return_unused_surplus_pages(struct hstate *h, |
| 752 | unsigned long unused_resv_pages) |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 753 | { |
| 754 | static int nid = -1; |
| 755 | struct page *page; |
| 756 | unsigned long nr_pages; |
| 757 | |
Nishanth Aravamudan | 11320d1 | 2008-03-26 14:40:20 -0700 | [diff] [blame] | 758 | /* |
| 759 | * We want to release as many surplus pages as possible, spread |
| 760 | * evenly across all nodes. Iterate across all nodes until we |
| 761 | * can no longer free unreserved surplus pages. This occurs when |
| 762 | * the nodes with surplus pages have no free pages. |
| 763 | */ |
| 764 | unsigned long remaining_iterations = num_online_nodes(); |
| 765 | |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 766 | /* Uncommit the reservation */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 767 | h->resv_huge_pages -= unused_resv_pages; |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 768 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 769 | nr_pages = min(unused_resv_pages, h->surplus_huge_pages); |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 770 | |
Nishanth Aravamudan | 11320d1 | 2008-03-26 14:40:20 -0700 | [diff] [blame] | 771 | while (remaining_iterations-- && nr_pages) { |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 772 | nid = next_node(nid, node_online_map); |
| 773 | if (nid == MAX_NUMNODES) |
| 774 | nid = first_node(node_online_map); |
| 775 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 776 | if (!h->surplus_huge_pages_node[nid]) |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 777 | continue; |
| 778 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 779 | if (!list_empty(&h->hugepage_freelists[nid])) { |
| 780 | page = list_entry(h->hugepage_freelists[nid].next, |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 781 | struct page, lru); |
| 782 | list_del(&page->lru); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 783 | update_and_free_page(h, page); |
| 784 | h->free_huge_pages--; |
| 785 | h->free_huge_pages_node[nid]--; |
| 786 | h->surplus_huge_pages--; |
| 787 | h->surplus_huge_pages_node[nid]--; |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 788 | nr_pages--; |
Nishanth Aravamudan | 11320d1 | 2008-03-26 14:40:20 -0700 | [diff] [blame] | 789 | remaining_iterations = num_online_nodes(); |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 790 | } |
| 791 | } |
| 792 | } |
| 793 | |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 794 | /* |
| 795 | * Determine if the huge page at addr within the vma has an associated |
| 796 | * reservation. Where it does not we will need to logically increase |
| 797 | * reservation and actually increase quota before an allocation can occur. |
| 798 | * Where any new reservation would be required the reservation change is |
| 799 | * prepared, but not committed. Once the page has been quota'd allocated |
| 800 | * an instantiated the change should be committed via vma_commit_reservation. |
| 801 | * No action is required on failure. |
| 802 | */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 803 | static int vma_needs_reservation(struct hstate *h, |
| 804 | struct vm_area_struct *vma, unsigned long addr) |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 805 | { |
| 806 | struct address_space *mapping = vma->vm_file->f_mapping; |
| 807 | struct inode *inode = mapping->host; |
| 808 | |
| 809 | if (vma->vm_flags & VM_SHARED) { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 810 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 811 | return region_chg(&inode->i_mapping->private_list, |
| 812 | idx, idx + 1); |
| 813 | |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 814 | } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
| 815 | return 1; |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 816 | |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 817 | } else { |
| 818 | int err; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 819 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 820 | struct resv_map *reservations = vma_resv_map(vma); |
| 821 | |
| 822 | err = region_chg(&reservations->regions, idx, idx + 1); |
| 823 | if (err < 0) |
| 824 | return err; |
| 825 | return 0; |
| 826 | } |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 827 | } |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 828 | static void vma_commit_reservation(struct hstate *h, |
| 829 | struct vm_area_struct *vma, unsigned long addr) |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 830 | { |
| 831 | struct address_space *mapping = vma->vm_file->f_mapping; |
| 832 | struct inode *inode = mapping->host; |
| 833 | |
| 834 | if (vma->vm_flags & VM_SHARED) { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 835 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 836 | region_add(&inode->i_mapping->private_list, idx, idx + 1); |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 837 | |
| 838 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 839 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 840 | struct resv_map *reservations = vma_resv_map(vma); |
| 841 | |
| 842 | /* Mark this page used in the map. */ |
| 843 | region_add(&reservations->regions, idx, idx + 1); |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 844 | } |
| 845 | } |
| 846 | |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 847 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 848 | unsigned long addr, int avoid_reserve) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 849 | { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 850 | struct hstate *h = hstate_vma(vma); |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 851 | struct page *page; |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 852 | struct address_space *mapping = vma->vm_file->f_mapping; |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 853 | struct inode *inode = mapping->host; |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 854 | unsigned int chg; |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 855 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 856 | /* |
| 857 | * Processes that did not create the mapping will have no reserves and |
| 858 | * will not have accounted against quota. Check that the quota can be |
| 859 | * made before satisfying the allocation |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 860 | * MAP_NORESERVE mappings may also need pages and quota allocated |
| 861 | * if no reserve mapping overlaps. |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 862 | */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 863 | chg = vma_needs_reservation(h, vma, addr); |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 864 | if (chg < 0) |
| 865 | return ERR_PTR(chg); |
| 866 | if (chg) |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 867 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
| 868 | return ERR_PTR(-ENOSPC); |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 869 | |
| 870 | spin_lock(&hugetlb_lock); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 871 | page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve); |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 872 | spin_unlock(&hugetlb_lock); |
