Commit | Line | Data |
---|---|---|
1da177e4 LT |
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> | |
1da177e4 LT |
10 | #include <linux/sysctl.h> |
11 | #include <linux/highmem.h> | |
12 | #include <linux/nodemask.h> | |
63551ae0 | 13 | #include <linux/pagemap.h> |
5da7ca86 | 14 | #include <linux/mempolicy.h> |
aea47ff3 | 15 | #include <linux/cpuset.h> |
3935baa9 | 16 | #include <linux/mutex.h> |
5da7ca86 | 17 | |
63551ae0 DG |
18 | #include <asm/page.h> |
19 | #include <asm/pgtable.h> | |
20 | ||
21 | #include <linux/hugetlb.h> | |
7835e98b | 22 | #include "internal.h" |
1da177e4 LT |
23 | |
24 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; | |
a43a8c39 | 25 | static unsigned long nr_huge_pages, free_huge_pages, resv_huge_pages; |
7893d1d5 | 26 | static unsigned long surplus_huge_pages; |
064d9efe | 27 | static unsigned long nr_overcommit_huge_pages; |
1da177e4 | 28 | unsigned long max_huge_pages; |
064d9efe | 29 | unsigned long sysctl_overcommit_huge_pages; |
1da177e4 LT |
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]; | |
7893d1d5 | 33 | static unsigned int surplus_huge_pages_node[MAX_NUMNODES]; |
396faf03 MG |
34 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
35 | unsigned long hugepages_treat_as_movable; | |
63b4613c | 36 | static int hugetlb_next_nid; |
396faf03 | 37 | |
3935baa9 DG |
38 | /* |
39 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages | |
40 | */ | |
41 | static DEFINE_SPINLOCK(hugetlb_lock); | |
0bd0f9fb | 42 | |
79ac6ba4 DG |
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(); | |
281e0e3b | 50 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
79ac6ba4 DG |
51 | } |
52 | } | |
53 | ||
54 | static void copy_huge_page(struct page *dst, struct page *src, | |
9de455b2 | 55 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
56 | { |
57 | int i; | |
58 | ||
59 | might_sleep(); | |
60 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { | |
61 | cond_resched(); | |
9de455b2 | 62 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
63 | } |
64 | } | |
65 | ||
1da177e4 LT |
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 | ||
348e1e04 NA |
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, | |
5da7ca86 | 93 | unsigned long address) |
1da177e4 | 94 | { |
31a5c6e4 | 95 | int nid; |
1da177e4 | 96 | struct page *page = NULL; |
480eccf9 | 97 | struct mempolicy *mpol; |
396faf03 | 98 | struct zonelist *zonelist = huge_zonelist(vma, address, |
480eccf9 | 99 | htlb_alloc_mask, &mpol); |
96df9333 | 100 | struct zone **z; |
1da177e4 | 101 | |
96df9333 | 102 | for (z = zonelist->zones; *z; z++) { |
89fa3024 | 103 | nid = zone_to_nid(*z); |
396faf03 | 104 | if (cpuset_zone_allowed_softwall(*z, htlb_alloc_mask) && |
3abf7afd AM |
105 | !list_empty(&hugepage_freelists[nid])) { |
106 | page = list_entry(hugepage_freelists[nid].next, | |
107 | struct page, lru); | |
108 | list_del(&page->lru); | |
109 | free_huge_pages--; | |
110 | free_huge_pages_node[nid]--; | |
e4e574b7 AL |
111 | if (vma && vma->vm_flags & VM_MAYSHARE) |
112 | resv_huge_pages--; | |
5ab3ee7b | 113 | break; |
3abf7afd | 114 | } |
1da177e4 | 115 | } |
480eccf9 | 116 | mpol_free(mpol); /* unref if mpol !NULL */ |
1da177e4 LT |
117 | return page; |
118 | } | |
119 | ||
6af2acb6 AL |
120 | static void update_and_free_page(struct page *page) |
121 | { | |
122 | int i; | |
123 | nr_huge_pages--; | |
124 | nr_huge_pages_node[page_to_nid(page)]--; | |
125 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { | |
126 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | | |
127 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
128 | 1 << PG_private | 1<< PG_writeback); | |
129 | } | |
130 | set_compound_page_dtor(page, NULL); | |
131 | set_page_refcounted(page); | |
132 | __free_pages(page, HUGETLB_PAGE_ORDER); | |
133 | } | |
134 | ||
27a85ef1 DG |
135 | static void free_huge_page(struct page *page) |
136 | { | |
7893d1d5 | 137 | int nid = page_to_nid(page); |
c79fb75e | 138 | struct address_space *mapping; |
27a85ef1 | 139 | |
c79fb75e | 140 | mapping = (struct address_space *) page_private(page); |
e5df70ab | 141 | set_page_private(page, 0); |
7893d1d5 | 142 | BUG_ON(page_count(page)); |
27a85ef1 DG |
143 | INIT_LIST_HEAD(&page->lru); |
144 | ||
145 | spin_lock(&hugetlb_lock); | |
7893d1d5 AL |
146 | if (surplus_huge_pages_node[nid]) { |
147 | update_and_free_page(page); | |
148 | surplus_huge_pages--; | |
149 | surplus_huge_pages_node[nid]--; | |
150 | } else { | |
151 | enqueue_huge_page(page); | |
152 | } | |
27a85ef1 | 153 | spin_unlock(&hugetlb_lock); |
c79fb75e | 154 | if (mapping) |
9a119c05 | 155 | hugetlb_put_quota(mapping, 1); |
27a85ef1 DG |
156 | } |
157 | ||
7893d1d5 AL |
158 | /* |
159 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
160 | * balanced by operating on them in a round-robin fashion. | |
161 | * Returns 1 if an adjustment was made. | |
162 | */ | |
163 | static int adjust_pool_surplus(int delta) | |
164 | { | |
165 | static int prev_nid; | |
166 | int nid = prev_nid; | |
167 | int ret = 0; | |
168 | ||
169 | VM_BUG_ON(delta != -1 && delta != 1); | |
170 | do { | |
171 | nid = next_node(nid, node_online_map); | |
172 | if (nid == MAX_NUMNODES) | |
173 | nid = first_node(node_online_map); | |
174 | ||
175 | /* To shrink on this node, there must be a surplus page */ | |
176 | if (delta < 0 && !surplus_huge_pages_node[nid]) | |
177 | continue; | |
178 | /* Surplus cannot exceed the total number of pages */ | |
179 | if (delta > 0 && surplus_huge_pages_node[nid] >= | |
180 | nr_huge_pages_node[nid]) | |
181 | continue; | |
182 | ||
183 | surplus_huge_pages += delta; | |
184 | surplus_huge_pages_node[nid] += delta; | |
185 | ret = 1; | |
186 | break; | |
187 | } while (nid != prev_nid); | |
188 | ||
189 | prev_nid = nid; | |
190 | return ret; | |
191 | } | |
192 | ||
