Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Generic hugetlb support. | |
3 | * (C) William Irwin, April 2004 | |
4 | */ | |
5 | #include <linux/gfp.h> | |
6 | #include <linux/list.h> | |
7 | #include <linux/init.h> | |
8 | #include <linux/module.h> | |
9 | #include <linux/mm.h> | |
1da177e4 LT |
10 | #include <linux/sysctl.h> |
11 | #include <linux/highmem.h> | |
12 | #include <linux/nodemask.h> | |
63551ae0 | 13 | #include <linux/pagemap.h> |
5da7ca86 | 14 | #include <linux/mempolicy.h> |
aea47ff3 | 15 | #include <linux/cpuset.h> |
3935baa9 | 16 | #include <linux/mutex.h> |
aa888a74 | 17 | #include <linux/bootmem.h> |
a3437870 | 18 | #include <linux/sysfs.h> |
5da7ca86 | 19 | |
63551ae0 DG |
20 | #include <asm/page.h> |
21 | #include <asm/pgtable.h> | |
22 | ||
23 | #include <linux/hugetlb.h> | |
7835e98b | 24 | #include "internal.h" |
1da177e4 LT |
25 | |
26 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; | |
396faf03 MG |
27 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
28 | unsigned long hugepages_treat_as_movable; | |
a5516438 | 29 | |
e5ff2159 AK |
30 | static int max_hstate; |
31 | unsigned int default_hstate_idx; | |
32 | struct hstate hstates[HUGE_MAX_HSTATE]; | |
33 | ||
34 | /* for command line parsing */ | |
35 | static struct hstate * __initdata parsed_hstate; | |
36 | static unsigned long __initdata default_hstate_max_huge_pages; | |
37 | ||
38 | #define for_each_hstate(h) \ | |
39 | for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++) | |
396faf03 | 40 | |
3935baa9 DG |
41 | /* |
42 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages | |
43 | */ | |
44 | static DEFINE_SPINLOCK(hugetlb_lock); | |
0bd0f9fb | 45 | |
96822904 AW |
46 | /* |
47 | * Region tracking -- allows tracking of reservations and instantiated pages | |
48 | * across the pages in a mapping. | |
84afd99b AW |
49 | * |
50 | * The region data structures are protected by a combination of the mmap_sem | |
51 | * and the hugetlb_instantion_mutex. To access or modify a region the caller | |
52 | * must either hold the mmap_sem for write, or the mmap_sem for read and | |
53 | * the hugetlb_instantiation mutex: | |
54 | * | |
55 | * down_write(&mm->mmap_sem); | |
56 | * or | |
57 | * down_read(&mm->mmap_sem); | |
58 | * mutex_lock(&hugetlb_instantiation_mutex); | |
96822904 AW |
59 | */ |
60 | struct file_region { | |
61 | struct list_head link; | |
62 | long from; | |
63 | long to; | |
64 | }; | |
65 | ||
66 | static long region_add(struct list_head *head, long f, long t) | |
67 | { | |
68 | struct file_region *rg, *nrg, *trg; | |
69 | ||
70 | /* Locate the region we are either in or before. */ | |
71 | list_for_each_entry(rg, head, link) | |
72 | if (f <= rg->to) | |
73 | break; | |
74 | ||
75 | /* Round our left edge to the current segment if it encloses us. */ | |
76 | if (f > rg->from) | |
77 | f = rg->from; | |
78 | ||
79 | /* Check for and consume any regions we now overlap with. */ | |
80 | nrg = rg; | |
81 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
82 | if (&rg->link == head) | |
83 | break; | |
84 | if (rg->from > t) | |
85 | break; | |
86 | ||
87 | /* If this area reaches higher then extend our area to | |
88 | * include it completely. If this is not the first area | |
89 | * which we intend to reuse, free it. */ | |
90 | if (rg->to > t) | |
91 | t = rg->to; | |
92 | if (rg != nrg) { | |
93 | list_del(&rg->link); | |
94 | kfree(rg); | |
95 | } | |
96 | } | |
97 | nrg->from = f; | |
98 | nrg->to = t; | |
99 | return 0; | |
100 | } | |
101 | ||
102 | static long region_chg(struct list_head *head, long f, long t) | |
103 | { | |
104 | struct file_region *rg, *nrg; | |
105 | long chg = 0; | |
106 | ||
107 | /* Locate the region we are before or in. */ | |
108 | list_for_each_entry(rg, head, link) | |
109 | if (f <= rg->to) | |
110 | break; | |
111 | ||
112 | /* If we are below the current region then a new region is required. | |
113 | * Subtle, allocate a new region at the position but make it zero | |
114 | * size such that we can guarantee to record the reservation. */ | |
115 | if (&rg->link == head || t < rg->from) { | |
116 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
117 | if (!nrg) | |
118 | return -ENOMEM; | |
119 | nrg->from = f; | |
120 | nrg->to = f; | |
121 | INIT_LIST_HEAD(&nrg->link); | |
122 | list_add(&nrg->link, rg->link.prev); | |
123 | ||
124 | return t - f; | |
125 | } | |
126 | ||
127 | /* Round our left edge to the current segment if it encloses us. */ | |
128 | if (f > rg->from) | |
129 | f = rg->from; | |
130 | chg = t - f; | |
131 | ||
132 | /* Check for and consume any regions we now overlap with. */ | |
133 | list_for_each_entry(rg, rg->link.prev, link) { | |
134 | if (&rg->link == head) | |
135 | break; | |
136 | if (rg->from > t) | |
137 | return chg; | |
138 | ||
139 | /* We overlap with this area, if it extends futher than | |
140 | * us then we must extend ourselves. Account for its | |
141 | * existing reservation. */ | |
142 | if (rg->to > t) { | |
143 | chg += rg->to - t; | |
144 | t = rg->to; | |
145 | } | |
146 | chg -= rg->to - rg->from; | |
147 | } | |
148 | return chg; | |
149 | } | |
150 | ||
151 | static long region_truncate(struct list_head *head, long end) | |
152 | { | |
153 | struct file_region *rg, *trg; | |
154 | long chg = 0; | |
155 | ||
156 | /* Locate the region we are either in or before. */ | |
157 | list_for_each_entry(rg, head, link) | |
158 | if (end <= rg->to) | |
159 | break; | |
160 | if (&rg->link == head) | |
161 | return 0; | |
162 | ||
163 | /* If we are in the middle of a region then adjust it. */ | |
164 | if (end > rg->from) { | |
165 | chg = rg->to - end; | |
166 | rg->to = end; | |
167 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
168 | } | |
169 | ||
170 | /* Drop any remaining regions. */ | |
171 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
172 | if (&rg->link == head) | |
173 | break; | |
174 | chg += rg->to - rg->from; | |
175 | list_del(&rg->link); | |
176 | kfree(rg); | |
177 | } | |
178 | return chg; | |
179 | } | |
180 | ||
84afd99b AW |
181 | static long region_count(struct list_head *head, long f, long t) |
182 | { | |
183 | struct file_region *rg; | |
184 | long chg = 0; | |
185 | ||
186 | /* Locate each segment we overlap with, and count that overlap. */ | |
187 | list_for_each_entry(rg, head, link) { | |
188 | int seg_from; | |
189 | int seg_to; | |
190 | ||
191 | if (rg->to <= f) | |
192 | continue; | |
193 | if (rg->from >= t) | |
194 | break; | |
195 | ||
196 | seg_from = max(rg->from, f); | |
197 | seg_to = min(rg->to, t); | |
198 | ||
199 | chg += seg_to - seg_from; | |
200 | } | |
201 | ||
202 | return chg; | |
203 | } | |
204 | ||
e7c4b0bf AW |
205 | /* |
206 | * Convert the address within this vma to the page offset within | |
207 | * the mapping, in pagecache page units; huge pages here. | |
208 | */ | |
a5516438 AK |
209 | static pgoff_t vma_hugecache_offset(struct hstate *h, |
210 | struct vm_area_struct *vma, unsigned long address) | |
e7c4b0bf | 211 | { |
a5516438 AK |
212 | return ((address - vma->vm_start) >> huge_page_shift(h)) + |
213 | (vma->vm_pgoff >> huge_page_order(h)); | |
e7c4b0bf AW |
214 | } |
215 | ||
84afd99b AW |
216 | /* |
217 | * Flags for MAP_PRIVATE reservations. These are stored in the bottom | |
218 | * bits of the reservation map pointer, which are always clear due to | |
219 | * alignment. | |
220 | */ | |
221 | #define HPAGE_RESV_OWNER (1UL << 0) | |
222 | #define HPAGE_RESV_UNMAPPED (1UL << 1) | |
04f2cbe3 | 223 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) |
84afd99b | 224 | |
a1e78772 MG |
225 | /* |
226 | * These helpers are used to track how many pages are reserved for | |
227 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() | |
228 | * is guaranteed to have their future faults succeed. | |
229 | * | |
230 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), | |
231 | * the reserve counters are updated with the hugetlb_lock held. It is safe | |
232 | * to reset the VMA at fork() time as it is not in use yet and there is no | |
233 | * chance of the global counters getting corrupted as a result of the values. | |
84afd99b AW |
234 | * |
235 | * The private mapping reservation is represented in a subtly different | |
236 | * manner to a shared mapping. A shared mapping has a region map associated | |
237 | * with the underlying file, this region map represents the backing file | |
238 | * pages which have ever had a reservation assigned which this persists even | |
239 | * after the page is instantiated. A private mapping has a region map | |
240 | * associated with the original mmap which is attached to all VMAs which | |
241 | * reference it, this region map represents those offsets which have consumed | |
242 | * reservation ie. where pages have been instantiated. | |
a1e78772 | 243 | */ |
e7c4b0bf AW |
244 | static unsigned long get_vma_private_data(struct vm_area_struct *vma) |
245 | { | |
246 | return (unsigned long)vma->vm_private_data; | |
247 | } | |
248 | ||
249 | static void set_vma_private_data(struct vm_area_struct *vma, | |
250 | unsigned long value) | |
251 | { | |
252 | vma->vm_private_data = (void *)value; | |
253 | } | |
254 | ||
84afd99b AW |
255 | struct resv_map { |
256 | struct kref refs; | |
257 | struct list_head regions; | |
258 | }; | |
259 | ||
260 | struct resv_map *resv_map_alloc(void) | |
261 | { | |
262 | struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); | |
263 | if (!resv_map) | |
264 | return NULL; | |
265 | ||
266 | kref_init(&resv_map->refs); | |
267 | INIT_LIST_HEAD(&resv_map->regions); | |
268 | ||
269 | return resv_map; | |
270 | } | |
271 | ||
272 | void resv_map_release(struct kref *ref) | |
273 | { | |
274 | struct resv_map *resv_map = container_of(ref, struct resv_map, refs); | |
275 | ||
276 | /* Clear out any active regions before we release the map. */ | |
277 | region_truncate(&resv_map->regions, 0); | |
278 | kfree(resv_map); | |
279 | } | |
280 | ||
281 | static struct resv_map *vma_resv_map(struct vm_area_struct *vma) | |
a1e78772 MG |
282 | { |
283 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
