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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. | |
46 | */ | |
47 | struct file_region { | |
48 | struct list_head link; | |
49 | long from; | |
50 | long to; | |
51 | }; | |
52 | ||
53 | static long region_add(struct list_head *head, long f, long t) | |
54 | { | |
55 | struct file_region *rg, *nrg, *trg; | |
56 | ||
57 | /* Locate the region we are either in or before. */ | |
58 | list_for_each_entry(rg, head, link) | |
59 | if (f <= rg->to) | |
60 | break; | |
61 | ||
62 | /* Round our left edge to the current segment if it encloses us. */ | |
63 | if (f > rg->from) | |
64 | f = rg->from; | |
65 | ||
66 | /* Check for and consume any regions we now overlap with. */ | |
67 | nrg = rg; | |
68 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
69 | if (&rg->link == head) | |
70 | break; | |
71 | if (rg->from > t) | |
72 | break; | |
73 | ||
74 | /* If this area reaches higher then extend our area to | |
75 | * include it completely. If this is not the first area | |
76 | * which we intend to reuse, free it. */ | |
77 | if (rg->to > t) | |
78 | t = rg->to; | |
79 | if (rg != nrg) { | |
80 | list_del(&rg->link); | |
81 | kfree(rg); | |
82 | } | |
83 | } | |
84 | nrg->from = f; | |
85 | nrg->to = t; | |
86 | return 0; | |
87 | } | |
88 | ||
89 | static long region_chg(struct list_head *head, long f, long t) | |
90 | { | |
91 | struct file_region *rg, *nrg; | |
92 | long chg = 0; | |
93 | ||
94 | /* Locate the region we are before or in. */ | |
95 | list_for_each_entry(rg, head, link) | |
96 | if (f <= rg->to) | |
97 | break; | |
98 | ||
99 | /* If we are below the current region then a new region is required. | |
100 | * Subtle, allocate a new region at the position but make it zero | |
101 | * size such that we can guarantee to record the reservation. */ | |
102 | if (&rg->link == head || t < rg->from) { | |
103 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
104 | if (!nrg) | |
105 | return -ENOMEM; | |
106 | nrg->from = f; | |
107 | nrg->to = f; | |
108 | INIT_LIST_HEAD(&nrg->link); | |
109 | list_add(&nrg->link, rg->link.prev); | |
110 | ||
111 | return t - f; | |
112 | } | |
113 | ||
114 | /* Round our left edge to the current segment if it encloses us. */ | |
115 | if (f > rg->from) | |
116 | f = rg->from; | |
117 | chg = t - f; | |
118 | ||
119 | /* Check for and consume any regions we now overlap with. */ | |
120 | list_for_each_entry(rg, rg->link.prev, link) { | |
121 | if (&rg->link == head) | |
122 | break; | |
123 | if (rg->from > t) | |
124 | return chg; | |
125 | ||
126 | /* We overlap with this area, if it extends futher than | |
127 | * us then we must extend ourselves. Account for its | |
128 | * existing reservation. */ | |
129 | if (rg->to > t) { | |
130 | chg += rg->to - t; | |
131 | t = rg->to; | |
132 | } | |
133 | chg -= rg->to - rg->from; | |
134 | } | |
135 | return chg; | |
136 | } | |
137 | ||
138 | static long region_truncate(struct list_head *head, long end) | |
139 | { | |
140 | struct file_region *rg, *trg; | |
141 | long chg = 0; | |
142 | ||
143 | /* Locate the region we are either in or before. */ | |
144 | list_for_each_entry(rg, head, link) | |
145 | if (end <= rg->to) | |
146 | break; | |
147 | if (&rg->link == head) | |
148 | return 0; | |
149 | ||
150 | /* If we are in the middle of a region then adjust it. */ | |
151 | if (end > rg->from) { | |
152 | chg = rg->to - end; | |
153 | rg->to = end; | |
154 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
155 | } | |
156 | ||
157 | /* Drop any remaining regions. */ | |
158 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
159 | if (&rg->link == head) | |
160 | break; | |
161 | chg += rg->to - rg->from; | |
162 | list_del(&rg->link); | |
163 | kfree(rg); | |
164 | } | |
165 | return chg; | |
166 | } | |
167 | ||
e7c4b0bf AW |
168 | /* |
169 | * Convert the address within this vma to the page offset within | |
170 | * the mapping, in base page units. | |
171 | */ | |
172 | static pgoff_t vma_page_offset(struct vm_area_struct *vma, | |
173 | unsigned long address) | |
174 | { | |
175 | return ((address - vma->vm_start) >> PAGE_SHIFT) + | |
176 | (vma->vm_pgoff >> PAGE_SHIFT); | |
177 | } | |
178 | ||
179 | /* | |
180 | * Convert the address within this vma to the page offset within | |
181 | * the mapping, in pagecache page units; huge pages here. | |
182 | */ | |
183 | static pgoff_t vma_pagecache_offset(struct vm_area_struct *vma, | |
184 | unsigned long address) | |
185 | { | |
186 | return ((address - vma->vm_start) >> HPAGE_SHIFT) + | |
187 | (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); | |
188 | } | |
189 | ||
04f2cbe3 MG |
190 | #define HPAGE_RESV_OWNER (1UL << (BITS_PER_LONG - 1)) |
191 | #define HPAGE_RESV_UNMAPPED (1UL << (BITS_PER_LONG - 2)) | |
192 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) | |
a1e78772 MG |
193 | /* |
194 | * These helpers are used to track how many pages are reserved for | |
195 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() | |
196 | * is guaranteed to have their future faults succeed. | |
197 | * | |
198 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), | |
199 | * the reserve counters are updated with the hugetlb_lock held. It is safe | |
200 | * to reset the VMA at fork() time as it is not in use yet and there is no | |
201 | * chance of the global counters getting corrupted as a result of the values. | |
202 | */ | |
e7c4b0bf AW |
203 | static unsigned long get_vma_private_data(struct vm_area_struct *vma) |
204 | { | |
205 | return (unsigned long)vma->vm_private_data; | |
206 | } | |
207 | ||
208 | static void set_vma_private_data(struct vm_area_struct *vma, | |
209 | unsigned long value) | |
210 | { | |
211 | vma->vm_private_data = (void *)value; | |
212 | } | |
213 | ||
a1e78772 MG |
214 | static unsigned long vma_resv_huge_pages(struct vm_area_struct *vma) |
215 | { | |
216 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
217 | if (!(vma->vm_flags & VM_SHARED)) | |
e7c4b0bf | 218 | return get_vma_private_data(vma) & ~HPAGE_RESV_MASK; |
a1e78772 MG |
219 | return 0; |
220 | } | |
221 | ||
222 | static void set_vma_resv_huge_pages(struct vm_area_struct *vma, | |
223 | unsigned long reserve) | |
224 | { | |
225 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
226 | VM_BUG_ON(vma->vm_flags & VM_SHARED); | |
227 | ||
e7c4b0bf AW |
228 | set_vma_private_data(vma, |
229 | (get_vma_private_data(vma) & HPAGE_RESV_MASK) | reserve); | |
04f2cbe3 MG |
230 | } |
231 | ||
232 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) | |
233 | { | |
04f2cbe3 | 234 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
e7c4b0bf AW |
235 | VM_BUG_ON(vma->vm_flags & VM_SHARED); |
236 | ||
237 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); | |
04f2cbe3 MG |
238 | } |
239 | ||
240 | static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) | |
241 | { | |
242 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
e7c4b0bf AW |
243 | |
244 | return (get_vma_private_data(vma) & flag) != 0; | |
a1e78772 MG |
245 | } |
246 | ||
247 | /* Decrement the reserved pages in the hugepage pool by one */ | |
248 | static void decrement_hugepage_resv_vma(struct vm_area_struct *vma) | |
249 | { | |
250 | if (vma->vm_flags & VM_SHARED) { | |
251 | /* Shared mappings always use reserves */ | |
252 | resv_huge_pages--; | |
253 | } else { | |
