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; |
Nishanth Aravamudan | 064d9ef | 2008-02-13 15:03:19 -0800 | [diff] [blame] | 27 | static unsigned long nr_overcommit_huge_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | unsigned long max_huge_pages; |
Nishanth Aravamudan | 064d9ef | 2008-02-13 15:03:19 -0800 | [diff] [blame] | 29 | unsigned long sysctl_overcommit_huge_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | static struct list_head hugepage_freelists[MAX_NUMNODES]; |
| 31 | static unsigned int nr_huge_pages_node[MAX_NUMNODES]; |
| 32 | static unsigned int free_huge_pages_node[MAX_NUMNODES]; |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 33 | static unsigned int surplus_huge_pages_node[MAX_NUMNODES]; |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 34 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
| 35 | unsigned long hugepages_treat_as_movable; |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 36 | static int hugetlb_next_nid; |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 37 | |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 38 | /* |
| 39 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages |
| 40 | */ |
| 41 | static DEFINE_SPINLOCK(hugetlb_lock); |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 42 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame^] | 43 | /* |
| 44 | * These helpers are used to track how many pages are reserved for |
| 45 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() |
| 46 | * is guaranteed to have their future faults succeed. |
| 47 | * |
| 48 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), |
| 49 | * the reserve counters are updated with the hugetlb_lock held. It is safe |
| 50 | * to reset the VMA at fork() time as it is not in use yet and there is no |
| 51 | * chance of the global counters getting corrupted as a result of the values. |
| 52 | */ |
| 53 | static unsigned long vma_resv_huge_pages(struct vm_area_struct *vma) |
| 54 | { |
| 55 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
| 56 | if (!(vma->vm_flags & VM_SHARED)) |
| 57 | return (unsigned long)vma->vm_private_data; |
| 58 | return 0; |
| 59 | } |
| 60 | |
| 61 | static void set_vma_resv_huge_pages(struct vm_area_struct *vma, |
| 62 | unsigned long reserve) |
| 63 | { |
| 64 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
| 65 | VM_BUG_ON(vma->vm_flags & VM_SHARED); |
| 66 | |
| 67 | vma->vm_private_data = (void *)reserve; |
| 68 | } |
| 69 | |
| 70 | /* Decrement the reserved pages in the hugepage pool by one */ |
| 71 | static void decrement_hugepage_resv_vma(struct vm_area_struct *vma) |
| 72 | { |
| 73 | if (vma->vm_flags & VM_SHARED) { |
| 74 | /* Shared mappings always use reserves */ |
| 75 | resv_huge_pages--; |
| 76 | } else { |
| 77 | /* |
| 78 | * Only the process that called mmap() has reserves for |
| 79 | * private mappings. |
| 80 | */ |
| 81 | if (vma_resv_huge_pages(vma)) { |
| 82 | resv_huge_pages--; |
| 83 | reserve = (unsigned long)vma->vm_private_data - 1; |
| 84 | vma->vm_private_data = (void *)reserve; |
| 85 | } |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
| 90 | { |
| 91 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
| 92 | if (!(vma->vm_flags & VM_SHARED)) |
| 93 | vma->vm_private_data = (void *)0; |
| 94 | } |
| 95 | |
| 96 | /* Returns true if the VMA has associated reserve pages */ |
| 97 | static int vma_has_private_reserves(struct vm_area_struct *vma) |
| 98 | { |
| 99 | if (vma->vm_flags & VM_SHARED) |
| 100 | return 0; |
| 101 | if (!vma_resv_huge_pages(vma)) |
| 102 | return 0; |
| 103 | return 1; |
| 104 | } |
| 105 | |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 106 | static void clear_huge_page(struct page *page, unsigned long addr) |
| 107 | { |
| 108 | int i; |
| 109 | |
| 110 | might_sleep(); |
| 111 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) { |
| 112 | cond_resched(); |
Ralf Baechle | 281e0e3 | 2007-10-01 01:20:10 -0700 | [diff] [blame] | 113 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 114 | } |
| 115 | } |
| 116 | |
| 117 | static void copy_huge_page(struct page *dst, struct page *src, |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 118 | unsigned long addr, struct vm_area_struct *vma) |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 119 | { |
| 120 | int i; |
| 121 | |
| 122 | might_sleep(); |
| 123 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { |
| 124 | cond_resched(); |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 125 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 126 | } |
| 127 | } |
| 128 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | static void enqueue_huge_page(struct page *page) |
| 130 | { |
| 131 | int nid = page_to_nid(page); |
| 132 | list_add(&page->lru, &hugepage_freelists[nid]); |
| 133 | free_huge_pages++; |
| 134 | free_huge_pages_node[nid]++; |
| 135 | } |
| 136 | |
Nishanth Aravamudan | 348e1e0 | 2008-03-04 14:29:42 -0800 | [diff] [blame] | 137 | static struct page *dequeue_huge_page(void) |
| 138 | { |
| 139 | int nid; |
| 140 | struct page *page = NULL; |
| 141 | |
| 142 | for (nid = 0; nid < MAX_NUMNODES; ++nid) { |
| 143 | if (!list_empty(&hugepage_freelists[nid])) { |
| 144 | page = list_entry(hugepage_freelists[nid].next, |
| 145 | struct page, lru); |
| 146 | list_del(&page->lru); |
| 147 | free_huge_pages--; |
| 148 | free_huge_pages_node[nid]--; |
| 149 | break; |
| 150 | } |
| 151 | } |
| 152 | return page; |
| 153 | } |
| 154 | |
| 155 | static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma, |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 156 | unsigned long address) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | { |
Nishanth Aravamudan | 31a5c6e | 2007-07-15 23:38:02 -0700 | [diff] [blame] | 158 | int nid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 159 | struct page *page = NULL; |
Lee Schermerhorn | 480eccf | 2007-09-18 22:46:47 -0700 | [diff] [blame] | 160 | struct mempolicy *mpol; |
Mel Gorman | 19770b3 | 2008-04-28 02:12:18 -0700 | [diff] [blame] | 161 | nodemask_t *nodemask; |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 162 | struct zonelist *zonelist = huge_zonelist(vma, address, |
Mel Gorman | 19770b3 | 2008-04-28 02:12:18 -0700 | [diff] [blame] | 163 | htlb_alloc_mask, &mpol, &nodemask); |
Mel Gorman | dd1a239 | 2008-04-28 02:12:17 -0700 | [diff] [blame] | 164 | struct zone *zone; |
| 165 | struct zoneref *z; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame^] | 167 | /* |
| 168 | * A child process with MAP_PRIVATE mappings created by their parent |
| 169 | * have no page reserves. This check ensures that reservations are |
| 170 | * not "stolen". The child may still get SIGKILLed |
| 171 | */ |
| 172 | if (!vma_has_private_reserves(vma) && |
| 173 | free_huge_pages - resv_huge_pages == 0) |
| 174 | return NULL; |
| 175 | |
Mel Gorman | 19770b3 | 2008-04-28 02:12:18 -0700 | [diff] [blame] | 176 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
| 177 | MAX_NR_ZONES - 1, nodemask) { |
Mel Gorman | 54a6eb5 | 2008-04-28 02:12:16 -0700 | [diff] [blame] | 178 | nid = zone_to_nid(zone); |
| 179 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && |
Andrew Morton | 3abf7af | 2007-07-19 01:49:08 -0700 | [diff] [blame] | 180 | !list_empty(&hugepage_freelists[nid])) { |
| 181 | page = list_entry(hugepage_freelists[nid].next, |
| 182 | struct page, lru); |
| 183 | list_del(&page->lru); |
| 184 | free_huge_pages--; |
| 185 | free_huge_pages_node[nid]--; |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame^] | 186 | decrement_hugepage_resv_vma(vma); |
| 187 | |
Ken Chen | 5ab3ee7 | 2007-07-23 18:44:00 -0700 | [diff] [blame] | 188 | break; |
Andrew Morton | 3abf7af | 2007-07-19 01:49:08 -0700 | [diff] [blame] | 189 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | } |
Lee Schermerhorn | 52cd3b0 | 2008-04-28 02:13:16 -0700 | [diff] [blame] | 191 | mpol_cond_put(mpol); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | return page; |
| 193 | } |
| 194 | |
Adam Litke | 6af2acb | 2007-10-16 01:26:16 -0700 | [diff] [blame] | 195 | static void update_and_free_page(struct page *page) |
| 196 | { |
| 197 | int i; |
| 198 | nr_huge_pages--; |
| 199 | nr_huge_pages_node[page_to_nid(page)]--; |
| 200 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { |
| 201 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | |
