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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; |
064d9efe | 27 | static unsigned long nr_overcommit_huge_pages; |
1da177e4 | 28 | unsigned long max_huge_pages; |
064d9efe | 29 | unsigned long sysctl_overcommit_huge_pages; |
1da177e4 LT |
30 | static struct list_head hugepage_freelists[MAX_NUMNODES]; |
31 | static unsigned int nr_huge_pages_node[MAX_NUMNODES]; | |
32 | static unsigned int free_huge_pages_node[MAX_NUMNODES]; | |
7893d1d5 | 33 | static unsigned int surplus_huge_pages_node[MAX_NUMNODES]; |
396faf03 MG |
34 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
35 | unsigned long hugepages_treat_as_movable; | |
63b4613c | 36 | static int hugetlb_next_nid; |
396faf03 | 37 | |
3935baa9 DG |
38 | /* |
39 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages | |
40 | */ | |
41 | static DEFINE_SPINLOCK(hugetlb_lock); | |
0bd0f9fb | 42 | |
96822904 AW |
43 | /* |
44 | * Region tracking -- allows tracking of reservations and instantiated pages | |
45 | * across the pages in a mapping. | |
84afd99b AW |
46 | * |
47 | * The region data structures are protected by a combination of the mmap_sem | |
48 | * and the hugetlb_instantion_mutex. To access or modify a region the caller | |
49 | * must either hold the mmap_sem for write, or the mmap_sem for read and | |
50 | * the hugetlb_instantiation mutex: | |
51 | * | |
52 | * down_write(&mm->mmap_sem); | |
53 | * or | |
54 | * down_read(&mm->mmap_sem); | |
55 | * mutex_lock(&hugetlb_instantiation_mutex); | |
96822904 AW |
56 | */ |
57 | struct file_region { | |
58 | struct list_head link; | |
59 | long from; | |
60 | long to; | |
61 | }; | |
62 | ||
63 | static long region_add(struct list_head *head, long f, long t) | |
64 | { | |
65 | struct file_region *rg, *nrg, *trg; | |
66 | ||
67 | /* Locate the region we are either in or before. */ | |
68 | list_for_each_entry(rg, head, link) | |
69 | if (f <= rg->to) | |
70 | break; | |
71 | ||
72 | /* Round our left edge to the current segment if it encloses us. */ | |
73 | if (f > rg->from) | |
74 | f = rg->from; | |
75 | ||
76 | /* Check for and consume any regions we now overlap with. */ | |
77 | nrg = rg; | |
78 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
79 | if (&rg->link == head) | |
80 | break; | |
81 | if (rg->from > t) | |
82 | break; | |
83 | ||
84 | /* If this area reaches higher then extend our area to | |
85 | * include it completely. If this is not the first area | |
86 | * which we intend to reuse, free it. */ | |
87 | if (rg->to > t) | |
88 | t = rg->to; | |
89 | if (rg != nrg) { | |
90 | list_del(&rg->link); | |
91 | kfree(rg); | |
92 | } | |
93 | } | |
94 | nrg->from = f; | |
95 | nrg->to = t; | |
96 | return 0; | |
97 | } | |
98 | ||
99 | static long region_chg(struct list_head *head, long f, long t) | |
100 | { | |
101 | struct file_region *rg, *nrg; | |
102 | long chg = 0; | |
103 | ||
104 | /* Locate the region we are before or in. */ | |
105 | list_for_each_entry(rg, head, link) | |
106 | if (f <= rg->to) | |
107 | break; | |
108 | ||
109 | /* If we are below the current region then a new region is required. | |
110 | * Subtle, allocate a new region at the position but make it zero | |
111 | * size such that we can guarantee to record the reservation. */ | |
112 | if (&rg->link == head || t < rg->from) { | |
113 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
114 | if (!nrg) | |
115 | return -ENOMEM; | |
116 | nrg->from = f; | |
117 | nrg->to = f; | |
118 | INIT_LIST_HEAD(&nrg->link); | |
119 | list_add(&nrg->link, rg->link.prev); | |
120 | ||
121 | return t - f; | |
122 | } | |
123 | ||
124 | /* Round our left edge to the current segment if it encloses us. */ | |
125 | if (f > rg->from) | |
126 | f = rg->from; | |
127 | chg = t - f; | |
128 | ||
129 | /* Check for and consume any regions we now overlap with. */ | |
130 | list_for_each_entry(rg, rg->link.prev, link) { | |
131 | if (&rg->link == head) | |
132 | break; | |
133 | if (rg->from > t) | |
134 | return chg; | |
135 | ||
136 | /* We overlap with this area, if it extends futher than | |
137 | * us then we must extend ourselves. Account for its | |
138 | * existing reservation. */ | |
139 | if (rg->to > t) { | |
140 | chg += rg->to - t; | |
141 | t = rg->to; | |
142 | } | |
143 | chg -= rg->to - rg->from; | |
144 | } | |
145 | return chg; | |
146 | } | |
147 | ||
148 | static long region_truncate(struct list_head *head, long end) | |
149 | { | |
150 | struct file_region *rg, *trg; | |
151 | long chg = 0; | |
152 | ||
153 | /* Locate the region we are either in or before. */ | |
154 | list_for_each_entry(rg, head, link) | |
155 | if (end <= rg->to) | |
156 | break; | |
157 | if (&rg->link == head) | |
158 | return 0; | |
159 | ||
160 | /* If we are in the middle of a region then adjust it. */ | |
161 | if (end > rg->from) { | |
162 | chg = rg->to - end; | |
163 | rg->to = end; | |
164 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
165 | } | |
166 | ||
167 | /* Drop any remaining regions. */ | |
168 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
169 | if (&rg->link == head) | |
170 | break; | |
171 | chg += rg->to - rg->from; | |
172 | list_del(&rg->link); | |
173 | kfree(rg); | |
174 | } | |
175 | return chg; | |
176 | } | |
177 | ||
84afd99b AW |
178 | static long region_count(struct list_head *head, long f, long t) |
179 | { | |
180 | struct file_region *rg; | |
181 | long chg = 0; | |
182 | ||
183 | /* Locate each segment we overlap with, and count that overlap. */ | |
184 | list_for_each_entry(rg, head, link) { | |
185 | int seg_from; | |
186 | int seg_to; | |
187 | ||
188 | if (rg->to <= f) | |
189 | continue; | |
190 | if (rg->from >= t) | |
191 | break; | |
192 | ||
193 | seg_from = max(rg->from, f); | |
194 | seg_to = min(rg->to, t); | |
195 | ||
196 | chg += seg_to - seg_from; | |
197 | } | |
198 | ||
199 | return chg; | |
200 | } | |
201 | ||
e7c4b0bf AW |
202 | /* |
203 | * Convert the address within this vma to the page offset within | |
204 | * the mapping, in pagecache page units; huge pages here. | |
205 | */ | |
a858f7b2 | 206 | static pgoff_t vma_hugecache_offset(struct vm_area_struct *vma, |
e7c4b0bf AW |
207 | unsigned long address) |
208 | { | |
209 | return ((address - vma->vm_start) >> HPAGE_SHIFT) + | |
210 | (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
211 | } | |
212 | ||
84afd99b AW |
213 | /* |
214 | * Flags for MAP_PRIVATE reservations. These are stored in the bottom | |
215 | * bits of the reservation map pointer, which are always clear due to | |
216 | * alignment. | |
217 | */ | |
218 | #define HPAGE_RESV_OWNER (1UL << 0) | |
219 | #define HPAGE_RESV_UNMAPPED (1UL << 1) | |
04f2cbe3 | 220 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) |
84afd99b | 221 | |
a1e78772 MG |
222 | /* |
223 | * These helpers are used to track how many pages are reserved for | |
224 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() | |
225 | * is guaranteed to have their future faults succeed. | |
226 | * | |
227 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), | |
228 | * the reserve counters are updated with the hugetlb_lock held. It is safe | |
229 | * to reset the VMA at fork() time as it is not in use yet and there is no | |
230 | * chance of the global counters getting corrupted as a result of the values. | |
84afd99b AW |
231 | * |
232 | * The private mapping reservation is represented in a subtly different | |
233 | * manner to a shared mapping. A shared mapping has a region map associated | |
234 | * with the underlying file, this region map represents the backing file | |
235 | * pages which have ever had a reservation assigned which this persists even | |
236 | * after the page is instantiated. A private mapping has a region map | |
237 | * associated with the original mmap which is attached to all VMAs which | |
238 | * reference it, this region map represents those offsets which have consumed | |
239 | * reservation ie. where pages have been instantiated. | |
a1e78772 | 240 | */ |
e7c4b0bf AW |
241 | static unsigned long get_vma_private_data(struct vm_area_struct *vma) |
242 | { | |
243 | return (unsigned long)vma->vm_private_data; | |
244 | } | |
245 | ||
246 | static void set_vma_private_data(struct vm_area_struct *vma, | |
247 | unsigned long value) | |
248 | { | |
