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; |
1da177e4 LT |
27 | unsigned long max_huge_pages; |
28 | static struct list_head hugepage_freelists[MAX_NUMNODES]; | |
29 | static unsigned int nr_huge_pages_node[MAX_NUMNODES]; | |
30 | static unsigned int free_huge_pages_node[MAX_NUMNODES]; | |
7893d1d5 | 31 | static unsigned int surplus_huge_pages_node[MAX_NUMNODES]; |
396faf03 MG |
32 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
33 | unsigned long hugepages_treat_as_movable; | |
34 | ||
3935baa9 DG |
35 | /* |
36 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages | |
37 | */ | |
38 | static DEFINE_SPINLOCK(hugetlb_lock); | |
0bd0f9fb | 39 | |
79ac6ba4 DG |
40 | static void clear_huge_page(struct page *page, unsigned long addr) |
41 | { | |
42 | int i; | |
43 | ||
44 | might_sleep(); | |
45 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) { | |
46 | cond_resched(); | |
281e0e3b | 47 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
79ac6ba4 DG |
48 | } |
49 | } | |
50 | ||
51 | static void copy_huge_page(struct page *dst, struct page *src, | |
9de455b2 | 52 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
53 | { |
54 | int i; | |
55 | ||
56 | might_sleep(); | |
57 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { | |
58 | cond_resched(); | |
9de455b2 | 59 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
60 | } |
61 | } | |
62 | ||
1da177e4 LT |
63 | static void enqueue_huge_page(struct page *page) |
64 | { | |
65 | int nid = page_to_nid(page); | |
66 | list_add(&page->lru, &hugepage_freelists[nid]); | |
67 | free_huge_pages++; | |
68 | free_huge_pages_node[nid]++; | |
69 | } | |
70 | ||
5da7ca86 CL |
71 | static struct page *dequeue_huge_page(struct vm_area_struct *vma, |
72 | unsigned long address) | |
1da177e4 | 73 | { |
31a5c6e4 | 74 | int nid; |
1da177e4 | 75 | struct page *page = NULL; |
480eccf9 | 76 | struct mempolicy *mpol; |
396faf03 | 77 | struct zonelist *zonelist = huge_zonelist(vma, address, |
480eccf9 | 78 | htlb_alloc_mask, &mpol); |
96df9333 | 79 | struct zone **z; |
1da177e4 | 80 | |
96df9333 | 81 | for (z = zonelist->zones; *z; z++) { |
89fa3024 | 82 | nid = zone_to_nid(*z); |
396faf03 | 83 | if (cpuset_zone_allowed_softwall(*z, htlb_alloc_mask) && |
3abf7afd AM |
84 | !list_empty(&hugepage_freelists[nid])) { |
85 | page = list_entry(hugepage_freelists[nid].next, | |
86 | struct page, lru); | |
87 | list_del(&page->lru); | |
88 | free_huge_pages--; | |
89 | free_huge_pages_node[nid]--; | |
e4e574b7 AL |
90 | if (vma && vma->vm_flags & VM_MAYSHARE) |
91 | resv_huge_pages--; | |
5ab3ee7b | 92 | break; |
3abf7afd | 93 | } |
1da177e4 | 94 | } |
480eccf9 | 95 | mpol_free(mpol); /* unref if mpol !NULL */ |
1da177e4 LT |
96 | return page; |
97 | } | |
98 | ||
6af2acb6 AL |
99 | static void update_and_free_page(struct page *page) |
100 | { | |
101 | int i; | |
102 | nr_huge_pages--; | |
103 | nr_huge_pages_node[page_to_nid(page)]--; | |
104 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { | |
105 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | | |
106 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
107 | 1 << PG_private | 1<< PG_writeback); | |
108 | } | |
109 | set_compound_page_dtor(page, NULL); | |
110 | set_page_refcounted(page); | |
111 | __free_pages(page, HUGETLB_PAGE_ORDER); | |
112 | } | |
113 | ||
27a85ef1 DG |
114 | static void free_huge_page(struct page *page) |
115 | { | |
7893d1d5 | 116 | int nid = page_to_nid(page); |
27a85ef1 | 117 | |
7893d1d5 | 118 | BUG_ON(page_count(page)); |
27a85ef1 DG |
119 | INIT_LIST_HEAD(&page->lru); |
120 | ||
121 | spin_lock(&hugetlb_lock); | |
7893d1d5 AL |
122 | if (surplus_huge_pages_node[nid]) { |
123 | update_and_free_page(page); | |
124 | surplus_huge_pages--; | |
125 | surplus_huge_pages_node[nid]--; | |
126 | } else { | |
127 | enqueue_huge_page(page); | |
128 | } | |
27a85ef1 DG |
129 | spin_unlock(&hugetlb_lock); |
130 | } | |
131 | ||
7893d1d5 AL |
132 | /* |
133 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
134 | * balanced by operating on them in a round-robin fashion. | |
135 | * Returns 1 if an adjustment was made. | |
136 | */ | |
137 | static int adjust_pool_surplus(int delta) | |
138 | { | |
139 | static int prev_nid; | |
140 | int nid = prev_nid; | |
141 | int ret = 0; | |
142 | ||
143 | VM_BUG_ON(delta != -1 && delta != 1); | |
144 | do { | |
145 | nid = next_node(nid, node_online_map); | |
146 | if (nid == MAX_NUMNODES) | |
147 | nid = first_node(node_online_map); | |
148 | ||
149 | /* To shrink on this node, there must be a surplus page */ | |
150 | if (delta < 0 && !surplus_huge_pages_node[nid]) | |
151 | continue; | |
152 | /* Surplus cannot exceed the total number of pages */ | |
153 | if (delta > 0 && surplus_huge_pages_node[nid] >= | |