284 | if (!(vma->vm_flags & VM_SHARED)) | |
84afd99b AW |
285 | return (struct resv_map *)(get_vma_private_data(vma) & |
286 | ~HPAGE_RESV_MASK); | |
a1e78772 MG |
287 | return 0; |
288 | } | |
289 | ||
84afd99b | 290 | static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) |
a1e78772 MG |
291 | { |
292 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
293 | VM_BUG_ON(vma->vm_flags & VM_SHARED); | |
294 | ||
84afd99b AW |
295 | set_vma_private_data(vma, (get_vma_private_data(vma) & |
296 | HPAGE_RESV_MASK) | (unsigned long)map); | |
04f2cbe3 MG |
297 | } |
298 | ||
299 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) | |
300 | { | |
04f2cbe3 | 301 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
e7c4b0bf AW |
302 | VM_BUG_ON(vma->vm_flags & VM_SHARED); |
303 | ||
304 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); | |
04f2cbe3 MG |
305 | } |
306 | ||
307 | static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) | |
308 | { | |
309 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
e7c4b0bf AW |
310 | |
311 | return (get_vma_private_data(vma) & flag) != 0; | |
a1e78772 MG |
312 | } |
313 | ||
314 | /* Decrement the reserved pages in the hugepage pool by one */ | |
a5516438 AK |
315 | static void decrement_hugepage_resv_vma(struct hstate *h, |
316 | struct vm_area_struct *vma) | |
a1e78772 | 317 | { |
c37f9fb1 AW |
318 | if (vma->vm_flags & VM_NORESERVE) |
319 | return; | |
320 | ||
a1e78772 MG |
321 | if (vma->vm_flags & VM_SHARED) { |
322 | /* Shared mappings always use reserves */ | |
a5516438 | 323 | h->resv_huge_pages--; |
84afd99b | 324 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
a1e78772 MG |
325 | /* |
326 | * Only the process that called mmap() has reserves for | |
327 | * private mappings. | |
328 | */ | |
a5516438 | 329 | h->resv_huge_pages--; |
a1e78772 MG |
330 | } |
331 | } | |
332 | ||
04f2cbe3 | 333 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
a1e78772 MG |
334 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
335 | { | |
336 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
337 | if (!(vma->vm_flags & VM_SHARED)) | |
338 | vma->vm_private_data = (void *)0; | |
339 | } | |
340 | ||
341 | /* Returns true if the VMA has associated reserve pages */ | |
342 | static int vma_has_private_reserves(struct vm_area_struct *vma) | |
343 | { | |
344 | if (vma->vm_flags & VM_SHARED) | |
345 | return 0; | |
84afd99b | 346 | if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
a1e78772 MG |
347 | return 0; |
348 | return 1; | |
349 | } | |
350 | ||
a5516438 AK |
351 | static void clear_huge_page(struct page *page, |
352 | unsigned long addr, unsigned long sz) | |
79ac6ba4 DG |
353 | { |
354 | int i; | |
355 | ||
356 | might_sleep(); | |
a5516438 | 357 | for (i = 0; i < sz/PAGE_SIZE; i++) { |
79ac6ba4 | 358 | cond_resched(); |
281e0e3b | 359 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
79ac6ba4 DG |
360 | } |
361 | } | |
362 | ||
363 | static void copy_huge_page(struct page *dst, struct page *src, | |
9de455b2 | 364 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
365 | { |
366 | int i; | |
a5516438 | 367 | struct hstate *h = hstate_vma(vma); |
79ac6ba4 DG |
368 | |
369 | might_sleep(); | |
a5516438 | 370 | for (i = 0; i < pages_per_huge_page(h); i++) { |
79ac6ba4 | 371 | cond_resched(); |
9de455b2 | 372 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
373 | } |
374 | } | |
375 | ||
a5516438 | 376 | static void enqueue_huge_page(struct hstate *h, struct page *page) |
1da177e4 LT |
377 | { |
378 | int nid = page_to_nid(page); | |
a5516438 AK |
379 | list_add(&page->lru, &h->hugepage_freelists[nid]); |
380 | h->free_huge_pages++; | |
381 | h->free_huge_pages_node[nid]++; | |
1da177e4 LT |
382 | } |
383 | ||
a5516438 | 384 | static struct page *dequeue_huge_page(struct hstate *h) |
348e1e04 NA |
385 | { |
386 | int nid; | |
387 | struct page *page = NULL; | |
388 | ||
389 | for (nid = 0; nid < MAX_NUMNODES; ++nid) { | |
a5516438 AK |
390 | if (!list_empty(&h->hugepage_freelists[nid])) { |
391 | page = list_entry(h->hugepage_freelists[nid].next, | |
348e1e04 NA |
392 | struct page, lru); |
393 | list_del(&page->lru); | |
a5516438 AK |
394 | h->free_huge_pages--; |
395 | h->free_huge_pages_node[nid]--; | |
348e1e04 NA |
396 | break; |
397 | } | |
398 | } | |
399 | return page; | |
400 | } | |
401 | ||
a5516438 AK |
402 | static struct page *dequeue_huge_page_vma(struct hstate *h, |
403 | struct vm_area_struct *vma, | |
04f2cbe3 | 404 | unsigned long address, int avoid_reserve) |
1da177e4 | 405 | { |
31a5c6e4 | 406 | int nid; |
1da177e4 | 407 | struct page *page = NULL; |
480eccf9 | 408 | struct mempolicy *mpol; |
19770b32 | 409 | nodemask_t *nodemask; |
396faf03 | 410 | struct zonelist *zonelist = huge_zonelist(vma, address, |
19770b32 | 411 | htlb_alloc_mask, &mpol, &nodemask); |
dd1a239f MG |
412 | struct zone *zone; |
413 | struct zoneref *z; | |
1da177e4 | 414 | |
a1e78772 MG |
415 | /* |
416 | * A child process with MAP_PRIVATE mappings created by their parent | |
417 | * have no page reserves. This check ensures that reservations are | |
418 | * not "stolen". The child may still get SIGKILLed | |
419 | */ | |
420 | if (!vma_has_private_reserves(vma) && | |
a5516438 | 421 | h->free_huge_pages - h->resv_huge_pages == 0) |
a1e78772 MG |
422 | return NULL; |
423 | ||
04f2cbe3 | 424 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
a5516438 | 425 | if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) |
04f2cbe3 MG |
426 | return NULL; |
427 | ||
19770b32 MG |
428 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
429 | MAX_NR_ZONES - 1, nodemask) { | |
54a6eb5c MG |
430 | nid = zone_to_nid(zone); |
431 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && | |
a5516438 AK |
432 | !list_empty(&h->hugepage_freelists[nid])) { |
433 | page = list_entry(h->hugepage_freelists[nid].next, | |
3abf7afd AM |
434 | struct page, lru); |
435 | list_del(&page->lru); | |
a5516438 AK |
436 | h->free_huge_pages--; |
437 | h->free_huge_pages_node[nid]--; | |
04f2cbe3 MG |
438 | |
439 | if (!avoid_reserve) | |
a5516438 | 440 | decrement_hugepage_resv_vma(h, vma); |
a1e78772 | 441 | |
5ab3ee7b | 442 | break; |
3abf7afd | 443 | } |
1da177e4 | 444 | } |
52cd3b07 | 445 | mpol_cond_put(mpol); |
1da177e4 LT |
446 | return page; |
447 | } | |
448 | ||
a5516438 | 449 | static void update_and_free_page(struct hstate *h, struct page *page) |
6af2acb6 AL |
450 | { |
451 | int i; | |
a5516438 AK |
452 | |
453 | h->nr_huge_pages--; | |
454 | h->nr_huge_pages_node[page_to_nid(page)]--; | |
455 | for (i = 0; i < pages_per_huge_page(h); i++) { | |
6af2acb6 AL |
456 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | |
457 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
458 | 1 << PG_private | 1<< PG_writeback); | |
459 | } | |
460 | set_compound_page_dtor(page, NULL); | |
461 | set_page_refcounted(page); | |
7f2e9525 | 462 | arch_release_hugepage(page); |
a5516438 | 463 | __free_pages(page, huge_page_order(h)); |
6af2acb6 AL |
464 | } |
465 | ||
e5ff2159 AK |
466 | struct hstate *size_to_hstate(unsigned long size) |
467 | { | |
468 | struct hstate *h; | |
469 | ||
470 | for_each_hstate(h) { | |
471 | if (huge_page_size(h) == size) | |
472 | return h; | |
473 | } | |
474 | return NULL; | |
475 | } | |
476 | ||
27a85ef1 DG |
477 | static void free_huge_page(struct page *page) |
478 | { | |
a5516438 AK |
479 | /* |
480 | * Can't pass hstate in here because it is called from the | |
481 | * compound page destructor. | |
482 | */ | |
e5ff2159 | 483 | struct hstate *h = page_hstate(page); |
7893d1d5 | 484 | int nid = page_to_nid(page); |
c79fb75e | 485 | struct address_space *mapping; |
27a85ef1 | 486 | |
c79fb75e | 487 | mapping = (struct address_space *) page_private(page); |
e5df70ab | 488 | set_page_private(page, 0); |
7893d1d5 | 489 | BUG_ON(page_count(page)); |
27a85ef1 DG |
490 | INIT_LIST_HEAD(&page->lru); |
491 | ||
492 | spin_lock(&hugetlb_lock); | |
aa888a74 | 493 | if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) { |
a5516438 AK |
494 | update_and_free_page(h, page); |
495 | h->surplus_huge_pages--; | |
496 | h->surplus_huge_pages_node[nid]--; | |
7893d1d5 | 497 | } else { |
a5516438 | 498 | enqueue_huge_page(h, page); |
7893d1d5 | 499 | } |
27a85ef1 | 500 | spin_unlock(&hugetlb_lock); |
c79fb75e | 501 | if (mapping) |
9a119c05 | 502 | hugetlb_put_quota(mapping, 1); |
27a85ef1 DG |
503 | } |
504 | ||
7893d1d5 AL |
505 | /* |
506 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
507 | * balanced by operating on them in a round-robin fashion. | |
508 | * Returns 1 if an adjustment was made. | |
509 | */ | |
a5516438 | 510 | static int adjust_pool_surplus(struct hstate *h, int delta) |
7893d1d5 AL |
511 | { |
512 | static int prev_nid; | |
513 | int nid = prev_nid; | |
514 | int ret = 0; | |
515 | ||
516 | VM_BUG_ON(delta != -1 && delta != 1); | |
517 | do { | |
518 | nid = next_node(nid, node_online_map); | |
519 | if (nid == MAX_NUMNODES) | |
520 | nid = first_node(node_online_map); | |
521 | ||
522 | /* To shrink on this node, there must be a surplus page */ | |
a5516438 | 523 | if (delta < 0 && !h->surplus_huge_pages_node[nid]) |
7893d1d5 AL |
524 | continue; |
525 | /* Surplus cannot exceed the total number of pages */ | |
a5516438 AK |
526 | if (delta > 0 && h->surplus_huge_pages_node[nid] >= |
527 | h->nr_huge_pages_node[nid]) | |
7893d1d5 AL |
528 | continue; |
529 | ||
a5516438 AK |
530 | h->surplus_huge_pages += delta; |
531 | h->surplus_huge_pages_node[nid] += delta; | |
7893d1d5 AL |
532 | ret = 1; |
533 | break; | |
534 | } while (nid != prev_nid); | |
535 | ||
536 | prev_nid = nid; | |
537 | return ret; | |
538 | } | |
539 | ||
a5516438 | 540 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) |
b7ba30c6 AK |
541 | { |
542 | set_compound_page_dtor(page, free_huge_page); | |
543 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
544 | h->nr_huge_pages++; |
545 | h->nr_huge_pages_node[nid]++; | |
b7ba30c6 AK |
546 | spin_unlock(&hugetlb_lock); |
547 | put_page(page); /* free it into the hugepage allocator */ | |
548 | } | |
549 | ||