249 | vma->vm_private_data = (void *)value; | |
250 | } | |
251 | ||
84afd99b AW |
252 | struct resv_map { |
253 | struct kref refs; | |
254 | struct list_head regions; | |
255 | }; | |
256 | ||
257 | struct resv_map *resv_map_alloc(void) | |
258 | { | |
259 | struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); | |
260 | if (!resv_map) | |
261 | return NULL; | |
262 | ||
263 | kref_init(&resv_map->refs); | |
264 | INIT_LIST_HEAD(&resv_map->regions); | |
265 | ||
266 | return resv_map; | |
267 | } | |
268 | ||
269 | void resv_map_release(struct kref *ref) | |
270 | { | |
271 | struct resv_map *resv_map = container_of(ref, struct resv_map, refs); | |
272 | ||
273 | /* Clear out any active regions before we release the map. */ | |
274 | region_truncate(&resv_map->regions, 0); | |
275 | kfree(resv_map); | |
276 | } | |
277 | ||
278 | static struct resv_map *vma_resv_map(struct vm_area_struct *vma) | |
a1e78772 MG |
279 | { |
280 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
281 | if (!(vma->vm_flags & VM_SHARED)) | |
84afd99b AW |
282 | return (struct resv_map *)(get_vma_private_data(vma) & |
283 | ~HPAGE_RESV_MASK); | |
a1e78772 MG |
284 | return 0; |
285 | } | |
286 | ||
84afd99b | 287 | static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) |
a1e78772 MG |
288 | { |
289 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
290 | VM_BUG_ON(vma->vm_flags & VM_SHARED); | |
291 | ||
84afd99b AW |
292 | set_vma_private_data(vma, (get_vma_private_data(vma) & |
293 | HPAGE_RESV_MASK) | (unsigned long)map); | |
04f2cbe3 MG |
294 | } |
295 | ||
296 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) | |
297 | { | |
04f2cbe3 | 298 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
e7c4b0bf AW |
299 | VM_BUG_ON(vma->vm_flags & VM_SHARED); |
300 | ||
301 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); | |
04f2cbe3 MG |
302 | } |
303 | ||
304 | static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) | |
305 | { | |
306 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
e7c4b0bf AW |
307 | |
308 | return (get_vma_private_data(vma) & flag) != 0; | |
a1e78772 MG |
309 | } |
310 | ||
311 | /* Decrement the reserved pages in the hugepage pool by one */ | |
312 | static void decrement_hugepage_resv_vma(struct vm_area_struct *vma) | |
313 | { | |
c37f9fb1 AW |
314 | if (vma->vm_flags & VM_NORESERVE) |
315 | return; | |
316 | ||
a1e78772 MG |
317 | if (vma->vm_flags & VM_SHARED) { |
318 | /* Shared mappings always use reserves */ | |
319 | resv_huge_pages--; | |
84afd99b | 320 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
a1e78772 MG |
321 | /* |
322 | * Only the process that called mmap() has reserves for | |
323 | * private mappings. | |
324 | */ | |
84afd99b | 325 | resv_huge_pages--; |
a1e78772 MG |
326 | } |
327 | } | |
328 | ||
04f2cbe3 | 329 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
a1e78772 MG |
330 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
331 | { | |
332 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
333 | if (!(vma->vm_flags & VM_SHARED)) | |
334 | vma->vm_private_data = (void *)0; | |
335 | } | |
336 | ||
337 | /* Returns true if the VMA has associated reserve pages */ | |
338 | static int vma_has_private_reserves(struct vm_area_struct *vma) | |
339 | { | |
340 | if (vma->vm_flags & VM_SHARED) | |
341 | return 0; | |
84afd99b | 342 | if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
a1e78772 MG |
343 | return 0; |
344 | return 1; | |
345 | } | |
346 | ||
79ac6ba4 DG |
347 | static void clear_huge_page(struct page *page, unsigned long addr) |
348 | { | |
349 | int i; | |
350 | ||
351 | might_sleep(); | |
352 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) { | |
353 | cond_resched(); | |
281e0e3b | 354 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
79ac6ba4 DG |
355 | } |
356 | } | |
357 | ||
358 | static void copy_huge_page(struct page *dst, struct page *src, | |
9de455b2 | 359 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
360 | { |
361 | int i; | |
362 | ||
363 | might_sleep(); | |
364 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { | |
365 | cond_resched(); | |
9de455b2 | 366 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
367 | } |
368 | } | |
369 | ||
1da177e4 LT |
370 | static void enqueue_huge_page(struct page *page) |
371 | { | |
372 | int nid = page_to_nid(page); | |
373 | list_add(&page->lru, &hugepage_freelists[nid]); | |
374 | free_huge_pages++; | |
375 | free_huge_pages_node[nid]++; | |
376 | } | |
377 | ||
348e1e04 NA |
378 | static struct page *dequeue_huge_page(void) |
379 | { | |
380 | int nid; | |
381 | struct page *page = NULL; | |
382 | ||
383 | for (nid = 0; nid < MAX_NUMNODES; ++nid) { | |
384 | if (!list_empty(&hugepage_freelists[nid])) { | |
385 | page = list_entry(hugepage_freelists[nid].next, | |
386 | struct page, lru); | |
387 | list_del(&page->lru); | |
388 | free_huge_pages--; | |
389 | free_huge_pages_node[nid]--; | |
390 | break; | |
391 | } | |
392 | } | |
393 | return page; | |
394 | } | |
395 | ||
396 | static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma, | |
04f2cbe3 | 397 | unsigned long address, int avoid_reserve) |
1da177e4 | 398 | { |
31a5c6e4 | 399 | int nid; |
1da177e4 | 400 | struct page *page = NULL; |
480eccf9 | 401 | struct mempolicy *mpol; |
19770b32 | 402 | nodemask_t *nodemask; |
396faf03 | 403 | struct zonelist *zonelist = huge_zonelist(vma, address, |
19770b32 | 404 | htlb_alloc_mask, &mpol, &nodemask); |
dd1a239f MG |
405 | struct zone *zone; |
406 | struct zoneref *z; | |
1da177e4 | 407 | |
a1e78772 MG |
408 | /* |
409 | * A child process with MAP_PRIVATE mappings created by their parent | |
410 | * have no page reserves. This check ensures that reservations are | |
411 | * not "stolen". The child may still get SIGKILLed | |
412 | */ | |
413 | if (!vma_has_private_reserves(vma) && | |
414 | free_huge_pages - resv_huge_pages == 0) | |
415 | return NULL; | |
416 | ||
04f2cbe3 MG |
417 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
418 | if (avoid_reserve && free_huge_pages - resv_huge_pages == 0) | |
419 | return NULL; | |
420 | ||
19770b32 MG |
421 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
422 | MAX_NR_ZONES - 1, nodemask) { | |
54a6eb5c MG |
423 | nid = zone_to_nid(zone); |
424 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && | |
3abf7afd AM |
425 | !list_empty(&hugepage_freelists[nid])) { |
426 | page = list_entry(hugepage_freelists[nid].next, | |
427 | struct page, lru); | |
428 | list_del(&page->lru); | |
429 | free_huge_pages--; | |
430 | free_huge_pages_node[nid]--; | |
04f2cbe3 MG |
431 | |
432 | if (!avoid_reserve) | |
433 | decrement_hugepage_resv_vma(vma); | |
a1e78772 | 434 | |
5ab3ee7b | 435 | break; |
3abf7afd | 436 | } |
1da177e4 | 437 | } |
52cd3b07 | 438 | mpol_cond_put(mpol); |
1da177e4 LT |
439 | return page; |
440 | } | |
441 | ||
6af2acb6 AL |
442 | static void update_and_free_page(struct page *page) |
443 | { | |
444 | int i; | |
445 | nr_huge_pages--; | |
446 | nr_huge_pages_node[page_to_nid(page)]--; | |
447 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { | |
448 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | | |
449 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
450 | 1 << PG_private | 1<< PG_writeback); | |
451 | } | |
452 | set_compound_page_dtor(page, NULL); | |
453 | set_page_refcounted(page); | |
7f2e9525 | 454 | arch_release_hugepage(page); |
6af2acb6 AL |
455 | __free_pages(page, HUGETLB_PAGE_ORDER); |
456 | } | |
457 | ||
27a85ef1 DG |
458 | static void free_huge_page(struct page *page) |
459 | { | |
7893d1d5 | 460 | int nid = page_to_nid(page); |
c79fb75e | 461 | struct address_space *mapping; |
27a85ef1 | 462 | |
c79fb75e | 463 | mapping = (struct address_space *) page_private(page); |
e5df70ab | 464 | set_page_private(page, 0); |
7893d1d5 | 465 | BUG_ON(page_count(page)); |
27a85ef1 DG |
466 | INIT_LIST_HEAD(&page->lru); |
467 | ||
468 | spin_lock(&hugetlb_lock); | |
7893d1d5 AL |
469 | if (surplus_huge_pages_node[nid]) { |
470 | update_and_free_page(page); | |
471 | surplus_huge_pages--; | |
472 | surplus_huge_pages_node[nid]--; | |
473 | } else { | |
474 | enqueue_huge_page(page); | |
475 | } | |
27a85ef1 | 476 | spin_unlock(&hugetlb_lock); |
c79fb75e | 477 | if (mapping) |
9a119c05 | 478 | hugetlb_put_quota(mapping, 1); |