63b4613c | 193 | static struct page *alloc_fresh_huge_page_node(int nid) |
1da177e4 | 194 | { |
1da177e4 | 195 | struct page *page; |
f96efd58 | 196 | |
63b4613c NA |
197 | page = alloc_pages_node(nid, |
198 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|__GFP_NOWARN, | |
199 | HUGETLB_PAGE_ORDER); | |
1da177e4 | 200 | if (page) { |
33f2ef89 | 201 | set_compound_page_dtor(page, free_huge_page); |
0bd0f9fb | 202 | spin_lock(&hugetlb_lock); |
1da177e4 | 203 | nr_huge_pages++; |
63b4613c | 204 | nr_huge_pages_node[nid]++; |
0bd0f9fb | 205 | spin_unlock(&hugetlb_lock); |
a482289d | 206 | put_page(page); /* free it into the hugepage allocator */ |
1da177e4 | 207 | } |
63b4613c NA |
208 | |
209 | return page; | |
210 | } | |
211 | ||
212 | static int alloc_fresh_huge_page(void) | |
213 | { | |
214 | struct page *page; | |
215 | int start_nid; | |
216 | int next_nid; | |
217 | int ret = 0; | |
218 | ||
219 | start_nid = hugetlb_next_nid; | |
220 | ||
221 | do { | |
222 | page = alloc_fresh_huge_page_node(hugetlb_next_nid); | |
223 | if (page) | |
224 | ret = 1; | |
225 | /* | |
226 | * Use a helper variable to find the next node and then | |
227 | * copy it back to hugetlb_next_nid afterwards: | |
228 | * otherwise there's a window in which a racer might | |
229 | * pass invalid nid MAX_NUMNODES to alloc_pages_node. | |
230 | * But we don't need to use a spin_lock here: it really | |
231 | * doesn't matter if occasionally a racer chooses the | |
232 | * same nid as we do. Move nid forward in the mask even | |
233 | * if we just successfully allocated a hugepage so that | |
234 | * the next caller gets hugepages on the next node. | |
235 | */ | |
236 | next_nid = next_node(hugetlb_next_nid, node_online_map); | |
237 | if (next_nid == MAX_NUMNODES) | |
238 | next_nid = first_node(node_online_map); | |
239 | hugetlb_next_nid = next_nid; | |
240 | } while (!page && hugetlb_next_nid != start_nid); | |
241 | ||
242 | return ret; | |
1da177e4 LT |
243 | } |
244 | ||
7893d1d5 AL |
245 | static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma, |
246 | unsigned long address) | |
247 | { | |
248 | struct page *page; | |
d1c3fb1f | 249 | unsigned int nid; |
7893d1d5 | 250 | |
d1c3fb1f NA |
251 | /* |
252 | * Assume we will successfully allocate the surplus page to | |
253 | * prevent racing processes from causing the surplus to exceed | |
254 | * overcommit | |
255 | * | |
256 | * This however introduces a different race, where a process B | |
257 | * tries to grow the static hugepage pool while alloc_pages() is | |
258 | * called by process A. B will only examine the per-node | |
259 | * counters in determining if surplus huge pages can be | |
260 | * converted to normal huge pages in adjust_pool_surplus(). A | |
261 | * won't be able to increment the per-node counter, until the | |
262 | * lock is dropped by B, but B doesn't drop hugetlb_lock until | |
263 | * no more huge pages can be converted from surplus to normal | |
264 | * state (and doesn't try to convert again). Thus, we have a | |
265 | * case where a surplus huge page exists, the pool is grown, and | |
266 | * the surplus huge page still exists after, even though it | |
267 | * should just have been converted to a normal huge page. This | |
268 | * does not leak memory, though, as the hugepage will be freed | |
269 | * once it is out of use. It also does not allow the counters to | |
270 | * go out of whack in adjust_pool_surplus() as we don't modify | |
271 | * the node values until we've gotten the hugepage and only the | |
272 | * per-node value is checked there. | |
273 | */ | |
274 | spin_lock(&hugetlb_lock); | |
275 | if (surplus_huge_pages >= nr_overcommit_huge_pages) { | |
276 | spin_unlock(&hugetlb_lock); | |
277 | return NULL; | |
278 | } else { | |
279 | nr_huge_pages++; | |
280 | surplus_huge_pages++; | |
281 | } | |
282 | spin_unlock(&hugetlb_lock); | |
283 | ||
7893d1d5 AL |
284 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN, |
285 | HUGETLB_PAGE_ORDER); | |
d1c3fb1f NA |
286 | |
287 | spin_lock(&hugetlb_lock); | |
7893d1d5 | 288 | if (page) { |
2668db91 AL |
289 | /* |
290 | * This page is now managed by the hugetlb allocator and has | |
291 | * no users -- drop the buddy allocator's reference. | |
292 | */ | |
293 | put_page_testzero(page); | |
294 | VM_BUG_ON(page_count(page)); | |
d1c3fb1f | 295 | nid = page_to_nid(page); |
7893d1d5 | 296 | set_compound_page_dtor(page, free_huge_page); |
d1c3fb1f NA |
297 | /* |
298 | * We incremented the global counters already | |
299 | */ | |
300 | nr_huge_pages_node[nid]++; | |
301 | surplus_huge_pages_node[nid]++; | |
302 | } else { | |
303 | nr_huge_pages--; | |
304 | surplus_huge_pages--; | |
7893d1d5 | 305 | } |
d1c3fb1f | 306 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
307 | |
308 | return page; | |
309 | } | |
310 | ||
e4e574b7 AL |
311 | /* |
312 | * Increase the hugetlb pool such that it can accomodate a reservation | |
313 | * of size 'delta'. | |
314 | */ | |
315 | static int gather_surplus_pages(int delta) | |
316 | { | |
317 | struct list_head surplus_list; | |
318 | struct page *page, *tmp; | |
319 | int ret, i; | |
320 | int needed, allocated; | |
321 | ||
322 | needed = (resv_huge_pages + delta) - free_huge_pages; | |
ac09b3a1 AL |
323 | if (needed <= 0) { |
324 | resv_huge_pages += delta; | |
e4e574b7 | 325 | return 0; |
ac09b3a1 | 326 | } |
e4e574b7 AL |
327 | |
328 | allocated = 0; | |
329 | INIT_LIST_HEAD(&surplus_list); | |
330 | ||
331 | ret = -ENOMEM; | |
332 | retry: | |
333 | spin_unlock(&hugetlb_lock); | |
334 | for (i = 0; i < needed; i++) { | |
335 | page = alloc_buddy_huge_page(NULL, 0); | |
336 | if (!page) { | |
337 | /* | |
338 | * We were not able to allocate enough pages to | |
339 | * satisfy the entire reservation so we free what | |
340 | * we've allocated so far. | |
