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); |
dd1a239f MG |
100 | struct zone *zone; |
101 | struct zoneref *z; | |
1da177e4 | 102 | |
54a6eb5c MG |
103 | for_each_zone_zonelist(zone, z, zonelist, MAX_NR_ZONES - 1) { |
104 | nid = zone_to_nid(zone); | |
105 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && | |
3abf7afd AM |
106 | !list_empty(&hugepage_freelists[nid])) { |
107 | page = list_entry(hugepage_freelists[nid].next, | |
108 | struct page, lru); | |
109 | list_del(&page->lru); | |
110 | free_huge_pages--; | |
111 | free_huge_pages_node[nid]--; | |
e4e574b7 AL |
112 | if (vma && vma->vm_flags & VM_MAYSHARE) |
113 | resv_huge_pages--; | |
5ab3ee7b | 114 | break; |
3abf7afd | 115 | } |
1da177e4 | 116 | } |
480eccf9 | 117 | mpol_free(mpol); /* unref if mpol !NULL */ |
1da177e4 LT |
118 | return page; |
119 | } | |
120 | ||
6af2acb6 AL |
121 | static void update_and_free_page(struct page *page) |
122 | { | |
123 | int i; | |
124 | nr_huge_pages--; | |
125 | nr_huge_pages_node[page_to_nid(page)]--; | |
126 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { | |
127 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | | |
128 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
129 | 1 << PG_private | 1<< PG_writeback); | |
130 | } | |
131 | set_compound_page_dtor(page, NULL); | |
132 | set_page_refcounted(page); | |
133 | __free_pages(page, HUGETLB_PAGE_ORDER); | |
134 | } | |
135 | ||
27a85ef1 DG |
136 | static void free_huge_page(struct page *page) |
137 | { | |
7893d1d5 | 138 | int nid = page_to_nid(page); |
c79fb75e | 139 | struct address_space *mapping; |
27a85ef1 | 140 | |
c79fb75e | 141 | mapping = (struct address_space *) page_private(page); |
e5df70ab | 142 | set_page_private(page, 0); |
7893d1d5 | 143 | BUG_ON(page_count(page)); |
27a85ef1 DG |
144 | INIT_LIST_HEAD(&page->lru); |
145 | ||
146 | spin_lock(&hugetlb_lock); | |
7893d1d5 AL |
147 | if (surplus_huge_pages_node[nid]) { |
148 | update_and_free_page(page); | |
149 | surplus_huge_pages--; | |
150 | surplus_huge_pages_node[nid]--; | |
151 | } else { | |
152 | enqueue_huge_page(page); | |
153 | } | |
27a85ef1 | 154 | spin_unlock(&hugetlb_lock); |
c79fb75e | 155 | if (mapping) |
9a119c05 | 156 | hugetlb_put_quota(mapping, 1); |
27a85ef1 DG |
157 | } |
158 | ||
7893d1d5 AL |
159 | /* |
160 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
161 | * balanced by operating on them in a round-robin fashion. | |
162 | * Returns 1 if an adjustment was made. | |
163 | */ | |
164 | static int adjust_pool_surplus(int delta) | |
165 | { | |
166 | static int prev_nid; | |
167 | int nid = prev_nid; | |
168 | int ret = 0; | |
169 | ||
170 | VM_BUG_ON(delta != -1 && delta != 1); | |
171 | do { | |
172 | nid = next_node(nid, node_online_map); | |
173 | if (nid == MAX_NUMNODES) | |
174 | nid = first_node(node_online_map); | |
175 | ||
176 | /* To shrink on this node, there must be a surplus page */ | |
177 | if (delta < 0 && !surplus_huge_pages_node[nid]) | |
178 | continue; | |
179 | /* Surplus cannot exceed the total number of pages */ | |
180 | if (delta > 0 && surplus_huge_pages_node[nid] >= | |
181 | nr_huge_pages_node[nid]) | |
182 | continue; | |
183 | ||
184 | surplus_huge_pages += delta; | |
185 | surplus_huge_pages_node[nid] += delta; | |
186 | ret = 1; | |
187 | break; | |
188 | } while (nid != prev_nid); | |
189 | ||
190 | prev_nid = nid; | |
191 | return ret; | |
192 | } | |
193 | ||
63b4613c | 194 | static struct page *alloc_fresh_huge_page_node(int nid) |
1da177e4 | 195 | { |
1da177e4 | 196 | struct page *page; |
f96efd58 | 197 | |
63b4613c NA |
198 | page = alloc_pages_node(nid, |
199 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|__GFP_NOWARN, | |
200 | HUGETLB_PAGE_ORDER); | |
1da177e4 | 201 | if (page) { |
33f2ef89 | 202 | set_compound_page_dtor(page, free_huge_page); |
0bd0f9fb | 203 | spin_lock(&hugetlb_lock); |
1da177e4 | 204 | nr_huge_pages++; |
63b4613c | 205 | nr_huge_pages_node[nid]++; |
0bd0f9fb | 206 | spin_unlock(&hugetlb_lock); |
a482289d | 207 | put_page(page); /* free it into the hugepage allocator */ |
1da177e4 | 208 | } |
63b4613c NA |
209 | |
210 | return page; | |
211 | } | |
212 | ||
213 | static int alloc_fresh_huge_page(void) | |
214 | { | |
215 | struct page *page; | |
216 | int start_nid; | |
217 | int next_nid; | |
218 | int ret = 0; | |
219 | ||
220 | start_nid = hugetlb_next_nid; | |
221 | ||
222 | do { | |
223 | page = alloc_fresh_huge_page_node(hugetlb_next_nid); | |
224 | if (page) | |
225 | ret = 1; | |
226 | /* | |
227 | * Use a helper variable to find the next node and then | |
228 | * copy it back to hugetlb_next_nid afterwards: | |
229 | * otherwise there's a window in which a racer might | |
230 | * pass invalid nid MAX_NUMNODES to alloc_pages_node. | |
231 | * But we don't need to use a spin_lock here: it really | |
232 | * doesn't matter if occasionally a racer chooses the | |
233 | * same nid as we do. Move nid forward in the mask even | |
234 | * if we just successfully allocated a hugepage so that | |
235 | * the next caller gets hugepages on the next node. | |
236 | */ | |
237 | next_nid = next_node(hugetlb_next_nid, node_online_map); | |
238 | if (next_nid == MAX_NUMNODES) | |
239 | next_nid = first_node(node_online_map); | |
240 | hugetlb_next_nid = next_nid; | |
241 | } while (!page && hugetlb_next_nid != start_nid); | |
242 | ||
243 | return ret; | |
1da177e4 LT |
244 | } |
245 | ||
7893d1d5 AL |
246 | static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma, |
247 | unsigned long address) | |