| 202 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | |
| 203 | 1 << PG_private | 1<< PG_writeback); |
| 204 | } |
| 205 | set_compound_page_dtor(page, NULL); |
| 206 | set_page_refcounted(page); |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 207 | arch_release_hugepage(page); |
Adam Litke | 6af2acb | 2007-10-16 01:26:16 -0700 | [diff] [blame] | 208 | __free_pages(page, HUGETLB_PAGE_ORDER); |
| 209 | } |
| 210 | |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 211 | static void free_huge_page(struct page *page) |
| 212 | { |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 213 | int nid = page_to_nid(page); |
Adam Litke | c79fb75 | 2007-11-14 16:59:38 -0800 | [diff] [blame] | 214 | struct address_space *mapping; |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 215 | |
Adam Litke | c79fb75 | 2007-11-14 16:59:38 -0800 | [diff] [blame] | 216 | mapping = (struct address_space *) page_private(page); |
Andy Whitcroft | e5df70a | 2008-02-23 15:23:32 -0800 | [diff] [blame] | 217 | set_page_private(page, 0); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 218 | BUG_ON(page_count(page)); |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 219 | INIT_LIST_HEAD(&page->lru); |
| 220 | |
| 221 | spin_lock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 222 | if (surplus_huge_pages_node[nid]) { |
| 223 | update_and_free_page(page); |
| 224 | surplus_huge_pages--; |
| 225 | surplus_huge_pages_node[nid]--; |
| 226 | } else { |
| 227 | enqueue_huge_page(page); |
| 228 | } |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 229 | spin_unlock(&hugetlb_lock); |
Adam Litke | c79fb75 | 2007-11-14 16:59:38 -0800 | [diff] [blame] | 230 | if (mapping) |
Adam Litke | 9a119c0 | 2007-11-14 16:59:41 -0800 | [diff] [blame] | 231 | hugetlb_put_quota(mapping, 1); |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 232 | } |
| 233 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 234 | /* |
| 235 | * Increment or decrement surplus_huge_pages. Keep node-specific counters |
| 236 | * balanced by operating on them in a round-robin fashion. |
| 237 | * Returns 1 if an adjustment was made. |
| 238 | */ |
| 239 | static int adjust_pool_surplus(int delta) |
| 240 | { |
| 241 | static int prev_nid; |
| 242 | int nid = prev_nid; |
| 243 | int ret = 0; |
| 244 | |
| 245 | VM_BUG_ON(delta != -1 && delta != 1); |
| 246 | do { |
| 247 | nid = next_node(nid, node_online_map); |
| 248 | if (nid == MAX_NUMNODES) |
| 249 | nid = first_node(node_online_map); |
| 250 | |
| 251 | /* To shrink on this node, there must be a surplus page */ |
| 252 | if (delta < 0 && !surplus_huge_pages_node[nid]) |
| 253 | continue; |
| 254 | /* Surplus cannot exceed the total number of pages */ |
| 255 | if (delta > 0 && surplus_huge_pages_node[nid] >= |
| 256 | nr_huge_pages_node[nid]) |
| 257 | continue; |
| 258 | |
| 259 | surplus_huge_pages += delta; |
| 260 | surplus_huge_pages_node[nid] += delta; |
| 261 | ret = 1; |
| 262 | break; |
| 263 | } while (nid != prev_nid); |
| 264 | |
| 265 | prev_nid = nid; |
| 266 | return ret; |
| 267 | } |
| 268 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 269 | static struct page *alloc_fresh_huge_page_node(int nid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | struct page *page; |
Joe Jin | f96efd5 | 2007-07-15 23:38:12 -0700 | [diff] [blame] | 272 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 273 | page = alloc_pages_node(nid, |
Nishanth Aravamudan | 551883a | 2008-04-29 00:58:26 -0700 | [diff] [blame] | 274 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| |
| 275 | __GFP_REPEAT|__GFP_NOWARN, |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 276 | HUGETLB_PAGE_ORDER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | if (page) { |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 278 | if (arch_prepare_hugepage(page)) { |
| 279 | __free_pages(page, HUGETLB_PAGE_ORDER); |
Harvey Harrison | 7b8ee84 | 2008-04-28 14:13:19 -0700 | [diff] [blame] | 280 | return NULL; |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 281 | } |
Andy Whitcroft | 33f2ef8 | 2006-12-06 20:33:32 -0800 | [diff] [blame] | 282 | set_compound_page_dtor(page, free_huge_page); |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 283 | spin_lock(&hugetlb_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | nr_huge_pages++; |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 285 | nr_huge_pages_node[nid]++; |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 286 | spin_unlock(&hugetlb_lock); |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 287 | put_page(page); /* free it into the hugepage allocator */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | } |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 289 | |
| 290 | return page; |
| 291 | } |
| 292 | |
| 293 | static int alloc_fresh_huge_page(void) |
| 294 | { |
| 295 | struct page *page; |
| 296 | int start_nid; |
| 297 | int next_nid; |
| 298 | int ret = 0; |
| 299 | |
| 300 | start_nid = hugetlb_next_nid; |
| 301 | |
| 302 | do { |
| 303 | page = alloc_fresh_huge_page_node(hugetlb_next_nid); |
| 304 | if (page) |
| 305 | ret = 1; |
| 306 | /* |
| 307 | * Use a helper variable to find the next node and then |
| 308 | * copy it back to hugetlb_next_nid afterwards: |
| 309 | * otherwise there's a window in which a racer might |
| 310 | * pass invalid nid MAX_NUMNODES to alloc_pages_node. |
| 311 | * But we don't need to use a spin_lock here: it really |
| 312 | * doesn't matter if occasionally a racer chooses the |
| 313 | * same nid as we do. Move nid forward in the mask even |
| 314 | * if we just successfully allocated a hugepage so that |
| 315 | * the next caller gets hugepages on the next node. |
| 316 | */ |
| 317 | next_nid = next_node(hugetlb_next_nid, node_online_map); |
| 318 | if (next_nid == MAX_NUMNODES) |
| 319 | next_nid = first_node(node_online_map); |
| 320 | hugetlb_next_nid = next_nid; |
| 321 | } while (!page && hugetlb_next_nid != start_nid); |
| 322 | |
Adam Litke | 3b11630 | 2008-04-28 02:13:06 -0700 | [diff] [blame] | 323 | if (ret) |
| 324 | count_vm_event(HTLB_BUDDY_PGALLOC); |
| 325 | else |
| 326 | count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
| 327 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 328 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | } |
| 330 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 331 | static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma, |
| 332 | unsigned long address) |
| 333 | { |
| 334 | struct page *page; |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 335 | unsigned int nid; |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 336 | |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 337 | /* |
| 338 | * Assume we will successfully allocate the surplus page to |
| 339 | * prevent racing processes from causing the surplus to exceed |
| 340 | * overcommit |
| 341 | * |
| 342 | * This however introduces a different race, where a process B |
| 343 | * tries to grow the static hugepage pool while alloc_pages() is |
| 344 | * called by process A. B will only examine the per-node |
| 345 | * counters in determining if surplus huge pages can be |
| 346 | * converted to normal huge pages in adjust_pool_surplus(). A |
| 347 | * won't be able to increment the per-node counter, until the |
| 348 | * lock is dropped by B, but B doesn't drop hugetlb_lock until |
| 349 | * no more huge pages can be converted from surplus to normal |
| 350 | * state (and doesn't try to convert again). Thus, we have a |
| 351 | * case where a surplus huge page exists, the pool is grown, and |
| 352 | * the surplus huge page still exists after, even though it |
| 353 | * should just have been converted to a normal huge page. This |
| 354 | * does not leak memory, though, as the hugepage will be freed |
| 355 | * once it is out of use. It also does not allow the counters to |
| 356 | * go out of whack in adjust_pool_surplus() as we don't modify |
| 357 | * the node values until we've gotten the hugepage and only the |
| 358 | * per-node value is checked there. |
| 359 | */ |
| 360 | spin_lock(&hugetlb_lock); |
| 361 | if (surplus_huge_pages >= nr_overcommit_huge_pages) { |
| 362 | spin_unlock(&hugetlb_lock); |
| 363 | return NULL; |
| 364 | } else { |
| 365 | nr_huge_pages++; |
| 366 | surplus_huge_pages++; |
| 367 | } |
