Root/
1 | /* |
2 | * Generic hugetlb support. |
3 | * (C) William Irwin, April 2004 |
4 | */ |
5 | #include <linux/list.h> |
6 | #include <linux/init.h> |
7 | #include <linux/module.h> |
8 | #include <linux/mm.h> |
9 | #include <linux/seq_file.h> |
10 | #include <linux/sysctl.h> |
11 | #include <linux/highmem.h> |
12 | #include <linux/mmu_notifier.h> |
13 | #include <linux/nodemask.h> |
14 | #include <linux/pagemap.h> |
15 | #include <linux/mempolicy.h> |
16 | #include <linux/cpuset.h> |
17 | #include <linux/mutex.h> |
18 | #include <linux/bootmem.h> |
19 | #include <linux/sysfs.h> |
20 | #include <linux/slab.h> |
21 | |
22 | #include <asm/page.h> |
23 | #include <asm/pgtable.h> |
24 | #include <asm/io.h> |
25 | |
26 | #include <linux/hugetlb.h> |
27 | #include <linux/node.h> |
28 | #include "internal.h" |
29 | |
30 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; |
31 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
32 | unsigned long hugepages_treat_as_movable; |
33 | |
34 | static int max_hstate; |
35 | unsigned int default_hstate_idx; |
36 | struct hstate hstates[HUGE_MAX_HSTATE]; |
37 | |
38 | __initdata LIST_HEAD(huge_boot_pages); |
39 | |
40 | /* for command line parsing */ |
41 | static struct hstate * __initdata parsed_hstate; |
42 | static unsigned long __initdata default_hstate_max_huge_pages; |
43 | static unsigned long __initdata default_hstate_size; |
44 | |
45 | #define for_each_hstate(h) \ |
46 | for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++) |
47 | |
48 | /* |
49 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages |
50 | */ |
51 | static DEFINE_SPINLOCK(hugetlb_lock); |
52 | |
53 | /* |
54 | * Region tracking -- allows tracking of reservations and instantiated pages |
55 | * across the pages in a mapping. |
56 | * |
57 | * The region data structures are protected by a combination of the mmap_sem |
58 | * and the hugetlb_instantion_mutex. To access or modify a region the caller |
59 | * must either hold the mmap_sem for write, or the mmap_sem for read and |
60 | * the hugetlb_instantiation mutex: |
61 | * |
62 | * down_write(&mm->mmap_sem); |
63 | * or |
64 | * down_read(&mm->mmap_sem); |
65 | * mutex_lock(&hugetlb_instantiation_mutex); |
66 | */ |
67 | struct file_region { |
68 | struct list_head link; |
69 | long from; |
70 | long to; |
71 | }; |
72 | |
73 | static long region_add(struct list_head *head, long f, long t) |
74 | { |
75 | struct file_region *rg, *nrg, *trg; |
76 | |
77 | /* Locate the region we are either in or before. */ |
78 | list_for_each_entry(rg, head, link) |
79 | if (f <= rg->to) |
80 | break; |
81 | |
82 | /* Round our left edge to the current segment if it encloses us. */ |
83 | if (f > rg->from) |
84 | f = rg->from; |
85 | |
86 | /* Check for and consume any regions we now overlap with. */ |
87 | nrg = rg; |
88 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
89 | if (&rg->link == head) |
90 | break; |
91 | if (rg->from > t) |
92 | break; |
93 | |
94 | /* If this area reaches higher then extend our area to |
95 | * include it completely. If this is not the first area |
96 | * which we intend to reuse, free it. */ |
97 | if (rg->to > t) |
98 | t = rg->to; |
99 | if (rg != nrg) { |
100 | list_del(&rg->link); |
101 | kfree(rg); |
102 | } |
103 | } |
104 | nrg->from = f; |
105 | nrg->to = t; |
106 | return 0; |
107 | } |
108 | |
109 | static long region_chg(struct list_head *head, long f, long t) |
110 | { |
111 | struct file_region *rg, *nrg; |
112 | long chg = 0; |
113 | |
114 | /* Locate the region we are before or in. */ |
115 | list_for_each_entry(rg, head, link) |
116 | if (f <= rg->to) |
117 | break; |
118 | |
119 | /* If we are below the current region then a new region is required. |
120 | * Subtle, allocate a new region at the position but make it zero |
121 | * size such that we can guarantee to record the reservation. */ |
122 | if (&rg->link == head || t < rg->from) { |
123 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); |
124 | if (!nrg) |
125 | return -ENOMEM; |
126 | nrg->from = f; |
127 | nrg->to = f; |
128 | INIT_LIST_HEAD(&nrg->link); |
129 | list_add(&nrg->link, rg->link.prev); |
130 | |
131 | return t - f; |
132 | } |
133 | |
134 | /* Round our left edge to the current segment if it encloses us. */ |
135 | if (f > rg->from) |
136 | f = rg->from; |
137 | chg = t - f; |
138 | |
139 | /* Check for and consume any regions we now overlap with. */ |
140 | list_for_each_entry(rg, rg->link.prev, link) { |
141 | if (&rg->link == head) |
142 | break; |
143 | if (rg->from > t) |
144 | return chg; |
145 | |
146 | /* We overlap with this area, if it extends futher than |
147 | * us then we must extend ourselves. Account for its |
148 | * existing reservation. */ |
149 | if (rg->to > t) { |
150 | chg += rg->to - t; |
151 | t = rg->to; |
152 | } |
153 | chg -= rg->to - rg->from; |
154 | } |
155 | return chg; |
156 | } |
157 | |
158 | static long region_truncate(struct list_head *head, long end) |
159 | { |
160 | struct file_region *rg, *trg; |
161 | long chg = 0; |
162 | |
163 | /* Locate the region we are either in or before. */ |
164 | list_for_each_entry(rg, head, link) |
165 | if (end <= rg->to) |
166 | break; |
167 | if (&rg->link == head) |
168 | return 0; |
169 | |
170 | /* If we are in the middle of a region then adjust it. */ |
171 | if (end > rg->from) { |
172 | chg = rg->to - end; |
173 | rg->to = end; |
174 | rg = list_entry(rg->link.next, typeof(*rg), link); |
175 | } |
176 | |
177 | /* Drop any remaining regions. */ |
178 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { |
179 | if (&rg->link == head) |
180 | break; |
181 | chg += rg->to - rg->from; |
182 | list_del(&rg->link); |
183 | kfree(rg); |
184 | } |
185 | return chg; |
186 | } |
187 | |
188 | static long region_count(struct list_head *head, long f, long t) |
189 | { |
190 | struct file_region *rg; |
191 | long chg = 0; |
192 | |
193 | /* Locate each segment we overlap with, and count that overlap. */ |
194 | list_for_each_entry(rg, head, link) { |
195 | int seg_from; |
196 | int seg_to; |
197 | |
198 | if (rg->to <= f) |
199 | continue; |
200 | if (rg->from >= t) |
201 | break; |
202 | |
203 | seg_from = max(rg->from, f); |
204 | seg_to = min(rg->to, t); |
205 | |
206 | chg += seg_to - seg_from; |
207 | } |
208 | |
209 | return chg; |
210 | } |
211 | |
212 | /* |
213 | * Convert the address within this vma to the page offset within |
214 | * the mapping, in pagecache page units; huge pages here. |
215 | */ |
216 | static pgoff_t vma_hugecache_offset(struct hstate *h, |
217 | struct vm_area_struct *vma, unsigned long address) |
218 | { |
219 | return ((address - vma->vm_start) >> huge_page_shift(h)) + |
220 | (vma->vm_pgoff >> huge_page_order(h)); |
221 | } |
222 | |
223 | /* |
224 | * Return the size of the pages allocated when backing a VMA. In the majority |
225 | * cases this will be same size as used by the page table entries. |
226 | */ |
227 | unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) |
228 | { |
229 | struct hstate *hstate; |
230 | |
231 | if (!is_vm_hugetlb_page(vma)) |
232 | return PAGE_SIZE; |
233 | |
234 | hstate = hstate_vma(vma); |
235 | |
236 | return 1UL << (hstate->order + PAGE_SHIFT); |
237 | } |
238 | EXPORT_SYMBOL_GPL(vma_kernel_pagesize); |
239 | |
240 | /* |
241 | * Return the page size being used by the MMU to back a VMA. In the majority |
242 | * of cases, the page size used by the kernel matches the MMU size. On |
243 | * architectures where it differs, an architecture-specific version of this |
244 | * function is required. |
245 | */ |
246 | #ifndef vma_mmu_pagesize |
247 | unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) |
248 | { |
249 | return vma_kernel_pagesize(vma); |
250 | } |
251 | #endif |
252 | |
253 | /* |
254 | * Flags for MAP_PRIVATE reservations. These are stored in the bottom |
255 | * bits of the reservation map pointer, which are always clear due to |
256 | * alignment. |
257 | */ |
258 | #define HPAGE_RESV_OWNER (1UL << 0) |
259 | #define HPAGE_RESV_UNMAPPED (1UL << 1) |
260 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) |
261 | |
262 | /* |
263 | * These helpers are used to track how many pages are reserved for |
264 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() |
265 | * is guaranteed to have their future faults succeed. |
266 | * |
267 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), |
268 | * the reserve counters are updated with the hugetlb_lock held. It is safe |
269 | * to reset the VMA at fork() time as it is not in use yet and there is no |
270 | * chance of the global counters getting corrupted as a result of the values. |
271 | * |
272 | * The private mapping reservation is represented in a subtly different |
273 | * manner to a shared mapping. A shared mapping has a region map associated |
274 | * with the underlying file, this region map represents the backing file |
275 | * pages which have ever had a reservation assigned which this persists even |
276 | * after the page is instantiated. A private mapping has a region map |
277 | * associated with the original mmap which is attached to all VMAs which |
278 | * reference it, this region map represents those offsets which have consumed |
279 | * reservation ie. where pages have been instantiated. |
280 | */ |
281 | static unsigned long get_vma_private_data(struct vm_area_struct *vma) |
282 | { |
283 | return (unsigned long)vma->vm_private_data; |
284 | } |
285 | |
286 | static void set_vma_private_data(struct vm_area_struct *vma, |
287 | unsigned long value) |
288 | { |
289 | vma->vm_private_data = (void *)value; |
290 | } |
291 | |
292 | struct resv_map { |
293 | struct kref refs; |
294 | struct list_head regions; |
295 | }; |
296 | |
297 | static struct resv_map *resv_map_alloc(void) |
298 | { |
299 | struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); |
300 | if (!resv_map) |
301 | return NULL; |
302 | |
303 | kref_init(&resv_map->refs); |
304 | INIT_LIST_HEAD(&resv_map->regions); |
305 | |
306 | return resv_map; |
307 | } |
308 | |
309 | static void resv_map_release(struct kref *ref) |
310 | { |
311 | struct resv_map *resv_map = container_of(ref, struct resv_map, refs); |
312 | |
313 | /* Clear out any active regions before we release the map. */ |
314 | region_truncate(&resv_map->regions, 0); |
315 | kfree(resv_map); |
316 | } |
317 | |
318 | static struct resv_map *vma_resv_map(struct vm_area_struct *vma) |
319 | { |
320 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
321 | if (!(vma->vm_flags & VM_MAYSHARE)) |
322 | return (struct resv_map *)(get_vma_private_data(vma) & |
323 | ~HPAGE_RESV_MASK); |
324 | return NULL; |
325 | } |
326 | |
327 | static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) |
328 | { |
329 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
330 | VM_BUG_ON(vma->vm_flags & VM_MAYSHARE); |
331 | |
332 | set_vma_private_data(vma, (get_vma_private_data(vma) & |
333 | HPAGE_RESV_MASK) | (unsigned long)map); |
334 | } |
335 | |
336 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) |
337 | { |
338 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
339 | VM_BUG_ON(vma->vm_flags & VM_MAYSHARE); |
340 | |
341 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); |
342 | } |
343 | |
344 | static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) |
345 | { |
346 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
347 | |
348 | return (get_vma_private_data(vma) & flag) != 0; |
349 | } |
350 | |
351 | /* Decrement the reserved pages in the hugepage pool by one */ |
