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Commit | Line | Data |
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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; | |
54f9f80d | 34 | int hugetlb_dynamic_pool; |
396faf03 | 35 | |
3935baa9 DG |
36 | /* |
37 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages | |
38 | */ | |
39 | static DEFINE_SPINLOCK(hugetlb_lock); | |
0bd0f9fb | 40 | |
79ac6ba4 DG |
41 | static void clear_huge_page(struct page *page, unsigned long addr) |
42 | { | |
43 | int i; | |
44 | ||
45 | might_sleep(); | |
46 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) { | |
47 | cond_resched(); | |
281e0e3b | 48 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
79ac6ba4 DG |
49 | } |
50 | } | |
51 | ||
52 | static void copy_huge_page(struct page *dst, struct page *src, | |
9de455b2 | 53 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
54 | { |
55 | int i; | |
56 | ||
57 | might_sleep(); | |
58 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { | |
59 | cond_resched(); | |
9de455b2 | 60 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
61 | } |
62 | } | |
63 | ||
1da177e4 LT |
64 | static void enqueue_huge_page(struct page *page) |
65 | { | |
66 | int nid = page_to_nid(page); | |
67 | list_add(&page->lru, &hugepage_freelists[nid]); | |
68 | free_huge_pages++; | |
69 | free_huge_pages_node[nid]++; | |
70 | } | |
71 | ||
5da7ca86 CL |
72 | static struct page *dequeue_huge_page(struct vm_area_struct *vma, |
73 | unsigned long address) | |
1da177e4 | 74 | { |
31a5c6e4 | 75 | int nid; |
1da177e4 | 76 | struct page *page = NULL; |
480eccf9 | 77 | struct mempolicy *mpol; |
396faf03 | 78 | struct zonelist *zonelist = huge_zonelist(vma, address, |
480eccf9 | 79 | htlb_alloc_mask, &mpol); |
96df9333 | 80 | struct zone **z; |
1da177e4 | 81 | |
96df9333 | 82 | for (z = zonelist->zones; *z; z++) { |
89fa3024 | 83 | nid = zone_to_nid(*z); |
396faf03 | 84 | if (cpuset_zone_allowed_softwall(*z, htlb_alloc_mask) && |
3abf7afd AM |
85 | !list_empty(&hugepage_freelists[nid])) { |
86 | page = list_entry(hugepage_freelists[nid].next, | |
87 | struct page, lru); | |
88 | list_del(&page->lru); | |
89 | free_huge_pages--; | |
90 | free_huge_pages_node[nid]--; | |
e4e574b7 AL |
91 | if (vma && vma->vm_flags & VM_MAYSHARE) |
92 | resv_huge_pages--; | |
5ab3ee7b | 93 | break; |
3abf7afd | 94 | } |
1da177e4 | 95 | } |
480eccf9 | 96 | mpol_free(mpol); /* unref if mpol !NULL */ |
1da177e4 LT |
97 | return page; |
98 | } | |
99 | ||
6af2acb6 AL |
100 | static void update_and_free_page(struct page *page) |
101 | { | |
102 | int i; | |
103 | nr_huge_pages--; | |
104 | nr_huge_pages_node[page_to_nid(page)]--; | |
105 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { | |
106 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | | |
107 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
108 | 1 << PG_private | 1<< PG_writeback); | |
109 | } | |
110 | set_compound_page_dtor(page, NULL); | |
111 | set_page_refcounted(page); | |
112 | __free_pages(page, HUGETLB_PAGE_ORDER); | |
113 | } | |
114 | ||
27a85ef1 DG |
115 | static void free_huge_page(struct page *page) |
116 | { | |
7893d1d5 | 117 | int nid = page_to_nid(page); |
27a85ef1 | 118 | |
7893d1d5 | 119 | BUG_ON(page_count(page)); |
27a85ef1 DG |
120 | INIT_LIST_HEAD(&page->lru); |
121 | ||
122 | spin_lock(&hugetlb_lock); | |
7893d1d5 AL |
123 | if (surplus_huge_pages_node[nid]) { |
124 | update_and_free_page(page); | |
125 | surplus_huge_pages--; | |
126 | surplus_huge_pages_node[nid]--; | |
127 | } else { | |
128 | enqueue_huge_page(page); | |
129 | } | |
27a85ef1 DG |
130 | spin_unlock(&hugetlb_lock); |
131 | } | |
132 | ||
7893d1d5 AL |
133 | /* |
134 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
135 | * balanced by operating on them in a round-robin fashion. | |
136 | * Returns 1 if an adjustment was made. | |
137 | */ | |
138 | static int adjust_pool_surplus(int delta) | |
139 | { | |
140 | static int prev_nid; | |
141 | int nid = prev_nid; | |
142 | int ret = 0; | |
143 | ||
144 | VM_BUG_ON(delta != -1 && delta != 1); | |
145 | do { | |
146 | nid = next_node(nid, node_online_map); | |
147 | if (nid == MAX_NUMNODES) | |
148 | nid = first_node(node_online_map); | |
149 | ||
150 | /* To shrink on this node, there must be a surplus page */ | |
151 | if (delta < 0 && !surplus_huge_pages_node[nid]) | |
152 | continue; | |
153 | /* Surplus cannot exceed the total number of pages */ | |
154 | if (delta > 0 && surplus_huge_pages_node[nid] >= | |
155 | nr_huge_pages_node[nid]) | |
156 | continue; | |
157 | ||
158 | surplus_huge_pages += delta; | |
159 | surplus_huge_pages_node[nid] += delta; | |
160 | ret = 1; | |
161 | break; | |
162 | } while (nid != prev_nid); | |
163 | ||
