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); |
Adam Litke | c79fb75 | 2007-11-14 16:59:38 -0800 | [diff] [blame] | 119 | struct address_space *mapping; |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 120 | |
Adam Litke | c79fb75 | 2007-11-14 16:59:38 -0800 | [diff] [blame] | 121 | mapping = (struct address_space *) page_private(page); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 122 | BUG_ON(page_count(page)); |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 123 | INIT_LIST_HEAD(&page->lru); |
| 124 | |
| 125 | spin_lock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 126 | if (surplus_huge_pages_node[nid]) { |
| 127 | update_and_free_page(page); |
| 128 | surplus_huge_pages--; |
| 129 | surplus_huge_pages_node[nid]--; |
| 130 | } else { |
| 131 | enqueue_huge_page(page); |
| 132 | } |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 133 | spin_unlock(&hugetlb_lock); |
Adam Litke | c79fb75 | 2007-11-14 16:59:38 -0800 | [diff] [blame] | 134 | if (mapping) |
Adam Litke | 9a119c0 | 2007-11-14 16:59:41 -0800 | [diff] [blame] | 135 | hugetlb_put_quota(mapping, 1); |
Adam Litke | c79fb75 | 2007-11-14 16:59:38 -0800 | [diff] [blame] | 136 | set_page_private(page, 0); |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 137 | } |
| 138 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 139 | /* |
| 140 | * Increment or decrement surplus_huge_pages. Keep node-specific counters |
| 141 | * balanced by operating on them in a round-robin fashion. |
| 142 | * Returns 1 if an adjustment was made. |
| 143 | */ |
| 144 | static int adjust_pool_surplus(int delta) |
| 145 | { |
| 146 | static int prev_nid; |
| 147 | int nid = prev_nid; |
| 148 | int ret = 0; |
| 149 | |
| 150 | VM_BUG_ON(delta != -1 && delta != 1); |
| 151 | do { |
| 152 | nid = next_node(nid, node_online_map); |
| 153 | if (nid == MAX_NUMNODES) |
| 154 | nid = first_node(node_online_map); |
| 155 | |
| 156 | /* To shrink on this node, there must be a surplus page */ |
| 157 | if (delta < 0 && !surplus_huge_pages_node[nid]) |
| 158 | continue; |
| 159 | /* Surplus cannot exceed the total number of pages */ |
| 160 | if (delta > 0 && surplus_huge_pages_node[nid] >= |
| 161 | nr_huge_pages_node[nid]) |
| 162 | continue; |
| 163 | |
| 164 | surplus_huge_pages += delta; |
| 165 | surplus_huge_pages_node[nid] += delta; |
| 166 | ret = 1; |
| 167 | break; |
| 168 | } while (nid != prev_nid); |
| 169 | |
| 170 | prev_nid = nid; |
| 171 | return ret; |
| 172 | } |
| 173 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 174 | static struct page *alloc_fresh_huge_page_node(int nid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | struct page *page; |
Joe Jin | f96efd5 | 2007-07-15 23:38:12 -0700 | [diff] [blame] | 177 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 178 | page = alloc_pages_node(nid, |
| 179 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|__GFP_NOWARN, |
| 180 | HUGETLB_PAGE_ORDER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | if (page) { |
Andy Whitcroft | 33f2ef8 | 2006-12-06 20:33:32 -0800 | [diff] [blame] | 182 | set_compound_page_dtor(page, free_huge_page); |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 183 | spin_lock(&hugetlb_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | nr_huge_pages++; |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 185 | nr_huge_pages_node[nid]++; |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 186 | spin_unlock(&hugetlb_lock); |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 187 | put_page(page); /* free it into the hugepage allocator */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | } |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 189 | |
| 190 | return page; |
| 191 | } |
| 192 | |
| 193 | static int alloc_fresh_huge_page(void) |
| 194 | { |
| 195 | struct page *page; |
| 196 | int start_nid; |
| 197 | int next_nid; |
| 198 | int ret = 0; |
| 199 | |
| 200 | start_nid = hugetlb_next_nid; |
| 201 | |
| 202 | do { |
| 203 | page = alloc_fresh_huge_page_node(hugetlb_next_nid); |
| 204 | if (page) |
| 205 | ret = 1; |
| 206 | /* |
| 207 | * Use a helper variable to find the next node and then |
| 208 | * copy it back to hugetlb_next_nid afterwards: |
| 209 | * otherwise there's a window in which a racer might |
| 210 | * pass invalid nid MAX_NUMNODES to alloc_pages_node. |
| 211 | * But we don't need to use a spin_lock here: it really |
| 212 | * doesn't matter if occasionally a racer chooses the |
| 213 | * same nid as we do. Move nid forward in the mask even |
| 214 | * if we just successfully allocated a hugepage so that |
| 215 | * the next caller gets hugepages on the next node. |
| 216 | */ |
| 217 | next_nid = next_node(hugetlb_next_nid, node_online_map); |
| 218 | if (next_nid == MAX_NUMNODES) |
| 219 | next_nid = first_node(node_online_map); |
| 220 | hugetlb_next_nid = next_nid; |
| 221 | } while (!page && hugetlb_next_nid != start_nid); |
| 222 | |
| 223 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | } |
| 225 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 226 | static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma, |
| 227 | unsigned long address) |
| 228 | { |
| 229 | struct page *page; |
| 230 | |
Adam Litke | 54f9f80 | 2007-10-16 01:26:20 -0700 | [diff] [blame] | 231 | /* Check if the dynamic pool is enabled */ |
| 232 | if (!hugetlb_dynamic_pool) |
| 233 | return NULL; |
| 234 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 235 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN, |
| 236 | HUGETLB_PAGE_ORDER); |
| 237 | if (page) { |
| 238 | set_compound_page_dtor(page, free_huge_page); |
| 239 | spin_lock(&hugetlb_lock); |
| 240 | nr_huge_pages++; |
| 241 | nr_huge_pages_node[page_to_nid(page)]++; |
| 242 | surplus_huge_pages++; |
| 243 | surplus_huge_pages_node[page_to_nid(page)]++; |
| 244 | spin_unlock(&hugetlb_lock); |
| 245 | } |