154 | nr_huge_pages_node[nid]) | |
155 | continue; | |
156 | ||
157 | surplus_huge_pages += delta; | |
158 | surplus_huge_pages_node[nid] += delta; | |
159 | ret = 1; | |
160 | break; | |
161 | } while (nid != prev_nid); | |
162 | ||
163 | prev_nid = nid; | |
164 | return ret; | |
165 | } | |
166 | ||
a482289d | 167 | static int alloc_fresh_huge_page(void) |
1da177e4 | 168 | { |
f96efd58 | 169 | static int prev_nid; |
1da177e4 | 170 | struct page *page; |
f96efd58 JJ |
171 | int nid; |
172 | ||
7ed5cb2b HD |
173 | /* |
174 | * Copy static prev_nid to local nid, work on that, then copy it | |
175 | * back to prev_nid afterwards: otherwise there's a window in which | |
176 | * a racer might pass invalid nid MAX_NUMNODES to alloc_pages_node. | |
177 | * But we don't need to use a spin_lock here: it really doesn't | |
178 | * matter if occasionally a racer chooses the same nid as we do. | |
179 | */ | |
f96efd58 | 180 | nid = next_node(prev_nid, node_online_map); |
fdb7cc59 PJ |
181 | if (nid == MAX_NUMNODES) |
182 | nid = first_node(node_online_map); | |
f96efd58 | 183 | prev_nid = nid; |
f96efd58 | 184 | |
396faf03 | 185 | page = alloc_pages_node(nid, htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN, |
f96efd58 | 186 | HUGETLB_PAGE_ORDER); |
1da177e4 | 187 | if (page) { |
33f2ef89 | 188 | set_compound_page_dtor(page, free_huge_page); |
0bd0f9fb | 189 | spin_lock(&hugetlb_lock); |
1da177e4 LT |
190 | nr_huge_pages++; |
191 | nr_huge_pages_node[page_to_nid(page)]++; | |
0bd0f9fb | 192 | spin_unlock(&hugetlb_lock); |
a482289d NP |
193 | put_page(page); /* free it into the hugepage allocator */ |
194 | return 1; | |
1da177e4 | 195 | } |
a482289d | 196 | return 0; |
1da177e4 LT |
197 | } |
198 | ||
7893d1d5 AL |
199 | static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma, |
200 | unsigned long address) | |
201 | { | |
202 | struct page *page; | |
203 | ||
204 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN, | |
205 | HUGETLB_PAGE_ORDER); | |
206 | if (page) { | |
207 | set_compound_page_dtor(page, free_huge_page); | |
208 | spin_lock(&hugetlb_lock); | |
209 | nr_huge_pages++; | |
210 | nr_huge_pages_node[page_to_nid(page)]++; | |
211 | surplus_huge_pages++; | |
212 | surplus_huge_pages_node[page_to_nid(page)]++; | |
213 | spin_unlock(&hugetlb_lock); | |
214 | } | |
215 | ||
216 | return page; | |
217 | } | |
218 | ||
e4e574b7 AL |
219 | /* |
220 | * Increase the hugetlb pool such that it can accomodate a reservation | |
221 | * of size 'delta'. | |
222 | */ | |
223 | static int gather_surplus_pages(int delta) | |
224 | { | |
225 | struct list_head surplus_list; | |
226 | struct page *page, *tmp; | |
227 | int ret, i; | |
228 | int needed, allocated; | |
229 | ||
230 | needed = (resv_huge_pages + delta) - free_huge_pages; | |
231 | if (needed <= 0) | |
232 | return 0; | |
233 | ||
234 | allocated = 0; | |
235 | INIT_LIST_HEAD(&surplus_list); | |
236 | ||
237 | ret = -ENOMEM; | |
238 | retry: | |
239 | spin_unlock(&hugetlb_lock); | |
240 | for (i = 0; i < needed; i++) { | |
241 | page = alloc_buddy_huge_page(NULL, 0); | |
242 | if (!page) { | |
243 | /* | |
244 | * We were not able to allocate enough pages to | |
245 | * satisfy the entire reservation so we free what | |
246 | * we've allocated so far. | |
247 | */ | |
248 | spin_lock(&hugetlb_lock); | |
249 | needed = 0; | |
250 | goto free; | |
251 | } | |
252 | ||
253 | list_add(&page->lru, &surplus_list); | |
254 | } | |
255 | allocated += needed; | |
256 | ||
257 | /* | |
258 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
259 | * because either resv_huge_pages or free_huge_pages may have changed. | |
260 | */ | |
261 | spin_lock(&hugetlb_lock); | |
262 | needed = (resv_huge_pages + delta) - (free_huge_pages + allocated); | |
263 | if (needed > 0) | |
264 | goto retry; | |
265 | ||
266 | /* | |
267 | * The surplus_list now contains _at_least_ the number of extra pages | |
268 | * needed to accomodate the reservation. Add the appropriate number | |
269 | * of pages to the hugetlb pool and free the extras back to the buddy | |
270 | * allocator. | |
271 | */ | |
272 | needed += allocated; | |
273 | ret = 0; | |
274 | free: | |
275 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { | |
276 | list_del(&page->lru); | |
277 | if ((--needed) >= 0) | |
278 | enqueue_huge_page(page); | |
279 | else | |
280 | update_and_free_page(page); | |
281 | } | |
282 | ||
283 | return ret; | |
284 | } | |
285 | ||
286 | /* | |
287 | * When releasing a hugetlb pool reservation, any surplus pages that were | |
288 | * allocated to satisfy the reservation must be explicitly freed if they were | |
289 | * never used. | |
290 | */ | |
291 | void return_unused_surplus_pages(unsigned long unused_resv_pages) | |