248 | { | |
249 | struct page *page; | |
d1c3fb1f | 250 | unsigned int nid; |
7893d1d5 | 251 | |
d1c3fb1f NA |
252 | /* |
253 | * Assume we will successfully allocate the surplus page to | |
254 | * prevent racing processes from causing the surplus to exceed | |
255 | * overcommit | |
256 | * | |
257 | * This however introduces a different race, where a process B | |
258 | * tries to grow the static hugepage pool while alloc_pages() is | |
259 | * called by process A. B will only examine the per-node | |
260 | * counters in determining if surplus huge pages can be | |
261 | * converted to normal huge pages in adjust_pool_surplus(). A | |
262 | * won't be able to increment the per-node counter, until the | |
263 | * lock is dropped by B, but B doesn't drop hugetlb_lock until | |
264 | * no more huge pages can be converted from surplus to normal | |
265 | * state (and doesn't try to convert again). Thus, we have a | |
266 | * case where a surplus huge page exists, the pool is grown, and | |
267 | * the surplus huge page still exists after, even though it | |
268 | * should just have been converted to a normal huge page. This | |
269 | * does not leak memory, though, as the hugepage will be freed | |
270 | * once it is out of use. It also does not allow the counters to | |
271 | * go out of whack in adjust_pool_surplus() as we don't modify | |
272 | * the node values until we've gotten the hugepage and only the | |
273 | * per-node value is checked there. | |
274 | */ | |
275 | spin_lock(&hugetlb_lock); | |
276 | if (surplus_huge_pages >= nr_overcommit_huge_pages) { | |
277 | spin_unlock(&hugetlb_lock); | |
278 | return NULL; | |
279 | } else { | |
280 | nr_huge_pages++; | |
281 | surplus_huge_pages++; | |
282 | } | |
283 | spin_unlock(&hugetlb_lock); | |
284 | ||
7893d1d5 AL |
285 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN, |
286 | HUGETLB_PAGE_ORDER); | |
d1c3fb1f NA |
287 | |
288 | spin_lock(&hugetlb_lock); | |
7893d1d5 | 289 | if (page) { |
2668db91 AL |
290 | /* |
291 | * This page is now managed by the hugetlb allocator and has | |
292 | * no users -- drop the buddy allocator's reference. | |
293 | */ | |
294 | put_page_testzero(page); | |
295 | VM_BUG_ON(page_count(page)); | |
d1c3fb1f | 296 | nid = page_to_nid(page); |
7893d1d5 | 297 | set_compound_page_dtor(page, free_huge_page); |
d1c3fb1f NA |
298 | /* |
299 | * We incremented the global counters already | |
300 | */ | |
301 | nr_huge_pages_node[nid]++; | |
302 | surplus_huge_pages_node[nid]++; | |
303 | } else { | |
304 | nr_huge_pages--; | |
305 | surplus_huge_pages--; | |
7893d1d5 | 306 | } |
d1c3fb1f | 307 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
308 | |
309 | return page; | |
310 | } | |
311 | ||
e4e574b7 AL |
312 | /* |
313 | * Increase the hugetlb pool such that it can accomodate a reservation | |
314 | * of size 'delta'. | |
315 | */ | |
316 | static int gather_surplus_pages(int delta) | |
317 | { | |
318 | struct list_head surplus_list; | |
319 | struct page *page, *tmp; | |
320 | int ret, i; | |
321 | int needed, allocated; | |
322 | ||
323 | needed = (resv_huge_pages + delta) - free_huge_pages; | |
ac09b3a1 AL |
324 | if (needed <= 0) { |
325 | resv_huge_pages += delta; | |
e4e574b7 | 326 | return 0; |
ac09b3a1 | 327 | } |
e4e574b7 AL |
328 | |
329 | allocated = 0; | |
330 | INIT_LIST_HEAD(&surplus_list); | |
331 | ||
332 | ret = -ENOMEM; | |
333 | retry: | |
334 | spin_unlock(&hugetlb_lock); | |
335 | for (i = 0; i < needed; i++) { | |
336 | page = alloc_buddy_huge_page(NULL, 0); | |
337 | if (!page) { | |
338 | /* | |
339 | * We were not able to allocate enough pages to | |
340 | * satisfy the entire reservation so we free what | |
341 | * we've allocated so far. | |
342 | */ | |
343 | spin_lock(&hugetlb_lock); | |
344 | needed = 0; | |
345 | goto free; | |
346 | } | |
347 | ||
348 | list_add(&page->lru, &surplus_list); | |
349 | } | |
350 | allocated += needed; | |
351 | ||
352 | /* | |
353 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
354 | * because either resv_huge_pages or free_huge_pages may have changed. | |
355 | */ | |
356 | spin_lock(&hugetlb_lock); | |
357 | needed = (resv_huge_pages + delta) - (free_huge_pages + allocated); | |
358 | if (needed > 0) | |
359 | goto retry; | |
360 | ||
361 | /* | |
362 | * The surplus_list now contains _at_least_ the number of extra pages | |
363 | * needed to accomodate the reservation. Add the appropriate number | |
364 | * of pages to the hugetlb pool and free the extras back to the buddy | |
ac09b3a1 AL |
365 | * allocator. Commit the entire reservation here to prevent another |
366 | * process from stealing the pages as they are added to the pool but | |
367 | * before they are reserved. | |
e4e574b7 AL |
368 | */ |
369 | needed += allocated; | |
ac09b3a1 | 370 | resv_huge_pages += delta; |
e4e574b7 AL |
371 | ret = 0; |
372 | free: | |
373 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { | |
374 | list_del(&page->lru); | |
375 | if ((--needed) >= 0) | |
376 | enqueue_huge_page(page); | |
af767cbd AL |
377 | else { |
378 | /* | |
2668db91 AL |
379 | * The page has a reference count of zero already, so |
380 | * call free_huge_page directly instead of using | |
381 | * put_page. This must be done with hugetlb_lock | |
af767cbd AL |
382 | * unlocked which is safe because free_huge_page takes |
383 | * hugetlb_lock before deciding how to free the page. | |
384 | */ | |
385 | spin_unlock(&hugetlb_lock); | |
2668db91 | 386 | free_huge_page(page); |
af767cbd AL |
