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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> | |
cddb8a5c | 12 | #include <linux/mmu_notifier.h> |
1da177e4 | 13 | #include <linux/nodemask.h> |
63551ae0 | 14 | #include <linux/pagemap.h> |
5da7ca86 | 15 | #include <linux/mempolicy.h> |
aea47ff3 | 16 | #include <linux/cpuset.h> |
3935baa9 | 17 | #include <linux/mutex.h> |
aa888a74 | 18 | #include <linux/bootmem.h> |
a3437870 | 19 | #include <linux/sysfs.h> |
5da7ca86 | 20 | |
63551ae0 DG |
21 | #include <asm/page.h> |
22 | #include <asm/pgtable.h> | |
23 | ||
24 | #include <linux/hugetlb.h> | |
7835e98b | 25 | #include "internal.h" |
1da177e4 LT |
26 | |
27 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; | |
396faf03 MG |
28 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
29 | unsigned long hugepages_treat_as_movable; | |
a5516438 | 30 | |
e5ff2159 AK |
31 | static int max_hstate; |
32 | unsigned int default_hstate_idx; | |
33 | struct hstate hstates[HUGE_MAX_HSTATE]; | |
34 | ||
53ba51d2 JT |
35 | __initdata LIST_HEAD(huge_boot_pages); |
36 | ||
e5ff2159 AK |
37 | /* for command line parsing */ |
38 | static struct hstate * __initdata parsed_hstate; | |
39 | static unsigned long __initdata default_hstate_max_huge_pages; | |
e11bfbfc | 40 | static unsigned long __initdata default_hstate_size; |
e5ff2159 AK |
41 | |
42 | #define for_each_hstate(h) \ | |
43 | for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++) | |
396faf03 | 44 | |
3935baa9 DG |
45 | /* |
46 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages | |
47 | */ | |
48 | static DEFINE_SPINLOCK(hugetlb_lock); | |
0bd0f9fb | 49 | |
96822904 AW |
50 | /* |
51 | * Region tracking -- allows tracking of reservations and instantiated pages | |
52 | * across the pages in a mapping. | |
84afd99b AW |
53 | * |
54 | * The region data structures are protected by a combination of the mmap_sem | |
55 | * and the hugetlb_instantion_mutex. To access or modify a region the caller | |
56 | * must either hold the mmap_sem for write, or the mmap_sem for read and | |
57 | * the hugetlb_instantiation mutex: | |
58 | * | |
59 | * down_write(&mm->mmap_sem); | |
60 | * or | |
61 | * down_read(&mm->mmap_sem); | |
62 | * mutex_lock(&hugetlb_instantiation_mutex); | |
96822904 AW |
63 | */ |
64 | struct file_region { | |
65 | struct list_head link; | |
66 | long from; | |
67 | long to; | |
68 | }; | |
69 | ||
70 | static long region_add(struct list_head *head, long f, long t) | |
71 | { | |
72 | struct file_region *rg, *nrg, *trg; | |
73 | ||
74 | /* Locate the region we are either in or before. */ | |
75 | list_for_each_entry(rg, head, link) | |
76 | if (f <= rg->to) | |
77 | break; | |
78 | ||
79 | /* Round our left edge to the current segment if it encloses us. */ | |
80 | if (f > rg->from) | |
81 | f = rg->from; | |
82 | ||
83 | /* Check for and consume any regions we now overlap with. */ | |
84 | nrg = rg; | |
85 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
86 | if (&rg->link == head) | |
87 | break; | |
88 | if (rg->from > t) | |
89 | break; | |
90 | ||
91 | /* If this area reaches higher then extend our area to | |
92 | * include it completely. If this is not the first area | |
93 | * which we intend to reuse, free it. */ | |
94 | if (rg->to > t) | |
95 | t = rg->to; | |
96 | if (rg != nrg) { | |
97 | list_del(&rg->link); | |
98 | kfree(rg); | |
99 | } | |
100 | } | |
101 | nrg->from = f; | |
102 | nrg->to = t; | |
103 | return 0; | |
104 | } | |
105 | ||
106 | static long region_chg(struct list_head *head, long f, long t) | |
107 | { | |
108 | struct file_region *rg, *nrg; | |
109 | long chg = 0; | |
110 | ||
111 | /* Locate the region we are before or in. */ | |
112 | list_for_each_entry(rg, head, link) | |
113 | if (f <= rg->to) | |
114 | break; | |
115 | ||
116 | /* If we are below the current region then a new region is required. | |
117 | * Subtle, allocate a new region at the position but make it zero | |
118 | * size such that we can guarantee to record the reservation. */ | |
119 | if (&rg->link == head || t < rg->from) { | |
120 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
121 | if (!nrg) | |
122 | return -ENOMEM; | |
123 | nrg->from = f; | |
124 | nrg->to = f; | |
125 | INIT_LIST_HEAD(&nrg->link); | |
126 | list_add(&nrg->link, rg->link.prev); | |
127 | ||
128 | return t - f; | |
129 | } | |
130 | ||
131 | /* Round our left edge to the current segment if it encloses us. */ | |
132 | if (f > rg->from) | |
133 | f = rg->from; | |
134 | chg = t - f; | |
135 | ||
136 | /* Check for and consume any regions we now overlap with. */ | |
137 | list_for_each_entry(rg, rg->link.prev, link) { | |
138 | if (&rg->link == head) | |
139 | break; | |
140 | if (rg->from > t) | |
141 | return chg; | |
142 | ||
143 | /* We overlap with this area, if it extends futher than | |
144 | * us then we must extend ourselves. Account for its | |
145 | * existing reservation. */ | |
146 | if (rg->to > t) { | |
147 | chg += rg->to - t; | |
148 | t = rg->to; | |
149 | } | |
150 | chg -= rg->to - rg->from; | |
151 | } | |
152 | return chg; | |
153 | } | |
154 | ||
155 | static long region_truncate(struct list_head *head, long end) | |
156 | { | |
157 | struct file_region *rg, *trg; | |
158 | long chg = 0; | |
159 | ||
160 | /* Locate the region we are either in or before. */ | |
161 | list_for_each_entry(rg, head, link) | |
162 | if (end <= rg->to) | |
163 | break; | |
164 | if (&rg->link == head) | |
165 | return 0; | |
166 | ||
167 | /* If we are in the middle of a region then adjust it. */ | |
168 | if (end > rg->from) { | |
169 | chg = rg->to - end; | |
170 | rg->to = end; | |
171 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
172 | } | |
173 | ||
174 | /* Drop any remaining regions. */ | |
175 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
176 | if (&rg->link == head) | |
177 | break; | |
178 | chg += rg->to - rg->from; | |
179 | list_del(&rg->link); | |
180 | kfree(rg); | |
181 | } | |
182 | return chg; | |
183 | } | |
184 | ||
84afd99b AW |
185 | static long region_count(struct list_head *head, long f, long t) |
186 | { | |
187 | struct file_region *rg; | |
188 | long chg = 0; | |
189 | ||
190 | /* Locate each segment we overlap with, and count that overlap. */ | |
191 | list_for_each_entry(rg, head, link) { | |
192 | int seg_from; | |
193 | int seg_to; | |
194 | ||
195 | if (rg->to <= f) | |
196 | continue; | |
197 | if (rg->from >= t) | |
198 | break; | |
199 | ||
200 | seg_from = max(rg->from, f); | |
201 | seg_to = min(rg->to, t); | |
202 | ||
203 | chg += seg_to - seg_from; | |
204 | } | |
205 | ||
206 | return chg; | |
207 | } | |
208 | ||
e7c4b0bf AW |
209 | /* |
210 | * Convert the address within this vma to the page offset within | |
211 | * the mapping, in pagecache page units; huge pages here. | |
212 | */ | |
a5516438 AK |
213 | static pgoff_t vma_hugecache_offset(struct hstate *h, |
214 | struct vm_area_struct *vma, unsigned long address) | |
e7c4b0bf | 215 | { |
a5516438 AK |
216 | return ((address - vma->vm_start) >> huge_page_shift(h)) + |
217 | (vma->vm_pgoff >> huge_page_order(h)); | |
e7c4b0bf AW |
218 | } |
219 | ||
84afd99b AW |
220 | /* |
221 | * Flags for MAP_PRIVATE reservations. These are stored in the bottom | |
222 | * bits of the reservation map pointer, which are always clear due to | |
223 | * alignment. | |
224 | */ | |
225 | #define HPAGE_RESV_OWNER (1UL << 0) | |
226 | #define HPAGE_RESV_UNMAPPED (1UL << 1) | |
04f2cbe3 | 227 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) |
84afd99b | 228 | |
a1e78772 MG |
229 | /* |
230 | * These helpers are used to track how many pages are reserved for | |
231 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() | |
232 | * is guaranteed to have their future faults succeed. | |
233 | * | |
234 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), | |
235 | * the reserve counters are updated with the hugetlb_lock held. It is safe | |
236 | * to reset the VMA at fork() time as it is not in use yet and there is no | |
237 | * chance of the global counters getting corrupted as a result of the values. | |
84afd99b AW |
238 | * |
239 | * The private mapping reservation is represented in a subtly different | |
240 | * manner to a shared mapping. A shared mapping has a region map associated | |
241 | * with the underlying file, this region map represents the backing file | |
242 | * pages which have ever had a reservation assigned which this persists even | |
243 | * after the page is instantiated. A private mapping has a region map | |
244 | * associated with the original mmap which is attached to all VMAs which | |
245 | * reference it, this region map represents those offsets which have consumed | |
246 | * reservation ie. where pages have been instantiated. | |
a1e78772 | 247 | */ |
e7c4b0bf AW |
248 | static unsigned long get_vma_private_data(struct vm_area_struct *vma) |
249 | { | |
250 | return (unsigned long)vma->vm_private_data; | |
251 | } | |
252 | ||
253 | static void set_vma_private_data(struct vm_area_struct *vma, | |
254 | unsigned long value) | |
255 | { | |
256 | vma->vm_private_data = (void *)value; | |
257 | } | |
258 | ||
84afd99b AW |
259 | struct resv_map { |
260 | struct kref refs; | |
261 | struct list_head regions; | |
262 | }; | |
263 | ||
264 | struct resv_map *resv_map_alloc(void) | |
265 | { | |
266 | struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); | |
267 | if (!resv_map) | |
268 | return NULL; | |
269 | ||
270 | kref_init(&resv_map->refs); | |
271 | INIT_LIST_HEAD(&resv_map->regions); | |
272 | ||
273 | return resv_map; | |
274 | } | |
275 | ||
276 | void resv_map_release(struct kref *ref) | |
277 | { | |
278 | struct resv_map *resv_map = container_of(ref, struct resv_map, refs); | |
279 | ||
280 | /* Clear out any active regions before we release the map. */ | |
281 | region_truncate(&resv_map->regions, 0); | |
282 | kfree(resv_map); | |
283 | } | |
284 | ||
285 | static struct resv_map *vma_resv_map(struct vm_area_struct *vma) | |
a1e78772 MG |
286 | { |
287 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
288 | if (!(vma->vm_flags & VM_SHARED)) | |
84afd99b AW |
289 | return (struct resv_map *)(get_vma_private_data(vma) & |
290 | ~HPAGE_RESV_MASK); | |
a1e78772 MG |
291 | return 0; |
292 | } | |
293 | ||
84afd99b | 294 | static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) |
a1e78772 MG |