341 | */ | |
342 | spin_lock(&hugetlb_lock); | |
343 | needed = 0; | |
344 | goto free; | |
345 | } | |
346 | ||
347 | list_add(&page->lru, &surplus_list); | |
348 | } | |
349 | allocated += needed; | |
350 | ||
351 | /* | |
352 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
353 | * because either resv_huge_pages or free_huge_pages may have changed. | |
354 | */ | |
355 | spin_lock(&hugetlb_lock); | |
356 | needed = (resv_huge_pages + delta) - (free_huge_pages + allocated); | |
357 | if (needed > 0) | |
358 | goto retry; | |
359 | ||
360 | /* | |
361 | * The surplus_list now contains _at_least_ the number of extra pages | |
362 | * needed to accomodate the reservation. Add the appropriate number | |
363 | * of pages to the hugetlb pool and free the extras back to the buddy | |
ac09b3a1 AL |
364 | * allocator. Commit the entire reservation here to prevent another |
365 | * process from stealing the pages as they are added to the pool but | |
366 | * before they are reserved. | |
e4e574b7 AL |
367 | */ |
368 | needed += allocated; | |
ac09b3a1 | 369 | resv_huge_pages += delta; |
e4e574b7 AL |
370 | ret = 0; |
371 | free: | |
372 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { | |
373 | list_del(&page->lru); | |
374 | if ((--needed) >= 0) | |
375 | enqueue_huge_page(page); | |
af767cbd AL |
376 | else { |
377 | /* | |
2668db91 AL |
378 | * The page has a reference count of zero already, so |
379 | * call free_huge_page directly instead of using | |
380 | * put_page. This must be done with hugetlb_lock | |
af767cbd AL |
381 | * unlocked which is safe because free_huge_page takes |
382 | * hugetlb_lock before deciding how to free the page. | |
383 | */ | |
384 | spin_unlock(&hugetlb_lock); | |
2668db91 | 385 | free_huge_page(page); |
af767cbd AL |
386 | spin_lock(&hugetlb_lock); |
387 | } | |
e4e574b7 AL |
388 | } |
389 | ||
390 | return ret; | |
391 | } | |
392 | ||
393 | /* | |
394 | * When releasing a hugetlb pool reservation, any surplus pages that were | |
395 | * allocated to satisfy the reservation must be explicitly freed if they were | |
396 | * never used. | |
397 | */ | |
8cde045c | 398 | static void return_unused_surplus_pages(unsigned long unused_resv_pages) |
e4e574b7 AL |
399 | { |
400 | static int nid = -1; | |
401 | struct page *page; | |
402 | unsigned long nr_pages; | |
403 | ||
11320d17 NA |
404 | /* |
405 | * We want to release as many surplus pages as possible, spread | |
406 | * evenly across all nodes. Iterate across all nodes until we | |
407 | * can no longer free unreserved surplus pages. This occurs when | |
408 | * the nodes with surplus pages have no free pages. | |
409 | */ | |
410 | unsigned long remaining_iterations = num_online_nodes(); | |
411 | ||
ac09b3a1 AL |
412 | /* Uncommit the reservation */ |
413 | resv_huge_pages -= unused_resv_pages; | |
414 | ||
e4e574b7 AL |
415 | nr_pages = min(unused_resv_pages, surplus_huge_pages); |
416 | ||
11320d17 | 417 | while (remaining_iterations-- && nr_pages) { |
e4e574b7 AL |
418 | nid = next_node(nid, node_online_map); |
419 | if (nid == MAX_NUMNODES) | |
420 | nid = first_node(node_online_map); | |
421 | ||
422 | if (!surplus_huge_pages_node[nid]) | |
423 | continue; | |
424 | ||
425 | if (!list_empty(&hugepage_freelists[nid])) { | |
426 | page = list_entry(hugepage_freelists[nid].next, | |
427 | struct page, lru); | |
428 | list_del(&page->lru); | |
429 | update_and_free_page(page); | |
430 | free_huge_pages--; | |
431 | free_huge_pages_node[nid]--; | |
432 | surplus_huge_pages--; | |
433 | surplus_huge_pages_node[nid]--; | |
434 | nr_pages--; | |
11320d17 | 435 | remaining_iterations = num_online_nodes(); |
e4e574b7 AL |
436 | } |
437 | } | |
438 | } | |
439 | ||
348ea204 AL |
440 | |
441 | static struct page *alloc_huge_page_shared(struct vm_area_struct *vma, | |
442 | unsigned long addr) | |
1da177e4 | 443 | { |
348ea204 | 444 | struct page *page; |
1da177e4 LT |
445 | |
446 | spin_lock(&hugetlb_lock); | |
348e1e04 | 447 | page = dequeue_huge_page_vma(vma, addr); |
1da177e4 | 448 | spin_unlock(&hugetlb_lock); |
90d8b7e6 | 449 | return page ? page : ERR_PTR(-VM_FAULT_OOM); |
348ea204 | 450 | } |
b45b5bd6 | 451 | |
348ea204 AL |
452 | static struct page *alloc_huge_page_private(struct vm_area_struct *vma, |
453 | unsigned long addr) | |
454 | { | |
455 | struct page *page = NULL; | |
7893d1d5 | 456 | |
90d8b7e6 AL |
457 | if (hugetlb_get_quota(vma->vm_file->f_mapping, 1)) |
458 | return ERR_PTR(-VM_FAULT_SIGBUS); | |
459 | ||
348ea204 AL |
460 | spin_lock(&hugetlb_lock); |
461 | if (free_huge_pages > resv_huge_pages) | |
348e1e04 | 462 | page = dequeue_huge_page_vma(vma, addr); |
348ea204 | 463 | spin_unlock(&hugetlb_lock); |
68842c9b | 464 | if (!page) { |
7893d1d5 | 465 | page = alloc_buddy_huge_page(vma, addr); |
68842c9b KC |
466 | if (!page) { |
467 | hugetlb_put_quota(vma->vm_file->f_mapping, 1); | |
468 | return ERR_PTR(-VM_FAULT_OOM); | |
469 | } | |
470 | } | |
471 | return page; | |
348ea204 AL |
472 | } |
473 | ||
474 | static struct page *alloc_huge_page(struct vm_area_struct *vma, | |
475 | unsigned long addr) | |
476 | { | |
477 | struct page *page; | |
2fc39cec AL |
478 | struct address_space *mapping = vma->vm_file->f_mapping; |
479 | ||
348ea204 AL |
480 | if (vma->vm_flags & VM_MAYSHARE) |
481 | page = alloc_huge_page_shared(vma, addr); | |
482 | else | |
483 | page = alloc_huge_page_private(vma, addr); | |
90d8b7e6 AL |
484 | |
485 | if (!IS_ERR(page)) { | |
348ea204 | 486 | set_page_refcounted(page); |
2fc39cec | 487 | set_page_private(page, (unsigned long) mapping); |
90d8b7e6 AL |
488 | } |
489 | return page; | |
b45b5bd6 DG |
490 | } |
491 | ||
1da177e4 LT |
492 | static int __init hugetlb_init(void) |
493 | { | |
494 | unsigned long i; | |
1da177e4 | 495 | |
3c726f8d BH |
496 | if (HPAGE_SHIFT == 0) |