| 246 | |
| 247 | return page; |
| 248 | } |
| 249 | |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 250 | /* |
| 251 | * Increase the hugetlb pool such that it can accomodate a reservation |
| 252 | * of size 'delta'. |
| 253 | */ |
| 254 | static int gather_surplus_pages(int delta) |
| 255 | { |
| 256 | struct list_head surplus_list; |
| 257 | struct page *page, *tmp; |
| 258 | int ret, i; |
| 259 | int needed, allocated; |
| 260 | |
| 261 | needed = (resv_huge_pages + delta) - free_huge_pages; |
| 262 | if (needed <= 0) |
| 263 | return 0; |
| 264 | |
| 265 | allocated = 0; |
| 266 | INIT_LIST_HEAD(&surplus_list); |
| 267 | |
| 268 | ret = -ENOMEM; |
| 269 | retry: |
| 270 | spin_unlock(&hugetlb_lock); |
| 271 | for (i = 0; i < needed; i++) { |
| 272 | page = alloc_buddy_huge_page(NULL, 0); |
| 273 | if (!page) { |
| 274 | /* |
| 275 | * We were not able to allocate enough pages to |
| 276 | * satisfy the entire reservation so we free what |
| 277 | * we've allocated so far. |
| 278 | */ |
| 279 | spin_lock(&hugetlb_lock); |
| 280 | needed = 0; |
| 281 | goto free; |
| 282 | } |
| 283 | |
| 284 | list_add(&page->lru, &surplus_list); |
| 285 | } |
| 286 | allocated += needed; |
| 287 | |
| 288 | /* |
| 289 | * After retaking hugetlb_lock, we need to recalculate 'needed' |
| 290 | * because either resv_huge_pages or free_huge_pages may have changed. |
| 291 | */ |
| 292 | spin_lock(&hugetlb_lock); |
| 293 | needed = (resv_huge_pages + delta) - (free_huge_pages + allocated); |
| 294 | if (needed > 0) |
| 295 | goto retry; |
| 296 | |
| 297 | /* |
| 298 | * The surplus_list now contains _at_least_ the number of extra pages |
| 299 | * needed to accomodate the reservation. Add the appropriate number |
| 300 | * of pages to the hugetlb pool and free the extras back to the buddy |
| 301 | * allocator. |
| 302 | */ |
| 303 | needed += allocated; |
| 304 | ret = 0; |
| 305 | free: |
| 306 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
| 307 | list_del(&page->lru); |
| 308 | if ((--needed) >= 0) |
| 309 | enqueue_huge_page(page); |
Adam Litke | af767cb | 2007-10-16 01:26:25 -0700 | [diff] [blame] | 310 | else { |
| 311 | /* |
| 312 | * Decrement the refcount and free the page using its |
| 313 | * destructor. This must be done with hugetlb_lock |
| 314 | * unlocked which is safe because free_huge_page takes |
| 315 | * hugetlb_lock before deciding how to free the page. |
| 316 | */ |
| 317 | spin_unlock(&hugetlb_lock); |
| 318 | put_page(page); |
| 319 | spin_lock(&hugetlb_lock); |
| 320 | } |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 321 | } |
| 322 | |
| 323 | return ret; |
| 324 | } |
| 325 | |
| 326 | /* |
| 327 | * When releasing a hugetlb pool reservation, any surplus pages that were |
| 328 | * allocated to satisfy the reservation must be explicitly freed if they were |
| 329 | * never used. |
| 330 | */ |
Adrian Bunk | 8cde045 | 2007-11-14 16:59:43 -0800 | [diff] [blame] | 331 | static void return_unused_surplus_pages(unsigned long unused_resv_pages) |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 332 | { |
| 333 | static int nid = -1; |
| 334 | struct page *page; |
| 335 | unsigned long nr_pages; |
| 336 | |
| 337 | nr_pages = min(unused_resv_pages, surplus_huge_pages); |
| 338 | |
| 339 | while (nr_pages) { |
| 340 | nid = next_node(nid, node_online_map); |
| 341 | if (nid == MAX_NUMNODES) |
| 342 | nid = first_node(node_online_map); |
| 343 | |
| 344 | if (!surplus_huge_pages_node[nid]) |
| 345 | continue; |
| 346 | |
| 347 | if (!list_empty(&hugepage_freelists[nid])) { |
| 348 | page = list_entry(hugepage_freelists[nid].next, |
| 349 | struct page, lru); |
| 350 | list_del(&page->lru); |
| 351 | update_and_free_page(page); |
| 352 | free_huge_pages--; |
| 353 | free_huge_pages_node[nid]--; |
| 354 | surplus_huge_pages--; |
| 355 | surplus_huge_pages_node[nid]--; |
| 356 | nr_pages--; |
| 357 | } |
| 358 | } |
| 359 | } |
| 360 | |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 361 | |
| 362 | static struct page *alloc_huge_page_shared(struct vm_area_struct *vma, |
| 363 | unsigned long addr) |
| 364 | { |
| 365 | struct page *page; |
| 366 | |
| 367 | spin_lock(&hugetlb_lock); |
| 368 | page = dequeue_huge_page(vma, addr); |
| 369 | spin_unlock(&hugetlb_lock); |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 370 | return page ? page : ERR_PTR(-VM_FAULT_OOM); |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 371 | } |
| 372 | |
| 373 | static struct page *alloc_huge_page_private(struct vm_area_struct *vma, |
| 374 | unsigned long addr) |
| 375 | { |
| 376 | struct page *page = NULL; |
| 377 | |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 378 | if (hugetlb_get_quota(vma->vm_file->f_mapping, 1)) |
| 379 | return ERR_PTR(-VM_FAULT_SIGBUS); |
| 380 | |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 381 | spin_lock(&hugetlb_lock); |
| 382 | if (free_huge_pages > resv_huge_pages) |
| 383 | page = dequeue_huge_page(vma, addr); |
| 384 | spin_unlock(&hugetlb_lock); |
| 385 | if (!page) |
| 386 | page = alloc_buddy_huge_page(vma, addr); |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 387 | return page ? page : ERR_PTR(-VM_FAULT_OOM); |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 388 | } |
| 389 | |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 390 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
| 391 | unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | { |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 393 | struct page *page; |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 394 | struct address_space *mapping = vma->vm_file->f_mapping; |
| 395 | |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 396 | if (vma->vm_flags & VM_MAYSHARE) |
| 397 | page = alloc_huge_page_shared(vma, addr); |
| 398 | else |
| 399 | page = alloc_huge_page_private(vma, addr); |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 400 | |
