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> | |
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> |
7cb93181 | 20 | #include <asm/io.h> |
63551ae0 DG |
21 | #include <asm/page.h> |
22 | #include <asm/pgtable.h> | |
78a34ae2 | 23 | #include <asm/io.h> |
63551ae0 DG |
24 | |
25 | #include <linux/hugetlb.h> | |
7835e98b | 26 | #include "internal.h" |
1da177e4 LT |
27 | |
28 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; | |
396faf03 MG |
29 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
30 | unsigned long hugepages_treat_as_movable; | |
a5516438 | 31 | |
e5ff2159 AK |
32 | static int max_hstate; |
33 | unsigned int default_hstate_idx; | |
34 | struct hstate hstates[HUGE_MAX_HSTATE]; | |
35 | ||
53ba51d2 JT |
36 | __initdata LIST_HEAD(huge_boot_pages); |
37 | ||
e5ff2159 AK |
38 | /* for command line parsing */ |
39 | static struct hstate * __initdata parsed_hstate; | |
40 | static unsigned long __initdata default_hstate_max_huge_pages; | |
e11bfbfc | 41 | static unsigned long __initdata default_hstate_size; |
e5ff2159 AK |
42 | |
43 | #define for_each_hstate(h) \ | |
44 | for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++) | |
396faf03 | 45 | |
3935baa9 DG |
46 | /* |
47 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages | |
48 | */ | |
49 | static DEFINE_SPINLOCK(hugetlb_lock); | |
0bd0f9fb | 50 | |
96822904 AW |
51 | /* |
52 | * Region tracking -- allows tracking of reservations and instantiated pages | |
53 | * across the pages in a mapping. | |
84afd99b AW |
54 | * |
55 | * The region data structures are protected by a combination of the mmap_sem | |
56 | * and the hugetlb_instantion_mutex. To access or modify a region the caller | |
57 | * must either hold the mmap_sem for write, or the mmap_sem for read and | |
58 | * the hugetlb_instantiation mutex: | |
59 | * | |
60 | * down_write(&mm->mmap_sem); | |
61 | * or | |
62 | * down_read(&mm->mmap_sem); | |
63 | * mutex_lock(&hugetlb_instantiation_mutex); | |
96822904 AW |
64 | */ |
65 | struct file_region { | |
66 | struct list_head link; | |
67 | long from; | |
68 | long to; | |
69 | }; | |
70 | ||
71 | static long region_add(struct list_head *head, long f, long t) | |
72 | { | |
73 | struct file_region *rg, *nrg, *trg; | |
74 | ||
75 | /* Locate the region we are either in or before. */ | |
76 | list_for_each_entry(rg, head, link) | |
77 | if (f <= rg->to) | |
78 | break; | |
79 | ||
80 | /* Round our left edge to the current segment if it encloses us. */ | |
81 | if (f > rg->from) | |
82 | f = rg->from; | |
83 | ||
84 | /* Check for and consume any regions we now overlap with. */ | |
85 | nrg = rg; | |
86 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
87 | if (&rg->link == head) | |
88 | break; | |
89 | if (rg->from > t) | |
90 | break; | |
91 | ||
92 | /* If this area reaches higher then extend our area to | |
93 | * include it completely. If this is not the first area | |
94 | * which we intend to reuse, free it. */ | |
95 | if (rg->to > t) | |
96 | t = rg->to; | |
97 | if (rg != nrg) { | |
98 | list_del(&rg->link); | |
99 | kfree(rg); | |
100 | } | |
101 | } | |
102 | nrg->from = f; | |
103 | nrg->to = t; | |
104 | return 0; | |
105 | } | |
106 | ||
107 | static long region_chg(struct list_head *head, long f, long t) | |
108 | { | |
109 | struct file_region *rg, *nrg; | |
110 | long chg = 0; | |
111 | ||
112 | /* Locate the region we are before or in. */ | |
113 | list_for_each_entry(rg, head, link) | |
114 | if (f <= rg->to) | |
115 | break; | |
116 | ||
117 | /* If we are below the current region then a new region is required. | |
118 | * Subtle, allocate a new region at the position but make it zero | |
119 | * size such that we can guarantee to record the reservation. */ | |
120 | if (&rg->link == head || t < rg->from) { | |
121 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
122 | if (!nrg) | |
123 | return -ENOMEM; | |
124 | nrg->from = f; | |
125 | nrg->to = f; | |
126 | INIT_LIST_HEAD(&nrg->link); | |
127 | list_add(&nrg->link, rg->link.prev); | |
128 | ||
129 | return t - f; | |
130 | } | |
131 | ||
132 | /* Round our left edge to the current segment if it encloses us. */ | |
133 | if (f > rg->from) | |
134 | f = rg->from; | |
135 | chg = t - f; | |
136 | ||
137 | /* Check for and consume any regions we now overlap with. */ | |
138 | list_for_each_entry(rg, rg->link.prev, link) { | |
139 | if (&rg->link == head) | |
140 | break; | |
141 | if (rg->from > t) | |
142 | return chg; | |
143 | ||
144 | /* We overlap with this area, if it extends futher than | |
145 | * us then we must extend ourselves. Account for its | |
146 | * existing reservation. */ | |
147 | if (rg->to > t) { | |
148 | chg += rg->to - t; | |
149 | t = rg->to; | |
150 | } | |
151 | chg -= rg->to - rg->from; | |
152 | } | |
153 | return chg; | |
154 | } | |
155 | ||
156 | static long region_truncate(struct list_head *head, long end) | |
157 | { | |
158 | struct file_region *rg, *trg; | |
159 | long chg = 0; | |
160 | ||
161 | /* Locate the region we are either in or before. */ | |
162 | list_for_each_entry(rg, head, link) | |
163 | if (end <= rg->to) | |
164 | break; | |
165 | if (&rg->link == head) | |
166 | return 0; | |
167 | ||
168 | /* If we are in the middle of a region then adjust it. */ | |
169 | if (end > rg->from) { | |
170 | chg = rg->to - end; | |
171 | rg->to = end; | |
172 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
173 | } | |
174 | ||
175 | /* Drop any remaining regions. */ | |
176 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
177 | if (&rg->link == head) | |
178 | break; | |
179 | chg += rg->to - rg->from; | |
180 | list_del(&rg->link); | |
181 | kfree(rg); | |
182 | } | |
183 | return chg; | |
184 | } | |
185 | ||
84afd99b AW |
186 | static long region_count(struct list_head *head, long f, long t) |
187 | { | |
188 | struct file_region *rg; | |
189 | long chg = 0; | |
190 | ||
191 | /* Locate each segment we overlap with, and count that overlap. */ | |
192 | list_for_each_entry(rg, head, link) { | |
193 | int seg_from; | |
194 | int seg_to; | |
195 | ||
196 | if (rg->to <= f) | |
197 | continue; | |
198 | if (rg->from >= t) | |
199 | break; | |
200 | ||
201 | seg_from = max(rg->from, f); | |
202 | seg_to = min(rg->to, t); | |
203 | ||
204 | chg += seg_to - seg_from; | |
205 | } | |
206 | ||
207 | return chg; | |
208 | } | |
209 | ||
e7c4b0bf AW |
210 | /* |
211 | * Convert the address within this vma to the page offset within | |
212 | * the mapping, in pagecache page units; huge pages here. | |
213 | */ | |
a5516438 AK |
214 | static pgoff_t vma_hugecache_offset(struct hstate *h, |
215 | struct vm_area_struct *vma, unsigned long address) | |
e7c4b0bf | 216 | { |
a5516438 AK |
217 | return ((address - vma->vm_start) >> huge_page_shift(h)) + |
218 | (vma->vm_pgoff >> huge_page_order(h)); | |
e7c4b0bf AW |
219 | } |
220 | ||
84afd99b AW |
221 | /* |
222 | * Flags for MAP_PRIVATE reservations. These are stored in the bottom | |
223 | * bits of the reservation map pointer, which are always clear due to | |
224 | * alignment. | |
225 | */ | |
226 | #define HPAGE_RESV_OWNER (1UL << 0) | |
227 | #define HPAGE_RESV_UNMAPPED (1UL << 1) | |
04f2cbe3 | 228 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) |
84afd99b | 229 | |
a1e78772 MG |
230 | /* |
231 | * These helpers are used to track how many pages are reserved for | |
232 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() | |
233 | * is guaranteed to have their future faults succeed. | |
234 | * | |
235 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), | |
236 | * the reserve counters are updated with the hugetlb_lock held. It is safe | |
237 | * to reset the VMA at fork() time as it is not in use yet and there is no | |
238 | * chance of the global counters getting corrupted as a result of the values. | |
84afd99b AW |
239 | * |
240 | * The private mapping reservation is represented in a subtly different | |
241 | * manner to a shared mapping. A shared mapping has a region map associated | |
242 | * with the underlying file, this region map represents the backing file | |
243 | * pages which have ever had a reservation assigned which this persists even | |
244 | * after the page is instantiated. A private mapping has a region map | |
245 | * associated with the original mmap which is attached to all VMAs which | |
246 | * reference it, this region map represents those offsets which have consumed | |
247 | * reservation ie. where pages have been instantiated. | |
a1e78772 | 248 | */ |
e7c4b0bf AW |
249 | static unsigned long get_vma_private_data(struct vm_area_struct *vma) |
250 | { | |
251 | return (unsigned long)vma->vm_private_data; | |
252 | } | |
253 | ||
254 | static void set_vma_private_data(struct vm_area_struct *vma, | |
255 | unsigned long value) | |
256 | { | |
257 | vma->vm_private_data = (void *)value; | |
258 | } | |
259 | ||
84afd99b AW |
260 | struct resv_map { |
261 | struct kref refs; | |
262 | struct list_head regions; | |
263 | }; | |
264 | ||
265 | struct resv_map *resv_map_alloc(void) | |
266 | { | |
267 | struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); | |
268 | if (!resv_map) | |
269 | return NULL; | |
270 | ||
271 | kref_init(&resv_map->refs); | |
272 | INIT_LIST_HEAD(&resv_map->regions); | |
273 | ||
274 | return resv_map; | |
275 | } | |
276 | ||
277 | void resv_map_release(struct kref *ref) | |
278 | { | |
279 | struct resv_map *resv_map = container_of(ref, struct resv_map, refs); | |
280 | ||
281 | /* Clear out any active regions before we release the map. */ | |
282 | region_truncate(&resv_map->regions, 0); | |
283 | kfree(resv_map); | |
284 | } | |
285 | ||
286 | static struct resv_map *vma_resv_map(struct vm_area_struct *vma) | |
a1e78772 MG |
287 | { |
288 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
289 | if (!(vma->vm_flags & VM_SHARED)) | |
84afd99b AW |
290 | return (struct resv_map *)(get_vma_private_data(vma) & |
291 | ~HPAGE_RESV_MASK); | |
a1e78772 MG |
292 | return 0; |
293 | } | |
294 | ||
84afd99b | 295 | static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) |
a1e78772 MG |
296 | { |
297 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
298 | VM_BUG_ON(vma->vm_flags & VM_SHARED); | |
299 | ||
84afd99b AW |
300 | set_vma_private_data(vma, (get_vma_private_data(vma) & |
301 | HPAGE_RESV_MASK) | (unsigned long)map); | |
04f2cbe3 MG |
302 | } |
303 | ||