164 | prev_nid = nid; | |
165 | return ret; | |
166 | } | |
167 | ||
a482289d | 168 | static int alloc_fresh_huge_page(void) |
1da177e4 | 169 | { |
f96efd58 | 170 | static int prev_nid; |
1da177e4 | 171 | struct page *page; |
f96efd58 JJ |
172 | int nid; |
173 | ||
7ed5cb2b HD |
174 | /* |
175 | * Copy static prev_nid to local nid, work on that, then copy it | |
176 | * back to prev_nid afterwards: otherwise there's a window in which | |
177 | * a racer might pass invalid nid MAX_NUMNODES to alloc_pages_node. | |
178 | * But we don't need to use a spin_lock here: it really doesn't | |
179 | * matter if occasionally a racer chooses the same nid as we do. | |
180 | */ | |
f96efd58 | 181 | nid = next_node(prev_nid, node_online_map); |
fdb7cc59 PJ |
182 | if (nid == MAX_NUMNODES) |
183 | nid = first_node(node_online_map); | |
f96efd58 | 184 | prev_nid = nid; |
f96efd58 | 185 | |
396faf03 | 186 | page = alloc_pages_node(nid, htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN, |
f96efd58 | 187 | HUGETLB_PAGE_ORDER); |
1da177e4 | 188 | if (page) { |
33f2ef89 | 189 | set_compound_page_dtor(page, free_huge_page); |
0bd0f9fb | 190 | spin_lock(&hugetlb_lock); |
1da177e4 LT |
191 | nr_huge_pages++; |
192 | nr_huge_pages_node[page_to_nid(page)]++; | |
0bd0f9fb | 193 | spin_unlock(&hugetlb_lock); |
a482289d NP |
194 | put_page(page); /* free it into the hugepage allocator */ |
195 | return 1; | |
1da177e4 | 196 | } |
a482289d | 197 | return 0; |
1da177e4 LT |
198 | } |
199 | ||
7893d1d5 AL |
200 | static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma, |
201 | unsigned long address) | |
202 | { | |
203 | struct page *page; | |
204 | ||
54f9f80d AL |
205 | /* Check if the dynamic pool is enabled */ |
206 | if (!hugetlb_dynamic_pool) | |
207 | return NULL; | |
208 | ||
7893d1d5 AL |
209 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN, |
210 | HUGETLB_PAGE_ORDER); | |
211 | if (page) { | |
212 | set_compound_page_dtor(page, free_huge_page); | |
213 | spin_lock(&hugetlb_lock); | |
214 | nr_huge_pages++; | |
215 | nr_huge_pages_node[page_to_nid(page)]++; | |
216 | surplus_huge_pages++; | |
217 | surplus_huge_pages_node[page_to_nid(page)]++; | |
218 | spin_unlock(&hugetlb_lock); | |
219 | } | |
220 | ||
221 | return page; | |
222 | } | |
223 | ||
e4e574b7 AL |
224 | /* |
225 | * Increase the hugetlb pool such that it can accomodate a reservation | |
226 | * of size 'delta'. | |
227 | */ | |
228 | static int gather_surplus_pages(int delta) | |
229 | { | |
230 | struct list_head surplus_list; | |
231 | struct page *page, *tmp; | |
232 | int ret, i; | |
233 | int needed, allocated; | |
234 | ||
235 | needed = (resv_huge_pages + delta) - free_huge_pages; | |
236 | if (needed <= 0) | |
237 | return 0; | |
238 | ||
239 | allocated = 0; | |
240 | INIT_LIST_HEAD(&surplus_list); | |
241 | ||
242 | ret = -ENOMEM; | |
243 | retry: | |
244 | spin_unlock(&hugetlb_lock); | |
245 | for (i = 0; i < needed; i++) { | |
246 | page = alloc_buddy_huge_page(NULL, 0); | |
247 | if (!page) { | |
248 | /* | |
249 | * We were not able to allocate enough pages to | |
250 | * satisfy the entire reservation so we free what | |
251 | * we've allocated so far. | |
252 | */ | |
253 | spin_lock(&hugetlb_lock); | |
254 | needed = 0; | |
255 | goto free; | |
256 | } | |
257 | ||
258 | list_add(&page->lru, &surplus_list); | |
259 | } | |
260 | allocated += needed; | |
261 | ||
262 | /* | |
263 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
264 | * because either resv_huge_pages or free_huge_pages may have changed. | |
265 | */ | |
266 | spin_lock(&hugetlb_lock); | |
267 | needed = (resv_huge_pages + delta) - (free_huge_pages + allocated); | |
268 | if (needed > 0) | |
269 | goto retry; | |
270 | ||
271 | /* | |
272 | * The surplus_list now contains _at_least_ the number of extra pages | |
273 | * needed to accomodate the reservation. Add the appropriate number | |
274 | * of pages to the hugetlb pool and free the extras back to the buddy | |
275 | * allocator. | |
276 | */ | |
277 | needed += allocated; | |
278 | ret = 0; | |
279 | free: | |
280 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { | |
281 | list_del(&page->lru); | |
282 | if ((--needed) >= 0) | |
283 | enqueue_huge_page(page); | |
284 | else | |
285 | update_and_free_page(page); | |
286 | } | |
287 | ||
288 | return ret; | |
289 | } | |
290 | ||
291 | /* | |
292 | * When releasing a hugetlb pool reservation, any surplus pages that were | |
293 | * allocated to satisfy the reservation must be explicitly freed if they were | |
294 | * never used. | |
295 | */ | |
296 | void return_unused_surplus_pages(unsigned long unused_resv_pages) | |
297 | { | |
298 | static int nid = -1; | |
299 | struct page *page; | |
