Commit | Line | Data |
---|---|---|
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> |
3b32123d | 16 | #include <linux/compiler.h> |
aea47ff3 | 17 | #include <linux/cpuset.h> |
3935baa9 | 18 | #include <linux/mutex.h> |
aa888a74 | 19 | #include <linux/bootmem.h> |
a3437870 | 20 | #include <linux/sysfs.h> |
5a0e3ad6 | 21 | #include <linux/slab.h> |
0fe6e20b | 22 | #include <linux/rmap.h> |
fd6a03ed NH |
23 | #include <linux/swap.h> |
24 | #include <linux/swapops.h> | |
c8721bbb | 25 | #include <linux/page-isolation.h> |
8382d914 | 26 | #include <linux/jhash.h> |
d6606683 | 27 | |
63551ae0 DG |
28 | #include <asm/page.h> |
29 | #include <asm/pgtable.h> | |
24669e58 | 30 | #include <asm/tlb.h> |
63551ae0 | 31 | |
24669e58 | 32 | #include <linux/io.h> |
63551ae0 | 33 | #include <linux/hugetlb.h> |
9dd540e2 | 34 | #include <linux/hugetlb_cgroup.h> |
9a305230 | 35 | #include <linux/node.h> |
7835e98b | 36 | #include "internal.h" |
1da177e4 | 37 | |
396faf03 | 38 | unsigned long hugepages_treat_as_movable; |
a5516438 | 39 | |
c3f38a38 | 40 | int hugetlb_max_hstate __read_mostly; |
e5ff2159 AK |
41 | unsigned int default_hstate_idx; |
42 | struct hstate hstates[HUGE_MAX_HSTATE]; | |
43 | ||
53ba51d2 JT |
44 | __initdata LIST_HEAD(huge_boot_pages); |
45 | ||
e5ff2159 AK |
46 | /* for command line parsing */ |
47 | static struct hstate * __initdata parsed_hstate; | |
48 | static unsigned long __initdata default_hstate_max_huge_pages; | |
e11bfbfc | 49 | static unsigned long __initdata default_hstate_size; |
e5ff2159 | 50 | |
3935baa9 | 51 | /* |
31caf665 NH |
52 | * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, |
53 | * free_huge_pages, and surplus_huge_pages. | |
3935baa9 | 54 | */ |
c3f38a38 | 55 | DEFINE_SPINLOCK(hugetlb_lock); |
0bd0f9fb | 56 | |
8382d914 DB |
57 | /* |
58 | * Serializes faults on the same logical page. This is used to | |
59 | * prevent spurious OOMs when the hugepage pool is fully utilized. | |
60 | */ | |
61 | static int num_fault_mutexes; | |
62 | static struct mutex *htlb_fault_mutex_table ____cacheline_aligned_in_smp; | |
63 | ||
90481622 DG |
64 | static inline void unlock_or_release_subpool(struct hugepage_subpool *spool) |
65 | { | |
66 | bool free = (spool->count == 0) && (spool->used_hpages == 0); | |
67 | ||
68 | spin_unlock(&spool->lock); | |
69 | ||
70 | /* If no pages are used, and no other handles to the subpool | |
71 | * remain, free the subpool the subpool remain */ | |
72 | if (free) | |
73 | kfree(spool); | |
74 | } | |
75 | ||
76 | struct hugepage_subpool *hugepage_new_subpool(long nr_blocks) | |
77 | { | |
78 | struct hugepage_subpool *spool; | |
79 | ||
80 | spool = kmalloc(sizeof(*spool), GFP_KERNEL); | |
81 | if (!spool) | |
82 | return NULL; | |
83 | ||
84 | spin_lock_init(&spool->lock); | |
85 | spool->count = 1; | |
86 | spool->max_hpages = nr_blocks; | |
87 | spool->used_hpages = 0; | |
88 | ||
89 | return spool; | |
90 | } | |
91 | ||
92 | void hugepage_put_subpool(struct hugepage_subpool *spool) | |
93 | { | |
94 | spin_lock(&spool->lock); | |
95 | BUG_ON(!spool->count); | |
96 | spool->count--; | |
97 | unlock_or_release_subpool(spool); | |
98 | } | |
99 | ||
100 | static int hugepage_subpool_get_pages(struct hugepage_subpool *spool, | |
101 | long delta) | |
102 | { | |
103 | int ret = 0; | |
104 | ||
105 | if (!spool) | |
106 | return 0; | |
107 | ||
108 | spin_lock(&spool->lock); | |
109 | if ((spool->used_hpages + delta) <= spool->max_hpages) { | |
110 | spool->used_hpages += delta; | |
111 | } else { | |
112 | ret = -ENOMEM; | |
113 | } | |
114 | spin_unlock(&spool->lock); | |
115 | ||
116 | return ret; | |
117 | } | |
118 | ||
119 | static void hugepage_subpool_put_pages(struct hugepage_subpool *spool, | |
120 | long delta) | |
121 | { | |
122 | if (!spool) | |
123 | return; | |
124 | ||
125 | spin_lock(&spool->lock); | |
126 | spool->used_hpages -= delta; | |
127 | /* If hugetlbfs_put_super couldn't free spool due to | |
128 | * an outstanding quota reference, free it now. */ | |
129 | unlock_or_release_subpool(spool); | |
130 | } | |
131 | ||
132 | static inline struct hugepage_subpool *subpool_inode(struct inode *inode) | |
133 | { | |
134 | return HUGETLBFS_SB(inode->i_sb)->spool; | |
135 | } | |
136 | ||
137 | static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma) | |
138 | { | |
496ad9aa | 139 | return subpool_inode(file_inode(vma->vm_file)); |
90481622 DG |
140 | } |
141 | ||
96822904 AW |
142 | /* |
143 | * Region tracking -- allows tracking of reservations and instantiated pages | |
144 | * across the pages in a mapping. | |
84afd99b | 145 | * |
7b24d861 DB |
146 | * The region data structures are embedded into a resv_map and |
147 | * protected by a resv_map's lock | |
96822904 AW |
148 | */ |
149 | struct file_region { | |
150 | struct list_head link; | |
151 | long from; | |
152 | long to; | |
153 | }; | |
154 | ||
1406ec9b | 155 | static long region_add(struct resv_map *resv, long f, long t) |
96822904 | 156 | { |
1406ec9b | 157 | struct list_head *head = &resv->regions; |
96822904 AW |
158 | struct file_region *rg, *nrg, *trg; |
159 | ||
7b24d861 | 160 | spin_lock(&resv->lock); |
96822904 AW |
161 | /* Locate the region we are either in or before. */ |
162 | list_for_each_entry(rg, head, link) | |
163 | if (f <= rg->to) | |
164 | break; | |
165 | ||
166 | /* Round our left edge to the current segment if it encloses us. */ | |
167 | if (f > rg->from) | |
168 | f = rg->from; | |
169 | ||
170 | /* Check for and consume any regions we now overlap with. */ | |
171 | nrg = rg; | |
172 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
173 | if (&rg->link == head) | |
174 | break; | |
175 | if (rg->from > t) | |
176 | break; | |
177 | ||
178 | /* If this area reaches higher then extend our area to | |
179 | * include it completely. If this is not the first area | |
180 | * which we intend to reuse, free it. */ | |
181 | if (rg->to > t) | |
182 | t = rg->to; | |
183 | if (rg != nrg) { | |
184 | list_del(&rg->link); | |
185 | kfree(rg); | |
186 | } | |
187 | } | |
188 | nrg->from = f; | |
189 | nrg->to = t; | |
7b24d861 | 190 | spin_unlock(&resv->lock); |
96822904 AW |
191 | return 0; |
192 | } | |
193 | ||
1406ec9b | 194 | static long region_chg(struct resv_map *resv, long f, long t) |
96822904 | 195 | { |
1406ec9b | 196 | struct list_head *head = &resv->regions; |
7b24d861 | 197 | struct file_region *rg, *nrg = NULL; |
96822904 AW |
198 | long chg = 0; |
199 | ||
7b24d861 DB |
200 | retry: |
201 | spin_lock(&resv->lock); | |
96822904 AW |
202 | /* Locate the region we are before or in. */ |
203 | list_for_each_entry(rg, head, link) | |
204 | if (f <= rg->to) | |
205 | break; | |
206 | ||
207 | /* If we are below the current region then a new region is required. | |
208 | * Subtle, allocate a new region at the position but make it zero | |
209 | * size such that we can guarantee to record the reservation. */ | |
210 | if (&rg->link == head || t < rg->from) { | |
7b24d861 DB |
211 | if (!nrg) { |
212 | spin_unlock(&resv->lock); | |
213 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
214 | if (!nrg) | |
215 | return -ENOMEM; | |
216 | ||
217 | nrg->from = f; | |
218 | nrg->to = f; | |
219 | INIT_LIST_HEAD(&nrg->link); | |
220 | goto retry; | |
221 | } | |
96822904 | 222 | |
7b24d861 DB |
223 | list_add(&nrg->link, rg->link.prev); |
224 | chg = t - f; | |
225 | goto out_nrg; | |
96822904 AW |
226 | } |
227 | ||
228 | /* Round our left edge to the current segment if it encloses us. */ | |
229 | if (f > rg->from) | |
230 | f = rg->from; | |
231 | chg = t - f; | |
232 | ||
233 | /* Check for and consume any regions we now overlap with. */ | |
234 | list_for_each_entry(rg, rg->link.prev, link) { | |
235 | if (&rg->link == head) | |
236 | break; | |
237 | if (rg->from > t) | |
7b24d861 | 238 | goto out; |
96822904 | 239 | |
25985edc | 240 | /* We overlap with this area, if it extends further than |
96822904 AW |
241 | * us then we must extend ourselves. Account for its |
242 | * existing reservation. */ | |
243 | if (rg->to > t) { | |
244 | chg += rg->to - t; | |
245 | t = rg->to; | |
246 | } | |
247 | chg -= rg->to - rg->from; | |
248 | } | |
7b24d861 DB |
249 | |
250 | out: | |
251 | spin_unlock(&resv->lock); | |
252 | /* We already know we raced and no longer need the new region */ | |
253 | kfree(nrg); | |
254 | return chg; | |
255 | out_nrg: | |
256 | spin_unlock(&resv->lock); | |
96822904 AW |
257 | return chg; |
258 | } | |
259 | ||
1406ec9b | 260 | static long region_truncate(struct resv_map *resv, long end) |
96822904 | 261 | { |
1406ec9b | 262 | struct list_head *head = &resv->regions; |
96822904 AW |
263 | struct file_region *rg, *trg; |
264 | long chg = 0; | |
265 | ||
7b24d861 | 266 | spin_lock(&resv->lock); |
96822904 AW |
267 | /* Locate the region we are either in or before. */ |
268 | list_for_each_entry(rg, head, link) | |
269 | if (end <= rg->to) | |
270 | break; | |
271 | if (&rg->link == head) | |
7b24d861 | 272 | goto out; |
96822904 AW |
273 | |
274 | /* If we are in the middle of a region then adjust it. */ | |
275 | if (end > rg->from) { | |
276 | chg = rg->to - end; | |
277 | rg->to = end; | |
278 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
279 | } | |
280 | ||
281 | /* Drop any remaining regions. */ | |
282 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
283 | if (&rg->link == head) | |
284 | break; | |
285 | chg += rg->to - rg->from; | |
286 | list_del(&rg->link); | |
287 | kfree(rg); | |
288 | } | |
7b24d861 DB |
289 | |
290 | out: | |
291 | spin_unlock(&resv->lock); | |
96822904 AW |
292 | return chg; |
293 | } | |
294 | ||
1406ec9b | 295 | static long region_count(struct resv_map *resv, long f, long t) |
84afd99b | 296 | { |
1406ec9b | 297 | struct list_head *head = &resv->regions; |
84afd99b AW |
298 | struct file_region *rg; |
299 | long chg = 0; | |
300 | ||
7b24d861 | 301 | spin_lock(&resv->lock); |
84afd99b AW |
302 | /* Locate each segment we overlap with, and count that overlap. */ |
303 | list_for_each_entry(rg, head, link) { | |
f2135a4a WSH |
304 | long seg_from; |
305 | long seg_to; | |
84afd99b AW |
306 | |
307 | if (rg->to <= f) | |
308 | continue; | |
309 | if (rg->from >= t) | |
310 | break; | |
311 | ||
312 | seg_from = max(rg->from, f); | |
313 | seg_to = min(rg->to, t); | |
314 | ||
315 | chg += seg_to - seg_from; | |
316 | } | |
7b24d861 | 317 | spin_unlock(&resv->lock); |
84afd99b AW |
318 | |
319 | return chg; | |
320 | } | |
321 | ||
e7c4b0bf AW |
322 | /* |
323 | * Convert the address within this vma to the page offset within | |
324 | * the mapping, in pagecache page units; huge pages here. | |
325 | */ | |
a5516438 AK |
326 | static pgoff_t vma_hugecache_offset(struct hstate *h, |
327 | struct vm_area_struct *vma, unsigned long address) | |
e7c4b0bf | 328 | { |
a5516438 AK |
329 | return ((address - vma->vm_start) >> huge_page_shift(h)) + |
330 | (vma->vm_pgoff >> huge_page_order(h)); | |
e7c4b0bf AW |
331 | } |
332 | ||
0fe6e20b NH |
333 | pgoff_t linear_hugepage_index(struct vm_area_struct *vma, |
334 | unsigned long address) | |
335 | { | |
336 | return vma_hugecache_offset(hstate_vma(vma), vma, address); | |
337 | } | |
338 | ||
08fba699 MG |
339 | /* |
340 | * Return the size of the pages allocated when backing a VMA. In the majority | |
341 | * cases this will be same size as used by the page table entries. | |
342 | */ | |
343 | unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) | |
344 | { | |
345 | struct hstate *hstate; | |
346 | ||
347 | if (!is_vm_hugetlb_page(vma)) | |
348 | return PAGE_SIZE; | |
349 | ||
350 | hstate = hstate_vma(vma); | |
351 | ||
2415cf12 | 352 | return 1UL << huge_page_shift(hstate); |
08fba699 | 353 | } |
f340ca0f | 354 | EXPORT_SYMBOL_GPL(vma_kernel_pagesize); |
08fba699 | 355 | |
3340289d MG |
356 | /* |
357 | * Return the page size being used by the MMU to back a VMA. In the majority | |
358 | * of cases, the page size used by the kernel matches the MMU size. On | |
359 | * architectures where it differs, an architecture-specific version of this | |
360 | * function is required. | |
361 | */ | |
362 | #ifndef vma_mmu_pagesize | |
363 | unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) | |
364 | { | |
365 | return vma_kernel_pagesize(vma); | |
366 | } | |
367 | #endif | |
368 | ||
84afd99b AW |
369 | /* |
370 | * Flags for MAP_PRIVATE reservations. These are stored in the bottom | |
371 | * bits of the reservation map pointer, which are always clear due to | |
372 | * alignment. | |
373 | */ | |
374 | #define HPAGE_RESV_OWNER (1UL << 0) | |
375 | #define HPAGE_RESV_UNMAPPED (1UL << 1) | |
04f2cbe3 | 376 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) |
84afd99b | 377 | |
a1e78772 MG |
378 | /* |
379 | * These helpers are used to track how many pages are reserved for | |
380 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() | |
381 | * is guaranteed to have their future faults succeed. | |
382 | * | |
383 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), | |
384 | * the reserve counters are updated with the hugetlb_lock held. It is safe | |
385 | * to reset the VMA at fork() time as it is not in use yet and there is no | |
386 | * chance of the global counters getting corrupted as a result of the values. | |
84afd99b AW |
387 | * |
388 | * The private mapping reservation is represented in a subtly different | |
389 | * manner to a shared mapping. A shared mapping has a region map associated | |
390 | * with the underlying file, this region map represents the backing file | |
391 | * pages which have ever had a reservation assigned which this persists even | |
392 | * after the page is instantiated. A private mapping has a region map | |
393 | * associated with the original mmap which is attached to all VMAs which | |
394 | * reference it, this region map represents those offsets which have consumed | |
395 | * reservation ie. where pages have been instantiated. | |
a1e78772 | 396 | */ |
e7c4b0bf AW |
397 | static unsigned long get_vma_private_data(struct vm_area_struct *vma) |
398 | { | |
399 | return (unsigned long)vma->vm_private_data; | |
400 | } | |
401 | ||
402 | static void set_vma_private_data(struct vm_area_struct *vma, | |
403 | unsigned long value) | |
404 | { | |
405 | vma->vm_private_data = (void *)value; | |
406 | } | |
407 | ||
9119a41e | 408 | struct resv_map *resv_map_alloc(void) |
84afd99b AW |
409 | { |
410 | struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); | |
411 | if (!resv_map) | |
412 | return NULL; | |
413 | ||
414 | kref_init(&resv_map->refs); | |
7b24d861 | 415 | spin_lock_init(&resv_map->lock); |
84afd99b AW |
416 | INIT_LIST_HEAD(&resv_map->regions); |
417 | ||
418 | return resv_map; | |
419 | } | |
420 | ||
9119a41e | 421 | void resv_map_release(struct kref *ref) |
84afd99b AW |
422 | { |
423 | struct resv_map *resv_map = container_of(ref, struct resv_map, refs); | |
424 | ||
425 | /* Clear out any active regions before we release the map. */ | |
1406ec9b | 426 | region_truncate(resv_map, 0); |
84afd99b AW |
427 | kfree(resv_map); |
428 | } | |
429 | ||
4e35f483 JK |
430 | static inline struct resv_map *inode_resv_map(struct inode *inode) |
431 | { | |
432 | return inode->i_mapping->private_data; | |
433 | } | |
434 | ||
84afd99b | 435 | static struct resv_map *vma_resv_map(struct vm_area_struct *vma) |
a1e78772 MG |
436 | { |
437 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
4e35f483 JK |
438 | if (vma->vm_flags & VM_MAYSHARE) { |
439 | struct address_space *mapping = vma->vm_file->f_mapping; | |
440 | struct inode *inode = mapping->host; | |
441 | ||
442 | return inode_resv_map(inode); | |
443 | ||
444 | } else { | |
84afd99b AW |
445 | return (struct resv_map *)(get_vma_private_data(vma) & |
446 | ~HPAGE_RESV_MASK); | |
4e35f483 | 447 | } |
a1e78772 MG |
448 | } |
449 | ||
84afd99b | 450 | static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) |
a1e78772 MG |
451 | { |
452 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
f83a275d | 453 | VM_BUG_ON(vma->vm_flags & VM_MAYSHARE); |
a1e78772 | 454 | |
84afd99b AW |
455 | set_vma_private_data(vma, (get_vma_private_data(vma) & |
456 | HPAGE_RESV_MASK) | (unsigned long)map); | |
04f2cbe3 MG |
457 | } |
458 | ||
459 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) | |
460 | { | |
04f2cbe3 | 461 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
f83a275d | 462 | VM_BUG_ON(vma->vm_flags & VM_MAYSHARE); |
e7c4b0bf AW |
463 | |
464 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); | |
04f2cbe3 MG |
465 | } |
466 | ||
467 | static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) | |
468 | { | |
469 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
e7c4b0bf AW |
470 | |
471 | return (get_vma_private_data(vma) & flag) != 0; | |
a1e78772 MG |
472 | } |
473 | ||
04f2cbe3 | 474 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
a1e78772 MG |
475 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
476 | { | |
477 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
f83a275d | 478 | if (!(vma->vm_flags & VM_MAYSHARE)) |
a1e78772 MG |
479 | vma->vm_private_data = (void *)0; |
480 | } | |
481 | ||
482 | /* Returns true if the VMA has associated reserve pages */ | |
af0ed73e | 483 | static int vma_has_reserves(struct vm_area_struct *vma, long chg) |
a1e78772 | 484 | { |
af0ed73e JK |
485 | if (vma->vm_flags & VM_NORESERVE) { |
486 | /* | |
487 | * This address is already reserved by other process(chg == 0), | |
488 | * so, we should decrement reserved count. Without decrementing, | |
489 | * reserve count remains after releasing inode, because this | |
490 | * allocated page will go into page cache and is regarded as | |
491 | * coming from reserved pool in releasing step. Currently, we | |
492 | * don't have any other solution to deal with this situation | |
493 | * properly, so add work-around here. | |
494 | */ | |
495 | if (vma->vm_flags & VM_MAYSHARE && chg == 0) | |
496 | return 1; | |
497 | else | |
498 | return 0; | |
499 | } | |
a63884e9 JK |
500 | |
501 | /* Shared mappings always use reserves */ | |
f83a275d | 502 | if (vma->vm_flags & VM_MAYSHARE) |
7f09ca51 | 503 | return 1; |
a63884e9 JK |
504 | |
505 | /* | |
506 | * Only the process that called mmap() has reserves for | |
507 | * private mappings. | |
508 | */ | |
7f09ca51 MG |
509 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
510 | return 1; | |
a63884e9 | 511 | |