295 | { |
296 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
297 | VM_BUG_ON(vma->vm_flags & VM_SHARED); | |
298 | ||
84afd99b AW |
299 | set_vma_private_data(vma, (get_vma_private_data(vma) & |
300 | HPAGE_RESV_MASK) | (unsigned long)map); | |
04f2cbe3 MG |
301 | } |
302 | ||
303 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) | |
304 | { | |
04f2cbe3 | 305 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
e7c4b0bf AW |
306 | VM_BUG_ON(vma->vm_flags & VM_SHARED); |
307 | ||
308 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); | |
04f2cbe3 MG |
309 | } |
310 | ||
311 | static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) | |
312 | { | |
313 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
e7c4b0bf AW |
314 | |
315 | return (get_vma_private_data(vma) & flag) != 0; | |
a1e78772 MG |
316 | } |
317 | ||
318 | /* Decrement the reserved pages in the hugepage pool by one */ | |
a5516438 AK |
319 | static void decrement_hugepage_resv_vma(struct hstate *h, |
320 | struct vm_area_struct *vma) | |
a1e78772 | 321 | { |
c37f9fb1 AW |
322 | if (vma->vm_flags & VM_NORESERVE) |
323 | return; | |
324 | ||
a1e78772 MG |
325 | if (vma->vm_flags & VM_SHARED) { |
326 | /* Shared mappings always use reserves */ | |
a5516438 | 327 | h->resv_huge_pages--; |
84afd99b | 328 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
a1e78772 MG |
329 | /* |
330 | * Only the process that called mmap() has reserves for | |
331 | * private mappings. | |
332 | */ | |
a5516438 | 333 | h->resv_huge_pages--; |
a1e78772 MG |
334 | } |
335 | } | |
336 | ||
04f2cbe3 | 337 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
a1e78772 MG |
338 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
339 | { | |
340 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
341 | if (!(vma->vm_flags & VM_SHARED)) | |
342 | vma->vm_private_data = (void *)0; | |
343 | } | |
344 | ||
345 | /* Returns true if the VMA has associated reserve pages */ | |
7f09ca51 | 346 | static int vma_has_reserves(struct vm_area_struct *vma) |
a1e78772 MG |
347 | { |
348 | if (vma->vm_flags & VM_SHARED) | |
7f09ca51 MG |
349 | return 1; |
350 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) | |
351 | return 1; | |
352 | return 0; | |
a1e78772 MG |
353 | } |
354 | ||
a5516438 AK |
355 | static void clear_huge_page(struct page *page, |
356 | unsigned long addr, unsigned long sz) | |
79ac6ba4 DG |
357 | { |
358 | int i; | |
359 | ||
360 | might_sleep(); | |
a5516438 | 361 | for (i = 0; i < sz/PAGE_SIZE; i++) { |
79ac6ba4 | 362 | cond_resched(); |
281e0e3b | 363 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
79ac6ba4 DG |
364 | } |
365 | } | |
366 | ||
367 | static void copy_huge_page(struct page *dst, struct page *src, | |
9de455b2 | 368 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
369 | { |
370 | int i; | |
a5516438 | 371 | struct hstate *h = hstate_vma(vma); |
79ac6ba4 DG |
372 | |
373 | might_sleep(); | |
a5516438 | 374 | for (i = 0; i < pages_per_huge_page(h); i++) { |
79ac6ba4 | 375 | cond_resched(); |
9de455b2 | 376 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
377 | } |
378 | } | |
379 | ||
a5516438 | 380 | static void enqueue_huge_page(struct hstate *h, struct page *page) |
1da177e4 LT |
381 | { |
382 | int nid = page_to_nid(page); | |
a5516438 AK |
383 | list_add(&page->lru, &h->hugepage_freelists[nid]); |
384 | h->free_huge_pages++; | |
385 | h->free_huge_pages_node[nid]++; | |
1da177e4 LT |
386 | } |
387 | ||
a5516438 | 388 | static struct page *dequeue_huge_page(struct hstate *h) |
348e1e04 NA |
389 | { |
390 | int nid; | |
391 | struct page *page = NULL; | |
392 | ||
393 | for (nid = 0; nid < MAX_NUMNODES; ++nid) { | |
a5516438 AK |
394 | if (!list_empty(&h->hugepage_freelists[nid])) { |
395 | page = list_entry(h->hugepage_freelists[nid].next, | |
348e1e04 NA |
396 | struct page, lru); |
397 | list_del(&page->lru); | |
a5516438 AK |
398 | h->free_huge_pages--; |
399 | h->free_huge_pages_node[nid]--; | |
348e1e04 NA |
400 | break; |
401 | } | |
402 | } | |
403 | return page; | |
404 | } | |
405 | ||
a5516438 AK |
406 | static struct page *dequeue_huge_page_vma(struct hstate *h, |
407 | struct vm_area_struct *vma, | |
04f2cbe3 | 408 | unsigned long address, int avoid_reserve) |
1da177e4 | 409 | { |
31a5c6e4 | 410 | int nid; |
1da177e4 | 411 | struct page *page = NULL; |
480eccf9 | 412 | struct mempolicy *mpol; |
19770b32 | 413 | nodemask_t *nodemask; |
396faf03 | 414 | struct zonelist *zonelist = huge_zonelist(vma, address, |
19770b32 | 415 | htlb_alloc_mask, &mpol, &nodemask); |
dd1a239f MG |
416 | struct zone *zone; |
417 | struct zoneref *z; | |
1da177e4 | 418 | |
a1e78772 MG |
419 | /* |
420 | * A child process with MAP_PRIVATE mappings created by their parent | |
421 | * have no page reserves. This check ensures that reservations are | |
422 | * not "stolen". The child may still get SIGKILLed | |
423 | */ | |
7f09ca51 | 424 | if (!vma_has_reserves(vma) && |
a5516438 | 425 | h->free_huge_pages - h->resv_huge_pages == 0) |
a1e78772 MG |
426 | return NULL; |
427 | ||
04f2cbe3 | 428 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
a5516438 | 429 | if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) |
04f2cbe3 MG |
430 | return NULL; |
431 | ||
19770b32 MG |
432 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
433 | MAX_NR_ZONES - 1, nodemask) { | |
54a6eb5c MG |
434 | nid = zone_to_nid(zone); |
435 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && | |
a5516438 AK |
436 | !list_empty(&h->hugepage_freelists[nid])) { |
437 | page = list_entry(h->hugepage_freelists[nid].next, | |
3abf7afd AM |
438 | struct page, lru); |
439 | list_del(&page->lru); | |
a5516438 AK |
440 | h->free_huge_pages--; |
441 | h->free_huge_pages_node[nid]--; | |
04f2cbe3 MG |
442 | |
443 | if (!avoid_reserve) | |
a5516438 | 444 | decrement_hugepage_resv_vma(h, vma); |
a1e78772 | 445 | |
5ab3ee7b | 446 | break; |
3abf7afd | 447 | } |
1da177e4 | 448 | } |
52cd3b07 | 449 | mpol_cond_put(mpol); |
1da177e4 LT |
450 | return page; |
451 | } | |
452 | ||
a5516438 | 453 | static void update_and_free_page(struct hstate *h, struct page *page) |
6af2acb6 AL |
454 | { |
455 | int i; | |
a5516438 AK |
456 | |
457 | h->nr_huge_pages--; | |
458 | h->nr_huge_pages_node[page_to_nid(page)]--; | |
459 | for (i = 0; i < pages_per_huge_page(h); i++) { | |
6af2acb6 AL |
460 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | |
461 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
462 | 1 << PG_private | 1<< PG_writeback); | |
463 | } | |
464 | set_compound_page_dtor(page, NULL); | |
465 | set_page_refcounted(page); | |
7f2e9525 | 466 | arch_release_hugepage(page); |
a5516438 | 467 | __free_pages(page, huge_page_order(h)); |
6af2acb6 AL |
468 | } |
469 | ||
e5ff2159 AK |
470 | struct hstate *size_to_hstate(unsigned long size) |
471 | { | |
472 | struct hstate *h; | |
473 | ||
474 | for_each_hstate(h) { | |
475 | if (huge_page_size(h) == size) | |
476 | return h; | |
477 | } | |
478 | return NULL; | |
479 | } | |
480 | ||
27a85ef1 DG |
481 | static void free_huge_page(struct page *page) |
482 | { | |
a5516438 AK |
483 | /* |
484 | * Can't pass hstate in here because it is called from the | |
485 | * compound page destructor. | |
486 | */ | |
e5ff2159 | 487 | struct hstate *h = page_hstate(page); |
7893d1d5 | 488 | int nid = page_to_nid(page); |
c79fb75e | 489 | struct address_space *mapping; |
27a85ef1 | 490 | |
c79fb75e | 491 | mapping = (struct address_space *) page_private(page); |
e5df70ab | 492 | set_page_private(page, 0); |
7893d1d5 | 493 | BUG_ON(page_count(page)); |
27a85ef1 DG |
494 | INIT_LIST_HEAD(&page->lru); |
495 | ||
496 | spin_lock(&hugetlb_lock); | |
aa888a74 | 497 | if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) { |
a5516438 AK |
498 | update_and_free_page(h, page); |
499 | h->surplus_huge_pages--; | |
500 | h->surplus_huge_pages_node[nid]--; | |
7893d1d5 | 501 | } else { |
a5516438 | 502 | enqueue_huge_page(h, page); |
7893d1d5 | 503 | } |
27a85ef1 | 504 | spin_unlock(&hugetlb_lock); |
c79fb75e | 505 | if (mapping) |
9a119c05 | 506 | hugetlb_put_quota(mapping, 1); |
27a85ef1 DG |
507 | } |
508 | ||
7893d1d5 AL |
509 | /* |
510 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
511 | * balanced by operating on them in a round-robin fashion. | |
512 | * Returns 1 if an adjustment was made. | |
513 | */ | |
a5516438 | 514 | static int adjust_pool_surplus(struct hstate *h, int delta) |
7893d1d5 AL |
515 | { |
516 | static int prev_nid; | |
517 | int nid = prev_nid; | |
518 | int ret = 0; | |
519 | ||
520 | VM_BUG_ON(delta != -1 && delta != 1); | |
521 | do { | |
522 | nid = next_node(nid, node_online_map); | |
523 | if (nid == MAX_NUMNODES) | |
524 | nid = first_node(node_online_map); | |
525 | ||
526 | /* To shrink on this node, there must be a surplus page */ | |
a5516438 | 527 | if (delta < 0 && !h->surplus_huge_pages_node[nid]) |
7893d1d5 AL |
528 | continue; |
529 | /* Surplus cannot exceed the total number of pages */ | |
a5516438 AK |
530 | if (delta > 0 && h->surplus_huge_pages_node[nid] >= |
531 | h->nr_huge_pages_node[nid]) | |
7893d1d5 AL |
532 | continue; |
533 | ||
a5516438 AK |
534 | h->surplus_huge_pages += delta; |
535 | h->surplus_huge_pages_node[nid] += delta; | |
7893d1d5 AL |
536 | ret = 1; |
537 | break; | |
538 | } while (nid != prev_nid); | |
539 | ||
540 | prev_nid = nid; | |
541 | return ret; | |
542 | } | |
543 | ||
a5516438 | 544 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) |
b7ba30c6 AK |
545 | { |
546 | set_compound_page_dtor(page, free_huge_page); | |
547 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
548 | h->nr_huge_pages++; |
549 | h->nr_huge_pages_node[nid]++; | |
b7ba30c6 AK |
550 | spin_unlock(&hugetlb_lock); |
551 | put_page(page); /* free it into the hugepage allocator */ | |
552 | } | |
553 | ||
a5516438 | 554 | static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) |
1da177e4 | 555 | { |
1da177e4 | 556 | struct page *page; |
f96efd58 | 557 | |
aa888a74 AK |
558 | if (h->order >= MAX_ORDER) |
559 | return NULL; | |
560 | ||
63b4613c | 561 | page = alloc_pages_node(nid, |
551883ae NA |
562 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| |
563 | __GFP_REPEAT|__GFP_NOWARN, | |
a5516438 | 564 | huge_page_order(h)); |
1da177e4 | 565 | if (page) { |
7f2e9525 GS |
566 | if (arch_prepare_hugepage(page)) { |
567 | __free_pages(page, HUGETLB_PAGE_ORDER); | |