304 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) | |
305 | { | |
04f2cbe3 | 306 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
e7c4b0bf AW |
307 | VM_BUG_ON(vma->vm_flags & VM_SHARED); |
308 | ||
309 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); | |
04f2cbe3 MG |
310 | } |
311 | ||
312 | static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) | |
313 | { | |
314 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
e7c4b0bf AW |
315 | |
316 | return (get_vma_private_data(vma) & flag) != 0; | |
a1e78772 MG |
317 | } |
318 | ||
319 | /* Decrement the reserved pages in the hugepage pool by one */ | |
a5516438 AK |
320 | static void decrement_hugepage_resv_vma(struct hstate *h, |
321 | struct vm_area_struct *vma) | |
a1e78772 | 322 | { |
c37f9fb1 AW |
323 | if (vma->vm_flags & VM_NORESERVE) |
324 | return; | |
325 | ||
a1e78772 MG |
326 | if (vma->vm_flags & VM_SHARED) { |
327 | /* Shared mappings always use reserves */ | |
a5516438 | 328 | h->resv_huge_pages--; |
84afd99b | 329 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
a1e78772 MG |
330 | /* |
331 | * Only the process that called mmap() has reserves for | |
332 | * private mappings. | |
333 | */ | |
a5516438 | 334 | h->resv_huge_pages--; |
a1e78772 MG |
335 | } |
336 | } | |
337 | ||
04f2cbe3 | 338 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
a1e78772 MG |
339 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
340 | { | |
341 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
342 | if (!(vma->vm_flags & VM_SHARED)) | |
343 | vma->vm_private_data = (void *)0; | |
344 | } | |
345 | ||
346 | /* Returns true if the VMA has associated reserve pages */ | |
7f09ca51 | 347 | static int vma_has_reserves(struct vm_area_struct *vma) |
a1e78772 MG |
348 | { |
349 | if (vma->vm_flags & VM_SHARED) | |
7f09ca51 MG |
350 | return 1; |
351 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) | |
352 | return 1; | |
353 | return 0; | |
a1e78772 MG |
354 | } |
355 | ||
a5516438 AK |
356 | static void clear_huge_page(struct page *page, |
357 | unsigned long addr, unsigned long sz) | |
79ac6ba4 DG |
358 | { |
359 | int i; | |
360 | ||
361 | might_sleep(); | |
a5516438 | 362 | for (i = 0; i < sz/PAGE_SIZE; i++) { |
79ac6ba4 | 363 | cond_resched(); |
281e0e3b | 364 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
79ac6ba4 DG |
365 | } |
366 | } | |
367 | ||
368 | static void copy_huge_page(struct page *dst, struct page *src, | |
9de455b2 | 369 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
370 | { |
371 | int i; | |
a5516438 | 372 | struct hstate *h = hstate_vma(vma); |
79ac6ba4 DG |
373 | |
374 | might_sleep(); | |
a5516438 | 375 | for (i = 0; i < pages_per_huge_page(h); i++) { |
79ac6ba4 | 376 | cond_resched(); |
9de455b2 | 377 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
378 | } |
379 | } | |
380 | ||
a5516438 | 381 | static void enqueue_huge_page(struct hstate *h, struct page *page) |
1da177e4 LT |
382 | { |
383 | int nid = page_to_nid(page); | |
a5516438 AK |
384 | list_add(&page->lru, &h->hugepage_freelists[nid]); |
385 | h->free_huge_pages++; | |
386 | h->free_huge_pages_node[nid]++; | |
1da177e4 LT |
387 | } |
388 | ||
a5516438 | 389 | static struct page *dequeue_huge_page(struct hstate *h) |
348e1e04 NA |
390 | { |
391 | int nid; | |
392 | struct page *page = NULL; | |
393 | ||
394 | for (nid = 0; nid < MAX_NUMNODES; ++nid) { | |
a5516438 AK |
395 | if (!list_empty(&h->hugepage_freelists[nid])) { |
396 | page = list_entry(h->hugepage_freelists[nid].next, | |
348e1e04 NA |
397 | struct page, lru); |
398 | list_del(&page->lru); | |
a5516438 AK |
399 | h->free_huge_pages--; |
400 | h->free_huge_pages_node[nid]--; | |
348e1e04 NA |
401 | break; |
402 | } | |
403 | } | |
404 | return page; | |
405 | } | |
406 | ||
a5516438 AK |
407 | static struct page *dequeue_huge_page_vma(struct hstate *h, |
408 | struct vm_area_struct *vma, | |
04f2cbe3 | 409 | unsigned long address, int avoid_reserve) |
1da177e4 | 410 | { |
31a5c6e4 | 411 | int nid; |
1da177e4 | 412 | struct page *page = NULL; |
480eccf9 | 413 | struct mempolicy *mpol; |
19770b32 | 414 | nodemask_t *nodemask; |
396faf03 | 415 | struct zonelist *zonelist = huge_zonelist(vma, address, |
19770b32 | 416 | htlb_alloc_mask, &mpol, &nodemask); |
dd1a239f MG |
417 | struct zone *zone; |
418 | struct zoneref *z; | |
1da177e4 | 419 | |
a1e78772 MG |
420 | /* |
421 | * A child process with MAP_PRIVATE mappings created by their parent | |
422 | * have no page reserves. This check ensures that reservations are | |
423 | * not "stolen". The child may still get SIGKILLed | |
424 | */ | |
7f09ca51 | 425 | if (!vma_has_reserves(vma) && |
a5516438 | 426 | h->free_huge_pages - h->resv_huge_pages == 0) |
a1e78772 MG |
427 | return NULL; |
428 | ||
04f2cbe3 | 429 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
a5516438 | 430 | if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) |
04f2cbe3 MG |
431 | return NULL; |
432 | ||
19770b32 MG |
433 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
434 | MAX_NR_ZONES - 1, nodemask) { | |
54a6eb5c MG |
435 | nid = zone_to_nid(zone); |
436 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && | |
a5516438 AK |
437 | !list_empty(&h->hugepage_freelists[nid])) { |
438 | page = list_entry(h->hugepage_freelists[nid].next, | |
3abf7afd AM |
439 | struct page, lru); |
440 | list_del(&page->lru); | |
a5516438 AK |
441 | h->free_huge_pages--; |
442 | h->free_huge_pages_node[nid]--; | |
04f2cbe3 MG |
443 | |
444 | if (!avoid_reserve) | |
a5516438 | 445 | decrement_hugepage_resv_vma(h, vma); |
a1e78772 | 446 | |
5ab3ee7b | 447 | break; |
3abf7afd | 448 | } |
1da177e4 | 449 | } |
52cd3b07 | 450 | mpol_cond_put(mpol); |
1da177e4 LT |
451 | return page; |
452 | } | |
453 | ||
a5516438 | 454 | static void update_and_free_page(struct hstate *h, struct page *page) |
6af2acb6 AL |
455 | { |
456 | int i; | |
a5516438 AK |
457 | |
458 | h->nr_huge_pages--; | |
459 | h->nr_huge_pages_node[page_to_nid(page)]--; | |
460 | for (i = 0; i < pages_per_huge_page(h); i++) { | |
6af2acb6 AL |
461 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | |
462 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
463 | 1 << PG_private | 1<< PG_writeback); | |
464 | } | |
465 | set_compound_page_dtor(page, NULL); | |
466 | set_page_refcounted(page); | |
7f2e9525 | 467 | arch_release_hugepage(page); |
a5516438 | 468 | __free_pages(page, huge_page_order(h)); |
6af2acb6 AL |
469 | } |
470 | ||
e5ff2159 AK |
471 | struct hstate *size_to_hstate(unsigned long size) |
472 | { | |
473 | struct hstate *h; | |
474 | ||
475 | for_each_hstate(h) { | |
476 | if (huge_page_size(h) == size) | |
477 | return h; | |
478 | } | |
479 | return NULL; | |
480 | } | |
481 | ||
27a85ef1 DG |
482 | static void free_huge_page(struct page *page) |
483 | { | |
a5516438 AK |
484 | /* |
485 | * Can't pass hstate in here because it is called from the | |
486 | * compound page destructor. | |
487 | */ | |
e5ff2159 | 488 | struct hstate *h = page_hstate(page); |
7893d1d5 | 489 | int nid = page_to_nid(page); |
c79fb75e | 490 | struct address_space *mapping; |
27a85ef1 | 491 | |
c79fb75e | 492 | mapping = (struct address_space *) page_private(page); |
e5df70ab | 493 | set_page_private(page, 0); |
7893d1d5 | 494 | BUG_ON(page_count(page)); |
27a85ef1 DG |
495 | INIT_LIST_HEAD(&page->lru); |
496 | ||
497 | spin_lock(&hugetlb_lock); | |
aa888a74 | 498 | if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) { |
a5516438 AK |
499 | update_and_free_page(h, page); |
500 | h->surplus_huge_pages--; | |
501 | h->surplus_huge_pages_node[nid]--; | |
7893d1d5 | 502 | } else { |
a5516438 | 503 | enqueue_huge_page(h, page); |
7893d1d5 | 504 | } |
27a85ef1 | 505 | spin_unlock(&hugetlb_lock); |
c79fb75e | 506 | if (mapping) |
9a119c05 | 507 | hugetlb_put_quota(mapping, 1); |
27a85ef1 DG |
508 | } |
509 | ||
7893d1d5 AL |
510 | /* |
511 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
512 | * balanced by operating on them in a round-robin fashion. | |
513 | * Returns 1 if an adjustment was made. | |
514 | */ | |
a5516438 | 515 | static int adjust_pool_surplus(struct hstate *h, int delta) |
7893d1d5 AL |
516 | { |
517 | static int prev_nid; | |
518 | int nid = prev_nid; | |
519 | int ret = 0; | |
520 | ||
521 | VM_BUG_ON(delta != -1 && delta != 1); | |
522 | do { | |
523 | nid = next_node(nid, node_online_map); | |
524 | if (nid == MAX_NUMNODES) | |
525 | nid = first_node(node_online_map); | |
526 | ||
527 | /* To shrink on this node, there must be a surplus page */ | |
a5516438 | 528 | if (delta < 0 && !h->surplus_huge_pages_node[nid]) |
7893d1d5 AL |
529 | continue; |
530 | /* Surplus cannot exceed the total number of pages */ | |
a5516438 AK |
531 | if (delta > 0 && h->surplus_huge_pages_node[nid] >= |
532 | h->nr_huge_pages_node[nid]) | |
7893d1d5 AL |
533 | continue; |
534 | ||
a5516438 AK |
535 | h->surplus_huge_pages += delta; |
536 | h->surplus_huge_pages_node[nid] += delta; | |
7893d1d5 AL |
537 | ret = 1; |
538 | break; | |
539 | } while (nid != prev_nid); | |
540 | ||
541 | prev_nid = nid; | |
542 | return ret; | |
543 | } | |
544 | ||
a5516438 | 545 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) |
b7ba30c6 AK |
546 | { |
547 | set_compound_page_dtor(page, free_huge_page); | |
548 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
549 | h->nr_huge_pages++; |
550 | h->nr_huge_pages_node[nid]++; | |
b7ba30c6 AK |
551 | spin_unlock(&hugetlb_lock); |
552 | put_page(page); /* free it into the hugepage allocator */ | |
553 | } | |
554 | ||
a5516438 | 555 | static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) |
1da177e4 | 556 | { |
1da177e4 | 557 | struct page *page; |
f96efd58 | 558 | |
aa888a74 AK |
559 | if (h->order >= MAX_ORDER) |
560 | return NULL; | |
561 | ||
63b4613c | 562 | page = alloc_pages_node(nid, |
551883ae NA |
563 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| |
564 | __GFP_REPEAT|__GFP_NOWARN, | |
a5516438 | 565 | huge_page_order(h)); |
1da177e4 | 566 | if (page) { |
7f2e9525 GS |
567 | if (arch_prepare_hugepage(page)) { |
568 | __free_pages(page, HUGETLB_PAGE_ORDER); | |
7b8ee84d | 569 | return NULL; |
7f2e9525 | 570 | } |
a5516438 | 571 | prep_new_huge_page(h, page, nid); |
1da177e4 | 572 | } |
63b4613c NA |
573 | |
574 | return page; | |
575 | } | |
576 | ||
5ced66c9 AK |
577 | /* |
578 | * Use a helper variable to find the next node and then | |
