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; |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 25 | static unsigned long nr_huge_pages, free_huge_pages, resv_huge_pages; |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 26 | static unsigned long surplus_huge_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | unsigned long max_huge_pages; |
| 28 | static struct list_head hugepage_freelists[MAX_NUMNODES]; |
| 29 | static unsigned int nr_huge_pages_node[MAX_NUMNODES]; |
| 30 | static unsigned int free_huge_pages_node[MAX_NUMNODES]; |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 31 | static unsigned int surplus_huge_pages_node[MAX_NUMNODES]; |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 32 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
| 33 | unsigned long hugepages_treat_as_movable; |
Adam Litke | 54f9f80 | 2007-10-16 01:26:20 -0700 | [diff] [blame] | 34 | int hugetlb_dynamic_pool; |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 35 | static int hugetlb_next_nid; |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 36 | |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 37 | /* |
| 38 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages |
| 39 | */ |
| 40 | static DEFINE_SPINLOCK(hugetlb_lock); |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 41 | |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 42 | static void clear_huge_page(struct page *page, unsigned long addr) |
| 43 | { |
| 44 | int i; |
| 45 | |
| 46 | might_sleep(); |
| 47 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) { |
| 48 | cond_resched(); |
Ralf Baechle | 281e0e3 | 2007-10-01 01:20:10 -0700 | [diff] [blame] | 49 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 50 | } |
| 51 | } |
| 52 | |
| 53 | static void copy_huge_page(struct page *dst, struct page *src, |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 54 | unsigned long addr, struct vm_area_struct *vma) |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 55 | { |
| 56 | int i; |
| 57 | |
| 58 | might_sleep(); |
| 59 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { |
| 60 | cond_resched(); |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 61 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 62 | } |
| 63 | } |
| 64 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | static void enqueue_huge_page(struct page *page) |
| 66 | { |
| 67 | int nid = page_to_nid(page); |
| 68 | list_add(&page->lru, &hugepage_freelists[nid]); |
| 69 | free_huge_pages++; |
| 70 | free_huge_pages_node[nid]++; |
| 71 | } |
| 72 | |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 73 | static struct page *dequeue_huge_page(struct vm_area_struct *vma, |
| 74 | unsigned long address) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | { |
Nishanth Aravamudan | 31a5c6e | 2007-07-15 23:38:02 -0700 | [diff] [blame] | 76 | int nid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | struct page *page = NULL; |
Lee Schermerhorn | 480eccf | 2007-09-18 22:46:47 -0700 | [diff] [blame] | 78 | struct mempolicy *mpol; |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 79 | struct zonelist *zonelist = huge_zonelist(vma, address, |
Lee Schermerhorn | 480eccf | 2007-09-18 22:46:47 -0700 | [diff] [blame] | 80 | htlb_alloc_mask, &mpol); |
Christoph Lameter | 96df933 | 2006-01-06 00:10:45 -0800 | [diff] [blame] | 81 | struct zone **z; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | |
Christoph Lameter | 96df933 | 2006-01-06 00:10:45 -0800 | [diff] [blame] | 83 | for (z = zonelist->zones; *z; z++) { |
Christoph Lameter | 89fa302 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 84 | nid = zone_to_nid(*z); |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 85 | if (cpuset_zone_allowed_softwall(*z, htlb_alloc_mask) && |
Andrew Morton | 3abf7af | 2007-07-19 01:49:08 -0700 | [diff] [blame] | 86 | !list_empty(&hugepage_freelists[nid])) { |
| 87 | page = list_entry(hugepage_freelists[nid].next, |
| 88 | struct page, lru); |
| 89 | list_del(&page->lru); |
| 90 | free_huge_pages--; |
| 91 | free_huge_pages_node[nid]--; |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 92 | if (vma && vma->vm_flags & VM_MAYSHARE) |
| 93 | resv_huge_pages--; |
Ken Chen | 5ab3ee7 | 2007-07-23 18:44:00 -0700 | [diff] [blame] | 94 | break; |
Andrew Morton | 3abf7af | 2007-07-19 01:49:08 -0700 | [diff] [blame] | 95 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | } |
Lee Schermerhorn | 480eccf | 2007-09-18 22:46:47 -0700 | [diff] [blame] | 97 | mpol_free(mpol); /* unref if mpol !NULL */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | return page; |
| 99 | } |
| 100 | |
Adam Litke | 6af2acb | 2007-10-16 01:26:16 -0700 | [diff] [blame] | 101 | static void update_and_free_page(struct page *page) |
| 102 | { |
| 103 | int i; |
| 104 | nr_huge_pages--; |
| 105 | nr_huge_pages_node[page_to_nid(page)]--; |
| 106 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { |
| 107 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | |
| 108 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | |
| 109 | 1 << PG_private | 1<< PG_writeback); |
| 110 | } |
| 111 | set_compound_page_dtor(page, NULL); |
| 112 | set_page_refcounted(page); |
| 113 | __free_pages(page, HUGETLB_PAGE_ORDER); |
| 114 | } |
| 115 | |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 116 | static void free_huge_page(struct page *page) |
| 117 | { |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 118 | int nid = page_to_nid(page); |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 119 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 120 | BUG_ON(page_count(page)); |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 121 | INIT_LIST_HEAD(&page->lru); |
| 122 | |
| 123 | spin_lock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 124 | if (surplus_huge_pages_node[nid]) { |
| 125 | update_and_free_page(page); |
| 126 | surplus_huge_pages--; |
| 127 | surplus_huge_pages_node[nid]--; |
| 128 | } else { |
| 129 | enqueue_huge_page(page); |
| 130 | } |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 131 | spin_unlock(&hugetlb_lock); |
| 132 | } |
| 133 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 134 | /* |
| 135 | * Increment or decrement surplus_huge_pages. Keep node-specific counters |
