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 | |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 43 | static void clear_huge_page(struct page *page, unsigned long addr) |
| 44 | { |
| 45 | int i; |
| 46 | |
| 47 | might_sleep(); |
| 48 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) { |
| 49 | cond_resched(); |
Ralf Baechle | 281e0e3 | 2007-10-01 01:20:10 -0700 | [diff] [blame] | 50 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 51 | } |
| 52 | } |
| 53 | |
| 54 | static void copy_huge_page(struct page *dst, struct page *src, |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 55 | unsigned long addr, struct vm_area_struct *vma) |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 56 | { |
| 57 | int i; |
| 58 | |
| 59 | might_sleep(); |
| 60 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { |
| 61 | cond_resched(); |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 62 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 63 | } |
| 64 | } |
| 65 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | static void enqueue_huge_page(struct page *page) |
| 67 | { |
| 68 | int nid = page_to_nid(page); |
| 69 | list_add(&page->lru, &hugepage_freelists[nid]); |
| 70 | free_huge_pages++; |
| 71 | free_huge_pages_node[nid]++; |
| 72 | } |
| 73 | |
Nishanth Aravamudan | 348e1e0 | 2008-03-04 14:29:42 -0800 | [diff] [blame] | 74 | static struct page *dequeue_huge_page(void) |
| 75 | { |
| 76 | int nid; |
| 77 | struct page *page = NULL; |
| 78 | |
| 79 | for (nid = 0; nid < MAX_NUMNODES; ++nid) { |
| 80 | if (!list_empty(&hugepage_freelists[nid])) { |
| 81 | page = list_entry(hugepage_freelists[nid].next, |
| 82 | struct page, lru); |
| 83 | list_del(&page->lru); |
| 84 | free_huge_pages--; |
| 85 | free_huge_pages_node[nid]--; |
| 86 | break; |
| 87 | } |
| 88 | } |
| 89 | return page; |
| 90 | } |
| 91 | |
| 92 | static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma, |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 93 | unsigned long address) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | { |
Nishanth Aravamudan | 31a5c6e | 2007-07-15 23:38:02 -0700 | [diff] [blame] | 95 | int nid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | struct page *page = NULL; |
Lee Schermerhorn | 480eccf | 2007-09-18 22:46:47 -0700 | [diff] [blame] | 97 | struct mempolicy *mpol; |
Mel Gorman | 19770b3 | 2008-04-28 02:12:18 -0700 | [diff] [blame] | 98 | nodemask_t *nodemask; |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 99 | struct zonelist *zonelist = huge_zonelist(vma, address, |
Mel Gorman | 19770b3 | 2008-04-28 02:12:18 -0700 | [diff] [blame] | 100 | htlb_alloc_mask, &mpol, &nodemask); |
Mel Gorman | dd1a239 | 2008-04-28 02:12:17 -0700 | [diff] [blame] | 101 | struct zone *zone; |
| 102 | struct zoneref *z; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | |
Mel Gorman | 19770b3 | 2008-04-28 02:12:18 -0700 | [diff] [blame] | 104 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
| 105 | MAX_NR_ZONES - 1, nodemask) { |
Mel Gorman | 54a6eb5 | 2008-04-28 02:12:16 -0700 | [diff] [blame] | 106 | nid = zone_to_nid(zone); |
| 107 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && |
Andrew Morton | 3abf7af | 2007-07-19 01:49:08 -0700 | [diff] [blame] | 108 | !list_empty(&hugepage_freelists[nid])) { |
| 109 | page = list_entry(hugepage_freelists[nid].next, |
| 110 | struct page, lru); |
| 111 | list_del(&page->lru); |
| 112 | free_huge_pages--; |
| 113 | free_huge_pages_node[nid]--; |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 114 | if (vma && vma->vm_flags & VM_MAYSHARE) |
| 115 | resv_huge_pages--; |
Ken Chen | 5ab3ee7 | 2007-07-23 18:44:00 -0700 | [diff] [blame] | 116 | break; |
Andrew Morton | 3abf7af | 2007-07-19 01:49:08 -0700 | [diff] [blame] | 117 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | } |
Lee Schermerhorn | 480eccf | 2007-09-18 22:46:47 -0700 | [diff] [blame] | 119 | mpol_free(mpol); /* unref if mpol !NULL */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | return page; |
| 121 | } |
| 122 | |
Adam Litke | 6af2acb | 2007-10-16 01:26:16 -0700 | [diff] [blame] | 123 | static void update_and_free_page(struct page *page) |
| 124 | { |
| 125 | int i; |
| 126 | nr_huge_pages--; |
| 127 | nr_huge_pages_node[page_to_nid(page)]--; |
| 128 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { |
| 129 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | |
| 130 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | |
| 131 | 1 << PG_private | 1<< PG_writeback); |
| 132 | } |
| 133 | set_compound_page_dtor(page, NULL); |
| 134 | set_page_refcounted(page); |
| 135 | __free_pages(page, HUGETLB_PAGE_ORDER); |
| 136 | } |
| 137 | |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 138 | static void free_huge_page(struct page *page) |
| 139 | { |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 140 | int nid = page_to_nid(page); |
Adam Litke | c79fb75 | 2007-11-14 16:59:38 -0800 | [diff] [blame] | 141 | struct address_space *mapping; |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 142 | |
Adam Litke | c79fb75 | 2007-11-14 16:59:38 -0800 | [diff] [blame] | 143 | mapping = (struct address_space *) page_private(page); |
Andy Whitcroft | e5df70a | 2008-02-23 15:23:32 -0800 | [diff] [blame] | 144 | set_page_private(page, 0); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 145 | BUG_ON(page_count(page)); |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 146 | INIT_LIST_HEAD(&page->lru); |
| 147 | |
| 148 | spin_lock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 149 | if (surplus_huge_pages_node[nid]) { |
| 150 | update_and_free_page(page); |
| 151 | surplus_huge_pages--; |
| 152 | surplus_huge_pages_node[nid]--; |
| 153 | } else { |
| 154 | enqueue_huge_page(page); |
| 155 | } |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 156 | spin_unlock(&hugetlb_lock); |
Adam Litke | c79fb75 | 2007-11-14 16:59:38 -0800 | [diff] [blame] | 157 | if (mapping) |
Adam Litke | 9a119c0 | 2007-11-14 16:59:41 -0800 | [diff] [blame] | 158 | hugetlb_put_quota(mapping, 1); |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 159 | } |
| 160 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 161 | /* |
| 162 | * Increment or decrement surplus_huge_pages. Keep node-specific counters |
| 163 | * balanced by operating on them in a round-robin fashion. |
| 164 | * Returns 1 if an adjustment was made. |
| 165 | */ |
| 166 | static int adjust_pool_surplus(int delta) |
| 167 | { |
| 168 | static int prev_nid; |
| 169 | int nid = prev_nid; |
| 170 | int ret = 0; |
| 171 | |
| 172 | VM_BUG_ON(delta != -1 && delta != 1); |
| 173 | do { |
| 174 | nid = next_node(nid, node_online_map); |
| 175 | if (nid == MAX_NUMNODES) |
| 176 | nid = first_node(node_online_map); |
| 177 | |
| 178 | /* To shrink on this node, there must be a surplus page */ |
| 179 | if (delta < 0 && !surplus_huge_pages_node[nid]) |
| 180 | continue; |
| 181 | /* Surplus cannot exceed the total number of pages */ |
| 182 | if (delta > 0 && surplus_huge_pages_node[nid] >= |
| 183 | nr_huge_pages_node[nid]) |
| 184 | continue; |
| 185 | |
| 186 | surplus_huge_pages += delta; |
| 187 | surplus_huge_pages_node[nid] += delta; |
| 188 | ret = 1; |
| 189 | break; |
| 190 | } while (nid != prev_nid); |
| 191 | |
| 192 | prev_nid = nid; |
| 193 | return ret; |
| 194 | } |
| 195 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 196 | static struct page *alloc_fresh_huge_page_node(int nid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | struct page *page; |