| 873 | |
| 874 | if (!page) { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 875 | page = alloc_buddy_huge_page(h, vma, addr); |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 876 | if (!page) { |
| 877 | hugetlb_put_quota(inode->i_mapping, chg); |
| 878 | return ERR_PTR(-VM_FAULT_OOM); |
| 879 | } |
| 880 | } |
| 881 | |
| 882 | set_page_refcounted(page); |
| 883 | set_page_private(page, (unsigned long) mapping); |
| 884 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 885 | vma_commit_reservation(h, vma, addr); |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 886 | |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 887 | return page; |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 888 | } |
| 889 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 890 | static int __init hugetlb_init(void) |
| 891 | { |
| 892 | unsigned long i; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 893 | struct hstate *h = &default_hstate; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 894 | |
Benjamin Herrenschmidt | 3c726f8 | 2005-11-07 11:06:55 +1100 | [diff] [blame] | 895 | if (HPAGE_SHIFT == 0) |
| 896 | return 0; |
| 897 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 898 | if (!h->order) { |
| 899 | h->order = HPAGE_SHIFT - PAGE_SHIFT; |
| 900 | h->mask = HPAGE_MASK; |
| 901 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 902 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 903 | for (i = 0; i < MAX_NUMNODES; ++i) |
| 904 | INIT_LIST_HEAD(&h->hugepage_freelists[i]); |
| 905 | |
| 906 | h->hugetlb_next_nid = first_node(node_online_map); |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 907 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 908 | for (i = 0; i < max_huge_pages; ++i) { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 909 | if (!alloc_fresh_huge_page(h)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 910 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 911 | } |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 912 | max_huge_pages = h->free_huge_pages = h->nr_huge_pages = i; |
| 913 | printk(KERN_INFO "Total HugeTLB memory allocated, %ld\n", |
| 914 | h->free_huge_pages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 915 | return 0; |
| 916 | } |
| 917 | module_init(hugetlb_init); |
| 918 | |
| 919 | static int __init hugetlb_setup(char *s) |
| 920 | { |
| 921 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) |
| 922 | max_huge_pages = 0; |
| 923 | return 1; |
| 924 | } |
| 925 | __setup("hugepages=", hugetlb_setup); |
| 926 | |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 927 | static unsigned int cpuset_mems_nr(unsigned int *array) |
| 928 | { |
| 929 | int node; |
| 930 | unsigned int nr = 0; |
| 931 | |
| 932 | for_each_node_mask(node, cpuset_current_mems_allowed) |
| 933 | nr += array[node]; |
| 934 | |
| 935 | return nr; |
| 936 | } |
| 937 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 938 | #ifdef CONFIG_SYSCTL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 939 | #ifdef CONFIG_HIGHMEM |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 940 | static void try_to_free_low(struct hstate *h, unsigned long count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 941 | { |
Christoph Lameter | 4415cc8 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 942 | int i; |
| 943 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 944 | for (i = 0; i < MAX_NUMNODES; ++i) { |
| 945 | struct page *page, *next; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 946 | struct list_head *freel = &h->hugepage_freelists[i]; |
| 947 | list_for_each_entry_safe(page, next, freel, lru) { |
| 948 | if (count >= h->nr_huge_pages) |
Adam Litke | 6b0c880 | 2007-10-16 01:26:23 -0700 | [diff] [blame] | 949 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 950 | if (PageHighMem(page)) |
| 951 | continue; |
| 952 | list_del(&page->lru); |
| 953 | update_and_free_page(page); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 954 | h->free_huge_pages--; |
| 955 | h->free_huge_pages_node[page_to_nid(page)]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 956 | } |
| 957 | } |
| 958 | } |
| 959 | #else |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 960 | static inline void try_to_free_low(struct hstate *h, unsigned long count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 961 | { |
| 962 | } |
| 963 | #endif |
| 964 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 965 | #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 966 | static unsigned long set_max_huge_pages(unsigned long count) |
| 967 | { |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 968 | unsigned long min_count, ret; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 969 | struct hstate *h = &default_hstate; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 970 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 971 | /* |
| 972 | * Increase the pool size |
| 973 | * First take pages out of surplus state. Then make up the |
| 974 | * remaining difference by allocating fresh huge pages. |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 975 | * |
| 976 | * We might race with alloc_buddy_huge_page() here and be unable |
| 977 | * to convert a surplus huge page to a normal huge page. That is |
| 978 | * not critical, though, it just means the overall size of the |
| 979 | * pool might be one hugepage larger than it needs to be, but |
| 980 | * within all the constraints specified by the sysctls. |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 981 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 982 | spin_lock(&hugetlb_lock); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 983 | while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { |
| 984 | if (!adjust_pool_surplus(h, -1)) |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 985 | break; |
| 986 | } |
| 987 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 988 | while (count > persistent_huge_pages(h)) { |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 989 | /* |
| 990 | * If this allocation races such that we no longer need the |
| 991 | * page, free_huge_page will handle it by freeing the page |
| 992 | * and reducing the surplus. |
| 993 | */ |
| 994 | spin_unlock(&hugetlb_lock); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 995 | ret = alloc_fresh_huge_page(h); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 996 | spin_lock(&hugetlb_lock); |
| 997 | if (!ret) |
| 998 | goto out; |
| 999 | |
| 1000 | } |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 1001 | |
| 1002 | /* |
| 1003 | * Decrease the pool size |
| 1004 | * First return free pages to the buddy allocator (being careful |
| 1005 | * to keep enough around to satisfy reservations). Then place |
| 1006 | * pages into surplus state as needed so the pool will shrink |
| 1007 | * to the desired size as pages become free. |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 1008 | * |
| 1009 | * By placing pages into the surplus state independent of the |
| 1010 | * overcommit value, we are allowing the surplus pool size to |