| 136 | * balanced by operating on them in a round-robin fashion. |
| 137 | * Returns 1 if an adjustment was made. |
| 138 | */ |
| 139 | static int adjust_pool_surplus(int delta) |
| 140 | { |
| 141 | static int prev_nid; |
| 142 | int nid = prev_nid; |
| 143 | int ret = 0; |
| 144 | |
| 145 | VM_BUG_ON(delta != -1 && delta != 1); |
| 146 | do { |
| 147 | nid = next_node(nid, node_online_map); |
| 148 | if (nid == MAX_NUMNODES) |
| 149 | nid = first_node(node_online_map); |
| 150 | |
| 151 | /* To shrink on this node, there must be a surplus page */ |
| 152 | if (delta < 0 && !surplus_huge_pages_node[nid]) |
| 153 | continue; |
| 154 | /* Surplus cannot exceed the total number of pages */ |
| 155 | if (delta > 0 && surplus_huge_pages_node[nid] >= |
| 156 | nr_huge_pages_node[nid]) |
| 157 | continue; |
| 158 | |
| 159 | surplus_huge_pages += delta; |
| 160 | surplus_huge_pages_node[nid] += delta; |
| 161 | ret = 1; |
| 162 | break; |
| 163 | } while (nid != prev_nid); |
| 164 | |
| 165 | prev_nid = nid; |
| 166 | return ret; |
| 167 | } |
| 168 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 169 | static struct page *alloc_fresh_huge_page_node(int nid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | struct page *page; |
Joe Jin | f96efd5 | 2007-07-15 23:38:12 -0700 | [diff] [blame] | 172 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 173 | page = alloc_pages_node(nid, |
| 174 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|__GFP_NOWARN, |
| 175 | HUGETLB_PAGE_ORDER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | if (page) { |
Andy Whitcroft | 33f2ef8 | 2006-12-06 20:33:32 -0800 | [diff] [blame] | 177 | set_compound_page_dtor(page, free_huge_page); |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 178 | spin_lock(&hugetlb_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | nr_huge_pages++; |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 180 | nr_huge_pages_node[nid]++; |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 181 | spin_unlock(&hugetlb_lock); |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 182 | put_page(page); /* free it into the hugepage allocator */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | } |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 184 | |
| 185 | return page; |
| 186 | } |
| 187 | |
| 188 | static int alloc_fresh_huge_page(void) |
| 189 | { |
| 190 | struct page *page; |
| 191 | int start_nid; |
| 192 | int next_nid; |
| 193 | int ret = 0; |
| 194 | |
| 195 | start_nid = hugetlb_next_nid; |
| 196 | |
| 197 | do { |
| 198 | page = alloc_fresh_huge_page_node(hugetlb_next_nid); |
| 199 | if (page) |
| 200 | ret = 1; |
| 201 | /* |
| 202 | * Use a helper variable to find the next node and then |
| 203 | * copy it back to hugetlb_next_nid afterwards: |
| 204 | * otherwise there's a window in which a racer might |
| 205 | * pass invalid nid MAX_NUMNODES to alloc_pages_node. |
| 206 | * But we don't need to use a spin_lock here: it really |
| 207 | * doesn't matter if occasionally a racer chooses the |
| 208 | * same nid as we do. Move nid forward in the mask even |
| 209 | * if we just successfully allocated a hugepage so that |
| 210 | * the next caller gets hugepages on the next node. |
| 211 | */ |
| 212 | next_nid = next_node(hugetlb_next_nid, node_online_map); |
| 213 | if (next_nid == MAX_NUMNODES) |
| 214 | next_nid = first_node(node_online_map); |
| 215 | hugetlb_next_nid = next_nid; |
| 216 | } while (!page && hugetlb_next_nid != start_nid); |
| 217 | |
| 218 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | } |
| 220 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 221 | static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma, |
| 222 | unsigned long address) |
| 223 | { |
| 224 | struct page *page; |
| 225 | |
Adam Litke | 54f9f80 | 2007-10-16 01:26:20 -0700 | [diff] [blame] | 226 | /* Check if the dynamic pool is enabled */ |
| 227 | if (!hugetlb_dynamic_pool) |
| 228 | return NULL; |
| 229 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 230 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN, |
| 231 | HUGETLB_PAGE_ORDER); |
| 232 | if (page) { |
| 233 | set_compound_page_dtor(page, free_huge_page); |
| 234 | spin_lock(&hugetlb_lock); |
| 235 | nr_huge_pages++; |
| 236 | nr_huge_pages_node[page_to_nid(page)]++; |
| 237 | surplus_huge_pages++; |
| 238 | surplus_huge_pages_node[page_to_nid(page)]++; |
| 239 | spin_unlock(&hugetlb_lock); |
| 240 | } |
| 241 | |
| 242 | return page; |
| 243 | } |
| 244 | |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 245 | /* |
| 246 | * Increase the hugetlb pool such that it can accomodate a reservation |
| 247 | * of size 'delta'. |
| 248 | */ |
| 249 | static int gather_surplus_pages(int delta) |
| 250 | { |
| 251 | struct list_head surplus_list; |
| 252 | struct page *page, *tmp; |
| 253 | int ret, i; |
| 254 | int needed, allocated; |
| 255 | |
| 256 | needed = (resv_huge_pages + delta) - free_huge_pages; |
| 257 | if (needed <= 0) |
| 258 | return 0; |
| 259 | |
| 260 | allocated = 0; |
| 261 | INIT_LIST_HEAD(&surplus_list); |
| 262 | |
| 263 | ret = -ENOMEM; |
| 264 | retry: |
| 265 | spin_unlock(&hugetlb_lock); |
| 266 | for (i = 0; i < needed; i++) { |
| 267 | page = alloc_buddy_huge_page(NULL, 0); |
| 268 | if (!page) { |
| 269 | /* |
| 270 | * We were not able to allocate enough pages to |
| 271 | * satisfy the entire reservation so we free what |
| 272 | * we've allocated so far. |
| 273 | */ |
| 274 | spin_lock(&hugetlb_lock); |
| 275 | needed = 0; |
| 276 | goto free; |
| 277 | } |
| 278 | |
| 279 | list_add(&page->lru, &surplus_list); |
| 280 | } |
| 281 | allocated += needed; |
| 282 | |
| 283 | /* |
| 284 | * After retaking hugetlb_lock, we need to recalculate 'needed' |
| 285 | * because either resv_huge_pages or free_huge_pages may have changed. |
| 286 | */ |
| 287 | spin_lock(&hugetlb_lock); |
| 288 | needed = (resv_huge_pages + delta) - (free_huge_pages + allocated); |
| 289 | if (needed > 0) |
| 290 | goto retry; |
| 291 | |
| 292 | /* |
| 293 | * The surplus_list now contains _at_least_ the number of extra pages |
| 294 | * needed to accomodate the reservation. Add the appropriate number |
| 295 | * of pages to the hugetlb pool and free the extras back to the buddy |