579 | * copy it back to hugetlb_next_nid afterwards: | |
580 | * otherwise there's a window in which a racer might | |
581 | * pass invalid nid MAX_NUMNODES to alloc_pages_node. | |
582 | * But we don't need to use a spin_lock here: it really | |
583 | * doesn't matter if occasionally a racer chooses the | |
584 | * same nid as we do. Move nid forward in the mask even | |
585 | * if we just successfully allocated a hugepage so that | |
586 | * the next caller gets hugepages on the next node. | |
587 | */ | |
588 | static int hstate_next_node(struct hstate *h) | |
589 | { | |
590 | int next_nid; | |
591 | next_nid = next_node(h->hugetlb_next_nid, node_online_map); | |
592 | if (next_nid == MAX_NUMNODES) | |
593 | next_nid = first_node(node_online_map); | |
594 | h->hugetlb_next_nid = next_nid; | |
595 | return next_nid; | |
596 | } | |
597 | ||
a5516438 | 598 | static int alloc_fresh_huge_page(struct hstate *h) |
63b4613c NA |
599 | { |
600 | struct page *page; | |
601 | int start_nid; | |
602 | int next_nid; | |
603 | int ret = 0; | |
604 | ||
a5516438 | 605 | start_nid = h->hugetlb_next_nid; |
63b4613c NA |
606 | |
607 | do { | |
a5516438 | 608 | page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid); |
63b4613c NA |
609 | if (page) |
610 | ret = 1; | |
5ced66c9 | 611 | next_nid = hstate_next_node(h); |
a5516438 | 612 | } while (!page && h->hugetlb_next_nid != start_nid); |
63b4613c | 613 | |
3b116300 AL |
614 | if (ret) |
615 | count_vm_event(HTLB_BUDDY_PGALLOC); | |
616 | else | |
617 | count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); | |
618 | ||
63b4613c | 619 | return ret; |
1da177e4 LT |
620 | } |
621 | ||
a5516438 AK |
622 | static struct page *alloc_buddy_huge_page(struct hstate *h, |
623 | struct vm_area_struct *vma, unsigned long address) | |
7893d1d5 AL |
624 | { |
625 | struct page *page; | |
d1c3fb1f | 626 | unsigned int nid; |
7893d1d5 | 627 | |
aa888a74 AK |
628 | if (h->order >= MAX_ORDER) |
629 | return NULL; | |
630 | ||
d1c3fb1f NA |
631 | /* |
632 | * Assume we will successfully allocate the surplus page to | |
633 | * prevent racing processes from causing the surplus to exceed | |
634 | * overcommit | |
635 | * | |
636 | * This however introduces a different race, where a process B | |
637 | * tries to grow the static hugepage pool while alloc_pages() is | |
638 | * called by process A. B will only examine the per-node | |
639 | * counters in determining if surplus huge pages can be | |
640 | * converted to normal huge pages in adjust_pool_surplus(). A | |
641 | * won't be able to increment the per-node counter, until the | |
642 | * lock is dropped by B, but B doesn't drop hugetlb_lock until | |
643 | * no more huge pages can be converted from surplus to normal | |
644 | * state (and doesn't try to convert again). Thus, we have a | |
645 | * case where a surplus huge page exists, the pool is grown, and | |
646 | * the surplus huge page still exists after, even though it | |
647 | * should just have been converted to a normal huge page. This | |
648 | * does not leak memory, though, as the hugepage will be freed | |
649 | * once it is out of use. It also does not allow the counters to | |
650 | * go out of whack in adjust_pool_surplus() as we don't modify | |
651 | * the node values until we've gotten the hugepage and only the | |
652 | * per-node value is checked there. | |
653 | */ | |
654 | spin_lock(&hugetlb_lock); | |
a5516438 | 655 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { |
d1c3fb1f NA |
656 | spin_unlock(&hugetlb_lock); |
657 | return NULL; | |
658 | } else { | |
a5516438 AK |
659 | h->nr_huge_pages++; |
660 | h->surplus_huge_pages++; | |
d1c3fb1f NA |
661 | } |
662 | spin_unlock(&hugetlb_lock); | |
663 | ||
551883ae NA |
664 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP| |
665 | __GFP_REPEAT|__GFP_NOWARN, | |
a5516438 | 666 | huge_page_order(h)); |
d1c3fb1f NA |
667 | |
668 | spin_lock(&hugetlb_lock); | |
7893d1d5 | 669 | if (page) { |
2668db91 AL |
670 | /* |
671 | * This page is now managed by the hugetlb allocator and has | |
672 | * no users -- drop the buddy allocator's reference. | |
673 | */ | |
674 | put_page_testzero(page); | |
675 | VM_BUG_ON(page_count(page)); | |
d1c3fb1f | 676 | nid = page_to_nid(page); |
7893d1d5 | 677 | set_compound_page_dtor(page, free_huge_page); |
d1c3fb1f NA |
678 | /* |
679 | * We incremented the global counters already | |
680 | */ | |
a5516438 AK |
681 | h->nr_huge_pages_node[nid]++; |
682 | h->surplus_huge_pages_node[nid]++; | |
3b116300 | 683 | __count_vm_event(HTLB_BUDDY_PGALLOC); |
d1c3fb1f | 684 | } else { |
a5516438 AK |
685 | h->nr_huge_pages--; |
686 | h->surplus_huge_pages--; | |
3b116300 | 687 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
7893d1d5 | 688 | } |
d1c3fb1f | 689 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
690 | |
691 | return page; | |
692 | } | |
693 | ||
e4e574b7 AL |
694 | /* |
695 | * Increase the hugetlb pool such that it can accomodate a reservation | |
696 | * of size 'delta'. | |
697 | */ | |
a5516438 | 698 | static int gather_surplus_pages(struct hstate *h, int delta) |
e4e574b7 AL |
699 | { |
700 | struct list_head surplus_list; | |
701 | struct page *page, *tmp; | |
702 | int ret, i; | |
703 | int needed, allocated; | |
704 | ||
a5516438 | 705 | needed = (h->resv_huge_pages + delta) - h->free_huge_pages; |
ac09b3a1 | 706 | if (needed <= 0) { |
a5516438 | 707 | h->resv_huge_pages += delta; |
e4e574b7 | 708 | return 0; |
ac09b3a1 | 709 | } |
e4e574b7 AL |
710 | |
711 | allocated = 0; | |
712 | INIT_LIST_HEAD(&surplus_list); | |
713 | ||
714 | ret = -ENOMEM; | |
715 | retry: | |
716 | spin_unlock(&hugetlb_lock); | |
717 | for (i = 0; i < needed; i++) { | |
a5516438 | 718 | page = alloc_buddy_huge_page(h, NULL, 0); |
e4e574b7 AL |
719 | if (!page) { |
720 | /* | |
721 | * We were not able to allocate enough pages to | |
722 | * satisfy the entire reservation so we free what | |
723 | * we've allocated so far. | |
724 | */ | |
725 | spin_lock(&hugetlb_lock); | |
726 | needed = 0; | |
727 | goto free; | |
728 | } | |
729 | ||
730 | list_add(&page->lru, &surplus_list); | |
731 | } | |
732 | allocated += needed; | |
733 | ||
734 | /* | |
735 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
736 | * because either resv_huge_pages or free_huge_pages may have changed. | |
737 | */ | |
738 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
739 | needed = (h->resv_huge_pages + delta) - |
740 | (h->free_huge_pages + allocated); | |
e4e574b7 AL |
741 | if (needed > 0) |
742 | goto retry; | |
743 | ||
744 | /* | |
745 | * The surplus_list now contains _at_least_ the number of extra pages | |
746 | * needed to accomodate the reservation. Add the appropriate number | |
747 | * of pages to the hugetlb pool and free the extras back to the buddy | |
ac09b3a1 AL |
748 | * allocator. Commit the entire reservation here to prevent another |
749 | * process from stealing the pages as they are added to the pool but | |
750 | * before they are reserved. | |
e4e574b7 AL |
751 | */ |
752 | needed += allocated; | |
a5516438 | 753 | h->resv_huge_pages += delta; |
e4e574b7 AL |
754 | ret = 0; |
755 | free: | |
19fc3f0a | 756 | /* Free the needed pages to the hugetlb pool */ |
e4e574b7 | 757 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
19fc3f0a AL |
758 | if ((--needed) < 0) |
759 | break; | |
e4e574b7 | 760 | list_del(&page->lru); |
a5516438 | 761 | enqueue_huge_page(h, page); |
19fc3f0a AL |
762 | } |
763 | ||
764 | /* Free unnecessary surplus pages to the buddy allocator */ | |
765 | if (!list_empty(&surplus_list)) { | |
766 | spin_unlock(&hugetlb_lock); | |
767 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { | |
768 | list_del(&page->lru); | |
af767cbd | 769 | /* |
2668db91 AL |
770 | * The page has a reference count of zero already, so |
771 | * call free_huge_page directly instead of using | |
772 | * put_page. This must be done with hugetlb_lock | |
af767cbd AL |
773 | * unlocked which is safe because free_huge_page takes |
774 | * hugetlb_lock before deciding how to free the page. | |
775 | */ | |
2668db91 | 776 | free_huge_page(page); |
af767cbd | 777 | } |
19fc3f0a | 778 | spin_lock(&hugetlb_lock); |
e4e574b7 AL |
779 | } |
780 | ||
781 | return ret; | |
782 | } | |
783 | ||
784 | /* | |
785 | * When releasing a hugetlb pool reservation, any surplus pages that were | |
786 | * allocated to satisfy the reservation must be explicitly freed if they were | |
787 | * never used. | |
788 | */ | |
a5516438 AK |
789 | static void return_unused_surplus_pages(struct hstate *h, |
790 | unsigned long unused_resv_pages) | |
e4e574b7 AL |
791 | { |
792 | static int nid = -1; | |
793 | struct page *page; | |
794 | unsigned long nr_pages; | |
795 | ||
11320d17 NA |
796 | /* |
797 | * We want to release as many surplus pages as possible, spread | |
798 | * evenly across all nodes. Iterate across all nodes until we | |
799 | * can no longer free unreserved surplus pages. This occurs when | |
800 | * the nodes with surplus pages have no free pages. | |
801 | */ | |
802 | unsigned long remaining_iterations = num_online_nodes(); | |
803 | ||
ac09b3a1 | 804 | /* Uncommit the reservation */ |
a5516438 | 805 | h->resv_huge_pages -= unused_resv_pages; |
ac09b3a1 | 806 | |
aa888a74 AK |
807 | /* Cannot return gigantic pages currently */ |
808 | if (h->order >= MAX_ORDER) | |
809 | return; | |
810 | ||
a5516438 | 811 | nr_pages = min(unused_resv_pages, h->surplus_huge_pages); |
e4e574b7 | 812 | |
11320d17 | 813 | while (remaining_iterations-- && nr_pages) { |
e4e574b7 AL |
814 | nid = next_node(nid, node_online_map); |
815 | if (nid == MAX_NUMNODES) | |
816 | nid = first_node(node_online_map); | |
817 | ||
a5516438 | 818 | if (!h->surplus_huge_pages_node[nid]) |
e4e574b7 AL |
819 | continue; |
820 | ||
a5516438 AK |
821 | if (!list_empty(&h->hugepage_freelists[nid])) { |
822 | page = list_entry(h->hugepage_freelists[nid].next, | |
e4e574b7 AL |
823 | struct page, lru); |
824 | list_del(&page->lru); | |
a5516438 AK |
825 | update_and_free_page(h, page); |
826 | h->free_huge_pages--; | |
827 | h->free_huge_pages_node[nid]--; | |
828 | h->surplus_huge_pages--; | |
829 | h->surplus_huge_pages_node[nid]--; | |
e4e574b7 | 830 | nr_pages--; |
11320d17 | 831 | remaining_iterations = num_online_nodes(); |
e4e574b7 AL |
832 | } |
833 | } | |
834 | } | |
835 | ||
c37f9fb1 AW |
836 | /* |