| 1011 | * exceed overcommit. There are few sane options here. Since |
| 1012 | * alloc_buddy_huge_page() is checking the global counter, |
| 1013 | * though, we'll note that we're not allowed to exceed surplus |
| 1014 | * and won't grow the pool anywhere else. Not until one of the |
| 1015 | * sysctls are changed, or the surplus pages go out of use. |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 1016 | */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1017 | min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; |
Adam Litke | 6b0c880 | 2007-10-16 01:26:23 -0700 | [diff] [blame] | 1018 | min_count = max(count, min_count); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1019 | try_to_free_low(h, min_count); |
| 1020 | while (min_count < persistent_huge_pages(h)) { |
| 1021 | struct page *page = dequeue_huge_page(h); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1022 | if (!page) |
| 1023 | break; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1024 | update_and_free_page(h, page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1025 | } |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1026 | while (count < persistent_huge_pages(h)) { |
| 1027 | if (!adjust_pool_surplus(h, 1)) |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 1028 | break; |
| 1029 | } |
| 1030 | out: |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1031 | ret = persistent_huge_pages(h); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1032 | spin_unlock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 1033 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1034 | } |
| 1035 | |
| 1036 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
| 1037 | struct file *file, void __user *buffer, |
| 1038 | size_t *length, loff_t *ppos) |
| 1039 | { |
| 1040 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
| 1041 | max_huge_pages = set_max_huge_pages(max_huge_pages); |
| 1042 | return 0; |
| 1043 | } |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 1044 | |
| 1045 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, |
| 1046 | struct file *file, void __user *buffer, |
| 1047 | size_t *length, loff_t *ppos) |
| 1048 | { |
| 1049 | proc_dointvec(table, write, file, buffer, length, ppos); |
| 1050 | if (hugepages_treat_as_movable) |
| 1051 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; |
| 1052 | else |
| 1053 | htlb_alloc_mask = GFP_HIGHUSER; |
| 1054 | return 0; |
| 1055 | } |
| 1056 | |
Nishanth Aravamudan | a3d0c6a | 2008-02-08 04:18:18 -0800 | [diff] [blame] | 1057 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
| 1058 | struct file *file, void __user *buffer, |
| 1059 | size_t *length, loff_t *ppos) |
| 1060 | { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1061 | struct hstate *h = &default_hstate; |
Nishanth Aravamudan | a3d0c6a | 2008-02-08 04:18:18 -0800 | [diff] [blame] | 1062 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
Nishanth Aravamudan | 064d9ef | 2008-02-13 15:03:19 -0800 | [diff] [blame] | 1063 | spin_lock(&hugetlb_lock); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1064 | h->nr_overcommit_huge_pages = sysctl_overcommit_huge_pages; |
Nishanth Aravamudan | a3d0c6a | 2008-02-08 04:18:18 -0800 | [diff] [blame] | 1065 | spin_unlock(&hugetlb_lock); |
| 1066 | return 0; |
| 1067 | } |
| 1068 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1069 | #endif /* CONFIG_SYSCTL */ |
| 1070 | |
| 1071 | int hugetlb_report_meminfo(char *buf) |
| 1072 | { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1073 | struct hstate *h = &default_hstate; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | return sprintf(buf, |
| 1075 | "HugePages_Total: %5lu\n" |
| 1076 | "HugePages_Free: %5lu\n" |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1077 | "HugePages_Rsvd: %5lu\n" |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 1078 | "HugePages_Surp: %5lu\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1079 | "Hugepagesize: %5lu kB\n", |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1080 | h->nr_huge_pages, |
| 1081 | h->free_huge_pages, |
| 1082 | h->resv_huge_pages, |
| 1083 | h->surplus_huge_pages, |
| 1084 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1085 | } |
| 1086 | |
| 1087 | int hugetlb_report_node_meminfo(int nid, char *buf) |
| 1088 | { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1089 | struct hstate *h = &default_hstate; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1090 | return sprintf(buf, |
| 1091 | "Node %d HugePages_Total: %5u\n" |
Nishanth Aravamudan | a1de091 | 2008-03-26 14:37:53 -0700 | [diff] [blame] | 1092 | "Node %d HugePages_Free: %5u\n" |
| 1093 | "Node %d HugePages_Surp: %5u\n", |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1094 | nid, h->nr_huge_pages_node[nid], |
| 1095 | nid, h->free_huge_pages_node[nid], |
| 1096 | nid, h->surplus_huge_pages_node[nid]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1097 | } |
| 1098 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1099 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
| 1100 | unsigned long hugetlb_total_pages(void) |
| 1101 | { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1102 | struct hstate *h = &default_hstate; |
| 1103 | return h->nr_huge_pages * pages_per_huge_page(h); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1104 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1105 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1106 | static int hugetlb_acct_memory(struct hstate *h, long delta) |
Mel Gorman | fc1b8a7 | 2008-07-23 21:27:22 -0700 | [diff] [blame] | 1107 | { |
| 1108 | int ret = -ENOMEM; |
| 1109 | |
| 1110 | spin_lock(&hugetlb_lock); |
| 1111 | /* |
| 1112 | * When cpuset is configured, it breaks the strict hugetlb page |
| 1113 | * reservation as the accounting is done on a global variable. Such |
| 1114 | * reservation is completely rubbish in the presence of cpuset because |
| 1115 | * the reservation is not checked against page availability for the |
| 1116 | * current cpuset. Application can still potentially OOM'ed by kernel |
| 1117 | * with lack of free htlb page in cpuset that the task is in. |
| 1118 | * Attempt to enforce strict accounting with cpuset is almost |
| 1119 | * impossible (or too ugly) because cpuset is too fluid that |
| 1120 | * task or memory node can be dynamically moved between cpusets. |
| 1121 | * |
| 1122 | * The change of semantics for shared hugetlb mapping with cpuset is |
| 1123 | * undesirable. However, in order to preserve some of the semantics, |
| 1124 | * we fall back to check against current free page availability as |
| 1125 | * a best attempt and hopefully to minimize the impact of changing |
| 1126 | * semantics that cpuset has. |
| 1127 | */ |
| 1128 | if (delta > 0) { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1129 | if (gather_surplus_pages(h, delta) < 0) |
Mel Gorman | fc1b8a7 | 2008-07-23 21:27:22 -0700 | [diff] [blame] | 1130 | goto out; |
| 1131 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1132 | if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { |
| 1133 | return_unused_surplus_pages(h, delta); |
Mel Gorman | fc1b8a7 | 2008-07-23 21:27:22 -0700 | [diff] [blame] | 1134 | goto out; |