a5516438 | 550 | static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) |
1da177e4 | 551 | { |
1da177e4 | 552 | struct page *page; |
f96efd58 | 553 | |
aa888a74 AK |
554 | if (h->order >= MAX_ORDER) |
555 | return NULL; | |
556 | ||
63b4613c | 557 | page = alloc_pages_node(nid, |
551883ae NA |
558 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| |
559 | __GFP_REPEAT|__GFP_NOWARN, | |
a5516438 | 560 | huge_page_order(h)); |
1da177e4 | 561 | if (page) { |
7f2e9525 GS |
562 | if (arch_prepare_hugepage(page)) { |
563 | __free_pages(page, HUGETLB_PAGE_ORDER); | |
7b8ee84d | 564 | return NULL; |
7f2e9525 | 565 | } |
a5516438 | 566 | prep_new_huge_page(h, page, nid); |
1da177e4 | 567 | } |
63b4613c NA |
568 | |
569 | return page; | |
570 | } | |
571 | ||
5ced66c9 AK |
572 | /* |
573 | * Use a helper variable to find the next node and then | |
574 | * copy it back to hugetlb_next_nid afterwards: | |
575 | * otherwise there's a window in which a racer might | |
576 | * pass invalid nid MAX_NUMNODES to alloc_pages_node. | |
577 | * But we don't need to use a spin_lock here: it really | |
578 | * doesn't matter if occasionally a racer chooses the | |
579 | * same nid as we do. Move nid forward in the mask even | |
580 | * if we just successfully allocated a hugepage so that | |
581 | * the next caller gets hugepages on the next node. | |
582 | */ | |
583 | static int hstate_next_node(struct hstate *h) | |
584 | { | |
585 | int next_nid; | |
586 | next_nid = next_node(h->hugetlb_next_nid, node_online_map); | |
587 | if (next_nid == MAX_NUMNODES) | |
588 | next_nid = first_node(node_online_map); | |
589 | h->hugetlb_next_nid = next_nid; | |
590 | return next_nid; | |
591 | } | |
592 | ||
a5516438 | 593 | static int alloc_fresh_huge_page(struct hstate *h) |
63b4613c NA |
594 | { |
595 | struct page *page; | |
596 | int start_nid; | |
597 | int next_nid; | |
598 | int ret = 0; | |
599 | ||
a5516438 | 600 | start_nid = h->hugetlb_next_nid; |
63b4613c NA |
601 | |
602 | do { | |
a5516438 | 603 | page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid); |
63b4613c NA |
604 | if (page) |
605 | ret = 1; | |
5ced66c9 | 606 | next_nid = hstate_next_node(h); |
a5516438 | 607 | } while (!page && h->hugetlb_next_nid != start_nid); |
63b4613c | 608 | |
3b116300 AL |
609 | if (ret) |
610 | count_vm_event(HTLB_BUDDY_PGALLOC); | |
611 | else | |
612 | count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); | |
613 | ||
63b4613c | 614 | return ret; |
1da177e4 LT |
615 | } |
616 | ||
a5516438 AK |
617 | static struct page *alloc_buddy_huge_page(struct hstate *h, |
618 | struct vm_area_struct *vma, unsigned long address) | |
7893d1d5 AL |
619 | { |
620 | struct page *page; | |
d1c3fb1f | 621 | unsigned int nid; |
7893d1d5 | 622 | |
aa888a74 AK |
623 | if (h->order >= MAX_ORDER) |
624 | return NULL; | |
625 | ||
d1c3fb1f NA |
626 | /* |
627 | * Assume we will successfully allocate the surplus page to | |
628 | * prevent racing processes from causing the surplus to exceed | |
629 | * overcommit | |
630 | * | |
631 | * This however introduces a different race, where a process B | |
632 | * tries to grow the static hugepage pool while alloc_pages() is | |
633 | * called by process A. B will only examine the per-node | |
634 | * counters in determining if surplus huge pages can be | |
635 | * converted to normal huge pages in adjust_pool_surplus(). A | |
636 | * won't be able to increment the per-node counter, until the | |
637 | * lock is dropped by B, but B doesn't drop hugetlb_lock until | |
638 | * no more huge pages can be converted from surplus to normal | |
639 | * state (and doesn't try to convert again). Thus, we have a | |
640 | * case where a surplus huge page exists, the pool is grown, and | |
641 | * the surplus huge page still exists after, even though it | |
642 | * should just have been converted to a normal huge page. This | |
643 | * does not leak memory, though, as the hugepage will be freed | |
644 | * once it is out of use. It also does not allow the counters to | |
645 | * go out of whack in adjust_pool_surplus() as we don't modify | |
646 | * the node values until we've gotten the hugepage and only the | |
647 | * per-node value is checked there. | |
648 | */ | |
649 | spin_lock(&hugetlb_lock); | |
a5516438 | 650 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { |
d1c3fb1f NA |
651 | spin_unlock(&hugetlb_lock); |
652 | return NULL; | |
653 | } else { | |
a5516438 AK |
654 | h->nr_huge_pages++; |
655 | h->surplus_huge_pages++; | |
d1c3fb1f NA |
656 | } |
657 | spin_unlock(&hugetlb_lock); | |
658 | ||
551883ae NA |
659 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP| |
660 | __GFP_REPEAT|__GFP_NOWARN, | |
a5516438 | 661 | huge_page_order(h)); |
d1c3fb1f NA |
662 | |
663 | spin_lock(&hugetlb_lock); | |
7893d1d5 | 664 | if (page) { |
2668db91 AL |
665 | /* |
666 | * This page is now managed by the hugetlb allocator and has | |
667 | * no users -- drop the buddy allocator's reference. | |
668 | */ | |
669 | put_page_testzero(page); | |
670 | VM_BUG_ON(page_count(page)); | |
d1c3fb1f | 671 | nid = page_to_nid(page); |
7893d1d5 | 672 | set_compound_page_dtor(page, free_huge_page); |
d1c3fb1f NA |
673 | /* |
674 | * We incremented the global counters already | |
675 | */ | |
a5516438 AK |
676 | h->nr_huge_pages_node[nid]++; |
677 | h->surplus_huge_pages_node[nid]++; | |
3b116300 | 678 | __count_vm_event(HTLB_BUDDY_PGALLOC); |
d1c3fb1f | 679 | } else { |
a5516438 AK |
680 | h->nr_huge_pages--; |
681 | h->surplus_huge_pages--; | |
3b116300 | 682 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
7893d1d5 | 683 | } |
d1c3fb1f | 684 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
685 | |
686 | return page; | |
687 | } | |
688 | ||
e4e574b7 AL |
689 | /* |
690 | * Increase the hugetlb pool such that it can accomodate a reservation | |
691 | * of size 'delta'. | |
692 | */ | |
a5516438 | 693 | static int gather_surplus_pages(struct hstate *h, int delta) |
e4e574b7 AL |
694 | { |
695 | struct list_head surplus_list; | |
696 | struct page *page, *tmp; | |
697 | int ret, i; | |
698 | int needed, allocated; | |
699 | ||
a5516438 | 700 | needed = (h->resv_huge_pages + delta) - h->free_huge_pages; |
ac09b3a1 | 701 | if (needed <= 0) { |
a5516438 | 702 | h->resv_huge_pages += delta; |
e4e574b7 | 703 | return 0; |
ac09b3a1 | 704 | } |
e4e574b7 AL |
705 | |
706 | allocated = 0; | |
707 | INIT_LIST_HEAD(&surplus_list); | |
708 | ||
709 | ret = -ENOMEM; | |
710 | retry: | |
711 | spin_unlock(&hugetlb_lock); | |
712 | for (i = 0; i < needed; i++) { | |
a5516438 | 713 | page = alloc_buddy_huge_page(h, NULL, 0); |
e4e574b7 AL |
714 | if (!page) { |
715 | /* | |
716 | * We were not able to allocate enough pages to | |
717 | * satisfy the entire reservation so we free what | |
718 | * we've allocated so far. | |
719 | */ | |
720 | spin_lock(&hugetlb_lock); | |
721 | needed = 0; | |
722 | goto free; | |
723 | } | |
724 | ||
725 | list_add(&page->lru, &surplus_list); | |
726 | } | |
727 | allocated += needed; | |
728 | ||
729 | /* | |
730 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
731 | * because either resv_huge_pages or free_huge_pages may have changed. | |
732 | */ | |
733 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
734 | needed = (h->resv_huge_pages + delta) - |
735 | (h->free_huge_pages + allocated); | |
e4e574b7 AL |
736 | if (needed > 0) |
737 | goto retry; | |
738 | ||
739 | /* | |
740 | * The surplus_list now contains _at_least_ the number of extra pages | |
741 | * needed to accomodate the reservation. Add the appropriate number | |
742 | * of pages to the hugetlb pool and free the extras back to the buddy | |
ac09b3a1 AL |
743 | * allocator. Commit the entire reservation here to prevent another |
744 | * process from stealing the pages as they are added to the pool but | |
745 | * before they are reserved. | |
e4e574b7 AL |
746 | */ |
747 | needed += allocated; | |
a5516438 | 748 | h->resv_huge_pages += delta; |
e4e574b7 AL |
749 | ret = 0; |
750 | free: | |
19fc3f0a | 751 | /* Free the needed pages to the hugetlb pool */ |
e4e574b7 | 752 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
19fc3f0a AL |
753 | if ((--needed) < 0) |
754 | break; | |
e4e574b7 | 755 | list_del(&page->lru); |
a5516438 | 756 | enqueue_huge_page(h, page); |
19fc3f0a AL |
757 | } |
758 | ||
759 | /* Free unnecessary surplus pages to the buddy allocator */ | |
760 | if (!list_empty(&surplus_list)) { | |
761 | spin_unlock(&hugetlb_lock); | |
762 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { | |
763 | list_del(&page->lru); | |
af767cbd | 764 | /* |
2668db91 AL |
765 | * The page has a reference count of zero already, so |
766 | * call free_huge_page directly instead of using | |
767 | * put_page. This must be done with hugetlb_lock | |
af767cbd AL |
768 | * unlocked which is safe because free_huge_page takes |
769 | * hugetlb_lock before deciding how to free the page. | |
770 | */ | |
2668db91 | 771 | free_huge_page(page); |
af767cbd | 772 | } |
19fc3f0a | 773 | spin_lock(&hugetlb_lock); |
e4e574b7 AL |
774 | } |
775 | ||
776 | return ret; | |
777 | } | |
778 | ||
779 | /* | |
780 | * When releasing a hugetlb pool reservation, any surplus pages that were | |
781 | * allocated to satisfy the reservation must be explicitly freed if they were | |
782 | * never used. | |
783 | */ | |
a5516438 AK |
784 | static void return_unused_surplus_pages(struct hstate *h, |
785 | unsigned long unused_resv_pages) | |
e4e574b7 AL |
786 | { |
787 | static int nid = -1; | |
788 | struct page *page; | |
789 | unsigned long nr_pages; | |
790 | ||
11320d17 NA |
791 | /* |
792 | * We want to release as many surplus pages as possible, spread | |
793 | * evenly across all nodes. Iterate across all nodes until we | |
794 | * can no longer free unreserved surplus pages. This occurs when | |
795 | * the nodes with surplus pages have no free pages. | |
796 | */ | |
797 | unsigned long remaining_iterations = num_online_nodes(); | |
798 | ||
ac09b3a1 | 799 | /* Uncommit the reservation */ |
a5516438 | 800 | h->resv_huge_pages -= unused_resv_pages; |
ac09b3a1 | 801 | |
aa888a74 AK |