27a85ef1 DG |
479 | } |
480 | ||
7893d1d5 AL |
481 | /* |
482 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
483 | * balanced by operating on them in a round-robin fashion. | |
484 | * Returns 1 if an adjustment was made. | |
485 | */ | |
486 | static int adjust_pool_surplus(int delta) | |
487 | { | |
488 | static int prev_nid; | |
489 | int nid = prev_nid; | |
490 | int ret = 0; | |
491 | ||
492 | VM_BUG_ON(delta != -1 && delta != 1); | |
493 | do { | |
494 | nid = next_node(nid, node_online_map); | |
495 | if (nid == MAX_NUMNODES) | |
496 | nid = first_node(node_online_map); | |
497 | ||
498 | /* To shrink on this node, there must be a surplus page */ | |
499 | if (delta < 0 && !surplus_huge_pages_node[nid]) | |
500 | continue; | |
501 | /* Surplus cannot exceed the total number of pages */ | |
502 | if (delta > 0 && surplus_huge_pages_node[nid] >= | |
503 | nr_huge_pages_node[nid]) | |
504 | continue; | |
505 | ||
506 | surplus_huge_pages += delta; | |
507 | surplus_huge_pages_node[nid] += delta; | |
508 | ret = 1; | |
509 | break; | |
510 | } while (nid != prev_nid); | |
511 | ||
512 | prev_nid = nid; | |
513 | return ret; | |
514 | } | |
515 | ||
b7ba30c6 AK |
516 | static void prep_new_huge_page(struct page *page, int nid) |
517 | { | |
518 | set_compound_page_dtor(page, free_huge_page); | |
519 | spin_lock(&hugetlb_lock); | |
520 | nr_huge_pages++; | |
521 | nr_huge_pages_node[nid]++; | |
522 | spin_unlock(&hugetlb_lock); | |
523 | put_page(page); /* free it into the hugepage allocator */ | |
524 | } | |
525 | ||
63b4613c | 526 | static struct page *alloc_fresh_huge_page_node(int nid) |
1da177e4 | 527 | { |
1da177e4 | 528 | struct page *page; |
f96efd58 | 529 | |
63b4613c | 530 | page = alloc_pages_node(nid, |
551883ae NA |
531 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| |
532 | __GFP_REPEAT|__GFP_NOWARN, | |
63b4613c | 533 | HUGETLB_PAGE_ORDER); |
1da177e4 | 534 | if (page) { |
7f2e9525 GS |
535 | if (arch_prepare_hugepage(page)) { |
536 | __free_pages(page, HUGETLB_PAGE_ORDER); | |
7b8ee84d | 537 | return NULL; |
7f2e9525 | 538 | } |
b7ba30c6 | 539 | prep_new_huge_page(page, nid); |
1da177e4 | 540 | } |
63b4613c NA |
541 | |
542 | return page; | |
543 | } | |
544 | ||
545 | static int alloc_fresh_huge_page(void) | |
546 | { | |
547 | struct page *page; | |
548 | int start_nid; | |
549 | int next_nid; | |
550 | int ret = 0; | |
551 | ||
552 | start_nid = hugetlb_next_nid; | |
553 | ||
554 | do { | |
555 | page = alloc_fresh_huge_page_node(hugetlb_next_nid); | |
556 | if (page) | |
557 | ret = 1; | |
558 | /* | |
559 | * Use a helper variable to find the next node and then | |
560 | * copy it back to hugetlb_next_nid afterwards: | |
561 | * otherwise there's a window in which a racer might | |
562 | * pass invalid nid MAX_NUMNODES to alloc_pages_node. | |
563 | * But we don't need to use a spin_lock here: it really | |
564 | * doesn't matter if occasionally a racer chooses the | |
565 | * same nid as we do. Move nid forward in the mask even | |
566 | * if we just successfully allocated a hugepage so that | |
567 | * the next caller gets hugepages on the next node. | |
568 | */ | |
569 | next_nid = next_node(hugetlb_next_nid, node_online_map); | |
570 | if (next_nid == MAX_NUMNODES) | |
571 | next_nid = first_node(node_online_map); | |
572 | hugetlb_next_nid = next_nid; | |
573 | } while (!page && hugetlb_next_nid != start_nid); | |
574 | ||
3b116300 AL |
575 | if (ret) |
576 | count_vm_event(HTLB_BUDDY_PGALLOC); | |
577 | else | |
578 | count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); | |
579 | ||
63b4613c | 580 | return ret; |
1da177e4 LT |
581 | } |
582 | ||
7893d1d5 AL |
583 | static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma, |
584 | unsigned long address) | |
585 | { | |
586 | struct page *page; | |
d1c3fb1f | 587 | unsigned int nid; |
7893d1d5 | 588 | |
d1c3fb1f NA |
589 | /* |
590 | * Assume we will successfully allocate the surplus page to | |
591 | * prevent racing processes from causing the surplus to exceed | |
592 | * overcommit | |
593 | * | |
594 | * This however introduces a different race, where a process B | |
595 | * tries to grow the static hugepage pool while alloc_pages() is | |
596 | * called by process A. B will only examine the per-node | |
597 | * counters in determining if surplus huge pages can be | |
598 | * converted to normal huge pages in adjust_pool_surplus(). A | |
599 | * won't be able to increment the per-node counter, until the | |
600 | * lock is dropped by B, but B doesn't drop hugetlb_lock until | |
601 | * no more huge pages can be converted from surplus to normal | |
602 | * state (and doesn't try to convert again). Thus, we have a | |
603 | * case where a surplus huge page exists, the pool is grown, and | |
604 | * the surplus huge page still exists after, even though it | |
605 | * should just have been converted to a normal huge page. This | |
606 | * does not leak memory, though, as the hugepage will be freed | |
607 | * once it is out of use. It also does not allow the counters to | |
608 | * go out of whack in adjust_pool_surplus() as we don't modify | |
609 | * the node values until we've gotten the hugepage and only the | |
610 | * per-node value is checked there. | |
611 | */ | |
612 | spin_lock(&hugetlb_lock); | |
613 | if (surplus_huge_pages >= nr_overcommit_huge_pages) { | |
614 | spin_unlock(&hugetlb_lock); | |
615 | return NULL; | |
616 | } else { | |
617 | nr_huge_pages++; | |
618 | surplus_huge_pages++; | |
619 | } | |
620 | spin_unlock(&hugetlb_lock); | |
621 | ||
551883ae NA |
622 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP| |
623 | __GFP_REPEAT|__GFP_NOWARN, | |
7893d1d5 | 624 | HUGETLB_PAGE_ORDER); |
d1c3fb1f NA |
625 | |
626 | spin_lock(&hugetlb_lock); | |
7893d1d5 | 627 | if (page) { |
2668db91 AL |
628 | /* |
629 | * This page is now managed by the hugetlb allocator and has | |
630 | * no users -- drop the buddy allocator's reference. | |
631 | */ | |
632 | put_page_testzero(page); | |
633 | VM_BUG_ON(page_count(page)); | |
d1c3fb1f | 634 | nid = page_to_nid(page); |
7893d1d5 | 635 | set_compound_page_dtor(page, free_huge_page); |
d1c3fb1f NA |
636 | /* |
637 | * We incremented the global counters already | |
638 | */ | |
639 | nr_huge_pages_node[nid]++; | |
640 | surplus_huge_pages_node[nid]++; | |
3b116300 | 641 | __count_vm_event(HTLB_BUDDY_PGALLOC); |
d1c3fb1f NA |
642 | } else { |
643 | nr_huge_pages--; | |
644 | surplus_huge_pages--; | |
3b116300 | 645 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
7893d1d5 | 646 | } |
d1c3fb1f | 647 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
648 | |
649 | return page; | |
650 | } | |
651 | ||
e4e574b7 AL |
652 | /* |
653 | * Increase the hugetlb pool such that it can accomodate a reservation | |
654 | * of size 'delta'. | |
655 | */ | |
656 | static int gather_surplus_pages(int delta) | |
657 | { | |
658 | struct list_head surplus_list; | |
659 | struct page *page, *tmp; | |
660 | int ret, i; | |
661 | int needed, allocated; | |
662 | ||
663 | needed = (resv_huge_pages + delta) - free_huge_pages; | |
ac09b3a1 AL |
664 | if (needed <= 0) { |
665 | resv_huge_pages += delta; | |
e4e574b7 | 666 | return 0; |
ac09b3a1 | 667 | } |
e4e574b7 AL |
668 | |
669 | allocated = 0; | |
670 | INIT_LIST_HEAD(&surplus_list); | |
671 | ||
672 | ret = -ENOMEM; | |
673 | retry: | |
674 | spin_unlock(&hugetlb_lock); | |
675 | for (i = 0; i < needed; i++) { | |
676 | page = alloc_buddy_huge_page(NULL, 0); | |
677 | if (!page) { | |
678 | /* | |
679 | * We were not able to allocate enough pages to | |
680 | * satisfy the entire reservation so we free what | |
681 | * we've allocated so far. | |
682 | */ | |
683 | spin_lock(&hugetlb_lock); | |
684 | needed = 0; | |
685 | goto free; | |
686 | } | |
687 | ||
688 | list_add(&page->lru, &surplus_list); | |
689 | } | |
690 | allocated += needed; | |
691 | ||
692 | /* | |
693 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
694 | * because either resv_huge_pages or free_huge_pages may have changed. | |
695 | */ | |
696 | spin_lock(&hugetlb_lock); | |
697 | needed = (resv_huge_pages + delta) - (free_huge_pages + allocated); | |
698 | if (needed > 0) | |
699 | goto retry; | |
700 | ||
701 | /* | |
702 | * The surplus_list now contains _at_least_ the number of extra pages | |