| 1135 | } |
| 1136 | } |
| 1137 | |
| 1138 | ret = 0; |
| 1139 | if (delta < 0) |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1140 | return_unused_surplus_pages(h, (unsigned long) -delta); |
Mel Gorman | fc1b8a7 | 2008-07-23 21:27:22 -0700 | [diff] [blame] | 1141 | |
| 1142 | out: |
| 1143 | spin_unlock(&hugetlb_lock); |
| 1144 | return ret; |
| 1145 | } |
| 1146 | |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 1147 | static void hugetlb_vm_op_open(struct vm_area_struct *vma) |
| 1148 | { |
| 1149 | struct resv_map *reservations = vma_resv_map(vma); |
| 1150 | |
| 1151 | /* |
| 1152 | * This new VMA should share its siblings reservation map if present. |
| 1153 | * The VMA will only ever have a valid reservation map pointer where |
| 1154 | * it is being copied for another still existing VMA. As that VMA |
| 1155 | * has a reference to the reservation map it cannot dissappear until |
| 1156 | * after this open call completes. It is therefore safe to take a |
| 1157 | * new reference here without additional locking. |
| 1158 | */ |
| 1159 | if (reservations) |
| 1160 | kref_get(&reservations->refs); |
| 1161 | } |
| 1162 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 1163 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
| 1164 | { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1165 | struct hstate *h = hstate_vma(vma); |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 1166 | struct resv_map *reservations = vma_resv_map(vma); |
| 1167 | unsigned long reserve; |
| 1168 | unsigned long start; |
| 1169 | unsigned long end; |
| 1170 | |
| 1171 | if (reservations) { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1172 | start = vma_hugecache_offset(h, vma, vma->vm_start); |
| 1173 | end = vma_hugecache_offset(h, vma, vma->vm_end); |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 1174 | |
| 1175 | reserve = (end - start) - |
| 1176 | region_count(&reservations->regions, start, end); |
| 1177 | |
| 1178 | kref_put(&reservations->refs, resv_map_release); |
| 1179 | |
| 1180 | if (reserve) |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1181 | hugetlb_acct_memory(h, -reserve); |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 1182 | } |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 1183 | } |
| 1184 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1185 | /* |
| 1186 | * We cannot handle pagefaults against hugetlb pages at all. They cause |
| 1187 | * handle_mm_fault() to try to instantiate regular-sized pages in the |
| 1188 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get |
| 1189 | * this far. |
| 1190 | */ |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1191 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1192 | { |
| 1193 | BUG(); |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1194 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1195 | } |
| 1196 | |
| 1197 | struct vm_operations_struct hugetlb_vm_ops = { |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1198 | .fault = hugetlb_vm_op_fault, |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 1199 | .open = hugetlb_vm_op_open, |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 1200 | .close = hugetlb_vm_op_close, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1201 | }; |
| 1202 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1203 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
| 1204 | int writable) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1205 | { |
| 1206 | pte_t entry; |
| 1207 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1208 | if (writable) { |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1209 | entry = |
| 1210 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); |
| 1211 | } else { |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1212 | entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1213 | } |
| 1214 | entry = pte_mkyoung(entry); |
| 1215 | entry = pte_mkhuge(entry); |
| 1216 | |
| 1217 | return entry; |
| 1218 | } |
| 1219 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1220 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
| 1221 | unsigned long address, pte_t *ptep) |
| 1222 | { |
| 1223 | pte_t entry; |
| 1224 | |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1225 | entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); |
| 1226 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { |
Benjamin Herrenschmidt | 8dab524 | 2007-06-16 10:16:12 -0700 | [diff] [blame] | 1227 | update_mmu_cache(vma, address, entry); |
Benjamin Herrenschmidt | 8dab524 | 2007-06-16 10:16:12 -0700 | [diff] [blame] | 1228 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1229 | } |
| 1230 | |
| 1231 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1232 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
| 1233 | struct vm_area_struct *vma) |
| 1234 | { |
| 1235 | pte_t *src_pte, *dst_pte, entry; |
| 1236 | struct page *ptepage; |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 1237 | unsigned long addr; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1238 | int cow; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1239 | struct hstate *h = hstate_vma(vma); |
| 1240 | unsigned long sz = huge_page_size(h); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1241 | |
| 1242 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1243 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1244 | for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 1245 | src_pte = huge_pte_offset(src, addr); |
| 1246 | if (!src_pte) |
| 1247 | continue; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1248 | dst_pte = huge_pte_alloc(dst, addr, sz); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1249 | if (!dst_pte) |
| 1250 | goto nomem; |
Larry Woodman | c5c9942 | 2008-01-24 05:49:25 -0800 | [diff] [blame] | 1251 | |
| 1252 | /* If the pagetables are shared don't copy or take references */ |
| 1253 | if (dst_pte == src_pte) |
| 1254 | continue; |
| 1255 | |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 1256 | spin_lock(&dst->page_table_lock); |
Nick Piggin | 4647875 | 2008-06-05 22:45:57 -0700 | [diff] [blame] | 1257 | spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1258 | if (!huge_pte_none(huge_ptep_get(src_pte))) { |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1259 | if (cow) |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1260 | huge_ptep_set_wrprotect(src, addr, src_pte); |
| 1261 | entry = huge_ptep_get(src_pte); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 1262 | ptepage = pte_page(entry); |
| 1263 | get_page(ptepage); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 1264 | set_huge_pte_at(dst, addr, dst_pte, entry); |
| 1265 | } |
| 1266 | spin_unlock(&src->page_table_lock); |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 1267 | spin_unlock(&dst->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1268 | } |
| 1269 | return 0; |
| 1270 | |
| 1271 | nomem: |
| 1272 | return -ENOMEM; |
| 1273 | } |
| 1274 | |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 1275 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1276 | unsigned long end, struct page *ref_page) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1277 | { |