Joe Jin | f96efd5 | 2007-07-15 23:38:12 -0700 | [diff] [blame] | 199 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 200 | page = alloc_pages_node(nid, |
| 201 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|__GFP_NOWARN, |
| 202 | HUGETLB_PAGE_ORDER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | if (page) { |
Andy Whitcroft | 33f2ef8 | 2006-12-06 20:33:32 -0800 | [diff] [blame] | 204 | set_compound_page_dtor(page, free_huge_page); |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 205 | spin_lock(&hugetlb_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | nr_huge_pages++; |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 207 | nr_huge_pages_node[nid]++; |
Eric Paris | 0bd0f9f | 2005-11-21 21:32:28 -0800 | [diff] [blame] | 208 | spin_unlock(&hugetlb_lock); |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 209 | put_page(page); /* free it into the hugepage allocator */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | } |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 211 | |
| 212 | return page; |
| 213 | } |
| 214 | |
| 215 | static int alloc_fresh_huge_page(void) |
| 216 | { |
| 217 | struct page *page; |
| 218 | int start_nid; |
| 219 | int next_nid; |
| 220 | int ret = 0; |
| 221 | |
| 222 | start_nid = hugetlb_next_nid; |
| 223 | |
| 224 | do { |
| 225 | page = alloc_fresh_huge_page_node(hugetlb_next_nid); |
| 226 | if (page) |
| 227 | ret = 1; |
| 228 | /* |
| 229 | * Use a helper variable to find the next node and then |
| 230 | * copy it back to hugetlb_next_nid afterwards: |
| 231 | * otherwise there's a window in which a racer might |
| 232 | * pass invalid nid MAX_NUMNODES to alloc_pages_node. |
| 233 | * But we don't need to use a spin_lock here: it really |
| 234 | * doesn't matter if occasionally a racer chooses the |
| 235 | * same nid as we do. Move nid forward in the mask even |
| 236 | * if we just successfully allocated a hugepage so that |
| 237 | * the next caller gets hugepages on the next node. |
| 238 | */ |
| 239 | next_nid = next_node(hugetlb_next_nid, node_online_map); |
| 240 | if (next_nid == MAX_NUMNODES) |
| 241 | next_nid = first_node(node_online_map); |
| 242 | hugetlb_next_nid = next_nid; |
| 243 | } while (!page && hugetlb_next_nid != start_nid); |
| 244 | |
| 245 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | } |
| 247 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 248 | static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma, |
| 249 | unsigned long address) |
| 250 | { |
| 251 | struct page *page; |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 252 | unsigned int nid; |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 253 | |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 254 | /* |
| 255 | * Assume we will successfully allocate the surplus page to |
| 256 | * prevent racing processes from causing the surplus to exceed |
| 257 | * overcommit |
| 258 | * |
| 259 | * This however introduces a different race, where a process B |
| 260 | * tries to grow the static hugepage pool while alloc_pages() is |
| 261 | * called by process A. B will only examine the per-node |
| 262 | * counters in determining if surplus huge pages can be |
| 263 | * converted to normal huge pages in adjust_pool_surplus(). A |
| 264 | * won't be able to increment the per-node counter, until the |
| 265 | * lock is dropped by B, but B doesn't drop hugetlb_lock until |
| 266 | * no more huge pages can be converted from surplus to normal |
| 267 | * state (and doesn't try to convert again). Thus, we have a |
| 268 | * case where a surplus huge page exists, the pool is grown, and |
| 269 | * the surplus huge page still exists after, even though it |
| 270 | * should just have been converted to a normal huge page. This |
| 271 | * does not leak memory, though, as the hugepage will be freed |
| 272 | * once it is out of use. It also does not allow the counters to |
| 273 | * go out of whack in adjust_pool_surplus() as we don't modify |
| 274 | * the node values until we've gotten the hugepage and only the |
| 275 | * per-node value is checked there. |
| 276 | */ |
| 277 | spin_lock(&hugetlb_lock); |
| 278 | if (surplus_huge_pages >= nr_overcommit_huge_pages) { |
| 279 | spin_unlock(&hugetlb_lock); |
| 280 | return NULL; |
| 281 | } else { |
| 282 | nr_huge_pages++; |
| 283 | surplus_huge_pages++; |
| 284 | } |
| 285 | spin_unlock(&hugetlb_lock); |
| 286 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 287 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN, |
| 288 | HUGETLB_PAGE_ORDER); |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 289 | |
| 290 | spin_lock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 291 | if (page) { |
Adam Litke | 2668db9 | 2008-03-10 11:43:50 -0700 | [diff] [blame] | 292 | /* |
| 293 | * This page is now managed by the hugetlb allocator and has |
| 294 | * no users -- drop the buddy allocator's reference. |
| 295 | */ |
| 296 | put_page_testzero(page); |
| 297 | VM_BUG_ON(page_count(page)); |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 298 | nid = page_to_nid(page); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 299 | set_compound_page_dtor(page, free_huge_page); |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 300 | /* |
| 301 | * We incremented the global counters already |
| 302 | */ |
| 303 | nr_huge_pages_node[nid]++; |
| 304 | surplus_huge_pages_node[nid]++; |
| 305 | } else { |
| 306 | nr_huge_pages--; |
| 307 | surplus_huge_pages--; |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 308 | } |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 309 | spin_unlock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 310 | |
| 311 | return page; |
| 312 | } |
| 313 | |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 314 | /* |
| 315 | * Increase the hugetlb pool such that it can accomodate a reservation |
| 316 | * of size 'delta'. |
| 317 | */ |
| 318 | static int gather_surplus_pages(int delta) |
| 319 | { |
| 320 | struct list_head surplus_list; |
| 321 | struct page *page, *tmp; |
| 322 | int ret, i; |
| 323 | int needed, allocated; |
| 324 | |
| 325 | needed = (resv_huge_pages + delta) - free_huge_pages; |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 326 | if (needed <= 0) { |
| 327 | resv_huge_pages += delta; |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 328 | return 0; |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 329 | } |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 330 | |
| 331 | allocated = 0; |
| 332 | INIT_LIST_HEAD(&surplus_list); |
| 333 | |
| 334 | ret = -ENOMEM; |
| 335 | retry: |
| 336 | spin_unlock(&hugetlb_lock); |
| 337 | for (i = 0; i < needed; i++) { |
| 338 | page = alloc_buddy_huge_page(NULL, 0); |
| 339 | if (!page) { |
| 340 | /* |
| 341 | * We were not able to allocate enough pages to |
| 342 | * satisfy the entire reservation so we free what |
| 343 | * we've allocated so far. |
| 344 | */ |
| 345 | spin_lock(&hugetlb_lock); |
| 346 | needed = 0; |
| 347 | goto free; |
| 348 | } |
| 349 | |
| 350 | list_add(&page->lru, &surplus_list); |
| 351 | } |
| 352 | allocated += needed; |
| 353 | |
| 354 | /* |
| 355 | * After retaking hugetlb_lock, we need to recalculate 'needed' |
| 356 | * because either resv_huge_pages or free_huge_pages may have changed. |
| 357 | */ |
| 358 | spin_lock(&hugetlb_lock); |
| 359 | needed = (resv_huge_pages + delta) - (free_huge_pages + allocated); |
| 360 | if (needed > 0) |
| 361 | goto retry; |
| 362 | |
| 363 | /* |
| 364 | * The surplus_list now contains _at_least_ the number of extra pages |
| 365 | * needed to accomodate the reservation. Add the appropriate number |