703 | * needed to accomodate the reservation. Add the appropriate number | |
704 | * of pages to the hugetlb pool and free the extras back to the buddy | |
ac09b3a1 AL |
705 | * allocator. Commit the entire reservation here to prevent another |
706 | * process from stealing the pages as they are added to the pool but | |
707 | * before they are reserved. | |
e4e574b7 AL |
708 | */ |
709 | needed += allocated; | |
ac09b3a1 | 710 | resv_huge_pages += delta; |
e4e574b7 AL |
711 | ret = 0; |
712 | free: | |
19fc3f0a | 713 | /* Free the needed pages to the hugetlb pool */ |
e4e574b7 | 714 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
19fc3f0a AL |
715 | if ((--needed) < 0) |
716 | break; | |
e4e574b7 | 717 | list_del(&page->lru); |
19fc3f0a AL |
718 | enqueue_huge_page(page); |
719 | } | |
720 | ||
721 | /* Free unnecessary surplus pages to the buddy allocator */ | |
722 | if (!list_empty(&surplus_list)) { | |
723 | spin_unlock(&hugetlb_lock); | |
724 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { | |
725 | list_del(&page->lru); | |
af767cbd | 726 | /* |
2668db91 AL |
727 | * The page has a reference count of zero already, so |
728 | * call free_huge_page directly instead of using | |
729 | * put_page. This must be done with hugetlb_lock | |
af767cbd AL |
730 | * unlocked which is safe because free_huge_page takes |
731 | * hugetlb_lock before deciding how to free the page. | |
732 | */ | |
2668db91 | 733 | free_huge_page(page); |
af767cbd | 734 | } |
19fc3f0a | 735 | spin_lock(&hugetlb_lock); |
e4e574b7 AL |
736 | } |
737 | ||
738 | return ret; | |
739 | } | |
740 | ||
741 | /* | |
742 | * When releasing a hugetlb pool reservation, any surplus pages that were | |
743 | * allocated to satisfy the reservation must be explicitly freed if they were | |
744 | * never used. | |
745 | */ | |
8cde045c | 746 | static void return_unused_surplus_pages(unsigned long unused_resv_pages) |
e4e574b7 AL |
747 | { |
748 | static int nid = -1; | |
749 | struct page *page; | |
750 | unsigned long nr_pages; | |
751 | ||
11320d17 NA |
752 | /* |
753 | * We want to release as many surplus pages as possible, spread | |
754 | * evenly across all nodes. Iterate across all nodes until we | |
755 | * can no longer free unreserved surplus pages. This occurs when | |
756 | * the nodes with surplus pages have no free pages. | |
757 | */ | |
758 | unsigned long remaining_iterations = num_online_nodes(); | |
759 | ||
ac09b3a1 AL |
760 | /* Uncommit the reservation */ |
761 | resv_huge_pages -= unused_resv_pages; | |
762 | ||
e4e574b7 AL |
763 | nr_pages = min(unused_resv_pages, surplus_huge_pages); |
764 | ||
11320d17 | 765 | while (remaining_iterations-- && nr_pages) { |
e4e574b7 AL |
766 | nid = next_node(nid, node_online_map); |
767 | if (nid == MAX_NUMNODES) | |
768 | nid = first_node(node_online_map); | |
769 | ||
770 | if (!surplus_huge_pages_node[nid]) | |
771 | continue; | |
772 | ||
773 | if (!list_empty(&hugepage_freelists[nid])) { | |
774 | page = list_entry(hugepage_freelists[nid].next, | |
775 | struct page, lru); | |
776 | list_del(&page->lru); | |
777 | update_and_free_page(page); | |
778 | free_huge_pages--; | |
779 | free_huge_pages_node[nid]--; | |
780 | surplus_huge_pages--; | |
781 | surplus_huge_pages_node[nid]--; | |
782 | nr_pages--; | |
11320d17 | 783 | remaining_iterations = num_online_nodes(); |
e4e574b7 AL |
784 | } |
785 | } | |
786 | } | |
787 | ||
c37f9fb1 AW |
788 | /* |
789 | * Determine if the huge page at addr within the vma has an associated | |
790 | * reservation. Where it does not we will need to logically increase | |
791 | * reservation and actually increase quota before an allocation can occur. | |
792 | * Where any new reservation would be required the reservation change is | |
793 | * prepared, but not committed. Once the page has been quota'd allocated | |
794 | * an instantiated the change should be committed via vma_commit_reservation. | |
795 | * No action is required on failure. | |
796 | */ | |
797 | static int vma_needs_reservation(struct vm_area_struct *vma, unsigned long addr) | |
798 | { | |
799 | struct address_space *mapping = vma->vm_file->f_mapping; | |
800 | struct inode *inode = mapping->host; | |
801 | ||
802 | if (vma->vm_flags & VM_SHARED) { | |
a858f7b2 | 803 | pgoff_t idx = vma_hugecache_offset(vma, addr); |
c37f9fb1 AW |
804 | return region_chg(&inode->i_mapping->private_list, |
805 | idx, idx + 1); | |
806 | ||
84afd99b AW |
807 | } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
808 | return 1; | |
c37f9fb1 | 809 | |
84afd99b AW |
810 | } else { |
811 | int err; | |
a858f7b2 | 812 | pgoff_t idx = vma_hugecache_offset(vma, addr); |
84afd99b AW |
813 | struct resv_map *reservations = vma_resv_map(vma); |
814 | ||
815 | err = region_chg(&reservations->regions, idx, idx + 1); | |
816 | if (err < 0) | |
817 | return err; | |
818 | return 0; | |
819 | } | |
c37f9fb1 AW |
820 | } |
821 | static void vma_commit_reservation(struct vm_area_struct *vma, | |
822 | unsigned long addr) | |
823 | { | |
824 | struct address_space *mapping = vma->vm_file->f_mapping; | |
825 | struct inode *inode = mapping->host; | |
826 | ||
827 | if (vma->vm_flags & VM_SHARED) { | |
a858f7b2 | 828 | pgoff_t idx = vma_hugecache_offset(vma, addr); |
c37f9fb1 | 829 | region_add(&inode->i_mapping->private_list, idx, idx + 1); |
84afd99b AW |
830 | |
831 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { | |
a858f7b2 | 832 | pgoff_t idx = vma_hugecache_offset(vma, addr); |
84afd99b AW |
833 | struct resv_map *reservations = vma_resv_map(vma); |
834 | ||
835 | /* Mark this page used in the map. */ | |
836 | region_add(&reservations->regions, idx, idx + 1); | |
c37f9fb1 AW |
837 | } |
838 | } | |
839 | ||
a1e78772 | 840 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
04f2cbe3 | 841 | unsigned long addr, int avoid_reserve) |
1da177e4 | 842 | { |
348ea204 | 843 | struct page *page; |
a1e78772 MG |
844 | struct address_space *mapping = vma->vm_file->f_mapping; |
845 | struct inode *inode = mapping->host; | |
c37f9fb1 | 846 | unsigned int chg; |
a1e78772 MG |
847 | |
848 | /* | |
849 | * Processes that did not create the mapping will have no reserves and | |
850 | * will not have accounted against quota. Check that the quota can be | |
851 | * made before satisfying the allocation | |
c37f9fb1 AW |
852 | * MAP_NORESERVE mappings may also need pages and quota allocated |
853 | * if no reserve mapping overlaps. | |
a1e78772 | 854 | */ |
c37f9fb1 AW |
855 | chg = vma_needs_reservation(vma, addr); |
856 | if (chg < 0) | |
857 | return ERR_PTR(chg); | |
858 | if (chg) | |
a1e78772 MG |
859 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
860 | return ERR_PTR(-ENOSPC); | |
1da177e4 LT |
861 | |
862 | spin_lock(&hugetlb_lock); | |
04f2cbe3 | 863 | page = dequeue_huge_page_vma(vma, addr, avoid_reserve); |
1da177e4 | 864 | spin_unlock(&hugetlb_lock); |
b45b5bd6 | 865 | |
68842c9b | 866 | if (!page) { |
7893d1d5 | 867 | page = alloc_buddy_huge_page(vma, addr); |
68842c9b | 868 | if (!page) { |
a1e78772 | 869 | hugetlb_put_quota(inode->i_mapping, chg); |
68842c9b KC |
870 | return ERR_PTR(-VM_FAULT_OOM); |
871 | } | |
872 | } | |
348ea204 | 873 | |
a1e78772 MG |
874 | set_page_refcounted(page); |
875 | set_page_private(page, (unsigned long) mapping); | |
90d8b7e6 | 876 | |
c37f9fb1 AW |
877 | vma_commit_reservation(vma, addr); |
878 | ||
90d8b7e6 | 879 | return page; |
b45b5bd6 DG |
880 | } |
881 | ||
1da177e4 LT |
882 | static int __init hugetlb_init(void) |
883 | { | |
884 | unsigned long i; | |
1da177e4 | 885 | |
3c726f8d BH |
886 | if (HPAGE_SHIFT == 0) |
887 | return 0; | |
888 | ||
1da177e4 LT |
889 | for (i = 0; i < MAX_NUMNODES; ++i) |
890 | INIT_LIST_HEAD(&hugepage_freelists[i]); | |
891 | ||
63b4613c NA |
892 | hugetlb_next_nid = first_node(node_online_map); |
893 | ||
1da177e4 | 894 | for (i = 0; i < max_huge_pages; ++i) { |
a482289d | 895 | if (!alloc_fresh_huge_page()) |
1da177e4 | 896 | break; |
1da177e4 LT |
897 | } |
898 | max_huge_pages = free_huge_pages = nr_huge_pages = i; | |
899 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); | |
900 | return 0; | |
901 | } | |
902 | module_init(hugetlb_init); | |
903 | ||
904 | static int __init hugetlb_setup(char *s) | |
905 | { | |
906 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) | |