387 | spin_lock(&hugetlb_lock); |
388 | } | |
e4e574b7 AL |
389 | } |
390 | ||
391 | return ret; | |
392 | } | |
393 | ||
394 | /* | |
395 | * When releasing a hugetlb pool reservation, any surplus pages that were | |
396 | * allocated to satisfy the reservation must be explicitly freed if they were | |
397 | * never used. | |
398 | */ | |
8cde045c | 399 | static void return_unused_surplus_pages(unsigned long unused_resv_pages) |
e4e574b7 AL |
400 | { |
401 | static int nid = -1; | |
402 | struct page *page; | |
403 | unsigned long nr_pages; | |
404 | ||
11320d17 NA |
405 | /* |
406 | * We want to release as many surplus pages as possible, spread | |
407 | * evenly across all nodes. Iterate across all nodes until we | |
408 | * can no longer free unreserved surplus pages. This occurs when | |
409 | * the nodes with surplus pages have no free pages. | |
410 | */ | |
411 | unsigned long remaining_iterations = num_online_nodes(); | |
412 | ||
ac09b3a1 AL |
413 | /* Uncommit the reservation */ |
414 | resv_huge_pages -= unused_resv_pages; | |
415 | ||
e4e574b7 AL |
416 | nr_pages = min(unused_resv_pages, surplus_huge_pages); |
417 | ||
11320d17 | 418 | while (remaining_iterations-- && nr_pages) { |
e4e574b7 AL |
419 | nid = next_node(nid, node_online_map); |
420 | if (nid == MAX_NUMNODES) | |
421 | nid = first_node(node_online_map); | |
422 | ||
423 | if (!surplus_huge_pages_node[nid]) | |
424 | continue; | |
425 | ||
426 | if (!list_empty(&hugepage_freelists[nid])) { | |
427 | page = list_entry(hugepage_freelists[nid].next, | |
428 | struct page, lru); | |
429 | list_del(&page->lru); | |
430 | update_and_free_page(page); | |
431 | free_huge_pages--; | |
432 | free_huge_pages_node[nid]--; | |
433 | surplus_huge_pages--; | |
434 | surplus_huge_pages_node[nid]--; | |
435 | nr_pages--; | |
11320d17 | 436 | remaining_iterations = num_online_nodes(); |
e4e574b7 AL |
437 | } |
438 | } | |
439 | } | |
440 | ||
348ea204 AL |
441 | |
442 | static struct page *alloc_huge_page_shared(struct vm_area_struct *vma, | |
443 | unsigned long addr) | |
1da177e4 | 444 | { |
348ea204 | 445 | struct page *page; |
1da177e4 LT |
446 | |
447 | spin_lock(&hugetlb_lock); | |
348e1e04 | 448 | page = dequeue_huge_page_vma(vma, addr); |
1da177e4 | 449 | spin_unlock(&hugetlb_lock); |
90d8b7e6 | 450 | return page ? page : ERR_PTR(-VM_FAULT_OOM); |
348ea204 | 451 | } |
b45b5bd6 | 452 | |
348ea204 AL |
453 | static struct page *alloc_huge_page_private(struct vm_area_struct *vma, |
454 | unsigned long addr) | |
455 | { | |
456 | struct page *page = NULL; | |
7893d1d5 | 457 | |
90d8b7e6 AL |
458 | if (hugetlb_get_quota(vma->vm_file->f_mapping, 1)) |
459 | return ERR_PTR(-VM_FAULT_SIGBUS); | |
460 | ||
348ea204 AL |
461 | spin_lock(&hugetlb_lock); |
462 | if (free_huge_pages > resv_huge_pages) | |
348e1e04 | 463 | page = dequeue_huge_page_vma(vma, addr); |
348ea204 | 464 | spin_unlock(&hugetlb_lock); |
68842c9b | 465 | if (!page) { |
7893d1d5 | 466 | page = alloc_buddy_huge_page(vma, addr); |
68842c9b KC |
467 | if (!page) { |
468 | hugetlb_put_quota(vma->vm_file->f_mapping, 1); | |
469 | return ERR_PTR(-VM_FAULT_OOM); | |
470 | } | |
471 | } | |
472 | return page; | |
348ea204 AL |
473 | } |
474 | ||
475 | static struct page *alloc_huge_page(struct vm_area_struct *vma, | |
476 | unsigned long addr) | |
477 | { | |
478 | struct page *page; | |
2fc39cec AL |
479 | struct address_space *mapping = vma->vm_file->f_mapping; |
480 | ||
348ea204 AL |
481 | if (vma->vm_flags & VM_MAYSHARE) |
482 | page = alloc_huge_page_shared(vma, addr); | |
483 | else | |
484 | page = alloc_huge_page_private(vma, addr); | |
90d8b7e6 AL |
485 | |
486 | if (!IS_ERR(page)) { | |
348ea204 | 487 | set_page_refcounted(page); |
2fc39cec | 488 | set_page_private(page, (unsigned long) mapping); |
90d8b7e6 AL |
489 | } |
490 | return page; | |
b45b5bd6 DG |
491 | } |
492 | ||
1da177e4 LT |
493 | static int __init hugetlb_init(void) |
494 | { | |
495 | unsigned long i; | |
1da177e4 | 496 | |
3c726f8d BH |
497 | if (HPAGE_SHIFT == 0) |
498 | return 0; | |
499 | ||
1da177e4 LT |
500 | for (i = 0; i < MAX_NUMNODES; ++i) |
501 | INIT_LIST_HEAD(&hugepage_freelists[i]); | |
502 | ||
63b4613c NA |
503 | hugetlb_next_nid = first_node(node_online_map); |
504 | ||
1da177e4 | 505 | for (i = 0; i < max_huge_pages; ++i) { |
a482289d | 506 | if (!alloc_fresh_huge_page()) |
1da177e4 | 507 | break; |
1da177e4 LT |
508 | } |
509 | max_huge_pages = free_huge_pages = nr_huge_pages = i; | |
510 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); | |
511 | return 0; | |
512 | } | |
513 | module_init(hugetlb_init); | |
514 | ||
515 | static int __init hugetlb_setup(char *s) | |
516 | { | |
517 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) | |
518 | max_huge_pages = 0; | |
519 | return 1; | |
520 | } | |
521 | __setup("hugepages=", hugetlb_setup); | |
522 | ||
8a630112 KC |
523 | static unsigned int cpuset_mems_nr(unsigned int *array) |
524 | { | |
525 | int node; | |
526 | unsigned int nr = 0; | |
527 | ||
528 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
529 | nr += array[node]; | |
530 | ||
531 | return nr; | |
532 | } | |
533 | ||
1da177e4 | 534 | #ifdef CONFIG_SYSCTL |
1da177e4 LT |
535 | #ifdef CONFIG_HIGHMEM |
536 | static void try_to_free_low(unsigned long count) | |
537 | { | |
4415cc8d CL |
538 | int i; |
539 | ||
1da177e4 LT |
540 | for (i = 0; i < MAX_NUMNODES; ++i) { |
541 | struct page *page, *next; | |
542 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { | |
6b0c880d AL |
543 | if (count >= nr_huge_pages) |