300 | unsigned long nr_pages; | |
301 | ||
302 | nr_pages = min(unused_resv_pages, surplus_huge_pages); | |
303 | ||
304 | while (nr_pages) { | |
305 | nid = next_node(nid, node_online_map); | |
306 | if (nid == MAX_NUMNODES) | |
307 | nid = first_node(node_online_map); | |
308 | ||
309 | if (!surplus_huge_pages_node[nid]) | |
310 | continue; | |
311 | ||
312 | if (!list_empty(&hugepage_freelists[nid])) { | |
313 | page = list_entry(hugepage_freelists[nid].next, | |
314 | struct page, lru); | |
315 | list_del(&page->lru); | |
316 | update_and_free_page(page); | |
317 | free_huge_pages--; | |
318 | free_huge_pages_node[nid]--; | |
319 | surplus_huge_pages--; | |
320 | surplus_huge_pages_node[nid]--; | |
321 | nr_pages--; | |
322 | } | |
323 | } | |
324 | } | |
325 | ||
27a85ef1 DG |
326 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
327 | unsigned long addr) | |
1da177e4 | 328 | { |
7893d1d5 | 329 | struct page *page = NULL; |
e4e574b7 | 330 | int use_reserved_page = vma->vm_flags & VM_MAYSHARE; |
1da177e4 LT |
331 | |
332 | spin_lock(&hugetlb_lock); | |
e4e574b7 | 333 | if (!use_reserved_page && (free_huge_pages <= resv_huge_pages)) |
a43a8c39 | 334 | goto fail; |
b45b5bd6 DG |
335 | |
336 | page = dequeue_huge_page(vma, addr); | |
337 | if (!page) | |
338 | goto fail; | |
339 | ||
1da177e4 | 340 | spin_unlock(&hugetlb_lock); |
7835e98b | 341 | set_page_refcounted(page); |
1da177e4 | 342 | return page; |
b45b5bd6 | 343 | |
a43a8c39 | 344 | fail: |
b45b5bd6 | 345 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
346 | |
347 | /* | |
348 | * Private mappings do not use reserved huge pages so the allocation | |
349 | * may have failed due to an undersized hugetlb pool. Try to grab a | |
350 | * surplus huge page from the buddy allocator. | |
351 | */ | |
e4e574b7 | 352 | if (!use_reserved_page) |
7893d1d5 AL |
353 | page = alloc_buddy_huge_page(vma, addr); |
354 | ||
355 | return page; | |
b45b5bd6 DG |
356 | } |
357 | ||
1da177e4 LT |
358 | static int __init hugetlb_init(void) |
359 | { | |
360 | unsigned long i; | |
1da177e4 | 361 | |
3c726f8d BH |
362 | if (HPAGE_SHIFT == 0) |
363 | return 0; | |
364 | ||
1da177e4 LT |
365 | for (i = 0; i < MAX_NUMNODES; ++i) |
366 | INIT_LIST_HEAD(&hugepage_freelists[i]); | |
367 | ||
368 | for (i = 0; i < max_huge_pages; ++i) { | |
a482289d | 369 | if (!alloc_fresh_huge_page()) |
1da177e4 | 370 | break; |
1da177e4 LT |
371 | } |
372 | max_huge_pages = free_huge_pages = nr_huge_pages = i; | |
373 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); | |
374 | return 0; | |
375 | } | |
376 | module_init(hugetlb_init); | |
377 | ||
378 | static int __init hugetlb_setup(char *s) | |
379 | { | |
380 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) | |
381 | max_huge_pages = 0; | |
382 | return 1; | |
383 | } | |
384 | __setup("hugepages=", hugetlb_setup); | |
385 | ||
8a630112 KC |
386 | static unsigned int cpuset_mems_nr(unsigned int *array) |
387 | { | |
388 | int node; | |
389 | unsigned int nr = 0; | |
390 | ||
391 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
392 | nr += array[node]; | |
393 | ||
394 | return nr; | |
395 | } | |
396 | ||
1da177e4 | 397 | #ifdef CONFIG_SYSCTL |
1da177e4 LT |
398 | #ifdef CONFIG_HIGHMEM |
399 | static void try_to_free_low(unsigned long count) | |
400 | { | |
4415cc8d CL |
401 | int i; |
402 | ||
1da177e4 LT |
403 | for (i = 0; i < MAX_NUMNODES; ++i) { |
404 | struct page *page, *next; | |
405 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { | |
6b0c880d AL |
406 | if (count >= nr_huge_pages) |
407 | return; | |
1da177e4 LT |
408 | if (PageHighMem(page)) |
409 | continue; | |
410 | list_del(&page->lru); | |
411 | update_and_free_page(page); | |
1da177e4 | 412 | free_huge_pages--; |
4415cc8d | 413 | free_huge_pages_node[page_to_nid(page)]--; |
1da177e4 LT |
414 | } |
415 | } | |
416 | } | |
417 | #else | |
418 | static inline void try_to_free_low(unsigned long count) | |
419 | { | |
420 | } | |
421 | #endif | |
422 | ||
7893d1d5 | 423 | #define persistent_huge_pages (nr_huge_pages - surplus_huge_pages) |
1da177e4 LT |
424 | static unsigned long set_max_huge_pages(unsigned long count) |
425 | { | |
7893d1d5 | 426 | unsigned long min_count, ret; |
1da177e4 | 427 | |
7893d1d5 AL |
428 | /* |
429 | * Increase the pool size | |
430 | * First take pages out of surplus state. Then make up the | |
431 | * remaining difference by allocating fresh huge pages. | |
432 | */ | |
1da177e4 | 433 | spin_lock(&hugetlb_lock); |
7893d1d5 AL |
434 | while (surplus_huge_pages && count > persistent_huge_pages) { |
435 | if (!adjust_pool_surplus(-1)) | |
436 | break; | |
437 | } | |
438 | ||
439 | while (count > persistent_huge_pages) { | |
440 | int ret; | |
441 | /* | |