| 401 | if (!IS_ERR(page)) { |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 402 | set_page_refcounted(page); |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 403 | set_page_private(page, (unsigned long) mapping); |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 404 | } |
| 405 | return page; |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 406 | } |
| 407 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | static int __init hugetlb_init(void) |
| 409 | { |
| 410 | unsigned long i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | |
Benjamin Herrenschmidt | 3c726f8 | 2005-11-07 11:06:55 +1100 | [diff] [blame] | 412 | if (HPAGE_SHIFT == 0) |
| 413 | return 0; |
| 414 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | for (i = 0; i < MAX_NUMNODES; ++i) |
| 416 | INIT_LIST_HEAD(&hugepage_freelists[i]); |
| 417 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 418 | hugetlb_next_nid = first_node(node_online_map); |
| 419 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | for (i = 0; i < max_huge_pages; ++i) { |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 421 | if (!alloc_fresh_huge_page()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 422 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | } |
| 424 | max_huge_pages = free_huge_pages = nr_huge_pages = i; |
| 425 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); |
| 426 | return 0; |
| 427 | } |
| 428 | module_init(hugetlb_init); |
| 429 | |
| 430 | static int __init hugetlb_setup(char *s) |
| 431 | { |
| 432 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) |
| 433 | max_huge_pages = 0; |
| 434 | return 1; |
| 435 | } |
| 436 | __setup("hugepages=", hugetlb_setup); |
| 437 | |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 438 | static unsigned int cpuset_mems_nr(unsigned int *array) |
| 439 | { |
| 440 | int node; |
| 441 | unsigned int nr = 0; |
| 442 | |
| 443 | for_each_node_mask(node, cpuset_current_mems_allowed) |
| 444 | nr += array[node]; |
| 445 | |
| 446 | return nr; |
| 447 | } |
| 448 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | #ifdef CONFIG_SYSCTL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | #ifdef CONFIG_HIGHMEM |
| 451 | static void try_to_free_low(unsigned long count) |
| 452 | { |
Christoph Lameter | 4415cc8 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 453 | int i; |
| 454 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | for (i = 0; i < MAX_NUMNODES; ++i) { |
| 456 | struct page *page, *next; |
| 457 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { |
Adam Litke | 6b0c880 | 2007-10-16 01:26:23 -0700 | [diff] [blame] | 458 | if (count >= nr_huge_pages) |
| 459 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | if (PageHighMem(page)) |
| 461 | continue; |
| 462 | list_del(&page->lru); |
| 463 | update_and_free_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 464 | free_huge_pages--; |
Christoph Lameter | 4415cc8 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 465 | free_huge_pages_node[page_to_nid(page)]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | } |
| 467 | } |
| 468 | } |
| 469 | #else |
| 470 | static inline void try_to_free_low(unsigned long count) |
| 471 | { |
| 472 | } |
| 473 | #endif |
| 474 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 475 | #define persistent_huge_pages (nr_huge_pages - surplus_huge_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | static unsigned long set_max_huge_pages(unsigned long count) |
| 477 | { |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 478 | unsigned long min_count, ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 480 | /* |
| 481 | * Increase the pool size |
| 482 | * First take pages out of surplus state. Then make up the |
| 483 | * remaining difference by allocating fresh huge pages. |
| 484 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | spin_lock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 486 | while (surplus_huge_pages && count > persistent_huge_pages) { |
| 487 | if (!adjust_pool_surplus(-1)) |
| 488 | break; |
| 489 | } |
| 490 | |
| 491 | while (count > persistent_huge_pages) { |
| 492 | int ret; |
| 493 | /* |
| 494 | * If this allocation races such that we no longer need the |
| 495 | * page, free_huge_page will handle it by freeing the page |
| 496 | * and reducing the surplus. |
| 497 | */ |
| 498 | spin_unlock(&hugetlb_lock); |
| 499 | ret = alloc_fresh_huge_page(); |
| 500 | spin_lock(&hugetlb_lock); |
| 501 | if (!ret) |
| 502 | goto out; |
| 503 | |
| 504 | } |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 505 | |
| 506 | /* |
| 507 | * Decrease the pool size |
| 508 | * First return free pages to the buddy allocator (being careful |
| 509 | * to keep enough around to satisfy reservations). Then place |
| 510 | * pages into surplus state as needed so the pool will shrink |
| 511 | * to the desired size as pages become free. |
| 512 | */ |
Adam Litke | 6b0c880 | 2007-10-16 01:26:23 -0700 | [diff] [blame] | 513 | min_count = resv_huge_pages + nr_huge_pages - free_huge_pages; |
| 514 | min_count = max(count, min_count); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 515 | try_to_free_low(min_count); |
| 516 | while (min_count < persistent_huge_pages) { |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 517 | struct page *page = dequeue_huge_page(NULL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | if (!page) |
| 519 | break; |
| 520 | update_and_free_page(page); |
| 521 | } |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 522 | while (count < persistent_huge_pages) { |
| 523 | if (!adjust_pool_surplus(1)) |
| 524 | break; |
| 525 | } |
| 526 | out: |
| 527 | ret = persistent_huge_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | spin_unlock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 529 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | } |
| 531 | |
| 532 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
| 533 | struct file *file, void __user *buffer, |
| 534 | size_t *length, loff_t *ppos) |
| 535 | { |
| 536 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
| 537 | max_huge_pages = set_max_huge_pages(max_huge_pages); |
| 538 | return 0; |
| 539 | } |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 540 | |
| 541 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, |
| 542 | struct file *file, void __user *buffer, |
| 543 | size_t *length, loff_t *ppos) |
| 544 | { |
| 545 | proc_dointvec(table, write, file, buffer, length, ppos); |
| 546 | if (hugepages_treat_as_movable) |
| 547 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; |
| 548 | else |
| 549 | htlb_alloc_mask = GFP_HIGHUSER; |
| 550 | return 0; |
| 551 | } |
| 552 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | #endif /* CONFIG_SYSCTL */ |
| 554 | |
| 555 | int hugetlb_report_meminfo(char *buf) |
| 556 | { |
| 557 | return sprintf(buf, |
| 558 | "HugePages_Total: %5lu\n" |
| 559 | "HugePages_Free: %5lu\n" |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 560 | "HugePages_Rsvd: %5lu\n" |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 561 | "HugePages_Surp: %5lu\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | "Hugepagesize: %5lu kB\n", |
| 563 | nr_huge_pages, |
| 564 | free_huge_pages, |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 565 | resv_huge_pages, |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 566 | surplus_huge_pages, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | HPAGE_SIZE/1024); |
| 568 | } |
| 569 | |
| 570 | int hugetlb_report_node_meminfo(int nid, char *buf) |
| 571 | { |
| 572 | return sprintf(buf, |
| 573 | "Node %d HugePages_Total: %5u\n" |
| 574 | "Node %d HugePages_Free: %5u\n", |
| 575 | nid, nr_huge_pages_node[nid], |
| 576 | nid, free_huge_pages_node[nid]); |
| 577 | } |
| 578 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 579 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
| 580 | unsigned long hugetlb_total_pages(void) |
| 581 | { |
| 582 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); |
| 583 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | |
| 585 | /* |
| 586 | * We cannot handle pagefaults against hugetlb pages at all. They cause |
| 587 | * handle_mm_fault() to try to instantiate regular-sized pages in the |
| 588 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get |
| 589 | * this far. |
| 590 | */ |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 591 | 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] | 592 | { |
| 593 | BUG(); |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 594 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 595 | } |
| 596 | |
| 597 | struct vm_operations_struct hugetlb_vm_ops = { |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 598 | .fault = hugetlb_vm_op_fault, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | }; |
| 600 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 601 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
| 602 | int writable) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 603 | { |
| 604 | pte_t entry; |
| 605 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 606 | if (writable) { |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 607 | entry = |
| 608 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); |
| 609 | } else { |
| 610 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
| 611 | } |
| 612 | entry = pte_mkyoung(entry); |
| 613 | entry = pte_mkhuge(entry); |
| 614 | |
| 615 | return entry; |
| 616 | } |
| 617 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 618 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
| 619 | unsigned long address, pte_t *ptep) |
| 620 | { |
| 621 | pte_t entry; |
| 622 | |
| 623 | entry = pte_mkwrite(pte_mkdirty(*ptep)); |
Benjamin Herrenschmidt | 8dab524 | 2007-06-16 10:16:12 -0700 | [diff] [blame] | 624 | if (ptep_set_access_flags(vma, address, ptep, entry, 1)) { |
| 625 | update_mmu_cache(vma, address, entry); |
Benjamin Herrenschmidt | 8dab524 | 2007-06-16 10:16:12 -0700 | [diff] [blame] | 626 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 627 | } |
| 628 | |
| 629 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 630 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
| 631 | struct vm_area_struct *vma) |
| 632 | { |
| 633 | pte_t *src_pte, *dst_pte, entry; |
| 634 | struct page *ptepage; |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 635 | unsigned long addr; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 636 | int cow; |
| 637 | |
| 638 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 639 | |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 640 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 641 | src_pte = huge_pte_offset(src, addr); |
| 642 | if (!src_pte) |
| 643 | continue; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 644 | dst_pte = huge_pte_alloc(dst, addr); |
| 645 | if (!dst_pte) |
| 646 | goto nomem; |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 647 | spin_lock(&dst->page_table_lock); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 648 | spin_lock(&src->page_table_lock); |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 649 | if (!pte_none(*src_pte)) { |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 650 | if (cow) |
| 651 | ptep_set_wrprotect(src, addr, src_pte); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 652 | entry = *src_pte; |
| 653 | ptepage = pte_page(entry); |
| 654 | get_page(ptepage); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 655 | set_huge_pte_at(dst, addr, dst_pte, entry); |
| 656 | } |
| 657 | spin_unlock(&src->page_table_lock); |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 658 | spin_unlock(&dst->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 659 | } |