907 | max_huge_pages = 0; | |
908 | return 1; | |
909 | } | |
910 | __setup("hugepages=", hugetlb_setup); | |
911 | ||
8a630112 KC |
912 | static unsigned int cpuset_mems_nr(unsigned int *array) |
913 | { | |
914 | int node; | |
915 | unsigned int nr = 0; | |
916 | ||
917 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
918 | nr += array[node]; | |
919 | ||
920 | return nr; | |
921 | } | |
922 | ||
1da177e4 | 923 | #ifdef CONFIG_SYSCTL |
1da177e4 LT |
924 | #ifdef CONFIG_HIGHMEM |
925 | static void try_to_free_low(unsigned long count) | |
926 | { | |
4415cc8d CL |
927 | int i; |
928 | ||
1da177e4 LT |
929 | for (i = 0; i < MAX_NUMNODES; ++i) { |
930 | struct page *page, *next; | |
931 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { | |
6b0c880d AL |
932 | if (count >= nr_huge_pages) |
933 | return; | |
1da177e4 LT |
934 | if (PageHighMem(page)) |
935 | continue; | |
936 | list_del(&page->lru); | |
937 | update_and_free_page(page); | |
1da177e4 | 938 | free_huge_pages--; |
4415cc8d | 939 | free_huge_pages_node[page_to_nid(page)]--; |
1da177e4 LT |
940 | } |
941 | } | |
942 | } | |
943 | #else | |
944 | static inline void try_to_free_low(unsigned long count) | |
945 | { | |
946 | } | |
947 | #endif | |
948 | ||
7893d1d5 | 949 | #define persistent_huge_pages (nr_huge_pages - surplus_huge_pages) |
1da177e4 LT |
950 | static unsigned long set_max_huge_pages(unsigned long count) |
951 | { | |
7893d1d5 | 952 | unsigned long min_count, ret; |
1da177e4 | 953 | |
7893d1d5 AL |
954 | /* |
955 | * Increase the pool size | |
956 | * First take pages out of surplus state. Then make up the | |
957 | * remaining difference by allocating fresh huge pages. | |
d1c3fb1f NA |
958 | * |
959 | * We might race with alloc_buddy_huge_page() here and be unable | |
960 | * to convert a surplus huge page to a normal huge page. That is | |
961 | * not critical, though, it just means the overall size of the | |
962 | * pool might be one hugepage larger than it needs to be, but | |
963 | * within all the constraints specified by the sysctls. | |
7893d1d5 | 964 | */ |
1da177e4 | 965 | spin_lock(&hugetlb_lock); |
7893d1d5 AL |
966 | while (surplus_huge_pages && count > persistent_huge_pages) { |
967 | if (!adjust_pool_surplus(-1)) | |
968 | break; | |
969 | } | |
970 | ||
971 | while (count > persistent_huge_pages) { | |
7893d1d5 AL |
972 | /* |
973 | * If this allocation races such that we no longer need the | |
974 | * page, free_huge_page will handle it by freeing the page | |
975 | * and reducing the surplus. | |
976 | */ | |
977 | spin_unlock(&hugetlb_lock); | |
978 | ret = alloc_fresh_huge_page(); | |
979 | spin_lock(&hugetlb_lock); | |
980 | if (!ret) | |
981 | goto out; | |
982 | ||
983 | } | |
7893d1d5 AL |
984 | |
985 | /* | |
986 | * Decrease the pool size | |
987 | * First return free pages to the buddy allocator (being careful | |
988 | * to keep enough around to satisfy reservations). Then place | |
989 | * pages into surplus state as needed so the pool will shrink | |
990 | * to the desired size as pages become free. | |
d1c3fb1f NA |
991 | * |
992 | * By placing pages into the surplus state independent of the | |
993 | * overcommit value, we are allowing the surplus pool size to | |
994 | * exceed overcommit. There are few sane options here. Since | |
995 | * alloc_buddy_huge_page() is checking the global counter, | |
996 | * though, we'll note that we're not allowed to exceed surplus | |
997 | * and won't grow the pool anywhere else. Not until one of the | |
998 | * sysctls are changed, or the surplus pages go out of use. | |
7893d1d5 | 999 | */ |
6b0c880d AL |
1000 | min_count = resv_huge_pages + nr_huge_pages - free_huge_pages; |
1001 | min_count = max(count, min_count); | |
7893d1d5 AL |
1002 | try_to_free_low(min_count); |
1003 | while (min_count < persistent_huge_pages) { | |
348e1e04 | 1004 | struct page *page = dequeue_huge_page(); |
1da177e4 LT |
1005 | if (!page) |
1006 | break; | |
1007 | update_and_free_page(page); | |
1008 | } | |
7893d1d5 AL |
1009 | while (count < persistent_huge_pages) { |
1010 | if (!adjust_pool_surplus(1)) | |
1011 | break; | |
1012 | } | |
1013 | out: | |
1014 | ret = persistent_huge_pages; | |
1da177e4 | 1015 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 1016 | return ret; |
1da177e4 LT |
1017 | } |
1018 | ||
1019 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, | |
1020 | struct file *file, void __user *buffer, | |
1021 | size_t *length, loff_t *ppos) | |
1022 | { | |
1023 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); | |
1024 | max_huge_pages = set_max_huge_pages(max_huge_pages); | |
1025 | return 0; | |
1026 | } | |
396faf03 MG |
1027 | |
1028 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, | |
1029 | struct file *file, void __user *buffer, | |
1030 | size_t *length, loff_t *ppos) | |
1031 | { | |
1032 | proc_dointvec(table, write, file, buffer, length, ppos); | |
1033 | if (hugepages_treat_as_movable) | |
1034 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; | |
1035 | else | |
1036 | htlb_alloc_mask = GFP_HIGHUSER; | |
1037 | return 0; | |
1038 | } | |
1039 | ||
a3d0c6aa NA |
1040 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
1041 | struct file *file, void __user *buffer, | |
1042 | size_t *length, loff_t *ppos) | |
1043 | { | |
a3d0c6aa | 1044 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
064d9efe NA |
1045 | spin_lock(&hugetlb_lock); |
1046 | nr_overcommit_huge_pages = sysctl_overcommit_huge_pages; | |
a3d0c6aa NA |
1047 | spin_unlock(&hugetlb_lock); |
1048 | return 0; | |
1049 | } | |
1050 | ||
1da177e4 LT |
1051 | #endif /* CONFIG_SYSCTL */ |
1052 | ||
1053 | int hugetlb_report_meminfo(char *buf) | |
1054 | { | |
1055 | return sprintf(buf, | |
1056 | "HugePages_Total: %5lu\n" | |
1057 | "HugePages_Free: %5lu\n" | |
a43a8c39 | 1058 | "HugePages_Rsvd: %5lu\n" |
7893d1d5 | 1059 | "HugePages_Surp: %5lu\n" |
1da177e4 LT |
1060 | "Hugepagesize: %5lu kB\n", |
1061 | nr_huge_pages, | |
1062 | free_huge_pages, | |
a43a8c39 | 1063 | resv_huge_pages, |
7893d1d5 | 1064 | surplus_huge_pages, |
1da177e4 LT |
1065 | HPAGE_SIZE/1024); |
1066 | } | |
1067 | ||
1068 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
1069 | { | |
1070 | return sprintf(buf, | |
1071 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
1072 | "Node %d HugePages_Free: %5u\n" |
1073 | "Node %d HugePages_Surp: %5u\n", | |
1da177e4 | 1074 | nid, nr_huge_pages_node[nid], |
a1de0919 NA |
1075 | nid, free_huge_pages_node[nid], |
1076 | nid, surplus_huge_pages_node[nid]); | |
1da177e4 LT |
1077 | } |
1078 | ||
1da177e4 LT |
1079 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
1080 | unsigned long hugetlb_total_pages(void) | |
1081 | { | |
1082 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); | |
1083 | } | |
1da177e4 | 1084 | |
fc1b8a73 MG |
1085 | static int hugetlb_acct_memory(long delta) |
1086 | { | |
1087 | int ret = -ENOMEM; | |
1088 | ||
1089 | spin_lock(&hugetlb_lock); | |
1090 | /* | |
1091 | * When cpuset is configured, it breaks the strict hugetlb page | |
1092 | * reservation as the accounting is done on a global variable. Such | |
1093 | * reservation is completely rubbish in the presence of cpuset because | |
1094 | * the reservation is not checked against page availability for the | |
1095 | * current cpuset. Application can still potentially OOM'ed by kernel | |
1096 | * with lack of free htlb page in cpuset that the task is in. | |
1097 | * Attempt to enforce strict accounting with cpuset is almost | |
1098 | * impossible (or too ugly) because cpuset is too fluid that | |
1099 | * task or memory node can be dynamically moved between cpusets. | |
1100 | * | |
1101 | * The change of semantics for shared hugetlb mapping with cpuset is | |
1102 | * undesirable. However, in order to preserve some of the semantics, | |
1103 | * we fall back to check against current free page availability as | |
1104 | * a best attempt and hopefully to minimize the impact of changing | |
1105 | * semantics that cpuset has. | |
1106 | */ | |
1107 | if (delta > 0) { | |
1108 | if (gather_surplus_pages(delta) < 0) | |
1109 | goto out; | |
1110 | ||
1111 | if (delta > cpuset_mems_nr(free_huge_pages_node)) { | |
1112 | return_unused_surplus_pages(delta); | |
1113 | goto out; | |
1114 | } | |
1115 | } | |
1116 | ||