7b8ee84d | 568 | return NULL; |
7f2e9525 | 569 | } |
a5516438 | 570 | prep_new_huge_page(h, page, nid); |
1da177e4 | 571 | } |
63b4613c NA |
572 | |
573 | return page; | |
574 | } | |
575 | ||
5ced66c9 AK |
576 | /* |
577 | * Use a helper variable to find the next node and then | |
578 | * copy it back to hugetlb_next_nid afterwards: | |
579 | * otherwise there's a window in which a racer might | |
580 | * pass invalid nid MAX_NUMNODES to alloc_pages_node. | |
581 | * But we don't need to use a spin_lock here: it really | |
582 | * doesn't matter if occasionally a racer chooses the | |
583 | * same nid as we do. Move nid forward in the mask even | |
584 | * if we just successfully allocated a hugepage so that | |
585 | * the next caller gets hugepages on the next node. | |
586 | */ | |
587 | static int hstate_next_node(struct hstate *h) | |
588 | { | |
589 | int next_nid; | |
590 | next_nid = next_node(h->hugetlb_next_nid, node_online_map); | |
591 | if (next_nid == MAX_NUMNODES) | |
592 | next_nid = first_node(node_online_map); | |
593 | h->hugetlb_next_nid = next_nid; | |
594 | return next_nid; | |
595 | } | |
596 | ||
a5516438 | 597 | static int alloc_fresh_huge_page(struct hstate *h) |
63b4613c NA |
598 | { |
599 | struct page *page; | |
600 | int start_nid; | |
601 | int next_nid; | |
602 | int ret = 0; | |
603 | ||
a5516438 | 604 | start_nid = h->hugetlb_next_nid; |
63b4613c NA |
605 | |
606 | do { | |
a5516438 | 607 | page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid); |
63b4613c NA |
608 | if (page) |
609 | ret = 1; | |
5ced66c9 | 610 | next_nid = hstate_next_node(h); |
a5516438 | 611 | } while (!page && h->hugetlb_next_nid != start_nid); |
63b4613c | 612 | |
3b116300 AL |
613 | if (ret) |
614 | count_vm_event(HTLB_BUDDY_PGALLOC); | |
615 | else | |
616 | count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); | |
617 | ||
63b4613c | 618 | return ret; |
1da177e4 LT |
619 | } |
620 | ||
a5516438 AK |
621 | static struct page *alloc_buddy_huge_page(struct hstate *h, |
622 | struct vm_area_struct *vma, unsigned long address) | |
7893d1d5 AL |
623 | { |
624 | struct page *page; | |
d1c3fb1f | 625 | unsigned int nid; |
7893d1d5 | 626 | |
aa888a74 AK |
627 | if (h->order >= MAX_ORDER) |
628 | return NULL; | |
629 | ||
d1c3fb1f NA |
630 | /* |
631 | * Assume we will successfully allocate the surplus page to | |
632 | * prevent racing processes from causing the surplus to exceed | |
633 | * overcommit | |
634 | * | |
635 | * This however introduces a different race, where a process B | |
636 | * tries to grow the static hugepage pool while alloc_pages() is | |
637 | * called by process A. B will only examine the per-node | |
638 | * counters in determining if surplus huge pages can be | |
639 | * converted to normal huge pages in adjust_pool_surplus(). A | |
640 | * won't be able to increment the per-node counter, until the | |
641 | * lock is dropped by B, but B doesn't drop hugetlb_lock until | |
642 | * no more huge pages can be converted from surplus to normal | |
643 | * state (and doesn't try to convert again). Thus, we have a | |
644 | * case where a surplus huge page exists, the pool is grown, and | |
645 | * the surplus huge page still exists after, even though it | |
646 | * should just have been converted to a normal huge page. This | |
647 | * does not leak memory, though, as the hugepage will be freed | |
648 | * once it is out of use. It also does not allow the counters to | |
649 | * go out of whack in adjust_pool_surplus() as we don't modify | |
650 | * the node values until we've gotten the hugepage and only the | |
651 | * per-node value is checked there. | |
652 | */ | |
653 | spin_lock(&hugetlb_lock); | |
a5516438 | 654 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { |
d1c3fb1f NA |
655 | spin_unlock(&hugetlb_lock); |
656 | return NULL; | |
657 | } else { | |
a5516438 AK |
658 | h->nr_huge_pages++; |
659 | h->surplus_huge_pages++; | |
d1c3fb1f NA |
660 | } |
661 | spin_unlock(&hugetlb_lock); | |
662 | ||
551883ae NA |
663 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP| |
664 | __GFP_REPEAT|__GFP_NOWARN, | |
a5516438 | 665 | huge_page_order(h)); |
d1c3fb1f NA |
666 | |
667 | spin_lock(&hugetlb_lock); | |
7893d1d5 | 668 | if (page) { |
2668db91 AL |
669 | /* |
670 | * This page is now managed by the hugetlb allocator and has | |
671 | * no users -- drop the buddy allocator's reference. | |
672 | */ | |
673 | put_page_testzero(page); | |
674 | VM_BUG_ON(page_count(page)); | |
d1c3fb1f | 675 | nid = page_to_nid(page); |
7893d1d5 | 676 | set_compound_page_dtor(page, free_huge_page); |
d1c3fb1f NA |
677 | /* |
678 | * We incremented the global counters already | |
679 | */ | |
a5516438 AK |
680 | h->nr_huge_pages_node[nid]++; |
681 | h->surplus_huge_pages_node[nid]++; | |
3b116300 | 682 | __count_vm_event(HTLB_BUDDY_PGALLOC); |
d1c3fb1f | 683 | } else { |
a5516438 AK |
684 | h->nr_huge_pages--; |
685 | h->surplus_huge_pages--; | |
3b116300 | 686 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
7893d1d5 | 687 | } |
d1c3fb1f | 688 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
689 | |
690 | return page; | |
691 | } | |
692 | ||
e4e574b7 AL |
693 | /* |
694 | * Increase the hugetlb pool such that it can accomodate a reservation | |
695 | * of size 'delta'. | |
696 | */ | |
a5516438 | 697 | static int gather_surplus_pages(struct hstate *h, int delta) |
e4e574b7 AL |
698 | { |
699 | struct list_head surplus_list; | |
700 | struct page *page, *tmp; | |
701 | int ret, i; | |
702 | int needed, allocated; | |
703 | ||
a5516438 | 704 | needed = (h->resv_huge_pages + delta) - h->free_huge_pages; |
ac09b3a1 | 705 | if (needed <= 0) { |
a5516438 | 706 | h->resv_huge_pages += delta; |
e4e574b7 | 707 | return 0; |
ac09b3a1 | 708 | } |
e4e574b7 AL |
709 | |
710 | allocated = 0; | |
711 | INIT_LIST_HEAD(&surplus_list); | |
712 | ||
713 | ret = -ENOMEM; | |
714 | retry: | |
715 | spin_unlock(&hugetlb_lock); | |
716 | for (i = 0; i < needed; i++) { | |
a5516438 | 717 | page = alloc_buddy_huge_page(h, NULL, 0); |
e4e574b7 AL |
718 | if (!page) { |
719 | /* | |
720 | * We were not able to allocate enough pages to | |
721 | * satisfy the entire reservation so we free what | |
722 | * we've allocated so far. | |
723 | */ | |
724 | spin_lock(&hugetlb_lock); | |
725 | needed = 0; | |
726 | goto free; | |
727 | } | |
728 | ||
729 | list_add(&page->lru, &surplus_list); | |
730 | } | |
731 | allocated += needed; | |
732 | ||
733 | /* | |
734 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
735 | * because either resv_huge_pages or free_huge_pages may have changed. | |
736 | */ | |
737 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
738 | needed = (h->resv_huge_pages + delta) - |
739 | (h->free_huge_pages + allocated); | |
e4e574b7 AL |
740 | if (needed > 0) |
741 | goto retry; | |
742 | ||
743 | /* | |
744 | * The surplus_list now contains _at_least_ the number of extra pages | |
745 | * needed to accomodate the reservation. Add the appropriate number | |
746 | * of pages to the hugetlb pool and free the extras back to the buddy | |
ac09b3a1 AL |
747 | * allocator. Commit the entire reservation here to prevent another |
748 | * process from stealing the pages as they are added to the pool but | |
749 | * before they are reserved. | |
e4e574b7 AL |
750 | */ |
751 | needed += allocated; | |
a5516438 | 752 | h->resv_huge_pages += delta; |
e4e574b7 AL |
753 | ret = 0; |
754 | free: | |
19fc3f0a | 755 | /* Free the needed pages to the hugetlb pool */ |
e4e574b7 | 756 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
19fc3f0a AL |
757 | if ((--needed) < 0) |
758 | break; | |
e4e574b7 | 759 | list_del(&page->lru); |
a5516438 | 760 | enqueue_huge_page(h, page); |
19fc3f0a AL |
761 | } |
762 | ||
763 | /* Free unnecessary surplus pages to the buddy allocator */ | |
764 | if (!list_empty(&surplus_list)) { | |
765 | spin_unlock(&hugetlb_lock); | |
766 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { | |
767 | list_del(&page->lru); | |
af767cbd | 768 | /* |
2668db91 AL |
769 | * The page has a reference count of zero already, so |
770 | * call free_huge_page directly instead of using | |
771 | * put_page. This must be done with hugetlb_lock | |
af767cbd AL |
772 | * unlocked which is safe because free_huge_page takes |
773 | * hugetlb_lock before deciding how to free the page. | |
774 | */ | |
2668db91 | 775 | free_huge_page(page); |
af767cbd | 776 | } |
19fc3f0a | 777 | spin_lock(&hugetlb_lock); |
e4e574b7 AL |
778 | } |
779 | ||
780 | return ret; | |
781 | } | |
782 | ||
783 | /* | |
784 | * When releasing a hugetlb pool reservation, any surplus pages that were | |
785 | * allocated to satisfy the reservation must be explicitly freed if they were | |
786 | * never used. | |
787 | */ | |
a5516438 AK |
788 | static void return_unused_surplus_pages(struct hstate *h, |
789 | unsigned long unused_resv_pages) | |
e4e574b7 AL |
790 | { |
791 | static int nid = -1; | |
792 | struct page *page; | |
793 | unsigned long nr_pages; | |
794 | ||
11320d17 NA |
795 | /* |
796 | * We want to release as many surplus pages as possible, spread | |
797 | * evenly across all nodes. Iterate across all nodes until we | |
798 | * can no longer free unreserved surplus pages. This occurs when | |
799 | * the nodes with surplus pages have no free pages. | |
800 | */ | |
801 | unsigned long remaining_iterations = num_online_nodes(); | |
802 | ||
ac09b3a1 | 803 | /* Uncommit the reservation */ |
a5516438 | 804 | h->resv_huge_pages -= unused_resv_pages; |
ac09b3a1 | 805 | |
aa888a74 AK |
806 | /* Cannot return gigantic pages currently */ |
807 | if (h->order >= MAX_ORDER) | |
808 | return; | |
809 | ||
a5516438 | 810 | nr_pages = min(unused_resv_pages, h->surplus_huge_pages); |
e4e574b7 | 811 | |
11320d17 | 812 | while (remaining_iterations-- && nr_pages) { |
e4e574b7 AL |
813 | nid = next_node(nid, node_online_map); |
814 | if (nid == MAX_NUMNODES) | |
815 | nid = first_node(node_online_map); | |
816 | ||
a5516438 | 817 | if (!h->surplus_huge_pages_node[nid]) |
e4e574b7 AL |
818 | continue; |
819 | ||
a5516438 AK |
820 | if (!list_empty(&h->hugepage_freelists[nid])) { |
821 | page = list_entry(h->hugepage_freelists[nid].next, | |
e4e574b7 AL |
822 | struct page, lru); |
823 | list_del(&page->lru); | |
a5516438 AK |
824 | update_and_free_page(h, page); |
825 | h->free_huge_pages--; | |