| 660 | return 0; |
| 661 | |
| 662 | nomem: |
| 663 | return -ENOMEM; |
| 664 | } |
| 665 | |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 666 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
| 667 | unsigned long end) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 668 | { |
| 669 | struct mm_struct *mm = vma->vm_mm; |
| 670 | unsigned long address; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 671 | pte_t *ptep; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 672 | pte_t pte; |
| 673 | struct page *page; |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 674 | struct page *tmp; |
Chen, Kenneth W | c0a499c | 2006-12-06 20:31:39 -0800 | [diff] [blame] | 675 | /* |
| 676 | * A page gathering list, protected by per file i_mmap_lock. The |
| 677 | * lock is used to avoid list corruption from multiple unmapping |
| 678 | * of the same page since we are using page->lru. |
| 679 | */ |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 680 | LIST_HEAD(page_list); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 681 | |
| 682 | WARN_ON(!is_vm_hugetlb_page(vma)); |
| 683 | BUG_ON(start & ~HPAGE_MASK); |
| 684 | BUG_ON(end & ~HPAGE_MASK); |
| 685 | |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 686 | spin_lock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 687 | for (address = start; address < end; address += HPAGE_SIZE) { |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 688 | ptep = huge_pte_offset(mm, address); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 689 | if (!ptep) |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 690 | continue; |
| 691 | |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 692 | if (huge_pmd_unshare(mm, &address, ptep)) |
| 693 | continue; |
| 694 | |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 695 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 696 | if (pte_none(pte)) |
| 697 | continue; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 698 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 699 | page = pte_page(pte); |
Ken Chen | 6649a38 | 2007-02-08 14:20:27 -0800 | [diff] [blame] | 700 | if (pte_dirty(pte)) |
| 701 | set_page_dirty(page); |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 702 | list_add(&page->lru, &page_list); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 703 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | spin_unlock(&mm->page_table_lock); |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 705 | flush_tlb_range(vma, start, end); |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 706 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
| 707 | list_del(&page->lru); |
| 708 | put_page(page); |
| 709 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 710 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 711 | |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 712 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
| 713 | unsigned long end) |
| 714 | { |
| 715 | /* |
| 716 | * It is undesirable to test vma->vm_file as it should be non-null |
| 717 | * for valid hugetlb area. However, vm_file will be NULL in the error |
| 718 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, |
| 719 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function |
| 720 | * to clean up. Since no pte has actually been setup, it is safe to |
| 721 | * do nothing in this case. |
| 722 | */ |
| 723 | if (vma->vm_file) { |
| 724 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
| 725 | __unmap_hugepage_range(vma, start, end); |
| 726 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
| 727 | } |
| 728 | } |
| 729 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 730 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
| 731 | unsigned long address, pte_t *ptep, pte_t pte) |
| 732 | { |
| 733 | struct page *old_page, *new_page; |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 734 | int avoidcopy; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 735 | |
| 736 | old_page = pte_page(pte); |
| 737 | |
| 738 | /* If no-one else is actually using this page, avoid the copy |
| 739 | * and just make the page writable */ |
| 740 | avoidcopy = (page_count(old_page) == 1); |
| 741 | if (avoidcopy) { |
| 742 | set_huge_ptep_writable(vma, address, ptep); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 743 | return 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 744 | } |
| 745 | |
| 746 | page_cache_get(old_page); |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 747 | new_page = alloc_huge_page(vma, address); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 748 | |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 749 | if (IS_ERR(new_page)) { |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 750 | page_cache_release(old_page); |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 751 | return -PTR_ERR(new_page); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 752 | } |
| 753 | |
| 754 | spin_unlock(&mm->page_table_lock); |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 755 | copy_huge_page(new_page, old_page, address, vma); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 756 | spin_lock(&mm->page_table_lock); |
| 757 | |
| 758 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); |
| 759 | if (likely(pte_same(*ptep, pte))) { |
| 760 | /* Break COW */ |
| 761 | set_huge_pte_at(mm, address, ptep, |
| 762 | make_huge_pte(vma, new_page, 1)); |
| 763 | /* Make the old page be freed below */ |
| 764 | new_page = old_page; |
| 765 | } |
| 766 | page_cache_release(new_page); |
| 767 | page_cache_release(old_page); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 768 | return 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 769 | } |
| 770 | |