802 | /* Cannot return gigantic pages currently */ |
803 | if (h->order >= MAX_ORDER) | |
804 | return; | |
805 | ||
a5516438 | 806 | nr_pages = min(unused_resv_pages, h->surplus_huge_pages); |
e4e574b7 | 807 | |
11320d17 | 808 | while (remaining_iterations-- && nr_pages) { |
e4e574b7 AL |
809 | nid = next_node(nid, node_online_map); |
810 | if (nid == MAX_NUMNODES) | |
811 | nid = first_node(node_online_map); | |
812 | ||
a5516438 | 813 | if (!h->surplus_huge_pages_node[nid]) |
e4e574b7 AL |
814 | continue; |
815 | ||
a5516438 AK |
816 | if (!list_empty(&h->hugepage_freelists[nid])) { |
817 | page = list_entry(h->hugepage_freelists[nid].next, | |
e4e574b7 AL |
818 | struct page, lru); |
819 | list_del(&page->lru); | |
a5516438 AK |
820 | update_and_free_page(h, page); |
821 | h->free_huge_pages--; | |
822 | h->free_huge_pages_node[nid]--; | |
823 | h->surplus_huge_pages--; | |
824 | h->surplus_huge_pages_node[nid]--; | |
e4e574b7 | 825 | nr_pages--; |
11320d17 | 826 | remaining_iterations = num_online_nodes(); |
e4e574b7 AL |
827 | } |
828 | } | |
829 | } | |
830 | ||
c37f9fb1 AW |
831 | /* |
832 | * Determine if the huge page at addr within the vma has an associated | |
833 | * reservation. Where it does not we will need to logically increase | |
834 | * reservation and actually increase quota before an allocation can occur. | |
835 | * Where any new reservation would be required the reservation change is | |
836 | * prepared, but not committed. Once the page has been quota'd allocated | |
837 | * an instantiated the change should be committed via vma_commit_reservation. | |
838 | * No action is required on failure. | |
839 | */ | |
a5516438 AK |
840 | static int vma_needs_reservation(struct hstate *h, |
841 | struct vm_area_struct *vma, unsigned long addr) | |
c37f9fb1 AW |
842 | { |
843 | struct address_space *mapping = vma->vm_file->f_mapping; | |
844 | struct inode *inode = mapping->host; | |
845 | ||
846 | if (vma->vm_flags & VM_SHARED) { | |
a5516438 | 847 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 AW |
848 | return region_chg(&inode->i_mapping->private_list, |
849 | idx, idx + 1); | |
850 | ||
84afd99b AW |
851 | } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
852 | return 1; | |
c37f9fb1 | 853 | |
84afd99b AW |
854 | } else { |
855 | int err; | |
a5516438 | 856 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
84afd99b AW |
857 | struct resv_map *reservations = vma_resv_map(vma); |
858 | ||
859 | err = region_chg(&reservations->regions, idx, idx + 1); | |
860 | if (err < 0) | |
861 | return err; | |
862 | return 0; | |
863 | } | |
c37f9fb1 | 864 | } |
a5516438 AK |
865 | static void vma_commit_reservation(struct hstate *h, |
866 | struct vm_area_struct *vma, unsigned long addr) | |
c37f9fb1 AW |
867 | { |
868 | struct address_space *mapping = vma->vm_file->f_mapping; | |
869 | struct inode *inode = mapping->host; | |
870 | ||
871 | if (vma->vm_flags & VM_SHARED) { | |
a5516438 | 872 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 | 873 | region_add(&inode->i_mapping->private_list, idx, idx + 1); |
84afd99b AW |
874 | |
875 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { | |
a5516438 | 876 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
84afd99b AW |
877 | struct resv_map *reservations = vma_resv_map(vma); |
878 | ||
879 | /* Mark this page used in the map. */ | |
880 | region_add(&reservations->regions, idx, idx + 1); | |
c37f9fb1 AW |
881 | } |
882 | } | |
883 | ||
a1e78772 | 884 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
04f2cbe3 | 885 | unsigned long addr, int avoid_reserve) |
1da177e4 | 886 | { |
a5516438 | 887 | struct hstate *h = hstate_vma(vma); |
348ea204 | 888 | struct page *page; |
a1e78772 MG |
889 | struct address_space *mapping = vma->vm_file->f_mapping; |
890 | struct inode *inode = mapping->host; | |
c37f9fb1 | 891 | unsigned int chg; |
a1e78772 MG |
892 | |
893 | /* | |
894 | * Processes that did not create the mapping will have no reserves and | |
895 | * will not have accounted against quota. Check that the quota can be | |
896 | * made before satisfying the allocation | |
c37f9fb1 AW |
897 | * MAP_NORESERVE mappings may also need pages and quota allocated |
898 | * if no reserve mapping overlaps. | |
a1e78772 | 899 | */ |
a5516438 | 900 | chg = vma_needs_reservation(h, vma, addr); |
c37f9fb1 AW |
901 | if (chg < 0) |
902 | return ERR_PTR(chg); | |
903 | if (chg) | |
a1e78772 MG |
904 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
905 | return ERR_PTR(-ENOSPC); | |
1da177e4 LT |
906 | |
907 | spin_lock(&hugetlb_lock); | |
a5516438 | 908 | page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve); |
1da177e4 | 909 | spin_unlock(&hugetlb_lock); |
b45b5bd6 | 910 | |
68842c9b | 911 | if (!page) { |
a5516438 | 912 | page = alloc_buddy_huge_page(h, vma, addr); |
68842c9b | 913 | if (!page) { |
a1e78772 | 914 | hugetlb_put_quota(inode->i_mapping, chg); |
68842c9b KC |
915 | return ERR_PTR(-VM_FAULT_OOM); |
916 | } | |
917 | } | |
348ea204 | 918 | |
a1e78772 MG |
919 | set_page_refcounted(page); |
920 | set_page_private(page, (unsigned long) mapping); | |
90d8b7e6 | 921 | |
a5516438 | 922 | vma_commit_reservation(h, vma, addr); |
c37f9fb1 | 923 | |
90d8b7e6 | 924 | return page; |
b45b5bd6 DG |
925 | } |
926 | ||
aa888a74 AK |
927 | static __initdata LIST_HEAD(huge_boot_pages); |
928 | ||
929 | struct huge_bootmem_page { | |
930 | struct list_head list; | |
931 | struct hstate *hstate; | |
932 | }; | |
933 | ||
934 | static int __init alloc_bootmem_huge_page(struct hstate *h) | |
935 | { | |
936 | struct huge_bootmem_page *m; | |
937 | int nr_nodes = nodes_weight(node_online_map); | |
938 | ||
939 | while (nr_nodes) { | |
940 | void *addr; | |
941 | ||
942 | addr = __alloc_bootmem_node_nopanic( | |
943 | NODE_DATA(h->hugetlb_next_nid), | |
944 | huge_page_size(h), huge_page_size(h), 0); | |
945 | ||
946 | if (addr) { | |
947 | /* | |
948 | * Use the beginning of the huge page to store the | |
949 | * huge_bootmem_page struct (until gather_bootmem | |
950 | * puts them into the mem_map). | |
951 | */ | |
952 | m = addr; | |
953 | if (m) | |
954 | goto found; | |
955 | } | |
956 | hstate_next_node(h); | |
957 | nr_nodes--; | |
958 | } | |
959 | return 0; | |
960 | ||
961 | found: | |
962 | BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1)); | |
963 | /* Put them into a private list first because mem_map is not up yet */ | |
964 | list_add(&m->list, &huge_boot_pages); | |
965 | m->hstate = h; | |
966 | return 1; | |
967 | } | |
968 | ||
969 | /* Put bootmem huge pages into the standard lists after mem_map is up */ | |
970 | static void __init gather_bootmem_prealloc(void) | |
971 | { | |
972 | struct huge_bootmem_page *m; | |
973 | ||
974 | list_for_each_entry(m, &huge_boot_pages, list) { | |
975 | struct page *page = virt_to_page(m); | |
976 | struct hstate *h = m->hstate; | |
977 | __ClearPageReserved(page); | |
978 | WARN_ON(page_count(page) != 1); | |
979 | prep_compound_page(page, h->order); | |
980 | prep_new_huge_page(h, page, page_to_nid(page)); | |
981 | } | |
982 | } | |
983 | ||
e5ff2159 | 984 | static void __init hugetlb_init_one_hstate(struct hstate *h) |
1da177e4 LT |
985 | { |
986 | unsigned long i; | |
a5516438 | 987 | |
1da177e4 | 988 | for (i = 0; i < MAX_NUMNODES; ++i) |
a5516438 | 989 | INIT_LIST_HEAD(&h->hugepage_freelists[i]); |
1da177e4 | 990 | |
a5516438 | 991 | h->hugetlb_next_nid = first_node(node_online_map); |
63b4613c | 992 | |
e5ff2159 | 993 | for (i = 0; i < h->max_huge_pages; ++i) { |
aa888a74 AK |
994 | if (h->order >= MAX_ORDER) { |
995 | if (!alloc_bootmem_huge_page(h)) | |
996 | break; | |
997 | } else if (!alloc_fresh_huge_page(h)) | |
1da177e4 | 998 | break; |
1da177e4 | 999 | } |
e5ff2159 AK |
1000 | h->max_huge_pages = h->free_huge_pages = h->nr_huge_pages = i; |
1001 | } | |
1002 | ||
1003 | static void __init hugetlb_init_hstates(void) | |
1004 | { | |
1005 | struct hstate *h; | |
1006 | ||
1007 | for_each_hstate(h) { | |
1008 | hugetlb_init_one_hstate(h); | |
1009 | } | |
1010 | } | |
1011 | ||
1012 | static void __init report_hugepages(void) | |
1013 | { | |
1014 | struct hstate *h; | |
1015 | ||
1016 | for_each_hstate(h) { | |
1017 | printk(KERN_INFO "Total HugeTLB memory allocated, " | |
1018 | "%ld %dMB pages\n", | |
1019 | h->free_huge_pages, | |
1020 | 1 << (h->order + PAGE_SHIFT - 20)); | |
1021 | } | |
1022 | } | |
1023 | ||
1da177e4 | 1024 | #ifdef CONFIG_SYSCTL |
1da177e4 | 1025 | #ifdef CONFIG_HIGHMEM |
a5516438 | 1026 | static void try_to_free_low(struct hstate *h, unsigned long count) |
1da177e4 | 1027 | { |
4415cc8d CL |
1028 | int i; |
1029 | ||
aa888a74 AK |
1030 | if (h->order >= MAX_ORDER) |
1031 | return; | |
1032 | ||
1da177e4 LT |
1033 | for (i = 0; i < MAX_NUMNODES; ++i) { |
1034 | struct page *page, *next; | |
a5516438 AK |
1035 | struct list_head *freel = &h->hugepage_freelists[i]; |
1036 | list_for_each_entry_safe(page, next, freel, lru) { | |
1037 | if (count >= h->nr_huge_pages) | |
6b0c880d | 1038 | return; |
1da177e4 LT |
1039 | if (PageHighMem(page)) |
1040 | continue; | |
1041 | list_del(&page->lru); | |
e5ff2159 | 1042 | update_and_free_page(h, page); |
a5516438 AK |
1043 | h->free_huge_pages--; |
1044 | h->free_huge_pages_node[page_to_nid(page)]--; | |
1da177e4 LT |
1045 | } |
1046 | } | |
1047 | } | |
1048 | #else | |
a5516438 | 1049 | static inline void try_to_free_low(struct hstate *h, unsigned long count) |
1da177e4 LT |
1050 | { |
1051 | } | |
1052 | #endif | |
1053 | ||
a5516438 | 1054 | #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) |
e5ff2159 | 1055 | static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count) |
1da177e4 | 1056 | { |
7893d1d5 | 1057 | unsigned long min_count, ret; |
1da177e4 | 1058 | |
aa888a74 AK |
1059 | if (h->order >= MAX_ORDER) |
1060 | return h->max_huge_pages; | |
1061 | ||
7893d1d5 AL |
1062 | /* |
1063 | * Increase the pool size | |
1064 | * First take pages out of surplus state. Then make up the | |
1065 | * remaining difference by allocating fresh huge pages. | |
d1c3fb1f NA |
1066 | * |
1067 | * We might race with alloc_buddy_huge_page() here and be unable | |