254 | /* | |
255 | * Only the process that called mmap() has reserves for | |
256 | * private mappings. | |
257 | */ | |
04f2cbe3 MG |
258 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
259 | unsigned long flags, reserve; | |
a1e78772 | 260 | resv_huge_pages--; |
04f2cbe3 MG |
261 | flags = (unsigned long)vma->vm_private_data & |
262 | HPAGE_RESV_MASK; | |
a1e78772 | 263 | reserve = (unsigned long)vma->vm_private_data - 1; |
04f2cbe3 | 264 | vma->vm_private_data = (void *)(reserve | flags); |
a1e78772 MG |
265 | } |
266 | } | |
267 | } | |
268 | ||
04f2cbe3 | 269 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
a1e78772 MG |
270 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
271 | { | |
272 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
273 | if (!(vma->vm_flags & VM_SHARED)) | |
274 | vma->vm_private_data = (void *)0; | |
275 | } | |
276 | ||
277 | /* Returns true if the VMA has associated reserve pages */ | |
278 | static int vma_has_private_reserves(struct vm_area_struct *vma) | |
279 | { | |
280 | if (vma->vm_flags & VM_SHARED) | |
281 | return 0; | |
282 | if (!vma_resv_huge_pages(vma)) | |
283 | return 0; | |
284 | return 1; | |
285 | } | |
286 | ||
79ac6ba4 DG |
287 | static void clear_huge_page(struct page *page, unsigned long addr) |
288 | { | |
289 | int i; | |
290 | ||
291 | might_sleep(); | |
292 | for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) { | |
293 | cond_resched(); | |
281e0e3b | 294 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
79ac6ba4 DG |
295 | } |
296 | } | |
297 | ||
298 | static void copy_huge_page(struct page *dst, struct page *src, | |
9de455b2 | 299 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
300 | { |
301 | int i; | |
302 | ||
303 | might_sleep(); | |
304 | for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { | |
305 | cond_resched(); | |
9de455b2 | 306 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
307 | } |
308 | } | |
309 | ||
1da177e4 LT |
310 | static void enqueue_huge_page(struct page *page) |
311 | { | |
312 | int nid = page_to_nid(page); | |
313 | list_add(&page->lru, &hugepage_freelists[nid]); | |
314 | free_huge_pages++; | |
315 | free_huge_pages_node[nid]++; | |
316 | } | |
317 | ||
348e1e04 NA |
318 | static struct page *dequeue_huge_page(void) |
319 | { | |
320 | int nid; | |
321 | struct page *page = NULL; | |
322 | ||
323 | for (nid = 0; nid < MAX_NUMNODES; ++nid) { | |
324 | if (!list_empty(&hugepage_freelists[nid])) { | |
325 | page = list_entry(hugepage_freelists[nid].next, | |
326 | struct page, lru); | |
327 | list_del(&page->lru); | |
328 | free_huge_pages--; | |
329 | free_huge_pages_node[nid]--; | |
330 | break; | |
331 | } | |
332 | } | |
333 | return page; | |
334 | } | |
335 | ||
336 | static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma, | |
04f2cbe3 | 337 | unsigned long address, int avoid_reserve) |
1da177e4 | 338 | { |
31a5c6e4 | 339 | int nid; |
1da177e4 | 340 | struct page *page = NULL; |
480eccf9 | 341 | struct mempolicy *mpol; |
19770b32 | 342 | nodemask_t *nodemask; |
396faf03 | 343 | struct zonelist *zonelist = huge_zonelist(vma, address, |
19770b32 | 344 | htlb_alloc_mask, &mpol, &nodemask); |
dd1a239f MG |
345 | struct zone *zone; |
346 | struct zoneref *z; | |
1da177e4 | 347 | |
a1e78772 MG |
348 | /* |
349 | * A child process with MAP_PRIVATE mappings created by their parent | |
350 | * have no page reserves. This check ensures that reservations are | |
351 | * not "stolen". The child may still get SIGKILLed | |
352 | */ | |
353 | if (!vma_has_private_reserves(vma) && | |
354 | free_huge_pages - resv_huge_pages == 0) | |
355 | return NULL; | |
356 | ||
04f2cbe3 MG |
357 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
358 | if (avoid_reserve && free_huge_pages - resv_huge_pages == 0) | |
359 | return NULL; | |
360 | ||
19770b32 MG |
361 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
362 | MAX_NR_ZONES - 1, nodemask) { | |
54a6eb5c MG |
363 | nid = zone_to_nid(zone); |
364 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && | |
3abf7afd AM |
365 | !list_empty(&hugepage_freelists[nid])) { |
366 | page = list_entry(hugepage_freelists[nid].next, | |
367 | struct page, lru); | |
368 | list_del(&page->lru); | |
369 | free_huge_pages--; | |
370 | free_huge_pages_node[nid]--; | |
04f2cbe3 MG |
371 | |
372 | if (!avoid_reserve) | |
373 | decrement_hugepage_resv_vma(vma); | |
a1e78772 | 374 | |
5ab3ee7b | 375 | break; |
3abf7afd | 376 | } |
1da177e4 | 377 | } |
52cd3b07 | 378 | mpol_cond_put(mpol); |
1da177e4 LT |
379 | return page; |
380 | } | |
381 | ||
6af2acb6 AL |
382 | static void update_and_free_page(struct page *page) |
383 | { | |
384 | int i; | |
385 | nr_huge_pages--; | |
386 | nr_huge_pages_node[page_to_nid(page)]--; | |
387 | for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { | |
388 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | | |
389 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
390 | 1 << PG_private | 1<< PG_writeback); | |
391 | } | |
392 | set_compound_page_dtor(page, NULL); | |
393 | set_page_refcounted(page); | |
7f2e9525 | 394 | arch_release_hugepage(page); |
6af2acb6 AL |
395 | __free_pages(page, HUGETLB_PAGE_ORDER); |
396 | } | |
397 | ||
27a85ef1 DG |
398 | static void free_huge_page(struct page *page) |
399 | { | |
7893d1d5 | 400 | int nid = page_to_nid(page); |
c79fb75e | 401 | struct address_space *mapping; |
27a85ef1 | 402 | |
c79fb75e | 403 | mapping = (struct address_space *) page_private(page); |
e5df70ab | 404 | set_page_private(page, 0); |
7893d1d5 | 405 | BUG_ON(page_count(page)); |
27a85ef1 DG |
406 | INIT_LIST_HEAD(&page->lru); |
407 | ||
408 | spin_lock(&hugetlb_lock); | |
7893d1d5 AL |
409 | if (surplus_huge_pages_node[nid]) { |
410 | update_and_free_page(page); | |
411 | surplus_huge_pages--; | |
412 | surplus_huge_pages_node[nid]--; | |
413 | } else { | |
414 | enqueue_huge_page(page); | |
415 | } | |
27a85ef1 | 416 | spin_unlock(&hugetlb_lock); |
c79fb75e | 417 | if (mapping) |
9a119c05 | 418 | hugetlb_put_quota(mapping, 1); |
27a85ef1 DG |
419 | } |
420 | ||
7893d1d5 AL |
421 | /* |
422 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
423 | * balanced by operating on them in a round-robin fashion. | |
424 | * Returns 1 if an adjustment was made. | |
425 | */ | |
426 | static int adjust_pool_surplus(int delta) | |
427 | { | |
428 | static int prev_nid; | |
429 | int nid = prev_nid; | |
430 | int ret = 0; | |
431 | ||
432 | VM_BUG_ON(delta != -1 && delta != 1); | |
433 | do { | |
434 | nid = next_node(nid, node_online_map); | |
435 | if (nid == MAX_NUMNODES) | |
436 | nid = first_node(node_online_map); | |
437 | ||
438 | /* To shrink on this node, there must be a surplus page */ | |
439 | if (delta < 0 && !surplus_huge_pages_node[nid]) | |
440 | continue; | |
441 | /* Surplus cannot exceed the total number of pages */ | |
442 | if (delta > 0 && surplus_huge_pages_node[nid] >= | |
443 | nr_huge_pages_node[nid]) | |
444 | continue; | |
445 | ||
446 | surplus_huge_pages += delta; | |
447 | surplus_huge_pages_node[nid] += delta; | |
448 | ret = 1; | |
449 | break; | |
450 | } while (nid != prev_nid); | |
451 | ||
452 | prev_nid = nid; | |
453 | return ret; | |
454 | } | |
455 | ||
63b4613c | 456 | static struct page *alloc_fresh_huge_page_node(int nid) |
1da177e4 | 457 | { |
1da177e4 | 458 | struct page *page; |
f96efd58 | 459 | |