442 | * If this allocation races such that we no longer need the | |
443 | * page, free_huge_page will handle it by freeing the page | |
444 | * and reducing the surplus. | |
445 | */ | |
446 | spin_unlock(&hugetlb_lock); | |
447 | ret = alloc_fresh_huge_page(); | |
448 | spin_lock(&hugetlb_lock); | |
449 | if (!ret) | |
450 | goto out; | |
451 | ||
452 | } | |
7893d1d5 AL |
453 | |
454 | /* | |
455 | * Decrease the pool size | |
456 | * First return free pages to the buddy allocator (being careful | |
457 | * to keep enough around to satisfy reservations). Then place | |
458 | * pages into surplus state as needed so the pool will shrink | |
459 | * to the desired size as pages become free. | |
460 | */ | |
6b0c880d AL |
461 | min_count = resv_huge_pages + nr_huge_pages - free_huge_pages; |
462 | min_count = max(count, min_count); | |
7893d1d5 AL |
463 | try_to_free_low(min_count); |
464 | while (min_count < persistent_huge_pages) { | |
5da7ca86 | 465 | struct page *page = dequeue_huge_page(NULL, 0); |
1da177e4 LT |
466 | if (!page) |
467 | break; | |
468 | update_and_free_page(page); | |
469 | } | |
7893d1d5 AL |
470 | while (count < persistent_huge_pages) { |
471 | if (!adjust_pool_surplus(1)) | |
472 | break; | |
473 | } | |
474 | out: | |
475 | ret = persistent_huge_pages; | |
1da177e4 | 476 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 477 | return ret; |
1da177e4 LT |
478 | } |
479 | ||
480 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, | |
481 | struct file *file, void __user *buffer, | |
482 | size_t *length, loff_t *ppos) | |
483 | { | |
484 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); | |
485 | max_huge_pages = set_max_huge_pages(max_huge_pages); | |
486 | return 0; | |
487 | } | |
396faf03 MG |
488 | |
489 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, | |
490 | struct file *file, void __user *buffer, | |
491 | size_t *length, loff_t *ppos) | |
492 | { | |
493 | proc_dointvec(table, write, file, buffer, length, ppos); | |
494 | if (hugepages_treat_as_movable) | |
495 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; | |
496 | else | |
497 | htlb_alloc_mask = GFP_HIGHUSER; | |
498 | return 0; | |
499 | } | |
500 | ||
1da177e4 LT |
501 | #endif /* CONFIG_SYSCTL */ |
502 | ||
503 | int hugetlb_report_meminfo(char *buf) | |
504 | { | |
505 | return sprintf(buf, | |
506 | "HugePages_Total: %5lu\n" | |
507 | "HugePages_Free: %5lu\n" | |
a43a8c39 | 508 | "HugePages_Rsvd: %5lu\n" |
7893d1d5 | 509 | "HugePages_Surp: %5lu\n" |
1da177e4 LT |
510 | "Hugepagesize: %5lu kB\n", |
511 | nr_huge_pages, | |
512 | free_huge_pages, | |
a43a8c39 | 513 | resv_huge_pages, |
7893d1d5 | 514 | surplus_huge_pages, |
1da177e4 LT |
515 | HPAGE_SIZE/1024); |
516 | } | |
517 | ||
518 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
519 | { | |
520 | return sprintf(buf, | |
521 | "Node %d HugePages_Total: %5u\n" | |
522 | "Node %d HugePages_Free: %5u\n", | |
523 | nid, nr_huge_pages_node[nid], | |
524 | nid, free_huge_pages_node[nid]); | |
525 | } | |
526 | ||
1da177e4 LT |
527 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
528 | unsigned long hugetlb_total_pages(void) | |
529 | { | |
530 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); | |
531 | } | |
1da177e4 LT |
532 | |
533 | /* | |
534 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
535 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
536 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
537 | * this far. | |
538 | */ | |
d0217ac0 | 539 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
540 | { |
541 | BUG(); | |
d0217ac0 | 542 | return 0; |
1da177e4 LT |
543 | } |
544 | ||
545 | struct vm_operations_struct hugetlb_vm_ops = { | |
d0217ac0 | 546 | .fault = hugetlb_vm_op_fault, |
1da177e4 LT |
547 | }; |
548 | ||
1e8f889b DG |
549 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
550 | int writable) | |
63551ae0 DG |
551 | { |
552 | pte_t entry; | |
553 | ||
1e8f889b | 554 | if (writable) { |
63551ae0 DG |
555 | entry = |
556 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
557 | } else { | |
558 | entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot)); | |
559 | } | |
560 | entry = pte_mkyoung(entry); | |
561 | entry = pte_mkhuge(entry); | |
562 | ||
563 | return entry; | |
564 | } | |
565 | ||
1e8f889b DG |
566 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
567 | unsigned long address, pte_t *ptep) | |
568 | { | |
569 | pte_t entry; | |
570 | ||
571 | entry = pte_mkwrite(pte_mkdirty(*ptep)); | |
8dab5241 BH |
572 | if (ptep_set_access_flags(vma, address, ptep, entry, 1)) { |
573 | update_mmu_cache(vma, address, entry); | |
8dab5241 | 574 | } |
1e8f889b DG |
575 | } |
576 | ||
577 | ||
63551ae0 DG |
578 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