7f09ca51 | 512 | return 0; |
a1e78772 MG |
513 | } |
514 | ||
a5516438 | 515 | static void enqueue_huge_page(struct hstate *h, struct page *page) |
1da177e4 LT |
516 | { |
517 | int nid = page_to_nid(page); | |
0edaecfa | 518 | list_move(&page->lru, &h->hugepage_freelists[nid]); |
a5516438 AK |
519 | h->free_huge_pages++; |
520 | h->free_huge_pages_node[nid]++; | |
1da177e4 LT |
521 | } |
522 | ||
bf50bab2 NH |
523 | static struct page *dequeue_huge_page_node(struct hstate *h, int nid) |
524 | { | |
525 | struct page *page; | |
526 | ||
c8721bbb NH |
527 | list_for_each_entry(page, &h->hugepage_freelists[nid], lru) |
528 | if (!is_migrate_isolate_page(page)) | |
529 | break; | |
530 | /* | |
531 | * if 'non-isolated free hugepage' not found on the list, | |
532 | * the allocation fails. | |
533 | */ | |
534 | if (&h->hugepage_freelists[nid] == &page->lru) | |
bf50bab2 | 535 | return NULL; |
0edaecfa | 536 | list_move(&page->lru, &h->hugepage_activelist); |
a9869b83 | 537 | set_page_refcounted(page); |
bf50bab2 NH |
538 | h->free_huge_pages--; |
539 | h->free_huge_pages_node[nid]--; | |
540 | return page; | |
541 | } | |
542 | ||
86cdb465 NH |
543 | /* Movability of hugepages depends on migration support. */ |
544 | static inline gfp_t htlb_alloc_mask(struct hstate *h) | |
545 | { | |
100873d7 | 546 | if (hugepages_treat_as_movable || hugepage_migration_supported(h)) |
86cdb465 NH |
547 | return GFP_HIGHUSER_MOVABLE; |
548 | else | |
549 | return GFP_HIGHUSER; | |
550 | } | |
551 | ||
a5516438 AK |
552 | static struct page *dequeue_huge_page_vma(struct hstate *h, |
553 | struct vm_area_struct *vma, | |
af0ed73e JK |
554 | unsigned long address, int avoid_reserve, |
555 | long chg) | |
1da177e4 | 556 | { |
b1c12cbc | 557 | struct page *page = NULL; |
480eccf9 | 558 | struct mempolicy *mpol; |
19770b32 | 559 | nodemask_t *nodemask; |
c0ff7453 | 560 | struct zonelist *zonelist; |
dd1a239f MG |
561 | struct zone *zone; |
562 | struct zoneref *z; | |
cc9a6c87 | 563 | unsigned int cpuset_mems_cookie; |
1da177e4 | 564 | |
a1e78772 MG |
565 | /* |
566 | * A child process with MAP_PRIVATE mappings created by their parent | |
567 | * have no page reserves. This check ensures that reservations are | |
568 | * not "stolen". The child may still get SIGKILLed | |
569 | */ | |
af0ed73e | 570 | if (!vma_has_reserves(vma, chg) && |
a5516438 | 571 | h->free_huge_pages - h->resv_huge_pages == 0) |
c0ff7453 | 572 | goto err; |
a1e78772 | 573 | |
04f2cbe3 | 574 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
a5516438 | 575 | if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) |
6eab04a8 | 576 | goto err; |
04f2cbe3 | 577 | |
9966c4bb | 578 | retry_cpuset: |
d26914d1 | 579 | cpuset_mems_cookie = read_mems_allowed_begin(); |
9966c4bb | 580 | zonelist = huge_zonelist(vma, address, |
86cdb465 | 581 | htlb_alloc_mask(h), &mpol, &nodemask); |
9966c4bb | 582 | |
19770b32 MG |
583 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
584 | MAX_NR_ZONES - 1, nodemask) { | |
86cdb465 | 585 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask(h))) { |
bf50bab2 NH |
586 | page = dequeue_huge_page_node(h, zone_to_nid(zone)); |
587 | if (page) { | |
af0ed73e JK |
588 | if (avoid_reserve) |
589 | break; | |
590 | if (!vma_has_reserves(vma, chg)) | |
591 | break; | |
592 | ||
07443a85 | 593 | SetPagePrivate(page); |
af0ed73e | 594 | h->resv_huge_pages--; |
bf50bab2 NH |
595 | break; |
596 | } | |
3abf7afd | 597 | } |
1da177e4 | 598 | } |
cc9a6c87 | 599 | |
52cd3b07 | 600 | mpol_cond_put(mpol); |
d26914d1 | 601 | if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) |
cc9a6c87 | 602 | goto retry_cpuset; |
1da177e4 | 603 | return page; |
cc9a6c87 MG |
604 | |
605 | err: | |
cc9a6c87 | 606 | return NULL; |
1da177e4 LT |
607 | } |
608 | ||
1cac6f2c LC |
609 | /* |
610 | * common helper functions for hstate_next_node_to_{alloc|free}. | |
611 | * We may have allocated or freed a huge page based on a different | |
612 | * nodes_allowed previously, so h->next_node_to_{alloc|free} might | |
613 | * be outside of *nodes_allowed. Ensure that we use an allowed | |
614 | * node for alloc or free. | |
615 | */ | |
616 | static int next_node_allowed(int nid, nodemask_t *nodes_allowed) | |
617 | { | |
618 | nid = next_node(nid, *nodes_allowed); | |
619 | if (nid == MAX_NUMNODES) | |
620 | nid = first_node(*nodes_allowed); | |
621 | VM_BUG_ON(nid >= MAX_NUMNODES); | |
622 | ||
623 | return nid; | |
624 | } | |
625 | ||
626 | static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) | |
627 | { | |
628 | if (!node_isset(nid, *nodes_allowed)) | |
629 | nid = next_node_allowed(nid, nodes_allowed); | |
630 | return nid; | |
631 | } | |
632 | ||
633 | /* | |
634 | * returns the previously saved node ["this node"] from which to | |
635 | * allocate a persistent huge page for the pool and advance the | |
636 | * next node from which to allocate, handling wrap at end of node | |
637 | * mask. | |
638 | */ | |
639 | static int hstate_next_node_to_alloc(struct hstate *h, | |
640 | nodemask_t *nodes_allowed) | |
641 | { | |
642 | int nid; | |
643 | ||
644 | VM_BUG_ON(!nodes_allowed); | |
645 | ||
646 | nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); | |
647 | h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); | |
648 | ||
649 | return nid; | |
650 | } | |
651 | ||
652 | /* | |
653 | * helper for free_pool_huge_page() - return the previously saved | |
654 | * node ["this node"] from which to free a huge page. Advance the | |
655 | * next node id whether or not we find a free huge page to free so | |
656 | * that the next attempt to free addresses the next node. | |
657 | */ | |
658 | static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) | |
659 | { | |
660 | int nid; | |
661 | ||
662 | VM_BUG_ON(!nodes_allowed); | |
663 | ||
664 | nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); | |
665 | h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); | |
666 | ||
667 | return nid; | |
668 | } | |
669 | ||
670 | #define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \ | |
671 | for (nr_nodes = nodes_weight(*mask); \ | |
672 | nr_nodes > 0 && \ | |
673 | ((node = hstate_next_node_to_alloc(hs, mask)) || 1); \ | |
674 | nr_nodes--) | |
675 | ||
676 | #define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \ | |
677 | for (nr_nodes = nodes_weight(*mask); \ | |
678 | nr_nodes > 0 && \ | |
679 | ((node = hstate_next_node_to_free(hs, mask)) || 1); \ | |
680 | nr_nodes--) | |
681 | ||
944d9fec LC |
682 | #if defined(CONFIG_CMA) && defined(CONFIG_X86_64) |
683 | static void destroy_compound_gigantic_page(struct page *page, | |
684 | unsigned long order) | |
685 | { | |
686 | int i; | |
687 | int nr_pages = 1 << order; | |
688 | struct page *p = page + 1; | |
689 | ||
690 | for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { | |
691 | __ClearPageTail(p); | |
692 | set_page_refcounted(p); | |
693 | p->first_page = NULL; | |
694 | } | |
695 | ||
696 | set_compound_order(page, 0); | |
697 | __ClearPageHead(page); | |
698 | } | |
699 | ||
700 | static void free_gigantic_page(struct page *page, unsigned order) | |
701 | { | |
702 | free_contig_range(page_to_pfn(page), 1 << order); | |
703 | } | |
704 | ||
705 | static int __alloc_gigantic_page(unsigned long start_pfn, | |
706 | unsigned long nr_pages) | |
707 | { | |
708 | unsigned long end_pfn = start_pfn + nr_pages; | |
709 | return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE); | |
710 | } | |
711 | ||
712 | static bool pfn_range_valid_gigantic(unsigned long start_pfn, | |
713 | unsigned long nr_pages) | |
714 | { | |
715 | unsigned long i, end_pfn = start_pfn + nr_pages; | |
716 | struct page *page; | |
717 | ||
718 | for (i = start_pfn; i < end_pfn; i++) { | |
719 | if (!pfn_valid(i)) | |
720 | return false; | |
721 | ||
722 | page = pfn_to_page(i); | |
723 | ||
724 | if (PageReserved(page)) | |
725 | return false; | |
726 | ||
727 | if (page_count(page) > 0) | |
728 | return false; | |
729 | ||
730 | if (PageHuge(page)) | |
731 | return false; | |
732 | } | |
733 | ||
734 | return true; | |
735 | } | |
736 | ||
737 | static bool zone_spans_last_pfn(const struct zone *zone, | |
738 | unsigned long start_pfn, unsigned long nr_pages) | |
739 | { | |
740 | unsigned long last_pfn = start_pfn + nr_pages - 1; | |
741 | return zone_spans_pfn(zone, last_pfn); | |
742 | } | |
743 | ||
744 | static struct page *alloc_gigantic_page(int nid, unsigned order) | |
745 | { | |
746 | unsigned long nr_pages = 1 << order; | |
747 | unsigned long ret, pfn, flags; | |
748 | struct zone *z; | |
749 | ||
750 | z = NODE_DATA(nid)->node_zones; | |
751 | for (; z - NODE_DATA(nid)->node_zones < MAX_NR_ZONES; z++) { | |
752 | spin_lock_irqsave(&z->lock, flags); | |
753 | ||
754 | pfn = ALIGN(z->zone_start_pfn, nr_pages); | |
755 | while (zone_spans_last_pfn(z, pfn, nr_pages)) { | |
756 | if (pfn_range_valid_gigantic(pfn, nr_pages)) { | |
757 | /* | |
758 | * We release the zone lock here because | |
759 | * alloc_contig_range() will also lock the zone | |
760 | * at some point. If there's an allocation | |
761 | * spinning on this lock, it may win the race | |
762 | * and cause alloc_contig_range() to fail... | |
763 | */ | |
764 | spin_unlock_irqrestore(&z->lock, flags); | |
765 | ret = __alloc_gigantic_page(pfn, nr_pages); | |
766 | if (!ret) | |
767 | return pfn_to_page(pfn); | |
768 | spin_lock_irqsave(&z->lock, flags); | |
769 | } | |
770 | pfn += nr_pages; | |
771 | } | |
772 | ||
773 | spin_unlock_irqrestore(&z->lock, flags); | |
774 | } | |
775 | ||
776 | return NULL; | |
777 | } | |
778 | ||
779 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid); | |
780 | static void prep_compound_gigantic_page(struct page *page, unsigned long order); | |
781 | ||
782 | static struct page *alloc_fresh_gigantic_page_node(struct hstate *h, int nid) | |
783 | { | |
784 | struct page *page; | |
785 | ||
786 | page = alloc_gigantic_page(nid, huge_page_order(h)); | |
787 | if (page) { | |
788 | prep_compound_gigantic_page(page, huge_page_order(h)); | |
789 | prep_new_huge_page(h, page, nid); | |
790 | } | |
791 | ||
792 | return page; | |
793 | } | |
794 | ||
795 | static int alloc_fresh_gigantic_page(struct hstate *h, | |
796 | nodemask_t *nodes_allowed) | |
797 | { | |
798 | struct page *page = NULL; | |
799 | int nr_nodes, node; | |
800 | ||
801 | for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { | |
802 | page = alloc_fresh_gigantic_page_node(h, node); | |
803 | if (page) | |
804 | return 1; | |
805 | } | |
806 | ||
807 | return 0; | |
808 | } | |
809 | ||
810 | static inline bool gigantic_page_supported(void) { return true; } | |
811 | #else | |
812 | static inline bool gigantic_page_supported(void) { return false; } | |
813 | static inline void free_gigantic_page(struct page *page, unsigned order) { } | |
814 | static inline void destroy_compound_gigantic_page(struct page *page, | |
815 | unsigned long order) { } | |
816 | static inline int alloc_fresh_gigantic_page(struct hstate *h, | |
817 | nodemask_t *nodes_allowed) { return 0; } | |
818 | #endif | |
819 | ||
a5516438 | 820 | static void update_and_free_page(struct hstate *h, struct page *page) |
6af2acb6 AL |
821 | { |
822 | int i; | |
a5516438 | 823 | |
944d9fec LC |
824 | if (hstate_is_gigantic(h) && !gigantic_page_supported()) |
825 | return; | |
18229df5 | 826 | |
a5516438 AK |
827 | h->nr_huge_pages--; |
828 | h->nr_huge_pages_node[page_to_nid(page)]--; | |
829 | for (i = 0; i < pages_per_huge_page(h); i++) { | |
32f84528 CF |
830 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | |
831 | 1 << PG_referenced | 1 << PG_dirty | | |
a7407a27 LC |
832 | 1 << PG_active | 1 << PG_private | |
833 | 1 << PG_writeback); | |
6af2acb6 | 834 | } |
309381fe | 835 | VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); |
6af2acb6 AL |
836 | set_compound_page_dtor(page, NULL); |
837 | set_page_refcounted(page); | |
944d9fec LC |
838 | if (hstate_is_gigantic(h)) { |
839 | destroy_compound_gigantic_page(page, huge_page_order(h)); | |
840 | free_gigantic_page(page, huge_page_order(h)); | |
841 | } else { | |
842 | arch_release_hugepage(page); | |
843 | __free_pages(page, huge_page_order(h)); | |
844 | } | |
6af2acb6 AL |
845 | } |
846 | ||
e5ff2159 AK |
847 | struct hstate *size_to_hstate(unsigned long size) |
848 | { | |
849 | struct hstate *h; | |
850 | ||
851 | for_each_hstate(h) { | |
852 | if (huge_page_size(h) == size) | |
853 | return h; | |
854 | } | |
855 | return NULL; | |
856 | } | |
857 | ||
8f1d26d0 | 858 | void free_huge_page(struct page *page) |
27a85ef1 | 859 | { |
a5516438 AK |
860 | /* |
861 | * Can't pass hstate in here because it is called from the | |
862 | * compound page destructor. | |
863 | */ | |
e5ff2159 | 864 | struct hstate *h = page_hstate(page); |
7893d1d5 | 865 | int nid = page_to_nid(page); |
90481622 DG |
866 | struct hugepage_subpool *spool = |
867 | (struct hugepage_subpool *)page_private(page); | |
07443a85 | 868 | bool restore_reserve; |
27a85ef1 | 869 | |
e5df70ab | 870 | set_page_private(page, 0); |
23be7468 | 871 | page->mapping = NULL; |
7893d1d5 | 872 | BUG_ON(page_count(page)); |
0fe6e20b | 873 | BUG_ON(page_mapcount(page)); |
07443a85 | 874 | restore_reserve = PagePrivate(page); |
16c794b4 | 875 | ClearPagePrivate(page); |
27a85ef1 DG |
876 | |
877 | spin_lock(&hugetlb_lock); | |
6d76dcf4 AK |
878 | hugetlb_cgroup_uncharge_page(hstate_index(h), |
879 | pages_per_huge_page(h), page); | |
07443a85 JK |
880 | if (restore_reserve) |
881 | h->resv_huge_pages++; | |
882 | ||
944d9fec | 883 | if (h->surplus_huge_pages_node[nid]) { |
0edaecfa AK |
884 | /* remove the page from active list */ |
885 | list_del(&page->lru); | |
a5516438 AK |
886 | update_and_free_page(h, page); |
887 | h->surplus_huge_pages--; | |
888 | h->surplus_huge_pages_node[nid]--; | |
7893d1d5 | 889 | } else { |
5d3a551c | 890 | arch_clear_hugepage_flags(page); |
a5516438 | 891 | enqueue_huge_page(h, page); |
7893d1d5 | 892 | } |
27a85ef1 | 893 | spin_unlock(&hugetlb_lock); |
90481622 | 894 | hugepage_subpool_put_pages(spool, 1); |
27a85ef1 DG |
895 | } |
896 | ||
a5516438 | 897 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) |
b7ba30c6 | 898 | { |
0edaecfa | 899 | INIT_LIST_HEAD(&page->lru); |
b7ba30c6 AK |
900 | set_compound_page_dtor(page, free_huge_page); |
901 | spin_lock(&hugetlb_lock); | |
9dd540e2 | 902 | set_hugetlb_cgroup(page, NULL); |
a5516438 AK |
903 | h->nr_huge_pages++; |
904 | h->nr_huge_pages_node[nid]++; | |
b7ba30c6 AK |
905 | spin_unlock(&hugetlb_lock); |
906 | put_page(page); /* free it into the hugepage allocator */ | |
907 | } | |
908 | ||
2906dd52 | 909 | static void prep_compound_gigantic_page(struct page *page, unsigned long order) |
20a0307c WF |
910 | { |
911 | int i; | |
912 | int nr_pages = 1 << order; | |
913 | struct page *p = page + 1; | |
914 | ||
915 | /* we rely on prep_new_huge_page to set the destructor */ | |
916 | set_compound_order(page, order); | |
917 | __SetPageHead(page); | |
ef5a22be | 918 | __ClearPageReserved(page); |
20a0307c WF |
919 | for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { |
920 | __SetPageTail(p); | |
ef5a22be AA |
921 | /* |
922 | * For gigantic hugepages allocated through bootmem at | |
923 | * boot, it's safer to be consistent with the not-gigantic | |
924 | * hugepages and clear the PG_reserved bit from all tail pages | |
925 | * too. Otherwse drivers using get_user_pages() to access tail | |
926 | * pages may get the reference counting wrong if they see | |
927 | * PG_reserved set on a tail page (despite the head page not | |
928 | * having PG_reserved set). Enforcing this consistency between | |
929 | * head and tail pages allows drivers to optimize away a check | |
930 | * on the head page when they need know if put_page() is needed | |
931 | * after get_user_pages(). | |
932 | */ | |
933 | __ClearPageReserved(p); | |
58a84aa9 | 934 | set_page_count(p, 0); |
20a0307c WF |
935 | p->first_page = page; |
936 | } | |
937 | } | |
938 | ||
7795912c AM |
939 | /* |
940 | * PageHuge() only returns true for hugetlbfs pages, but not for normal or | |
941 | * transparent huge pages. See the PageTransHuge() documentation for more | |
942 | * details. | |
943 | */ | |
20a0307c WF |
944 | int PageHuge(struct page *page) |
945 | { | |
20a0307c WF |
946 | if (!PageCompound(page)) |
947 | return 0; | |
948 | ||
949 | page = compound_head(page); | |
758f66a2 | 950 | return get_compound_page_dtor(page) == free_huge_page; |
20a0307c | 951 | } |
43131e14 NH |
952 | EXPORT_SYMBOL_GPL(PageHuge); |
953 | ||
27c73ae7 AA |
954 | /* |
955 | * PageHeadHuge() only returns true for hugetlbfs head page, but not for | |
956 | * normal or transparent huge pages. | |
957 | */ | |
958 | int PageHeadHuge(struct page *page_head) | |
959 | { | |
27c73ae7 AA |
960 | if (!PageHead(page_head)) |
961 | return 0; | |
962 | ||
758f66a2 | 963 | return get_compound_page_dtor(page_head) == free_huge_page; |
27c73ae7 | 964 | } |
27c73ae7 | 965 | |
13d60f4b ZY |
966 | pgoff_t __basepage_index(struct page *page) |
967 | { | |
968 | struct page *page_head = compound_head(page); | |
969 | pgoff_t index = page_index(page_head); | |
970 | unsigned long compound_idx; | |
971 | ||
972 | if (!PageHuge(page_head)) | |
973 | return page_index(page); | |
974 | ||
975 | if (compound_order(page_head) >= MAX_ORDER) | |
976 | compound_idx = page_to_pfn(page) - page_to_pfn(page_head); | |
977 | else | |
978 | compound_idx = page - page_head; | |
979 | ||
980 | return (index << compound_order(page_head)) + compound_idx; | |
981 | } | |
982 | ||
a5516438 | 983 | static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) |
1da177e4 | 984 | { |
1da177e4 | 985 | struct page *page; |
f96efd58 | 986 | |
6484eb3e | 987 | page = alloc_pages_exact_node(nid, |
86cdb465 | 988 | htlb_alloc_mask(h)|__GFP_COMP|__GFP_THISNODE| |
551883ae | 989 | __GFP_REPEAT|__GFP_NOWARN, |
a5516438 | 990 | huge_page_order(h)); |
1da177e4 | 991 | if (page) { |
7f2e9525 | 992 | if (arch_prepare_hugepage(page)) { |
caff3a2c | 993 | __free_pages(page, huge_page_order(h)); |
7b8ee84d | 994 | return NULL; |
7f2e9525 | 995 | } |
a5516438 | 996 | prep_new_huge_page(h, page, nid); |
1da177e4 | 997 | } |
63b4613c NA |
998 | |
999 | return page; | |
1000 | } | |
1001 | ||
b2261026 JK |
1002 | static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed) |
1003 | { | |
1004 | struct page *page; | |