| 366 | * 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] | 367 | * allocator. Commit the entire reservation here to prevent another |
| 368 | * process from stealing the pages as they are added to the pool but |
| 369 | * before they are reserved. |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 370 | */ |
| 371 | needed += allocated; |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 372 | resv_huge_pages += delta; |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 373 | ret = 0; |
| 374 | free: |
| 375 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
| 376 | list_del(&page->lru); |
| 377 | if ((--needed) >= 0) |
| 378 | enqueue_huge_page(page); |
Adam Litke | af767cb | 2007-10-16 01:26:25 -0700 | [diff] [blame] | 379 | else { |
| 380 | /* |
Adam Litke | 2668db9 | 2008-03-10 11:43:50 -0700 | [diff] [blame] | 381 | * The page has a reference count of zero already, so |
| 382 | * call free_huge_page directly instead of using |
| 383 | * put_page. This must be done with hugetlb_lock |
Adam Litke | af767cb | 2007-10-16 01:26:25 -0700 | [diff] [blame] | 384 | * unlocked which is safe because free_huge_page takes |
| 385 | * hugetlb_lock before deciding how to free the page. |
| 386 | */ |
| 387 | spin_unlock(&hugetlb_lock); |
Adam Litke | 2668db9 | 2008-03-10 11:43:50 -0700 | [diff] [blame] | 388 | free_huge_page(page); |
Adam Litke | af767cb | 2007-10-16 01:26:25 -0700 | [diff] [blame] | 389 | spin_lock(&hugetlb_lock); |
| 390 | } |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 391 | } |
| 392 | |
| 393 | return ret; |
| 394 | } |
| 395 | |
| 396 | /* |
| 397 | * When releasing a hugetlb pool reservation, any surplus pages that were |
| 398 | * allocated to satisfy the reservation must be explicitly freed if they were |
| 399 | * never used. |
| 400 | */ |
Adrian Bunk | 8cde045 | 2007-11-14 16:59:43 -0800 | [diff] [blame] | 401 | static void return_unused_surplus_pages(unsigned long unused_resv_pages) |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 402 | { |
| 403 | static int nid = -1; |
| 404 | struct page *page; |
| 405 | unsigned long nr_pages; |
| 406 | |
Nishanth Aravamudan | 11320d1 | 2008-03-26 14:40:20 -0700 | [diff] [blame] | 407 | /* |
| 408 | * We want to release as many surplus pages as possible, spread |
| 409 | * evenly across all nodes. Iterate across all nodes until we |
| 410 | * can no longer free unreserved surplus pages. This occurs when |
| 411 | * the nodes with surplus pages have no free pages. |
| 412 | */ |
| 413 | unsigned long remaining_iterations = num_online_nodes(); |
| 414 | |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 415 | /* Uncommit the reservation */ |
| 416 | resv_huge_pages -= unused_resv_pages; |
| 417 | |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 418 | nr_pages = min(unused_resv_pages, surplus_huge_pages); |
| 419 | |
Nishanth Aravamudan | 11320d1 | 2008-03-26 14:40:20 -0700 | [diff] [blame] | 420 | while (remaining_iterations-- && nr_pages) { |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 421 | nid = next_node(nid, node_online_map); |
| 422 | if (nid == MAX_NUMNODES) |
| 423 | nid = first_node(node_online_map); |
| 424 | |
| 425 | if (!surplus_huge_pages_node[nid]) |
| 426 | continue; |
| 427 | |
| 428 | if (!list_empty(&hugepage_freelists[nid])) { |
| 429 | page = list_entry(hugepage_freelists[nid].next, |
| 430 | struct page, lru); |
| 431 | list_del(&page->lru); |
| 432 | update_and_free_page(page); |
| 433 | free_huge_pages--; |
| 434 | free_huge_pages_node[nid]--; |
| 435 | surplus_huge_pages--; |
| 436 | surplus_huge_pages_node[nid]--; |
| 437 | nr_pages--; |
Nishanth Aravamudan | 11320d1 | 2008-03-26 14:40:20 -0700 | [diff] [blame] | 438 | remaining_iterations = num_online_nodes(); |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 439 | } |
| 440 | } |
| 441 | } |
| 442 | |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 443 | |
| 444 | static struct page *alloc_huge_page_shared(struct vm_area_struct *vma, |
| 445 | unsigned long addr) |
| 446 | { |
| 447 | struct page *page; |
| 448 | |
| 449 | spin_lock(&hugetlb_lock); |
Nishanth Aravamudan | 348e1e0 | 2008-03-04 14:29:42 -0800 | [diff] [blame] | 450 | page = dequeue_huge_page_vma(vma, addr); |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 451 | spin_unlock(&hugetlb_lock); |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 452 | return page ? page : ERR_PTR(-VM_FAULT_OOM); |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 453 | } |
| 454 | |
| 455 | static struct page *alloc_huge_page_private(struct vm_area_struct *vma, |
| 456 | unsigned long addr) |
| 457 | { |
| 458 | struct page *page = NULL; |
| 459 | |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 460 | if (hugetlb_get_quota(vma->vm_file->f_mapping, 1)) |
| 461 | return ERR_PTR(-VM_FAULT_SIGBUS); |
| 462 | |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 463 | spin_lock(&hugetlb_lock); |
| 464 | if (free_huge_pages > resv_huge_pages) |
Nishanth Aravamudan | 348e1e0 | 2008-03-04 14:29:42 -0800 | [diff] [blame] | 465 | page = dequeue_huge_page_vma(vma, addr); |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 466 | spin_unlock(&hugetlb_lock); |
Ken Chen | 68842c9 | 2008-01-14 00:55:19 -0800 | [diff] [blame] | 467 | if (!page) { |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 468 | page = alloc_buddy_huge_page(vma, addr); |
Ken Chen | 68842c9 | 2008-01-14 00:55:19 -0800 | [diff] [blame] | 469 | if (!page) { |
| 470 | hugetlb_put_quota(vma->vm_file->f_mapping, 1); |
| 471 | return ERR_PTR(-VM_FAULT_OOM); |
| 472 | } |
| 473 | } |
| 474 | return page; |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 475 | } |
| 476 | |
David Gibson | 27a85ef | 2006-03-22 00:08:56 -0800 | [diff] [blame] | 477 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
| 478 | unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | { |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 480 | struct page *page; |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 481 | struct address_space *mapping = vma->vm_file->f_mapping; |
| 482 | |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 483 | if (vma->vm_flags & VM_MAYSHARE) |
| 484 | page = alloc_huge_page_shared(vma, addr); |
| 485 | else |
| 486 | page = alloc_huge_page_private(vma, addr); |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 487 | |
| 488 | if (!IS_ERR(page)) { |
Adam Litke | 348ea20 | 2007-11-14 16:59:37 -0800 | [diff] [blame] | 489 | set_page_refcounted(page); |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 490 | set_page_private(page, (unsigned long) mapping); |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 491 | } |
| 492 | return page; |
David Gibson | b45b5bd | 2006-03-22 00:08:55 -0800 | [diff] [blame] | 493 | } |
| 494 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | static int __init hugetlb_init(void) |
| 496 | { |
| 497 | unsigned long i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | |
Benjamin Herrenschmidt | 3c726f8 | 2005-11-07 11:06:55 +1100 | [diff] [blame] | 499 | if (HPAGE_SHIFT == 0) |
| 500 | return 0; |
| 501 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | for (i = 0; i < MAX_NUMNODES; ++i) |
| 503 | INIT_LIST_HEAD(&hugepage_freelists[i]); |
| 504 | |
Nishanth Aravamudan | 63b4613 | 2007-10-16 01:26:24 -0700 | [diff] [blame] | 505 | hugetlb_next_nid = first_node(node_online_map); |
| 506 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 507 | for (i = 0; i < max_huge_pages; ++i) { |
Nick Piggin | a482289 | 2006-03-22 00:08:08 -0800 | [diff] [blame] | 508 | if (!alloc_fresh_huge_page()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | } |
| 511 | max_huge_pages = free_huge_pages = nr_huge_pages = i; |
| 512 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); |
| 513 | return 0; |
| 514 | } |
| 515 | module_init(hugetlb_init); |
| 516 | |
| 517 | static int __init hugetlb_setup(char *s) |
| 518 | { |
| 519 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) |
| 520 | max_huge_pages = 0; |
| 521 | return 1; |
| 522 | } |
| 523 | __setup("hugepages=", hugetlb_setup); |
| 524 | |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 525 | static unsigned int cpuset_mems_nr(unsigned int *array) |
| 526 | { |
| 527 | int node; |
| 528 | unsigned int nr = 0; |
| 529 | |
| 530 | for_each_node_mask(node, cpuset_current_mems_allowed) |
| 531 | nr += array[node]; |
| 532 | |
| 533 | return nr; |
| 534 | } |
| 535 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 536 | #ifdef CONFIG_SYSCTL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | #ifdef CONFIG_HIGHMEM |
| 538 | static void try_to_free_low(unsigned long count) |
| 539 | { |
Christoph Lameter | 4415cc8 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 540 | int i; |
| 541 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | for (i = 0; i < MAX_NUMNODES; ++i) { |
| 543 | struct page *page, *next; |
| 544 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { |
Adam Litke | 6b0c880 | 2007-10-16 01:26:23 -0700 | [diff] [blame] | 545 | if (count >= nr_huge_pages) |
| 546 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | if (PageHighMem(page)) |
| 548 | continue; |
| 549 | list_del(&page->lru); |
| 550 | update_and_free_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | free_huge_pages--; |
Christoph Lameter | 4415cc8 | 2006-09-25 23:31:55 -0700 | [diff] [blame] | 552 | free_huge_pages_node[page_to_nid(page)]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | } |
| 554 | } |
| 555 | } |
| 556 | #else |
| 557 | static inline void try_to_free_low(unsigned long count) |
| 558 | { |
| 559 | } |
| 560 | #endif |
| 561 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 562 | #define persistent_huge_pages (nr_huge_pages - surplus_huge_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | static unsigned long set_max_huge_pages(unsigned long count) |
| 564 | { |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 565 | unsigned long min_count, ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 567 | /* |
| 568 | * Increase the pool size |
| 569 | * First take pages out of surplus state. Then make up the |
| 570 | * remaining difference by allocating fresh huge pages. |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 571 | * |
| 572 | * We might race with alloc_buddy_huge_page() here and be unable |
| 573 | * to convert a surplus huge page to a normal huge page. That is |
| 574 | * not critical, though, it just means the overall size of the |
| 575 | * pool might be one hugepage larger than it needs to be, but |
| 576 | * within all the constraints specified by the sysctls. |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 577 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | spin_lock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 579 | while (surplus_huge_pages && count > persistent_huge_pages) { |
| 580 | if (!adjust_pool_surplus(-1)) |
| 581 | break; |
| 582 | } |
| 583 | |
| 584 | while (count > persistent_huge_pages) { |
| 585 | int ret; |
| 586 | /* |
| 587 | * If this allocation races such that we no longer need the |
| 588 | * page, free_huge_page will handle it by freeing the page |
| 589 | * and reducing the surplus. |
| 590 | */ |
| 591 | spin_unlock(&hugetlb_lock); |
| 592 | ret = alloc_fresh_huge_page(); |
| 593 | spin_lock(&hugetlb_lock); |
| 594 | if (!ret) |
| 595 | goto out; |
| 596 | |
| 597 | } |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 598 | |
| 599 | /* |
| 600 | * Decrease the pool size |
| 601 | * First return free pages to the buddy allocator (being careful |
| 602 | * to keep enough around to satisfy reservations). Then place |
| 603 | * pages into surplus state as needed so the pool will shrink |
| 604 | * to the desired size as pages become free. |
Nishanth Aravamudan | d1c3fb1 | 2007-12-17 16:20:12 -0800 | [diff] [blame] | 605 | * |
| 606 | * By placing pages into the surplus state independent of the |
| 607 | * overcommit value, we are allowing the surplus pool size to |
| 608 | * exceed overcommit. There are few sane options here. Since |
| 609 | * alloc_buddy_huge_page() is checking the global counter, |
| 610 | * though, we'll note that we're not allowed to exceed surplus |
| 611 | * and won't grow the pool anywhere else. Not until one of the |
| 612 | * sysctls are changed, or the surplus pages go out of use. |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 613 | */ |
Adam Litke | 6b0c880 | 2007-10-16 01:26:23 -0700 | [diff] [blame] | 614 | min_count = resv_huge_pages + nr_huge_pages - free_huge_pages; |
| 615 | min_count = max(count, min_count); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 616 | try_to_free_low(min_count); |
| 617 | while (min_count < persistent_huge_pages) { |
Nishanth Aravamudan | 348e1e0 | 2008-03-04 14:29:42 -0800 | [diff] [blame] | 618 | struct page *page = dequeue_huge_page(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 619 | if (!page) |
| 620 | break; |
| 621 | update_and_free_page(page); |
| 622 | } |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 623 | while (count < persistent_huge_pages) { |
| 624 | if (!adjust_pool_surplus(1)) |
| 625 | break; |
| 626 | } |
| 627 | out: |
| 628 | ret = persistent_huge_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 629 | spin_unlock(&hugetlb_lock); |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 630 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | } |
| 632 | |
| 633 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
| 634 | struct file *file, void __user *buffer, |
| 635 | size_t *length, loff_t *ppos) |
| 636 | { |
| 637 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
| 638 | max_huge_pages = set_max_huge_pages(max_huge_pages); |
| 639 | return 0; |
| 640 | } |
Mel Gorman | 396faf0 | 2007-07-17 04:03:13 -0700 | [diff] [blame] | 641 | |
| 642 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, |
| 643 | struct file *file, void __user *buffer, |
| 644 | size_t *length, loff_t *ppos) |
| 645 | { |
| 646 | proc_dointvec(table, write, file, buffer, length, ppos); |
| 647 | if (hugepages_treat_as_movable) |
| 648 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; |
| 649 | else |
| 650 | htlb_alloc_mask = GFP_HIGHUSER; |
| 651 | return 0; |
| 652 | } |
| 653 | |
Nishanth Aravamudan | a3d0c6a | 2008-02-08 04:18:18 -0800 | [diff] [blame] | 654 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
| 655 | struct file *file, void __user *buffer, |
| 656 | size_t *length, loff_t *ppos) |
| 657 | { |
Nishanth Aravamudan | a3d0c6a | 2008-02-08 04:18:18 -0800 | [diff] [blame] | 658 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
Nishanth Aravamudan | 064d9ef | 2008-02-13 15:03:19 -0800 | [diff] [blame] | 659 | spin_lock(&hugetlb_lock); |
| 660 | nr_overcommit_huge_pages = sysctl_overcommit_huge_pages; |
Nishanth Aravamudan | a3d0c6a | 2008-02-08 04:18:18 -0800 | [diff] [blame] | 661 | spin_unlock(&hugetlb_lock); |
| 662 | return 0; |
| 663 | } |
| 664 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 665 | #endif /* CONFIG_SYSCTL */ |
| 666 | |
| 667 | int hugetlb_report_meminfo(char *buf) |
| 668 | { |
| 669 | return sprintf(buf, |
| 670 | "HugePages_Total: %5lu\n" |
