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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Generic hugetlb support. | |
6d49e352 | 3 | * (C) Nadia Yvette Chambers, April 2004 |
1da177e4 | 4 | */ |
1da177e4 LT |
5 | #include <linux/list.h> |
6 | #include <linux/init.h> | |
7 | #include <linux/module.h> | |
8 | #include <linux/mm.h> | |
e1759c21 | 9 | #include <linux/seq_file.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> |
5a0e3ad6 | 20 | #include <linux/slab.h> |
0fe6e20b | 21 | #include <linux/rmap.h> |
fd6a03ed NH |
22 | #include <linux/swap.h> |
23 | #include <linux/swapops.h> | |
c8721bbb | 24 | #include <linux/page-isolation.h> |
d6606683 | 25 | |
63551ae0 DG |
26 | #include <asm/page.h> |
27 | #include <asm/pgtable.h> | |
24669e58 | 28 | #include <asm/tlb.h> |
63551ae0 | 29 | |
24669e58 | 30 | #include <linux/io.h> |
63551ae0 | 31 | #include <linux/hugetlb.h> |
9dd540e2 | 32 | #include <linux/hugetlb_cgroup.h> |
9a305230 | 33 | #include <linux/node.h> |
7835e98b | 34 | #include "internal.h" |
1da177e4 LT |
35 | |
36 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; | |
396faf03 | 37 | unsigned long hugepages_treat_as_movable; |
a5516438 | 38 | |
c3f38a38 | 39 | int hugetlb_max_hstate __read_mostly; |
e5ff2159 AK |
40 | unsigned int default_hstate_idx; |
41 | struct hstate hstates[HUGE_MAX_HSTATE]; | |
42 | ||
53ba51d2 JT |
43 | __initdata LIST_HEAD(huge_boot_pages); |
44 | ||
e5ff2159 AK |
45 | /* for command line parsing */ |
46 | static struct hstate * __initdata parsed_hstate; | |
47 | static unsigned long __initdata default_hstate_max_huge_pages; | |
e11bfbfc | 48 | static unsigned long __initdata default_hstate_size; |
e5ff2159 | 49 | |
3935baa9 | 50 | /* |
31caf665 NH |
51 | * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, |
52 | * free_huge_pages, and surplus_huge_pages. | |
3935baa9 | 53 | */ |
c3f38a38 | 54 | DEFINE_SPINLOCK(hugetlb_lock); |
0bd0f9fb | 55 | |
90481622 DG |
56 | static inline void unlock_or_release_subpool(struct hugepage_subpool *spool) |
57 | { | |
58 | bool free = (spool->count == 0) && (spool->used_hpages == 0); | |
59 | ||
60 | spin_unlock(&spool->lock); | |
61 | ||
62 | /* If no pages are used, and no other handles to the subpool | |
63 | * remain, free the subpool the subpool remain */ | |
64 | if (free) | |
65 | kfree(spool); | |
66 | } | |
67 | ||
68 | struct hugepage_subpool *hugepage_new_subpool(long nr_blocks) | |
69 | { | |
70 | struct hugepage_subpool *spool; | |
71 | ||
72 | spool = kmalloc(sizeof(*spool), GFP_KERNEL); | |
73 | if (!spool) | |
74 | return NULL; | |
75 | ||
76 | spin_lock_init(&spool->lock); | |
77 | spool->count = 1; | |
78 | spool->max_hpages = nr_blocks; | |
79 | spool->used_hpages = 0; | |
80 | ||
81 | return spool; | |
82 | } | |
83 | ||
84 | void hugepage_put_subpool(struct hugepage_subpool *spool) | |
85 | { | |
86 | spin_lock(&spool->lock); | |
87 | BUG_ON(!spool->count); | |
88 | spool->count--; | |
89 | unlock_or_release_subpool(spool); | |
90 | } | |
91 | ||
92 | static int hugepage_subpool_get_pages(struct hugepage_subpool *spool, | |
93 | long delta) | |
94 | { | |
95 | int ret = 0; | |
96 | ||
97 | if (!spool) | |
98 | return 0; | |
99 | ||
100 | spin_lock(&spool->lock); | |
101 | if ((spool->used_hpages + delta) <= spool->max_hpages) { | |
102 | spool->used_hpages += delta; | |
103 | } else { | |
104 | ret = -ENOMEM; | |
105 | } | |
106 | spin_unlock(&spool->lock); | |
107 | ||
108 | return ret; | |
109 | } | |
110 | ||
111 | static void hugepage_subpool_put_pages(struct hugepage_subpool *spool, | |
112 | long delta) | |
113 | { | |
114 | if (!spool) | |
115 | return; | |
116 | ||
117 | spin_lock(&spool->lock); | |
118 | spool->used_hpages -= delta; | |
119 | /* If hugetlbfs_put_super couldn't free spool due to | |
120 | * an outstanding quota reference, free it now. */ | |
121 | unlock_or_release_subpool(spool); | |
122 | } | |
123 | ||
124 | static inline struct hugepage_subpool *subpool_inode(struct inode *inode) | |
125 | { | |
126 | return HUGETLBFS_SB(inode->i_sb)->spool; | |
127 | } | |
128 | ||
129 | static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) | |
130 | { | |
496ad9aa | 131 | return subpool_inode(file_inode(vma->vm_file)); |
90481622 DG |
132 | } |
133 | ||
96822904 AW |
134 | /* |
135 | * Region tracking -- allows tracking of reservations and instantiated pages | |
136 | * across the pages in a mapping. | |
84afd99b AW |
137 | * |
138 | * The region data structures are protected by a combination of the mmap_sem | |
c748c262 | 139 | * and the hugetlb_instantiation_mutex. To access or modify a region the caller |
84afd99b | 140 | * must either hold the mmap_sem for write, or the mmap_sem for read and |
c748c262 | 141 | * the hugetlb_instantiation_mutex: |
84afd99b | 142 | * |
32f84528 | 143 | * down_write(&mm->mmap_sem); |
84afd99b | 144 | * or |
32f84528 CF |
145 | * down_read(&mm->mmap_sem); |
146 | * mutex_lock(&hugetlb_instantiation_mutex); | |
96822904 AW |
147 | */ |
148 | struct file_region { | |
149 | struct list_head link; | |
150 | long from; | |
151 | long to; | |
152 | }; | |
153 | ||
154 | static long region_add(struct list_head *head, long f, long t) | |
155 | { | |
156 | struct file_region *rg, *nrg, *trg; | |
157 | ||
158 | /* Locate the region we are either in or before. */ | |
159 | list_for_each_entry(rg, head, link) | |
160 | if (f <= rg->to) | |
161 | break; | |
162 | ||
163 | /* Round our left edge to the current segment if it encloses us. */ | |
164 | if (f > rg->from) | |
165 | f = rg->from; | |
166 | ||
167 | /* Check for and consume any regions we now overlap with. */ | |
168 | nrg = rg; | |
169 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
170 | if (&rg->link == head) | |
171 | break; | |
172 | if (rg->from > t) | |
173 | break; | |
174 | ||
175 | /* If this area reaches higher then extend our area to | |
176 | * include it completely. If this is not the first area | |
177 | * which we intend to reuse, free it. */ | |
178 | if (rg->to > t) | |
179 | t = rg->to; | |
180 | if (rg != nrg) { | |
181 | list_del(&rg->link); | |
182 | kfree(rg); | |
183 | } | |
184 | } | |
185 | nrg->from = f; | |
186 | nrg->to = t; | |
187 | return 0; | |
188 | } | |
189 | ||
190 | static long region_chg(struct list_head *head, long f, long t) | |
191 | { | |
192 | struct file_region *rg, *nrg; | |
193 | long chg = 0; | |
194 | ||
195 | /* Locate the region we are before or in. */ | |
196 | list_for_each_entry(rg, head, link) | |
197 | if (f <= rg->to) | |
198 | break; | |
199 | ||
200 | /* If we are below the current region then a new region is required. | |
201 | * Subtle, allocate a new region at the position but make it zero | |
202 | * size such that we can guarantee to record the reservation. */ | |
203 | if (&rg->link == head || t < rg->from) { | |
204 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
205 | if (!nrg) | |
206 | return -ENOMEM; | |
207 | nrg->from = f; | |
208 | nrg->to = f; | |
209 | INIT_LIST_HEAD(&nrg->link); | |
210 | list_add(&nrg->link, rg->link.prev); | |
211 | ||
212 | return t - f; | |
213 | } | |
214 | ||
215 | /* Round our left edge to the current segment if it encloses us. */ | |
216 | if (f > rg->from) | |
217 | f = rg->from; | |
218 | chg = t - f; | |
219 | ||
220 | /* Check for and consume any regions we now overlap with. */ | |
221 | list_for_each_entry(rg, rg->link.prev, link) { | |
222 | if (&rg->link == head) | |
223 | break; | |
224 | if (rg->from > t) | |
225 | return chg; | |
226 | ||
25985edc | 227 | /* We overlap with this area, if it extends further than |
96822904 AW |
228 | * us then we must extend ourselves. Account for its |
229 | * existing reservation. */ | |
230 | if (rg->to > t) { | |
231 | chg += rg->to - t; | |
232 | t = rg->to; | |
233 | } | |
234 | chg -= rg->to - rg->from; | |
235 | } | |
236 | return chg; | |
237 | } | |
238 | ||
239 | static long region_truncate(struct list_head *head, long end) | |
240 | { | |
241 | struct file_region *rg, *trg; | |
242 | long chg = 0; | |
243 | ||
244 | /* Locate the region we are either in or before. */ | |
245 | list_for_each_entry(rg, head, link) | |
246 | if (end <= rg->to) | |
247 | break; | |
248 | if (&rg->link == head) | |
249 | return 0; | |
250 | ||
251 | /* If we are in the middle of a region then adjust it. */ | |
252 | if (end > rg->from) { | |
253 | chg = rg->to - end; | |
254 | rg->to = end; | |
255 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
256 | } | |
257 | ||
258 | /* Drop any remaining regions. */ | |
259 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
260 | if (&rg->link == head) | |
261 | break; | |
262 | chg += rg->to - rg->from; | |
263 | list_del(&rg->link); | |
264 | kfree(rg); | |
265 | } | |
266 | return chg; | |
267 | } | |
268 | ||
84afd99b AW |
269 | static long region_count(struct list_head *head, long f, long t) |
270 | { | |
271 | struct file_region *rg; | |
272 | long chg = 0; | |
273 | ||
274 | /* Locate each segment we overlap with, and count that overlap. */ | |
275 | list_for_each_entry(rg, head, link) { | |
f2135a4a WSH |
276 | long seg_from; |
277 | long seg_to; | |
84afd99b AW |
278 | |
279 | if (rg->to <= f) | |
280 | continue; | |
281 | if (rg->from >= t) | |
282 | break; | |
283 | ||
284 | seg_from = max(rg->from, f); | |
285 | seg_to = min(rg->to, t); | |
286 | ||
287 | chg += seg_to - seg_from; | |
288 | } | |
289 | ||
290 | return chg; | |
291 | } | |
292 | ||
e7c4b0bf AW |
293 | /* |
294 | * Convert the address within this vma to the page offset within | |
295 | * the mapping, in pagecache page units; huge pages here. | |
296 | */ | |
a5516438 AK |
297 | static pgoff_t vma_hugecache_offset(struct hstate *h, |
298 | struct vm_area_struct *vma, unsigned long address) | |
e7c4b0bf | 299 | { |
a5516438 AK |
300 | return ((address - vma->vm_start) >> huge_page_shift(h)) + |
301 | (vma->vm_pgoff >> huge_page_order(h)); | |
e7c4b0bf AW |
302 | } |
303 | ||
0fe6e20b NH |
304 | pgoff_t linear_hugepage_index(struct vm_area_struct *vma, |
305 | unsigned long address) | |
306 | { | |
307 | return vma_hugecache_offset(hstate_vma(vma), vma, address); | |
308 | } | |
309 | ||
08fba699 MG |
310 | /* |
311 | * Return the size of the pages allocated when backing a VMA. In the majority | |
312 | * cases this will be same size as used by the page table entries. | |
313 | */ | |
314 | unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) | |
315 | { | |
316 | struct hstate *hstate; | |
317 | ||
318 | if (!is_vm_hugetlb_page(vma)) | |
319 | return PAGE_SIZE; | |
320 | ||
321 | hstate = hstate_vma(vma); | |
322 | ||
2415cf12 | 323 | return 1UL << huge_page_shift(hstate); |
08fba699 | 324 | } |
f340ca0f | 325 | EXPORT_SYMBOL_GPL(vma_kernel_pagesize); |
08fba699 | 326 | |
3340289d MG |
327 | /* |
328 | * Return the page size being used by the MMU to back a VMA. In the majority | |
329 | * of cases, the page size used by the kernel matches the MMU size. On | |
330 | * architectures where it differs, an architecture-specific version of this | |
331 | * function is required. | |
332 | */ | |
333 | #ifndef vma_mmu_pagesize | |
334 | unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) | |
335 | { | |
336 | return vma_kernel_pagesize(vma); | |
337 | } | |
338 | #endif | |
339 | ||
84afd99b AW |
340 | /* |
341 | * Flags for MAP_PRIVATE reservations. These are stored in the bottom | |
342 | * bits of the reservation map pointer, which are always clear due to | |
343 | * alignment. | |
344 | */ | |
345 | #define HPAGE_RESV_OWNER (1UL << 0) | |
346 | #define HPAGE_RESV_UNMAPPED (1UL << 1) | |
04f2cbe3 | 347 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) |
84afd99b | 348 | |
a1e78772 MG |
349 | /* |
350 | * These helpers are used to track how many pages are reserved for | |
351 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() | |
352 | * is guaranteed to have their future faults succeed. | |
353 | * | |
354 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), | |
355 | * the reserve counters are updated with the hugetlb_lock held. It is safe | |
356 | * to reset the VMA at fork() time as it is not in use yet and there is no | |
357 | * chance of the global counters getting corrupted as a result of the values. | |
84afd99b AW |
358 | * |
359 | * The private mapping reservation is represented in a subtly different | |
360 | * manner to a shared mapping. A shared mapping has a region map associated | |
361 | * with the underlying file, this region map represents the backing file | |
362 | * pages which have ever had a reservation assigned which this persists even | |
363 | * after the page is instantiated. A private mapping has a region map | |
364 | * associated with the original mmap which is attached to all VMAs which | |
365 | * reference it, this region map represents those offsets which have consumed | |
366 | * reservation ie. where pages have been instantiated. | |
a1e78772 | 367 | */ |
e7c4b0bf AW |
368 | static unsigned long get_vma_private_data(struct vm_area_struct *vma) |
369 | { | |
370 | return (unsigned long)vma->vm_private_data; | |
371 | } | |
372 | ||
373 | static void set_vma_private_data(struct vm_area_struct *vma, | |
374 | unsigned long value) | |
375 | { | |
376 | vma->vm_private_data = (void *)value; | |
377 | } | |
378 | ||
84afd99b AW |
379 | struct resv_map { |
380 | struct kref refs; | |
381 | struct list_head regions; | |
382 | }; | |
383 | ||
2a4b3ded | 384 | static struct resv_map *resv_map_alloc(void) |
84afd99b AW |
385 | { |
386 | struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); | |
387 | if (!resv_map) | |
388 | return NULL; | |
389 | ||
390 | kref_init(&resv_map->refs); | |
391 | INIT_LIST_HEAD(&resv_map->regions); | |
392 | ||
393 | return resv_map; | |
394 | } | |
395 | ||
2a4b3ded | 396 | static void resv_map_release(struct kref *ref) |
84afd99b AW |
397 | { |
398 | struct resv_map *resv_map = container_of(ref, struct resv_map, refs); | |
399 | ||
400 | /* Clear out any active regions before we release the map. */ | |
401 | region_truncate(&resv_map->regions, 0); | |
402 | kfree(resv_map); | |
403 | } | |
404 | ||
405 | static struct resv_map *vma_resv_map(struct vm_area_struct *vma) | |
a1e78772 MG |
406 | { |
407 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
f83a275d | 408 | if (!(vma->vm_flags & VM_MAYSHARE)) |
84afd99b AW |
409 | return (struct resv_map *)(get_vma_private_data(vma) & |
410 | ~HPAGE_RESV_MASK); | |
2a4b3ded | 411 | return NULL; |
a1e78772 MG |
412 | } |
413 | ||
84afd99b | 414 | static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) |
a1e78772 MG |
415 | { |
416 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
f83a275d | 417 | VM_BUG_ON(vma->vm_flags & VM_MAYSHARE); |
a1e78772 | 418 | |
84afd99b AW |
419 | set_vma_private_data(vma, (get_vma_private_data(vma) & |
420 | HPAGE_RESV_MASK) | (unsigned long)map); | |
04f2cbe3 MG |
421 | } |
422 | ||
423 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) | |
424 | { | |
04f2cbe3 | 425 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
f83a275d | 426 | VM_BUG_ON(vma->vm_flags & VM_MAYSHARE); |
e7c4b0bf AW |
427 | |
428 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); | |
04f2cbe3 MG |
429 | } |
430 | ||
431 | static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) | |
432 | { | |
433 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
e7c4b0bf AW |
434 | |
435 | return (get_vma_private_data(vma) & flag) != 0; | |
a1e78772 MG |
436 | } |
437 | ||
04f2cbe3 | 438 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
a1e78772 MG |
439 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
440 | { | |
441 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
f83a275d | 442 | if (!(vma->vm_flags & VM_MAYSHARE)) |
a1e78772 MG |
443 | vma->vm_private_data = (void *)0; |
444 | } | |
445 | ||
446 | /* Returns true if the VMA has associated reserve pages */ | |
af0ed73e | 447 | static int vma_has_reserves(struct vm_area_struct *vma, long chg) |
a1e78772 | 448 | { |
af0ed73e JK |
449 | if (vma->vm_flags & VM_NORESERVE) { |
450 | /* | |
451 | * This address is already reserved by other process(chg == 0), | |
452 | * so, we should decrement reserved count. Without decrementing, | |
453 | * reserve count remains after releasing inode, because this | |
454 | * allocated page will go into page cache and is regarded as | |
455 | * coming from reserved pool in releasing step. Currently, we | |
456 | * don't have any other solution to deal with this situation | |
457 | * properly, so add work-around here. | |
458 | */ | |
459 | if (vma->vm_flags & VM_MAYSHARE && chg == 0) | |
460 | return 1; | |
461 | else | |
462 | return 0; | |
463 | } | |
a63884e9 JK |
464 | |
465 | /* Shared mappings always use reserves */ | |
f83a275d | 466 | if (vma->vm_flags & VM_MAYSHARE) |
7f09ca51 | 467 | return 1; |
a63884e9 JK |
468 | |
469 | /* | |
470 | * Only the process that called mmap() has reserves for | |
471 | * private mappings. | |
472 | */ | |
7f09ca51 MG |
473 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
474 | return 1; | |
a63884e9 | 475 | |
7f09ca51 | 476 | return 0; |
a1e78772 MG |
477 | } |
478 | ||
0ebabb41 NH |
479 | static void copy_gigantic_page(struct page *dst, struct page *src) |