497 | return 0; | |
498 | ||
1da177e4 LT |
499 | for (i = 0; i < MAX_NUMNODES; ++i) |
500 | INIT_LIST_HEAD(&hugepage_freelists[i]); | |
501 | ||
63b4613c NA |
502 | hugetlb_next_nid = first_node(node_online_map); |
503 | ||
1da177e4 | 504 | for (i = 0; i < max_huge_pages; ++i) { |
a482289d | 505 | if (!alloc_fresh_huge_page()) |
1da177e4 | 506 | break; |
1da177e4 LT |
507 | } |
508 | max_huge_pages = free_huge_pages = nr_huge_pages = i; | |
509 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); | |
510 | return 0; | |
511 | } | |
512 | module_init(hugetlb_init); | |
513 | ||
514 | static int __init hugetlb_setup(char *s) | |
515 | { | |
516 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) | |
517 | max_huge_pages = 0; | |
518 | return 1; | |
519 | } | |
520 | __setup("hugepages=", hugetlb_setup); | |
521 | ||
8a630112 KC |
522 | static unsigned int cpuset_mems_nr(unsigned int *array) |
523 | { | |
524 | int node; | |
525 | unsigned int nr = 0; | |
526 | ||
527 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
528 | nr += array[node]; | |
529 | ||
530 | return nr; | |
531 | } | |
532 | ||
1da177e4 | 533 | #ifdef CONFIG_SYSCTL |
1da177e4 LT |
534 | #ifdef CONFIG_HIGHMEM |
535 | static void try_to_free_low(unsigned long count) | |
536 | { | |
4415cc8d CL |
537 | int i; |
538 | ||
1da177e4 LT |
539 | for (i = 0; i < MAX_NUMNODES; ++i) { |
540 | struct page *page, *next; | |
541 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { | |
6b0c880d AL |
542 | if (count >= nr_huge_pages) |
543 | return; | |
1da177e4 LT |
544 | if (PageHighMem(page)) |
545 | continue; | |
546 | list_del(&page->lru); | |
547 | update_and_free_page(page); | |
1da177e4 | 548 | free_huge_pages--; |
4415cc8d | 549 | free_huge_pages_node[page_to_nid(page)]--; |
1da177e4 LT |
550 | } |
551 | } | |
552 | } | |
553 | #else | |
554 | static inline void try_to_free_low(unsigned long count) | |
555 | { | |
556 | } | |
557 | #endif | |
558 | ||
7893d1d5 | 559 | #define persistent_huge_pages (nr_huge_pages - surplus_huge_pages) |
1da177e4 LT |
560 | static unsigned long set_max_huge_pages(unsigned long count) |
561 | { | |
7893d1d5 | 562 | unsigned long min_count, ret; |
1da177e4 | 563 | |
7893d1d5 AL |
564 | /* |
565 | * Increase the pool size | |
566 | * First take pages out of surplus state. Then make up the | |
567 | * remaining difference by allocating fresh huge pages. | |
d1c3fb1f NA |
568 | * |
569 | * We might race with alloc_buddy_huge_page() here and be unable | |
570 | * to convert a surplus huge page to a normal huge page. That is | |
571 | * not critical, though, it just means the overall size of the | |
572 | * pool might be one hugepage larger than it needs to be, but | |
573 | * within all the constraints specified by the sysctls. | |
7893d1d5 | 574 | */ |
1da177e4 | 575 | spin_lock(&hugetlb_lock); |
7893d1d5 AL |
576 | while (surplus_huge_pages && count > persistent_huge_pages) { |
577 | if (!adjust_pool_surplus(-1)) | |
578 | break; | |
579 | } | |
580 | ||
581 | while (count > persistent_huge_pages) { | |
582 | int ret; | |
583 | /* | |
584 | * If this allocation races such that we no longer need the | |
585 | * page, free_huge_page will handle it by freeing the page | |
586 | * and reducing the surplus. | |
587 | */ | |
588 | spin_unlock(&hugetlb_lock); | |
589 | ret = alloc_fresh_huge_page(); | |
590 | spin_lock(&hugetlb_lock); | |
591 | if (!ret) | |
592 | goto out; | |
593 | ||
594 | } | |
7893d1d5 AL |
595 | |
596 | /* | |
597 | * Decrease the pool size | |
598 | * First return free pages to the buddy allocator (being careful | |
599 | * to keep enough around to satisfy reservations). Then place | |
600 | * pages into surplus state as needed so the pool will shrink | |
601 | * to the desired size as pages become free. | |
d1c3fb1f NA |
602 | * |
603 | * By placing pages into the surplus state independent of the | |
604 | * overcommit value, we are allowing the surplus pool size to | |
605 | * exceed overcommit. There are few sane options here. Since | |
606 | * alloc_buddy_huge_page() is checking the global counter, | |
607 | * though, we'll note that we're not allowed to exceed surplus | |
608 | * and won't grow the pool anywhere else. Not until one of the | |
609 | * sysctls are changed, or the surplus pages go out of use. | |
7893d1d5 | 610 | */ |
6b0c880d AL |
611 | min_count = resv_huge_pages + nr_huge_pages - free_huge_pages; |
612 | min_count = max(count, min_count); | |
7893d1d5 AL |
613 | try_to_free_low(min_count); |
614 | while (min_count < persistent_huge_pages) { | |
348e1e04 | 615 | struct page *page = dequeue_huge_page(); |
1da177e4 LT |
616 | if (!page) |
617 | break; | |
618 | update_and_free_page(page); | |
619 | } | |
7893d1d5 AL |
620 | while (count < persistent_huge_pages) { |
621 | if (!adjust_pool_surplus(1)) | |
622 | break; | |
623 | } | |
624 | out: | |
625 | ret = persistent_huge_pages; | |
1da177e4 | 626 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 627 | return ret; |
1da177e4 LT |
628 | } |
629 | ||
630 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, | |
631 | struct file *file, void __user *buffer, | |
632 | size_t *length, loff_t *ppos) | |
633 | { | |
634 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); | |
635 | max_huge_pages = set_max_huge_pages(max_huge_pages); | |
636 | return 0; | |
637 | } | |
396faf03 MG |
638 | |
639 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, | |
640 | struct file *file, void __user *buffer, | |
641 | size_t *length, loff_t *ppos) | |
642 | { | |
643 | proc_dointvec(table, write, file, buffer, length, ppos); | |
644 | if (hugepages_treat_as_movable) | |
645 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; | |
646 | else | |
647 | htlb_alloc_mask = GFP_HIGHUSER; | |
648 | return 0; | |
649 | } | |
650 | ||
a3d0c6aa NA |
