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> |
a3437870 | 17 | #include <linux/sysfs.h> |
5da7ca86 | 18 | |
63551ae0 DG |
19 | #include <asm/page.h> |
20 | #include <asm/pgtable.h> | |
21 | ||
22 | #include <linux/hugetlb.h> | |
7835e98b | 23 | #include "internal.h" |
1da177e4 LT |
24 | |
25 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; | |
396faf03 MG |
26 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
27 | unsigned long hugepages_treat_as_movable; | |
a5516438 | 28 | |
e5ff2159 AK |
29 | static int max_hstate; |
30 | unsigned int default_hstate_idx; | |
31 | struct hstate hstates[HUGE_MAX_HSTATE]; | |
32 | ||
33 | /* for command line parsing */ | |
34 | static struct hstate * __initdata parsed_hstate; | |
35 | static unsigned long __initdata default_hstate_max_huge_pages; | |
36 | ||
37 | #define for_each_hstate(h) \ | |
38 | for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++) | |
396faf03 | 39 | |
3935baa9 DG |
40 | /* |
41 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages | |
42 | */ | |
43 | static DEFINE_SPINLOCK(hugetlb_lock); | |
0bd0f9fb | 44 | |
96822904 AW |
45 | /* |
46 | * Region tracking -- allows tracking of reservations and instantiated pages | |
47 | * across the pages in a mapping. | |
84afd99b AW |
48 | * |
49 | * The region data structures are protected by a combination of the mmap_sem | |
50 | * and the hugetlb_instantion_mutex. To access or modify a region the caller | |
51 | * must either hold the mmap_sem for write, or the mmap_sem for read and | |
52 | * the hugetlb_instantiation mutex: | |
53 | * | |
54 | * down_write(&mm->mmap_sem); | |
55 | * or | |
56 | * down_read(&mm->mmap_sem); | |
57 | * mutex_lock(&hugetlb_instantiation_mutex); | |
96822904 AW |
58 | */ |
59 | struct file_region { | |
60 | struct list_head link; | |
61 | long from; | |
62 | long to; | |
63 | }; | |
64 | ||
65 | static long region_add(struct list_head *head, long f, long t) | |
66 | { | |
67 | struct file_region *rg, *nrg, *trg; | |
68 | ||
69 | /* Locate the region we are either in or before. */ | |
70 | list_for_each_entry(rg, head, link) | |
71 | if (f <= rg->to) | |
72 | break; | |
73 | ||
74 | /* Round our left edge to the current segment if it encloses us. */ | |
75 | if (f > rg->from) | |
76 | f = rg->from; | |
77 | ||
78 | /* Check for and consume any regions we now overlap with. */ | |
79 | nrg = rg; | |
80 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
81 | if (&rg->link == head) | |
82 | break; | |
83 | if (rg->from > t) | |
84 | break; | |
85 | ||
86 | /* If this area reaches higher then extend our area to | |
87 | * include it completely. If this is not the first area | |
88 | * which we intend to reuse, free it. */ | |
89 | if (rg->to > t) | |
90 | t = rg->to; | |
91 | if (rg != nrg) { | |
92 | list_del(&rg->link); | |
93 | kfree(rg); | |
94 | } | |
95 | } | |
96 | nrg->from = f; | |
97 | nrg->to = t; | |
98 | return 0; | |
99 | } | |
100 | ||
101 | static long region_chg(struct list_head *head, long f, long t) | |
102 | { | |
103 | struct file_region *rg, *nrg; | |
104 | long chg = 0; | |
105 | ||
106 | /* Locate the region we are before or in. */ | |
107 | list_for_each_entry(rg, head, link) | |
108 | if (f <= rg->to) | |
109 | break; | |
110 | ||
111 | /* If we are below the current region then a new region is required. | |
112 | * Subtle, allocate a new region at the position but make it zero | |
113 | * size such that we can guarantee to record the reservation. */ | |
114 | if (&rg->link == head || t < rg->from) { | |
115 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
116 | if (!nrg) | |
117 | return -ENOMEM; | |
118 | nrg->from = f; | |
119 | nrg->to = f; | |
120 | INIT_LIST_HEAD(&nrg->link); | |
121 | list_add(&nrg->link, rg->link.prev); | |
122 | ||
123 | return t - f; | |
124 | } | |
125 | ||
126 | /* Round our left edge to the current segment if it encloses us. */ | |
127 | if (f > rg->from) | |
128 | f = rg->from; | |
129 | chg = t - f; | |
130 | ||
131 | /* Check for and consume any regions we now overlap with. */ | |
132 | list_for_each_entry(rg, rg->link.prev, link) { | |
133 | if (&rg->link == head) | |
134 | break; | |
135 | if (rg->from > t) | |
136 | return chg; | |
137 | ||
138 | /* We overlap with this area, if it extends futher than | |
139 | * us then we must extend ourselves. Account for its | |
140 | * existing reservation. */ | |
141 | if (rg->to > t) { | |
142 | chg += rg->to - t; | |
143 | t = rg->to; | |
144 | } | |
145 | chg -= rg->to - rg->from; | |
146 | } | |
147 | return chg; | |
148 | } | |
149 | ||
150 | static long region_truncate(struct list_head *head, long end) | |
151 | { | |
152 | struct file_region *rg, *trg; | |
153 | long chg = 0; | |
154 | ||
155 | /* Locate the region we are either in or before. */ | |
156 | list_for_each_entry(rg, head, link) | |
157 | if (end <= rg->to) | |
158 | break; | |
159 | if (&rg->link == head) | |
160 | return 0; | |
161 | ||
162 | /* If we are in the middle of a region then adjust it. */ | |
163 | if (end > rg->from) { | |
164 | chg = rg->to - end; | |
165 | rg->to = end; | |
166 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
167 | } | |
168 | ||
169 | /* Drop any remaining regions. */ | |
170 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
171 | if (&rg->link == head) | |
172 | break; | |
173 | chg += rg->to - rg->from; | |
174 | list_del(&rg->link); | |
175 | kfree(rg); | |
176 | } | |
177 | return chg; | |
178 | } | |
179 | ||
84afd99b AW |
180 | static long region_count(struct list_head *head, long f, long t) |
181 | { | |
182 | struct file_region *rg; | |
183 | long chg = 0; | |
184 | ||
185 | /* Locate each segment we overlap with, and count that overlap. */ | |
186 | list_for_each_entry(rg, head, link) { | |
187 | int seg_from; | |
188 | int seg_to; | |
189 | ||
190 | if (rg->to <= f) | |
191 | continue; | |
192 | if (rg->from >= t) | |
193 | break; | |
194 | ||
195 | seg_from = max(rg->from, f); | |
196 | seg_to = min(rg->to, t); | |
197 | ||
198 | chg += seg_to - seg_from; | |
199 | } | |
200 | ||
201 | return chg; | |
202 | } | |
203 | ||
e7c4b0bf AW |
204 | /* |
205 | * Convert the address within this vma to the page offset within | |
206 | * the mapping, in pagecache page units; huge pages here. | |
207 | */ | |
a5516438 AK |
208 | static pgoff_t vma_hugecache_offset(struct hstate *h, |
209 | struct vm_area_struct *vma, unsigned long address) | |
e7c4b0bf | 210 | { |
a5516438 AK |
211 | return ((address - vma->vm_start) >> huge_page_shift(h)) + |
212 | (vma->vm_pgoff >> huge_page_order(h)); | |
e7c4b0bf AW |
213 | } |
214 | ||
84afd99b AW |
215 | /* |
216 | * Flags for MAP_PRIVATE reservations. These are stored in the bottom | |
217 | * bits of the reservation map pointer, which are always clear due to | |
218 | * alignment. | |
219 | */ | |
220 | #define HPAGE_RESV_OWNER (1UL << 0) | |
221 | #define HPAGE_RESV_UNMAPPED (1UL << 1) | |
04f2cbe3 | 222 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) |
84afd99b | 223 | |
a1e78772 MG |
224 | /* |
225 | * These helpers are used to track how many pages are reserved for | |
226 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() | |
227 | * is guaranteed to have their future faults succeed. | |
228 | * | |
229 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), | |
230 | * the reserve counters are updated with the hugetlb_lock held. It is safe | |
231 | * to reset the VMA at fork() time as it is not in use yet and there is no | |
232 | * chance of the global counters getting corrupted as a result of the values. | |
84afd99b AW |
233 | * |
234 | * The private mapping reservation is represented in a subtly different | |
235 | * manner to a shared mapping. A shared mapping has a region map associated | |
236 | * with the underlying file, this region map represents the backing file | |
237 | * pages which have ever had a reservation assigned which this persists even | |
238 | * after the page is instantiated. A private mapping has a region map | |
239 | * associated with the original mmap which is attached to all VMAs which | |
240 | * reference it, this region map represents those offsets which have consumed | |
241 | * reservation ie. where pages have been instantiated. | |
a1e78772 | 242 | */ |
e7c4b0bf AW |
243 | static unsigned long get_vma_private_data(struct vm_area_struct *vma) |
244 | { | |
245 | return (unsigned long)vma->vm_private_data; | |
246 | } | |
247 | ||
248 | static void set_vma_private_data(struct vm_area_struct *vma, | |
249 | unsigned long value) | |
250 | { | |
251 | vma->vm_private_data = (void *)value; | |
252 | } | |
253 | ||
84afd99b AW |
254 | struct resv_map { |
255 | struct kref refs; | |
256 | struct list_head regions; | |
257 | }; | |
258 | ||
259 | struct resv_map *resv_map_alloc(void) | |
260 | { | |
261 | struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); | |
262 | if (!resv_map) | |
263 | return NULL; | |
264 | ||
265 | kref_init(&resv_map->refs); | |
266 | INIT_LIST_HEAD(&resv_map->regions); | |
267 | ||
268 | return resv_map; | |
269 | } | |
270 | ||
271 | void resv_map_release(struct kref *ref) | |
272 | { | |
273 | struct resv_map *resv_map = container_of(ref, struct resv_map, refs); | |
274 | ||
275 | /* Clear out any active regions before we release the map. */ | |
276 | region_truncate(&resv_map->regions, 0); | |
277 | kfree(resv_map); | |
278 | } | |
279 | ||
280 | static struct resv_map *vma_resv_map(struct vm_area_struct *vma) | |
a1e78772 MG |
281 | { |
282 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
283 | if (!(vma->vm_flags & VM_SHARED)) | |
84afd99b AW |
284 | return (struct resv_map *)(get_vma_private_data(vma) & |
285 | ~HPAGE_RESV_MASK); | |
a1e78772 MG |