544 | return; | |
1da177e4 LT |
545 | if (PageHighMem(page)) |
546 | continue; | |
547 | list_del(&page->lru); | |
548 | update_and_free_page(page); | |
1da177e4 | 549 | free_huge_pages--; |
4415cc8d | 550 | free_huge_pages_node[page_to_nid(page)]--; |
1da177e4 LT |
551 | } |
552 | } | |
553 | } | |
554 | #else | |
555 | static inline void try_to_free_low(unsigned long count) | |
556 | { | |
557 | } | |
558 | #endif | |
559 | ||
7893d1d5 | 560 | #define persistent_huge_pages (nr_huge_pages - surplus_huge_pages) |
1da177e4 LT |
561 | static unsigned long set_max_huge_pages(unsigned long count) |
562 | { | |
7893d1d5 | 563 | unsigned long min_count, ret; |
1da177e4 | 564 | |
7893d1d5 AL |
565 | /* |
566 | * Increase the pool size | |
567 | * First take pages out of surplus state. Then make up the | |
568 | * remaining difference by allocating fresh huge pages. | |
d1c3fb1f NA |
569 | * |
570 | * We might race with alloc_buddy_huge_page() here and be unable | |
571 | * to convert a surplus huge page to a normal huge page. That is | |
572 | * not critical, though, it just means the overall size of the | |
573 | * pool might be one hugepage larger than it needs to be, but | |
574 | * within all the constraints specified by the sysctls. | |
7893d1d5 | 575 | */ |
1da177e4 | 576 | spin_lock(&hugetlb_lock); |
7893d1d5 AL |
577 | while (surplus_huge_pages && count > persistent_huge_pages) { |
578 | if (!adjust_pool_surplus(-1)) | |
579 | break; | |
580 | } | |
581 | ||
582 | while (count > persistent_huge_pages) { | |
583 | int ret; | |
584 | /* | |
585 | * If this allocation races such that we no longer need the | |
586 | * page, free_huge_page will handle it by freeing the page | |
587 | * and reducing the surplus. | |
588 | */ | |
589 | spin_unlock(&hugetlb_lock); | |
590 | ret = alloc_fresh_huge_page(); | |
591 | spin_lock(&hugetlb_lock); | |
592 | if (!ret) | |
593 | goto out; | |
594 | ||
595 | } | |
7893d1d5 AL |
596 | |
597 | /* | |
598 | * Decrease the pool size | |
599 | * First return free pages to the buddy allocator (being careful | |
600 | * to keep enough around to satisfy reservations). Then place | |
601 | * pages into surplus state as needed so the pool will shrink | |
602 | * to the desired size as pages become free. | |
d1c3fb1f NA |
603 | * |
604 | * By placing pages into the surplus state independent of the | |
605 | * overcommit value, we are allowing the surplus pool size to | |
606 | * exceed overcommit. There are few sane options here. Since | |
607 | * alloc_buddy_huge_page() is checking the global counter, | |
608 | * though, we'll note that we're not allowed to exceed surplus | |
609 | * and won't grow the pool anywhere else. Not until one of the | |
610 | * sysctls are changed, or the surplus pages go out of use. | |
7893d1d5 | 611 | */ |
6b0c880d AL |
612 | min_count = resv_huge_pages + nr_huge_pages - free_huge_pages; |
613 | min_count = max(count, min_count); | |
7893d1d5 AL |
614 | try_to_free_low(min_count); |
615 | while (min_count < persistent_huge_pages) { | |
348e1e04 | 616 | struct page *page = dequeue_huge_page(); |
1da177e4 LT |
617 | if (!page) |
618 | break; | |
619 | update_and_free_page(page); | |
620 | } | |
7893d1d5 AL |
621 | while (count < persistent_huge_pages) { |
622 | if (!adjust_pool_surplus(1)) | |
623 | break; | |
624 | } | |
625 | out: | |
626 | ret = persistent_huge_pages; | |
1da177e4 | 627 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 628 | return ret; |
1da177e4 LT |
629 | } |
630 | ||
631 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, | |
632 | struct file *file, void __user *buffer, | |
633 | size_t *length, loff_t *ppos) | |
634 | { | |
635 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); | |
636 | max_huge_pages = set_max_huge_pages(max_huge_pages); | |
637 | return 0; | |
638 | } | |
396faf03 MG |
639 | |
640 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, | |
641 | struct file *file, void __user *buffer, | |
642 | size_t *length, loff_t *ppos) | |
643 | { | |
644 | proc_dointvec(table, write, file, buffer, length, ppos); | |
645 | if (hugepages_treat_as_movable) | |
646 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; | |
647 | else | |
648 | htlb_alloc_mask = GFP_HIGHUSER; | |
649 | return 0; | |
650 | } | |
651 | ||
a3d0c6aa NA |
652 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
653 | struct file *file, void __user *buffer, | |
654 | size_t *length, loff_t *ppos) | |
655 | { | |
a3d0c6aa | 656 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
064d9efe NA |
657 | spin_lock(&hugetlb_lock); |
658 | nr_overcommit_huge_pages = sysctl_overcommit_huge_pages; | |
a3d0c6aa NA |
659 | spin_unlock(&hugetlb_lock); |
660 | return 0; | |
661 | } | |
662 | ||
1da177e4 LT |
663 | #endif /* CONFIG_SYSCTL */ |
664 | ||
665 | int hugetlb_report_meminfo(char *buf) | |
666 | { | |
667 | return sprintf(buf, | |
668 | "HugePages_Total: %5lu\n" | |
669 | "HugePages_Free: %5lu\n" | |
a43a8c39 | 670 | "HugePages_Rsvd: %5lu\n" |
7893d1d5 | 671 | "HugePages_Surp: %5lu\n" |
1da177e4 LT |
672 | "Hugepagesize: %5lu kB\n", |
673 | nr_huge_pages, | |
674 | free_huge_pages, | |
a43a8c39 | 675 | resv_huge_pages, |
7893d1d5 | 676 | surplus_huge_pages, |
1da177e4 LT |
677 | HPAGE_SIZE/1024); |
678 | } | |
679 | ||
680 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
681 | { | |
682 | return sprintf(buf, | |
683 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
684 | "Node %d HugePages_Free: %5u\n" |
685 | "Node %d HugePages_Surp: %5u\n", | |