| 671 | "HugePages_Free: %5lu\n" |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 672 | "HugePages_Rsvd: %5lu\n" |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 673 | "HugePages_Surp: %5lu\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 674 | "Hugepagesize: %5lu kB\n", |
| 675 | nr_huge_pages, |
| 676 | free_huge_pages, |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 677 | resv_huge_pages, |
Adam Litke | 7893d1d | 2007-10-16 01:26:18 -0700 | [diff] [blame] | 678 | surplus_huge_pages, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 679 | HPAGE_SIZE/1024); |
| 680 | } |
| 681 | |
| 682 | int hugetlb_report_node_meminfo(int nid, char *buf) |
| 683 | { |
| 684 | return sprintf(buf, |
| 685 | "Node %d HugePages_Total: %5u\n" |
Nishanth Aravamudan | a1de091 | 2008-03-26 14:37:53 -0700 | [diff] [blame] | 686 | "Node %d HugePages_Free: %5u\n" |
| 687 | "Node %d HugePages_Surp: %5u\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 688 | nid, nr_huge_pages_node[nid], |
Nishanth Aravamudan | a1de091 | 2008-03-26 14:37:53 -0700 | [diff] [blame] | 689 | nid, free_huge_pages_node[nid], |
| 690 | nid, surplus_huge_pages_node[nid]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | } |
| 692 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
| 694 | unsigned long hugetlb_total_pages(void) |
| 695 | { |
| 696 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); |
| 697 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | |
| 699 | /* |
| 700 | * We cannot handle pagefaults against hugetlb pages at all. They cause |
| 701 | * handle_mm_fault() to try to instantiate regular-sized pages in the |
| 702 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get |
| 703 | * this far. |
| 704 | */ |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 705 | 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] | 706 | { |
| 707 | BUG(); |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 708 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 709 | } |
| 710 | |
| 711 | struct vm_operations_struct hugetlb_vm_ops = { |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 712 | .fault = hugetlb_vm_op_fault, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 713 | }; |
| 714 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 715 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
| 716 | int writable) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 717 | { |
| 718 | pte_t entry; |
| 719 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 720 | if (writable) { |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 721 | entry = |
| 722 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); |
| 723 | } else { |
| 724 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
| 725 | } |
| 726 | entry = pte_mkyoung(entry); |
| 727 | entry = pte_mkhuge(entry); |
| 728 | |
| 729 | return entry; |
| 730 | } |
| 731 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 732 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
| 733 | unsigned long address, pte_t *ptep) |
| 734 | { |
| 735 | pte_t entry; |
| 736 | |
| 737 | entry = pte_mkwrite(pte_mkdirty(*ptep)); |
Benjamin Herrenschmidt | 8dab524 | 2007-06-16 10:16:12 -0700 | [diff] [blame] | 738 | if (ptep_set_access_flags(vma, address, ptep, entry, 1)) { |
| 739 | update_mmu_cache(vma, address, entry); |
Benjamin Herrenschmidt | 8dab524 | 2007-06-16 10:16:12 -0700 | [diff] [blame] | 740 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 741 | } |
| 742 | |
| 743 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 744 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
| 745 | struct vm_area_struct *vma) |
| 746 | { |
| 747 | pte_t *src_pte, *dst_pte, entry; |
| 748 | struct page *ptepage; |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 749 | unsigned long addr; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 750 | int cow; |
| 751 | |
| 752 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 753 | |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 754 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 755 | src_pte = huge_pte_offset(src, addr); |
| 756 | if (!src_pte) |
| 757 | continue; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 758 | dst_pte = huge_pte_alloc(dst, addr); |
| 759 | if (!dst_pte) |
| 760 | goto nomem; |
Larry Woodman | c5c9942 | 2008-01-24 05:49:25 -0800 | [diff] [blame] | 761 | |
| 762 | /* If the pagetables are shared don't copy or take references */ |
| 763 | if (dst_pte == src_pte) |
| 764 | continue; |
| 765 | |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 766 | spin_lock(&dst->page_table_lock); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 767 | spin_lock(&src->page_table_lock); |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 768 | if (!pte_none(*src_pte)) { |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 769 | if (cow) |
| 770 | ptep_set_wrprotect(src, addr, src_pte); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 771 | entry = *src_pte; |
| 772 | ptepage = pte_page(entry); |
| 773 | get_page(ptepage); |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 774 | set_huge_pte_at(dst, addr, dst_pte, entry); |
| 775 | } |
| 776 | spin_unlock(&src->page_table_lock); |
Hugh Dickins | c74df32 | 2005-10-29 18:16:23 -0700 | [diff] [blame] | 777 | spin_unlock(&dst->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 778 | } |
| 779 | return 0; |
| 780 | |
| 781 | nomem: |
| 782 | return -ENOMEM; |
| 783 | } |
| 784 | |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 785 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
| 786 | unsigned long end) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 787 | { |
| 788 | struct mm_struct *mm = vma->vm_mm; |
| 789 | unsigned long address; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 790 | pte_t *ptep; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 791 | pte_t pte; |
| 792 | struct page *page; |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 793 | struct page *tmp; |
Chen, Kenneth W | c0a499c | 2006-12-06 20:31:39 -0800 | [diff] [blame] | 794 | /* |
| 795 | * A page gathering list, protected by per file i_mmap_lock. The |
| 796 | * lock is used to avoid list corruption from multiple unmapping |
| 797 | * of the same page since we are using page->lru. |
| 798 | */ |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 799 | LIST_HEAD(page_list); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 800 | |
| 801 | WARN_ON(!is_vm_hugetlb_page(vma)); |
| 802 | BUG_ON(start & ~HPAGE_MASK); |
| 803 | BUG_ON(end & ~HPAGE_MASK); |
| 804 | |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 805 | spin_lock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 806 | for (address = start; address < end; address += HPAGE_SIZE) { |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 807 | ptep = huge_pte_offset(mm, address); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 808 | if (!ptep) |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 809 | continue; |
| 810 | |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 811 | if (huge_pmd_unshare(mm, &address, ptep)) |
| 812 | continue; |
| 813 | |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 814 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 815 | if (pte_none(pte)) |
| 816 | continue; |
David Gibson | c7546f8 | 2005-08-05 11:59:35 -0700 | [diff] [blame] | 817 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 818 | page = pte_page(pte); |
Ken Chen | 6649a38 | 2007-02-08 14:20:27 -0800 | [diff] [blame] | 819 | if (pte_dirty(pte)) |