| 368 | spin_unlock(&hugetlb_lock); |
| 369 | |
Nishanth Aravamudan | 551883a | 2008-04-29 00:58:26 -0700 | [diff] [blame] | 370 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP| |
| 371 | __GFP_REPEAT|__GFP_NOWARN, |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 372 | HUGETLB_PAGE_ORDER); |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 373 | |
| 374 | spin_lock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 375 | if (page) { |
Adam Litke | 2668db9 | 2008-03-10 11:43:50 -0700 | [diff] [blame] | 376 | /* |
| 377 | * This page is now managed by the hugetlb allocator and has |
| 378 | * no users -- drop the buddy allocator's reference. |
| 379 | */ |
| 380 | put_page_testzero(page); |
| 381 | VM_BUG_ON(page_count(page)); |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 382 | nid = page_to_nid(page); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 383 | set_compound_page_dtor(page, free_huge_page); |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 384 | /* |
| 385 | * We incremented the global counters already |
| 386 | */ |
| 387 | nr_huge_pages_node[nid]++; |
| 388 | surplus_huge_pages_node[nid]++; |
Adam Litke | 3b11630 | 2008-04-28 02:13:06 -0700 | [diff] [blame] | 389 | __count_vm_event(HTLB_BUDDY_PGALLOC); |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 390 | } else { |
| 391 | nr_huge_pages--; |
| 392 | surplus_huge_pages--; |
Adam Litke | 3b11630 | 2008-04-28 02:13:06 -0700 | [diff] [blame] | 393 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 394 | } |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 395 | spin_unlock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 396 | |
| 397 | return page; |
| 398 | } |
| 399 | |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 400 | /* |
| 401 | * Increase the hugetlb pool such that it can accomodate a reservation |
| 402 | * of size 'delta'. |
| 403 | */ |
| 404 | static int gather_surplus_pages(int delta) |
| 405 | { |
| 406 | struct list_head surplus_list; |
| 407 | struct page *page, *tmp; |
| 408 | int ret, i; |
| 409 | int needed, allocated; |
| 410 | |
| 411 | needed = (resv_huge_pages + delta) - free_huge_pages; |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 412 | if (needed <= 0) { |
| 413 | resv_huge_pages += delta; |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 414 | return 0; |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 415 | } |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 416 | |
| 417 | allocated = 0; |
| 418 | INIT_LIST_HEAD(&surplus_list); |
| 419 | |
| 420 | ret = -ENOMEM; |
| 421 | retry: |
| 422 | spin_unlock(&hugetlb_lock); |
| 423 | for (i = 0; i < needed; i++) { |
| 424 | page = alloc_buddy_huge_page(NULL, 0); |
| 425 | if (!page) { |
| 426 | /* |
| 427 | * We were not able to allocate enough pages to |
| 428 | * satisfy the entire reservation so we free what |
| 429 | * we've allocated so far. |
| 430 | */ |
| 431 | spin_lock(&hugetlb_lock); |
| 432 | needed = 0; |
| 433 | goto free; |
| 434 | } |
| 435 | |
| 436 | list_add(&page->lru, &surplus_list); |
| 437 | } |
| 438 | allocated += needed; |
| 439 | |
| 440 | /* |
| 441 | * After retaking hugetlb_lock, we need to recalculate 'needed' |
| 442 | * because either resv_huge_pages or free_huge_pages may have changed. |
| 443 | */ |
| 444 | spin_lock(&hugetlb_lock); |
| 445 | needed = (resv_huge_pages + delta) - (free_huge_pages + allocated); |
| 446 | if (needed > 0) |
| 447 | goto retry; |
| 448 | |
| 449 | /* |
| 450 | * The surplus_list now contains _at_least_ the number of extra pages |
| 451 | * needed to accomodate the reservation. Add the appropriate number |
| 452 | * of pages to the hugetlb pool and free the extras back to the buddy |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 453 | * allocator. Commit the entire reservation here to prevent another |
| 454 | * process from stealing the pages as they are added to the pool but |
| 455 | * before they are reserved. |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 456 | */ |
| 457 | needed += allocated; |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 458 | resv_huge_pages += delta; |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 459 | ret = 0; |
| 460 | free: |
Adam Litke | 19fc3f0 | 2008-04-28 02:12:20 -0700 | [diff] [blame] | 461 | /* Free the needed pages to the hugetlb pool */ |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 462 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
Adam Litke | 19fc3f0 | 2008-04-28 02:12:20 -0700 | [diff] [blame] | 463 | if ((--needed) < 0) |
| 464 | break; |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 465 | list_del(&page->lru); |
Adam Litke | 19fc3f0 | 2008-04-28 02:12:20 -0700 | [diff] [blame] | 466 | enqueue_huge_page(page); |
| 467 | } |
| 468 | |
| 469 | /* Free unnecessary surplus pages to the buddy allocator */ |
| 470 | if (!list_empty(&surplus_list)) { |
| 471 | spin_unlock(&hugetlb_lock); |
| 472 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
| 473 | list_del(&page->lru); |
Adam Litke | af767cb | 2007-10-16 01:26:25 -0700 | [diff] [blame] | 474 | /* |
Adam Litke | 2668db9 | 2008-03-10 11:43:50 -0700 | [diff] [blame] | 475 | * The page has a reference count of zero already, so |
| 476 | * call free_huge_page directly instead of using |
| 477 | * put_page. This must be done with hugetlb_lock |
Adam Litke | af767cb | 2007-10-16 01:26:25 -0700 | [diff] [blame] | 478 | * unlocked which is safe because free_huge_page takes |
| 479 | * hugetlb_lock before deciding how to free the page. |
| 480 | */ |
Adam Litke | 2668db9 | 2008-03-10 11:43:50 -0700 | [diff] [blame] | 481 | free_huge_page(page); |
Adam Litke | af767cb | 2007-10-16 01:26:25 -0700 | [diff] [blame] | 482 | } |
Adam Litke | 19fc3f0 | 2008-04-28 02:12:20 -0700 | [diff] [blame] | 483 | spin_lock(&hugetlb_lock); |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 484 | } |
| 485 | |
| 486 | return ret; |
| 487 | } |
| 488 | |
| 489 | /* |
| 490 | * When releasing a hugetlb pool reservation, any surplus pages that were |
| 491 | * allocated to satisfy the reservation must be explicitly freed if they were |
| 492 | * never used. |
| 493 | */ |
Adrian Bunk | 8cde045 | 2007-11-14 16:59:43 -0800 | [diff] [blame] | 494 | static void return_unused_surplus_pages(unsigned long unused_resv_pages) |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 495 | { |
| 496 | static int nid = -1; |
| 497 | struct page *page; |
| 498 | unsigned long nr_pages; |
| 499 | |
Nishanth Aravamudan | 11320d1 | 2008-03-26 14:40:20 -0700 | [diff] [blame] | 500 | /* |
| 501 | * We want to release as many surplus pages as possible, spread |
| 502 | * evenly across all nodes. Iterate across all nodes until we |
| 503 | * can no longer free unreserved surplus pages. This occurs when |
| 504 | * the nodes with surplus pages have no free pages. |
| 505 | */ |
| 506 | unsigned long remaining_iterations = num_online_nodes(); |
| 507 | |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 508 | /* Uncommit the reservation */ |
| 509 | resv_huge_pages -= unused_resv_pages; |
| 510 | |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 511 | nr_pages = min(unused_resv_pages, surplus_huge_pages); |
| 512 | |
Nishanth Aravamudan | 11320d1 | 2008-03-26 14:40:20 -0700 | [diff] [blame] | 513 | while (remaining_iterations-- && nr_pages) { |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 514 | nid = next_node(nid, node_online_map); |
| 515 | if (nid == MAX_NUMNODES) |
| 516 | nid = first_node(node_online_map); |
| 517 | |
| 518 | if (!surplus_huge_pages_node[nid]) |
| 519 | continue; |
| 520 | |
| 521 | if (!list_empty(&hugepage_freelists[nid])) { |
| 522 | page = list_entry(hugepage_freelists[nid].next, |
| 523 | struct page, lru); |
| 524 | list_del(&page->lru); |
| 525 | update_and_free_page(page); |
| 526 | free_huge_pages--; |
| 527 | free_huge_pages_node[nid]--; |
| 528 | surplus_huge_pages--; |
| 529 | surplus_huge_pages_node[nid]--; |
| 530 | nr_pages--; |
Nishanth Aravamudan | 11320d1 | 2008-03-26 14:40:20 -0700 | [diff] [blame] | 531 | remaining_iterations = num_online_nodes(); |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 532 | } |
| 533 | } |
| 534 | } |
| 535 | |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 536 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