579 | struct vm_area_struct *vma) | |
580 | { | |
581 | pte_t *src_pte, *dst_pte, entry; | |
582 | struct page *ptepage; | |
1c59827d | 583 | unsigned long addr; |
1e8f889b DG |
584 | int cow; |
585 | ||
586 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 587 | |
1c59827d | 588 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
c74df32c HD |
589 | src_pte = huge_pte_offset(src, addr); |
590 | if (!src_pte) | |
591 | continue; | |
63551ae0 DG |
592 | dst_pte = huge_pte_alloc(dst, addr); |
593 | if (!dst_pte) | |
594 | goto nomem; | |
c74df32c | 595 | spin_lock(&dst->page_table_lock); |
1c59827d | 596 | spin_lock(&src->page_table_lock); |
c74df32c | 597 | if (!pte_none(*src_pte)) { |
1e8f889b DG |
598 | if (cow) |
599 | ptep_set_wrprotect(src, addr, src_pte); | |
1c59827d HD |
600 | entry = *src_pte; |
601 | ptepage = pte_page(entry); | |
602 | get_page(ptepage); | |
1c59827d HD |
603 | set_huge_pte_at(dst, addr, dst_pte, entry); |
604 | } | |
605 | spin_unlock(&src->page_table_lock); | |
c74df32c | 606 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
607 | } |
608 | return 0; | |
609 | ||
610 | nomem: | |
611 | return -ENOMEM; | |
612 | } | |
613 | ||
502717f4 CK |
614 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
615 | unsigned long end) | |
63551ae0 DG |
616 | { |
617 | struct mm_struct *mm = vma->vm_mm; | |
618 | unsigned long address; | |
c7546f8f | 619 | pte_t *ptep; |
63551ae0 DG |
620 | pte_t pte; |
621 | struct page *page; | |
fe1668ae | 622 | struct page *tmp; |
c0a499c2 CK |
623 | /* |
624 | * A page gathering list, protected by per file i_mmap_lock. The | |
625 | * lock is used to avoid list corruption from multiple unmapping | |
626 | * of the same page since we are using page->lru. | |
627 | */ | |
fe1668ae | 628 | LIST_HEAD(page_list); |
63551ae0 DG |
629 | |
630 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
631 | BUG_ON(start & ~HPAGE_MASK); | |
632 | BUG_ON(end & ~HPAGE_MASK); | |
633 | ||
508034a3 | 634 | spin_lock(&mm->page_table_lock); |
63551ae0 | 635 | for (address = start; address < end; address += HPAGE_SIZE) { |
c7546f8f | 636 | ptep = huge_pte_offset(mm, address); |
4c887265 | 637 | if (!ptep) |
c7546f8f DG |
638 | continue; |
639 | ||
39dde65c CK |
640 | if (huge_pmd_unshare(mm, &address, ptep)) |
641 | continue; | |
642 | ||
c7546f8f | 643 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
63551ae0 DG |
644 | if (pte_none(pte)) |
645 | continue; | |
c7546f8f | 646 | |
63551ae0 | 647 | page = pte_page(pte); |
6649a386 KC |
648 | if (pte_dirty(pte)) |
649 | set_page_dirty(page); | |
fe1668ae | 650 | list_add(&page->lru, &page_list); |
63551ae0 | 651 | } |
1da177e4 | 652 | spin_unlock(&mm->page_table_lock); |
508034a3 | 653 | flush_tlb_range(vma, start, end); |
fe1668ae CK |
654 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
655 | list_del(&page->lru); | |
656 | put_page(page); | |
657 | } | |
1da177e4 | 658 | } |
63551ae0 | 659 | |
502717f4 CK |
660 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
661 | unsigned long end) | |
662 | { | |
663 | /* | |
664 | * It is undesirable to test vma->vm_file as it should be non-null | |
665 | * for valid hugetlb area. However, vm_file will be NULL in the error | |
666 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, | |
667 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function | |
668 | * to clean up. Since no pte has actually been setup, it is safe to | |
669 | * do nothing in this case. | |
670 | */ | |
671 | if (vma->vm_file) { | |
672 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); | |
673 | __unmap_hugepage_range(vma, start, end); | |
674 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); | |
675 | } | |
676 | } | |
677 | ||
1e8f889b DG |
678 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
679 | unsigned long address, pte_t *ptep, pte_t pte) | |
680 | { | |
681 | struct page *old_page, *new_page; | |
79ac6ba4 | 682 | int avoidcopy; |
1e8f889b DG |
683 | |
684 | old_page = pte_page(pte); | |
685 | ||
686 | /* If no-one else is actually using this page, avoid the copy | |
687 | * and just make the page writable */ | |
688 | avoidcopy = (page_count(old_page) == 1); | |
689 | if (avoidcopy) { | |
690 | set_huge_ptep_writable(vma, address, ptep); | |
83c54070 | 691 | return 0; |
1e8f889b DG |
692 | } |
693 | ||
694 | page_cache_get(old_page); | |
5da7ca86 | 695 | new_page = alloc_huge_page(vma, address); |
1e8f889b DG |
696 | |
697 | if (!new_page) { | |
698 | page_cache_release(old_page); | |
0df420d8 | 699 | return VM_FAULT_OOM; |
1e8f889b DG |
700 | } |
701 | ||
702 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 703 | copy_huge_page(new_page, old_page, address, vma); |
1e8f889b DG |
704 | spin_lock(&mm->page_table_lock); |