1005 | int nr_nodes, node; | |
1006 | int ret = 0; | |
1007 | ||
1008 | for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { | |
1009 | page = alloc_fresh_huge_page_node(h, node); | |
1010 | if (page) { | |
1011 | ret = 1; | |
1012 | break; | |
1013 | } | |
1014 | } | |
1015 | ||
1016 | if (ret) | |
1017 | count_vm_event(HTLB_BUDDY_PGALLOC); | |
1018 | else | |
1019 | count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); | |
1020 | ||
1021 | return ret; | |
1022 | } | |
1023 | ||
e8c5c824 LS |
1024 | /* |
1025 | * Free huge page from pool from next node to free. | |
1026 | * Attempt to keep persistent huge pages more or less | |
1027 | * balanced over allowed nodes. | |
1028 | * Called with hugetlb_lock locked. | |
1029 | */ | |
6ae11b27 LS |
1030 | static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, |
1031 | bool acct_surplus) | |
e8c5c824 | 1032 | { |
b2261026 | 1033 | int nr_nodes, node; |
e8c5c824 LS |
1034 | int ret = 0; |
1035 | ||
b2261026 | 1036 | for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { |
685f3457 LS |
1037 | /* |
1038 | * If we're returning unused surplus pages, only examine | |
1039 | * nodes with surplus pages. | |
1040 | */ | |
b2261026 JK |
1041 | if ((!acct_surplus || h->surplus_huge_pages_node[node]) && |
1042 | !list_empty(&h->hugepage_freelists[node])) { | |
e8c5c824 | 1043 | struct page *page = |
b2261026 | 1044 | list_entry(h->hugepage_freelists[node].next, |
e8c5c824 LS |
1045 | struct page, lru); |
1046 | list_del(&page->lru); | |
1047 | h->free_huge_pages--; | |
b2261026 | 1048 | h->free_huge_pages_node[node]--; |
685f3457 LS |
1049 | if (acct_surplus) { |
1050 | h->surplus_huge_pages--; | |
b2261026 | 1051 | h->surplus_huge_pages_node[node]--; |
685f3457 | 1052 | } |
e8c5c824 LS |
1053 | update_and_free_page(h, page); |
1054 | ret = 1; | |
9a76db09 | 1055 | break; |
e8c5c824 | 1056 | } |
b2261026 | 1057 | } |
e8c5c824 LS |
1058 | |
1059 | return ret; | |
1060 | } | |
1061 | ||
c8721bbb NH |
1062 | /* |
1063 | * Dissolve a given free hugepage into free buddy pages. This function does | |
1064 | * nothing for in-use (including surplus) hugepages. | |
1065 | */ | |
1066 | static void dissolve_free_huge_page(struct page *page) | |
1067 | { | |
1068 | spin_lock(&hugetlb_lock); | |
1069 | if (PageHuge(page) && !page_count(page)) { | |
1070 | struct hstate *h = page_hstate(page); | |
1071 | int nid = page_to_nid(page); | |
1072 | list_del(&page->lru); | |
1073 | h->free_huge_pages--; | |
1074 | h->free_huge_pages_node[nid]--; | |
1075 | update_and_free_page(h, page); | |
1076 | } | |
1077 | spin_unlock(&hugetlb_lock); | |
1078 | } | |
1079 | ||
1080 | /* | |
1081 | * Dissolve free hugepages in a given pfn range. Used by memory hotplug to | |
1082 | * make specified memory blocks removable from the system. | |
1083 | * Note that start_pfn should aligned with (minimum) hugepage size. | |
1084 | */ | |
1085 | void dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn) | |
1086 | { | |
1087 | unsigned int order = 8 * sizeof(void *); | |
1088 | unsigned long pfn; | |
1089 | struct hstate *h; | |
1090 | ||
1091 | /* Set scan step to minimum hugepage size */ | |
1092 | for_each_hstate(h) | |
1093 | if (order > huge_page_order(h)) | |
1094 | order = huge_page_order(h); | |
1095 | VM_BUG_ON(!IS_ALIGNED(start_pfn, 1 << order)); | |
1096 | for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << order) | |
1097 | dissolve_free_huge_page(pfn_to_page(pfn)); | |
1098 | } | |
1099 | ||
bf50bab2 | 1100 | static struct page *alloc_buddy_huge_page(struct hstate *h, int nid) |
7893d1d5 AL |
1101 | { |
1102 | struct page *page; | |
bf50bab2 | 1103 | unsigned int r_nid; |
7893d1d5 | 1104 | |
bae7f4ae | 1105 | if (hstate_is_gigantic(h)) |
aa888a74 AK |
1106 | return NULL; |
1107 | ||
d1c3fb1f NA |
1108 | /* |
1109 | * Assume we will successfully allocate the surplus page to | |
1110 | * prevent racing processes from causing the surplus to exceed | |
1111 | * overcommit | |
1112 | * | |
1113 | * This however introduces a different race, where a process B | |
1114 | * tries to grow the static hugepage pool while alloc_pages() is | |
1115 | * called by process A. B will only examine the per-node | |
1116 | * counters in determining if surplus huge pages can be | |
1117 | * converted to normal huge pages in adjust_pool_surplus(). A | |
1118 | * won't be able to increment the per-node counter, until the | |
1119 | * lock is dropped by B, but B doesn't drop hugetlb_lock until | |
1120 | * no more huge pages can be converted from surplus to normal | |
1121 | * state (and doesn't try to convert again). Thus, we have a | |
1122 | * case where a surplus huge page exists, the pool is grown, and | |
1123 | * the surplus huge page still exists after, even though it | |
1124 | * should just have been converted to a normal huge page. This | |
1125 | * does not leak memory, though, as the hugepage will be freed | |
1126 | * once it is out of use. It also does not allow the counters to | |
1127 | * go out of whack in adjust_pool_surplus() as we don't modify | |
1128 | * the node values until we've gotten the hugepage and only the | |
1129 | * per-node value is checked there. | |
1130 | */ | |
1131 | spin_lock(&hugetlb_lock); | |
a5516438 | 1132 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { |
d1c3fb1f NA |
1133 | spin_unlock(&hugetlb_lock); |
1134 | return NULL; | |
1135 | } else { | |
a5516438 AK |
1136 | h->nr_huge_pages++; |
1137 | h->surplus_huge_pages++; | |
d1c3fb1f NA |
1138 | } |
1139 | spin_unlock(&hugetlb_lock); | |
1140 | ||
bf50bab2 | 1141 | if (nid == NUMA_NO_NODE) |
86cdb465 | 1142 | page = alloc_pages(htlb_alloc_mask(h)|__GFP_COMP| |
bf50bab2 NH |
1143 | __GFP_REPEAT|__GFP_NOWARN, |
1144 | huge_page_order(h)); | |
1145 | else | |
1146 | page = alloc_pages_exact_node(nid, | |
86cdb465 | 1147 | htlb_alloc_mask(h)|__GFP_COMP|__GFP_THISNODE| |
bf50bab2 | 1148 | __GFP_REPEAT|__GFP_NOWARN, huge_page_order(h)); |
d1c3fb1f | 1149 | |
caff3a2c GS |
1150 | if (page && arch_prepare_hugepage(page)) { |
1151 | __free_pages(page, huge_page_order(h)); | |
ea5768c7 | 1152 | page = NULL; |
caff3a2c GS |
1153 | } |
1154 | ||
d1c3fb1f | 1155 | spin_lock(&hugetlb_lock); |
7893d1d5 | 1156 | if (page) { |
0edaecfa | 1157 | INIT_LIST_HEAD(&page->lru); |
bf50bab2 | 1158 | r_nid = page_to_nid(page); |
7893d1d5 | 1159 | set_compound_page_dtor(page, free_huge_page); |
9dd540e2 | 1160 | set_hugetlb_cgroup(page, NULL); |
d1c3fb1f NA |
1161 | /* |
1162 | * We incremented the global counters already | |
1163 | */ | |
bf50bab2 NH |
1164 | h->nr_huge_pages_node[r_nid]++; |
1165 | h->surplus_huge_pages_node[r_nid]++; | |
3b116300 | 1166 | __count_vm_event(HTLB_BUDDY_PGALLOC); |
d1c3fb1f | 1167 | } else { |
a5516438 AK |
1168 | h->nr_huge_pages--; |
1169 | h->surplus_huge_pages--; | |
3b116300 | 1170 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
7893d1d5 | 1171 | } |
d1c3fb1f | 1172 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
1173 | |
1174 | return page; | |
1175 | } | |
1176 | ||
bf50bab2 NH |
1177 | /* |
1178 | * This allocation function is useful in the context where vma is irrelevant. | |
1179 | * E.g. soft-offlining uses this function because it only cares physical | |
1180 | * address of error page. | |
1181 | */ | |
1182 | struct page *alloc_huge_page_node(struct hstate *h, int nid) | |
1183 | { | |
4ef91848 | 1184 | struct page *page = NULL; |
bf50bab2 NH |
1185 | |
1186 | spin_lock(&hugetlb_lock); | |
4ef91848 JK |
1187 | if (h->free_huge_pages - h->resv_huge_pages > 0) |
1188 | page = dequeue_huge_page_node(h, nid); | |
bf50bab2 NH |
1189 | spin_unlock(&hugetlb_lock); |
1190 | ||
94ae8ba7 | 1191 | if (!page) |
bf50bab2 NH |
1192 | page = alloc_buddy_huge_page(h, nid); |
1193 | ||
1194 | return page; | |
1195 | } | |
1196 | ||
e4e574b7 | 1197 | /* |
25985edc | 1198 | * Increase the hugetlb pool such that it can accommodate a reservation |
e4e574b7 AL |
1199 | * of size 'delta'. |
1200 | */ | |
a5516438 | 1201 | static int gather_surplus_pages(struct hstate *h, int delta) |
e4e574b7 AL |
1202 | { |
1203 | struct list_head surplus_list; | |
1204 | struct page *page, *tmp; | |
1205 | int ret, i; | |
1206 | int needed, allocated; | |
28073b02 | 1207 | bool alloc_ok = true; |
e4e574b7 | 1208 | |
a5516438 | 1209 | needed = (h->resv_huge_pages + delta) - h->free_huge_pages; |
ac09b3a1 | 1210 | if (needed <= 0) { |
a5516438 | 1211 | h->resv_huge_pages += delta; |
e4e574b7 | 1212 | return 0; |
ac09b3a1 | 1213 | } |
e4e574b7 AL |
1214 | |
1215 | allocated = 0; | |
1216 | INIT_LIST_HEAD(&surplus_list); | |
1217 | ||
1218 | ret = -ENOMEM; | |
1219 | retry: | |
1220 | spin_unlock(&hugetlb_lock); | |
1221 | for (i = 0; i < needed; i++) { | |
bf50bab2 | 1222 | page = alloc_buddy_huge_page(h, NUMA_NO_NODE); |
28073b02 HD |
1223 | if (!page) { |
1224 | alloc_ok = false; | |
1225 | break; | |
1226 | } | |
e4e574b7 AL |
1227 | list_add(&page->lru, &surplus_list); |
1228 | } | |
28073b02 | 1229 | allocated += i; |
e4e574b7 AL |
1230 | |
1231 | /* | |
1232 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
1233 | * because either resv_huge_pages or free_huge_pages may have changed. | |
1234 | */ | |
1235 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
1236 | needed = (h->resv_huge_pages + delta) - |
1237 | (h->free_huge_pages + allocated); | |
28073b02 HD |
1238 | if (needed > 0) { |
1239 | if (alloc_ok) | |
1240 | goto retry; | |
1241 | /* | |
1242 | * We were not able to allocate enough pages to | |
1243 | * satisfy the entire reservation so we free what | |
1244 | * we've allocated so far. | |
1245 | */ | |
1246 | goto free; | |
1247 | } | |
e4e574b7 AL |
1248 | /* |
1249 | * The surplus_list now contains _at_least_ the number of extra pages | |
25985edc | 1250 | * needed to accommodate the reservation. Add the appropriate number |
e4e574b7 | 1251 | * of pages to the hugetlb pool and free the extras back to the buddy |
ac09b3a1 AL |
1252 | * allocator. Commit the entire reservation here to prevent another |
1253 | * process from stealing the pages as they are added to the pool but | |
1254 | * before they are reserved. | |
e4e574b7 AL |
1255 | */ |
1256 | needed += allocated; | |
a5516438 | 1257 | h->resv_huge_pages += delta; |
e4e574b7 | 1258 | ret = 0; |
a9869b83 | 1259 | |
19fc3f0a | 1260 | /* Free the needed pages to the hugetlb pool */ |
e4e574b7 | 1261 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
19fc3f0a AL |
1262 | if ((--needed) < 0) |
1263 | break; | |
a9869b83 NH |
1264 | /* |
1265 | * This page is now managed by the hugetlb allocator and has | |
1266 | * no users -- drop the buddy allocator's reference. | |
1267 | */ | |
1268 | put_page_testzero(page); | |
309381fe | 1269 | VM_BUG_ON_PAGE(page_count(page), page); |
a5516438 | 1270 | enqueue_huge_page(h, page); |
19fc3f0a | 1271 | } |
28073b02 | 1272 | free: |
b0365c8d | 1273 | spin_unlock(&hugetlb_lock); |
19fc3f0a AL |
1274 | |
1275 | /* Free unnecessary surplus pages to the buddy allocator */ | |
c0d934ba JK |
1276 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) |
1277 | put_page(page); | |
a9869b83 | 1278 | spin_lock(&hugetlb_lock); |
e4e574b7 AL |
1279 | |
1280 | return ret; | |
1281 | } | |
1282 | ||
1283 | /* | |
1284 | * When releasing a hugetlb pool reservation, any surplus pages that were | |
1285 | * allocated to satisfy the reservation must be explicitly freed if they were | |
1286 | * never used. | |
685f3457 | 1287 | * Called with hugetlb_lock held. |
e4e574b7 | 1288 | */ |
a5516438 AK |
1289 | static void return_unused_surplus_pages(struct hstate *h, |
1290 | unsigned long unused_resv_pages) | |
e4e574b7 | 1291 | { |
e4e574b7 AL |
1292 | unsigned long nr_pages; |
1293 | ||
ac09b3a1 | 1294 | /* Uncommit the reservation */ |
a5516438 | 1295 | h->resv_huge_pages -= unused_resv_pages; |
ac09b3a1 | 1296 | |
aa888a74 | 1297 | /* Cannot return gigantic pages currently */ |
bae7f4ae | 1298 | if (hstate_is_gigantic(h)) |
aa888a74 AK |
1299 | return; |
1300 | ||
a5516438 | 1301 | nr_pages = min(unused_resv_pages, h->surplus_huge_pages); |
e4e574b7 | 1302 | |
685f3457 LS |
1303 | /* |
1304 | * We want to release as many surplus pages as possible, spread | |
9b5e5d0f LS |
1305 | * evenly across all nodes with memory. Iterate across these nodes |
1306 | * until we can no longer free unreserved surplus pages. This occurs | |
1307 | * when the nodes with surplus pages have no free pages. | |
1308 | * free_pool_huge_page() will balance the the freed pages across the | |
1309 | * on-line nodes with memory and will handle the hstate accounting. | |
685f3457 LS |
1310 | */ |
1311 | while (nr_pages--) { | |
8cebfcd0 | 1312 | if (!free_pool_huge_page(h, &node_states[N_MEMORY], 1)) |
685f3457 | 1313 | break; |
7848a4bf | 1314 | cond_resched_lock(&hugetlb_lock); |
e4e574b7 AL |
1315 | } |
1316 | } | |
1317 | ||
c37f9fb1 AW |
1318 | /* |
1319 | * Determine if the huge page at addr within the vma has an associated | |
1320 | * reservation. Where it does not we will need to logically increase | |
90481622 DG |
1321 | * reservation and actually increase subpool usage before an allocation |
1322 | * can occur. Where any new reservation would be required the | |
1323 | * reservation change is prepared, but not committed. Once the page | |
1324 | * has been allocated from the subpool and instantiated the change should | |
1325 | * be committed via vma_commit_reservation. No action is required on | |
1326 | * failure. | |
c37f9fb1 | 1327 | */ |
e2f17d94 | 1328 | static long vma_needs_reservation(struct hstate *h, |
a5516438 | 1329 | struct vm_area_struct *vma, unsigned long addr) |
c37f9fb1 | 1330 | { |
4e35f483 JK |
1331 | struct resv_map *resv; |
1332 | pgoff_t idx; | |
1333 | long chg; | |
c37f9fb1 | 1334 | |
4e35f483 JK |
1335 | resv = vma_resv_map(vma); |
1336 | if (!resv) | |
84afd99b | 1337 | return 1; |
c37f9fb1 | 1338 | |
4e35f483 JK |
1339 | idx = vma_hugecache_offset(h, vma, addr); |
1340 | chg = region_chg(resv, idx, idx + 1); | |
84afd99b | 1341 | |
4e35f483 JK |
1342 | if (vma->vm_flags & VM_MAYSHARE) |
1343 | return chg; | |
1344 | else | |
1345 | return chg < 0 ? chg : 0; | |
c37f9fb1 | 1346 | } |
a5516438 AK |
1347 | static void vma_commit_reservation(struct hstate *h, |
1348 | struct vm_area_struct *vma, unsigned long addr) | |
c37f9fb1 | 1349 | { |
4e35f483 JK |
1350 | struct resv_map *resv; |
1351 | pgoff_t idx; | |
84afd99b | 1352 | |
4e35f483 JK |
1353 | resv = vma_resv_map(vma); |
1354 | if (!resv) | |
1355 | return; | |
84afd99b | 1356 | |
4e35f483 JK |
1357 | idx = vma_hugecache_offset(h, vma, addr); |
1358 | region_add(resv, idx, idx + 1); | |
c37f9fb1 AW |
1359 | } |
1360 | ||
a1e78772 | 1361 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
04f2cbe3 | 1362 | unsigned long addr, int avoid_reserve) |
1da177e4 | 1363 | { |
90481622 | 1364 | struct hugepage_subpool *spool = subpool_vma(vma); |
a5516438 | 1365 | struct hstate *h = hstate_vma(vma); |
348ea204 | 1366 | struct page *page; |
e2f17d94 | 1367 | long chg; |
6d76dcf4 AK |
1368 | int ret, idx; |
1369 | struct hugetlb_cgroup *h_cg; | |
a1e78772 | 1370 | |
6d76dcf4 | 1371 | idx = hstate_index(h); |
a1e78772 | 1372 | /* |
90481622 DG |
1373 | * Processes that did not create the mapping will have no |
1374 | * reserves and will not have accounted against subpool | |
1375 | * limit. Check that the subpool limit can be made before | |
1376 | * satisfying the allocation MAP_NORESERVE mappings may also | |
1377 | * need pages and subpool limit allocated allocated if no reserve | |
1378 | * mapping overlaps. | |
a1e78772 | 1379 | */ |
a5516438 | 1380 | chg = vma_needs_reservation(h, vma, addr); |
c37f9fb1 | 1381 | if (chg < 0) |
76dcee75 | 1382 | return ERR_PTR(-ENOMEM); |
8bb3f12e JK |
1383 | if (chg || avoid_reserve) |
1384 | if (hugepage_subpool_get_pages(spool, 1)) | |
76dcee75 | 1385 | return ERR_PTR(-ENOSPC); |
1da177e4 | 1386 | |
6d76dcf4 | 1387 | ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg); |
8f34af6f JZ |
1388 | if (ret) |
1389 | goto out_subpool_put; | |
1390 | ||
1da177e4 | 1391 | spin_lock(&hugetlb_lock); |
af0ed73e | 1392 | page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, chg); |
81a6fcae | 1393 | if (!page) { |
94ae8ba7 | 1394 | spin_unlock(&hugetlb_lock); |
bf50bab2 | 1395 | page = alloc_buddy_huge_page(h, NUMA_NO_NODE); |
8f34af6f JZ |
1396 | if (!page) |
1397 | goto out_uncharge_cgroup; | |
1398 | ||
79dbb236 AK |
1399 | spin_lock(&hugetlb_lock); |
1400 | list_move(&page->lru, &h->hugepage_activelist); | |
81a6fcae | 1401 | /* Fall through */ |
68842c9b | 1402 | } |
81a6fcae JK |
1403 | hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page); |
1404 | spin_unlock(&hugetlb_lock); | |
348ea204 | 1405 | |
90481622 | 1406 | set_page_private(page, (unsigned long)spool); |
90d8b7e6 | 1407 | |
a5516438 | 1408 | vma_commit_reservation(h, vma, addr); |
90d8b7e6 | 1409 | return page; |
8f34af6f JZ |
1410 | |
1411 | out_uncharge_cgroup: | |
1412 | hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg); | |
1413 | out_subpool_put: | |
1414 | if (chg || avoid_reserve) | |
1415 | hugepage_subpool_put_pages(spool, 1); | |
1416 | return ERR_PTR(-ENOSPC); | |
b45b5bd6 DG |
1417 | } |
1418 | ||
74060e4d NH |
1419 | /* |
1420 | * alloc_huge_page()'s wrapper which simply returns the page if allocation | |
1421 | * succeeds, otherwise NULL. This function is called from new_vma_page(), | |
1422 | * where no ERR_VALUE is expected to be returned. | |
1423 | */ | |
1424 | struct page *alloc_huge_page_noerr(struct vm_area_struct *vma, | |
1425 | unsigned long addr, int avoid_reserve) | |
1426 | { | |
1427 | struct page *page = alloc_huge_page(vma, addr, avoid_reserve); | |
1428 | if (IS_ERR(page)) | |
1429 | page = NULL; | |
1430 | return page; | |
1431 | } | |
1432 | ||
91f47662 | 1433 | int __weak alloc_bootmem_huge_page(struct hstate *h) |
aa888a74 AK |
1434 | { |
1435 | struct huge_bootmem_page *m; | |
b2261026 | 1436 | int nr_nodes, node; |
aa888a74 | 1437 | |
b2261026 | 1438 | for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) { |
aa888a74 AK |
1439 | void *addr; |
1440 | ||
8b89a116 GS |
1441 | addr = memblock_virt_alloc_try_nid_nopanic( |
1442 | huge_page_size(h), huge_page_size(h), | |
1443 | 0, BOOTMEM_ALLOC_ACCESSIBLE, node); | |
aa888a74 AK |
1444 | if (addr) { |
1445 | /* | |
1446 | * Use the beginning of the huge page to store the | |
1447 | * huge_bootmem_page struct (until gather_bootmem | |