286 | return 0; |
287 | } | |
288 | ||
84afd99b | 289 | static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) |
a1e78772 MG |
290 | { |
291 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
292 | VM_BUG_ON(vma->vm_flags & VM_SHARED); | |
293 | ||
84afd99b AW |
294 | set_vma_private_data(vma, (get_vma_private_data(vma) & |
295 | HPAGE_RESV_MASK) | (unsigned long)map); | |
04f2cbe3 MG |
296 | } |
297 | ||
298 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) | |
299 | { | |
04f2cbe3 | 300 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
e7c4b0bf AW |
301 | VM_BUG_ON(vma->vm_flags & VM_SHARED); |
302 | ||
303 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); | |
04f2cbe3 MG |
304 | } |
305 | ||
306 | static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) | |
307 | { | |
308 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
e7c4b0bf AW |
309 | |
310 | return (get_vma_private_data(vma) & flag) != 0; | |
a1e78772 MG |
311 | } |
312 | ||
313 | /* Decrement the reserved pages in the hugepage pool by one */ | |
a5516438 AK |
314 | static void decrement_hugepage_resv_vma(struct hstate *h, |
315 | struct vm_area_struct *vma) | |
a1e78772 | 316 | { |
c37f9fb1 AW |
317 | if (vma->vm_flags & VM_NORESERVE) |
318 | return; | |
319 | ||
a1e78772 MG |
320 | if (vma->vm_flags & VM_SHARED) { |
321 | /* Shared mappings always use reserves */ | |
a5516438 | 322 | h->resv_huge_pages--; |
84afd99b | 323 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
a1e78772 MG |
324 | /* |
325 | * Only the process that called mmap() has reserves for | |
326 | * private mappings. | |
327 | */ | |
a5516438 | 328 | h->resv_huge_pages--; |
a1e78772 MG |
329 | } |
330 | } | |
331 | ||
04f2cbe3 | 332 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
a1e78772 MG |
333 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
334 | { | |
335 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
336 | if (!(vma->vm_flags & VM_SHARED)) | |
337 | vma->vm_private_data = (void *)0; | |
338 | } | |
339 | ||
340 | /* Returns true if the VMA has associated reserve pages */ | |
341 | static int vma_has_private_reserves(struct vm_area_struct *vma) | |
342 | { | |
343 | if (vma->vm_flags & VM_SHARED) | |
344 | return 0; | |
84afd99b | 345 | if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
a1e78772 MG |
346 | return 0; |
347 | return 1; | |
348 | } | |
349 | ||
a5516438 AK |
350 | static void clear_huge_page(struct page *page, |
351 | unsigned long addr, unsigned long sz) | |
79ac6ba4 DG |
352 | { |
353 | int i; | |
354 | ||
355 | might_sleep(); | |
a5516438 | 356 | for (i = 0; i < sz/PAGE_SIZE; i++) { |
79ac6ba4 | 357 | cond_resched(); |
281e0e3b | 358 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
79ac6ba4 DG |
359 | } |
360 | } | |
361 | ||
362 | static void copy_huge_page(struct page *dst, struct page *src, | |
9de455b2 | 363 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
364 | { |
365 | int i; | |
a5516438 | 366 | struct hstate *h = hstate_vma(vma); |
79ac6ba4 DG |
367 | |
368 | might_sleep(); | |
a5516438 | 369 | for (i = 0; i < pages_per_huge_page(h); i++) { |
79ac6ba4 | 370 | cond_resched(); |
9de455b2 | 371 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
372 | } |
373 | } | |
374 | ||
a5516438 | 375 | static void enqueue_huge_page(struct hstate *h, struct page *page) |
1da177e4 LT |
376 | { |
377 | int nid = page_to_nid(page); | |
a5516438 AK |
378 | list_add(&page->lru, &h->hugepage_freelists[nid]); |
379 | h->free_huge_pages++; | |
380 | h->free_huge_pages_node[nid]++; | |
1da177e4 LT |
381 | } |
382 | ||
a5516438 | 383 | static struct page *dequeue_huge_page(struct hstate *h) |
348e1e04 NA |
384 | { |
385 | int nid; | |
386 | struct page *page = NULL; | |
387 | ||
388 | for (nid = 0; nid < MAX_NUMNODES; ++nid) { | |
a5516438 AK |
389 | if (!list_empty(&h->hugepage_freelists[nid])) { |
390 | page = list_entry(h->hugepage_freelists[nid].next, | |
348e1e04 NA |
391 | struct page, lru); |
392 | list_del(&page->lru); | |
a5516438 AK |
393 | h->free_huge_pages--; |
394 | h->free_huge_pages_node[nid]--; | |
348e1e04 NA |
395 | break; |
396 | } | |
397 | } | |
398 | return page; | |
399 | } | |
400 | ||
a5516438 AK |
401 | static struct page *dequeue_huge_page_vma(struct hstate *h, |
402 | struct vm_area_struct *vma, | |
04f2cbe3 | 403 | unsigned long address, int avoid_reserve) |
1da177e4 | 404 | { |
31a5c6e4 | 405 | int nid; |
1da177e4 | 406 | struct page *page = NULL; |
480eccf9 | 407 | struct mempolicy *mpol; |
19770b32 | 408 | nodemask_t *nodemask; |
396faf03 | 409 | struct zonelist *zonelist = huge_zonelist(vma, address, |
19770b32 | 410 | htlb_alloc_mask, &mpol, &nodemask); |
dd1a239f MG |
411 | struct zone *zone; |
412 | struct zoneref *z; | |
1da177e4 | 413 | |
a1e78772 MG |
414 | /* |
415 | * A child process with MAP_PRIVATE mappings created by their parent | |
416 | * have no page reserves. This check ensures that reservations are | |
417 | * not "stolen". The child may still get SIGKILLed | |
418 | */ | |
419 | if (!vma_has_private_reserves(vma) && | |
a5516438 | 420 | h->free_huge_pages - h->resv_huge_pages == 0) |
a1e78772 MG |
421 | return NULL; |
422 | ||
04f2cbe3 | 423 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
a5516438 | 424 | if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) |
04f2cbe3 MG |
425 | return NULL; |
426 | ||
19770b32 MG |
427 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
428 | MAX_NR_ZONES - 1, nodemask) { | |
54a6eb5c MG |
429 | nid = zone_to_nid(zone); |
430 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && | |
a5516438 AK |
431 | !list_empty(&h->hugepage_freelists[nid])) { |
432 | page = list_entry(h->hugepage_freelists[nid].next, | |
3abf7afd AM |
433 | struct page, lru); |
434 | list_del(&page->lru); | |
a5516438 AK |
435 | h->free_huge_pages--; |
436 | h->free_huge_pages_node[nid]--; | |
04f2cbe3 MG |
437 | |
438 | if (!avoid_reserve) | |
a5516438 | 439 | decrement_hugepage_resv_vma(h, vma); |
a1e78772 | 440 | |
5ab3ee7b | 441 | break; |
3abf7afd | 442 | } |
1da177e4 | 443 | } |
52cd3b07 | 444 | mpol_cond_put(mpol); |
1da177e4 LT |
445 | return page; |
446 | } | |
447 | ||
a5516438 | 448 | static void update_and_free_page(struct hstate *h, struct page *page) |
6af2acb6 AL |
449 | { |
450 | int i; | |
a5516438 AK |
451 | |
452 | h->nr_huge_pages--; | |
453 | h->nr_huge_pages_node[page_to_nid(page)]--; | |
454 | for (i = 0; i < pages_per_huge_page(h); i++) { | |
6af2acb6 AL |
455 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | |
456 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
457 | 1 << PG_private | 1<< PG_writeback); | |
458 | } | |
459 | set_compound_page_dtor(page, NULL); | |
460 | set_page_refcounted(page); | |
7f2e9525 | 461 | arch_release_hugepage(page); |
a5516438 | 462 | __free_pages(page, huge_page_order(h)); |
6af2acb6 AL |
463 | } |
464 | ||
e5ff2159 AK |
465 | struct hstate *size_to_hstate(unsigned long size) |
466 | { | |
467 | struct hstate *h; | |
468 | ||
469 | for_each_hstate(h) { | |
470 | if (huge_page_size(h) == size) | |
471 | return h; | |
472 | } | |
473 | return NULL; | |
474 | } | |
475 | ||
27a85ef1 DG |
476 | static void free_huge_page(struct page *page) |
477 | { | |
a5516438 AK |
478 | /* |
479 | * Can't pass hstate in here because it is called from the | |
480 | * compound page destructor. | |
481 | */ | |
e5ff2159 | 482 | struct hstate *h = page_hstate(page); |
7893d1d5 | 483 | int nid = page_to_nid(page); |
c79fb75e | 484 | struct address_space *mapping; |
27a85ef1 | 485 | |
c79fb75e | 486 | mapping = (struct address_space *) page_private(page); |
e5df70ab | 487 | set_page_private(page, 0); |
7893d1d5 | 488 | BUG_ON(page_count(page)); |
27a85ef1 DG |
489 | INIT_LIST_HEAD(&page->lru); |
490 | ||
491 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
492 | if (h->surplus_huge_pages_node[nid]) { |
493 | update_and_free_page(h, page); | |
494 | h->surplus_huge_pages--; | |
495 | h->surplus_huge_pages_node[nid]--; | |
7893d1d5 | 496 | } else { |
a5516438 | 497 | enqueue_huge_page(h, page); |
7893d1d5 | 498 | } |
27a85ef1 | 499 | spin_unlock(&hugetlb_lock); |
c79fb75e | 500 | if (mapping) |
9a119c05 | 501 | hugetlb_put_quota(mapping, 1); |
27a85ef1 DG |
502 | } |
503 | ||
7893d1d5 AL |
504 | /* |
505 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
506 | * balanced by operating on them in a round-robin fashion. | |
507 | * Returns 1 if an adjustment was made. | |
508 | */ | |
a5516438 | 509 | static int adjust_pool_surplus(struct hstate *h, int delta) |
7893d1d5 AL |
510 | { |
511 | static int prev_nid; | |
512 | int nid = prev_nid; | |
513 | int ret = 0; | |
514 | ||
515 | VM_BUG_ON(delta != -1 && delta != 1); | |
516 | do { | |
517 | nid = next_node(nid, node_online_map); | |
518 | if (nid == MAX_NUMNODES) | |
519 | nid = first_node(node_online_map); | |
520 | ||
521 | /* To shrink on this node, there must be a surplus page */ | |
a5516438 | 522 | if (delta < 0 && !h->surplus_huge_pages_node[nid]) |
7893d1d5 AL |
523 | continue; |
524 | /* Surplus cannot exceed the total number of pages */ | |
a5516438 AK |
525 | if (delta > 0 && h->surplus_huge_pages_node[nid] >= |
526 | h->nr_huge_pages_node[nid]) | |
7893d1d5 AL |
527 | continue; |
528 | ||
a5516438 AK |
529 | h->surplus_huge_pages += delta; |
530 | h->surplus_huge_pages_node[nid] += delta; | |
7893d1d5 AL |
531 | ret = 1; |
532 | break; | |
533 | } while (nid != prev_nid); | |
534 | ||
535 | prev_nid = nid; | |
536 | return ret; | |
537 | } | |
538 | ||
a5516438 | 539 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) |
b7ba30c6 AK |
540 | { |
541 | set_compound_page_dtor(page, free_huge_page); | |
542 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