837 | * Determine if the huge page at addr within the vma has an associated | |
838 | * reservation. Where it does not we will need to logically increase | |
839 | * reservation and actually increase quota before an allocation can occur. | |
840 | * Where any new reservation would be required the reservation change is | |
841 | * prepared, but not committed. Once the page has been quota'd allocated | |
842 | * an instantiated the change should be committed via vma_commit_reservation. | |
843 | * No action is required on failure. | |
844 | */ | |
a5516438 AK |
845 | static int vma_needs_reservation(struct hstate *h, |
846 | struct vm_area_struct *vma, unsigned long addr) | |
c37f9fb1 AW |
847 | { |
848 | struct address_space *mapping = vma->vm_file->f_mapping; | |
849 | struct inode *inode = mapping->host; | |
850 | ||
851 | if (vma->vm_flags & VM_SHARED) { | |
a5516438 | 852 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 AW |
853 | return region_chg(&inode->i_mapping->private_list, |
854 | idx, idx + 1); | |
855 | ||
84afd99b AW |
856 | } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
857 | return 1; | |
c37f9fb1 | 858 | |
84afd99b AW |
859 | } else { |
860 | int err; | |
a5516438 | 861 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
84afd99b AW |
862 | struct resv_map *reservations = vma_resv_map(vma); |
863 | ||
864 | err = region_chg(&reservations->regions, idx, idx + 1); | |
865 | if (err < 0) | |
866 | return err; | |
867 | return 0; | |
868 | } | |
c37f9fb1 | 869 | } |
a5516438 AK |
870 | static void vma_commit_reservation(struct hstate *h, |
871 | struct vm_area_struct *vma, unsigned long addr) | |
c37f9fb1 AW |
872 | { |
873 | struct address_space *mapping = vma->vm_file->f_mapping; | |
874 | struct inode *inode = mapping->host; | |
875 | ||
876 | if (vma->vm_flags & VM_SHARED) { | |
a5516438 | 877 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 | 878 | region_add(&inode->i_mapping->private_list, idx, idx + 1); |
84afd99b AW |
879 | |
880 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { | |
a5516438 | 881 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
84afd99b AW |
882 | struct resv_map *reservations = vma_resv_map(vma); |
883 | ||
884 | /* Mark this page used in the map. */ | |
885 | region_add(&reservations->regions, idx, idx + 1); | |
c37f9fb1 AW |
886 | } |
887 | } | |
888 | ||
a1e78772 | 889 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
04f2cbe3 | 890 | unsigned long addr, int avoid_reserve) |
1da177e4 | 891 | { |
a5516438 | 892 | struct hstate *h = hstate_vma(vma); |
348ea204 | 893 | struct page *page; |
a1e78772 MG |
894 | struct address_space *mapping = vma->vm_file->f_mapping; |
895 | struct inode *inode = mapping->host; | |
c37f9fb1 | 896 | unsigned int chg; |
a1e78772 MG |
897 | |
898 | /* | |
899 | * Processes that did not create the mapping will have no reserves and | |
900 | * will not have accounted against quota. Check that the quota can be | |
901 | * made before satisfying the allocation | |
c37f9fb1 AW |
902 | * MAP_NORESERVE mappings may also need pages and quota allocated |
903 | * if no reserve mapping overlaps. | |
a1e78772 | 904 | */ |
a5516438 | 905 | chg = vma_needs_reservation(h, vma, addr); |
c37f9fb1 AW |
906 | if (chg < 0) |
907 | return ERR_PTR(chg); | |
908 | if (chg) | |
a1e78772 MG |
909 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
910 | return ERR_PTR(-ENOSPC); | |
1da177e4 LT |
911 | |
912 | spin_lock(&hugetlb_lock); | |
a5516438 | 913 | page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve); |
1da177e4 | 914 | spin_unlock(&hugetlb_lock); |
b45b5bd6 | 915 | |
68842c9b | 916 | if (!page) { |
a5516438 | 917 | page = alloc_buddy_huge_page(h, vma, addr); |
68842c9b | 918 | if (!page) { |
a1e78772 | 919 | hugetlb_put_quota(inode->i_mapping, chg); |
68842c9b KC |
920 | return ERR_PTR(-VM_FAULT_OOM); |
921 | } | |
922 | } | |
348ea204 | 923 | |
a1e78772 MG |
924 | set_page_refcounted(page); |
925 | set_page_private(page, (unsigned long) mapping); | |
90d8b7e6 | 926 | |
a5516438 | 927 | vma_commit_reservation(h, vma, addr); |
c37f9fb1 | 928 | |
90d8b7e6 | 929 | return page; |
b45b5bd6 DG |
930 | } |
931 | ||
53ba51d2 | 932 | __attribute__((weak)) int alloc_bootmem_huge_page(struct hstate *h) |
aa888a74 AK |
933 | { |
934 | struct huge_bootmem_page *m; | |
935 | int nr_nodes = nodes_weight(node_online_map); | |
936 | ||
937 | while (nr_nodes) { | |
938 | void *addr; | |
939 | ||
940 | addr = __alloc_bootmem_node_nopanic( | |
941 | NODE_DATA(h->hugetlb_next_nid), | |
942 | huge_page_size(h), huge_page_size(h), 0); | |
943 | ||
944 | if (addr) { | |
945 | /* | |
946 | * Use the beginning of the huge page to store the | |
947 | * huge_bootmem_page struct (until gather_bootmem | |
948 | * puts them into the mem_map). | |
949 | */ | |
950 | m = addr; | |
951 | if (m) | |
952 | goto found; | |
953 | } | |
954 | hstate_next_node(h); | |
955 | nr_nodes--; | |
956 | } | |
957 | return 0; | |
958 | ||
959 | found: | |
960 | BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1)); | |
961 | /* Put them into a private list first because mem_map is not up yet */ | |
962 | list_add(&m->list, &huge_boot_pages); | |
963 | m->hstate = h; | |
964 | return 1; | |
965 | } | |
966 | ||
967 | /* Put bootmem huge pages into the standard lists after mem_map is up */ | |
968 | static void __init gather_bootmem_prealloc(void) | |
969 | { | |
970 | struct huge_bootmem_page *m; | |
971 | ||
972 | list_for_each_entry(m, &huge_boot_pages, list) { | |
973 | struct page *page = virt_to_page(m); | |
974 | struct hstate *h = m->hstate; | |
975 | __ClearPageReserved(page); | |
976 | WARN_ON(page_count(page) != 1); | |
977 | prep_compound_page(page, h->order); | |
978 | prep_new_huge_page(h, page, page_to_nid(page)); | |
979 | } | |
980 | } | |
981 | ||
8faa8b07 | 982 | static void __init hugetlb_hstate_alloc_pages(struct hstate *h) |
1da177e4 LT |
983 | { |
984 | unsigned long i; | |
a5516438 | 985 | |
e5ff2159 | 986 | for (i = 0; i < h->max_huge_pages; ++i) { |
aa888a74 AK |
987 | if (h->order >= MAX_ORDER) { |
988 | if (!alloc_bootmem_huge_page(h)) | |
989 | break; | |
990 | } else if (!alloc_fresh_huge_page(h)) | |
1da177e4 | 991 | break; |
1da177e4 | 992 | } |
8faa8b07 | 993 | h->max_huge_pages = i; |
e5ff2159 AK |
994 | } |
995 | ||
996 | static void __init hugetlb_init_hstates(void) | |
997 | { | |
998 | struct hstate *h; | |
999 | ||
1000 | for_each_hstate(h) { | |
8faa8b07 AK |
1001 | /* oversize hugepages were init'ed in early boot */ |
1002 | if (h->order < MAX_ORDER) | |
1003 | hugetlb_hstate_alloc_pages(h); | |
e5ff2159 AK |
1004 | } |
1005 | } | |
1006 | ||
4abd32db AK |
1007 | static char * __init memfmt(char *buf, unsigned long n) |
1008 | { | |
1009 | if (n >= (1UL << 30)) | |
1010 | sprintf(buf, "%lu GB", n >> 30); | |
1011 | else if (n >= (1UL << 20)) | |
1012 | sprintf(buf, "%lu MB", n >> 20); | |
1013 | else | |
1014 | sprintf(buf, "%lu KB", n >> 10); | |
1015 | return buf; | |
1016 | } | |
1017 | ||
e5ff2159 AK |
1018 | static void __init report_hugepages(void) |
1019 | { | |
1020 | struct hstate *h; | |
1021 | ||
1022 | for_each_hstate(h) { | |
4abd32db AK |
1023 | char buf[32]; |
1024 | printk(KERN_INFO "HugeTLB registered %s page size, " | |
1025 | "pre-allocated %ld pages\n", | |
1026 | memfmt(buf, huge_page_size(h)), | |
1027 | h->free_huge_pages); | |
e5ff2159 AK |
1028 | } |
1029 | } | |
1030 | ||
1da177e4 | 1031 | #ifdef CONFIG_HIGHMEM |
a5516438 | 1032 | static void try_to_free_low(struct hstate *h, unsigned long count) |
1da177e4 | 1033 | { |
4415cc8d CL |
1034 | int i; |
1035 | ||
aa888a74 AK |
1036 | if (h->order >= MAX_ORDER) |
1037 | return; | |
1038 | ||
1da177e4 LT |
1039 | for (i = 0; i < MAX_NUMNODES; ++i) { |
1040 | struct page *page, *next; | |
a5516438 AK |
1041 | struct list_head *freel = &h->hugepage_freelists[i]; |
1042 | list_for_each_entry_safe(page, next, freel, lru) { | |
1043 | if (count >= h->nr_huge_pages) | |
6b0c880d | 1044 | return; |
1da177e4 LT |
1045 | if (PageHighMem(page)) |
1046 | continue; | |
1047 | list_del(&page->lru); | |
e5ff2159 | 1048 | update_and_free_page(h, page); |
a5516438 AK |
1049 | h->free_huge_pages--; |
1050 | h->free_huge_pages_node[page_to_nid(page)]--; | |
1da177e4 LT |
1051 | } |
1052 | } | |
1053 | } | |
1054 | #else | |
a5516438 | 1055 | static inline void try_to_free_low(struct hstate *h, unsigned long count) |
1da177e4 LT |
1056 | { |
1057 | } | |
1058 | #endif | |
1059 | ||
a5516438 | 1060 | #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) |
e5ff2159 | 1061 | static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count) |
1da177e4 | 1062 | { |
7893d1d5 | 1063 | unsigned long min_count, ret; |
1da177e4 | 1064 | |
aa888a74 AK |
1065 | if (h->order >= MAX_ORDER) |
1066 | return h->max_huge_pages; | |
1067 | ||
7893d1d5 AL |
1068 | /* |
1069 | * Increase the pool size | |
1070 | * First take pages out of surplus state. Then make up the | |
1071 | * remaining difference by allocating fresh huge pages. | |
d1c3fb1f NA |
1072 | * |
1073 | * We might race with alloc_buddy_huge_page() here and be unable | |
1074 | * to convert a surplus huge page to a normal huge page. That is | |
1075 | * not critical, though, it just means the overall size of the | |
1076 | * pool might be one hugepage larger than it needs to be, but | |
1077 | * within all the constraints specified by the sysctls. | |
7893d1d5 | 1078 | */ |
1da177e4 | 1079 | spin_lock(&hugetlb_lock); |
a5516438 AK |
1080 | while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { |
1081 | if (!adjust_pool_surplus(h, -1)) | |
7893d1d5 AL |
1082 | break; |
1083 | } | |
1084 | ||
a5516438 | 1085 | while (count > persistent_huge_pages(h)) { |
7893d1d5 AL |
1086 | /* |
1087 | * If this allocation races such that we no longer need the | |
1088 | * page, free_huge_page will handle it by freeing the page | |
1089 | * and reducing the surplus. | |
1090 | */ | |
1091 | spin_unlock(&hugetlb_lock); | |
a5516438 | 1092 | ret = alloc_fresh_huge_page(h); |
7893d1d5 AL |
1093 | spin_lock(&hugetlb_lock); |
1094 | if (!ret) | |
1095 | goto out; | |
1096 | ||
1097 | } | |
7893d1d5 AL |
1098 | |
1099 | /* | |
1100 | * Decrease the pool size | |
1101 | * First return free pages to the buddy allocator (being careful | |
1102 | * to keep enough around to satisfy reservations). Then place | |
1103 | * pages into surplus state as needed so the pool will shrink | |