352 | static void decrement_hugepage_resv_vma(struct hstate *h, |
353 | struct vm_area_struct *vma) |
354 | { |
355 | if (vma->vm_flags & VM_NORESERVE) |
356 | return; |
357 | |
358 | if (vma->vm_flags & VM_MAYSHARE) { |
359 | /* Shared mappings always use reserves */ |
360 | h->resv_huge_pages--; |
361 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
362 | /* |
363 | * Only the process that called mmap() has reserves for |
364 | * private mappings. |
365 | */ |
366 | h->resv_huge_pages--; |
367 | } |
368 | } |
369 | |
370 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
371 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
372 | { |
373 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
374 | if (!(vma->vm_flags & VM_MAYSHARE)) |
375 | vma->vm_private_data = (void *)0; |
376 | } |
377 | |
378 | /* Returns true if the VMA has associated reserve pages */ |
379 | static int vma_has_reserves(struct vm_area_struct *vma) |
380 | { |
381 | if (vma->vm_flags & VM_MAYSHARE) |
382 | return 1; |
383 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) |
384 | return 1; |
385 | return 0; |
386 | } |
387 | |
388 | static void clear_gigantic_page(struct page *page, |
389 | unsigned long addr, unsigned long sz) |
390 | { |
391 | int i; |
392 | struct page *p = page; |
393 | |
394 | might_sleep(); |
395 | for (i = 0; i < sz/PAGE_SIZE; i++, p = mem_map_next(p, page, i)) { |
396 | cond_resched(); |
397 | clear_user_highpage(p, addr + i * PAGE_SIZE); |
398 | } |
399 | } |
400 | static void clear_huge_page(struct page *page, |
401 | unsigned long addr, unsigned long sz) |
402 | { |
403 | int i; |
404 | |
405 | if (unlikely(sz/PAGE_SIZE > MAX_ORDER_NR_PAGES)) { |
406 | clear_gigantic_page(page, addr, sz); |
407 | return; |
408 | } |
409 | |
410 | might_sleep(); |
411 | for (i = 0; i < sz/PAGE_SIZE; i++) { |
412 | cond_resched(); |
413 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
414 | } |
415 | } |
416 | |
417 | static void copy_gigantic_page(struct page *dst, struct page *src, |
418 | unsigned long addr, struct vm_area_struct *vma) |
419 | { |
420 | int i; |
421 | struct hstate *h = hstate_vma(vma); |
422 | struct page *dst_base = dst; |
423 | struct page *src_base = src; |
424 | might_sleep(); |
425 | for (i = 0; i < pages_per_huge_page(h); ) { |
426 | cond_resched(); |
427 | copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma); |
428 | |
429 | i++; |
430 | dst = mem_map_next(dst, dst_base, i); |
431 | src = mem_map_next(src, src_base, i); |
432 | } |
433 | } |
434 | static void copy_huge_page(struct page *dst, struct page *src, |
435 | unsigned long addr, struct vm_area_struct *vma) |
436 | { |
437 | int i; |
438 | struct hstate *h = hstate_vma(vma); |
439 | |
440 | if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) { |
441 | copy_gigantic_page(dst, src, addr, vma); |
442 | return; |
443 | } |
444 | |
445 | might_sleep(); |
446 | for (i = 0; i < pages_per_huge_page(h); i++) { |
447 | cond_resched(); |
448 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
449 | } |
450 | } |
451 | |
452 | static void enqueue_huge_page(struct hstate *h, struct page *page) |
453 | { |
454 | int nid = page_to_nid(page); |
455 | list_add(&page->lru, &h->hugepage_freelists[nid]); |
456 | h->free_huge_pages++; |
457 | h->free_huge_pages_node[nid]++; |
458 | } |
459 | |
460 | static struct page *dequeue_huge_page_vma(struct hstate *h, |
461 | struct vm_area_struct *vma, |
462 | unsigned long address, int avoid_reserve) |
463 | { |
464 | int nid; |
465 | struct page *page = NULL; |
466 | struct mempolicy *mpol; |
467 | nodemask_t *nodemask; |
468 | struct zonelist *zonelist = huge_zonelist(vma, address, |
469 | htlb_alloc_mask, &mpol, &nodemask); |
470 | struct zone *zone; |
471 | struct zoneref *z; |
472 | |
473 | /* |
474 | * A child process with MAP_PRIVATE mappings created by their parent |
475 | * have no page reserves. This check ensures that reservations are |
476 | * not "stolen". The child may still get SIGKILLed |
477 | */ |
478 | if (!vma_has_reserves(vma) && |
479 | h->free_huge_pages - h->resv_huge_pages == 0) |
480 | return NULL; |
481 | |
482 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
483 | if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) |
484 | return NULL; |
485 | |
486 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
487 | MAX_NR_ZONES - 1, nodemask) { |
488 | nid = zone_to_nid(zone); |
489 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && |
490 | !list_empty(&h->hugepage_freelists[nid])) { |
491 | page = list_entry(h->hugepage_freelists[nid].next, |
492 | struct page, lru); |
493 | list_del(&page->lru); |
494 | h->free_huge_pages--; |
495 | h->free_huge_pages_node[nid]--; |
496 | |
497 | if (!avoid_reserve) |
498 | decrement_hugepage_resv_vma(h, vma); |
499 | |
500 | break; |
501 | } |
502 | } |
503 | mpol_cond_put(mpol); |
504 | return page; |
505 | } |
506 | |
507 | static void update_and_free_page(struct hstate *h, struct page *page) |
508 | { |
509 | int i; |
510 | |
511 | VM_BUG_ON(h->order >= MAX_ORDER); |
512 | |
513 | h->nr_huge_pages--; |
514 | h->nr_huge_pages_node[page_to_nid(page)]--; |
515 | for (i = 0; i < pages_per_huge_page(h); i++) { |
516 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | |
517 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | |
518 | 1 << PG_private | 1<< PG_writeback); |
519 | } |
520 | set_compound_page_dtor(page, NULL); |
521 | set_page_refcounted(page); |
522 | arch_release_hugepage(page); |
523 | __free_pages(page, huge_page_order(h)); |
524 | } |
525 | |
526 | struct hstate *size_to_hstate(unsigned long size) |
527 | { |
528 | struct hstate *h; |
529 | |
530 | for_each_hstate(h) { |
531 | if (huge_page_size(h) == size) |
532 | return h; |
533 | } |
534 | return NULL; |
535 | } |
536 | |
537 | static void free_huge_page(struct page *page) |
538 | { |
539 | /* |
540 | * Can't pass hstate in here because it is called from the |
541 | * compound page destructor. |
542 | */ |
543 | struct hstate *h = page_hstate(page); |
544 | int nid = page_to_nid(page); |
545 | struct address_space *mapping; |
546 | |
547 | mapping = (struct address_space *) page_private(page); |
548 | set_page_private(page, 0); |
549 | BUG_ON(page_count(page)); |
550 | INIT_LIST_HEAD(&page->lru); |
551 | |
552 | spin_lock(&hugetlb_lock); |
553 | if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) { |
554 | update_and_free_page(h, page); |
555 | h->surplus_huge_pages--; |
556 | h->surplus_huge_pages_node[nid]--; |
557 | } else { |
558 | enqueue_huge_page(h, page); |
559 | } |
560 | spin_unlock(&hugetlb_lock); |
561 | if (mapping) |
562 | hugetlb_put_quota(mapping, 1); |
563 | } |
564 | |
565 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) |
566 | { |
567 | set_compound_page_dtor(page, free_huge_page); |
568 | spin_lock(&hugetlb_lock); |
569 | h->nr_huge_pages++; |
570 | h->nr_huge_pages_node[nid]++; |
571 | spin_unlock(&hugetlb_lock); |
572 | put_page(page); /* free it into the hugepage allocator */ |
573 | } |
574 | |
575 | static void prep_compound_gigantic_page(struct page *page, unsigned long order) |
576 | { |
577 | int i; |
578 | int nr_pages = 1 << order; |
579 | struct page *p = page + 1; |
580 | |
581 | /* we rely on prep_new_huge_page to set the destructor */ |
582 | set_compound_order(page, order); |
583 | __SetPageHead(page); |
584 | for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { |
585 | __SetPageTail(p); |
586 | p->first_page = page; |
587 | } |
588 | } |
589 | |
590 | int PageHuge(struct page *page) |
591 | { |
592 | compound_page_dtor *dtor; |
593 | |
594 | if (!PageCompound(page)) |
595 | return 0; |
596 | |
597 | page = compound_head(page); |
598 | dtor = get_compound_page_dtor(page); |
599 | |
600 | return dtor == free_huge_page; |
601 | } |
602 | |
603 | static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) |
604 | { |
605 | struct page *page; |
606 | |
607 | if (h->order >= MAX_ORDER) |
608 | return NULL; |
609 | |
610 | page = alloc_pages_exact_node(nid, |
611 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| |
612 | __GFP_REPEAT|__GFP_NOWARN, |
613 | huge_page_order(h)); |
614 | if (page) { |
615 | if (arch_prepare_hugepage(page)) { |
616 | __free_pages(page, huge_page_order(h)); |
617 | return NULL; |
618 | } |
619 | prep_new_huge_page(h, page, nid); |
620 | } |
621 | |
622 | return page; |
623 | } |
624 | |
625 | /* |
626 | * common helper functions for hstate_next_node_to_{alloc|free}. |
627 | * We may have allocated or freed a huge page based on a different |
628 | * nodes_allowed previously, so h->next_node_to_{alloc|free} might |
629 | * be outside of *nodes_allowed. Ensure that we use an allowed |
630 | * node for alloc or free. |
631 | */ |
632 | static int next_node_allowed(int nid, nodemask_t *nodes_allowed) |
633 | { |
634 | nid = next_node(nid, *nodes_allowed); |
635 | if (nid == MAX_NUMNODES) |
636 | nid = first_node(*nodes_allowed); |
637 | VM_BUG_ON(nid >= MAX_NUMNODES); |
638 | |
639 | return nid; |
640 | } |
641 | |
642 | static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed) |
643 | { |
644 | if (!node_isset(nid, *nodes_allowed)) |
645 | nid = next_node_allowed(nid, nodes_allowed); |
646 | return nid; |
647 | } |
648 | |
649 | /* |
650 | * returns the previously saved node ["this node"] from which to |
651 | * allocate a persistent huge page for the pool and advance the |
652 | * next node from which to allocate, handling wrap at end of node |
653 | * mask. |
654 | */ |
655 | static int hstate_next_node_to_alloc(struct hstate *h, |
656 | nodemask_t *nodes_allowed) |
657 | { |
658 | int nid; |
659 | |
660 | VM_BUG_ON(!nodes_allowed); |
661 | |
662 | nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed); |
663 | h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed); |
664 | |
665 | return nid; |
666 | } |
667 | |
668 | static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed) |
669 | { |
670 | struct page *page; |
671 | int start_nid; |
672 | int next_nid; |
673 | int ret = 0; |
674 | |
675 | start_nid = hstate_next_node_to_alloc(h, nodes_allowed); |
676 | next_nid = start_nid; |
677 | |
678 | do { |
679 | page = alloc_fresh_huge_page_node(h, next_nid); |
680 | if (page) { |
681 | ret = 1; |
682 | break; |
683 | } |
684 | next_nid = hstate_next_node_to_alloc(h, nodes_allowed); |
685 | } while (next_nid != start_nid); |
686 | |
687 | if (ret) |
688 | count_vm_event(HTLB_BUDDY_PGALLOC); |
689 | else |
690 | count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
691 | |
692 | return ret; |
693 | } |
694 | |
695 | /* |
696 | * helper for free_pool_huge_page() - return the previously saved |
697 | * node ["this node"] from which to free a huge page. Advance the |
698 | * next node id whether or not we find a free huge page to free so |
699 | * that the next attempt to free addresses the next node. |
700 | */ |
701 | static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) |
702 | { |
703 | int nid; |
704 | |
705 | VM_BUG_ON(!nodes_allowed); |
706 | |
707 | nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed); |
708 | h->next_nid_to_free = next_node_allowed(nid, nodes_allowed); |
709 | |
710 | return nid; |
711 | } |
712 | |
713 | /* |
714 | * Free huge page from pool from next node to free. |
715 | * Attempt to keep persistent huge pages more or less |
716 | * balanced over allowed nodes. |
717 | * Called with hugetlb_lock locked. |
718 | */ |
719 | static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, |
720 | bool acct_surplus) |
721 | { |
722 | int start_nid; |
723 | int next_nid; |
724 | int ret = 0; |
725 | |