| 1278 | struct mm_struct *mm = vma->vm_mm; |
| 1279 | unsigned long address; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 1280 | pte_t *ptep; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1281 | pte_t pte; |
| 1282 | struct page *page; |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 1283 | struct page *tmp; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1284 | struct hstate *h = hstate_vma(vma); |
| 1285 | unsigned long sz = huge_page_size(h); |
| 1286 | |
Chen, Kenneth W | c0a499c | 2006-12-06 20:31:39 -0800 | [diff] [blame] | 1287 | /* |
| 1288 | * A page gathering list, protected by per file i_mmap_lock. The |
| 1289 | * lock is used to avoid list corruption from multiple unmapping |
| 1290 | * of the same page since we are using page->lru. |
| 1291 | */ |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 1292 | LIST_HEAD(page_list); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1293 | |
| 1294 | WARN_ON(!is_vm_hugetlb_page(vma)); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1295 | BUG_ON(start & ~huge_page_mask(h)); |
| 1296 | BUG_ON(end & ~huge_page_mask(h)); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1297 | |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 1298 | spin_lock(&mm->page_table_lock); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1299 | for (address = start; address < end; address += sz) { |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 1300 | ptep = huge_pte_offset(mm, address); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1301 | if (!ptep) |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 1302 | continue; |
| 1303 | |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 1304 | if (huge_pmd_unshare(mm, &address, ptep)) |
| 1305 | continue; |
| 1306 | |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1307 | /* |
| 1308 | * If a reference page is supplied, it is because a specific |
| 1309 | * page is being unmapped, not a range. Ensure the page we |
| 1310 | * are about to unmap is the actual page of interest. |
| 1311 | */ |
| 1312 | if (ref_page) { |
| 1313 | pte = huge_ptep_get(ptep); |
| 1314 | if (huge_pte_none(pte)) |
| 1315 | continue; |
| 1316 | page = pte_page(pte); |
| 1317 | if (page != ref_page) |
| 1318 | continue; |
| 1319 | |
| 1320 | /* |
| 1321 | * Mark the VMA as having unmapped its page so that |
| 1322 | * future faults in this VMA will fail rather than |
| 1323 | * looking like data was lost |
| 1324 | */ |
| 1325 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); |
| 1326 | } |
| 1327 | |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 1328 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1329 | if (huge_pte_none(pte)) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1330 | continue; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 1331 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1332 | page = pte_page(pte); |
Ken Chen | 6649a38 | 2007-02-08 14:20:27 -0800 | [diff] [blame] | 1333 | if (pte_dirty(pte)) |
| 1334 | set_page_dirty(page); |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 1335 | list_add(&page->lru, &page_list); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1336 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1337 | spin_unlock(&mm->page_table_lock); |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 1338 | flush_tlb_range(vma, start, end); |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 1339 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
| 1340 | list_del(&page->lru); |
| 1341 | put_page(page); |
| 1342 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1343 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1344 | |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 1345 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1346 | unsigned long end, struct page *ref_page) |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 1347 | { |
| 1348 | /* |
| 1349 | * It is undesirable to test vma->vm_file as it should be non-null |
| 1350 | * for valid hugetlb area. However, vm_file will be NULL in the error |
| 1351 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, |
| 1352 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function |
| 1353 | * to clean up. Since no pte has actually been setup, it is safe to |
| 1354 | * do nothing in this case. |
| 1355 | */ |
| 1356 | if (vma->vm_file) { |
| 1357 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1358 | __unmap_hugepage_range(vma, start, end, ref_page); |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 1359 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
| 1360 | } |
| 1361 | } |
| 1362 | |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1363 | /* |
| 1364 | * This is called when the original mapper is failing to COW a MAP_PRIVATE |
| 1365 | * mappping it owns the reserve page for. The intention is to unmap the page |
| 1366 | * from other VMAs and let the children be SIGKILLed if they are faulting the |
| 1367 | * same region. |
| 1368 | */ |
| 1369 | int unmap_ref_private(struct mm_struct *mm, |
| 1370 | struct vm_area_struct *vma, |
| 1371 | struct page *page, |
| 1372 | unsigned long address) |
| 1373 | { |
| 1374 | struct vm_area_struct *iter_vma; |
| 1375 | struct address_space *mapping; |
| 1376 | struct prio_tree_iter iter; |
| 1377 | pgoff_t pgoff; |
| 1378 | |
| 1379 | /* |
| 1380 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation |
| 1381 | * from page cache lookup which is in HPAGE_SIZE units. |
| 1382 | */ |
| 1383 | address = address & huge_page_mask(hstate_vma(vma)); |
| 1384 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) |
| 1385 | + (vma->vm_pgoff >> PAGE_SHIFT); |
| 1386 | mapping = (struct address_space *)page_private(page); |
| 1387 | |
| 1388 | vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { |
| 1389 | /* Do not unmap the current VMA */ |
| 1390 | if (iter_vma == vma) |
| 1391 | continue; |
| 1392 | |
| 1393 | /* |
| 1394 | * Unmap the page from other VMAs without their own reserves. |
| 1395 | * They get marked to be SIGKILLed if they fault in these |
| 1396 | * areas. This is because a future no-page fault on this VMA |
| 1397 | * could insert a zeroed page instead of the data existing |
| 1398 | * from the time of fork. This would look like data corruption |
| 1399 | */ |
| 1400 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) |
| 1401 | unmap_hugepage_range(iter_vma, |
| 1402 | address, address + HPAGE_SIZE, |
| 1403 | page); |
| 1404 | } |
| 1405 | |
| 1406 | return 1; |
| 1407 | } |
| 1408 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1409 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1410 | unsigned long address, pte_t *ptep, pte_t pte, |
| 1411 | struct page *pagecache_page) |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1412 | { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1413 | struct hstate *h = hstate_vma(vma); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1414 | struct page *old_page, *new_page; |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 1415 | int avoidcopy; |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1416 | int outside_reserve = 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1417 | |