1117 | ret = 0; | |
1118 | if (delta < 0) | |
1119 | return_unused_surplus_pages((unsigned long) -delta); | |
1120 | ||
1121 | out: | |
1122 | spin_unlock(&hugetlb_lock); | |
1123 | return ret; | |
1124 | } | |
1125 | ||
84afd99b AW |
1126 | static void hugetlb_vm_op_open(struct vm_area_struct *vma) |
1127 | { | |
1128 | struct resv_map *reservations = vma_resv_map(vma); | |
1129 | ||
1130 | /* | |
1131 | * This new VMA should share its siblings reservation map if present. | |
1132 | * The VMA will only ever have a valid reservation map pointer where | |
1133 | * it is being copied for another still existing VMA. As that VMA | |
1134 | * has a reference to the reservation map it cannot dissappear until | |
1135 | * after this open call completes. It is therefore safe to take a | |
1136 | * new reference here without additional locking. | |
1137 | */ | |
1138 | if (reservations) | |
1139 | kref_get(&reservations->refs); | |
1140 | } | |
1141 | ||
a1e78772 MG |
1142 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
1143 | { | |
84afd99b AW |
1144 | struct resv_map *reservations = vma_resv_map(vma); |
1145 | unsigned long reserve; | |
1146 | unsigned long start; | |
1147 | unsigned long end; | |
1148 | ||
1149 | if (reservations) { | |
a858f7b2 JW |
1150 | start = vma_hugecache_offset(vma, vma->vm_start); |
1151 | end = vma_hugecache_offset(vma, vma->vm_end); | |
84afd99b AW |
1152 | |
1153 | reserve = (end - start) - | |
1154 | region_count(&reservations->regions, start, end); | |
1155 | ||
1156 | kref_put(&reservations->refs, resv_map_release); | |
1157 | ||
1158 | if (reserve) | |
1159 | hugetlb_acct_memory(-reserve); | |
1160 | } | |
a1e78772 MG |
1161 | } |
1162 | ||
1da177e4 LT |
1163 | /* |
1164 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
1165 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
1166 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
1167 | * this far. | |
1168 | */ | |
d0217ac0 | 1169 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
1170 | { |
1171 | BUG(); | |
d0217ac0 | 1172 | return 0; |
1da177e4 LT |
1173 | } |
1174 | ||
1175 | struct vm_operations_struct hugetlb_vm_ops = { | |
d0217ac0 | 1176 | .fault = hugetlb_vm_op_fault, |
84afd99b | 1177 | .open = hugetlb_vm_op_open, |
a1e78772 | 1178 | .close = hugetlb_vm_op_close, |
1da177e4 LT |
1179 | }; |
1180 | ||
1e8f889b DG |
1181 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
1182 | int writable) | |
63551ae0 DG |
1183 | { |
1184 | pte_t entry; | |
1185 | ||
1e8f889b | 1186 | if (writable) { |
63551ae0 DG |
1187 | entry = |
1188 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
1189 | } else { | |
7f2e9525 | 1190 | entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
63551ae0 DG |
1191 | } |
1192 | entry = pte_mkyoung(entry); | |
1193 | entry = pte_mkhuge(entry); | |
1194 | ||
1195 | return entry; | |
1196 | } | |
1197 | ||
1e8f889b DG |
1198 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
1199 | unsigned long address, pte_t *ptep) | |
1200 | { | |
1201 | pte_t entry; | |
1202 | ||
7f2e9525 GS |
1203 | entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); |
1204 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { | |
8dab5241 | 1205 | update_mmu_cache(vma, address, entry); |
8dab5241 | 1206 | } |
1e8f889b DG |
1207 | } |
1208 | ||
1209 | ||
63551ae0 DG |
1210 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
1211 | struct vm_area_struct *vma) | |
1212 | { | |
1213 | pte_t *src_pte, *dst_pte, entry; | |
1214 | struct page *ptepage; | |
1c59827d | 1215 | unsigned long addr; |
1e8f889b DG |
1216 | int cow; |
1217 | ||
1218 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 1219 | |
1c59827d | 1220 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
c74df32c HD |
1221 | src_pte = huge_pte_offset(src, addr); |
1222 | if (!src_pte) | |
1223 | continue; | |
63551ae0 DG |
1224 | dst_pte = huge_pte_alloc(dst, addr); |
1225 | if (!dst_pte) | |
1226 | goto nomem; | |
c5c99429 LW |
1227 | |
1228 | /* If the pagetables are shared don't copy or take references */ | |
1229 | if (dst_pte == src_pte) | |
1230 | continue; | |
1231 | ||
c74df32c | 1232 | spin_lock(&dst->page_table_lock); |
46478758 | 1233 | spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); |
7f2e9525 | 1234 | if (!huge_pte_none(huge_ptep_get(src_pte))) { |
1e8f889b | 1235 | if (cow) |
7f2e9525 GS |
1236 | huge_ptep_set_wrprotect(src, addr, src_pte); |
1237 | entry = huge_ptep_get(src_pte); | |
1c59827d HD |
1238 | ptepage = pte_page(entry); |
1239 | get_page(ptepage); | |
1c59827d HD |
1240 | set_huge_pte_at(dst, addr, dst_pte, entry); |
1241 | } | |
1242 | spin_unlock(&src->page_table_lock); | |
c74df32c | 1243 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
1244 | } |
1245 | return 0; | |
1246 | ||
1247 | nomem: | |
1248 | return -ENOMEM; | |
1249 | } | |
1250 | ||
502717f4 | 1251 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1252 | unsigned long end, struct page *ref_page) |
63551ae0 DG |
1253 | { |
1254 | struct mm_struct *mm = vma->vm_mm; | |
1255 | unsigned long address; | |
c7546f8f | 1256 | pte_t *ptep; |
63551ae0 DG |
1257 | pte_t pte; |
1258 | struct page *page; | |
fe1668ae | 1259 | struct page *tmp; |
c0a499c2 KC |
1260 | /* |
1261 | * A page gathering list, protected by per file i_mmap_lock. The | |
1262 | * lock is used to avoid list corruption from multiple unmapping | |
1263 | * of the same page since we are using page->lru. | |
1264 | */ | |
fe1668ae | 1265 | LIST_HEAD(page_list); |
63551ae0 DG |
1266 | |
1267 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
1268 | BUG_ON(start & ~HPAGE_MASK); | |
1269 | BUG_ON(end & ~HPAGE_MASK); | |
1270 | ||
508034a3 | 1271 | spin_lock(&mm->page_table_lock); |
63551ae0 | 1272 | for (address = start; address < end; address += HPAGE_SIZE) { |
c7546f8f | 1273 | ptep = huge_pte_offset(mm, address); |
4c887265 | 1274 | if (!ptep) |
c7546f8f DG |
1275 | continue; |
1276 | ||
39dde65c KC |
1277 | if (huge_pmd_unshare(mm, &address, ptep)) |
1278 | continue; | |
1279 | ||
04f2cbe3 MG |
1280 | /* |
1281 | * If a reference page is supplied, it is because a specific | |
1282 | * page is being unmapped, not a range. Ensure the page we | |
1283 | * are about to unmap is the actual page of interest. | |
1284 | */ | |
1285 | if (ref_page) { | |
1286 | pte = huge_ptep_get(ptep); | |
1287 | if (huge_pte_none(pte)) | |
1288 | continue; | |
1289 | page = pte_page(pte); | |
1290 | if (page != ref_page) | |
1291 | continue; | |
1292 | ||
1293 | /* | |
1294 | * Mark the VMA as having unmapped its page so that | |
1295 | * future faults in this VMA will fail rather than | |
1296 | * looking like data was lost | |
1297 | */ | |
1298 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); | |
1299 | } | |
1300 | ||
c7546f8f | 1301 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
7f2e9525 | 1302 | if (huge_pte_none(pte)) |
63551ae0 | 1303 | continue; |
c7546f8f | 1304 | |
63551ae0 | 1305 | page = pte_page(pte); |
6649a386 KC |
1306 | if (pte_dirty(pte)) |
1307 | set_page_dirty(page); | |
fe1668ae | 1308 | list_add(&page->lru, &page_list); |
63551ae0 | 1309 | } |
1da177e4 | 1310 | spin_unlock(&mm->page_table_lock); |
508034a3 | 1311 | flush_tlb_range(vma, start, end); |
fe1668ae KC |
1312 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
1313 | list_del(&page->lru); | |
1314 | put_page(page); | |
1315 | } | |
1da177e4 | 1316 | } |
63551ae0 | 1317 | |
502717f4 | 1318 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1319 | unsigned long end, struct page *ref_page) |
502717f4 KC |
1320 | { |
1321 | /* | |
1322 | * It is undesirable to test vma->vm_file as it should be non-null | |
1323 | * for valid hugetlb area. However, vm_file will be NULL in the error | |
1324 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, | |
1325 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function | |
1326 | * to clean up. Since no pte has actually been setup, it is safe to | |
1327 | * do nothing in this case. | |
1328 | */ | |
1329 | if (vma->vm_file) { | |
1330 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); | |
04f2cbe3 | 1331 | __unmap_hugepage_range(vma, start, end, ref_page); |
502717f4 KC |
1332 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
1333 | } | |
1334 | } | |
1335 | ||
04f2cbe3 MG |
1336 | /* |