63b4613c | 460 | page = alloc_pages_node(nid, |
551883ae NA |
461 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| |
462 | __GFP_REPEAT|__GFP_NOWARN, | |
63b4613c | 463 | HUGETLB_PAGE_ORDER); |
1da177e4 | 464 | if (page) { |
7f2e9525 GS |
465 | if (arch_prepare_hugepage(page)) { |
466 | __free_pages(page, HUGETLB_PAGE_ORDER); | |
7b8ee84d | 467 | return NULL; |
7f2e9525 | 468 | } |
33f2ef89 | 469 | set_compound_page_dtor(page, free_huge_page); |
0bd0f9fb | 470 | spin_lock(&hugetlb_lock); |
1da177e4 | 471 | nr_huge_pages++; |
63b4613c | 472 | nr_huge_pages_node[nid]++; |
0bd0f9fb | 473 | spin_unlock(&hugetlb_lock); |
a482289d | 474 | put_page(page); /* free it into the hugepage allocator */ |
1da177e4 | 475 | } |
63b4613c NA |
476 | |
477 | return page; | |
478 | } | |
479 | ||
480 | static int alloc_fresh_huge_page(void) | |
481 | { | |
482 | struct page *page; | |
483 | int start_nid; | |
484 | int next_nid; | |
485 | int ret = 0; | |
486 | ||
487 | start_nid = hugetlb_next_nid; | |
488 | ||
489 | do { | |
490 | page = alloc_fresh_huge_page_node(hugetlb_next_nid); | |
491 | if (page) | |
492 | ret = 1; | |
493 | /* | |
494 | * Use a helper variable to find the next node and then | |
495 | * copy it back to hugetlb_next_nid afterwards: | |
496 | * otherwise there's a window in which a racer might | |
497 | * pass invalid nid MAX_NUMNODES to alloc_pages_node. | |
498 | * But we don't need to use a spin_lock here: it really | |
499 | * doesn't matter if occasionally a racer chooses the | |
500 | * same nid as we do. Move nid forward in the mask even | |
501 | * if we just successfully allocated a hugepage so that | |
502 | * the next caller gets hugepages on the next node. | |
503 | */ | |
504 | next_nid = next_node(hugetlb_next_nid, node_online_map); | |
505 | if (next_nid == MAX_NUMNODES) | |
506 | next_nid = first_node(node_online_map); | |
507 | hugetlb_next_nid = next_nid; | |
508 | } while (!page && hugetlb_next_nid != start_nid); | |
509 | ||
3b116300 AL |
510 | if (ret) |
511 | count_vm_event(HTLB_BUDDY_PGALLOC); | |
512 | else | |
513 | count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); | |
514 | ||
63b4613c | 515 | return ret; |
1da177e4 LT |
516 | } |
517 | ||
7893d1d5 AL |
518 | static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma, |
519 | unsigned long address) | |
520 | { | |
521 | struct page *page; | |
d1c3fb1f | 522 | unsigned int nid; |
7893d1d5 | 523 | |
d1c3fb1f NA |
524 | /* |
525 | * Assume we will successfully allocate the surplus page to | |
526 | * prevent racing processes from causing the surplus to exceed | |
527 | * overcommit | |
528 | * | |
529 | * This however introduces a different race, where a process B | |
530 | * tries to grow the static hugepage pool while alloc_pages() is | |
531 | * called by process A. B will only examine the per-node | |
532 | * counters in determining if surplus huge pages can be | |
533 | * converted to normal huge pages in adjust_pool_surplus(). A | |
534 | * won't be able to increment the per-node counter, until the | |
535 | * lock is dropped by B, but B doesn't drop hugetlb_lock until | |
536 | * no more huge pages can be converted from surplus to normal | |
537 | * state (and doesn't try to convert again). Thus, we have a | |
538 | * case where a surplus huge page exists, the pool is grown, and | |
539 | * the surplus huge page still exists after, even though it | |
540 | * should just have been converted to a normal huge page. This | |
541 | * does not leak memory, though, as the hugepage will be freed | |
542 | * once it is out of use. It also does not allow the counters to | |
543 | * go out of whack in adjust_pool_surplus() as we don't modify | |
544 | * the node values until we've gotten the hugepage and only the | |
545 | * per-node value is checked there. | |
546 | */ | |
547 | spin_lock(&hugetlb_lock); | |
548 | if (surplus_huge_pages >= nr_overcommit_huge_pages) { | |
549 | spin_unlock(&hugetlb_lock); | |
550 | return NULL; | |
551 | } else { | |
552 | nr_huge_pages++; | |
553 | surplus_huge_pages++; | |
554 | } | |
555 | spin_unlock(&hugetlb_lock); | |
556 | ||
551883ae NA |
557 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP| |
558 | __GFP_REPEAT|__GFP_NOWARN, | |
7893d1d5 | 559 | HUGETLB_PAGE_ORDER); |
d1c3fb1f NA |
560 | |
561 | spin_lock(&hugetlb_lock); | |
7893d1d5 | 562 | if (page) { |
2668db91 AL |
563 | /* |
564 | * This page is now managed by the hugetlb allocator and has | |
565 | * no users -- drop the buddy allocator's reference. | |
566 | */ | |
567 | put_page_testzero(page); | |
568 | VM_BUG_ON(page_count(page)); | |
d1c3fb1f | 569 | nid = page_to_nid(page); |
7893d1d5 | 570 | set_compound_page_dtor(page, free_huge_page); |
d1c3fb1f NA |
571 | /* |
572 | * We incremented the global counters already | |
573 | */ | |
574 | nr_huge_pages_node[nid]++; | |
575 | surplus_huge_pages_node[nid]++; | |
3b116300 | 576 | __count_vm_event(HTLB_BUDDY_PGALLOC); |
d1c3fb1f NA |
577 | } else { |
578 | nr_huge_pages--; | |
579 | surplus_huge_pages--; | |
3b116300 | 580 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
7893d1d5 | 581 | } |
d1c3fb1f | 582 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
583 | |
584 | return page; | |
585 | } | |
586 | ||
e4e574b7 AL |
587 | /* |
588 | * Increase the hugetlb pool such that it can accomodate a reservation | |
589 | * of size 'delta'. | |
590 | */ | |
591 | static int gather_surplus_pages(int delta) | |
592 | { | |
593 | struct list_head surplus_list; | |
594 | struct page *page, *tmp; | |
595 | int ret, i; | |
596 | int needed, allocated; | |
597 | ||
598 | needed = (resv_huge_pages + delta) - free_huge_pages; | |
ac09b3a1 AL |
599 | if (needed <= 0) { |
600 | resv_huge_pages += delta; | |
e4e574b7 | 601 | return 0; |
ac09b3a1 | 602 | } |
e4e574b7 AL |
603 | |
604 | allocated = 0; | |
605 | INIT_LIST_HEAD(&surplus_list); | |
606 | ||
607 | ret = -ENOMEM; | |
608 | retry: | |
609 | spin_unlock(&hugetlb_lock); | |
610 | for (i = 0; i < needed; i++) { | |
611 | page = alloc_buddy_huge_page(NULL, 0); | |
612 | if (!page) { | |
613 | /* | |
614 | * We were not able to allocate enough pages to | |
615 | * satisfy the entire reservation so we free what | |
616 | * we've allocated so far. | |
617 | */ | |
618 | spin_lock(&hugetlb_lock); | |
619 | needed = 0; | |
620 | goto free; | |
621 | } | |
622 | ||
623 | list_add(&page->lru, &surplus_list); | |
624 | } | |
625 | allocated += needed; | |
626 | ||
627 | /* | |
628 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
629 | * because either resv_huge_pages or free_huge_pages may have changed. | |
630 | */ | |
631 | spin_lock(&hugetlb_lock); | |
632 | needed = (resv_huge_pages + delta) - (free_huge_pages + allocated); | |
633 | if (needed > 0) | |
634 | goto retry; | |
635 | ||
636 | /* | |
637 | * The surplus_list now contains _at_least_ the number of extra pages | |
638 | * needed to accomodate the reservation. Add the appropriate number | |
639 | * of pages to the hugetlb pool and free the extras back to the buddy | |
ac09b3a1 AL |
640 | * allocator. Commit the entire reservation here to prevent another |
641 | * process from stealing the pages as they are added to the pool but | |
642 | * before they are reserved. | |
e4e574b7 AL |
643 | */ |
644 | needed += allocated; | |
ac09b3a1 | 645 | resv_huge_pages += delta; |
e4e574b7 AL |
646 | ret = 0; |
647 | free: | |
