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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Generic hugetlb support. | |
3 | * (C) William Irwin, April 2004 | |
4 | */ | |
5 | #include <linux/gfp.h> | |
6 | #include <linux/list.h> | |
7 | #include <linux/init.h> | |
8 | #include <linux/module.h> | |
9 | #include <linux/mm.h> | |
e1759c21 | 10 | #include <linux/seq_file.h> |
1da177e4 LT |
11 | #include <linux/sysctl.h> |
12 | #include <linux/highmem.h> | |
cddb8a5c | 13 | #include <linux/mmu_notifier.h> |
1da177e4 | 14 | #include <linux/nodemask.h> |
63551ae0 | 15 | #include <linux/pagemap.h> |
5da7ca86 | 16 | #include <linux/mempolicy.h> |
aea47ff3 | 17 | #include <linux/cpuset.h> |
3935baa9 | 18 | #include <linux/mutex.h> |
aa888a74 | 19 | #include <linux/bootmem.h> |
a3437870 | 20 | #include <linux/sysfs.h> |
d6606683 | 21 | |
63551ae0 DG |
22 | #include <asm/page.h> |
23 | #include <asm/pgtable.h> | |
78a34ae2 | 24 | #include <asm/io.h> |
63551ae0 DG |
25 | |
26 | #include <linux/hugetlb.h> | |
9a305230 | 27 | #include <linux/node.h> |
7835e98b | 28 | #include "internal.h" |
1da177e4 LT |
29 | |
30 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; | |
396faf03 MG |
31 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
32 | unsigned long hugepages_treat_as_movable; | |
a5516438 | 33 | |
e5ff2159 AK |
34 | static int max_hstate; |
35 | unsigned int default_hstate_idx; | |
36 | struct hstate hstates[HUGE_MAX_HSTATE]; | |
37 | ||
53ba51d2 JT |
38 | __initdata LIST_HEAD(huge_boot_pages); |
39 | ||
e5ff2159 AK |
40 | /* for command line parsing */ |
41 | static struct hstate * __initdata parsed_hstate; | |
42 | static unsigned long __initdata default_hstate_max_huge_pages; | |
e11bfbfc | 43 | static unsigned long __initdata default_hstate_size; |
e5ff2159 AK |
44 | |
45 | #define for_each_hstate(h) \ | |
46 | for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++) | |
396faf03 | 47 | |
3935baa9 DG |
48 | /* |
49 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages | |
50 | */ | |
51 | static DEFINE_SPINLOCK(hugetlb_lock); | |
0bd0f9fb | 52 | |
96822904 AW |
53 | /* |
54 | * Region tracking -- allows tracking of reservations and instantiated pages | |
55 | * across the pages in a mapping. | |
84afd99b AW |
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); | |
96822904 AW |
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 | ||
84afd99b AW |
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 | ||
e7c4b0bf AW |
212 | /* |
213 | * Convert the address within this vma to the page offset within | |
214 | * the mapping, in pagecache page units; huge pages here. | |
215 | */ | |
a5516438 AK |
216 | static pgoff_t vma_hugecache_offset(struct hstate *h, |
217 | struct vm_area_struct *vma, unsigned long address) | |
e7c4b0bf | 218 | { |
a5516438 AK |
219 | return ((address - vma->vm_start) >> huge_page_shift(h)) + |
220 | (vma->vm_pgoff >> huge_page_order(h)); | |
e7c4b0bf AW |
221 | } |
222 | ||
08fba699 MG |
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 | } | |
f340ca0f | 238 | EXPORT_SYMBOL_GPL(vma_kernel_pagesize); |
08fba699 | 239 | |
3340289d MG |
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 | ||
84afd99b AW |
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) | |
04f2cbe3 | 260 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) |
84afd99b | 261 | |
a1e78772 MG |
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. | |
84afd99b AW |
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. | |
a1e78772 | 280 | */ |
e7c4b0bf AW |
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 | ||
84afd99b AW |
292 | struct resv_map { |
293 | struct kref refs; | |
294 | struct list_head regions; | |
295 | }; | |
296 | ||
2a4b3ded | 297 | static struct resv_map *resv_map_alloc(void) |
84afd99b AW |
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 | ||
2a4b3ded | 309 | static void resv_map_release(struct kref *ref) |
84afd99b AW |
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) | |
a1e78772 MG |
319 | { |
320 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
f83a275d | 321 | if (!(vma->vm_flags & VM_MAYSHARE)) |
84afd99b AW |
322 | return (struct resv_map *)(get_vma_private_data(vma) & |
323 | ~HPAGE_RESV_MASK); | |
2a4b3ded | 324 | return NULL; |
a1e78772 MG |
325 | } |
326 | ||
84afd99b | 327 | static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) |
a1e78772 MG |
328 | { |
329 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
f83a275d | 330 | VM_BUG_ON(vma->vm_flags & VM_MAYSHARE); |
a1e78772 | 331 | |
84afd99b AW |
332 | set_vma_private_data(vma, (get_vma_private_data(vma) & |
333 | HPAGE_RESV_MASK) | (unsigned long)map); | |
04f2cbe3 MG |
334 | } |
335 | ||
336 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) | |
337 | { | |
04f2cbe3 | 338 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
f83a275d | 339 | VM_BUG_ON(vma->vm_flags & VM_MAYSHARE); |
e7c4b0bf AW |
340 | |
341 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); | |
04f2cbe3 MG |
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)); | |
e7c4b0bf AW |
347 | |
348 | return (get_vma_private_data(vma) & flag) != 0; | |
a1e78772 MG |
349 | } |
350 | ||
351 | /* Decrement the reserved pages in the hugepage pool by one */ | |
a5516438 AK |
352 | static void decrement_hugepage_resv_vma(struct hstate *h, |
353 | struct vm_area_struct *vma) | |
a1e78772 | 354 | { |
c37f9fb1 AW |
355 | if (vma->vm_flags & VM_NORESERVE) |
356 | return; | |
357 | ||
f83a275d | 358 | if (vma->vm_flags & VM_MAYSHARE) { |
a1e78772 | 359 | /* Shared mappings always use reserves */ |
a5516438 | 360 | h->resv_huge_pages--; |
84afd99b | 361 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
a1e78772 MG |
362 | /* |
363 | * Only the process that called mmap() has reserves for | |
364 | * private mappings. | |
365 | */ | |
a5516438 | 366 | h->resv_huge_pages--; |
a1e78772 MG |
367 | } |
368 | } | |
369 | ||
04f2cbe3 | 370 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
a1e78772 MG |
371 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
372 | { | |
373 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
f83a275d | 374 | if (!(vma->vm_flags & VM_MAYSHARE)) |
a1e78772 MG |
375 | vma->vm_private_data = (void *)0; |
376 | } | |
377 | ||
378 | /* Returns true if the VMA has associated reserve pages */ | |
7f09ca51 | 379 | static int vma_has_reserves(struct vm_area_struct *vma) |
a1e78772 | 380 | { |
f83a275d | 381 | if (vma->vm_flags & VM_MAYSHARE) |
7f09ca51 MG |
382 | return 1; |
383 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) | |
384 | return 1; | |
385 | return 0; | |
a1e78772 MG |
386 | } |
387 | ||
69d177c2 AW |
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 | } | |
a5516438 AK |
400 | static void clear_huge_page(struct page *page, |
401 | unsigned long addr, unsigned long sz) | |
79ac6ba4 DG |
402 | { |
403 | int i; | |
404 | ||
74dbdd23 | 405 | if (unlikely(sz/PAGE_SIZE > MAX_ORDER_NR_PAGES)) { |
ebdd4aea HE |
406 | clear_gigantic_page(page, addr, sz); |
407 | return; | |
408 | } | |
69d177c2 | 409 | |
79ac6ba4 | 410 | might_sleep(); |
a5516438 | 411 | for (i = 0; i < sz/PAGE_SIZE; i++) { |
79ac6ba4 | 412 | cond_resched(); |
281e0e3b | 413 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
79ac6ba4 DG |
414 | } |
415 | } | |
416 | ||
69d177c2 AW |
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 | } | |
79ac6ba4 | 434 | static void copy_huge_page(struct page *dst, struct page *src, |