826 | h->free_huge_pages_node[nid]--; | |
827 | h->surplus_huge_pages--; | |
828 | h->surplus_huge_pages_node[nid]--; | |
e4e574b7 | 829 | nr_pages--; |
11320d17 | 830 | remaining_iterations = num_online_nodes(); |
e4e574b7 AL |
831 | } |
832 | } | |
833 | } | |
834 | ||
c37f9fb1 AW |
835 | /* |
836 | * Determine if the huge page at addr within the vma has an associated | |
837 | * reservation. Where it does not we will need to logically increase | |
838 | * reservation and actually increase quota before an allocation can occur. | |
839 | * Where any new reservation would be required the reservation change is | |
840 | * prepared, but not committed. Once the page has been quota'd allocated | |
841 | * an instantiated the change should be committed via vma_commit_reservation. | |
842 | * No action is required on failure. | |
843 | */ | |
a5516438 AK |
844 | static int vma_needs_reservation(struct hstate *h, |
845 | struct vm_area_struct *vma, unsigned long addr) | |
c37f9fb1 AW |
846 | { |
847 | struct address_space *mapping = vma->vm_file->f_mapping; | |
848 | struct inode *inode = mapping->host; | |
849 | ||
850 | if (vma->vm_flags & VM_SHARED) { | |
a5516438 | 851 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 AW |
852 | return region_chg(&inode->i_mapping->private_list, |
853 | idx, idx + 1); | |
854 | ||
84afd99b AW |
855 | } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
856 | return 1; | |
c37f9fb1 | 857 | |
84afd99b AW |
858 | } else { |
859 | int err; | |
a5516438 | 860 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
84afd99b AW |
861 | struct resv_map *reservations = vma_resv_map(vma); |
862 | ||
863 | err = region_chg(&reservations->regions, idx, idx + 1); | |
864 | if (err < 0) | |
865 | return err; | |
866 | return 0; | |
867 | } | |
c37f9fb1 | 868 | } |
a5516438 AK |
869 | static void vma_commit_reservation(struct hstate *h, |
870 | struct vm_area_struct *vma, unsigned long addr) | |
c37f9fb1 AW |
871 | { |
872 | struct address_space *mapping = vma->vm_file->f_mapping; | |
873 | struct inode *inode = mapping->host; | |
874 | ||
875 | if (vma->vm_flags & VM_SHARED) { | |
a5516438 | 876 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 | 877 | region_add(&inode->i_mapping->private_list, idx, idx + 1); |
84afd99b AW |
878 | |
879 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { | |
a5516438 | 880 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
84afd99b AW |
881 | struct resv_map *reservations = vma_resv_map(vma); |
882 | ||
883 | /* Mark this page used in the map. */ | |
884 | region_add(&reservations->regions, idx, idx + 1); | |
c37f9fb1 AW |
885 | } |
886 | } | |
887 | ||
a1e78772 | 888 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
04f2cbe3 | 889 | unsigned long addr, int avoid_reserve) |
1da177e4 | 890 | { |
a5516438 | 891 | struct hstate *h = hstate_vma(vma); |
348ea204 | 892 | struct page *page; |
a1e78772 MG |
893 | struct address_space *mapping = vma->vm_file->f_mapping; |
894 | struct inode *inode = mapping->host; | |
c37f9fb1 | 895 | unsigned int chg; |
a1e78772 MG |
896 | |
897 | /* | |
898 | * Processes that did not create the mapping will have no reserves and | |
899 | * will not have accounted against quota. Check that the quota can be | |
900 | * made before satisfying the allocation | |
c37f9fb1 AW |
901 | * MAP_NORESERVE mappings may also need pages and quota allocated |
902 | * if no reserve mapping overlaps. | |
a1e78772 | 903 | */ |
a5516438 | 904 | chg = vma_needs_reservation(h, vma, addr); |
c37f9fb1 AW |
905 | if (chg < 0) |
906 | return ERR_PTR(chg); | |
907 | if (chg) | |
a1e78772 MG |
908 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
909 | return ERR_PTR(-ENOSPC); | |
1da177e4 LT |
910 | |
911 | spin_lock(&hugetlb_lock); | |
a5516438 | 912 | page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve); |
1da177e4 | 913 | spin_unlock(&hugetlb_lock); |
b45b5bd6 | 914 | |
68842c9b | 915 | if (!page) { |
a5516438 | 916 | page = alloc_buddy_huge_page(h, vma, addr); |
68842c9b | 917 | if (!page) { |
a1e78772 | 918 | hugetlb_put_quota(inode->i_mapping, chg); |
68842c9b KC |
919 | return ERR_PTR(-VM_FAULT_OOM); |
920 | } | |
921 | } | |
348ea204 | 922 | |
a1e78772 MG |
923 | set_page_refcounted(page); |
924 | set_page_private(page, (unsigned long) mapping); | |
90d8b7e6 | 925 | |
a5516438 | 926 | vma_commit_reservation(h, vma, addr); |
c37f9fb1 | 927 | |
90d8b7e6 | 928 | return page; |
b45b5bd6 DG |
929 | } |
930 | ||
53ba51d2 | 931 | __attribute__((weak)) int alloc_bootmem_huge_page(struct hstate *h) |
aa888a74 AK |
932 | { |
933 | struct huge_bootmem_page *m; | |
934 | int nr_nodes = nodes_weight(node_online_map); | |
935 | ||
936 | while (nr_nodes) { | |
937 | void *addr; | |
938 | ||
939 | addr = __alloc_bootmem_node_nopanic( | |
940 | NODE_DATA(h->hugetlb_next_nid), | |
941 | huge_page_size(h), huge_page_size(h), 0); | |
942 | ||
943 | if (addr) { | |
944 | /* | |
945 | * Use the beginning of the huge page to store the | |
946 | * huge_bootmem_page struct (until gather_bootmem | |
947 | * puts them into the mem_map). | |
948 | */ | |
949 | m = addr; | |
950 | if (m) | |
951 | goto found; | |
952 | } | |
953 | hstate_next_node(h); | |
954 | nr_nodes--; | |
955 | } | |
956 | return 0; | |
957 | ||
958 | found: | |
959 | BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1)); | |
960 | /* Put them into a private list first because mem_map is not up yet */ | |
961 | list_add(&m->list, &huge_boot_pages); | |
962 | m->hstate = h; | |
963 | return 1; | |
964 | } | |
965 | ||
966 | /* Put bootmem huge pages into the standard lists after mem_map is up */ | |
967 | static void __init gather_bootmem_prealloc(void) | |
968 | { | |
969 | struct huge_bootmem_page *m; | |
970 | ||
971 | list_for_each_entry(m, &huge_boot_pages, list) { | |
972 | struct page *page = virt_to_page(m); | |
973 | struct hstate *h = m->hstate; | |
974 | __ClearPageReserved(page); | |
975 | WARN_ON(page_count(page) != 1); | |
976 | prep_compound_page(page, h->order); | |
977 | prep_new_huge_page(h, page, page_to_nid(page)); | |
978 | } | |
979 | } | |
980 | ||
8faa8b07 | 981 | static void __init hugetlb_hstate_alloc_pages(struct hstate *h) |
1da177e4 LT |
982 | { |
983 | unsigned long i; | |
a5516438 | 984 | |
e5ff2159 | 985 | for (i = 0; i < h->max_huge_pages; ++i) { |
aa888a74 AK |
986 | if (h->order >= MAX_ORDER) { |
987 | if (!alloc_bootmem_huge_page(h)) | |
988 | break; | |
989 | } else if (!alloc_fresh_huge_page(h)) | |
1da177e4 | 990 | break; |
1da177e4 | 991 | } |
8faa8b07 | 992 | h->max_huge_pages = i; |
e5ff2159 AK |
993 | } |
994 | ||
995 | static void __init hugetlb_init_hstates(void) | |
996 | { | |
997 | struct hstate *h; | |
998 | ||
999 | for_each_hstate(h) { | |
8faa8b07 AK |
1000 | /* oversize hugepages were init'ed in early boot */ |
1001 | if (h->order < MAX_ORDER) | |
1002 | hugetlb_hstate_alloc_pages(h); | |
e5ff2159 AK |
1003 | } |
1004 | } | |
1005 | ||
4abd32db AK |
1006 | static char * __init memfmt(char *buf, unsigned long n) |
1007 | { | |
1008 | if (n >= (1UL << 30)) | |
1009 | sprintf(buf, "%lu GB", n >> 30); | |
1010 | else if (n >= (1UL << 20)) | |
1011 | sprintf(buf, "%lu MB", n >> 20); | |
1012 | else | |
1013 | sprintf(buf, "%lu KB", n >> 10); | |
1014 | return buf; | |
1015 | } | |
1016 | ||
e5ff2159 AK |
1017 | static void __init report_hugepages(void) |
1018 | { | |
1019 | struct hstate *h; | |
1020 | ||
1021 | for_each_hstate(h) { | |
4abd32db AK |
1022 | char buf[32]; |
1023 | printk(KERN_INFO "HugeTLB registered %s page size, " | |
1024 | "pre-allocated %ld pages\n", | |
1025 | memfmt(buf, huge_page_size(h)), | |
1026 | h->free_huge_pages); | |
e5ff2159 AK |
1027 | } |
1028 | } | |
1029 | ||
1da177e4 | 1030 | #ifdef CONFIG_HIGHMEM |
a5516438 | 1031 | static void try_to_free_low(struct hstate *h, unsigned long count) |
1da177e4 | 1032 | { |
4415cc8d CL |
1033 | int i; |
1034 | ||
aa888a74 AK |
1035 | if (h->order >= MAX_ORDER) |
1036 | return; | |
1037 | ||
1da177e4 LT |
1038 | for (i = 0; i < MAX_NUMNODES; ++i) { |
1039 | struct page *page, *next; | |
a5516438 AK |
1040 | struct list_head *freel = &h->hugepage_freelists[i]; |
1041 | list_for_each_entry_safe(page, next, freel, lru) { | |
1042 | if (count >= h->nr_huge_pages) | |
6b0c880d | 1043 | return; |
1da177e4 LT |
1044 | if (PageHighMem(page)) |
1045 | continue; | |
1046 | list_del(&page->lru); | |
e5ff2159 | 1047 | update_and_free_page(h, page); |
a5516438 AK |
1048 | h->free_huge_pages--; |
1049 | h->free_huge_pages_node[page_to_nid(page)]--; | |
1da177e4 LT |
1050 | } |
1051 | } | |
1052 | } | |
1053 | #else | |
a5516438 | 1054 | static inline void try_to_free_low(struct hstate *h, unsigned long count) |
1da177e4 LT |
1055 | { |
1056 | } | |
1057 | #endif | |
1058 | ||
a5516438 | 1059 | #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) |
e5ff2159 | 1060 | static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count) |
1da177e4 | 1061 | { |
7893d1d5 | 1062 | unsigned long min_count, ret; |
1da177e4 | 1063 | |
aa888a74 AK |
1064 | if (h->order >= MAX_ORDER) |
1065 | return h->max_huge_pages; | |
1066 | ||
7893d1d5 AL |
1067 | /* |
1068 | * Increase the pool size | |
1069 | * First take pages out of surplus state. Then make up the | |
1070 | * remaining difference by allocating fresh huge pages. | |
d1c3fb1f NA |
1071 | * |
1072 | * We might race with alloc_buddy_huge_page() here and be unable | |
1073 | * to convert a surplus huge page to a normal huge page. That is | |
1074 | * not critical, though, it just means the overall size of the | |
1075 | * pool might be one hugepage larger than it needs to be, but | |
1076 | * within all the constraints specified by the sysctls. | |
7893d1d5 | 1077 | */ |
1da177e4 | 1078 | spin_lock(&hugetlb_lock); |
a5516438 AK |
1079 | while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { |
1080 | if (!adjust_pool_surplus(h, -1)) | |
7893d1d5 AL |
1081 | break; |
1082 | } | |
1083 | ||
a5516438 | 1084 | while (count > persistent_huge_pages(h)) { |
7893d1d5 AL |
1085 | /* |
1086 | * If this allocation races such that we no longer need the | |
1087 | * page, free_huge_page will handle it by freeing the page | |
1088 | * and reducing the surplus. | |
1089 | */ | |
1090 | spin_unlock(&hugetlb_lock); | |
a5516438 | 1091 | ret = alloc_fresh_huge_page(h); |
7893d1d5 AL |
1092 | spin_lock(&hugetlb_lock); |
1093 | if (!ret) | |
1094 | goto out; | |
1095 | ||