480 | { | |
481 | int i; | |
482 | struct hstate *h = page_hstate(src); | |
483 | struct page *dst_base = dst; | |
484 | struct page *src_base = src; | |
485 | ||
486 | for (i = 0; i < pages_per_huge_page(h); ) { | |
487 | cond_resched(); | |
488 | copy_highpage(dst, src); | |
489 | ||
490 | i++; | |
491 | dst = mem_map_next(dst, dst_base, i); | |
492 | src = mem_map_next(src, src_base, i); | |
493 | } | |
494 | } | |
495 | ||
496 | void copy_huge_page(struct page *dst, struct page *src) | |
497 | { | |
498 | int i; | |
499 | struct hstate *h = page_hstate(src); | |
500 | ||
501 | if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) { | |
502 | copy_gigantic_page(dst, src); | |
503 | return; | |
504 | } | |
505 | ||
506 | might_sleep(); | |
507 | for (i = 0; i < pages_per_huge_page(h); i++) { | |
508 | cond_resched(); | |
509 | copy_highpage(dst + i, src + i); | |
510 | } | |
511 | } | |
512 | ||
a5516438 | 513 | static void enqueue_huge_page(struct hstate *h, struct page *page) |
1da177e4 LT |
514 | { |
515 | int nid = page_to_nid(page); | |
0edaecfa | 516 | list_move(&page->lru, &h->hugepage_freelists[nid]); |
a5516438 AK |
517 | h->free_huge_pages++; |
518 | h->free_huge_pages_node[nid]++; | |
1da177e4 LT |
519 | } |
520 | ||
bf50bab2 NH |
521 | static struct page *dequeue_huge_page_node(struct hstate *h, int nid) |
522 | { | |
523 | struct page *page; | |
524 | ||
c8721bbb NH |
525 | list_for_each_entry(page, &h->hugepage_freelists[nid], lru) |
526 | if (!is_migrate_isolate_page(page)) | |
527 | break; | |
528 | /* | |
529 | * if 'non-isolated free hugepage' not found on the list, | |
530 | * the allocation fails. | |
531 | */ | |
532 | if (&h->hugepage_freelists[nid] == &page->lru) | |
bf50bab2 | 533 | return NULL; |
0edaecfa | 534 | list_move(&page->lru, &h->hugepage_activelist); |
a9869b83 | 535 | set_page_refcounted(page); |
bf50bab2 NH |
536 | h->free_huge_pages--; |
537 | h->free_huge_pages_node[nid]--; | |
538 | return page; | |
539 | } | |
540 | ||
86cdb465 NH |
541 | /* Movability of hugepages depends on migration support. */ |
542 | static inline gfp_t htlb_alloc_mask(struct hstate *h) | |
543 | { | |
544 | if (hugepages_treat_as_movable || hugepage_migration_support(h)) | |
545 | return GFP_HIGHUSER_MOVABLE; | |
546 | else | |
547 | return GFP_HIGHUSER; | |
548 | } | |
549 | ||
a5516438 AK |
550 | static struct page *dequeue_huge_page_vma(struct hstate *h, |
551 | struct vm_area_struct *vma, | |
af0ed73e JK |
552 | unsigned long address, int avoid_reserve, |
553 | long chg) | |
1da177e4 | 554 | { |
b1c12cbc | 555 | struct page *page = NULL; |
480eccf9 | 556 | struct mempolicy *mpol; |
19770b32 | 557 | nodemask_t *nodemask; |
c0ff7453 | 558 | struct zonelist *zonelist; |
dd1a239f MG |
559 | struct zone *zone; |
560 | struct zoneref *z; | |
cc9a6c87 | 561 | unsigned int cpuset_mems_cookie; |
1da177e4 | 562 | |
a1e78772 MG |
563 | /* |
564 | * A child process with MAP_PRIVATE mappings created by their parent | |
565 | * have no page reserves. This check ensures that reservations are | |
566 | * not "stolen". The child may still get SIGKILLed | |
567 | */ | |
af0ed73e | 568 | if (!vma_has_reserves(vma, chg) && |
a5516438 | 569 | h->free_huge_pages - h->resv_huge_pages == 0) |
c0ff7453 | 570 | goto err; |
a1e78772 | 571 | |
04f2cbe3 | 572 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
a5516438 | 573 | if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) |
6eab04a8 | 574 | goto err; |
04f2cbe3 | 575 | |
9966c4bb JK |
576 | retry_cpuset: |
577 | cpuset_mems_cookie = get_mems_allowed(); | |
578 | zonelist = huge_zonelist(vma, address, | |
86cdb465 | 579 | htlb_alloc_mask(h), &mpol, &nodemask); |
9966c4bb | 580 | |
19770b32 MG |
581 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
582 | MAX_NR_ZONES - 1, nodemask) { | |
86cdb465 | 583 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask(h))) { |
bf50bab2 NH |
584 | page = dequeue_huge_page_node(h, zone_to_nid(zone)); |
585 | if (page) { | |
af0ed73e JK |
586 | if (avoid_reserve) |
587 | break; | |
588 | if (!vma_has_reserves(vma, chg)) | |
589 | break; | |
590 | ||
07443a85 | 591 | SetPagePrivate(page); |
af0ed73e | 592 | h->resv_huge_pages--; |
bf50bab2 NH |
593 | break; |
594 | } | |
3abf7afd | 595 | } |
1da177e4 | 596 | } |
cc9a6c87 | 597 | |
52cd3b07 | 598 | mpol_cond_put(mpol); |
cc9a6c87 MG |
599 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) |
600 | goto retry_cpuset; | |
1da177e4 | 601 | return page; |
cc9a6c87 MG |
602 | |
603 | err: | |
cc9a6c87 | 604 | return NULL; |
1da177e4 LT |
605 | } |
606 | ||
a5516438 | 607 | static void update_and_free_page(struct hstate *h, struct page *page) |
6af2acb6 AL |
608 | { |
609 | int i; | |
a5516438 | 610 | |
18229df5 AW |
611 | VM_BUG_ON(h->order >= MAX_ORDER); |
612 | ||
a5516438 AK |
613 | h->nr_huge_pages--; |
614 | h->nr_huge_pages_node[page_to_nid(page)]--; | |
615 | for (i = 0; i < pages_per_huge_page(h); i++) { | |
32f84528 CF |
616 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | |
617 | 1 << PG_referenced | 1 << PG_dirty | | |
618 | 1 << PG_active | 1 << PG_reserved | | |
619 | 1 << PG_private | 1 << PG_writeback); | |
6af2acb6 | 620 | } |
9dd540e2 | 621 | VM_BUG_ON(hugetlb_cgroup_from_page(page)); |
6af2acb6 AL |
622 | set_compound_page_dtor(page, NULL); |
623 | set_page_refcounted(page); | |
7f2e9525 | 624 | arch_release_hugepage(page); |
a5516438 | 625 | __free_pages(page, huge_page_order(h)); |
6af2acb6 AL |
626 | } |
627 | ||
e5ff2159 AK |
628 | struct hstate *size_to_hstate(unsigned long size) |
629 | { | |
630 | struct hstate *h; | |
631 | ||
632 | for_each_hstate(h) { | |
633 | if (huge_page_size(h) == size) | |
634 | return h; | |
635 | } | |
636 | return NULL; | |
637 | } | |
638 | ||
27a85ef1 DG |
639 | static void free_huge_page(struct page *page) |
640 | { | |
a5516438 AK |
641 | /* |
642 | * Can't pass hstate in here because it is called from the | |
643 | * compound page destructor. | |
644 | */ | |
e5ff2159 | 645 | struct hstate *h = page_hstate(page); |
7893d1d5 | 646 | int nid = page_to_nid(page); |
90481622 DG |
647 | struct hugepage_subpool *spool = |
648 | (struct hugepage_subpool *)page_private(page); | |
07443a85 | 649 | bool restore_reserve; |
27a85ef1 | 650 | |
e5df70ab | 651 | set_page_private(page, 0); |
23be7468 | 652 | page->mapping = NULL; |
7893d1d5 | 653 | BUG_ON(page_count(page)); |
0fe6e20b | 654 | BUG_ON(page_mapcount(page)); |
07443a85 | 655 | restore_reserve = PagePrivate(page); |
16c794b4 | 656 | ClearPagePrivate(page); |
27a85ef1 DG |
657 | |
658 | spin_lock(&hugetlb_lock); | |
6d76dcf4 AK |
659 | hugetlb_cgroup_uncharge_page(hstate_index(h), |
660 | pages_per_huge_page(h), page); | |
07443a85 JK |
661 | if (restore_reserve) |
662 | h->resv_huge_pages++; | |
663 | ||
aa888a74 | 664 | if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) { |
0edaecfa AK |
665 | /* remove the page from active list */ |
666 | list_del(&page->lru); | |
a5516438 AK |
667 | update_and_free_page(h, page); |
668 | h->surplus_huge_pages--; | |
669 | h->surplus_huge_pages_node[nid]--; | |
7893d1d5 | 670 | } else { |
5d3a551c | 671 | arch_clear_hugepage_flags(page); |
a5516438 | 672 | enqueue_huge_page(h, page); |
7893d1d5 | 673 | } |
27a85ef1 | 674 | spin_unlock(&hugetlb_lock); |
90481622 | 675 | hugepage_subpool_put_pages(spool, 1); |
27a85ef1 DG |
676 | } |
677 | ||
a5516438 | 678 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) |
b7ba30c6 | 679 | { |
0edaecfa | 680 | INIT_LIST_HEAD(&page->lru); |
b7ba30c6 AK |
681 | set_compound_page_dtor(page, free_huge_page); |
682 | spin_lock(&hugetlb_lock); | |
9dd540e2 | 683 | set_hugetlb_cgroup(page, NULL); |
a5516438 AK |
684 | h->nr_huge_pages++; |
685 | h->nr_huge_pages_node[nid]++; | |
b7ba30c6 AK |
686 | spin_unlock(&hugetlb_lock); |
687 | put_page(page); /* free it into the hugepage allocator */ | |
688 | } | |
689 | ||
20a0307c WF |
690 | static void prep_compound_gigantic_page(struct page *page, unsigned long order) |
691 | { | |
692 | int i; | |
693 | int nr_pages = 1 << order; | |
694 | struct page *p = page + 1; | |
695 | ||
696 | /* we rely on prep_new_huge_page to set the destructor */ | |
697 | set_compound_order(page, order); | |
698 | __SetPageHead(page); | |
699 | for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { | |
700 | __SetPageTail(p); | |
58a84aa9 | 701 | set_page_count(p, 0); |
20a0307c WF |
702 | p->first_page = page; |
703 | } | |
704 | } | |
705 | ||
7795912c AM |
706 | /* |
707 | * PageHuge() only returns true for hugetlbfs pages, but not for normal or | |
708 | * transparent huge pages. See the PageTransHuge() documentation for more | |
709 | * details. | |
710 | */ | |
20a0307c WF |
711 | int PageHuge(struct page *page) |
712 | { | |
713 | compound_page_dtor *dtor; | |
714 | ||
715 | if (!PageCompound(page)) | |
716 | return 0; | |
717 | ||
718 | page = compound_head(page); | |
719 | dtor = get_compound_page_dtor(page); | |
720 | ||
721 | return dtor == free_huge_page; | |
722 | } | |
43131e14 NH |
723 | EXPORT_SYMBOL_GPL(PageHuge); |
724 | ||
13d60f4b ZY |
725 | pgoff_t __basepage_index(struct page *page) |
726 | { | |
727 | struct page *page_head = compound_head(page); | |
728 | pgoff_t index = page_index(page_head); | |
729 | unsigned long compound_idx; | |
730 | ||
731 | if (!PageHuge(page_head)) | |
732 | return page_index(page); | |
733 | ||
734 | if (compound_order(page_head) >= MAX_ORDER) | |
735 | compound_idx = page_to_pfn(page) - page_to_pfn(page_head); | |
736 | else | |
737 | compound_idx = page - page_head; | |
738 | ||
739 | return (index << compound_order(page_head)) + compound_idx; | |
740 | } | |
741 | ||
a5516438 | 742 | static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) |
1da177e4 | 743 | { |
1da177e4 | 744 | struct page *page; |
f96efd58 | 745 | |
aa888a74 AK |
746 | if (h->order >= MAX_ORDER) |
747 | return NULL; | |
748 | ||
6484eb3e | 749 | page = alloc_pages_exact_node(nid, |
86cdb465 | 750 | htlb_alloc_mask(h)|__GFP_COMP|__GFP_THISNODE| |
551883ae | 751 | __GFP_REPEAT|__GFP_NOWARN, |
a5516438 | 752 | huge_page_order(h)); |
1da177e4 | 753 | if (page) { |
7f2e9525 | 754 | if (arch_prepare_hugepage(page)) { |
caff3a2c | 755 | __free_pages(page, huge_page_order(h)); |
7b8ee84d | 756 | return NULL; |
7f2e9525 | 757 | } |
a5516438 | 758 | prep_new_huge_page(h, page, nid); |
1da177e4 | 759 | } |
63b4613c NA |
760 | |
761 | return page; | |
762 | } | |
763 | ||
9a76db09 | 764 | /* |
6ae11b27 LS |
765 | * common helper functions for hstate_next_node_to_{alloc|free}. |
766 | * We may have allocated or freed a huge page based on a different | |
767 | * nodes_allowed previously, so h->next_node_to_{alloc|free} might | |
768 | * be outside of *nodes_allowed. Ensure that we use an allowed | |
769 | * node for alloc or free. | |
9a76db09 | 770 | */ |
6ae11b27 | 771 | static int next_node_allowed(int nid, nodemask_t *nodes_allowed) |
9a76db09 | 772 | { |
6ae11b27 | 773 | nid = next_node(nid, *nodes_allowed); |
9a76db09 | 774 | if (nid == MAX_NUMNODES) |
6ae11b27 | 775 | nid = first_node(*nodes_allowed); |
9a76db09 LS |
776 | VM_BUG_ON(nid >= MAX_NUMNODES); |
777 | ||
778 | return nid; | |
779 | } | |
780 | ||
6ae11b27 LS |
781 | static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) |
782 | { | |
783 | if (!node_isset(nid, *nodes_allowed)) | |
784 | nid = next_node_allowed(nid, nodes_allowed); | |
785 | return nid; | |
786 | } | |
787 | ||
5ced66c9 | 788 | /* |
6ae11b27 LS |
789 | * returns the previously saved node ["this node"] from which to |
790 | * allocate a persistent huge page for the pool and advance the | |
791 | * next node from which to allocate, handling wrap at end of node | |
792 | * mask. | |
5ced66c9 | 793 | */ |
6ae11b27 LS |
794 | static int hstate_next_node_to_alloc(struct hstate *h, |
795 | nodemask_t *nodes_allowed) | |
5ced66c9 | 796 | { |
6ae11b27 LS |
797 | int nid; |
798 | ||
799 | VM_BUG_ON(!nodes_allowed); | |
800 | ||
801 | nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); | |
802 | h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); | |
9a76db09 | 803 | |
9a76db09 | 804 | return nid; |
5ced66c9 AK |
805 | } |
806 | ||
e8c5c824 | 807 | /* |
6ae11b27 LS |
808 | * helper for free_pool_huge_page() - return the previously saved |
809 | * node ["this node"] from which to free a huge page. Advance the | |
810 | * next node id whether or not we find a free huge page to free so | |
811 | * that the next attempt to free addresses the next node. | |
e8c5c824 | 812 | */ |
6ae11b27 | 813 | static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) |
e8c5c824 | 814 | { |
6ae11b27 LS |
815 | int nid; |
816 | ||
817 | VM_BUG_ON(!nodes_allowed); | |
818 | ||
819 | nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); | |
820 | h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); | |
9a76db09 | 821 | |
9a76db09 | 822 | return nid; |
e8c5c824 LS |
823 | } |
824 | ||
b2261026 JK |
825 | #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ |
826 | for (nr_nodes = nodes_weight(*mask); \ | |
827 | nr_nodes > 0 && \ | |
828 | ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ | |
829 | nr_nodes--) | |
830 | ||
831 | #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ | |
832 | for (nr_nodes = nodes_weight(*mask); \ | |
833 | nr_nodes > 0 && \ | |
834 | ((node = hstate_next_node_to_free(hs, mask)) || 1); \ | |
835 | nr_nodes--) | |
836 | ||
837 | static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed) | |
838 | { | |
839 | struct page *page; | |
840 | int nr_nodes, node; | |
841 | int ret = 0; | |
842 | ||
843 | for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { | |
844 | page = alloc_fresh_huge_page_node(h, node); | |
845 | if (page) { | |
846 | ret = 1; | |
847 | break; | |
848 | } | |
849 | } | |
850 | ||
851 | if (ret) | |
852 | count_vm_event(HTLB_BUDDY_PGALLOC); | |
853 | else | |
854 | count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); | |
855 | ||
856 | return ret; | |
857 | } | |
858 | ||
e8c5c824 LS |
859 | /* |
860 | * Free huge page from pool from next node to free. | |
861 | * Attempt to keep persistent huge pages more or less | |
862 | * balanced over allowed nodes. | |
863 | * Called with hugetlb_lock locked. | |
864 | */ | |
6ae11b27 LS |
865 | static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, |
866 | bool acct_surplus) | |
e8c5c824 | 867 | { |
b2261026 | 868 | int nr_nodes, node; |
e8c5c824 LS |
869 | int ret = 0; |
870 | ||
b2261026 | 871 | for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { |
685f3457 LS |
872 | /* |
873 | * If we're returning unused surplus pages, only examine | |
874 | * nodes with surplus pages. | |
875 | */ | |
b2261026 JK |
876 | if ((!acct_surplus || h->surplus_huge_pages_node[node]) && |
877 | !list_empty(&h->hugepage_freelists[node])) { | |
e8c5c824 | 878 | struct page *page = |
b2261026 | 879 | list_entry(h->hugepage_freelists[node].next, |
e8c5c824 LS |
880 | struct page, lru); |
881 | list_del(&page->lru); | |
882 | h->free_huge_pages--; | |
b2261026 | 883 | h->free_huge_pages_node[node]--; |
685f3457 LS |
884 | if (acct_surplus) { |
885 | h->surplus_huge_pages--; | |
b2261026 | 886 | h->surplus_huge_pages_node[node]--; |
685f3457 | 887 | } |
e8c5c824 LS |
888 | update_and_free_page(h, page); |
889 | ret = 1; | |
9a76db09 | 890 | break; |
e8c5c824 | 891 | } |
b2261026 | 892 | } |
e8c5c824 LS |
893 | |
894 | return ret; | |
895 | } | |
896 | ||
c8721bbb NH |
897 | /* |
898 | * Dissolve a given free hugepage into free buddy pages. This function does | |
899 | * nothing for in-use (including surplus) hugepages. | |
900 | */ | |
901 | static void dissolve_free_huge_page(struct page *page) | |
902 | { | |
903 | spin_lock(&hugetlb_lock); | |
904 | if (PageHuge(page) && !page_count(page)) { | |
905 | struct hstate *h = page_hstate(page); | |
906 | int nid = page_to_nid(page); | |
907 | list_del(&page->lru); | |
908 | h->free_huge_pages--; | |
909 | h->free_huge_pages_node[nid]--; | |
910 | update_and_free_page(h, page); | |
911 | } | |
912 | spin_unlock(&hugetlb_lock); | |
913 | } | |
914 | ||
915 | /* | |
916 | * Dissolve free hugepages in a given pfn range. Used by memory hotplug to | |
917 | * make specified memory blocks removable from the system. | |
918 | * Note that start_pfn should aligned with (minimum) hugepage size. | |
919 | */ | |
920 | void dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) | |
921 | { | |
922 | unsigned int order = 8 * sizeof(void *); | |
923 | unsigned long pfn; | |
924 | struct hstate *h; | |
925 | ||
926 | /* Set scan step to minimum hugepage size */ | |
927 | for_each_hstate(h) | |
928 | if (order > huge_page_order(h)) | |
929 | order = huge_page_order(h); | |
930 | VM_BUG_ON(!IS_ALIGNED(start_pfn, 1 << order)); | |
931 | for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << order) | |
932 | dissolve_free_huge_page(pfn_to_page(pfn)); | |
933 | } | |
934 | ||
bf50bab2 | 935 | static struct page *alloc_buddy_huge_page(struct hstate *h, int nid) |
7893d1d5 AL |
936 | { |
937 | struct page *page; | |
bf50bab2 | 938 | unsigned int r_nid; |
7893d1d5 | 939 | |
aa888a74 AK |
940 | if (h->order >= MAX_ORDER) |
941 | return NULL; | |
942 | ||