19fc3f0a | 648 | /* Free the needed pages to the hugetlb pool */ |
e4e574b7 | 649 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
19fc3f0a AL |
650 | if ((--needed) < 0) |
651 | break; | |
e4e574b7 | 652 | list_del(&page->lru); |
19fc3f0a AL |
653 | enqueue_huge_page(page); |
654 | } | |
655 | ||
656 | /* Free unnecessary surplus pages to the buddy allocator */ | |
657 | if (!list_empty(&surplus_list)) { | |
658 | spin_unlock(&hugetlb_lock); | |
659 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { | |
660 | list_del(&page->lru); | |
af767cbd | 661 | /* |
2668db91 AL |
662 | * The page has a reference count of zero already, so |
663 | * call free_huge_page directly instead of using | |
664 | * put_page. This must be done with hugetlb_lock | |
af767cbd AL |
665 | * unlocked which is safe because free_huge_page takes |
666 | * hugetlb_lock before deciding how to free the page. | |
667 | */ | |
2668db91 | 668 | free_huge_page(page); |
af767cbd | 669 | } |
19fc3f0a | 670 | spin_lock(&hugetlb_lock); |
e4e574b7 AL |
671 | } |
672 | ||
673 | return ret; | |
674 | } | |
675 | ||
676 | /* | |
677 | * When releasing a hugetlb pool reservation, any surplus pages that were | |
678 | * allocated to satisfy the reservation must be explicitly freed if they were | |
679 | * never used. | |
680 | */ | |
8cde045c | 681 | static void return_unused_surplus_pages(unsigned long unused_resv_pages) |
e4e574b7 AL |
682 | { |
683 | static int nid = -1; | |
684 | struct page *page; | |
685 | unsigned long nr_pages; | |
686 | ||
11320d17 NA |
687 | /* |
688 | * We want to release as many surplus pages as possible, spread | |
689 | * evenly across all nodes. Iterate across all nodes until we | |
690 | * can no longer free unreserved surplus pages. This occurs when | |
691 | * the nodes with surplus pages have no free pages. | |
692 | */ | |
693 | unsigned long remaining_iterations = num_online_nodes(); | |
694 | ||
ac09b3a1 AL |
695 | /* Uncommit the reservation */ |
696 | resv_huge_pages -= unused_resv_pages; | |
697 | ||
e4e574b7 AL |
698 | nr_pages = min(unused_resv_pages, surplus_huge_pages); |
699 | ||
11320d17 | 700 | while (remaining_iterations-- && nr_pages) { |
e4e574b7 AL |
701 | nid = next_node(nid, node_online_map); |
702 | if (nid == MAX_NUMNODES) | |
703 | nid = first_node(node_online_map); | |
704 | ||
705 | if (!surplus_huge_pages_node[nid]) | |
706 | continue; | |
707 | ||
708 | if (!list_empty(&hugepage_freelists[nid])) { | |
709 | page = list_entry(hugepage_freelists[nid].next, | |
710 | struct page, lru); | |
711 | list_del(&page->lru); | |
712 | update_and_free_page(page); | |
713 | free_huge_pages--; | |
714 | free_huge_pages_node[nid]--; | |
715 | surplus_huge_pages--; | |
716 | surplus_huge_pages_node[nid]--; | |
717 | nr_pages--; | |
11320d17 | 718 | remaining_iterations = num_online_nodes(); |
e4e574b7 AL |
719 | } |
720 | } | |
721 | } | |
722 | ||
a1e78772 | 723 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
04f2cbe3 | 724 | unsigned long addr, int avoid_reserve) |
1da177e4 | 725 | { |
348ea204 | 726 | struct page *page; |
a1e78772 MG |
727 | struct address_space *mapping = vma->vm_file->f_mapping; |
728 | struct inode *inode = mapping->host; | |
729 | unsigned int chg = 0; | |
730 | ||
731 | /* | |
732 | * Processes that did not create the mapping will have no reserves and | |
733 | * will not have accounted against quota. Check that the quota can be | |
734 | * made before satisfying the allocation | |
735 | */ | |
04f2cbe3 MG |
736 | if (!(vma->vm_flags & VM_SHARED) && |
737 | !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { | |
a1e78772 MG |
738 | chg = 1; |
739 | if (hugetlb_get_quota(inode->i_mapping, chg)) | |
740 | return ERR_PTR(-ENOSPC); | |
741 | } | |
1da177e4 LT |
742 | |
743 | spin_lock(&hugetlb_lock); | |
04f2cbe3 | 744 | page = dequeue_huge_page_vma(vma, addr, avoid_reserve); |
1da177e4 | 745 | spin_unlock(&hugetlb_lock); |
b45b5bd6 | 746 | |
68842c9b | 747 | if (!page) { |
7893d1d5 | 748 | page = alloc_buddy_huge_page(vma, addr); |
68842c9b | 749 | if (!page) { |
a1e78772 | 750 | hugetlb_put_quota(inode->i_mapping, chg); |
68842c9b KC |
751 | return ERR_PTR(-VM_FAULT_OOM); |
752 | } | |
753 | } | |
348ea204 | 754 | |
a1e78772 MG |
755 | set_page_refcounted(page); |
756 | set_page_private(page, (unsigned long) mapping); | |
90d8b7e6 | 757 | |
90d8b7e6 | 758 | return page; |
b45b5bd6 DG |
759 | } |
760 | ||
1da177e4 LT |
761 | static int __init hugetlb_init(void) |
762 | { | |
763 | unsigned long i; | |
1da177e4 | 764 | |
3c726f8d BH |
765 | if (HPAGE_SHIFT == 0) |
766 | return 0; | |
767 | ||
1da177e4 LT |
768 | for (i = 0; i < MAX_NUMNODES; ++i) |
769 | INIT_LIST_HEAD(&hugepage_freelists[i]); | |
770 | ||
63b4613c NA |
771 | hugetlb_next_nid = first_node(node_online_map); |
772 | ||
1da177e4 | 773 | for (i = 0; i < max_huge_pages; ++i) { |
a482289d | 774 | if (!alloc_fresh_huge_page()) |
1da177e4 | 775 | break; |
1da177e4 LT |
776 | } |
777 | max_huge_pages = free_huge_pages = nr_huge_pages = i; | |
778 | printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); | |
779 | return 0; | |
780 | } | |
781 | module_init(hugetlb_init); | |
782 | ||
783 | static int __init hugetlb_setup(char *s) | |
784 | { | |
785 | if (sscanf(s, "%lu", &max_huge_pages) <= 0) | |
786 | max_huge_pages = 0; | |
787 | return 1; | |
788 | } | |
789 | __setup("hugepages=", hugetlb_setup); | |
790 | ||
8a630112 KC |
791 | static unsigned int cpuset_mems_nr(unsigned int *array) |
792 | { | |
793 | int node; | |
794 | unsigned int nr = 0; | |
795 | ||
796 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
797 | nr += array[node]; | |
798 | ||
799 | return nr; | |
800 | } | |
801 | ||
1da177e4 | 802 | #ifdef CONFIG_SYSCTL |
1da177e4 LT |
803 | #ifdef CONFIG_HIGHMEM |
804 | static void try_to_free_low(unsigned long count) | |
805 | { | |
4415cc8d CL |
806 | int i; |
807 | ||
1da177e4 LT |
808 | for (i = 0; i < MAX_NUMNODES; ++i) { |
809 | struct page *page, *next; | |
810 | list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { | |
6b0c880d AL |
811 | if (count >= nr_huge_pages) |
812 | return; | |
1da177e4 LT |
813 | if (PageHighMem(page)) |
814 | continue; | |
815 | list_del(&page->lru); | |
816 | update_and_free_page(page); | |
1da177e4 | 817 | free_huge_pages--; |
4415cc8d | 818 | free_huge_pages_node[page_to_nid(page)]--; |
1da177e4 LT |
819 | } |
820 | } | |
821 | } | |
822 | #else | |
823 | static inline void try_to_free_low(unsigned long count) | |
824 | { | |
825 | } | |
826 | #endif | |
827 | ||
7893d1d5 | 828 | #define persistent_huge_pages (nr_huge_pages - surplus_huge_pages) |
1da177e4 LT |
829 | static unsigned long set_max_huge_pages(unsigned long count) |
830 | { | |
7893d1d5 | 831 | unsigned long min_count, ret; |
1da177e4 | 832 | |
7893d1d5 AL |
833 | /* |
834 | * Increase the pool size | |
835 | * First take pages out of surplus state. Then make up the | |
836 | * remaining difference by allocating fresh huge pages. | |
d1c3fb1f NA |
837 | * |
838 | * We might race with alloc_buddy_huge_page() here and be unable | |
839 | * to convert a surplus huge page to a normal huge page. That is | |
840 | * not critical, though, it just means the overall size of the | |
841 | * pool might be one hugepage larger than it needs to be, but | |
842 | * within all the constraints specified by the sysctls. | |
7893d1d5 | 843 | */ |