543 | h->nr_huge_pages++; |
544 | h->nr_huge_pages_node[nid]++; | |
b7ba30c6 AK |
545 | spin_unlock(&hugetlb_lock); |
546 | put_page(page); /* free it into the hugepage allocator */ | |
547 | } | |
548 | ||
a5516438 | 549 | static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) |
1da177e4 | 550 | { |
1da177e4 | 551 | struct page *page; |
f96efd58 | 552 | |
63b4613c | 553 | page = alloc_pages_node(nid, |
551883ae NA |
554 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| |
555 | __GFP_REPEAT|__GFP_NOWARN, | |
a5516438 | 556 | huge_page_order(h)); |
1da177e4 | 557 | if (page) { |
7f2e9525 GS |
558 | if (arch_prepare_hugepage(page)) { |
559 | __free_pages(page, HUGETLB_PAGE_ORDER); | |
7b8ee84d | 560 | return NULL; |
7f2e9525 | 561 | } |
a5516438 | 562 | prep_new_huge_page(h, page, nid); |
1da177e4 | 563 | } |
63b4613c NA |
564 | |
565 | return page; | |
566 | } | |
567 | ||
a5516438 | 568 | static int alloc_fresh_huge_page(struct hstate *h) |
63b4613c NA |
569 | { |
570 | struct page *page; | |
571 | int start_nid; | |
572 | int next_nid; | |
573 | int ret = 0; | |
574 | ||
a5516438 | 575 | start_nid = h->hugetlb_next_nid; |
63b4613c NA |
576 | |
577 | do { | |
a5516438 | 578 | page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid); |
63b4613c NA |
579 | if (page) |
580 | ret = 1; | |
581 | /* | |
582 | * Use a helper variable to find the next node and then | |
583 | * copy it back to hugetlb_next_nid afterwards: | |
584 | * otherwise there's a window in which a racer might | |
585 | * pass invalid nid MAX_NUMNODES to alloc_pages_node. | |
586 | * But we don't need to use a spin_lock here: it really | |
587 | * doesn't matter if occasionally a racer chooses the | |
588 | * same nid as we do. Move nid forward in the mask even | |
589 | * if we just successfully allocated a hugepage so that | |
590 | * the next caller gets hugepages on the next node. | |
591 | */ | |
a5516438 | 592 | next_nid = next_node(h->hugetlb_next_nid, node_online_map); |
63b4613c NA |
593 | if (next_nid == MAX_NUMNODES) |
594 | next_nid = first_node(node_online_map); | |
a5516438 AK |
595 | h->hugetlb_next_nid = next_nid; |
596 | } while (!page && h->hugetlb_next_nid != start_nid); | |
63b4613c | 597 | |
3b116300 AL |
598 | if (ret) |
599 | count_vm_event(HTLB_BUDDY_PGALLOC); | |
600 | else | |
601 | count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); | |
602 | ||
63b4613c | 603 | return ret; |
1da177e4 LT |
604 | } |
605 | ||
a5516438 AK |
606 | static struct page *alloc_buddy_huge_page(struct hstate *h, |
607 | struct vm_area_struct *vma, unsigned long address) | |
7893d1d5 AL |
608 | { |
609 | struct page *page; | |
d1c3fb1f | 610 | unsigned int nid; |
7893d1d5 | 611 | |
d1c3fb1f NA |
612 | /* |
613 | * Assume we will successfully allocate the surplus page to | |
614 | * prevent racing processes from causing the surplus to exceed | |
615 | * overcommit | |
616 | * | |
617 | * This however introduces a different race, where a process B | |
618 | * tries to grow the static hugepage pool while alloc_pages() is | |
619 | * called by process A. B will only examine the per-node | |
620 | * counters in determining if surplus huge pages can be | |
621 | * converted to normal huge pages in adjust_pool_surplus(). A | |
622 | * won't be able to increment the per-node counter, until the | |
623 | * lock is dropped by B, but B doesn't drop hugetlb_lock until | |
624 | * no more huge pages can be converted from surplus to normal | |
625 | * state (and doesn't try to convert again). Thus, we have a | |
626 | * case where a surplus huge page exists, the pool is grown, and | |
627 | * the surplus huge page still exists after, even though it | |
628 | * should just have been converted to a normal huge page. This | |
629 | * does not leak memory, though, as the hugepage will be freed | |
630 | * once it is out of use. It also does not allow the counters to | |
631 | * go out of whack in adjust_pool_surplus() as we don't modify | |
632 | * the node values until we've gotten the hugepage and only the | |
633 | * per-node value is checked there. | |
634 | */ | |
635 | spin_lock(&hugetlb_lock); | |
a5516438 | 636 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { |
d1c3fb1f NA |
637 | spin_unlock(&hugetlb_lock); |
638 | return NULL; | |
639 | } else { | |
a5516438 AK |
640 | h->nr_huge_pages++; |
641 | h->surplus_huge_pages++; | |
d1c3fb1f NA |
642 | } |
643 | spin_unlock(&hugetlb_lock); | |
644 | ||
551883ae NA |
645 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP| |
646 | __GFP_REPEAT|__GFP_NOWARN, | |
a5516438 | 647 | huge_page_order(h)); |
d1c3fb1f NA |
648 | |
649 | spin_lock(&hugetlb_lock); | |
7893d1d5 | 650 | if (page) { |
2668db91 AL |
651 | /* |
652 | * This page is now managed by the hugetlb allocator and has | |
653 | * no users -- drop the buddy allocator's reference. | |
654 | */ | |
655 | put_page_testzero(page); | |
656 | VM_BUG_ON(page_count(page)); | |
d1c3fb1f | 657 | nid = page_to_nid(page); |
7893d1d5 | 658 | set_compound_page_dtor(page, free_huge_page); |
d1c3fb1f NA |
659 | /* |
660 | * We incremented the global counters already | |
661 | */ | |
a5516438 AK |
662 | h->nr_huge_pages_node[nid]++; |
663 | h->surplus_huge_pages_node[nid]++; | |
3b116300 | 664 | __count_vm_event(HTLB_BUDDY_PGALLOC); |
d1c3fb1f | 665 | } else { |
a5516438 AK |
666 | h->nr_huge_pages--; |
667 | h->surplus_huge_pages--; | |
3b116300 | 668 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
7893d1d5 | 669 | } |
d1c3fb1f | 670 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
671 | |
672 | return page; | |
673 | } | |
674 | ||
e4e574b7 AL |
675 | /* |
676 | * Increase the hugetlb pool such that it can accomodate a reservation | |
677 | * of size 'delta'. | |
678 | */ | |
a5516438 | 679 | static int gather_surplus_pages(struct hstate *h, int delta) |
e4e574b7 AL |
680 | { |
681 | struct list_head surplus_list; | |
682 | struct page *page, *tmp; | |
683 | int ret, i; | |
684 | int needed, allocated; | |
685 | ||
a5516438 | 686 | needed = (h->resv_huge_pages + delta) - h->free_huge_pages; |
ac09b3a1 | 687 | if (needed <= 0) { |
a5516438 | 688 | h->resv_huge_pages += delta; |
e4e574b7 | 689 | return 0; |
ac09b3a1 | 690 | } |
e4e574b7 AL |
691 | |
692 | allocated = 0; | |
693 | INIT_LIST_HEAD(&surplus_list); | |
694 | ||
695 | ret = -ENOMEM; | |
696 | retry: | |
697 | spin_unlock(&hugetlb_lock); | |
698 | for (i = 0; i < needed; i++) { | |
a5516438 | 699 | page = alloc_buddy_huge_page(h, NULL, 0); |
e4e574b7 AL |
700 | if (!page) { |
701 | /* | |
702 | * We were not able to allocate enough pages to | |
703 | * satisfy the entire reservation so we free what | |
704 | * we've allocated so far. | |
705 | */ | |
706 | spin_lock(&hugetlb_lock); | |
707 | needed = 0; | |
708 | goto free; | |
709 | } | |
710 | ||
711 | list_add(&page->lru, &surplus_list); | |
712 | } | |
713 | allocated += needed; | |
714 | ||
715 | /* | |
716 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
717 | * because either resv_huge_pages or free_huge_pages may have changed. | |
718 | */ | |
719 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
720 | needed = (h->resv_huge_pages + delta) - |
721 | (h->free_huge_pages + allocated); | |
e4e574b7 AL |
722 | if (needed > 0) |
723 | goto retry; | |
724 | ||
725 | /* | |
726 | * The surplus_list now contains _at_least_ the number of extra pages | |
727 | * needed to accomodate the reservation. Add the appropriate number | |
728 | * of pages to the hugetlb pool and free the extras back to the buddy | |
ac09b3a1 AL |
729 | * allocator. Commit the entire reservation here to prevent another |
730 | * process from stealing the pages as they are added to the pool but | |
731 | * before they are reserved. | |
e4e574b7 AL |
732 | */ |
733 | needed += allocated; | |
a5516438 | 734 | h->resv_huge_pages += delta; |
e4e574b7 AL |
735 | ret = 0; |
736 | free: | |
19fc3f0a | 737 | /* Free the needed pages to the hugetlb pool */ |
e4e574b7 | 738 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
19fc3f0a AL |
739 | if ((--needed) < 0) |
740 | break; | |
e4e574b7 | 741 | list_del(&page->lru); |
a5516438 | 742 | enqueue_huge_page(h, page); |
19fc3f0a AL |
743 | } |
744 | ||
745 | /* Free unnecessary surplus pages to the buddy allocator */ | |
746 | if (!list_empty(&surplus_list)) { | |
747 | spin_unlock(&hugetlb_lock); | |
748 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { | |
749 | list_del(&page->lru); | |
af767cbd | 750 | /* |
2668db91 AL |
751 | * The page has a reference count of zero already, so |
752 | * call free_huge_page directly instead of using | |
753 | * put_page. This must be done with hugetlb_lock | |
af767cbd AL |
754 | * unlocked which is safe because free_huge_page takes |
755 | * hugetlb_lock before deciding how to free the page. | |
756 | */ | |
2668db91 | 757 | free_huge_page(page); |
af767cbd | 758 | } |
19fc3f0a | 759 | spin_lock(&hugetlb_lock); |
e4e574b7 AL |
760 | } |
761 | ||
762 | return ret; | |
763 | } | |
764 | ||
765 | /* | |
766 | * When releasing a hugetlb pool reservation, any surplus pages that were | |
767 | * allocated to satisfy the reservation must be explicitly freed if they were | |
768 | * never used. | |
769 | */ | |
a5516438 AK |
770 | static void return_unused_surplus_pages(struct hstate *h, |
771 | unsigned long unused_resv_pages) | |
e4e574b7 AL |
772 | { |
773 | static int nid = -1; | |
774 | struct page *page; | |
775 | unsigned long nr_pages; | |
776 | ||
11320d17 NA |
777 | /* |
778 | * We want to release as many surplus pages as possible, spread | |
779 | * evenly across all nodes. Iterate across all nodes until we | |
780 | * can no longer free unreserved surplus pages. This occurs when | |