1104 | * to the desired size as pages become free. | |
d1c3fb1f NA |
1105 | * |
1106 | * By placing pages into the surplus state independent of the | |
1107 | * overcommit value, we are allowing the surplus pool size to | |
1108 | * exceed overcommit. There are few sane options here. Since | |
1109 | * alloc_buddy_huge_page() is checking the global counter, | |
1110 | * though, we'll note that we're not allowed to exceed surplus | |
1111 | * and won't grow the pool anywhere else. Not until one of the | |
1112 | * sysctls are changed, or the surplus pages go out of use. | |
7893d1d5 | 1113 | */ |
a5516438 | 1114 | min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; |
6b0c880d | 1115 | min_count = max(count, min_count); |
a5516438 AK |
1116 | try_to_free_low(h, min_count); |
1117 | while (min_count < persistent_huge_pages(h)) { | |
1118 | struct page *page = dequeue_huge_page(h); | |
1da177e4 LT |
1119 | if (!page) |
1120 | break; | |
a5516438 | 1121 | update_and_free_page(h, page); |
1da177e4 | 1122 | } |
a5516438 AK |
1123 | while (count < persistent_huge_pages(h)) { |
1124 | if (!adjust_pool_surplus(h, 1)) | |
7893d1d5 AL |
1125 | break; |
1126 | } | |
1127 | out: | |
a5516438 | 1128 | ret = persistent_huge_pages(h); |
1da177e4 | 1129 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 1130 | return ret; |
1da177e4 LT |
1131 | } |
1132 | ||
a3437870 NA |
1133 | #define HSTATE_ATTR_RO(_name) \ |
1134 | static struct kobj_attribute _name##_attr = __ATTR_RO(_name) | |
1135 | ||
1136 | #define HSTATE_ATTR(_name) \ | |
1137 | static struct kobj_attribute _name##_attr = \ | |
1138 | __ATTR(_name, 0644, _name##_show, _name##_store) | |
1139 | ||
1140 | static struct kobject *hugepages_kobj; | |
1141 | static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
1142 | ||
1143 | static struct hstate *kobj_to_hstate(struct kobject *kobj) | |
1144 | { | |
1145 | int i; | |
1146 | for (i = 0; i < HUGE_MAX_HSTATE; i++) | |
1147 | if (hstate_kobjs[i] == kobj) | |
1148 | return &hstates[i]; | |
1149 | BUG(); | |
1150 | return NULL; | |
1151 | } | |
1152 | ||
1153 | static ssize_t nr_hugepages_show(struct kobject *kobj, | |
1154 | struct kobj_attribute *attr, char *buf) | |
1155 | { | |
1156 | struct hstate *h = kobj_to_hstate(kobj); | |
1157 | return sprintf(buf, "%lu\n", h->nr_huge_pages); | |
1158 | } | |
1159 | static ssize_t nr_hugepages_store(struct kobject *kobj, | |
1160 | struct kobj_attribute *attr, const char *buf, size_t count) | |
1161 | { | |
1162 | int err; | |
1163 | unsigned long input; | |
1164 | struct hstate *h = kobj_to_hstate(kobj); | |
1165 | ||
1166 | err = strict_strtoul(buf, 10, &input); | |
1167 | if (err) | |
1168 | return 0; | |
1169 | ||
1170 | h->max_huge_pages = set_max_huge_pages(h, input); | |
1171 | ||
1172 | return count; | |
1173 | } | |
1174 | HSTATE_ATTR(nr_hugepages); | |
1175 | ||
1176 | static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, | |
1177 | struct kobj_attribute *attr, char *buf) | |
1178 | { | |
1179 | struct hstate *h = kobj_to_hstate(kobj); | |
1180 | return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); | |
1181 | } | |
1182 | static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, | |
1183 | struct kobj_attribute *attr, const char *buf, size_t count) | |
1184 | { | |
1185 | int err; | |
1186 | unsigned long input; | |
1187 | struct hstate *h = kobj_to_hstate(kobj); | |
1188 | ||
1189 | err = strict_strtoul(buf, 10, &input); | |
1190 | if (err) | |
1191 | return 0; | |
1192 | ||
1193 | spin_lock(&hugetlb_lock); | |
1194 | h->nr_overcommit_huge_pages = input; | |
1195 | spin_unlock(&hugetlb_lock); | |
1196 | ||
1197 | return count; | |
1198 | } | |
1199 | HSTATE_ATTR(nr_overcommit_hugepages); | |
1200 | ||
1201 | static ssize_t free_hugepages_show(struct kobject *kobj, | |
1202 | struct kobj_attribute *attr, char *buf) | |
1203 | { | |
1204 | struct hstate *h = kobj_to_hstate(kobj); | |
1205 | return sprintf(buf, "%lu\n", h->free_huge_pages); | |
1206 | } | |
1207 | HSTATE_ATTR_RO(free_hugepages); | |
1208 | ||
1209 | static ssize_t resv_hugepages_show(struct kobject *kobj, | |
1210 | struct kobj_attribute *attr, char *buf) | |
1211 | { | |
1212 | struct hstate *h = kobj_to_hstate(kobj); | |
1213 | return sprintf(buf, "%lu\n", h->resv_huge_pages); | |
1214 | } | |
1215 | HSTATE_ATTR_RO(resv_hugepages); | |
1216 | ||
1217 | static ssize_t surplus_hugepages_show(struct kobject *kobj, | |
1218 | struct kobj_attribute *attr, char *buf) | |
1219 | { | |
1220 | struct hstate *h = kobj_to_hstate(kobj); | |
1221 | return sprintf(buf, "%lu\n", h->surplus_huge_pages); | |
1222 | } | |
1223 | HSTATE_ATTR_RO(surplus_hugepages); | |
1224 | ||
1225 | static struct attribute *hstate_attrs[] = { | |
1226 | &nr_hugepages_attr.attr, | |
1227 | &nr_overcommit_hugepages_attr.attr, | |
1228 | &free_hugepages_attr.attr, | |
1229 | &resv_hugepages_attr.attr, | |
1230 | &surplus_hugepages_attr.attr, | |
1231 | NULL, | |
1232 | }; | |
1233 | ||
1234 | static struct attribute_group hstate_attr_group = { | |
1235 | .attrs = hstate_attrs, | |
1236 | }; | |
1237 | ||
1238 | static int __init hugetlb_sysfs_add_hstate(struct hstate *h) | |
1239 | { | |
1240 | int retval; | |
1241 | ||
1242 | hstate_kobjs[h - hstates] = kobject_create_and_add(h->name, | |
1243 | hugepages_kobj); | |
1244 | if (!hstate_kobjs[h - hstates]) | |
1245 | return -ENOMEM; | |
1246 | ||
1247 | retval = sysfs_create_group(hstate_kobjs[h - hstates], | |
1248 | &hstate_attr_group); | |
1249 | if (retval) | |
1250 | kobject_put(hstate_kobjs[h - hstates]); | |
1251 | ||
1252 | return retval; | |
1253 | } | |
1254 | ||
1255 | static void __init hugetlb_sysfs_init(void) | |
1256 | { | |
1257 | struct hstate *h; | |
1258 | int err; | |
1259 | ||
1260 | hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); | |
1261 | if (!hugepages_kobj) | |
1262 | return; | |
1263 | ||
1264 | for_each_hstate(h) { | |
1265 | err = hugetlb_sysfs_add_hstate(h); | |
1266 | if (err) | |
1267 | printk(KERN_ERR "Hugetlb: Unable to add hstate %s", | |
1268 | h->name); | |
1269 | } | |
1270 | } | |
1271 | ||
1272 | static void __exit hugetlb_exit(void) | |
1273 | { | |
1274 | struct hstate *h; | |
1275 | ||
1276 | for_each_hstate(h) { | |
1277 | kobject_put(hstate_kobjs[h - hstates]); | |
1278 | } | |
1279 | ||
1280 | kobject_put(hugepages_kobj); | |
1281 | } | |
1282 | module_exit(hugetlb_exit); | |
1283 | ||
1284 | static int __init hugetlb_init(void) | |
1285 | { | |
0ef89d25 BH |
1286 | /* Some platform decide whether they support huge pages at boot |
1287 | * time. On these, such as powerpc, HPAGE_SHIFT is set to 0 when | |
1288 | * there is no such support | |
1289 | */ | |
1290 | if (HPAGE_SHIFT == 0) | |
1291 | return 0; | |
a3437870 | 1292 | |
e11bfbfc NP |
1293 | if (!size_to_hstate(default_hstate_size)) { |
1294 | default_hstate_size = HPAGE_SIZE; | |
1295 | if (!size_to_hstate(default_hstate_size)) | |
1296 | hugetlb_add_hstate(HUGETLB_PAGE_ORDER); | |
a3437870 | 1297 | } |
e11bfbfc NP |
1298 | default_hstate_idx = size_to_hstate(default_hstate_size) - hstates; |
1299 | if (default_hstate_max_huge_pages) | |
1300 | default_hstate.max_huge_pages = default_hstate_max_huge_pages; | |
a3437870 NA |
1301 | |
1302 | hugetlb_init_hstates(); | |
1303 | ||
aa888a74 AK |
1304 | gather_bootmem_prealloc(); |
1305 | ||
a3437870 NA |
1306 | report_hugepages(); |
1307 | ||
1308 | hugetlb_sysfs_init(); | |
1309 | ||
1310 | return 0; | |
1311 | } | |
1312 | module_init(hugetlb_init); | |
1313 | ||
1314 | /* Should be called on processing a hugepagesz=... option */ | |
1315 | void __init hugetlb_add_hstate(unsigned order) | |
1316 | { | |
1317 | struct hstate *h; | |
8faa8b07 AK |
1318 | unsigned long i; |
1319 | ||
a3437870 NA |
1320 | if (size_to_hstate(PAGE_SIZE << order)) { |
1321 | printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n"); | |
1322 | return; | |
1323 | } | |
1324 | BUG_ON(max_hstate >= HUGE_MAX_HSTATE); | |
1325 | BUG_ON(order == 0); | |
1326 | h = &hstates[max_hstate++]; | |
1327 | h->order = order; | |
1328 | h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); | |
8faa8b07 AK |
1329 | h->nr_huge_pages = 0; |
1330 | h->free_huge_pages = 0; | |
1331 | for (i = 0; i < MAX_NUMNODES; ++i) | |
1332 | INIT_LIST_HEAD(&h->hugepage_freelists[i]); | |
1333 | h->hugetlb_next_nid = first_node(node_online_map); | |
a3437870 NA |
1334 | snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", |
1335 | huge_page_size(h)/1024); | |
8faa8b07 | 1336 | |
a3437870 NA |
1337 | parsed_hstate = h; |
1338 | } | |
1339 | ||
e11bfbfc | 1340 | static int __init hugetlb_nrpages_setup(char *s) |
a3437870 NA |
1341 | { |
1342 | unsigned long *mhp; | |
8faa8b07 | 1343 | static unsigned long *last_mhp; |
a3437870 NA |
1344 | |
1345 | /* | |
1346 | * !max_hstate means we haven't parsed a hugepagesz= parameter yet, | |
1347 | * so this hugepages= parameter goes to the "default hstate". | |
1348 | */ | |
1349 | if (!max_hstate) | |
1350 | mhp = &default_hstate_max_huge_pages; | |
1351 | else | |
1352 | mhp = &parsed_hstate->max_huge_pages; | |
1353 | ||
8faa8b07 AK |
1354 | if (mhp == last_mhp) { |
1355 | printk(KERN_WARNING "hugepages= specified twice without " | |
1356 | "interleaving hugepagesz=, ignoring\n"); | |
1357 | return 1; | |
1358 | } | |
1359 | ||
a3437870 NA |
1360 | if (sscanf(s, "%lu", mhp) <= 0) |
1361 | *mhp = 0; | |
1362 | ||
8faa8b07 AK |
1363 | /* |
1364 | * Global state is always initialized later in hugetlb_init. | |
1365 | * But we need to allocate >= MAX_ORDER hstates here early to still | |
1366 | * use the bootmem allocator. | |
1367 | */ | |
1368 | if (max_hstate && parsed_hstate->order >= MAX_ORDER) | |
1369 | hugetlb_hstate_alloc_pages(parsed_hstate); | |
1370 | ||
1371 | last_mhp = mhp; | |
1372 | ||
a3437870 NA |
1373 | return 1; |
1374 | } | |
e11bfbfc NP |
1375 | __setup("hugepages=", hugetlb_nrpages_setup); |
1376 | ||
1377 | static int __init hugetlb_default_setup(char *s) | |
1378 | { | |
1379 | default_hstate_size = memparse(s, &s); | |
1380 | return 1; | |
1381 | } | |
1382 | __setup("default_hugepagesz=", hugetlb_default_setup); | |
a3437870 | 1383 | |
8a213460 NA |
1384 | static unsigned int cpuset_mems_nr(unsigned int *array) |
1385 | { | |
1386 | int node; | |
1387 | unsigned int nr = 0; | |
1388 | ||
1389 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