| 296 | * allocator. |
| 297 | */ |
| 298 | needed += allocated; |
| 299 | ret = 0; |
| 300 | free: |
| 301 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
| 302 | list_del(&page->lru); |
| 303 | if ((--needed) >= 0) |
| 304 | enqueue_huge_page(page); |
Adam Litke | af767cb | 2007-10-16 01:26:25 -0700 | [diff] [blame] | 305 | else { |
| 306 | /* |
| 307 | * Decrement the refcount and free the page using its |
| 308 | * destructor. This must be done with hugetlb_lock |
| 309 | * unlocked which is safe because free_huge_page takes |
| 310 | * hugetlb_lock before deciding how to free the page. |
| 311 | */ |
| 312 | spin_unlock(&hugetlb_lock); |
| 313 | put_page(page); |
| 314 | spin_lock(&hugetlb_lock); |
| 315 | } |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 316 | } |
| 317 | |
| 318 | return ret; |
| 319 | } |
| 320 | |
| 321 | /* |
| 322 | * When releasing a hugetlb pool reservation, any surplus pages that were |
| 323 | * allocated to satisfy the reservation must be explicitly freed if they were |
| 324 | * never used. |
| 325 | */ |
| 326 | void return_unused_surplus_pages(unsigned long unused_resv_pages) |
| 327 | { |
| 328 | static int nid = -1; |
| 329 | struct page *page; |
| 330 | unsigned long nr_pages; |
| 331 | |
| 332 | nr_pages = min(unused_resv_pages, surplus_huge_pages); |
| 333 | |
| 334 | while (nr_pages) { |
| 335 | nid = next_node(nid, node_online_map); |
| 336 | if (nid == MAX_NUMNODES) |
| 337 | nid = first_node(node_online_map); |
| 338 | |
| 339 | if (!surplus_huge_pages_node[nid]) |
| 340 | continue; |
| 341 | |
| 342 | if (!list_empty(&hugepage_freelists[nid])) { |
| 343 | page = list_entry(hugepage_freelists[nid].next, |
| 344 | struct page, lru); |
| 345 | list_del(&page->lru); |
| 346 | update_and_free_page(page); |
| 347 | free_huge_pages--; |
| 348 | free_huge_pages_node[nid]--; |
| 349 | surplus_huge_pages--; |
| 350 | surplus_huge_pages_node[nid]--; |
| 351 | nr_pages--; |
| 352 | } |
| 353 | } |
| 354 | } |
| 355 | |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 356 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
| 357 | unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | { |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 359 | struct page *page = NULL; |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 360 | int use_reserved_page = vma->vm_flags & VM_MAYSHARE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | |
| 362 | spin_lock(&hugetlb_lock); |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 363 | if (!use_reserved_page && (free_huge_pages <= resv_huge_pages)) |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 364 | goto fail; |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 365 | |
| 366 | page = dequeue_huge_page(vma, addr); |
| 367 | if (!page) |
| 368 | goto fail; |
| 369 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 370 | spin_unlock(&hugetlb_lock); |
Nick Piggin | 7835e98 | 2006-03-22 00:08:40 -0800 | [diff] [blame] | 371 | set_page_refcounted(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | return page; |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 373 | |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 374 | fail: |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 375 | spin_unlock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 376 | |
| 377 | /* |
| 378 | * Private mappings do not use reserved huge pages so the allocation |
| 379 | * may have failed due to an undersized hugetlb pool. Try to grab a |
| 380 | * surplus huge page from the buddy allocator. |
| 381 | */ |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 382 | if (!use_reserved_page) |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 383 | page = alloc_buddy_huge_page(vma, addr); |
| 384 | |
| 385 | return page; |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 386 | } |
| 387 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | static int __init hugetlb_init(void) |
| 389 | { |
| 390 | unsigned long i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | |
Benjamin Herrenschmidt | 3c726f8 | 2005-11-07 11:06:55 +1100 | [diff] [blame] | 392 | if (HPAGE_SHIFT == 0) |
| 393 | return 0; |
| 394 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | for (i = 0; i < MAX_NUMNODES; ++i) |
| 396 | INIT_LIST_HEAD(&hugepage_freelists[i]); |
| 397 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 398 | hugetlb_next_nid = first_node(node_online_map); |
| 399 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | for (i = 0; i < max_huge_pages; ++i) { |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 401 | if (!alloc_fresh_huge_page()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | } |
| 404 | max_huge_pages = free_huge_pages = nr_huge_pages = i; |
| 405 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); |
| 406 | return 0; |
| 407 | } |
| 408 | module_init(hugetlb_init); |
| 409 | |
| 410 | static int __init hugetlb_setup(char *s) |
| 411 | { |
| 412 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) |
| 413 | max_huge_pages = 0; |
| 414 | return 1; |
| 415 | } |
| 416 | __setup("hugepages=", hugetlb_setup); |
| 417 | |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 418 | static unsigned int cpuset_mems_nr(unsigned int *array) |
| 419 | { |
| 420 | int node; |
| 421 | unsigned int nr = 0; |
| 422 | |
| 423 | for_each_node_mask(node, cpuset_current_mems_allowed) |
| 424 | nr += array[node]; |
| 425 | |
| 426 | return nr; |
| 427 | } |
| 428 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | #ifdef CONFIG_SYSCTL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | #ifdef CONFIG_HIGHMEM |
| 431 | static void try_to_free_low(unsigned long count) |
| 432 | { |
Christoph Lameter | 4415cc8 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 433 | int i; |
| 434 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | for (i = 0; i < MAX_NUMNODES; ++i) { |
| 436 | struct page *page, *next; |
| 437 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { |
Adam Litke | 6b0c880 | 2007-10-16 01:26:23 -0700 | [diff] [blame] | 438 | if (count >= nr_huge_pages) |
| 439 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | if (PageHighMem(page)) |
| 441 | continue; |
| 442 | list_del(&page->lru); |