292 | { | |
293 | static int nid = -1; | |
294 | struct page *page; | |
295 | unsigned long nr_pages; | |
296 | ||
297 | nr_pages = min(unused_resv_pages, surplus_huge_pages); | |
298 | ||
299 | while (nr_pages) { | |
300 | nid = next_node(nid, node_online_map); | |
301 | if (nid == MAX_NUMNODES) | |
302 | nid = first_node(node_online_map); | |
303 | ||
304 | if (!surplus_huge_pages_node[nid]) | |
305 | continue; | |
306 | ||
307 | if (!list_empty(&hugepage_freelists[nid])) { | |
308 | page = list_entry(hugepage_freelists[nid].next, | |
309 | struct page, lru); | |
310 | list_del(&page->lru); | |
311 | update_and_free_page(page); | |
312 | free_huge_pages--; | |
313 | free_huge_pages_node[nid]--; | |
314 | surplus_huge_pages--; | |
315 | surplus_huge_pages_node[nid]--; | |
316 | nr_pages--; | |
317 | } | |
318 | } | |
319 | } | |
320 | ||
27a85ef1 DG |
321 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
322 | unsigned long addr) | |
1da177e4 | 323 | { |
7893d1d5 | 324 | struct page *page = NULL; |
e4e574b7 | 325 | int use_reserved_page = vma->vm_flags & VM_MAYSHARE; |
1da177e4 LT |
326 | |
327 | spin_lock(&hugetlb_lock); | |
e4e574b7 | 328 | if (!use_reserved_page && (free_huge_pages <= resv_huge_pages)) |
a43a8c39 | 329 | goto fail; |
b45b5bd6 DG |
330 | |
331 | page = dequeue_huge_page(vma, addr); | |
332 | if (!page) | |
333 | goto fail; | |
334 | ||
1da177e4 | 335 | spin_unlock(&hugetlb_lock); |
7835e98b | 336 | set_page_refcounted(page); |
1da177e4 | 337 | return page; |
b45b5bd6 | 338 | |
a43a8c39 | 339 | fail: |
b45b5bd6 | 340 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
341 | |
342 | /* | |
343 | * Private mappings do not use reserved huge pages so the allocation | |
344 | * may have failed due to an undersized hugetlb pool. Try to grab a | |
345 | * surplus huge page from the buddy allocator. | |
346 | */ | |
e4e574b7 | 347 | if (!use_reserved_page) |
7893d1d5 AL |
348 | page = alloc_buddy_huge_page(vma, addr); |
349 | ||
350 | return page; | |
b45b5bd6 DG |
351 | } |
352 | ||
1da177e4 LT |
353 | static int __init hugetlb_init(void) |
354 | { | |
355 | unsigned long i; | |
1da177e4 | 356 | |
3c726f8d BH |
357 | if (HPAGE_SHIFT == 0) |
358 | return 0; | |
359 | ||
1da177e4 LT |
360 | for (i = 0; i < MAX_NUMNODES; ++i) |
361 | INIT_LIST_HEAD(&hugepage_freelists[i]); | |
362 | ||
363 | for (i = 0; i < max_huge_pages; ++i) { | |
a482289d | 364 | if (!alloc_fresh_huge_page()) |
1da177e4 | 365 | break; |
1da177e4 LT |
366 | } |
367 | max_huge_pages = free_huge_pages = nr_huge_pages = i; | |
368 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); | |
369 | return 0; | |
370 | } | |
371 | module_init(hugetlb_init); | |
372 | ||
373 | static int __init hugetlb_setup(char *s) | |
374 | { | |
375 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) | |
376 | max_huge_pages = 0; | |
377 | return 1; | |
378 | } | |
379 | __setup("hugepages=", hugetlb_setup); | |
380 | ||
8a630112 KC |
381 | static unsigned int cpuset_mems_nr(unsigned int *array) |
382 | { | |
383 | int node; | |
384 | unsigned int nr = 0; | |
385 | ||
386 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
387 | nr += array[node]; | |
388 | ||
389 | return nr; | |
390 | } | |
391 | ||
1da177e4 | 392 | #ifdef CONFIG_SYSCTL |
1da177e4 LT |
393 | #ifdef CONFIG_HIGHMEM |
394 | static void try_to_free_low(unsigned long count) | |
395 | { | |
4415cc8d CL |
396 | int i; |
397 | ||
1da177e4 LT |
398 | for (i = 0; i < MAX_NUMNODES; ++i) { |
399 | struct page *page, *next; | |
400 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { | |
401 | if (PageHighMem(page)) | |
402 | continue; | |
403 | list_del(&page->lru); | |
404 | update_and_free_page(page); | |
1da177e4 | 405 | free_huge_pages--; |
4415cc8d | 406 | free_huge_pages_node[page_to_nid(page)]--; |
1da177e4 LT |
407 | if (count >= nr_huge_pages) |
408 | return; | |
409 | } | |
410 | } | |
411 | } | |
412 | #else | |
413 | static inline void try_to_free_low(unsigned long count) | |
414 | { | |
415 | } | |
416 | #endif | |
417 | ||
7893d1d5 | 418 | #define persistent_huge_pages (nr_huge_pages - surplus_huge_pages) |
1da177e4 LT |
419 | static unsigned long set_max_huge_pages(unsigned long count) |
420 | { | |
7893d1d5 | 421 | unsigned long min_count, ret; |
1da177e4 | 422 | |
7893d1d5 AL |
423 | /* |
424 | * Increase the pool size | |
425 | * First take pages out of surplus state. Then make up the | |
426 | * remaining difference by allocating fresh huge pages. | |
427 | */ | |
1da177e4 | 428 | spin_lock(&hugetlb_lock); |
7893d1d5 AL |
429 | while (surplus_huge_pages && count > persistent_huge_pages) { |
430 | if (!adjust_pool_surplus(-1)) | |
431 | break; | |
432 | } | |
433 | ||
434 | while (count > persistent_huge_pages) { | |