9de455b2 | 435 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
436 | { |
437 | int i; | |
a5516438 | 438 | struct hstate *h = hstate_vma(vma); |
79ac6ba4 | 439 | |
ebdd4aea HE |
440 | if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) { |
441 | copy_gigantic_page(dst, src, addr, vma); | |
442 | return; | |
443 | } | |
69d177c2 | 444 | |
79ac6ba4 | 445 | might_sleep(); |
a5516438 | 446 | for (i = 0; i < pages_per_huge_page(h); i++) { |
79ac6ba4 | 447 | cond_resched(); |
9de455b2 | 448 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
449 | } |
450 | } | |
451 | ||
a5516438 | 452 | static void enqueue_huge_page(struct hstate *h, struct page *page) |
1da177e4 LT |
453 | { |
454 | int nid = page_to_nid(page); | |
a5516438 AK |
455 | list_add(&page->lru, &h->hugepage_freelists[nid]); |
456 | h->free_huge_pages++; | |
457 | h->free_huge_pages_node[nid]++; | |
1da177e4 LT |
458 | } |
459 | ||
a5516438 AK |
460 | static struct page *dequeue_huge_page_vma(struct hstate *h, |
461 | struct vm_area_struct *vma, | |
04f2cbe3 | 462 | unsigned long address, int avoid_reserve) |
1da177e4 | 463 | { |
31a5c6e4 | 464 | int nid; |
1da177e4 | 465 | struct page *page = NULL; |
480eccf9 | 466 | struct mempolicy *mpol; |
19770b32 | 467 | nodemask_t *nodemask; |
396faf03 | 468 | struct zonelist *zonelist = huge_zonelist(vma, address, |
19770b32 | 469 | htlb_alloc_mask, &mpol, &nodemask); |
dd1a239f MG |
470 | struct zone *zone; |
471 | struct zoneref *z; | |
1da177e4 | 472 | |
a1e78772 MG |
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 | */ | |
7f09ca51 | 478 | if (!vma_has_reserves(vma) && |
a5516438 | 479 | h->free_huge_pages - h->resv_huge_pages == 0) |
a1e78772 MG |
480 | return NULL; |
481 | ||
04f2cbe3 | 482 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
a5516438 | 483 | if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) |
04f2cbe3 MG |
484 | return NULL; |
485 | ||
19770b32 MG |
486 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
487 | MAX_NR_ZONES - 1, nodemask) { | |
54a6eb5c MG |
488 | nid = zone_to_nid(zone); |
489 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && | |
a5516438 AK |
490 | !list_empty(&h->hugepage_freelists[nid])) { |
491 | page = list_entry(h->hugepage_freelists[nid].next, | |
3abf7afd AM |
492 | struct page, lru); |
493 | list_del(&page->lru); | |
a5516438 AK |
494 | h->free_huge_pages--; |
495 | h->free_huge_pages_node[nid]--; | |
04f2cbe3 MG |
496 | |
497 | if (!avoid_reserve) | |
a5516438 | 498 | decrement_hugepage_resv_vma(h, vma); |
a1e78772 | 499 | |
5ab3ee7b | 500 | break; |
3abf7afd | 501 | } |
1da177e4 | 502 | } |
52cd3b07 | 503 | mpol_cond_put(mpol); |
1da177e4 LT |
504 | return page; |
505 | } | |
506 | ||
a5516438 | 507 | static void update_and_free_page(struct hstate *h, struct page *page) |
6af2acb6 AL |
508 | { |
509 | int i; | |
a5516438 | 510 | |
18229df5 AW |
511 | VM_BUG_ON(h->order >= MAX_ORDER); |
512 | ||
a5516438 AK |
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++) { | |
6af2acb6 AL |
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); | |
7f2e9525 | 522 | arch_release_hugepage(page); |
a5516438 | 523 | __free_pages(page, huge_page_order(h)); |
6af2acb6 AL |
524 | } |
525 | ||
e5ff2159 AK |
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 | ||
27a85ef1 DG |
537 | static void free_huge_page(struct page *page) |
538 | { | |
a5516438 AK |
539 | /* |
540 | * Can't pass hstate in here because it is called from the | |
541 | * compound page destructor. | |
542 | */ | |
e5ff2159 | 543 | struct hstate *h = page_hstate(page); |
7893d1d5 | 544 | int nid = page_to_nid(page); |
c79fb75e | 545 | struct address_space *mapping; |
27a85ef1 | 546 | |
c79fb75e | 547 | mapping = (struct address_space *) page_private(page); |
e5df70ab | 548 | set_page_private(page, 0); |
7893d1d5 | 549 | BUG_ON(page_count(page)); |
27a85ef1 DG |
550 | INIT_LIST_HEAD(&page->lru); |
551 | ||
552 | spin_lock(&hugetlb_lock); | |
aa888a74 | 553 | if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) { |
a5516438 AK |
554 | update_and_free_page(h, page); |
555 | h->surplus_huge_pages--; | |
556 | h->surplus_huge_pages_node[nid]--; | |
7893d1d5 | 557 | } else { |
a5516438 | 558 | enqueue_huge_page(h, page); |
7893d1d5 | 559 | } |
27a85ef1 | 560 | spin_unlock(&hugetlb_lock); |
c79fb75e | 561 | if (mapping) |
9a119c05 | 562 | hugetlb_put_quota(mapping, 1); |
27a85ef1 DG |
563 | } |
564 | ||
a5516438 | 565 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) |
b7ba30c6 AK |
566 | { |
567 | set_compound_page_dtor(page, free_huge_page); | |
568 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
569 | h->nr_huge_pages++; |
570 | h->nr_huge_pages_node[nid]++; | |
b7ba30c6 AK |
571 | spin_unlock(&hugetlb_lock); |
572 | put_page(page); /* free it into the hugepage allocator */ | |
573 | } | |
574 | ||
20a0307c WF |
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 | ||
a5516438 | 603 | static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) |
1da177e4 | 604 | { |
1da177e4 | 605 | struct page *page; |
f96efd58 | 606 | |
aa888a74 AK |
607 | if (h->order >= MAX_ORDER) |
608 | return NULL; | |
609 | ||
6484eb3e | 610 | page = alloc_pages_exact_node(nid, |
551883ae NA |
611 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| |
612 | __GFP_REPEAT|__GFP_NOWARN, | |
a5516438 | 613 | huge_page_order(h)); |
1da177e4 | 614 | if (page) { |
7f2e9525 | 615 | if (arch_prepare_hugepage(page)) { |
caff3a2c | 616 | __free_pages(page, huge_page_order(h)); |
7b8ee84d | 617 | return NULL; |
7f2e9525 | 618 | } |
a5516438 | 619 | prep_new_huge_page(h, page, nid); |
1da177e4 | 620 | } |
63b4613c NA |
621 | |
622 | return page; | |
623 | } | |
624 | ||
9a76db09 | 625 | /* |
6ae11b27 LS |
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. | |
9a76db09 | 631 | */ |
6ae11b27 | 632 | static int next_node_allowed(int nid, nodemask_t *nodes_allowed) |
9a76db09 | 633 | { |
6ae11b27 | 634 | nid = next_node(nid, *nodes_allowed); |
9a76db09 | 635 | if (nid == MAX_NUMNODES) |
6ae11b27 | 636 | nid = first_node(*nodes_allowed); |
9a76db09 LS |
637 | VM_BUG_ON(nid >= MAX_NUMNODES); |
638 | ||
639 | return nid; | |
640 | } | |
641 | ||
6ae11b27 LS |
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 | ||
5ced66c9 | 649 | /* |
6ae11b27 LS |
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. | |
5ced66c9 | 654 | */ |
6ae11b27 LS |
655 | static int hstate_next_node_to_alloc(struct hstate *h, |
656 | nodemask_t *nodes_allowed) | |
5ced66c9 | 657 | { |
6ae11b27 LS |
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); | |
9a76db09 | 664 | |
9a76db09 | 665 | return nid; |
5ced66c9 AK |
666 | } |
667 | ||
6ae11b27 | 668 | static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed) |
63b4613c NA |
669 | { |
670 | struct page *page; | |
671 | int start_nid; | |
672 | int next_nid; | |
673 | int ret = 0; | |
674 | ||
6ae11b27 | 675 | start_nid = hstate_next_node_to_alloc(h, nodes_allowed); |
e8c5c824 | 676 | next_nid = start_nid; |
63b4613c NA |
677 | |
678 | do { | |
e8c5c824 | 679 | page = alloc_fresh_huge_page_node(h, next_nid); |
9a76db09 | 680 | if (page) { |
63b4613c | 681 | ret = 1; |
9a76db09 LS |
682 | break; |
683 | } | |
6ae11b27 | 684 | next_nid = hstate_next_node_to_alloc(h, nodes_allowed); |
9a76db09 | 685 | } while (next_nid != start_nid); |
63b4613c | 686 | |
3b116300 AL |
687 | if (ret) |
688 | count_vm_event(HTLB_BUDDY_PGALLOC); | |
689 | else | |
690 | count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); | |