651 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
652 | struct file *file, void __user *buffer, | |
653 | size_t *length, loff_t *ppos) | |
654 | { | |
a3d0c6aa | 655 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
064d9efe NA |
656 | spin_lock(&hugetlb_lock); |
657 | nr_overcommit_huge_pages = sysctl_overcommit_huge_pages; | |
a3d0c6aa NA |
658 | spin_unlock(&hugetlb_lock); |
659 | return 0; | |
660 | } | |
661 | ||
1da177e4 LT |
662 | #endif /* CONFIG_SYSCTL */ |
663 | ||
664 | int hugetlb_report_meminfo(char *buf) | |
665 | { | |
666 | return sprintf(buf, | |
667 | "HugePages_Total: %5lu\n" | |
668 | "HugePages_Free: %5lu\n" | |
a43a8c39 | 669 | "HugePages_Rsvd: %5lu\n" |
7893d1d5 | 670 | "HugePages_Surp: %5lu\n" |
1da177e4 LT |
671 | "Hugepagesize: %5lu kB\n", |
672 | nr_huge_pages, | |
673 | free_huge_pages, | |
a43a8c39 | 674 | resv_huge_pages, |
7893d1d5 | 675 | surplus_huge_pages, |
1da177e4 LT |
676 | HPAGE_SIZE/1024); |
677 | } | |
678 | ||
679 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
680 | { | |
681 | return sprintf(buf, | |
682 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
683 | "Node %d HugePages_Free: %5u\n" |
684 | "Node %d HugePages_Surp: %5u\n", | |
1da177e4 | 685 | nid, nr_huge_pages_node[nid], |
a1de0919 NA |
686 | nid, free_huge_pages_node[nid], |
687 | nid, surplus_huge_pages_node[nid]); | |
1da177e4 LT |
688 | } |
689 | ||
1da177e4 LT |
690 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
691 | unsigned long hugetlb_total_pages(void) | |
692 | { | |
693 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); | |
694 | } | |
1da177e4 LT |
695 | |
696 | /* | |
697 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
698 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
699 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
700 | * this far. | |
701 | */ | |
d0217ac0 | 702 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
703 | { |
704 | BUG(); | |
d0217ac0 | 705 | return 0; |
1da177e4 LT |
706 | } |
707 | ||
708 | struct vm_operations_struct hugetlb_vm_ops = { | |
d0217ac0 | 709 | .fault = hugetlb_vm_op_fault, |
1da177e4 LT |
710 | }; |
711 | ||
1e8f889b DG |
712 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
713 | int writable) | |
63551ae0 DG |
714 | { |
715 | pte_t entry; | |
716 | ||
1e8f889b | 717 | if (writable) { |
63551ae0 DG |
718 | entry = |
719 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
720 | } else { | |
721 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); | |
722 | } | |
723 | entry = pte_mkyoung(entry); | |
724 | entry = pte_mkhuge(entry); | |
725 | ||
726 | return entry; | |
727 | } | |
728 | ||
1e8f889b DG |
729 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
730 | unsigned long address, pte_t *ptep) | |
731 | { | |
732 | pte_t entry; | |
733 | ||
734 | entry = pte_mkwrite(pte_mkdirty(*ptep)); | |
8dab5241 BH |
735 | if (ptep_set_access_flags(vma, address, ptep, entry, 1)) { |
736 | update_mmu_cache(vma, address, entry); | |
8dab5241 | 737 | } |
1e8f889b DG |
738 | } |
739 | ||
740 | ||
63551ae0 DG |
741 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
742 | struct vm_area_struct *vma) | |
743 | { | |
744 | pte_t *src_pte, *dst_pte, entry; | |
745 | struct page *ptepage; | |
1c59827d | 746 | unsigned long addr; |
1e8f889b DG |
747 | int cow; |
748 | ||
749 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 750 | |
1c59827d | 751 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
c74df32c HD |
752 | src_pte = huge_pte_offset(src, addr); |
753 | if (!src_pte) | |
754 | continue; | |
63551ae0 DG |
755 | dst_pte = huge_pte_alloc(dst, addr); |
756 | if (!dst_pte) | |
757 | goto nomem; | |
c5c99429 LW |
758 | |
759 | /* If the pagetables are shared don't copy or take references */ | |
760 | if (dst_pte == src_pte) | |
761 | continue; | |
762 | ||
c74df32c | 763 | spin_lock(&dst->page_table_lock); |
1c59827d | 764 | spin_lock(&src->page_table_lock); |
c74df32c | 765 | if (!pte_none(*src_pte)) { |
1e8f889b DG |
766 | if (cow) |
767 | ptep_set_wrprotect(src, addr, src_pte); | |
1c59827d HD |
768 | entry = *src_pte; |
769 | ptepage = pte_page(entry); | |
770 | get_page(ptepage); | |
1c59827d HD |
771 | set_huge_pte_at(dst, addr, dst_pte, entry); |
772 | } | |
773 | spin_unlock(&src->page_table_lock); | |
c74df32c | 774 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
775 | } |
776 | return 0; | |
777 | ||
778 | nomem: | |
779 | return -ENOMEM; | |
780 | } | |
781 | ||
502717f4 CK |
782 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
783 | unsigned long end) | |
63551ae0 DG |
784 | { |
785 | struct mm_struct *mm = vma->vm_mm; | |
786 | unsigned long address; | |
c7546f8f | 787 | pte_t *ptep; |
63551ae0 DG |
788 | pte_t pte; |
789 | struct page *page; | |
fe1668ae | 790 | struct page *tmp; |
c0a499c2 CK |
791 | /* |
792 | * A page gathering list, protected by per file i_mmap_lock. The | |
793 | * lock is used to avoid list corruption from multiple unmapping | |
794 | * of the same page since we are using page->lru. | |
795 | */ | |
fe1668ae | 796 | LIST_HEAD(page_list); |
63551ae0 DG |
797 | |
798 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
799 | BUG_ON(start & ~HPAGE_MASK); | |
800 | BUG_ON(end & ~HPAGE_MASK); | |
801 | ||
508034a3 | 802 | spin_lock(&mm->page_table_lock); |
63551ae0 | 803 | for (address = start; address < end; address += HPAGE_SIZE) { |
c7546f8f | 804 | ptep = huge_pte_offset(mm, address); |
4c887265 | 805 | if (!ptep) |
c7546f8f DG |
806 | continue; |
807 | ||
39dde65c CK |
808 | if (huge_pmd_unshare(mm, &address, ptep)) |
809 | continue; | |
810 | ||
c7546f8f | 811 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
63551ae0 DG |
812 | if (pte_none(pte)) |
813 | continue; | |
c7546f8f | 814 | |
63551ae0 | 815 | page = pte_page(pte); |
6649a386 KC |
816 | if (pte_dirty(pte)) |