Robert P. J. Day | a1ed3dd | 2007-07-17 04:03:33 -0700 | [diff] [blame] | 771 | 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] | 772 | unsigned long address, pte_t *ptep, int write_access) |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 773 | { |
| 774 | int ret = VM_FAULT_SIGBUS; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 775 | unsigned long idx; |
| 776 | unsigned long size; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 777 | struct page *page; |
| 778 | struct address_space *mapping; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 779 | pte_t new_pte; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 780 | |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 781 | mapping = vma->vm_file->f_mapping; |
| 782 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) |
| 783 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); |
| 784 | |
| 785 | /* |
| 786 | * Use page lock to guard against racing truncation |
| 787 | * before we get page_table_lock. |
| 788 | */ |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 789 | retry: |
| 790 | page = find_lock_page(mapping, idx); |
| 791 | if (!page) { |
Hugh Dickins | ebed4bf | 2006-10-28 10:38:43 -0700 | [diff] [blame] | 792 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
| 793 | if (idx >= size) |
| 794 | goto out; |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 795 | page = alloc_huge_page(vma, address); |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 796 | if (IS_ERR(page)) { |
| 797 | ret = -PTR_ERR(page); |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 798 | goto out; |
| 799 | } |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 800 | clear_huge_page(page, address); |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 801 | |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 802 | if (vma->vm_flags & VM_SHARED) { |
| 803 | int err; |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 804 | struct inode *inode = mapping->host; |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 805 | |
| 806 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); |
| 807 | if (err) { |
| 808 | put_page(page); |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 809 | if (err == -EEXIST) |
| 810 | goto retry; |
| 811 | goto out; |
| 812 | } |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 813 | |
| 814 | spin_lock(&inode->i_lock); |
| 815 | inode->i_blocks += BLOCKS_PER_HUGEPAGE; |
| 816 | spin_unlock(&inode->i_lock); |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 817 | } else |
| 818 | lock_page(page); |
| 819 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 820 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 821 | spin_lock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 822 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
| 823 | if (idx >= size) |
| 824 | goto backout; |
| 825 | |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 826 | ret = 0; |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 827 | if (!pte_none(*ptep)) |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 828 | goto backout; |
| 829 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 830 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
| 831 | && (vma->vm_flags & VM_SHARED))); |
| 832 | set_huge_pte_at(mm, address, ptep, new_pte); |
| 833 | |
| 834 | if (write_access && !(vma->vm_flags & VM_SHARED)) { |
| 835 | /* Optimization, do the COW without a second fault */ |
| 836 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); |
| 837 | } |
| 838 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 839 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 840 | unlock_page(page); |
| 841 | out: |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 842 | return ret; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 843 | |
| 844 | backout: |
| 845 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 846 | unlock_page(page); |
| 847 | put_page(page); |
| 848 | goto out; |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 849 | } |
| 850 | |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 851 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
| 852 | unsigned long address, int write_access) |
| 853 | { |
| 854 | pte_t *ptep; |
| 855 | pte_t entry; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 856 | int ret; |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 857 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 858 | |
| 859 | ptep = huge_pte_alloc(mm, address); |
| 860 | if (!ptep) |
| 861 | return VM_FAULT_OOM; |
| 862 | |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 863 | /* |
| 864 | * Serialize hugepage allocation and instantiation, so that we don't |
| 865 | * get spurious allocation failures if two CPUs race to instantiate |
| 866 | * the same page in the page cache. |
| 867 | */ |
| 868 | mutex_lock(&hugetlb_instantiation_mutex); |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 869 | entry = *ptep; |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 870 | if (pte_none(entry)) { |
| 871 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); |
| 872 | mutex_unlock(&hugetlb_instantiation_mutex); |
| 873 | return ret; |
| 874 | } |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 875 | |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 876 | ret = 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 877 | |
| 878 | spin_lock(&mm->page_table_lock); |
| 879 | /* Check for a racing update before calling hugetlb_cow */ |
| 880 | if (likely(pte_same(entry, *ptep))) |
| 881 | if (write_access && !pte_write(entry)) |
| 882 | ret = hugetlb_cow(mm, vma, address, ptep, entry); |
| 883 | spin_unlock(&mm->page_table_lock); |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 884 | mutex_unlock(&hugetlb_instantiation_mutex); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 885 | |
| 886 | return ret; |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 887 | } |