d1c3fb1f NA |
943 | /* |
944 | * Assume we will successfully allocate the surplus page to | |
945 | * prevent racing processes from causing the surplus to exceed | |
946 | * overcommit | |
947 | * | |
948 | * This however introduces a different race, where a process B | |
949 | * tries to grow the static hugepage pool while alloc_pages() is | |
950 | * called by process A. B will only examine the per-node | |
951 | * counters in determining if surplus huge pages can be | |
952 | * converted to normal huge pages in adjust_pool_surplus(). A | |
953 | * won't be able to increment the per-node counter, until the | |
954 | * lock is dropped by B, but B doesn't drop hugetlb_lock until | |
955 | * no more huge pages can be converted from surplus to normal | |
956 | * state (and doesn't try to convert again). Thus, we have a | |
957 | * case where a surplus huge page exists, the pool is grown, and | |
958 | * the surplus huge page still exists after, even though it | |
959 | * should just have been converted to a normal huge page. This | |
960 | * does not leak memory, though, as the hugepage will be freed | |
961 | * once it is out of use. It also does not allow the counters to | |
962 | * go out of whack in adjust_pool_surplus() as we don't modify | |
963 | * the node values until we've gotten the hugepage and only the | |
964 | * per-node value is checked there. | |
965 | */ | |
966 | spin_lock(&hugetlb_lock); | |
a5516438 | 967 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { |
d1c3fb1f NA |
968 | spin_unlock(&hugetlb_lock); |
969 | return NULL; | |
970 | } else { | |
a5516438 AK |
971 | h->nr_huge_pages++; |
972 | h->surplus_huge_pages++; | |
d1c3fb1f NA |
973 | } |
974 | spin_unlock(&hugetlb_lock); | |
975 | ||
bf50bab2 | 976 | if (nid == NUMA_NO_NODE) |
86cdb465 | 977 | page = alloc_pages(htlb_alloc_mask(h)|__GFP_COMP| |
bf50bab2 NH |
978 | __GFP_REPEAT|__GFP_NOWARN, |
979 | huge_page_order(h)); | |
980 | else | |
981 | page = alloc_pages_exact_node(nid, | |
86cdb465 | 982 | htlb_alloc_mask(h)|__GFP_COMP|__GFP_THISNODE| |
bf50bab2 | 983 | __GFP_REPEAT|__GFP_NOWARN, huge_page_order(h)); |
d1c3fb1f | 984 | |
caff3a2c GS |
985 | if (page && arch_prepare_hugepage(page)) { |
986 | __free_pages(page, huge_page_order(h)); | |
ea5768c7 | 987 | page = NULL; |
caff3a2c GS |
988 | } |
989 | ||
d1c3fb1f | 990 | spin_lock(&hugetlb_lock); |
7893d1d5 | 991 | if (page) { |
0edaecfa | 992 | INIT_LIST_HEAD(&page->lru); |
bf50bab2 | 993 | r_nid = page_to_nid(page); |
7893d1d5 | 994 | set_compound_page_dtor(page, free_huge_page); |
9dd540e2 | 995 | set_hugetlb_cgroup(page, NULL); |
d1c3fb1f NA |
996 | /* |
997 | * We incremented the global counters already | |
998 | */ | |
bf50bab2 NH |
999 | h->nr_huge_pages_node[r_nid]++; |
1000 | h->surplus_huge_pages_node[r_nid]++; | |
3b116300 | 1001 | __count_vm_event(HTLB_BUDDY_PGALLOC); |
d1c3fb1f | 1002 | } else { |
a5516438 AK |
1003 | h->nr_huge_pages--; |
1004 | h->surplus_huge_pages--; | |
3b116300 | 1005 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
7893d1d5 | 1006 | } |
d1c3fb1f | 1007 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
1008 | |
1009 | return page; | |
1010 | } | |
1011 | ||
bf50bab2 NH |
1012 | /* |
1013 | * This allocation function is useful in the context where vma is irrelevant. | |
1014 | * E.g. soft-offlining uses this function because it only cares physical | |
1015 | * address of error page. | |
1016 | */ | |
1017 | struct page *alloc_huge_page_node(struct hstate *h, int nid) | |
1018 | { | |
4ef91848 | 1019 | struct page *page = NULL; |
bf50bab2 NH |
1020 | |
1021 | spin_lock(&hugetlb_lock); | |
4ef91848 JK |
1022 | if (h->free_huge_pages - h->resv_huge_pages > 0) |
1023 | page = dequeue_huge_page_node(h, nid); | |
bf50bab2 NH |
1024 | spin_unlock(&hugetlb_lock); |
1025 | ||
94ae8ba7 | 1026 | if (!page) |
bf50bab2 NH |
1027 | page = alloc_buddy_huge_page(h, nid); |
1028 | ||
1029 | return page; | |
1030 | } | |
1031 | ||
e4e574b7 | 1032 | /* |
25985edc | 1033 | * Increase the hugetlb pool such that it can accommodate a reservation |
e4e574b7 AL |
1034 | * of size 'delta'. |
1035 | */ | |
a5516438 | 1036 | static int gather_surplus_pages(struct hstate *h, int delta) |
e4e574b7 AL |
1037 | { |
1038 | struct list_head surplus_list; | |
1039 | struct page *page, *tmp; | |
1040 | int ret, i; | |
1041 | int needed, allocated; | |
28073b02 | 1042 | bool alloc_ok = true; |
e4e574b7 | 1043 | |
a5516438 | 1044 | needed = (h->resv_huge_pages + delta) - h->free_huge_pages; |
ac09b3a1 | 1045 | if (needed <= 0) { |
a5516438 | 1046 | h->resv_huge_pages += delta; |
e4e574b7 | 1047 | return 0; |
ac09b3a1 | 1048 | } |
e4e574b7 AL |
1049 | |
1050 | allocated = 0; | |
1051 | INIT_LIST_HEAD(&surplus_list); | |
1052 | ||
1053 | ret = -ENOMEM; | |
1054 | retry: | |
1055 | spin_unlock(&hugetlb_lock); | |
1056 | for (i = 0; i < needed; i++) { | |
bf50bab2 | 1057 | page = alloc_buddy_huge_page(h, NUMA_NO_NODE); |
28073b02 HD |
1058 | if (!page) { |
1059 | alloc_ok = false; | |
1060 | break; | |
1061 | } | |
e4e574b7 AL |
1062 | list_add(&page->lru, &surplus_list); |
1063 | } | |
28073b02 | 1064 | allocated += i; |
e4e574b7 AL |
1065 | |
1066 | /* | |
1067 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
1068 | * because either resv_huge_pages or free_huge_pages may have changed. | |
1069 | */ | |
1070 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
1071 | needed = (h->resv_huge_pages + delta) - |
1072 | (h->free_huge_pages + allocated); | |
28073b02 HD |
1073 | if (needed > 0) { |
1074 | if (alloc_ok) | |
1075 | goto retry; | |
1076 | /* | |
1077 | * We were not able to allocate enough pages to | |
1078 | * satisfy the entire reservation so we free what | |
1079 | * we've allocated so far. | |
1080 | */ | |
1081 | goto free; | |
1082 | } | |
e4e574b7 AL |
1083 | /* |
1084 | * The surplus_list now contains _at_least_ the number of extra pages | |
25985edc | 1085 | * needed to accommodate the reservation. Add the appropriate number |
e4e574b7 | 1086 | * of pages to the hugetlb pool and free the extras back to the buddy |
ac09b3a1 AL |
1087 | * allocator. Commit the entire reservation here to prevent another |
1088 | * process from stealing the pages as they are added to the pool but | |
1089 | * before they are reserved. | |
e4e574b7 AL |
1090 | */ |
1091 | needed += allocated; | |
a5516438 | 1092 | h->resv_huge_pages += delta; |
e4e574b7 | 1093 | ret = 0; |
a9869b83 | 1094 | |
19fc3f0a | 1095 | /* Free the needed pages to the hugetlb pool */ |
e4e574b7 | 1096 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
19fc3f0a AL |
1097 | if ((--needed) < 0) |
1098 | break; | |
a9869b83 NH |
1099 | /* |
1100 | * This page is now managed by the hugetlb allocator and has | |
1101 | * no users -- drop the buddy allocator's reference. | |
1102 | */ | |
1103 | put_page_testzero(page); | |
1104 | VM_BUG_ON(page_count(page)); | |
a5516438 | 1105 | enqueue_huge_page(h, page); |
19fc3f0a | 1106 | } |
28073b02 | 1107 | free: |
b0365c8d | 1108 | spin_unlock(&hugetlb_lock); |
19fc3f0a AL |
1109 | |
1110 | /* Free unnecessary surplus pages to the buddy allocator */ | |
c0d934ba JK |
1111 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) |
1112 | put_page(page); | |
a9869b83 | 1113 | spin_lock(&hugetlb_lock); |
e4e574b7 AL |
1114 | |
1115 | return ret; | |
1116 | } | |
1117 | ||
1118 | /* | |
1119 | * When releasing a hugetlb pool reservation, any surplus pages that were | |
1120 | * allocated to satisfy the reservation must be explicitly freed if they were | |
1121 | * never used. | |
685f3457 | 1122 | * Called with hugetlb_lock held. |
e4e574b7 | 1123 | */ |
a5516438 AK |
1124 | static void return_unused_surplus_pages(struct hstate *h, |
1125 | unsigned long unused_resv_pages) | |
e4e574b7 | 1126 | { |
e4e574b7 AL |
1127 | unsigned long nr_pages; |
1128 | ||
ac09b3a1 | 1129 | /* Uncommit the reservation */ |
a5516438 | 1130 | h->resv_huge_pages -= unused_resv_pages; |
ac09b3a1 | 1131 | |
aa888a74 AK |
1132 | /* Cannot return gigantic pages currently */ |
1133 | if (h->order >= MAX_ORDER) | |
1134 | return; | |
1135 | ||
a5516438 | 1136 | nr_pages = min(unused_resv_pages, h->surplus_huge_pages); |
e4e574b7 | 1137 | |
685f3457 LS |
1138 | /* |
1139 | * We want to release as many surplus pages as possible, spread | |
9b5e5d0f LS |
1140 | * evenly across all nodes with memory. Iterate across these nodes |
1141 | * until we can no longer free unreserved surplus pages. This occurs | |
1142 | * when the nodes with surplus pages have no free pages. | |
1143 | * free_pool_huge_page() will balance the the freed pages across the | |
1144 | * on-line nodes with memory and will handle the hstate accounting. | |
685f3457 LS |
1145 | */ |
1146 | while (nr_pages--) { | |
8cebfcd0 | 1147 | if (!free_pool_huge_page(h, &node_states[N_MEMORY], 1)) |
685f3457 | 1148 | break; |
e4e574b7 AL |
1149 | } |
1150 | } | |
1151 | ||
c37f9fb1 AW |
1152 | /* |
1153 | * Determine if the huge page at addr within the vma has an associated | |
1154 | * reservation. Where it does not we will need to logically increase | |
90481622 DG |
1155 | * reservation and actually increase subpool usage before an allocation |
1156 | * can occur. Where any new reservation would be required the | |
1157 | * reservation change is prepared, but not committed. Once the page | |
1158 | * has been allocated from the subpool and instantiated the change should | |
1159 | * be committed via vma_commit_reservation. No action is required on | |
1160 | * failure. | |
c37f9fb1 | 1161 | */ |
e2f17d94 | 1162 | static long vma_needs_reservation(struct hstate *h, |
a5516438 | 1163 | struct vm_area_struct *vma, unsigned long addr) |
c37f9fb1 AW |
1164 | { |
1165 | struct address_space *mapping = vma->vm_file->f_mapping; | |
1166 | struct inode *inode = mapping->host; | |
1167 | ||
f83a275d | 1168 | if (vma->vm_flags & VM_MAYSHARE) { |
a5516438 | 1169 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 AW |
1170 | return region_chg(&inode->i_mapping->private_list, |
1171 | idx, idx + 1); | |
1172 | ||
84afd99b AW |
1173 | } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
1174 | return 1; | |
c37f9fb1 | 1175 | |
84afd99b | 1176 | } else { |
e2f17d94 | 1177 | long err; |
a5516438 | 1178 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
f522c3ac | 1179 | struct resv_map *resv = vma_resv_map(vma); |
84afd99b | 1180 | |
f522c3ac | 1181 | err = region_chg(&resv->regions, idx, idx + 1); |
84afd99b AW |
1182 | if (err < 0) |
1183 | return err; | |
1184 | return 0; | |
1185 | } | |
c37f9fb1 | 1186 | } |
a5516438 AK |
1187 | static void vma_commit_reservation(struct hstate *h, |
1188 | struct vm_area_struct *vma, unsigned long addr) | |
c37f9fb1 AW |
1189 | { |
1190 | struct address_space *mapping = vma->vm_file->f_mapping; | |
1191 | struct inode *inode = mapping->host; | |
1192 | ||
f83a275d | 1193 | if (vma->vm_flags & VM_MAYSHARE) { |
a5516438 | 1194 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 | 1195 | region_add(&inode->i_mapping->private_list, idx, idx + 1); |
84afd99b AW |
1196 | |
1197 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { | |
a5516438 | 1198 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
f522c3ac | 1199 | struct resv_map *resv = vma_resv_map(vma); |
84afd99b AW |
1200 | |
1201 | /* Mark this page used in the map. */ | |
f522c3ac | 1202 | region_add(&resv->regions, idx, idx + 1); |
c37f9fb1 AW |
1203 | } |
1204 | } | |
1205 | ||
a1e78772 | 1206 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
04f2cbe3 | 1207 | unsigned long addr, int avoid_reserve) |
1da177e4 | 1208 | { |
90481622 | 1209 | struct hugepage_subpool *spool = subpool_vma(vma); |
a5516438 | 1210 | struct hstate *h = hstate_vma(vma); |
348ea204 | 1211 | struct page *page; |
e2f17d94 | 1212 | long chg; |
6d76dcf4 AK |
1213 | int ret, idx; |
1214 | struct hugetlb_cgroup *h_cg; | |
a1e78772 | 1215 | |
6d76dcf4 | 1216 | idx = hstate_index(h); |
a1e78772 | 1217 | /* |
90481622 DG |
1218 | * Processes that did not create the mapping will have no |
1219 | * reserves and will not have accounted against subpool | |
1220 | * limit. Check that the subpool limit can be made before | |
1221 | * satisfying the allocation MAP_NORESERVE mappings may also | |
1222 | * need pages and subpool limit allocated allocated if no reserve | |
1223 | * mapping overlaps. | |
a1e78772 | 1224 | */ |
a5516438 | 1225 | chg = vma_needs_reservation(h, vma, addr); |
c37f9fb1 | 1226 | if (chg < 0) |
76dcee75 | 1227 | return ERR_PTR(-ENOMEM); |
8bb3f12e JK |
1228 | if (chg || avoid_reserve) |
1229 | if (hugepage_subpool_get_pages(spool, 1)) | |
76dcee75 | 1230 | return ERR_PTR(-ENOSPC); |
1da177e4 | 1231 | |
6d76dcf4 AK |
1232 | ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); |
1233 | if (ret) { | |
8bb3f12e JK |
1234 | if (chg || avoid_reserve) |
1235 | hugepage_subpool_put_pages(spool, 1); | |
6d76dcf4 AK |
1236 | return ERR_PTR(-ENOSPC); |
1237 | } | |
1da177e4 | 1238 | spin_lock(&hugetlb_lock); |
af0ed73e | 1239 | page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, chg); |
81a6fcae | 1240 | if (!page) { |
94ae8ba7 | 1241 | spin_unlock(&hugetlb_lock); |
bf50bab2 | 1242 | page = alloc_buddy_huge_page(h, NUMA_NO_NODE); |
68842c9b | 1243 | if (!page) { |
6d76dcf4 AK |
1244 | hugetlb_cgroup_uncharge_cgroup(idx, |
1245 | pages_per_huge_page(h), | |
1246 | h_cg); | |
8bb3f12e JK |
1247 | if (chg || avoid_reserve) |
1248 | hugepage_subpool_put_pages(spool, 1); | |
76dcee75 | 1249 | return ERR_PTR(-ENOSPC); |
68842c9b | 1250 | } |
79dbb236 AK |
1251 | spin_lock(&hugetlb_lock); |
1252 | list_move(&page->lru, &h->hugepage_activelist); | |
81a6fcae | 1253 | /* Fall through */ |
68842c9b | 1254 | } |
81a6fcae JK |
1255 | hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); |
1256 | spin_unlock(&hugetlb_lock); | |
348ea204 | 1257 | |
90481622 | 1258 | set_page_private(page, (unsigned long)spool); |
90d8b7e6 | 1259 | |
a5516438 | 1260 | vma_commit_reservation(h, vma, addr); |
90d8b7e6 | 1261 | return page; |
b45b5bd6 DG |
1262 | } |
1263 | ||
74060e4d NH |
1264 | /* |
1265 | * alloc_huge_page()'s wrapper which simply returns the page if allocation | |
1266 | * succeeds, otherwise NULL. This function is called from new_vma_page(), | |
1267 | * where no ERR_VALUE is expected to be returned. | |
1268 | */ | |
1269 | struct page *alloc_huge_page_noerr(struct vm_area_struct *vma, | |
1270 | unsigned long addr, int avoid_reserve) | |
1271 | { | |
1272 | struct page *page = alloc_huge_page(vma, addr, avoid_reserve); | |
1273 | if (IS_ERR(page)) | |
1274 | page = NULL; | |
1275 | return page; | |
1276 | } | |
1277 | ||
91f47662 | 1278 | int __weak alloc_bootmem_huge_page(struct hstate *h) |
aa888a74 AK |
1279 | { |
1280 | struct huge_bootmem_page *m; | |
b2261026 | 1281 | int nr_nodes, node; |
aa888a74 | 1282 | |
b2261026 | 1283 | for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { |
aa888a74 AK |
1284 | void *addr; |
1285 | ||
b2261026 | 1286 | addr = __alloc_bootmem_node_nopanic(NODE_DATA(node), |
aa888a74 AK |
1287 | huge_page_size(h), huge_page_size(h), 0); |
1288 | ||
1289 | if (addr) { | |
1290 | /* | |
1291 | * Use the beginning of the huge page to store the | |
1292 | * huge_bootmem_page struct (until gather_bootmem | |
1293 | * puts them into the mem_map). | |
1294 | */ | |
1295 | m = addr; | |
91f47662 | 1296 | goto found; |
aa888a74 | 1297 | } |
aa888a74 AK |
1298 | } |
1299 | return 0; | |
1300 | ||
1301 | found: | |
1302 | BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1)); | |
1303 | /* Put them into a private list first because mem_map is not up yet */ | |
1304 | list_add(&m->list, &huge_boot_pages); | |
1305 | m->hstate = h; | |
1306 | return 1; | |
1307 | } | |
1308 | ||
18229df5 AW |
1309 | static void prep_compound_huge_page(struct page *page, int order) |
1310 | { | |
1311 | if (unlikely(order > (MAX_ORDER - 1))) | |
1312 | prep_compound_gigantic_page(page, order); | |
1313 | else | |
1314 | prep_compound_page(page, order); | |
1315 | } | |
1316 | ||
aa888a74 AK |
1317 | /* Put bootmem huge pages into the standard lists after mem_map is up */ |
1318 | static void __init gather_bootmem_prealloc(void) | |
1319 | { | |
1320 | struct huge_bootmem_page *m; | |
1321 | ||
1322 | list_for_each_entry(m, &huge_boot_pages, list) { | |
aa888a74 | 1323 | struct hstate *h = m->hstate; |
ee8f248d BB |
1324 | struct page *page; |
1325 | ||
1326 | #ifdef CONFIG_HIGHMEM | |
1327 | page = pfn_to_page(m->phys >> PAGE_SHIFT); | |
1328 | free_bootmem_late((unsigned long)m, | |
1329 | sizeof(struct huge_bootmem_page)); | |
1330 | #else | |
1331 | page = virt_to_page(m); | |
1332 | #endif | |
aa888a74 AK |
1333 | __ClearPageReserved(page); |
1334 | WARN_ON(page_count(page) != 1); | |
18229df5 | 1335 | prep_compound_huge_page(page, h->order); |
aa888a74 | 1336 | prep_new_huge_page(h, page, page_to_nid(page)); |
b0320c7b RA |
1337 | /* |
1338 | * If we had gigantic hugepages allocated at boot time, we need | |
1339 | * to restore the 'stolen' pages to totalram_pages in order to | |
1340 | * fix confusing memory reports from free(1) and another | |
1341 | * side-effects, like CommitLimit going negative. | |
1342 | */ | |
1343 | if (h->order > (MAX_ORDER - 1)) | |