691 | ||
63b4613c | 692 | return ret; |
1da177e4 LT |
693 | } |
694 | ||
e8c5c824 | 695 | /* |
6ae11b27 LS |
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. | |
e8c5c824 | 700 | */ |
6ae11b27 | 701 | static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) |
e8c5c824 | 702 | { |
6ae11b27 LS |
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); | |
9a76db09 | 709 | |
9a76db09 | 710 | return nid; |
e8c5c824 LS |
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 | */ | |
6ae11b27 LS |
719 | static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed, |
720 | bool acct_surplus) | |
e8c5c824 LS |
721 | { |
722 | int start_nid; | |
723 | int next_nid; | |
724 | int ret = 0; | |
725 | ||
6ae11b27 | 726 | start_nid = hstate_next_node_to_free(h, nodes_allowed); |
e8c5c824 LS |
727 | next_nid = start_nid; |
728 | ||
729 | do { | |
685f3457 LS |
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])) { | |
e8c5c824 LS |
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]--; | |
685f3457 LS |
742 | if (acct_surplus) { |
743 | h->surplus_huge_pages--; | |
744 | h->surplus_huge_pages_node[next_nid]--; | |
745 | } | |
e8c5c824 LS |
746 | update_and_free_page(h, page); |
747 | ret = 1; | |
9a76db09 | 748 | break; |
e8c5c824 | 749 | } |
6ae11b27 | 750 | next_nid = hstate_next_node_to_free(h, nodes_allowed); |
9a76db09 | 751 | } while (next_nid != start_nid); |
e8c5c824 LS |
752 | |
753 | return ret; | |
754 | } | |
755 | ||
a5516438 AK |
756 | static struct page *alloc_buddy_huge_page(struct hstate *h, |
757 | struct vm_area_struct *vma, unsigned long address) | |
7893d1d5 AL |
758 | { |
759 | struct page *page; | |
d1c3fb1f | 760 | unsigned int nid; |
7893d1d5 | 761 | |
aa888a74 AK |
762 | if (h->order >= MAX_ORDER) |
763 | return NULL; | |
764 | ||
d1c3fb1f NA |
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); | |
a5516438 | 789 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { |
d1c3fb1f NA |
790 | spin_unlock(&hugetlb_lock); |
791 | return NULL; | |
792 | } else { | |
a5516438 AK |
793 | h->nr_huge_pages++; |
794 | h->surplus_huge_pages++; | |
d1c3fb1f NA |
795 | } |
796 | spin_unlock(&hugetlb_lock); | |
797 | ||
551883ae NA |
798 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP| |
799 | __GFP_REPEAT|__GFP_NOWARN, | |
a5516438 | 800 | huge_page_order(h)); |
d1c3fb1f | 801 | |
caff3a2c GS |
802 | if (page && arch_prepare_hugepage(page)) { |
803 | __free_pages(page, huge_page_order(h)); | |
804 | return NULL; | |
805 | } | |
806 | ||
d1c3fb1f | 807 | spin_lock(&hugetlb_lock); |
7893d1d5 | 808 | if (page) { |
2668db91 AL |
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)); | |
d1c3fb1f | 815 | nid = page_to_nid(page); |
7893d1d5 | 816 | set_compound_page_dtor(page, free_huge_page); |
d1c3fb1f NA |
817 | /* |
818 | * We incremented the global counters already | |
819 | */ | |
a5516438 AK |
820 | h->nr_huge_pages_node[nid]++; |
821 | h->surplus_huge_pages_node[nid]++; | |
3b116300 | 822 | __count_vm_event(HTLB_BUDDY_PGALLOC); |
d1c3fb1f | 823 | } else { |
a5516438 AK |
824 | h->nr_huge_pages--; |
825 | h->surplus_huge_pages--; | |
3b116300 | 826 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
7893d1d5 | 827 | } |
d1c3fb1f | 828 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
829 | |
830 | return page; | |
831 | } | |
832 | ||
e4e574b7 AL |
833 | /* |
834 | * Increase the hugetlb pool such that it can accomodate a reservation | |
835 | * of size 'delta'. | |
836 | */ | |
a5516438 | 837 | static int gather_surplus_pages(struct hstate *h, int delta) |
e4e574b7 AL |
838 | { |
839 | struct list_head surplus_list; | |
840 | struct page *page, *tmp; | |
841 | int ret, i; | |
842 | int needed, allocated; | |
843 | ||
a5516438 | 844 | needed = (h->resv_huge_pages + delta) - h->free_huge_pages; |
ac09b3a1 | 845 | if (needed <= 0) { |
a5516438 | 846 | h->resv_huge_pages += delta; |
e4e574b7 | 847 | return 0; |
ac09b3a1 | 848 | } |
e4e574b7 AL |
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++) { | |
a5516438 | 857 | page = alloc_buddy_huge_page(h, NULL, 0); |
e4e574b7 AL |
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); | |
a5516438 AK |
878 | needed = (h->resv_huge_pages + delta) - |
879 | (h->free_huge_pages + allocated); | |
e4e574b7 AL |
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 | |
ac09b3a1 AL |
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. | |
e4e574b7 AL |
890 | */ |
891 | needed += allocated; | |
a5516438 | 892 | h->resv_huge_pages += delta; |
e4e574b7 AL |
893 | ret = 0; |
894 | free: | |
19fc3f0a | 895 | /* Free the needed pages to the hugetlb pool */ |
e4e574b7 | 896 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
19fc3f0a AL |
897 | if ((--needed) < 0) |
898 | break; | |
e4e574b7 | 899 | list_del(&page->lru); |
a5516438 | 900 | enqueue_huge_page(h, page); |
19fc3f0a AL |
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); | |
af767cbd | 908 | /* |
2668db91 AL |
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 | |
af767cbd AL |
912 | * unlocked which is safe because free_huge_page takes |
913 | * hugetlb_lock before deciding how to free the page. | |
914 | */ | |
2668db91 | 915 | free_huge_page(page); |
af767cbd | 916 | } |
19fc3f0a | 917 | spin_lock(&hugetlb_lock); |
e4e574b7 AL |
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. | |
685f3457 | 927 | * Called with hugetlb_lock held. |
e4e574b7 | 928 | */ |
a5516438 AK |
929 | static void return_unused_surplus_pages(struct hstate *h, |
930 | unsigned long unused_resv_pages) | |
e4e574b7 | 931 | { |
e4e574b7 AL |
932 | unsigned long nr_pages; |
933 | ||
ac09b3a1 | 934 | /* Uncommit the reservation */ |
a5516438 | 935 | h->resv_huge_pages -= unused_resv_pages; |
ac09b3a1 | 936 | |
aa888a74 AK |
937 | /* Cannot return gigantic pages currently */ |
938 | if (h->order >= MAX_ORDER) | |
939 | return; | |
940 | ||
a5516438 | 941 | nr_pages = min(unused_resv_pages, h->surplus_huge_pages); |
e4e574b7 | 942 | |
685f3457 LS |
943 | /* |
944 | * We want to release as many surplus pages as possible, spread | |
9b5e5d0f LS |
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. | |
685f3457 LS |
950 | */ |
951 | while (nr_pages--) { | |
9b5e5d0f | 952 | if (!free_pool_huge_page(h, &node_states[N_HIGH_MEMORY], 1)) |
685f3457 | 953 | break; |
e4e574b7 AL |
954 | } |
955 | } | |
956 | ||
c37f9fb1 AW |
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 | */ | |
e2f17d94 | 966 | static long vma_needs_reservation(struct hstate *h, |
a5516438 | 967 | struct vm_area_struct *vma, unsigned long addr) |
c37f9fb1 AW |
968 | { |
969 | struct address_space *mapping = vma->vm_file->f_mapping; | |
970 | struct inode *inode = mapping->host; | |
971 | ||
f83a275d | 972 | if (vma->vm_flags & VM_MAYSHARE) { |
a5516438 | 973 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 AW |
974 | return region_chg(&inode->i_mapping->private_list, |
975 | idx, idx + 1); | |
976 | ||
84afd99b AW |
977 | } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
978 | return 1; | |
c37f9fb1 | 979 | |
84afd99b | 980 | } else { |
e2f17d94 | 981 | long err; |
a5516438 | 982 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
84afd99b AW |
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 | } | |
c37f9fb1 | 990 | } |
a5516438 AK |
991 | static void vma_commit_reservation(struct hstate *h, |
992 | struct vm_area_struct *vma, unsigned long addr) | |
c37f9fb1 AW |
993 | { |
994 | struct address_space *mapping = vma->vm_file->f_mapping; | |