1337 | * This is called when the original mapper is failing to COW a MAP_PRIVATE | |
1338 | * mappping it owns the reserve page for. The intention is to unmap the page | |
1339 | * from other VMAs and let the children be SIGKILLed if they are faulting the | |
1340 | * same region. | |
1341 | */ | |
1342 | int unmap_ref_private(struct mm_struct *mm, | |
1343 | struct vm_area_struct *vma, | |
1344 | struct page *page, | |
1345 | unsigned long address) | |
1346 | { | |
1347 | struct vm_area_struct *iter_vma; | |
1348 | struct address_space *mapping; | |
1349 | struct prio_tree_iter iter; | |
1350 | pgoff_t pgoff; | |
1351 | ||
1352 | /* | |
1353 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation | |
1354 | * from page cache lookup which is in HPAGE_SIZE units. | |
1355 | */ | |
1356 | address = address & huge_page_mask(hstate_vma(vma)); | |
1357 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) | |
1358 | + (vma->vm_pgoff >> PAGE_SHIFT); | |
1359 | mapping = (struct address_space *)page_private(page); | |
1360 | ||
1361 | vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { | |
1362 | /* Do not unmap the current VMA */ | |
1363 | if (iter_vma == vma) | |
1364 | continue; | |
1365 | ||
1366 | /* | |
1367 | * Unmap the page from other VMAs without their own reserves. | |
1368 | * They get marked to be SIGKILLed if they fault in these | |
1369 | * areas. This is because a future no-page fault on this VMA | |
1370 | * could insert a zeroed page instead of the data existing | |
1371 | * from the time of fork. This would look like data corruption | |
1372 | */ | |
1373 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) | |
1374 | unmap_hugepage_range(iter_vma, | |
1375 | address, address + HPAGE_SIZE, | |
1376 | page); | |
1377 | } | |
1378 | ||
1379 | return 1; | |
1380 | } | |
1381 | ||
1e8f889b | 1382 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
04f2cbe3 MG |
1383 | unsigned long address, pte_t *ptep, pte_t pte, |
1384 | struct page *pagecache_page) | |
1e8f889b DG |
1385 | { |
1386 | struct page *old_page, *new_page; | |
79ac6ba4 | 1387 | int avoidcopy; |
04f2cbe3 | 1388 | int outside_reserve = 0; |
1e8f889b DG |
1389 | |
1390 | old_page = pte_page(pte); | |
1391 | ||
04f2cbe3 | 1392 | retry_avoidcopy: |
1e8f889b DG |
1393 | /* If no-one else is actually using this page, avoid the copy |
1394 | * and just make the page writable */ | |
1395 | avoidcopy = (page_count(old_page) == 1); | |
1396 | if (avoidcopy) { | |
1397 | set_huge_ptep_writable(vma, address, ptep); | |
83c54070 | 1398 | return 0; |
1e8f889b DG |
1399 | } |
1400 | ||
04f2cbe3 MG |
1401 | /* |
1402 | * If the process that created a MAP_PRIVATE mapping is about to | |
1403 | * perform a COW due to a shared page count, attempt to satisfy | |
1404 | * the allocation without using the existing reserves. The pagecache | |
1405 | * page is used to determine if the reserve at this address was | |
1406 | * consumed or not. If reserves were used, a partial faulted mapping | |
1407 | * at the time of fork() could consume its reserves on COW instead | |
1408 | * of the full address range. | |
1409 | */ | |
1410 | if (!(vma->vm_flags & VM_SHARED) && | |
1411 | is_vma_resv_set(vma, HPAGE_RESV_OWNER) && | |
1412 | old_page != pagecache_page) | |
1413 | outside_reserve = 1; | |
1414 | ||
1e8f889b | 1415 | page_cache_get(old_page); |
04f2cbe3 | 1416 | new_page = alloc_huge_page(vma, address, outside_reserve); |
1e8f889b | 1417 | |
2fc39cec | 1418 | if (IS_ERR(new_page)) { |
1e8f889b | 1419 | page_cache_release(old_page); |
04f2cbe3 MG |
1420 | |
1421 | /* | |
1422 | * If a process owning a MAP_PRIVATE mapping fails to COW, | |
1423 | * it is due to references held by a child and an insufficient | |
1424 | * huge page pool. To guarantee the original mappers | |
1425 | * reliability, unmap the page from child processes. The child | |
1426 | * may get SIGKILLed if it later faults. | |
1427 | */ | |
1428 | if (outside_reserve) { | |
1429 | BUG_ON(huge_pte_none(pte)); | |
1430 | if (unmap_ref_private(mm, vma, old_page, address)) { | |
1431 | BUG_ON(page_count(old_page) != 1); | |
1432 | BUG_ON(huge_pte_none(pte)); | |
1433 | goto retry_avoidcopy; | |
1434 | } | |
1435 | WARN_ON_ONCE(1); | |
1436 | } | |
1437 | ||
2fc39cec | 1438 | return -PTR_ERR(new_page); |
1e8f889b DG |
1439 | } |
1440 | ||
1441 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 1442 | copy_huge_page(new_page, old_page, address, vma); |
0ed361de | 1443 | __SetPageUptodate(new_page); |
1e8f889b DG |
1444 | spin_lock(&mm->page_table_lock); |
1445 | ||
1446 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); | |
7f2e9525 | 1447 | if (likely(pte_same(huge_ptep_get(ptep), pte))) { |
1e8f889b | 1448 | /* Break COW */ |
8fe627ec | 1449 | huge_ptep_clear_flush(vma, address, ptep); |
1e8f889b DG |
1450 | set_huge_pte_at(mm, address, ptep, |
1451 | make_huge_pte(vma, new_page, 1)); | |
1452 | /* Make the old page be freed below */ | |
1453 | new_page = old_page; | |
1454 | } | |
1455 | page_cache_release(new_page); | |
1456 | page_cache_release(old_page); | |
83c54070 | 1457 | return 0; |
1e8f889b DG |
1458 | } |
1459 | ||
04f2cbe3 MG |
1460 | /* Return the pagecache page at a given address within a VMA */ |
1461 | static struct page *hugetlbfs_pagecache_page(struct vm_area_struct *vma, | |
1462 | unsigned long address) | |
1463 | { | |
1464 | struct address_space *mapping; | |
e7c4b0bf | 1465 | pgoff_t idx; |
04f2cbe3 MG |
1466 | |
1467 | mapping = vma->vm_file->f_mapping; | |
a858f7b2 | 1468 | idx = vma_hugecache_offset(vma, address); |
04f2cbe3 MG |
1469 | |
1470 | return find_lock_page(mapping, idx); | |
1471 | } | |
1472 | ||
a1ed3dda | 1473 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 1474 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 HD |
1475 | { |
1476 | int ret = VM_FAULT_SIGBUS; | |
e7c4b0bf | 1477 | pgoff_t idx; |
4c887265 | 1478 | unsigned long size; |
4c887265 AL |
1479 | struct page *page; |
1480 | struct address_space *mapping; | |
1e8f889b | 1481 | pte_t new_pte; |
4c887265 | 1482 | |
04f2cbe3 MG |
1483 | /* |
1484 | * Currently, we are forced to kill the process in the event the | |
1485 | * original mapper has unmapped pages from the child due to a failed | |
1486 | * COW. Warn that such a situation has occured as it may not be obvious | |
1487 | */ | |
1488 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { | |
1489 | printk(KERN_WARNING | |
1490 | "PID %d killed due to inadequate hugepage pool\n", | |
1491 | current->pid); | |
1492 | return ret; | |
1493 | } | |
1494 | ||
4c887265 | 1495 | mapping = vma->vm_file->f_mapping; |
a858f7b2 | 1496 | idx = vma_hugecache_offset(vma, address); |
4c887265 AL |
1497 | |
1498 | /* | |
1499 | * Use page lock to guard against racing truncation | |
1500 | * before we get page_table_lock. | |
1501 | */ | |
6bda666a CL |
1502 | retry: |
1503 | page = find_lock_page(mapping, idx); | |
1504 | if (!page) { | |
ebed4bfc HD |
1505 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
1506 | if (idx >= size) | |
1507 | goto out; | |
04f2cbe3 | 1508 | page = alloc_huge_page(vma, address, 0); |
2fc39cec AL |
1509 | if (IS_ERR(page)) { |
1510 | ret = -PTR_ERR(page); | |
6bda666a CL |
1511 | goto out; |
1512 | } | |
79ac6ba4 | 1513 | clear_huge_page(page, address); |
0ed361de | 1514 | __SetPageUptodate(page); |
ac9b9c66 | 1515 | |
6bda666a CL |
1516 | if (vma->vm_flags & VM_SHARED) { |
1517 | int err; | |
45c682a6 | 1518 | struct inode *inode = mapping->host; |
6bda666a CL |
1519 | |
1520 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
1521 | if (err) { | |
1522 | put_page(page); | |
6bda666a CL |
1523 | if (err == -EEXIST) |
1524 | goto retry; | |
1525 | goto out; | |
1526 | } | |
45c682a6 KC |
1527 | |
1528 | spin_lock(&inode->i_lock); | |
1529 | inode->i_blocks += BLOCKS_PER_HUGEPAGE; | |
1530 | spin_unlock(&inode->i_lock); | |
6bda666a CL |
1531 | } else |
1532 | lock_page(page); | |
1533 | } | |
1e8f889b | 1534 | |
ac9b9c66 | 1535 | spin_lock(&mm->page_table_lock); |
4c887265 AL |
1536 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
1537 | if (idx >= size) | |
1538 | goto backout; | |
1539 | ||
83c54070 | 1540 | ret = 0; |
7f2e9525 | 1541 | if (!huge_pte_none(huge_ptep_get(ptep))) |
4c887265 AL |
1542 | goto backout; |
1543 | ||
1e8f889b DG |
1544 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