726 | start_nid = hstate_next_node_to_free(h, nodes_allowed); |
727 | next_nid = start_nid; |
728 | |
729 | do { |
730 | /* |
731 | * If we're returning unused surplus pages, only examine |
732 | * nodes with surplus pages. |
733 | */ |
734 | if ((!acct_surplus || h->surplus_huge_pages_node[next_nid]) && |
735 | !list_empty(&h->hugepage_freelists[next_nid])) { |
736 | struct page *page = |
737 | list_entry(h->hugepage_freelists[next_nid].next, |
738 | struct page, lru); |
739 | list_del(&page->lru); |
740 | h->free_huge_pages--; |
741 | h->free_huge_pages_node[next_nid]--; |
742 | if (acct_surplus) { |
743 | h->surplus_huge_pages--; |
744 | h->surplus_huge_pages_node[next_nid]--; |
745 | } |
746 | update_and_free_page(h, page); |
747 | ret = 1; |
748 | break; |
749 | } |
750 | next_nid = hstate_next_node_to_free(h, nodes_allowed); |
751 | } while (next_nid != start_nid); |
752 | |
753 | return ret; |
754 | } |
755 | |
756 | static struct page *alloc_buddy_huge_page(struct hstate *h, |
757 | struct vm_area_struct *vma, unsigned long address) |
758 | { |
759 | struct page *page; |
760 | unsigned int nid; |
761 | |
762 | if (h->order >= MAX_ORDER) |
763 | return NULL; |
764 | |
765 | /* |
766 | * Assume we will successfully allocate the surplus page to |
767 | * prevent racing processes from causing the surplus to exceed |
768 | * overcommit |
769 | * |
770 | * This however introduces a different race, where a process B |
771 | * tries to grow the static hugepage pool while alloc_pages() is |
772 | * called by process A. B will only examine the per-node |
773 | * counters in determining if surplus huge pages can be |
774 | * converted to normal huge pages in adjust_pool_surplus(). A |
775 | * won't be able to increment the per-node counter, until the |
776 | * lock is dropped by B, but B doesn't drop hugetlb_lock until |
777 | * no more huge pages can be converted from surplus to normal |
778 | * state (and doesn't try to convert again). Thus, we have a |
779 | * case where a surplus huge page exists, the pool is grown, and |
780 | * the surplus huge page still exists after, even though it |
781 | * should just have been converted to a normal huge page. This |
782 | * does not leak memory, though, as the hugepage will be freed |
783 | * once it is out of use. It also does not allow the counters to |
784 | * go out of whack in adjust_pool_surplus() as we don't modify |
785 | * the node values until we've gotten the hugepage and only the |
786 | * per-node value is checked there. |
787 | */ |
788 | spin_lock(&hugetlb_lock); |
789 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { |
790 | spin_unlock(&hugetlb_lock); |
791 | return NULL; |
792 | } else { |
793 | h->nr_huge_pages++; |
794 | h->surplus_huge_pages++; |
795 | } |
796 | spin_unlock(&hugetlb_lock); |
797 | |
798 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP| |
799 | __GFP_REPEAT|__GFP_NOWARN, |
800 | huge_page_order(h)); |
801 | |
802 | if (page && arch_prepare_hugepage(page)) { |
803 | __free_pages(page, huge_page_order(h)); |
804 | return NULL; |
805 | } |
806 | |
807 | spin_lock(&hugetlb_lock); |
808 | if (page) { |
809 | /* |
810 | * This page is now managed by the hugetlb allocator and has |
811 | * no users -- drop the buddy allocator's reference. |
812 | */ |
813 | put_page_testzero(page); |
814 | VM_BUG_ON(page_count(page)); |
815 | nid = page_to_nid(page); |
816 | set_compound_page_dtor(page, free_huge_page); |
817 | /* |
818 | * We incremented the global counters already |
819 | */ |
820 | h->nr_huge_pages_node[nid]++; |
821 | h->surplus_huge_pages_node[nid]++; |
822 | __count_vm_event(HTLB_BUDDY_PGALLOC); |
823 | } else { |
824 | h->nr_huge_pages--; |
825 | h->surplus_huge_pages--; |
826 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
827 | } |
828 | spin_unlock(&hugetlb_lock); |
829 | |
830 | return page; |
831 | } |
832 | |
833 | /* |
834 | * Increase the hugetlb pool such that it can accomodate a reservation |
835 | * of size 'delta'. |
836 | */ |
837 | static int gather_surplus_pages(struct hstate *h, int delta) |
838 | { |
839 | struct list_head surplus_list; |
840 | struct page *page, *tmp; |
841 | int ret, i; |
842 | int needed, allocated; |
843 | |
844 | needed = (h->resv_huge_pages + delta) - h->free_huge_pages; |
845 | if (needed <= 0) { |
846 | h->resv_huge_pages += delta; |
847 | return 0; |
848 | } |
849 | |
850 | allocated = 0; |
851 | INIT_LIST_HEAD(&surplus_list); |
852 | |
853 | ret = -ENOMEM; |
854 | retry: |
855 | spin_unlock(&hugetlb_lock); |
856 | for (i = 0; i < needed; i++) { |
857 | page = alloc_buddy_huge_page(h, NULL, 0); |
858 | if (!page) { |
859 | /* |
860 | * We were not able to allocate enough pages to |
861 | * satisfy the entire reservation so we free what |
862 | * we've allocated so far. |
863 | */ |
864 | spin_lock(&hugetlb_lock); |
865 | needed = 0; |
866 | goto free; |
867 | } |
868 | |
869 | list_add(&page->lru, &surplus_list); |
870 | } |
871 | allocated += needed; |
872 | |
873 | /* |
874 | * After retaking hugetlb_lock, we need to recalculate 'needed' |
875 | * because either resv_huge_pages or free_huge_pages may have changed. |
876 | */ |
877 | spin_lock(&hugetlb_lock); |
878 | needed = (h->resv_huge_pages + delta) - |
879 | (h->free_huge_pages + allocated); |
880 | if (needed > 0) |
881 | goto retry; |
882 | |
883 | /* |
884 | * The surplus_list now contains _at_least_ the number of extra pages |
885 | * needed to accomodate the reservation. Add the appropriate number |
886 | * of pages to the hugetlb pool and free the extras back to the buddy |
887 | * allocator. Commit the entire reservation here to prevent another |
888 | * process from stealing the pages as they are added to the pool but |
889 | * before they are reserved. |
890 | */ |
891 | needed += allocated; |
892 | h->resv_huge_pages += delta; |
893 | ret = 0; |
894 | free: |
895 | /* Free the needed pages to the hugetlb pool */ |
896 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
897 | if ((--needed) < 0) |
898 | break; |
899 | list_del(&page->lru); |
900 | enqueue_huge_page(h, page); |
901 | } |
902 | |
903 | /* Free unnecessary surplus pages to the buddy allocator */ |
904 | if (!list_empty(&surplus_list)) { |
905 | spin_unlock(&hugetlb_lock); |
906 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
907 | list_del(&page->lru); |
908 | /* |
909 | * The page has a reference count of zero already, so |
910 | * call free_huge_page directly instead of using |
911 | * put_page. This must be done with hugetlb_lock |
912 | * unlocked which is safe because free_huge_page takes |
913 | * hugetlb_lock before deciding how to free the page. |
914 | */ |
915 | free_huge_page(page); |
916 | } |
917 | spin_lock(&hugetlb_lock); |
918 | } |
919 | |
920 | return ret; |
921 | } |
922 | |
923 | /* |
924 | * When releasing a hugetlb pool reservation, any surplus pages that were |
925 | * allocated to satisfy the reservation must be explicitly freed if they were |
926 | * never used. |
927 | * Called with hugetlb_lock held. |
928 | */ |
929 | static void return_unused_surplus_pages(struct hstate *h, |
930 | unsigned long unused_resv_pages) |
931 | { |
932 | unsigned long nr_pages; |
933 | |
934 | /* Uncommit the reservation */ |
935 | h->resv_huge_pages -= unused_resv_pages; |
936 | |
937 | /* Cannot return gigantic pages currently */ |
938 | if (h->order >= MAX_ORDER) |
939 | return; |
940 | |
941 | nr_pages = min(unused_resv_pages, h->surplus_huge_pages); |
942 | |
943 | /* |
944 | * We want to release as many surplus pages as possible, spread |
945 | * evenly across all nodes with memory. Iterate across these nodes |
946 | * until we can no longer free unreserved surplus pages. This occurs |
947 | * when the nodes with surplus pages have no free pages. |
948 | * free_pool_huge_page() will balance the the freed pages across the |
949 | * on-line nodes with memory and will handle the hstate accounting. |
950 | */ |
951 | while (nr_pages--) { |
952 | if (!free_pool_huge_page(h, &node_states[N_HIGH_MEMORY], 1)) |
953 | break; |
954 | } |
955 | } |
956 | |
957 | /* |
958 | * Determine if the huge page at addr within the vma has an associated |
959 | * reservation. Where it does not we will need to logically increase |
960 | * reservation and actually increase quota before an allocation can occur. |
961 | * Where any new reservation would be required the reservation change is |
962 | * prepared, but not committed. Once the page has been quota'd allocated |
963 | * an instantiated the change should be committed via vma_commit_reservation. |
964 | * No action is required on failure. |
965 | */ |
966 | static long vma_needs_reservation(struct hstate *h, |
967 | struct vm_area_struct *vma, unsigned long addr) |
968 | { |
969 | struct address_space *mapping = vma->vm_file->f_mapping; |
970 | struct inode *inode = mapping->host; |
971 | |
972 | if (vma->vm_flags & VM_MAYSHARE) { |
973 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
974 | return region_chg(&inode->i_mapping->private_list, |
975 | idx, idx + 1); |
976 | |
977 | } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
978 | return 1; |
979 | |
980 | } else { |
981 | long err; |
982 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
983 | struct resv_map *reservations = vma_resv_map(vma); |
984 | |
985 | err = region_chg(&reservations->regions, idx, idx + 1); |
986 | if (err < 0) |
987 | return err; |
988 | return 0; |
989 | } |
990 | } |
991 | static void vma_commit_reservation(struct hstate *h, |
992 | struct vm_area_struct *vma, unsigned long addr) |
993 | { |
994 | struct address_space *mapping = vma->vm_file->f_mapping; |
995 | struct inode *inode = mapping->host; |
996 | |
997 | if (vma->vm_flags & VM_MAYSHARE) { |
998 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
999 | region_add(&inode->i_mapping->private_list, idx, idx + 1); |
1000 | |
1001 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
1002 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
1003 | struct resv_map *reservations = vma_resv_map(vma); |
1004 | |
1005 | /* Mark this page used in the map. */ |
1006 | region_add(&reservations->regions, idx, idx + 1); |
1007 | } |
1008 | } |
1009 | |
1010 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
1011 | unsigned long addr, int avoid_reserve) |
1012 | { |
1013 | struct hstate *h = hstate_vma(vma); |
1014 | struct page *page; |
1015 | struct address_space *mapping = vma->vm_file->f_mapping; |
1016 | struct inode *inode = mapping->host; |
1017 | long chg; |
1018 | |
1019 | /* |
1020 | * Processes that did not create the mapping will have no reserves and |
1021 | * will not have accounted against quota. Check that the quota can be |
1022 | * made before satisfying the allocation |
1023 | * MAP_NORESERVE mappings may also need pages and quota allocated |
1024 | * if no reserve mapping overlaps. |
1025 | */ |
1026 | chg = vma_needs_reservation(h, vma, addr); |
1027 | if (chg < 0) |
1028 | return ERR_PTR(chg); |
1029 | if (chg) |
1030 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
1031 | return ERR_PTR(-ENOSPC); |
1032 | |
1033 | spin_lock(&hugetlb_lock); |
1034 | page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve); |
1035 | spin_unlock(&hugetlb_lock); |
1036 | |
1037 | if (!page) { |
1038 | page = alloc_buddy_huge_page(h, vma, addr); |
1039 | if (!page) { |
1040 | hugetlb_put_quota(inode->i_mapping, chg); |
1041 | return ERR_PTR(-VM_FAULT_OOM); |
1042 | } |
1043 | } |
1044 | |
1045 | set_page_refcounted(page); |
1046 | set_page_private(page, (unsigned long) mapping); |
1047 | |