| 1418 | old_page = pte_page(pte); |
| 1419 | |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1420 | retry_avoidcopy: |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1421 | /* If no-one else is actually using this page, avoid the copy |
| 1422 | * and just make the page writable */ |
| 1423 | avoidcopy = (page_count(old_page) == 1); |
| 1424 | if (avoidcopy) { |
| 1425 | set_huge_ptep_writable(vma, address, ptep); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 1426 | return 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1427 | } |
| 1428 | |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1429 | /* |
| 1430 | * If the process that created a MAP_PRIVATE mapping is about to |
| 1431 | * perform a COW due to a shared page count, attempt to satisfy |
| 1432 | * the allocation without using the existing reserves. The pagecache |
| 1433 | * page is used to determine if the reserve at this address was |
| 1434 | * consumed or not. If reserves were used, a partial faulted mapping |
| 1435 | * at the time of fork() could consume its reserves on COW instead |
| 1436 | * of the full address range. |
| 1437 | */ |
| 1438 | if (!(vma->vm_flags & VM_SHARED) && |
| 1439 | is_vma_resv_set(vma, HPAGE_RESV_OWNER) && |
| 1440 | old_page != pagecache_page) |
| 1441 | outside_reserve = 1; |
| 1442 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1443 | page_cache_get(old_page); |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1444 | new_page = alloc_huge_page(vma, address, outside_reserve); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1445 | |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 1446 | if (IS_ERR(new_page)) { |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1447 | page_cache_release(old_page); |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1448 | |
| 1449 | /* |
| 1450 | * If a process owning a MAP_PRIVATE mapping fails to COW, |
| 1451 | * it is due to references held by a child and an insufficient |
| 1452 | * huge page pool. To guarantee the original mappers |
| 1453 | * reliability, unmap the page from child processes. The child |
| 1454 | * may get SIGKILLed if it later faults. |
| 1455 | */ |
| 1456 | if (outside_reserve) { |
| 1457 | BUG_ON(huge_pte_none(pte)); |
| 1458 | if (unmap_ref_private(mm, vma, old_page, address)) { |
| 1459 | BUG_ON(page_count(old_page) != 1); |
| 1460 | BUG_ON(huge_pte_none(pte)); |
| 1461 | goto retry_avoidcopy; |
| 1462 | } |
| 1463 | WARN_ON_ONCE(1); |
| 1464 | } |
| 1465 | |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 1466 | return -PTR_ERR(new_page); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1467 | } |
| 1468 | |
| 1469 | spin_unlock(&mm->page_table_lock); |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 1470 | copy_huge_page(new_page, old_page, address, vma); |
Nick Piggin | 0ed361d | 2008-02-04 22:29:34 -0800 | [diff] [blame] | 1471 | __SetPageUptodate(new_page); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1472 | spin_lock(&mm->page_table_lock); |
| 1473 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1474 | ptep = huge_pte_offset(mm, address & huge_page_mask(h)); |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1475 | if (likely(pte_same(huge_ptep_get(ptep), pte))) { |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1476 | /* Break COW */ |
Gerald Schaefer | 8fe627e | 2008-04-28 02:13:28 -0700 | [diff] [blame] | 1477 | huge_ptep_clear_flush(vma, address, ptep); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1478 | set_huge_pte_at(mm, address, ptep, |
| 1479 | make_huge_pte(vma, new_page, 1)); |
| 1480 | /* Make the old page be freed below */ |
| 1481 | new_page = old_page; |
| 1482 | } |
| 1483 | page_cache_release(new_page); |
| 1484 | page_cache_release(old_page); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 1485 | return 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1486 | } |
| 1487 | |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1488 | /* Return the pagecache page at a given address within a VMA */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1489 | static struct page *hugetlbfs_pagecache_page(struct hstate *h, |
| 1490 | struct vm_area_struct *vma, unsigned long address) |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1491 | { |
| 1492 | struct address_space *mapping; |
Andy Whitcroft | e7c4b0b | 2008-07-23 21:27:26 -0700 | [diff] [blame] | 1493 | pgoff_t idx; |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1494 | |
| 1495 | mapping = vma->vm_file->f_mapping; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1496 | idx = vma_hugecache_offset(h, vma, address); |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1497 | |
| 1498 | return find_lock_page(mapping, idx); |
| 1499 | } |
| 1500 | |
Robert P. J. Day | a1ed3dd | 2007-07-17 04:03:33 -0700 | [diff] [blame] | 1501 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1502 | unsigned long address, pte_t *ptep, int write_access) |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 1503 | { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1504 | struct hstate *h = hstate_vma(vma); |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 1505 | int ret = VM_FAULT_SIGBUS; |
Andy Whitcroft | e7c4b0b | 2008-07-23 21:27:26 -0700 | [diff] [blame] | 1506 | pgoff_t idx; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1507 | unsigned long size; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1508 | struct page *page; |
| 1509 | struct address_space *mapping; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1510 | pte_t new_pte; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1511 | |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1512 | /* |
| 1513 | * Currently, we are forced to kill the process in the event the |
| 1514 | * original mapper has unmapped pages from the child due to a failed |
| 1515 | * COW. Warn that such a situation has occured as it may not be obvious |
| 1516 | */ |
| 1517 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { |
| 1518 | printk(KERN_WARNING |
| 1519 | "PID %d killed due to inadequate hugepage pool\n", |
| 1520 | current->pid); |
| 1521 | return ret; |
| 1522 | } |
| 1523 | |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1524 | mapping = vma->vm_file->f_mapping; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1525 | idx = vma_hugecache_offset(h, vma, address); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1526 | |
| 1527 | /* |
| 1528 | * Use page lock to guard against racing truncation |
| 1529 | * before we get page_table_lock. |
| 1530 | */ |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 1531 | retry: |
| 1532 | page = find_lock_page(mapping, idx); |
| 1533 | if (!page) { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1534 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
Hugh Dickins | ebed4bf | 2006-10-28 10:38:43 -0700 | [diff] [blame] | 1535 | if (idx >= size) |
| 1536 | goto out; |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1537 | page = alloc_huge_page(vma, address, 0); |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 1538 | if (IS_ERR(page)) { |
| 1539 | ret = -PTR_ERR(page); |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 1540 | goto out; |