| 537 | unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | { |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 539 | struct page *page; |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 540 | struct address_space *mapping = vma->vm_file->f_mapping; |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame^] | 541 | struct inode *inode = mapping->host; |
| 542 | unsigned int chg = 0; |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 543 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame^] | 544 | /* |
| 545 | * Processes that did not create the mapping will have no reserves and |
| 546 | * will not have accounted against quota. Check that the quota can be |
| 547 | * made before satisfying the allocation |
| 548 | */ |
| 549 | if (!vma_has_private_reserves(vma)) { |
| 550 | chg = 1; |
| 551 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
| 552 | return ERR_PTR(-ENOSPC); |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 553 | } |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame^] | 554 | |
| 555 | spin_lock(&hugetlb_lock); |
| 556 | page = dequeue_huge_page_vma(vma, addr); |
| 557 | spin_unlock(&hugetlb_lock); |
| 558 | |
| 559 | if (!page) { |
| 560 | page = alloc_buddy_huge_page(vma, addr); |
| 561 | if (!page) { |
| 562 | hugetlb_put_quota(inode->i_mapping, chg); |
| 563 | return ERR_PTR(-VM_FAULT_OOM); |
| 564 | } |
| 565 | } |
| 566 | |
| 567 | set_page_refcounted(page); |
| 568 | set_page_private(page, (unsigned long) mapping); |
| 569 | |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 570 | return page; |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 571 | } |
| 572 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | static int __init hugetlb_init(void) |
| 574 | { |
| 575 | unsigned long i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | |
Benjamin Herrenschmidt | 3c726f8 | 2005-11-07 11:06:55 +1100 | [diff] [blame] | 577 | if (HPAGE_SHIFT == 0) |
| 578 | return 0; |
| 579 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 580 | for (i = 0; i < MAX_NUMNODES; ++i) |
| 581 | INIT_LIST_HEAD(&hugepage_freelists[i]); |
| 582 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 583 | hugetlb_next_nid = first_node(node_online_map); |
| 584 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 585 | for (i = 0; i < max_huge_pages; ++i) { |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 586 | if (!alloc_fresh_huge_page()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | } |
| 589 | max_huge_pages = free_huge_pages = nr_huge_pages = i; |
| 590 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); |
| 591 | return 0; |
| 592 | } |
| 593 | module_init(hugetlb_init); |
| 594 | |
| 595 | static int __init hugetlb_setup(char *s) |
| 596 | { |
| 597 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) |
| 598 | max_huge_pages = 0; |
| 599 | return 1; |
| 600 | } |
| 601 | __setup("hugepages=", hugetlb_setup); |
| 602 | |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 603 | static unsigned int cpuset_mems_nr(unsigned int *array) |
| 604 | { |
| 605 | int node; |
| 606 | unsigned int nr = 0; |
| 607 | |
| 608 | for_each_node_mask(node, cpuset_current_mems_allowed) |
| 609 | nr += array[node]; |
| 610 | |
| 611 | return nr; |
| 612 | } |
| 613 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | #ifdef CONFIG_SYSCTL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | #ifdef CONFIG_HIGHMEM |
| 616 | static void try_to_free_low(unsigned long count) |
| 617 | { |
Christoph Lameter | 4415cc8 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 618 | int i; |
| 619 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 620 | for (i = 0; i < MAX_NUMNODES; ++i) { |
| 621 | struct page *page, *next; |
| 622 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { |
Adam Litke | 6b0c880 | 2007-10-16 01:26:23 -0700 | [diff] [blame] | 623 | if (count >= nr_huge_pages) |
| 624 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 625 | if (PageHighMem(page)) |
| 626 | continue; |
| 627 | list_del(&page->lru); |
| 628 | update_and_free_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 629 | free_huge_pages--; |
Christoph Lameter | 4415cc8 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 630 | free_huge_pages_node[page_to_nid(page)]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | } |
| 632 | } |
| 633 | } |
| 634 | #else |
| 635 | static inline void try_to_free_low(unsigned long count) |
| 636 | { |
| 637 | } |
| 638 | #endif |
| 639 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 640 | #define persistent_huge_pages (nr_huge_pages - surplus_huge_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 641 | static unsigned long set_max_huge_pages(unsigned long count) |
| 642 | { |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 643 | unsigned long min_count, ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 645 | /* |
| 646 | * Increase the pool size |
| 647 | * First take pages out of surplus state. Then make up the |
| 648 | * remaining difference by allocating fresh huge pages. |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 649 | * |
| 650 | * We might race with alloc_buddy_huge_page() here and be unable |
| 651 | * to convert a surplus huge page to a normal huge page. That is |
| 652 | * not critical, though, it just means the overall size of the |
| 653 | * pool might be one hugepage larger than it needs to be, but |
| 654 | * within all the constraints specified by the sysctls. |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 655 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | spin_lock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 657 | while (surplus_huge_pages && count > persistent_huge_pages) { |
| 658 | if (!adjust_pool_surplus(-1)) |
| 659 | break; |
| 660 | } |
| 661 | |
| 662 | while (count > persistent_huge_pages) { |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 663 | /* |
| 664 | * If this allocation races such that we no longer need the |
| 665 | * page, free_huge_page will handle it by freeing the page |
| 666 | * and reducing the surplus. |
| 667 | */ |
| 668 | spin_unlock(&hugetlb_lock); |
| 669 | ret = alloc_fresh_huge_page(); |
| 670 | spin_lock(&hugetlb_lock); |
| 671 | if (!ret) |
| 672 | goto out; |
| 673 | |
| 674 | } |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 675 | |
| 676 | /* |
| 677 | * Decrease the pool size |
| 678 | * First return free pages to the buddy allocator (being careful |
| 679 | * to keep enough around to satisfy reservations). Then place |
| 680 | * pages into surplus state as needed so the pool will shrink |
| 681 | * to the desired size as pages become free. |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 682 | * |
| 683 | * By placing pages into the surplus state independent of the |
| 684 | * overcommit value, we are allowing the surplus pool size to |
| 685 | * exceed overcommit. There are few sane options here. Since |
| 686 | * alloc_buddy_huge_page() is checking the global counter, |
| 687 | * though, we'll note that we're not allowed to exceed surplus |
| 688 | * and won't grow the pool anywhere else. Not until one of the |
| 689 | * sysctls are changed, or the surplus pages go out of use. |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 690 | */ |
Adam Litke | 6b0c880 | 2007-10-16 01:26:23 -0700 | [diff] [blame] | 691 | min_count = resv_huge_pages + nr_huge_pages - free_huge_pages; |
| 692 | min_count = max(count, min_count); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 693 | try_to_free_low(min_count); |
| 694 | while (min_count < persistent_huge_pages) { |
Nishanth Aravamudan | 348e1e0 | 2008-03-04 14:29:42 -0800 | [diff] [blame] | 695 | struct page *page = dequeue_huge_page(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | if (!page) |
| 697 | break; |
| 698 | update_and_free_page(page); |
| 699 | } |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 700 | while (count < persistent_huge_pages) { |
| 701 | if (!adjust_pool_surplus(1)) |
| 702 | break; |
| 703 | } |
| 704 | out: |
| 705 | ret = persistent_huge_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 706 | spin_unlock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 707 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 708 | } |
| 709 | |
| 710 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
| 711 | struct file *file, void __user *buffer, |