1da177e4 | 844 | spin_lock(&hugetlb_lock); |
7893d1d5 AL |
845 | while (surplus_huge_pages && count > persistent_huge_pages) { |
846 | if (!adjust_pool_surplus(-1)) | |
847 | break; | |
848 | } | |
849 | ||
850 | while (count > persistent_huge_pages) { | |
7893d1d5 AL |
851 | /* |
852 | * If this allocation races such that we no longer need the | |
853 | * page, free_huge_page will handle it by freeing the page | |
854 | * and reducing the surplus. | |
855 | */ | |
856 | spin_unlock(&hugetlb_lock); | |
857 | ret = alloc_fresh_huge_page(); | |
858 | spin_lock(&hugetlb_lock); | |
859 | if (!ret) | |
860 | goto out; | |
861 | ||
862 | } | |
7893d1d5 AL |
863 | |
864 | /* | |
865 | * Decrease the pool size | |
866 | * First return free pages to the buddy allocator (being careful | |
867 | * to keep enough around to satisfy reservations). Then place | |
868 | * pages into surplus state as needed so the pool will shrink | |
869 | * to the desired size as pages become free. | |
d1c3fb1f NA |
870 | * |
871 | * By placing pages into the surplus state independent of the | |
872 | * overcommit value, we are allowing the surplus pool size to | |
873 | * exceed overcommit. There are few sane options here. Since | |
874 | * alloc_buddy_huge_page() is checking the global counter, | |
875 | * though, we'll note that we're not allowed to exceed surplus | |
876 | * and won't grow the pool anywhere else. Not until one of the | |
877 | * sysctls are changed, or the surplus pages go out of use. | |
7893d1d5 | 878 | */ |
6b0c880d AL |
879 | min_count = resv_huge_pages + nr_huge_pages - free_huge_pages; |
880 | min_count = max(count, min_count); | |
7893d1d5 AL |
881 | try_to_free_low(min_count); |
882 | while (min_count < persistent_huge_pages) { | |
348e1e04 | 883 | struct page *page = dequeue_huge_page(); |
1da177e4 LT |
884 | if (!page) |
885 | break; | |
886 | update_and_free_page(page); | |
887 | } | |
7893d1d5 AL |
888 | while (count < persistent_huge_pages) { |
889 | if (!adjust_pool_surplus(1)) | |
890 | break; | |
891 | } | |
892 | out: | |
893 | ret = persistent_huge_pages; | |
1da177e4 | 894 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 895 | return ret; |
1da177e4 LT |
896 | } |
897 | ||
898 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, | |
899 | struct file *file, void __user *buffer, | |
900 | size_t *length, loff_t *ppos) | |
901 | { | |
902 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); | |
903 | max_huge_pages = set_max_huge_pages(max_huge_pages); | |
904 | return 0; | |
905 | } | |
396faf03 MG |
906 | |
907 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, | |
908 | struct file *file, void __user *buffer, | |
909 | size_t *length, loff_t *ppos) | |
910 | { | |
911 | proc_dointvec(table, write, file, buffer, length, ppos); | |
912 | if (hugepages_treat_as_movable) | |
913 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; | |
914 | else | |
915 | htlb_alloc_mask = GFP_HIGHUSER; | |
916 | return 0; | |
917 | } | |
918 | ||
a3d0c6aa NA |
919 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
920 | struct file *file, void __user *buffer, | |
921 | size_t *length, loff_t *ppos) | |
922 | { | |
a3d0c6aa | 923 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
064d9efe NA |
924 | spin_lock(&hugetlb_lock); |
925 | nr_overcommit_huge_pages = sysctl_overcommit_huge_pages; | |
a3d0c6aa NA |
926 | spin_unlock(&hugetlb_lock); |
927 | return 0; | |
928 | } | |
929 | ||
1da177e4 LT |
930 | #endif /* CONFIG_SYSCTL */ |
931 | ||
932 | int hugetlb_report_meminfo(char *buf) | |
933 | { | |
934 | return sprintf(buf, | |
935 | "HugePages_Total: %5lu\n" | |
936 | "HugePages_Free: %5lu\n" | |
a43a8c39 | 937 | "HugePages_Rsvd: %5lu\n" |
7893d1d5 | 938 | "HugePages_Surp: %5lu\n" |
1da177e4 LT |
939 | "Hugepagesize: %5lu kB\n", |
940 | nr_huge_pages, | |
941 | free_huge_pages, | |
a43a8c39 | 942 | resv_huge_pages, |
7893d1d5 | 943 | surplus_huge_pages, |
1da177e4 LT |
944 | HPAGE_SIZE/1024); |
945 | } | |
946 | ||
947 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
948 | { | |
949 | return sprintf(buf, | |
950 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
951 | "Node %d HugePages_Free: %5u\n" |
952 | "Node %d HugePages_Surp: %5u\n", | |
1da177e4 | 953 | nid, nr_huge_pages_node[nid], |
a1de0919 NA |
954 | nid, free_huge_pages_node[nid], |
955 | nid, surplus_huge_pages_node[nid]); | |
1da177e4 LT |
956 | } |
957 | ||
1da177e4 LT |
958 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
959 | unsigned long hugetlb_total_pages(void) | |
960 | { | |
961 | return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); | |
962 | } | |
1da177e4 | 963 | |
fc1b8a73 MG |
964 | static int hugetlb_acct_memory(long delta) |
965 | { | |
966 | int ret = -ENOMEM; | |
967 | ||
968 | spin_lock(&hugetlb_lock); | |
969 | /* | |
970 | * When cpuset is configured, it breaks the strict hugetlb page | |
971 | * reservation as the accounting is done on a global variable. Such | |
972 | * reservation is completely rubbish in the presence of cpuset because | |
973 | * the reservation is not checked against page availability for the | |
974 | * current cpuset. Application can still potentially OOM'ed by kernel | |
975 | * with lack of free htlb page in cpuset that the task is in. | |
976 | * Attempt to enforce strict accounting with cpuset is almost | |
977 | * impossible (or too ugly) because cpuset is too fluid that | |
978 | * task or memory node can be dynamically moved between cpusets. | |
979 | * | |
980 | * The change of semantics for shared hugetlb mapping with cpuset is | |
981 | * undesirable. However, in order to preserve some of the semantics, | |
982 | * we fall back to check against current free page availability as | |
983 | * a best attempt and hopefully to minimize the impact of changing | |
984 | * semantics that cpuset has. | |
985 | */ | |
986 | if (delta > 0) { | |
987 | if (gather_surplus_pages(delta) < 0) | |
988 | goto out; | |
989 | ||
990 | if (delta > cpuset_mems_nr(free_huge_pages_node)) { | |
991 | return_unused_surplus_pages(delta); | |
992 | goto out; | |
993 | } | |
994 | } | |
995 | ||
996 | ret = 0; | |
997 | if (delta < 0) | |
998 | return_unused_surplus_pages((unsigned long) -delta); | |
999 | ||
1000 | out: | |
1001 | spin_unlock(&hugetlb_lock); | |
1002 | return ret; | |
1003 | } | |
1004 | ||
a1e78772 MG |
1005 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
1006 | { | |
1007 | unsigned long reserve = vma_resv_huge_pages(vma); | |
1008 | if (reserve) | |
1009 | hugetlb_acct_memory(-reserve); | |
1010 | } | |
1011 | ||
1da177e4 LT |
1012 | /* |
1013 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
1014 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
1015 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
1016 | * this far. | |
1017 | */ | |
d0217ac0 | 1018 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
1019 | { |
1020 | BUG(); | |
d0217ac0 | 1021 | return 0; |
1da177e4 LT |
1022 | } |
1023 | ||
1024 | struct vm_operations_struct hugetlb_vm_ops = { | |
d0217ac0 | 1025 | .fault = hugetlb_vm_op_fault, |
a1e78772 | 1026 | .close = hugetlb_vm_op_close, |
1da177e4 LT |
1027 | }; |
1028 | ||
1e8f889b DG |
1029 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
1030 | int writable) | |
63551ae0 DG |
1031 | { |
1032 | pte_t entry; | |
1033 | ||
1e8f889b | 1034 | if (writable) { |
63551ae0 DG |
1035 | entry = |