1448 | * puts them into the mem_map). | |
1449 | */ | |
1450 | m = addr; | |
91f47662 | 1451 | goto found; |
aa888a74 | 1452 | } |
aa888a74 AK |
1453 | } |
1454 | return 0; | |
1455 | ||
1456 | found: | |
1457 | BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1)); | |
1458 | /* Put them into a private list first because mem_map is not up yet */ | |
1459 | list_add(&m->list, &huge_boot_pages); | |
1460 | m->hstate = h; | |
1461 | return 1; | |
1462 | } | |
1463 | ||
f412c97a | 1464 | static void __init prep_compound_huge_page(struct page *page, int order) |
18229df5 AW |
1465 | { |
1466 | if (unlikely(order > (MAX_ORDER - 1))) | |
1467 | prep_compound_gigantic_page(page, order); | |
1468 | else | |
1469 | prep_compound_page(page, order); | |
1470 | } | |
1471 | ||
aa888a74 AK |
1472 | /* Put bootmem huge pages into the standard lists after mem_map is up */ |
1473 | static void __init gather_bootmem_prealloc(void) | |
1474 | { | |
1475 | struct huge_bootmem_page *m; | |
1476 | ||
1477 | list_for_each_entry(m, &huge_boot_pages, list) { | |
aa888a74 | 1478 | struct hstate *h = m->hstate; |
ee8f248d BB |
1479 | struct page *page; |
1480 | ||
1481 | #ifdef CONFIG_HIGHMEM | |
1482 | page = pfn_to_page(m->phys >> PAGE_SHIFT); | |
8b89a116 GS |
1483 | memblock_free_late(__pa(m), |
1484 | sizeof(struct huge_bootmem_page)); | |
ee8f248d BB |
1485 | #else |
1486 | page = virt_to_page(m); | |
1487 | #endif | |
aa888a74 | 1488 | WARN_ON(page_count(page) != 1); |
18229df5 | 1489 | prep_compound_huge_page(page, h->order); |
ef5a22be | 1490 | WARN_ON(PageReserved(page)); |
aa888a74 | 1491 | prep_new_huge_page(h, page, page_to_nid(page)); |
b0320c7b RA |
1492 | /* |
1493 | * If we had gigantic hugepages allocated at boot time, we need | |
1494 | * to restore the 'stolen' pages to totalram_pages in order to | |
1495 | * fix confusing memory reports from free(1) and another | |
1496 | * side-effects, like CommitLimit going negative. | |
1497 | */ | |
bae7f4ae | 1498 | if (hstate_is_gigantic(h)) |
3dcc0571 | 1499 | adjust_managed_page_count(page, 1 << h->order); |
aa888a74 AK |
1500 | } |
1501 | } | |
1502 | ||
8faa8b07 | 1503 | static void __init hugetlb_hstate_alloc_pages(struct hstate *h) |
1da177e4 LT |
1504 | { |
1505 | unsigned long i; | |
a5516438 | 1506 | |
e5ff2159 | 1507 | for (i = 0; i < h->max_huge_pages; ++i) { |
bae7f4ae | 1508 | if (hstate_is_gigantic(h)) { |
aa888a74 AK |
1509 | if (!alloc_bootmem_huge_page(h)) |
1510 | break; | |
9b5e5d0f | 1511 | } else if (!alloc_fresh_huge_page(h, |
8cebfcd0 | 1512 | &node_states[N_MEMORY])) |
1da177e4 | 1513 | break; |
1da177e4 | 1514 | } |
8faa8b07 | 1515 | h->max_huge_pages = i; |
e5ff2159 AK |
1516 | } |
1517 | ||
1518 | static void __init hugetlb_init_hstates(void) | |
1519 | { | |
1520 | struct hstate *h; | |
1521 | ||
1522 | for_each_hstate(h) { | |
8faa8b07 | 1523 | /* oversize hugepages were init'ed in early boot */ |
bae7f4ae | 1524 | if (!hstate_is_gigantic(h)) |
8faa8b07 | 1525 | hugetlb_hstate_alloc_pages(h); |
e5ff2159 AK |
1526 | } |
1527 | } | |
1528 | ||
4abd32db AK |
1529 | static char * __init memfmt(char *buf, unsigned long n) |
1530 | { | |
1531 | if (n >= (1UL << 30)) | |
1532 | sprintf(buf, "%lu GB", n >> 30); | |
1533 | else if (n >= (1UL << 20)) | |
1534 | sprintf(buf, "%lu MB", n >> 20); | |
1535 | else | |
1536 | sprintf(buf, "%lu KB", n >> 10); | |
1537 | return buf; | |
1538 | } | |
1539 | ||
e5ff2159 AK |
1540 | static void __init report_hugepages(void) |
1541 | { | |
1542 | struct hstate *h; | |
1543 | ||
1544 | for_each_hstate(h) { | |
4abd32db | 1545 | char buf[32]; |
ffb22af5 | 1546 | pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n", |
4abd32db AK |
1547 | memfmt(buf, huge_page_size(h)), |
1548 | h->free_huge_pages); | |
e5ff2159 AK |
1549 | } |
1550 | } | |
1551 | ||
1da177e4 | 1552 | #ifdef CONFIG_HIGHMEM |
6ae11b27 LS |
1553 | static void try_to_free_low(struct hstate *h, unsigned long count, |
1554 | nodemask_t *nodes_allowed) | |
1da177e4 | 1555 | { |
4415cc8d CL |
1556 | int i; |
1557 | ||
bae7f4ae | 1558 | if (hstate_is_gigantic(h)) |
aa888a74 AK |
1559 | return; |
1560 | ||
6ae11b27 | 1561 | for_each_node_mask(i, *nodes_allowed) { |
1da177e4 | 1562 | struct page *page, *next; |
a5516438 AK |
1563 | struct list_head *freel = &h->hugepage_freelists[i]; |
1564 | list_for_each_entry_safe(page, next, freel, lru) { | |
1565 | if (count >= h->nr_huge_pages) | |
6b0c880d | 1566 | return; |
1da177e4 LT |
1567 | if (PageHighMem(page)) |
1568 | continue; | |
1569 | list_del(&page->lru); | |
e5ff2159 | 1570 | update_and_free_page(h, page); |
a5516438 AK |
1571 | h->free_huge_pages--; |
1572 | h->free_huge_pages_node[page_to_nid(page)]--; | |
1da177e4 LT |
1573 | } |
1574 | } | |
1575 | } | |
1576 | #else | |
6ae11b27 LS |
1577 | static inline void try_to_free_low(struct hstate *h, unsigned long count, |
1578 | nodemask_t *nodes_allowed) | |
1da177e4 LT |
1579 | { |
1580 | } | |
1581 | #endif | |
1582 | ||
20a0307c WF |
1583 | /* |
1584 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
1585 | * balanced by operating on them in a round-robin fashion. | |
1586 | * Returns 1 if an adjustment was made. | |
1587 | */ | |
6ae11b27 LS |
1588 | static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, |
1589 | int delta) | |
20a0307c | 1590 | { |
b2261026 | 1591 | int nr_nodes, node; |
20a0307c WF |
1592 | |
1593 | VM_BUG_ON(delta != -1 && delta != 1); | |
20a0307c | 1594 | |
b2261026 JK |
1595 | if (delta < 0) { |
1596 | for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) { | |
1597 | if (h->surplus_huge_pages_node[node]) | |
1598 | goto found; | |
e8c5c824 | 1599 | } |
b2261026 JK |
1600 | } else { |
1601 | for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { | |
1602 | if (h->surplus_huge_pages_node[node] < | |
1603 | h->nr_huge_pages_node[node]) | |
1604 | goto found; | |
e8c5c824 | 1605 | } |
b2261026 JK |
1606 | } |
1607 | return 0; | |
20a0307c | 1608 | |
b2261026 JK |
1609 | found: |
1610 | h->surplus_huge_pages += delta; | |
1611 | h->surplus_huge_pages_node[node] += delta; | |
1612 | return 1; | |
20a0307c WF |
1613 | } |
1614 | ||
a5516438 | 1615 | #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) |
6ae11b27 LS |
1616 | static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count, |
1617 | nodemask_t *nodes_allowed) | |
1da177e4 | 1618 | { |
7893d1d5 | 1619 | unsigned long min_count, ret; |
1da177e4 | 1620 | |
944d9fec | 1621 | if (hstate_is_gigantic(h) && !gigantic_page_supported()) |
aa888a74 AK |
1622 | return h->max_huge_pages; |
1623 | ||
7893d1d5 AL |
1624 | /* |
1625 | * Increase the pool size | |
1626 | * First take pages out of surplus state. Then make up the | |
1627 | * remaining difference by allocating fresh huge pages. | |
d1c3fb1f NA |
1628 | * |
1629 | * We might race with alloc_buddy_huge_page() here and be unable | |
1630 | * to convert a surplus huge page to a normal huge page. That is | |
1631 | * not critical, though, it just means the overall size of the | |
1632 | * pool might be one hugepage larger than it needs to be, but | |
1633 | * within all the constraints specified by the sysctls. | |
7893d1d5 | 1634 | */ |
1da177e4 | 1635 | spin_lock(&hugetlb_lock); |
a5516438 | 1636 | while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { |
6ae11b27 | 1637 | if (!adjust_pool_surplus(h, nodes_allowed, -1)) |
7893d1d5 AL |
1638 | break; |
1639 | } | |
1640 | ||
a5516438 | 1641 | while (count > persistent_huge_pages(h)) { |
7893d1d5 AL |
1642 | /* |
1643 | * If this allocation races such that we no longer need the | |
1644 | * page, free_huge_page will handle it by freeing the page | |
1645 | * and reducing the surplus. | |
1646 | */ | |
1647 | spin_unlock(&hugetlb_lock); | |
944d9fec LC |
1648 | if (hstate_is_gigantic(h)) |
1649 | ret = alloc_fresh_gigantic_page(h, nodes_allowed); | |
1650 | else | |
1651 | ret = alloc_fresh_huge_page(h, nodes_allowed); | |
7893d1d5 AL |
1652 | spin_lock(&hugetlb_lock); |
1653 | if (!ret) | |
1654 | goto out; | |
1655 | ||
536240f2 MG |
1656 | /* Bail for signals. Probably ctrl-c from user */ |
1657 | if (signal_pending(current)) | |
1658 | goto out; | |
7893d1d5 | 1659 | } |
7893d1d5 AL |
1660 | |
1661 | /* | |
1662 | * Decrease the pool size | |
1663 | * First return free pages to the buddy allocator (being careful | |
1664 | * to keep enough around to satisfy reservations). Then place | |
1665 | * pages into surplus state as needed so the pool will shrink | |
1666 | * to the desired size as pages become free. | |
d1c3fb1f NA |
1667 | * |
1668 | * By placing pages into the surplus state independent of the | |
1669 | * overcommit value, we are allowing the surplus pool size to | |
1670 | * exceed overcommit. There are few sane options here. Since | |
1671 | * alloc_buddy_huge_page() is checking the global counter, | |
1672 | * though, we'll note that we're not allowed to exceed surplus | |
1673 | * and won't grow the pool anywhere else. Not until one of the | |
1674 | * sysctls are changed, or the surplus pages go out of use. | |
7893d1d5 | 1675 | */ |
a5516438 | 1676 | min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; |
6b0c880d | 1677 | min_count = max(count, min_count); |
6ae11b27 | 1678 | try_to_free_low(h, min_count, nodes_allowed); |
a5516438 | 1679 | while (min_count < persistent_huge_pages(h)) { |
6ae11b27 | 1680 | if (!free_pool_huge_page(h, nodes_allowed, 0)) |
1da177e4 | 1681 | break; |
55f67141 | 1682 | cond_resched_lock(&hugetlb_lock); |
1da177e4 | 1683 | } |
a5516438 | 1684 | while (count < persistent_huge_pages(h)) { |
6ae11b27 | 1685 | if (!adjust_pool_surplus(h, nodes_allowed, 1)) |
7893d1d5 AL |
1686 | break; |
1687 | } | |
1688 | out: | |
a5516438 | 1689 | ret = persistent_huge_pages(h); |
1da177e4 | 1690 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 1691 | return ret; |
1da177e4 LT |
1692 | } |
1693 | ||
a3437870 NA |
1694 | #define HSTATE_ATTR_RO(_name) \ |
1695 | static struct kobj_attribute _name##_attr = __ATTR_RO(_name) | |
1696 | ||
1697 | #define HSTATE_ATTR(_name) \ | |
1698 | static struct kobj_attribute _name##_attr = \ | |
1699 | __ATTR(_name, 0644, _name##_show, _name##_store) | |
1700 | ||
1701 | static struct kobject *hugepages_kobj; | |
1702 | static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
1703 | ||
9a305230 LS |
1704 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); |
1705 | ||
1706 | static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) | |
a3437870 NA |
1707 | { |
1708 | int i; | |
9a305230 | 1709 | |
a3437870 | 1710 | for (i = 0; i < HUGE_MAX_HSTATE; i++) |
9a305230 LS |
1711 | if (hstate_kobjs[i] == kobj) { |
1712 | if (nidp) | |
1713 | *nidp = NUMA_NO_NODE; | |
a3437870 | 1714 | return &hstates[i]; |
9a305230 LS |
1715 | } |
1716 | ||
1717 | return kobj_to_node_hstate(kobj, nidp); | |
a3437870 NA |
1718 | } |
1719 | ||
06808b08 | 1720 | static ssize_t nr_hugepages_show_common(struct kobject *kobj, |
a3437870 NA |
1721 | struct kobj_attribute *attr, char *buf) |
1722 | { | |
9a305230 LS |
1723 | struct hstate *h; |
1724 | unsigned long nr_huge_pages; | |
1725 | int nid; | |
1726 | ||
1727 | h = kobj_to_hstate(kobj, &nid); | |
1728 | if (nid == NUMA_NO_NODE) | |
1729 | nr_huge_pages = h->nr_huge_pages; | |
1730 | else | |
1731 | nr_huge_pages = h->nr_huge_pages_node[nid]; | |
1732 | ||
1733 | return sprintf(buf, "%lu\n", nr_huge_pages); | |
a3437870 | 1734 | } |
adbe8726 | 1735 | |
238d3c13 DR |
1736 | static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, |
1737 | struct hstate *h, int nid, | |
1738 | unsigned long count, size_t len) | |
a3437870 NA |
1739 | { |
1740 | int err; | |
bad44b5b | 1741 | NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY); |
a3437870 | 1742 | |
944d9fec | 1743 | if (hstate_is_gigantic(h) && !gigantic_page_supported()) { |
adbe8726 EM |
1744 | err = -EINVAL; |
1745 | goto out; | |
1746 | } | |
1747 | ||
9a305230 LS |
1748 | if (nid == NUMA_NO_NODE) { |
1749 | /* | |
1750 | * global hstate attribute | |
1751 | */ | |
1752 | if (!(obey_mempolicy && | |
1753 | init_nodemask_of_mempolicy(nodes_allowed))) { | |
1754 | NODEMASK_FREE(nodes_allowed); | |
8cebfcd0 | 1755 | nodes_allowed = &node_states[N_MEMORY]; |
9a305230 LS |
1756 | } |
1757 | } else if (nodes_allowed) { | |
1758 | /* | |
1759 | * per node hstate attribute: adjust count to global, | |
1760 | * but restrict alloc/free to the specified node. | |
1761 | */ | |
1762 | count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; | |
1763 | init_nodemask_of_node(nodes_allowed, nid); | |
1764 | } else | |
8cebfcd0 | 1765 | nodes_allowed = &node_states[N_MEMORY]; |
9a305230 | 1766 | |
06808b08 | 1767 | h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed); |
a3437870 | 1768 | |
8cebfcd0 | 1769 | if (nodes_allowed != &node_states[N_MEMORY]) |
06808b08 LS |
1770 | NODEMASK_FREE(nodes_allowed); |
1771 | ||
1772 | return len; | |
adbe8726 EM |
1773 | out: |
1774 | NODEMASK_FREE(nodes_allowed); | |
1775 | return err; | |
06808b08 LS |
1776 | } |
1777 | ||
238d3c13 DR |
1778 | static ssize_t nr_hugepages_store_common(bool obey_mempolicy, |
1779 | struct kobject *kobj, const char *buf, | |
1780 | size_t len) | |
1781 | { | |
1782 | struct hstate *h; | |
1783 | unsigned long count; | |
1784 | int nid; | |
1785 | int err; | |
1786 | ||
1787 | err = kstrtoul(buf, 10, &count); | |
1788 | if (err) | |
1789 | return err; | |
1790 | ||
1791 | h = kobj_to_hstate(kobj, &nid); | |
1792 | return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len); | |
1793 | } | |
1794 | ||
06808b08 LS |
1795 | static ssize_t nr_hugepages_show(struct kobject *kobj, |
1796 | struct kobj_attribute *attr, char *buf) | |
1797 | { | |
1798 | return nr_hugepages_show_common(kobj, attr, buf); | |
1799 | } | |
1800 | ||
1801 | static ssize_t nr_hugepages_store(struct kobject *kobj, | |
1802 | struct kobj_attribute *attr, const char *buf, size_t len) | |
1803 | { | |
238d3c13 | 1804 | return nr_hugepages_store_common(false, kobj, buf, len); |
a3437870 NA |
1805 | } |
1806 | HSTATE_ATTR(nr_hugepages); | |
1807 | ||
06808b08 LS |
1808 | #ifdef CONFIG_NUMA |
1809 | ||
1810 | /* | |
1811 | * hstate attribute for optionally mempolicy-based constraint on persistent | |
1812 | * huge page alloc/free. | |
1813 | */ | |
1814 | static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, | |
1815 | struct kobj_attribute *attr, char *buf) | |
1816 | { | |
1817 | return nr_hugepages_show_common(kobj, attr, buf); | |
1818 | } | |
1819 | ||
1820 | static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, | |
1821 | struct kobj_attribute *attr, const char *buf, size_t len) | |
1822 | { | |
238d3c13 | 1823 | return nr_hugepages_store_common(true, kobj, buf, len); |
06808b08 LS |
1824 | } |
1825 | HSTATE_ATTR(nr_hugepages_mempolicy); | |
1826 | #endif | |
1827 | ||
1828 | ||
a3437870 NA |
1829 | static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, |
1830 | struct kobj_attribute *attr, char *buf) | |
1831 | { | |
9a305230 | 1832 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 NA |
1833 | return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); |
1834 | } | |
adbe8726 | 1835 | |
a3437870 NA |
1836 | static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, |
1837 | struct kobj_attribute *attr, const char *buf, size_t count) | |
1838 | { | |
1839 | int err; | |
1840 | unsigned long input; | |
9a305230 | 1841 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 | 1842 | |
bae7f4ae | 1843 | if (hstate_is_gigantic(h)) |
adbe8726 EM |
1844 | return -EINVAL; |
1845 | ||
3dbb95f7 | 1846 | err = kstrtoul(buf, 10, &input); |
a3437870 | 1847 | if (err) |
73ae31e5 | 1848 | return err; |
a3437870 NA |
1849 | |
1850 | spin_lock(&hugetlb_lock); | |
1851 | h->nr_overcommit_huge_pages = input; | |
1852 | spin_unlock(&hugetlb_lock); | |
1853 | ||
1854 | return count; | |
1855 | } | |
1856 | HSTATE_ATTR(nr_overcommit_hugepages); | |
1857 | ||
1858 | static ssize_t free_hugepages_show(struct kobject *kobj, | |
1859 | struct kobj_attribute *attr, char *buf) | |
1860 | { | |
9a305230 LS |
1861 | struct hstate *h; |
1862 | unsigned long free_huge_pages; | |
1863 | int nid; | |
1864 | ||
1865 | h = kobj_to_hstate(kobj, &nid); | |
1866 | if (nid == NUMA_NO_NODE) | |
1867 | free_huge_pages = h->free_huge_pages; | |
1868 | else | |
1869 | free_huge_pages = h->free_huge_pages_node[nid]; | |
1870 | ||
1871 | return sprintf(buf, "%lu\n", free_huge_pages); | |
a3437870 NA |
1872 | } |
1873 | HSTATE_ATTR_RO(free_hugepages); | |
1874 | ||
1875 | static ssize_t resv_hugepages_show(struct kobject *kobj, | |
1876 | struct kobj_attribute *attr, char *buf) | |
1877 | { | |
9a305230 | 1878 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 NA |
1879 | return sprintf(buf, "%lu\n", h->resv_huge_pages); |
1880 | } | |
1881 | HSTATE_ATTR_RO(resv_hugepages); | |
1882 | ||
1883 | static ssize_t surplus_hugepages_show(struct kobject *kobj, | |
1884 | struct kobj_attribute *attr, char *buf) | |
1885 | { | |
9a305230 LS |
1886 | struct hstate *h; |
1887 | unsigned long surplus_huge_pages; | |
1888 | int nid; | |
1889 | ||
1890 | h = kobj_to_hstate(kobj, &nid); | |
1891 | if (nid == NUMA_NO_NODE) | |
1892 | surplus_huge_pages = h->surplus_huge_pages; | |
1893 | else | |
1894 | surplus_huge_pages = h->surplus_huge_pages_node[nid]; | |
1895 | ||
1896 | return sprintf(buf, "%lu\n", surplus_huge_pages); | |
a3437870 NA |
1897 | } |
1898 | HSTATE_ATTR_RO(surplus_hugepages); | |
1899 | ||
1900 | static struct attribute *hstate_attrs[] = { | |
1901 | &nr_hugepages_attr.attr, | |
1902 | &nr_overcommit_hugepages_attr.attr, | |
1903 | &free_hugepages_attr.attr, | |
1904 | &resv_hugepages_attr.attr, | |
1905 | &surplus_hugepages_attr.attr, | |
06808b08 LS |
1906 | #ifdef CONFIG_NUMA |
1907 | &nr_hugepages_mempolicy_attr.attr, | |
1908 | #endif | |
a3437870 NA |
1909 | NULL, |
1910 | }; | |
1911 | ||
1912 | static struct attribute_group hstate_attr_group = { | |
1913 | .attrs = hstate_attrs, | |
1914 | }; | |
1915 | ||
094e9539 JM |
1916 | static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, |
1917 | struct kobject **hstate_kobjs, | |
1918 | struct attribute_group *hstate_attr_group) | |
a3437870 NA |
1919 | { |
1920 | int retval; | |
972dc4de | 1921 | int hi = hstate_index(h); |
a3437870 | 1922 | |
9a305230 LS |
1923 | hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); |
1924 | if (!hstate_kobjs[hi]) | |