| 1541 | } |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1542 | clear_huge_page(page, address, huge_page_size(h)); |
Nick Piggin | 0ed361d | 2008-02-04 22:29:34 -0800 | [diff] [blame] | 1543 | __SetPageUptodate(page); |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 1544 | |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 1545 | if (vma->vm_flags & VM_SHARED) { |
| 1546 | int err; |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 1547 | struct inode *inode = mapping->host; |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 1548 | |
| 1549 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); |
| 1550 | if (err) { |
| 1551 | put_page(page); |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 1552 | if (err == -EEXIST) |
| 1553 | goto retry; |
| 1554 | goto out; |
| 1555 | } |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 1556 | |
| 1557 | spin_lock(&inode->i_lock); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1558 | inode->i_blocks += blocks_per_huge_page(h); |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 1559 | spin_unlock(&inode->i_lock); |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 1560 | } else |
| 1561 | lock_page(page); |
| 1562 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1563 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 1564 | spin_lock(&mm->page_table_lock); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1565 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1566 | if (idx >= size) |
| 1567 | goto backout; |
| 1568 | |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 1569 | ret = 0; |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1570 | if (!huge_pte_none(huge_ptep_get(ptep))) |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1571 | goto backout; |
| 1572 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1573 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
| 1574 | && (vma->vm_flags & VM_SHARED))); |
| 1575 | set_huge_pte_at(mm, address, ptep, new_pte); |
| 1576 | |
| 1577 | if (write_access && !(vma->vm_flags & VM_SHARED)) { |
| 1578 | /* Optimization, do the COW without a second fault */ |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1579 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1580 | } |
| 1581 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 1582 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1583 | unlock_page(page); |
| 1584 | out: |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 1585 | return ret; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1586 | |
| 1587 | backout: |
| 1588 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1589 | unlock_page(page); |
| 1590 | put_page(page); |
| 1591 | goto out; |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 1592 | } |
| 1593 | |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 1594 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
| 1595 | unsigned long address, int write_access) |
| 1596 | { |
| 1597 | pte_t *ptep; |
| 1598 | pte_t entry; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1599 | int ret; |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 1600 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1601 | struct hstate *h = hstate_vma(vma); |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 1602 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1603 | ptep = huge_pte_alloc(mm, address, huge_page_size(h)); |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 1604 | if (!ptep) |
| 1605 | return VM_FAULT_OOM; |
| 1606 | |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 1607 | /* |
| 1608 | * Serialize hugepage allocation and instantiation, so that we don't |
| 1609 | * get spurious allocation failures if two CPUs race to instantiate |
| 1610 | * the same page in the page cache. |
| 1611 | */ |
| 1612 | mutex_lock(&hugetlb_instantiation_mutex); |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1613 | entry = huge_ptep_get(ptep); |
| 1614 | if (huge_pte_none(entry)) { |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 1615 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); |
| 1616 | mutex_unlock(&hugetlb_instantiation_mutex); |
| 1617 | return ret; |
| 1618 | } |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 1619 | |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 1620 | ret = 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1621 | |
| 1622 | spin_lock(&mm->page_table_lock); |
| 1623 | /* Check for a racing update before calling hugetlb_cow */ |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1624 | if (likely(pte_same(entry, huge_ptep_get(ptep)))) |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1625 | if (write_access && !pte_write(entry)) { |
| 1626 | struct page *page; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1627 | page = hugetlbfs_pagecache_page(h, vma, address); |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1628 | ret = hugetlb_cow(mm, vma, address, ptep, entry, page); |
| 1629 | if (page) { |
| 1630 | unlock_page(page); |
| 1631 | put_page(page); |
| 1632 | } |
| 1633 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1634 | spin_unlock(&mm->page_table_lock); |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 1635 | mutex_unlock(&hugetlb_instantiation_mutex); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1636 | |
| 1637 | return ret; |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 1638 | } |
| 1639 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1640 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
| 1641 | struct page **pages, struct vm_area_struct **vmas, |
Adam Litke | 5b23dbe | 2007-11-14 16:59:33 -0800 | [diff] [blame] | 1642 | unsigned long *position, int *length, int i, |
| 1643 | int write) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1644 | { |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1645 | unsigned long pfn_offset; |
| 1646 | unsigned long vaddr = *position; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1647 | int remainder = *length; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1648 | struct hstate *h = hstate_vma(vma); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1649 | |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 1650 | spin_lock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1651 | while (vaddr < vma->vm_end && remainder) { |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1652 | pte_t *pte; |
| 1653 | struct page *page; |
| 1654 | |
| 1655 | /* |
| 1656 | * Some archs (sparc64, sh*) have multiple pte_ts to |
| 1657 | * each hugepage. We have to make * sure we get the |
| 1658 | * first, for the page indexing below to work. |
| 1659 | */ |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1660 | pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1661 | |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1662 | if (!pte || huge_pte_none(huge_ptep_get(pte)) || |
| 1663 | (write && !pte_write(huge_ptep_get(pte)))) { |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1664 | int ret; |
| 1665 | |