1390 | nr += array[node]; | |
1391 | ||
1392 | return nr; | |
1393 | } | |
1394 | ||
1395 | #ifdef CONFIG_SYSCTL | |
1da177e4 LT |
1396 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
1397 | struct file *file, void __user *buffer, | |
1398 | size_t *length, loff_t *ppos) | |
1399 | { | |
e5ff2159 AK |
1400 | struct hstate *h = &default_hstate; |
1401 | unsigned long tmp; | |
1402 | ||
1403 | if (!write) | |
1404 | tmp = h->max_huge_pages; | |
1405 | ||
1406 | table->data = &tmp; | |
1407 | table->maxlen = sizeof(unsigned long); | |
1da177e4 | 1408 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
e5ff2159 AK |
1409 | |
1410 | if (write) | |
1411 | h->max_huge_pages = set_max_huge_pages(h, tmp); | |
1412 | ||
1da177e4 LT |
1413 | return 0; |
1414 | } | |
396faf03 MG |
1415 | |
1416 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, | |
1417 | struct file *file, void __user *buffer, | |
1418 | size_t *length, loff_t *ppos) | |
1419 | { | |
1420 | proc_dointvec(table, write, file, buffer, length, ppos); | |
1421 | if (hugepages_treat_as_movable) | |
1422 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; | |
1423 | else | |
1424 | htlb_alloc_mask = GFP_HIGHUSER; | |
1425 | return 0; | |
1426 | } | |
1427 | ||
a3d0c6aa NA |
1428 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
1429 | struct file *file, void __user *buffer, | |
1430 | size_t *length, loff_t *ppos) | |
1431 | { | |
a5516438 | 1432 | struct hstate *h = &default_hstate; |
e5ff2159 AK |
1433 | unsigned long tmp; |
1434 | ||
1435 | if (!write) | |
1436 | tmp = h->nr_overcommit_huge_pages; | |
1437 | ||
1438 | table->data = &tmp; | |
1439 | table->maxlen = sizeof(unsigned long); | |
a3d0c6aa | 1440 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
e5ff2159 AK |
1441 | |
1442 | if (write) { | |
1443 | spin_lock(&hugetlb_lock); | |
1444 | h->nr_overcommit_huge_pages = tmp; | |
1445 | spin_unlock(&hugetlb_lock); | |
1446 | } | |
1447 | ||
a3d0c6aa NA |
1448 | return 0; |
1449 | } | |
1450 | ||
1da177e4 LT |
1451 | #endif /* CONFIG_SYSCTL */ |
1452 | ||
1453 | int hugetlb_report_meminfo(char *buf) | |
1454 | { | |
a5516438 | 1455 | struct hstate *h = &default_hstate; |
1da177e4 LT |
1456 | return sprintf(buf, |
1457 | "HugePages_Total: %5lu\n" | |
1458 | "HugePages_Free: %5lu\n" | |
a43a8c39 | 1459 | "HugePages_Rsvd: %5lu\n" |
7893d1d5 | 1460 | "HugePages_Surp: %5lu\n" |
1da177e4 | 1461 | "Hugepagesize: %5lu kB\n", |
a5516438 AK |
1462 | h->nr_huge_pages, |
1463 | h->free_huge_pages, | |
1464 | h->resv_huge_pages, | |
1465 | h->surplus_huge_pages, | |
1466 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); | |
1da177e4 LT |
1467 | } |
1468 | ||
1469 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
1470 | { | |
a5516438 | 1471 | struct hstate *h = &default_hstate; |
1da177e4 LT |
1472 | return sprintf(buf, |
1473 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
1474 | "Node %d HugePages_Free: %5u\n" |
1475 | "Node %d HugePages_Surp: %5u\n", | |
a5516438 AK |
1476 | nid, h->nr_huge_pages_node[nid], |
1477 | nid, h->free_huge_pages_node[nid], | |
1478 | nid, h->surplus_huge_pages_node[nid]); | |
1da177e4 LT |
1479 | } |
1480 | ||
1da177e4 LT |
1481 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
1482 | unsigned long hugetlb_total_pages(void) | |
1483 | { | |
a5516438 AK |
1484 | struct hstate *h = &default_hstate; |
1485 | return h->nr_huge_pages * pages_per_huge_page(h); | |
1da177e4 | 1486 | } |
1da177e4 | 1487 | |
a5516438 | 1488 | static int hugetlb_acct_memory(struct hstate *h, long delta) |
fc1b8a73 MG |
1489 | { |
1490 | int ret = -ENOMEM; | |
1491 | ||
1492 | spin_lock(&hugetlb_lock); | |
1493 | /* | |
1494 | * When cpuset is configured, it breaks the strict hugetlb page | |
1495 | * reservation as the accounting is done on a global variable. Such | |
1496 | * reservation is completely rubbish in the presence of cpuset because | |
1497 | * the reservation is not checked against page availability for the | |
1498 | * current cpuset. Application can still potentially OOM'ed by kernel | |
1499 | * with lack of free htlb page in cpuset that the task is in. | |
1500 | * Attempt to enforce strict accounting with cpuset is almost | |
1501 | * impossible (or too ugly) because cpuset is too fluid that | |
1502 | * task or memory node can be dynamically moved between cpusets. | |
1503 | * | |
1504 | * The change of semantics for shared hugetlb mapping with cpuset is | |
1505 | * undesirable. However, in order to preserve some of the semantics, | |
1506 | * we fall back to check against current free page availability as | |
1507 | * a best attempt and hopefully to minimize the impact of changing | |
1508 | * semantics that cpuset has. | |
1509 | */ | |
1510 | if (delta > 0) { | |
a5516438 | 1511 | if (gather_surplus_pages(h, delta) < 0) |
fc1b8a73 MG |
1512 | goto out; |
1513 | ||
a5516438 AK |
1514 | if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { |
1515 | return_unused_surplus_pages(h, delta); | |
fc1b8a73 MG |
1516 | goto out; |
1517 | } | |
1518 | } | |
1519 | ||
1520 | ret = 0; | |
1521 | if (delta < 0) | |
a5516438 | 1522 | return_unused_surplus_pages(h, (unsigned long) -delta); |
fc1b8a73 MG |
1523 | |
1524 | out: | |
1525 | spin_unlock(&hugetlb_lock); | |
1526 | return ret; | |
1527 | } | |
1528 | ||
84afd99b AW |
1529 | static void hugetlb_vm_op_open(struct vm_area_struct *vma) |
1530 | { | |
1531 | struct resv_map *reservations = vma_resv_map(vma); | |
1532 | ||
1533 | /* | |
1534 | * This new VMA should share its siblings reservation map if present. | |
1535 | * The VMA will only ever have a valid reservation map pointer where | |
1536 | * it is being copied for another still existing VMA. As that VMA | |
1537 | * has a reference to the reservation map it cannot dissappear until | |
1538 | * after this open call completes. It is therefore safe to take a | |
1539 | * new reference here without additional locking. | |
1540 | */ | |
1541 | if (reservations) | |
1542 | kref_get(&reservations->refs); | |
1543 | } | |
1544 | ||
a1e78772 MG |
1545 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
1546 | { | |
a5516438 | 1547 | struct hstate *h = hstate_vma(vma); |
84afd99b AW |
1548 | struct resv_map *reservations = vma_resv_map(vma); |
1549 | unsigned long reserve; | |
1550 | unsigned long start; | |
1551 | unsigned long end; | |
1552 | ||
1553 | if (reservations) { | |
a5516438 AK |
1554 | start = vma_hugecache_offset(h, vma, vma->vm_start); |
1555 | end = vma_hugecache_offset(h, vma, vma->vm_end); | |
84afd99b AW |
1556 | |
1557 | reserve = (end - start) - | |
1558 | region_count(&reservations->regions, start, end); | |
1559 | ||
1560 | kref_put(&reservations->refs, resv_map_release); | |
1561 | ||
7251ff78 | 1562 | if (reserve) { |
a5516438 | 1563 | hugetlb_acct_memory(h, -reserve); |
7251ff78 AL |
1564 | hugetlb_put_quota(vma->vm_file->f_mapping, reserve); |
1565 | } | |
84afd99b | 1566 | } |
a1e78772 MG |
1567 | } |
1568 | ||
1da177e4 LT |
1569 | /* |
1570 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
1571 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
1572 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
1573 | * this far. | |
1574 | */ | |
d0217ac0 | 1575 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
1576 | { |
1577 | BUG(); | |
d0217ac0 | 1578 | return 0; |
1da177e4 LT |
1579 | } |
1580 | ||
1581 | struct vm_operations_struct hugetlb_vm_ops = { | |
d0217ac0 | 1582 | .fault = hugetlb_vm_op_fault, |
84afd99b | 1583 | .open = hugetlb_vm_op_open, |
a1e78772 | 1584 | .close = hugetlb_vm_op_close, |
1da177e4 LT |
1585 | }; |
1586 | ||
1e8f889b DG |
1587 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
1588 | int writable) | |
63551ae0 DG |
1589 | { |
1590 | pte_t entry; | |
1591 | ||
1e8f889b | 1592 | if (writable) { |
63551ae0 DG |
1593 | entry = |
1594 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
1595 | } else { | |
7f2e9525 | 1596 | entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
63551ae0 DG |
1597 | } |
1598 | entry = pte_mkyoung(entry); | |
1599 | entry = pte_mkhuge(entry); | |
1600 | ||
1601 | return entry; | |
1602 | } | |
1603 | ||
1e8f889b DG |
1604 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
1605 | unsigned long address, pte_t *ptep) | |
1606 | { | |
1607 | pte_t entry; | |
1608 | ||
7f2e9525 GS |
1609 | entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); |
1610 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { | |
8dab5241 | 1611 | update_mmu_cache(vma, address, entry); |
8dab5241 | 1612 | } |
1e8f889b DG |
1613 | } |
1614 | ||
1615 | ||
63551ae0 DG |
1616 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
1617 | struct vm_area_struct *vma) | |
1618 | { | |
1619 | pte_t *src_pte, *dst_pte, entry; | |
1620 | struct page *ptepage; | |
1c59827d | 1621 | unsigned long addr; |
1e8f889b | 1622 | int cow; |
a5516438 AK |
1623 | struct hstate *h = hstate_vma(vma); |
1624 | unsigned long sz = huge_page_size(h); | |
1e8f889b DG |
1625 | |
1626 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 1627 | |
a5516438 | 1628 | for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { |
c74df32c HD |
1629 | src_pte = huge_pte_offset(src, addr); |
1630 | if (!src_pte) | |
1631 | continue; | |
a5516438 | 1632 | dst_pte = huge_pte_alloc(dst, addr, sz); |
63551ae0 DG |
1633 | if (!dst_pte) |
1634 | goto nomem; | |
c5c99429 LW |
1635 | |
1636 | /* If the pagetables are shared don't copy or take references */ | |
1637 | if (dst_pte == src_pte) | |
1638 | continue; | |
1639 | ||
c74df32c | 1640 | spin_lock(&dst->page_table_lock); |
46478758 | 1641 | spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); |
7f2e9525 | 1642 | if (!huge_pte_none(huge_ptep_get(src_pte))) { |
1e8f889b | 1643 | if (cow) |
7f2e9525 GS |
1644 | huge_ptep_set_wrprotect(src, addr, src_pte); |
1645 | entry = huge_ptep_get(src_pte); | |
1c59827d HD |
1646 | ptepage = pte_page(entry); |
1647 | get_page(ptepage); | |
1c59827d HD |
1648 | set_huge_pte_at(dst, addr, dst_pte, entry); |
1649 | } | |
1650 | spin_unlock(&src->page_table_lock); | |
c74df32c | 1651 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
1652 | } |
1653 | return 0; | |
1654 | ||
1655 | nomem: | |
1656 | return -ENOMEM; | |
1657 | } | |
1658 | ||
502717f4 | 1659 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1660 | unsigned long end, struct page *ref_page) |
63551ae0 DG |
1661 | { |