a3437870 NA |
1925 | return -ENOMEM; |
1926 | ||
9a305230 | 1927 | retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); |
a3437870 | 1928 | if (retval) |
9a305230 | 1929 | kobject_put(hstate_kobjs[hi]); |
a3437870 NA |
1930 | |
1931 | return retval; | |
1932 | } | |
1933 | ||
1934 | static void __init hugetlb_sysfs_init(void) | |
1935 | { | |
1936 | struct hstate *h; | |
1937 | int err; | |
1938 | ||
1939 | hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); | |
1940 | if (!hugepages_kobj) | |
1941 | return; | |
1942 | ||
1943 | for_each_hstate(h) { | |
9a305230 LS |
1944 | err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, |
1945 | hstate_kobjs, &hstate_attr_group); | |
a3437870 | 1946 | if (err) |
ffb22af5 | 1947 | pr_err("Hugetlb: Unable to add hstate %s", h->name); |
a3437870 NA |
1948 | } |
1949 | } | |
1950 | ||
9a305230 LS |
1951 | #ifdef CONFIG_NUMA |
1952 | ||
1953 | /* | |
1954 | * node_hstate/s - associate per node hstate attributes, via their kobjects, | |
10fbcf4c KS |
1955 | * with node devices in node_devices[] using a parallel array. The array |
1956 | * index of a node device or _hstate == node id. | |
1957 | * This is here to avoid any static dependency of the node device driver, in | |
9a305230 LS |
1958 | * the base kernel, on the hugetlb module. |
1959 | */ | |
1960 | struct node_hstate { | |
1961 | struct kobject *hugepages_kobj; | |
1962 | struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
1963 | }; | |
1964 | struct node_hstate node_hstates[MAX_NUMNODES]; | |
1965 | ||
1966 | /* | |
10fbcf4c | 1967 | * A subset of global hstate attributes for node devices |
9a305230 LS |
1968 | */ |
1969 | static struct attribute *per_node_hstate_attrs[] = { | |
1970 | &nr_hugepages_attr.attr, | |
1971 | &free_hugepages_attr.attr, | |
1972 | &surplus_hugepages_attr.attr, | |
1973 | NULL, | |
1974 | }; | |
1975 | ||
1976 | static struct attribute_group per_node_hstate_attr_group = { | |
1977 | .attrs = per_node_hstate_attrs, | |
1978 | }; | |
1979 | ||
1980 | /* | |
10fbcf4c | 1981 | * kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj. |
9a305230 LS |
1982 | * Returns node id via non-NULL nidp. |
1983 | */ | |
1984 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) | |
1985 | { | |
1986 | int nid; | |
1987 | ||
1988 | for (nid = 0; nid < nr_node_ids; nid++) { | |
1989 | struct node_hstate *nhs = &node_hstates[nid]; | |
1990 | int i; | |
1991 | for (i = 0; i < HUGE_MAX_HSTATE; i++) | |
1992 | if (nhs->hstate_kobjs[i] == kobj) { | |
1993 | if (nidp) | |
1994 | *nidp = nid; | |
1995 | return &hstates[i]; | |
1996 | } | |
1997 | } | |
1998 | ||
1999 | BUG(); | |
2000 | return NULL; | |
2001 | } | |
2002 | ||
2003 | /* | |
10fbcf4c | 2004 | * Unregister hstate attributes from a single node device. |
9a305230 LS |
2005 | * No-op if no hstate attributes attached. |
2006 | */ | |
3cd8b44f | 2007 | static void hugetlb_unregister_node(struct node *node) |
9a305230 LS |
2008 | { |
2009 | struct hstate *h; | |
10fbcf4c | 2010 | struct node_hstate *nhs = &node_hstates[node->dev.id]; |
9a305230 LS |
2011 | |
2012 | if (!nhs->hugepages_kobj) | |
9b5e5d0f | 2013 | return; /* no hstate attributes */ |
9a305230 | 2014 | |
972dc4de AK |
2015 | for_each_hstate(h) { |
2016 | int idx = hstate_index(h); | |
2017 | if (nhs->hstate_kobjs[idx]) { | |
2018 | kobject_put(nhs->hstate_kobjs[idx]); | |
2019 | nhs->hstate_kobjs[idx] = NULL; | |
9a305230 | 2020 | } |
972dc4de | 2021 | } |
9a305230 LS |
2022 | |
2023 | kobject_put(nhs->hugepages_kobj); | |
2024 | nhs->hugepages_kobj = NULL; | |
2025 | } | |
2026 | ||
2027 | /* | |
10fbcf4c | 2028 | * hugetlb module exit: unregister hstate attributes from node devices |
9a305230 LS |
2029 | * that have them. |
2030 | */ | |
2031 | static void hugetlb_unregister_all_nodes(void) | |
2032 | { | |
2033 | int nid; | |
2034 | ||
2035 | /* | |
10fbcf4c | 2036 | * disable node device registrations. |
9a305230 LS |
2037 | */ |
2038 | register_hugetlbfs_with_node(NULL, NULL); | |
2039 | ||
2040 | /* | |
2041 | * remove hstate attributes from any nodes that have them. | |
2042 | */ | |
2043 | for (nid = 0; nid < nr_node_ids; nid++) | |
8732794b | 2044 | hugetlb_unregister_node(node_devices[nid]); |
9a305230 LS |
2045 | } |
2046 | ||
2047 | /* | |
10fbcf4c | 2048 | * Register hstate attributes for a single node device. |
9a305230 LS |
2049 | * No-op if attributes already registered. |
2050 | */ | |
3cd8b44f | 2051 | static void hugetlb_register_node(struct node *node) |
9a305230 LS |
2052 | { |
2053 | struct hstate *h; | |
10fbcf4c | 2054 | struct node_hstate *nhs = &node_hstates[node->dev.id]; |
9a305230 LS |
2055 | int err; |
2056 | ||
2057 | if (nhs->hugepages_kobj) | |
2058 | return; /* already allocated */ | |
2059 | ||
2060 | nhs->hugepages_kobj = kobject_create_and_add("hugepages", | |
10fbcf4c | 2061 | &node->dev.kobj); |
9a305230 LS |
2062 | if (!nhs->hugepages_kobj) |
2063 | return; | |
2064 | ||
2065 | for_each_hstate(h) { | |
2066 | err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, | |
2067 | nhs->hstate_kobjs, | |
2068 | &per_node_hstate_attr_group); | |
2069 | if (err) { | |
ffb22af5 AM |
2070 | pr_err("Hugetlb: Unable to add hstate %s for node %d\n", |
2071 | h->name, node->dev.id); | |
9a305230 LS |
2072 | hugetlb_unregister_node(node); |
2073 | break; | |
2074 | } | |
2075 | } | |
2076 | } | |
2077 | ||
2078 | /* | |
9b5e5d0f | 2079 | * hugetlb init time: register hstate attributes for all registered node |
10fbcf4c KS |
2080 | * devices of nodes that have memory. All on-line nodes should have |
2081 | * registered their associated device by this time. | |
9a305230 LS |
2082 | */ |
2083 | static void hugetlb_register_all_nodes(void) | |
2084 | { | |
2085 | int nid; | |
2086 | ||
8cebfcd0 | 2087 | for_each_node_state(nid, N_MEMORY) { |
8732794b | 2088 | struct node *node = node_devices[nid]; |
10fbcf4c | 2089 | if (node->dev.id == nid) |
9a305230 LS |
2090 | hugetlb_register_node(node); |
2091 | } | |
2092 | ||
2093 | /* | |
10fbcf4c | 2094 | * Let the node device driver know we're here so it can |
9a305230 LS |
2095 | * [un]register hstate attributes on node hotplug. |
2096 | */ | |
2097 | register_hugetlbfs_with_node(hugetlb_register_node, | |
2098 | hugetlb_unregister_node); | |
2099 | } | |
2100 | #else /* !CONFIG_NUMA */ | |
2101 | ||
2102 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) | |
2103 | { | |
2104 | BUG(); | |
2105 | if (nidp) | |
2106 | *nidp = -1; | |
2107 | return NULL; | |
2108 | } | |
2109 | ||
2110 | static void hugetlb_unregister_all_nodes(void) { } | |
2111 | ||
2112 | static void hugetlb_register_all_nodes(void) { } | |
2113 | ||
2114 | #endif | |
2115 | ||
a3437870 NA |
2116 | static void __exit hugetlb_exit(void) |
2117 | { | |
2118 | struct hstate *h; | |
2119 | ||
9a305230 LS |
2120 | hugetlb_unregister_all_nodes(); |
2121 | ||
a3437870 | 2122 | for_each_hstate(h) { |
972dc4de | 2123 | kobject_put(hstate_kobjs[hstate_index(h)]); |
a3437870 NA |
2124 | } |
2125 | ||
2126 | kobject_put(hugepages_kobj); | |
8382d914 | 2127 | kfree(htlb_fault_mutex_table); |
a3437870 NA |
2128 | } |
2129 | module_exit(hugetlb_exit); | |
2130 | ||
2131 | static int __init hugetlb_init(void) | |
2132 | { | |
8382d914 DB |
2133 | int i; |
2134 | ||
457c1b27 | 2135 | if (!hugepages_supported()) |
0ef89d25 | 2136 | return 0; |
a3437870 | 2137 | |
e11bfbfc NP |
2138 | if (!size_to_hstate(default_hstate_size)) { |
2139 | default_hstate_size = HPAGE_SIZE; | |
2140 | if (!size_to_hstate(default_hstate_size)) | |
2141 | hugetlb_add_hstate(HUGETLB_PAGE_ORDER); | |
a3437870 | 2142 | } |
972dc4de | 2143 | default_hstate_idx = hstate_index(size_to_hstate(default_hstate_size)); |
e11bfbfc NP |
2144 | if (default_hstate_max_huge_pages) |
2145 | default_hstate.max_huge_pages = default_hstate_max_huge_pages; | |
a3437870 NA |
2146 | |
2147 | hugetlb_init_hstates(); | |
aa888a74 | 2148 | gather_bootmem_prealloc(); |
a3437870 NA |
2149 | report_hugepages(); |
2150 | ||
2151 | hugetlb_sysfs_init(); | |
9a305230 | 2152 | hugetlb_register_all_nodes(); |
7179e7bf | 2153 | hugetlb_cgroup_file_init(); |
9a305230 | 2154 | |
8382d914 DB |
2155 | #ifdef CONFIG_SMP |
2156 | num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus()); | |
2157 | #else | |
2158 | num_fault_mutexes = 1; | |
2159 | #endif | |
2160 | htlb_fault_mutex_table = | |
2161 | kmalloc(sizeof(struct mutex) * num_fault_mutexes, GFP_KERNEL); | |
2162 | BUG_ON(!htlb_fault_mutex_table); | |
2163 | ||
2164 | for (i = 0; i < num_fault_mutexes; i++) | |
2165 | mutex_init(&htlb_fault_mutex_table[i]); | |
a3437870 NA |
2166 | return 0; |
2167 | } | |
2168 | module_init(hugetlb_init); | |
2169 | ||
2170 | /* Should be called on processing a hugepagesz=... option */ | |
2171 | void __init hugetlb_add_hstate(unsigned order) | |
2172 | { | |
2173 | struct hstate *h; | |
8faa8b07 AK |
2174 | unsigned long i; |
2175 | ||
a3437870 | 2176 | if (size_to_hstate(PAGE_SIZE << order)) { |
ffb22af5 | 2177 | pr_warning("hugepagesz= specified twice, ignoring\n"); |
a3437870 NA |
2178 | return; |
2179 | } | |
47d38344 | 2180 | BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); |
a3437870 | 2181 | BUG_ON(order == 0); |
47d38344 | 2182 | h = &hstates[hugetlb_max_hstate++]; |
a3437870 NA |
2183 | h->order = order; |
2184 | h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); | |
8faa8b07 AK |
2185 | h->nr_huge_pages = 0; |
2186 | h->free_huge_pages = 0; | |
2187 | for (i = 0; i < MAX_NUMNODES; ++i) | |
2188 | INIT_LIST_HEAD(&h->hugepage_freelists[i]); | |
0edaecfa | 2189 | INIT_LIST_HEAD(&h->hugepage_activelist); |
8cebfcd0 LJ |
2190 | h->next_nid_to_alloc = first_node(node_states[N_MEMORY]); |
2191 | h->next_nid_to_free = first_node(node_states[N_MEMORY]); | |
a3437870 NA |
2192 | snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", |
2193 | huge_page_size(h)/1024); | |
8faa8b07 | 2194 | |
a3437870 NA |
2195 | parsed_hstate = h; |
2196 | } | |
2197 | ||
e11bfbfc | 2198 | static int __init hugetlb_nrpages_setup(char *s) |
a3437870 NA |
2199 | { |
2200 | unsigned long *mhp; | |
8faa8b07 | 2201 | static unsigned long *last_mhp; |
a3437870 NA |
2202 | |
2203 | /* | |
47d38344 | 2204 | * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter yet, |
a3437870 NA |
2205 | * so this hugepages= parameter goes to the "default hstate". |
2206 | */ | |
47d38344 | 2207 | if (!hugetlb_max_hstate) |
a3437870 NA |
2208 | mhp = &default_hstate_max_huge_pages; |
2209 | else | |
2210 | mhp = &parsed_hstate->max_huge_pages; | |
2211 | ||
8faa8b07 | 2212 | if (mhp == last_mhp) { |
ffb22af5 AM |
2213 | pr_warning("hugepages= specified twice without " |
2214 | "interleaving hugepagesz=, ignoring\n"); | |
8faa8b07 AK |
2215 | return 1; |
2216 | } | |
2217 | ||
a3437870 NA |
2218 | if (sscanf(s, "%lu", mhp) <= 0) |
2219 | *mhp = 0; | |
2220 | ||
8faa8b07 AK |
2221 | /* |
2222 | * Global state is always initialized later in hugetlb_init. | |
2223 | * But we need to allocate >= MAX_ORDER hstates here early to still | |
2224 | * use the bootmem allocator. | |
2225 | */ | |
47d38344 | 2226 | if (hugetlb_max_hstate && parsed_hstate->order >= MAX_ORDER) |
8faa8b07 AK |
2227 | hugetlb_hstate_alloc_pages(parsed_hstate); |
2228 | ||
2229 | last_mhp = mhp; | |
2230 | ||
a3437870 NA |
2231 | return 1; |
2232 | } | |
e11bfbfc NP |
2233 | __setup("hugepages=", hugetlb_nrpages_setup); |
2234 | ||
2235 | static int __init hugetlb_default_setup(char *s) | |
2236 | { | |
2237 | default_hstate_size = memparse(s, &s); | |
2238 | return 1; | |
2239 | } | |
2240 | __setup("default_hugepagesz=", hugetlb_default_setup); | |
a3437870 | 2241 | |
8a213460 NA |
2242 | static unsigned int cpuset_mems_nr(unsigned int *array) |
2243 | { | |
2244 | int node; | |
2245 | unsigned int nr = 0; | |
2246 | ||
2247 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
2248 | nr += array[node]; | |
2249 | ||
2250 | return nr; | |
2251 | } | |
2252 | ||
2253 | #ifdef CONFIG_SYSCTL | |
06808b08 LS |
2254 | static int hugetlb_sysctl_handler_common(bool obey_mempolicy, |
2255 | struct ctl_table *table, int write, | |
2256 | void __user *buffer, size_t *length, loff_t *ppos) | |
1da177e4 | 2257 | { |
e5ff2159 | 2258 | struct hstate *h = &default_hstate; |
238d3c13 | 2259 | unsigned long tmp = h->max_huge_pages; |
08d4a246 | 2260 | int ret; |
e5ff2159 | 2261 | |
457c1b27 NA |
2262 | if (!hugepages_supported()) |
2263 | return -ENOTSUPP; | |
2264 | ||
e5ff2159 AK |
2265 | table->data = &tmp; |
2266 | table->maxlen = sizeof(unsigned long); | |
08d4a246 MH |
2267 | ret = proc_doulongvec_minmax(table, write, buffer, length, ppos); |
2268 | if (ret) | |
2269 | goto out; | |
e5ff2159 | 2270 | |
238d3c13 DR |
2271 | if (write) |
2272 | ret = __nr_hugepages_store_common(obey_mempolicy, h, | |
2273 | NUMA_NO_NODE, tmp, *length); | |
08d4a246 MH |
2274 | out: |
2275 | return ret; | |
1da177e4 | 2276 | } |
396faf03 | 2277 | |
06808b08 LS |
2278 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
2279 | void __user *buffer, size_t *length, loff_t *ppos) | |
2280 | { | |
2281 | ||
2282 | return hugetlb_sysctl_handler_common(false, table, write, | |
2283 | buffer, length, ppos); | |
2284 | } | |
2285 | ||
2286 | #ifdef CONFIG_NUMA | |
2287 | int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, | |
2288 | void __user *buffer, size_t *length, loff_t *ppos) | |
2289 | { | |
2290 | return hugetlb_sysctl_handler_common(true, table, write, | |
2291 | buffer, length, ppos); | |
2292 | } | |
2293 | #endif /* CONFIG_NUMA */ | |
2294 | ||
a3d0c6aa | 2295 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
8d65af78 | 2296 | void __user *buffer, |
a3d0c6aa NA |
2297 | size_t *length, loff_t *ppos) |
2298 | { | |
a5516438 | 2299 | struct hstate *h = &default_hstate; |
e5ff2159 | 2300 | unsigned long tmp; |
08d4a246 | 2301 | int ret; |
e5ff2159 | 2302 | |
457c1b27 NA |
2303 | if (!hugepages_supported()) |
2304 | return -ENOTSUPP; | |
2305 | ||
c033a93c | 2306 | tmp = h->nr_overcommit_huge_pages; |
e5ff2159 | 2307 | |
bae7f4ae | 2308 | if (write && hstate_is_gigantic(h)) |
adbe8726 EM |
2309 | return -EINVAL; |
2310 | ||
e5ff2159 AK |
2311 | table->data = &tmp; |
2312 | table->maxlen = sizeof(unsigned long); | |
08d4a246 MH |
2313 | ret = proc_doulongvec_minmax(table, write, buffer, length, ppos); |
2314 | if (ret) | |
2315 | goto out; | |
e5ff2159 AK |
2316 | |
2317 | if (write) { | |
2318 | spin_lock(&hugetlb_lock); | |
2319 | h->nr_overcommit_huge_pages = tmp; | |
2320 | spin_unlock(&hugetlb_lock); | |
2321 | } | |
08d4a246 MH |
2322 | out: |
2323 | return ret; | |
a3d0c6aa NA |
2324 | } |
2325 | ||
1da177e4 LT |
2326 | #endif /* CONFIG_SYSCTL */ |
2327 | ||
e1759c21 | 2328 | void hugetlb_report_meminfo(struct seq_file *m) |
1da177e4 | 2329 | { |
a5516438 | 2330 | struct hstate *h = &default_hstate; |
457c1b27 NA |
2331 | if (!hugepages_supported()) |
2332 | return; | |
e1759c21 | 2333 | seq_printf(m, |
4f98a2fe RR |
2334 | "HugePages_Total: %5lu\n" |
2335 | "HugePages_Free: %5lu\n" | |
2336 | "HugePages_Rsvd: %5lu\n" | |
2337 | "HugePages_Surp: %5lu\n" | |
2338 | "Hugepagesize: %8lu kB\n", | |
a5516438 AK |
2339 | h->nr_huge_pages, |
2340 | h->free_huge_pages, | |
2341 | h->resv_huge_pages, | |
2342 | h->surplus_huge_pages, | |
2343 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); | |
1da177e4 LT |
2344 | } |
2345 | ||
2346 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
2347 | { | |
a5516438 | 2348 | struct hstate *h = &default_hstate; |
457c1b27 NA |
2349 | if (!hugepages_supported()) |
2350 | return 0; | |
1da177e4 LT |
2351 | return sprintf(buf, |
2352 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
2353 | "Node %d HugePages_Free: %5u\n" |
2354 | "Node %d HugePages_Surp: %5u\n", | |
a5516438 AK |
2355 | nid, h->nr_huge_pages_node[nid], |
2356 | nid, h->free_huge_pages_node[nid], | |
2357 | nid, h->surplus_huge_pages_node[nid]); | |
1da177e4 LT |
2358 | } |
2359 | ||
949f7ec5 DR |
2360 | void hugetlb_show_meminfo(void) |
2361 | { | |
2362 | struct hstate *h; | |
2363 | int nid; | |
2364 | ||
457c1b27 NA |
2365 | if (!hugepages_supported()) |
2366 | return; | |
2367 | ||
949f7ec5 DR |
2368 | for_each_node_state(nid, N_MEMORY) |
2369 | for_each_hstate(h) | |
2370 | pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n", | |
2371 | nid, | |
2372 | h->nr_huge_pages_node[nid], | |
2373 | h->free_huge_pages_node[nid], | |
2374 | h->surplus_huge_pages_node[nid], | |
2375 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); | |
2376 | } | |
2377 | ||
1da177e4 LT |
2378 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
2379 | unsigned long hugetlb_total_pages(void) | |
2380 | { | |
d0028588 WL |
2381 | struct hstate *h; |
2382 | unsigned long nr_total_pages = 0; | |
2383 | ||
2384 | for_each_hstate(h) | |
2385 | nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); | |
2386 | return nr_total_pages; | |
1da177e4 | 2387 | } |
1da177e4 | 2388 | |
a5516438 | 2389 | static int hugetlb_acct_memory(struct hstate *h, long delta) |
fc1b8a73 MG |
2390 | { |
2391 | int ret = -ENOMEM; | |
2392 | ||
2393 | spin_lock(&hugetlb_lock); | |
2394 | /* | |
2395 | * When cpuset is configured, it breaks the strict hugetlb page | |
2396 | * reservation as the accounting is done on a global variable. Such | |
2397 | * reservation is completely rubbish in the presence of cpuset because | |
2398 | * the reservation is not checked against page availability for the | |
2399 | * current cpuset. Application can still potentially OOM'ed by kernel | |
2400 | * with lack of free htlb page in cpuset that the task is in. | |
2401 | * Attempt to enforce strict accounting with cpuset is almost | |
2402 | * impossible (or too ugly) because cpuset is too fluid that | |
2403 | * task or memory node can be dynamically moved between cpusets. | |
2404 | * | |
2405 | * The change of semantics for shared hugetlb mapping with cpuset is | |
2406 | * undesirable. However, in order to preserve some of the semantics, | |
2407 | * we fall back to check against current free page availability as | |
2408 | * a best attempt and hopefully to minimize the impact of changing | |
2409 | * semantics that cpuset has. | |
2410 | */ | |
2411 | if (delta > 0) { | |
a5516438 | 2412 | if (gather_surplus_pages(h, delta) < 0) |
fc1b8a73 MG |
2413 | goto out; |
2414 | ||
a5516438 AK |
2415 | if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { |
2416 | return_unused_surplus_pages(h, delta); | |