1096 | } | |
7893d1d5 AL |
1097 | |
1098 | /* | |
1099 | * Decrease the pool size | |
1100 | * First return free pages to the buddy allocator (being careful | |
1101 | * to keep enough around to satisfy reservations). Then place | |
1102 | * pages into surplus state as needed so the pool will shrink | |
1103 | * to the desired size as pages become free. | |
d1c3fb1f NA |
1104 | * |
1105 | * By placing pages into the surplus state independent of the | |
1106 | * overcommit value, we are allowing the surplus pool size to | |
1107 | * exceed overcommit. There are few sane options here. Since | |
1108 | * alloc_buddy_huge_page() is checking the global counter, | |
1109 | * though, we'll note that we're not allowed to exceed surplus | |
1110 | * and won't grow the pool anywhere else. Not until one of the | |
1111 | * sysctls are changed, or the surplus pages go out of use. | |
7893d1d5 | 1112 | */ |
a5516438 | 1113 | min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; |
6b0c880d | 1114 | min_count = max(count, min_count); |
a5516438 AK |
1115 | try_to_free_low(h, min_count); |
1116 | while (min_count < persistent_huge_pages(h)) { | |
1117 | struct page *page = dequeue_huge_page(h); | |
1da177e4 LT |
1118 | if (!page) |
1119 | break; | |
a5516438 | 1120 | update_and_free_page(h, page); |
1da177e4 | 1121 | } |
a5516438 AK |
1122 | while (count < persistent_huge_pages(h)) { |
1123 | if (!adjust_pool_surplus(h, 1)) | |
7893d1d5 AL |
1124 | break; |
1125 | } | |
1126 | out: | |
a5516438 | 1127 | ret = persistent_huge_pages(h); |
1da177e4 | 1128 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 1129 | return ret; |
1da177e4 LT |
1130 | } |
1131 | ||
a3437870 NA |
1132 | #define HSTATE_ATTR_RO(_name) \ |
1133 | static struct kobj_attribute _name##_attr = __ATTR_RO(_name) | |
1134 | ||
1135 | #define HSTATE_ATTR(_name) \ | |
1136 | static struct kobj_attribute _name##_attr = \ | |
1137 | __ATTR(_name, 0644, _name##_show, _name##_store) | |
1138 | ||
1139 | static struct kobject *hugepages_kobj; | |
1140 | static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
1141 | ||
1142 | static struct hstate *kobj_to_hstate(struct kobject *kobj) | |
1143 | { | |
1144 | int i; | |
1145 | for (i = 0; i < HUGE_MAX_HSTATE; i++) | |
1146 | if (hstate_kobjs[i] == kobj) | |
1147 | return &hstates[i]; | |
1148 | BUG(); | |
1149 | return NULL; | |
1150 | } | |
1151 | ||
1152 | static ssize_t nr_hugepages_show(struct kobject *kobj, | |
1153 | struct kobj_attribute *attr, char *buf) | |
1154 | { | |
1155 | struct hstate *h = kobj_to_hstate(kobj); | |
1156 | return sprintf(buf, "%lu\n", h->nr_huge_pages); | |
1157 | } | |
1158 | static ssize_t nr_hugepages_store(struct kobject *kobj, | |
1159 | struct kobj_attribute *attr, const char *buf, size_t count) | |
1160 | { | |
1161 | int err; | |
1162 | unsigned long input; | |
1163 | struct hstate *h = kobj_to_hstate(kobj); | |
1164 | ||
1165 | err = strict_strtoul(buf, 10, &input); | |
1166 | if (err) | |
1167 | return 0; | |
1168 | ||
1169 | h->max_huge_pages = set_max_huge_pages(h, input); | |
1170 | ||
1171 | return count; | |
1172 | } | |
1173 | HSTATE_ATTR(nr_hugepages); | |
1174 | ||
1175 | static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, | |
1176 | struct kobj_attribute *attr, char *buf) | |
1177 | { | |
1178 | struct hstate *h = kobj_to_hstate(kobj); | |
1179 | return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); | |
1180 | } | |
1181 | static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, | |
1182 | struct kobj_attribute *attr, const char *buf, size_t count) | |
1183 | { | |
1184 | int err; | |
1185 | unsigned long input; | |
1186 | struct hstate *h = kobj_to_hstate(kobj); | |
1187 | ||
1188 | err = strict_strtoul(buf, 10, &input); | |
1189 | if (err) | |
1190 | return 0; | |
1191 | ||
1192 | spin_lock(&hugetlb_lock); | |
1193 | h->nr_overcommit_huge_pages = input; | |
1194 | spin_unlock(&hugetlb_lock); | |
1195 | ||
1196 | return count; | |
1197 | } | |
1198 | HSTATE_ATTR(nr_overcommit_hugepages); | |
1199 | ||
1200 | static ssize_t free_hugepages_show(struct kobject *kobj, | |
1201 | struct kobj_attribute *attr, char *buf) | |
1202 | { | |
1203 | struct hstate *h = kobj_to_hstate(kobj); | |
1204 | return sprintf(buf, "%lu\n", h->free_huge_pages); | |
1205 | } | |
1206 | HSTATE_ATTR_RO(free_hugepages); | |
1207 | ||
1208 | static ssize_t resv_hugepages_show(struct kobject *kobj, | |
1209 | struct kobj_attribute *attr, char *buf) | |
1210 | { | |
1211 | struct hstate *h = kobj_to_hstate(kobj); | |
1212 | return sprintf(buf, "%lu\n", h->resv_huge_pages); | |
1213 | } | |
1214 | HSTATE_ATTR_RO(resv_hugepages); | |
1215 | ||
1216 | static ssize_t surplus_hugepages_show(struct kobject *kobj, | |
1217 | struct kobj_attribute *attr, char *buf) | |
1218 | { | |
1219 | struct hstate *h = kobj_to_hstate(kobj); | |
1220 | return sprintf(buf, "%lu\n", h->surplus_huge_pages); | |
1221 | } | |
1222 | HSTATE_ATTR_RO(surplus_hugepages); | |
1223 | ||
1224 | static struct attribute *hstate_attrs[] = { | |
1225 | &nr_hugepages_attr.attr, | |
1226 | &nr_overcommit_hugepages_attr.attr, | |
1227 | &free_hugepages_attr.attr, | |
1228 | &resv_hugepages_attr.attr, | |
1229 | &surplus_hugepages_attr.attr, | |
1230 | NULL, | |
1231 | }; | |
1232 | ||
1233 | static struct attribute_group hstate_attr_group = { | |
1234 | .attrs = hstate_attrs, | |
1235 | }; | |
1236 | ||
1237 | static int __init hugetlb_sysfs_add_hstate(struct hstate *h) | |
1238 | { | |
1239 | int retval; | |
1240 | ||
1241 | hstate_kobjs[h - hstates] = kobject_create_and_add(h->name, | |
1242 | hugepages_kobj); | |
1243 | if (!hstate_kobjs[h - hstates]) | |
1244 | return -ENOMEM; | |
1245 | ||
1246 | retval = sysfs_create_group(hstate_kobjs[h - hstates], | |
1247 | &hstate_attr_group); | |
1248 | if (retval) | |
1249 | kobject_put(hstate_kobjs[h - hstates]); | |
1250 | ||
1251 | return retval; | |
1252 | } | |
1253 | ||
1254 | static void __init hugetlb_sysfs_init(void) | |
1255 | { | |
1256 | struct hstate *h; | |
1257 | int err; | |
1258 | ||
1259 | hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); | |
1260 | if (!hugepages_kobj) | |
1261 | return; | |
1262 | ||
1263 | for_each_hstate(h) { | |
1264 | err = hugetlb_sysfs_add_hstate(h); | |
1265 | if (err) | |
1266 | printk(KERN_ERR "Hugetlb: Unable to add hstate %s", | |
1267 | h->name); | |
1268 | } | |
1269 | } | |
1270 | ||
1271 | static void __exit hugetlb_exit(void) | |
1272 | { | |
1273 | struct hstate *h; | |
1274 | ||
1275 | for_each_hstate(h) { | |
1276 | kobject_put(hstate_kobjs[h - hstates]); | |
1277 | } | |
1278 | ||
1279 | kobject_put(hugepages_kobj); | |
1280 | } | |
1281 | module_exit(hugetlb_exit); | |
1282 | ||
1283 | static int __init hugetlb_init(void) | |
1284 | { | |
1285 | BUILD_BUG_ON(HPAGE_SHIFT == 0); | |
1286 | ||
e11bfbfc NP |
1287 | if (!size_to_hstate(default_hstate_size)) { |
1288 | default_hstate_size = HPAGE_SIZE; | |
1289 | if (!size_to_hstate(default_hstate_size)) | |
1290 | hugetlb_add_hstate(HUGETLB_PAGE_ORDER); | |
a3437870 | 1291 | } |
e11bfbfc NP |
1292 | default_hstate_idx = size_to_hstate(default_hstate_size) - hstates; |
1293 | if (default_hstate_max_huge_pages) | |
1294 | default_hstate.max_huge_pages = default_hstate_max_huge_pages; | |
a3437870 NA |
1295 | |
1296 | hugetlb_init_hstates(); | |
1297 | ||
aa888a74 AK |
1298 | gather_bootmem_prealloc(); |
1299 | ||
a3437870 NA |
1300 | report_hugepages(); |
1301 | ||
1302 | hugetlb_sysfs_init(); | |
1303 | ||
1304 | return 0; | |
1305 | } | |
1306 | module_init(hugetlb_init); | |
1307 | ||
1308 | /* Should be called on processing a hugepagesz=... option */ | |
1309 | void __init hugetlb_add_hstate(unsigned order) | |
1310 | { | |
1311 | struct hstate *h; | |
8faa8b07 AK |
1312 | unsigned long i; |
1313 | ||
a3437870 NA |
1314 | if (size_to_hstate(PAGE_SIZE << order)) { |
1315 | printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n"); | |
1316 | return; | |
1317 | } | |
1318 | BUG_ON(max_hstate >= HUGE_MAX_HSTATE); | |
1319 | BUG_ON(order == 0); | |
1320 | h = &hstates[max_hstate++]; | |
1321 | h->order = order; | |
1322 | h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); | |
8faa8b07 AK |
1323 | h->nr_huge_pages = 0; |
1324 | h->free_huge_pages = 0; | |
1325 | for (i = 0; i < MAX_NUMNODES; ++i) | |
1326 | INIT_LIST_HEAD(&h->hugepage_freelists[i]); | |
1327 | h->hugetlb_next_nid = first_node(node_online_map); | |
a3437870 NA |
1328 | snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", |
1329 | huge_page_size(h)/1024); | |
8faa8b07 | 1330 | |
a3437870 NA |
1331 | parsed_hstate = h; |
1332 | } | |
1333 | ||
e11bfbfc | 1334 | static int __init hugetlb_nrpages_setup(char *s) |
a3437870 NA |
1335 | { |
1336 | unsigned long *mhp; | |
8faa8b07 | 1337 | static unsigned long *last_mhp; |
a3437870 NA |
1338 | |
1339 | /* | |
1340 | * !max_hstate means we haven't parsed a hugepagesz= parameter yet, | |
1341 | * so this hugepages= parameter goes to the "default hstate". | |
1342 | */ | |
1343 | if (!max_hstate) | |
1344 | mhp = &default_hstate_max_huge_pages; | |
1345 | else | |
1346 | mhp = &parsed_hstate->max_huge_pages; | |
1347 | ||
8faa8b07 AK |
1348 | if (mhp == last_mhp) { |
1349 | printk(KERN_WARNING "hugepages= specified twice without " | |
1350 | "interleaving hugepagesz=, ignoring\n"); | |
1351 | return 1; | |
1352 | } | |
1353 | ||
a3437870 NA |
1354 | if (sscanf(s, "%lu", mhp) <= 0) |
1355 | *mhp = 0; | |
1356 | ||
8faa8b07 AK |
1357 | /* |
1358 | * Global state is always initialized later in hugetlb_init. | |
1359 | * But we need to allocate >= MAX_ORDER hstates here early to still | |
1360 | * use the bootmem allocator. | |
1361 | */ | |
1362 | if (max_hstate && parsed_hstate->order >= MAX_ORDER) | |
1363 | hugetlb_hstate_alloc_pages(parsed_hstate); | |
1364 | ||
1365 | last_mhp = mhp; | |
1366 | ||
a3437870 NA |
1367 | return 1; |
1368 | } | |
e11bfbfc NP |
1369 | __setup("hugepages=", hugetlb_nrpages_setup); |
1370 | ||
1371 | static int __init hugetlb_default_setup(char *s) | |
1372 | { | |
1373 | default_hstate_size = memparse(s, &s); | |
1374 | return 1; | |
1375 | } | |
1376 | __setup("default_hugepagesz=", hugetlb_default_setup); | |
a3437870 | 1377 | |
8a213460 NA |
1378 | static unsigned int cpuset_mems_nr(unsigned int *array) |
1379 | { | |
1380 | int node; | |
1381 | unsigned int nr = 0; | |
1382 | ||