| 443 | update_and_free_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 444 | free_huge_pages--; |
Christoph Lameter | 4415cc8 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 445 | free_huge_pages_node[page_to_nid(page)]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | } |
| 447 | } |
| 448 | } |
| 449 | #else |
| 450 | static inline void try_to_free_low(unsigned long count) |
| 451 | { |
| 452 | } |
| 453 | #endif |
| 454 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 455 | #define persistent_huge_pages (nr_huge_pages - surplus_huge_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | static unsigned long set_max_huge_pages(unsigned long count) |
| 457 | { |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 458 | unsigned long min_count, ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 460 | /* |
| 461 | * Increase the pool size |
| 462 | * First take pages out of surplus state. Then make up the |
| 463 | * remaining difference by allocating fresh huge pages. |
| 464 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | spin_lock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 466 | while (surplus_huge_pages && count > persistent_huge_pages) { |
| 467 | if (!adjust_pool_surplus(-1)) |
| 468 | break; |
| 469 | } |
| 470 | |
| 471 | while (count > persistent_huge_pages) { |
| 472 | int ret; |
| 473 | /* |
| 474 | * If this allocation races such that we no longer need the |
| 475 | * page, free_huge_page will handle it by freeing the page |
| 476 | * and reducing the surplus. |
| 477 | */ |
| 478 | spin_unlock(&hugetlb_lock); |
| 479 | ret = alloc_fresh_huge_page(); |
| 480 | spin_lock(&hugetlb_lock); |
| 481 | if (!ret) |
| 482 | goto out; |
| 483 | |
| 484 | } |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 485 | |
| 486 | /* |
| 487 | * Decrease the pool size |
| 488 | * First return free pages to the buddy allocator (being careful |
| 489 | * to keep enough around to satisfy reservations). Then place |
| 490 | * pages into surplus state as needed so the pool will shrink |
| 491 | * to the desired size as pages become free. |
| 492 | */ |
Adam Litke | 6b0c880 | 2007-10-16 01:26:23 -0700 | [diff] [blame] | 493 | min_count = resv_huge_pages + nr_huge_pages - free_huge_pages; |
| 494 | min_count = max(count, min_count); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 495 | try_to_free_low(min_count); |
| 496 | while (min_count < persistent_huge_pages) { |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 497 | struct page *page = dequeue_huge_page(NULL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | if (!page) |
| 499 | break; |
| 500 | update_and_free_page(page); |
| 501 | } |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 502 | while (count < persistent_huge_pages) { |
| 503 | if (!adjust_pool_surplus(1)) |
| 504 | break; |
| 505 | } |
| 506 | out: |
| 507 | ret = persistent_huge_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | spin_unlock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 509 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | } |
| 511 | |
| 512 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
| 513 | struct file *file, void __user *buffer, |
| 514 | size_t *length, loff_t *ppos) |
| 515 | { |
| 516 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
| 517 | max_huge_pages = set_max_huge_pages(max_huge_pages); |
| 518 | return 0; |
| 519 | } |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 520 | |
| 521 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, |
| 522 | struct file *file, void __user *buffer, |
| 523 | size_t *length, loff_t *ppos) |
| 524 | { |
| 525 | proc_dointvec(table, write, file, buffer, length, ppos); |
| 526 | if (hugepages_treat_as_movable) |
| 527 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; |
| 528 | else |
| 529 | htlb_alloc_mask = GFP_HIGHUSER; |
| 530 | return 0; |
| 531 | } |
| 532 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | #endif /* CONFIG_SYSCTL */ |
| 534 | |
| 535 | int hugetlb_report_meminfo(char *buf) |
| 536 | { |
| 537 | return sprintf(buf, |
| 538 | "HugePages_Total: %5lu\n" |
| 539 | "HugePages_Free: %5lu\n" |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 540 | "HugePages_Rsvd: %5lu\n" |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 541 | "HugePages_Surp: %5lu\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | "Hugepagesize: %5lu kB\n", |
| 543 | nr_huge_pages, |
| 544 | free_huge_pages, |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 545 | resv_huge_pages, |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 546 | surplus_huge_pages, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | HPAGE_SIZE/1024); |
| 548 | } |
| 549 | |
| 550 | int hugetlb_report_node_meminfo(int nid, char *buf) |
| 551 | { |
| 552 | return sprintf(buf, |
| 553 | "Node %d HugePages_Total: %5u\n" |
| 554 | "Node %d HugePages_Free: %5u\n", |
| 555 | nid, nr_huge_pages_node[nid], |
| 556 | nid, free_huge_pages_node[nid]); |
| 557 | } |
| 558 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
| 560 | unsigned long hugetlb_total_pages(void) |
| 561 | { |
| 562 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); |
| 563 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | |
| 565 | /* |
| 566 | * We cannot handle pagefaults against hugetlb pages at all. They cause |
| 567 | * handle_mm_fault() to try to instantiate regular-sized pages in the |
| 568 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get |
| 569 | * this far. |
| 570 | */ |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 571 | 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] | 572 | { |
| 573 | BUG(); |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 574 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 575 | } |
| 576 | |
| 577 | struct vm_operations_struct hugetlb_vm_ops = { |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 578 | .fault = hugetlb_vm_op_fault, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 579 | }; |
| 580 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 581 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
| 582 | int writable) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 583 | { |
| 584 | pte_t entry; |