1662 | struct mm_struct *mm = vma->vm_mm; | |
1663 | unsigned long address; | |
c7546f8f | 1664 | pte_t *ptep; |
63551ae0 DG |
1665 | pte_t pte; |
1666 | struct page *page; | |
fe1668ae | 1667 | struct page *tmp; |
a5516438 AK |
1668 | struct hstate *h = hstate_vma(vma); |
1669 | unsigned long sz = huge_page_size(h); | |
1670 | ||
c0a499c2 CK |
1671 | /* |
1672 | * A page gathering list, protected by per file i_mmap_lock. The | |
1673 | * lock is used to avoid list corruption from multiple unmapping | |
1674 | * of the same page since we are using page->lru. | |
1675 | */ | |
fe1668ae | 1676 | LIST_HEAD(page_list); |
63551ae0 DG |
1677 | |
1678 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
a5516438 AK |
1679 | BUG_ON(start & ~huge_page_mask(h)); |
1680 | BUG_ON(end & ~huge_page_mask(h)); | |
63551ae0 | 1681 | |
cddb8a5c | 1682 | mmu_notifier_invalidate_range_start(mm, start, end); |
508034a3 | 1683 | spin_lock(&mm->page_table_lock); |
a5516438 | 1684 | for (address = start; address < end; address += sz) { |
c7546f8f | 1685 | ptep = huge_pte_offset(mm, address); |
4c887265 | 1686 | if (!ptep) |
c7546f8f DG |
1687 | continue; |
1688 | ||
39dde65c CK |
1689 | if (huge_pmd_unshare(mm, &address, ptep)) |
1690 | continue; | |
1691 | ||
04f2cbe3 MG |
1692 | /* |
1693 | * If a reference page is supplied, it is because a specific | |
1694 | * page is being unmapped, not a range. Ensure the page we | |
1695 | * are about to unmap is the actual page of interest. | |
1696 | */ | |
1697 | if (ref_page) { | |
1698 | pte = huge_ptep_get(ptep); | |
1699 | if (huge_pte_none(pte)) | |
1700 | continue; | |
1701 | page = pte_page(pte); | |
1702 | if (page != ref_page) | |
1703 | continue; | |
1704 | ||
1705 | /* | |
1706 | * Mark the VMA as having unmapped its page so that | |
1707 | * future faults in this VMA will fail rather than | |
1708 | * looking like data was lost | |
1709 | */ | |
1710 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); | |
1711 | } | |
1712 | ||
c7546f8f | 1713 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
7f2e9525 | 1714 | if (huge_pte_none(pte)) |
63551ae0 | 1715 | continue; |
c7546f8f | 1716 | |
63551ae0 | 1717 | page = pte_page(pte); |
6649a386 KC |
1718 | if (pte_dirty(pte)) |
1719 | set_page_dirty(page); | |
fe1668ae | 1720 | list_add(&page->lru, &page_list); |
63551ae0 | 1721 | } |
1da177e4 | 1722 | spin_unlock(&mm->page_table_lock); |
508034a3 | 1723 | flush_tlb_range(vma, start, end); |
cddb8a5c | 1724 | mmu_notifier_invalidate_range_end(mm, start, end); |
fe1668ae CK |
1725 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
1726 | list_del(&page->lru); | |
1727 | put_page(page); | |
1728 | } | |
1da177e4 | 1729 | } |
63551ae0 | 1730 | |
502717f4 | 1731 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1732 | unsigned long end, struct page *ref_page) |
502717f4 | 1733 | { |
a137e1cc AK |
1734 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
1735 | __unmap_hugepage_range(vma, start, end, ref_page); | |
1736 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); | |
502717f4 CK |
1737 | } |
1738 | ||
04f2cbe3 MG |
1739 | /* |
1740 | * This is called when the original mapper is failing to COW a MAP_PRIVATE | |
1741 | * mappping it owns the reserve page for. The intention is to unmap the page | |
1742 | * from other VMAs and let the children be SIGKILLed if they are faulting the | |
1743 | * same region. | |
1744 | */ | |
1745 | int unmap_ref_private(struct mm_struct *mm, | |
1746 | struct vm_area_struct *vma, | |
1747 | struct page *page, | |
1748 | unsigned long address) | |
1749 | { | |
1750 | struct vm_area_struct *iter_vma; | |
1751 | struct address_space *mapping; | |
1752 | struct prio_tree_iter iter; | |
1753 | pgoff_t pgoff; | |
1754 | ||
1755 | /* | |
1756 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation | |
1757 | * from page cache lookup which is in HPAGE_SIZE units. | |
1758 | */ | |
1759 | address = address & huge_page_mask(hstate_vma(vma)); | |
1760 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) | |
1761 | + (vma->vm_pgoff >> PAGE_SHIFT); | |
1762 | mapping = (struct address_space *)page_private(page); | |
1763 | ||
1764 | vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { | |
1765 | /* Do not unmap the current VMA */ | |
1766 | if (iter_vma == vma) | |
1767 | continue; | |
1768 | ||
1769 | /* | |
1770 | * Unmap the page from other VMAs without their own reserves. | |
1771 | * They get marked to be SIGKILLed if they fault in these | |
1772 | * areas. This is because a future no-page fault on this VMA | |
1773 | * could insert a zeroed page instead of the data existing | |
1774 | * from the time of fork. This would look like data corruption | |
1775 | */ | |
1776 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) | |
1777 | unmap_hugepage_range(iter_vma, | |
1778 | address, address + HPAGE_SIZE, | |
1779 | page); | |
1780 | } | |
1781 | ||
1782 | return 1; | |
1783 | } | |
1784 | ||
1e8f889b | 1785 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
04f2cbe3 MG |
1786 | unsigned long address, pte_t *ptep, pte_t pte, |
1787 | struct page *pagecache_page) | |
1e8f889b | 1788 | { |
a5516438 | 1789 | struct hstate *h = hstate_vma(vma); |
1e8f889b | 1790 | struct page *old_page, *new_page; |
79ac6ba4 | 1791 | int avoidcopy; |
04f2cbe3 | 1792 | int outside_reserve = 0; |
1e8f889b DG |
1793 | |
1794 | old_page = pte_page(pte); | |
1795 | ||
04f2cbe3 | 1796 | retry_avoidcopy: |
1e8f889b DG |
1797 | /* If no-one else is actually using this page, avoid the copy |
1798 | * and just make the page writable */ | |
1799 | avoidcopy = (page_count(old_page) == 1); | |
1800 | if (avoidcopy) { | |
1801 | set_huge_ptep_writable(vma, address, ptep); | |
83c54070 | 1802 | return 0; |
1e8f889b DG |
1803 | } |
1804 | ||
04f2cbe3 MG |
1805 | /* |
1806 | * If the process that created a MAP_PRIVATE mapping is about to | |
1807 | * perform a COW due to a shared page count, attempt to satisfy | |
1808 | * the allocation without using the existing reserves. The pagecache | |
1809 | * page is used to determine if the reserve at this address was | |
1810 | * consumed or not. If reserves were used, a partial faulted mapping | |
1811 | * at the time of fork() could consume its reserves on COW instead | |
1812 | * of the full address range. | |
1813 | */ | |
1814 | if (!(vma->vm_flags & VM_SHARED) && | |
1815 | is_vma_resv_set(vma, HPAGE_RESV_OWNER) && | |
1816 | old_page != pagecache_page) | |
1817 | outside_reserve = 1; | |
1818 | ||
1e8f889b | 1819 | page_cache_get(old_page); |
04f2cbe3 | 1820 | new_page = alloc_huge_page(vma, address, outside_reserve); |
1e8f889b | 1821 | |
2fc39cec | 1822 | if (IS_ERR(new_page)) { |
1e8f889b | 1823 | page_cache_release(old_page); |
04f2cbe3 MG |
1824 | |
1825 | /* | |
1826 | * If a process owning a MAP_PRIVATE mapping fails to COW, | |
1827 | * it is due to references held by a child and an insufficient | |
1828 | * huge page pool. To guarantee the original mappers | |
1829 | * reliability, unmap the page from child processes. The child | |
1830 | * may get SIGKILLed if it later faults. | |
1831 | */ | |
1832 | if (outside_reserve) { | |
1833 | BUG_ON(huge_pte_none(pte)); | |
1834 | if (unmap_ref_private(mm, vma, old_page, address)) { | |
1835 | BUG_ON(page_count(old_page) != 1); | |
1836 | BUG_ON(huge_pte_none(pte)); | |
1837 | goto retry_avoidcopy; | |
1838 | } | |
1839 | WARN_ON_ONCE(1); | |
1840 | } | |
1841 | ||
2fc39cec | 1842 | return -PTR_ERR(new_page); |
1e8f889b DG |
1843 | } |
1844 | ||
1845 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 1846 | copy_huge_page(new_page, old_page, address, vma); |
0ed361de | 1847 | __SetPageUptodate(new_page); |
1e8f889b DG |
1848 | spin_lock(&mm->page_table_lock); |
1849 | ||
a5516438 | 1850 | ptep = huge_pte_offset(mm, address & huge_page_mask(h)); |
7f2e9525 | 1851 | if (likely(pte_same(huge_ptep_get(ptep), pte))) { |
1e8f889b | 1852 | /* Break COW */ |
8fe627ec | 1853 | huge_ptep_clear_flush(vma, address, ptep); |
1e8f889b DG |
1854 | set_huge_pte_at(mm, address, ptep, |
1855 | make_huge_pte(vma, new_page, 1)); | |
1856 | /* Make the old page be freed below */ | |
1857 | new_page = old_page; | |
1858 | } | |
1859 | page_cache_release(new_page); | |
1860 | page_cache_release(old_page); | |
83c54070 | 1861 | return 0; |
1e8f889b DG |
1862 | } |
1863 | ||
04f2cbe3 | 1864 | /* Return the pagecache page at a given address within a VMA */ |
a5516438 AK |
1865 | static struct page *hugetlbfs_pagecache_page(struct hstate *h, |
1866 | struct vm_area_struct *vma, unsigned long address) | |
04f2cbe3 MG |
1867 | { |
1868 | struct address_space *mapping; | |
e7c4b0bf | 1869 | pgoff_t idx; |
04f2cbe3 MG |
1870 | |
1871 | mapping = vma->vm_file->f_mapping; | |
a5516438 | 1872 | idx = vma_hugecache_offset(h, vma, address); |
04f2cbe3 MG |
1873 | |
1874 | return find_lock_page(mapping, idx); | |
1875 | } | |
1876 | ||
a1ed3dda | 1877 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
1e8f889b | 1878 | unsigned long address, pte_t *ptep, int write_access) |
ac9b9c66 | 1879 | { |
a5516438 | 1880 | struct hstate *h = hstate_vma(vma); |
ac9b9c66 | 1881 | int ret = VM_FAULT_SIGBUS; |
e7c4b0bf | 1882 | pgoff_t idx; |
4c887265 | 1883 | unsigned long size; |
4c887265 AL |
1884 | struct page *page; |
1885 | struct address_space *mapping; | |
1e8f889b | 1886 | pte_t new_pte; |
4c887265 | 1887 | |
04f2cbe3 MG |
1888 | /* |
1889 | * Currently, we are forced to kill the process in the event the | |
1890 | * original mapper has unmapped pages from the child due to a failed | |
1891 | * COW. Warn that such a situation has occured as it may not be obvious | |
1892 | */ | |
1893 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { | |
1894 | printk(KERN_WARNING | |
1895 | "PID %d killed due to inadequate hugepage pool\n", | |
1896 | current->pid); | |
1897 | return ret; | |
1898 | } | |
1899 | ||
4c887265 | 1900 | mapping = vma->vm_file->f_mapping; |
a5516438 | 1901 | idx = vma_hugecache_offset(h, vma, address); |
4c887265 AL |
1902 | |
1903 | /* | |
1904 | * Use page lock to guard against racing truncation | |
1905 | * before we get page_table_lock. | |
1906 | */ | |
6bda666a CL |
1907 | retry: |
1908 | page = find_lock_page(mapping, idx); | |
1909 | if (!page) { | |
a5516438 | 1910 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
ebed4bfc HD |
1911 | if (idx >= size) |
1912 | goto out; | |