1036 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
1037 | } else { | |
7f2e9525 | 1038 | entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
63551ae0 DG |
1039 | } |
1040 | entry = pte_mkyoung(entry); | |
1041 | entry = pte_mkhuge(entry); | |
1042 | ||
1043 | return entry; | |
1044 | } | |
1045 | ||
1e8f889b DG |
1046 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
1047 | unsigned long address, pte_t *ptep) | |
1048 | { | |
1049 | pte_t entry; | |
1050 | ||
7f2e9525 GS |
1051 | entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); |
1052 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { | |
8dab5241 | 1053 | update_mmu_cache(vma, address, entry); |
8dab5241 | 1054 | } |
1e8f889b DG |
1055 | } |
1056 | ||
1057 | ||
63551ae0 DG |
1058 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
1059 | struct vm_area_struct *vma) | |
1060 | { | |
1061 | pte_t *src_pte, *dst_pte, entry; | |
1062 | struct page *ptepage; | |
1c59827d | 1063 | unsigned long addr; |
1e8f889b DG |
1064 | int cow; |
1065 | ||
1066 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 1067 | |
1c59827d | 1068 | for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) { |
c74df32c HD |
1069 | src_pte = huge_pte_offset(src, addr); |
1070 | if (!src_pte) | |
1071 | continue; | |
63551ae0 DG |
1072 | dst_pte = huge_pte_alloc(dst, addr); |
1073 | if (!dst_pte) | |
1074 | goto nomem; | |
c5c99429 LW |
1075 | |
1076 | /* If the pagetables are shared don't copy or take references */ | |
1077 | if (dst_pte == src_pte) | |
1078 | continue; | |
1079 | ||
c74df32c | 1080 | spin_lock(&dst->page_table_lock); |
46478758 | 1081 | spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); |
7f2e9525 | 1082 | if (!huge_pte_none(huge_ptep_get(src_pte))) { |
1e8f889b | 1083 | if (cow) |
7f2e9525 GS |
1084 | huge_ptep_set_wrprotect(src, addr, src_pte); |
1085 | entry = huge_ptep_get(src_pte); | |
1c59827d HD |
1086 | ptepage = pte_page(entry); |
1087 | get_page(ptepage); | |
1c59827d HD |
1088 | set_huge_pte_at(dst, addr, dst_pte, entry); |
1089 | } | |
1090 | spin_unlock(&src->page_table_lock); | |
c74df32c | 1091 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
1092 | } |
1093 | return 0; | |
1094 | ||
1095 | nomem: | |
1096 | return -ENOMEM; | |
1097 | } | |
1098 | ||
502717f4 | 1099 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1100 | unsigned long end, struct page *ref_page) |
63551ae0 DG |
1101 | { |
1102 | struct mm_struct *mm = vma->vm_mm; | |
1103 | unsigned long address; | |
c7546f8f | 1104 | pte_t *ptep; |
63551ae0 DG |
1105 | pte_t pte; |
1106 | struct page *page; | |
fe1668ae | 1107 | struct page *tmp; |
c0a499c2 KC |
1108 | /* |
1109 | * A page gathering list, protected by per file i_mmap_lock. The | |
1110 | * lock is used to avoid list corruption from multiple unmapping | |
1111 | * of the same page since we are using page->lru. | |
1112 | */ | |
fe1668ae | 1113 | LIST_HEAD(page_list); |
63551ae0 DG |
1114 | |
1115 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
1116 | BUG_ON(start & ~HPAGE_MASK); | |
1117 | BUG_ON(end & ~HPAGE_MASK); | |
1118 | ||
508034a3 | 1119 | spin_lock(&mm->page_table_lock); |
63551ae0 | 1120 | for (address = start; address < end; address += HPAGE_SIZE) { |
c7546f8f | 1121 | ptep = huge_pte_offset(mm, address); |
4c887265 | 1122 | if (!ptep) |
c7546f8f DG |
1123 | continue; |
1124 | ||
39dde65c KC |
1125 | if (huge_pmd_unshare(mm, &address, ptep)) |
1126 | continue; | |
1127 | ||
04f2cbe3 MG |
1128 | /* |
1129 | * If a reference page is supplied, it is because a specific | |
1130 | * page is being unmapped, not a range. Ensure the page we | |
1131 | * are about to unmap is the actual page of interest. | |
1132 | */ | |
1133 | if (ref_page) { | |
1134 | pte = huge_ptep_get(ptep); | |
1135 | if (huge_pte_none(pte)) | |
1136 | continue; | |
1137 | page = pte_page(pte); | |
1138 | if (page != ref_page) | |
1139 | continue; | |
1140 | ||
1141 | /* | |
1142 | * Mark the VMA as having unmapped its page so that | |
1143 | * future faults in this VMA will fail rather than | |
1144 | * looking like data was lost | |
1145 | */ | |
1146 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); | |
1147 | } | |
1148 | ||
c7546f8f | 1149 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
7f2e9525 | 1150 | if (huge_pte_none(pte)) |
63551ae0 | 1151 | continue; |
c7546f8f | 1152 | |
63551ae0 | 1153 | page = pte_page(pte); |
6649a386 KC |
1154 | if (pte_dirty(pte)) |
1155 | set_page_dirty(page); | |
fe1668ae | 1156 | list_add(&page->lru, &page_list); |
63551ae0 | 1157 | } |
1da177e4 | 1158 | spin_unlock(&mm->page_table_lock); |
508034a3 | 1159 | flush_tlb_range(vma, start, end); |
fe1668ae KC |
1160 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
1161 | list_del(&page->lru); | |
1162 | put_page(page); | |
1163 | } | |
1da177e4 | 1164 | } |
63551ae0 | 1165 | |
502717f4 | 1166 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1167 | unsigned long end, struct page *ref_page) |
502717f4 KC |
1168 | { |
1169 | /* | |
1170 | * It is undesirable to test vma->vm_file as it should be non-null | |
1171 | * for valid hugetlb area. However, vm_file will be NULL in the error | |
1172 | * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, | |
1173 | * do_mmap_pgoff() nullifies vma->vm_file before calling this function | |
1174 | * to clean up. Since no pte has actually been setup, it is safe to | |
1175 | * do nothing in this case. | |
1176 | */ | |
1177 | if (vma->vm_file) { | |
1178 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); | |
04f2cbe3 | 1179 | __unmap_hugepage_range(vma, start, end, ref_page); |
502717f4 KC |
1180 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
1181 | } | |
1182 | } | |
1183 | ||
04f2cbe3 MG |
1184 | /* |
1185 | * This is called when the original mapper is failing to COW a MAP_PRIVATE | |
1186 | * mappping it owns the reserve page for. The intention is to unmap the page | |
1187 | * from other VMAs and let the children be SIGKILLed if they are faulting the | |
1188 | * same region. | |
1189 | */ | |
1190 | int unmap_ref_private(struct mm_struct *mm, | |
1191 | struct vm_area_struct *vma, | |
1192 | struct page *page, | |
1193 | unsigned long address) | |
1194 | { | |
1195 | struct vm_area_struct *iter_vma; | |
1196 | struct address_space *mapping; | |
1197 | struct prio_tree_iter iter; | |
1198 | pgoff_t pgoff; | |
1199 | ||
1200 | /* | |
1201 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation | |
1202 | * from page cache lookup which is in HPAGE_SIZE units. | |
1203 | */ | |
1204 | address = address & huge_page_mask(hstate_vma(vma)); | |
1205 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) | |
1206 | + (vma->vm_pgoff >> PAGE_SHIFT); | |
1207 | mapping = (struct address_space *)page_private(page); | |
1208 | ||
1209 | vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { | |
1210 | /* Do not unmap the current VMA */ | |
1211 | if (iter_vma == vma) | |
1212 | continue; | |
1213 | ||
1214 | /* | |
1215 | * Unmap the page from other VMAs without their own reserves. | |
1216 | * They get marked to be SIGKILLed if they fault in these | |
1217 | * areas. This is because a future no-page fault on this VMA | |
1218 | * could insert a zeroed page instead of the data existing | |
1219 | * from the time of fork. This would look like data corruption | |
1220 | */ | |