781 | * the nodes with surplus pages have no free pages. | |
782 | */ | |
783 | unsigned long remaining_iterations = num_online_nodes(); | |
784 | ||
ac09b3a1 | 785 | /* Uncommit the reservation */ |
a5516438 | 786 | h->resv_huge_pages -= unused_resv_pages; |
ac09b3a1 | 787 | |
a5516438 | 788 | nr_pages = min(unused_resv_pages, h->surplus_huge_pages); |
e4e574b7 | 789 | |
11320d17 | 790 | while (remaining_iterations-- && nr_pages) { |
e4e574b7 AL |
791 | nid = next_node(nid, node_online_map); |
792 | if (nid == MAX_NUMNODES) | |
793 | nid = first_node(node_online_map); | |
794 | ||
a5516438 | 795 | if (!h->surplus_huge_pages_node[nid]) |
e4e574b7 AL |
796 | continue; |
797 | ||
a5516438 AK |
798 | if (!list_empty(&h->hugepage_freelists[nid])) { |
799 | page = list_entry(h->hugepage_freelists[nid].next, | |
e4e574b7 AL |
800 | struct page, lru); |
801 | list_del(&page->lru); | |
a5516438 AK |
802 | update_and_free_page(h, page); |
803 | h->free_huge_pages--; | |
804 | h->free_huge_pages_node[nid]--; | |
805 | h->surplus_huge_pages--; | |
806 | h->surplus_huge_pages_node[nid]--; | |
e4e574b7 | 807 | nr_pages--; |
11320d17 | 808 | remaining_iterations = num_online_nodes(); |
e4e574b7 AL |
809 | } |
810 | } | |
811 | } | |
812 | ||
c37f9fb1 AW |
813 | /* |
814 | * Determine if the huge page at addr within the vma has an associated | |
815 | * reservation. Where it does not we will need to logically increase | |
816 | * reservation and actually increase quota before an allocation can occur. | |
817 | * Where any new reservation would be required the reservation change is | |
818 | * prepared, but not committed. Once the page has been quota'd allocated | |
819 | * an instantiated the change should be committed via vma_commit_reservation. | |
820 | * No action is required on failure. | |
821 | */ | |
a5516438 AK |
822 | static int vma_needs_reservation(struct hstate *h, |
823 | struct vm_area_struct *vma, unsigned long addr) | |
c37f9fb1 AW |
824 | { |
825 | struct address_space *mapping = vma->vm_file->f_mapping; | |
826 | struct inode *inode = mapping->host; | |
827 | ||
828 | if (vma->vm_flags & VM_SHARED) { | |
a5516438 | 829 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 AW |
830 | return region_chg(&inode->i_mapping->private_list, |
831 | idx, idx + 1); | |
832 | ||
84afd99b AW |
833 | } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
834 | return 1; | |
c37f9fb1 | 835 | |
84afd99b AW |
836 | } else { |
837 | int err; | |
a5516438 | 838 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
84afd99b AW |
839 | struct resv_map *reservations = vma_resv_map(vma); |
840 | ||
841 | err = region_chg(&reservations->regions, idx, idx + 1); | |
842 | if (err < 0) | |
843 | return err; | |
844 | return 0; | |
845 | } | |
c37f9fb1 | 846 | } |
a5516438 AK |
847 | static void vma_commit_reservation(struct hstate *h, |
848 | struct vm_area_struct *vma, unsigned long addr) | |
c37f9fb1 AW |
849 | { |
850 | struct address_space *mapping = vma->vm_file->f_mapping; | |
851 | struct inode *inode = mapping->host; | |
852 | ||
853 | if (vma->vm_flags & VM_SHARED) { | |
a5516438 | 854 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 | 855 | region_add(&inode->i_mapping->private_list, idx, idx + 1); |
84afd99b AW |
856 | |
857 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { | |
a5516438 | 858 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
84afd99b AW |
859 | struct resv_map *reservations = vma_resv_map(vma); |
860 | ||
861 | /* Mark this page used in the map. */ | |
862 | region_add(&reservations->regions, idx, idx + 1); | |
c37f9fb1 AW |
863 | } |
864 | } | |
865 | ||
a1e78772 | 866 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
04f2cbe3 | 867 | unsigned long addr, int avoid_reserve) |
1da177e4 | 868 | { |
a5516438 | 869 | struct hstate *h = hstate_vma(vma); |
348ea204 | 870 | struct page *page; |
a1e78772 MG |
871 | struct address_space *mapping = vma->vm_file->f_mapping; |
872 | struct inode *inode = mapping->host; | |
c37f9fb1 | 873 | unsigned int chg; |
a1e78772 MG |
874 | |
875 | /* | |
876 | * Processes that did not create the mapping will have no reserves and | |
877 | * will not have accounted against quota. Check that the quota can be | |
878 | * made before satisfying the allocation | |
c37f9fb1 AW |
879 | * MAP_NORESERVE mappings may also need pages and quota allocated |
880 | * if no reserve mapping overlaps. | |
a1e78772 | 881 | */ |
a5516438 | 882 | chg = vma_needs_reservation(h, vma, addr); |
c37f9fb1 AW |
883 | if (chg < 0) |
884 | return ERR_PTR(chg); | |
885 | if (chg) | |
a1e78772 MG |
886 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
887 | return ERR_PTR(-ENOSPC); | |
1da177e4 LT |
888 | |
889 | spin_lock(&hugetlb_lock); | |
a5516438 | 890 | page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve); |
1da177e4 | 891 | spin_unlock(&hugetlb_lock); |
b45b5bd6 | 892 | |
68842c9b | 893 | if (!page) { |
a5516438 | 894 | page = alloc_buddy_huge_page(h, vma, addr); |
68842c9b | 895 | if (!page) { |
a1e78772 | 896 | hugetlb_put_quota(inode->i_mapping, chg); |
68842c9b KC |
897 | return ERR_PTR(-VM_FAULT_OOM); |
898 | } | |
899 | } | |
348ea204 | 900 | |
a1e78772 MG |
901 | set_page_refcounted(page); |
902 | set_page_private(page, (unsigned long) mapping); | |
90d8b7e6 | 903 | |
a5516438 | 904 | vma_commit_reservation(h, vma, addr); |
c37f9fb1 | 905 | |
90d8b7e6 | 906 | return page; |
b45b5bd6 DG |
907 | } |
908 | ||
e5ff2159 | 909 | static void __init hugetlb_init_one_hstate(struct hstate *h) |
1da177e4 LT |
910 | { |
911 | unsigned long i; | |
a5516438 | 912 | |
1da177e4 | 913 | for (i = 0; i < MAX_NUMNODES; ++i) |
a5516438 | 914 | INIT_LIST_HEAD(&h->hugepage_freelists[i]); |
1da177e4 | 915 | |
a5516438 | 916 | h->hugetlb_next_nid = first_node(node_online_map); |
63b4613c | 917 | |
e5ff2159 | 918 | for (i = 0; i < h->max_huge_pages; ++i) { |
a5516438 | 919 | if (!alloc_fresh_huge_page(h)) |
1da177e4 | 920 | break; |
1da177e4 | 921 | } |
e5ff2159 AK |
922 | h->max_huge_pages = h->free_huge_pages = h->nr_huge_pages = i; |
923 | } | |
924 | ||
925 | static void __init hugetlb_init_hstates(void) | |
926 | { | |
927 | struct hstate *h; | |
928 | ||
929 | for_each_hstate(h) { | |
930 | hugetlb_init_one_hstate(h); | |
931 | } | |
932 | } | |
933 | ||
934 | static void __init report_hugepages(void) | |
935 | { | |
936 | struct hstate *h; | |
937 | ||
938 | for_each_hstate(h) { | |
939 | printk(KERN_INFO "Total HugeTLB memory allocated, " | |
940 | "%ld %dMB pages\n", | |
941 | h->free_huge_pages, | |
942 | 1 << (h->order + PAGE_SHIFT - 20)); | |
943 | } | |
944 | } | |
945 | ||
1da177e4 | 946 | #ifdef CONFIG_SYSCTL |
1da177e4 | 947 | #ifdef CONFIG_HIGHMEM |
a5516438 | 948 | static void try_to_free_low(struct hstate *h, unsigned long count) |
1da177e4 | 949 | { |
4415cc8d CL |
950 | int i; |
951 | ||
1da177e4 LT |
952 | for (i = 0; i < MAX_NUMNODES; ++i) { |
953 | struct page *page, *next; | |
a5516438 AK |
954 | struct list_head *freel = &h->hugepage_freelists[i]; |
955 | list_for_each_entry_safe(page, next, freel, lru) { | |
956 | if (count >= h->nr_huge_pages) | |
6b0c880d | 957 | return; |
1da177e4 LT |
958 | if (PageHighMem(page)) |
959 | continue; | |
960 | list_del(&page->lru); | |
e5ff2159 | 961 | update_and_free_page(h, page); |
a5516438 AK |
962 | h->free_huge_pages--; |
963 | h->free_huge_pages_node[page_to_nid(page)]--; | |
1da177e4 LT |
964 | } |
965 | } | |
966 | } | |
967 | #else | |
a5516438 | 968 | static inline void try_to_free_low(struct hstate *h, unsigned long count) |
1da177e4 LT |
969 | { |
970 | } | |
971 | #endif | |
972 | ||
a5516438 | 973 | #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) |
e5ff2159 | 974 | static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count) |
1da177e4 | 975 | { |
7893d1d5 | 976 | unsigned long min_count, ret; |
1da177e4 | 977 | |
7893d1d5 AL |
978 | /* |
979 | * Increase the pool size | |
980 | * First take pages out of surplus state. Then make up the | |
981 | * remaining difference by allocating fresh huge pages. | |
d1c3fb1f NA |
982 | * |
983 | * We might race with alloc_buddy_huge_page() here and be unable | |
984 | * to convert a surplus huge page to a normal huge page. That is | |
985 | * not critical, though, it just means the overall size of the | |
986 | * pool might be one hugepage larger than it needs to be, but | |
987 | * within all the constraints specified by the sysctls. | |
7893d1d5 | 988 | */ |
1da177e4 | 989 | spin_lock(&hugetlb_lock); |
a5516438 AK |
990 | while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { |
991 | if (!adjust_pool_surplus(h, -1)) | |
7893d1d5 AL |
992 | break; |
993 | } | |
994 | ||
a5516438 | 995 | while (count > persistent_huge_pages(h)) { |
7893d1d5 AL |
996 | /* |
997 | * If this allocation races such that we no longer need the | |
998 | * page, free_huge_page will handle it by freeing the page | |
999 | * and reducing the surplus. | |
1000 | */ | |
1001 | spin_unlock(&hugetlb_lock); | |
a5516438 | 1002 | ret = alloc_fresh_huge_page(h); |
7893d1d5 AL |
1003 | spin_lock(&hugetlb_lock); |
1004 | if (!ret) | |
1005 | goto out; | |
1006 | ||
1007 | } | |
7893d1d5 AL |
1008 | |
1009 | /* | |
1010 | * Decrease the pool size | |
1011 | * First return free pages to the buddy allocator (being careful | |
1012 | * to keep enough around to satisfy reservations). Then place | |
1013 | * pages into surplus state as needed so the pool will shrink | |
1014 | * to the desired size as pages become free. | |
d1c3fb1f NA |
1015 | * |
1016 | * By placing pages into the surplus state independent of the | |
1017 | * overcommit value, we are allowing the surplus pool size to | |
1018 | * exceed overcommit. There are few sane options here. Since | |