| 820 | set_page_dirty(page); |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 821 | list_add(&page->lru, &page_list); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 822 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 823 | spin_unlock(&mm->page_table_lock); |
Hugh Dickins | 508034a | 2005-10-29 18:16:30 -0700 | [diff] [blame] | 824 | flush_tlb_range(vma, start, end); |
Chen, Kenneth W | fe1668a | 2006-10-04 02:15:24 -0700 | [diff] [blame] | 825 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
| 826 | list_del(&page->lru); |
| 827 | put_page(page); |
| 828 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 830 | |
Chen, Kenneth W | 502717f | 2006-10-11 01:20:46 -0700 | [diff] [blame] | 831 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
| 832 | unsigned long end) |
| 833 | { |
| 834 | /* |
| 835 | * It is undesirable to test vma->vm_file as it should be non-null |
| 836 | * for valid hugetlb area. However, vm_file will be NULL in the error |
| 837 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, |
| 838 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function |
| 839 | * to clean up. Since no pte has actually been setup, it is safe to |
| 840 | * do nothing in this case. |
| 841 | */ |
| 842 | if (vma->vm_file) { |
| 843 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
| 844 | __unmap_hugepage_range(vma, start, end); |
| 845 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
| 846 | } |
| 847 | } |
| 848 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 849 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
| 850 | unsigned long address, pte_t *ptep, pte_t pte) |
| 851 | { |
| 852 | struct page *old_page, *new_page; |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 853 | int avoidcopy; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 854 | |
| 855 | old_page = pte_page(pte); |
| 856 | |
| 857 | /* If no-one else is actually using this page, avoid the copy |
| 858 | * and just make the page writable */ |
| 859 | avoidcopy = (page_count(old_page) == 1); |
| 860 | if (avoidcopy) { |
| 861 | set_huge_ptep_writable(vma, address, ptep); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 862 | return 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 863 | } |
| 864 | |
| 865 | page_cache_get(old_page); |
Christoph Lameter | 5da7ca8 | 2006-01-06 00:10:46 -0800 | [diff] [blame] | 866 | new_page = alloc_huge_page(vma, address); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 867 | |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 868 | if (IS_ERR(new_page)) { |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 869 | page_cache_release(old_page); |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 870 | return -PTR_ERR(new_page); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 871 | } |
| 872 | |
| 873 | spin_unlock(&mm->page_table_lock); |
Atsushi Nemoto | 9de455b | 2006-12-12 17:14:55 +0000 | [diff] [blame] | 874 | copy_huge_page(new_page, old_page, address, vma); |
Nick Piggin | 0ed361d | 2008-02-04 22:29:34 -0800 | [diff] [blame] | 875 | __SetPageUptodate(new_page); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 876 | spin_lock(&mm->page_table_lock); |
| 877 | |
| 878 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); |
| 879 | if (likely(pte_same(*ptep, pte))) { |
| 880 | /* Break COW */ |
| 881 | set_huge_pte_at(mm, address, ptep, |
| 882 | make_huge_pte(vma, new_page, 1)); |
| 883 | /* Make the old page be freed below */ |
| 884 | new_page = old_page; |
| 885 | } |
| 886 | page_cache_release(new_page); |
| 887 | page_cache_release(old_page); |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 888 | return 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 889 | } |
| 890 | |
Robert P. J. Day | a1ed3dd | 2007-07-17 04:03:33 -0700 | [diff] [blame] | 891 | 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] | 892 | unsigned long address, pte_t *ptep, int write_access) |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 893 | { |
| 894 | int ret = VM_FAULT_SIGBUS; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 895 | unsigned long idx; |
| 896 | unsigned long size; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 897 | struct page *page; |
| 898 | struct address_space *mapping; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 899 | pte_t new_pte; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 900 | |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 901 | mapping = vma->vm_file->f_mapping; |
| 902 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) |
| 903 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); |
| 904 | |
| 905 | /* |
| 906 | * Use page lock to guard against racing truncation |
| 907 | * before we get page_table_lock. |
| 908 | */ |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 909 | retry: |
| 910 | page = find_lock_page(mapping, idx); |
| 911 | if (!page) { |
Hugh Dickins | ebed4bf | 2006-10-28 10:38:43 -0700 | [diff] [blame] | 912 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
| 913 | if (idx >= size) |
| 914 | goto out; |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 915 | page = alloc_huge_page(vma, address); |
Adam Litke | 2fc39ce | 2007-11-14 16:59:39 -0800 | [diff] [blame] | 916 | if (IS_ERR(page)) { |
| 917 | ret = -PTR_ERR(page); |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 918 | goto out; |
| 919 | } |
David Gibson | 79ac6ba | 2006-03-22 00:08:51 -0800 | [diff] [blame] | 920 | clear_huge_page(page, address); |
Nick Piggin | 0ed361d | 2008-02-04 22:29:34 -0800 | [diff] [blame] | 921 | __SetPageUptodate(page); |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 922 | |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 923 | if (vma->vm_flags & VM_SHARED) { |
| 924 | int err; |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 925 | struct inode *inode = mapping->host; |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 926 | |
| 927 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); |
| 928 | if (err) { |
| 929 | put_page(page); |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 930 | if (err == -EEXIST) |
| 931 | goto retry; |
| 932 | goto out; |
| 933 | } |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 934 | |
| 935 | spin_lock(&inode->i_lock); |
| 936 | inode->i_blocks += BLOCKS_PER_HUGEPAGE; |
| 937 | spin_unlock(&inode->i_lock); |
Christoph Lameter | 6bda666 | 2006-01-06 00:10:49 -0800 | [diff] [blame] | 938 | } else |
| 939 | lock_page(page); |
| 940 | } |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 941 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 942 | spin_lock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 943 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
| 944 | if (idx >= size) |
| 945 | goto backout; |
| 946 | |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 947 | ret = 0; |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 948 | if (!pte_none(*ptep)) |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 949 | goto backout; |
| 950 | |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 951 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
| 952 | && (vma->vm_flags & VM_SHARED))); |
| 953 | set_huge_pte_at(mm, address, ptep, new_pte); |
| 954 | |
| 955 | if (write_access && !(vma->vm_flags & VM_SHARED)) { |
| 956 | /* Optimization, do the COW without a second fault */ |
| 957 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); |
| 958 | } |
| 959 | |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 960 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 961 | unlock_page(page); |
| 962 | out: |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 963 | return ret; |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 964 | |