3dcc0571 | 1344 | adjust_managed_page_count(page, 1 << h->order); |
aa888a74 AK |
1345 | } |
1346 | } | |
1347 | ||
8faa8b07 | 1348 | static void __init hugetlb_hstate_alloc_pages(struct hstate *h) |
1da177e4 LT |
1349 | { |
1350 | unsigned long i; | |
a5516438 | 1351 | |
e5ff2159 | 1352 | for (i = 0; i < h->max_huge_pages; ++i) { |
aa888a74 AK |
1353 | if (h->order >= MAX_ORDER) { |
1354 | if (!alloc_bootmem_huge_page(h)) | |
1355 | break; | |
9b5e5d0f | 1356 | } else if (!alloc_fresh_huge_page(h, |
8cebfcd0 | 1357 | &node_states[N_MEMORY])) |
1da177e4 | 1358 | break; |
1da177e4 | 1359 | } |
8faa8b07 | 1360 | h->max_huge_pages = i; |
e5ff2159 AK |
1361 | } |
1362 | ||
1363 | static void __init hugetlb_init_hstates(void) | |
1364 | { | |
1365 | struct hstate *h; | |
1366 | ||
1367 | for_each_hstate(h) { | |
8faa8b07 AK |
1368 | /* oversize hugepages were init'ed in early boot */ |
1369 | if (h->order < MAX_ORDER) | |
1370 | hugetlb_hstate_alloc_pages(h); | |
e5ff2159 AK |
1371 | } |
1372 | } | |
1373 | ||
4abd32db AK |
1374 | static char * __init memfmt(char *buf, unsigned long n) |
1375 | { | |
1376 | if (n >= (1UL << 30)) | |
1377 | sprintf(buf, "%lu GB", n >> 30); | |
1378 | else if (n >= (1UL << 20)) | |
1379 | sprintf(buf, "%lu MB", n >> 20); | |
1380 | else | |
1381 | sprintf(buf, "%lu KB", n >> 10); | |
1382 | return buf; | |
1383 | } | |
1384 | ||
e5ff2159 AK |
1385 | static void __init report_hugepages(void) |
1386 | { | |
1387 | struct hstate *h; | |
1388 | ||
1389 | for_each_hstate(h) { | |
4abd32db | 1390 | char buf[32]; |
ffb22af5 | 1391 | pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n", |
4abd32db AK |
1392 | memfmt(buf, huge_page_size(h)), |
1393 | h->free_huge_pages); | |
e5ff2159 AK |
1394 | } |
1395 | } | |
1396 | ||
1da177e4 | 1397 | #ifdef CONFIG_HIGHMEM |
6ae11b27 LS |
1398 | static void try_to_free_low(struct hstate *h, unsigned long count, |
1399 | nodemask_t *nodes_allowed) | |
1da177e4 | 1400 | { |
4415cc8d CL |
1401 | int i; |
1402 | ||
aa888a74 AK |
1403 | if (h->order >= MAX_ORDER) |
1404 | return; | |
1405 | ||
6ae11b27 | 1406 | for_each_node_mask(i, *nodes_allowed) { |
1da177e4 | 1407 | struct page *page, *next; |
a5516438 AK |
1408 | struct list_head *freel = &h->hugepage_freelists[i]; |
1409 | list_for_each_entry_safe(page, next, freel, lru) { | |
1410 | if (count >= h->nr_huge_pages) | |
6b0c880d | 1411 | return; |
1da177e4 LT |
1412 | if (PageHighMem(page)) |
1413 | continue; | |
1414 | list_del(&page->lru); | |
e5ff2159 | 1415 | update_and_free_page(h, page); |
a5516438 AK |
1416 | h->free_huge_pages--; |
1417 | h->free_huge_pages_node[page_to_nid(page)]--; | |
1da177e4 LT |
1418 | } |
1419 | } | |
1420 | } | |
1421 | #else | |
6ae11b27 LS |
1422 | static inline void try_to_free_low(struct hstate *h, unsigned long count, |
1423 | nodemask_t *nodes_allowed) | |
1da177e4 LT |
1424 | { |
1425 | } | |
1426 | #endif | |
1427 | ||
20a0307c WF |
1428 | /* |
1429 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
1430 | * balanced by operating on them in a round-robin fashion. | |
1431 | * Returns 1 if an adjustment was made. | |
1432 | */ | |
6ae11b27 LS |
1433 | static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, |
1434 | int delta) | |
20a0307c | 1435 | { |
b2261026 | 1436 | int nr_nodes, node; |
20a0307c WF |
1437 | |
1438 | VM_BUG_ON(delta != -1 && delta != 1); | |
20a0307c | 1439 | |
b2261026 JK |
1440 | if (delta < 0) { |
1441 | for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { | |
1442 | if (h->surplus_huge_pages_node[node]) | |
1443 | goto found; | |
e8c5c824 | 1444 | } |
b2261026 JK |
1445 | } else { |
1446 | for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { | |
1447 | if (h->surplus_huge_pages_node[node] < | |
1448 | h->nr_huge_pages_node[node]) | |
1449 | goto found; | |
e8c5c824 | 1450 | } |
b2261026 JK |
1451 | } |
1452 | return 0; | |
20a0307c | 1453 | |
b2261026 JK |
1454 | found: |
1455 | h->surplus_huge_pages += delta; | |
1456 | h->surplus_huge_pages_node[node] += delta; | |
1457 | return 1; | |
20a0307c WF |
1458 | } |
1459 | ||
a5516438 | 1460 | #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) |
6ae11b27 LS |
1461 | static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count, |
1462 | nodemask_t *nodes_allowed) | |
1da177e4 | 1463 | { |
7893d1d5 | 1464 | unsigned long min_count, ret; |
1da177e4 | 1465 | |
aa888a74 AK |
1466 | if (h->order >= MAX_ORDER) |
1467 | return h->max_huge_pages; | |
1468 | ||
7893d1d5 AL |
1469 | /* |
1470 | * Increase the pool size | |
1471 | * First take pages out of surplus state. Then make up the | |
1472 | * remaining difference by allocating fresh huge pages. | |
d1c3fb1f NA |
1473 | * |
1474 | * We might race with alloc_buddy_huge_page() here and be unable | |
1475 | * to convert a surplus huge page to a normal huge page. That is | |
1476 | * not critical, though, it just means the overall size of the | |
1477 | * pool might be one hugepage larger than it needs to be, but | |
1478 | * within all the constraints specified by the sysctls. | |
7893d1d5 | 1479 | */ |
1da177e4 | 1480 | spin_lock(&hugetlb_lock); |
a5516438 | 1481 | while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { |
6ae11b27 | 1482 | if (!adjust_pool_surplus(h, nodes_allowed, -1)) |
7893d1d5 AL |
1483 | break; |
1484 | } | |
1485 | ||
a5516438 | 1486 | while (count > persistent_huge_pages(h)) { |
7893d1d5 AL |
1487 | /* |
1488 | * If this allocation races such that we no longer need the | |
1489 | * page, free_huge_page will handle it by freeing the page | |
1490 | * and reducing the surplus. | |
1491 | */ | |
1492 | spin_unlock(&hugetlb_lock); | |
6ae11b27 | 1493 | ret = alloc_fresh_huge_page(h, nodes_allowed); |
7893d1d5 AL |
1494 | spin_lock(&hugetlb_lock); |
1495 | if (!ret) | |
1496 | goto out; | |
1497 | ||
536240f2 MG |
1498 | /* Bail for signals. Probably ctrl-c from user */ |
1499 | if (signal_pending(current)) | |
1500 | goto out; | |
7893d1d5 | 1501 | } |
7893d1d5 AL |
1502 | |
1503 | /* | |
1504 | * Decrease the pool size | |
1505 | * First return free pages to the buddy allocator (being careful | |
1506 | * to keep enough around to satisfy reservations). Then place | |
1507 | * pages into surplus state as needed so the pool will shrink | |
1508 | * to the desired size as pages become free. | |
d1c3fb1f NA |
1509 | * |
1510 | * By placing pages into the surplus state independent of the | |
1511 | * overcommit value, we are allowing the surplus pool size to | |
1512 | * exceed overcommit. There are few sane options here. Since | |
1513 | * alloc_buddy_huge_page() is checking the global counter, | |
1514 | * though, we'll note that we're not allowed to exceed surplus | |
1515 | * and won't grow the pool anywhere else. Not until one of the | |
1516 | * sysctls are changed, or the surplus pages go out of use. | |
7893d1d5 | 1517 | */ |
a5516438 | 1518 | min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; |
6b0c880d | 1519 | min_count = max(count, min_count); |
6ae11b27 | 1520 | try_to_free_low(h, min_count, nodes_allowed); |
a5516438 | 1521 | while (min_count < persistent_huge_pages(h)) { |
6ae11b27 | 1522 | if (!free_pool_huge_page(h, nodes_allowed, 0)) |
1da177e4 | 1523 | break; |
1da177e4 | 1524 | } |
a5516438 | 1525 | while (count < persistent_huge_pages(h)) { |
6ae11b27 | 1526 | if (!adjust_pool_surplus(h, nodes_allowed, 1)) |
7893d1d5 AL |
1527 | break; |
1528 | } | |
1529 | out: | |
a5516438 | 1530 | ret = persistent_huge_pages(h); |
1da177e4 | 1531 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 1532 | return ret; |
1da177e4 LT |
1533 | } |
1534 | ||
a3437870 NA |
1535 | #define HSTATE_ATTR_RO(_name) \ |
1536 | static struct kobj_attribute _name##_attr = __ATTR_RO(_name) | |
1537 | ||
1538 | #define HSTATE_ATTR(_name) \ | |
1539 | static struct kobj_attribute _name##_attr = \ | |
1540 | __ATTR(_name, 0644, _name##_show, _name##_store) | |
1541 | ||
1542 | static struct kobject *hugepages_kobj; | |
1543 | static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
1544 | ||
9a305230 LS |
1545 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); |
1546 | ||
1547 | static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) | |
a3437870 NA |
1548 | { |
1549 | int i; | |
9a305230 | 1550 | |
a3437870 | 1551 | for (i = 0; i < HUGE_MAX_HSTATE; i++) |
9a305230 LS |
1552 | if (hstate_kobjs[i] == kobj) { |
1553 | if (nidp) | |
1554 | *nidp = NUMA_NO_NODE; | |
a3437870 | 1555 | return &hstates[i]; |
9a305230 LS |
1556 | } |
1557 | ||
1558 | return kobj_to_node_hstate(kobj, nidp); | |
a3437870 NA |
1559 | } |
1560 | ||
06808b08 | 1561 | static ssize_t nr_hugepages_show_common(struct kobject *kobj, |
a3437870 NA |
1562 | struct kobj_attribute *attr, char *buf) |
1563 | { | |
9a305230 LS |
1564 | struct hstate *h; |
1565 | unsigned long nr_huge_pages; | |
1566 | int nid; | |
1567 | ||
1568 | h = kobj_to_hstate(kobj, &nid); | |
1569 | if (nid == NUMA_NO_NODE) | |
1570 | nr_huge_pages = h->nr_huge_pages; | |
1571 | else | |
1572 | nr_huge_pages = h->nr_huge_pages_node[nid]; | |
1573 | ||
1574 | return sprintf(buf, "%lu\n", nr_huge_pages); | |
a3437870 | 1575 | } |
adbe8726 | 1576 | |
06808b08 LS |
1577 | static ssize_t nr_hugepages_store_common(bool obey_mempolicy, |
1578 | struct kobject *kobj, struct kobj_attribute *attr, | |
1579 | const char *buf, size_t len) | |
a3437870 NA |
1580 | { |
1581 | int err; | |
9a305230 | 1582 | int nid; |
06808b08 | 1583 | unsigned long count; |
9a305230 | 1584 | struct hstate *h; |
bad44b5b | 1585 | NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY); |
a3437870 | 1586 | |
3dbb95f7 | 1587 | err = kstrtoul(buf, 10, &count); |
73ae31e5 | 1588 | if (err) |
adbe8726 | 1589 | goto out; |
a3437870 | 1590 | |
9a305230 | 1591 | h = kobj_to_hstate(kobj, &nid); |
adbe8726 EM |
1592 | if (h->order >= MAX_ORDER) { |
1593 | err = -EINVAL; | |
1594 | goto out; | |
1595 | } | |
1596 | ||
9a305230 LS |
1597 | if (nid == NUMA_NO_NODE) { |
1598 | /* | |
1599 | * global hstate attribute | |
1600 | */ | |
1601 | if (!(obey_mempolicy && | |
1602 | init_nodemask_of_mempolicy(nodes_allowed))) { | |
1603 | NODEMASK_FREE(nodes_allowed); | |
8cebfcd0 | 1604 | nodes_allowed = &node_states[N_MEMORY]; |
9a305230 LS |
1605 | } |
1606 | } else if (nodes_allowed) { | |
1607 | /* | |
1608 | * per node hstate attribute: adjust count to global, | |
1609 | * but restrict alloc/free to the specified node. | |
1610 | */ | |
1611 | count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; | |
1612 | init_nodemask_of_node(nodes_allowed, nid); | |
1613 | } else | |
8cebfcd0 | 1614 | nodes_allowed = &node_states[N_MEMORY]; |
9a305230 | 1615 | |
06808b08 | 1616 | h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed); |
a3437870 | 1617 | |
8cebfcd0 | 1618 | if (nodes_allowed != &node_states[N_MEMORY]) |
06808b08 LS |
1619 | NODEMASK_FREE(nodes_allowed); |
1620 | ||
1621 | return len; | |
adbe8726 EM |
1622 | out: |
1623 | NODEMASK_FREE(nodes_allowed); | |
1624 | return err; | |
06808b08 LS |
1625 | } |
1626 | ||
1627 | static ssize_t nr_hugepages_show(struct kobject *kobj, | |
1628 | struct kobj_attribute *attr, char *buf) | |
1629 | { | |
1630 | return nr_hugepages_show_common(kobj, attr, buf); | |
1631 | } | |
1632 | ||
1633 | static ssize_t nr_hugepages_store(struct kobject *kobj, | |
1634 | struct kobj_attribute *attr, const char *buf, size_t len) | |
1635 | { | |
1636 | return nr_hugepages_store_common(false, kobj, attr, buf, len); | |
a3437870 NA |
1637 | } |
1638 | HSTATE_ATTR(nr_hugepages); | |
1639 | ||
06808b08 LS |
1640 | #ifdef CONFIG_NUMA |
1641 | ||
1642 | /* | |
1643 | * hstate attribute for optionally mempolicy-based constraint on persistent | |
1644 | * huge page alloc/free. | |
1645 | */ | |
1646 | static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, | |
1647 | struct kobj_attribute *attr, char *buf) | |
1648 | { | |
1649 | return nr_hugepages_show_common(kobj, attr, buf); | |
1650 | } | |
1651 | ||
1652 | static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, | |
1653 | struct kobj_attribute *attr, const char *buf, size_t len) | |
1654 | { | |
1655 | return nr_hugepages_store_common(true, kobj, attr, buf, len); | |
1656 | } | |
1657 | HSTATE_ATTR(nr_hugepages_mempolicy); | |
1658 | #endif | |
1659 | ||
1660 | ||
a3437870 NA |
1661 | static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, |
1662 | struct kobj_attribute *attr, char *buf) | |
1663 | { | |
9a305230 | 1664 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 NA |
1665 | return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); |
1666 | } | |
adbe8726 | 1667 | |
a3437870 NA |
1668 | static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, |
1669 | struct kobj_attribute *attr, const char *buf, size_t count) | |
1670 | { | |
1671 | int err; | |
1672 | unsigned long input; | |
9a305230 | 1673 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 | 1674 | |
adbe8726 EM |
1675 | if (h->order >= MAX_ORDER) |
1676 | return -EINVAL; | |
1677 | ||
3dbb95f7 | 1678 | err = kstrtoul(buf, 10, &input); |
a3437870 | 1679 | if (err) |
73ae31e5 | 1680 | return err; |
a3437870 NA |
1681 | |
1682 | spin_lock(&hugetlb_lock); | |
1683 | h->nr_overcommit_huge_pages = input; | |
1684 | spin_unlock(&hugetlb_lock); | |
1685 | ||
1686 | return count; | |
1687 | } | |
1688 | HSTATE_ATTR(nr_overcommit_hugepages); | |
1689 | ||
1690 | static ssize_t free_hugepages_show(struct kobject *kobj, | |
1691 | struct kobj_attribute *attr, char *buf) | |
1692 | { | |
9a305230 LS |
1693 | struct hstate *h; |
1694 | unsigned long free_huge_pages; | |
1695 | int nid; | |
1696 | ||
1697 | h = kobj_to_hstate(kobj, &nid); | |
1698 | if (nid == NUMA_NO_NODE) | |
1699 | free_huge_pages = h->free_huge_pages; | |
1700 | else | |
1701 | free_huge_pages = h->free_huge_pages_node[nid]; | |
1702 | ||
1703 | return sprintf(buf, "%lu\n", free_huge_pages); | |
a3437870 NA |
1704 | } |
1705 | HSTATE_ATTR_RO(free_hugepages); | |
1706 | ||
1707 | static ssize_t resv_hugepages_show(struct kobject *kobj, | |
1708 | struct kobj_attribute *attr, char *buf) | |
1709 | { | |
9a305230 | 1710 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 NA |
1711 | return sprintf(buf, "%lu\n", h->resv_huge_pages); |
1712 | } | |
1713 | HSTATE_ATTR_RO(resv_hugepages); | |
1714 | ||
1715 | static ssize_t surplus_hugepages_show(struct kobject *kobj, | |
1716 | struct kobj_attribute *attr, char *buf) | |
1717 | { | |
9a305230 LS |
1718 | struct hstate *h; |
1719 | unsigned long surplus_huge_pages; | |
1720 | int nid; | |
1721 | ||
1722 | h = kobj_to_hstate(kobj, &nid); | |
1723 | if (nid == NUMA_NO_NODE) | |
1724 | surplus_huge_pages = h->surplus_huge_pages; | |
1725 | else | |
1726 | surplus_huge_pages = h->surplus_huge_pages_node[nid]; | |
1727 | ||
1728 | return sprintf(buf, "%lu\n", surplus_huge_pages); | |
a3437870 NA |
1729 | } |
1730 | HSTATE_ATTR_RO(surplus_hugepages); | |
1731 | ||
1732 | static struct attribute *hstate_attrs[] = { | |
1733 | &nr_hugepages_attr.attr, | |
1734 | &nr_overcommit_hugepages_attr.attr, | |
1735 | &free_hugepages_attr.attr, | |
1736 | &resv_hugepages_attr.attr, | |
1737 | &surplus_hugepages_attr.attr, | |
06808b08 LS |
1738 | #ifdef CONFIG_NUMA |
1739 | &nr_hugepages_mempolicy_attr.attr, | |
1740 | #endif | |
a3437870 NA |
1741 | NULL, |
1742 | }; | |
1743 | ||
1744 | static struct attribute_group hstate_attr_group = { | |
1745 | .attrs = hstate_attrs, | |
1746 | }; | |
1747 | ||
094e9539 JM |
1748 | static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, |
1749 | struct kobject **hstate_kobjs, | |
1750 | struct attribute_group *hstate_attr_group) | |
a3437870 NA |
1751 | { |
1752 | int retval; | |
972dc4de | 1753 | int hi = hstate_index(h); |
a3437870 | 1754 | |
9a305230 LS |
1755 | hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); |
1756 | if (!hstate_kobjs[hi]) | |
a3437870 NA |
1757 | return -ENOMEM; |
1758 | ||
9a305230 | 1759 | retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); |
a3437870 | 1760 | if (retval) |
9a305230 | 1761 | kobject_put(hstate_kobjs[hi]); |
a3437870 NA |
1762 | |
1763 | return retval; | |
1764 | } | |
1765 | ||
1766 | static void __init hugetlb_sysfs_init(void) | |
1767 | { | |
1768 | struct hstate *h; | |
1769 | int err; | |
1770 | ||
1771 | hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); | |
1772 | if (!hugepages_kobj) | |
1773 | return; | |
1774 | ||
1775 | for_each_hstate(h) { | |
9a305230 LS |
1776 | err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, |
1777 | hstate_kobjs, &hstate_attr_group); | |
a3437870 | 1778 | if (err) |
ffb22af5 | 1779 | pr_err("Hugetlb: Unable to add hstate %s", h->name); |
a3437870 NA |
1780 | } |
1781 | } | |
1782 | ||
9a305230 LS |
1783 | #ifdef CONFIG_NUMA |
1784 | ||
1785 | /* | |
1786 | * node_hstate/s - associate per node hstate attributes, via their kobjects, | |
10fbcf4c KS |
1787 | * with node devices in node_devices[] using a parallel array. The array |
1788 | * index of a node device or _hstate == node id. | |
1789 | * This is here to avoid any static dependency of the node device driver, in | |
9a305230 LS |
1790 | * the base kernel, on the hugetlb module. |
1791 | */ | |
1792 | struct node_hstate { | |