04f2cbe3 | 1913 | page = alloc_huge_page(vma, address, 0); |
2fc39cec AL |
1914 | if (IS_ERR(page)) { |
1915 | ret = -PTR_ERR(page); | |
6bda666a CL |
1916 | goto out; |
1917 | } | |
a5516438 | 1918 | clear_huge_page(page, address, huge_page_size(h)); |
0ed361de | 1919 | __SetPageUptodate(page); |
ac9b9c66 | 1920 | |
6bda666a CL |
1921 | if (vma->vm_flags & VM_SHARED) { |
1922 | int err; | |
45c682a6 | 1923 | struct inode *inode = mapping->host; |
6bda666a CL |
1924 | |
1925 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
1926 | if (err) { | |
1927 | put_page(page); | |
6bda666a CL |
1928 | if (err == -EEXIST) |
1929 | goto retry; | |
1930 | goto out; | |
1931 | } | |
45c682a6 KC |
1932 | |
1933 | spin_lock(&inode->i_lock); | |
a5516438 | 1934 | inode->i_blocks += blocks_per_huge_page(h); |
45c682a6 | 1935 | spin_unlock(&inode->i_lock); |
6bda666a CL |
1936 | } else |
1937 | lock_page(page); | |
1938 | } | |
1e8f889b | 1939 | |
ac9b9c66 | 1940 | spin_lock(&mm->page_table_lock); |
a5516438 | 1941 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
4c887265 AL |
1942 | if (idx >= size) |
1943 | goto backout; | |
1944 | ||
83c54070 | 1945 | ret = 0; |
7f2e9525 | 1946 | if (!huge_pte_none(huge_ptep_get(ptep))) |
4c887265 AL |
1947 | goto backout; |
1948 | ||
1e8f889b DG |
1949 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
1950 | && (vma->vm_flags & VM_SHARED))); | |
1951 | set_huge_pte_at(mm, address, ptep, new_pte); | |
1952 | ||
1953 | if (write_access && !(vma->vm_flags & VM_SHARED)) { | |
1954 | /* Optimization, do the COW without a second fault */ | |
04f2cbe3 | 1955 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); |
1e8f889b DG |
1956 | } |
1957 | ||
ac9b9c66 | 1958 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
1959 | unlock_page(page); |
1960 | out: | |
ac9b9c66 | 1961 | return ret; |
4c887265 AL |
1962 | |
1963 | backout: | |
1964 | spin_unlock(&mm->page_table_lock); | |
4c887265 AL |
1965 | unlock_page(page); |
1966 | put_page(page); | |
1967 | goto out; | |
ac9b9c66 HD |
1968 | } |
1969 | ||
86e5216f AL |
1970 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
1971 | unsigned long address, int write_access) | |
1972 | { | |
1973 | pte_t *ptep; | |
1974 | pte_t entry; | |
1e8f889b | 1975 | int ret; |
3935baa9 | 1976 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
a5516438 | 1977 | struct hstate *h = hstate_vma(vma); |
86e5216f | 1978 | |
a5516438 | 1979 | ptep = huge_pte_alloc(mm, address, huge_page_size(h)); |
86e5216f AL |
1980 | if (!ptep) |
1981 | return VM_FAULT_OOM; | |
1982 | ||
3935baa9 DG |
1983 | /* |
1984 | * Serialize hugepage allocation and instantiation, so that we don't | |
1985 | * get spurious allocation failures if two CPUs race to instantiate | |
1986 | * the same page in the page cache. | |
1987 | */ | |
1988 | mutex_lock(&hugetlb_instantiation_mutex); | |
7f2e9525 GS |
1989 | entry = huge_ptep_get(ptep); |
1990 | if (huge_pte_none(entry)) { | |
3935baa9 DG |
1991 | ret = hugetlb_no_page(mm, vma, address, ptep, write_access); |
1992 | mutex_unlock(&hugetlb_instantiation_mutex); | |
1993 | return ret; | |
1994 | } | |
86e5216f | 1995 | |
83c54070 | 1996 | ret = 0; |
1e8f889b DG |
1997 | |
1998 | spin_lock(&mm->page_table_lock); | |
1999 | /* Check for a racing update before calling hugetlb_cow */ | |
7f2e9525 | 2000 | if (likely(pte_same(entry, huge_ptep_get(ptep)))) |
04f2cbe3 MG |
2001 | if (write_access && !pte_write(entry)) { |
2002 | struct page *page; | |
a5516438 | 2003 | page = hugetlbfs_pagecache_page(h, vma, address); |
04f2cbe3 MG |
2004 | ret = hugetlb_cow(mm, vma, address, ptep, entry, page); |
2005 | if (page) { | |
2006 | unlock_page(page); | |
2007 | put_page(page); | |
2008 | } | |
2009 | } | |
1e8f889b | 2010 | spin_unlock(&mm->page_table_lock); |
3935baa9 | 2011 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
2012 | |
2013 | return ret; | |
86e5216f AL |
2014 | } |
2015 | ||
ceb86879 AK |
2016 | /* Can be overriden by architectures */ |
2017 | __attribute__((weak)) struct page * | |
2018 | follow_huge_pud(struct mm_struct *mm, unsigned long address, | |
2019 | pud_t *pud, int write) | |
2020 | { | |
2021 | BUG(); | |
2022 | return NULL; | |
2023 | } | |
2024 | ||
63551ae0 DG |
2025 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
2026 | struct page **pages, struct vm_area_struct **vmas, | |
5b23dbe8 AL |
2027 | unsigned long *position, int *length, int i, |
2028 | int write) | |
63551ae0 | 2029 | { |
d5d4b0aa CK |
2030 | unsigned long pfn_offset; |
2031 | unsigned long vaddr = *position; | |
63551ae0 | 2032 | int remainder = *length; |
a5516438 | 2033 | struct hstate *h = hstate_vma(vma); |
63551ae0 | 2034 | |
1c59827d | 2035 | spin_lock(&mm->page_table_lock); |
63551ae0 | 2036 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
2037 | pte_t *pte; |
2038 | struct page *page; | |
63551ae0 | 2039 | |
4c887265 AL |
2040 | /* |
2041 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
2042 | * each hugepage. We have to make * sure we get the | |
2043 | * first, for the page indexing below to work. | |
2044 | */ | |
a5516438 | 2045 | pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); |
63551ae0 | 2046 | |
7f2e9525 GS |
2047 | if (!pte || huge_pte_none(huge_ptep_get(pte)) || |
2048 | (write && !pte_write(huge_ptep_get(pte)))) { | |
4c887265 | 2049 | int ret; |
63551ae0 | 2050 | |
4c887265 | 2051 | spin_unlock(&mm->page_table_lock); |
5b23dbe8 | 2052 | ret = hugetlb_fault(mm, vma, vaddr, write); |
4c887265 | 2053 | spin_lock(&mm->page_table_lock); |
a89182c7 | 2054 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 2055 | continue; |
63551ae0 | 2056 | |
4c887265 AL |
2057 | remainder = 0; |
2058 | if (!i) | |
2059 | i = -EFAULT; | |
2060 | break; | |
2061 | } | |
2062 | ||
a5516438 | 2063 | pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; |
7f2e9525 | 2064 | page = pte_page(huge_ptep_get(pte)); |
d5d4b0aa | 2065 | same_page: |
d6692183 CK |
2066 | if (pages) { |
2067 | get_page(page); | |
d5d4b0aa | 2068 | pages[i] = page + pfn_offset; |
d6692183 | 2069 | } |
63551ae0 DG |
2070 | |
2071 | if (vmas) | |
2072 | vmas[i] = vma; | |
2073 | ||
2074 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 2075 | ++pfn_offset; |
63551ae0 DG |
2076 | --remainder; |
2077 | ++i; | |
d5d4b0aa | 2078 | if (vaddr < vma->vm_end && remainder && |
a5516438 | 2079 | pfn_offset < pages_per_huge_page(h)) { |
d5d4b0aa CK |
2080 | /* |
2081 | * We use pfn_offset to avoid touching the pageframes | |
2082 | * of this compound page. | |
2083 | */ | |
2084 | goto same_page; | |
2085 | } | |
63551ae0 | 2086 | } |
1c59827d | 2087 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
2088 | *length = remainder; |
2089 | *position = vaddr; | |
2090 | ||
2091 | return i; | |
2092 | } | |
8f860591 ZY |
2093 | |
2094 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
2095 | unsigned long address, unsigned long end, pgprot_t newprot) | |
2096 | { | |
2097 | struct mm_struct *mm = vma->vm_mm; | |
2098 | unsigned long start = address; | |
2099 | pte_t *ptep; | |
2100 | pte_t pte; | |
a5516438 | 2101 | struct hstate *h = hstate_vma(vma); |
8f860591 ZY |
2102 | |
2103 | BUG_ON(address >= end); | |
2104 | flush_cache_range(vma, address, end); | |
2105 | ||
39dde65c | 2106 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 | 2107 | spin_lock(&mm->page_table_lock); |
a5516438 | 2108 | for (; address < end; address += huge_page_size(h)) { |
8f860591 ZY |
2109 | ptep = huge_pte_offset(mm, address); |
2110 | if (!ptep) | |
2111 | continue; | |
39dde65c CK |
2112 | if (huge_pmd_unshare(mm, &address, ptep)) |
2113 | continue; | |
7f2e9525 | 2114 | if (!huge_pte_none(huge_ptep_get(ptep))) { |
8f860591 ZY |
2115 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
2116 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
2117 | set_huge_pte_at(mm, address, ptep, pte); | |
8f860591 ZY |
2118 | } |
2119 | } | |
2120 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 2121 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
2122 | |
2123 | flush_tlb_range(vma, start, end); | |
2124 | } | |
2125 | ||
a1e78772 MG |
2126 | int hugetlb_reserve_pages(struct inode *inode, |
2127 | long from, long to, | |
2128 | struct vm_area_struct *vma) | |
e4e574b7 AL |
2129 | { |
2130 | long ret, chg; | |
a5516438 | 2131 | struct hstate *h = hstate_inode(inode); |
e4e574b7 | 2132 | |
c37f9fb1 AW |
2133 | if (vma && vma->vm_flags & VM_NORESERVE) |
2134 | return 0; | |
2135 | ||
a1e78772 MG |
2136 | /* |
2137 | * Shared mappings base their reservation on the number of pages that | |
2138 | * are already allocated on behalf of the file. Private mappings need | |
2139 | * to reserve the full area even if read-only as mprotect() may be | |
2140 | * called to make the mapping read-write. Assume !vma is a shm mapping | |
2141 | */ | |
2142 | if (!vma || vma->vm_flags & VM_SHARED) | |
2143 | chg = region_chg(&inode->i_mapping->private_list, from, to); | |
2144 | else { | |
84afd99b AW |
2145 | struct resv_map *resv_map = resv_map_alloc(); |
2146 | if (!resv_map) | |
2147 | return -ENOMEM; | |
2148 | ||
a1e78772 | 2149 | chg = to - from; |
84afd99b AW |
2150 | |
2151 | set_vma_resv_map(vma, resv_map); | |
04f2cbe3 | 2152 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); |
a1e78772 MG |
2153 | } |
2154 | ||
e4e574b7 AL |
2155 | if (chg < 0) |
2156 | return chg; | |
8a630112 | 2157 | |
90d8b7e6 AL |
2158 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
2159 | return -ENOSPC; | |
a5516438 | 2160 | ret = hugetlb_acct_memory(h, chg); |
68842c9b KC |
2161 | if (ret < 0) { |
2162 | hugetlb_put_quota(inode->i_mapping, chg); | |
a43a8c39 | 2163 | return ret; |
68842c9b | 2164 | } |
a1e78772 MG |
2165 | if (!vma || vma->vm_flags & VM_SHARED) |
2166 | region_add(&inode->i_mapping->private_list, from, to); | |
a43a8c39 CK |
2167 | return 0; |
2168 | } | |
2169 | ||
2170 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
2171 | { | |
a5516438 | 2172 | struct hstate *h = hstate_inode(inode); |
a43a8c39 | 2173 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
45c682a6 KC |
2174 | |
2175 | spin_lock(&inode->i_lock); | |
a5516438 | 2176 | inode->i_blocks -= blocks_per_huge_page(h); |
45c682a6 KC |
2177 | spin_unlock(&inode->i_lock); |
2178 | ||
90d8b7e6 | 2179 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
a5516438 | 2180 | hugetlb_acct_memory(h, -(chg - freed)); |
a43a8c39 | 2181 | } |