817 | set_page_dirty(page); | |
fe1668ae | 818 | list_add(&page->lru, &page_list); |
63551ae0 | 819 | } |
1da177e4 | 820 | spin_unlock(&mm->page_table_lock); |
508034a3 | 821 | flush_tlb_range(vma, start, end); |
fe1668ae CK |
822 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
823 | list_del(&page->lru); | |
824 | put_page(page); | |
825 | } | |
1da177e4 | 826 | } |
63551ae0 | 827 | |
502717f4 CK |
828 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
829 | unsigned long end) | |
830 | { | |
831 | /* | |
832 | * It is undesirable to test vma->vm_file as it should be non-null | |
833 | * for valid hugetlb area. However, vm_file will be NULL in the error | |
834 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, | |
835 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function | |
836 | * to clean up. Since no pte has actually been setup, it is safe to | |
837 | * do nothing in this case. | |
838 | */ | |
839 | if (vma->vm_file) { | |
840 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); | |
841 | __unmap_hugepage_range(vma, start, end); | |
842 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); | |
843 | } | |
844 | } | |
845 | ||
1e8f889b DG |
846 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
847 | unsigned long address, pte_t *ptep, pte_t pte) | |
848 | { | |
849 | struct page *old_page, *new_page; | |
79ac6ba4 | 850 | int avoidcopy; |
1e8f889b DG |
851 | |
852 | old_page = pte_page(pte); | |
853 | ||
854 | /* If no-one else is actually using this page, avoid the copy | |
855 | * and just make the page writable */ | |
856 | avoidcopy = (page_count(old_page) == 1); | |
857 | if (avoidcopy) { | |
858 | set_huge_ptep_writable(vma, address, ptep); | |
83c54070 | 859 | return 0; |
1e8f889b DG |
860 | } |
861 | ||
862 | page_cache_get(old_page); | |
5da7ca86 | 863 | new_page = alloc_huge_page(vma, address); |
1e8f889b | 864 | |
2fc39cec | 865 | if (IS_ERR(new_page)) { |
1e8f889b | 866 | page_cache_release(old_page); |
2fc39cec | 867 | return -PTR_ERR(new_page); |
1e8f889b DG |
868 | } |
869 | ||
870 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 871 | copy_huge_page(new_page, old_page, address, vma); |
0ed361de | 872 | __SetPageUptodate(new_page); |
1e8f889b DG |
873 | spin_lock(&mm->page_table_lock); |
874 | ||
875 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); | |
876 | if (likely(pte_same(*ptep, pte))) { | |
877 | /* Break COW */ | |
878 | set_huge_pte_at(mm, address, ptep, | |
879 | make_huge_pte(vma, new_page, 1)); | |
880 | /* Make the old page be freed below */ | |
881 | new_page = old_page; | |
882 | } | |
883 | page_cache_release(new_page); | |
884 | page_cache_release(old_page); | |
83c54070 | 885 | return 0; |
1e8f889b DG |
886 | } |
887 | ||
a1ed3dda | 888 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 889 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 HD |
890 | { |
891 | int ret = VM_FAULT_SIGBUS; | |
4c887265 AL |
892 | unsigned long idx; |
893 | unsigned long size; | |
4c887265 AL |
894 | struct page *page; |
895 | struct address_space *mapping; | |
1e8f889b | 896 | pte_t new_pte; |
4c887265 | 897 | |
4c887265 AL |
898 | mapping = vma->vm_file->f_mapping; |
899 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) | |
900 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
901 | ||
902 | /* | |
903 | * Use page lock to guard against racing truncation | |
904 | * before we get page_table_lock. | |
905 | */ | |
6bda666a CL |
906 | retry: |
907 | page = find_lock_page(mapping, idx); | |
908 | if (!page) { | |
ebed4bfc HD |
909 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
910 | if (idx >= size) | |
911 | goto out; | |
6bda666a | 912 | page = alloc_huge_page(vma, address); |
2fc39cec AL |
913 | if (IS_ERR(page)) { |
914 | ret = -PTR_ERR(page); | |
6bda666a CL |
915 | goto out; |
916 | } | |
79ac6ba4 | 917 | clear_huge_page(page, address); |
0ed361de | 918 | __SetPageUptodate(page); |
ac9b9c66 | 919 | |
6bda666a CL |
920 | if (vma->vm_flags & VM_SHARED) { |
921 | int err; | |
45c682a6 | 922 | struct inode *inode = mapping->host; |
6bda666a CL |
923 | |
924 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
925 | if (err) { | |
926 | put_page(page); | |
6bda666a CL |
927 | if (err == -EEXIST) |
928 | goto retry; | |
929 | goto out; | |
930 | } | |
45c682a6 KC |
931 | |
932 | spin_lock(&inode->i_lock); | |
933 | inode->i_blocks += BLOCKS_PER_HUGEPAGE; | |
934 | spin_unlock(&inode->i_lock); | |
6bda666a CL |
935 | } else |
936 | lock_page(page); | |
937 | } | |
1e8f889b | 938 | |
ac9b9c66 | 939 | spin_lock(&mm->page_table_lock); |
4c887265 AL |
940 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
941 | if (idx >= size) | |
942 | goto backout; | |
943 | ||
83c54070 | 944 | ret = 0; |
86e5216f | 945 | if (!pte_none(*ptep)) |
4c887265 AL |
946 | goto backout; |
947 | ||
1e8f889b DG |
948 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
949 | && (vma->vm_flags & VM_SHARED))); | |
950 | set_huge_pte_at(mm, address, ptep, new_pte); | |
951 | ||
952 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
953 | /* Optimization, do the COW without a second fault */ | |
954 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); | |
955 | } | |
956 | ||
ac9b9c66 | 957 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
958 | unlock_page(page); |
959 | out: | |
ac9b9c66 | 960 | return ret; |
4c887265 AL |
961 | |
962 | backout: | |
963 | spin_unlock(&mm->page_table_lock); | |
4c887265 AL |
964 | unlock_page(page); |
965 | put_page(page); | |
966 | goto out; | |
ac9b9c66 HD |
967 | } |
968 | ||
86e5216f AL |
969 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
970 | unsigned long address, int write_access) | |
971 | { | |
972 | pte_t *ptep; | |
973 | pte_t entry; | |
1e8f889b | 974 | int ret; |
3935baa9 | 975 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