1048 | vma_commit_reservation(h, vma, addr); |
1049 | |
1050 | return page; |
1051 | } |
1052 | |
1053 | int __weak alloc_bootmem_huge_page(struct hstate *h) |
1054 | { |
1055 | struct huge_bootmem_page *m; |
1056 | int nr_nodes = nodes_weight(node_states[N_HIGH_MEMORY]); |
1057 | |
1058 | while (nr_nodes) { |
1059 | void *addr; |
1060 | |
1061 | addr = __alloc_bootmem_node_nopanic( |
1062 | NODE_DATA(hstate_next_node_to_alloc(h, |
1063 | &node_states[N_HIGH_MEMORY])), |
1064 | huge_page_size(h), huge_page_size(h), 0); |
1065 | |
1066 | if (addr) { |
1067 | /* |
1068 | * Use the beginning of the huge page to store the |
1069 | * huge_bootmem_page struct (until gather_bootmem |
1070 | * puts them into the mem_map). |
1071 | */ |
1072 | m = addr; |
1073 | goto found; |
1074 | } |
1075 | nr_nodes--; |
1076 | } |
1077 | return 0; |
1078 | |
1079 | found: |
1080 | BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1)); |
1081 | /* Put them into a private list first because mem_map is not up yet */ |
1082 | list_add(&m->list, &huge_boot_pages); |
1083 | m->hstate = h; |
1084 | return 1; |
1085 | } |
1086 | |
1087 | static void prep_compound_huge_page(struct page *page, int order) |
1088 | { |
1089 | if (unlikely(order > (MAX_ORDER - 1))) |
1090 | prep_compound_gigantic_page(page, order); |
1091 | else |
1092 | prep_compound_page(page, order); |
1093 | } |
1094 | |
1095 | /* Put bootmem huge pages into the standard lists after mem_map is up */ |
1096 | static void __init gather_bootmem_prealloc(void) |
1097 | { |
1098 | struct huge_bootmem_page *m; |
1099 | |
1100 | list_for_each_entry(m, &huge_boot_pages, list) { |
1101 | struct page *page = virt_to_page(m); |
1102 | struct hstate *h = m->hstate; |
1103 | __ClearPageReserved(page); |
1104 | WARN_ON(page_count(page) != 1); |
1105 | prep_compound_huge_page(page, h->order); |
1106 | prep_new_huge_page(h, page, page_to_nid(page)); |
1107 | } |
1108 | } |
1109 | |
1110 | static void __init hugetlb_hstate_alloc_pages(struct hstate *h) |
1111 | { |
1112 | unsigned long i; |
1113 | |
1114 | for (i = 0; i < h->max_huge_pages; ++i) { |
1115 | if (h->order >= MAX_ORDER) { |
1116 | if (!alloc_bootmem_huge_page(h)) |
1117 | break; |
1118 | } else if (!alloc_fresh_huge_page(h, |
1119 | &node_states[N_HIGH_MEMORY])) |
1120 | break; |
1121 | } |
1122 | h->max_huge_pages = i; |
1123 | } |
1124 | |
1125 | static void __init hugetlb_init_hstates(void) |
1126 | { |
1127 | struct hstate *h; |
1128 | |
1129 | for_each_hstate(h) { |
1130 | /* oversize hugepages were init'ed in early boot */ |
1131 | if (h->order < MAX_ORDER) |
1132 | hugetlb_hstate_alloc_pages(h); |
1133 | } |
1134 | } |
1135 | |
1136 | static char * __init memfmt(char *buf, unsigned long n) |
1137 | { |
1138 | if (n >= (1UL << 30)) |
1139 | sprintf(buf, "%lu GB", n >> 30); |
1140 | else if (n >= (1UL << 20)) |
1141 | sprintf(buf, "%lu MB", n >> 20); |
1142 | else |
1143 | sprintf(buf, "%lu KB", n >> 10); |
1144 | return buf; |
1145 | } |
1146 | |
1147 | static void __init report_hugepages(void) |
1148 | { |
1149 | struct hstate *h; |
1150 | |
1151 | for_each_hstate(h) { |
1152 | char buf[32]; |
1153 | printk(KERN_INFO "HugeTLB registered %s page size, " |
1154 | "pre-allocated %ld pages\n", |
1155 | memfmt(buf, huge_page_size(h)), |
1156 | h->free_huge_pages); |
1157 | } |
1158 | } |
1159 | |
1160 | #ifdef CONFIG_HIGHMEM |
1161 | static void try_to_free_low(struct hstate *h, unsigned long count, |
1162 | nodemask_t *nodes_allowed) |
1163 | { |
1164 | int i; |
1165 | |
1166 | if (h->order >= MAX_ORDER) |
1167 | return; |
1168 | |
1169 | for_each_node_mask(i, *nodes_allowed) { |
1170 | struct page *page, *next; |
1171 | struct list_head *freel = &h->hugepage_freelists[i]; |
1172 | list_for_each_entry_safe(page, next, freel, lru) { |
1173 | if (count >= h->nr_huge_pages) |
1174 | return; |
1175 | if (PageHighMem(page)) |
1176 | continue; |
1177 | list_del(&page->lru); |
1178 | update_and_free_page(h, page); |
1179 | h->free_huge_pages--; |
1180 | h->free_huge_pages_node[page_to_nid(page)]--; |
1181 | } |
1182 | } |
1183 | } |
1184 | #else |
1185 | static inline void try_to_free_low(struct hstate *h, unsigned long count, |
1186 | nodemask_t *nodes_allowed) |
1187 | { |
1188 | } |
1189 | #endif |
1190 | |
1191 | /* |
1192 | * Increment or decrement surplus_huge_pages. Keep node-specific counters |
1193 | * balanced by operating on them in a round-robin fashion. |
1194 | * Returns 1 if an adjustment was made. |
1195 | */ |
1196 | static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, |
1197 | int delta) |
1198 | { |
1199 | int start_nid, next_nid; |
1200 | int ret = 0; |
1201 | |
1202 | VM_BUG_ON(delta != -1 && delta != 1); |
1203 | |
1204 | if (delta < 0) |
1205 | start_nid = hstate_next_node_to_alloc(h, nodes_allowed); |
1206 | else |
1207 | start_nid = hstate_next_node_to_free(h, nodes_allowed); |
1208 | next_nid = start_nid; |
1209 | |
1210 | do { |
1211 | int nid = next_nid; |
1212 | if (delta < 0) { |
1213 | /* |
1214 | * To shrink on this node, there must be a surplus page |
1215 | */ |
1216 | if (!h->surplus_huge_pages_node[nid]) { |
1217 | next_nid = hstate_next_node_to_alloc(h, |
1218 | nodes_allowed); |
1219 | continue; |
1220 | } |
1221 | } |
1222 | if (delta > 0) { |
1223 | /* |
1224 | * Surplus cannot exceed the total number of pages |
1225 | */ |
1226 | if (h->surplus_huge_pages_node[nid] >= |
1227 | h->nr_huge_pages_node[nid]) { |
1228 | next_nid = hstate_next_node_to_free(h, |
1229 | nodes_allowed); |
1230 | continue; |
1231 | } |
1232 | } |
1233 | |
1234 | h->surplus_huge_pages += delta; |
1235 | h->surplus_huge_pages_node[nid] += delta; |
1236 | ret = 1; |
1237 | break; |
1238 | } while (next_nid != start_nid); |
1239 | |
1240 | return ret; |
1241 | } |
1242 | |
1243 | #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) |
1244 | static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count, |
1245 | nodemask_t *nodes_allowed) |
1246 | { |
1247 | unsigned long min_count, ret; |
1248 | |
1249 | if (h->order >= MAX_ORDER) |
1250 | return h->max_huge_pages; |
1251 | |
1252 | /* |
1253 | * Increase the pool size |
1254 | * First take pages out of surplus state. Then make up the |
1255 | * remaining difference by allocating fresh huge pages. |
1256 | * |
1257 | * We might race with alloc_buddy_huge_page() here and be unable |
1258 | * to convert a surplus huge page to a normal huge page. That is |
1259 | * not critical, though, it just means the overall size of the |
1260 | * pool might be one hugepage larger than it needs to be, but |
1261 | * within all the constraints specified by the sysctls. |
1262 | */ |
1263 | spin_lock(&hugetlb_lock); |
1264 | while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { |
1265 | if (!adjust_pool_surplus(h, nodes_allowed, -1)) |
1266 | break; |
1267 | } |
1268 | |
1269 | while (count > persistent_huge_pages(h)) { |
1270 | /* |
1271 | * If this allocation races such that we no longer need the |
1272 | * page, free_huge_page will handle it by freeing the page |
1273 | * and reducing the surplus. |
1274 | */ |
1275 | spin_unlock(&hugetlb_lock); |
1276 | ret = alloc_fresh_huge_page(h, nodes_allowed); |
1277 | spin_lock(&hugetlb_lock); |
1278 | if (!ret) |
1279 | goto out; |
1280 | |
1281 | /* Bail for signals. Probably ctrl-c from user */ |
1282 | if (signal_pending(current)) |
1283 | goto out; |
1284 | } |
1285 | |
1286 | /* |
1287 | * Decrease the pool size |
1288 | * First return free pages to the buddy allocator (being careful |
1289 | * to keep enough around to satisfy reservations). Then place |
1290 | * pages into surplus state as needed so the pool will shrink |
1291 | * to the desired size as pages become free. |
1292 | * |
1293 | * By placing pages into the surplus state independent of the |
1294 | * overcommit value, we are allowing the surplus pool size to |
1295 | * exceed overcommit. There are few sane options here. Since |
1296 | * alloc_buddy_huge_page() is checking the global counter, |
1297 | * though, we'll note that we're not allowed to exceed surplus |
1298 | * and won't grow the pool anywhere else. Not until one of the |
1299 | * sysctls are changed, or the surplus pages go out of use. |
1300 | */ |
1301 | min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; |
1302 | min_count = max(count, min_count); |
1303 | try_to_free_low(h, min_count, nodes_allowed); |
1304 | while (min_count < persistent_huge_pages(h)) { |
1305 | if (!free_pool_huge_page(h, nodes_allowed, 0)) |
1306 | break; |
1307 | } |
1308 | while (count < persistent_huge_pages(h)) { |
1309 | if (!adjust_pool_surplus(h, nodes_allowed, 1)) |
1310 | break; |
1311 | } |
1312 | out: |
1313 | ret = persistent_huge_pages(h); |
1314 | spin_unlock(&hugetlb_lock); |
1315 | return ret; |
1316 | } |
1317 | |
1318 | #define HSTATE_ATTR_RO(_name) \ |
1319 | static struct kobj_attribute _name##_attr = __ATTR_RO(_name) |
1320 | |
1321 | #define HSTATE_ATTR(_name) \ |
1322 | static struct kobj_attribute _name##_attr = \ |
1323 | __ATTR(_name, 0644, _name##_show, _name##_store) |
1324 | |
1325 | static struct kobject *hugepages_kobj; |
1326 | static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; |
1327 | |
1328 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp); |
1329 | |
1330 | static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp) |
1331 | { |
1332 | int i; |
1333 | |
1334 | for (i = 0; i < HUGE_MAX_HSTATE; i++) |
1335 | if (hstate_kobjs[i] == kobj) { |
1336 | if (nidp) |
1337 | *nidp = NUMA_NO_NODE; |
1338 | return &hstates[i]; |
1339 | } |
1340 | |
1341 | return kobj_to_node_hstate(kobj, nidp); |
1342 | } |
1343 | |
1344 | static ssize_t nr_hugepages_show_common(struct kobject *kobj, |
1345 | struct kobj_attribute *attr, char *buf) |
1346 | { |
1347 | struct hstate *h; |
1348 | unsigned long nr_huge_pages; |
1349 | int nid; |
1350 | |
1351 | h = kobj_to_hstate(kobj, &nid); |
1352 | if (nid == NUMA_NO_NODE) |
1353 | nr_huge_pages = h->nr_huge_pages; |
1354 | else |
1355 | nr_huge_pages = h->nr_huge_pages_node[nid]; |
1356 | |
1357 | return sprintf(buf, "%lu\n", nr_huge_pages); |
1358 | } |
1359 | static ssize_t nr_hugepages_store_common(bool obey_mempolicy, |
1360 | struct kobject *kobj, struct kobj_attribute *attr, |
1361 | const char *buf, size_t len) |
1362 | { |
1363 | int err; |
1364 | int nid; |
1365 | unsigned long count; |
1366 | struct hstate *h; |
1367 | NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY); |
1368 | |
1369 | err = strict_strtoul(buf, 10, &count); |
1370 | if (err) |
1371 | return 0; |
1372 | |
1373 | h = kobj_to_hstate(kobj, &nid); |
1374 | if (nid == NUMA_NO_NODE) { |
1375 | /* |
1376 | * global hstate attribute |
1377 | */ |
1378 | if (!(obey_mempolicy && |
1379 | init_nodemask_of_mempolicy(nodes_allowed))) { |
1380 | NODEMASK_FREE(nodes_allowed); |
1381 | nodes_allowed = &node_states[N_HIGH_MEMORY]; |
1382 | } |
1383 | } else if (nodes_allowed) { |
1384 | /* |
1385 | * per node hstate attribute: adjust count to global, |
1386 | * but restrict alloc/free to the specified node. |
1387 | */ |
1388 | count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; |
1389 | init_nodemask_of_node(nodes_allowed, nid); |
1390 | } else |
1391 | nodes_allowed = &node_states[N_HIGH_MEMORY]; |
1392 | |
1393 | h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed); |
1394 | |
1395 | if (nodes_allowed != &node_states[N_HIGH_MEMORY]) |
1396 | NODEMASK_FREE(nodes_allowed); |
1397 | |
1398 | return len; |
1399 | } |
1400 | |
1401 | static ssize_t nr_hugepages_show(struct kobject *kobj, |
1402 | struct kobj_attribute *attr, char *buf) |