995 | struct inode *inode = mapping->host; | |
996 | ||
f83a275d | 997 | if (vma->vm_flags & VM_MAYSHARE) { |
a5516438 | 998 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 | 999 | region_add(&inode->i_mapping->private_list, idx, idx + 1); |
84afd99b AW |
1000 | |
1001 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { | |
a5516438 | 1002 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
84afd99b AW |
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); | |
c37f9fb1 AW |
1007 | } |
1008 | } | |
1009 | ||
a1e78772 | 1010 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
04f2cbe3 | 1011 | unsigned long addr, int avoid_reserve) |
1da177e4 | 1012 | { |
a5516438 | 1013 | struct hstate *h = hstate_vma(vma); |
348ea204 | 1014 | struct page *page; |
a1e78772 MG |
1015 | struct address_space *mapping = vma->vm_file->f_mapping; |
1016 | struct inode *inode = mapping->host; | |
e2f17d94 | 1017 | long chg; |
a1e78772 MG |
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 | |
c37f9fb1 AW |
1023 | * MAP_NORESERVE mappings may also need pages and quota allocated |
1024 | * if no reserve mapping overlaps. | |
a1e78772 | 1025 | */ |
a5516438 | 1026 | chg = vma_needs_reservation(h, vma, addr); |
c37f9fb1 AW |
1027 | if (chg < 0) |
1028 | return ERR_PTR(chg); | |
1029 | if (chg) | |
a1e78772 MG |
1030 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
1031 | return ERR_PTR(-ENOSPC); | |
1da177e4 LT |
1032 | |
1033 | spin_lock(&hugetlb_lock); | |
a5516438 | 1034 | page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve); |
1da177e4 | 1035 | spin_unlock(&hugetlb_lock); |
b45b5bd6 | 1036 | |
68842c9b | 1037 | if (!page) { |
a5516438 | 1038 | page = alloc_buddy_huge_page(h, vma, addr); |
68842c9b | 1039 | if (!page) { |
a1e78772 | 1040 | hugetlb_put_quota(inode->i_mapping, chg); |
68842c9b KC |
1041 | return ERR_PTR(-VM_FAULT_OOM); |
1042 | } | |
1043 | } | |
348ea204 | 1044 | |
a1e78772 MG |
1045 | set_page_refcounted(page); |
1046 | set_page_private(page, (unsigned long) mapping); | |
90d8b7e6 | 1047 | |
a5516438 | 1048 | vma_commit_reservation(h, vma, addr); |
c37f9fb1 | 1049 | |
90d8b7e6 | 1050 | return page; |
b45b5bd6 DG |
1051 | } |
1052 | ||
91f47662 | 1053 | int __weak alloc_bootmem_huge_page(struct hstate *h) |
aa888a74 AK |
1054 | { |
1055 | struct huge_bootmem_page *m; | |
9b5e5d0f | 1056 | int nr_nodes = nodes_weight(node_states[N_HIGH_MEMORY]); |
aa888a74 AK |
1057 | |
1058 | while (nr_nodes) { | |
1059 | void *addr; | |
1060 | ||
1061 | addr = __alloc_bootmem_node_nopanic( | |
6ae11b27 | 1062 | NODE_DATA(hstate_next_node_to_alloc(h, |
9b5e5d0f | 1063 | &node_states[N_HIGH_MEMORY])), |
aa888a74 AK |
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; | |
91f47662 | 1073 | goto found; |
aa888a74 | 1074 | } |
aa888a74 AK |
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 | ||
18229df5 AW |
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 | ||
aa888a74 AK |
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); | |
18229df5 | 1105 | prep_compound_huge_page(page, h->order); |
aa888a74 AK |
1106 | prep_new_huge_page(h, page, page_to_nid(page)); |
1107 | } | |
1108 | } | |
1109 | ||
8faa8b07 | 1110 | static void __init hugetlb_hstate_alloc_pages(struct hstate *h) |
1da177e4 LT |
1111 | { |
1112 | unsigned long i; | |
a5516438 | 1113 | |
e5ff2159 | 1114 | for (i = 0; i < h->max_huge_pages; ++i) { |
aa888a74 AK |
1115 | if (h->order >= MAX_ORDER) { |
1116 | if (!alloc_bootmem_huge_page(h)) | |
1117 | break; | |
9b5e5d0f LS |
1118 | } else if (!alloc_fresh_huge_page(h, |
1119 | &node_states[N_HIGH_MEMORY])) | |
1da177e4 | 1120 | break; |
1da177e4 | 1121 | } |
8faa8b07 | 1122 | h->max_huge_pages = i; |
e5ff2159 AK |
1123 | } |
1124 | ||
1125 | static void __init hugetlb_init_hstates(void) | |
1126 | { | |
1127 | struct hstate *h; | |
1128 | ||
1129 | for_each_hstate(h) { | |
8faa8b07 AK |
1130 | /* oversize hugepages were init'ed in early boot */ |
1131 | if (h->order < MAX_ORDER) | |
1132 | hugetlb_hstate_alloc_pages(h); | |
e5ff2159 AK |
1133 | } |
1134 | } | |
1135 | ||
4abd32db AK |
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 | ||
e5ff2159 AK |
1147 | static void __init report_hugepages(void) |
1148 | { | |
1149 | struct hstate *h; | |
1150 | ||
1151 | for_each_hstate(h) { | |
4abd32db AK |
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); | |
e5ff2159 AK |
1157 | } |
1158 | } | |
1159 | ||
1da177e4 | 1160 | #ifdef CONFIG_HIGHMEM |
6ae11b27 LS |
1161 | static void try_to_free_low(struct hstate *h, unsigned long count, |
1162 | nodemask_t *nodes_allowed) | |
1da177e4 | 1163 | { |
4415cc8d CL |
1164 | int i; |
1165 | ||
aa888a74 AK |
1166 | if (h->order >= MAX_ORDER) |
1167 | return; | |
1168 | ||
6ae11b27 | 1169 | for_each_node_mask(i, *nodes_allowed) { |
1da177e4 | 1170 | struct page *page, *next; |
a5516438 AK |
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) | |
6b0c880d | 1174 | return; |
1da177e4 LT |
1175 | if (PageHighMem(page)) |
1176 | continue; | |
1177 | list_del(&page->lru); | |
e5ff2159 | 1178 | update_and_free_page(h, page); |
a5516438 AK |
1179 | h->free_huge_pages--; |
1180 | h->free_huge_pages_node[page_to_nid(page)]--; | |
1da177e4 LT |
1181 | } |
1182 | } | |
1183 | } | |
1184 | #else | |
6ae11b27 LS |
1185 | static inline void try_to_free_low(struct hstate *h, unsigned long count, |
1186 | nodemask_t *nodes_allowed) | |
1da177e4 LT |
1187 | { |
1188 | } | |
1189 | #endif | |
1190 | ||
20a0307c WF |
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 | */ | |
6ae11b27 LS |
1196 | static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, |
1197 | int delta) | |
20a0307c | 1198 | { |
e8c5c824 | 1199 | int start_nid, next_nid; |
20a0307c WF |
1200 | int ret = 0; |
1201 | ||
1202 | VM_BUG_ON(delta != -1 && delta != 1); | |
20a0307c | 1203 | |
e8c5c824 | 1204 | if (delta < 0) |
6ae11b27 | 1205 | start_nid = hstate_next_node_to_alloc(h, nodes_allowed); |
e8c5c824 | 1206 | else |
6ae11b27 | 1207 | start_nid = hstate_next_node_to_free(h, nodes_allowed); |
e8c5c824 LS |
1208 | next_nid = start_nid; |
1209 | ||
1210 | do { | |
1211 | int nid = next_nid; | |
1212 | if (delta < 0) { | |
e8c5c824 LS |
1213 | /* |
1214 | * To shrink on this node, there must be a surplus page | |
1215 | */ | |
9a76db09 | 1216 | if (!h->surplus_huge_pages_node[nid]) { |
6ae11b27 LS |
1217 | next_nid = hstate_next_node_to_alloc(h, |
1218 | nodes_allowed); | |
e8c5c824 | 1219 | continue; |
9a76db09 | 1220 | } |
e8c5c824 LS |
1221 | } |
1222 | if (delta > 0) { | |
e8c5c824 LS |
1223 | /* |
1224 | * Surplus cannot exceed the total number of pages | |
1225 | */ | |
1226 | if (h->surplus_huge_pages_node[nid] >= | |
9a76db09 | 1227 | h->nr_huge_pages_node[nid]) { |
6ae11b27 LS |
1228 | next_nid = hstate_next_node_to_free(h, |
1229 | nodes_allowed); | |
e8c5c824 | 1230 | continue; |
9a76db09 | 1231 | } |
e8c5c824 | 1232 | } |
20a0307c WF |
1233 | |
1234 | h->surplus_huge_pages += delta; | |
1235 | h->surplus_huge_pages_node[nid] += delta; | |
1236 | ret = 1; | |
1237 | break; | |
e8c5c824 | 1238 | } while (next_nid != start_nid); |
20a0307c | 1239 | |
20a0307c WF |
1240 | return ret; |
1241 | } | |
1242 | ||
a5516438 | 1243 | #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) |
6ae11b27 LS |
1244 | static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count, |
1245 | nodemask_t *nodes_allowed) | |
1da177e4 | 1246 | { |
7893d1d5 | 1247 | unsigned long min_count, ret; |
1da177e4 | 1248 | |
aa888a74 AK |