| 888 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 889 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
| 890 | struct page **pages, struct vm_area_struct **vmas, |
Adam Litke | 5b23dbe | 2007-11-14 16:59:33 -0800 | [diff] [blame] | 891 | unsigned long *position, int *length, int i, |
| 892 | int write) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 893 | { |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 894 | unsigned long pfn_offset; |
| 895 | unsigned long vaddr = *position; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 896 | int remainder = *length; |
| 897 | |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 898 | spin_lock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 899 | while (vaddr < vma->vm_end && remainder) { |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 900 | pte_t *pte; |
| 901 | struct page *page; |
| 902 | |
| 903 | /* |
| 904 | * Some archs (sparc64, sh*) have multiple pte_ts to |
| 905 | * each hugepage. We have to make * sure we get the |
| 906 | * first, for the page indexing below to work. |
| 907 | */ |
| 908 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); |
| 909 | |
| 910 | if (!pte || pte_none(*pte)) { |
| 911 | int ret; |
| 912 | |
| 913 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 5b23dbe | 2007-11-14 16:59:33 -0800 | [diff] [blame] | 914 | ret = hugetlb_fault(mm, vma, vaddr, write); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 915 | spin_lock(&mm->page_table_lock); |
Adam Litke | a89182c | 2007-08-22 14:01:51 -0700 | [diff] [blame] | 916 | if (!(ret & VM_FAULT_ERROR)) |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 917 | continue; |
| 918 | |
| 919 | remainder = 0; |
| 920 | if (!i) |
| 921 | i = -EFAULT; |
| 922 | break; |
| 923 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 924 | |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 925 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
| 926 | page = pte_page(*pte); |
| 927 | same_page: |
Chen, Kenneth W | d669218 | 2006-03-31 02:29:57 -0800 | [diff] [blame] | 928 | if (pages) { |
| 929 | get_page(page); |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 930 | pages[i] = page + pfn_offset; |
Chen, Kenneth W | d669218 | 2006-03-31 02:29:57 -0800 | [diff] [blame] | 931 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 932 | |
| 933 | if (vmas) |
| 934 | vmas[i] = vma; |
| 935 | |
| 936 | vaddr += PAGE_SIZE; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 937 | ++pfn_offset; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 938 | --remainder; |
| 939 | ++i; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 940 | if (vaddr < vma->vm_end && remainder && |
| 941 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { |
| 942 | /* |
| 943 | * We use pfn_offset to avoid touching the pageframes |
| 944 | * of this compound page. |
| 945 | */ |
| 946 | goto same_page; |
| 947 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 948 | } |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 949 | spin_unlock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 950 | *length = remainder; |
| 951 | *position = vaddr; |
| 952 | |
| 953 | return i; |
| 954 | } |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 955 | |
| 956 | void hugetlb_change_protection(struct vm_area_struct *vma, |
| 957 | unsigned long address, unsigned long end, pgprot_t newprot) |
| 958 | { |
| 959 | struct mm_struct *mm = vma->vm_mm; |
| 960 | unsigned long start = address; |
| 961 | pte_t *ptep; |
| 962 | pte_t pte; |
| 963 | |
| 964 | BUG_ON(address >= end); |
| 965 | flush_cache_range(vma, address, end); |
| 966 | |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 967 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 968 | spin_lock(&mm->page_table_lock); |
| 969 | for (; address < end; address += HPAGE_SIZE) { |
| 970 | ptep = huge_pte_offset(mm, address); |
| 971 | if (!ptep) |
| 972 | continue; |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 973 | if (huge_pmd_unshare(mm, &address, ptep)) |
| 974 | continue; |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 975 | if (!pte_none(*ptep)) { |
| 976 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
| 977 | pte = pte_mkhuge(pte_modify(pte, newprot)); |
| 978 | set_huge_pte_at(mm, address, ptep, pte); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 979 | } |
| 980 | } |
| 981 | spin_unlock(&mm->page_table_lock); |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 982 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 983 | |
| 984 | flush_tlb_range(vma, start, end); |
| 985 | } |
| 986 | |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 987 | struct file_region { |
| 988 | struct list_head link; |
| 989 | long from; |
| 990 | long to; |
| 991 | }; |
| 992 | |
| 993 | static long region_add(struct list_head *head, long f, long t) |
| 994 | { |
| 995 | struct file_region *rg, *nrg, *trg; |
| 996 | |
| 997 | /* Locate the region we are either in or before. */ |
| 998 | list_for_each_entry(rg, head, link) |
| 999 | if (f <= rg->to) |
| 1000 | break; |
| 1001 | |
| 1002 | /* Round our left edge to the current segment if it encloses us. */ |
| 1003 | if (f > rg->from) |
| 1004 | f = rg->from; |
| 1005 | |
| 1006 | /* Check for and consume any regions we now overlap with. */ |
| 1007 | nrg = rg; |
| 1008 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
| 1009 | if (&rg->link == head) |
| 1010 | break; |
| 1011 | if (rg->from > t) |
| 1012 | break; |
| 1013 | |
| 1014 | /* If this area reaches higher then extend our area to |
| 1015 | * include it completely. If this is not the first area |
| 1016 | * which we intend to reuse, free it. */ |
| 1017 | if (rg->to > t) |
| 1018 | t = rg->to; |
| 1019 | if (rg != nrg) { |
| 1020 | list_del(&rg->link); |
| 1021 | kfree(rg); |
| 1022 | } |
| 1023 | } |
| 1024 | nrg->from = f; |
| 1025 | nrg->to = t; |
| 1026 | return 0; |
| 1027 | } |