1793 | struct kobject *hugepages_kobj; | |
1794 | struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
1795 | }; | |
1796 | struct node_hstate node_hstates[MAX_NUMNODES]; | |
1797 | ||
1798 | /* | |
10fbcf4c | 1799 | * A subset of global hstate attributes for node devices |
9a305230 LS |
1800 | */ |
1801 | static struct attribute *per_node_hstate_attrs[] = { | |
1802 | &nr_hugepages_attr.attr, | |
1803 | &free_hugepages_attr.attr, | |
1804 | &surplus_hugepages_attr.attr, | |
1805 | NULL, | |
1806 | }; | |
1807 | ||
1808 | static struct attribute_group per_node_hstate_attr_group = { | |
1809 | .attrs = per_node_hstate_attrs, | |
1810 | }; | |
1811 | ||
1812 | /* | |
10fbcf4c | 1813 | * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. |
9a305230 LS |
1814 | * Returns node id via non-NULL nidp. |
1815 | */ | |
1816 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) | |
1817 | { | |
1818 | int nid; | |
1819 | ||
1820 | for (nid = 0; nid < nr_node_ids; nid++) { | |
1821 | struct node_hstate *nhs = &node_hstates[nid]; | |
1822 | int i; | |
1823 | for (i = 0; i < HUGE_MAX_HSTATE; i++) | |
1824 | if (nhs->hstate_kobjs[i] == kobj) { | |
1825 | if (nidp) | |
1826 | *nidp = nid; | |
1827 | return &hstates[i]; | |
1828 | } | |
1829 | } | |
1830 | ||
1831 | BUG(); | |
1832 | return NULL; | |
1833 | } | |
1834 | ||
1835 | /* | |
10fbcf4c | 1836 | * Unregister hstate attributes from a single node device. |
9a305230 LS |
1837 | * No-op if no hstate attributes attached. |
1838 | */ | |
3cd8b44f | 1839 | static void hugetlb_unregister_node(struct node *node) |
9a305230 LS |
1840 | { |
1841 | struct hstate *h; | |
10fbcf4c | 1842 | struct node_hstate *nhs = &node_hstates[node->dev.id]; |
9a305230 LS |
1843 | |
1844 | if (!nhs->hugepages_kobj) | |
9b5e5d0f | 1845 | return; /* no hstate attributes */ |
9a305230 | 1846 | |
972dc4de AK |
1847 | for_each_hstate(h) { |
1848 | int idx = hstate_index(h); | |
1849 | if (nhs->hstate_kobjs[idx]) { | |
1850 | kobject_put(nhs->hstate_kobjs[idx]); | |
1851 | nhs->hstate_kobjs[idx] = NULL; | |
9a305230 | 1852 | } |
972dc4de | 1853 | } |
9a305230 LS |
1854 | |
1855 | kobject_put(nhs->hugepages_kobj); | |
1856 | nhs->hugepages_kobj = NULL; | |
1857 | } | |
1858 | ||
1859 | /* | |
10fbcf4c | 1860 | * hugetlb module exit: unregister hstate attributes from node devices |
9a305230 LS |
1861 | * that have them. |
1862 | */ | |
1863 | static void hugetlb_unregister_all_nodes(void) | |
1864 | { | |
1865 | int nid; | |
1866 | ||
1867 | /* | |
10fbcf4c | 1868 | * disable node device registrations. |
9a305230 LS |
1869 | */ |
1870 | register_hugetlbfs_with_node(NULL, NULL); | |
1871 | ||
1872 | /* | |
1873 | * remove hstate attributes from any nodes that have them. | |
1874 | */ | |
1875 | for (nid = 0; nid < nr_node_ids; nid++) | |
8732794b | 1876 | hugetlb_unregister_node(node_devices[nid]); |
9a305230 LS |
1877 | } |
1878 | ||
1879 | /* | |
10fbcf4c | 1880 | * Register hstate attributes for a single node device. |
9a305230 LS |
1881 | * No-op if attributes already registered. |
1882 | */ | |
3cd8b44f | 1883 | static void hugetlb_register_node(struct node *node) |
9a305230 LS |
1884 | { |
1885 | struct hstate *h; | |
10fbcf4c | 1886 | struct node_hstate *nhs = &node_hstates[node->dev.id]; |
9a305230 LS |
1887 | int err; |
1888 | ||
1889 | if (nhs->hugepages_kobj) | |
1890 | return; /* already allocated */ | |
1891 | ||
1892 | nhs->hugepages_kobj = kobject_create_and_add("hugepages", | |
10fbcf4c | 1893 | &node->dev.kobj); |
9a305230 LS |
1894 | if (!nhs->hugepages_kobj) |
1895 | return; | |
1896 | ||
1897 | for_each_hstate(h) { | |
1898 | err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, | |
1899 | nhs->hstate_kobjs, | |
1900 | &per_node_hstate_attr_group); | |
1901 | if (err) { | |
ffb22af5 AM |
1902 | pr_err("Hugetlb: Unable to add hstate %s for node %d\n", |
1903 | h->name, node->dev.id); | |
9a305230 LS |
1904 | hugetlb_unregister_node(node); |
1905 | break; | |
1906 | } | |
1907 | } | |
1908 | } | |
1909 | ||
1910 | /* | |
9b5e5d0f | 1911 | * hugetlb init time: register hstate attributes for all registered node |
10fbcf4c KS |
1912 | * devices of nodes that have memory. All on-line nodes should have |
1913 | * registered their associated device by this time. | |
9a305230 LS |
1914 | */ |
1915 | static void hugetlb_register_all_nodes(void) | |
1916 | { | |
1917 | int nid; | |
1918 | ||
8cebfcd0 | 1919 | for_each_node_state(nid, N_MEMORY) { |
8732794b | 1920 | struct node *node = node_devices[nid]; |
10fbcf4c | 1921 | if (node->dev.id == nid) |
9a305230 LS |
1922 | hugetlb_register_node(node); |
1923 | } | |
1924 | ||
1925 | /* | |
10fbcf4c | 1926 | * Let the node device driver know we're here so it can |
9a305230 LS |
1927 | * [un]register hstate attributes on node hotplug. |
1928 | */ | |
1929 | register_hugetlbfs_with_node(hugetlb_register_node, | |
1930 | hugetlb_unregister_node); | |
1931 | } | |
1932 | #else /* !CONFIG_NUMA */ | |
1933 | ||
1934 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) | |
1935 | { | |
1936 | BUG(); | |
1937 | if (nidp) | |
1938 | *nidp = -1; | |
1939 | return NULL; | |
1940 | } | |
1941 | ||
1942 | static void hugetlb_unregister_all_nodes(void) { } | |
1943 | ||
1944 | static void hugetlb_register_all_nodes(void) { } | |
1945 | ||
1946 | #endif | |
1947 | ||
a3437870 NA |
1948 | static void __exit hugetlb_exit(void) |
1949 | { | |
1950 | struct hstate *h; | |
1951 | ||
9a305230 LS |
1952 | hugetlb_unregister_all_nodes(); |
1953 | ||
a3437870 | 1954 | for_each_hstate(h) { |
972dc4de | 1955 | kobject_put(hstate_kobjs[hstate_index(h)]); |
a3437870 NA |
1956 | } |
1957 | ||
1958 | kobject_put(hugepages_kobj); | |
1959 | } | |
1960 | module_exit(hugetlb_exit); | |
1961 | ||
1962 | static int __init hugetlb_init(void) | |
1963 | { | |
0ef89d25 BH |
1964 | /* Some platform decide whether they support huge pages at boot |
1965 | * time. On these, such as powerpc, HPAGE_SHIFT is set to 0 when | |
1966 | * there is no such support | |
1967 | */ | |
1968 | if (HPAGE_SHIFT == 0) | |
1969 | return 0; | |
a3437870 | 1970 | |
e11bfbfc NP |
1971 | if (!size_to_hstate(default_hstate_size)) { |
1972 | default_hstate_size = HPAGE_SIZE; | |
1973 | if (!size_to_hstate(default_hstate_size)) | |
1974 | hugetlb_add_hstate(HUGETLB_PAGE_ORDER); | |
a3437870 | 1975 | } |
972dc4de | 1976 | default_hstate_idx = hstate_index(size_to_hstate(default_hstate_size)); |
e11bfbfc NP |
1977 | if (default_hstate_max_huge_pages) |
1978 | default_hstate.max_huge_pages = default_hstate_max_huge_pages; | |
a3437870 NA |
1979 | |
1980 | hugetlb_init_hstates(); | |
aa888a74 | 1981 | gather_bootmem_prealloc(); |
a3437870 NA |
1982 | report_hugepages(); |
1983 | ||
1984 | hugetlb_sysfs_init(); | |
9a305230 | 1985 | hugetlb_register_all_nodes(); |
7179e7bf | 1986 | hugetlb_cgroup_file_init(); |
9a305230 | 1987 | |
a3437870 NA |
1988 | return 0; |
1989 | } | |
1990 | module_init(hugetlb_init); | |
1991 | ||
1992 | /* Should be called on processing a hugepagesz=... option */ | |
1993 | void __init hugetlb_add_hstate(unsigned order) | |
1994 | { | |
1995 | struct hstate *h; | |
8faa8b07 AK |
1996 | unsigned long i; |
1997 | ||
a3437870 | 1998 | if (size_to_hstate(PAGE_SIZE << order)) { |
ffb22af5 | 1999 | pr_warning("hugepagesz= specified twice, ignoring\n"); |
a3437870 NA |
2000 | return; |
2001 | } | |
47d38344 | 2002 | BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); |
a3437870 | 2003 | BUG_ON(order == 0); |
47d38344 | 2004 | h = &hstates[hugetlb_max_hstate++]; |
a3437870 NA |
2005 | h->order = order; |
2006 | h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); | |
8faa8b07 AK |
2007 | h->nr_huge_pages = 0; |
2008 | h->free_huge_pages = 0; | |
2009 | for (i = 0; i < MAX_NUMNODES; ++i) | |
2010 | INIT_LIST_HEAD(&h->hugepage_freelists[i]); | |
0edaecfa | 2011 | INIT_LIST_HEAD(&h->hugepage_activelist); |
8cebfcd0 LJ |
2012 | h->next_nid_to_alloc = first_node(node_states[N_MEMORY]); |
2013 | h->next_nid_to_free = first_node(node_states[N_MEMORY]); | |
a3437870 NA |
2014 | snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", |
2015 | huge_page_size(h)/1024); | |
8faa8b07 | 2016 | |
a3437870 NA |
2017 | parsed_hstate = h; |
2018 | } | |
2019 | ||
e11bfbfc | 2020 | static int __init hugetlb_nrpages_setup(char *s) |
a3437870 NA |
2021 | { |
2022 | unsigned long *mhp; | |
8faa8b07 | 2023 | static unsigned long *last_mhp; |
a3437870 NA |
2024 | |
2025 | /* | |
47d38344 | 2026 | * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter yet, |
a3437870 NA |
2027 | * so this hugepages= parameter goes to the "default hstate". |
2028 | */ | |
47d38344 | 2029 | if (!hugetlb_max_hstate) |
a3437870 NA |
2030 | mhp = &default_hstate_max_huge_pages; |
2031 | else | |
2032 | mhp = &parsed_hstate->max_huge_pages; | |
2033 | ||
8faa8b07 | 2034 | if (mhp == last_mhp) { |
ffb22af5 AM |
2035 | pr_warning("hugepages= specified twice without " |
2036 | "interleaving hugepagesz=, ignoring\n"); | |
8faa8b07 AK |
2037 | return 1; |
2038 | } | |
2039 | ||
a3437870 NA |
2040 | if (sscanf(s, "%lu", mhp) <= 0) |
2041 | *mhp = 0; | |
2042 | ||
8faa8b07 AK |
2043 | /* |
2044 | * Global state is always initialized later in hugetlb_init. | |
2045 | * But we need to allocate >= MAX_ORDER hstates here early to still | |
2046 | * use the bootmem allocator. | |
2047 | */ | |
47d38344 | 2048 | if (hugetlb_max_hstate && parsed_hstate->order >= MAX_ORDER) |
8faa8b07 AK |
2049 | hugetlb_hstate_alloc_pages(parsed_hstate); |
2050 | ||
2051 | last_mhp = mhp; | |
2052 | ||
a3437870 NA |
2053 | return 1; |
2054 | } | |
e11bfbfc NP |
2055 | __setup("hugepages=", hugetlb_nrpages_setup); |
2056 | ||
2057 | static int __init hugetlb_default_setup(char *s) | |
2058 | { | |
2059 | default_hstate_size = memparse(s, &s); | |
2060 | return 1; | |
2061 | } | |
2062 | __setup("default_hugepagesz=", hugetlb_default_setup); | |
a3437870 | 2063 | |
8a213460 NA |
2064 | static unsigned int cpuset_mems_nr(unsigned int *array) |
2065 | { | |
2066 | int node; | |
2067 | unsigned int nr = 0; | |
2068 | ||
2069 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
2070 | nr += array[node]; | |
2071 | ||
2072 | return nr; | |
2073 | } | |
2074 | ||
2075 | #ifdef CONFIG_SYSCTL | |
06808b08 LS |
2076 | static int hugetlb_sysctl_handler_common(bool obey_mempolicy, |
2077 | struct ctl_table *table, int write, | |
2078 | void __user *buffer, size_t *length, loff_t *ppos) | |
1da177e4 | 2079 | { |
e5ff2159 AK |
2080 | struct hstate *h = &default_hstate; |
2081 | unsigned long tmp; | |
08d4a246 | 2082 | int ret; |
e5ff2159 | 2083 | |
c033a93c | 2084 | tmp = h->max_huge_pages; |
e5ff2159 | 2085 | |
adbe8726 EM |
2086 | if (write && h->order >= MAX_ORDER) |
2087 | return -EINVAL; | |
2088 | ||
e5ff2159 AK |
2089 | table->data = &tmp; |
2090 | table->maxlen = sizeof(unsigned long); | |
08d4a246 MH |
2091 | ret = proc_doulongvec_minmax(table, write, buffer, length, ppos); |
2092 | if (ret) | |
2093 | goto out; | |
e5ff2159 | 2094 | |
06808b08 | 2095 | if (write) { |
bad44b5b DR |
2096 | NODEMASK_ALLOC(nodemask_t, nodes_allowed, |
2097 | GFP_KERNEL | __GFP_NORETRY); | |
06808b08 LS |
2098 | if (!(obey_mempolicy && |
2099 | init_nodemask_of_mempolicy(nodes_allowed))) { | |
2100 | NODEMASK_FREE(nodes_allowed); | |
8cebfcd0 | 2101 | nodes_allowed = &node_states[N_MEMORY]; |
06808b08 LS |
2102 | } |
2103 | h->max_huge_pages = set_max_huge_pages(h, tmp, nodes_allowed); | |
2104 | ||
8cebfcd0 | 2105 | if (nodes_allowed != &node_states[N_MEMORY]) |
06808b08 LS |
2106 | NODEMASK_FREE(nodes_allowed); |
2107 | } | |
08d4a246 MH |
2108 | out: |
2109 | return ret; | |
1da177e4 | 2110 | } |
396faf03 | 2111 | |
06808b08 LS |
2112 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
2113 | void __user *buffer, size_t *length, loff_t *ppos) | |
2114 | { | |
2115 | ||
2116 | return hugetlb_sysctl_handler_common(false, table, write, | |
2117 | buffer, length, ppos); | |
2118 | } | |
2119 | ||
2120 | #ifdef CONFIG_NUMA | |
2121 | int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, | |
2122 | void __user *buffer, size_t *length, loff_t *ppos) | |
2123 | { | |
2124 | return hugetlb_sysctl_handler_common(true, table, write, | |
2125 | buffer, length, ppos); | |
2126 | } | |
2127 | #endif /* CONFIG_NUMA */ | |
2128 | ||
a3d0c6aa | 2129 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
8d65af78 | 2130 | void __user *buffer, |
a3d0c6aa NA |
2131 | size_t *length, loff_t *ppos) |
2132 | { | |
a5516438 | 2133 | struct hstate *h = &default_hstate; |
e5ff2159 | 2134 | unsigned long tmp; |
08d4a246 | 2135 | int ret; |
e5ff2159 | 2136 | |
c033a93c | 2137 | tmp = h->nr_overcommit_huge_pages; |
e5ff2159 | 2138 | |
adbe8726 EM |
2139 | if (write && h->order >= MAX_ORDER) |
2140 | return -EINVAL; | |
2141 | ||
e5ff2159 AK |
2142 | table->data = &tmp; |
2143 | table->maxlen = sizeof(unsigned long); | |
08d4a246 MH |
2144 | ret = proc_doulongvec_minmax(table, write, buffer, length, ppos); |
2145 | if (ret) | |
2146 | goto out; | |
e5ff2159 AK |
2147 | |
2148 | if (write) { | |
2149 | spin_lock(&hugetlb_lock); | |
2150 | h->nr_overcommit_huge_pages = tmp; | |
2151 | spin_unlock(&hugetlb_lock); | |
2152 | } | |
08d4a246 MH |
2153 | out: |
2154 | return ret; | |
a3d0c6aa NA |
2155 | } |
2156 | ||
1da177e4 LT |
2157 | #endif /* CONFIG_SYSCTL */ |
2158 | ||
e1759c21 | 2159 | void hugetlb_report_meminfo(struct seq_file *m) |
1da177e4 | 2160 | { |
a5516438 | 2161 | struct hstate *h = &default_hstate; |
e1759c21 | 2162 | seq_printf(m, |
4f98a2fe RR |
2163 | "HugePages_Total: %5lu\n" |
2164 | "HugePages_Free: %5lu\n" | |
2165 | "HugePages_Rsvd: %5lu\n" | |
2166 | "HugePages_Surp: %5lu\n" | |
2167 | "Hugepagesize: %8lu kB\n", | |
a5516438 AK |
2168 | h->nr_huge_pages, |
2169 | h->free_huge_pages, | |
2170 | h->resv_huge_pages, | |
2171 | h->surplus_huge_pages, | |
2172 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); | |
1da177e4 LT |
2173 | } |
2174 | ||
2175 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
2176 | { | |
a5516438 | 2177 | struct hstate *h = &default_hstate; |
1da177e4 LT |
2178 | return sprintf(buf, |
2179 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
2180 | "Node %d HugePages_Free: %5u\n" |
2181 | "Node %d HugePages_Surp: %5u\n", | |
a5516438 AK |
2182 | nid, h->nr_huge_pages_node[nid], |
2183 | nid, h->free_huge_pages_node[nid], | |
2184 | nid, h->surplus_huge_pages_node[nid]); | |
1da177e4 LT |
2185 | } |
2186 | ||
949f7ec5 DR |
2187 | void hugetlb_show_meminfo(void) |
2188 | { | |
2189 | struct hstate *h; | |
2190 | int nid; | |
2191 | ||
2192 | for_each_node_state(nid, N_MEMORY) | |
2193 | for_each_hstate(h) | |
2194 | pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", | |
2195 | nid, | |
2196 | h->nr_huge_pages_node[nid], | |
2197 | h->free_huge_pages_node[nid], | |
2198 | h->surplus_huge_pages_node[nid], | |
2199 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); | |
2200 | } | |
2201 | ||
1da177e4 LT |
2202 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
2203 | unsigned long hugetlb_total_pages(void) | |
2204 | { | |
d0028588 WL |
2205 | struct hstate *h; |
2206 | unsigned long nr_total_pages = 0; | |
2207 | ||
2208 | for_each_hstate(h) | |
2209 | nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); | |
2210 | return nr_total_pages; | |
1da177e4 | 2211 | } |
1da177e4 | 2212 | |
a5516438 | 2213 | static int hugetlb_acct_memory(struct hstate *h, long delta) |
fc1b8a73 MG |
2214 | { |
2215 | int ret = -ENOMEM; | |
2216 | ||
2217 | spin_lock(&hugetlb_lock); | |
2218 | /* | |
2219 | * When cpuset is configured, it breaks the strict hugetlb page | |
2220 | * reservation as the accounting is done on a global variable. Such | |
2221 | * reservation is completely rubbish in the presence of cpuset because | |
2222 | * the reservation is not checked against page availability for the | |
2223 | * current cpuset. Application can still potentially OOM'ed by kernel | |
2224 | * with lack of free htlb page in cpuset that the task is in. | |
2225 | * Attempt to enforce strict accounting with cpuset is almost | |
2226 | * impossible (or too ugly) because cpuset is too fluid that | |
2227 | * task or memory node can be dynamically moved between cpusets. | |
2228 | * | |
2229 | * The change of semantics for shared hugetlb mapping with cpuset is | |
2230 | * undesirable. However, in order to preserve some of the semantics, | |
2231 | * we fall back to check against current free page availability as | |
2232 | * a best attempt and hopefully to minimize the impact of changing | |
2233 | * semantics that cpuset has. | |
2234 | */ | |
2235 | if (delta > 0) { | |
a5516438 | 2236 | if (gather_surplus_pages(h, delta) < 0) |
fc1b8a73 MG |
2237 | goto out; |
2238 | ||
a5516438 AK |
2239 | if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { |
2240 | return_unused_surplus_pages(h, delta); | |
fc1b8a73 MG |
2241 | goto out; |
2242 | } | |
2243 | } | |
2244 | ||
2245 | ret = 0; | |
2246 | if (delta < 0) | |
a5516438 | 2247 | return_unused_surplus_pages(h, (unsigned long) -delta); |
fc1b8a73 MG |
2248 | |
2249 | out: | |
2250 | spin_unlock(&hugetlb_lock); | |
2251 | return ret; | |
2252 | } | |
2253 | ||
84afd99b AW |