1249 | if (h->order >= MAX_ORDER) |
1250 | return h->max_huge_pages; | |
1251 | ||
7893d1d5 AL |
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. | |
d1c3fb1f NA |
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. | |
7893d1d5 | 1262 | */ |
1da177e4 | 1263 | spin_lock(&hugetlb_lock); |
a5516438 | 1264 | while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { |
6ae11b27 | 1265 | if (!adjust_pool_surplus(h, nodes_allowed, -1)) |
7893d1d5 AL |
1266 | break; |
1267 | } | |
1268 | ||
a5516438 | 1269 | while (count > persistent_huge_pages(h)) { |
7893d1d5 AL |
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); | |
6ae11b27 | 1276 | ret = alloc_fresh_huge_page(h, nodes_allowed); |
7893d1d5 AL |
1277 | spin_lock(&hugetlb_lock); |
1278 | if (!ret) | |
1279 | goto out; | |
1280 | ||
536240f2 MG |
1281 | /* Bail for signals. Probably ctrl-c from user */ |
1282 | if (signal_pending(current)) | |
1283 | goto out; | |
7893d1d5 | 1284 | } |
7893d1d5 AL |
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. | |
d1c3fb1f NA |
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. | |
7893d1d5 | 1300 | */ |
a5516438 | 1301 | min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; |
6b0c880d | 1302 | min_count = max(count, min_count); |
6ae11b27 | 1303 | try_to_free_low(h, min_count, nodes_allowed); |
a5516438 | 1304 | while (min_count < persistent_huge_pages(h)) { |
6ae11b27 | 1305 | if (!free_pool_huge_page(h, nodes_allowed, 0)) |
1da177e4 | 1306 | break; |
1da177e4 | 1307 | } |
a5516438 | 1308 | while (count < persistent_huge_pages(h)) { |
6ae11b27 | 1309 | if (!adjust_pool_surplus(h, nodes_allowed, 1)) |
7893d1d5 AL |
1310 | break; |
1311 | } | |
1312 | out: | |
a5516438 | 1313 | ret = persistent_huge_pages(h); |
1da177e4 | 1314 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 1315 | return ret; |
1da177e4 LT |
1316 | } |
1317 | ||
a3437870 NA |
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 | ||
9a305230 LS |
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) | |
a3437870 NA |
1331 | { |
1332 | int i; | |
9a305230 | 1333 | |
a3437870 | 1334 | for (i = 0; i < HUGE_MAX_HSTATE; i++) |
9a305230 LS |
1335 | if (hstate_kobjs[i] == kobj) { |
1336 | if (nidp) | |
1337 | *nidp = NUMA_NO_NODE; | |
a3437870 | 1338 | return &hstates[i]; |
9a305230 LS |
1339 | } |
1340 | ||
1341 | return kobj_to_node_hstate(kobj, nidp); | |
a3437870 NA |
1342 | } |
1343 | ||
06808b08 | 1344 | static ssize_t nr_hugepages_show_common(struct kobject *kobj, |
a3437870 NA |
1345 | struct kobj_attribute *attr, char *buf) |
1346 | { | |
9a305230 LS |
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); | |
a3437870 | 1358 | } |
06808b08 LS |
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) | |
a3437870 NA |
1362 | { |
1363 | int err; | |
9a305230 | 1364 | int nid; |
06808b08 | 1365 | unsigned long count; |
9a305230 | 1366 | struct hstate *h; |
bad44b5b | 1367 | NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY); |
a3437870 | 1368 | |
06808b08 | 1369 | err = strict_strtoul(buf, 10, &count); |
a3437870 NA |
1370 | if (err) |
1371 | return 0; | |
1372 | ||
9a305230 LS |
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 | ||
06808b08 | 1393 | h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed); |
a3437870 | 1394 | |
9b5e5d0f | 1395 | if (nodes_allowed != &node_states[N_HIGH_MEMORY]) |
06808b08 LS |
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); | |
a3437870 NA |
1411 | } |
1412 | HSTATE_ATTR(nr_hugepages); | |
1413 | ||
06808b08 LS |
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 | ||
a3437870 NA |
1435 | static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, |
1436 | struct kobj_attribute *attr, char *buf) | |
1437 | { | |
9a305230 | 1438 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 NA |
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; | |
9a305230 | 1446 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 NA |
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 | { | |
9a305230 LS |
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); | |
a3437870 NA |
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 | { | |
9a305230 | 1480 | struct hstate *h = kobj_to_hstate(kobj, NULL); |
a3437870 NA |
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 | { | |
9a305230 LS |
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); | |
a3437870 NA |
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, | |
06808b08 LS |
1508 | #ifdef CONFIG_NUMA |
1509 | &nr_hugepages_mempolicy_attr.attr, | |
1510 | #endif | |
a3437870 NA |
1511 | NULL, |
1512 | }; | |
1513 | ||
1514 | static struct attribute_group hstate_attr_group = { | |
1515 | .attrs = hstate_attrs, | |
1516 | }; | |
1517 | ||
9a305230 LS |
1518 | static int __init hugetlb_sysfs_add_hstate(struct hstate *h, |
1519 | struct kobject *parent, | |
1520 | struct kobject **hstate_kobjs, | |
1521 | struct attribute_group *hstate_attr_group) | |
a3437870 NA |
1522 | { |
1523 | int retval; | |
9a305230 | 1524 | int hi = h - hstates; |
a3437870 | 1525 | |
9a305230 LS |
1526 | hstate_kobjs[hi] = kobject_create_and_add(h->name, parent); |
1527 | if (!hstate_kobjs[hi]) | |
a3437870 NA |
1528 | return -ENOMEM; |
1529 | ||
9a305230 | 1530 | retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); |
a3437870 | 1531 | if (retval) |
9a305230 | 1532 | kobject_put(hstate_kobjs[hi]); |
a3437870 NA |
1533 | |
1534 | return retval; | |
1535 | } | |
1536 | ||
1537 | static void __init hugetlb_sysfs_init(void) | |
1538 | { | |
1539 | struct hstate *h; | |
1540 | int err; | |
1541 | ||
1542 | hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); | |
1543 | if (!hugepages_kobj) | |
1544 | return; | |
1545 | ||
1546 | for_each_hstate(h) { | |
9a305230 LS |
1547 | err = hugetlb_sysfs_add_hstate(h, hugepages_kobj, |
1548 | hstate_kobjs, &hstate_attr_group); | |
a3437870 NA |
1549 | if (err) |
1550 | printk(KERN_ERR "Hugetlb: Unable to add hstate %s", | |
1551 | h->name); | |
1552 | } | |
1553 | } | |
1554 | ||
9a305230 LS |
1555 | #ifdef CONFIG_NUMA |
1556 | ||
1557 | /* | |
1558 | * node_hstate/s - associate per node hstate attributes, via their kobjects, | |
1559 | * with node sysdevs in node_devices[] using a parallel array. The array | |
1560 | * index of a node sysdev or _hstate == node id. | |
1561 | * This is here to avoid any static dependency of the node sysdev driver, in | |
1562 | * the base kernel, on the hugetlb module. | |
1563 | */ | |
1564 | struct node_hstate { | |
1565 | struct kobject *hugepages_kobj; | |
1566 | struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
1567 | }; | |
1568 | struct node_hstate node_hstates[MAX_NUMNODES]; | |
1569 | ||
1570 | /* | |
1571 | * A subset of global hstate attributes for node sysdevs | |
1572 | */ | |
1573 | static struct attribute *per_node_hstate_attrs[] = { | |
1574 | &nr_hugepages_attr.attr, | |
1575 | &free_hugepages_attr.attr, | |
1576 | &surplus_hugepages_attr.attr, | |
1577 | NULL, | |
1578 | }; | |
1579 | ||
1580 | static struct attribute_group per_node_hstate_attr_group = { | |
1581 | .attrs = per_node_hstate_attrs, | |
1582 | }; | |
1583 | ||
1584 | /* | |
1585 | * kobj_to_node_hstate - lookup global hstate for node sysdev hstate attr kobj. | |
1586 | * Returns node id via non-NULL nidp. | |
1587 | */ | |
1588 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) | |
1589 | { | |
1590 | int nid; | |
1591 | ||
1592 | for (nid = 0; nid < nr_node_ids; nid++) { | |
1593 | struct node_hstate *nhs = &node_hstates[nid]; | |