1383 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
1384 | nr += array[node]; | |
1385 | ||
1386 | return nr; | |
1387 | } | |
1388 | ||
1389 | #ifdef CONFIG_SYSCTL | |
1da177e4 LT |
1390 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
1391 | struct file *file, void __user *buffer, | |
1392 | size_t *length, loff_t *ppos) | |
1393 | { | |
e5ff2159 AK |
1394 | struct hstate *h = &default_hstate; |
1395 | unsigned long tmp; | |
1396 | ||
1397 | if (!write) | |
1398 | tmp = h->max_huge_pages; | |
1399 | ||
1400 | table->data = &tmp; | |
1401 | table->maxlen = sizeof(unsigned long); | |
1da177e4 | 1402 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
e5ff2159 AK |
1403 | |
1404 | if (write) | |
1405 | h->max_huge_pages = set_max_huge_pages(h, tmp); | |
1406 | ||
1da177e4 LT |
1407 | return 0; |
1408 | } | |
396faf03 MG |
1409 | |
1410 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, | |
1411 | struct file *file, void __user *buffer, | |
1412 | size_t *length, loff_t *ppos) | |
1413 | { | |
1414 | proc_dointvec(table, write, file, buffer, length, ppos); | |
1415 | if (hugepages_treat_as_movable) | |
1416 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; | |
1417 | else | |
1418 | htlb_alloc_mask = GFP_HIGHUSER; | |
1419 | return 0; | |
1420 | } | |
1421 | ||
a3d0c6aa NA |
1422 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
1423 | struct file *file, void __user *buffer, | |
1424 | size_t *length, loff_t *ppos) | |
1425 | { | |
a5516438 | 1426 | struct hstate *h = &default_hstate; |
e5ff2159 AK |
1427 | unsigned long tmp; |
1428 | ||
1429 | if (!write) | |
1430 | tmp = h->nr_overcommit_huge_pages; | |
1431 | ||
1432 | table->data = &tmp; | |
1433 | table->maxlen = sizeof(unsigned long); | |
a3d0c6aa | 1434 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
e5ff2159 AK |
1435 | |
1436 | if (write) { | |
1437 | spin_lock(&hugetlb_lock); | |
1438 | h->nr_overcommit_huge_pages = tmp; | |
1439 | spin_unlock(&hugetlb_lock); | |
1440 | } | |
1441 | ||
a3d0c6aa NA |
1442 | return 0; |
1443 | } | |
1444 | ||
1da177e4 LT |
1445 | #endif /* CONFIG_SYSCTL */ |
1446 | ||
1447 | int hugetlb_report_meminfo(char *buf) | |
1448 | { | |
a5516438 | 1449 | struct hstate *h = &default_hstate; |
1da177e4 LT |
1450 | return sprintf(buf, |
1451 | "HugePages_Total: %5lu\n" | |
1452 | "HugePages_Free: %5lu\n" | |
a43a8c39 | 1453 | "HugePages_Rsvd: %5lu\n" |
7893d1d5 | 1454 | "HugePages_Surp: %5lu\n" |
1da177e4 | 1455 | "Hugepagesize: %5lu kB\n", |
a5516438 AK |
1456 | h->nr_huge_pages, |
1457 | h->free_huge_pages, | |
1458 | h->resv_huge_pages, | |
1459 | h->surplus_huge_pages, | |
1460 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); | |
1da177e4 LT |
1461 | } |
1462 | ||
1463 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
1464 | { | |
a5516438 | 1465 | struct hstate *h = &default_hstate; |
1da177e4 LT |
1466 | return sprintf(buf, |
1467 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
1468 | "Node %d HugePages_Free: %5u\n" |
1469 | "Node %d HugePages_Surp: %5u\n", | |
a5516438 AK |
1470 | nid, h->nr_huge_pages_node[nid], |
1471 | nid, h->free_huge_pages_node[nid], | |
1472 | nid, h->surplus_huge_pages_node[nid]); | |
1da177e4 LT |
1473 | } |
1474 | ||
1da177e4 LT |
1475 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
1476 | unsigned long hugetlb_total_pages(void) | |
1477 | { | |
a5516438 AK |
1478 | struct hstate *h = &default_hstate; |
1479 | return h->nr_huge_pages * pages_per_huge_page(h); | |
1da177e4 | 1480 | } |
1da177e4 | 1481 | |
a5516438 | 1482 | static int hugetlb_acct_memory(struct hstate *h, long delta) |
fc1b8a73 MG |
1483 | { |
1484 | int ret = -ENOMEM; | |
1485 | ||
1486 | spin_lock(&hugetlb_lock); | |
1487 | /* | |
1488 | * When cpuset is configured, it breaks the strict hugetlb page | |
1489 | * reservation as the accounting is done on a global variable. Such | |
1490 | * reservation is completely rubbish in the presence of cpuset because | |
1491 | * the reservation is not checked against page availability for the | |
1492 | * current cpuset. Application can still potentially OOM'ed by kernel | |
1493 | * with lack of free htlb page in cpuset that the task is in. | |
1494 | * Attempt to enforce strict accounting with cpuset is almost | |
1495 | * impossible (or too ugly) because cpuset is too fluid that | |
1496 | * task or memory node can be dynamically moved between cpusets. | |
1497 | * | |
1498 | * The change of semantics for shared hugetlb mapping with cpuset is | |
1499 | * undesirable. However, in order to preserve some of the semantics, | |
1500 | * we fall back to check against current free page availability as | |
1501 | * a best attempt and hopefully to minimize the impact of changing | |
1502 | * semantics that cpuset has. | |
1503 | */ | |
1504 | if (delta > 0) { | |
a5516438 | 1505 | if (gather_surplus_pages(h, delta) < 0) |
fc1b8a73 MG |
1506 | goto out; |
1507 | ||
a5516438 AK |
1508 | if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { |
1509 | return_unused_surplus_pages(h, delta); | |
fc1b8a73 MG |
1510 | goto out; |
1511 | } | |
1512 | } | |
1513 | ||
1514 | ret = 0; | |
1515 | if (delta < 0) | |
a5516438 | 1516 | return_unused_surplus_pages(h, (unsigned long) -delta); |
fc1b8a73 MG |
1517 | |
1518 | out: | |
1519 | spin_unlock(&hugetlb_lock); | |
1520 | return ret; | |
1521 | } | |
1522 | ||
84afd99b AW |
1523 | static void hugetlb_vm_op_open(struct vm_area_struct *vma) |
1524 | { | |
1525 | struct resv_map *reservations = vma_resv_map(vma); | |
1526 | ||
1527 | /* | |
1528 | * This new VMA should share its siblings reservation map if present. | |
1529 | * The VMA will only ever have a valid reservation map pointer where | |
1530 | * it is being copied for another still existing VMA. As that VMA | |
1531 | * has a reference to the reservation map it cannot dissappear until | |
1532 | * after this open call completes. It is therefore safe to take a | |
1533 | * new reference here without additional locking. | |
1534 | */ | |
1535 | if (reservations) | |
1536 | kref_get(&reservations->refs); | |
1537 | } | |
1538 | ||
a1e78772 MG |
1539 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
1540 | { | |
a5516438 | 1541 | struct hstate *h = hstate_vma(vma); |
84afd99b AW |
1542 | struct resv_map *reservations = vma_resv_map(vma); |
1543 | unsigned long reserve; | |
1544 | unsigned long start; | |
1545 | unsigned long end; | |
1546 | ||
1547 | if (reservations) { | |
a5516438 AK |
1548 | start = vma_hugecache_offset(h, vma, vma->vm_start); |
1549 | end = vma_hugecache_offset(h, vma, vma->vm_end); | |
84afd99b AW |
1550 | |
1551 | reserve = (end - start) - | |
1552 | region_count(&reservations->regions, start, end); | |
1553 | ||
1554 | kref_put(&reservations->refs, resv_map_release); | |
1555 | ||
7251ff78 | 1556 | if (reserve) { |
a5516438 | 1557 | hugetlb_acct_memory(h, -reserve); |
7251ff78 AL |
1558 | hugetlb_put_quota(vma->vm_file->f_mapping, reserve); |
1559 | } | |
84afd99b | 1560 | } |
a1e78772 MG |
1561 | } |
1562 | ||
1da177e4 LT |
1563 | /* |
1564 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
1565 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
1566 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
1567 | * this far. | |
1568 | */ | |
d0217ac0 | 1569 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
1570 | { |
1571 | BUG(); | |
d0217ac0 | 1572 | return 0; |
1da177e4 LT |
1573 | } |
1574 | ||
1575 | struct vm_operations_struct hugetlb_vm_ops = { | |
d0217ac0 | 1576 | .fault = hugetlb_vm_op_fault, |
84afd99b | 1577 | .open = hugetlb_vm_op_open, |
a1e78772 | 1578 | .close = hugetlb_vm_op_close, |
1da177e4 LT |
1579 | }; |
1580 | ||
1e8f889b DG |
1581 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
1582 | int writable) | |
63551ae0 DG |
1583 | { |
1584 | pte_t entry; | |
1585 | ||
1e8f889b | 1586 | if (writable) { |
63551ae0 DG |
1587 | entry = |
1588 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
1589 | } else { | |
7f2e9525 | 1590 | entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
63551ae0 DG |
1591 | } |
1592 | entry = pte_mkyoung(entry); | |
1593 | entry = pte_mkhuge(entry); | |
1594 | ||
1595 | return entry; | |
1596 | } | |
1597 | ||
1e8f889b DG |
1598 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
1599 | unsigned long address, pte_t *ptep) | |
1600 | { | |
1601 | pte_t entry; | |
1602 | ||
7f2e9525 GS |
1603 | entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); |
1604 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { | |
8dab5241 | 1605 | update_mmu_cache(vma, address, entry); |
8dab5241 | 1606 | } |
1e8f889b DG |
1607 | } |
1608 | ||
1609 | ||
63551ae0 DG |
1610 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
1611 | struct vm_area_struct *vma) | |
1612 | { | |
1613 | pte_t *src_pte, *dst_pte, entry; | |
1614 | struct page *ptepage; | |
1c59827d | 1615 | unsigned long addr; |
1e8f889b | 1616 | int cow; |
a5516438 AK |
1617 | struct hstate *h = hstate_vma(vma); |
1618 | unsigned long sz = huge_page_size(h); | |
1e8f889b DG |
1619 | |
1620 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 1621 | |
a5516438 | 1622 | for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { |
c74df32c HD |
1623 | src_pte = huge_pte_offset(src, addr); |
1624 | if (!src_pte) | |
1625 | continue; | |
a5516438 | 1626 | dst_pte = huge_pte_alloc(dst, addr, sz); |
63551ae0 DG |
1627 | if (!dst_pte) |
1628 | goto nomem; | |
c5c99429 LW |
1629 | |
1630 | /* If the pagetables are shared don't copy or take references */ | |
1631 | if (dst_pte == src_pte) | |
1632 | continue; | |
1633 | ||
c74df32c | 1634 | spin_lock(&dst->page_table_lock); |
46478758 | 1635 | spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); |
7f2e9525 | 1636 | if (!huge_pte_none(huge_ptep_get(src_pte))) { |
1e8f889b | 1637 | if (cow) |
7f2e9525 GS |
1638 | huge_ptep_set_wrprotect(src, addr, src_pte); |
1639 | entry = huge_ptep_get(src_pte); | |
1c59827d HD |
1640 | ptepage = pte_page(entry); |
1641 | get_page(ptepage); | |
1c59827d HD |
1642 | set_huge_pte_at(dst, addr, dst_pte, entry); |
1643 | } | |
1644 | spin_unlock(&src->page_table_lock); | |
c74df32c | 1645 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
1646 | } |
1647 | return 0; | |
1648 | ||
1649 | nomem: | |
1650 | return -ENOMEM; | |
1651 | } | |
1652 | ||
502717f4 | 1653 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1654 | unsigned long end, struct page *ref_page) |