1068 | * to convert a surplus huge page to a normal huge page. That is | |
1069 | * not critical, though, it just means the overall size of the | |
1070 | * pool might be one hugepage larger than it needs to be, but | |
1071 | * within all the constraints specified by the sysctls. | |
7893d1d5 | 1072 | */ |
1da177e4 | 1073 | spin_lock(&hugetlb_lock); |
a5516438 AK |
1074 | while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { |
1075 | if (!adjust_pool_surplus(h, -1)) | |
7893d1d5 AL |
1076 | break; |
1077 | } | |
1078 | ||
a5516438 | 1079 | while (count > persistent_huge_pages(h)) { |
7893d1d5 AL |
1080 | /* |
1081 | * If this allocation races such that we no longer need the | |
1082 | * page, free_huge_page will handle it by freeing the page | |
1083 | * and reducing the surplus. | |
1084 | */ | |
1085 | spin_unlock(&hugetlb_lock); | |
a5516438 | 1086 | ret = alloc_fresh_huge_page(h); |
7893d1d5 AL |
1087 | spin_lock(&hugetlb_lock); |
1088 | if (!ret) | |
1089 | goto out; | |
1090 | ||
1091 | } | |
7893d1d5 AL |
1092 | |
1093 | /* | |
1094 | * Decrease the pool size | |
1095 | * First return free pages to the buddy allocator (being careful | |
1096 | * to keep enough around to satisfy reservations). Then place | |
1097 | * pages into surplus state as needed so the pool will shrink | |
1098 | * to the desired size as pages become free. | |
d1c3fb1f NA |
1099 | * |
1100 | * By placing pages into the surplus state independent of the | |
1101 | * overcommit value, we are allowing the surplus pool size to | |
1102 | * exceed overcommit. There are few sane options here. Since | |
1103 | * alloc_buddy_huge_page() is checking the global counter, | |
1104 | * though, we'll note that we're not allowed to exceed surplus | |
1105 | * and won't grow the pool anywhere else. Not until one of the | |
1106 | * sysctls are changed, or the surplus pages go out of use. | |
7893d1d5 | 1107 | */ |
a5516438 | 1108 | min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; |
6b0c880d | 1109 | min_count = max(count, min_count); |
a5516438 AK |
1110 | try_to_free_low(h, min_count); |
1111 | while (min_count < persistent_huge_pages(h)) { | |
1112 | struct page *page = dequeue_huge_page(h); | |
1da177e4 LT |
1113 | if (!page) |
1114 | break; | |
a5516438 | 1115 | update_and_free_page(h, page); |
1da177e4 | 1116 | } |
a5516438 AK |
1117 | while (count < persistent_huge_pages(h)) { |
1118 | if (!adjust_pool_surplus(h, 1)) | |
7893d1d5 AL |
1119 | break; |
1120 | } | |
1121 | out: | |
a5516438 | 1122 | ret = persistent_huge_pages(h); |
1da177e4 | 1123 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 1124 | return ret; |
1da177e4 LT |
1125 | } |
1126 | ||
a3437870 NA |
1127 | #define HSTATE_ATTR_RO(_name) \ |
1128 | static struct kobj_attribute _name##_attr = __ATTR_RO(_name) | |
1129 | ||
1130 | #define HSTATE_ATTR(_name) \ | |
1131 | static struct kobj_attribute _name##_attr = \ | |
1132 | __ATTR(_name, 0644, _name##_show, _name##_store) | |
1133 | ||
1134 | static struct kobject *hugepages_kobj; | |
1135 | static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
1136 | ||
1137 | static struct hstate *kobj_to_hstate(struct kobject *kobj) | |
1138 | { | |
1139 | int i; | |
1140 | for (i = 0; i < HUGE_MAX_HSTATE; i++) | |
1141 | if (hstate_kobjs[i] == kobj) | |
1142 | return &hstates[i]; | |
1143 | BUG(); | |
1144 | return NULL; | |
1145 | } | |
1146 | ||
1147 | static ssize_t nr_hugepages_show(struct kobject *kobj, | |
1148 | struct kobj_attribute *attr, char *buf) | |
1149 | { | |
1150 | struct hstate *h = kobj_to_hstate(kobj); | |
1151 | return sprintf(buf, "%lu\n", h->nr_huge_pages); | |
1152 | } | |
1153 | static ssize_t nr_hugepages_store(struct kobject *kobj, | |
1154 | struct kobj_attribute *attr, const char *buf, size_t count) | |
1155 | { | |
1156 | int err; | |
1157 | unsigned long input; | |
1158 | struct hstate *h = kobj_to_hstate(kobj); | |
1159 | ||
1160 | err = strict_strtoul(buf, 10, &input); | |
1161 | if (err) | |
1162 | return 0; | |
1163 | ||
1164 | h->max_huge_pages = set_max_huge_pages(h, input); | |
1165 | ||
1166 | return count; | |
1167 | } | |
1168 | HSTATE_ATTR(nr_hugepages); | |
1169 | ||
1170 | static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, | |
1171 | struct kobj_attribute *attr, char *buf) | |
1172 | { | |
1173 | struct hstate *h = kobj_to_hstate(kobj); | |
1174 | return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); | |
1175 | } | |
1176 | static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, | |
1177 | struct kobj_attribute *attr, const char *buf, size_t count) | |
1178 | { | |
1179 | int err; | |
1180 | unsigned long input; | |
1181 | struct hstate *h = kobj_to_hstate(kobj); | |
1182 | ||
1183 | err = strict_strtoul(buf, 10, &input); | |
1184 | if (err) | |
1185 | return 0; | |
1186 | ||
1187 | spin_lock(&hugetlb_lock); | |
1188 | h->nr_overcommit_huge_pages = input; | |
1189 | spin_unlock(&hugetlb_lock); | |
1190 | ||
1191 | return count; | |
1192 | } | |
1193 | HSTATE_ATTR(nr_overcommit_hugepages); | |
1194 | ||
1195 | static ssize_t free_hugepages_show(struct kobject *kobj, | |
1196 | struct kobj_attribute *attr, char *buf) | |
1197 | { | |
1198 | struct hstate *h = kobj_to_hstate(kobj); | |
1199 | return sprintf(buf, "%lu\n", h->free_huge_pages); | |
1200 | } | |
1201 | HSTATE_ATTR_RO(free_hugepages); | |
1202 | ||
1203 | static ssize_t resv_hugepages_show(struct kobject *kobj, | |
1204 | struct kobj_attribute *attr, char *buf) | |
1205 | { | |
1206 | struct hstate *h = kobj_to_hstate(kobj); | |
1207 | return sprintf(buf, "%lu\n", h->resv_huge_pages); | |
1208 | } | |
1209 | HSTATE_ATTR_RO(resv_hugepages); | |
1210 | ||
1211 | static ssize_t surplus_hugepages_show(struct kobject *kobj, | |
1212 | struct kobj_attribute *attr, char *buf) | |
1213 | { | |
1214 | struct hstate *h = kobj_to_hstate(kobj); | |
1215 | return sprintf(buf, "%lu\n", h->surplus_huge_pages); | |
1216 | } | |
1217 | HSTATE_ATTR_RO(surplus_hugepages); | |
1218 | ||
1219 | static struct attribute *hstate_attrs[] = { | |
1220 | &nr_hugepages_attr.attr, | |
1221 | &nr_overcommit_hugepages_attr.attr, | |
1222 | &free_hugepages_attr.attr, | |
1223 | &resv_hugepages_attr.attr, | |
1224 | &surplus_hugepages_attr.attr, | |
1225 | NULL, | |
1226 | }; | |
1227 | ||
1228 | static struct attribute_group hstate_attr_group = { | |
1229 | .attrs = hstate_attrs, | |
1230 | }; | |
1231 | ||
1232 | static int __init hugetlb_sysfs_add_hstate(struct hstate *h) | |
1233 | { | |
1234 | int retval; | |
1235 | ||
1236 | hstate_kobjs[h - hstates] = kobject_create_and_add(h->name, | |
1237 | hugepages_kobj); | |
1238 | if (!hstate_kobjs[h - hstates]) | |
1239 | return -ENOMEM; | |
1240 | ||
1241 | retval = sysfs_create_group(hstate_kobjs[h - hstates], | |
1242 | &hstate_attr_group); | |
1243 | if (retval) | |
1244 | kobject_put(hstate_kobjs[h - hstates]); | |
1245 | ||
1246 | return retval; | |
1247 | } | |
1248 | ||
1249 | static void __init hugetlb_sysfs_init(void) | |
1250 | { | |
1251 | struct hstate *h; | |
1252 | int err; | |
1253 | ||
1254 | hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); | |
1255 | if (!hugepages_kobj) | |
1256 | return; | |
1257 | ||
1258 | for_each_hstate(h) { | |
1259 | err = hugetlb_sysfs_add_hstate(h); | |
1260 | if (err) | |
1261 | printk(KERN_ERR "Hugetlb: Unable to add hstate %s", | |
1262 | h->name); | |
1263 | } | |
1264 | } | |
1265 | ||
1266 | static void __exit hugetlb_exit(void) | |
1267 | { | |
1268 | struct hstate *h; | |
1269 | ||
1270 | for_each_hstate(h) { | |
1271 | kobject_put(hstate_kobjs[h - hstates]); | |
1272 | } | |
1273 | ||
1274 | kobject_put(hugepages_kobj); | |
1275 | } | |
1276 | module_exit(hugetlb_exit); | |
1277 | ||
1278 | static int __init hugetlb_init(void) | |
1279 | { | |
1280 | BUILD_BUG_ON(HPAGE_SHIFT == 0); | |
1281 | ||
1282 | if (!size_to_hstate(HPAGE_SIZE)) { | |
1283 | hugetlb_add_hstate(HUGETLB_PAGE_ORDER); | |
1284 | parsed_hstate->max_huge_pages = default_hstate_max_huge_pages; | |
1285 | } | |
1286 | default_hstate_idx = size_to_hstate(HPAGE_SIZE) - hstates; | |
1287 | ||
1288 | hugetlb_init_hstates(); | |
1289 | ||
aa888a74 AK |
1290 | gather_bootmem_prealloc(); |
1291 | ||
a3437870 NA |
1292 | report_hugepages(); |
1293 | ||
1294 | hugetlb_sysfs_init(); | |
1295 | ||
1296 | return 0; | |
1297 | } | |
1298 | module_init(hugetlb_init); | |
1299 | ||
1300 | /* Should be called on processing a hugepagesz=... option */ | |
1301 | void __init hugetlb_add_hstate(unsigned order) | |
1302 | { | |
1303 | struct hstate *h; | |
1304 | if (size_to_hstate(PAGE_SIZE << order)) { | |
1305 | printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n"); | |
1306 | return; | |
1307 | } | |
1308 | BUG_ON(max_hstate >= HUGE_MAX_HSTATE); | |
1309 | BUG_ON(order == 0); | |
1310 | h = &hstates[max_hstate++]; | |
1311 | h->order = order; | |
1312 | h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); | |
1313 | snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", | |
1314 | huge_page_size(h)/1024); | |
1315 | hugetlb_init_one_hstate(h); | |
1316 | parsed_hstate = h; | |
1317 | } | |
1318 | ||
1319 | static int __init hugetlb_setup(char *s) | |
1320 | { | |
1321 | unsigned long *mhp; | |
1322 | ||
1323 | /* | |
1324 | * !max_hstate means we haven't parsed a hugepagesz= parameter yet, | |
1325 | * so this hugepages= parameter goes to the "default hstate". | |
1326 | */ | |
1327 | if (!max_hstate) | |
1328 | mhp = &default_hstate_max_huge_pages; | |
1329 | else | |
1330 | mhp = &parsed_hstate->max_huge_pages; | |
1331 | ||
1332 | if (sscanf(s, "%lu", mhp) <= 0) | |
1333 | *mhp = 0; | |
1334 | ||
1335 | return 1; | |
1336 | } | |
1337 | __setup("hugepages=", hugetlb_setup); | |
1338 | ||
1339 | static unsigned int cpuset_mems_nr(unsigned int *array) | |
1340 | { | |
1341 | int node; | |
1342 | unsigned int nr = 0; | |
1343 | ||
1344 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
1345 | nr += array[node]; | |
1346 | ||
1347 | return nr; | |
1348 | } | |
1349 | ||
1da177e4 LT |
1350 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
1351 | struct file *file, void __user *buffer, | |