| 585 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 586 | if (writable) { |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 587 | entry = |
| 588 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); |
| 589 | } else { |
| 590 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
| 591 | } |
| 592 | entry = pte_mkyoung(entry); |
| 593 | entry = pte_mkhuge(entry); |
| 594 | |
| 595 | return entry; |
| 596 | } |
| 597 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 598 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
| 599 | unsigned long address, pte_t *ptep) |
| 600 | { |
| 601 | pte_t entry; |
| 602 | |
| 603 | entry = pte_mkwrite(pte_mkdirty(*ptep)); |
Benjamin Herrenschmidt | 8dab524 | 2007-06-16 10:16:12 -0700 | [diff] [blame] | 604 | if (ptep_set_access_flags(vma, address, ptep, entry, 1)) { |
| 605 | update_mmu_cache(vma, address, entry); |
Benjamin Herrenschmidt | 8dab524 | 2007-06-16 10:16:12 -0700 | [diff] [blame] | 606 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 607 | } |
| 608 | |
| 609 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 610 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
| 611 | struct vm_area_struct *vma) |
| 612 | { |
| 613 | pte_t *src_pte, *dst_pte, entry; |
| 614 | struct page *ptepage; |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 615 | unsigned long addr; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 616 | int cow; |
| 617 | |
| 618 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 619 | |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 620 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 621 | src_pte = huge_pte_offset(src, addr); |
| 622 | if (!src_pte) |
| 623 | continue; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 624 | dst_pte = huge_pte_alloc(dst, addr); |
| 625 | if (!dst_pte) |
| 626 | goto nomem; |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 627 | spin_lock(&dst->page_table_lock); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 628 | spin_lock(&src->page_table_lock); |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 629 | if (!pte_none(*src_pte)) { |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 630 | if (cow) |
| 631 | ptep_set_wrprotect(src, addr, src_pte); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 632 | entry = *src_pte; |
| 633 | ptepage = pte_page(entry); |
| 634 | get_page(ptepage); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 635 | set_huge_pte_at(dst, addr, dst_pte, entry); |
| 636 | } |
| 637 | spin_unlock(&src->page_table_lock); |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 638 | spin_unlock(&dst->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 639 | } |
| 640 | return 0; |
| 641 | |
| 642 | nomem: |
| 643 | return -ENOMEM; |
| 644 | } |
| 645 | |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 646 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
| 647 | unsigned long end) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 648 | { |
| 649 | struct mm_struct *mm = vma->vm_mm; |
| 650 | unsigned long address; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 651 | pte_t *ptep; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 652 | pte_t pte; |
| 653 | struct page *page; |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 654 | struct page *tmp; |
Chen, Kenneth W | c0a499c | 2006-12-06 20:31:39 -0800 | [diff] [blame] | 655 | /* |
| 656 | * A page gathering list, protected by per file i_mmap_lock. The |
| 657 | * lock is used to avoid list corruption from multiple unmapping |
| 658 | * of the same page since we are using page->lru. |
| 659 | */ |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 660 | LIST_HEAD(page_list); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 661 | |
| 662 | WARN_ON(!is_vm_hugetlb_page(vma)); |
| 663 | BUG_ON(start & ~HPAGE_MASK); |
| 664 | BUG_ON(end & ~HPAGE_MASK); |
| 665 | |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 666 | spin_lock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 667 | for (address = start; address < end; address += HPAGE_SIZE) { |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 668 | ptep = huge_pte_offset(mm, address); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 669 | if (!ptep) |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 670 | continue; |
| 671 | |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 672 | if (huge_pmd_unshare(mm, &address, ptep)) |
| 673 | continue; |
| 674 | |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 675 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 676 | if (pte_none(pte)) |
| 677 | continue; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 678 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 679 | page = pte_page(pte); |
Ken Chen | 6649a38 | 2007-02-08 14:20:27 -0800 | [diff] [blame] | 680 | if (pte_dirty(pte)) |
| 681 | set_page_dirty(page); |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 682 | list_add(&page->lru, &page_list); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 683 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 684 | spin_unlock(&mm->page_table_lock); |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 685 | flush_tlb_range(vma, start, end); |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 686 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
| 687 | list_del(&page->lru); |
| 688 | put_page(page); |
| 689 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 690 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 691 | |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 692 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
| 693 | unsigned long end) |
| 694 | { |
| 695 | /* |
| 696 | * It is undesirable to test vma->vm_file as it should be non-null |
| 697 | * for valid hugetlb area. However, vm_file will be NULL in the error |
| 698 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, |
| 699 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function |
| 700 | * to clean up. Since no pte has actually been setup, it is safe to |
| 701 | * do nothing in this case. |
| 702 | */ |
| 703 | if (vma->vm_file) { |
| 704 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
| 705 | __unmap_hugepage_range(vma, start, end); |
| 706 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
| 707 | } |
| 708 | } |