63551ae0 DG |
1655 | { |
1656 | struct mm_struct *mm = vma->vm_mm; | |
1657 | unsigned long address; | |
c7546f8f | 1658 | pte_t *ptep; |
63551ae0 DG |
1659 | pte_t pte; |
1660 | struct page *page; | |
fe1668ae | 1661 | struct page *tmp; |
a5516438 AK |
1662 | struct hstate *h = hstate_vma(vma); |
1663 | unsigned long sz = huge_page_size(h); | |
1664 | ||
c0a499c2 KC |
1665 | /* |
1666 | * A page gathering list, protected by per file i_mmap_lock. The | |
1667 | * lock is used to avoid list corruption from multiple unmapping | |
1668 | * of the same page since we are using page->lru. | |
1669 | */ | |
fe1668ae | 1670 | LIST_HEAD(page_list); |
63551ae0 DG |
1671 | |
1672 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
a5516438 AK |
1673 | BUG_ON(start & ~huge_page_mask(h)); |
1674 | BUG_ON(end & ~huge_page_mask(h)); | |
63551ae0 | 1675 | |
cddb8a5c | 1676 | mmu_notifier_invalidate_range_start(mm, start, end); |
508034a3 | 1677 | spin_lock(&mm->page_table_lock); |
a5516438 | 1678 | for (address = start; address < end; address += sz) { |
c7546f8f | 1679 | ptep = huge_pte_offset(mm, address); |
4c887265 | 1680 | if (!ptep) |
c7546f8f DG |
1681 | continue; |
1682 | ||
39dde65c KC |
1683 | if (huge_pmd_unshare(mm, &address, ptep)) |
1684 | continue; | |
1685 | ||
04f2cbe3 MG |
1686 | /* |
1687 | * If a reference page is supplied, it is because a specific | |
1688 | * page is being unmapped, not a range. Ensure the page we | |
1689 | * are about to unmap is the actual page of interest. | |
1690 | */ | |
1691 | if (ref_page) { | |
1692 | pte = huge_ptep_get(ptep); | |
1693 | if (huge_pte_none(pte)) | |
1694 | continue; | |
1695 | page = pte_page(pte); | |
1696 | if (page != ref_page) | |
1697 | continue; | |
1698 | ||
1699 | /* | |
1700 | * Mark the VMA as having unmapped its page so that | |
1701 | * future faults in this VMA will fail rather than | |
1702 | * looking like data was lost | |
1703 | */ | |
1704 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); | |
1705 | } | |
1706 | ||
c7546f8f | 1707 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
7f2e9525 | 1708 | if (huge_pte_none(pte)) |
63551ae0 | 1709 | continue; |
c7546f8f | 1710 | |
63551ae0 | 1711 | page = pte_page(pte); |
6649a386 KC |
1712 | if (pte_dirty(pte)) |
1713 | set_page_dirty(page); | |
fe1668ae | 1714 | list_add(&page->lru, &page_list); |
63551ae0 | 1715 | } |
1da177e4 | 1716 | spin_unlock(&mm->page_table_lock); |
508034a3 | 1717 | flush_tlb_range(vma, start, end); |
cddb8a5c | 1718 | mmu_notifier_invalidate_range_end(mm, start, end); |
fe1668ae KC |
1719 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
1720 | list_del(&page->lru); | |
1721 | put_page(page); | |
1722 | } | |
1da177e4 | 1723 | } |
63551ae0 | 1724 | |
502717f4 | 1725 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1726 | unsigned long end, struct page *ref_page) |
502717f4 | 1727 | { |
a137e1cc AK |
1728 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
1729 | __unmap_hugepage_range(vma, start, end, ref_page); | |
1730 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); | |
502717f4 KC |
1731 | } |
1732 | ||
04f2cbe3 MG |
1733 | /* |
1734 | * This is called when the original mapper is failing to COW a MAP_PRIVATE | |
1735 | * mappping it owns the reserve page for. The intention is to unmap the page | |
1736 | * from other VMAs and let the children be SIGKILLed if they are faulting the | |
1737 | * same region. | |
1738 | */ | |
1739 | int unmap_ref_private(struct mm_struct *mm, | |
1740 | struct vm_area_struct *vma, | |
1741 | struct page *page, | |
1742 | unsigned long address) | |
1743 | { | |
1744 | struct vm_area_struct *iter_vma; | |
1745 | struct address_space *mapping; | |
1746 | struct prio_tree_iter iter; | |
1747 | pgoff_t pgoff; | |
1748 | ||
1749 | /* | |
1750 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation | |
1751 | * from page cache lookup which is in HPAGE_SIZE units. | |
1752 | */ | |
1753 | address = address & huge_page_mask(hstate_vma(vma)); | |
1754 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) | |
1755 | + (vma->vm_pgoff >> PAGE_SHIFT); | |
1756 | mapping = (struct address_space *)page_private(page); | |
1757 | ||
1758 | vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { | |
1759 | /* Do not unmap the current VMA */ | |
1760 | if (iter_vma == vma) | |
1761 | continue; | |
1762 | ||
1763 | /* | |
1764 | * Unmap the page from other VMAs without their own reserves. | |
1765 | * They get marked to be SIGKILLed if they fault in these | |
1766 | * areas. This is because a future no-page fault on this VMA | |
1767 | * could insert a zeroed page instead of the data existing | |
1768 | * from the time of fork. This would look like data corruption | |
1769 | */ | |
1770 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) | |
1771 | unmap_hugepage_range(iter_vma, | |
1772 | address, address + HPAGE_SIZE, | |
1773 | page); | |
1774 | } | |
1775 | ||
1776 | return 1; | |
1777 | } | |
1778 | ||
1e8f889b | 1779 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
04f2cbe3 MG |
1780 | unsigned long address, pte_t *ptep, pte_t pte, |
1781 | struct page *pagecache_page) | |
1e8f889b | 1782 | { |
a5516438 | 1783 | struct hstate *h = hstate_vma(vma); |
1e8f889b | 1784 | struct page *old_page, *new_page; |
79ac6ba4 | 1785 | int avoidcopy; |
04f2cbe3 | 1786 | int outside_reserve = 0; |
1e8f889b DG |
1787 | |
1788 | old_page = pte_page(pte); | |
1789 | ||
04f2cbe3 | 1790 | retry_avoidcopy: |
1e8f889b DG |
1791 | /* If no-one else is actually using this page, avoid the copy |
1792 | * and just make the page writable */ | |
1793 | avoidcopy = (page_count(old_page) == 1); | |
1794 | if (avoidcopy) { | |
1795 | set_huge_ptep_writable(vma, address, ptep); | |
83c54070 | 1796 | return 0; |
1e8f889b DG |
1797 | } |
1798 | ||
04f2cbe3 MG |
1799 | /* |
1800 | * If the process that created a MAP_PRIVATE mapping is about to | |
1801 | * perform a COW due to a shared page count, attempt to satisfy | |
1802 | * the allocation without using the existing reserves. The pagecache | |
1803 | * page is used to determine if the reserve at this address was | |
1804 | * consumed or not. If reserves were used, a partial faulted mapping | |
1805 | * at the time of fork() could consume its reserves on COW instead | |
1806 | * of the full address range. | |
1807 | */ | |
1808 | if (!(vma->vm_flags & VM_SHARED) && | |
1809 | is_vma_resv_set(vma, HPAGE_RESV_OWNER) && | |
1810 | old_page != pagecache_page) | |
1811 | outside_reserve = 1; | |
1812 | ||
1e8f889b | 1813 | page_cache_get(old_page); |
04f2cbe3 | 1814 | new_page = alloc_huge_page(vma, address, outside_reserve); |
1e8f889b | 1815 | |
2fc39cec | 1816 | if (IS_ERR(new_page)) { |
1e8f889b | 1817 | page_cache_release(old_page); |
04f2cbe3 MG |
1818 | |
1819 | /* | |
1820 | * If a process owning a MAP_PRIVATE mapping fails to COW, | |
1821 | * it is due to references held by a child and an insufficient | |
1822 | * huge page pool. To guarantee the original mappers | |
1823 | * reliability, unmap the page from child processes. The child | |
1824 | * may get SIGKILLed if it later faults. | |
1825 | */ | |
1826 | if (outside_reserve) { | |
1827 | BUG_ON(huge_pte_none(pte)); | |
1828 | if (unmap_ref_private(mm, vma, old_page, address)) { | |
1829 | BUG_ON(page_count(old_page) != 1); | |
1830 | BUG_ON(huge_pte_none(pte)); | |
1831 | goto retry_avoidcopy; | |
1832 | } | |
1833 | WARN_ON_ONCE(1); | |
1834 | } | |
1835 | ||
2fc39cec | 1836 | return -PTR_ERR(new_page); |
1e8f889b DG |
1837 | } |
1838 | ||
1839 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 1840 | copy_huge_page(new_page, old_page, address, vma); |
0ed361de | 1841 | __SetPageUptodate(new_page); |
1e8f889b DG |
1842 | spin_lock(&mm->page_table_lock); |
1843 | ||
a5516438 | 1844 | ptep = huge_pte_offset(mm, address & huge_page_mask(h)); |
7f2e9525 | 1845 | if (likely(pte_same(huge_ptep_get(ptep), pte))) { |
1e8f889b | 1846 | /* Break COW */ |
8fe627ec | 1847 | huge_ptep_clear_flush(vma, address, ptep); |
1e8f889b DG |
1848 | set_huge_pte_at(mm, address, ptep, |
1849 | make_huge_pte(vma, new_page, 1)); | |
1850 | /* Make the old page be freed below */ | |
1851 | new_page = old_page; | |
1852 | } | |
1853 | page_cache_release(new_page); | |
1854 | page_cache_release(old_page); | |
83c54070 | 1855 | return 0; |
1e8f889b DG |
1856 | } |
1857 | ||
04f2cbe3 | 1858 | /* Return the pagecache page at a given address within a VMA */ |
a5516438 AK |
1859 | static struct page *hugetlbfs_pagecache_page(struct hstate *h, |
1860 | struct vm_area_struct *vma, unsigned long address) | |
04f2cbe3 MG |
1861 | { |
1862 | struct address_space *mapping; | |
e7c4b0bf | 1863 | pgoff_t idx; |
04f2cbe3 MG |
1864 | |
1865 | mapping = vma->vm_file->f_mapping; | |
a5516438 | 1866 | idx = vma_hugecache_offset(h, vma, address); |
04f2cbe3 MG |
1867 | |
1868 | return find_lock_page(mapping, idx); | |
1869 | } | |
1870 | ||
a1ed3dda | 1871 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 1872 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 | 1873 | { |
a5516438 | 1874 | struct hstate *h = hstate_vma(vma); |
ac9b9c66 | 1875 | int ret = VM_FAULT_SIGBUS; |
e7c4b0bf | 1876 | pgoff_t idx; |
4c887265 | 1877 | unsigned long size; |
4c887265 AL |
1878 | struct page *page; |
1879 | struct address_space *mapping; | |
1e8f889b | 1880 | pte_t new_pte; |
4c887265 | 1881 | |
04f2cbe3 MG |
1882 | /* |
1883 | * Currently, we are forced to kill the process in the event the | |
1884 | * original mapper has unmapped pages from the child due to a failed | |
1885 | * COW. Warn that such a situation has occured as it may not be obvious | |
1886 | */ | |
1887 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { | |
1888 | printk(KERN_WARNING | |
1889 | "PID %d killed due to inadequate hugepage pool\n", | |
1890 | current->pid); | |
1891 | return ret; | |
1892 | } | |
1893 | ||
4c887265 | 1894 | mapping = vma->vm_file->f_mapping; |
a5516438 | 1895 | idx = vma_hugecache_offset(h, vma, address); |
4c887265 AL |
1896 | |
1897 | /* | |
1898 | * Use page lock to guard against racing truncation | |
1899 | * before we get page_table_lock. | |
1900 | */ | |
6bda666a CL |
1901 | retry: |
1902 | page = find_lock_page(mapping, idx); | |
1903 | if (!page) { | |
a5516438 | 1904 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
ebed4bfc HD |
1905 | if (idx >= size) |
1906 | goto out; | |