1352 | size_t *length, loff_t *ppos) | |
1353 | { | |
e5ff2159 AK |
1354 | struct hstate *h = &default_hstate; |
1355 | unsigned long tmp; | |
1356 | ||
1357 | if (!write) | |
1358 | tmp = h->max_huge_pages; | |
1359 | ||
1360 | table->data = &tmp; | |
1361 | table->maxlen = sizeof(unsigned long); | |
1da177e4 | 1362 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
e5ff2159 AK |
1363 | |
1364 | if (write) | |
1365 | h->max_huge_pages = set_max_huge_pages(h, tmp); | |
1366 | ||
1da177e4 LT |
1367 | return 0; |
1368 | } | |
396faf03 MG |
1369 | |
1370 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, | |
1371 | struct file *file, void __user *buffer, | |
1372 | size_t *length, loff_t *ppos) | |
1373 | { | |
1374 | proc_dointvec(table, write, file, buffer, length, ppos); | |
1375 | if (hugepages_treat_as_movable) | |
1376 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; | |
1377 | else | |
1378 | htlb_alloc_mask = GFP_HIGHUSER; | |
1379 | return 0; | |
1380 | } | |
1381 | ||
a3d0c6aa NA |
1382 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
1383 | struct file *file, void __user *buffer, | |
1384 | size_t *length, loff_t *ppos) | |
1385 | { | |
a5516438 | 1386 | struct hstate *h = &default_hstate; |
e5ff2159 AK |
1387 | unsigned long tmp; |
1388 | ||
1389 | if (!write) | |
1390 | tmp = h->nr_overcommit_huge_pages; | |
1391 | ||
1392 | table->data = &tmp; | |
1393 | table->maxlen = sizeof(unsigned long); | |
a3d0c6aa | 1394 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
e5ff2159 AK |
1395 | |
1396 | if (write) { | |
1397 | spin_lock(&hugetlb_lock); | |
1398 | h->nr_overcommit_huge_pages = tmp; | |
1399 | spin_unlock(&hugetlb_lock); | |
1400 | } | |
1401 | ||
a3d0c6aa NA |
1402 | return 0; |
1403 | } | |
1404 | ||
1da177e4 LT |
1405 | #endif /* CONFIG_SYSCTL */ |
1406 | ||
1407 | int hugetlb_report_meminfo(char *buf) | |
1408 | { | |
a5516438 | 1409 | struct hstate *h = &default_hstate; |
1da177e4 LT |
1410 | return sprintf(buf, |
1411 | "HugePages_Total: %5lu\n" | |
1412 | "HugePages_Free: %5lu\n" | |
a43a8c39 | 1413 | "HugePages_Rsvd: %5lu\n" |
7893d1d5 | 1414 | "HugePages_Surp: %5lu\n" |
1da177e4 | 1415 | "Hugepagesize: %5lu kB\n", |
a5516438 AK |
1416 | h->nr_huge_pages, |
1417 | h->free_huge_pages, | |
1418 | h->resv_huge_pages, | |
1419 | h->surplus_huge_pages, | |
1420 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); | |
1da177e4 LT |
1421 | } |
1422 | ||
1423 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
1424 | { | |
a5516438 | 1425 | struct hstate *h = &default_hstate; |
1da177e4 LT |
1426 | return sprintf(buf, |
1427 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
1428 | "Node %d HugePages_Free: %5u\n" |
1429 | "Node %d HugePages_Surp: %5u\n", | |
a5516438 AK |
1430 | nid, h->nr_huge_pages_node[nid], |
1431 | nid, h->free_huge_pages_node[nid], | |
1432 | nid, h->surplus_huge_pages_node[nid]); | |
1da177e4 LT |
1433 | } |
1434 | ||
1da177e4 LT |
1435 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
1436 | unsigned long hugetlb_total_pages(void) | |
1437 | { | |
a5516438 AK |
1438 | struct hstate *h = &default_hstate; |
1439 | return h->nr_huge_pages * pages_per_huge_page(h); | |
1da177e4 | 1440 | } |
1da177e4 | 1441 | |
a5516438 | 1442 | static int hugetlb_acct_memory(struct hstate *h, long delta) |
fc1b8a73 MG |
1443 | { |
1444 | int ret = -ENOMEM; | |
1445 | ||
1446 | spin_lock(&hugetlb_lock); | |
1447 | /* | |
1448 | * When cpuset is configured, it breaks the strict hugetlb page | |
1449 | * reservation as the accounting is done on a global variable. Such | |
1450 | * reservation is completely rubbish in the presence of cpuset because | |
1451 | * the reservation is not checked against page availability for the | |
1452 | * current cpuset. Application can still potentially OOM'ed by kernel | |
1453 | * with lack of free htlb page in cpuset that the task is in. | |
1454 | * Attempt to enforce strict accounting with cpuset is almost | |
1455 | * impossible (or too ugly) because cpuset is too fluid that | |
1456 | * task or memory node can be dynamically moved between cpusets. | |
1457 | * | |
1458 | * The change of semantics for shared hugetlb mapping with cpuset is | |
1459 | * undesirable. However, in order to preserve some of the semantics, | |
1460 | * we fall back to check against current free page availability as | |
1461 | * a best attempt and hopefully to minimize the impact of changing | |
1462 | * semantics that cpuset has. | |
1463 | */ | |
1464 | if (delta > 0) { | |
a5516438 | 1465 | if (gather_surplus_pages(h, delta) < 0) |
fc1b8a73 MG |
1466 | goto out; |
1467 | ||
a5516438 AK |
1468 | if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { |
1469 | return_unused_surplus_pages(h, delta); | |
fc1b8a73 MG |
1470 | goto out; |
1471 | } | |
1472 | } | |
1473 | ||
1474 | ret = 0; | |
1475 | if (delta < 0) | |
a5516438 | 1476 | return_unused_surplus_pages(h, (unsigned long) -delta); |
fc1b8a73 MG |
1477 | |
1478 | out: | |
1479 | spin_unlock(&hugetlb_lock); | |
1480 | return ret; | |
1481 | } | |
1482 | ||
84afd99b AW |
1483 | static void hugetlb_vm_op_open(struct vm_area_struct *vma) |
1484 | { | |
1485 | struct resv_map *reservations = vma_resv_map(vma); | |
1486 | ||
1487 | /* | |
1488 | * This new VMA should share its siblings reservation map if present. | |
1489 | * The VMA will only ever have a valid reservation map pointer where | |
1490 | * it is being copied for another still existing VMA. As that VMA | |
1491 | * has a reference to the reservation map it cannot dissappear until | |
1492 | * after this open call completes. It is therefore safe to take a | |
1493 | * new reference here without additional locking. | |
1494 | */ | |
1495 | if (reservations) | |
1496 | kref_get(&reservations->refs); | |
1497 | } | |
1498 | ||
a1e78772 MG |
1499 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
1500 | { | |
a5516438 | 1501 | struct hstate *h = hstate_vma(vma); |
84afd99b AW |
1502 | struct resv_map *reservations = vma_resv_map(vma); |
1503 | unsigned long reserve; | |
1504 | unsigned long start; | |
1505 | unsigned long end; | |
1506 | ||
1507 | if (reservations) { | |
a5516438 AK |
1508 | start = vma_hugecache_offset(h, vma, vma->vm_start); |
1509 | end = vma_hugecache_offset(h, vma, vma->vm_end); | |
84afd99b AW |
1510 | |
1511 | reserve = (end - start) - | |
1512 | region_count(&reservations->regions, start, end); | |
1513 | ||
1514 | kref_put(&reservations->refs, resv_map_release); | |
1515 | ||
1516 | if (reserve) | |
a5516438 | 1517 | hugetlb_acct_memory(h, -reserve); |
84afd99b | 1518 | } |
a1e78772 MG |
1519 | } |
1520 | ||
1da177e4 LT |
1521 | /* |
1522 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
1523 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
1524 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
1525 | * this far. | |
1526 | */ | |
d0217ac0 | 1527 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
1528 | { |
1529 | BUG(); | |
d0217ac0 | 1530 | return 0; |
1da177e4 LT |
1531 | } |
1532 | ||
1533 | struct vm_operations_struct hugetlb_vm_ops = { | |
d0217ac0 | 1534 | .fault = hugetlb_vm_op_fault, |
84afd99b | 1535 | .open = hugetlb_vm_op_open, |
a1e78772 | 1536 | .close = hugetlb_vm_op_close, |
1da177e4 LT |
1537 | }; |
1538 | ||
1e8f889b DG |
1539 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
1540 | int writable) | |
63551ae0 DG |
1541 | { |
1542 | pte_t entry; | |
1543 | ||
1e8f889b | 1544 | if (writable) { |
63551ae0 DG |
1545 | entry = |
1546 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
1547 | } else { | |
7f2e9525 | 1548 | entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
63551ae0 DG |
1549 | } |
1550 | entry = pte_mkyoung(entry); | |
1551 | entry = pte_mkhuge(entry); | |
1552 | ||
1553 | return entry; | |
1554 | } | |
1555 | ||
1e8f889b DG |
1556 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
1557 | unsigned long address, pte_t *ptep) | |
1558 | { | |
1559 | pte_t entry; | |
1560 | ||
7f2e9525 GS |
1561 | entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); |
1562 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { | |
8dab5241 | 1563 | update_mmu_cache(vma, address, entry); |
8dab5241 | 1564 | } |
1e8f889b DG |
1565 | } |
1566 | ||
1567 | ||
63551ae0 DG |
1568 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
1569 | struct vm_area_struct *vma) | |
1570 | { | |
1571 | pte_t *src_pte, *dst_pte, entry; | |
1572 | struct page *ptepage; | |
1c59827d | 1573 | unsigned long addr; |
1e8f889b | 1574 | int cow; |
a5516438 AK |
1575 | struct hstate *h = hstate_vma(vma); |
1576 | unsigned long sz = huge_page_size(h); | |
1e8f889b DG |
1577 | |
1578 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 1579 | |
a5516438 | 1580 | for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { |
c74df32c HD |
1581 | src_pte = huge_pte_offset(src, addr); |
1582 | if (!src_pte) | |
1583 | continue; | |
a5516438 | 1584 | dst_pte = huge_pte_alloc(dst, addr, sz); |
63551ae0 DG |
1585 | if (!dst_pte) |
1586 | goto nomem; | |
c5c99429 LW |
1587 | |
1588 | /* If the pagetables are shared don't copy or take references */ | |
1589 | if (dst_pte == src_pte) | |
1590 | continue; | |
1591 | ||
c74df32c | 1592 | spin_lock(&dst->page_table_lock); |
46478758 | 1593 | spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); |
7f2e9525 | 1594 | if (!huge_pte_none(huge_ptep_get(src_pte))) { |
1e8f889b | 1595 | if (cow) |
7f2e9525 GS |
1596 | huge_ptep_set_wrprotect(src, addr, src_pte); |
1597 | entry = huge_ptep_get(src_pte); | |
1c59827d HD |
1598 | ptepage = pte_page(entry); |
1599 | get_page(ptepage); | |
1c59827d HD |
1600 | set_huge_pte_at(dst, addr, dst_pte, entry); |
1601 | } | |
1602 | spin_unlock(&src->page_table_lock); | |
c74df32c | 1603 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
1604 | } |
1605 | return 0; | |
1606 | ||
1607 | nomem: | |
1608 | return -ENOMEM; | |
1609 | } | |
1610 | ||
502717f4 | 1611 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1612 | unsigned long end, struct page *ref_page) |
63551ae0 DG |
1613 | { |
1614 | struct mm_struct *mm = vma->vm_mm; | |
1615 | unsigned long address; | |