1221 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) | |
1222 | unmap_hugepage_range(iter_vma, | |
1223 | address, address + HPAGE_SIZE, | |
1224 | page); | |
1225 | } | |
1226 | ||
1227 | return 1; | |
1228 | } | |
1229 | ||
1e8f889b | 1230 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
04f2cbe3 MG |
1231 | unsigned long address, pte_t *ptep, pte_t pte, |
1232 | struct page *pagecache_page) | |
1e8f889b DG |
1233 | { |
1234 | struct page *old_page, *new_page; | |
79ac6ba4 | 1235 | int avoidcopy; |
04f2cbe3 | 1236 | int outside_reserve = 0; |
1e8f889b DG |
1237 | |
1238 | old_page = pte_page(pte); | |
1239 | ||
04f2cbe3 | 1240 | retry_avoidcopy: |
1e8f889b DG |
1241 | /* If no-one else is actually using this page, avoid the copy |
1242 | * and just make the page writable */ | |
1243 | avoidcopy = (page_count(old_page) == 1); | |
1244 | if (avoidcopy) { | |
1245 | set_huge_ptep_writable(vma, address, ptep); | |
83c54070 | 1246 | return 0; |
1e8f889b DG |
1247 | } |
1248 | ||
04f2cbe3 MG |
1249 | /* |
1250 | * If the process that created a MAP_PRIVATE mapping is about to | |
1251 | * perform a COW due to a shared page count, attempt to satisfy | |
1252 | * the allocation without using the existing reserves. The pagecache | |
1253 | * page is used to determine if the reserve at this address was | |
1254 | * consumed or not. If reserves were used, a partial faulted mapping | |
1255 | * at the time of fork() could consume its reserves on COW instead | |
1256 | * of the full address range. | |
1257 | */ | |
1258 | if (!(vma->vm_flags & VM_SHARED) && | |
1259 | is_vma_resv_set(vma, HPAGE_RESV_OWNER) && | |
1260 | old_page != pagecache_page) | |
1261 | outside_reserve = 1; | |
1262 | ||
1e8f889b | 1263 | page_cache_get(old_page); |
04f2cbe3 | 1264 | new_page = alloc_huge_page(vma, address, outside_reserve); |
1e8f889b | 1265 | |
2fc39cec | 1266 | if (IS_ERR(new_page)) { |
1e8f889b | 1267 | page_cache_release(old_page); |
04f2cbe3 MG |
1268 | |
1269 | /* | |
1270 | * If a process owning a MAP_PRIVATE mapping fails to COW, | |
1271 | * it is due to references held by a child and an insufficient | |
1272 | * huge page pool. To guarantee the original mappers | |
1273 | * reliability, unmap the page from child processes. The child | |
1274 | * may get SIGKILLed if it later faults. | |
1275 | */ | |
1276 | if (outside_reserve) { | |
1277 | BUG_ON(huge_pte_none(pte)); | |
1278 | if (unmap_ref_private(mm, vma, old_page, address)) { | |
1279 | BUG_ON(page_count(old_page) != 1); | |
1280 | BUG_ON(huge_pte_none(pte)); | |
1281 | goto retry_avoidcopy; | |
1282 | } | |
1283 | WARN_ON_ONCE(1); | |
1284 | } | |
1285 | ||
2fc39cec | 1286 | return -PTR_ERR(new_page); |
1e8f889b DG |
1287 | } |
1288 | ||
1289 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 1290 | copy_huge_page(new_page, old_page, address, vma); |
0ed361de | 1291 | __SetPageUptodate(new_page); |
1e8f889b DG |
1292 | spin_lock(&mm->page_table_lock); |
1293 | ||
1294 | ptep = huge_pte_offset(mm, address & HPAGE_MASK); | |
7f2e9525 | 1295 | if (likely(pte_same(huge_ptep_get(ptep), pte))) { |
1e8f889b | 1296 | /* Break COW */ |
8fe627ec | 1297 | huge_ptep_clear_flush(vma, address, ptep); |
1e8f889b DG |
1298 | set_huge_pte_at(mm, address, ptep, |
1299 | make_huge_pte(vma, new_page, 1)); | |
1300 | /* Make the old page be freed below */ | |
1301 | new_page = old_page; | |
1302 | } | |
1303 | page_cache_release(new_page); | |
1304 | page_cache_release(old_page); | |
83c54070 | 1305 | return 0; |
1e8f889b DG |
1306 | } |
1307 | ||
04f2cbe3 MG |
1308 | /* Return the pagecache page at a given address within a VMA */ |
1309 | static struct page *hugetlbfs_pagecache_page(struct vm_area_struct *vma, | |
1310 | unsigned long address) | |
1311 | { | |
1312 | struct address_space *mapping; | |
e7c4b0bf | 1313 | pgoff_t idx; |
04f2cbe3 MG |
1314 | |
1315 | mapping = vma->vm_file->f_mapping; | |
e7c4b0bf | 1316 | idx = vma_pagecache_offset(vma, address); |
04f2cbe3 MG |
1317 | |
1318 | return find_lock_page(mapping, idx); | |
1319 | } | |
1320 | ||
a1ed3dda | 1321 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 1322 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 HD |
1323 | { |
1324 | int ret = VM_FAULT_SIGBUS; | |
e7c4b0bf | 1325 | pgoff_t idx; |
4c887265 | 1326 | unsigned long size; |
4c887265 AL |
1327 | struct page *page; |
1328 | struct address_space *mapping; | |
1e8f889b | 1329 | pte_t new_pte; |
4c887265 | 1330 | |
04f2cbe3 MG |
1331 | /* |
1332 | * Currently, we are forced to kill the process in the event the | |
1333 | * original mapper has unmapped pages from the child due to a failed | |
1334 | * COW. Warn that such a situation has occured as it may not be obvious | |
1335 | */ | |
1336 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { | |
1337 | printk(KERN_WARNING | |
1338 | "PID %d killed due to inadequate hugepage pool\n", | |
1339 | current->pid); | |
1340 | return ret; | |
1341 | } | |
1342 | ||
4c887265 | 1343 | mapping = vma->vm_file->f_mapping; |
e7c4b0bf | 1344 | idx = vma_pagecache_offset(vma, address); |
4c887265 AL |
1345 | |
1346 | /* | |
1347 | * Use page lock to guard against racing truncation | |
1348 | * before we get page_table_lock. | |
1349 | */ | |
6bda666a CL |
1350 | retry: |
1351 | page = find_lock_page(mapping, idx); | |
1352 | if (!page) { | |
ebed4bfc HD |
1353 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
1354 | if (idx >= size) | |
1355 | goto out; | |
04f2cbe3 | 1356 | page = alloc_huge_page(vma, address, 0); |
2fc39cec AL |
1357 | if (IS_ERR(page)) { |
1358 | ret = -PTR_ERR(page); | |
6bda666a CL |
1359 | goto out; |
1360 | } | |
79ac6ba4 | 1361 | clear_huge_page(page, address); |
0ed361de | 1362 | __SetPageUptodate(page); |
ac9b9c66 | 1363 | |
6bda666a CL |
1364 | if (vma->vm_flags & VM_SHARED) { |
1365 | int err; | |
45c682a6 | 1366 | struct inode *inode = mapping->host; |
6bda666a CL |
1367 | |
1368 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
1369 | if (err) { | |
1370 | put_page(page); | |
6bda666a CL |
1371 | if (err == -EEXIST) |
1372 | goto retry; | |
1373 | goto out; | |
1374 | } | |
45c682a6 KC |
1375 | |
1376 | spin_lock(&inode->i_lock); | |
1377 | inode->i_blocks += BLOCKS_PER_HUGEPAGE; | |
1378 | spin_unlock(&inode->i_lock); | |
6bda666a CL |
1379 | } else |
1380 | lock_page(page); | |
1381 | } | |
1e8f889b | 1382 | |
ac9b9c66 | 1383 | spin_lock(&mm->page_table_lock); |
4c887265 AL |
1384 | size = i_size_read(mapping->host) >> HPAGE_SHIFT; |
1385 | if (idx >= size) | |
1386 | goto backout; | |
1387 | ||
83c54070 | 1388 | ret = 0; |
7f2e9525 | 1389 | if (!huge_pte_none(huge_ptep_get(ptep))) |
4c887265 AL |
1390 | goto backout; |
1391 | ||
1e8f889b DG |
1392 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
1393 | && (vma->vm_flags & VM_SHARED))); | |
1394 | set_huge_pte_at(mm, address, ptep, new_pte); | |
1395 | ||
1396 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
1397 | /* Optimization, do the COW without a second fault */ | |
04f2cbe3 | 1398 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); |
1e8f889b DG |
1399 | } |
1400 | ||
ac9b9c66 | 1401 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
1402 | unlock_page(page); |
1403 | out: | |
ac9b9c66 | 1404 | return ret; |
4c887265 AL |
1405 | |
1406 | backout: | |
1407 | spin_unlock(&mm->page_table_lock); | |
4c887265 AL |
1408 | unlock_page(page); |
1409 | put_page(page); | |