| 712 | size_t *length, loff_t *ppos) |
| 713 | { |
| 714 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
| 715 | max_huge_pages = set_max_huge_pages(max_huge_pages); |
| 716 | return 0; |
| 717 | } |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 718 | |
| 719 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, |
| 720 | struct file *file, void __user *buffer, |
| 721 | size_t *length, loff_t *ppos) |
| 722 | { |
| 723 | proc_dointvec(table, write, file, buffer, length, ppos); |
| 724 | if (hugepages_treat_as_movable) |
| 725 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; |
| 726 | else |
| 727 | htlb_alloc_mask = GFP_HIGHUSER; |
| 728 | return 0; |
| 729 | } |
| 730 | |
Nishanth Aravamudan | a3d0c6a | 2008-02-08 04:18:18 -0800 | [diff] [blame] | 731 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
| 732 | struct file *file, void __user *buffer, |
| 733 | size_t *length, loff_t *ppos) |
| 734 | { |
Nishanth Aravamudan | a3d0c6a | 2008-02-08 04:18:18 -0800 | [diff] [blame] | 735 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
Nishanth Aravamudan | 064d9ef | 2008-02-13 15:03:19 -0800 | [diff] [blame] | 736 | spin_lock(&hugetlb_lock); |
| 737 | nr_overcommit_huge_pages = sysctl_overcommit_huge_pages; |
Nishanth Aravamudan | a3d0c6a | 2008-02-08 04:18:18 -0800 | [diff] [blame] | 738 | spin_unlock(&hugetlb_lock); |
| 739 | return 0; |
| 740 | } |
| 741 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 742 | #endif /* CONFIG_SYSCTL */ |
| 743 | |
| 744 | int hugetlb_report_meminfo(char *buf) |
| 745 | { |
| 746 | return sprintf(buf, |
| 747 | "HugePages_Total: %5lu\n" |
| 748 | "HugePages_Free: %5lu\n" |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 749 | "HugePages_Rsvd: %5lu\n" |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 750 | "HugePages_Surp: %5lu\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 751 | "Hugepagesize: %5lu kB\n", |
| 752 | nr_huge_pages, |
| 753 | free_huge_pages, |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 754 | resv_huge_pages, |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 755 | surplus_huge_pages, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 756 | HPAGE_SIZE/1024); |
| 757 | } |
| 758 | |
| 759 | int hugetlb_report_node_meminfo(int nid, char *buf) |
| 760 | { |
| 761 | return sprintf(buf, |
| 762 | "Node %d HugePages_Total: %5u\n" |
Nishanth Aravamudan | a1de091 | 2008-03-26 14:37:53 -0700 | [diff] [blame] | 763 | "Node %d HugePages_Free: %5u\n" |
| 764 | "Node %d HugePages_Surp: %5u\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | nid, nr_huge_pages_node[nid], |
Nishanth Aravamudan | a1de091 | 2008-03-26 14:37:53 -0700 | [diff] [blame] | 766 | nid, free_huge_pages_node[nid], |
| 767 | nid, surplus_huge_pages_node[nid]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | } |
| 769 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 770 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
| 771 | unsigned long hugetlb_total_pages(void) |
| 772 | { |
| 773 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); |
| 774 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 775 | |
Mel Gorman | fc1b8a7 | 2008-07-23 21:27:22 -0700 | [diff] [blame] | 776 | static int hugetlb_acct_memory(long delta) |
| 777 | { |
| 778 | int ret = -ENOMEM; |
| 779 | |
| 780 | spin_lock(&hugetlb_lock); |
| 781 | /* |
| 782 | * When cpuset is configured, it breaks the strict hugetlb page |
| 783 | * reservation as the accounting is done on a global variable. Such |
| 784 | * reservation is completely rubbish in the presence of cpuset because |
| 785 | * the reservation is not checked against page availability for the |
| 786 | * current cpuset. Application can still potentially OOM'ed by kernel |
| 787 | * with lack of free htlb page in cpuset that the task is in. |
| 788 | * Attempt to enforce strict accounting with cpuset is almost |
| 789 | * impossible (or too ugly) because cpuset is too fluid that |
| 790 | * task or memory node can be dynamically moved between cpusets. |
| 791 | * |
| 792 | * The change of semantics for shared hugetlb mapping with cpuset is |
| 793 | * undesirable. However, in order to preserve some of the semantics, |
| 794 | * we fall back to check against current free page availability as |
| 795 | * a best attempt and hopefully to minimize the impact of changing |
| 796 | * semantics that cpuset has. |
| 797 | */ |
| 798 | if (delta > 0) { |
| 799 | if (gather_surplus_pages(delta) < 0) |
| 800 | goto out; |
| 801 | |
| 802 | if (delta > cpuset_mems_nr(free_huge_pages_node)) { |
| 803 | return_unused_surplus_pages(delta); |
| 804 | goto out; |
| 805 | } |
| 806 | } |
| 807 | |
| 808 | ret = 0; |
| 809 | if (delta < 0) |
| 810 | return_unused_surplus_pages((unsigned long) -delta); |
| 811 | |
| 812 | out: |
| 813 | spin_unlock(&hugetlb_lock); |
| 814 | return ret; |
| 815 | } |
| 816 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame^] | 817 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
| 818 | { |
| 819 | unsigned long reserve = vma_resv_huge_pages(vma); |
| 820 | if (reserve) |
| 821 | hugetlb_acct_memory(-reserve); |
| 822 | } |
| 823 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 824 | /* |
| 825 | * We cannot handle pagefaults against hugetlb pages at all. They cause |
| 826 | * handle_mm_fault() to try to instantiate regular-sized pages in the |
| 827 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get |
| 828 | * this far. |
| 829 | */ |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 830 | 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] | 831 | { |
| 832 | BUG(); |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 833 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 834 | } |
| 835 | |
| 836 | struct vm_operations_struct hugetlb_vm_ops = { |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 837 | .fault = hugetlb_vm_op_fault, |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame^] | 838 | .close = hugetlb_vm_op_close, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 839 | }; |
| 840 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 841 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
| 842 | int writable) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 843 | { |
| 844 | pte_t entry; |
| 845 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 846 | if (writable) { |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 847 | entry = |
| 848 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); |
| 849 | } else { |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 850 | entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 851 | } |
| 852 | entry = pte_mkyoung(entry); |
| 853 | entry = pte_mkhuge(entry); |
| 854 | |
| 855 | return entry; |
| 856 | } |
| 857 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 858 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
| 859 | unsigned long address, pte_t *ptep) |
| 860 | { |
| 861 | pte_t entry; |
| 862 | |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 863 | entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); |
| 864 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { |
Benjamin Herrenschmidt | 8dab524 | 2007-06-16 10:16:12 -0700 | [diff] [blame] | 865 | update_mmu_cache(vma, address, entry); |
Benjamin Herrenschmidt | 8dab524 | 2007-06-16 10:16:12 -0700 | [diff] [blame] | 866 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 867 | } |
| 868 | |
| 869 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 870 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
| 871 | struct vm_area_struct *vma) |
| 872 | { |
| 873 | pte_t *src_pte, *dst_pte, entry; |
| 874 | struct page *ptepage; |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 875 | unsigned long addr; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 876 | int cow; |
| 877 | |
| 878 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 879 | |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 880 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 881 | src_pte = huge_pte_offset(src, addr); |
| 882 | if (!src_pte) |
| 883 | continue; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 884 | dst_pte = huge_pte_alloc(dst, addr); |
| 885 | if (!dst_pte) |
| 886 | goto nomem; |
Larry Woodman | c5c9942 | 2008-01-24 05:49:25 -0800 | [diff] [blame] | 887 | |
| 888 | /* If the pagetables are shared don't copy or take references */ |