435 | int ret; | |
436 | /* | |
437 | * If this allocation races such that we no longer need the | |
438 | * page, free_huge_page will handle it by freeing the page | |
439 | * and reducing the surplus. | |
440 | */ | |
441 | spin_unlock(&hugetlb_lock); | |
442 | ret = alloc_fresh_huge_page(); | |
443 | spin_lock(&hugetlb_lock); | |
444 | if (!ret) | |
445 | goto out; | |
446 | ||
447 | } | |
448 | if (count >= persistent_huge_pages) | |
449 | goto out; | |
450 | ||
451 | /* | |
452 | * Decrease the pool size | |
453 | * First return free pages to the buddy allocator (being careful | |
454 | * to keep enough around to satisfy reservations). Then place | |
455 | * pages into surplus state as needed so the pool will shrink | |
456 | * to the desired size as pages become free. | |
457 | */ | |
458 | min_count = max(count, resv_huge_pages); | |
459 | try_to_free_low(min_count); | |
460 | while (min_count < persistent_huge_pages) { | |
5da7ca86 | 461 | struct page *page = dequeue_huge_page(NULL, 0); |
1da177e4 LT |
462 | if (!page) |
463 | break; | |
464 | update_and_free_page(page); | |
465 | } | |
7893d1d5 AL |
466 | while (count < persistent_huge_pages) { |
467 | if (!adjust_pool_surplus(1)) | |
468 | break; | |
469 | } | |
470 | out: | |
471 | ret = persistent_huge_pages; | |
1da177e4 | 472 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 473 | return ret; |
1da177e4 LT |
474 | } |
475 | ||
476 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, | |
477 | struct file *file, void __user *buffer, | |
478 | size_t *length, loff_t *ppos) | |
479 | { | |
480 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); | |
481 | max_huge_pages = set_max_huge_pages(max_huge_pages); | |
482 | return 0; | |
483 | } | |
396faf03 MG |
484 | |
485 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, | |
486 | struct file *file, void __user *buffer, | |
487 | size_t *length, loff_t *ppos) | |
488 | { | |
489 | proc_dointvec(table, write, file, buffer, length, ppos); | |
490 | if (hugepages_treat_as_movable) | |
491 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; | |
492 | else | |
493 | htlb_alloc_mask = GFP_HIGHUSER; | |
494 | return 0; | |
495 | } | |
496 | ||
1da177e4 LT |
497 | #endif /* CONFIG_SYSCTL */ |
498 | ||
499 | int hugetlb_report_meminfo(char *buf) | |
500 | { | |
501 | return sprintf(buf, | |
502 | "HugePages_Total: %5lu\n" | |
503 | "HugePages_Free: %5lu\n" | |
a43a8c39 | 504 | "HugePages_Rsvd: %5lu\n" |
7893d1d5 | 505 | "HugePages_Surp: %5lu\n" |
1da177e4 LT |
506 | "Hugepagesize: %5lu kB\n", |
507 | nr_huge_pages, | |
508 | free_huge_pages, | |
a43a8c39 | 509 | resv_huge_pages, |
7893d1d5 | 510 | surplus_huge_pages, |
1da177e4 LT |
511 | HPAGE_SIZE/1024); |
512 | } | |
513 | ||
514 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
515 | { | |
516 | return sprintf(buf, | |
517 | "Node %d HugePages_Total: %5u\n" | |
518 | "Node %d HugePages_Free: %5u\n", | |
519 | nid, nr_huge_pages_node[nid], | |
520 | nid, free_huge_pages_node[nid]); | |
521 | } | |
522 | ||
1da177e4 LT |
523 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
524 | unsigned long hugetlb_total_pages(void) | |
525 | { | |
526 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); | |
527 | } | |
1da177e4 LT |
528 | |
529 | /* | |
530 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
531 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
532 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
533 | * this far. | |
534 | */ | |
d0217ac0 | 535 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
536 | { |
537 | BUG(); | |
d0217ac0 | 538 | return 0; |
1da177e4 LT |
539 | } |
540 | ||
541 | struct vm_operations_struct hugetlb_vm_ops = { | |
d0217ac0 | 542 | .fault = hugetlb_vm_op_fault, |
1da177e4 LT |
543 | }; |
544 | ||
1e8f889b DG |
545 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
546 | int writable) | |
63551ae0 DG |
547 | { |
548 | pte_t entry; | |
549 | ||
1e8f889b | 550 | if (writable) { |
63551ae0 DG |
551 | entry = |
552 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
553 | } else { | |
554 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); | |
555 | } | |
556 | entry = pte_mkyoung(entry); | |
557 | entry = pte_mkhuge(entry); | |
558 | ||
559 | return entry; | |
560 | } | |
561 | ||
1e8f889b DG |
562 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
563 | unsigned long address, pte_t *ptep) | |
564 | { | |
565 | pte_t entry; | |
566 | ||
567 | entry = pte_mkwrite(pte_mkdirty(*ptep)); | |
8dab5241 BH |
568 | if (ptep_set_access_flags(vma, address, ptep, entry, 1)) { |
569 | update_mmu_cache(vma, address, entry); | |
8dab5241 | 570 | } |
1e8f889b DG |
571 | } |
572 | ||
573 | ||
63551ae0 DG |
574 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