| 709 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 710 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
| 711 | unsigned long address, pte_t *ptep, pte_t pte) |
| 712 | { |
| 713 | struct page *old_page, *new_page; |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 714 | int avoidcopy; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 715 | |
| 716 | old_page = pte_page(pte); |
| 717 | |
| 718 | /* If no-one else is actually using this page, avoid the copy |
| 719 | * and just make the page writable */ |
| 720 | avoidcopy = (page_count(old_page) == 1); |
| 721 | if (avoidcopy) { |
| 722 | set_huge_ptep_writable(vma, address, ptep); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 723 | return 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 724 | } |
| 725 | |
| 726 | page_cache_get(old_page); |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 727 | new_page = alloc_huge_page(vma, address); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 728 | |
| 729 | if (!new_page) { |
| 730 | page_cache_release(old_page); |
Christoph Lameter | 0df420d | 2006-02-07 12:58:30 -0800 | [diff] [blame] | 731 | return VM_FAULT_OOM; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 732 | } |
| 733 | |
| 734 | spin_unlock(&mm->page_table_lock); |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 735 | copy_huge_page(new_page, old_page, address, vma); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 736 | spin_lock(&mm->page_table_lock); |
| 737 | |
| 738 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); |
| 739 | if (likely(pte_same(*ptep, pte))) { |
| 740 | /* Break COW */ |
| 741 | set_huge_pte_at(mm, address, ptep, |
| 742 | make_huge_pte(vma, new_page, 1)); |
| 743 | /* Make the old page be freed below */ |
| 744 | new_page = old_page; |
| 745 | } |
| 746 | page_cache_release(new_page); |
| 747 | page_cache_release(old_page); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 748 | return 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 749 | } |
| 750 | |
Robert P. J. Day | a1ed3dd | 2007-07-17 04:03:33 -0700 | [diff] [blame] | 751 | 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] | 752 | unsigned long address, pte_t *ptep, int write_access) |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 753 | { |
| 754 | int ret = VM_FAULT_SIGBUS; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 755 | unsigned long idx; |
| 756 | unsigned long size; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 757 | struct page *page; |
| 758 | struct address_space *mapping; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 759 | pte_t new_pte; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 760 | |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 761 | mapping = vma->vm_file->f_mapping; |
| 762 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) |
| 763 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); |
| 764 | |
| 765 | /* |
| 766 | * Use page lock to guard against racing truncation |
| 767 | * before we get page_table_lock. |
| 768 | */ |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 769 | retry: |
| 770 | page = find_lock_page(mapping, idx); |
| 771 | if (!page) { |
Hugh Dickins | ebed4bf | 2006-10-28 10:38:43 -0700 | [diff] [blame] | 772 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
| 773 | if (idx >= size) |
| 774 | goto out; |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 775 | if (hugetlb_get_quota(mapping)) |
| 776 | goto out; |
| 777 | page = alloc_huge_page(vma, address); |
| 778 | if (!page) { |
| 779 | hugetlb_put_quota(mapping); |
Christoph Lameter | 0df420d | 2006-02-07 12:58:30 -0800 | [diff] [blame] | 780 | ret = VM_FAULT_OOM; |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 781 | goto out; |
| 782 | } |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 783 | clear_huge_page(page, address); |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 784 | |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 785 | if (vma->vm_flags & VM_SHARED) { |
| 786 | int err; |
| 787 | |
| 788 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); |
| 789 | if (err) { |
| 790 | put_page(page); |
| 791 | hugetlb_put_quota(mapping); |
| 792 | if (err == -EEXIST) |
| 793 | goto retry; |
| 794 | goto out; |
| 795 | } |
| 796 | } else |
| 797 | lock_page(page); |
| 798 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 799 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 800 | spin_lock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 801 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
| 802 | if (idx >= size) |
| 803 | goto backout; |
| 804 | |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 805 | ret = 0; |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 806 | if (!pte_none(*ptep)) |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 807 | goto backout; |
| 808 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 809 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
| 810 | && (vma->vm_flags & VM_SHARED))); |
| 811 | set_huge_pte_at(mm, address, ptep, new_pte); |
| 812 | |
| 813 | if (write_access && !(vma->vm_flags & VM_SHARED)) { |
| 814 | /* Optimization, do the COW without a second fault */ |
| 815 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); |
| 816 | } |
| 817 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 818 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 819 | unlock_page(page); |
| 820 | out: |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 821 | return ret; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 822 | |
| 823 | backout: |
| 824 | spin_unlock(&mm->page_table_lock); |
| 825 | hugetlb_put_quota(mapping); |
| 826 | unlock_page(page); |
| 827 | put_page(page); |
| 828 | goto out; |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 829 | } |
| 830 | |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 831 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
| 832 | unsigned long address, int write_access) |
| 833 | { |
| 834 | pte_t *ptep; |
| 835 | pte_t entry; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 836 | int ret; |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 837 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 838 | |
| 839 | ptep = huge_pte_alloc(mm, address); |