| 1028 | |
| 1029 | static long region_chg(struct list_head *head, long f, long t) |
| 1030 | { |
| 1031 | struct file_region *rg, *nrg; |
| 1032 | long chg = 0; |
| 1033 | |
| 1034 | /* Locate the region we are before or in. */ |
| 1035 | list_for_each_entry(rg, head, link) |
| 1036 | if (f <= rg->to) |
| 1037 | break; |
| 1038 | |
| 1039 | /* If we are below the current region then a new region is required. |
| 1040 | * Subtle, allocate a new region at the position but make it zero |
Simon Arlott | 183ff22 | 2007-10-20 01:27:18 +0200 | [diff] [blame] | 1041 | * size such that we can guarantee to record the reservation. */ |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1042 | if (&rg->link == head || t < rg->from) { |
| 1043 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); |
Stephen Hemminger | c80544d | 2007-10-18 03:07:05 -0700 | [diff] [blame] | 1044 | if (!nrg) |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1045 | return -ENOMEM; |
| 1046 | nrg->from = f; |
| 1047 | nrg->to = f; |
| 1048 | INIT_LIST_HEAD(&nrg->link); |
| 1049 | list_add(&nrg->link, rg->link.prev); |
| 1050 | |
| 1051 | return t - f; |
| 1052 | } |
| 1053 | |
| 1054 | /* Round our left edge to the current segment if it encloses us. */ |
| 1055 | if (f > rg->from) |
| 1056 | f = rg->from; |
| 1057 | chg = t - f; |
| 1058 | |
| 1059 | /* Check for and consume any regions we now overlap with. */ |
| 1060 | list_for_each_entry(rg, rg->link.prev, link) { |
| 1061 | if (&rg->link == head) |
| 1062 | break; |
| 1063 | if (rg->from > t) |
| 1064 | return chg; |
| 1065 | |
| 1066 | /* We overlap with this area, if it extends futher than |
| 1067 | * us then we must extend ourselves. Account for its |
| 1068 | * existing reservation. */ |
| 1069 | if (rg->to > t) { |
| 1070 | chg += rg->to - t; |
| 1071 | t = rg->to; |
| 1072 | } |
| 1073 | chg -= rg->to - rg->from; |
| 1074 | } |
| 1075 | return chg; |
| 1076 | } |
| 1077 | |
| 1078 | static long region_truncate(struct list_head *head, long end) |
| 1079 | { |
| 1080 | struct file_region *rg, *trg; |
| 1081 | long chg = 0; |
| 1082 | |
| 1083 | /* Locate the region we are either in or before. */ |
| 1084 | list_for_each_entry(rg, head, link) |
| 1085 | if (end <= rg->to) |
| 1086 | break; |
| 1087 | if (&rg->link == head) |
| 1088 | return 0; |
| 1089 | |
| 1090 | /* If we are in the middle of a region then adjust it. */ |
| 1091 | if (end > rg->from) { |
| 1092 | chg = rg->to - end; |
| 1093 | rg->to = end; |
| 1094 | rg = list_entry(rg->link.next, typeof(*rg), link); |
| 1095 | } |
| 1096 | |
| 1097 | /* Drop any remaining regions. */ |
| 1098 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
| 1099 | if (&rg->link == head) |
| 1100 | break; |
| 1101 | chg += rg->to - rg->from; |
| 1102 | list_del(&rg->link); |
| 1103 | kfree(rg); |
| 1104 | } |
| 1105 | return chg; |
| 1106 | } |
| 1107 | |
| 1108 | static int hugetlb_acct_memory(long delta) |
| 1109 | { |
| 1110 | int ret = -ENOMEM; |
| 1111 | |
| 1112 | spin_lock(&hugetlb_lock); |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 1113 | /* |
| 1114 | * When cpuset is configured, it breaks the strict hugetlb page |
| 1115 | * reservation as the accounting is done on a global variable. Such |
| 1116 | * reservation is completely rubbish in the presence of cpuset because |
| 1117 | * the reservation is not checked against page availability for the |
| 1118 | * current cpuset. Application can still potentially OOM'ed by kernel |
| 1119 | * with lack of free htlb page in cpuset that the task is in. |
| 1120 | * Attempt to enforce strict accounting with cpuset is almost |
| 1121 | * impossible (or too ugly) because cpuset is too fluid that |
| 1122 | * task or memory node can be dynamically moved between cpusets. |
| 1123 | * |
| 1124 | * The change of semantics for shared hugetlb mapping with cpuset is |
| 1125 | * undesirable. However, in order to preserve some of the semantics, |
| 1126 | * we fall back to check against current free page availability as |
| 1127 | * a best attempt and hopefully to minimize the impact of changing |
| 1128 | * semantics that cpuset has. |
| 1129 | */ |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 1130 | if (delta > 0) { |
| 1131 | if (gather_surplus_pages(delta) < 0) |
| 1132 | goto out; |
| 1133 | |
| 1134 | if (delta > cpuset_mems_nr(free_huge_pages_node)) |
| 1135 | goto out; |
| 1136 | } |
| 1137 | |
| 1138 | ret = 0; |
| 1139 | resv_huge_pages += delta; |
| 1140 | if (delta < 0) |
| 1141 | return_unused_surplus_pages((unsigned long) -delta); |
| 1142 | |
| 1143 | out: |
| 1144 | spin_unlock(&hugetlb_lock); |
| 1145 | return ret; |
| 1146 | } |
| 1147 | |
| 1148 | int hugetlb_reserve_pages(struct inode *inode, long from, long to) |
| 1149 | { |
| 1150 | long ret, chg; |
| 1151 | |
| 1152 | chg = region_chg(&inode->i_mapping->private_list, from, to); |
| 1153 | if (chg < 0) |
| 1154 | return chg; |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 1155 | |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 1156 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
| 1157 | return -ENOSPC; |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1158 | ret = hugetlb_acct_memory(chg); |
| 1159 | if (ret < 0) |
| 1160 | return ret; |
| 1161 | region_add(&inode->i_mapping->private_list, from, to); |
| 1162 | return 0; |
| 1163 | } |
| 1164 | |
| 1165 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) |
| 1166 | { |
| 1167 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 1168 | |
| 1169 | spin_lock(&inode->i_lock); |
| 1170 | inode->i_blocks -= BLOCKS_PER_HUGEPAGE * freed; |
| 1171 | spin_unlock(&inode->i_lock); |
| 1172 | |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 1173 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
| 1174 | hugetlb_acct_memory(-(chg - freed)); |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1175 | } |