575 | struct vm_area_struct *vma) | |
576 | { | |
577 | pte_t *src_pte, *dst_pte, entry; | |
578 | struct page *ptepage; | |
1c59827d | 579 | unsigned long addr; |
1e8f889b DG |
580 | int cow; |
581 | ||
582 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 583 | |
1c59827d | 584 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
c74df32c HD |
585 | src_pte = huge_pte_offset(src, addr); |
586 | if (!src_pte) | |
587 | continue; | |
63551ae0 DG |
588 | dst_pte = huge_pte_alloc(dst, addr); |
589 | if (!dst_pte) | |
590 | goto nomem; | |
c74df32c | 591 | spin_lock(&dst->page_table_lock); |
1c59827d | 592 | spin_lock(&src->page_table_lock); |
c74df32c | 593 | if (!pte_none(*src_pte)) { |
1e8f889b DG |
594 | if (cow) |
595 | ptep_set_wrprotect(src, addr, src_pte); | |
1c59827d HD |
596 | entry = *src_pte; |
597 | ptepage = pte_page(entry); | |
598 | get_page(ptepage); | |
1c59827d HD |
599 | set_huge_pte_at(dst, addr, dst_pte, entry); |
600 | } | |
601 | spin_unlock(&src->page_table_lock); | |
c74df32c | 602 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
603 | } |
604 | return 0; | |
605 | ||
606 | nomem: | |
607 | return -ENOMEM; | |
608 | } | |
609 | ||
502717f4 KC |
610 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
611 | unsigned long end) | |
63551ae0 DG |
612 | { |
613 | struct mm_struct *mm = vma->vm_mm; | |
614 | unsigned long address; | |
c7546f8f | 615 | pte_t *ptep; |
63551ae0 DG |
616 | pte_t pte; |
617 | struct page *page; | |
fe1668ae | 618 | struct page *tmp; |
c0a499c2 KC |
619 | /* |
620 | * A page gathering list, protected by per file i_mmap_lock. The | |
621 | * lock is used to avoid list corruption from multiple unmapping | |
622 | * of the same page since we are using page->lru. | |
623 | */ | |
fe1668ae | 624 | LIST_HEAD(page_list); |
63551ae0 DG |
625 | |
626 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
627 | BUG_ON(start & ~HPAGE_MASK); | |
628 | BUG_ON(end & ~HPAGE_MASK); | |
629 | ||
508034a3 | 630 | spin_lock(&mm->page_table_lock); |
63551ae0 | 631 | for (address = start; address < end; address += HPAGE_SIZE) { |
c7546f8f | 632 | ptep = huge_pte_offset(mm, address); |
4c887265 | 633 | if (!ptep) |
c7546f8f DG |
634 | continue; |
635 | ||
39dde65c KC |
636 | if (huge_pmd_unshare(mm, &address, ptep)) |
637 | continue; | |
638 | ||
c7546f8f | 639 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
63551ae0 DG |
640 | if (pte_none(pte)) |
641 | continue; | |
c7546f8f | 642 | |
63551ae0 | 643 | page = pte_page(pte); |
6649a386 KC |
644 | if (pte_dirty(pte)) |
645 | set_page_dirty(page); | |
fe1668ae | 646 | list_add(&page->lru, &page_list); |
63551ae0 | 647 | } |
1da177e4 | 648 | spin_unlock(&mm->page_table_lock); |
508034a3 | 649 | flush_tlb_range(vma, start, end); |
fe1668ae KC |
650 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
651 | list_del(&page->lru); | |
652 | put_page(page); | |
653 | } | |
1da177e4 | 654 | } |
63551ae0 | 655 | |
502717f4 KC |
656 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
657 | unsigned long end) | |
658 | { | |
659 | /* | |
660 | * It is undesirable to test vma->vm_file as it should be non-null | |
661 | * for valid hugetlb area. However, vm_file will be NULL in the error | |
662 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, | |
663 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function | |
664 | * to clean up. Since no pte has actually been setup, it is safe to | |
665 | * do nothing in this case. | |
666 | */ | |
667 | if (vma->vm_file) { | |
668 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); | |
669 | __unmap_hugepage_range(vma, start, end); | |
670 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); | |
671 | } | |
672 | } | |
673 | ||
1e8f889b DG |
674 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
675 | unsigned long address, pte_t *ptep, pte_t pte) | |
676 | { | |
677 | struct page *old_page, *new_page; | |
79ac6ba4 | 678 | int avoidcopy; |
1e8f889b DG |
679 | |
680 | old_page = pte_page(pte); | |
681 | ||
682 | /* If no-one else is actually using this page, avoid the copy | |
683 | * and just make the page writable */ | |
684 | avoidcopy = (page_count(old_page) == 1); | |
685 | if (avoidcopy) { | |
686 | set_huge_ptep_writable(vma, address, ptep); | |
83c54070 | 687 | return 0; |
1e8f889b DG |
688 | } |
689 | ||
690 | page_cache_get(old_page); | |
5da7ca86 | 691 | new_page = alloc_huge_page(vma, address); |
1e8f889b DG |
692 | |
693 | if (!new_page) { | |
694 | page_cache_release(old_page); | |
0df420d8 | 695 | return VM_FAULT_OOM; |
1e8f889b DG |
696 | } |
697 | ||
698 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 699 | copy_huge_page(new_page, old_page, address, vma); |
1e8f889b DG |