| 840 | if (!ptep) |
| 841 | return VM_FAULT_OOM; |
| 842 | |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 843 | /* |
| 844 | * Serialize hugepage allocation and instantiation, so that we don't |
| 845 | * get spurious allocation failures if two CPUs race to instantiate |
| 846 | * the same page in the page cache. |
| 847 | */ |
| 848 | mutex_lock(&hugetlb_instantiation_mutex); |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 849 | entry = *ptep; |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 850 | if (pte_none(entry)) { |
| 851 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); |
| 852 | mutex_unlock(&hugetlb_instantiation_mutex); |
| 853 | return ret; |
| 854 | } |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 855 | |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 856 | ret = 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 857 | |
| 858 | spin_lock(&mm->page_table_lock); |
| 859 | /* Check for a racing update before calling hugetlb_cow */ |
| 860 | if (likely(pte_same(entry, *ptep))) |
| 861 | if (write_access && !pte_write(entry)) |
| 862 | ret = hugetlb_cow(mm, vma, address, ptep, entry); |
| 863 | spin_unlock(&mm->page_table_lock); |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 864 | mutex_unlock(&hugetlb_instantiation_mutex); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 865 | |
| 866 | return ret; |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 867 | } |
| 868 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 869 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
| 870 | struct page **pages, struct vm_area_struct **vmas, |
| 871 | unsigned long *position, int *length, int i) |
| 872 | { |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 873 | unsigned long pfn_offset; |
| 874 | unsigned long vaddr = *position; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 875 | int remainder = *length; |
| 876 | |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 877 | spin_lock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 878 | while (vaddr < vma->vm_end && remainder) { |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 879 | pte_t *pte; |
| 880 | struct page *page; |
| 881 | |
| 882 | /* |
| 883 | * Some archs (sparc64, sh*) have multiple pte_ts to |
| 884 | * each hugepage. We have to make * sure we get the |
| 885 | * first, for the page indexing below to work. |
| 886 | */ |
| 887 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); |
| 888 | |
| 889 | if (!pte || pte_none(*pte)) { |
| 890 | int ret; |
| 891 | |
| 892 | spin_unlock(&mm->page_table_lock); |
| 893 | ret = hugetlb_fault(mm, vma, vaddr, 0); |
| 894 | spin_lock(&mm->page_table_lock); |
Adam Litke | a89182c | 2007-08-22 14:01:51 -0700 | [diff] [blame] | 895 | if (!(ret & VM_FAULT_ERROR)) |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 896 | continue; |
| 897 | |
| 898 | remainder = 0; |
| 899 | if (!i) |
| 900 | i = -EFAULT; |
| 901 | break; |
| 902 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 903 | |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 904 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
| 905 | page = pte_page(*pte); |
| 906 | same_page: |
Chen, Kenneth W | d669218 | 2006-03-31 02:29:57 -0800 | [diff] [blame] | 907 | if (pages) { |
| 908 | get_page(page); |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 909 | pages[i] = page + pfn_offset; |
Chen, Kenneth W | d669218 | 2006-03-31 02:29:57 -0800 | [diff] [blame] | 910 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 911 | |
| 912 | if (vmas) |
| 913 | vmas[i] = vma; |
| 914 | |
| 915 | vaddr += PAGE_SIZE; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 916 | ++pfn_offset; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 917 | --remainder; |
| 918 | ++i; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 919 | if (vaddr < vma->vm_end && remainder && |
| 920 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { |
| 921 | /* |
| 922 | * We use pfn_offset to avoid touching the pageframes |
| 923 | * of this compound page. |
| 924 | */ |
| 925 | goto same_page; |
| 926 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 927 | } |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 928 | spin_unlock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 929 | *length = remainder; |
| 930 | *position = vaddr; |
| 931 | |
| 932 | return i; |
| 933 | } |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 934 | |
| 935 | void hugetlb_change_protection(struct vm_area_struct *vma, |
| 936 | unsigned long address, unsigned long end, pgprot_t newprot) |
| 937 | { |
| 938 | struct mm_struct *mm = vma->vm_mm; |
| 939 | unsigned long start = address; |
| 940 | pte_t *ptep; |
| 941 | pte_t pte; |
| 942 | |
| 943 | BUG_ON(address >= end); |
| 944 | flush_cache_range(vma, address, end); |
| 945 | |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 946 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 947 | spin_lock(&mm->page_table_lock); |
| 948 | for (; address < end; address += HPAGE_SIZE) { |
| 949 | ptep = huge_pte_offset(mm, address); |
| 950 | if (!ptep) |
| 951 | continue; |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 952 | if (huge_pmd_unshare(mm, &address, ptep)) |
| 953 | continue; |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 954 | if (!pte_none(*ptep)) { |
| 955 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
| 956 | pte = pte_mkhuge(pte_modify(pte, newprot)); |
| 957 | set_huge_pte_at(mm, address, ptep, pte); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 958 | } |
| 959 | } |
| 960 | spin_unlock(&mm->page_table_lock); |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 961 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 962 | |
| 963 | flush_tlb_range(vma, start, end); |
| 964 | } |
| 965 | |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 966 | struct file_region { |
| 967 | struct list_head link; |
| 968 | long from; |
| 969 | long to; |
| 970 | }; |
| 971 | |
| 972 | static long region_add(struct list_head *head, long f, long t) |
| 973 | { |
| 974 | struct file_region *rg, *nrg, *trg; |
| 975 | |
| 976 | /* Locate the region we are either in or before. */ |
| 977 | list_for_each_entry(rg, head, link) |
| 978 | if (f <= rg->to) |