1403 | { |
1404 | return nr_hugepages_show_common(kobj, attr, buf); |
1405 | } |
1406 | |
1407 | static ssize_t nr_hugepages_store(struct kobject *kobj, |
1408 | struct kobj_attribute *attr, const char *buf, size_t len) |
1409 | { |
1410 | return nr_hugepages_store_common(false, kobj, attr, buf, len); |
1411 | } |
1412 | HSTATE_ATTR(nr_hugepages); |
1413 | |
1414 | #ifdef CONFIG_NUMA |
1415 | |
1416 | /* |
1417 | * hstate attribute for optionally mempolicy-based constraint on persistent |
1418 | * huge page alloc/free. |
1419 | */ |
1420 | static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj, |
1421 | struct kobj_attribute *attr, char *buf) |
1422 | { |
1423 | return nr_hugepages_show_common(kobj, attr, buf); |
1424 | } |
1425 | |
1426 | static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj, |
1427 | struct kobj_attribute *attr, const char *buf, size_t len) |
1428 | { |
1429 | return nr_hugepages_store_common(true, kobj, attr, buf, len); |
1430 | } |
1431 | HSTATE_ATTR(nr_hugepages_mempolicy); |
1432 | #endif |
1433 | |
1434 | |
1435 | static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, |
1436 | struct kobj_attribute *attr, char *buf) |
1437 | { |
1438 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
1439 | return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); |
1440 | } |
1441 | static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, |
1442 | struct kobj_attribute *attr, const char *buf, size_t count) |
1443 | { |
1444 | int err; |
1445 | unsigned long input; |
1446 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
1447 | |
1448 | err = strict_strtoul(buf, 10, &input); |
1449 | if (err) |
1450 | return 0; |
1451 | |
1452 | spin_lock(&hugetlb_lock); |
1453 | h->nr_overcommit_huge_pages = input; |
1454 | spin_unlock(&hugetlb_lock); |
1455 | |
1456 | return count; |
1457 | } |
1458 | HSTATE_ATTR(nr_overcommit_hugepages); |
1459 | |
1460 | static ssize_t free_hugepages_show(struct kobject *kobj, |
1461 | struct kobj_attribute *attr, char *buf) |
1462 | { |
1463 | struct hstate *h; |
1464 | unsigned long free_huge_pages; |
1465 | int nid; |
1466 | |
1467 | h = kobj_to_hstate(kobj, &nid); |
1468 | if (nid == NUMA_NO_NODE) |
1469 | free_huge_pages = h->free_huge_pages; |
1470 | else |
1471 | free_huge_pages = h->free_huge_pages_node[nid]; |
1472 | |
1473 | return sprintf(buf, "%lu\n", free_huge_pages); |
1474 | } |
1475 | HSTATE_ATTR_RO(free_hugepages); |
1476 | |
1477 | static ssize_t resv_hugepages_show(struct kobject *kobj, |
1478 | struct kobj_attribute *attr, char *buf) |
1479 | { |
1480 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
1481 | return sprintf(buf, "%lu\n", h->resv_huge_pages); |
1482 | } |
1483 | HSTATE_ATTR_RO(resv_hugepages); |
1484 | |
1485 | static ssize_t surplus_hugepages_show(struct kobject *kobj, |
1486 | struct kobj_attribute *attr, char *buf) |
1487 | { |
1488 | struct hstate *h; |
1489 | unsigned long surplus_huge_pages; |
1490 | int nid; |
1491 | |
1492 | h = kobj_to_hstate(kobj, &nid); |
1493 | if (nid == NUMA_NO_NODE) |
1494 | surplus_huge_pages = h->surplus_huge_pages; |
1495 | else |
1496 | surplus_huge_pages = h->surplus_huge_pages_node[nid]; |
1497 | |
1498 | return sprintf(buf, "%lu\n", surplus_huge_pages); |
1499 | } |
1500 | HSTATE_ATTR_RO(surplus_hugepages); |
1501 | |
1502 | static struct attribute *hstate_attrs[] = { |
1503 | &nr_hugepages_attr.attr, |
1504 | &nr_overcommit_hugepages_attr.attr, |
1505 | &free_hugepages_attr.attr, |
1506 | &resv_hugepages_attr.attr, |
1507 | &surplus_hugepages_attr.attr, |
1508 | #ifdef CONFIG_NUMA |
1509 | &nr_hugepages_mempolicy_attr.attr, |
1510 | #endif |
1511 | NULL, |
1512 | }; |
1513 | |
1514 | static struct attribute_group hstate_attr_group = { |
1515 | .attrs = hstate_attrs, |
1516 | }; |
1517 | |
1518 | static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent, |
1519 | struct kobject **hstate_kobjs, |
1520 | struct attribute_group *hstate_attr_group) |
1521 | { |
1522 | int retval; |
1523 | int hi = h - hstates; |
1524 | |
1525 | hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); |
1526 | if (!hstate_kobjs[hi]) |
1527 | return -ENOMEM; |
1528 | |
1529 | retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); |
1530 | if (retval) |
1531 | kobject_put(hstate_kobjs[hi]); |
1532 | |
1533 | return retval; |
1534 | } |
1535 | |
1536 | static void __init hugetlb_sysfs_init(void) |
1537 | { |
1538 | struct hstate *h; |
1539 | int err; |
1540 | |
1541 | hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); |
1542 | if (!hugepages_kobj) |
1543 | return; |
1544 | |
1545 | for_each_hstate(h) { |
1546 | err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, |
1547 | hstate_kobjs, &hstate_attr_group); |
1548 | if (err) |
1549 | printk(KERN_ERR "Hugetlb: Unable to add hstate %s", |
1550 | h->name); |
1551 | } |
1552 | } |
1553 | |
1554 | #ifdef CONFIG_NUMA |
1555 | |
1556 | /* |
1557 | * node_hstate/s - associate per node hstate attributes, via their kobjects, |
1558 | * with node sysdevs in node_devices[] using a parallel array. The array |
1559 | * index of a node sysdev or _hstate == node id. |
1560 | * This is here to avoid any static dependency of the node sysdev driver, in |
1561 | * the base kernel, on the hugetlb module. |
1562 | */ |
1563 | struct node_hstate { |
1564 | struct kobject *hugepages_kobj; |
1565 | struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; |
1566 | }; |
1567 | struct node_hstate node_hstates[MAX_NUMNODES]; |
1568 | |
1569 | /* |
1570 | * A subset of global hstate attributes for node sysdevs |
1571 | */ |
1572 | static struct attribute *per_node_hstate_attrs[] = { |
1573 | &nr_hugepages_attr.attr, |
1574 | &free_hugepages_attr.attr, |
1575 | &surplus_hugepages_attr.attr, |
1576 | NULL, |
1577 | }; |
1578 | |
1579 | static struct attribute_group per_node_hstate_attr_group = { |
1580 | .attrs = per_node_hstate_attrs, |
1581 | }; |
1582 | |
1583 | /* |
1584 | * kobj_to_node_hstate - lookup global hstate for node sysdev hstate attr kobj. |
1585 | * Returns node id via non-NULL nidp. |
1586 | */ |
1587 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) |
1588 | { |
1589 | int nid; |
1590 | |
1591 | for (nid = 0; nid < nr_node_ids; nid++) { |
1592 | struct node_hstate *nhs = &node_hstates[nid]; |
1593 | int i; |
1594 | for (i = 0; i < HUGE_MAX_HSTATE; i++) |
1595 | if (nhs->hstate_kobjs[i] == kobj) { |
1596 | if (nidp) |
1597 | *nidp = nid; |
1598 | return &hstates[i]; |
1599 | } |
1600 | } |
1601 | |
1602 | BUG(); |
1603 | return NULL; |
1604 | } |
1605 | |
1606 | /* |
1607 | * Unregister hstate attributes from a single node sysdev. |
1608 | * No-op if no hstate attributes attached. |
1609 | */ |
1610 | void hugetlb_unregister_node(struct node *node) |
1611 | { |
1612 | struct hstate *h; |
1613 | struct node_hstate *nhs = &node_hstates[node->sysdev.id]; |
1614 | |
1615 | if (!nhs->hugepages_kobj) |
1616 | return; /* no hstate attributes */ |
1617 | |
1618 | for_each_hstate(h) |
1619 | if (nhs->hstate_kobjs[h - hstates]) { |
1620 | kobject_put(nhs->hstate_kobjs[h - hstates]); |
1621 | nhs->hstate_kobjs[h - hstates] = NULL; |
1622 | } |
1623 | |
1624 | kobject_put(nhs->hugepages_kobj); |
1625 | nhs->hugepages_kobj = NULL; |
1626 | } |
1627 | |
1628 | /* |
1629 | * hugetlb module exit: unregister hstate attributes from node sysdevs |
1630 | * that have them. |
1631 | */ |
1632 | static void hugetlb_unregister_all_nodes(void) |
1633 | { |
1634 | int nid; |
1635 | |
1636 | /* |
1637 | * disable node sysdev registrations. |
1638 | */ |
1639 | register_hugetlbfs_with_node(NULL, NULL); |
1640 | |
1641 | /* |
1642 | * remove hstate attributes from any nodes that have them. |
1643 | */ |
1644 | for (nid = 0; nid < nr_node_ids; nid++) |
1645 | hugetlb_unregister_node(&node_devices[nid]); |
1646 | } |
1647 | |
1648 | /* |
1649 | * Register hstate attributes for a single node sysdev. |
1650 | * No-op if attributes already registered. |
1651 | */ |
1652 | void hugetlb_register_node(struct node *node) |
1653 | { |
1654 | struct hstate *h; |
1655 | struct node_hstate *nhs = &node_hstates[node->sysdev.id]; |
1656 | int err; |
1657 | |
1658 | if (nhs->hugepages_kobj) |
1659 | return; /* already allocated */ |
1660 | |
1661 | nhs->hugepages_kobj = kobject_create_and_add("hugepages", |
1662 | &node->sysdev.kobj); |
1663 | if (!nhs->hugepages_kobj) |
1664 | return; |
1665 | |
1666 | for_each_hstate(h) { |
1667 | err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, |
1668 | nhs->hstate_kobjs, |
1669 | &per_node_hstate_attr_group); |
1670 | if (err) { |
1671 | printk(KERN_ERR "Hugetlb: Unable to add hstate %s" |
1672 | " for node %d\n", |
1673 | h->name, node->sysdev.id); |
1674 | hugetlb_unregister_node(node); |
1675 | break; |
1676 | } |
1677 | } |
1678 | } |
1679 | |
1680 | /* |
1681 | * hugetlb init time: register hstate attributes for all registered node |
1682 | * sysdevs of nodes that have memory. All on-line nodes should have |
1683 | * registered their associated sysdev by this time. |
1684 | */ |
1685 | static void hugetlb_register_all_nodes(void) |
1686 | { |
1687 | int nid; |
1688 | |
1689 | for_each_node_state(nid, N_HIGH_MEMORY) { |
1690 | struct node *node = &node_devices[nid]; |
1691 | if (node->sysdev.id == nid) |
1692 | hugetlb_register_node(node); |
1693 | } |
1694 | |
1695 | /* |
1696 | * Let the node sysdev driver know we're here so it can |
1697 | * [un]register hstate attributes on node hotplug. |
1698 | */ |
1699 | register_hugetlbfs_with_node(hugetlb_register_node, |
1700 | hugetlb_unregister_node); |
1701 | } |
1702 | #else /* !CONFIG_NUMA */ |
1703 | |
1704 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) |
1705 | { |
1706 | BUG(); |
1707 | if (nidp) |
1708 | *nidp = -1; |
1709 | return NULL; |
1710 | } |
1711 | |
1712 | static void hugetlb_unregister_all_nodes(void) { } |
1713 | |
1714 | static void hugetlb_register_all_nodes(void) { } |
1715 | |
1716 | #endif |
1717 | |
1718 | static void __exit hugetlb_exit(void) |
1719 | { |
1720 | struct hstate *h; |
1721 | |
1722 | hugetlb_unregister_all_nodes(); |
1723 | |
1724 | for_each_hstate(h) { |
1725 | kobject_put(hstate_kobjs[h - hstates]); |
1726 | } |
1727 | |
1728 | kobject_put(hugepages_kobj); |
1729 | } |
1730 | module_exit(hugetlb_exit); |
1731 | |
1732 | static int __init hugetlb_init(void) |
1733 | { |
1734 | /* Some platform decide whether they support huge pages at boot |
1735 | * time. On these, such as powerpc, HPAGE_SHIFT is set to 0 when |
1736 | * there is no such support |
1737 | */ |
1738 | if (HPAGE_SHIFT == 0) |
1739 | return 0; |
1740 | |
1741 | if (!size_to_hstate(default_hstate_size)) { |
1742 | default_hstate_size = HPAGE_SIZE; |
1743 | if (!size_to_hstate(default_hstate_size)) |
1744 | hugetlb_add_hstate(HUGETLB_PAGE_ORDER); |
1745 | } |
1746 | default_hstate_idx = size_to_hstate(default_hstate_size) - hstates; |
1747 | if (default_hstate_max_huge_pages) |
1748 | default_hstate.max_huge_pages = default_hstate_max_huge_pages; |
1749 | |
1750 | hugetlb_init_hstates(); |
1751 | |
1752 | gather_bootmem_prealloc(); |
1753 | |
1754 | report_hugepages(); |
1755 | |
1756 | hugetlb_sysfs_init(); |
1757 | |
1758 | hugetlb_register_all_nodes(); |
1759 | |
1760 | return 0; |
1761 | } |
1762 | module_init(hugetlb_init); |
1763 | |
1764 | /* Should be called on processing a hugepagesz=... option */ |
1765 | void __init hugetlb_add_hstate(unsigned order) |
1766 | { |
1767 | struct hstate *h; |
1768 | unsigned long i; |
1769 | |
1770 | if (size_to_hstate(PAGE_SIZE << order)) { |