1594 | int i; | |
1595 | for (i = 0; i < HUGE_MAX_HSTATE; i++) | |
1596 | if (nhs->hstate_kobjs[i] == kobj) { | |
1597 | if (nidp) | |
1598 | *nidp = nid; | |
1599 | return &hstates[i]; | |
1600 | } | |
1601 | } | |
1602 | ||
1603 | BUG(); | |
1604 | return NULL; | |
1605 | } | |
1606 | ||
1607 | /* | |
1608 | * Unregister hstate attributes from a single node sysdev. | |
1609 | * No-op if no hstate attributes attached. | |
1610 | */ | |
1611 | void hugetlb_unregister_node(struct node *node) | |
1612 | { | |
1613 | struct hstate *h; | |
1614 | struct node_hstate *nhs = &node_hstates[node->sysdev.id]; | |
1615 | ||
1616 | if (!nhs->hugepages_kobj) | |
9b5e5d0f | 1617 | return; /* no hstate attributes */ |
9a305230 LS |
1618 | |
1619 | for_each_hstate(h) | |
1620 | if (nhs->hstate_kobjs[h - hstates]) { | |
1621 | kobject_put(nhs->hstate_kobjs[h - hstates]); | |
1622 | nhs->hstate_kobjs[h - hstates] = NULL; | |
1623 | } | |
1624 | ||
1625 | kobject_put(nhs->hugepages_kobj); | |
1626 | nhs->hugepages_kobj = NULL; | |
1627 | } | |
1628 | ||
1629 | /* | |
1630 | * hugetlb module exit: unregister hstate attributes from node sysdevs | |
1631 | * that have them. | |
1632 | */ | |
1633 | static void hugetlb_unregister_all_nodes(void) | |
1634 | { | |
1635 | int nid; | |
1636 | ||
1637 | /* | |
1638 | * disable node sysdev registrations. | |
1639 | */ | |
1640 | register_hugetlbfs_with_node(NULL, NULL); | |
1641 | ||
1642 | /* | |
1643 | * remove hstate attributes from any nodes that have them. | |
1644 | */ | |
1645 | for (nid = 0; nid < nr_node_ids; nid++) | |
1646 | hugetlb_unregister_node(&node_devices[nid]); | |
1647 | } | |
1648 | ||
1649 | /* | |
1650 | * Register hstate attributes for a single node sysdev. | |
1651 | * No-op if attributes already registered. | |
1652 | */ | |
1653 | void hugetlb_register_node(struct node *node) | |
1654 | { | |
1655 | struct hstate *h; | |
1656 | struct node_hstate *nhs = &node_hstates[node->sysdev.id]; | |
1657 | int err; | |
1658 | ||
1659 | if (nhs->hugepages_kobj) | |
1660 | return; /* already allocated */ | |
1661 | ||
1662 | nhs->hugepages_kobj = kobject_create_and_add("hugepages", | |
1663 | &node->sysdev.kobj); | |
1664 | if (!nhs->hugepages_kobj) | |
1665 | return; | |
1666 | ||
1667 | for_each_hstate(h) { | |
1668 | err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj, | |
1669 | nhs->hstate_kobjs, | |
1670 | &per_node_hstate_attr_group); | |
1671 | if (err) { | |
1672 | printk(KERN_ERR "Hugetlb: Unable to add hstate %s" | |
1673 | " for node %d\n", | |
1674 | h->name, node->sysdev.id); | |
1675 | hugetlb_unregister_node(node); | |
1676 | break; | |
1677 | } | |
1678 | } | |
1679 | } | |
1680 | ||
1681 | /* | |
9b5e5d0f LS |
1682 | * hugetlb init time: register hstate attributes for all registered node |
1683 | * sysdevs of nodes that have memory. All on-line nodes should have | |
1684 | * registered their associated sysdev by this time. | |
9a305230 LS |
1685 | */ |
1686 | static void hugetlb_register_all_nodes(void) | |
1687 | { | |
1688 | int nid; | |
1689 | ||
9b5e5d0f | 1690 | for_each_node_state(nid, N_HIGH_MEMORY) { |
9a305230 LS |
1691 | struct node *node = &node_devices[nid]; |
1692 | if (node->sysdev.id == nid) | |
1693 | hugetlb_register_node(node); | |
1694 | } | |
1695 | ||
1696 | /* | |
1697 | * Let the node sysdev driver know we're here so it can | |
1698 | * [un]register hstate attributes on node hotplug. | |
1699 | */ | |
1700 | register_hugetlbfs_with_node(hugetlb_register_node, | |
1701 | hugetlb_unregister_node); | |
1702 | } | |
1703 | #else /* !CONFIG_NUMA */ | |
1704 | ||
1705 | static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp) | |
1706 | { | |
1707 | BUG(); | |
1708 | if (nidp) | |
1709 | *nidp = -1; | |
1710 | return NULL; | |
1711 | } | |
1712 | ||
1713 | static void hugetlb_unregister_all_nodes(void) { } | |
1714 | ||
1715 | static void hugetlb_register_all_nodes(void) { } | |
1716 | ||
1717 | #endif | |
1718 | ||
a3437870 NA |
1719 | static void __exit hugetlb_exit(void) |
1720 | { | |
1721 | struct hstate *h; | |
1722 | ||
9a305230 LS |
1723 | hugetlb_unregister_all_nodes(); |
1724 | ||
a3437870 NA |
1725 | for_each_hstate(h) { |
1726 | kobject_put(hstate_kobjs[h - hstates]); | |
1727 | } | |
1728 | ||
1729 | kobject_put(hugepages_kobj); | |
1730 | } | |
1731 | module_exit(hugetlb_exit); | |
1732 | ||
1733 | static int __init hugetlb_init(void) | |
1734 | { | |
0ef89d25 BH |
1735 | /* Some platform decide whether they support huge pages at boot |
1736 | * time. On these, such as powerpc, HPAGE_SHIFT is set to 0 when | |
1737 | * there is no such support | |
1738 | */ | |
1739 | if (HPAGE_SHIFT == 0) | |
1740 | return 0; | |
a3437870 | 1741 | |
e11bfbfc NP |
1742 | if (!size_to_hstate(default_hstate_size)) { |
1743 | default_hstate_size = HPAGE_SIZE; | |
1744 | if (!size_to_hstate(default_hstate_size)) | |
1745 | hugetlb_add_hstate(HUGETLB_PAGE_ORDER); | |
a3437870 | 1746 | } |
e11bfbfc NP |
1747 | default_hstate_idx = size_to_hstate(default_hstate_size) - hstates; |
1748 | if (default_hstate_max_huge_pages) | |
1749 | default_hstate.max_huge_pages = default_hstate_max_huge_pages; | |
a3437870 NA |
1750 | |
1751 | hugetlb_init_hstates(); | |
1752 | ||
aa888a74 AK |
1753 | gather_bootmem_prealloc(); |
1754 | ||
a3437870 NA |
1755 | report_hugepages(); |
1756 | ||
1757 | hugetlb_sysfs_init(); | |
1758 | ||
9a305230 LS |
1759 | hugetlb_register_all_nodes(); |
1760 | ||
a3437870 NA |
1761 | return 0; |
1762 | } | |
1763 | module_init(hugetlb_init); | |
1764 | ||
1765 | /* Should be called on processing a hugepagesz=... option */ | |
1766 | void __init hugetlb_add_hstate(unsigned order) | |
1767 | { | |
1768 | struct hstate *h; | |
8faa8b07 AK |
1769 | unsigned long i; |
1770 | ||
a3437870 NA |
1771 | if (size_to_hstate(PAGE_SIZE << order)) { |
1772 | printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n"); | |
1773 | return; | |
1774 | } | |
1775 | BUG_ON(max_hstate >= HUGE_MAX_HSTATE); | |
1776 | BUG_ON(order == 0); | |
1777 | h = &hstates[max_hstate++]; | |
1778 | h->order = order; | |
1779 | h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); | |
8faa8b07 AK |
1780 | h->nr_huge_pages = 0; |
1781 | h->free_huge_pages = 0; | |
1782 | for (i = 0; i < MAX_NUMNODES; ++i) | |
1783 | INIT_LIST_HEAD(&h->hugepage_freelists[i]); | |
9b5e5d0f LS |
1784 | h->next_nid_to_alloc = first_node(node_states[N_HIGH_MEMORY]); |
1785 | h->next_nid_to_free = first_node(node_states[N_HIGH_MEMORY]); | |
a3437870 NA |
1786 | snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", |
1787 | huge_page_size(h)/1024); | |
8faa8b07 | 1788 | |
a3437870 NA |
1789 | parsed_hstate = h; |
1790 | } | |
1791 | ||
e11bfbfc | 1792 | static int __init hugetlb_nrpages_setup(char *s) |
a3437870 NA |
1793 | { |
1794 | unsigned long *mhp; | |
8faa8b07 | 1795 | static unsigned long *last_mhp; |
a3437870 NA |
1796 | |
1797 | /* | |
1798 | * !max_hstate means we haven't parsed a hugepagesz= parameter yet, | |
1799 | * so this hugepages= parameter goes to the "default hstate". | |
1800 | */ | |
1801 | if (!max_hstate) | |
1802 | mhp = &default_hstate_max_huge_pages; | |
1803 | else | |
1804 | mhp = &parsed_hstate->max_huge_pages; | |
1805 | ||
8faa8b07 AK |
1806 | if (mhp == last_mhp) { |
1807 | printk(KERN_WARNING "hugepages= specified twice without " | |
1808 | "interleaving hugepagesz=, ignoring\n"); | |
1809 | return 1; | |
1810 | } | |
1811 | ||
a3437870 NA |
1812 | if (sscanf(s, "%lu", mhp) <= 0) |