1da177e4 | 686 | nid, nr_huge_pages_node[nid], |
a1de0919 NA |
687 | nid, free_huge_pages_node[nid], |
688 | nid, surplus_huge_pages_node[nid]); | |
1da177e4 LT |
689 | } |
690 | ||
1da177e4 LT |
691 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
692 | unsigned long hugetlb_total_pages(void) | |
693 | { | |
694 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); | |
695 | } | |
1da177e4 LT |
696 | |
697 | /* | |
698 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
699 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
700 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
701 | * this far. | |
702 | */ | |
d0217ac0 | 703 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
704 | { |
705 | BUG(); | |
d0217ac0 | 706 | return 0; |
1da177e4 LT |
707 | } |
708 | ||
709 | struct vm_operations_struct hugetlb_vm_ops = { | |
d0217ac0 | 710 | .fault = hugetlb_vm_op_fault, |
1da177e4 LT |
711 | }; |
712 | ||
1e8f889b DG |
713 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
714 | int writable) | |
63551ae0 DG |
715 | { |
716 | pte_t entry; | |
717 | ||
1e8f889b | 718 | if (writable) { |
63551ae0 DG |
719 | entry = |
720 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
721 | } else { | |
722 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); | |
723 | } | |
724 | entry = pte_mkyoung(entry); | |
725 | entry = pte_mkhuge(entry); | |
726 | ||
727 | return entry; | |
728 | } | |
729 | ||
1e8f889b DG |
730 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
731 | unsigned long address, pte_t *ptep) | |
732 | { | |
733 | pte_t entry; | |
734 | ||
735 | entry = pte_mkwrite(pte_mkdirty(*ptep)); | |
8dab5241 BH |
736 | if (ptep_set_access_flags(vma, address, ptep, entry, 1)) { |
737 | update_mmu_cache(vma, address, entry); | |
8dab5241 | 738 | } |
1e8f889b DG |
739 | } |
740 | ||
741 | ||
63551ae0 DG |
742 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
743 | struct vm_area_struct *vma) | |
744 | { | |
745 | pte_t *src_pte, *dst_pte, entry; | |
746 | struct page *ptepage; | |
1c59827d | 747 | unsigned long addr; |
1e8f889b DG |
748 | int cow; |
749 | ||
750 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 751 | |
1c59827d | 752 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
c74df32c HD |
753 | src_pte = huge_pte_offset(src, addr); |
754 | if (!src_pte) | |
755 | continue; | |
63551ae0 DG |
756 | dst_pte = huge_pte_alloc(dst, addr); |
757 | if (!dst_pte) | |
758 | goto nomem; | |
c5c99429 LW |
759 | |
760 | /* If the pagetables are shared don't copy or take references */ | |
761 | if (dst_pte == src_pte) | |
762 | continue; | |
763 | ||
c74df32c | 764 | spin_lock(&dst->page_table_lock); |
1c59827d | 765 | spin_lock(&src->page_table_lock); |
c74df32c | 766 | if (!pte_none(*src_pte)) { |
1e8f889b DG |
767 | if (cow) |
768 | ptep_set_wrprotect(src, addr, src_pte); | |
1c59827d HD |
769 | entry = *src_pte; |
770 | ptepage = pte_page(entry); | |
771 | get_page(ptepage); | |
1c59827d HD |
772 | set_huge_pte_at(dst, addr, dst_pte, entry); |
773 | } | |
774 | spin_unlock(&src->page_table_lock); | |
c74df32c | 775 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
776 | } |
777 | return 0; | |
778 | ||
779 | nomem: | |
780 | return -ENOMEM; | |
781 | } | |
782 | ||
502717f4 CK |
783 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
784 | unsigned long end) | |
63551ae0 DG |
785 | { |
786 | struct mm_struct *mm = vma->vm_mm; | |
787 | unsigned long address; | |
c7546f8f | 788 | pte_t *ptep; |
63551ae0 DG |
789 | pte_t pte; |
790 | struct page *page; | |
fe1668ae | 791 | struct page *tmp; |
c0a499c2 CK |
792 | /* |
793 | * A page gathering list, protected by per file i_mmap_lock. The | |
794 | * lock is used to avoid list corruption from multiple unmapping | |
795 | * of the same page since we are using page->lru. | |
796 | */ | |
fe1668ae | 797 | LIST_HEAD(page_list); |
63551ae0 DG |
798 | |
799 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
800 | BUG_ON(start & ~HPAGE_MASK); | |
801 | BUG_ON(end & ~HPAGE_MASK); | |
802 | ||
508034a3 | 803 | spin_lock(&mm->page_table_lock); |
63551ae0 | 804 | for (address = start; address < end; address += HPAGE_SIZE) { |
c7546f8f | 805 | ptep = huge_pte_offset(mm, address); |
4c887265 | 806 | if (!ptep) |
c7546f8f DG |
807 | continue; |
808 | ||
39dde65c CK |
809 | if (huge_pmd_unshare(mm, &address, ptep)) |
810 | continue; | |
811 | ||
c7546f8f | 812 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
63551ae0 DG |
813 | if (pte_none(pte)) |
814 | continue; | |
c7546f8f | 815 | |
63551ae0 | 816 | page = pte_page(pte); |
6649a386 KC |
817 | if (pte_dirty(pte)) |
818 | set_page_dirty(page); | |
fe1668ae | 819 | list_add(&page->lru, &page_list); |
63551ae0 | 820 | } |
1da177e4 | 821 | spin_unlock(&mm->page_table_lock); |
508034a3 | 822 | flush_tlb_range(vma, start, end); |
fe1668ae CK |
823 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
824 | list_del(&page->lru); | |
825 | put_page(page); | |
826 | } | |
1da177e4 | 827 | } |
63551ae0 | 828 | |
502717f4 CK |
829 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
830 | unsigned long end) | |
831 | { | |
832 | /* | |
833 | * It is undesirable to test vma->vm_file as it should be non-null | |
834 | * for valid hugetlb area. However, vm_file will be NULL in the error | |
835 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, | |
836 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function | |
837 | * to clean up. Since no pte has actually been setup, it is safe to | |
838 | * do nothing in this case. | |