1410 | goto out; | |
ac9b9c66 HD |
1411 | } |
1412 | ||
86e5216f AL |
1413 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
1414 | unsigned long address, int write_access) | |
1415 | { | |
1416 | pte_t *ptep; | |
1417 | pte_t entry; | |
1e8f889b | 1418 | int ret; |
3935baa9 | 1419 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
86e5216f AL |
1420 | |
1421 | ptep = huge_pte_alloc(mm, address); | |
1422 | if (!ptep) | |
1423 | return VM_FAULT_OOM; | |
1424 | ||
3935baa9 DG |
1425 | /* |
1426 | * Serialize hugepage allocation and instantiation, so that we don't | |
1427 | * get spurious allocation failures if two CPUs race to instantiate | |
1428 | * the same page in the page cache. | |
1429 | */ | |
1430 | mutex_lock(&hugetlb_instantiation_mutex); | |
7f2e9525 GS |
1431 | entry = huge_ptep_get(ptep); |
1432 | if (huge_pte_none(entry)) { | |
3935baa9 DG |
1433 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); |
1434 | mutex_unlock(&hugetlb_instantiation_mutex); | |
1435 | return ret; | |
1436 | } | |
86e5216f | 1437 | |
83c54070 | 1438 | ret = 0; |
1e8f889b DG |
1439 | |
1440 | spin_lock(&mm->page_table_lock); | |
1441 | /* Check for a racing update before calling hugetlb_cow */ | |
7f2e9525 | 1442 | if (likely(pte_same(entry, huge_ptep_get(ptep)))) |
04f2cbe3 MG |
1443 | if (write_access && !pte_write(entry)) { |
1444 | struct page *page; | |
1445 | page = hugetlbfs_pagecache_page(vma, address); | |
1446 | ret = hugetlb_cow(mm, vma, address, ptep, entry, page); | |
1447 | if (page) { | |
1448 | unlock_page(page); | |
1449 | put_page(page); | |
1450 | } | |
1451 | } | |
1e8f889b | 1452 | spin_unlock(&mm->page_table_lock); |
3935baa9 | 1453 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
1454 | |
1455 | return ret; | |
86e5216f AL |
1456 | } |
1457 | ||
63551ae0 DG |
1458 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1459 | struct page **pages, struct vm_area_struct **vmas, | |
5b23dbe8 AL |
1460 | unsigned long *position, int *length, int i, |
1461 | int write) | |
63551ae0 | 1462 | { |
d5d4b0aa KC |
1463 | unsigned long pfn_offset; |
1464 | unsigned long vaddr = *position; | |
63551ae0 DG |
1465 | int remainder = *length; |
1466 | ||
1c59827d | 1467 | spin_lock(&mm->page_table_lock); |
63551ae0 | 1468 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
1469 | pte_t *pte; |
1470 | struct page *page; | |
63551ae0 | 1471 | |
4c887265 AL |
1472 | /* |
1473 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
1474 | * each hugepage. We have to make * sure we get the | |
1475 | * first, for the page indexing below to work. | |
1476 | */ | |
1477 | pte = huge_pte_offset(mm, vaddr & HPAGE_MASK); | |
63551ae0 | 1478 | |
7f2e9525 GS |
1479 | if (!pte || huge_pte_none(huge_ptep_get(pte)) || |
1480 | (write && !pte_write(huge_ptep_get(pte)))) { | |
4c887265 | 1481 | int ret; |
63551ae0 | 1482 | |
4c887265 | 1483 | spin_unlock(&mm->page_table_lock); |
5b23dbe8 | 1484 | ret = hugetlb_fault(mm, vma, vaddr, write); |
4c887265 | 1485 | spin_lock(&mm->page_table_lock); |
a89182c7 | 1486 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 1487 | continue; |
63551ae0 | 1488 | |
4c887265 AL |
1489 | remainder = 0; |
1490 | if (!i) | |
1491 | i = -EFAULT; | |
1492 | break; | |
1493 | } | |
1494 | ||
d5d4b0aa | 1495 | pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT; |
7f2e9525 | 1496 | page = pte_page(huge_ptep_get(pte)); |
d5d4b0aa | 1497 | same_page: |
d6692183 KC |
1498 | if (pages) { |
1499 | get_page(page); | |
d5d4b0aa | 1500 | pages[i] = page + pfn_offset; |
d6692183 | 1501 | } |
63551ae0 DG |
1502 | |
1503 | if (vmas) | |
1504 | vmas[i] = vma; | |
1505 | ||
1506 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 1507 | ++pfn_offset; |
63551ae0 DG |
1508 | --remainder; |
1509 | ++i; | |
d5d4b0aa KC |
1510 | if (vaddr < vma->vm_end && remainder && |
1511 | pfn_offset < HPAGE_SIZE/PAGE_SIZE) { | |
1512 | /* | |
1513 | * We use pfn_offset to avoid touching the pageframes | |
1514 | * of this compound page. | |
1515 | */ | |
1516 | goto same_page; | |
1517 | } | |
63551ae0 | 1518 | } |
1c59827d | 1519 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
1520 | *length = remainder; |
1521 | *position = vaddr; | |
1522 | ||
1523 | return i; | |
1524 | } | |
8f860591 ZY |
1525 | |
1526 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
1527 | unsigned long address, unsigned long end, pgprot_t newprot) | |
1528 | { | |
1529 | struct mm_struct *mm = vma->vm_mm; | |
1530 | unsigned long start = address; | |
1531 | pte_t *ptep; | |
1532 | pte_t pte; | |
1533 | ||
1534 | BUG_ON(address >= end); | |
1535 | flush_cache_range(vma, address, end); | |
1536 | ||
39dde65c | 1537 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
1538 | spin_lock(&mm->page_table_lock); |
1539 | for (; address < end; address += HPAGE_SIZE) { | |
1540 | ptep = huge_pte_offset(mm, address); | |
1541 | if (!ptep) | |
1542 | continue; | |
39dde65c KC |
1543 | if (huge_pmd_unshare(mm, &address, ptep)) |
1544 | continue; | |
7f2e9525 | 1545 | if (!huge_pte_none(huge_ptep_get(ptep))) { |
8f860591 ZY |
1546 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
1547 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
1548 | set_huge_pte_at(mm, address, ptep, pte); | |
8f860591 ZY |
1549 | } |
1550 | } | |
1551 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 1552 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
1553 | |
1554 | flush_tlb_range(vma, start, end); | |
1555 | } | |
1556 | ||
a1e78772 MG |
1557 | int hugetlb_reserve_pages(struct inode *inode, |
1558 | long from, long to, | |
1559 | struct vm_area_struct *vma) | |
e4e574b7 AL |
1560 | { |
1561 | long ret, chg; | |
1562 | ||
a1e78772 MG |
1563 | /* |
1564 | * Shared mappings base their reservation on the number of pages that | |
1565 | * are already allocated on behalf of the file. Private mappings need | |
1566 | * to reserve the full area even if read-only as mprotect() may be | |
1567 | * called to make the mapping read-write. Assume !vma is a shm mapping | |
1568 | */ | |
1569 | if (!vma || vma->vm_flags & VM_SHARED) | |
1570 | chg = region_chg(&inode->i_mapping->private_list, from, to); | |
1571 | else { | |
1572 | chg = to - from; | |
1573 | set_vma_resv_huge_pages(vma, chg); | |
04f2cbe3 | 1574 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); |
a1e78772 MG |
1575 | } |
1576 | ||
e4e574b7 AL |
1577 | if (chg < 0) |
1578 | return chg; | |
8a630112 | 1579 | |
90d8b7e6 AL |
1580 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
1581 | return -ENOSPC; | |
a43a8c39 | 1582 | ret = hugetlb_acct_memory(chg); |
68842c9b KC |
1583 | if (ret < 0) { |
1584 | hugetlb_put_quota(inode->i_mapping, chg); | |
a43a8c39 | 1585 | return ret; |
68842c9b | 1586 | } |
a1e78772 MG |
1587 | if (!vma || vma->vm_flags & VM_SHARED) |
1588 | region_add(&inode->i_mapping->private_list, from, to); | |
a43a8c39 KC |
1589 | return 0; |
1590 | } | |
1591 | ||
1592 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
1593 | { | |
1594 | long chg = region_truncate(&inode->i_mapping->private_list, offset); | |
45c682a6 KC |
1595 | |
1596 | spin_lock(&inode->i_lock); | |
1597 | inode->i_blocks -= BLOCKS_PER_HUGEPAGE * freed; | |
1598 | spin_unlock(&inode->i_lock); | |
1599 | ||
90d8b7e6 AL |
1600 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
1601 | hugetlb_acct_memory(-(chg - freed)); | |
a43a8c39 | 1602 | } |