1771 | printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n"); |
1772 | return; |
1773 | } |
1774 | BUG_ON(max_hstate >= HUGE_MAX_HSTATE); |
1775 | BUG_ON(order == 0); |
1776 | h = &hstates[max_hstate++]; |
1777 | h->order = order; |
1778 | h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); |
1779 | h->nr_huge_pages = 0; |
1780 | h->free_huge_pages = 0; |
1781 | for (i = 0; i < MAX_NUMNODES; ++i) |
1782 | INIT_LIST_HEAD(&h->hugepage_freelists[i]); |
1783 | h->next_nid_to_alloc = first_node(node_states[N_HIGH_MEMORY]); |
1784 | h->next_nid_to_free = first_node(node_states[N_HIGH_MEMORY]); |
1785 | snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", |
1786 | huge_page_size(h)/1024); |
1787 | |
1788 | parsed_hstate = h; |
1789 | } |
1790 | |
1791 | static int __init hugetlb_nrpages_setup(char *s) |
1792 | { |
1793 | unsigned long *mhp; |
1794 | static unsigned long *last_mhp; |
1795 | |
1796 | /* |
1797 | * !max_hstate means we haven't parsed a hugepagesz= parameter yet, |
1798 | * so this hugepages= parameter goes to the "default hstate". |
1799 | */ |
1800 | if (!max_hstate) |
1801 | mhp = &default_hstate_max_huge_pages; |
1802 | else |
1803 | mhp = &parsed_hstate->max_huge_pages; |
1804 | |
1805 | if (mhp == last_mhp) { |
1806 | printk(KERN_WARNING "hugepages= specified twice without " |
1807 | "interleaving hugepagesz=, ignoring\n"); |
1808 | return 1; |
1809 | } |
1810 | |
1811 | if (sscanf(s, "%lu", mhp) <= 0) |
1812 | *mhp = 0; |
1813 | |
1814 | /* |
1815 | * Global state is always initialized later in hugetlb_init. |
1816 | * But we need to allocate >= MAX_ORDER hstates here early to still |
1817 | * use the bootmem allocator. |
1818 | */ |
1819 | if (max_hstate && parsed_hstate->order >= MAX_ORDER) |
1820 | hugetlb_hstate_alloc_pages(parsed_hstate); |
1821 | |
1822 | last_mhp = mhp; |
1823 | |
1824 | return 1; |
1825 | } |
1826 | __setup("hugepages=", hugetlb_nrpages_setup); |
1827 | |
1828 | static int __init hugetlb_default_setup(char *s) |
1829 | { |
1830 | default_hstate_size = memparse(s, &s); |
1831 | return 1; |
1832 | } |
1833 | __setup("default_hugepagesz=", hugetlb_default_setup); |
1834 | |
1835 | static unsigned int cpuset_mems_nr(unsigned int *array) |
1836 | { |
1837 | int node; |
1838 | unsigned int nr = 0; |
1839 | |
1840 | for_each_node_mask(node, cpuset_current_mems_allowed) |
1841 | nr += array[node]; |
1842 | |
1843 | return nr; |
1844 | } |
1845 | |
1846 | #ifdef CONFIG_SYSCTL |
1847 | static int hugetlb_sysctl_handler_common(bool obey_mempolicy, |
1848 | struct ctl_table *table, int write, |
1849 | void __user *buffer, size_t *length, loff_t *ppos) |
1850 | { |
1851 | struct hstate *h = &default_hstate; |
1852 | unsigned long tmp; |
1853 | |
1854 | if (!write) |
1855 | tmp = h->max_huge_pages; |
1856 | |
1857 | table->data = &tmp; |
1858 | table->maxlen = sizeof(unsigned long); |
1859 | proc_doulongvec_minmax(table, write, buffer, length, ppos); |
1860 | |
1861 | if (write) { |
1862 | NODEMASK_ALLOC(nodemask_t, nodes_allowed, |
1863 | GFP_KERNEL | __GFP_NORETRY); |
1864 | if (!(obey_mempolicy && |
1865 | init_nodemask_of_mempolicy(nodes_allowed))) { |
1866 | NODEMASK_FREE(nodes_allowed); |
1867 | nodes_allowed = &node_states[N_HIGH_MEMORY]; |
1868 | } |
1869 | h->max_huge_pages = set_max_huge_pages(h, tmp, nodes_allowed); |
1870 | |
1871 | if (nodes_allowed != &node_states[N_HIGH_MEMORY]) |
1872 | NODEMASK_FREE(nodes_allowed); |
1873 | } |
1874 | |
1875 | return 0; |
1876 | } |
1877 | |
1878 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
1879 | void __user *buffer, size_t *length, loff_t *ppos) |
1880 | { |
1881 | |
1882 | return hugetlb_sysctl_handler_common(false, table, write, |
1883 | buffer, length, ppos); |
1884 | } |
1885 | |
1886 | #ifdef CONFIG_NUMA |
1887 | int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, |
1888 | void __user *buffer, size_t *length, loff_t *ppos) |
1889 | { |
1890 | return hugetlb_sysctl_handler_common(true, table, write, |
1891 | buffer, length, ppos); |
1892 | } |
1893 | #endif /* CONFIG_NUMA */ |
1894 | |
1895 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, |
1896 | void __user *buffer, |
1897 | size_t *length, loff_t *ppos) |
1898 | { |
1899 | proc_dointvec(table, write, buffer, length, ppos); |
1900 | if (hugepages_treat_as_movable) |
1901 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; |
1902 | else |
1903 | htlb_alloc_mask = GFP_HIGHUSER; |
1904 | return 0; |
1905 | } |
1906 | |
1907 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
1908 | void __user *buffer, |
1909 | size_t *length, loff_t *ppos) |
1910 | { |
1911 | struct hstate *h = &default_hstate; |
1912 | unsigned long tmp; |
1913 | |
1914 | if (!write) |
1915 | tmp = h->nr_overcommit_huge_pages; |
1916 | |
1917 | table->data = &tmp; |
1918 | table->maxlen = sizeof(unsigned long); |
1919 | proc_doulongvec_minmax(table, write, buffer, length, ppos); |
1920 | |
1921 | if (write) { |
1922 | spin_lock(&hugetlb_lock); |
1923 | h->nr_overcommit_huge_pages = tmp; |
1924 | spin_unlock(&hugetlb_lock); |
1925 | } |
1926 | |
1927 | return 0; |
1928 | } |
1929 | |
1930 | #endif /* CONFIG_SYSCTL */ |
1931 | |
1932 | void hugetlb_report_meminfo(struct seq_file *m) |
1933 | { |
1934 | struct hstate *h = &default_hstate; |
1935 | seq_printf(m, |
1936 | "HugePages_Total: %5lu\n" |
1937 | "HugePages_Free: %5lu\n" |
1938 | "HugePages_Rsvd: %5lu\n" |
1939 | "HugePages_Surp: %5lu\n" |
1940 | "Hugepagesize: %8lu kB\n", |
1941 | h->nr_huge_pages, |
1942 | h->free_huge_pages, |
1943 | h->resv_huge_pages, |
1944 | h->surplus_huge_pages, |
1945 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); |
1946 | } |
1947 | |
1948 | int hugetlb_report_node_meminfo(int nid, char *buf) |
1949 | { |
1950 | struct hstate *h = &default_hstate; |
1951 | return sprintf(buf, |
1952 | "Node %d HugePages_Total: %5u\n" |
1953 | "Node %d HugePages_Free: %5u\n" |
1954 | "Node %d HugePages_Surp: %5u\n", |
1955 | nid, h->nr_huge_pages_node[nid], |
1956 | nid, h->free_huge_pages_node[nid], |
1957 | nid, h->surplus_huge_pages_node[nid]); |
1958 | } |
1959 | |
1960 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
1961 | unsigned long hugetlb_total_pages(void) |
1962 | { |
1963 | struct hstate *h = &default_hstate; |
1964 | return h->nr_huge_pages * pages_per_huge_page(h); |
1965 | } |
1966 | |
1967 | static int hugetlb_acct_memory(struct hstate *h, long delta) |
1968 | { |
1969 | int ret = -ENOMEM; |
1970 | |
1971 | spin_lock(&hugetlb_lock); |
1972 | /* |
1973 | * When cpuset is configured, it breaks the strict hugetlb page |
1974 | * reservation as the accounting is done on a global variable. Such |
1975 | * reservation is completely rubbish in the presence of cpuset because |
1976 | * the reservation is not checked against page availability for the |
1977 | * current cpuset. Application can still potentially OOM'ed by kernel |
1978 | * with lack of free htlb page in cpuset that the task is in. |
1979 | * Attempt to enforce strict accounting with cpuset is almost |
1980 | * impossible (or too ugly) because cpuset is too fluid that |
1981 | * task or memory node can be dynamically moved between cpusets. |
1982 | * |
1983 | * The change of semantics for shared hugetlb mapping with cpuset is |
1984 | * undesirable. However, in order to preserve some of the semantics, |
1985 | * we fall back to check against current free page availability as |
1986 | * a best attempt and hopefully to minimize the impact of changing |
1987 | * semantics that cpuset has. |
1988 | */ |
1989 | if (delta > 0) { |
1990 | if (gather_surplus_pages(h, delta) < 0) |
1991 | goto out; |
1992 | |
1993 | if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { |
1994 | return_unused_surplus_pages(h, delta); |
1995 | goto out; |
1996 | } |
1997 | } |
1998 | |
1999 | ret = 0; |
2000 | if (delta < 0) |
2001 | return_unused_surplus_pages(h, (unsigned long) -delta); |
2002 | |
2003 | out: |
2004 | spin_unlock(&hugetlb_lock); |
2005 | return ret; |
2006 | } |
2007 | |
2008 | static void hugetlb_vm_op_open(struct vm_area_struct *vma) |
2009 | { |
2010 | struct resv_map *reservations = vma_resv_map(vma); |
2011 | |
2012 | /* |
2013 | * This new VMA should share its siblings reservation map if present. |
2014 | * The VMA will only ever have a valid reservation map pointer where |
2015 | * it is being copied for another still existing VMA. As that VMA |
2016 | * has a reference to the reservation map it cannot dissappear until |
2017 | * after this open call completes. It is therefore safe to take a |
2018 | * new reference here without additional locking. |
2019 | */ |
2020 | if (reservations) |
2021 | kref_get(&reservations->refs); |
2022 | } |
2023 | |
2024 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
2025 | { |
2026 | struct hstate *h = hstate_vma(vma); |
2027 | struct resv_map *reservations = vma_resv_map(vma); |
2028 | unsigned long reserve; |
2029 | unsigned long start; |
2030 | unsigned long end; |
2031 | |
2032 | if (reservations) { |
2033 | start = vma_hugecache_offset(h, vma, vma->vm_start); |
2034 | end = vma_hugecache_offset(h, vma, vma->vm_end); |
2035 | |
2036 | reserve = (end - start) - |
2037 | region_count(&reservations->regions, start, end); |
2038 | |
2039 | kref_put(&reservations->refs, resv_map_release); |
2040 | |
2041 | if (reserve) { |
2042 | hugetlb_acct_memory(h, -reserve); |
2043 | hugetlb_put_quota(vma->vm_file->f_mapping, reserve); |
2044 | } |
2045 | } |
2046 | } |
2047 | |
2048 | /* |
2049 | * We cannot handle pagefaults against hugetlb pages at all. They cause |
2050 | * handle_mm_fault() to try to instantiate regular-sized pages in the |
2051 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get |
2052 | * this far. |
2053 | */ |
2054 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
2055 | { |
2056 | BUG(); |
2057 | return 0; |
2058 | } |
2059 | |
2060 | const struct vm_operations_struct hugetlb_vm_ops = { |
2061 | .fault = hugetlb_vm_op_fault, |
2062 | .open = hugetlb_vm_op_open, |
2063 | .close = hugetlb_vm_op_close, |
2064 | }; |
2065 | |
2066 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
2067 | int writable) |
2068 | { |
2069 | pte_t entry; |
2070 | |
2071 | if (writable) { |
2072 | entry = |
2073 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); |
2074 | } else { |
2075 | entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
2076 | } |
2077 | entry = pte_mkyoung(entry); |
2078 | entry = pte_mkhuge(entry); |
2079 | |
2080 | return entry; |
2081 | } |
2082 | |
2083 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
2084 | unsigned long address, pte_t *ptep) |
2085 | { |
2086 | pte_t entry; |
2087 | |
2088 | entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); |
2089 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { |
2090 | update_mmu_cache(vma, address, ptep); |
2091 | } |
2092 | } |
2093 | |
2094 | |
2095 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
2096 | struct vm_area_struct *vma) |
2097 | { |
2098 | pte_t *src_pte, *dst_pte, entry; |
2099 | struct page *ptepage; |
2100 | unsigned long addr; |
2101 | int cow; |
2102 | struct hstate *h = hstate_vma(vma); |
2103 | unsigned long sz = huge_page_size(h); |
2104 | |
2105 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; |
2106 | |
2107 | for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { |
2108 | src_pte = huge_pte_offset(src, addr); |
2109 | if (!src_pte) |
2110 | continue; |
2111 | dst_pte = huge_pte_alloc(dst, addr, sz); |
2112 | if (!dst_pte) |
2113 | goto nomem; |
2114 | |
2115 | /* If the pagetables are shared don't copy or take references */ |