04f2cbe3 | 1907 | page = alloc_huge_page(vma, address, 0); |
2fc39cec AL |
1908 | if (IS_ERR(page)) { |
1909 | ret = -PTR_ERR(page); | |
6bda666a CL |
1910 | goto out; |
1911 | } | |
a5516438 | 1912 | clear_huge_page(page, address, huge_page_size(h)); |
0ed361de | 1913 | __SetPageUptodate(page); |
ac9b9c66 | 1914 | |
6bda666a CL |
1915 | if (vma->vm_flags & VM_SHARED) { |
1916 | int err; | |
45c682a6 | 1917 | struct inode *inode = mapping->host; |
6bda666a CL |
1918 | |
1919 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
1920 | if (err) { | |
1921 | put_page(page); | |
6bda666a CL |
1922 | if (err == -EEXIST) |
1923 | goto retry; | |
1924 | goto out; | |
1925 | } | |
45c682a6 KC |
1926 | |
1927 | spin_lock(&inode->i_lock); | |
a5516438 | 1928 | inode->i_blocks += blocks_per_huge_page(h); |
45c682a6 | 1929 | spin_unlock(&inode->i_lock); |
6bda666a CL |
1930 | } else |
1931 | lock_page(page); | |
1932 | } | |
1e8f889b | 1933 | |
ac9b9c66 | 1934 | spin_lock(&mm->page_table_lock); |
a5516438 | 1935 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
4c887265 AL |
1936 | if (idx >= size) |
1937 | goto backout; | |
1938 | ||
83c54070 | 1939 | ret = 0; |
7f2e9525 | 1940 | if (!huge_pte_none(huge_ptep_get(ptep))) |
4c887265 AL |
1941 | goto backout; |
1942 | ||
1e8f889b DG |
1943 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
1944 | && (vma->vm_flags & VM_SHARED))); | |
1945 | set_huge_pte_at(mm, address, ptep, new_pte); | |
1946 | ||
1947 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
1948 | /* Optimization, do the COW without a second fault */ | |
04f2cbe3 | 1949 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); |
1e8f889b DG |
1950 | } |
1951 | ||
ac9b9c66 | 1952 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
1953 | unlock_page(page); |
1954 | out: | |
ac9b9c66 | 1955 | return ret; |
4c887265 AL |
1956 | |
1957 | backout: | |
1958 | spin_unlock(&mm->page_table_lock); | |
4c887265 AL |
1959 | unlock_page(page); |
1960 | put_page(page); | |
1961 | goto out; | |
ac9b9c66 HD |
1962 | } |
1963 | ||
86e5216f AL |
1964 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
1965 | unsigned long address, int write_access) | |
1966 | { | |
1967 | pte_t *ptep; | |
1968 | pte_t entry; | |
1e8f889b | 1969 | int ret; |
3935baa9 | 1970 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
a5516438 | 1971 | struct hstate *h = hstate_vma(vma); |
86e5216f | 1972 | |
a5516438 | 1973 | ptep = huge_pte_alloc(mm, address, huge_page_size(h)); |
86e5216f AL |
1974 | if (!ptep) |
1975 | return VM_FAULT_OOM; | |
1976 | ||
3935baa9 DG |
1977 | /* |
1978 | * Serialize hugepage allocation and instantiation, so that we don't | |
1979 | * get spurious allocation failures if two CPUs race to instantiate | |
1980 | * the same page in the page cache. | |
1981 | */ | |
1982 | mutex_lock(&hugetlb_instantiation_mutex); | |
7f2e9525 GS |
1983 | entry = huge_ptep_get(ptep); |
1984 | if (huge_pte_none(entry)) { | |
3935baa9 DG |
1985 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); |
1986 | mutex_unlock(&hugetlb_instantiation_mutex); | |
1987 | return ret; | |
1988 | } | |
86e5216f | 1989 | |
83c54070 | 1990 | ret = 0; |
1e8f889b DG |
1991 | |
1992 | spin_lock(&mm->page_table_lock); | |
1993 | /* Check for a racing update before calling hugetlb_cow */ | |
7f2e9525 | 1994 | if (likely(pte_same(entry, huge_ptep_get(ptep)))) |
04f2cbe3 MG |
1995 | if (write_access && !pte_write(entry)) { |
1996 | struct page *page; | |
a5516438 | 1997 | page = hugetlbfs_pagecache_page(h, vma, address); |
04f2cbe3 MG |
1998 | ret = hugetlb_cow(mm, vma, address, ptep, entry, page); |
1999 | if (page) { | |
2000 | unlock_page(page); | |
2001 | put_page(page); | |
2002 | } | |
2003 | } | |
1e8f889b | 2004 | spin_unlock(&mm->page_table_lock); |
3935baa9 | 2005 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
2006 | |
2007 | return ret; | |
86e5216f AL |
2008 | } |
2009 | ||
ceb86879 AK |
2010 | /* Can be overriden by architectures */ |
2011 | __attribute__((weak)) struct page * | |
2012 | follow_huge_pud(struct mm_struct *mm, unsigned long address, | |
2013 | pud_t *pud, int write) | |
2014 | { | |
2015 | BUG(); | |
2016 | return NULL; | |
2017 | } | |
2018 | ||
63551ae0 DG |
2019 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
2020 | struct page **pages, struct vm_area_struct **vmas, | |
5b23dbe8 AL |
2021 | unsigned long *position, int *length, int i, |
2022 | int write) | |
63551ae0 | 2023 | { |
d5d4b0aa KC |
2024 | unsigned long pfn_offset; |
2025 | unsigned long vaddr = *position; | |
63551ae0 | 2026 | int remainder = *length; |
a5516438 | 2027 | struct hstate *h = hstate_vma(vma); |
63551ae0 | 2028 | |
1c59827d | 2029 | spin_lock(&mm->page_table_lock); |
63551ae0 | 2030 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
2031 | pte_t *pte; |
2032 | struct page *page; | |
63551ae0 | 2033 | |
4c887265 AL |
2034 | /* |
2035 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
2036 | * each hugepage. We have to make * sure we get the | |
2037 | * first, for the page indexing below to work. | |
2038 | */ | |
a5516438 | 2039 | pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); |
63551ae0 | 2040 | |
7f2e9525 GS |
2041 | if (!pte || huge_pte_none(huge_ptep_get(pte)) || |
2042 | (write && !pte_write(huge_ptep_get(pte)))) { | |
4c887265 | 2043 | int ret; |
63551ae0 | 2044 | |
4c887265 | 2045 | spin_unlock(&mm->page_table_lock); |
5b23dbe8 | 2046 | ret = hugetlb_fault(mm, vma, vaddr, write); |
4c887265 | 2047 | spin_lock(&mm->page_table_lock); |
a89182c7 | 2048 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 2049 | continue; |
63551ae0 | 2050 | |
4c887265 AL |
2051 | remainder = 0; |
2052 | if (!i) | |
2053 | i = -EFAULT; | |
2054 | break; | |
2055 | } | |
2056 | ||
a5516438 | 2057 | pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; |
7f2e9525 | 2058 | page = pte_page(huge_ptep_get(pte)); |
d5d4b0aa | 2059 | same_page: |
d6692183 KC |
2060 | if (pages) { |
2061 | get_page(page); | |
d5d4b0aa | 2062 | pages[i] = page + pfn_offset; |
d6692183 | 2063 | } |
63551ae0 DG |
2064 | |
2065 | if (vmas) | |
2066 | vmas[i] = vma; | |
2067 | ||
2068 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 2069 | ++pfn_offset; |
63551ae0 DG |
2070 | --remainder; |
2071 | ++i; | |
d5d4b0aa | 2072 | if (vaddr < vma->vm_end && remainder && |
a5516438 | 2073 | pfn_offset < pages_per_huge_page(h)) { |
d5d4b0aa KC |
2074 | /* |
2075 | * We use pfn_offset to avoid touching the pageframes | |
2076 | * of this compound page. | |
2077 | */ | |
2078 | goto same_page; | |
2079 | } | |
63551ae0 | 2080 | } |
1c59827d | 2081 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
2082 | *length = remainder; |
2083 | *position = vaddr; | |
2084 | ||
2085 | return i; | |
2086 | } | |
8f860591 ZY |
2087 | |
2088 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
2089 | unsigned long address, unsigned long end, pgprot_t newprot) | |
2090 | { | |
2091 | struct mm_struct *mm = vma->vm_mm; | |
2092 | unsigned long start = address; | |
2093 | pte_t *ptep; | |
2094 | pte_t pte; | |
a5516438 | 2095 | struct hstate *h = hstate_vma(vma); |
8f860591 ZY |
2096 | |
2097 | BUG_ON(address >= end); | |
2098 | flush_cache_range(vma, address, end); | |
2099 | ||
39dde65c | 2100 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 | 2101 | spin_lock(&mm->page_table_lock); |
a5516438 | 2102 | for (; address < end; address += huge_page_size(h)) { |
8f860591 ZY |
2103 | ptep = huge_pte_offset(mm, address); |
2104 | if (!ptep) | |
2105 | continue; | |
39dde65c KC |
2106 | if (huge_pmd_unshare(mm, &address, ptep)) |
2107 | continue; | |
7f2e9525 | 2108 | if (!huge_pte_none(huge_ptep_get(ptep))) { |
8f860591 ZY |
2109 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
2110 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
2111 | set_huge_pte_at(mm, address, ptep, pte); | |
8f860591 ZY |
2112 | } |
2113 | } | |
2114 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 2115 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
2116 | |
2117 | flush_tlb_range(vma, start, end); | |
2118 | } | |
2119 | ||
a1e78772 MG |
2120 | int hugetlb_reserve_pages(struct inode *inode, |
2121 | long from, long to, | |
2122 | struct vm_area_struct *vma) | |
e4e574b7 AL |
2123 | { |
2124 | long ret, chg; | |
a5516438 | 2125 | struct hstate *h = hstate_inode(inode); |
e4e574b7 | 2126 | |
c37f9fb1 AW |
2127 | if (vma && vma->vm_flags & VM_NORESERVE) |
2128 | return 0; | |
2129 | ||
a1e78772 MG |
2130 | /* |
2131 | * Shared mappings base their reservation on the number of pages that | |
2132 | * are already allocated on behalf of the file. Private mappings need | |
2133 | * to reserve the full area even if read-only as mprotect() may be | |
2134 | * called to make the mapping read-write. Assume !vma is a shm mapping | |
2135 | */ | |
2136 | if (!vma || vma->vm_flags & VM_SHARED) | |
2137 | chg = region_chg(&inode->i_mapping->private_list, from, to); | |
2138 | else { | |
84afd99b AW |
2139 | struct resv_map *resv_map = resv_map_alloc(); |
2140 | if (!resv_map) | |
2141 | return -ENOMEM; | |
2142 | ||
a1e78772 | 2143 | chg = to - from; |
84afd99b AW |
2144 | |
2145 | set_vma_resv_map(vma, resv_map); | |
04f2cbe3 | 2146 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); |
a1e78772 MG |
2147 | } |
2148 | ||
e4e574b7 AL |
2149 | if (chg < 0) |
2150 | return chg; | |
8a630112 | 2151 | |
90d8b7e6 AL |
2152 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
2153 | return -ENOSPC; | |
a5516438 | 2154 | ret = hugetlb_acct_memory(h, chg); |
68842c9b KC |
2155 | if (ret < 0) { |
2156 | hugetlb_put_quota(inode->i_mapping, chg); | |
a43a8c39 | 2157 | return ret; |
68842c9b | 2158 | } |
a1e78772 MG |
2159 | if (!vma || vma->vm_flags & VM_SHARED) |
2160 | region_add(&inode->i_mapping->private_list, from, to); | |
a43a8c39 KC |
2161 | return 0; |
2162 | } | |
2163 | ||
2164 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
2165 | { | |
a5516438 | 2166 | struct hstate *h = hstate_inode(inode); |
a43a8c39 | 2167 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
45c682a6 KC |
2168 | |
2169 | spin_lock(&inode->i_lock); | |
a5516438 | 2170 | inode->i_blocks -= blocks_per_huge_page(h); |
45c682a6 KC |
2171 | spin_unlock(&inode->i_lock); |
2172 | ||
90d8b7e6 | 2173 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
a5516438 | 2174 | hugetlb_acct_memory(h, -(chg - freed)); |
a43a8c39 | 2175 | } |