700 | spin_lock(&mm->page_table_lock); |
701 | ||
702 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); | |
703 | if (likely(pte_same(*ptep, pte))) { | |
704 | /* Break COW */ | |
705 | set_huge_pte_at(mm, address, ptep, | |
706 | make_huge_pte(vma, new_page, 1)); | |
707 | /* Make the old page be freed below */ | |
708 | new_page = old_page; | |
709 | } | |
710 | page_cache_release(new_page); | |
711 | page_cache_release(old_page); | |
83c54070 | 712 | return 0; |
1e8f889b DG |
713 | } |
714 | ||
a1ed3dda | 715 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 716 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 HD |
717 | { |
718 | int ret = VM_FAULT_SIGBUS; | |
4c887265 AL |
719 | unsigned long idx; |
720 | unsigned long size; | |
4c887265 AL |
721 | struct page *page; |
722 | struct address_space *mapping; | |
1e8f889b | 723 | pte_t new_pte; |
4c887265 | 724 | |
4c887265 AL |
725 | mapping = vma->vm_file->f_mapping; |
726 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) | |
727 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
728 | ||
729 | /* | |
730 | * Use page lock to guard against racing truncation | |
731 | * before we get page_table_lock. | |
732 | */ | |
6bda666a CL |
733 | retry: |
734 | page = find_lock_page(mapping, idx); | |
735 | if (!page) { | |
ebed4bfc HD |
736 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
737 | if (idx >= size) | |
738 | goto out; | |
6bda666a CL |
739 | if (hugetlb_get_quota(mapping)) |
740 | goto out; | |
741 | page = alloc_huge_page(vma, address); | |
742 | if (!page) { | |
743 | hugetlb_put_quota(mapping); | |
0df420d8 | 744 | ret = VM_FAULT_OOM; |
6bda666a CL |
745 | goto out; |
746 | } | |
79ac6ba4 | 747 | clear_huge_page(page, address); |
ac9b9c66 | 748 | |
6bda666a CL |
749 | if (vma->vm_flags & VM_SHARED) { |
750 | int err; | |
751 | ||
752 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
753 | if (err) { | |
754 | put_page(page); | |
755 | hugetlb_put_quota(mapping); | |
756 | if (err == -EEXIST) | |
757 | goto retry; | |
758 | goto out; | |
759 | } | |
760 | } else | |
761 | lock_page(page); | |
762 | } | |
1e8f889b | 763 | |
ac9b9c66 | 764 | spin_lock(&mm->page_table_lock); |
4c887265 AL |
765 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
766 | if (idx >= size) | |
767 | goto backout; | |
768 | ||
83c54070 | 769 | ret = 0; |
86e5216f | 770 | if (!pte_none(*ptep)) |
4c887265 AL |
771 | goto backout; |
772 | ||
1e8f889b DG |
773 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
774 | && (vma->vm_flags & VM_SHARED))); | |
775 | set_huge_pte_at(mm, address, ptep, new_pte); | |
776 | ||
777 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
778 | /* Optimization, do the COW without a second fault */ | |
779 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); | |
780 | } | |
781 | ||
ac9b9c66 | 782 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
783 | unlock_page(page); |
784 | out: | |
ac9b9c66 | 785 | return ret; |
4c887265 AL |
786 | |
787 | backout: | |
788 | spin_unlock(&mm->page_table_lock); | |
789 | hugetlb_put_quota(mapping); | |
790 | unlock_page(page); | |
791 | put_page(page); | |
792 | goto out; | |
ac9b9c66 HD |
793 | } |
794 | ||
86e5216f AL |
795 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
796 | unsigned long address, int write_access) | |
797 | { | |
798 | pte_t *ptep; | |
799 | pte_t entry; | |
1e8f889b | 800 | int ret; |
3935baa9 | 801 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
86e5216f AL |
802 | |
803 | ptep = huge_pte_alloc(mm, address); | |
804 | if (!ptep) | |
805 | return VM_FAULT_OOM; | |
806 | ||
3935baa9 DG |
807 | /* |
808 | * Serialize hugepage allocation and instantiation, so that we don't | |
809 | * get spurious allocation failures if two CPUs race to instantiate | |
810 | * the same page in the page cache. | |
811 | */ | |
812 | mutex_lock(&hugetlb_instantiation_mutex); | |
86e5216f | 813 | entry = *ptep; |
3935baa9 DG |
814 | if (pte_none(entry)) { |
815 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); | |
816 | mutex_unlock(&hugetlb_instantiation_mutex); | |
817 | return ret; | |
818 | } | |
86e5216f | 819 | |
83c54070 | 820 | ret = 0; |
1e8f889b DG |
821 | |
822 | spin_lock(&mm->page_table_lock); | |
823 | /* Check for a racing update before calling hugetlb_cow */ | |
824 | if (likely(pte_same(entry, *ptep))) | |
825 | if (write_access && !pte_write(entry)) | |
826 | ret = hugetlb_cow(mm, vma, address, ptep, entry); | |
827 | spin_unlock(&mm->page_table_lock); | |
3935baa9 | 828 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
829 | |
830 | return ret; | |
86e5216f AL |
831 | } |
832 | ||
63551ae0 DG |
833 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
834 | struct page **pages, struct vm_area_struct **vmas, | |