fc1b8a73 MG |
2417 | goto out; |
2418 | } | |
2419 | } | |
2420 | ||
2421 | ret = 0; | |
2422 | if (delta < 0) | |
a5516438 | 2423 | return_unused_surplus_pages(h, (unsigned long) -delta); |
fc1b8a73 MG |
2424 | |
2425 | out: | |
2426 | spin_unlock(&hugetlb_lock); | |
2427 | return ret; | |
2428 | } | |
2429 | ||
84afd99b AW |
2430 | static void hugetlb_vm_op_open(struct vm_area_struct *vma) |
2431 | { | |
f522c3ac | 2432 | struct resv_map *resv = vma_resv_map(vma); |
84afd99b AW |
2433 | |
2434 | /* | |
2435 | * This new VMA should share its siblings reservation map if present. | |
2436 | * The VMA will only ever have a valid reservation map pointer where | |
2437 | * it is being copied for another still existing VMA. As that VMA | |
25985edc | 2438 | * has a reference to the reservation map it cannot disappear until |
84afd99b AW |
2439 | * after this open call completes. It is therefore safe to take a |
2440 | * new reference here without additional locking. | |
2441 | */ | |
4e35f483 | 2442 | if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
f522c3ac | 2443 | kref_get(&resv->refs); |
84afd99b AW |
2444 | } |
2445 | ||
a1e78772 MG |
2446 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
2447 | { | |
a5516438 | 2448 | struct hstate *h = hstate_vma(vma); |
f522c3ac | 2449 | struct resv_map *resv = vma_resv_map(vma); |
90481622 | 2450 | struct hugepage_subpool *spool = subpool_vma(vma); |
4e35f483 | 2451 | unsigned long reserve, start, end; |
84afd99b | 2452 | |
4e35f483 JK |
2453 | if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
2454 | return; | |
84afd99b | 2455 | |
4e35f483 JK |
2456 | start = vma_hugecache_offset(h, vma, vma->vm_start); |
2457 | end = vma_hugecache_offset(h, vma, vma->vm_end); | |
84afd99b | 2458 | |
4e35f483 | 2459 | reserve = (end - start) - region_count(resv, start, end); |
84afd99b | 2460 | |
4e35f483 JK |
2461 | kref_put(&resv->refs, resv_map_release); |
2462 | ||
2463 | if (reserve) { | |
2464 | hugetlb_acct_memory(h, -reserve); | |
2465 | hugepage_subpool_put_pages(spool, reserve); | |
84afd99b | 2466 | } |
a1e78772 MG |
2467 | } |
2468 | ||
1da177e4 LT |
2469 | /* |
2470 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
2471 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
2472 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
2473 | * this far. | |
2474 | */ | |
d0217ac0 | 2475 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
2476 | { |
2477 | BUG(); | |
d0217ac0 | 2478 | return 0; |
1da177e4 LT |
2479 | } |
2480 | ||
f0f37e2f | 2481 | const struct vm_operations_struct hugetlb_vm_ops = { |
d0217ac0 | 2482 | .fault = hugetlb_vm_op_fault, |
84afd99b | 2483 | .open = hugetlb_vm_op_open, |
a1e78772 | 2484 | .close = hugetlb_vm_op_close, |
1da177e4 LT |
2485 | }; |
2486 | ||
1e8f889b DG |
2487 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
2488 | int writable) | |
63551ae0 DG |
2489 | { |
2490 | pte_t entry; | |
2491 | ||
1e8f889b | 2492 | if (writable) { |
106c992a GS |
2493 | entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page, |
2494 | vma->vm_page_prot))); | |
63551ae0 | 2495 | } else { |
106c992a GS |
2496 | entry = huge_pte_wrprotect(mk_huge_pte(page, |
2497 | vma->vm_page_prot)); | |
63551ae0 DG |
2498 | } |
2499 | entry = pte_mkyoung(entry); | |
2500 | entry = pte_mkhuge(entry); | |
d9ed9faa | 2501 | entry = arch_make_huge_pte(entry, vma, page, writable); |
63551ae0 DG |
2502 | |
2503 | return entry; | |
2504 | } | |
2505 | ||
1e8f889b DG |
2506 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
2507 | unsigned long address, pte_t *ptep) | |
2508 | { | |
2509 | pte_t entry; | |
2510 | ||
106c992a | 2511 | entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep))); |
32f84528 | 2512 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) |
4b3073e1 | 2513 | update_mmu_cache(vma, address, ptep); |
1e8f889b DG |
2514 | } |
2515 | ||
4a705fef NH |
2516 | static int is_hugetlb_entry_migration(pte_t pte) |
2517 | { | |
2518 | swp_entry_t swp; | |
2519 | ||
2520 | if (huge_pte_none(pte) || pte_present(pte)) | |
2521 | return 0; | |
2522 | swp = pte_to_swp_entry(pte); | |
2523 | if (non_swap_entry(swp) && is_migration_entry(swp)) | |
2524 | return 1; | |
2525 | else | |
2526 | return 0; | |
2527 | } | |
2528 | ||
2529 | static int is_hugetlb_entry_hwpoisoned(pte_t pte) | |
2530 | { | |
2531 | swp_entry_t swp; | |
2532 | ||
2533 | if (huge_pte_none(pte) || pte_present(pte)) | |
2534 | return 0; | |
2535 | swp = pte_to_swp_entry(pte); | |
2536 | if (non_swap_entry(swp) && is_hwpoison_entry(swp)) | |
2537 | return 1; | |
2538 | else | |
2539 | return 0; | |
2540 | } | |
1e8f889b | 2541 | |
63551ae0 DG |
2542 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
2543 | struct vm_area_struct *vma) | |
2544 | { | |
2545 | pte_t *src_pte, *dst_pte, entry; | |
2546 | struct page *ptepage; | |
1c59827d | 2547 | unsigned long addr; |
1e8f889b | 2548 | int cow; |
a5516438 AK |
2549 | struct hstate *h = hstate_vma(vma); |
2550 | unsigned long sz = huge_page_size(h); | |
e8569dd2 AS |
2551 | unsigned long mmun_start; /* For mmu_notifiers */ |
2552 | unsigned long mmun_end; /* For mmu_notifiers */ | |
2553 | int ret = 0; | |
1e8f889b DG |
2554 | |
2555 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 2556 | |
e8569dd2 AS |
2557 | mmun_start = vma->vm_start; |
2558 | mmun_end = vma->vm_end; | |
2559 | if (cow) | |
2560 | mmu_notifier_invalidate_range_start(src, mmun_start, mmun_end); | |
2561 | ||
a5516438 | 2562 | for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { |
cb900f41 | 2563 | spinlock_t *src_ptl, *dst_ptl; |
c74df32c HD |
2564 | src_pte = huge_pte_offset(src, addr); |
2565 | if (!src_pte) | |
2566 | continue; | |
a5516438 | 2567 | dst_pte = huge_pte_alloc(dst, addr, sz); |
e8569dd2 AS |
2568 | if (!dst_pte) { |
2569 | ret = -ENOMEM; | |
2570 | break; | |
2571 | } | |
c5c99429 LW |
2572 | |
2573 | /* If the pagetables are shared don't copy or take references */ | |
2574 | if (dst_pte == src_pte) | |
2575 | continue; | |
2576 | ||
cb900f41 KS |
2577 | dst_ptl = huge_pte_lock(h, dst, dst_pte); |
2578 | src_ptl = huge_pte_lockptr(h, src, src_pte); | |
2579 | spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); | |
4a705fef NH |
2580 | entry = huge_ptep_get(src_pte); |
2581 | if (huge_pte_none(entry)) { /* skip none entry */ | |
2582 | ; | |
2583 | } else if (unlikely(is_hugetlb_entry_migration(entry) || | |
2584 | is_hugetlb_entry_hwpoisoned(entry))) { | |
2585 | swp_entry_t swp_entry = pte_to_swp_entry(entry); | |
2586 | ||
2587 | if (is_write_migration_entry(swp_entry) && cow) { | |
2588 | /* | |
2589 | * COW mappings require pages in both | |
2590 | * parent and child to be set to read. | |
2591 | */ | |
2592 | make_migration_entry_read(&swp_entry); | |
2593 | entry = swp_entry_to_pte(swp_entry); | |
2594 | set_huge_pte_at(src, addr, src_pte, entry); | |
2595 | } | |
2596 | set_huge_pte_at(dst, addr, dst_pte, entry); | |
2597 | } else { | |
1e8f889b | 2598 | if (cow) |
7f2e9525 | 2599 | huge_ptep_set_wrprotect(src, addr, src_pte); |
0253d634 | 2600 | entry = huge_ptep_get(src_pte); |
1c59827d HD |
2601 | ptepage = pte_page(entry); |
2602 | get_page(ptepage); | |
0fe6e20b | 2603 | page_dup_rmap(ptepage); |
1c59827d HD |
2604 | set_huge_pte_at(dst, addr, dst_pte, entry); |
2605 | } | |
cb900f41 KS |
2606 | spin_unlock(src_ptl); |
2607 | spin_unlock(dst_ptl); | |
63551ae0 | 2608 | } |
63551ae0 | 2609 | |
e8569dd2 AS |
2610 | if (cow) |
2611 | mmu_notifier_invalidate_range_end(src, mmun_start, mmun_end); | |
2612 | ||
2613 | return ret; | |
63551ae0 DG |
2614 | } |
2615 | ||
24669e58 AK |
2616 | void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, |
2617 | unsigned long start, unsigned long end, | |
2618 | struct page *ref_page) | |
63551ae0 | 2619 | { |
24669e58 | 2620 | int force_flush = 0; |
63551ae0 DG |
2621 | struct mm_struct *mm = vma->vm_mm; |
2622 | unsigned long address; | |
c7546f8f | 2623 | pte_t *ptep; |
63551ae0 | 2624 | pte_t pte; |
cb900f41 | 2625 | spinlock_t *ptl; |
63551ae0 | 2626 | struct page *page; |
a5516438 AK |
2627 | struct hstate *h = hstate_vma(vma); |
2628 | unsigned long sz = huge_page_size(h); | |
2ec74c3e SG |
2629 | const unsigned long mmun_start = start; /* For mmu_notifiers */ |
2630 | const unsigned long mmun_end = end; /* For mmu_notifiers */ | |
a5516438 | 2631 | |
63551ae0 | 2632 | WARN_ON(!is_vm_hugetlb_page(vma)); |
a5516438 AK |
2633 | BUG_ON(start & ~huge_page_mask(h)); |
2634 | BUG_ON(end & ~huge_page_mask(h)); | |
63551ae0 | 2635 | |
24669e58 | 2636 | tlb_start_vma(tlb, vma); |
2ec74c3e | 2637 | mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); |
24669e58 | 2638 | again: |
a5516438 | 2639 | for (address = start; address < end; address += sz) { |
c7546f8f | 2640 | ptep = huge_pte_offset(mm, address); |
4c887265 | 2641 | if (!ptep) |
c7546f8f DG |
2642 | continue; |
2643 | ||
cb900f41 | 2644 | ptl = huge_pte_lock(h, mm, ptep); |
39dde65c | 2645 | if (huge_pmd_unshare(mm, &address, ptep)) |
cb900f41 | 2646 | goto unlock; |
39dde65c | 2647 | |
6629326b HD |
2648 | pte = huge_ptep_get(ptep); |
2649 | if (huge_pte_none(pte)) | |
cb900f41 | 2650 | goto unlock; |
6629326b HD |
2651 | |
2652 | /* | |
2653 | * HWPoisoned hugepage is already unmapped and dropped reference | |
2654 | */ | |
8c4894c6 | 2655 | if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { |
106c992a | 2656 | huge_pte_clear(mm, address, ptep); |
cb900f41 | 2657 | goto unlock; |
8c4894c6 | 2658 | } |
6629326b HD |
2659 | |
2660 | page = pte_page(pte); | |
04f2cbe3 MG |
2661 | /* |
2662 | * If a reference page is supplied, it is because a specific | |
2663 | * page is being unmapped, not a range. Ensure the page we | |
2664 | * are about to unmap is the actual page of interest. | |
2665 | */ | |
2666 | if (ref_page) { | |
04f2cbe3 | 2667 | if (page != ref_page) |
cb900f41 | 2668 | goto unlock; |
04f2cbe3 MG |
2669 | |
2670 | /* | |
2671 | * Mark the VMA as having unmapped its page so that | |
2672 | * future faults in this VMA will fail rather than | |
2673 | * looking like data was lost | |
2674 | */ | |
2675 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); | |
2676 | } | |
2677 | ||
c7546f8f | 2678 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
24669e58 | 2679 | tlb_remove_tlb_entry(tlb, ptep, address); |
106c992a | 2680 | if (huge_pte_dirty(pte)) |
6649a386 | 2681 | set_page_dirty(page); |
9e81130b | 2682 | |
24669e58 AK |
2683 | page_remove_rmap(page); |
2684 | force_flush = !__tlb_remove_page(tlb, page); | |
cb900f41 KS |
2685 | if (force_flush) { |
2686 | spin_unlock(ptl); | |
24669e58 | 2687 | break; |
cb900f41 | 2688 | } |
9e81130b | 2689 | /* Bail out after unmapping reference page if supplied */ |
cb900f41 KS |
2690 | if (ref_page) { |
2691 | spin_unlock(ptl); | |
9e81130b | 2692 | break; |
cb900f41 KS |
2693 | } |
2694 | unlock: | |
2695 | spin_unlock(ptl); | |
63551ae0 | 2696 | } |
24669e58 AK |
2697 | /* |
2698 | * mmu_gather ran out of room to batch pages, we break out of | |
2699 | * the PTE lock to avoid doing the potential expensive TLB invalidate | |
2700 | * and page-free while holding it. | |
2701 | */ | |
2702 | if (force_flush) { | |
2703 | force_flush = 0; | |
2704 | tlb_flush_mmu(tlb); | |
2705 | if (address < end && !ref_page) | |
2706 | goto again; | |
fe1668ae | 2707 | } |
2ec74c3e | 2708 | mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); |
24669e58 | 2709 | tlb_end_vma(tlb, vma); |
1da177e4 | 2710 | } |
63551ae0 | 2711 | |
d833352a MG |
2712 | void __unmap_hugepage_range_final(struct mmu_gather *tlb, |
2713 | struct vm_area_struct *vma, unsigned long start, | |
2714 | unsigned long end, struct page *ref_page) | |
2715 | { | |
2716 | __unmap_hugepage_range(tlb, vma, start, end, ref_page); | |
2717 | ||
2718 | /* | |
2719 | * Clear this flag so that x86's huge_pmd_share page_table_shareable | |
2720 | * test will fail on a vma being torn down, and not grab a page table | |
2721 | * on its way out. We're lucky that the flag has such an appropriate | |
2722 | * name, and can in fact be safely cleared here. We could clear it | |
2723 | * before the __unmap_hugepage_range above, but all that's necessary | |
2724 | * is to clear it before releasing the i_mmap_mutex. This works | |
2725 | * because in the context this is called, the VMA is about to be | |
2726 | * destroyed and the i_mmap_mutex is held. | |
2727 | */ | |
2728 | vma->vm_flags &= ~VM_MAYSHARE; | |
2729 | } | |
2730 | ||
502717f4 | 2731 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 2732 | unsigned long end, struct page *ref_page) |
502717f4 | 2733 | { |
24669e58 AK |
2734 | struct mm_struct *mm; |
2735 | struct mmu_gather tlb; | |
2736 | ||
2737 | mm = vma->vm_mm; | |
2738 | ||
2b047252 | 2739 | tlb_gather_mmu(&tlb, mm, start, end); |
24669e58 AK |
2740 | __unmap_hugepage_range(&tlb, vma, start, end, ref_page); |
2741 | tlb_finish_mmu(&tlb, start, end); | |
502717f4 CK |
2742 | } |
2743 | ||
04f2cbe3 MG |
2744 | /* |
2745 | * This is called when the original mapper is failing to COW a MAP_PRIVATE | |
2746 | * mappping it owns the reserve page for. The intention is to unmap the page | |
2747 | * from other VMAs and let the children be SIGKILLed if they are faulting the | |
2748 | * same region. | |
2749 | */ | |
2f4612af DB |
2750 | static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, |
2751 | struct page *page, unsigned long address) | |
04f2cbe3 | 2752 | { |
7526674d | 2753 | struct hstate *h = hstate_vma(vma); |
04f2cbe3 MG |
2754 | struct vm_area_struct *iter_vma; |
2755 | struct address_space *mapping; | |
04f2cbe3 MG |
2756 | pgoff_t pgoff; |
2757 | ||
2758 | /* | |
2759 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation | |
2760 | * from page cache lookup which is in HPAGE_SIZE units. | |
2761 | */ | |
7526674d | 2762 | address = address & huge_page_mask(h); |
36e4f20a MH |
2763 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + |
2764 | vma->vm_pgoff; | |
496ad9aa | 2765 | mapping = file_inode(vma->vm_file)->i_mapping; |
04f2cbe3 | 2766 | |
4eb2b1dc MG |
2767 | /* |
2768 | * Take the mapping lock for the duration of the table walk. As | |
2769 | * this mapping should be shared between all the VMAs, | |
2770 | * __unmap_hugepage_range() is called as the lock is already held | |
2771 | */ | |
3d48ae45 | 2772 | mutex_lock(&mapping->i_mmap_mutex); |
6b2dbba8 | 2773 | vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) { |
04f2cbe3 MG |
2774 | /* Do not unmap the current VMA */ |
2775 | if (iter_vma == vma) | |
2776 | continue; | |
2777 | ||
2778 | /* | |
2779 | * Unmap the page from other VMAs without their own reserves. | |
2780 | * They get marked to be SIGKILLed if they fault in these | |
2781 | * areas. This is because a future no-page fault on this VMA | |
2782 | * could insert a zeroed page instead of the data existing | |
2783 | * from the time of fork. This would look like data corruption | |
2784 | */ | |
2785 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) | |
24669e58 AK |
2786 | unmap_hugepage_range(iter_vma, address, |
2787 | address + huge_page_size(h), page); | |
04f2cbe3 | 2788 | } |
3d48ae45 | 2789 | mutex_unlock(&mapping->i_mmap_mutex); |
04f2cbe3 MG |
2790 | } |
2791 | ||
0fe6e20b NH |
2792 | /* |
2793 | * Hugetlb_cow() should be called with page lock of the original hugepage held. | |
ef009b25 MH |
2794 | * Called with hugetlb_instantiation_mutex held and pte_page locked so we |
2795 | * cannot race with other handlers or page migration. | |
2796 | * Keep the pte_same checks anyway to make transition from the mutex easier. | |
0fe6e20b | 2797 | */ |
1e8f889b | 2798 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
04f2cbe3 | 2799 | unsigned long address, pte_t *ptep, pte_t pte, |
cb900f41 | 2800 | struct page *pagecache_page, spinlock_t *ptl) |
1e8f889b | 2801 | { |
a5516438 | 2802 | struct hstate *h = hstate_vma(vma); |
1e8f889b | 2803 | struct page *old_page, *new_page; |
ad4404a2 | 2804 | int ret = 0, outside_reserve = 0; |
2ec74c3e SG |
2805 | unsigned long mmun_start; /* For mmu_notifiers */ |
2806 | unsigned long mmun_end; /* For mmu_notifiers */ | |
1e8f889b DG |
2807 | |
2808 | old_page = pte_page(pte); | |
2809 | ||
04f2cbe3 | 2810 | retry_avoidcopy: |
1e8f889b DG |
2811 | /* If no-one else is actually using this page, avoid the copy |
2812 | * and just make the page writable */ | |
37a2140d JK |
2813 | if (page_mapcount(old_page) == 1 && PageAnon(old_page)) { |
2814 | page_move_anon_rmap(old_page, vma, address); | |
1e8f889b | 2815 | set_huge_ptep_writable(vma, address, ptep); |
83c54070 | 2816 | return 0; |
1e8f889b DG |
2817 | } |
2818 | ||
04f2cbe3 MG |
2819 | /* |
2820 | * If the process that created a MAP_PRIVATE mapping is about to | |
2821 | * perform a COW due to a shared page count, attempt to satisfy | |
2822 | * the allocation without using the existing reserves. The pagecache | |
2823 | * page is used to determine if the reserve at this address was | |
2824 | * consumed or not. If reserves were used, a partial faulted mapping | |
2825 | * at the time of fork() could consume its reserves on COW instead | |
2826 | * of the full address range. | |
2827 | */ | |
5944d011 | 2828 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && |
04f2cbe3 MG |
2829 | old_page != pagecache_page) |
2830 | outside_reserve = 1; | |
2831 | ||
1e8f889b | 2832 | page_cache_get(old_page); |
b76c8cfb | 2833 | |
ad4404a2 DB |
2834 | /* |
2835 | * Drop page table lock as buddy allocator may be called. It will | |
2836 | * be acquired again before returning to the caller, as expected. | |
2837 | */ | |
cb900f41 | 2838 | spin_unlock(ptl); |
04f2cbe3 | 2839 | new_page = alloc_huge_page(vma, address, outside_reserve); |
1e8f889b | 2840 | |
2fc39cec | 2841 | if (IS_ERR(new_page)) { |
04f2cbe3 MG |
2842 | /* |
2843 | * If a process owning a MAP_PRIVATE mapping fails to COW, | |
2844 | * it is due to references held by a child and an insufficient | |
2845 | * huge page pool. To guarantee the original mappers | |
2846 | * reliability, unmap the page from child processes. The child | |
2847 | * may get SIGKILLed if it later faults. | |
2848 | */ | |
2849 | if (outside_reserve) { | |
ad4404a2 | 2850 | page_cache_release(old_page); |
04f2cbe3 | 2851 | BUG_ON(huge_pte_none(pte)); |
2f4612af DB |
2852 | unmap_ref_private(mm, vma, old_page, address); |
2853 | BUG_ON(huge_pte_none(pte)); | |