705 | ||
706 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); | |
707 | if (likely(pte_same(*ptep, pte))) { | |
708 | /* Break COW */ | |
709 | set_huge_pte_at(mm, address, ptep, | |
710 | make_huge_pte(vma, new_page, 1)); | |
711 | /* Make the old page be freed below */ | |
712 | new_page = old_page; | |
713 | } | |
714 | page_cache_release(new_page); | |
715 | page_cache_release(old_page); | |
83c54070 | 716 | return 0; |
1e8f889b DG |
717 | } |
718 | ||
a1ed3dda | 719 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 720 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 HD |
721 | { |
722 | int ret = VM_FAULT_SIGBUS; | |
4c887265 AL |
723 | unsigned long idx; |
724 | unsigned long size; | |
4c887265 AL |
725 | struct page *page; |
726 | struct address_space *mapping; | |
1e8f889b | 727 | pte_t new_pte; |
4c887265 | 728 | |
4c887265 AL |
729 | mapping = vma->vm_file->f_mapping; |
730 | idx = ((address - vma->vm_start) >> HPAGE_SHIFT) | |
731 | + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
732 | ||
733 | /* | |
734 | * Use page lock to guard against racing truncation | |
735 | * before we get page_table_lock. | |
736 | */ | |
6bda666a CL |
737 | retry: |
738 | page = find_lock_page(mapping, idx); | |
739 | if (!page) { | |
ebed4bfc HD |
740 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
741 | if (idx >= size) | |
742 | goto out; | |
6bda666a CL |
743 | if (hugetlb_get_quota(mapping)) |
744 | goto out; | |
745 | page = alloc_huge_page(vma, address); | |
746 | if (!page) { | |
747 | hugetlb_put_quota(mapping); | |
0df420d8 | 748 | ret = VM_FAULT_OOM; |
6bda666a CL |
749 | goto out; |
750 | } | |
79ac6ba4 | 751 | clear_huge_page(page, address); |
ac9b9c66 | 752 | |
6bda666a CL |
753 | if (vma->vm_flags & VM_SHARED) { |
754 | int err; | |
755 | ||
756 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
757 | if (err) { | |
758 | put_page(page); | |
759 | hugetlb_put_quota(mapping); | |
760 | if (err == -EEXIST) | |
761 | goto retry; | |
762 | goto out; | |
763 | } | |
764 | } else | |
765 | lock_page(page); | |
766 | } | |
1e8f889b | 767 | |
ac9b9c66 | 768 | spin_lock(&mm->page_table_lock); |
4c887265 AL |
769 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
770 | if (idx >= size) | |
771 | goto backout; | |
772 | ||
83c54070 | 773 | ret = 0; |
86e5216f | 774 | if (!pte_none(*ptep)) |
4c887265 AL |
775 | goto backout; |
776 | ||
1e8f889b DG |
777 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
778 | && (vma->vm_flags & VM_SHARED))); | |
779 | set_huge_pte_at(mm, address, ptep, new_pte); | |
780 | ||
781 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
782 | /* Optimization, do the COW without a second fault */ | |
783 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte); | |
784 | } | |
785 | ||
ac9b9c66 | 786 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
787 | unlock_page(page); |
788 | out: | |
ac9b9c66 | 789 | return ret; |
4c887265 AL |
790 | |
791 | backout: | |
792 | spin_unlock(&mm->page_table_lock); | |
793 | hugetlb_put_quota(mapping); | |
794 | unlock_page(page); | |
795 | put_page(page); | |
796 | goto out; | |
ac9b9c66 HD |
797 | } |
798 | ||
86e5216f AL |
799 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
800 | unsigned long address, int write_access) | |
801 | { | |
802 | pte_t *ptep; | |
803 | pte_t entry; | |
1e8f889b | 804 | int ret; |
3935baa9 | 805 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
86e5216f AL |
806 | |
807 | ptep = huge_pte_alloc(mm, address); | |
808 | if (!ptep) | |
809 | return VM_FAULT_OOM; | |
810 | ||
3935baa9 DG |
811 | /* |
812 | * Serialize hugepage allocation and instantiation, so that we don't | |
813 | * get spurious allocation failures if two CPUs race to instantiate | |
814 | * the same page in the page cache. | |
815 | */ | |
816 | mutex_lock(&hugetlb_instantiation_mutex); | |
86e5216f | 817 | entry = *ptep; |
3935baa9 DG |
818 | if (pte_none(entry)) { |
819 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); | |
820 | mutex_unlock(&hugetlb_instantiation_mutex); | |
821 | return ret; | |
822 | } | |
86e5216f | 823 | |
83c54070 | 824 | ret = 0; |
1e8f889b DG |
825 | |
826 | spin_lock(&mm->page_table_lock); | |
827 | /* Check for a racing update before calling hugetlb_cow */ | |
828 | if (likely(pte_same(entry, *ptep))) | |
829 | if (write_access && !pte_write(entry)) | |
830 | ret = hugetlb_cow(mm, vma, address, ptep, entry); | |
831 | spin_unlock(&mm->page_table_lock); | |
3935baa9 | 832 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
833 | |
834 | return ret; | |
86e5216f AL |
835 | } |
836 | ||
63551ae0 DG |
837 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
838 | struct page **pages, struct vm_area_struct **vmas, | |