2254 | static void hugetlb_vm_op_open(struct vm_area_struct *vma) |
2255 | { | |
f522c3ac | 2256 | struct resv_map *resv = vma_resv_map(vma); |
84afd99b AW |
2257 | |
2258 | /* | |
2259 | * This new VMA should share its siblings reservation map if present. | |
2260 | * The VMA will only ever have a valid reservation map pointer where | |
2261 | * it is being copied for another still existing VMA. As that VMA | |
25985edc | 2262 | * has a reference to the reservation map it cannot disappear until |
84afd99b AW |
2263 | * after this open call completes. It is therefore safe to take a |
2264 | * new reference here without additional locking. | |
2265 | */ | |
f522c3ac JK |
2266 | if (resv) |
2267 | kref_get(&resv->refs); | |
84afd99b AW |
2268 | } |
2269 | ||
c50ac050 DH |
2270 | static void resv_map_put(struct vm_area_struct *vma) |
2271 | { | |
f522c3ac | 2272 | struct resv_map *resv = vma_resv_map(vma); |
c50ac050 | 2273 | |
f522c3ac | 2274 | if (!resv) |
c50ac050 | 2275 | return; |
f522c3ac | 2276 | kref_put(&resv->refs, resv_map_release); |
c50ac050 DH |
2277 | } |
2278 | ||
a1e78772 MG |
2279 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
2280 | { | |
a5516438 | 2281 | struct hstate *h = hstate_vma(vma); |
f522c3ac | 2282 | struct resv_map *resv = vma_resv_map(vma); |
90481622 | 2283 | struct hugepage_subpool *spool = subpool_vma(vma); |
84afd99b AW |
2284 | unsigned long reserve; |
2285 | unsigned long start; | |
2286 | unsigned long end; | |
2287 | ||
f522c3ac | 2288 | if (resv) { |
a5516438 AK |
2289 | start = vma_hugecache_offset(h, vma, vma->vm_start); |
2290 | end = vma_hugecache_offset(h, vma, vma->vm_end); | |
84afd99b AW |
2291 | |
2292 | reserve = (end - start) - | |
f522c3ac | 2293 | region_count(&resv->regions, start, end); |
84afd99b | 2294 | |
c50ac050 | 2295 | resv_map_put(vma); |
84afd99b | 2296 | |
7251ff78 | 2297 | if (reserve) { |
a5516438 | 2298 | hugetlb_acct_memory(h, -reserve); |
90481622 | 2299 | hugepage_subpool_put_pages(spool, reserve); |
7251ff78 | 2300 | } |
84afd99b | 2301 | } |
a1e78772 MG |
2302 | } |
2303 | ||
1da177e4 LT |
2304 | /* |
2305 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
2306 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
2307 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
2308 | * this far. | |
2309 | */ | |
d0217ac0 | 2310 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
2311 | { |
2312 | BUG(); | |
d0217ac0 | 2313 | return 0; |
1da177e4 LT |
2314 | } |
2315 | ||
f0f37e2f | 2316 | const struct vm_operations_struct hugetlb_vm_ops = { |
d0217ac0 | 2317 | .fault = hugetlb_vm_op_fault, |
84afd99b | 2318 | .open = hugetlb_vm_op_open, |
a1e78772 | 2319 | .close = hugetlb_vm_op_close, |
1da177e4 LT |
2320 | }; |
2321 | ||
1e8f889b DG |
2322 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
2323 | int writable) | |
63551ae0 DG |
2324 | { |
2325 | pte_t entry; | |
2326 | ||
1e8f889b | 2327 | if (writable) { |
106c992a GS |
2328 | entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, |
2329 | vma->vm_page_prot))); | |
63551ae0 | 2330 | } else { |
106c992a GS |
2331 | entry = huge_pte_wrprotect(mk_huge_pte(page, |
2332 | vma->vm_page_prot)); | |
63551ae0 DG |
2333 | } |
2334 | entry = pte_mkyoung(entry); | |
2335 | entry = pte_mkhuge(entry); | |
d9ed9faa | 2336 | entry = arch_make_huge_pte(entry, vma, page, writable); |
63551ae0 DG |
2337 | |
2338 | return entry; | |
2339 | } | |
2340 | ||
1e8f889b DG |
2341 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
2342 | unsigned long address, pte_t *ptep) | |
2343 | { | |
2344 | pte_t entry; | |
2345 | ||
106c992a | 2346 | entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); |
32f84528 | 2347 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) |
4b3073e1 | 2348 | update_mmu_cache(vma, address, ptep); |
1e8f889b DG |
2349 | } |
2350 | ||
2351 | ||
63551ae0 DG |
2352 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
2353 | struct vm_area_struct *vma) | |
2354 | { | |
2355 | pte_t *src_pte, *dst_pte, entry; | |
2356 | struct page *ptepage; | |
1c59827d | 2357 | unsigned long addr; |
1e8f889b | 2358 | int cow; |
a5516438 AK |
2359 | struct hstate *h = hstate_vma(vma); |
2360 | unsigned long sz = huge_page_size(h); | |
1e8f889b DG |
2361 | |
2362 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 2363 | |
a5516438 | 2364 | for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { |
c74df32c HD |
2365 | src_pte = huge_pte_offset(src, addr); |
2366 | if (!src_pte) | |
2367 | continue; | |
a5516438 | 2368 | dst_pte = huge_pte_alloc(dst, addr, sz); |
63551ae0 DG |
2369 | if (!dst_pte) |
2370 | goto nomem; | |
c5c99429 LW |
2371 | |
2372 | /* If the pagetables are shared don't copy or take references */ | |
2373 | if (dst_pte == src_pte) | |
2374 | continue; | |
2375 | ||
c74df32c | 2376 | spin_lock(&dst->page_table_lock); |
46478758 | 2377 | spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); |
7f2e9525 | 2378 | if (!huge_pte_none(huge_ptep_get(src_pte))) { |
1e8f889b | 2379 | if (cow) |
7f2e9525 GS |
2380 | huge_ptep_set_wrprotect(src, addr, src_pte); |
2381 | entry = huge_ptep_get(src_pte); | |
1c59827d HD |
2382 | ptepage = pte_page(entry); |
2383 | get_page(ptepage); | |
0fe6e20b | 2384 | page_dup_rmap(ptepage); |
1c59827d HD |
2385 | set_huge_pte_at(dst, addr, dst_pte, entry); |
2386 | } | |
2387 | spin_unlock(&src->page_table_lock); | |
c74df32c | 2388 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
2389 | } |
2390 | return 0; | |
2391 | ||
2392 | nomem: | |
2393 | return -ENOMEM; | |
2394 | } | |
2395 | ||
290408d4 NH |
2396 | static int is_hugetlb_entry_migration(pte_t pte) |
2397 | { | |
2398 | swp_entry_t swp; | |
2399 | ||
2400 | if (huge_pte_none(pte) || pte_present(pte)) | |
2401 | return 0; | |
2402 | swp = pte_to_swp_entry(pte); | |
32f84528 | 2403 | if (non_swap_entry(swp) && is_migration_entry(swp)) |
290408d4 | 2404 | return 1; |
32f84528 | 2405 | else |
290408d4 NH |
2406 | return 0; |
2407 | } | |
2408 | ||
fd6a03ed NH |
2409 | static int is_hugetlb_entry_hwpoisoned(pte_t pte) |
2410 | { | |
2411 | swp_entry_t swp; | |
2412 | ||
2413 | if (huge_pte_none(pte) || pte_present(pte)) | |
2414 | return 0; | |
2415 | swp = pte_to_swp_entry(pte); | |
32f84528 | 2416 | if (non_swap_entry(swp) && is_hwpoison_entry(swp)) |
fd6a03ed | 2417 | return 1; |
32f84528 | 2418 | else |
fd6a03ed NH |
2419 | return 0; |
2420 | } | |
2421 | ||
24669e58 AK |
2422 | void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, |
2423 | unsigned long start, unsigned long end, | |
2424 | struct page *ref_page) | |
63551ae0 | 2425 | { |
24669e58 | 2426 | int force_flush = 0; |
63551ae0 DG |
2427 | struct mm_struct *mm = vma->vm_mm; |
2428 | unsigned long address; | |
c7546f8f | 2429 | pte_t *ptep; |
63551ae0 DG |
2430 | pte_t pte; |
2431 | struct page *page; | |
a5516438 AK |
2432 | struct hstate *h = hstate_vma(vma); |
2433 | unsigned long sz = huge_page_size(h); | |
2ec74c3e SG |
2434 | const unsigned long mmun_start = start; /* For mmu_notifiers */ |
2435 | const unsigned long mmun_end = end; /* For mmu_notifiers */ | |
a5516438 | 2436 | |
63551ae0 | 2437 | WARN_ON(!is_vm_hugetlb_page(vma)); |
a5516438 AK |
2438 | BUG_ON(start & ~huge_page_mask(h)); |
2439 | BUG_ON(end & ~huge_page_mask(h)); | |
63551ae0 | 2440 | |
24669e58 | 2441 | tlb_start_vma(tlb, vma); |
2ec74c3e | 2442 | mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); |
24669e58 | 2443 | again: |
508034a3 | 2444 | spin_lock(&mm->page_table_lock); |
a5516438 | 2445 | for (address = start; address < end; address += sz) { |
c7546f8f | 2446 | ptep = huge_pte_offset(mm, address); |
4c887265 | 2447 | if (!ptep) |
c7546f8f DG |
2448 | continue; |
2449 | ||
39dde65c KC |
2450 | if (huge_pmd_unshare(mm, &address, ptep)) |
2451 | continue; | |
2452 | ||
6629326b HD |
2453 | pte = huge_ptep_get(ptep); |
2454 | if (huge_pte_none(pte)) | |
2455 | continue; | |
2456 | ||
2457 | /* | |
2458 | * HWPoisoned hugepage is already unmapped and dropped reference | |
2459 | */ | |
8c4894c6 | 2460 | if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { |
106c992a | 2461 | huge_pte_clear(mm, address, ptep); |
6629326b | 2462 | continue; |
8c4894c6 | 2463 | } |
6629326b HD |
2464 | |
2465 | page = pte_page(pte); | |
04f2cbe3 MG |
2466 | /* |
2467 | * If a reference page is supplied, it is because a specific | |
2468 | * page is being unmapped, not a range. Ensure the page we | |
2469 | * are about to unmap is the actual page of interest. | |
2470 | */ | |
2471 | if (ref_page) { | |
04f2cbe3 MG |
2472 | if (page != ref_page) |
2473 | continue; | |
2474 | ||
2475 | /* | |
2476 | * Mark the VMA as having unmapped its page so that | |
2477 | * future faults in this VMA will fail rather than | |
2478 | * looking like data was lost | |
2479 | */ | |
2480 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); | |
2481 | } | |
2482 | ||
c7546f8f | 2483 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
24669e58 | 2484 | tlb_remove_tlb_entry(tlb, ptep, address); |
106c992a | 2485 | if (huge_pte_dirty(pte)) |
6649a386 | 2486 | set_page_dirty(page); |
9e81130b | 2487 | |
24669e58 AK |
2488 | page_remove_rmap(page); |
2489 | force_flush = !__tlb_remove_page(tlb, page); | |
2490 | if (force_flush) | |
2491 | break; | |
9e81130b HD |
2492 | /* Bail out after unmapping reference page if supplied */ |
2493 | if (ref_page) | |
2494 | break; | |
63551ae0 | 2495 | } |
cd2934a3 | 2496 | spin_unlock(&mm->page_table_lock); |
24669e58 AK |
2497 | /* |
2498 | * mmu_gather ran out of room to batch pages, we break out of | |
2499 | * the PTE lock to avoid doing the potential expensive TLB invalidate | |
2500 | * and page-free while holding it. | |
2501 | */ | |
2502 | if (force_flush) { | |
2503 | force_flush = 0; | |
2504 | tlb_flush_mmu(tlb); | |
2505 | if (address < end && !ref_page) | |
2506 | goto again; | |
fe1668ae | 2507 | } |
2ec74c3e | 2508 | mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); |
24669e58 | 2509 | tlb_end_vma(tlb, vma); |
1da177e4 | 2510 | } |
63551ae0 | 2511 | |
d833352a MG |
2512 | void __unmap_hugepage_range_final(struct mmu_gather *tlb, |
2513 | struct vm_area_struct *vma, unsigned long start, | |
2514 | unsigned long end, struct page *ref_page) | |
2515 | { | |
2516 | __unmap_hugepage_range(tlb, vma, start, end, ref_page); | |
2517 | ||
2518 | /* | |
2519 | * Clear this flag so that x86's huge_pmd_share page_table_shareable | |
2520 | * test will fail on a vma being torn down, and not grab a page table | |
2521 | * on its way out. We're lucky that the flag has such an appropriate | |
2522 | * name, and can in fact be safely cleared here. We could clear it | |
2523 | * before the __unmap_hugepage_range above, but all that's necessary | |
2524 | * is to clear it before releasing the i_mmap_mutex. This works | |
2525 | * because in the context this is called, the VMA is about to be | |
2526 | * destroyed and the i_mmap_mutex is held. | |
2527 | */ | |
2528 | vma->vm_flags &= ~VM_MAYSHARE; | |
2529 | } | |
2530 | ||
502717f4 | 2531 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 2532 | unsigned long end, struct page *ref_page) |
502717f4 | 2533 | { |
24669e58 AK |
2534 | struct mm_struct *mm; |
2535 | struct mmu_gather tlb; | |
2536 | ||
2537 | mm = vma->vm_mm; | |
2538 | ||
2b047252 | 2539 | tlb_gather_mmu(&tlb, mm, start, end); |
24669e58 AK |
2540 | __unmap_hugepage_range(&tlb, vma, start, end, ref_page); |
2541 | tlb_finish_mmu(&tlb, start, end); | |
502717f4 KC |
2542 | } |
2543 | ||
04f2cbe3 MG |
2544 | /* |
2545 | * This is called when the original mapper is failing to COW a MAP_PRIVATE | |
2546 | * mappping it owns the reserve page for. The intention is to unmap the page | |
2547 | * from other VMAs and let the children be SIGKILLed if they are faulting the | |
2548 | * same region. | |
2549 | */ | |
2a4b3ded HH |
2550 | static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, |
2551 | struct page *page, unsigned long address) | |
04f2cbe3 | 2552 | { |
7526674d | 2553 | struct hstate *h = hstate_vma(vma); |
04f2cbe3 MG |
2554 | struct vm_area_struct *iter_vma; |
2555 | struct address_space *mapping; | |
04f2cbe3 MG |
2556 | pgoff_t pgoff; |
2557 | ||
2558 | /* | |
2559 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation | |
2560 | * from page cache lookup which is in HPAGE_SIZE units. | |
2561 | */ | |
7526674d | 2562 | address = address & huge_page_mask(h); |
36e4f20a MH |
2563 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + |
2564 | vma->vm_pgoff; | |
496ad9aa | 2565 | mapping = file_inode(vma->vm_file)->i_mapping; |
04f2cbe3 | 2566 | |
4eb2b1dc MG |
2567 | /* |
2568 | * Take the mapping lock for the duration of the table walk. As | |
2569 | * this mapping should be shared between all the VMAs, | |
2570 | * __unmap_hugepage_range() is called as the lock is already held | |
2571 | */ | |
3d48ae45 | 2572 | mutex_lock(&mapping->i_mmap_mutex); |
6b2dbba8 | 2573 | vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { |
04f2cbe3 MG |
2574 | /* Do not unmap the current VMA */ |
2575 | if (iter_vma == vma) | |
2576 | continue; | |
2577 | ||
2578 | /* | |
2579 | * Unmap the page from other VMAs without their own reserves. | |
2580 | * They get marked to be SIGKILLed if they fault in these | |
2581 | * areas. This is because a future no-page fault on this VMA | |
2582 | * could insert a zeroed page instead of the data existing | |
2583 | * from the time of fork. This would look like data corruption | |
2584 | */ | |
2585 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) | |
24669e58 AK |
2586 | unmap_hugepage_range(iter_vma, address, |
2587 | address + huge_page_size(h), page); | |
04f2cbe3 | 2588 | } |
3d48ae45 | 2589 | mutex_unlock(&mapping->i_mmap_mutex); |
04f2cbe3 MG |
2590 | |
2591 | return 1; | |
2592 | } | |
2593 | ||
0fe6e20b NH |
2594 | /* |
2595 | * Hugetlb_cow() should be called with page lock of the original hugepage held. | |
ef009b25 MH |
2596 | * Called with hugetlb_instantiation_mutex held and pte_page locked so we |
2597 | * cannot race with other handlers or page migration. | |
2598 | * Keep the pte_same checks anyway to make transition from the mutex easier. | |
0fe6e20b | 2599 | */ |
1e8f889b | 2600 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
04f2cbe3 MG |
2601 | unsigned long address, pte_t *ptep, pte_t pte, |
2602 | struct page *pagecache_page) | |
1e8f889b | 2603 | { |
a5516438 | 2604 | struct hstate *h = hstate_vma(vma); |
1e8f889b | 2605 | struct page *old_page, *new_page; |
04f2cbe3 | 2606 | int outside_reserve = 0; |
2ec74c3e SG |
2607 | unsigned long mmun_start; /* For mmu_notifiers */ |
2608 | unsigned long mmun_end; /* For mmu_notifiers */ | |
1e8f889b DG |
2609 | |
2610 | old_page = pte_page(pte); | |
2611 | ||
04f2cbe3 | 2612 | retry_avoidcopy: |
1e8f889b DG |
2613 | /* If no-one else is actually using this page, avoid the copy |
2614 | * and just make the page writable */ | |
37a2140d JK |
2615 | if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { |
2616 | page_move_anon_rmap(old_page, vma, address); | |
1e8f889b | 2617 | set_huge_ptep_writable(vma, address, ptep); |
83c54070 | 2618 | return 0; |
1e8f889b DG |
2619 | } |
2620 | ||
04f2cbe3 MG |
2621 | /* |
2622 | * If the process that created a MAP_PRIVATE mapping is about to | |
2623 | * perform a COW due to a shared page count, attempt to satisfy | |
2624 | * the allocation without using the existing reserves. The pagecache | |
2625 | * page is used to determine if the reserve at this address was | |
2626 | * consumed or not. If reserves were used, a partial faulted mapping | |
2627 | * at the time of fork() could consume its reserves on COW instead | |
2628 | * of the full address range. | |
2629 | */ | |
5944d011 | 2630 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && |
04f2cbe3 MG |
2631 | old_page != pagecache_page) |
2632 | outside_reserve = 1; | |
2633 | ||
1e8f889b | 2634 | page_cache_get(old_page); |
b76c8cfb LW |
2635 | |
2636 | /* Drop page_table_lock as buddy allocator may be called */ | |
2637 | spin_unlock(&mm->page_table_lock); | |
04f2cbe3 | 2638 | new_page = alloc_huge_page(vma, address, outside_reserve); |
1e8f889b | 2639 | |
2fc39cec | 2640 | if (IS_ERR(new_page)) { |
76dcee75 | 2641 | long err = PTR_ERR(new_page); |
1e8f889b | 2642 | page_cache_release(old_page); |
04f2cbe3 MG |
2643 | |
2644 | /* | |
2645 | * If a process owning a MAP_PRIVATE mapping fails to COW, | |
2646 | * it is due to references held by a child and an insufficient | |
2647 | * huge page pool. To guarantee the original mappers | |
2648 | * reliability, unmap the page from child processes. The child | |
2649 | * may get SIGKILLed if it later faults. | |
2650 | */ | |
2651 | if (outside_reserve) { | |
2652 | BUG_ON(huge_pte_none(pte)); | |
2653 | if (unmap_ref_private(mm, vma, old_page, address)) { | |
04f2cbe3 | 2654 | BUG_ON(huge_pte_none(pte)); |
b76c8cfb | 2655 | spin_lock(&mm->page_table_lock); |
a734bcc8 HD |
2656 | ptep = huge_pte_offset(mm, address & huge_page_mask(h)); |
2657 | if (likely(pte_same(huge_ptep_get(ptep), pte))) | |
2658 | goto retry_avoidcopy; | |
2659 | /* | |
2660 | * race occurs while re-acquiring page_table_lock, and | |
2661 | * our job is done. | |