| 889 | if (dst_pte == src_pte) |
| 890 | continue; |
| 891 | |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 892 | spin_lock(&dst->page_table_lock); |
Nick Piggin | 4647875 | 2008-06-05 22:45:57 -0700 | [diff] [blame] | 893 | spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 894 | if (!huge_pte_none(huge_ptep_get(src_pte))) { |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 895 | if (cow) |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 896 | huge_ptep_set_wrprotect(src, addr, src_pte); |
| 897 | entry = huge_ptep_get(src_pte); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 898 | ptepage = pte_page(entry); |
| 899 | get_page(ptepage); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 900 | set_huge_pte_at(dst, addr, dst_pte, entry); |
| 901 | } |
| 902 | spin_unlock(&src->page_table_lock); |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 903 | spin_unlock(&dst->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 904 | } |
| 905 | return 0; |
| 906 | |
| 907 | nomem: |
| 908 | return -ENOMEM; |
| 909 | } |
| 910 | |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 911 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
| 912 | unsigned long end) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 913 | { |
| 914 | struct mm_struct *mm = vma->vm_mm; |
| 915 | unsigned long address; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 916 | pte_t *ptep; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 917 | pte_t pte; |
| 918 | struct page *page; |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 919 | struct page *tmp; |
Chen, Kenneth W | c0a499c | 2006-12-06 20:31:39 -0800 | [diff] [blame] | 920 | /* |
| 921 | * A page gathering list, protected by per file i_mmap_lock. The |
| 922 | * lock is used to avoid list corruption from multiple unmapping |
| 923 | * of the same page since we are using page->lru. |
| 924 | */ |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 925 | LIST_HEAD(page_list); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 926 | |
| 927 | WARN_ON(!is_vm_hugetlb_page(vma)); |
| 928 | BUG_ON(start & ~HPAGE_MASK); |
| 929 | BUG_ON(end & ~HPAGE_MASK); |
| 930 | |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 931 | spin_lock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 932 | for (address = start; address < end; address += HPAGE_SIZE) { |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 933 | ptep = huge_pte_offset(mm, address); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 934 | if (!ptep) |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 935 | continue; |
| 936 | |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 937 | if (huge_pmd_unshare(mm, &address, ptep)) |
| 938 | continue; |
| 939 | |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 940 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 941 | if (huge_pte_none(pte)) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 942 | continue; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 943 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 944 | page = pte_page(pte); |
Ken Chen | 6649a38 | 2007-02-08 14:20:27 -0800 | [diff] [blame] | 945 | if (pte_dirty(pte)) |
| 946 | set_page_dirty(page); |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 947 | list_add(&page->lru, &page_list); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 948 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 949 | spin_unlock(&mm->page_table_lock); |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 950 | flush_tlb_range(vma, start, end); |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 951 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
| 952 | list_del(&page->lru); |
| 953 | put_page(page); |
| 954 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 955 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 956 | |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 957 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
| 958 | unsigned long end) |
| 959 | { |
| 960 | /* |
| 961 | * It is undesirable to test vma->vm_file as it should be non-null |
| 962 | * for valid hugetlb area. However, vm_file will be NULL in the error |
| 963 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, |
| 964 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function |
| 965 | * to clean up. Since no pte has actually been setup, it is safe to |
| 966 | * do nothing in this case. |
| 967 | */ |
| 968 | if (vma->vm_file) { |
| 969 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
| 970 | __unmap_hugepage_range(vma, start, end); |
| 971 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
| 972 | } |
| 973 | } |
| 974 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 975 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
| 976 | unsigned long address, pte_t *ptep, pte_t pte) |
| 977 | { |
| 978 | struct page *old_page, *new_page; |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 979 | int avoidcopy; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 980 | |
| 981 | old_page = pte_page(pte); |
| 982 | |
| 983 | /* If no-one else is actually using this page, avoid the copy |
| 984 | * and just make the page writable */ |
| 985 | avoidcopy = (page_count(old_page) == 1); |
| 986 | if (avoidcopy) { |
| 987 | set_huge_ptep_writable(vma, address, ptep); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 988 | return 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 989 | } |
| 990 | |
| 991 | page_cache_get(old_page); |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 992 | new_page = alloc_huge_page(vma, address); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 993 | |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 994 | if (IS_ERR(new_page)) { |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 995 | page_cache_release(old_page); |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 996 | return -PTR_ERR(new_page); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 997 | } |
| 998 | |
| 999 | spin_unlock(&mm->page_table_lock); |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 1000 | copy_huge_page(new_page, old_page, address, vma); |
Nick Piggin | 0ed361d | 2008-02-04 22:29:34 -0800 | [diff] [blame] | 1001 | __SetPageUptodate(new_page); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1002 | spin_lock(&mm->page_table_lock); |
| 1003 | |
| 1004 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1005 | if (likely(pte_same(huge_ptep_get(ptep), pte))) { |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1006 | /* Break COW */ |
Gerald Schaefer | 8fe627e | 2008-04-28 02:13:28 -0700 | [diff] [blame] | 1007 | huge_ptep_clear_flush(vma, address, ptep); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1008 | set_huge_pte_at(mm, address, ptep, |
| 1009 | make_huge_pte(vma, new_page, 1)); |
| 1010 | /* Make the old page be freed below */ |
| 1011 | new_page = old_page; |
| 1012 | } |
| 1013 | page_cache_release(new_page); |
| 1014 | page_cache_release(old_page); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 1015 | return 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1016 | } |
| 1017 | |
Robert P. J. Day | a1ed3dd | 2007-07-17 04:03:33 -0700 | [diff] [blame] | 1018 | 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] | 1019 | unsigned long address, pte_t *ptep, int write_access) |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 1020 | { |
| 1021 | int ret = VM_FAULT_SIGBUS; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1022 | unsigned long idx; |
| 1023 | unsigned long size; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1024 | struct page *page; |
| 1025 | struct address_space *mapping; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1026 | pte_t new_pte; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1027 | |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1028 | mapping = vma->vm_file->f_mapping; |
| 1029 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) |
| 1030 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); |
| 1031 | |
| 1032 | /* |
| 1033 | * Use page lock to guard against racing truncation |
| 1034 | * before we get page_table_lock. |
| 1035 | */ |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 1036 | retry: |
| 1037 | page = find_lock_page(mapping, idx); |
| 1038 | if (!page) { |