| 965 | backout: |
| 966 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 967 | unlock_page(page); |
| 968 | put_page(page); |
| 969 | goto out; |
Hugh Dickins | ac9b9c6 | 2005-10-20 16:24:28 +0100 | [diff] [blame] | 970 | } |
| 971 | |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 972 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
| 973 | unsigned long address, int write_access) |
| 974 | { |
| 975 | pte_t *ptep; |
| 976 | pte_t entry; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 977 | int ret; |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 978 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 979 | |
| 980 | ptep = huge_pte_alloc(mm, address); |
| 981 | if (!ptep) |
| 982 | return VM_FAULT_OOM; |
| 983 | |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 984 | /* |
| 985 | * Serialize hugepage allocation and instantiation, so that we don't |
| 986 | * get spurious allocation failures if two CPUs race to instantiate |
| 987 | * the same page in the page cache. |
| 988 | */ |
| 989 | mutex_lock(&hugetlb_instantiation_mutex); |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 990 | entry = *ptep; |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 991 | if (pte_none(entry)) { |
| 992 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); |
| 993 | mutex_unlock(&hugetlb_instantiation_mutex); |
| 994 | return ret; |
| 995 | } |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 996 | |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 997 | ret = 0; |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 998 | |
| 999 | spin_lock(&mm->page_table_lock); |
| 1000 | /* Check for a racing update before calling hugetlb_cow */ |
| 1001 | if (likely(pte_same(entry, *ptep))) |
| 1002 | if (write_access && !pte_write(entry)) |
| 1003 | ret = hugetlb_cow(mm, vma, address, ptep, entry); |
| 1004 | spin_unlock(&mm->page_table_lock); |
David Gibson | 3935baa | 2006-03-22 00:08:53 -0800 | [diff] [blame] | 1005 | mutex_unlock(&hugetlb_instantiation_mutex); |
David Gibson | 1e8f889 | 2006-01-06 00:10:44 -0800 | [diff] [blame] | 1006 | |
| 1007 | return ret; |
Adam Litke | 86e5216 | 2006-01-06 00:10:43 -0800 | [diff] [blame] | 1008 | } |
| 1009 | |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1010 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
| 1011 | struct page **pages, struct vm_area_struct **vmas, |
Adam Litke | 5b23dbe | 2007-11-14 16:59:33 -0800 | [diff] [blame] | 1012 | unsigned long *position, int *length, int i, |
| 1013 | int write) |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1014 | { |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1015 | unsigned long pfn_offset; |
| 1016 | unsigned long vaddr = *position; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1017 | int remainder = *length; |
| 1018 | |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 1019 | spin_lock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1020 | while (vaddr < vma->vm_end && remainder) { |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1021 | pte_t *pte; |
| 1022 | struct page *page; |
| 1023 | |
| 1024 | /* |
| 1025 | * Some archs (sparc64, sh*) have multiple pte_ts to |
| 1026 | * each hugepage. We have to make * sure we get the |
| 1027 | * first, for the page indexing below to work. |
| 1028 | */ |
| 1029 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); |
| 1030 | |
Adam Litke | 72fad71 | 2007-12-10 15:49:28 -0800 | [diff] [blame] | 1031 | if (!pte || pte_none(*pte) || (write && !pte_write(*pte))) { |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1032 | int ret; |
| 1033 | |
| 1034 | spin_unlock(&mm->page_table_lock); |
Adam Litke | 5b23dbe | 2007-11-14 16:59:33 -0800 | [diff] [blame] | 1035 | ret = hugetlb_fault(mm, vma, vaddr, write); |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1036 | spin_lock(&mm->page_table_lock); |
Adam Litke | a89182c | 2007-08-22 14:01:51 -0700 | [diff] [blame] | 1037 | if (!(ret & VM_FAULT_ERROR)) |
Adam Litke | 4c88726 | 2005-10-29 18:16:46 -0700 | [diff] [blame] | 1038 | continue; |
| 1039 | |
| 1040 | remainder = 0; |
| 1041 | if (!i) |
| 1042 | i = -EFAULT; |
| 1043 | break; |
| 1044 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1045 | |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1046 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
| 1047 | page = pte_page(*pte); |
| 1048 | same_page: |
Chen, Kenneth W | d669218 | 2006-03-31 02:29:57 -0800 | [diff] [blame] | 1049 | if (pages) { |
| 1050 | get_page(page); |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1051 | pages[i] = page + pfn_offset; |
Chen, Kenneth W | d669218 | 2006-03-31 02:29:57 -0800 | [diff] [blame] | 1052 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1053 | |
| 1054 | if (vmas) |
| 1055 | vmas[i] = vma; |
| 1056 | |
| 1057 | vaddr += PAGE_SIZE; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1058 | ++pfn_offset; |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1059 | --remainder; |
| 1060 | ++i; |
Chen, Kenneth W | d5d4b0a | 2006-03-22 00:09:03 -0800 | [diff] [blame] | 1061 | if (vaddr < vma->vm_end && remainder && |
| 1062 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { |
| 1063 | /* |
| 1064 | * We use pfn_offset to avoid touching the pageframes |
| 1065 | * of this compound page. |
| 1066 | */ |
| 1067 | goto same_page; |
| 1068 | } |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1069 | } |
Hugh Dickins | 1c59827 | 2005-10-19 21:23:43 -0700 | [diff] [blame] | 1070 | spin_unlock(&mm->page_table_lock); |
David Gibson | 63551ae | 2005-06-21 17:14:44 -0700 | [diff] [blame] | 1071 | *length = remainder; |
| 1072 | *position = vaddr; |
| 1073 | |
| 1074 | return i; |
| 1075 | } |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1076 | |
| 1077 | void hugetlb_change_protection(struct vm_area_struct *vma, |
| 1078 | unsigned long address, unsigned long end, pgprot_t newprot) |
| 1079 | { |
| 1080 | struct mm_struct *mm = vma->vm_mm; |
| 1081 | unsigned long start = address; |
| 1082 | pte_t *ptep; |
| 1083 | pte_t pte; |
| 1084 | |
| 1085 | BUG_ON(address >= end); |
| 1086 | flush_cache_range(vma, address, end); |
| 1087 | |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 1088 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1089 | spin_lock(&mm->page_table_lock); |
| 1090 | for (; address < end; address += HPAGE_SIZE) { |
| 1091 | ptep = huge_pte_offset(mm, address); |
| 1092 | if (!ptep) |
| 1093 | continue; |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 1094 | if (huge_pmd_unshare(mm, &address, ptep)) |
| 1095 | continue; |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1096 | if (!pte_none(*ptep)) { |
| 1097 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
| 1098 | pte = pte_mkhuge(pte_modify(pte, newprot)); |
| 1099 | set_huge_pte_at(mm, address, ptep, pte); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1100 | } |
| 1101 | } |
| 1102 | spin_unlock(&mm->page_table_lock); |
Chen, Kenneth W | 39dde65 | 2006-12-06 20:32:03 -0800 | [diff] [blame] | 1103 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
Zhang, Yanmin | 8f86059 | 2006-03-22 00:08:50 -0800 | [diff] [blame] | 1104 | |
| 1105 | flush_tlb_range(vma, start, end); |
| 1106 | } |
| 1107 | |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1108 | struct file_region { |
| 1109 | struct list_head link; |
| 1110 | long from; |
| 1111 | long to; |
| 1112 | }; |
| 1113 | |
| 1114 | static long region_add(struct list_head *head, long f, long t) |
| 1115 | { |
| 1116 | struct file_region *rg, *nrg, *trg; |
| 1117 | |