2662 | */ | |
2663 | return 0; | |
04f2cbe3 MG |
2664 | } |
2665 | WARN_ON_ONCE(1); | |
2666 | } | |
2667 | ||
b76c8cfb LW |
2668 | /* Caller expects lock to be held */ |
2669 | spin_lock(&mm->page_table_lock); | |
76dcee75 AK |
2670 | if (err == -ENOMEM) |
2671 | return VM_FAULT_OOM; | |
2672 | else | |
2673 | return VM_FAULT_SIGBUS; | |
1e8f889b DG |
2674 | } |
2675 | ||
0fe6e20b NH |
2676 | /* |
2677 | * When the original hugepage is shared one, it does not have | |
2678 | * anon_vma prepared. | |
2679 | */ | |
44e2aa93 | 2680 | if (unlikely(anon_vma_prepare(vma))) { |
ea4039a3 HD |
2681 | page_cache_release(new_page); |
2682 | page_cache_release(old_page); | |
44e2aa93 DN |
2683 | /* Caller expects lock to be held */ |
2684 | spin_lock(&mm->page_table_lock); | |
0fe6e20b | 2685 | return VM_FAULT_OOM; |
44e2aa93 | 2686 | } |
0fe6e20b | 2687 | |
47ad8475 AA |
2688 | copy_user_huge_page(new_page, old_page, address, vma, |
2689 | pages_per_huge_page(h)); | |
0ed361de | 2690 | __SetPageUptodate(new_page); |
1e8f889b | 2691 | |
2ec74c3e SG |
2692 | mmun_start = address & huge_page_mask(h); |
2693 | mmun_end = mmun_start + huge_page_size(h); | |
2694 | mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); | |
b76c8cfb LW |
2695 | /* |
2696 | * Retake the page_table_lock to check for racing updates | |
2697 | * before the page tables are altered | |
2698 | */ | |
2699 | spin_lock(&mm->page_table_lock); | |
a5516438 | 2700 | ptep = huge_pte_offset(mm, address & huge_page_mask(h)); |
7f2e9525 | 2701 | if (likely(pte_same(huge_ptep_get(ptep), pte))) { |
07443a85 JK |
2702 | ClearPagePrivate(new_page); |
2703 | ||
1e8f889b | 2704 | /* Break COW */ |
8fe627ec | 2705 | huge_ptep_clear_flush(vma, address, ptep); |
1e8f889b DG |
2706 | set_huge_pte_at(mm, address, ptep, |
2707 | make_huge_pte(vma, new_page, 1)); | |
0fe6e20b | 2708 | page_remove_rmap(old_page); |
cd67f0d2 | 2709 | hugepage_add_new_anon_rmap(new_page, vma, address); |
1e8f889b DG |
2710 | /* Make the old page be freed below */ |
2711 | new_page = old_page; | |
2712 | } | |
2ec74c3e SG |
2713 | spin_unlock(&mm->page_table_lock); |
2714 | mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); | |
1e8f889b DG |
2715 | page_cache_release(new_page); |
2716 | page_cache_release(old_page); | |
8312034f JK |
2717 | |
2718 | /* Caller expects lock to be held */ | |
2719 | spin_lock(&mm->page_table_lock); | |
83c54070 | 2720 | return 0; |
1e8f889b DG |
2721 | } |
2722 | ||
04f2cbe3 | 2723 | /* Return the pagecache page at a given address within a VMA */ |
a5516438 AK |
2724 | static struct page *hugetlbfs_pagecache_page(struct hstate *h, |
2725 | struct vm_area_struct *vma, unsigned long address) | |
04f2cbe3 MG |
2726 | { |
2727 | struct address_space *mapping; | |
e7c4b0bf | 2728 | pgoff_t idx; |
04f2cbe3 MG |
2729 | |
2730 | mapping = vma->vm_file->f_mapping; | |
a5516438 | 2731 | idx = vma_hugecache_offset(h, vma, address); |
04f2cbe3 MG |
2732 | |
2733 | return find_lock_page(mapping, idx); | |
2734 | } | |
2735 | ||
3ae77f43 HD |
2736 | /* |
2737 | * Return whether there is a pagecache page to back given address within VMA. | |
2738 | * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. | |
2739 | */ | |
2740 | static bool hugetlbfs_pagecache_present(struct hstate *h, | |
2a15efc9 HD |
2741 | struct vm_area_struct *vma, unsigned long address) |
2742 | { | |
2743 | struct address_space *mapping; | |
2744 | pgoff_t idx; | |
2745 | struct page *page; | |
2746 | ||
2747 | mapping = vma->vm_file->f_mapping; | |
2748 | idx = vma_hugecache_offset(h, vma, address); | |
2749 | ||
2750 | page = find_get_page(mapping, idx); | |
2751 | if (page) | |
2752 | put_page(page); | |
2753 | return page != NULL; | |
2754 | } | |
2755 | ||
a1ed3dda | 2756 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
788c7df4 | 2757 | unsigned long address, pte_t *ptep, unsigned int flags) |
ac9b9c66 | 2758 | { |
a5516438 | 2759 | struct hstate *h = hstate_vma(vma); |
ac9b9c66 | 2760 | int ret = VM_FAULT_SIGBUS; |
409eb8c2 | 2761 | int anon_rmap = 0; |
e7c4b0bf | 2762 | pgoff_t idx; |
4c887265 | 2763 | unsigned long size; |
4c887265 AL |
2764 | struct page *page; |
2765 | struct address_space *mapping; | |
1e8f889b | 2766 | pte_t new_pte; |
4c887265 | 2767 | |
04f2cbe3 MG |
2768 | /* |
2769 | * Currently, we are forced to kill the process in the event the | |
2770 | * original mapper has unmapped pages from the child due to a failed | |
25985edc | 2771 | * COW. Warn that such a situation has occurred as it may not be obvious |
04f2cbe3 MG |
2772 | */ |
2773 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { | |
ffb22af5 AM |
2774 | pr_warning("PID %d killed due to inadequate hugepage pool\n", |
2775 | current->pid); | |
04f2cbe3 MG |
2776 | return ret; |
2777 | } | |
2778 | ||
4c887265 | 2779 | mapping = vma->vm_file->f_mapping; |
a5516438 | 2780 | idx = vma_hugecache_offset(h, vma, address); |
4c887265 AL |
2781 | |
2782 | /* | |
2783 | * Use page lock to guard against racing truncation | |
2784 | * before we get page_table_lock. | |
2785 | */ | |
6bda666a CL |
2786 | retry: |
2787 | page = find_lock_page(mapping, idx); | |
2788 | if (!page) { | |
a5516438 | 2789 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
ebed4bfc HD |
2790 | if (idx >= size) |
2791 | goto out; | |
04f2cbe3 | 2792 | page = alloc_huge_page(vma, address, 0); |
2fc39cec | 2793 | if (IS_ERR(page)) { |
76dcee75 AK |
2794 | ret = PTR_ERR(page); |
2795 | if (ret == -ENOMEM) | |
2796 | ret = VM_FAULT_OOM; | |
2797 | else | |
2798 | ret = VM_FAULT_SIGBUS; | |
6bda666a CL |
2799 | goto out; |
2800 | } | |
47ad8475 | 2801 | clear_huge_page(page, address, pages_per_huge_page(h)); |
0ed361de | 2802 | __SetPageUptodate(page); |
ac9b9c66 | 2803 | |
f83a275d | 2804 | if (vma->vm_flags & VM_MAYSHARE) { |
6bda666a | 2805 | int err; |
45c682a6 | 2806 | struct inode *inode = mapping->host; |
6bda666a CL |
2807 | |
2808 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
2809 | if (err) { | |
2810 | put_page(page); | |
6bda666a CL |
2811 | if (err == -EEXIST) |
2812 | goto retry; | |
2813 | goto out; | |
2814 | } | |
07443a85 | 2815 | ClearPagePrivate(page); |
45c682a6 KC |
2816 | |
2817 | spin_lock(&inode->i_lock); | |
a5516438 | 2818 | inode->i_blocks += blocks_per_huge_page(h); |
45c682a6 | 2819 | spin_unlock(&inode->i_lock); |
23be7468 | 2820 | } else { |
6bda666a | 2821 | lock_page(page); |
0fe6e20b NH |
2822 | if (unlikely(anon_vma_prepare(vma))) { |
2823 | ret = VM_FAULT_OOM; | |
2824 | goto backout_unlocked; | |
2825 | } | |
409eb8c2 | 2826 | anon_rmap = 1; |
23be7468 | 2827 | } |
0fe6e20b | 2828 | } else { |
998b4382 NH |
2829 | /* |
2830 | * If memory error occurs between mmap() and fault, some process | |
2831 | * don't have hwpoisoned swap entry for errored virtual address. | |
2832 | * So we need to block hugepage fault by PG_hwpoison bit check. | |
2833 | */ | |
2834 | if (unlikely(PageHWPoison(page))) { | |
32f84528 | 2835 | ret = VM_FAULT_HWPOISON | |
972dc4de | 2836 | VM_FAULT_SET_HINDEX(hstate_index(h)); |
998b4382 NH |
2837 | goto backout_unlocked; |
2838 | } | |
6bda666a | 2839 | } |
1e8f889b | 2840 | |
57303d80 AW |
2841 | /* |
2842 | * If we are going to COW a private mapping later, we examine the | |
2843 | * pending reservations for this page now. This will ensure that | |
2844 | * any allocations necessary to record that reservation occur outside | |
2845 | * the spinlock. | |
2846 | */ | |
788c7df4 | 2847 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) |
2b26736c AW |
2848 | if (vma_needs_reservation(h, vma, address) < 0) { |
2849 | ret = VM_FAULT_OOM; | |
2850 | goto backout_unlocked; | |
2851 | } | |
57303d80 | 2852 | |
ac9b9c66 | 2853 | spin_lock(&mm->page_table_lock); |
a5516438 | 2854 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
4c887265 AL |
2855 | if (idx >= size) |
2856 | goto backout; | |
2857 | ||
83c54070 | 2858 | ret = 0; |
7f2e9525 | 2859 | if (!huge_pte_none(huge_ptep_get(ptep))) |
4c887265 AL |
2860 | goto backout; |
2861 | ||
07443a85 JK |
2862 | if (anon_rmap) { |
2863 | ClearPagePrivate(page); | |
409eb8c2 | 2864 | hugepage_add_new_anon_rmap(page, vma, address); |
07443a85 | 2865 | } |
409eb8c2 HD |
2866 | else |
2867 | page_dup_rmap(page); | |
1e8f889b DG |
2868 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
2869 | && (vma->vm_flags & VM_SHARED))); | |
2870 | set_huge_pte_at(mm, address, ptep, new_pte); | |
2871 | ||
788c7df4 | 2872 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { |
1e8f889b | 2873 | /* Optimization, do the COW without a second fault */ |
04f2cbe3 | 2874 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); |
1e8f889b DG |
2875 | } |
2876 | ||
ac9b9c66 | 2877 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
2878 | unlock_page(page); |
2879 | out: | |
ac9b9c66 | 2880 | return ret; |
4c887265 AL |
2881 | |
2882 | backout: | |
2883 | spin_unlock(&mm->page_table_lock); | |
2b26736c | 2884 | backout_unlocked: |
4c887265 AL |
2885 | unlock_page(page); |
2886 | put_page(page); | |
2887 | goto out; | |
ac9b9c66 HD |
2888 | } |
2889 | ||
86e5216f | 2890 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
788c7df4 | 2891 | unsigned long address, unsigned int flags) |
86e5216f AL |
2892 | { |
2893 | pte_t *ptep; | |
2894 | pte_t entry; | |
1e8f889b | 2895 | int ret; |
0fe6e20b | 2896 | struct page *page = NULL; |
57303d80 | 2897 | struct page *pagecache_page = NULL; |
3935baa9 | 2898 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
a5516438 | 2899 | struct hstate *h = hstate_vma(vma); |
86e5216f | 2900 | |
1e16a539 KH |
2901 | address &= huge_page_mask(h); |
2902 | ||
fd6a03ed NH |
2903 | ptep = huge_pte_offset(mm, address); |
2904 | if (ptep) { | |
2905 | entry = huge_ptep_get(ptep); | |
290408d4 | 2906 | if (unlikely(is_hugetlb_entry_migration(entry))) { |
30dad309 | 2907 | migration_entry_wait_huge(mm, ptep); |
290408d4 NH |
2908 | return 0; |
2909 | } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) | |
32f84528 | 2910 | return VM_FAULT_HWPOISON_LARGE | |
972dc4de | 2911 | VM_FAULT_SET_HINDEX(hstate_index(h)); |
fd6a03ed NH |
2912 | } |
2913 | ||
a5516438 | 2914 | ptep = huge_pte_alloc(mm, address, huge_page_size(h)); |
86e5216f AL |
2915 | if (!ptep) |
2916 | return VM_FAULT_OOM; | |
2917 | ||
3935baa9 DG |
2918 | /* |
2919 | * Serialize hugepage allocation and instantiation, so that we don't | |
2920 | * get spurious allocation failures if two CPUs race to instantiate | |
2921 | * the same page in the page cache. | |
2922 | */ | |
2923 | mutex_lock(&hugetlb_instantiation_mutex); | |
7f2e9525 GS |
2924 | entry = huge_ptep_get(ptep); |
2925 | if (huge_pte_none(entry)) { | |
788c7df4 | 2926 | ret = hugetlb_no_page(mm, vma, address, ptep, flags); |
b4d1d99f | 2927 | goto out_mutex; |
3935baa9 | 2928 | } |
86e5216f | 2929 | |
83c54070 | 2930 | ret = 0; |
1e8f889b | 2931 | |
57303d80 AW |
2932 | /* |
2933 | * If we are going to COW the mapping later, we examine the pending | |
2934 | * reservations for this page now. This will ensure that any | |
2935 | * allocations necessary to record that reservation occur outside the | |
2936 | * spinlock. For private mappings, we also lookup the pagecache | |
2937 | * page now as it is used to determine if a reservation has been | |
2938 | * consumed. | |
2939 | */ | |
106c992a | 2940 | if ((flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { |
2b26736c AW |
2941 | if (vma_needs_reservation(h, vma, address) < 0) { |
2942 | ret = VM_FAULT_OOM; | |
b4d1d99f | 2943 | goto out_mutex; |
2b26736c | 2944 | } |
57303d80 | 2945 | |
f83a275d | 2946 | if (!(vma->vm_flags & VM_MAYSHARE)) |
57303d80 AW |
2947 | pagecache_page = hugetlbfs_pagecache_page(h, |
2948 | vma, address); | |
2949 | } | |
2950 | ||
56c9cfb1 NH |
2951 | /* |
2952 | * hugetlb_cow() requires page locks of pte_page(entry) and | |
2953 | * pagecache_page, so here we need take the former one | |
2954 | * when page != pagecache_page or !pagecache_page. | |
2955 | * Note that locking order is always pagecache_page -> page, | |
2956 | * so no worry about deadlock. | |
2957 | */ | |
2958 | page = pte_page(entry); | |
66aebce7 | 2959 | get_page(page); |
56c9cfb1 | 2960 | if (page != pagecache_page) |
0fe6e20b | 2961 | lock_page(page); |
0fe6e20b | 2962 | |
1e8f889b DG |
2963 | spin_lock(&mm->page_table_lock); |
2964 | /* Check for a racing update before calling hugetlb_cow */ | |
b4d1d99f DG |
2965 | if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) |
2966 | goto out_page_table_lock; | |
2967 | ||
2968 | ||
788c7df4 | 2969 | if (flags & FAULT_FLAG_WRITE) { |
106c992a | 2970 | if (!huge_pte_write(entry)) { |
57303d80 AW |
2971 | ret = hugetlb_cow(mm, vma, address, ptep, entry, |
2972 | pagecache_page); | |
b4d1d99f DG |
2973 | goto out_page_table_lock; |
2974 | } | |
106c992a | 2975 | entry = huge_pte_mkdirty(entry); |
b4d1d99f DG |
2976 | } |
2977 | entry = pte_mkyoung(entry); | |
788c7df4 HD |
2978 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, |
2979 | flags & FAULT_FLAG_WRITE)) | |
4b3073e1 | 2980 | update_mmu_cache(vma, address, ptep); |
b4d1d99f DG |
2981 | |
2982 | out_page_table_lock: | |
1e8f889b | 2983 | spin_unlock(&mm->page_table_lock); |
57303d80 AW |
2984 | |
2985 | if (pagecache_page) { | |
2986 | unlock_page(pagecache_page); | |
2987 | put_page(pagecache_page); | |
2988 | } | |
1f64d69c DN |
2989 | if (page != pagecache_page) |
2990 | unlock_page(page); | |
66aebce7 | 2991 | put_page(page); |
57303d80 | 2992 | |
b4d1d99f | 2993 | out_mutex: |
3935baa9 | 2994 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
2995 | |
2996 | return ret; | |
86e5216f AL |
2997 | } |
2998 | ||
28a35716 ML |
2999 | long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
3000 | struct page **pages, struct vm_area_struct **vmas, | |
3001 | unsigned long *position, unsigned long *nr_pages, | |
3002 | long i, unsigned int flags) | |
63551ae0 | 3003 | { |
d5d4b0aa KC |
3004 | unsigned long pfn_offset; |
3005 | unsigned long vaddr = *position; | |
28a35716 | 3006 | unsigned long remainder = *nr_pages; |
a5516438 | 3007 | struct hstate *h = hstate_vma(vma); |
63551ae0 | 3008 | |
1c59827d | 3009 | spin_lock(&mm->page_table_lock); |
63551ae0 | 3010 | while (vaddr < vma->vm_end && remainder) { |
4c887265 | 3011 | pte_t *pte; |
2a15efc9 | 3012 | int absent; |
4c887265 | 3013 | struct page *page; |
63551ae0 | 3014 | |
4c887265 AL |
3015 | /* |
3016 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
2a15efc9 | 3017 | * each hugepage. We have to make sure we get the |
4c887265 AL |
3018 | * first, for the page indexing below to work. |
3019 | */ | |
a5516438 | 3020 | pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); |
2a15efc9 HD |
3021 | absent = !pte || huge_pte_none(huge_ptep_get(pte)); |
3022 | ||
3023 | /* | |
3024 | * When coredumping, it suits get_dump_page if we just return | |
3ae77f43 HD |
3025 | * an error where there's an empty slot with no huge pagecache |
3026 | * to back it. This way, we avoid allocating a hugepage, and | |
3027 | * the sparse dumpfile avoids allocating disk blocks, but its | |
3028 | * huge holes still show up with zeroes where they need to be. | |
2a15efc9 | 3029 | */ |
3ae77f43 HD |
3030 | if (absent && (flags & FOLL_DUMP) && |
3031 | !hugetlbfs_pagecache_present(h, vma, vaddr)) { | |
2a15efc9 HD |
3032 | remainder = 0; |
3033 | break; | |
3034 | } | |
63551ae0 | 3035 | |
9cc3a5bd NH |
3036 | /* |
3037 | * We need call hugetlb_fault for both hugepages under migration | |
3038 | * (in which case hugetlb_fault waits for the migration,) and | |
3039 | * hwpoisoned hugepages (in which case we need to prevent the | |
3040 | * caller from accessing to them.) In order to do this, we use | |
3041 | * here is_swap_pte instead of is_hugetlb_entry_migration and | |
3042 | * is_hugetlb_entry_hwpoisoned. This is because it simply covers | |
3043 | * both cases, and because we can't follow correct pages | |
3044 | * directly from any kind of swap entries. | |
3045 | */ | |
3046 | if (absent || is_swap_pte(huge_ptep_get(pte)) || | |
106c992a GS |
3047 | ((flags & FOLL_WRITE) && |
3048 | !huge_pte_write(huge_ptep_get(pte)))) { | |
4c887265 | 3049 | int ret; |
63551ae0 | 3050 | |
4c887265 | 3051 | spin_unlock(&mm->page_table_lock); |
2a15efc9 HD |
3052 | ret = hugetlb_fault(mm, vma, vaddr, |
3053 | (flags & FOLL_WRITE) ? FAULT_FLAG_WRITE : 0); | |
4c887265 | 3054 | spin_lock(&mm->page_table_lock); |
a89182c7 | 3055 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 3056 | continue; |
63551ae0 | 3057 | |
4c887265 | 3058 | remainder = 0; |
4c887265 AL |
3059 | break; |
3060 | } | |
3061 | ||
a5516438 | 3062 | pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; |
7f2e9525 | 3063 | page = pte_page(huge_ptep_get(pte)); |
d5d4b0aa | 3064 | same_page: |
d6692183 | 3065 | if (pages) { |
2a15efc9 | 3066 | pages[i] = mem_map_offset(page, pfn_offset); |
4b2e38ad | 3067 | get_page(pages[i]); |
d6692183 | 3068 | } |
63551ae0 DG |
3069 | |
3070 | if (vmas) | |
3071 | vmas[i] = vma; | |
3072 | ||
3073 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 3074 | ++pfn_offset; |
63551ae0 DG |
3075 | --remainder; |
3076 | ++i; | |
d5d4b0aa | 3077 | if (vaddr < vma->vm_end && remainder && |