Hugh Dickins | ebed4bf | 2006-10-28 10:38:43 -0700 | [diff] [blame] | 1039 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
| 1040 | if (idx >= size) |
| 1041 | goto out; |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 1042 | page = alloc_huge_page(vma, address); |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 1043 | if (IS_ERR(page)) { |
| 1044 | ret = -PTR_ERR(page); |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 1045 | goto out; |
| 1046 | } |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 1047 | clear_huge_page(page, address); |
Nick Piggin | 0ed361d | 2008-02-04 22:29:34 -0800 | [diff] [blame] | 1048 | __SetPageUptodate(page); |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 1049 | |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 1050 | if (vma->vm_flags & VM_SHARED) { |
| 1051 | int err; |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 1052 | struct inode *inode = mapping->host; |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 1053 | |
| 1054 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); |
| 1055 | if (err) { |
| 1056 | put_page(page); |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 1057 | if (err == -EEXIST) |
| 1058 | goto retry; |
| 1059 | goto out; |
| 1060 | } |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 1061 | |
| 1062 | spin_lock(&inode->i_lock); |
| 1063 | inode->i_blocks += BLOCKS_PER_HUGEPAGE; |
| 1064 | spin_unlock(&inode->i_lock); |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 1065 | } else |
| 1066 | lock_page(page); |
| 1067 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1068 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 1069 | spin_lock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1070 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
| 1071 | if (idx >= size) |
| 1072 | goto backout; |
| 1073 | |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 1074 | ret = 0; |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1075 | if (!huge_pte_none(huge_ptep_get(ptep))) |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1076 | goto backout; |
| 1077 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1078 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
| 1079 | && (vma->vm_flags & VM_SHARED))); |
| 1080 | set_huge_pte_at(mm, address, ptep, new_pte); |
| 1081 | |
| 1082 | if (write_access && !(vma->vm_flags & VM_SHARED)) { |
| 1083 | /* Optimization, do the COW without a second fault */ |
| 1084 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); |
| 1085 | } |
| 1086 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 1087 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1088 | unlock_page(page); |
| 1089 | out: |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 1090 | return ret; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1091 | |
| 1092 | backout: |
| 1093 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1094 | unlock_page(page); |
| 1095 | put_page(page); |
| 1096 | goto out; |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 1097 | } |
| 1098 | |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 1099 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
| 1100 | unsigned long address, int write_access) |
| 1101 | { |
| 1102 | pte_t *ptep; |
| 1103 | pte_t entry; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1104 | int ret; |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 1105 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 1106 | |
| 1107 | ptep = huge_pte_alloc(mm, address); |
| 1108 | if (!ptep) |
| 1109 | return VM_FAULT_OOM; |
| 1110 | |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 1111 | /* |
| 1112 | * Serialize hugepage allocation and instantiation, so that we don't |
| 1113 | * get spurious allocation failures if two CPUs race to instantiate |
| 1114 | * the same page in the page cache. |
| 1115 | */ |
| 1116 | mutex_lock(&hugetlb_instantiation_mutex); |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1117 | entry = huge_ptep_get(ptep); |
| 1118 | if (huge_pte_none(entry)) { |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 1119 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); |
| 1120 | mutex_unlock(&hugetlb_instantiation_mutex); |
| 1121 | return ret; |
| 1122 | } |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 1123 | |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 1124 | ret = 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1125 | |
| 1126 | spin_lock(&mm->page_table_lock); |
| 1127 | /* Check for a racing update before calling hugetlb_cow */ |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1128 | if (likely(pte_same(entry, huge_ptep_get(ptep)))) |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1129 | if (write_access && !pte_write(entry)) |
| 1130 | ret = hugetlb_cow(mm, vma, address, ptep, entry); |
| 1131 | spin_unlock(&mm->page_table_lock); |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 1132 | mutex_unlock(&hugetlb_instantiation_mutex); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1133 | |
| 1134 | return ret; |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 1135 | } |
| 1136 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1137 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
| 1138 | struct page **pages, struct vm_area_struct **vmas, |
Adam Litke | 5b23dbe | 2007-11-14 16:59:33 -0800 | [diff] [blame] | 1139 | unsigned long *position, int *length, int i, |
| 1140 | int write) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1141 | { |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1142 | unsigned long pfn_offset; |
| 1143 | unsigned long vaddr = *position; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1144 | int remainder = *length; |
| 1145 | |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 1146 | spin_lock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1147 | while (vaddr < vma->vm_end && remainder) { |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1148 | pte_t *pte; |
| 1149 | struct page *page; |
| 1150 | |
| 1151 | /* |
| 1152 | * Some archs (sparc64, sh*) have multiple pte_ts to |
| 1153 | * each hugepage. We have to make * sure we get the |
| 1154 | * first, for the page indexing below to work. |
| 1155 | */ |
| 1156 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); |
| 1157 | |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1158 | if (!pte || huge_pte_none(huge_ptep_get(pte)) || |
| 1159 | (write && !pte_write(huge_ptep_get(pte)))) { |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1160 | int ret; |
| 1161 | |
| 1162 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 5b23dbe | 2007-11-14 16:59:33 -0800 | [diff] [blame] | 1163 | ret = hugetlb_fault(mm, vma, vaddr, write); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1164 | spin_lock(&mm->page_table_lock); |
Adam Litke | a89182c | 2007-08-22 14:01:51 -0700 | [diff] [blame] | 1165 | if (!(ret & VM_FAULT_ERROR)) |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1166 | continue; |
| 1167 | |
| 1168 | remainder = 0; |
| 1169 | if (!i) |
| 1170 | i = -EFAULT; |
| 1171 | break; |
| 1172 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1173 | |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1174 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1175 | page = pte_page(huge_ptep_get(pte)); |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1176 | same_page: |
Chen, Kenneth W | d669218 | 2006-03-31 02:29:57 -0800 | [diff] [blame] | 1177 | if (pages) { |
| 1178 | get_page(page); |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1179 | pages[i] = page + pfn_offset; |
Chen, Kenneth W | d669218 | 2006-03-31 02:29:57 -0800 | [diff] [blame] | 1180 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1181 | |
| 1182 | if (vmas) |
| 1183 | vmas[i] = vma; |
| 1184 | |
| 1185 | vaddr += PAGE_SIZE; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1186 | ++pfn_offset; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1187 | --remainder; |
| 1188 | ++i; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1189 | if (vaddr < vma->vm_end && remainder && |
| 1190 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { |
| 1191 | /* |
| 1192 | * We use pfn_offset to avoid touching the pageframes |
| 1193 | * of this compound page. |
| 1194 | */ |
| 1195 | goto same_page; |