1813 | *mhp = 0; | |
1814 | ||
8faa8b07 AK |
1815 | /* |
1816 | * Global state is always initialized later in hugetlb_init. | |
1817 | * But we need to allocate >= MAX_ORDER hstates here early to still | |
1818 | * use the bootmem allocator. | |
1819 | */ | |
1820 | if (max_hstate && parsed_hstate->order >= MAX_ORDER) | |
1821 | hugetlb_hstate_alloc_pages(parsed_hstate); | |
1822 | ||
1823 | last_mhp = mhp; | |
1824 | ||
a3437870 NA |
1825 | return 1; |
1826 | } | |
e11bfbfc NP |
1827 | __setup("hugepages=", hugetlb_nrpages_setup); |
1828 | ||
1829 | static int __init hugetlb_default_setup(char *s) | |
1830 | { | |
1831 | default_hstate_size = memparse(s, &s); | |
1832 | return 1; | |
1833 | } | |
1834 | __setup("default_hugepagesz=", hugetlb_default_setup); | |
a3437870 | 1835 | |
8a213460 NA |
1836 | static unsigned int cpuset_mems_nr(unsigned int *array) |
1837 | { | |
1838 | int node; | |
1839 | unsigned int nr = 0; | |
1840 | ||
1841 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
1842 | nr += array[node]; | |
1843 | ||
1844 | return nr; | |
1845 | } | |
1846 | ||
1847 | #ifdef CONFIG_SYSCTL | |
06808b08 LS |
1848 | static int hugetlb_sysctl_handler_common(bool obey_mempolicy, |
1849 | struct ctl_table *table, int write, | |
1850 | void __user *buffer, size_t *length, loff_t *ppos) | |
1da177e4 | 1851 | { |
e5ff2159 AK |
1852 | struct hstate *h = &default_hstate; |
1853 | unsigned long tmp; | |
1854 | ||
1855 | if (!write) | |
1856 | tmp = h->max_huge_pages; | |
1857 | ||
1858 | table->data = &tmp; | |
1859 | table->maxlen = sizeof(unsigned long); | |
8d65af78 | 1860 | proc_doulongvec_minmax(table, write, buffer, length, ppos); |
e5ff2159 | 1861 | |
06808b08 | 1862 | if (write) { |
bad44b5b DR |
1863 | NODEMASK_ALLOC(nodemask_t, nodes_allowed, |
1864 | GFP_KERNEL | __GFP_NORETRY); | |
06808b08 LS |
1865 | if (!(obey_mempolicy && |
1866 | init_nodemask_of_mempolicy(nodes_allowed))) { | |
1867 | NODEMASK_FREE(nodes_allowed); | |
1868 | nodes_allowed = &node_states[N_HIGH_MEMORY]; | |
1869 | } | |
1870 | h->max_huge_pages = set_max_huge_pages(h, tmp, nodes_allowed); | |
1871 | ||
1872 | if (nodes_allowed != &node_states[N_HIGH_MEMORY]) | |
1873 | NODEMASK_FREE(nodes_allowed); | |
1874 | } | |
e5ff2159 | 1875 | |
1da177e4 LT |
1876 | return 0; |
1877 | } | |
396faf03 | 1878 | |
06808b08 LS |
1879 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
1880 | void __user *buffer, size_t *length, loff_t *ppos) | |
1881 | { | |
1882 | ||
1883 | return hugetlb_sysctl_handler_common(false, table, write, | |
1884 | buffer, length, ppos); | |
1885 | } | |
1886 | ||
1887 | #ifdef CONFIG_NUMA | |
1888 | int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write, | |
1889 | void __user *buffer, size_t *length, loff_t *ppos) | |
1890 | { | |
1891 | return hugetlb_sysctl_handler_common(true, table, write, | |
1892 | buffer, length, ppos); | |
1893 | } | |
1894 | #endif /* CONFIG_NUMA */ | |
1895 | ||
396faf03 | 1896 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, |
8d65af78 | 1897 | void __user *buffer, |
396faf03 MG |
1898 | size_t *length, loff_t *ppos) |
1899 | { | |
8d65af78 | 1900 | proc_dointvec(table, write, buffer, length, ppos); |
396faf03 MG |
1901 | if (hugepages_treat_as_movable) |
1902 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; | |
1903 | else | |
1904 | htlb_alloc_mask = GFP_HIGHUSER; | |
1905 | return 0; | |
1906 | } | |
1907 | ||
a3d0c6aa | 1908 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
8d65af78 | 1909 | void __user *buffer, |
a3d0c6aa NA |
1910 | size_t *length, loff_t *ppos) |
1911 | { | |
a5516438 | 1912 | struct hstate *h = &default_hstate; |
e5ff2159 AK |
1913 | unsigned long tmp; |
1914 | ||
1915 | if (!write) | |
1916 | tmp = h->nr_overcommit_huge_pages; | |
1917 | ||
1918 | table->data = &tmp; | |
1919 | table->maxlen = sizeof(unsigned long); | |
8d65af78 | 1920 | proc_doulongvec_minmax(table, write, buffer, length, ppos); |
e5ff2159 AK |
1921 | |
1922 | if (write) { | |
1923 | spin_lock(&hugetlb_lock); | |
1924 | h->nr_overcommit_huge_pages = tmp; | |
1925 | spin_unlock(&hugetlb_lock); | |
1926 | } | |
1927 | ||
a3d0c6aa NA |
1928 | return 0; |
1929 | } | |
1930 | ||
1da177e4 LT |
1931 | #endif /* CONFIG_SYSCTL */ |
1932 | ||
e1759c21 | 1933 | void hugetlb_report_meminfo(struct seq_file *m) |
1da177e4 | 1934 | { |
a5516438 | 1935 | struct hstate *h = &default_hstate; |
e1759c21 | 1936 | seq_printf(m, |
4f98a2fe RR |
1937 | "HugePages_Total: %5lu\n" |
1938 | "HugePages_Free: %5lu\n" | |
1939 | "HugePages_Rsvd: %5lu\n" | |
1940 | "HugePages_Surp: %5lu\n" | |
1941 | "Hugepagesize: %8lu kB\n", | |
a5516438 AK |
1942 | h->nr_huge_pages, |
1943 | h->free_huge_pages, | |
1944 | h->resv_huge_pages, | |
1945 | h->surplus_huge_pages, | |
1946 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); | |
1da177e4 LT |
1947 | } |
1948 | ||
1949 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
1950 | { | |
a5516438 | 1951 | struct hstate *h = &default_hstate; |
1da177e4 LT |
1952 | return sprintf(buf, |
1953 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
1954 | "Node %d HugePages_Free: %5u\n" |
1955 | "Node %d HugePages_Surp: %5u\n", | |
a5516438 AK |
1956 | nid, h->nr_huge_pages_node[nid], |
1957 | nid, h->free_huge_pages_node[nid], | |
1958 | nid, h->surplus_huge_pages_node[nid]); | |
1da177e4 LT |
1959 | } |
1960 | ||
1da177e4 LT |
1961 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
1962 | unsigned long hugetlb_total_pages(void) | |
1963 | { | |
a5516438 AK |
1964 | struct hstate *h = &default_hstate; |
1965 | return h->nr_huge_pages * pages_per_huge_page(h); | |
1da177e4 | 1966 | } |
1da177e4 | 1967 | |
a5516438 | 1968 | static int hugetlb_acct_memory(struct hstate *h, long delta) |
fc1b8a73 MG |
1969 | { |
1970 | int ret = -ENOMEM; | |
1971 | ||
1972 | spin_lock(&hugetlb_lock); | |
1973 | /* | |
1974 | * When cpuset is configured, it breaks the strict hugetlb page | |
1975 | * reservation as the accounting is done on a global variable. Such | |
1976 | * reservation is completely rubbish in the presence of cpuset because | |
1977 | * the reservation is not checked against page availability for the | |
1978 | * current cpuset. Application can still potentially OOM'ed by kernel | |
1979 | * with lack of free htlb page in cpuset that the task is in. | |
1980 | * Attempt to enforce strict accounting with cpuset is almost | |
1981 | * impossible (or too ugly) because cpuset is too fluid that | |
1982 | * task or memory node can be dynamically moved between cpusets. | |
1983 | * | |
1984 | * The change of semantics for shared hugetlb mapping with cpuset is | |
1985 | * undesirable. However, in order to preserve some of the semantics, | |
1986 | * we fall back to check against current free page availability as | |
1987 | * a best attempt and hopefully to minimize the impact of changing | |
1988 | * semantics that cpuset has. | |
1989 | */ | |
1990 | if (delta > 0) { | |
a5516438 | 1991 | if (gather_surplus_pages(h, delta) < 0) |
fc1b8a73 MG |
1992 | goto out; |
1993 | ||
a5516438 AK |
1994 | if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { |
1995 | return_unused_surplus_pages(h, delta); | |
fc1b8a73 MG |
1996 | goto out; |
1997 | } | |
1998 | } | |
1999 | ||
2000 | ret = 0; | |
2001 | if (delta < 0) | |
a5516438 | 2002 | return_unused_surplus_pages(h, (unsigned long) -delta); |
fc1b8a73 MG |
2003 | |
2004 | out: | |
2005 | spin_unlock(&hugetlb_lock); | |
2006 | return ret; | |
2007 | } | |