1019 | * alloc_buddy_huge_page() is checking the global counter, | |
1020 | * though, we'll note that we're not allowed to exceed surplus | |
1021 | * and won't grow the pool anywhere else. Not until one of the | |
1022 | * sysctls are changed, or the surplus pages go out of use. | |
7893d1d5 | 1023 | */ |
a5516438 | 1024 | min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; |
6b0c880d | 1025 | min_count = max(count, min_count); |
a5516438 AK |
1026 | try_to_free_low(h, min_count); |
1027 | while (min_count < persistent_huge_pages(h)) { | |
1028 | struct page *page = dequeue_huge_page(h); | |
1da177e4 LT |
1029 | if (!page) |
1030 | break; | |
a5516438 | 1031 | update_and_free_page(h, page); |
1da177e4 | 1032 | } |
a5516438 AK |
1033 | while (count < persistent_huge_pages(h)) { |
1034 | if (!adjust_pool_surplus(h, 1)) | |
7893d1d5 AL |
1035 | break; |
1036 | } | |
1037 | out: | |
a5516438 | 1038 | ret = persistent_huge_pages(h); |
1da177e4 | 1039 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 1040 | return ret; |
1da177e4 LT |
1041 | } |
1042 | ||
a3437870 NA |
1043 | #define HSTATE_ATTR_RO(_name) \ |
1044 | static struct kobj_attribute _name##_attr = __ATTR_RO(_name) | |
1045 | ||
1046 | #define HSTATE_ATTR(_name) \ | |
1047 | static struct kobj_attribute _name##_attr = \ | |
1048 | __ATTR(_name, 0644, _name##_show, _name##_store) | |
1049 | ||
1050 | static struct kobject *hugepages_kobj; | |
1051 | static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
1052 | ||
1053 | static struct hstate *kobj_to_hstate(struct kobject *kobj) | |
1054 | { | |
1055 | int i; | |
1056 | for (i = 0; i < HUGE_MAX_HSTATE; i++) | |
1057 | if (hstate_kobjs[i] == kobj) | |
1058 | return &hstates[i]; | |
1059 | BUG(); | |
1060 | return NULL; | |
1061 | } | |
1062 | ||
1063 | static ssize_t nr_hugepages_show(struct kobject *kobj, | |
1064 | struct kobj_attribute *attr, char *buf) | |
1065 | { | |
1066 | struct hstate *h = kobj_to_hstate(kobj); | |
1067 | return sprintf(buf, "%lu\n", h->nr_huge_pages); | |
1068 | } | |
1069 | static ssize_t nr_hugepages_store(struct kobject *kobj, | |
1070 | struct kobj_attribute *attr, const char *buf, size_t count) | |
1071 | { | |
1072 | int err; | |
1073 | unsigned long input; | |
1074 | struct hstate *h = kobj_to_hstate(kobj); | |
1075 | ||
1076 | err = strict_strtoul(buf, 10, &input); | |
1077 | if (err) | |
1078 | return 0; | |
1079 | ||
1080 | h->max_huge_pages = set_max_huge_pages(h, input); | |
1081 | ||
1082 | return count; | |
1083 | } | |
1084 | HSTATE_ATTR(nr_hugepages); | |
1085 | ||
1086 | static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, | |
1087 | struct kobj_attribute *attr, char *buf) | |
1088 | { | |
1089 | struct hstate *h = kobj_to_hstate(kobj); | |
1090 | return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); | |
1091 | } | |
1092 | static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, | |
1093 | struct kobj_attribute *attr, const char *buf, size_t count) | |
1094 | { | |
1095 | int err; | |
1096 | unsigned long input; | |
1097 | struct hstate *h = kobj_to_hstate(kobj); | |
1098 | ||
1099 | err = strict_strtoul(buf, 10, &input); | |
1100 | if (err) | |
1101 | return 0; | |
1102 | ||
1103 | spin_lock(&hugetlb_lock); | |
1104 | h->nr_overcommit_huge_pages = input; | |
1105 | spin_unlock(&hugetlb_lock); | |
1106 | ||
1107 | return count; | |
1108 | } | |
1109 | HSTATE_ATTR(nr_overcommit_hugepages); | |
1110 | ||
1111 | static ssize_t free_hugepages_show(struct kobject *kobj, | |
1112 | struct kobj_attribute *attr, char *buf) | |
1113 | { | |
1114 | struct hstate *h = kobj_to_hstate(kobj); | |
1115 | return sprintf(buf, "%lu\n", h->free_huge_pages); | |
1116 | } | |
1117 | HSTATE_ATTR_RO(free_hugepages); | |
1118 | ||
1119 | static ssize_t resv_hugepages_show(struct kobject *kobj, | |
1120 | struct kobj_attribute *attr, char *buf) | |
1121 | { | |
1122 | struct hstate *h = kobj_to_hstate(kobj); | |
1123 | return sprintf(buf, "%lu\n", h->resv_huge_pages); | |
1124 | } | |
1125 | HSTATE_ATTR_RO(resv_hugepages); | |
1126 | ||
1127 | static ssize_t surplus_hugepages_show(struct kobject *kobj, | |
1128 | struct kobj_attribute *attr, char *buf) | |
1129 | { | |
1130 | struct hstate *h = kobj_to_hstate(kobj); | |
1131 | return sprintf(buf, "%lu\n", h->surplus_huge_pages); | |
1132 | } | |
1133 | HSTATE_ATTR_RO(surplus_hugepages); | |
1134 | ||
1135 | static struct attribute *hstate_attrs[] = { | |
1136 | &nr_hugepages_attr.attr, | |
1137 | &nr_overcommit_hugepages_attr.attr, | |
1138 | &free_hugepages_attr.attr, | |
1139 | &resv_hugepages_attr.attr, | |
1140 | &surplus_hugepages_attr.attr, | |
1141 | NULL, | |
1142 | }; | |
1143 | ||
1144 | static struct attribute_group hstate_attr_group = { | |
1145 | .attrs = hstate_attrs, | |
1146 | }; | |
1147 | ||
1148 | static int __init hugetlb_sysfs_add_hstate(struct hstate *h) | |
1149 | { | |
1150 | int retval; | |
1151 | ||
1152 | hstate_kobjs[h - hstates] = kobject_create_and_add(h->name, | |
1153 | hugepages_kobj); | |
1154 | if (!hstate_kobjs[h - hstates]) | |
1155 | return -ENOMEM; | |
1156 | ||
1157 | retval = sysfs_create_group(hstate_kobjs[h - hstates], | |
1158 | &hstate_attr_group); | |
1159 | if (retval) | |
1160 | kobject_put(hstate_kobjs[h - hstates]); | |
1161 | ||
1162 | return retval; | |
1163 | } | |
1164 | ||
1165 | static void __init hugetlb_sysfs_init(void) | |
1166 | { | |
1167 | struct hstate *h; | |
1168 | int err; | |
1169 | ||
1170 | hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); | |
1171 | if (!hugepages_kobj) | |
1172 | return; | |
1173 | ||
1174 | for_each_hstate(h) { | |
1175 | err = hugetlb_sysfs_add_hstate(h); | |
1176 | if (err) | |
1177 | printk(KERN_ERR "Hugetlb: Unable to add hstate %s", | |
1178 | h->name); | |
1179 | } | |
1180 | } | |
1181 | ||
1182 | static void __exit hugetlb_exit(void) | |
1183 | { | |
1184 | struct hstate *h; | |
1185 | ||
1186 | for_each_hstate(h) { | |
1187 | kobject_put(hstate_kobjs[h - hstates]); | |
1188 | } | |
1189 | ||
1190 | kobject_put(hugepages_kobj); | |
1191 | } | |
1192 | module_exit(hugetlb_exit); | |
1193 | ||
1194 | static int __init hugetlb_init(void) | |
1195 | { | |
1196 | BUILD_BUG_ON(HPAGE_SHIFT == 0); | |
1197 | ||
1198 | if (!size_to_hstate(HPAGE_SIZE)) { | |
1199 | hugetlb_add_hstate(HUGETLB_PAGE_ORDER); | |
1200 | parsed_hstate->max_huge_pages = default_hstate_max_huge_pages; | |
1201 | } | |
1202 | default_hstate_idx = size_to_hstate(HPAGE_SIZE) - hstates; | |
1203 | ||
1204 | hugetlb_init_hstates(); | |
1205 | ||
1206 | report_hugepages(); | |
1207 | ||
1208 | hugetlb_sysfs_init(); | |
1209 | ||
1210 | return 0; | |
1211 | } | |
1212 | module_init(hugetlb_init); | |
1213 | ||
1214 | /* Should be called on processing a hugepagesz=... option */ | |
1215 | void __init hugetlb_add_hstate(unsigned order) | |
1216 | { | |
1217 | struct hstate *h; | |
1218 | if (size_to_hstate(PAGE_SIZE << order)) { | |
1219 | printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n"); | |
1220 | return; | |
1221 | } | |
1222 | BUG_ON(max_hstate >= HUGE_MAX_HSTATE); | |
1223 | BUG_ON(order == 0); | |
1224 | h = &hstates[max_hstate++]; | |
1225 | h->order = order; | |
1226 | h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); | |
1227 | snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", | |
1228 | huge_page_size(h)/1024); | |
1229 | hugetlb_init_one_hstate(h); | |
1230 | parsed_hstate = h; | |
1231 | } | |
1232 | ||
1233 | static int __init hugetlb_setup(char *s) | |
1234 | { | |
1235 | unsigned long *mhp; | |
1236 | ||
1237 | /* | |
1238 | * !max_hstate means we haven't parsed a hugepagesz= parameter yet, | |
1239 | * so this hugepages= parameter goes to the "default hstate". | |
1240 | */ | |
1241 | if (!max_hstate) | |
1242 | mhp = &default_hstate_max_huge_pages; | |
1243 | else | |
1244 | mhp = &parsed_hstate->max_huge_pages; | |
1245 | ||
1246 | if (sscanf(s, "%lu", mhp) <= 0) | |
1247 | *mhp = 0; | |
1248 | ||
1249 | return 1; | |
1250 | } | |
1251 | __setup("hugepages=", hugetlb_setup); | |
1252 | ||
1253 | static unsigned int cpuset_mems_nr(unsigned int *array) | |
1254 | { | |
1255 | int node; | |
1256 | unsigned int nr = 0; | |
1257 | ||
1258 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
1259 | nr += array[node]; | |
1260 | ||
1261 | return nr; | |
1262 | } | |
1263 | ||
1da177e4 LT |
1264 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
1265 | struct file *file, void __user *buffer, | |
1266 | size_t *length, loff_t *ppos) | |
1267 | { | |
e5ff2159 AK |
1268 | struct hstate *h = &default_hstate; |
1269 | unsigned long tmp; | |
1270 | ||
1271 | if (!write) | |
1272 | tmp = h->max_huge_pages; | |
1273 | ||
1274 | table->data = &tmp; | |
1275 | table->maxlen = sizeof(unsigned long); | |
1da177e4 | 1276 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
e5ff2159 AK |
1277 | |
1278 | if (write) | |
1279 | h->max_huge_pages = set_max_huge_pages(h, tmp); | |
1280 | ||
1da177e4 LT |
1281 | return 0; |
1282 | } | |
396faf03 MG |
1283 | |
1284 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, | |
1285 | struct file *file, void __user *buffer, | |
1286 | size_t *length, loff_t *ppos) | |
1287 | { | |
1288 | proc_dointvec(table, write, file, buffer, length, ppos); | |
1289 | if (hugepages_treat_as_movable) | |
1290 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; | |
1291 | else | |
1292 | htlb_alloc_mask = GFP_HIGHUSER; | |
1293 | return 0; | |
1294 | } | |
1295 | ||
a3d0c6aa NA |
1296 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
1297 | struct file *file, void __user *buffer, | |
1298 | size_t *length, loff_t *ppos) | |
1299 | { | |
a5516438 | 1300 | struct hstate *h = &default_hstate; |