c7546f8f | 1616 | pte_t *ptep; |
63551ae0 DG |
1617 | pte_t pte; |
1618 | struct page *page; | |
fe1668ae | 1619 | struct page *tmp; |
a5516438 AK |
1620 | struct hstate *h = hstate_vma(vma); |
1621 | unsigned long sz = huge_page_size(h); | |
1622 | ||
c0a499c2 CK |
1623 | /* |
1624 | * A page gathering list, protected by per file i_mmap_lock. The | |
1625 | * lock is used to avoid list corruption from multiple unmapping | |
1626 | * of the same page since we are using page->lru. | |
1627 | */ | |
fe1668ae | 1628 | LIST_HEAD(page_list); |
63551ae0 DG |
1629 | |
1630 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
a5516438 AK |
1631 | BUG_ON(start & ~huge_page_mask(h)); |
1632 | BUG_ON(end & ~huge_page_mask(h)); | |
63551ae0 | 1633 | |
508034a3 | 1634 | spin_lock(&mm->page_table_lock); |
a5516438 | 1635 | for (address = start; address < end; address += sz) { |
c7546f8f | 1636 | ptep = huge_pte_offset(mm, address); |
4c887265 | 1637 | if (!ptep) |
c7546f8f DG |
1638 | continue; |
1639 | ||
39dde65c CK |
1640 | if (huge_pmd_unshare(mm, &address, ptep)) |
1641 | continue; | |
1642 | ||
04f2cbe3 MG |
1643 | /* |
1644 | * If a reference page is supplied, it is because a specific | |
1645 | * page is being unmapped, not a range. Ensure the page we | |
1646 | * are about to unmap is the actual page of interest. | |
1647 | */ | |
1648 | if (ref_page) { | |
1649 | pte = huge_ptep_get(ptep); | |
1650 | if (huge_pte_none(pte)) | |
1651 | continue; | |
1652 | page = pte_page(pte); | |
1653 | if (page != ref_page) | |
1654 | continue; | |
1655 | ||
1656 | /* | |
1657 | * Mark the VMA as having unmapped its page so that | |
1658 | * future faults in this VMA will fail rather than | |
1659 | * looking like data was lost | |
1660 | */ | |
1661 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); | |
1662 | } | |
1663 | ||
c7546f8f | 1664 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
7f2e9525 | 1665 | if (huge_pte_none(pte)) |
63551ae0 | 1666 | continue; |
c7546f8f | 1667 | |
63551ae0 | 1668 | page = pte_page(pte); |
6649a386 KC |
1669 | if (pte_dirty(pte)) |
1670 | set_page_dirty(page); | |
fe1668ae | 1671 | list_add(&page->lru, &page_list); |
63551ae0 | 1672 | } |
1da177e4 | 1673 | spin_unlock(&mm->page_table_lock); |
508034a3 | 1674 | flush_tlb_range(vma, start, end); |
fe1668ae CK |
1675 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
1676 | list_del(&page->lru); | |
1677 | put_page(page); | |
1678 | } | |
1da177e4 | 1679 | } |
63551ae0 | 1680 | |
502717f4 | 1681 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1682 | unsigned long end, struct page *ref_page) |
502717f4 | 1683 | { |
a137e1cc AK |
1684 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
1685 | __unmap_hugepage_range(vma, start, end, ref_page); | |
1686 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); | |
502717f4 CK |
1687 | } |
1688 | ||
04f2cbe3 MG |
1689 | /* |
1690 | * This is called when the original mapper is failing to COW a MAP_PRIVATE | |
1691 | * mappping it owns the reserve page for. The intention is to unmap the page | |
1692 | * from other VMAs and let the children be SIGKILLed if they are faulting the | |
1693 | * same region. | |
1694 | */ | |
1695 | int unmap_ref_private(struct mm_struct *mm, | |
1696 | struct vm_area_struct *vma, | |
1697 | struct page *page, | |
1698 | unsigned long address) | |
1699 | { | |
1700 | struct vm_area_struct *iter_vma; | |
1701 | struct address_space *mapping; | |
1702 | struct prio_tree_iter iter; | |
1703 | pgoff_t pgoff; | |
1704 | ||
1705 | /* | |
1706 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation | |
1707 | * from page cache lookup which is in HPAGE_SIZE units. | |
1708 | */ | |
1709 | address = address & huge_page_mask(hstate_vma(vma)); | |
1710 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) | |
1711 | + (vma->vm_pgoff >> PAGE_SHIFT); | |
1712 | mapping = (struct address_space *)page_private(page); | |
1713 | ||
1714 | vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { | |
1715 | /* Do not unmap the current VMA */ | |
1716 | if (iter_vma == vma) | |
1717 | continue; | |
1718 | ||
1719 | /* | |
1720 | * Unmap the page from other VMAs without their own reserves. | |
1721 | * They get marked to be SIGKILLed if they fault in these | |
1722 | * areas. This is because a future no-page fault on this VMA | |
1723 | * could insert a zeroed page instead of the data existing | |
1724 | * from the time of fork. This would look like data corruption | |
1725 | */ | |
1726 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) | |
1727 | unmap_hugepage_range(iter_vma, | |
1728 | address, address + HPAGE_SIZE, | |
1729 | page); | |
1730 | } | |
1731 | ||
1732 | return 1; | |
1733 | } | |
1734 | ||
1e8f889b | 1735 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
04f2cbe3 MG |
1736 | unsigned long address, pte_t *ptep, pte_t pte, |
1737 | struct page *pagecache_page) | |
1e8f889b | 1738 | { |
a5516438 | 1739 | struct hstate *h = hstate_vma(vma); |
1e8f889b | 1740 | struct page *old_page, *new_page; |
79ac6ba4 | 1741 | int avoidcopy; |
04f2cbe3 | 1742 | int outside_reserve = 0; |
1e8f889b DG |
1743 | |
1744 | old_page = pte_page(pte); | |
1745 | ||
04f2cbe3 | 1746 | retry_avoidcopy: |
1e8f889b DG |
1747 | /* If no-one else is actually using this page, avoid the copy |
1748 | * and just make the page writable */ | |
1749 | avoidcopy = (page_count(old_page) == 1); | |
1750 | if (avoidcopy) { | |
1751 | set_huge_ptep_writable(vma, address, ptep); | |
83c54070 | 1752 | return 0; |
1e8f889b DG |
1753 | } |
1754 | ||
04f2cbe3 MG |
1755 | /* |
1756 | * If the process that created a MAP_PRIVATE mapping is about to | |
1757 | * perform a COW due to a shared page count, attempt to satisfy | |
1758 | * the allocation without using the existing reserves. The pagecache | |
1759 | * page is used to determine if the reserve at this address was | |
1760 | * consumed or not. If reserves were used, a partial faulted mapping | |
1761 | * at the time of fork() could consume its reserves on COW instead | |
1762 | * of the full address range. | |
1763 | */ | |
1764 | if (!(vma->vm_flags & VM_SHARED) && | |
1765 | is_vma_resv_set(vma, HPAGE_RESV_OWNER) && | |
1766 | old_page != pagecache_page) | |
1767 | outside_reserve = 1; | |
1768 | ||
1e8f889b | 1769 | page_cache_get(old_page); |
04f2cbe3 | 1770 | new_page = alloc_huge_page(vma, address, outside_reserve); |
1e8f889b | 1771 | |
2fc39cec | 1772 | if (IS_ERR(new_page)) { |
1e8f889b | 1773 | page_cache_release(old_page); |
04f2cbe3 MG |
1774 | |
1775 | /* | |
1776 | * If a process owning a MAP_PRIVATE mapping fails to COW, | |
1777 | * it is due to references held by a child and an insufficient | |
1778 | * huge page pool. To guarantee the original mappers | |
1779 | * reliability, unmap the page from child processes. The child | |
1780 | * may get SIGKILLed if it later faults. | |
1781 | */ | |
1782 | if (outside_reserve) { | |
1783 | BUG_ON(huge_pte_none(pte)); | |
1784 | if (unmap_ref_private(mm, vma, old_page, address)) { | |
1785 | BUG_ON(page_count(old_page) != 1); | |
1786 | BUG_ON(huge_pte_none(pte)); | |
1787 | goto retry_avoidcopy; | |
1788 | } | |
1789 | WARN_ON_ONCE(1); | |
1790 | } | |
1791 | ||
2fc39cec | 1792 | return -PTR_ERR(new_page); |
1e8f889b DG |
1793 | } |
1794 | ||
1795 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 1796 | copy_huge_page(new_page, old_page, address, vma); |
0ed361de | 1797 | __SetPageUptodate(new_page); |
1e8f889b DG |
1798 | spin_lock(&mm->page_table_lock); |
1799 | ||
a5516438 | 1800 | ptep = huge_pte_offset(mm, address & huge_page_mask(h)); |
7f2e9525 | 1801 | if (likely(pte_same(huge_ptep_get(ptep), pte))) { |
1e8f889b | 1802 | /* Break COW */ |
8fe627ec | 1803 | huge_ptep_clear_flush(vma, address, ptep); |
1e8f889b DG |
1804 | set_huge_pte_at(mm, address, ptep, |
1805 | make_huge_pte(vma, new_page, 1)); | |
1806 | /* Make the old page be freed below */ | |
1807 | new_page = old_page; | |
1808 | } | |
1809 | page_cache_release(new_page); | |
1810 | page_cache_release(old_page); | |
83c54070 | 1811 | return 0; |
1e8f889b DG |
1812 | } |
1813 | ||
04f2cbe3 | 1814 | /* Return the pagecache page at a given address within a VMA */ |
a5516438 AK |
1815 | static struct page *hugetlbfs_pagecache_page(struct hstate *h, |
1816 | struct vm_area_struct *vma, unsigned long address) | |
04f2cbe3 MG |
1817 | { |
1818 | struct address_space *mapping; | |
e7c4b0bf | 1819 | pgoff_t idx; |
04f2cbe3 MG |
1820 | |
1821 | mapping = vma->vm_file->f_mapping; | |
a5516438 | 1822 | idx = vma_hugecache_offset(h, vma, address); |
04f2cbe3 MG |
1823 | |
1824 | return find_lock_page(mapping, idx); | |
1825 | } | |
1826 | ||
a1ed3dda | 1827 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 1828 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 | 1829 | { |
a5516438 | 1830 | struct hstate *h = hstate_vma(vma); |
ac9b9c66 | 1831 | int ret = VM_FAULT_SIGBUS; |
e7c4b0bf | 1832 | pgoff_t idx; |
4c887265 | 1833 | unsigned long size; |
4c887265 AL |
1834 | struct page *page; |
1835 | struct address_space *mapping; | |
1e8f889b | 1836 | pte_t new_pte; |
4c887265 | 1837 | |
04f2cbe3 MG |
1838 | /* |
1839 | * Currently, we are forced to kill the process in the event the | |
1840 | * original mapper has unmapped pages from the child due to a failed | |
1841 | * COW. Warn that such a situation has occured as it may not be obvious | |
1842 | */ | |
1843 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { | |
1844 | printk(KERN_WARNING | |
1845 | "PID %d killed due to inadequate hugepage pool\n", | |
1846 | current->pid); | |
1847 | return ret; | |
1848 | } | |
1849 | ||
4c887265 | 1850 | mapping = vma->vm_file->f_mapping; |
a5516438 | 1851 | idx = vma_hugecache_offset(h, vma, address); |
4c887265 AL |
1852 | |
1853 | /* | |
1854 | * Use page lock to guard against racing truncation | |
1855 | * before we get page_table_lock. | |
1856 | */ | |
6bda666a CL |
1857 | retry: |
1858 | page = find_lock_page(mapping, idx); | |
1859 | if (!page) { | |
a5516438 | 1860 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
ebed4bfc HD |
1861 | if (idx >= size) |