2854 | spin_lock(ptl); | |
2855 | ptep = huge_pte_offset(mm, address & huge_page_mask(h)); | |
2856 | if (likely(ptep && | |
2857 | pte_same(huge_ptep_get(ptep), pte))) | |
2858 | goto retry_avoidcopy; | |
2859 | /* | |
2860 | * race occurs while re-acquiring page table | |
2861 | * lock, and our job is done. | |
2862 | */ | |
2863 | return 0; | |
04f2cbe3 MG |
2864 | } |
2865 | ||
ad4404a2 DB |
2866 | ret = (PTR_ERR(new_page) == -ENOMEM) ? |
2867 | VM_FAULT_OOM : VM_FAULT_SIGBUS; | |
2868 | goto out_release_old; | |
1e8f889b DG |
2869 | } |
2870 | ||
0fe6e20b NH |
2871 | /* |
2872 | * When the original hugepage is shared one, it does not have | |
2873 | * anon_vma prepared. | |
2874 | */ | |
44e2aa93 | 2875 | if (unlikely(anon_vma_prepare(vma))) { |
ad4404a2 DB |
2876 | ret = VM_FAULT_OOM; |
2877 | goto out_release_all; | |
44e2aa93 | 2878 | } |
0fe6e20b | 2879 | |
47ad8475 AA |
2880 | copy_user_huge_page(new_page, old_page, address, vma, |
2881 | pages_per_huge_page(h)); | |
0ed361de | 2882 | __SetPageUptodate(new_page); |
1e8f889b | 2883 | |
2ec74c3e SG |
2884 | mmun_start = address & huge_page_mask(h); |
2885 | mmun_end = mmun_start + huge_page_size(h); | |
2886 | mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); | |
ad4404a2 | 2887 | |
b76c8cfb | 2888 | /* |
cb900f41 | 2889 | * Retake the page table lock to check for racing updates |
b76c8cfb LW |
2890 | * before the page tables are altered |
2891 | */ | |
cb900f41 | 2892 | spin_lock(ptl); |
a5516438 | 2893 | ptep = huge_pte_offset(mm, address & huge_page_mask(h)); |
a9af0c5d | 2894 | if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) { |
07443a85 JK |
2895 | ClearPagePrivate(new_page); |
2896 | ||
1e8f889b | 2897 | /* Break COW */ |
8fe627ec | 2898 | huge_ptep_clear_flush(vma, address, ptep); |
1e8f889b DG |
2899 | set_huge_pte_at(mm, address, ptep, |
2900 | make_huge_pte(vma, new_page, 1)); | |
0fe6e20b | 2901 | page_remove_rmap(old_page); |
cd67f0d2 | 2902 | hugepage_add_new_anon_rmap(new_page, vma, address); |
1e8f889b DG |
2903 | /* Make the old page be freed below */ |
2904 | new_page = old_page; | |
2905 | } | |
cb900f41 | 2906 | spin_unlock(ptl); |
2ec74c3e | 2907 | mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); |
ad4404a2 | 2908 | out_release_all: |
1e8f889b | 2909 | page_cache_release(new_page); |
ad4404a2 | 2910 | out_release_old: |
1e8f889b | 2911 | page_cache_release(old_page); |
8312034f | 2912 | |
ad4404a2 DB |
2913 | spin_lock(ptl); /* Caller expects lock to be held */ |
2914 | return ret; | |
1e8f889b DG |
2915 | } |
2916 | ||
04f2cbe3 | 2917 | /* Return the pagecache page at a given address within a VMA */ |
a5516438 AK |
2918 | static struct page *hugetlbfs_pagecache_page(struct hstate *h, |
2919 | struct vm_area_struct *vma, unsigned long address) | |
04f2cbe3 MG |
2920 | { |
2921 | struct address_space *mapping; | |
e7c4b0bf | 2922 | pgoff_t idx; |
04f2cbe3 MG |
2923 | |
2924 | mapping = vma->vm_file->f_mapping; | |
a5516438 | 2925 | idx = vma_hugecache_offset(h, vma, address); |
04f2cbe3 MG |
2926 | |
2927 | return find_lock_page(mapping, idx); | |
2928 | } | |
2929 | ||
3ae77f43 HD |
2930 | /* |
2931 | * Return whether there is a pagecache page to back given address within VMA. | |
2932 | * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. | |
2933 | */ | |
2934 | static bool hugetlbfs_pagecache_present(struct hstate *h, | |
2a15efc9 HD |
2935 | struct vm_area_struct *vma, unsigned long address) |
2936 | { | |
2937 | struct address_space *mapping; | |
2938 | pgoff_t idx; | |
2939 | struct page *page; | |
2940 | ||
2941 | mapping = vma->vm_file->f_mapping; | |
2942 | idx = vma_hugecache_offset(h, vma, address); | |
2943 | ||
2944 | page = find_get_page(mapping, idx); | |
2945 | if (page) | |
2946 | put_page(page); | |
2947 | return page != NULL; | |
2948 | } | |
2949 | ||
a1ed3dda | 2950 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
8382d914 DB |
2951 | struct address_space *mapping, pgoff_t idx, |
2952 | unsigned long address, pte_t *ptep, unsigned int flags) | |
ac9b9c66 | 2953 | { |
a5516438 | 2954 | struct hstate *h = hstate_vma(vma); |
ac9b9c66 | 2955 | int ret = VM_FAULT_SIGBUS; |
409eb8c2 | 2956 | int anon_rmap = 0; |
4c887265 | 2957 | unsigned long size; |
4c887265 | 2958 | struct page *page; |
1e8f889b | 2959 | pte_t new_pte; |
cb900f41 | 2960 | spinlock_t *ptl; |
4c887265 | 2961 | |
04f2cbe3 MG |
2962 | /* |
2963 | * Currently, we are forced to kill the process in the event the | |
2964 | * original mapper has unmapped pages from the child due to a failed | |
25985edc | 2965 | * COW. Warn that such a situation has occurred as it may not be obvious |
04f2cbe3 MG |
2966 | */ |
2967 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { | |
ffb22af5 AM |
2968 | pr_warning("PID %d killed due to inadequate hugepage pool\n", |
2969 | current->pid); | |
04f2cbe3 MG |
2970 | return ret; |
2971 | } | |
2972 | ||
4c887265 AL |
2973 | /* |
2974 | * Use page lock to guard against racing truncation | |
2975 | * before we get page_table_lock. | |
2976 | */ | |
6bda666a CL |
2977 | retry: |
2978 | page = find_lock_page(mapping, idx); | |
2979 | if (!page) { | |
a5516438 | 2980 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
ebed4bfc HD |
2981 | if (idx >= size) |
2982 | goto out; | |
04f2cbe3 | 2983 | page = alloc_huge_page(vma, address, 0); |
2fc39cec | 2984 | if (IS_ERR(page)) { |
76dcee75 AK |
2985 | ret = PTR_ERR(page); |
2986 | if (ret == -ENOMEM) | |
2987 | ret = VM_FAULT_OOM; | |
2988 | else | |
2989 | ret = VM_FAULT_SIGBUS; | |
6bda666a CL |
2990 | goto out; |
2991 | } | |
47ad8475 | 2992 | clear_huge_page(page, address, pages_per_huge_page(h)); |
0ed361de | 2993 | __SetPageUptodate(page); |
ac9b9c66 | 2994 | |
f83a275d | 2995 | if (vma->vm_flags & VM_MAYSHARE) { |
6bda666a | 2996 | int err; |
45c682a6 | 2997 | struct inode *inode = mapping->host; |
6bda666a CL |
2998 | |
2999 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
3000 | if (err) { | |
3001 | put_page(page); | |
6bda666a CL |
3002 | if (err == -EEXIST) |
3003 | goto retry; | |
3004 | goto out; | |
3005 | } | |
07443a85 | 3006 | ClearPagePrivate(page); |
45c682a6 KC |
3007 | |
3008 | spin_lock(&inode->i_lock); | |
a5516438 | 3009 | inode->i_blocks += blocks_per_huge_page(h); |
45c682a6 | 3010 | spin_unlock(&inode->i_lock); |
23be7468 | 3011 | } else { |
6bda666a | 3012 | lock_page(page); |
0fe6e20b NH |
3013 | if (unlikely(anon_vma_prepare(vma))) { |
3014 | ret = VM_FAULT_OOM; | |
3015 | goto backout_unlocked; | |
3016 | } | |
409eb8c2 | 3017 | anon_rmap = 1; |
23be7468 | 3018 | } |
0fe6e20b | 3019 | } else { |
998b4382 NH |
3020 | /* |
3021 | * If memory error occurs between mmap() and fault, some process | |
3022 | * don't have hwpoisoned swap entry for errored virtual address. | |
3023 | * So we need to block hugepage fault by PG_hwpoison bit check. | |
3024 | */ | |
3025 | if (unlikely(PageHWPoison(page))) { | |
32f84528 | 3026 | ret = VM_FAULT_HWPOISON | |
972dc4de | 3027 | VM_FAULT_SET_HINDEX(hstate_index(h)); |
998b4382 NH |
3028 | goto backout_unlocked; |
3029 | } | |
6bda666a | 3030 | } |
1e8f889b | 3031 | |
57303d80 AW |
3032 | /* |
3033 | * If we are going to COW a private mapping later, we examine the | |
3034 | * pending reservations for this page now. This will ensure that | |
3035 | * any allocations necessary to record that reservation occur outside | |
3036 | * the spinlock. | |
3037 | */ | |
788c7df4 | 3038 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) |
2b26736c AW |
3039 | if (vma_needs_reservation(h, vma, address) < 0) { |
3040 | ret = VM_FAULT_OOM; | |
3041 | goto backout_unlocked; | |
3042 | } | |
57303d80 | 3043 | |
cb900f41 KS |
3044 | ptl = huge_pte_lockptr(h, mm, ptep); |
3045 | spin_lock(ptl); | |
a5516438 | 3046 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
4c887265 AL |
3047 | if (idx >= size) |
3048 | goto backout; | |
3049 | ||
83c54070 | 3050 | ret = 0; |
7f2e9525 | 3051 | if (!huge_pte_none(huge_ptep_get(ptep))) |
4c887265 AL |
3052 | goto backout; |
3053 | ||
07443a85 JK |
3054 | if (anon_rmap) { |
3055 | ClearPagePrivate(page); | |
409eb8c2 | 3056 | hugepage_add_new_anon_rmap(page, vma, address); |
ac714904 | 3057 | } else |
409eb8c2 | 3058 | page_dup_rmap(page); |
1e8f889b DG |
3059 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
3060 | && (vma->vm_flags & VM_SHARED))); | |
3061 | set_huge_pte_at(mm, address, ptep, new_pte); | |
3062 | ||
788c7df4 | 3063 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { |
1e8f889b | 3064 | /* Optimization, do the COW without a second fault */ |
cb900f41 | 3065 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page, ptl); |
1e8f889b DG |
3066 | } |
3067 | ||
cb900f41 | 3068 | spin_unlock(ptl); |
4c887265 AL |
3069 | unlock_page(page); |
3070 | out: | |
ac9b9c66 | 3071 | return ret; |
4c887265 AL |
3072 | |
3073 | backout: | |
cb900f41 | 3074 | spin_unlock(ptl); |
2b26736c | 3075 | backout_unlocked: |
4c887265 AL |
3076 | unlock_page(page); |
3077 | put_page(page); | |
3078 | goto out; | |
ac9b9c66 HD |
3079 | } |
3080 | ||
8382d914 DB |
3081 | #ifdef CONFIG_SMP |
3082 | static u32 fault_mutex_hash(struct hstate *h, struct mm_struct *mm, | |
3083 | struct vm_area_struct *vma, | |
3084 | struct address_space *mapping, | |
3085 | pgoff_t idx, unsigned long address) | |
3086 | { | |
3087 | unsigned long key[2]; | |
3088 | u32 hash; | |
3089 | ||
3090 | if (vma->vm_flags & VM_SHARED) { | |
3091 | key[0] = (unsigned long) mapping; | |
3092 | key[1] = idx; | |
3093 | } else { | |
3094 | key[0] = (unsigned long) mm; | |
3095 | key[1] = address >> huge_page_shift(h); | |
3096 | } | |
3097 | ||
3098 | hash = jhash2((u32 *)&key, sizeof(key)/sizeof(u32), 0); | |
3099 | ||
3100 | return hash & (num_fault_mutexes - 1); | |
3101 | } | |
3102 | #else | |
3103 | /* | |
3104 | * For uniprocesor systems we always use a single mutex, so just | |
3105 | * return 0 and avoid the hashing overhead. | |
3106 | */ | |
3107 | static u32 fault_mutex_hash(struct hstate *h, struct mm_struct *mm, | |
3108 | struct vm_area_struct *vma, | |
3109 | struct address_space *mapping, | |
3110 | pgoff_t idx, unsigned long address) | |
3111 | { | |
3112 | return 0; | |
3113 | } | |
3114 | #endif | |
3115 | ||
86e5216f | 3116 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
788c7df4 | 3117 | unsigned long address, unsigned int flags) |
86e5216f | 3118 | { |
8382d914 | 3119 | pte_t *ptep, entry; |
cb900f41 | 3120 | spinlock_t *ptl; |
1e8f889b | 3121 | int ret; |
8382d914 DB |
3122 | u32 hash; |
3123 | pgoff_t idx; | |
0fe6e20b | 3124 | struct page *page = NULL; |
57303d80 | 3125 | struct page *pagecache_page = NULL; |
a5516438 | 3126 | struct hstate *h = hstate_vma(vma); |
8382d914 | 3127 | struct address_space *mapping; |
86e5216f | 3128 | |
1e16a539 KH |
3129 | address &= huge_page_mask(h); |
3130 | ||
fd6a03ed NH |
3131 | ptep = huge_pte_offset(mm, address); |
3132 | if (ptep) { | |
3133 | entry = huge_ptep_get(ptep); | |
290408d4 | 3134 | if (unlikely(is_hugetlb_entry_migration(entry))) { |
cb900f41 | 3135 | migration_entry_wait_huge(vma, mm, ptep); |
290408d4 NH |
3136 | return 0; |
3137 | } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) | |
32f84528 | 3138 | return VM_FAULT_HWPOISON_LARGE | |
972dc4de | 3139 | VM_FAULT_SET_HINDEX(hstate_index(h)); |
fd6a03ed NH |
3140 | } |
3141 | ||
a5516438 | 3142 | ptep = huge_pte_alloc(mm, address, huge_page_size(h)); |
86e5216f AL |
3143 | if (!ptep) |
3144 | return VM_FAULT_OOM; | |
3145 | ||
8382d914 DB |
3146 | mapping = vma->vm_file->f_mapping; |
3147 | idx = vma_hugecache_offset(h, vma, address); | |
3148 | ||
3935baa9 DG |
3149 | /* |
3150 | * Serialize hugepage allocation and instantiation, so that we don't | |
3151 | * get spurious allocation failures if two CPUs race to instantiate | |
3152 | * the same page in the page cache. | |
3153 | */ | |
8382d914 DB |
3154 | hash = fault_mutex_hash(h, mm, vma, mapping, idx, address); |
3155 | mutex_lock(&htlb_fault_mutex_table[hash]); | |
3156 | ||
7f2e9525 GS |
3157 | entry = huge_ptep_get(ptep); |
3158 | if (huge_pte_none(entry)) { | |
8382d914 | 3159 | ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, flags); |
b4d1d99f | 3160 | goto out_mutex; |
3935baa9 | 3161 | } |
86e5216f | 3162 | |
83c54070 | 3163 | ret = 0; |
1e8f889b | 3164 | |
57303d80 AW |
3165 | /* |
3166 | * If we are going to COW the mapping later, we examine the pending | |
3167 | * reservations for this page now. This will ensure that any | |
3168 | * allocations necessary to record that reservation occur outside the | |
3169 | * spinlock. For private mappings, we also lookup the pagecache | |
3170 | * page now as it is used to determine if a reservation has been | |
3171 | * consumed. | |
3172 | */ | |
106c992a | 3173 | if ((flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) { |
2b26736c AW |
3174 | if (vma_needs_reservation(h, vma, address) < 0) { |
3175 | ret = VM_FAULT_OOM; | |
b4d1d99f | 3176 | goto out_mutex; |
2b26736c | 3177 | } |
57303d80 | 3178 | |
f83a275d | 3179 | if (!(vma->vm_flags & VM_MAYSHARE)) |
57303d80 AW |
3180 | pagecache_page = hugetlbfs_pagecache_page(h, |
3181 | vma, address); | |
3182 | } | |
3183 | ||
56c9cfb1 NH |
3184 | /* |
3185 | * hugetlb_cow() requires page locks of pte_page(entry) and | |
3186 | * pagecache_page, so here we need take the former one | |
3187 | * when page != pagecache_page or !pagecache_page. | |
3188 | * Note that locking order is always pagecache_page -> page, | |
3189 | * so no worry about deadlock. | |
3190 | */ | |
3191 | page = pte_page(entry); | |
66aebce7 | 3192 | get_page(page); |
56c9cfb1 | 3193 | if (page != pagecache_page) |
0fe6e20b | 3194 | lock_page(page); |
0fe6e20b | 3195 | |
cb900f41 KS |
3196 | ptl = huge_pte_lockptr(h, mm, ptep); |
3197 | spin_lock(ptl); | |
1e8f889b | 3198 | /* Check for a racing update before calling hugetlb_cow */ |
b4d1d99f | 3199 | if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) |
cb900f41 | 3200 | goto out_ptl; |
b4d1d99f DG |
3201 | |
3202 | ||
788c7df4 | 3203 | if (flags & FAULT_FLAG_WRITE) { |
106c992a | 3204 | if (!huge_pte_write(entry)) { |
57303d80 | 3205 | ret = hugetlb_cow(mm, vma, address, ptep, entry, |
cb900f41 KS |
3206 | pagecache_page, ptl); |
3207 | goto out_ptl; | |
b4d1d99f | 3208 | } |
106c992a | 3209 | entry = huge_pte_mkdirty(entry); |
b4d1d99f DG |
3210 | } |
3211 | entry = pte_mkyoung(entry); | |
788c7df4 HD |
3212 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, |
3213 | flags & FAULT_FLAG_WRITE)) | |
4b3073e1 | 3214 | update_mmu_cache(vma, address, ptep); |
b4d1d99f | 3215 | |
cb900f41 KS |
3216 | out_ptl: |
3217 | spin_unlock(ptl); | |
57303d80 AW |
3218 | |
3219 | if (pagecache_page) { | |
3220 | unlock_page(pagecache_page); | |
3221 | put_page(pagecache_page); | |
3222 | } | |
1f64d69c DN |
3223 | if (page != pagecache_page) |
3224 | unlock_page(page); | |
66aebce7 | 3225 | put_page(page); |
57303d80 | 3226 | |
b4d1d99f | 3227 | out_mutex: |
8382d914 | 3228 | mutex_unlock(&htlb_fault_mutex_table[hash]); |
1e8f889b | 3229 | return ret; |
86e5216f AL |
3230 | } |
3231 | ||
28a35716 ML |
3232 | long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
3233 | struct page **pages, struct vm_area_struct **vmas, | |
3234 | unsigned long *position, unsigned long *nr_pages, | |
3235 | long i, unsigned int flags) | |
63551ae0 | 3236 | { |
d5d4b0aa CK |
3237 | unsigned long pfn_offset; |
3238 | unsigned long vaddr = *position; | |
28a35716 | 3239 | unsigned long remainder = *nr_pages; |
a5516438 | 3240 | struct hstate *h = hstate_vma(vma); |
63551ae0 | 3241 | |
63551ae0 | 3242 | while (vaddr < vma->vm_end && remainder) { |
4c887265 | 3243 | pte_t *pte; |
cb900f41 | 3244 | spinlock_t *ptl = NULL; |
2a15efc9 | 3245 | int absent; |
4c887265 | 3246 | struct page *page; |
63551ae0 | 3247 | |
4c887265 AL |
3248 | /* |
3249 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
2a15efc9 | 3250 | * each hugepage. We have to make sure we get the |
4c887265 | 3251 | * first, for the page indexing below to work. |
cb900f41 KS |
3252 | * |
3253 | * Note that page table lock is not held when pte is null. | |
4c887265 | 3254 | */ |
a5516438 | 3255 | pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); |
cb900f41 KS |
3256 | if (pte) |
3257 | ptl = huge_pte_lock(h, mm, pte); | |
2a15efc9 HD |
3258 | absent = !pte || huge_pte_none(huge_ptep_get(pte)); |
3259 | ||
3260 | /* | |
3261 | * When coredumping, it suits get_dump_page if we just return | |
3ae77f43 HD |
3262 | * an error where there's an empty slot with no huge pagecache |
3263 | * to back it. This way, we avoid allocating a hugepage, and | |
3264 | * the sparse dumpfile avoids allocating disk blocks, but its | |
3265 | * huge holes still show up with zeroes where they need to be. | |
2a15efc9 | 3266 | */ |
3ae77f43 HD |
3267 | if (absent && (flags & FOLL_DUMP) && |
3268 | !hugetlbfs_pagecache_present(h, vma, vaddr)) { | |
cb900f41 KS |
3269 | if (pte) |
3270 | spin_unlock(ptl); | |
2a15efc9 HD |
3271 | remainder = 0; |
3272 | break; | |
3273 | } | |
63551ae0 | 3274 | |
9cc3a5bd NH |
3275 | /* |
3276 | * We need call hugetlb_fault for both hugepages under migration | |
3277 | * (in which case hugetlb_fault waits for the migration,) and | |
3278 | * hwpoisoned hugepages (in which case we need to prevent the | |
3279 | * caller from accessing to them.) In order to do this, we use | |
3280 | * here is_swap_pte instead of is_hugetlb_entry_migration and | |
3281 | * is_hugetlb_entry_hwpoisoned. This is because it simply covers | |
3282 | * both cases, and because we can't follow correct pages | |
3283 | * directly from any kind of swap entries. | |
3284 | */ | |
3285 | if (absent || is_swap_pte(huge_ptep_get(pte)) || | |
106c992a GS |
3286 | ((flags & FOLL_WRITE) && |
3287 | !huge_pte_write(huge_ptep_get(pte)))) { | |
4c887265 | 3288 | int ret; |
63551ae0 | 3289 | |
cb900f41 KS |
3290 | if (pte) |
3291 | spin_unlock(ptl); | |
2a15efc9 HD |
3292 | ret = hugetlb_fault(mm, vma, vaddr, |
3293 | (flags & FOLL_WRITE) ? FAULT_FLAG_WRITE : 0); | |
a89182c7 | 3294 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 3295 | continue; |
63551ae0 | 3296 | |
4c887265 | 3297 | remainder = 0; |
4c887265 AL |
3298 | break; |
3299 | } | |
3300 | ||
a5516438 | 3301 | pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; |
7f2e9525 | 3302 | page = pte_page(huge_ptep_get(pte)); |
d5d4b0aa | 3303 | same_page: |