| 1196 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1197 | } |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 1198 | spin_unlock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1199 | *length = remainder; |
| 1200 | *position = vaddr; |
| 1201 | |
| 1202 | return i; |
| 1203 | } |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1204 | |
| 1205 | void hugetlb_change_protection(struct vm_area_struct *vma, |
| 1206 | unsigned long address, unsigned long end, pgprot_t newprot) |
| 1207 | { |
| 1208 | struct mm_struct *mm = vma->vm_mm; |
| 1209 | unsigned long start = address; |
| 1210 | pte_t *ptep; |
| 1211 | pte_t pte; |
| 1212 | |
| 1213 | BUG_ON(address >= end); |
| 1214 | flush_cache_range(vma, address, end); |
| 1215 | |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 1216 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1217 | spin_lock(&mm->page_table_lock); |
| 1218 | for (; address < end; address += HPAGE_SIZE) { |
| 1219 | ptep = huge_pte_offset(mm, address); |
| 1220 | if (!ptep) |
| 1221 | continue; |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 1222 | if (huge_pmd_unshare(mm, &address, ptep)) |
| 1223 | continue; |
Gerald Schaefer | 7f2e952 | 2008-04-28 02:13:29 -0700 | [diff] [blame] | 1224 | if (!huge_pte_none(huge_ptep_get(ptep))) { |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1225 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
| 1226 | pte = pte_mkhuge(pte_modify(pte, newprot)); |
| 1227 | set_huge_pte_at(mm, address, ptep, pte); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1228 | } |
| 1229 | } |
| 1230 | spin_unlock(&mm->page_table_lock); |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 1231 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1232 | |
| 1233 | flush_tlb_range(vma, start, end); |
| 1234 | } |
| 1235 | |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1236 | struct file_region { |
| 1237 | struct list_head link; |
| 1238 | long from; |
| 1239 | long to; |
| 1240 | }; |
| 1241 | |
| 1242 | static long region_add(struct list_head *head, long f, long t) |
| 1243 | { |
| 1244 | struct file_region *rg, *nrg, *trg; |
| 1245 | |
| 1246 | /* Locate the region we are either in or before. */ |
| 1247 | list_for_each_entry(rg, head, link) |
| 1248 | if (f <= rg->to) |
| 1249 | break; |
| 1250 | |
| 1251 | /* Round our left edge to the current segment if it encloses us. */ |
| 1252 | if (f > rg->from) |
| 1253 | f = rg->from; |
| 1254 | |
| 1255 | /* Check for and consume any regions we now overlap with. */ |
| 1256 | nrg = rg; |
| 1257 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
| 1258 | if (&rg->link == head) |
| 1259 | break; |
| 1260 | if (rg->from > t) |
| 1261 | break; |
| 1262 | |
| 1263 | /* If this area reaches higher then extend our area to |
| 1264 | * include it completely. If this is not the first area |
| 1265 | * which we intend to reuse, free it. */ |
| 1266 | if (rg->to > t) |
| 1267 | t = rg->to; |
| 1268 | if (rg != nrg) { |
| 1269 | list_del(&rg->link); |
| 1270 | kfree(rg); |
| 1271 | } |
| 1272 | } |
| 1273 | nrg->from = f; |
| 1274 | nrg->to = t; |
| 1275 | return 0; |
| 1276 | } |
| 1277 | |
| 1278 | static long region_chg(struct list_head *head, long f, long t) |
| 1279 | { |
| 1280 | struct file_region *rg, *nrg; |
| 1281 | long chg = 0; |
| 1282 | |
| 1283 | /* Locate the region we are before or in. */ |
| 1284 | list_for_each_entry(rg, head, link) |
| 1285 | if (f <= rg->to) |
| 1286 | break; |
| 1287 | |
| 1288 | /* If we are below the current region then a new region is required. |
| 1289 | * Subtle, allocate a new region at the position but make it zero |
Simon Arlott | 183ff22 | 2007-10-20 01:27:18 +0200 | [diff] [blame] | 1290 | * size such that we can guarantee to record the reservation. */ |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1291 | if (&rg->link == head || t < rg->from) { |
| 1292 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); |
Stephen Hemminger | c80544d | 2007-10-18 03:07:05 -0700 | [diff] [blame] | 1293 | if (!nrg) |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1294 | return -ENOMEM; |
| 1295 | nrg->from = f; |
| 1296 | nrg->to = f; |
| 1297 | INIT_LIST_HEAD(&nrg->link); |
| 1298 | list_add(&nrg->link, rg->link.prev); |
| 1299 | |
| 1300 | return t - f; |
| 1301 | } |
| 1302 | |
| 1303 | /* Round our left edge to the current segment if it encloses us. */ |
| 1304 | if (f > rg->from) |
| 1305 | f = rg->from; |
| 1306 | chg = t - f; |
| 1307 | |
| 1308 | /* Check for and consume any regions we now overlap with. */ |
| 1309 | list_for_each_entry(rg, rg->link.prev, link) { |
| 1310 | if (&rg->link == head) |
| 1311 | break; |
| 1312 | if (rg->from > t) |
| 1313 | return chg; |
| 1314 | |
| 1315 | /* We overlap with this area, if it extends futher than |
| 1316 | * us then we must extend ourselves. Account for its |
| 1317 | * existing reservation. */ |
| 1318 | if (rg->to > t) { |
| 1319 | chg += rg->to - t; |
| 1320 | t = rg->to; |
| 1321 | } |
| 1322 | chg -= rg->to - rg->from; |
| 1323 | } |
| 1324 | return chg; |
| 1325 | } |
| 1326 | |
| 1327 | static long region_truncate(struct list_head *head, long end) |
| 1328 | { |
| 1329 | struct file_region *rg, *trg; |
| 1330 | long chg = 0; |
| 1331 | |
| 1332 | /* Locate the region we are either in or before. */ |
| 1333 | list_for_each_entry(rg, head, link) |
| 1334 | if (end <= rg->to) |
| 1335 | break; |
| 1336 | if (&rg->link == head) |
| 1337 | return 0; |
| 1338 | |
| 1339 | /* If we are in the middle of a region then adjust it. */ |
| 1340 | if (end > rg->from) { |
| 1341 | chg = rg->to - end; |
| 1342 | rg->to = end; |
| 1343 | rg = list_entry(rg->link.next, typeof(*rg), link); |
| 1344 | } |
| 1345 | |
| 1346 | /* Drop any remaining regions. */ |
| 1347 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
| 1348 | if (&rg->link == head) |
| 1349 | break; |
| 1350 | chg += rg->to - rg->from; |
| 1351 | list_del(&rg->link); |
| 1352 | kfree(rg); |
| 1353 | } |
| 1354 | return chg; |
| 1355 | } |
| 1356 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame^] | 1357 | int hugetlb_reserve_pages(struct inode *inode, |
| 1358 | long from, long to, |
| 1359 | struct vm_area_struct *vma) |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 1360 | { |
| 1361 | long ret, chg; |
| 1362 | |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame^] | 1363 | /* |
| 1364 | * Shared mappings base their reservation on the number of pages that |
| 1365 | * are already allocated on behalf of the file. Private mappings need |
| 1366 | * to reserve the full area even if read-only as mprotect() may be |
| 1367 | * called to make the mapping read-write. Assume !vma is a shm mapping |
| 1368 | */ |
| 1369 | if (!vma || vma->vm_flags & VM_SHARED) |
| 1370 | chg = region_chg(&inode->i_mapping->private_list, from, to); |
| 1371 | else { |
| 1372 | chg = to - from; |
| 1373 | set_vma_resv_huge_pages(vma, chg); |
| 1374 | } |
| 1375 | |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 1376 | if (chg < 0) |
| 1377 | return chg; |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 1378 | |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 1379 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
| 1380 | return -ENOSPC; |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1381 | ret = hugetlb_acct_memory(chg); |
Ken Chen | 68842c9 | 2008-01-14 00:55:19 -0800 | [diff] [blame] | 1382 | if (ret < 0) { |
| 1383 | hugetlb_put_quota(inode->i_mapping, chg); |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1384 | return ret; |
Ken Chen | 68842c9 | 2008-01-14 00:55:19 -0800 | [diff] [blame] | 1385 | } |
Mel Gorman | a1e7877 | 2008-07-23 21:27:23 -0700 | [diff] [blame^] | 1386 | if (!vma || vma->vm_flags & VM_SHARED) |
| 1387 | region_add(&inode->i_mapping->private_list, from, to); |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1388 | return 0; |
| 1389 | } |
| 1390 | |
| 1391 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) |
| 1392 | { |
| 1393 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 1394 | |
| 1395 | spin_lock(&inode->i_lock); |
| 1396 | inode->i_blocks -= BLOCKS_PER_HUGEPAGE * freed; |
| 1397 | spin_unlock(&inode->i_lock); |
| 1398 | |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 1399 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
| 1400 | hugetlb_acct_memory(-(chg - freed)); |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1401 | } |