839 | */ | |
840 | if (vma->vm_file) { | |
841 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); | |
842 | __unmap_hugepage_range(vma, start, end); | |
843 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); | |
844 | } | |
845 | } | |
846 | ||
1e8f889b DG |
847 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
848 | unsigned long address, pte_t *ptep, pte_t pte) | |
849 | { | |
850 | struct page *old_page, *new_page; | |
79ac6ba4 | 851 | int avoidcopy; |
1e8f889b DG |
852 | |
853 | old_page = pte_page(pte); | |
854 | ||
855 | /* If no-one else is actually using this page, avoid the copy | |
856 | * and just make the page writable */ | |
857 | avoidcopy = (page_count(old_page) == 1); | |
858 | if (avoidcopy) { | |
859 | set_huge_ptep_writable(vma, address, ptep); | |
83c54070 | 860 | return 0; |
1e8f889b DG |
861 | } |
862 | ||
863 | page_cache_get(old_page); | |
5da7ca86 | 864 | new_page = alloc_huge_page(vma, address); |
1e8f889b | 865 | |
2fc39cec | 866 | if (IS_ERR(new_page)) { |
1e8f889b | 867 | page_cache_release(old_page); |
2fc39cec | 868 | return -PTR_ERR(new_page); |
1e8f889b DG |
869 | } |
870 | ||
871 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 872 | copy_huge_page(new_page, old_page, address, vma); |
0ed361de | 873 | __SetPageUptodate(new_page); |
1e8f889b DG |
874 | spin_lock(&mm->page_table_lock); |
875 | ||
876 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); | |
877 | if (likely(pte_same(*ptep, pte))) { | |
878 | /* Break COW */ | |
879 | set_huge_pte_at(mm, address, ptep, | |
880 | make_huge_pte(vma, new_page, 1)); | |
881 | /* Make the old page be freed below */ | |
882 | new_page = old_page; | |
883 | } | |
884 | page_cache_release(new_page); | |
885 | page_cache_release(old_page); | |
83c54070 | 886 | return 0; |
1e8f889b DG |
887 | } |
888 | ||
a1ed3dda | 889 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 890 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 HD |
891 | { |
892 | int ret = VM_FAULT_SIGBUS; | |
4c887265 AL |
893 | unsigned long idx; |
894 | unsigned long size; | |
4c887265 AL |
895 | struct page *page; |
896 | struct address_space *mapping; | |
1e8f889b | 897 | pte_t new_pte; |
4c887265 | 898 | |
4c887265 AL |
899 | mapping = vma->vm_file->f_mapping; |
900 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) | |
901 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
902 | ||
903 | /* | |
904 | * Use page lock to guard against racing truncation | |
905 | * before we get page_table_lock. | |
906 | */ | |
6bda666a CL |
907 | retry: |
908 | page = find_lock_page(mapping, idx); | |
909 | if (!page) { | |
ebed4bfc HD |
910 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
911 | if (idx >= size) | |
912 | goto out; | |
6bda666a | 913 | page = alloc_huge_page(vma, address); |
2fc39cec AL |
914 | if (IS_ERR(page)) { |
915 | ret = -PTR_ERR(page); | |
6bda666a CL |
916 | goto out; |
917 | } | |
79ac6ba4 | 918 | clear_huge_page(page, address); |
0ed361de | 919 | __SetPageUptodate(page); |
ac9b9c66 | 920 | |
6bda666a CL |
921 | if (vma->vm_flags & VM_SHARED) { |
922 | int err; | |
45c682a6 | 923 | struct inode *inode = mapping->host; |
6bda666a CL |
924 | |
925 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
926 | if (err) { | |
927 | put_page(page); | |
6bda666a CL |
928 | if (err == -EEXIST) |
929 | goto retry; | |
930 | goto out; | |
931 | } | |
45c682a6 KC |
932 | |
933 | spin_lock(&inode->i_lock); | |
934 | inode->i_blocks += BLOCKS_PER_HUGEPAGE; | |
935 | spin_unlock(&inode->i_lock); | |
6bda666a CL |
936 | } else |
937 | lock_page(page); | |
938 | } | |
1e8f889b | 939 | |
ac9b9c66 | 940 | spin_lock(&mm->page_table_lock); |
4c887265 AL |
941 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
942 | if (idx >= size) | |
943 | goto backout; | |
944 | ||
83c54070 | 945 | ret = 0; |
86e5216f | 946 | if (!pte_none(*ptep)) |
4c887265 AL |
947 | goto backout; |
948 | ||
1e8f889b DG |
949 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
950 | && (vma->vm_flags & VM_SHARED))); | |
951 | set_huge_pte_at(mm, address, ptep, new_pte); | |
952 | ||
953 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
954 | /* Optimization, do the COW without a second fault */ | |
955 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); | |
956 | } | |
957 | ||
ac9b9c66 | 958 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
959 | unlock_page(page); |
960 | out: | |
ac9b9c66 | 961 | return ret; |
4c887265 AL |
962 | |
963 | backout: | |
964 | spin_unlock(&mm->page_table_lock); | |
4c887265 AL |
965 | unlock_page(page); |
966 | put_page(page); | |
967 | goto out; | |
ac9b9c66 HD |
968 | } |
969 | ||
86e5216f AL |
970 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
971 | unsigned long address, int write_access) | |
972 | { | |
973 | pte_t *ptep; | |
974 | pte_t entry; | |
1e8f889b | 975 | int ret; |
3935baa9 | 976 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
86e5216f AL |
977 | |
978 | ptep = huge_pte_alloc(mm, address); | |
979 | if (!ptep) | |
980 | return VM_FAULT_OOM; | |
981 | ||
3935baa9 DG |
982 | /* |
983 | * Serialize hugepage allocation and instantiation, so that we don't | |
984 | * get spurious allocation failures if two CPUs race to instantiate | |
985 | * the same page in the page cache. | |
986 | */ | |
987 | mutex_lock(&hugetlb_instantiation_mutex); | |
86e5216f | 988 | entry = *ptep; |
3935baa9 DG |
989 | if (pte_none(entry)) { |
990 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); | |