835 | unsigned long *position, int *length, int i) | |
836 | { | |
d5d4b0aa KC |
837 | unsigned long pfn_offset; |
838 | unsigned long vaddr = *position; | |
63551ae0 DG |
839 | int remainder = *length; |
840 | ||
1c59827d | 841 | spin_lock(&mm->page_table_lock); |
63551ae0 | 842 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
843 | pte_t *pte; |
844 | struct page *page; | |
63551ae0 | 845 | |
4c887265 AL |
846 | /* |
847 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
848 | * each hugepage. We have to make * sure we get the | |
849 | * first, for the page indexing below to work. | |
850 | */ | |
851 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); | |
63551ae0 | 852 | |
4c887265 AL |
853 | if (!pte || pte_none(*pte)) { |
854 | int ret; | |
63551ae0 | 855 | |
4c887265 AL |
856 | spin_unlock(&mm->page_table_lock); |
857 | ret = hugetlb_fault(mm, vma, vaddr, 0); | |
858 | spin_lock(&mm->page_table_lock); | |
a89182c7 | 859 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 860 | continue; |
63551ae0 | 861 | |
4c887265 AL |
862 | remainder = 0; |
863 | if (!i) | |
864 | i = -EFAULT; | |
865 | break; | |
866 | } | |
867 | ||
d5d4b0aa KC |
868 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
869 | page = pte_page(*pte); | |
870 | same_page: | |
d6692183 KC |
871 | if (pages) { |
872 | get_page(page); | |
d5d4b0aa | 873 | pages[i] = page + pfn_offset; |
d6692183 | 874 | } |
63551ae0 DG |
875 | |
876 | if (vmas) | |
877 | vmas[i] = vma; | |
878 | ||
879 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 880 | ++pfn_offset; |
63551ae0 DG |
881 | --remainder; |
882 | ++i; | |
d5d4b0aa KC |
883 | if (vaddr < vma->vm_end && remainder && |
884 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { | |
885 | /* | |
886 | * We use pfn_offset to avoid touching the pageframes | |
887 | * of this compound page. | |
888 | */ | |
889 | goto same_page; | |
890 | } | |
63551ae0 | 891 | } |
1c59827d | 892 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
893 | *length = remainder; |
894 | *position = vaddr; | |
895 | ||
896 | return i; | |
897 | } | |
8f860591 ZY |
898 | |
899 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
900 | unsigned long address, unsigned long end, pgprot_t newprot) | |
901 | { | |
902 | struct mm_struct *mm = vma->vm_mm; | |
903 | unsigned long start = address; | |
904 | pte_t *ptep; | |
905 | pte_t pte; | |
906 | ||
907 | BUG_ON(address >= end); | |
908 | flush_cache_range(vma, address, end); | |
909 | ||
39dde65c | 910 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
911 | spin_lock(&mm->page_table_lock); |
912 | for (; address < end; address += HPAGE_SIZE) { | |
913 | ptep = huge_pte_offset(mm, address); | |
914 | if (!ptep) | |
915 | continue; | |
39dde65c KC |
916 | if (huge_pmd_unshare(mm, &address, ptep)) |
917 | continue; | |
8f860591 ZY |
918 | if (!pte_none(*ptep)) { |
919 | pte = huge_ptep_get_and_clear(mm, address, ptep); | |
920 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
921 | set_huge_pte_at(mm, address, ptep, pte); | |
8f860591 ZY |
922 | } |
923 | } | |
924 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 925 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
926 | |
927 | flush_tlb_range(vma, start, end); | |
928 | } | |
929 | ||
a43a8c39 KC |
930 | struct file_region { |
931 | struct list_head link; | |
932 | long from; | |
933 | long to; | |
934 | }; | |
935 | ||
936 | static long region_add(struct list_head *head, long f, long t) | |
937 | { | |
938 | struct file_region *rg, *nrg, *trg; | |
939 | ||
940 | /* Locate the region we are either in or before. */ | |
941 | list_for_each_entry(rg, head, link) | |
942 | if (f <= rg->to) | |
943 | break; | |
944 | ||
945 | /* Round our left edge to the current segment if it encloses us. */ | |
946 | if (f > rg->from) | |
947 | f = rg->from; | |
948 | ||
949 | /* Check for and consume any regions we now overlap with. */ | |
950 | nrg = rg; | |
951 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
952 | if (&rg->link == head) | |
953 | break; | |
954 | if (rg->from > t) | |
955 | break; | |
956 | ||
957 | /* If this area reaches higher then extend our area to | |
958 | * include it completely. If this is not the first area | |
959 | * which we intend to reuse, free it. */ | |
960 | if (rg->to > t) | |
961 | t = rg->to; | |
962 | if (rg != nrg) { | |
963 | list_del(&rg->link); | |
964 | kfree(rg); | |
965 | } | |
966 | } | |
967 | nrg->from = f; | |
968 | nrg->to = t; | |
969 | return 0; | |
970 | } | |
971 | ||
972 | static long region_chg(struct list_head *head, long f, long t) | |
973 | { | |
974 | struct file_region *rg, *nrg; | |
975 | long chg = 0; | |
976 | ||
977 | /* Locate the region we are before or in. */ | |