| 1118 | /* Locate the region we are either in or before. */ |
| 1119 | list_for_each_entry(rg, head, link) |
| 1120 | if (f <= rg->to) |
| 1121 | break; |
| 1122 | |
| 1123 | /* Round our left edge to the current segment if it encloses us. */ |
| 1124 | if (f > rg->from) |
| 1125 | f = rg->from; |
| 1126 | |
| 1127 | /* Check for and consume any regions we now overlap with. */ |
| 1128 | nrg = rg; |
| 1129 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
| 1130 | if (&rg->link == head) |
| 1131 | break; |
| 1132 | if (rg->from > t) |
| 1133 | break; |
| 1134 | |
| 1135 | /* If this area reaches higher then extend our area to |
| 1136 | * include it completely. If this is not the first area |
| 1137 | * which we intend to reuse, free it. */ |
| 1138 | if (rg->to > t) |
| 1139 | t = rg->to; |
| 1140 | if (rg != nrg) { |
| 1141 | list_del(&rg->link); |
| 1142 | kfree(rg); |
| 1143 | } |
| 1144 | } |
| 1145 | nrg->from = f; |
| 1146 | nrg->to = t; |
| 1147 | return 0; |
| 1148 | } |
| 1149 | |
| 1150 | static long region_chg(struct list_head *head, long f, long t) |
| 1151 | { |
| 1152 | struct file_region *rg, *nrg; |
| 1153 | long chg = 0; |
| 1154 | |
| 1155 | /* Locate the region we are before or in. */ |
| 1156 | list_for_each_entry(rg, head, link) |
| 1157 | if (f <= rg->to) |
| 1158 | break; |
| 1159 | |
| 1160 | /* If we are below the current region then a new region is required. |
| 1161 | * Subtle, allocate a new region at the position but make it zero |
Simon Arlott | 183ff22 | 2007-10-20 01:27:18 +0200 | [diff] [blame] | 1162 | * size such that we can guarantee to record the reservation. */ |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1163 | if (&rg->link == head || t < rg->from) { |
| 1164 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); |
Stephen Hemminger | c80544d | 2007-10-18 03:07:05 -0700 | [diff] [blame] | 1165 | if (!nrg) |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1166 | return -ENOMEM; |
| 1167 | nrg->from = f; |
| 1168 | nrg->to = f; |
| 1169 | INIT_LIST_HEAD(&nrg->link); |
| 1170 | list_add(&nrg->link, rg->link.prev); |
| 1171 | |
| 1172 | return t - f; |
| 1173 | } |
| 1174 | |
| 1175 | /* Round our left edge to the current segment if it encloses us. */ |
| 1176 | if (f > rg->from) |
| 1177 | f = rg->from; |
| 1178 | chg = t - f; |
| 1179 | |
| 1180 | /* Check for and consume any regions we now overlap with. */ |
| 1181 | list_for_each_entry(rg, rg->link.prev, link) { |
| 1182 | if (&rg->link == head) |
| 1183 | break; |
| 1184 | if (rg->from > t) |
| 1185 | return chg; |
| 1186 | |
| 1187 | /* We overlap with this area, if it extends futher than |
| 1188 | * us then we must extend ourselves. Account for its |
| 1189 | * existing reservation. */ |
| 1190 | if (rg->to > t) { |
| 1191 | chg += rg->to - t; |
| 1192 | t = rg->to; |
| 1193 | } |
| 1194 | chg -= rg->to - rg->from; |
| 1195 | } |
| 1196 | return chg; |
| 1197 | } |
| 1198 | |
| 1199 | static long region_truncate(struct list_head *head, long end) |
| 1200 | { |
| 1201 | struct file_region *rg, *trg; |
| 1202 | long chg = 0; |
| 1203 | |
| 1204 | /* Locate the region we are either in or before. */ |
| 1205 | list_for_each_entry(rg, head, link) |
| 1206 | if (end <= rg->to) |
| 1207 | break; |
| 1208 | if (&rg->link == head) |
| 1209 | return 0; |
| 1210 | |
| 1211 | /* If we are in the middle of a region then adjust it. */ |
| 1212 | if (end > rg->from) { |
| 1213 | chg = rg->to - end; |
| 1214 | rg->to = end; |
| 1215 | rg = list_entry(rg->link.next, typeof(*rg), link); |
| 1216 | } |
| 1217 | |
| 1218 | /* Drop any remaining regions. */ |
| 1219 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
| 1220 | if (&rg->link == head) |
| 1221 | break; |
| 1222 | chg += rg->to - rg->from; |
| 1223 | list_del(&rg->link); |
| 1224 | kfree(rg); |
| 1225 | } |
| 1226 | return chg; |
| 1227 | } |
| 1228 | |
| 1229 | static int hugetlb_acct_memory(long delta) |
| 1230 | { |
| 1231 | int ret = -ENOMEM; |
| 1232 | |
| 1233 | spin_lock(&hugetlb_lock); |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 1234 | /* |
| 1235 | * When cpuset is configured, it breaks the strict hugetlb page |
| 1236 | * reservation as the accounting is done on a global variable. Such |
| 1237 | * reservation is completely rubbish in the presence of cpuset because |
| 1238 | * the reservation is not checked against page availability for the |
| 1239 | * current cpuset. Application can still potentially OOM'ed by kernel |
| 1240 | * with lack of free htlb page in cpuset that the task is in. |
| 1241 | * Attempt to enforce strict accounting with cpuset is almost |
| 1242 | * impossible (or too ugly) because cpuset is too fluid that |
| 1243 | * task or memory node can be dynamically moved between cpusets. |
| 1244 | * |
| 1245 | * The change of semantics for shared hugetlb mapping with cpuset is |
| 1246 | * undesirable. However, in order to preserve some of the semantics, |
| 1247 | * we fall back to check against current free page availability as |
| 1248 | * a best attempt and hopefully to minimize the impact of changing |
| 1249 | * semantics that cpuset has. |
| 1250 | */ |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 1251 | if (delta > 0) { |
| 1252 | if (gather_surplus_pages(delta) < 0) |
| 1253 | goto out; |
| 1254 | |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 1255 | if (delta > cpuset_mems_nr(free_huge_pages_node)) { |
| 1256 | return_unused_surplus_pages(delta); |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 1257 | goto out; |
Adam Litke | ac09b3a | 2008-03-04 14:29:38 -0800 | [diff] [blame] | 1258 | } |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 1259 | } |
| 1260 | |
| 1261 | ret = 0; |
Adam Litke | e4e574b | 2007-10-16 01:26:19 -0700 | [diff] [blame] | 1262 | if (delta < 0) |
| 1263 | return_unused_surplus_pages((unsigned long) -delta); |
| 1264 | |
| 1265 | out: |
| 1266 | spin_unlock(&hugetlb_lock); |
| 1267 | return ret; |
| 1268 | } |
| 1269 | |
| 1270 | int hugetlb_reserve_pages(struct inode *inode, long from, long to) |
| 1271 | { |
| 1272 | long ret, chg; |
| 1273 | |
| 1274 | chg = region_chg(&inode->i_mapping->private_list, from, to); |
| 1275 | if (chg < 0) |
| 1276 | return chg; |
Ken Chen | 8a63011 | 2007-05-09 02:33:34 -0700 | [diff] [blame] | 1277 | |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 1278 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
| 1279 | return -ENOSPC; |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1280 | ret = hugetlb_acct_memory(chg); |
Ken Chen | 68842c9 | 2008-01-14 00:55:19 -0800 | [diff] [blame] | 1281 | if (ret < 0) { |
| 1282 | hugetlb_put_quota(inode->i_mapping, chg); |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1283 | return ret; |
Ken Chen | 68842c9 | 2008-01-14 00:55:19 -0800 | [diff] [blame] | 1284 | } |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1285 | region_add(&inode->i_mapping->private_list, from, to); |
| 1286 | return 0; |
| 1287 | } |
| 1288 | |
| 1289 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) |
| 1290 | { |
| 1291 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
Ken Chen | 45c682a | 2007-11-14 16:59:44 -0800 | [diff] [blame] | 1292 | |
| 1293 | spin_lock(&inode->i_lock); |
| 1294 | inode->i_blocks -= BLOCKS_PER_HUGEPAGE * freed; |
| 1295 | spin_unlock(&inode->i_lock); |
| 1296 | |
Adam Litke | 90d8b7e | 2007-11-14 16:59:42 -0800 | [diff] [blame] | 1297 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
| 1298 | hugetlb_acct_memory(-(chg - freed)); |
Chen, Kenneth W | a43a8c3 | 2006-06-23 02:03:15 -0700 | [diff] [blame] | 1299 | } |