2116 | if (dst_pte == src_pte) |
2117 | continue; |
2118 | |
2119 | spin_lock(&dst->page_table_lock); |
2120 | spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); |
2121 | if (!huge_pte_none(huge_ptep_get(src_pte))) { |
2122 | if (cow) |
2123 | huge_ptep_set_wrprotect(src, addr, src_pte); |
2124 | entry = huge_ptep_get(src_pte); |
2125 | ptepage = pte_page(entry); |
2126 | get_page(ptepage); |
2127 | set_huge_pte_at(dst, addr, dst_pte, entry); |
2128 | } |
2129 | spin_unlock(&src->page_table_lock); |
2130 | spin_unlock(&dst->page_table_lock); |
2131 | } |
2132 | return 0; |
2133 | |
2134 | nomem: |
2135 | return -ENOMEM; |
2136 | } |
2137 | |
2138 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
2139 | unsigned long end, struct page *ref_page) |
2140 | { |
2141 | struct mm_struct *mm = vma->vm_mm; |
2142 | unsigned long address; |
2143 | pte_t *ptep; |
2144 | pte_t pte; |
2145 | struct page *page; |
2146 | struct page *tmp; |
2147 | struct hstate *h = hstate_vma(vma); |
2148 | unsigned long sz = huge_page_size(h); |
2149 | |
2150 | /* |
2151 | * A page gathering list, protected by per file i_mmap_lock. The |
2152 | * lock is used to avoid list corruption from multiple unmapping |
2153 | * of the same page since we are using page->lru. |
2154 | */ |
2155 | LIST_HEAD(page_list); |
2156 | |
2157 | WARN_ON(!is_vm_hugetlb_page(vma)); |
2158 | BUG_ON(start & ~huge_page_mask(h)); |
2159 | BUG_ON(end & ~huge_page_mask(h)); |
2160 | |
2161 | mmu_notifier_invalidate_range_start(mm, start, end); |
2162 | spin_lock(&mm->page_table_lock); |
2163 | for (address = start; address < end; address += sz) { |
2164 | ptep = huge_pte_offset(mm, address); |
2165 | if (!ptep) |
2166 | continue; |
2167 | |
2168 | if (huge_pmd_unshare(mm, &address, ptep)) |
2169 | continue; |
2170 | |
2171 | /* |
2172 | * If a reference page is supplied, it is because a specific |
2173 | * page is being unmapped, not a range. Ensure the page we |
2174 | * are about to unmap is the actual page of interest. |
2175 | */ |
2176 | if (ref_page) { |
2177 | pte = huge_ptep_get(ptep); |
2178 | if (huge_pte_none(pte)) |
2179 | continue; |
2180 | page = pte_page(pte); |
2181 | if (page != ref_page) |
2182 | continue; |
2183 | |
2184 | /* |
2185 | * Mark the VMA as having unmapped its page so that |
2186 | * future faults in this VMA will fail rather than |
2187 | * looking like data was lost |
2188 | */ |
2189 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); |
2190 | } |
2191 | |
2192 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
2193 | if (huge_pte_none(pte)) |
2194 | continue; |
2195 | |
2196 | page = pte_page(pte); |
2197 | if (pte_dirty(pte)) |
2198 | set_page_dirty(page); |
2199 | list_add(&page->lru, &page_list); |
2200 | } |
2201 | spin_unlock(&mm->page_table_lock); |
2202 | flush_tlb_range(vma, start, end); |
2203 | mmu_notifier_invalidate_range_end(mm, start, end); |
2204 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
2205 | list_del(&page->lru); |
2206 | put_page(page); |
2207 | } |
2208 | } |
2209 | |
2210 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
2211 | unsigned long end, struct page *ref_page) |
2212 | { |
2213 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
2214 | __unmap_hugepage_range(vma, start, end, ref_page); |
2215 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
2216 | } |
2217 | |
2218 | /* |
2219 | * This is called when the original mapper is failing to COW a MAP_PRIVATE |
2220 | * mappping it owns the reserve page for. The intention is to unmap the page |
2221 | * from other VMAs and let the children be SIGKILLed if they are faulting the |
2222 | * same region. |
2223 | */ |
2224 | static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, |
2225 | struct page *page, unsigned long address) |
2226 | { |
2227 | struct hstate *h = hstate_vma(vma); |
2228 | struct vm_area_struct *iter_vma; |
2229 | struct address_space *mapping; |
2230 | struct prio_tree_iter iter; |
2231 | pgoff_t pgoff; |
2232 | |
2233 | /* |
2234 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation |
2235 | * from page cache lookup which is in HPAGE_SIZE units. |
2236 | */ |
2237 | address = address & huge_page_mask(h); |
2238 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) |
2239 | + (vma->vm_pgoff >> PAGE_SHIFT); |
2240 | mapping = (struct address_space *)page_private(page); |
2241 | |
2242 | /* |
2243 | * Take the mapping lock for the duration of the table walk. As |
2244 | * this mapping should be shared between all the VMAs, |
2245 | * __unmap_hugepage_range() is called as the lock is already held |
2246 | */ |
2247 | spin_lock(&mapping->i_mmap_lock); |
2248 | vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { |
2249 | /* Do not unmap the current VMA */ |
2250 | if (iter_vma == vma) |
2251 | continue; |
2252 | |
2253 | /* |
2254 | * Unmap the page from other VMAs without their own reserves. |
2255 | * They get marked to be SIGKILLed if they fault in these |
2256 | * areas. This is because a future no-page fault on this VMA |
2257 | * could insert a zeroed page instead of the data existing |
2258 | * from the time of fork. This would look like data corruption |
2259 | */ |
2260 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) |
2261 | __unmap_hugepage_range(iter_vma, |
2262 | address, address + huge_page_size(h), |
2263 | page); |
2264 | } |
2265 | spin_unlock(&mapping->i_mmap_lock); |
2266 | |
2267 | return 1; |
2268 | } |
2269 | |
2270 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
2271 | unsigned long address, pte_t *ptep, pte_t pte, |
2272 | struct page *pagecache_page) |
2273 | { |
2274 | struct hstate *h = hstate_vma(vma); |
2275 | struct page *old_page, *new_page; |
2276 | int avoidcopy; |
2277 | int outside_reserve = 0; |
2278 | |
2279 | old_page = pte_page(pte); |
2280 | |
2281 | retry_avoidcopy: |
2282 | /* If no-one else is actually using this page, avoid the copy |
2283 | * and just make the page writable */ |
2284 | avoidcopy = (page_count(old_page) == 1); |
2285 | if (avoidcopy) { |
2286 | set_huge_ptep_writable(vma, address, ptep); |
2287 | return 0; |
2288 | } |
2289 | |
2290 | /* |
2291 | * If the process that created a MAP_PRIVATE mapping is about to |
2292 | * perform a COW due to a shared page count, attempt to satisfy |
2293 | * the allocation without using the existing reserves. The pagecache |
2294 | * page is used to determine if the reserve at this address was |
2295 | * consumed or not. If reserves were used, a partial faulted mapping |
2296 | * at the time of fork() could consume its reserves on COW instead |
2297 | * of the full address range. |
2298 | */ |
2299 | if (!(vma->vm_flags & VM_MAYSHARE) && |
2300 | is_vma_resv_set(vma, HPAGE_RESV_OWNER) && |
2301 | old_page != pagecache_page) |
2302 | outside_reserve = 1; |
2303 | |
2304 | page_cache_get(old_page); |
2305 | |
2306 | /* Drop page_table_lock as buddy allocator may be called */ |
2307 | spin_unlock(&mm->page_table_lock); |
2308 | new_page = alloc_huge_page(vma, address, outside_reserve); |
2309 | |
2310 | if (IS_ERR(new_page)) { |
2311 | page_cache_release(old_page); |
2312 | |
2313 | /* |
2314 | * If a process owning a MAP_PRIVATE mapping fails to COW, |
2315 | * it is due to references held by a child and an insufficient |
2316 | * huge page pool. To guarantee the original mappers |
2317 | * reliability, unmap the page from child processes. The child |
2318 | * may get SIGKILLed if it later faults. |
2319 | */ |
2320 | if (outside_reserve) { |
2321 | BUG_ON(huge_pte_none(pte)); |
2322 | if (unmap_ref_private(mm, vma, old_page, address)) { |
2323 | BUG_ON(page_count(old_page) != 1); |
2324 | BUG_ON(huge_pte_none(pte)); |
2325 | spin_lock(&mm->page_table_lock); |
2326 | goto retry_avoidcopy; |
2327 | } |
2328 | WARN_ON_ONCE(1); |
2329 | } |
2330 | |
2331 | /* Caller expects lock to be held */ |
2332 | spin_lock(&mm->page_table_lock); |
2333 | return -PTR_ERR(new_page); |
2334 | } |
2335 | |
2336 | copy_huge_page(new_page, old_page, address, vma); |
2337 | __SetPageUptodate(new_page); |
2338 | |
2339 | /* |
2340 | * Retake the page_table_lock to check for racing updates |
2341 | * before the page tables are altered |
2342 | */ |
2343 | spin_lock(&mm->page_table_lock); |
2344 | ptep = huge_pte_offset(mm, address & huge_page_mask(h)); |
2345 | if (likely(pte_same(huge_ptep_get(ptep), pte))) { |
2346 | /* Break COW */ |
2347 | huge_ptep_clear_flush(vma, address, ptep); |
2348 | set_huge_pte_at(mm, address, ptep, |
2349 | make_huge_pte(vma, new_page, 1)); |
2350 | /* Make the old page be freed below */ |
2351 | new_page = old_page; |
2352 | } |
2353 | page_cache_release(new_page); |
2354 | page_cache_release(old_page); |
2355 | return 0; |
2356 | } |
2357 | |
2358 | /* Return the pagecache page at a given address within a VMA */ |
2359 | static struct page *hugetlbfs_pagecache_page(struct hstate *h, |
2360 | struct vm_area_struct *vma, unsigned long address) |
2361 | { |
2362 | struct address_space *mapping; |
2363 | pgoff_t idx; |
2364 | |
2365 | mapping = vma->vm_file->f_mapping; |
2366 | idx = vma_hugecache_offset(h, vma, address); |
2367 | |
2368 | return find_lock_page(mapping, idx); |
2369 | } |
2370 | |
2371 | /* |
2372 | * Return whether there is a pagecache page to back given address within VMA. |
2373 | * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. |
2374 | */ |
2375 | static bool hugetlbfs_pagecache_present(struct hstate *h, |
2376 | struct vm_area_struct *vma, unsigned long address) |
2377 | { |
2378 | struct address_space *mapping; |
2379 | pgoff_t idx; |
2380 | struct page *page; |
2381 | |
2382 | mapping = vma->vm_file->f_mapping; |
2383 | idx = vma_hugecache_offset(h, vma, address); |
2384 | |
2385 | page = find_get_page(mapping, idx); |
2386 | if (page) |
2387 | put_page(page); |
2388 | return page != NULL; |
2389 | } |
2390 | |
2391 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
2392 | unsigned long address, pte_t *ptep, unsigned int flags) |
2393 | { |
2394 | struct hstate *h = hstate_vma(vma); |
2395 | int ret = VM_FAULT_SIGBUS; |
2396 | pgoff_t idx; |
2397 | unsigned long size; |
2398 | struct page *page; |
2399 | struct address_space *mapping; |
2400 | pte_t new_pte; |
2401 | |
2402 | /* |
2403 | * Currently, we are forced to kill the process in the event the |
2404 | * original mapper has unmapped pages from the child due to a failed |
2405 | * COW. Warn that such a situation has occured as it may not be obvious |
2406 | */ |
2407 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { |
2408 | printk(KERN_WARNING |
2409 | "PID %d killed due to inadequate hugepage pool\n", |
2410 | current->pid); |
2411 | return ret; |
2412 | } |
2413 | |
2414 | mapping = vma->vm_file->f_mapping; |
2415 | idx = vma_hugecache_offset(h, vma, address); |
2416 | |
2417 | /* |
2418 | * Use page lock to guard against racing truncation |
2419 | * before we get page_table_lock. |
2420 | */ |
2421 | retry: |
2422 | page = find_lock_page(mapping, idx); |
2423 | if (!page) { |
2424 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
2425 | if (idx >= size) |
2426 | goto out; |
2427 | page = alloc_huge_page(vma, address, 0); |
2428 | if (IS_ERR(page)) { |
2429 | ret = -PTR_ERR(page); |
2430 | goto out; |
2431 | } |
2432 | clear_huge_page(page, address, huge_page_size(h)); |
2433 | __SetPageUptodate(page); |
2434 | |
2435 | if (vma->vm_flags & VM_MAYSHARE) { |
2436 | int err; |
2437 | struct inode *inode = mapping->host; |
2438 | |
2439 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); |
2440 | if (err) { |
2441 | put_page(page); |