1545 | && (vma->vm_flags & VM_SHARED))); | |
1546 | set_huge_pte_at(mm, address, ptep, new_pte); | |
1547 | ||
1548 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
1549 | /* Optimization, do the COW without a second fault */ | |
04f2cbe3 | 1550 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); |
1e8f889b DG |
1551 | } |
1552 | ||
ac9b9c66 | 1553 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
1554 | unlock_page(page); |
1555 | out: | |
ac9b9c66 | 1556 | return ret; |
4c887265 AL |
1557 | |
1558 | backout: | |
1559 | spin_unlock(&mm->page_table_lock); | |
4c887265 AL |
1560 | unlock_page(page); |
1561 | put_page(page); | |
1562 | goto out; | |
ac9b9c66 HD |
1563 | } |
1564 | ||
86e5216f AL |
1565 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
1566 | unsigned long address, int write_access) | |
1567 | { | |
1568 | pte_t *ptep; | |
1569 | pte_t entry; | |
1e8f889b | 1570 | int ret; |
3935baa9 | 1571 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
86e5216f AL |
1572 | |
1573 | ptep = huge_pte_alloc(mm, address); | |
1574 | if (!ptep) | |
1575 | return VM_FAULT_OOM; | |
1576 | ||
3935baa9 DG |
1577 | /* |
1578 | * Serialize hugepage allocation and instantiation, so that we don't | |
1579 | * get spurious allocation failures if two CPUs race to instantiate | |
1580 | * the same page in the page cache. | |
1581 | */ | |
1582 | mutex_lock(&hugetlb_instantiation_mutex); | |
7f2e9525 GS |
1583 | entry = huge_ptep_get(ptep); |
1584 | if (huge_pte_none(entry)) { | |
3935baa9 DG |
1585 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); |
1586 | mutex_unlock(&hugetlb_instantiation_mutex); | |
1587 | return ret; | |
1588 | } | |
86e5216f | 1589 | |
83c54070 | 1590 | ret = 0; |
1e8f889b DG |
1591 | |
1592 | spin_lock(&mm->page_table_lock); | |
1593 | /* Check for a racing update before calling hugetlb_cow */ | |
7f2e9525 | 1594 | if (likely(pte_same(entry, huge_ptep_get(ptep)))) |
04f2cbe3 MG |
1595 | if (write_access && !pte_write(entry)) { |
1596 | struct page *page; | |
1597 | page = hugetlbfs_pagecache_page(vma, address); | |
1598 | ret = hugetlb_cow(mm, vma, address, ptep, entry, page); | |
1599 | if (page) { | |
1600 | unlock_page(page); | |
1601 | put_page(page); | |
1602 | } | |
1603 | } | |
1e8f889b | 1604 | spin_unlock(&mm->page_table_lock); |
3935baa9 | 1605 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
1606 | |
1607 | return ret; | |
86e5216f AL |
1608 | } |
1609 | ||
63551ae0 DG |
1610 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1611 | struct page **pages, struct vm_area_struct **vmas, | |
5b23dbe8 AL |
1612 | unsigned long *position, int *length, int i, |
1613 | int write) | |
63551ae0 | 1614 | { |
d5d4b0aa KC |
1615 | unsigned long pfn_offset; |
1616 | unsigned long vaddr = *position; | |
63551ae0 DG |
1617 | int remainder = *length; |
1618 | ||
1c59827d | 1619 | spin_lock(&mm->page_table_lock); |
63551ae0 | 1620 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
1621 | pte_t *pte; |
1622 | struct page *page; | |
63551ae0 | 1623 | |
4c887265 AL |
1624 | /* |
1625 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
1626 | * each hugepage. We have to make * sure we get the | |
1627 | * first, for the page indexing below to work. | |
1628 | */ | |
1629 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); | |
63551ae0 | 1630 | |
7f2e9525 GS |
1631 | if (!pte || huge_pte_none(huge_ptep_get(pte)) || |
1632 | (write && !pte_write(huge_ptep_get(pte)))) { | |
4c887265 | 1633 | int ret; |
63551ae0 | 1634 | |
4c887265 | 1635 | spin_unlock(&mm->page_table_lock); |
5b23dbe8 | 1636 | ret = hugetlb_fault(mm, vma, vaddr, write); |
4c887265 | 1637 | spin_lock(&mm->page_table_lock); |
a89182c7 | 1638 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 1639 | continue; |
63551ae0 | 1640 | |
4c887265 AL |
1641 | remainder = 0; |
1642 | if (!i) | |
1643 | i = -EFAULT; | |
1644 | break; | |
1645 | } | |
1646 | ||
d5d4b0aa | 1647 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
7f2e9525 | 1648 | page = pte_page(huge_ptep_get(pte)); |
d5d4b0aa | 1649 | same_page: |
d6692183 KC |
1650 | if (pages) { |
1651 | get_page(page); | |
d5d4b0aa | 1652 | pages[i] = page + pfn_offset; |
d6692183 | 1653 | } |
63551ae0 DG |
1654 | |
1655 | if (vmas) | |
1656 | vmas[i] = vma; | |
1657 | ||
1658 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 1659 | ++pfn_offset; |
63551ae0 DG |
1660 | --remainder; |
1661 | ++i; | |
d5d4b0aa KC |
1662 | if (vaddr < vma->vm_end && remainder && |
1663 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { | |
1664 | /* | |
1665 | * We use pfn_offset to avoid touching the pageframes | |
1666 | * of this compound page. | |
1667 | */ | |
1668 | goto same_page; | |
1669 | } | |
63551ae0 | 1670 | } |
1c59827d | 1671 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
1672 | *length = remainder; |
1673 | *position = vaddr; | |
1674 | ||
1675 | return i; | |
1676 | } | |
8f860591 ZY |
1677 | |
1678 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
1679 | unsigned long address, unsigned long end, pgprot_t newprot) | |
1680 | { | |
1681 | struct mm_struct *mm = vma->vm_mm; | |
1682 | unsigned long start = address; | |
1683 | pte_t *ptep; | |
1684 | pte_t pte; | |
1685 | ||
1686 | BUG_ON(address >= end); | |
1687 | flush_cache_range(vma, address, end); | |
1688 | ||
39dde65c | 1689 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
1690 | spin_lock(&mm->page_table_lock); |
1691 | for (; address < end; address += HPAGE_SIZE) { | |
1692 | ptep = huge_pte_offset(mm, address); | |
1693 | if (!ptep) | |
1694 | continue; | |
39dde65c KC |
1695 | if (huge_pmd_unshare(mm, &address, ptep)) |
1696 | continue; | |
7f2e9525 | 1697 | if (!huge_pte_none(huge_ptep_get(ptep))) { |
8f860591 ZY |
1698 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
1699 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
1700 | set_huge_pte_at(mm, address, ptep, pte); | |
8f860591 ZY |
1701 | } |
1702 | } | |
1703 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 1704 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
1705 | |
1706 | flush_tlb_range(vma, start, end); | |
1707 | } | |
1708 | ||
a1e78772 MG |
1709 | int hugetlb_reserve_pages(struct inode *inode, |
1710 | long from, long to, | |
1711 | struct vm_area_struct *vma) | |
e4e574b7 AL |
1712 | { |
1713 | long ret, chg; | |
1714 | ||
c37f9fb1 AW |
1715 | if (vma && vma->vm_flags & VM_NORESERVE) |
1716 | return 0; | |
1717 | ||
a1e78772 MG |
1718 | /* |
1719 | * Shared mappings base their reservation on the number of pages that | |
1720 | * are already allocated on behalf of the file. Private mappings need | |
1721 | * to reserve the full area even if read-only as mprotect() may be | |
1722 | * called to make the mapping read-write. Assume !vma is a shm mapping | |
1723 | */ | |
1724 | if (!vma || vma->vm_flags & VM_SHARED) | |
1725 | chg = region_chg(&inode->i_mapping->private_list, from, to); | |
1726 | else { | |
84afd99b AW |
1727 | struct resv_map *resv_map = resv_map_alloc(); |
1728 | if (!resv_map) | |
1729 | return -ENOMEM; | |
1730 | ||
a1e78772 | 1731 | chg = to - from; |
84afd99b AW |
1732 | |
1733 | set_vma_resv_map(vma, resv_map); | |
04f2cbe3 | 1734 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); |
a1e78772 MG |
1735 | } |
1736 | ||
e4e574b7 AL |
1737 | if (chg < 0) |
1738 | return chg; | |
8a630112 | 1739 | |
90d8b7e6 AL |
1740 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
1741 | return -ENOSPC; | |
a43a8c39 | 1742 | ret = hugetlb_acct_memory(chg); |
68842c9b KC |
1743 | if (ret < 0) { |
1744 | hugetlb_put_quota(inode->i_mapping, chg); | |
a43a8c39 | 1745 | return ret; |
68842c9b | 1746 | } |
a1e78772 MG |
1747 | if (!vma || vma->vm_flags & VM_SHARED) |
1748 | region_add(&inode->i_mapping->private_list, from, to); | |
a43a8c39 KC |
1749 | return 0; |
1750 | } | |
1751 | ||
1752 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
1753 | { | |
1754 | long chg = region_truncate(&inode->i_mapping->private_list, offset); | |
45c682a6 KC |
1755 | |
1756 | spin_lock(&inode->i_lock); | |
1757 | inode->i_blocks -= BLOCKS_PER_HUGEPAGE * freed; | |
1758 | spin_unlock(&inode->i_lock); | |
1759 | ||
90d8b7e6 AL |
1760 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
1761 | hugetlb_acct_memory(-(chg - freed)); | |
a43a8c39 | 1762 | } |