86e5216f AL |
976 | |
977 | ptep = huge_pte_alloc(mm, address); | |
978 | if (!ptep) | |
979 | return VM_FAULT_OOM; | |
980 | ||
3935baa9 DG |
981 | /* |
982 | * Serialize hugepage allocation and instantiation, so that we don't | |
983 | * get spurious allocation failures if two CPUs race to instantiate | |
984 | * the same page in the page cache. | |
985 | */ | |
986 | mutex_lock(&hugetlb_instantiation_mutex); | |
86e5216f | 987 | entry = *ptep; |
3935baa9 DG |
988 | if (pte_none(entry)) { |
989 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); | |
990 | mutex_unlock(&hugetlb_instantiation_mutex); | |
991 | return ret; | |
992 | } | |
86e5216f | 993 | |
83c54070 | 994 | ret = 0; |
1e8f889b DG |
995 | |
996 | spin_lock(&mm->page_table_lock); | |
997 | /* Check for a racing update before calling hugetlb_cow */ | |
998 | if (likely(pte_same(entry, *ptep))) | |
999 | if (write_access && !pte_write(entry)) | |
1000 | ret = hugetlb_cow(mm, vma, address, ptep, entry); | |
1001 | spin_unlock(&mm->page_table_lock); | |
3935baa9 | 1002 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
1003 | |
1004 | return ret; | |
86e5216f AL |
1005 | } |
1006 | ||
63551ae0 DG |
1007 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1008 | struct page **pages, struct vm_area_struct **vmas, | |
5b23dbe8 AL |
1009 | unsigned long *position, int *length, int i, |
1010 | int write) | |
63551ae0 | 1011 | { |
d5d4b0aa CK |
1012 | unsigned long pfn_offset; |
1013 | unsigned long vaddr = *position; | |
63551ae0 DG |
1014 | int remainder = *length; |
1015 | ||
1c59827d | 1016 | spin_lock(&mm->page_table_lock); |
63551ae0 | 1017 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
1018 | pte_t *pte; |
1019 | struct page *page; | |
63551ae0 | 1020 | |
4c887265 AL |
1021 | /* |
1022 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
1023 | * each hugepage. We have to make * sure we get the | |
1024 | * first, for the page indexing below to work. | |
1025 | */ | |
1026 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); | |
63551ae0 | 1027 | |
72fad713 | 1028 | if (!pte || pte_none(*pte) || (write && !pte_write(*pte))) { |
4c887265 | 1029 | int ret; |
63551ae0 | 1030 | |
4c887265 | 1031 | spin_unlock(&mm->page_table_lock); |
5b23dbe8 | 1032 | ret = hugetlb_fault(mm, vma, vaddr, write); |
4c887265 | 1033 | spin_lock(&mm->page_table_lock); |
a89182c7 | 1034 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 1035 | continue; |
63551ae0 | 1036 | |
4c887265 AL |
1037 | remainder = 0; |
1038 | if (!i) | |
1039 | i = -EFAULT; | |
1040 | break; | |
1041 | } | |
1042 | ||
d5d4b0aa CK |
1043 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
1044 | page = pte_page(*pte); | |
1045 | same_page: | |
d6692183 CK |
1046 | if (pages) { |
1047 | get_page(page); | |
d5d4b0aa | 1048 | pages[i] = page + pfn_offset; |
d6692183 | 1049 | } |
63551ae0 DG |
1050 | |
1051 | if (vmas) | |
1052 | vmas[i] = vma; | |
1053 | ||
1054 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 1055 | ++pfn_offset; |
63551ae0 DG |
1056 | --remainder; |
1057 | ++i; | |
d5d4b0aa CK |
1058 | if (vaddr < vma->vm_end && remainder && |
1059 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { | |
1060 | /* | |
1061 | * We use pfn_offset to avoid touching the pageframes | |
1062 | * of this compound page. | |
1063 | */ | |
1064 | goto same_page; | |
1065 | } | |
63551ae0 | 1066 | } |
1c59827d | 1067 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
1068 | *length = remainder; |
1069 | *position = vaddr; | |
1070 | ||
1071 | return i; | |
1072 | } | |
8f860591 ZY |
1073 | |
1074 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
1075 | unsigned long address, unsigned long end, pgprot_t newprot) | |
1076 | { | |
1077 | struct mm_struct *mm = vma->vm_mm; | |
1078 | unsigned long start = address; | |
1079 | pte_t *ptep; | |
1080 | pte_t pte; | |
1081 | ||
1082 | BUG_ON(address >= end); | |
1083 | flush_cache_range(vma, address, end); | |
1084 | ||
39dde65c | 1085 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
1086 | spin_lock(&mm->page_table_lock); |
1087 | for (; address < end; address += HPAGE_SIZE) { | |
1088 | ptep = huge_pte_offset(mm, address); | |
1089 | if (!ptep) | |
1090 | continue; | |
39dde65c CK |
1091 | if (huge_pmd_unshare(mm, &address, ptep)) |
1092 | continue; | |
8f860591 ZY |
1093 | if (!pte_none(*ptep)) { |
1094 | pte = huge_ptep_get_and_clear(mm, address, ptep); | |
1095 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
1096 | set_huge_pte_at(mm, address, ptep, pte); | |
8f860591 ZY |
1097 | } |
1098 | } | |
1099 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 1100 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
1101 | |
1102 | flush_tlb_range(vma, start, end); | |
1103 | } | |
1104 | ||
a43a8c39 CK |
1105 | struct file_region { |
1106 | struct list_head link; | |
1107 | long from; | |
1108 | long to; | |
1109 | }; | |
1110 | ||
1111 | static long region_add(struct list_head *head, long f, long t) | |
1112 | { | |
1113 | struct file_region *rg, *nrg, *trg; | |
1114 | ||
1115 | /* Locate the region we are either in or before. */ | |
1116 | list_for_each_entry(rg, head, link) | |
1117 | if (f <= rg->to) | |
1118 | break; | |
1119 | ||
1120 | /* Round our left edge to the current segment if it encloses us. */ | |
1121 | if (f > rg->from) | |
1122 | f = rg->from; | |
1123 | ||
1124 | /* Check for and consume any regions we now overlap with. */ | |
1125 | nrg = rg; | |
1126 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
1127 | if (&rg->link == head) | |
1128 | break; | |
1129 | if (rg->from > t) | |
1130 | break; | |
1131 | ||
1132 | /* If this area reaches higher then extend our area to | |
1133 | * include it completely. If this is not the first area | |
1134 | * which we intend to reuse, free it. */ | |