d6692183 | 3304 | if (pages) { |
2a15efc9 | 3305 | pages[i] = mem_map_offset(page, pfn_offset); |
a0368d4e | 3306 | get_page_foll(pages[i]); |
d6692183 | 3307 | } |
63551ae0 DG |
3308 | |
3309 | if (vmas) | |
3310 | vmas[i] = vma; | |
3311 | ||
3312 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 3313 | ++pfn_offset; |
63551ae0 DG |
3314 | --remainder; |
3315 | ++i; | |
d5d4b0aa | 3316 | if (vaddr < vma->vm_end && remainder && |
a5516438 | 3317 | pfn_offset < pages_per_huge_page(h)) { |
d5d4b0aa CK |
3318 | /* |
3319 | * We use pfn_offset to avoid touching the pageframes | |
3320 | * of this compound page. | |
3321 | */ | |
3322 | goto same_page; | |
3323 | } | |
cb900f41 | 3324 | spin_unlock(ptl); |
63551ae0 | 3325 | } |
28a35716 | 3326 | *nr_pages = remainder; |
63551ae0 DG |
3327 | *position = vaddr; |
3328 | ||
2a15efc9 | 3329 | return i ? i : -EFAULT; |
63551ae0 | 3330 | } |
8f860591 | 3331 | |
7da4d641 | 3332 | unsigned long hugetlb_change_protection(struct vm_area_struct *vma, |
8f860591 ZY |
3333 | unsigned long address, unsigned long end, pgprot_t newprot) |
3334 | { | |
3335 | struct mm_struct *mm = vma->vm_mm; | |
3336 | unsigned long start = address; | |
3337 | pte_t *ptep; | |
3338 | pte_t pte; | |
a5516438 | 3339 | struct hstate *h = hstate_vma(vma); |
7da4d641 | 3340 | unsigned long pages = 0; |
8f860591 ZY |
3341 | |
3342 | BUG_ON(address >= end); | |
3343 | flush_cache_range(vma, address, end); | |
3344 | ||
a5338093 | 3345 | mmu_notifier_invalidate_range_start(mm, start, end); |
3d48ae45 | 3346 | mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex); |
a5516438 | 3347 | for (; address < end; address += huge_page_size(h)) { |
cb900f41 | 3348 | spinlock_t *ptl; |
8f860591 ZY |
3349 | ptep = huge_pte_offset(mm, address); |
3350 | if (!ptep) | |
3351 | continue; | |
cb900f41 | 3352 | ptl = huge_pte_lock(h, mm, ptep); |
7da4d641 PZ |
3353 | if (huge_pmd_unshare(mm, &address, ptep)) { |
3354 | pages++; | |
cb900f41 | 3355 | spin_unlock(ptl); |
39dde65c | 3356 | continue; |
7da4d641 | 3357 | } |
7f2e9525 | 3358 | if (!huge_pte_none(huge_ptep_get(ptep))) { |
8f860591 | 3359 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
106c992a | 3360 | pte = pte_mkhuge(huge_pte_modify(pte, newprot)); |
be7517d6 | 3361 | pte = arch_make_huge_pte(pte, vma, NULL, 0); |
8f860591 | 3362 | set_huge_pte_at(mm, address, ptep, pte); |
7da4d641 | 3363 | pages++; |
8f860591 | 3364 | } |
cb900f41 | 3365 | spin_unlock(ptl); |
8f860591 | 3366 | } |
d833352a MG |
3367 | /* |
3368 | * Must flush TLB before releasing i_mmap_mutex: x86's huge_pmd_unshare | |
3369 | * may have cleared our pud entry and done put_page on the page table: | |
3370 | * once we release i_mmap_mutex, another task can do the final put_page | |
3371 | * and that page table be reused and filled with junk. | |
3372 | */ | |
8f860591 | 3373 | flush_tlb_range(vma, start, end); |
d833352a | 3374 | mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex); |
a5338093 | 3375 | mmu_notifier_invalidate_range_end(mm, start, end); |
7da4d641 PZ |
3376 | |
3377 | return pages << h->order; | |
8f860591 ZY |
3378 | } |
3379 | ||
a1e78772 MG |
3380 | int hugetlb_reserve_pages(struct inode *inode, |
3381 | long from, long to, | |
5a6fe125 | 3382 | struct vm_area_struct *vma, |
ca16d140 | 3383 | vm_flags_t vm_flags) |
e4e574b7 | 3384 | { |
17c9d12e | 3385 | long ret, chg; |
a5516438 | 3386 | struct hstate *h = hstate_inode(inode); |
90481622 | 3387 | struct hugepage_subpool *spool = subpool_inode(inode); |
9119a41e | 3388 | struct resv_map *resv_map; |
e4e574b7 | 3389 | |
17c9d12e MG |
3390 | /* |
3391 | * Only apply hugepage reservation if asked. At fault time, an | |
3392 | * attempt will be made for VM_NORESERVE to allocate a page | |
90481622 | 3393 | * without using reserves |
17c9d12e | 3394 | */ |
ca16d140 | 3395 | if (vm_flags & VM_NORESERVE) |
17c9d12e MG |
3396 | return 0; |
3397 | ||
a1e78772 MG |
3398 | /* |
3399 | * Shared mappings base their reservation on the number of pages that | |
3400 | * are already allocated on behalf of the file. Private mappings need | |
3401 | * to reserve the full area even if read-only as mprotect() may be | |
3402 | * called to make the mapping read-write. Assume !vma is a shm mapping | |
3403 | */ | |
9119a41e | 3404 | if (!vma || vma->vm_flags & VM_MAYSHARE) { |
4e35f483 | 3405 | resv_map = inode_resv_map(inode); |
9119a41e | 3406 | |
1406ec9b | 3407 | chg = region_chg(resv_map, from, to); |
9119a41e JK |
3408 | |
3409 | } else { | |
3410 | resv_map = resv_map_alloc(); | |
17c9d12e MG |
3411 | if (!resv_map) |
3412 | return -ENOMEM; | |
3413 | ||
a1e78772 | 3414 | chg = to - from; |
84afd99b | 3415 | |
17c9d12e MG |
3416 | set_vma_resv_map(vma, resv_map); |
3417 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); | |
3418 | } | |
3419 | ||
c50ac050 DH |
3420 | if (chg < 0) { |
3421 | ret = chg; | |
3422 | goto out_err; | |
3423 | } | |
8a630112 | 3424 | |
90481622 | 3425 | /* There must be enough pages in the subpool for the mapping */ |
c50ac050 DH |
3426 | if (hugepage_subpool_get_pages(spool, chg)) { |
3427 | ret = -ENOSPC; | |
3428 | goto out_err; | |
3429 | } | |
5a6fe125 MG |
3430 | |
3431 | /* | |
17c9d12e | 3432 | * Check enough hugepages are available for the reservation. |
90481622 | 3433 | * Hand the pages back to the subpool if there are not |
5a6fe125 | 3434 | */ |
a5516438 | 3435 | ret = hugetlb_acct_memory(h, chg); |
68842c9b | 3436 | if (ret < 0) { |
90481622 | 3437 | hugepage_subpool_put_pages(spool, chg); |
c50ac050 | 3438 | goto out_err; |
68842c9b | 3439 | } |
17c9d12e MG |
3440 | |
3441 | /* | |
3442 | * Account for the reservations made. Shared mappings record regions | |
3443 | * that have reservations as they are shared by multiple VMAs. | |
3444 | * When the last VMA disappears, the region map says how much | |
3445 | * the reservation was and the page cache tells how much of | |
3446 | * the reservation was consumed. Private mappings are per-VMA and | |
3447 | * only the consumed reservations are tracked. When the VMA | |
3448 | * disappears, the original reservation is the VMA size and the | |
3449 | * consumed reservations are stored in the map. Hence, nothing | |
3450 | * else has to be done for private mappings here | |
3451 | */ | |
f83a275d | 3452 | if (!vma || vma->vm_flags & VM_MAYSHARE) |
1406ec9b | 3453 | region_add(resv_map, from, to); |
a43a8c39 | 3454 | return 0; |
c50ac050 | 3455 | out_err: |
f031dd27 JK |
3456 | if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
3457 | kref_put(&resv_map->refs, resv_map_release); | |
c50ac050 | 3458 | return ret; |
a43a8c39 CK |
3459 | } |
3460 | ||
3461 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
3462 | { | |
a5516438 | 3463 | struct hstate *h = hstate_inode(inode); |
4e35f483 | 3464 | struct resv_map *resv_map = inode_resv_map(inode); |
9119a41e | 3465 | long chg = 0; |
90481622 | 3466 | struct hugepage_subpool *spool = subpool_inode(inode); |
45c682a6 | 3467 | |
9119a41e | 3468 | if (resv_map) |
1406ec9b | 3469 | chg = region_truncate(resv_map, offset); |
45c682a6 | 3470 | spin_lock(&inode->i_lock); |
e4c6f8be | 3471 | inode->i_blocks -= (blocks_per_huge_page(h) * freed); |
45c682a6 KC |
3472 | spin_unlock(&inode->i_lock); |
3473 | ||
90481622 | 3474 | hugepage_subpool_put_pages(spool, (chg - freed)); |
a5516438 | 3475 | hugetlb_acct_memory(h, -(chg - freed)); |
a43a8c39 | 3476 | } |
93f70f90 | 3477 | |
3212b535 SC |
3478 | #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE |
3479 | static unsigned long page_table_shareable(struct vm_area_struct *svma, | |
3480 | struct vm_area_struct *vma, | |
3481 | unsigned long addr, pgoff_t idx) | |
3482 | { | |
3483 | unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) + | |
3484 | svma->vm_start; | |
3485 | unsigned long sbase = saddr & PUD_MASK; | |
3486 | unsigned long s_end = sbase + PUD_SIZE; | |
3487 | ||
3488 | /* Allow segments to share if only one is marked locked */ | |
3489 | unsigned long vm_flags = vma->vm_flags & ~VM_LOCKED; | |
3490 | unsigned long svm_flags = svma->vm_flags & ~VM_LOCKED; | |
3491 | ||
3492 | /* | |
3493 | * match the virtual addresses, permission and the alignment of the | |
3494 | * page table page. | |
3495 | */ | |
3496 | if (pmd_index(addr) != pmd_index(saddr) || | |
3497 | vm_flags != svm_flags || | |
3498 | sbase < svma->vm_start || svma->vm_end < s_end) | |
3499 | return 0; | |
3500 | ||
3501 | return saddr; | |
3502 | } | |
3503 | ||
3504 | static int vma_shareable(struct vm_area_struct *vma, unsigned long addr) | |
3505 | { | |
3506 | unsigned long base = addr & PUD_MASK; | |
3507 | unsigned long end = base + PUD_SIZE; | |
3508 | ||
3509 | /* | |
3510 | * check on proper vm_flags and page table alignment | |
3511 | */ | |
3512 | if (vma->vm_flags & VM_MAYSHARE && | |
3513 | vma->vm_start <= base && end <= vma->vm_end) | |
3514 | return 1; | |
3515 | return 0; | |
3516 | } | |
3517 | ||
3518 | /* | |
3519 | * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() | |
3520 | * and returns the corresponding pte. While this is not necessary for the | |
3521 | * !shared pmd case because we can allocate the pmd later as well, it makes the | |
3522 | * code much cleaner. pmd allocation is essential for the shared case because | |
3523 | * pud has to be populated inside the same i_mmap_mutex section - otherwise | |
3524 | * racing tasks could either miss the sharing (see huge_pte_offset) or select a | |
3525 | * bad pmd for sharing. | |
3526 | */ | |
3527 | pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) | |
3528 | { | |
3529 | struct vm_area_struct *vma = find_vma(mm, addr); | |
3530 | struct address_space *mapping = vma->vm_file->f_mapping; | |
3531 | pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + | |
3532 | vma->vm_pgoff; | |
3533 | struct vm_area_struct *svma; | |
3534 | unsigned long saddr; | |
3535 | pte_t *spte = NULL; | |
3536 | pte_t *pte; | |
cb900f41 | 3537 | spinlock_t *ptl; |
3212b535 SC |
3538 | |
3539 | if (!vma_shareable(vma, addr)) | |
3540 | return (pte_t *)pmd_alloc(mm, pud, addr); | |
3541 | ||
3542 | mutex_lock(&mapping->i_mmap_mutex); | |
3543 | vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) { | |
3544 | if (svma == vma) | |
3545 | continue; | |
3546 | ||
3547 | saddr = page_table_shareable(svma, vma, addr, idx); | |
3548 | if (saddr) { | |
3549 | spte = huge_pte_offset(svma->vm_mm, saddr); | |
3550 | if (spte) { | |
3551 | get_page(virt_to_page(spte)); | |
3552 | break; | |
3553 | } | |
3554 | } | |
3555 | } | |
3556 | ||
3557 | if (!spte) | |
3558 | goto out; | |
3559 | ||
cb900f41 KS |
3560 | ptl = huge_pte_lockptr(hstate_vma(vma), mm, spte); |
3561 | spin_lock(ptl); | |
3212b535 SC |
3562 | if (pud_none(*pud)) |
3563 | pud_populate(mm, pud, | |
3564 | (pmd_t *)((unsigned long)spte & PAGE_MASK)); | |
3565 | else | |
3566 | put_page(virt_to_page(spte)); | |
cb900f41 | 3567 | spin_unlock(ptl); |
3212b535 SC |
3568 | out: |
3569 | pte = (pte_t *)pmd_alloc(mm, pud, addr); | |
3570 | mutex_unlock(&mapping->i_mmap_mutex); | |
3571 | return pte; | |
3572 | } | |
3573 | ||
3574 | /* | |
3575 | * unmap huge page backed by shared pte. | |
3576 | * | |
3577 | * Hugetlb pte page is ref counted at the time of mapping. If pte is shared | |
3578 | * indicated by page_count > 1, unmap is achieved by clearing pud and | |
3579 | * decrementing the ref count. If count == 1, the pte page is not shared. | |
3580 | * | |
cb900f41 | 3581 | * called with page table lock held. |
3212b535 SC |
3582 | * |
3583 | * returns: 1 successfully unmapped a shared pte page | |
3584 | * 0 the underlying pte page is not shared, or it is the last user | |
3585 | */ | |
3586 | int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) | |
3587 | { | |
3588 | pgd_t *pgd = pgd_offset(mm, *addr); | |
3589 | pud_t *pud = pud_offset(pgd, *addr); | |
3590 | ||
3591 | BUG_ON(page_count(virt_to_page(ptep)) == 0); | |
3592 | if (page_count(virt_to_page(ptep)) == 1) | |
3593 | return 0; | |
3594 | ||
3595 | pud_clear(pud); | |
3596 | put_page(virt_to_page(ptep)); | |
3597 | *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE; | |
3598 | return 1; | |
3599 | } | |
9e5fc74c SC |
3600 | #define want_pmd_share() (1) |
3601 | #else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ | |
3602 | pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) | |
3603 | { | |
3604 | return NULL; | |
3605 | } | |
3606 | #define want_pmd_share() (0) | |
3212b535 SC |
3607 | #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */ |
3608 | ||
9e5fc74c SC |
3609 | #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB |
3610 | pte_t *huge_pte_alloc(struct mm_struct *mm, | |
3611 | unsigned long addr, unsigned long sz) | |
3612 | { | |
3613 | pgd_t *pgd; | |
3614 | pud_t *pud; | |
3615 | pte_t *pte = NULL; | |
3616 | ||
3617 | pgd = pgd_offset(mm, addr); | |
3618 | pud = pud_alloc(mm, pgd, addr); | |
3619 | if (pud) { | |
3620 | if (sz == PUD_SIZE) { | |
3621 | pte = (pte_t *)pud; | |
3622 | } else { | |
3623 | BUG_ON(sz != PMD_SIZE); | |
3624 | if (want_pmd_share() && pud_none(*pud)) | |
3625 | pte = huge_pmd_share(mm, addr, pud); | |
3626 | else | |
3627 | pte = (pte_t *)pmd_alloc(mm, pud, addr); | |
3628 | } | |
3629 | } | |
3630 | BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte)); | |
3631 | ||
3632 | return pte; | |
3633 | } | |
3634 | ||
3635 | pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) | |
3636 | { | |
3637 | pgd_t *pgd; | |
3638 | pud_t *pud; | |
3639 | pmd_t *pmd = NULL; | |
3640 | ||
3641 | pgd = pgd_offset(mm, addr); | |
3642 | if (pgd_present(*pgd)) { | |
3643 | pud = pud_offset(pgd, addr); | |
3644 | if (pud_present(*pud)) { | |
3645 | if (pud_huge(*pud)) | |
3646 | return (pte_t *)pud; | |
3647 | pmd = pmd_offset(pud, addr); | |
3648 | } | |
3649 | } | |
3650 | return (pte_t *) pmd; | |
3651 | } | |
3652 | ||
3653 | struct page * | |
3654 | follow_huge_pmd(struct mm_struct *mm, unsigned long address, | |
3655 | pmd_t *pmd, int write) | |
3656 | { | |
3657 | struct page *page; | |
3658 | ||
3659 | page = pte_page(*(pte_t *)pmd); | |
3660 | if (page) | |
3661 | page += ((address & ~PMD_MASK) >> PAGE_SHIFT); | |
3662 | return page; | |
3663 | } | |
3664 | ||
3665 | struct page * | |
3666 | follow_huge_pud(struct mm_struct *mm, unsigned long address, | |
3667 | pud_t *pud, int write) | |
3668 | { | |
3669 | struct page *page; | |
3670 | ||
3671 | page = pte_page(*(pte_t *)pud); | |
3672 | if (page) | |
3673 | page += ((address & ~PUD_MASK) >> PAGE_SHIFT); | |
3674 | return page; | |
3675 | } | |
3676 | ||
3677 | #else /* !CONFIG_ARCH_WANT_GENERAL_HUGETLB */ | |
3678 | ||
3679 | /* Can be overriden by architectures */ | |
3b32123d | 3680 | struct page * __weak |
9e5fc74c SC |
3681 | follow_huge_pud(struct mm_struct *mm, unsigned long address, |
3682 | pud_t *pud, int write) | |
3683 | { | |
3684 | BUG(); | |
3685 | return NULL; | |
3686 | } | |
3687 | ||
3688 | #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ | |
3689 | ||
d5bd9106 AK |
3690 | #ifdef CONFIG_MEMORY_FAILURE |
3691 | ||
6de2b1aa NH |
3692 | /* Should be called in hugetlb_lock */ |
3693 | static int is_hugepage_on_freelist(struct page *hpage) | |
3694 | { | |
3695 | struct page *page; | |
3696 | struct page *tmp; | |
3697 | struct hstate *h = page_hstate(hpage); | |
3698 | int nid = page_to_nid(hpage); | |
3699 | ||
3700 | list_for_each_entry_safe(page, tmp, &h->hugepage_freelists[nid], lru) | |
3701 | if (page == hpage) | |
3702 | return 1; | |
3703 | return 0; | |
3704 | } | |
3705 | ||
93f70f90 NH |
3706 | /* |
3707 | * This function is called from memory failure code. | |
3708 | * Assume the caller holds page lock of the head page. | |
3709 | */ | |
6de2b1aa | 3710 | int dequeue_hwpoisoned_huge_page(struct page *hpage) |
93f70f90 NH |
3711 | { |
3712 | struct hstate *h = page_hstate(hpage); | |
3713 | int nid = page_to_nid(hpage); | |
6de2b1aa | 3714 | int ret = -EBUSY; |
93f70f90 NH |
3715 | |
3716 | spin_lock(&hugetlb_lock); | |
6de2b1aa | 3717 | if (is_hugepage_on_freelist(hpage)) { |
56f2fb14 NH |
3718 | /* |
3719 | * Hwpoisoned hugepage isn't linked to activelist or freelist, | |
3720 | * but dangling hpage->lru can trigger list-debug warnings | |
3721 | * (this happens when we call unpoison_memory() on it), | |
3722 | * so let it point to itself with list_del_init(). | |
3723 | */ | |
3724 | list_del_init(&hpage->lru); | |
8c6c2ecb | 3725 | set_page_refcounted(hpage); |
6de2b1aa NH |
3726 | h->free_huge_pages--; |
3727 | h->free_huge_pages_node[nid]--; | |
3728 | ret = 0; | |
3729 | } | |
93f70f90 | 3730 | spin_unlock(&hugetlb_lock); |
6de2b1aa | 3731 | return ret; |
93f70f90 | 3732 | } |
6de2b1aa | 3733 | #endif |
31caf665 NH |
3734 | |
3735 | bool isolate_huge_page(struct page *page, struct list_head *list) | |
3736 | { | |
309381fe | 3737 | VM_BUG_ON_PAGE(!PageHead(page), page); |
31caf665 NH |
3738 | if (!get_page_unless_zero(page)) |
3739 | return false; | |
3740 | spin_lock(&hugetlb_lock); | |
3741 | list_move_tail(&page->lru, list); | |
3742 | spin_unlock(&hugetlb_lock); | |
3743 | return true; | |
3744 | } | |
3745 | ||
3746 | void putback_active_hugepage(struct page *page) | |
3747 | { | |
309381fe | 3748 | VM_BUG_ON_PAGE(!PageHead(page), page); |
31caf665 NH |
3749 | spin_lock(&hugetlb_lock); |
3750 | list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); | |
3751 | spin_unlock(&hugetlb_lock); | |
3752 | put_page(page); | |
3753 | } | |
c8721bbb NH |
3754 | |
3755 | bool is_hugepage_active(struct page *page) | |
3756 | { | |
309381fe | 3757 | VM_BUG_ON_PAGE(!PageHuge(page), page); |
c8721bbb NH |
3758 | /* |
3759 | * This function can be called for a tail page because the caller, | |
3760 | * scan_movable_pages, scans through a given pfn-range which typically | |
3761 | * covers one memory block. In systems using gigantic hugepage (1GB | |
3762 | * for x86_64,) a hugepage is larger than a memory block, and we don't | |
3763 | * support migrating such large hugepages for now, so return false | |
3764 | * when called for tail pages. | |
3765 | */ | |
3766 | if (PageTail(page)) | |
3767 | return false; | |
3768 | /* | |
3769 | * Refcount of a hwpoisoned hugepages is 1, but they are not active, | |
3770 | * so we should return false for them. | |
3771 | */ | |
3772 | if (unlikely(PageHWPoison(page))) | |
3773 | return false; | |
3774 | return page_count(page) > 0; | |
3775 | } |