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