839 | unsigned long *position, int *length, int i) | |
840 | { | |
d5d4b0aa CK |
841 | unsigned long pfn_offset; |
842 | unsigned long vaddr = *position; | |
63551ae0 DG |
843 | int remainder = *length; |
844 | ||
1c59827d | 845 | spin_lock(&mm->page_table_lock); |
63551ae0 | 846 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
847 | pte_t *pte; |
848 | struct page *page; | |
63551ae0 | 849 | |
4c887265 AL |
850 | /* |
851 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
852 | * each hugepage. We have to make * sure we get the | |
853 | * first, for the page indexing below to work. | |
854 | */ | |
855 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); | |
63551ae0 | 856 | |
4c887265 AL |
857 | if (!pte || pte_none(*pte)) { |
858 | int ret; | |
63551ae0 | 859 | |
4c887265 AL |
860 | spin_unlock(&mm->page_table_lock); |
861 | ret = hugetlb_fault(mm, vma, vaddr, 0); | |
862 | spin_lock(&mm->page_table_lock); | |
a89182c7 | 863 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 864 | continue; |
63551ae0 | 865 | |
4c887265 AL |
866 | remainder = 0; |
867 | if (!i) | |
868 | i = -EFAULT; | |
869 | break; | |
870 | } | |
871 | ||
d5d4b0aa CK |
872 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
873 | page = pte_page(*pte); | |
874 | same_page: | |
d6692183 CK |
875 | if (pages) { |
876 | get_page(page); | |
d5d4b0aa | 877 | pages[i] = page + pfn_offset; |
d6692183 | 878 | } |
63551ae0 DG |
879 | |
880 | if (vmas) | |
881 | vmas[i] = vma; | |
882 | ||
883 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 884 | ++pfn_offset; |
63551ae0 DG |
885 | --remainder; |
886 | ++i; | |
d5d4b0aa CK |
887 | if (vaddr < vma->vm_end && remainder && |
888 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { | |
889 | /* | |
890 | * We use pfn_offset to avoid touching the pageframes | |
891 | * of this compound page. | |
892 | */ | |
893 | goto same_page; | |
894 | } | |
63551ae0 | 895 | } |
1c59827d | 896 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
897 | *length = remainder; |
898 | *position = vaddr; | |
899 | ||
900 | return i; | |
901 | } | |
8f860591 ZY |
902 | |
903 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
904 | unsigned long address, unsigned long end, pgprot_t newprot) | |
905 | { | |
906 | struct mm_struct *mm = vma->vm_mm; | |
907 | unsigned long start = address; | |
908 | pte_t *ptep; | |
909 | pte_t pte; | |
910 | ||
911 | BUG_ON(address >= end); | |
912 | flush_cache_range(vma, address, end); | |
913 | ||
39dde65c | 914 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
915 | spin_lock(&mm->page_table_lock); |
916 | for (; address < end; address += HPAGE_SIZE) { | |
917 | ptep = huge_pte_offset(mm, address); | |
918 | if (!ptep) | |
919 | continue; | |
39dde65c CK |
920 | if (huge_pmd_unshare(mm, &address, ptep)) |
921 | continue; | |
8f860591 ZY |
922 | if (!pte_none(*ptep)) { |
923 | pte = huge_ptep_get_and_clear(mm, address, ptep); | |
924 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
925 | set_huge_pte_at(mm, address, ptep, pte); | |
8f860591 ZY |
926 | } |
927 | } | |
928 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 929 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
930 | |
931 | flush_tlb_range(vma, start, end); | |
932 | } | |
933 | ||
a43a8c39 CK |
934 | struct file_region { |
935 | struct list_head link; | |
936 | long from; | |
937 | long to; | |
938 | }; | |
939 | ||
940 | static long region_add(struct list_head *head, long f, long t) | |
941 | { | |
942 | struct file_region *rg, *nrg, *trg; | |
943 | ||
944 | /* Locate the region we are either in or before. */ | |
945 | list_for_each_entry(rg, head, link) | |
946 | if (f <= rg->to) | |
947 | break; | |
948 | ||
949 | /* Round our left edge to the current segment if it encloses us. */ | |
950 | if (f > rg->from) | |
951 | f = rg->from; | |
952 | ||
953 | /* Check for and consume any regions we now overlap with. */ | |
954 | nrg = rg; | |
955 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
956 | if (&rg->link == head) | |
957 | break; | |
958 | if (rg->from > t) | |
959 | break; | |
960 | ||
961 | /* If this area reaches higher then extend our area to | |
962 | * include it completely. If this is not the first area | |
963 | * which we intend to reuse, free it. */ | |
964 | if (rg->to > t) | |
965 | t = rg->to; | |
966 | if (rg != nrg) { | |
967 | list_del(&rg->link); | |
968 | kfree(rg); | |
969 | } | |
970 | } | |
971 | nrg->from = f; | |
972 | nrg->to = t; | |
973 | return 0; | |
974 | } | |
975 | ||
976 | static long region_chg(struct list_head *head, long f, long t) | |
977 | { | |
978 | struct file_region *rg, *nrg; | |
979 | long chg = 0; | |
980 | ||
981 | /* Locate the region we are before or in. */ | |