| 1666 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 5b23dbe | 2007-11-14 16:59:33 -0800 | [diff] [blame] | 1667 | ret = hugetlb_fault(mm, vma, vaddr, write); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1668 | spin_lock(&mm->page_table_lock); |
Adam Litke | a89182c | 2007-08-22 14:01:51 -0700 | [diff] [blame] | 1669 | if (!(ret & VM_FAULT_ERROR)) |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1670 | continue; |
| 1671 | |
| 1672 | remainder = 0; |
| 1673 | if (!i) |
| 1674 | i = -EFAULT; |
| 1675 | break; |
| 1676 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1677 | |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1678 | pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1679 | page = pte_page(huge_ptep_get(pte)); |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1680 | same_page: |
Chen, Kenneth W | d669218 | 2006-03-31 02:29:57 -0800 | [diff] [blame] | 1681 | if (pages) { |
| 1682 | get_page(page); |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1683 | pages[i] = page + pfn_offset; |
Chen, Kenneth W | d669218 | 2006-03-31 02:29:57 -0800 | [diff] [blame] | 1684 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1685 | |
| 1686 | if (vmas) |
| 1687 | vmas[i] = vma; |
| 1688 | |
| 1689 | vaddr += PAGE_SIZE; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1690 | ++pfn_offset; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1691 | --remainder; |
| 1692 | ++i; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1693 | if (vaddr < vma->vm_end && remainder && |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1694 | pfn_offset < pages_per_huge_page(h)) { |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1695 | /* |
| 1696 | * We use pfn_offset to avoid touching the pageframes |
| 1697 | * of this compound page. |
| 1698 | */ |
| 1699 | goto same_page; |
| 1700 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1701 | } |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 1702 | spin_unlock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1703 | *length = remainder; |
| 1704 | *position = vaddr; |
| 1705 | |
| 1706 | return i; |
| 1707 | } |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1708 | |
| 1709 | void hugetlb_change_protection(struct vm_area_struct *vma, |
| 1710 | unsigned long address, unsigned long end, pgprot_t newprot) |
| 1711 | { |
| 1712 | struct mm_struct *mm = vma->vm_mm; |
| 1713 | unsigned long start = address; |
| 1714 | pte_t *ptep; |
| 1715 | pte_t pte; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1716 | struct hstate *h = hstate_vma(vma); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1717 | |
| 1718 | BUG_ON(address >= end); |
| 1719 | flush_cache_range(vma, address, end); |
| 1720 | |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 1721 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1722 | spin_lock(&mm->page_table_lock); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1723 | for (; address < end; address += huge_page_size(h)) { |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1724 | ptep = huge_pte_offset(mm, address); |
| 1725 | if (!ptep) |
| 1726 | continue; |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 1727 | if (huge_pmd_unshare(mm, &address, ptep)) |
| 1728 | continue; |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1729 | if (!huge_pte_none(huge_ptep_get(ptep))) { |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1730 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
| 1731 | pte = pte_mkhuge(pte_modify(pte, newprot)); |
| 1732 | set_huge_pte_at(mm, address, ptep, pte); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1733 | } |
| 1734 | } |
| 1735 | spin_unlock(&mm->page_table_lock); |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 1736 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1737 | |
| 1738 | flush_tlb_range(vma, start, end); |
| 1739 | } |
| 1740 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 1741 | int hugetlb_reserve_pages(struct inode *inode, |
| 1742 | long from, long to, |
| 1743 | struct vm_area_struct *vma) |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 1744 | { |
| 1745 | long ret, chg; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1746 | struct hstate *h = hstate_inode(inode); |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 1747 | |
Andy Whitcroft | c37f9fb | 2008-07-23 21:27:30 -0700 | [diff] [blame] | 1748 | if (vma && vma->vm_flags & VM_NORESERVE) |
| 1749 | return 0; |
| 1750 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 1751 | /* |
| 1752 | * Shared mappings base their reservation on the number of pages that |
| 1753 | * are already allocated on behalf of the file. Private mappings need |
| 1754 | * to reserve the full area even if read-only as mprotect() may be |
| 1755 | * called to make the mapping read-write. Assume !vma is a shm mapping |
| 1756 | */ |
| 1757 | if (!vma || vma->vm_flags & VM_SHARED) |
| 1758 | chg = region_chg(&inode->i_mapping->private_list, from, to); |
| 1759 | else { |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 1760 | struct resv_map *resv_map = resv_map_alloc(); |
| 1761 | if (!resv_map) |
| 1762 | return -ENOMEM; |
| 1763 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 1764 | chg = to - from; |
Andy Whitcroft | 84afd99 | 2008-07-23 21:27:32 -0700 | [diff] [blame] | 1765 | |
| 1766 | set_vma_resv_map(vma, resv_map); |
Mel Gorman | 04f2cbe | 2008-07-23 21:27:25 -0700 | [diff] [blame] | 1767 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 1768 | } |
| 1769 | |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 1770 | if (chg < 0) |
| 1771 | return chg; |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 1772 | |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 1773 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
| 1774 | return -ENOSPC; |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1775 | ret = hugetlb_acct_memory(h, chg); |
Ken Chen | 68842c9 | 2008-01-14 00:55:19 -0800 | [diff] [blame] | 1776 | if (ret < 0) { |
| 1777 | hugetlb_put_quota(inode->i_mapping, chg); |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1778 | return ret; |
Ken Chen | 68842c9 | 2008-01-14 00:55:19 -0800 | [diff] [blame] | 1779 | } |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame] | 1780 | if (!vma || vma->vm_flags & VM_SHARED) |
| 1781 | region_add(&inode->i_mapping->private_list, from, to); |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1782 | return 0; |
| 1783 | } |
| 1784 | |
| 1785 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) |
| 1786 | { |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1787 | struct hstate *h = hstate_inode(inode); |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1788 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 1789 | |
| 1790 | spin_lock(&inode->i_lock); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1791 | inode->i_blocks -= blocks_per_huge_page(h); |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 1792 | spin_unlock(&inode->i_lock); |
| 1793 | |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 1794 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
Andi Kleen | a551643 | 2008-07-23 21:27:41 -0700 | [diff] [blame^] | 1795 | hugetlb_acct_memory(h, -(chg - freed)); |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1796 | } |