e5ff2159 AK |
1301 | unsigned long tmp; |
1302 | ||
1303 | if (!write) | |
1304 | tmp = h->nr_overcommit_huge_pages; | |
1305 | ||
1306 | table->data = &tmp; | |
1307 | table->maxlen = sizeof(unsigned long); | |
a3d0c6aa | 1308 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
e5ff2159 AK |
1309 | |
1310 | if (write) { | |
1311 | spin_lock(&hugetlb_lock); | |
1312 | h->nr_overcommit_huge_pages = tmp; | |
1313 | spin_unlock(&hugetlb_lock); | |
1314 | } | |
1315 | ||
a3d0c6aa NA |
1316 | return 0; |
1317 | } | |
1318 | ||
1da177e4 LT |
1319 | #endif /* CONFIG_SYSCTL */ |
1320 | ||
1321 | int hugetlb_report_meminfo(char *buf) | |
1322 | { | |
a5516438 | 1323 | struct hstate *h = &default_hstate; |
1da177e4 LT |
1324 | return sprintf(buf, |
1325 | "HugePages_Total: %5lu\n" | |
1326 | "HugePages_Free: %5lu\n" | |
a43a8c39 | 1327 | "HugePages_Rsvd: %5lu\n" |
7893d1d5 | 1328 | "HugePages_Surp: %5lu\n" |
1da177e4 | 1329 | "Hugepagesize: %5lu kB\n", |
a5516438 AK |
1330 | h->nr_huge_pages, |
1331 | h->free_huge_pages, | |
1332 | h->resv_huge_pages, | |
1333 | h->surplus_huge_pages, | |
1334 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); | |
1da177e4 LT |
1335 | } |
1336 | ||
1337 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
1338 | { | |
a5516438 | 1339 | struct hstate *h = &default_hstate; |
1da177e4 LT |
1340 | return sprintf(buf, |
1341 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
1342 | "Node %d HugePages_Free: %5u\n" |
1343 | "Node %d HugePages_Surp: %5u\n", | |
a5516438 AK |
1344 | nid, h->nr_huge_pages_node[nid], |
1345 | nid, h->free_huge_pages_node[nid], | |
1346 | nid, h->surplus_huge_pages_node[nid]); | |
1da177e4 LT |
1347 | } |
1348 | ||
1da177e4 LT |
1349 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
1350 | unsigned long hugetlb_total_pages(void) | |
1351 | { | |
a5516438 AK |
1352 | struct hstate *h = &default_hstate; |
1353 | return h->nr_huge_pages * pages_per_huge_page(h); | |
1da177e4 | 1354 | } |
1da177e4 | 1355 | |
a5516438 | 1356 | static int hugetlb_acct_memory(struct hstate *h, long delta) |
fc1b8a73 MG |
1357 | { |
1358 | int ret = -ENOMEM; | |
1359 | ||
1360 | spin_lock(&hugetlb_lock); | |
1361 | /* | |
1362 | * When cpuset is configured, it breaks the strict hugetlb page | |
1363 | * reservation as the accounting is done on a global variable. Such | |
1364 | * reservation is completely rubbish in the presence of cpuset because | |
1365 | * the reservation is not checked against page availability for the | |
1366 | * current cpuset. Application can still potentially OOM'ed by kernel | |
1367 | * with lack of free htlb page in cpuset that the task is in. | |
1368 | * Attempt to enforce strict accounting with cpuset is almost | |
1369 | * impossible (or too ugly) because cpuset is too fluid that | |
1370 | * task or memory node can be dynamically moved between cpusets. | |
1371 | * | |
1372 | * The change of semantics for shared hugetlb mapping with cpuset is | |
1373 | * undesirable. However, in order to preserve some of the semantics, | |
1374 | * we fall back to check against current free page availability as | |
1375 | * a best attempt and hopefully to minimize the impact of changing | |
1376 | * semantics that cpuset has. | |
1377 | */ | |
1378 | if (delta > 0) { | |
a5516438 | 1379 | if (gather_surplus_pages(h, delta) < 0) |
fc1b8a73 MG |
1380 | goto out; |
1381 | ||
a5516438 AK |
1382 | if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { |
1383 | return_unused_surplus_pages(h, delta); | |
fc1b8a73 MG |
1384 | goto out; |
1385 | } | |
1386 | } | |
1387 | ||
1388 | ret = 0; | |
1389 | if (delta < 0) | |
a5516438 | 1390 | return_unused_surplus_pages(h, (unsigned long) -delta); |
fc1b8a73 MG |
1391 | |
1392 | out: | |
1393 | spin_unlock(&hugetlb_lock); | |
1394 | return ret; | |
1395 | } | |
1396 | ||
84afd99b AW |
1397 | static void hugetlb_vm_op_open(struct vm_area_struct *vma) |
1398 | { | |
1399 | struct resv_map *reservations = vma_resv_map(vma); | |
1400 | ||
1401 | /* | |
1402 | * This new VMA should share its siblings reservation map if present. | |
1403 | * The VMA will only ever have a valid reservation map pointer where | |
1404 | * it is being copied for another still existing VMA. As that VMA | |
1405 | * has a reference to the reservation map it cannot dissappear until | |
1406 | * after this open call completes. It is therefore safe to take a | |
1407 | * new reference here without additional locking. | |
1408 | */ | |
1409 | if (reservations) | |
1410 | kref_get(&reservations->refs); | |
1411 | } | |
1412 | ||
a1e78772 MG |
1413 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
1414 | { | |
a5516438 | 1415 | struct hstate *h = hstate_vma(vma); |
84afd99b AW |
1416 | struct resv_map *reservations = vma_resv_map(vma); |
1417 | unsigned long reserve; | |
1418 | unsigned long start; | |
1419 | unsigned long end; | |
1420 | ||
1421 | if (reservations) { | |
a5516438 AK |
1422 | start = vma_hugecache_offset(h, vma, vma->vm_start); |
1423 | end = vma_hugecache_offset(h, vma, vma->vm_end); | |
84afd99b AW |
1424 | |
1425 | reserve = (end - start) - | |
1426 | region_count(&reservations->regions, start, end); | |
1427 | ||
1428 | kref_put(&reservations->refs, resv_map_release); | |
1429 | ||
1430 | if (reserve) | |
a5516438 | 1431 | hugetlb_acct_memory(h, -reserve); |
84afd99b | 1432 | } |
a1e78772 MG |
1433 | } |
1434 | ||
1da177e4 LT |
1435 | /* |
1436 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
1437 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
1438 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
1439 | * this far. | |
1440 | */ | |
d0217ac0 | 1441 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
1442 | { |
1443 | BUG(); | |
d0217ac0 | 1444 | return 0; |
1da177e4 LT |
1445 | } |
1446 | ||
1447 | struct vm_operations_struct hugetlb_vm_ops = { | |
d0217ac0 | 1448 | .fault = hugetlb_vm_op_fault, |
84afd99b | 1449 | .open = hugetlb_vm_op_open, |
a1e78772 | 1450 | .close = hugetlb_vm_op_close, |
1da177e4 LT |
1451 | }; |
1452 | ||
1e8f889b DG |
1453 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
1454 | int writable) | |
63551ae0 DG |
1455 | { |
1456 | pte_t entry; | |
1457 | ||
1e8f889b | 1458 | if (writable) { |
63551ae0 DG |
1459 | entry = |
1460 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
1461 | } else { | |
7f2e9525 | 1462 | entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
63551ae0 DG |
1463 | } |
1464 | entry = pte_mkyoung(entry); | |
1465 | entry = pte_mkhuge(entry); | |
1466 | ||
1467 | return entry; | |
1468 | } | |
1469 | ||
1e8f889b DG |
1470 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
1471 | unsigned long address, pte_t *ptep) | |
1472 | { | |
1473 | pte_t entry; | |
1474 | ||
7f2e9525 GS |
1475 | entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); |
1476 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { | |
8dab5241 | 1477 | update_mmu_cache(vma, address, entry); |
8dab5241 | 1478 | } |
1e8f889b DG |
1479 | } |
1480 | ||
1481 | ||
63551ae0 DG |
1482 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
1483 | struct vm_area_struct *vma) | |
1484 | { | |
1485 | pte_t *src_pte, *dst_pte, entry; | |
1486 | struct page *ptepage; | |
1c59827d | 1487 | unsigned long addr; |
1e8f889b | 1488 | int cow; |
a5516438 AK |
1489 | struct hstate *h = hstate_vma(vma); |
1490 | unsigned long sz = huge_page_size(h); | |
1e8f889b DG |
1491 | |
1492 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 1493 | |
a5516438 | 1494 | for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { |
c74df32c HD |
1495 | src_pte = huge_pte_offset(src, addr); |
1496 | if (!src_pte) | |
1497 | continue; | |
a5516438 | 1498 | dst_pte = huge_pte_alloc(dst, addr, sz); |
63551ae0 DG |
1499 | if (!dst_pte) |
1500 | goto nomem; | |
c5c99429 LW |
1501 | |
1502 | /* If the pagetables are shared don't copy or take references */ | |
1503 | if (dst_pte == src_pte) | |
1504 | continue; | |
1505 | ||
c74df32c | 1506 | spin_lock(&dst->page_table_lock); |
46478758 | 1507 | spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); |
7f2e9525 | 1508 | if (!huge_pte_none(huge_ptep_get(src_pte))) { |
1e8f889b | 1509 | if (cow) |
7f2e9525 GS |
1510 | huge_ptep_set_wrprotect(src, addr, src_pte); |
1511 | entry = huge_ptep_get(src_pte); | |
1c59827d HD |
1512 | ptepage = pte_page(entry); |
1513 | get_page(ptepage); | |
1c59827d HD |
1514 | set_huge_pte_at(dst, addr, dst_pte, entry); |
1515 | } | |
1516 | spin_unlock(&src->page_table_lock); | |
c74df32c | 1517 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
1518 | } |
1519 | return 0; | |
1520 | ||
1521 | nomem: | |
1522 | return -ENOMEM; | |
1523 | } | |
1524 | ||
502717f4 | 1525 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1526 | unsigned long end, struct page *ref_page) |
63551ae0 DG |
1527 | { |
1528 | struct mm_struct *mm = vma->vm_mm; | |
1529 | unsigned long address; | |
c7546f8f | 1530 | pte_t *ptep; |
63551ae0 DG |
1531 | pte_t pte; |
1532 | struct page *page; | |
fe1668ae | 1533 | struct page *tmp; |
a5516438 AK |
1534 | struct hstate *h = hstate_vma(vma); |
1535 | unsigned long sz = huge_page_size(h); | |
1536 | ||
c0a499c2 CK |
1537 | /* |
1538 | * A page gathering list, protected by per file i_mmap_lock. The | |
1539 | * lock is used to avoid list corruption from multiple unmapping | |
1540 | * of the same page since we are using page->lru. | |
1541 | */ | |
fe1668ae | 1542 | LIST_HEAD(page_list); |
63551ae0 DG |
1543 | |
1544 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
a5516438 AK |
1545 | BUG_ON(start & ~huge_page_mask(h)); |
1546 | BUG_ON(end & ~huge_page_mask(h)); | |
63551ae0 | 1547 | |
508034a3 | 1548 | spin_lock(&mm->page_table_lock); |