a5516438 | 3078 | pfn_offset < pages_per_huge_page(h)) { |
d5d4b0aa KC |
3079 | /* |
3080 | * We use pfn_offset to avoid touching the pageframes | |
3081 | * of this compound page. | |
3082 | */ | |
3083 | goto same_page; | |
3084 | } | |
63551ae0 | 3085 | } |
1c59827d | 3086 | spin_unlock(&mm->page_table_lock); |
28a35716 | 3087 | *nr_pages = remainder; |
63551ae0 DG |
3088 | *position = vaddr; |
3089 | ||
2a15efc9 | 3090 | return i ? i : -EFAULT; |
63551ae0 | 3091 | } |
8f860591 | 3092 | |
7da4d641 | 3093 | unsigned long hugetlb_change_protection(struct vm_area_struct *vma, |
8f860591 ZY |
3094 | unsigned long address, unsigned long end, pgprot_t newprot) |
3095 | { | |
3096 | struct mm_struct *mm = vma->vm_mm; | |
3097 | unsigned long start = address; | |
3098 | pte_t *ptep; | |
3099 | pte_t pte; | |
a5516438 | 3100 | struct hstate *h = hstate_vma(vma); |
7da4d641 | 3101 | unsigned long pages = 0; |
8f860591 ZY |
3102 | |
3103 | BUG_ON(address >= end); | |
3104 | flush_cache_range(vma, address, end); | |
3105 | ||
3d48ae45 | 3106 | mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex); |
8f860591 | 3107 | spin_lock(&mm->page_table_lock); |
a5516438 | 3108 | for (; address < end; address += huge_page_size(h)) { |
8f860591 ZY |
3109 | ptep = huge_pte_offset(mm, address); |
3110 | if (!ptep) | |
3111 | continue; | |
7da4d641 PZ |
3112 | if (huge_pmd_unshare(mm, &address, ptep)) { |
3113 | pages++; | |
39dde65c | 3114 | continue; |
7da4d641 | 3115 | } |
7f2e9525 | 3116 | if (!huge_pte_none(huge_ptep_get(ptep))) { |
8f860591 | 3117 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
106c992a | 3118 | pte = pte_mkhuge(huge_pte_modify(pte, newprot)); |
be7517d6 | 3119 | pte = arch_make_huge_pte(pte, vma, NULL, 0); |
8f860591 | 3120 | set_huge_pte_at(mm, address, ptep, pte); |
7da4d641 | 3121 | pages++; |
8f860591 ZY |
3122 | } |
3123 | } | |
3124 | spin_unlock(&mm->page_table_lock); | |
d833352a MG |
3125 | /* |
3126 | * Must flush TLB before releasing i_mmap_mutex: x86's huge_pmd_unshare | |
3127 | * may have cleared our pud entry and done put_page on the page table: | |
3128 | * once we release i_mmap_mutex, another task can do the final put_page | |
3129 | * and that page table be reused and filled with junk. | |
3130 | */ | |
8f860591 | 3131 | flush_tlb_range(vma, start, end); |
d833352a | 3132 | mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex); |
7da4d641 PZ |
3133 | |
3134 | return pages << h->order; | |
8f860591 ZY |
3135 | } |
3136 | ||
a1e78772 MG |
3137 | int hugetlb_reserve_pages(struct inode *inode, |
3138 | long from, long to, | |
5a6fe125 | 3139 | struct vm_area_struct *vma, |
ca16d140 | 3140 | vm_flags_t vm_flags) |
e4e574b7 | 3141 | { |
17c9d12e | 3142 | long ret, chg; |
a5516438 | 3143 | struct hstate *h = hstate_inode(inode); |
90481622 | 3144 | struct hugepage_subpool *spool = subpool_inode(inode); |
e4e574b7 | 3145 | |
17c9d12e MG |
3146 | /* |
3147 | * Only apply hugepage reservation if asked. At fault time, an | |
3148 | * attempt will be made for VM_NORESERVE to allocate a page | |
90481622 | 3149 | * without using reserves |
17c9d12e | 3150 | */ |
ca16d140 | 3151 | if (vm_flags & VM_NORESERVE) |
17c9d12e MG |
3152 | return 0; |
3153 | ||
a1e78772 MG |
3154 | /* |
3155 | * Shared mappings base their reservation on the number of pages that | |
3156 | * are already allocated on behalf of the file. Private mappings need | |
3157 | * to reserve the full area even if read-only as mprotect() may be | |
3158 | * called to make the mapping read-write. Assume !vma is a shm mapping | |
3159 | */ | |
f83a275d | 3160 | if (!vma || vma->vm_flags & VM_MAYSHARE) |
a1e78772 | 3161 | chg = region_chg(&inode->i_mapping->private_list, from, to); |
17c9d12e MG |
3162 | else { |
3163 | struct resv_map *resv_map = resv_map_alloc(); | |
3164 | if (!resv_map) | |
3165 | return -ENOMEM; | |
3166 | ||
a1e78772 | 3167 | chg = to - from; |
84afd99b | 3168 | |
17c9d12e MG |
3169 | set_vma_resv_map(vma, resv_map); |
3170 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); | |
3171 | } | |
3172 | ||
c50ac050 DH |
3173 | if (chg < 0) { |
3174 | ret = chg; | |
3175 | goto out_err; | |
3176 | } | |
8a630112 | 3177 | |
90481622 | 3178 | /* There must be enough pages in the subpool for the mapping */ |
c50ac050 DH |
3179 | if (hugepage_subpool_get_pages(spool, chg)) { |
3180 | ret = -ENOSPC; | |
3181 | goto out_err; | |
3182 | } | |
5a6fe125 MG |
3183 | |
3184 | /* | |
17c9d12e | 3185 | * Check enough hugepages are available for the reservation. |
90481622 | 3186 | * Hand the pages back to the subpool if there are not |
5a6fe125 | 3187 | */ |
a5516438 | 3188 | ret = hugetlb_acct_memory(h, chg); |
68842c9b | 3189 | if (ret < 0) { |
90481622 | 3190 | hugepage_subpool_put_pages(spool, chg); |
c50ac050 | 3191 | goto out_err; |
68842c9b | 3192 | } |
17c9d12e MG |
3193 | |
3194 | /* | |
3195 | * Account for the reservations made. Shared mappings record regions | |
3196 | * that have reservations as they are shared by multiple VMAs. | |
3197 | * When the last VMA disappears, the region map says how much | |
3198 | * the reservation was and the page cache tells how much of | |
3199 | * the reservation was consumed. Private mappings are per-VMA and | |
3200 | * only the consumed reservations are tracked. When the VMA | |
3201 | * disappears, the original reservation is the VMA size and the | |
3202 | * consumed reservations are stored in the map. Hence, nothing | |
3203 | * else has to be done for private mappings here | |
3204 | */ | |
f83a275d | 3205 | if (!vma || vma->vm_flags & VM_MAYSHARE) |
a1e78772 | 3206 | region_add(&inode->i_mapping->private_list, from, to); |
a43a8c39 | 3207 | return 0; |
c50ac050 | 3208 | out_err: |
4523e145 DH |
3209 | if (vma) |
3210 | resv_map_put(vma); | |
c50ac050 | 3211 | return ret; |
a43a8c39 KC |
3212 | } |
3213 | ||
3214 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
3215 | { | |
a5516438 | 3216 | struct hstate *h = hstate_inode(inode); |
a43a8c39 | 3217 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
90481622 | 3218 | struct hugepage_subpool *spool = subpool_inode(inode); |
45c682a6 KC |
3219 | |
3220 | spin_lock(&inode->i_lock); | |
e4c6f8be | 3221 | inode->i_blocks -= (blocks_per_huge_page(h) * freed); |
45c682a6 KC |
3222 | spin_unlock(&inode->i_lock); |
3223 | ||
90481622 | 3224 | hugepage_subpool_put_pages(spool, (chg - freed)); |
a5516438 | 3225 | hugetlb_acct_memory(h, -(chg - freed)); |
a43a8c39 | 3226 | } |
93f70f90 | 3227 | |
3212b535 SC |
3228 | #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE |
3229 | static unsigned long page_table_shareable(struct vm_area_struct *svma, | |
3230 | struct vm_area_struct *vma, | |
3231 | unsigned long addr, pgoff_t idx) | |
3232 | { | |
3233 | unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + | |
3234 | svma->vm_start; | |
3235 | unsigned long sbase = saddr & PUD_MASK; | |
3236 | unsigned long s_end = sbase + PUD_SIZE; | |
3237 | ||
3238 | /* Allow segments to share if only one is marked locked */ | |
3239 | unsigned long vm_flags = vma->vm_flags & ~VM_LOCKED; | |
3240 | unsigned long svm_flags = svma->vm_flags & ~VM_LOCKED; | |
3241 | ||
3242 | /* | |
3243 | * match the virtual addresses, permission and the alignment of the | |
3244 | * page table page. | |
3245 | */ | |
3246 | if (pmd_index(addr) != pmd_index(saddr) || | |
3247 | vm_flags != svm_flags || | |
3248 | sbase < svma->vm_start || svma->vm_end < s_end) | |
3249 | return 0; | |
3250 | ||
3251 | return saddr; | |
3252 | } | |
3253 | ||
3254 | static int vma_shareable(struct vm_area_struct *vma, unsigned long addr) | |
3255 | { | |
3256 | unsigned long base = addr & PUD_MASK; | |
3257 | unsigned long end = base + PUD_SIZE; | |
3258 | ||
3259 | /* | |
3260 | * check on proper vm_flags and page table alignment | |
3261 | */ | |
3262 | if (vma->vm_flags & VM_MAYSHARE && | |
3263 | vma->vm_start <= base && end <= vma->vm_end) | |
3264 | return 1; | |
3265 | return 0; | |
3266 | } | |
3267 | ||
3268 | /* | |
3269 | * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() | |
3270 | * and returns the corresponding pte. While this is not necessary for the | |
3271 | * !shared pmd case because we can allocate the pmd later as well, it makes the | |
3272 | * code much cleaner. pmd allocation is essential for the shared case because | |
3273 | * pud has to be populated inside the same i_mmap_mutex section - otherwise | |
3274 | * racing tasks could either miss the sharing (see huge_pte_offset) or select a | |
3275 | * bad pmd for sharing. | |
3276 | */ | |
3277 | pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) | |
3278 | { | |
3279 | struct vm_area_struct *vma = find_vma(mm, addr); | |
3280 | struct address_space *mapping = vma->vm_file->f_mapping; | |
3281 | pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + | |
3282 | vma->vm_pgoff; | |
3283 | struct vm_area_struct *svma; | |
3284 | unsigned long saddr; | |
3285 | pte_t *spte = NULL; | |
3286 | pte_t *pte; | |
3287 | ||
3288 | if (!vma_shareable(vma, addr)) | |
3289 | return (pte_t *)pmd_alloc(mm, pud, addr); | |
3290 | ||
3291 | mutex_lock(&mapping->i_mmap_mutex); | |
3292 | vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { | |
3293 | if (svma == vma) | |
3294 | continue; | |
3295 | ||
3296 | saddr = page_table_shareable(svma, vma, addr, idx); | |
3297 | if (saddr) { | |
3298 | spte = huge_pte_offset(svma->vm_mm, saddr); | |
3299 | if (spte) { | |
3300 | get_page(virt_to_page(spte)); | |
3301 | break; | |
3302 | } | |
3303 | } | |
3304 | } | |
3305 | ||
3306 | if (!spte) | |
3307 | goto out; | |
3308 | ||
3309 | spin_lock(&mm->page_table_lock); | |
3310 | if (pud_none(*pud)) | |
3311 | pud_populate(mm, pud, | |
3312 | (pmd_t *)((unsigned long)spte & PAGE_MASK)); | |
3313 | else | |
3314 | put_page(virt_to_page(spte)); | |
3315 | spin_unlock(&mm->page_table_lock); | |
3316 | out: | |
3317 | pte = (pte_t *)pmd_alloc(mm, pud, addr); | |
3318 | mutex_unlock(&mapping->i_mmap_mutex); | |
3319 | return pte; | |
3320 | } | |
3321 | ||
3322 | /* | |
3323 | * unmap huge page backed by shared pte. | |
3324 | * | |
3325 | * Hugetlb pte page is ref counted at the time of mapping. If pte is shared | |
3326 | * indicated by page_count > 1, unmap is achieved by clearing pud and | |
3327 | * decrementing the ref count. If count == 1, the pte page is not shared. | |
3328 | * | |
3329 | * called with vma->vm_mm->page_table_lock held. | |
3330 | * | |
3331 | * returns: 1 successfully unmapped a shared pte page | |
3332 | * 0 the underlying pte page is not shared, or it is the last user | |
3333 | */ | |
3334 | int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) | |
3335 | { | |
3336 | pgd_t *pgd = pgd_offset(mm, *addr); | |
3337 | pud_t *pud = pud_offset(pgd, *addr); | |
3338 | ||
3339 | BUG_ON(page_count(virt_to_page(ptep)) == 0); | |
3340 | if (page_count(virt_to_page(ptep)) == 1) | |
3341 | return 0; | |
3342 | ||
3343 | pud_clear(pud); | |
3344 | put_page(virt_to_page(ptep)); | |
3345 | *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE; | |
3346 | return 1; | |
3347 | } | |
9e5fc74c SC |
3348 | #define want_pmd_share() (1) |
3349 | #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ | |
3350 | pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) | |
3351 | { | |
3352 | return NULL; | |
3353 | } | |
3354 | #define want_pmd_share() (0) | |
3212b535 SC |
3355 | #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ |
3356 | ||
9e5fc74c SC |
3357 | #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB |
3358 | pte_t *huge_pte_alloc(struct mm_struct *mm, | |
3359 | unsigned long addr, unsigned long sz) | |
3360 | { | |
3361 | pgd_t *pgd; | |
3362 | pud_t *pud; | |
3363 | pte_t *pte = NULL; | |
3364 | ||
3365 | pgd = pgd_offset(mm, addr); | |
3366 | pud = pud_alloc(mm, pgd, addr); | |
3367 | if (pud) { | |
3368 | if (sz == PUD_SIZE) { | |
3369 | pte = (pte_t *)pud; | |
3370 | } else { | |
3371 | BUG_ON(sz != PMD_SIZE); | |
3372 | if (want_pmd_share() && pud_none(*pud)) | |
3373 | pte = huge_pmd_share(mm, addr, pud); | |
3374 | else | |
3375 | pte = (pte_t *)pmd_alloc(mm, pud, addr); | |
3376 | } | |
3377 | } | |
3378 | BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte)); | |
3379 | ||
3380 | return pte; | |
3381 | } | |
3382 | ||
3383 | pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) | |
3384 | { | |
3385 | pgd_t *pgd; | |
3386 | pud_t *pud; | |
3387 | pmd_t *pmd = NULL; | |
3388 | ||
3389 | pgd = pgd_offset(mm, addr); | |
3390 | if (pgd_present(*pgd)) { | |
3391 | pud = pud_offset(pgd, addr); | |
3392 | if (pud_present(*pud)) { | |
3393 | if (pud_huge(*pud)) | |
3394 | return (pte_t *)pud; | |
3395 | pmd = pmd_offset(pud, addr); | |
3396 | } | |
3397 | } | |
3398 | return (pte_t *) pmd; | |
3399 | } | |
3400 | ||
3401 | struct page * | |
3402 | follow_huge_pmd(struct mm_struct *mm, unsigned long address, | |
3403 | pmd_t *pmd, int write) | |
3404 | { | |
3405 | struct page *page; | |
3406 | ||
3407 | page = pte_page(*(pte_t *)pmd); | |
3408 | if (page) | |
3409 | page += ((address & ~PMD_MASK) >> PAGE_SHIFT); | |
3410 | return page; | |
3411 | } | |
3412 | ||
3413 | struct page * | |
3414 | follow_huge_pud(struct mm_struct *mm, unsigned long address, | |
3415 | pud_t *pud, int write) | |
3416 | { | |
3417 | struct page *page; | |
3418 | ||
3419 | page = pte_page(*(pte_t *)pud); | |
3420 | if (page) | |
3421 | page += ((address & ~PUD_MASK) >> PAGE_SHIFT); | |
3422 | return page; | |
3423 | } | |
3424 | ||
3425 | #else /* !CONFIG_ARCH_WANT_GENERAL_HUGETLB */ | |
3426 | ||
3427 | /* Can be overriden by architectures */ | |
3428 | __attribute__((weak)) struct page * | |
3429 | follow_huge_pud(struct mm_struct *mm, unsigned long address, | |
3430 | pud_t *pud, int write) | |
3431 | { | |
3432 | BUG(); | |
3433 | return NULL; | |
3434 | } | |
3435 | ||
3436 | #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ | |
3437 | ||
d5bd9106 AK |
3438 | #ifdef CONFIG_MEMORY_FAILURE |
3439 | ||
6de2b1aa NH |
3440 | /* Should be called in hugetlb_lock */ |
3441 | static int is_hugepage_on_freelist(struct page *hpage) | |
3442 | { | |
3443 | struct page *page; | |
3444 | struct page *tmp; | |
3445 | struct hstate *h = page_hstate(hpage); | |
3446 | int nid = page_to_nid(hpage); | |
3447 | ||
3448 | list_for_each_entry_safe(page, tmp, &h->hugepage_freelists[nid], lru) | |
3449 | if (page == hpage) | |
3450 | return 1; | |
3451 | return 0; | |
3452 | } | |
3453 | ||
93f70f90 NH |
3454 | /* |
3455 | * This function is called from memory failure code. | |
3456 | * Assume the caller holds page lock of the head page. | |
3457 | */ | |
6de2b1aa | 3458 | int dequeue_hwpoisoned_huge_page(struct page *hpage) |
93f70f90 NH |
3459 | { |
3460 | struct hstate *h = page_hstate(hpage); | |
3461 | int nid = page_to_nid(hpage); | |
6de2b1aa | 3462 | int ret = -EBUSY; |
93f70f90 NH |
3463 | |
3464 | spin_lock(&hugetlb_lock); | |
6de2b1aa | 3465 | if (is_hugepage_on_freelist(hpage)) { |
56f2fb14 NH |
3466 | /* |
3467 | * Hwpoisoned hugepage isn't linked to activelist or freelist, | |
3468 | * but dangling hpage->lru can trigger list-debug warnings | |
3469 | * (this happens when we call unpoison_memory() on it), | |
3470 | * so let it point to itself with list_del_init(). | |
3471 | */ | |
3472 | list_del_init(&hpage->lru); | |
8c6c2ecb | 3473 | set_page_refcounted(hpage); |
6de2b1aa NH |
3474 | h->free_huge_pages--; |
3475 | h->free_huge_pages_node[nid]--; | |
3476 | ret = 0; | |
3477 | } | |
93f70f90 | 3478 | spin_unlock(&hugetlb_lock); |
6de2b1aa | 3479 | return ret; |
93f70f90 | 3480 | } |
6de2b1aa | 3481 | #endif |
31caf665 NH |
3482 | |
3483 | bool isolate_huge_page(struct page *page, struct list_head *list) | |
3484 | { | |
3485 | VM_BUG_ON(!PageHead(page)); | |
3486 | if (!get_page_unless_zero(page)) | |
3487 | return false; | |
3488 | spin_lock(&hugetlb_lock); | |
3489 | list_move_tail(&page->lru, list); | |
3490 | spin_unlock(&hugetlb_lock); | |
3491 | return true; | |
3492 | } | |
3493 | ||
3494 | void putback_active_hugepage(struct page *page) | |
3495 | { | |
3496 | VM_BUG_ON(!PageHead(page)); | |
3497 | spin_lock(&hugetlb_lock); | |
3498 | list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); | |
3499 | spin_unlock(&hugetlb_lock); | |
3500 | put_page(page); | |
3501 | } | |
c8721bbb NH |
3502 | |
3503 | bool is_hugepage_active(struct page *page) | |
3504 | { | |
3505 | VM_BUG_ON(!PageHuge(page)); | |
3506 | /* | |
3507 | * This function can be called for a tail page because the caller, | |
3508 | * scan_movable_pages, scans through a given pfn-range which typically | |
3509 | * covers one memory block. In systems using gigantic hugepage (1GB | |
3510 | * for x86_64,) a hugepage is larger than a memory block, and we don't | |
3511 | * support migrating such large hugepages for now, so return false | |
3512 | * when called for tail pages. | |
3513 | */ | |
3514 | if (PageTail(page)) | |
3515 | return false; | |
3516 | /* | |
3517 | * Refcount of a hwpoisoned hugepages is 1, but they are not active, | |
3518 | * so we should return false for them. | |
3519 | */ | |
3520 | if (unlikely(PageHWPoison(page))) | |
3521 | return false; | |
3522 | return page_count(page) > 0; | |
3523 | } |