2442 | if (err == -EEXIST) |
2443 | goto retry; |
2444 | goto out; |
2445 | } |
2446 | |
2447 | spin_lock(&inode->i_lock); |
2448 | inode->i_blocks += blocks_per_huge_page(h); |
2449 | spin_unlock(&inode->i_lock); |
2450 | } else |
2451 | lock_page(page); |
2452 | } |
2453 | |
2454 | /* |
2455 | * If we are going to COW a private mapping later, we examine the |
2456 | * pending reservations for this page now. This will ensure that |
2457 | * any allocations necessary to record that reservation occur outside |
2458 | * the spinlock. |
2459 | */ |
2460 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) |
2461 | if (vma_needs_reservation(h, vma, address) < 0) { |
2462 | ret = VM_FAULT_OOM; |
2463 | goto backout_unlocked; |
2464 | } |
2465 | |
2466 | spin_lock(&mm->page_table_lock); |
2467 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
2468 | if (idx >= size) |
2469 | goto backout; |
2470 | |
2471 | ret = 0; |
2472 | if (!huge_pte_none(huge_ptep_get(ptep))) |
2473 | goto backout; |
2474 | |
2475 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
2476 | && (vma->vm_flags & VM_SHARED))); |
2477 | set_huge_pte_at(mm, address, ptep, new_pte); |
2478 | |
2479 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { |
2480 | /* Optimization, do the COW without a second fault */ |
2481 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); |
2482 | } |
2483 | |
2484 | spin_unlock(&mm->page_table_lock); |
2485 | unlock_page(page); |
2486 | out: |
2487 | return ret; |
2488 | |
2489 | backout: |
2490 | spin_unlock(&mm->page_table_lock); |
2491 | backout_unlocked: |
2492 | unlock_page(page); |
2493 | put_page(page); |
2494 | goto out; |
2495 | } |
2496 | |
2497 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
2498 | unsigned long address, unsigned int flags) |
2499 | { |
2500 | pte_t *ptep; |
2501 | pte_t entry; |
2502 | int ret; |
2503 | struct page *pagecache_page = NULL; |
2504 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
2505 | struct hstate *h = hstate_vma(vma); |
2506 | |
2507 | ptep = huge_pte_alloc(mm, address, huge_page_size(h)); |
2508 | if (!ptep) |
2509 | return VM_FAULT_OOM; |
2510 | |
2511 | /* |
2512 | * Serialize hugepage allocation and instantiation, so that we don't |
2513 | * get spurious allocation failures if two CPUs race to instantiate |
2514 | * the same page in the page cache. |
2515 | */ |
2516 | mutex_lock(&hugetlb_instantiation_mutex); |
2517 | entry = huge_ptep_get(ptep); |
2518 | if (huge_pte_none(entry)) { |
2519 | ret = hugetlb_no_page(mm, vma, address, ptep, flags); |
2520 | goto out_mutex; |
2521 | } |
2522 | |
2523 | ret = 0; |
2524 | |
2525 | /* |
2526 | * If we are going to COW the mapping later, we examine the pending |
2527 | * reservations for this page now. This will ensure that any |
2528 | * allocations necessary to record that reservation occur outside the |
2529 | * spinlock. For private mappings, we also lookup the pagecache |
2530 | * page now as it is used to determine if a reservation has been |
2531 | * consumed. |
2532 | */ |
2533 | if ((flags & FAULT_FLAG_WRITE) && !pte_write(entry)) { |
2534 | if (vma_needs_reservation(h, vma, address) < 0) { |
2535 | ret = VM_FAULT_OOM; |
2536 | goto out_mutex; |
2537 | } |
2538 | |
2539 | if (!(vma->vm_flags & VM_MAYSHARE)) |
2540 | pagecache_page = hugetlbfs_pagecache_page(h, |
2541 | vma, address); |
2542 | } |
2543 | |
2544 | spin_lock(&mm->page_table_lock); |
2545 | /* Check for a racing update before calling hugetlb_cow */ |
2546 | if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) |
2547 | goto out_page_table_lock; |
2548 | |
2549 | |
2550 | if (flags & FAULT_FLAG_WRITE) { |
2551 | if (!pte_write(entry)) { |
2552 | ret = hugetlb_cow(mm, vma, address, ptep, entry, |
2553 | pagecache_page); |
2554 | goto out_page_table_lock; |
2555 | } |
2556 | entry = pte_mkdirty(entry); |
2557 | } |
2558 | entry = pte_mkyoung(entry); |
2559 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, |
2560 | flags & FAULT_FLAG_WRITE)) |
2561 | update_mmu_cache(vma, address, ptep); |
2562 | |
2563 | out_page_table_lock: |
2564 | spin_unlock(&mm->page_table_lock); |
2565 | |
2566 | if (pagecache_page) { |
2567 | unlock_page(pagecache_page); |
2568 | put_page(pagecache_page); |
2569 | } |
2570 | |
2571 | out_mutex: |
2572 | mutex_unlock(&hugetlb_instantiation_mutex); |
2573 | |
2574 | return ret; |
2575 | } |
2576 | |
2577 | /* Can be overriden by architectures */ |
2578 | __attribute__((weak)) struct page * |
2579 | follow_huge_pud(struct mm_struct *mm, unsigned long address, |
2580 | pud_t *pud, int write) |
2581 | { |
2582 | BUG(); |
2583 | return NULL; |
2584 | } |
2585 | |
2586 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
2587 | struct page **pages, struct vm_area_struct **vmas, |
2588 | unsigned long *position, int *length, int i, |
2589 | unsigned int flags) |
2590 | { |
2591 | unsigned long pfn_offset; |
2592 | unsigned long vaddr = *position; |
2593 | int remainder = *length; |
2594 | struct hstate *h = hstate_vma(vma); |
2595 | |
2596 | spin_lock(&mm->page_table_lock); |
2597 | while (vaddr < vma->vm_end && remainder) { |
2598 | pte_t *pte; |
2599 | int absent; |
2600 | struct page *page; |
2601 | |
2602 | /* |
2603 | * Some archs (sparc64, sh*) have multiple pte_ts to |
2604 | * each hugepage. We have to make sure we get the |
2605 | * first, for the page indexing below to work. |
2606 | */ |
2607 | pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); |
2608 | absent = !pte || huge_pte_none(huge_ptep_get(pte)); |
2609 | |
2610 | /* |
2611 | * When coredumping, it suits get_dump_page if we just return |
2612 | * an error where there's an empty slot with no huge pagecache |
2613 | * to back it. This way, we avoid allocating a hugepage, and |
2614 | * the sparse dumpfile avoids allocating disk blocks, but its |
2615 | * huge holes still show up with zeroes where they need to be. |
2616 | */ |
2617 | if (absent && (flags & FOLL_DUMP) && |
2618 | !hugetlbfs_pagecache_present(h, vma, vaddr)) { |
2619 | remainder = 0; |
2620 | break; |
2621 | } |
2622 | |
2623 | if (absent || |
2624 | ((flags & FOLL_WRITE) && !pte_write(huge_ptep_get(pte)))) { |
2625 | int ret; |
2626 | |
2627 | spin_unlock(&mm->page_table_lock); |
2628 | ret = hugetlb_fault(mm, vma, vaddr, |
2629 | (flags & FOLL_WRITE) ? FAULT_FLAG_WRITE : 0); |
2630 | spin_lock(&mm->page_table_lock); |
2631 | if (!(ret & VM_FAULT_ERROR)) |
2632 | continue; |
2633 | |
2634 | remainder = 0; |
2635 | break; |
2636 | } |
2637 | |
2638 | pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; |
2639 | page = pte_page(huge_ptep_get(pte)); |
2640 | same_page: |
2641 | if (pages) { |
2642 | pages[i] = mem_map_offset(page, pfn_offset); |
2643 | get_page(pages[i]); |
2644 | } |
2645 | |
2646 | if (vmas) |
2647 | vmas[i] = vma; |
2648 | |
2649 | vaddr += PAGE_SIZE; |
2650 | ++pfn_offset; |
2651 | --remainder; |
2652 | ++i; |
2653 | if (vaddr < vma->vm_end && remainder && |
2654 | pfn_offset < pages_per_huge_page(h)) { |
2655 | /* |
2656 | * We use pfn_offset to avoid touching the pageframes |
2657 | * of this compound page. |
2658 | */ |
2659 | goto same_page; |
2660 | } |
2661 | } |
2662 | spin_unlock(&mm->page_table_lock); |
2663 | *length = remainder; |
2664 | *position = vaddr; |
2665 | |
2666 | return i ? i : -EFAULT; |
2667 | } |
2668 | |
2669 | void hugetlb_change_protection(struct vm_area_struct *vma, |
2670 | unsigned long address, unsigned long end, pgprot_t newprot) |
2671 | { |
2672 | struct mm_struct *mm = vma->vm_mm; |
2673 | unsigned long start = address; |
2674 | pte_t *ptep; |
2675 | pte_t pte; |
2676 | struct hstate *h = hstate_vma(vma); |
2677 | |
2678 | BUG_ON(address >= end); |
2679 | flush_cache_range(vma, address, end); |
2680 | |
2681 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
2682 | spin_lock(&mm->page_table_lock); |
2683 | for (; address < end; address += huge_page_size(h)) { |
2684 | ptep = huge_pte_offset(mm, address); |
2685 | if (!ptep) |
2686 | continue; |
2687 | if (huge_pmd_unshare(mm, &address, ptep)) |
2688 | continue; |
2689 | if (!huge_pte_none(huge_ptep_get(ptep))) { |
2690 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
2691 | pte = pte_mkhuge(pte_modify(pte, newprot)); |
2692 | set_huge_pte_at(mm, address, ptep, pte); |
2693 | } |
2694 | } |
2695 | spin_unlock(&mm->page_table_lock); |
2696 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
2697 | |
2698 | flush_tlb_range(vma, start, end); |
2699 | } |
2700 | |
2701 | int hugetlb_reserve_pages(struct inode *inode, |
2702 | long from, long to, |
2703 | struct vm_area_struct *vma, |
2704 | int acctflag) |
2705 | { |
2706 | long ret, chg; |
2707 | struct hstate *h = hstate_inode(inode); |
2708 | |
2709 | /* |
2710 | * Only apply hugepage reservation if asked. At fault time, an |
2711 | * attempt will be made for VM_NORESERVE to allocate a page |
2712 | * and filesystem quota without using reserves |
2713 | */ |
2714 | if (acctflag & VM_NORESERVE) |
2715 | return 0; |
2716 | |
2717 | /* |
2718 | * Shared mappings base their reservation on the number of pages that |
2719 | * are already allocated on behalf of the file. Private mappings need |
2720 | * to reserve the full area even if read-only as mprotect() may be |
2721 | * called to make the mapping read-write. Assume !vma is a shm mapping |
2722 | */ |
2723 | if (!vma || vma->vm_flags & VM_MAYSHARE) |
2724 | chg = region_chg(&inode->i_mapping->private_list, from, to); |
2725 | else { |
2726 | struct resv_map *resv_map = resv_map_alloc(); |
2727 | if (!resv_map) |
2728 | return -ENOMEM; |
2729 | |
2730 | chg = to - from; |
2731 | |
2732 | set_vma_resv_map(vma, resv_map); |
2733 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); |
2734 | } |
2735 | |
2736 | if (chg < 0) |
2737 | return chg; |
2738 | |
2739 | /* There must be enough filesystem quota for the mapping */ |
2740 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
2741 | return -ENOSPC; |
2742 | |
2743 | /* |
2744 | * Check enough hugepages are available for the reservation. |
2745 | * Hand back the quota if there are not |
2746 | */ |
2747 | ret = hugetlb_acct_memory(h, chg); |
2748 | if (ret < 0) { |
2749 | hugetlb_put_quota(inode->i_mapping, chg); |
2750 | return ret; |
2751 | } |
2752 | |
2753 | /* |
2754 | * Account for the reservations made. Shared mappings record regions |
2755 | * that have reservations as they are shared by multiple VMAs. |
2756 | * When the last VMA disappears, the region map says how much |
2757 | * the reservation was and the page cache tells how much of |
2758 | * the reservation was consumed. Private mappings are per-VMA and |
2759 | * only the consumed reservations are tracked. When the VMA |
2760 | * disappears, the original reservation is the VMA size and the |
2761 | * consumed reservations are stored in the map. Hence, nothing |
2762 | * else has to be done for private mappings here |
2763 | */ |
2764 | if (!vma || vma->vm_flags & VM_MAYSHARE) |
2765 | region_add(&inode->i_mapping->private_list, from, to); |
2766 | return 0; |
2767 | } |
2768 | |
2769 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) |
2770 | { |
2771 | struct hstate *h = hstate_inode(inode); |
2772 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
2773 | |
2774 | spin_lock(&inode->i_lock); |
2775 | inode->i_blocks -= (blocks_per_huge_page(h) * freed); |
2776 | spin_unlock(&inode->i_lock); |
2777 | |
2778 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
2779 | hugetlb_acct_memory(h, -(chg - freed)); |
2780 | } |
2781 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9