| 979 | break; |
| 980 | |
| 981 | /* Round our left edge to the current segment if it encloses us. */ |
| 982 | if (f > rg->from) |
| 983 | f = rg->from; |
| 984 | |
| 985 | /* Check for and consume any regions we now overlap with. */ |
| 986 | nrg = rg; |
| 987 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
| 988 | if (&rg->link == head) |
| 989 | break; |
| 990 | if (rg->from > t) |
| 991 | break; |
| 992 | |
| 993 | /* If this area reaches higher then extend our area to |
| 994 | * include it completely. If this is not the first area |
| 995 | * which we intend to reuse, free it. */ |
| 996 | if (rg->to > t) |
| 997 | t = rg->to; |
| 998 | if (rg != nrg) { |
| 999 | list_del(&rg->link); |
| 1000 | kfree(rg); |
| 1001 | } |
| 1002 | } |
| 1003 | nrg->from = f; |
| 1004 | nrg->to = t; |
| 1005 | return 0; |
| 1006 | } |
| 1007 | |
| 1008 | static long region_chg(struct list_head *head, long f, long t) |
| 1009 | { |
| 1010 | struct file_region *rg, *nrg; |
| 1011 | long chg = 0; |
| 1012 | |
| 1013 | /* Locate the region we are before or in. */ |
| 1014 | list_for_each_entry(rg, head, link) |
| 1015 | if (f <= rg->to) |
| 1016 | break; |
| 1017 | |
| 1018 | /* If we are below the current region then a new region is required. |
| 1019 | * Subtle, allocate a new region at the position but make it zero |
Simon Arlott | 183ff22 | 2007-10-20 01:27:18 +0200 | [diff] [blame] | 1020 | * size such that we can guarantee to record the reservation. */ |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1021 | if (&rg->link == head || t < rg->from) { |
| 1022 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); |
Stephen Hemminger | c80544d | 2007-10-18 03:07:05 -0700 | [diff] [blame] | 1023 | if (!nrg) |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1024 | return -ENOMEM; |
| 1025 | nrg->from = f; |
| 1026 | nrg->to = f; |
| 1027 | INIT_LIST_HEAD(&nrg->link); |
| 1028 | list_add(&nrg->link, rg->link.prev); |
| 1029 | |
| 1030 | return t - f; |
| 1031 | } |
| 1032 | |
| 1033 | /* Round our left edge to the current segment if it encloses us. */ |
| 1034 | if (f > rg->from) |
| 1035 | f = rg->from; |
| 1036 | chg = t - f; |
| 1037 | |
| 1038 | /* Check for and consume any regions we now overlap with. */ |
| 1039 | list_for_each_entry(rg, rg->link.prev, link) { |
| 1040 | if (&rg->link == head) |
| 1041 | break; |
| 1042 | if (rg->from > t) |
| 1043 | return chg; |
| 1044 | |
| 1045 | /* We overlap with this area, if it extends futher than |
| 1046 | * us then we must extend ourselves. Account for its |
| 1047 | * existing reservation. */ |
| 1048 | if (rg->to > t) { |
| 1049 | chg += rg->to - t; |
| 1050 | t = rg->to; |
| 1051 | } |
| 1052 | chg -= rg->to - rg->from; |
| 1053 | } |
| 1054 | return chg; |
| 1055 | } |
| 1056 | |
| 1057 | static long region_truncate(struct list_head *head, long end) |
| 1058 | { |
| 1059 | struct file_region *rg, *trg; |
| 1060 | long chg = 0; |
| 1061 | |
| 1062 | /* Locate the region we are either in or before. */ |
| 1063 | list_for_each_entry(rg, head, link) |
| 1064 | if (end <= rg->to) |
| 1065 | break; |
| 1066 | if (&rg->link == head) |
| 1067 | return 0; |
| 1068 | |
| 1069 | /* If we are in the middle of a region then adjust it. */ |
| 1070 | if (end > rg->from) { |
| 1071 | chg = rg->to - end; |
| 1072 | rg->to = end; |
| 1073 | rg = list_entry(rg->link.next, typeof(*rg), link); |
| 1074 | } |
| 1075 | |
| 1076 | /* Drop any remaining regions. */ |
| 1077 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
| 1078 | if (&rg->link == head) |
| 1079 | break; |
| 1080 | chg += rg->to - rg->from; |
| 1081 | list_del(&rg->link); |
| 1082 | kfree(rg); |
| 1083 | } |
| 1084 | return chg; |
| 1085 | } |
| 1086 | |
| 1087 | static int hugetlb_acct_memory(long delta) |
| 1088 | { |
| 1089 | int ret = -ENOMEM; |
| 1090 | |
| 1091 | spin_lock(&hugetlb_lock); |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 1092 | /* |
| 1093 | * When cpuset is configured, it breaks the strict hugetlb page |
| 1094 | * reservation as the accounting is done on a global variable. Such |
| 1095 | * reservation is completely rubbish in the presence of cpuset because |
| 1096 | * the reservation is not checked against page availability for the |
| 1097 | * current cpuset. Application can still potentially OOM'ed by kernel |
| 1098 | * with lack of free htlb page in cpuset that the task is in. |
| 1099 | * Attempt to enforce strict accounting with cpuset is almost |
| 1100 | * impossible (or too ugly) because cpuset is too fluid that |
| 1101 | * task or memory node can be dynamically moved between cpusets. |
| 1102 | * |
| 1103 | * The change of semantics for shared hugetlb mapping with cpuset is |
| 1104 | * undesirable. However, in order to preserve some of the semantics, |
| 1105 | * we fall back to check against current free page availability as |
| 1106 | * a best attempt and hopefully to minimize the impact of changing |
| 1107 | * semantics that cpuset has. |
| 1108 | */ |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 1109 | if (delta > 0) { |
| 1110 | if (gather_surplus_pages(delta) < 0) |
| 1111 | goto out; |
| 1112 | |
| 1113 | if (delta > cpuset_mems_nr(free_huge_pages_node)) |
| 1114 | goto out; |
| 1115 | } |
| 1116 | |
| 1117 | ret = 0; |
| 1118 | resv_huge_pages += delta; |
| 1119 | if (delta < 0) |
| 1120 | return_unused_surplus_pages((unsigned long) -delta); |
| 1121 | |
| 1122 | out: |
| 1123 | spin_unlock(&hugetlb_lock); |
| 1124 | return ret; |
| 1125 | } |
| 1126 | |
| 1127 | int hugetlb_reserve_pages(struct inode *inode, long from, long to) |
| 1128 | { |
| 1129 | long ret, chg; |
| 1130 | |
| 1131 | chg = region_chg(&inode->i_mapping->private_list, from, to); |
| 1132 | if (chg < 0) |
| 1133 | return chg; |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 1134 | |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1135 | ret = hugetlb_acct_memory(chg); |
| 1136 | if (ret < 0) |
| 1137 | return ret; |
| 1138 | region_add(&inode->i_mapping->private_list, from, to); |
| 1139 | return 0; |
| 1140 | } |
| 1141 | |
| 1142 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) |
| 1143 | { |
| 1144 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
| 1145 | hugetlb_acct_memory(freed - chg); |
| 1146 | } |