982 | list_for_each_entry(rg, head, link) | |
983 | if (f <= rg->to) | |
984 | break; | |
985 | ||
986 | /* If we are below the current region then a new region is required. | |
987 | * Subtle, allocate a new region at the position but make it zero | |
988 | * size such that we can guarentee to record the reservation. */ | |
989 | if (&rg->link == head || t < rg->from) { | |
990 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
991 | if (nrg == 0) | |
992 | return -ENOMEM; | |
993 | nrg->from = f; | |
994 | nrg->to = f; | |
995 | INIT_LIST_HEAD(&nrg->link); | |
996 | list_add(&nrg->link, rg->link.prev); | |
997 | ||
998 | return t - f; | |
999 | } | |
1000 | ||
1001 | /* Round our left edge to the current segment if it encloses us. */ | |
1002 | if (f > rg->from) | |
1003 | f = rg->from; | |
1004 | chg = t - f; | |
1005 | ||
1006 | /* Check for and consume any regions we now overlap with. */ | |
1007 | list_for_each_entry(rg, rg->link.prev, link) { | |
1008 | if (&rg->link == head) | |
1009 | break; | |
1010 | if (rg->from > t) | |
1011 | return chg; | |
1012 | ||
1013 | /* We overlap with this area, if it extends futher than | |
1014 | * us then we must extend ourselves. Account for its | |
1015 | * existing reservation. */ | |
1016 | if (rg->to > t) { | |
1017 | chg += rg->to - t; | |
1018 | t = rg->to; | |
1019 | } | |
1020 | chg -= rg->to - rg->from; | |
1021 | } | |
1022 | return chg; | |
1023 | } | |
1024 | ||
1025 | static long region_truncate(struct list_head *head, long end) | |
1026 | { | |
1027 | struct file_region *rg, *trg; | |
1028 | long chg = 0; | |
1029 | ||
1030 | /* Locate the region we are either in or before. */ | |
1031 | list_for_each_entry(rg, head, link) | |
1032 | if (end <= rg->to) | |
1033 | break; | |
1034 | if (&rg->link == head) | |
1035 | return 0; | |
1036 | ||
1037 | /* If we are in the middle of a region then adjust it. */ | |
1038 | if (end > rg->from) { | |
1039 | chg = rg->to - end; | |
1040 | rg->to = end; | |
1041 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
1042 | } | |
1043 | ||
1044 | /* Drop any remaining regions. */ | |
1045 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
1046 | if (&rg->link == head) | |
1047 | break; | |
1048 | chg += rg->to - rg->from; | |
1049 | list_del(&rg->link); | |
1050 | kfree(rg); | |
1051 | } | |
1052 | return chg; | |
1053 | } | |
1054 | ||
1055 | static int hugetlb_acct_memory(long delta) | |
1056 | { | |
1057 | int ret = -ENOMEM; | |
1058 | ||
1059 | spin_lock(&hugetlb_lock); | |
8a630112 KC |
1060 | /* |
1061 | * When cpuset is configured, it breaks the strict hugetlb page | |
1062 | * reservation as the accounting is done on a global variable. Such | |
1063 | * reservation is completely rubbish in the presence of cpuset because | |
1064 | * the reservation is not checked against page availability for the | |
1065 | * current cpuset. Application can still potentially OOM'ed by kernel | |
1066 | * with lack of free htlb page in cpuset that the task is in. | |
1067 | * Attempt to enforce strict accounting with cpuset is almost | |
1068 | * impossible (or too ugly) because cpuset is too fluid that | |
1069 | * task or memory node can be dynamically moved between cpusets. | |
1070 | * | |
1071 | * The change of semantics for shared hugetlb mapping with cpuset is | |
1072 | * undesirable. However, in order to preserve some of the semantics, | |
1073 | * we fall back to check against current free page availability as | |
1074 | * a best attempt and hopefully to minimize the impact of changing | |
1075 | * semantics that cpuset has. | |
1076 | */ | |
e4e574b7 AL |
1077 | if (delta > 0) { |
1078 | if (gather_surplus_pages(delta) < 0) | |
1079 | goto out; | |
1080 | ||
1081 | if (delta > cpuset_mems_nr(free_huge_pages_node)) | |
1082 | goto out; | |
1083 | } | |
1084 | ||
1085 | ret = 0; | |
1086 | resv_huge_pages += delta; | |
1087 | if (delta < 0) | |
1088 | return_unused_surplus_pages((unsigned long) -delta); | |
1089 | ||
1090 | out: | |
1091 | spin_unlock(&hugetlb_lock); | |
1092 | return ret; | |
1093 | } | |
1094 | ||
1095 | int hugetlb_reserve_pages(struct inode *inode, long from, long to) | |
1096 | { | |
1097 | long ret, chg; | |
1098 | ||
1099 | chg = region_chg(&inode->i_mapping->private_list, from, to); | |
1100 | if (chg < 0) | |
1101 | return chg; | |
8a630112 | 1102 | |
a43a8c39 CK |
1103 | ret = hugetlb_acct_memory(chg); |
1104 | if (ret < 0) | |
1105 | return ret; | |
1106 | region_add(&inode->i_mapping->private_list, from, to); | |
1107 | return 0; | |
1108 | } | |
1109 | ||
1110 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
1111 | { | |
1112 | long chg = region_truncate(&inode->i_mapping->private_list, offset); | |
1113 | hugetlb_acct_memory(freed - chg); | |
1114 | } |