a5516438 | 1549 | for (address = start; address < end; address += sz) { |
c7546f8f | 1550 | ptep = huge_pte_offset(mm, address); |
4c887265 | 1551 | if (!ptep) |
c7546f8f DG |
1552 | continue; |
1553 | ||
39dde65c CK |
1554 | if (huge_pmd_unshare(mm, &address, ptep)) |
1555 | continue; | |
1556 | ||
04f2cbe3 MG |
1557 | /* |
1558 | * If a reference page is supplied, it is because a specific | |
1559 | * page is being unmapped, not a range. Ensure the page we | |
1560 | * are about to unmap is the actual page of interest. | |
1561 | */ | |
1562 | if (ref_page) { | |
1563 | pte = huge_ptep_get(ptep); | |
1564 | if (huge_pte_none(pte)) | |
1565 | continue; | |
1566 | page = pte_page(pte); | |
1567 | if (page != ref_page) | |
1568 | continue; | |
1569 | ||
1570 | /* | |
1571 | * Mark the VMA as having unmapped its page so that | |
1572 | * future faults in this VMA will fail rather than | |
1573 | * looking like data was lost | |
1574 | */ | |
1575 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); | |
1576 | } | |
1577 | ||
c7546f8f | 1578 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
7f2e9525 | 1579 | if (huge_pte_none(pte)) |
63551ae0 | 1580 | continue; |
c7546f8f | 1581 | |
63551ae0 | 1582 | page = pte_page(pte); |
6649a386 KC |
1583 | if (pte_dirty(pte)) |
1584 | set_page_dirty(page); | |
fe1668ae | 1585 | list_add(&page->lru, &page_list); |
63551ae0 | 1586 | } |
1da177e4 | 1587 | spin_unlock(&mm->page_table_lock); |
508034a3 | 1588 | flush_tlb_range(vma, start, end); |
fe1668ae CK |
1589 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
1590 | list_del(&page->lru); | |
1591 | put_page(page); | |
1592 | } | |
1da177e4 | 1593 | } |
63551ae0 | 1594 | |
502717f4 | 1595 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1596 | unsigned long end, struct page *ref_page) |
502717f4 | 1597 | { |
a137e1cc AK |
1598 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
1599 | __unmap_hugepage_range(vma, start, end, ref_page); | |
1600 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); | |
502717f4 CK |
1601 | } |
1602 | ||
04f2cbe3 MG |
1603 | /* |
1604 | * This is called when the original mapper is failing to COW a MAP_PRIVATE | |
1605 | * mappping it owns the reserve page for. The intention is to unmap the page | |
1606 | * from other VMAs and let the children be SIGKILLed if they are faulting the | |
1607 | * same region. | |
1608 | */ | |
1609 | int unmap_ref_private(struct mm_struct *mm, | |
1610 | struct vm_area_struct *vma, | |
1611 | struct page *page, | |
1612 | unsigned long address) | |
1613 | { | |
1614 | struct vm_area_struct *iter_vma; | |
1615 | struct address_space *mapping; | |
1616 | struct prio_tree_iter iter; | |
1617 | pgoff_t pgoff; | |
1618 | ||
1619 | /* | |
1620 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation | |
1621 | * from page cache lookup which is in HPAGE_SIZE units. | |
1622 | */ | |
1623 | address = address & huge_page_mask(hstate_vma(vma)); | |
1624 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) | |
1625 | + (vma->vm_pgoff >> PAGE_SHIFT); | |
1626 | mapping = (struct address_space *)page_private(page); | |
1627 | ||
1628 | vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { | |
1629 | /* Do not unmap the current VMA */ | |
1630 | if (iter_vma == vma) | |
1631 | continue; | |
1632 | ||
1633 | /* | |
1634 | * Unmap the page from other VMAs without their own reserves. | |
1635 | * They get marked to be SIGKILLed if they fault in these | |
1636 | * areas. This is because a future no-page fault on this VMA | |
1637 | * could insert a zeroed page instead of the data existing | |
1638 | * from the time of fork. This would look like data corruption | |
1639 | */ | |
1640 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) | |
1641 | unmap_hugepage_range(iter_vma, | |
1642 | address, address + HPAGE_SIZE, | |
1643 | page); | |
1644 | } | |
1645 | ||
1646 | return 1; | |
1647 | } | |
1648 | ||
1e8f889b | 1649 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
04f2cbe3 MG |
1650 | unsigned long address, pte_t *ptep, pte_t pte, |
1651 | struct page *pagecache_page) | |
1e8f889b | 1652 | { |
a5516438 | 1653 | struct hstate *h = hstate_vma(vma); |
1e8f889b | 1654 | struct page *old_page, *new_page; |
79ac6ba4 | 1655 | int avoidcopy; |
04f2cbe3 | 1656 | int outside_reserve = 0; |
1e8f889b DG |
1657 | |
1658 | old_page = pte_page(pte); | |
1659 | ||
04f2cbe3 | 1660 | retry_avoidcopy: |
1e8f889b DG |
1661 | /* If no-one else is actually using this page, avoid the copy |
1662 | * and just make the page writable */ | |
1663 | avoidcopy = (page_count(old_page) == 1); | |
1664 | if (avoidcopy) { | |
1665 | set_huge_ptep_writable(vma, address, ptep); | |
83c54070 | 1666 | return 0; |
1e8f889b DG |
1667 | } |
1668 | ||
04f2cbe3 MG |
1669 | /* |
1670 | * If the process that created a MAP_PRIVATE mapping is about to | |
1671 | * perform a COW due to a shared page count, attempt to satisfy | |
1672 | * the allocation without using the existing reserves. The pagecache | |
1673 | * page is used to determine if the reserve at this address was | |
1674 | * consumed or not. If reserves were used, a partial faulted mapping | |
1675 | * at the time of fork() could consume its reserves on COW instead | |
1676 | * of the full address range. | |
1677 | */ | |
1678 | if (!(vma->vm_flags & VM_SHARED) && | |
1679 | is_vma_resv_set(vma, HPAGE_RESV_OWNER) && | |
1680 | old_page != pagecache_page) | |
1681 | outside_reserve = 1; | |
1682 | ||
1e8f889b | 1683 | page_cache_get(old_page); |
04f2cbe3 | 1684 | new_page = alloc_huge_page(vma, address, outside_reserve); |
1e8f889b | 1685 | |
2fc39cec | 1686 | if (IS_ERR(new_page)) { |
1e8f889b | 1687 | page_cache_release(old_page); |
04f2cbe3 MG |
1688 | |
1689 | /* | |
1690 | * If a process owning a MAP_PRIVATE mapping fails to COW, | |
1691 | * it is due to references held by a child and an insufficient | |
1692 | * huge page pool. To guarantee the original mappers | |
1693 | * reliability, unmap the page from child processes. The child | |
1694 | * may get SIGKILLed if it later faults. | |
1695 | */ | |
1696 | if (outside_reserve) { | |
1697 | BUG_ON(huge_pte_none(pte)); | |
1698 | if (unmap_ref_private(mm, vma, old_page, address)) { | |
1699 | BUG_ON(page_count(old_page) != 1); | |
1700 | BUG_ON(huge_pte_none(pte)); | |
1701 | goto retry_avoidcopy; | |
1702 | } | |
1703 | WARN_ON_ONCE(1); | |
1704 | } | |
1705 | ||
2fc39cec | 1706 | return -PTR_ERR(new_page); |
1e8f889b DG |
1707 | } |
1708 | ||
1709 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 1710 | copy_huge_page(new_page, old_page, address, vma); |
0ed361de | 1711 | __SetPageUptodate(new_page); |
1e8f889b DG |
1712 | spin_lock(&mm->page_table_lock); |
1713 | ||
a5516438 | 1714 | ptep = huge_pte_offset(mm, address & huge_page_mask(h)); |
7f2e9525 | 1715 | if (likely(pte_same(huge_ptep_get(ptep), pte))) { |
1e8f889b | 1716 | /* Break COW */ |
8fe627ec | 1717 | huge_ptep_clear_flush(vma, address, ptep); |
1e8f889b DG |
1718 | set_huge_pte_at(mm, address, ptep, |
1719 | make_huge_pte(vma, new_page, 1)); | |
1720 | /* Make the old page be freed below */ | |
1721 | new_page = old_page; | |
1722 | } | |
1723 | page_cache_release(new_page); | |
1724 | page_cache_release(old_page); | |
83c54070 | 1725 | return 0; |
1e8f889b DG |
1726 | } |
1727 | ||
04f2cbe3 | 1728 | /* Return the pagecache page at a given address within a VMA */ |
a5516438 AK |
1729 | static struct page *hugetlbfs_pagecache_page(struct hstate *h, |
1730 | struct vm_area_struct *vma, unsigned long address) | |
04f2cbe3 MG |
1731 | { |
1732 | struct address_space *mapping; | |
e7c4b0bf | 1733 | pgoff_t idx; |
04f2cbe3 MG |
1734 | |
1735 | mapping = vma->vm_file->f_mapping; | |
a5516438 | 1736 | idx = vma_hugecache_offset(h, vma, address); |
04f2cbe3 MG |
1737 | |
1738 | return find_lock_page(mapping, idx); | |
1739 | } | |
1740 | ||
a1ed3dda | 1741 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 1742 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 | 1743 | { |
a5516438 | 1744 | struct hstate *h = hstate_vma(vma); |
ac9b9c66 | 1745 | int ret = VM_FAULT_SIGBUS; |
e7c4b0bf | 1746 | pgoff_t idx; |
4c887265 | 1747 | unsigned long size; |
4c887265 AL |
1748 | struct page *page; |
1749 | struct address_space *mapping; | |
1e8f889b | 1750 | pte_t new_pte; |
4c887265 | 1751 | |
04f2cbe3 MG |
1752 | /* |
1753 | * Currently, we are forced to kill the process in the event the | |
1754 | * original mapper has unmapped pages from the child due to a failed | |
1755 | * COW. Warn that such a situation has occured as it may not be obvious | |
1756 | */ | |
1757 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { | |
1758 | printk(KERN_WARNING | |
1759 | "PID %d killed due to inadequate hugepage pool\n", | |
1760 | current->pid); | |
1761 | return ret; | |
1762 | } | |
1763 | ||
4c887265 | 1764 | mapping = vma->vm_file->f_mapping; |
a5516438 | 1765 | idx = vma_hugecache_offset(h, vma, address); |
4c887265 AL |
1766 | |
1767 | /* | |
1768 | * Use page lock to guard against racing truncation | |
1769 | * before we get page_table_lock. | |
1770 | */ | |
6bda666a CL |
1771 | retry: |
1772 | page = find_lock_page(mapping, idx); | |
1773 | if (!page) { | |
a5516438 | 1774 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
ebed4bfc HD |
1775 | if (idx >= size) |
1776 | goto out; | |
04f2cbe3 | 1777 | page = alloc_huge_page(vma, address, 0); |
2fc39cec AL |
1778 | if (IS_ERR(page)) { |
1779 | ret = -PTR_ERR(page); | |
6bda666a CL |
1780 | goto out; |
1781 | } | |
a5516438 | 1782 | clear_huge_page(page, address, huge_page_size(h)); |
0ed361de | 1783 | __SetPageUptodate(page); |
ac9b9c66 | 1784 | |
6bda666a CL |
1785 | if (vma->vm_flags & VM_SHARED) { |
1786 | int err; | |