991 | mutex_unlock(&hugetlb_instantiation_mutex); | |
992 | return ret; | |
993 | } | |
86e5216f | 994 | |
83c54070 | 995 | ret = 0; |
1e8f889b DG |
996 | |
997 | spin_lock(&mm->page_table_lock); | |
998 | /* Check for a racing update before calling hugetlb_cow */ | |
999 | if (likely(pte_same(entry, *ptep))) | |
1000 | if (write_access && !pte_write(entry)) | |
1001 | ret = hugetlb_cow(mm, vma, address, ptep, entry); | |
1002 | spin_unlock(&mm->page_table_lock); | |
3935baa9 | 1003 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
1004 | |
1005 | return ret; | |
86e5216f AL |
1006 | } |
1007 | ||
63551ae0 DG |
1008 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1009 | struct page **pages, struct vm_area_struct **vmas, | |
5b23dbe8 AL |
1010 | unsigned long *position, int *length, int i, |
1011 | int write) | |
63551ae0 | 1012 | { |
d5d4b0aa CK |
1013 | unsigned long pfn_offset; |
1014 | unsigned long vaddr = *position; | |
63551ae0 DG |
1015 | int remainder = *length; |
1016 | ||
1c59827d | 1017 | spin_lock(&mm->page_table_lock); |
63551ae0 | 1018 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
1019 | pte_t *pte; |
1020 | struct page *page; | |
63551ae0 | 1021 | |
4c887265 AL |
1022 | /* |
1023 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
1024 | * each hugepage. We have to make * sure we get the | |
1025 | * first, for the page indexing below to work. | |
1026 | */ | |
1027 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); | |
63551ae0 | 1028 | |
72fad713 | 1029 | if (!pte || pte_none(*pte) || (write && !pte_write(*pte))) { |
4c887265 | 1030 | int ret; |
63551ae0 | 1031 | |
4c887265 | 1032 | spin_unlock(&mm->page_table_lock); |
5b23dbe8 | 1033 | ret = hugetlb_fault(mm, vma, vaddr, write); |
4c887265 | 1034 | spin_lock(&mm->page_table_lock); |
a89182c7 | 1035 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 1036 | continue; |
63551ae0 | 1037 | |
4c887265 AL |
1038 | remainder = 0; |
1039 | if (!i) | |
1040 | i = -EFAULT; | |
1041 | break; | |
1042 | } | |
1043 | ||
d5d4b0aa CK |
1044 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
1045 | page = pte_page(*pte); | |
1046 | same_page: | |
d6692183 CK |
1047 | if (pages) { |
1048 | get_page(page); | |
d5d4b0aa | 1049 | pages[i] = page + pfn_offset; |
d6692183 | 1050 | } |
63551ae0 DG |
1051 | |
1052 | if (vmas) | |
1053 | vmas[i] = vma; | |
1054 | ||
1055 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 1056 | ++pfn_offset; |
63551ae0 DG |
1057 | --remainder; |
1058 | ++i; | |
d5d4b0aa CK |
1059 | if (vaddr < vma->vm_end && remainder && |
1060 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { | |
1061 | /* | |
1062 | * We use pfn_offset to avoid touching the pageframes | |
1063 | * of this compound page. | |
1064 | */ | |
1065 | goto same_page; | |
1066 | } | |
63551ae0 | 1067 | } |
1c59827d | 1068 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
1069 | *length = remainder; |
1070 | *position = vaddr; | |
1071 | ||
1072 | return i; | |
1073 | } | |
8f860591 ZY |
1074 | |
1075 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
1076 | unsigned long address, unsigned long end, pgprot_t newprot) | |
1077 | { | |
1078 | struct mm_struct *mm = vma->vm_mm; | |
1079 | unsigned long start = address; | |
1080 | pte_t *ptep; | |
1081 | pte_t pte; | |
1082 | ||
1083 | BUG_ON(address >= end); | |
1084 | flush_cache_range(vma, address, end); | |
1085 | ||
39dde65c | 1086 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
1087 | spin_lock(&mm->page_table_lock); |
1088 | for (; address < end; address += HPAGE_SIZE) { | |
1089 | ptep = huge_pte_offset(mm, address); | |
1090 | if (!ptep) | |
1091 | continue; | |
39dde65c CK |
1092 | if (huge_pmd_unshare(mm, &address, ptep)) |
1093 | continue; | |
8f860591 ZY |
1094 | if (!pte_none(*ptep)) { |
1095 | pte = huge_ptep_get_and_clear(mm, address, ptep); | |
1096 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
1097 | set_huge_pte_at(mm, address, ptep, pte); | |
8f860591 ZY |
1098 | } |
1099 | } | |
1100 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 1101 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
1102 | |
1103 | flush_tlb_range(vma, start, end); | |
1104 | } | |
1105 | ||
a43a8c39 CK |
1106 | struct file_region { |
1107 | struct list_head link; | |
1108 | long from; | |
1109 | long to; | |
1110 | }; | |
1111 | ||
1112 | static long region_add(struct list_head *head, long f, long t) | |
1113 | { | |
1114 | struct file_region *rg, *nrg, *trg; | |
1115 | ||
1116 | /* Locate the region we are either in or before. */ | |
1117 | list_for_each_entry(rg, head, link) | |
1118 | if (f <= rg->to) | |
1119 | break; | |
1120 | ||
1121 | /* Round our left edge to the current segment if it encloses us. */ | |
1122 | if (f > rg->from) | |
1123 | f = rg->from; | |
1124 | ||
1125 | /* Check for and consume any regions we now overlap with. */ | |
1126 | nrg = rg; | |
1127 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
1128 | if (&rg->link == head) | |
1129 | break; | |
1130 | if (rg->from > t) | |
1131 | break; | |
1132 | ||
1133 | /* If this area reaches higher then extend our area to | |
1134 | * include it completely. If this is not the first area | |
1135 | * which we intend to reuse, free it. */ | |
1136 | if (rg->to > t) | |
1137 | t = rg->to; | |
1138 | if (rg != nrg) { | |
1139 | list_del(&rg->link); | |
1140 | kfree(rg); | |
1141 | } | |
1142 | } | |
1143 | nrg->from = f; | |
1144 | nrg->to = t; | |
1145 | return 0; | |
1146 | } | |
1147 | ||
1148 | static long region_chg(struct list_head *head, long f, long t) | |