978 | list_for_each_entry(rg, head, link) | |
979 | if (f <= rg->to) | |
980 | break; | |
981 | ||
982 | /* If we are below the current region then a new region is required. | |
983 | * Subtle, allocate a new region at the position but make it zero | |
984 | * size such that we can guarentee to record the reservation. */ | |
985 | if (&rg->link == head || t < rg->from) { | |
986 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
987 | if (nrg == 0) | |
988 | return -ENOMEM; | |
989 | nrg->from = f; | |
990 | nrg->to = f; | |
991 | INIT_LIST_HEAD(&nrg->link); | |
992 | list_add(&nrg->link, rg->link.prev); | |
993 | ||
994 | return t - f; | |
995 | } | |
996 | ||
997 | /* Round our left edge to the current segment if it encloses us. */ | |
998 | if (f > rg->from) | |
999 | f = rg->from; | |
1000 | chg = t - f; | |
1001 | ||
1002 | /* Check for and consume any regions we now overlap with. */ | |
1003 | list_for_each_entry(rg, rg->link.prev, link) { | |
1004 | if (&rg->link == head) | |
1005 | break; | |
1006 | if (rg->from > t) | |
1007 | return chg; | |
1008 | ||
1009 | /* We overlap with this area, if it extends futher than | |
1010 | * us then we must extend ourselves. Account for its | |
1011 | * existing reservation. */ | |
1012 | if (rg->to > t) { | |
1013 | chg += rg->to - t; | |
1014 | t = rg->to; | |
1015 | } | |
1016 | chg -= rg->to - rg->from; | |
1017 | } | |
1018 | return chg; | |
1019 | } | |
1020 | ||
1021 | static long region_truncate(struct list_head *head, long end) | |
1022 | { | |
1023 | struct file_region *rg, *trg; | |
1024 | long chg = 0; | |
1025 | ||
1026 | /* Locate the region we are either in or before. */ | |
1027 | list_for_each_entry(rg, head, link) | |
1028 | if (end <= rg->to) | |
1029 | break; | |
1030 | if (&rg->link == head) | |
1031 | return 0; | |
1032 | ||
1033 | /* If we are in the middle of a region then adjust it. */ | |
1034 | if (end > rg->from) { | |
1035 | chg = rg->to - end; | |
1036 | rg->to = end; | |
1037 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
1038 | } | |
1039 | ||
1040 | /* Drop any remaining regions. */ | |
1041 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
1042 | if (&rg->link == head) | |
1043 | break; | |
1044 | chg += rg->to - rg->from; | |
1045 | list_del(&rg->link); | |
1046 | kfree(rg); | |
1047 | } | |
1048 | return chg; | |
1049 | } | |
1050 | ||
1051 | static int hugetlb_acct_memory(long delta) | |
1052 | { | |
1053 | int ret = -ENOMEM; | |
1054 | ||
1055 | spin_lock(&hugetlb_lock); | |
8a630112 KC |
1056 | /* |
1057 | * When cpuset is configured, it breaks the strict hugetlb page | |
1058 | * reservation as the accounting is done on a global variable. Such | |
1059 | * reservation is completely rubbish in the presence of cpuset because | |
1060 | * the reservation is not checked against page availability for the | |
1061 | * current cpuset. Application can still potentially OOM'ed by kernel | |
1062 | * with lack of free htlb page in cpuset that the task is in. | |
1063 | * Attempt to enforce strict accounting with cpuset is almost | |
1064 | * impossible (or too ugly) because cpuset is too fluid that | |
1065 | * task or memory node can be dynamically moved between cpusets. | |
1066 | * | |
1067 | * The change of semantics for shared hugetlb mapping with cpuset is | |
1068 | * undesirable. However, in order to preserve some of the semantics, | |
1069 | * we fall back to check against current free page availability as | |
1070 | * a best attempt and hopefully to minimize the impact of changing | |
1071 | * semantics that cpuset has. | |
1072 | */ | |
e4e574b7 AL |
1073 | if (delta > 0) { |
1074 | if (gather_surplus_pages(delta) < 0) | |
1075 | goto out; | |
1076 | ||
1077 | if (delta > cpuset_mems_nr(free_huge_pages_node)) | |
1078 | goto out; | |
1079 | } | |
1080 | ||
1081 | ret = 0; | |
1082 | resv_huge_pages += delta; | |
1083 | if (delta < 0) | |
1084 | return_unused_surplus_pages((unsigned long) -delta); | |
1085 | ||
1086 | out: | |
1087 | spin_unlock(&hugetlb_lock); | |
1088 | return ret; | |
1089 | } | |
1090 | ||
1091 | int hugetlb_reserve_pages(struct inode *inode, long from, long to) | |
1092 | { | |
1093 | long ret, chg; | |
1094 | ||
1095 | chg = region_chg(&inode->i_mapping->private_list, from, to); | |
1096 | if (chg < 0) | |
1097 | return chg; | |
8a630112 | 1098 | |
a43a8c39 KC |
1099 | ret = hugetlb_acct_memory(chg); |
1100 | if (ret < 0) | |
1101 | return ret; | |
1102 | region_add(&inode->i_mapping->private_list, from, to); | |
1103 | return 0; | |
1104 | } | |
1105 | ||
1106 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
1107 | { | |
1108 | long chg = region_truncate(&inode->i_mapping->private_list, offset); | |
1109 | hugetlb_acct_memory(freed - chg); | |
1110 | } |