1135 | if (rg->to > t) | |
1136 | t = rg->to; | |
1137 | if (rg != nrg) { | |
1138 | list_del(&rg->link); | |
1139 | kfree(rg); | |
1140 | } | |
1141 | } | |
1142 | nrg->from = f; | |
1143 | nrg->to = t; | |
1144 | return 0; | |
1145 | } | |
1146 | ||
1147 | static long region_chg(struct list_head *head, long f, long t) | |
1148 | { | |
1149 | struct file_region *rg, *nrg; | |
1150 | long chg = 0; | |
1151 | ||
1152 | /* Locate the region we are before or in. */ | |
1153 | list_for_each_entry(rg, head, link) | |
1154 | if (f <= rg->to) | |
1155 | break; | |
1156 | ||
1157 | /* If we are below the current region then a new region is required. | |
1158 | * Subtle, allocate a new region at the position but make it zero | |
183ff22b | 1159 | * size such that we can guarantee to record the reservation. */ |
a43a8c39 CK |
1160 | if (&rg->link == head || t < rg->from) { |
1161 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
c80544dc | 1162 | if (!nrg) |
a43a8c39 CK |
1163 | return -ENOMEM; |
1164 | nrg->from = f; | |
1165 | nrg->to = f; | |
1166 | INIT_LIST_HEAD(&nrg->link); | |
1167 | list_add(&nrg->link, rg->link.prev); | |
1168 | ||
1169 | return t - f; | |
1170 | } | |
1171 | ||
1172 | /* Round our left edge to the current segment if it encloses us. */ | |
1173 | if (f > rg->from) | |
1174 | f = rg->from; | |
1175 | chg = t - f; | |
1176 | ||
1177 | /* Check for and consume any regions we now overlap with. */ | |
1178 | list_for_each_entry(rg, rg->link.prev, link) { | |
1179 | if (&rg->link == head) | |
1180 | break; | |
1181 | if (rg->from > t) | |
1182 | return chg; | |
1183 | ||
1184 | /* We overlap with this area, if it extends futher than | |
1185 | * us then we must extend ourselves. Account for its | |
1186 | * existing reservation. */ | |
1187 | if (rg->to > t) { | |
1188 | chg += rg->to - t; | |
1189 | t = rg->to; | |
1190 | } | |
1191 | chg -= rg->to - rg->from; | |
1192 | } | |
1193 | return chg; | |
1194 | } | |
1195 | ||
1196 | static long region_truncate(struct list_head *head, long end) | |
1197 | { | |
1198 | struct file_region *rg, *trg; | |
1199 | long chg = 0; | |
1200 | ||
1201 | /* Locate the region we are either in or before. */ | |
1202 | list_for_each_entry(rg, head, link) | |
1203 | if (end <= rg->to) | |
1204 | break; | |
1205 | if (&rg->link == head) | |
1206 | return 0; | |
1207 | ||
1208 | /* If we are in the middle of a region then adjust it. */ | |
1209 | if (end > rg->from) { | |
1210 | chg = rg->to - end; | |
1211 | rg->to = end; | |
1212 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
1213 | } | |
1214 | ||
1215 | /* Drop any remaining regions. */ | |
1216 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
1217 | if (&rg->link == head) | |
1218 | break; | |
1219 | chg += rg->to - rg->from; | |
1220 | list_del(&rg->link); | |
1221 | kfree(rg); | |
1222 | } | |
1223 | return chg; | |
1224 | } | |
1225 | ||
1226 | static int hugetlb_acct_memory(long delta) | |
1227 | { | |
1228 | int ret = -ENOMEM; | |
1229 | ||
1230 | spin_lock(&hugetlb_lock); | |
8a630112 KC |
1231 | /* |
1232 | * When cpuset is configured, it breaks the strict hugetlb page | |
1233 | * reservation as the accounting is done on a global variable. Such | |
1234 | * reservation is completely rubbish in the presence of cpuset because | |
1235 | * the reservation is not checked against page availability for the | |
1236 | * current cpuset. Application can still potentially OOM'ed by kernel | |
1237 | * with lack of free htlb page in cpuset that the task is in. | |
1238 | * Attempt to enforce strict accounting with cpuset is almost | |
1239 | * impossible (or too ugly) because cpuset is too fluid that | |
1240 | * task or memory node can be dynamically moved between cpusets. | |
1241 | * | |
1242 | * The change of semantics for shared hugetlb mapping with cpuset is | |
1243 | * undesirable. However, in order to preserve some of the semantics, | |
1244 | * we fall back to check against current free page availability as | |
1245 | * a best attempt and hopefully to minimize the impact of changing | |
1246 | * semantics that cpuset has. | |
1247 | */ | |
e4e574b7 AL |
1248 | if (delta > 0) { |
1249 | if (gather_surplus_pages(delta) < 0) | |
1250 | goto out; | |
1251 | ||
ac09b3a1 AL |
1252 | if (delta > cpuset_mems_nr(free_huge_pages_node)) { |
1253 | return_unused_surplus_pages(delta); | |
e4e574b7 | 1254 | goto out; |
ac09b3a1 | 1255 | } |
e4e574b7 AL |
1256 | } |
1257 | ||
1258 | ret = 0; | |
e4e574b7 AL |
1259 | if (delta < 0) |
1260 | return_unused_surplus_pages((unsigned long) -delta); | |
1261 | ||
1262 | out: | |
1263 | spin_unlock(&hugetlb_lock); | |
1264 | return ret; | |
1265 | } | |
1266 | ||
1267 | int hugetlb_reserve_pages(struct inode *inode, long from, long to) | |
1268 | { | |
1269 | long ret, chg; | |
1270 | ||
1271 | chg = region_chg(&inode->i_mapping->private_list, from, to); | |
1272 | if (chg < 0) | |
1273 | return chg; | |
8a630112 | 1274 | |
90d8b7e6 AL |
1275 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
1276 | return -ENOSPC; | |
a43a8c39 | 1277 | ret = hugetlb_acct_memory(chg); |
68842c9b KC |
1278 | if (ret < 0) { |
1279 | hugetlb_put_quota(inode->i_mapping, chg); | |
a43a8c39 | 1280 | return ret; |
68842c9b | 1281 | } |
a43a8c39 CK |
1282 | region_add(&inode->i_mapping->private_list, from, to); |
1283 | return 0; | |
1284 | } | |
1285 | ||
1286 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
1287 | { | |
1288 | long chg = region_truncate(&inode->i_mapping->private_list, offset); | |
45c682a6 KC |
1289 | |
1290 | spin_lock(&inode->i_lock); | |
1291 | inode->i_blocks -= BLOCKS_PER_HUGEPAGE * freed; | |
1292 | spin_unlock(&inode->i_lock); | |
1293 | ||
90d8b7e6 AL |
1294 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
1295 | hugetlb_acct_memory(-(chg - freed)); | |
a43a8c39 | 1296 | } |