1149 | { | |
1150 | struct file_region *rg, *nrg; | |
1151 | long chg = 0; | |
1152 | ||
1153 | /* Locate the region we are before or in. */ | |
1154 | list_for_each_entry(rg, head, link) | |
1155 | if (f <= rg->to) | |
1156 | break; | |
1157 | ||
1158 | /* If we are below the current region then a new region is required. | |
1159 | * Subtle, allocate a new region at the position but make it zero | |
183ff22b | 1160 | * size such that we can guarantee to record the reservation. */ |
a43a8c39 CK |
1161 | if (&rg->link == head || t < rg->from) { |
1162 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
c80544dc | 1163 | if (!nrg) |
a43a8c39 CK |
1164 | return -ENOMEM; |
1165 | nrg->from = f; | |
1166 | nrg->to = f; | |
1167 | INIT_LIST_HEAD(&nrg->link); | |
1168 | list_add(&nrg->link, rg->link.prev); | |
1169 | ||
1170 | return t - f; | |
1171 | } | |
1172 | ||
1173 | /* Round our left edge to the current segment if it encloses us. */ | |
1174 | if (f > rg->from) | |
1175 | f = rg->from; | |
1176 | chg = t - f; | |
1177 | ||
1178 | /* Check for and consume any regions we now overlap with. */ | |
1179 | list_for_each_entry(rg, rg->link.prev, link) { | |
1180 | if (&rg->link == head) | |
1181 | break; | |
1182 | if (rg->from > t) | |
1183 | return chg; | |
1184 | ||
1185 | /* We overlap with this area, if it extends futher than | |
1186 | * us then we must extend ourselves. Account for its | |
1187 | * existing reservation. */ | |
1188 | if (rg->to > t) { | |
1189 | chg += rg->to - t; | |
1190 | t = rg->to; | |
1191 | } | |
1192 | chg -= rg->to - rg->from; | |
1193 | } | |
1194 | return chg; | |
1195 | } | |
1196 | ||
1197 | static long region_truncate(struct list_head *head, long end) | |
1198 | { | |
1199 | struct file_region *rg, *trg; | |
1200 | long chg = 0; | |
1201 | ||
1202 | /* Locate the region we are either in or before. */ | |
1203 | list_for_each_entry(rg, head, link) | |
1204 | if (end <= rg->to) | |
1205 | break; | |
1206 | if (&rg->link == head) | |
1207 | return 0; | |
1208 | ||
1209 | /* If we are in the middle of a region then adjust it. */ | |
1210 | if (end > rg->from) { | |
1211 | chg = rg->to - end; | |
1212 | rg->to = end; | |
1213 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
1214 | } | |
1215 | ||
1216 | /* Drop any remaining regions. */ | |
1217 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
1218 | if (&rg->link == head) | |
1219 | break; | |
1220 | chg += rg->to - rg->from; | |
1221 | list_del(&rg->link); | |
1222 | kfree(rg); | |
1223 | } | |
1224 | return chg; | |
1225 | } | |
1226 | ||
1227 | static int hugetlb_acct_memory(long delta) | |
1228 | { | |
1229 | int ret = -ENOMEM; | |
1230 | ||
1231 | spin_lock(&hugetlb_lock); | |
8a630112 KC |
1232 | /* |
1233 | * When cpuset is configured, it breaks the strict hugetlb page | |
1234 | * reservation as the accounting is done on a global variable. Such | |
1235 | * reservation is completely rubbish in the presence of cpuset because | |
1236 | * the reservation is not checked against page availability for the | |
1237 | * current cpuset. Application can still potentially OOM'ed by kernel | |
1238 | * with lack of free htlb page in cpuset that the task is in. | |
1239 | * Attempt to enforce strict accounting with cpuset is almost | |
1240 | * impossible (or too ugly) because cpuset is too fluid that | |
1241 | * task or memory node can be dynamically moved between cpusets. | |
1242 | * | |
1243 | * The change of semantics for shared hugetlb mapping with cpuset is | |
1244 | * undesirable. However, in order to preserve some of the semantics, | |
1245 | * we fall back to check against current free page availability as | |
1246 | * a best attempt and hopefully to minimize the impact of changing | |
1247 | * semantics that cpuset has. | |
1248 | */ | |
e4e574b7 AL |
1249 | if (delta > 0) { |
1250 | if (gather_surplus_pages(delta) < 0) | |
1251 | goto out; | |
1252 | ||
ac09b3a1 AL |
1253 | if (delta > cpuset_mems_nr(free_huge_pages_node)) { |
1254 | return_unused_surplus_pages(delta); | |
e4e574b7 | 1255 | goto out; |
ac09b3a1 | 1256 | } |
e4e574b7 AL |
1257 | } |
1258 | ||
1259 | ret = 0; | |
e4e574b7 AL |
1260 | if (delta < 0) |
1261 | return_unused_surplus_pages((unsigned long) -delta); | |
1262 | ||
1263 | out: | |
1264 | spin_unlock(&hugetlb_lock); | |
1265 | return ret; | |
1266 | } | |
1267 | ||
1268 | int hugetlb_reserve_pages(struct inode *inode, long from, long to) | |
1269 | { | |
1270 | long ret, chg; | |
1271 | ||
1272 | chg = region_chg(&inode->i_mapping->private_list, from, to); | |
1273 | if (chg < 0) | |
1274 | return chg; | |
8a630112 | 1275 | |
90d8b7e6 AL |
1276 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
1277 | return -ENOSPC; | |
a43a8c39 | 1278 | ret = hugetlb_acct_memory(chg); |
68842c9b KC |
1279 | if (ret < 0) { |
1280 | hugetlb_put_quota(inode->i_mapping, chg); | |
a43a8c39 | 1281 | return ret; |
68842c9b | 1282 | } |
a43a8c39 CK |
1283 | region_add(&inode->i_mapping->private_list, from, to); |
1284 | return 0; | |
1285 | } | |
1286 | ||
1287 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
1288 | { | |
1289 | long chg = region_truncate(&inode->i_mapping->private_list, offset); | |
45c682a6 KC |
1290 | |
1291 | spin_lock(&inode->i_lock); | |
1292 | inode->i_blocks -= BLOCKS_PER_HUGEPAGE * freed; | |
1293 | spin_unlock(&inode->i_lock); | |
1294 | ||
90d8b7e6 AL |
1295 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
1296 | hugetlb_acct_memory(-(chg - freed)); | |
a43a8c39 | 1297 | } |