45c682a6 | 1787 | struct inode *inode = mapping->host; |
6bda666a CL |
1788 | |
1789 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
1790 | if (err) { | |
1791 | put_page(page); | |
6bda666a CL |
1792 | if (err == -EEXIST) |
1793 | goto retry; | |
1794 | goto out; | |
1795 | } | |
45c682a6 KC |
1796 | |
1797 | spin_lock(&inode->i_lock); | |
a5516438 | 1798 | inode->i_blocks += blocks_per_huge_page(h); |
45c682a6 | 1799 | spin_unlock(&inode->i_lock); |
6bda666a CL |
1800 | } else |
1801 | lock_page(page); | |
1802 | } | |
1e8f889b | 1803 | |
ac9b9c66 | 1804 | spin_lock(&mm->page_table_lock); |
a5516438 | 1805 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
4c887265 AL |
1806 | if (idx >= size) |
1807 | goto backout; | |
1808 | ||
83c54070 | 1809 | ret = 0; |
7f2e9525 | 1810 | if (!huge_pte_none(huge_ptep_get(ptep))) |
4c887265 AL |
1811 | goto backout; |
1812 | ||
1e8f889b DG |
1813 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
1814 | && (vma->vm_flags & VM_SHARED))); | |
1815 | set_huge_pte_at(mm, address, ptep, new_pte); | |
1816 | ||
1817 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
1818 | /* Optimization, do the COW without a second fault */ | |
04f2cbe3 | 1819 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); |
1e8f889b DG |
1820 | } |
1821 | ||
ac9b9c66 | 1822 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
1823 | unlock_page(page); |
1824 | out: | |
ac9b9c66 | 1825 | return ret; |
4c887265 AL |
1826 | |
1827 | backout: | |
1828 | spin_unlock(&mm->page_table_lock); | |
4c887265 AL |
1829 | unlock_page(page); |
1830 | put_page(page); | |
1831 | goto out; | |
ac9b9c66 HD |
1832 | } |
1833 | ||
86e5216f AL |
1834 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
1835 | unsigned long address, int write_access) | |
1836 | { | |
1837 | pte_t *ptep; | |
1838 | pte_t entry; | |
1e8f889b | 1839 | int ret; |
3935baa9 | 1840 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
a5516438 | 1841 | struct hstate *h = hstate_vma(vma); |
86e5216f | 1842 | |
a5516438 | 1843 | ptep = huge_pte_alloc(mm, address, huge_page_size(h)); |
86e5216f AL |
1844 | if (!ptep) |
1845 | return VM_FAULT_OOM; | |
1846 | ||
3935baa9 DG |
1847 | /* |
1848 | * Serialize hugepage allocation and instantiation, so that we don't | |
1849 | * get spurious allocation failures if two CPUs race to instantiate | |
1850 | * the same page in the page cache. | |
1851 | */ | |
1852 | mutex_lock(&hugetlb_instantiation_mutex); | |
7f2e9525 GS |
1853 | entry = huge_ptep_get(ptep); |
1854 | if (huge_pte_none(entry)) { | |
3935baa9 DG |
1855 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); |
1856 | mutex_unlock(&hugetlb_instantiation_mutex); | |
1857 | return ret; | |
1858 | } | |
86e5216f | 1859 | |
83c54070 | 1860 | ret = 0; |
1e8f889b DG |
1861 | |
1862 | spin_lock(&mm->page_table_lock); | |
1863 | /* Check for a racing update before calling hugetlb_cow */ | |
7f2e9525 | 1864 | if (likely(pte_same(entry, huge_ptep_get(ptep)))) |
04f2cbe3 MG |
1865 | if (write_access && !pte_write(entry)) { |
1866 | struct page *page; | |
a5516438 | 1867 | page = hugetlbfs_pagecache_page(h, vma, address); |
04f2cbe3 MG |
1868 | ret = hugetlb_cow(mm, vma, address, ptep, entry, page); |
1869 | if (page) { | |
1870 | unlock_page(page); | |
1871 | put_page(page); | |
1872 | } | |
1873 | } | |
1e8f889b | 1874 | spin_unlock(&mm->page_table_lock); |
3935baa9 | 1875 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
1876 | |
1877 | return ret; | |
86e5216f AL |
1878 | } |
1879 | ||
63551ae0 DG |
1880 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1881 | struct page **pages, struct vm_area_struct **vmas, | |
5b23dbe8 AL |
1882 | unsigned long *position, int *length, int i, |
1883 | int write) | |
63551ae0 | 1884 | { |
d5d4b0aa CK |
1885 | unsigned long pfn_offset; |
1886 | unsigned long vaddr = *position; | |
63551ae0 | 1887 | int remainder = *length; |
a5516438 | 1888 | struct hstate *h = hstate_vma(vma); |
63551ae0 | 1889 | |
1c59827d | 1890 | spin_lock(&mm->page_table_lock); |
63551ae0 | 1891 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
1892 | pte_t *pte; |
1893 | struct page *page; | |
63551ae0 | 1894 | |
4c887265 AL |
1895 | /* |
1896 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
1897 | * each hugepage. We have to make * sure we get the | |
1898 | * first, for the page indexing below to work. | |
1899 | */ | |
a5516438 | 1900 | pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); |
63551ae0 | 1901 | |
7f2e9525 GS |
1902 | if (!pte || huge_pte_none(huge_ptep_get(pte)) || |
1903 | (write && !pte_write(huge_ptep_get(pte)))) { | |
4c887265 | 1904 | int ret; |
63551ae0 | 1905 | |
4c887265 | 1906 | spin_unlock(&mm->page_table_lock); |
5b23dbe8 | 1907 | ret = hugetlb_fault(mm, vma, vaddr, write); |
4c887265 | 1908 | spin_lock(&mm->page_table_lock); |
a89182c7 | 1909 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 1910 | continue; |
63551ae0 | 1911 | |
4c887265 AL |
1912 | remainder = 0; |
1913 | if (!i) | |
1914 | i = -EFAULT; | |
1915 | break; | |
1916 | } | |
1917 | ||
a5516438 | 1918 | pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; |
7f2e9525 | 1919 | page = pte_page(huge_ptep_get(pte)); |
d5d4b0aa | 1920 | same_page: |
d6692183 CK |
1921 | if (pages) { |
1922 | get_page(page); | |
d5d4b0aa | 1923 | pages[i] = page + pfn_offset; |
d6692183 | 1924 | } |
63551ae0 DG |
1925 | |
1926 | if (vmas) | |
1927 | vmas[i] = vma; | |
1928 | ||
1929 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 1930 | ++pfn_offset; |
63551ae0 DG |
1931 | --remainder; |
1932 | ++i; | |
d5d4b0aa | 1933 | if (vaddr < vma->vm_end && remainder && |
a5516438 | 1934 | pfn_offset < pages_per_huge_page(h)) { |
d5d4b0aa CK |
1935 | /* |
1936 | * We use pfn_offset to avoid touching the pageframes | |
1937 | * of this compound page. | |
1938 | */ | |
1939 | goto same_page; | |
1940 | } | |
63551ae0 | 1941 | } |
1c59827d | 1942 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
1943 | *length = remainder; |
1944 | *position = vaddr; | |
1945 | ||
1946 | return i; | |
1947 | } | |
8f860591 ZY |
1948 | |
1949 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
1950 | unsigned long address, unsigned long end, pgprot_t newprot) | |
1951 | { | |
1952 | struct mm_struct *mm = vma->vm_mm; | |
1953 | unsigned long start = address; | |
1954 | pte_t *ptep; | |
1955 | pte_t pte; | |
a5516438 | 1956 | struct hstate *h = hstate_vma(vma); |
8f860591 ZY |
1957 | |
1958 | BUG_ON(address >= end); | |
1959 | flush_cache_range(vma, address, end); | |
1960 | ||
39dde65c | 1961 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 | 1962 | spin_lock(&mm->page_table_lock); |
a5516438 | 1963 | for (; address < end; address += huge_page_size(h)) { |
8f860591 ZY |
1964 | ptep = huge_pte_offset(mm, address); |
1965 | if (!ptep) | |
1966 | continue; | |
39dde65c CK |
1967 | if (huge_pmd_unshare(mm, &address, ptep)) |
1968 | continue; | |
7f2e9525 | 1969 | if (!huge_pte_none(huge_ptep_get(ptep))) { |
8f860591 ZY |
1970 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
1971 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
1972 | set_huge_pte_at(mm, address, ptep, pte); | |
8f860591 ZY |
1973 | } |
1974 | } | |
1975 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 1976 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
1977 | |
1978 | flush_tlb_range(vma, start, end); | |
1979 | } | |
1980 | ||
a1e78772 MG |
1981 | int hugetlb_reserve_pages(struct inode *inode, |
1982 | long from, long to, | |
1983 | struct vm_area_struct *vma) | |
e4e574b7 AL |
1984 | { |
1985 | long ret, chg; | |
a5516438 | 1986 | struct hstate *h = hstate_inode(inode); |
e4e574b7 | 1987 | |
c37f9fb1 AW |
1988 | if (vma && vma->vm_flags & VM_NORESERVE) |
1989 | return 0; | |
1990 | ||
a1e78772 MG |
1991 | /* |
1992 | * Shared mappings base their reservation on the number of pages that | |
1993 | * are already allocated on behalf of the file. Private mappings need | |
1994 | * to reserve the full area even if read-only as mprotect() may be | |
1995 | * called to make the mapping read-write. Assume !vma is a shm mapping | |
1996 | */ | |
1997 | if (!vma || vma->vm_flags & VM_SHARED) | |
1998 | chg = region_chg(&inode->i_mapping->private_list, from, to); | |
1999 | else { | |
84afd99b AW |
2000 | struct resv_map *resv_map = resv_map_alloc(); |
2001 | if (!resv_map) | |
2002 | return -ENOMEM; | |
2003 | ||
a1e78772 | 2004 | chg = to - from; |
84afd99b AW |
2005 | |
2006 | set_vma_resv_map(vma, resv_map); | |
04f2cbe3 | 2007 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); |
a1e78772 MG |
2008 | } |
2009 | ||
e4e574b7 AL |
2010 | if (chg < 0) |
2011 | return chg; | |
8a630112 | 2012 | |
90d8b7e6 AL |
2013 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
2014 | return -ENOSPC; | |
a5516438 | 2015 | ret = hugetlb_acct_memory(h, chg); |
68842c9b KC |
2016 | if (ret < 0) { |
2017 | hugetlb_put_quota(inode->i_mapping, chg); | |
a43a8c39 | 2018 | return ret; |
68842c9b | 2019 | } |
a1e78772 MG |
2020 | if (!vma || vma->vm_flags & VM_SHARED) |
2021 | region_add(&inode->i_mapping->private_list, from, to); | |
a43a8c39 CK |
2022 | return 0; |
2023 | } | |
2024 | ||
2025 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
2026 | { | |
a5516438 | 2027 | struct hstate *h = hstate_inode(inode); |
a43a8c39 | 2028 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
45c682a6 KC |
2029 | |
2030 | spin_lock(&inode->i_lock); | |
a5516438 | 2031 | inode->i_blocks -= blocks_per_huge_page(h); |
45c682a6 KC |
2032 | spin_unlock(&inode->i_lock); |
2033 | ||
90d8b7e6 | 2034 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
a5516438 | 2035 | hugetlb_acct_memory(h, -(chg - freed)); |
a43a8c39 | 2036 | } |