1862 | goto out; | |
04f2cbe3 | 1863 | page = alloc_huge_page(vma, address, 0); |
2fc39cec AL |
1864 | if (IS_ERR(page)) { |
1865 | ret = -PTR_ERR(page); | |
6bda666a CL |
1866 | goto out; |
1867 | } | |
a5516438 | 1868 | clear_huge_page(page, address, huge_page_size(h)); |
0ed361de | 1869 | __SetPageUptodate(page); |
ac9b9c66 | 1870 | |
6bda666a CL |
1871 | if (vma->vm_flags & VM_SHARED) { |
1872 | int err; | |
45c682a6 | 1873 | struct inode *inode = mapping->host; |
6bda666a CL |
1874 | |
1875 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
1876 | if (err) { | |
1877 | put_page(page); | |
6bda666a CL |
1878 | if (err == -EEXIST) |
1879 | goto retry; | |
1880 | goto out; | |
1881 | } | |
45c682a6 KC |
1882 | |
1883 | spin_lock(&inode->i_lock); | |
a5516438 | 1884 | inode->i_blocks += blocks_per_huge_page(h); |
45c682a6 | 1885 | spin_unlock(&inode->i_lock); |
6bda666a CL |
1886 | } else |
1887 | lock_page(page); | |
1888 | } | |
1e8f889b | 1889 | |
ac9b9c66 | 1890 | spin_lock(&mm->page_table_lock); |
a5516438 | 1891 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
4c887265 AL |
1892 | if (idx >= size) |
1893 | goto backout; | |
1894 | ||
83c54070 | 1895 | ret = 0; |
7f2e9525 | 1896 | if (!huge_pte_none(huge_ptep_get(ptep))) |
4c887265 AL |
1897 | goto backout; |
1898 | ||
1e8f889b DG |
1899 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
1900 | && (vma->vm_flags & VM_SHARED))); | |
1901 | set_huge_pte_at(mm, address, ptep, new_pte); | |
1902 | ||
1903 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
1904 | /* Optimization, do the COW without a second fault */ | |
04f2cbe3 | 1905 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); |
1e8f889b DG |
1906 | } |
1907 | ||
ac9b9c66 | 1908 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
1909 | unlock_page(page); |
1910 | out: | |
ac9b9c66 | 1911 | return ret; |
4c887265 AL |
1912 | |
1913 | backout: | |
1914 | spin_unlock(&mm->page_table_lock); | |
4c887265 AL |
1915 | unlock_page(page); |
1916 | put_page(page); | |
1917 | goto out; | |
ac9b9c66 HD |
1918 | } |
1919 | ||
86e5216f AL |
1920 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
1921 | unsigned long address, int write_access) | |
1922 | { | |
1923 | pte_t *ptep; | |
1924 | pte_t entry; | |
1e8f889b | 1925 | int ret; |
3935baa9 | 1926 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
a5516438 | 1927 | struct hstate *h = hstate_vma(vma); |
86e5216f | 1928 | |
a5516438 | 1929 | ptep = huge_pte_alloc(mm, address, huge_page_size(h)); |
86e5216f AL |
1930 | if (!ptep) |
1931 | return VM_FAULT_OOM; | |
1932 | ||
3935baa9 DG |
1933 | /* |
1934 | * Serialize hugepage allocation and instantiation, so that we don't | |
1935 | * get spurious allocation failures if two CPUs race to instantiate | |
1936 | * the same page in the page cache. | |
1937 | */ | |
1938 | mutex_lock(&hugetlb_instantiation_mutex); | |
7f2e9525 GS |
1939 | entry = huge_ptep_get(ptep); |
1940 | if (huge_pte_none(entry)) { | |
3935baa9 DG |
1941 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); |
1942 | mutex_unlock(&hugetlb_instantiation_mutex); | |
1943 | return ret; | |
1944 | } | |
86e5216f | 1945 | |
83c54070 | 1946 | ret = 0; |
1e8f889b DG |
1947 | |
1948 | spin_lock(&mm->page_table_lock); | |
1949 | /* Check for a racing update before calling hugetlb_cow */ | |
7f2e9525 | 1950 | if (likely(pte_same(entry, huge_ptep_get(ptep)))) |
04f2cbe3 MG |
1951 | if (write_access && !pte_write(entry)) { |
1952 | struct page *page; | |
a5516438 | 1953 | page = hugetlbfs_pagecache_page(h, vma, address); |
04f2cbe3 MG |
1954 | ret = hugetlb_cow(mm, vma, address, ptep, entry, page); |
1955 | if (page) { | |
1956 | unlock_page(page); | |
1957 | put_page(page); | |
1958 | } | |
1959 | } | |
1e8f889b | 1960 | spin_unlock(&mm->page_table_lock); |
3935baa9 | 1961 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
1962 | |
1963 | return ret; | |
86e5216f AL |
1964 | } |
1965 | ||
63551ae0 DG |
1966 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1967 | struct page **pages, struct vm_area_struct **vmas, | |
5b23dbe8 AL |
1968 | unsigned long *position, int *length, int i, |
1969 | int write) | |
63551ae0 | 1970 | { |
d5d4b0aa CK |
1971 | unsigned long pfn_offset; |
1972 | unsigned long vaddr = *position; | |
63551ae0 | 1973 | int remainder = *length; |
a5516438 | 1974 | struct hstate *h = hstate_vma(vma); |
63551ae0 | 1975 | |
1c59827d | 1976 | spin_lock(&mm->page_table_lock); |
63551ae0 | 1977 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
1978 | pte_t *pte; |
1979 | struct page *page; | |
63551ae0 | 1980 | |
4c887265 AL |
1981 | /* |
1982 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
1983 | * each hugepage. We have to make * sure we get the | |
1984 | * first, for the page indexing below to work. | |
1985 | */ | |
a5516438 | 1986 | pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); |
63551ae0 | 1987 | |
7f2e9525 GS |
1988 | if (!pte || huge_pte_none(huge_ptep_get(pte)) || |
1989 | (write && !pte_write(huge_ptep_get(pte)))) { | |
4c887265 | 1990 | int ret; |
63551ae0 | 1991 | |
4c887265 | 1992 | spin_unlock(&mm->page_table_lock); |
5b23dbe8 | 1993 | ret = hugetlb_fault(mm, vma, vaddr, write); |
4c887265 | 1994 | spin_lock(&mm->page_table_lock); |
a89182c7 | 1995 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 1996 | continue; |
63551ae0 | 1997 | |
4c887265 AL |
1998 | remainder = 0; |
1999 | if (!i) | |
2000 | i = -EFAULT; | |
2001 | break; | |
2002 | } | |
2003 | ||
a5516438 | 2004 | pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; |
7f2e9525 | 2005 | page = pte_page(huge_ptep_get(pte)); |
d5d4b0aa | 2006 | same_page: |
d6692183 CK |
2007 | if (pages) { |
2008 | get_page(page); | |
d5d4b0aa | 2009 | pages[i] = page + pfn_offset; |
d6692183 | 2010 | } |
63551ae0 DG |
2011 | |
2012 | if (vmas) | |
2013 | vmas[i] = vma; | |
2014 | ||
2015 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 2016 | ++pfn_offset; |
63551ae0 DG |
2017 | --remainder; |
2018 | ++i; | |
d5d4b0aa | 2019 | if (vaddr < vma->vm_end && remainder && |
a5516438 | 2020 | pfn_offset < pages_per_huge_page(h)) { |
d5d4b0aa CK |
2021 | /* |
2022 | * We use pfn_offset to avoid touching the pageframes | |
2023 | * of this compound page. | |
2024 | */ | |
2025 | goto same_page; | |
2026 | } | |
63551ae0 | 2027 | } |
1c59827d | 2028 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
2029 | *length = remainder; |
2030 | *position = vaddr; | |
2031 | ||
2032 | return i; | |
2033 | } | |
8f860591 ZY |
2034 | |
2035 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
2036 | unsigned long address, unsigned long end, pgprot_t newprot) | |
2037 | { | |
2038 | struct mm_struct *mm = vma->vm_mm; | |
2039 | unsigned long start = address; | |
2040 | pte_t *ptep; | |
2041 | pte_t pte; | |
a5516438 | 2042 | struct hstate *h = hstate_vma(vma); |
8f860591 ZY |
2043 | |
2044 | BUG_ON(address >= end); | |
2045 | flush_cache_range(vma, address, end); | |
2046 | ||
39dde65c | 2047 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 | 2048 | spin_lock(&mm->page_table_lock); |
a5516438 | 2049 | for (; address < end; address += huge_page_size(h)) { |
8f860591 ZY |
2050 | ptep = huge_pte_offset(mm, address); |
2051 | if (!ptep) | |
2052 | continue; | |
39dde65c CK |
2053 | if (huge_pmd_unshare(mm, &address, ptep)) |
2054 | continue; | |
7f2e9525 | 2055 | if (!huge_pte_none(huge_ptep_get(ptep))) { |
8f860591 ZY |
2056 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
2057 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
2058 | set_huge_pte_at(mm, address, ptep, pte); | |
8f860591 ZY |
2059 | } |
2060 | } | |
2061 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 2062 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
2063 | |
2064 | flush_tlb_range(vma, start, end); | |
2065 | } | |
2066 | ||
a1e78772 MG |
2067 | int hugetlb_reserve_pages(struct inode *inode, |
2068 | long from, long to, | |
2069 | struct vm_area_struct *vma) | |
e4e574b7 AL |
2070 | { |
2071 | long ret, chg; | |
a5516438 | 2072 | struct hstate *h = hstate_inode(inode); |
e4e574b7 | 2073 | |
c37f9fb1 AW |
2074 | if (vma && vma->vm_flags & VM_NORESERVE) |
2075 | return 0; | |
2076 | ||
a1e78772 MG |
2077 | /* |
2078 | * Shared mappings base their reservation on the number of pages that | |
2079 | * are already allocated on behalf of the file. Private mappings need | |
2080 | * to reserve the full area even if read-only as mprotect() may be | |
2081 | * called to make the mapping read-write. Assume !vma is a shm mapping | |
2082 | */ | |
2083 | if (!vma || vma->vm_flags & VM_SHARED) | |
2084 | chg = region_chg(&inode->i_mapping->private_list, from, to); | |
2085 | else { | |
84afd99b AW |
2086 | struct resv_map *resv_map = resv_map_alloc(); |
2087 | if (!resv_map) | |
2088 | return -ENOMEM; | |
2089 | ||
a1e78772 | 2090 | chg = to - from; |
84afd99b AW |
2091 | |
2092 | set_vma_resv_map(vma, resv_map); | |
04f2cbe3 | 2093 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); |
a1e78772 MG |
2094 | } |
2095 | ||
e4e574b7 AL |
2096 | if (chg < 0) |
2097 | return chg; | |
8a630112 | 2098 | |
90d8b7e6 AL |
2099 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
2100 | return -ENOSPC; | |
a5516438 | 2101 | ret = hugetlb_acct_memory(h, chg); |
68842c9b KC |
2102 | if (ret < 0) { |
2103 | hugetlb_put_quota(inode->i_mapping, chg); | |
a43a8c39 | 2104 | return ret; |
68842c9b | 2105 | } |
a1e78772 MG |
2106 | if (!vma || vma->vm_flags & VM_SHARED) |
2107 | region_add(&inode->i_mapping->private_list, from, to); | |
a43a8c39 CK |
2108 | return 0; |
2109 | } | |
2110 | ||
2111 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
2112 | { | |
a5516438 | 2113 | struct hstate *h = hstate_inode(inode); |
a43a8c39 | 2114 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
45c682a6 KC |
2115 | |
2116 | spin_lock(&inode->i_lock); | |
a5516438 | 2117 | inode->i_blocks -= blocks_per_huge_page(h); |
45c682a6 KC |
2118 | spin_unlock(&inode->i_lock); |
2119 | ||
90d8b7e6 | 2120 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
a5516438 | 2121 | hugetlb_acct_memory(h, -(chg - freed)); |
a43a8c39 | 2122 | } |