2008 | ||
84afd99b AW |
2009 | static void hugetlb_vm_op_open(struct vm_area_struct *vma) |
2010 | { | |
2011 | struct resv_map *reservations = vma_resv_map(vma); | |
2012 | ||
2013 | /* | |
2014 | * This new VMA should share its siblings reservation map if present. | |
2015 | * The VMA will only ever have a valid reservation map pointer where | |
2016 | * it is being copied for another still existing VMA. As that VMA | |
2017 | * has a reference to the reservation map it cannot dissappear until | |
2018 | * after this open call completes. It is therefore safe to take a | |
2019 | * new reference here without additional locking. | |
2020 | */ | |
2021 | if (reservations) | |
2022 | kref_get(&reservations->refs); | |
2023 | } | |
2024 | ||
a1e78772 MG |
2025 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
2026 | { | |
a5516438 | 2027 | struct hstate *h = hstate_vma(vma); |
84afd99b AW |
2028 | struct resv_map *reservations = vma_resv_map(vma); |
2029 | unsigned long reserve; | |
2030 | unsigned long start; | |
2031 | unsigned long end; | |
2032 | ||
2033 | if (reservations) { | |
a5516438 AK |
2034 | start = vma_hugecache_offset(h, vma, vma->vm_start); |
2035 | end = vma_hugecache_offset(h, vma, vma->vm_end); | |
84afd99b AW |
2036 | |
2037 | reserve = (end - start) - | |
2038 | region_count(&reservations->regions, start, end); | |
2039 | ||
2040 | kref_put(&reservations->refs, resv_map_release); | |
2041 | ||
7251ff78 | 2042 | if (reserve) { |
a5516438 | 2043 | hugetlb_acct_memory(h, -reserve); |
7251ff78 AL |
2044 | hugetlb_put_quota(vma->vm_file->f_mapping, reserve); |
2045 | } | |
84afd99b | 2046 | } |
a1e78772 MG |
2047 | } |
2048 | ||
1da177e4 LT |
2049 | /* |
2050 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
2051 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
2052 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
2053 | * this far. | |
2054 | */ | |
d0217ac0 | 2055 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
2056 | { |
2057 | BUG(); | |
d0217ac0 | 2058 | return 0; |
1da177e4 LT |
2059 | } |
2060 | ||
f0f37e2f | 2061 | const struct vm_operations_struct hugetlb_vm_ops = { |
d0217ac0 | 2062 | .fault = hugetlb_vm_op_fault, |
84afd99b | 2063 | .open = hugetlb_vm_op_open, |
a1e78772 | 2064 | .close = hugetlb_vm_op_close, |
1da177e4 LT |
2065 | }; |
2066 | ||
1e8f889b DG |
2067 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
2068 | int writable) | |
63551ae0 DG |
2069 | { |
2070 | pte_t entry; | |
2071 | ||
1e8f889b | 2072 | if (writable) { |
63551ae0 DG |
2073 | entry = |
2074 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
2075 | } else { | |
7f2e9525 | 2076 | entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
63551ae0 DG |
2077 | } |
2078 | entry = pte_mkyoung(entry); | |
2079 | entry = pte_mkhuge(entry); | |
2080 | ||
2081 | return entry; | |
2082 | } | |
2083 | ||
1e8f889b DG |
2084 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
2085 | unsigned long address, pte_t *ptep) | |
2086 | { | |
2087 | pte_t entry; | |
2088 | ||
7f2e9525 GS |
2089 | entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); |
2090 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { | |
8dab5241 | 2091 | update_mmu_cache(vma, address, entry); |
8dab5241 | 2092 | } |
1e8f889b DG |
2093 | } |
2094 | ||
2095 | ||
63551ae0 DG |
2096 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
2097 | struct vm_area_struct *vma) | |
2098 | { | |
2099 | pte_t *src_pte, *dst_pte, entry; | |
2100 | struct page *ptepage; | |
1c59827d | 2101 | unsigned long addr; |
1e8f889b | 2102 | int cow; |
a5516438 AK |
2103 | struct hstate *h = hstate_vma(vma); |
2104 | unsigned long sz = huge_page_size(h); | |
1e8f889b DG |
2105 | |
2106 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 2107 | |
a5516438 | 2108 | for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { |
c74df32c HD |
2109 | src_pte = huge_pte_offset(src, addr); |
2110 | if (!src_pte) | |
2111 | continue; | |
a5516438 | 2112 | dst_pte = huge_pte_alloc(dst, addr, sz); |
63551ae0 DG |
2113 | if (!dst_pte) |
2114 | goto nomem; | |
c5c99429 LW |
2115 | |
2116 | /* If the pagetables are shared don't copy or take references */ | |
2117 | if (dst_pte == src_pte) | |
2118 | continue; | |
2119 | ||
c74df32c | 2120 | spin_lock(&dst->page_table_lock); |
46478758 | 2121 | spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); |
7f2e9525 | 2122 | if (!huge_pte_none(huge_ptep_get(src_pte))) { |
1e8f889b | 2123 | if (cow) |
7f2e9525 GS |
2124 | huge_ptep_set_wrprotect(src, addr, src_pte); |
2125 | entry = huge_ptep_get(src_pte); | |
1c59827d HD |
2126 | ptepage = pte_page(entry); |
2127 | get_page(ptepage); | |
1c59827d HD |
2128 | set_huge_pte_at(dst, addr, dst_pte, entry); |
2129 | } | |
2130 | spin_unlock(&src->page_table_lock); | |
c74df32c | 2131 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
2132 | } |
2133 | return 0; | |
2134 | ||
2135 | nomem: | |
2136 | return -ENOMEM; | |
2137 | } | |
2138 | ||
502717f4 | 2139 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 2140 | unsigned long end, struct page *ref_page) |
63551ae0 DG |
2141 | { |
2142 | struct mm_struct *mm = vma->vm_mm; | |
2143 | unsigned long address; | |
c7546f8f | 2144 | pte_t *ptep; |
63551ae0 DG |
2145 | pte_t pte; |
2146 | struct page *page; | |
fe1668ae | 2147 | struct page *tmp; |
a5516438 AK |
2148 | struct hstate *h = hstate_vma(vma); |
2149 | unsigned long sz = huge_page_size(h); | |
2150 | ||
c0a499c2 KC |
2151 | /* |
2152 | * A page gathering list, protected by per file i_mmap_lock. The | |
2153 | * lock is used to avoid list corruption from multiple unmapping | |
2154 | * of the same page since we are using page->lru. | |
2155 | */ | |
fe1668ae | 2156 | LIST_HEAD(page_list); |
63551ae0 DG |
2157 | |
2158 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
a5516438 AK |
2159 | BUG_ON(start & ~huge_page_mask(h)); |
2160 | BUG_ON(end & ~huge_page_mask(h)); | |
63551ae0 | 2161 | |
cddb8a5c | 2162 | mmu_notifier_invalidate_range_start(mm, start, end); |
508034a3 | 2163 | spin_lock(&mm->page_table_lock); |
a5516438 | 2164 | for (address = start; address < end; address += sz) { |
c7546f8f | 2165 | ptep = huge_pte_offset(mm, address); |
4c887265 | 2166 | if (!ptep) |
c7546f8f DG |
2167 | continue; |
2168 | ||
39dde65c KC |
2169 | if (huge_pmd_unshare(mm, &address, ptep)) |
2170 | continue; | |
2171 | ||
04f2cbe3 MG |
2172 | /* |
2173 | * If a reference page is supplied, it is because a specific | |
2174 | * page is being unmapped, not a range. Ensure the page we | |
2175 | * are about to unmap is the actual page of interest. | |
2176 | */ | |
2177 | if (ref_page) { | |
2178 | pte = huge_ptep_get(ptep); | |
2179 | if (huge_pte_none(pte)) | |
2180 | continue; | |
2181 | page = pte_page(pte); | |
2182 | if (page != ref_page) | |
2183 | continue; | |
2184 | ||
2185 | /* | |
2186 | * Mark the VMA as having unmapped its page so that | |
2187 | * future faults in this VMA will fail rather than | |
2188 | * looking like data was lost | |
2189 | */ | |
2190 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); | |
2191 | } | |
2192 | ||
c7546f8f | 2193 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
7f2e9525 | 2194 | if (huge_pte_none(pte)) |
63551ae0 | 2195 | continue; |
c7546f8f | 2196 | |
63551ae0 | 2197 | page = pte_page(pte); |
6649a386 KC |
2198 | if (pte_dirty(pte)) |
2199 | set_page_dirty(page); | |
fe1668ae | 2200 | list_add(&page->lru, &page_list); |
63551ae0 | 2201 | } |
1da177e4 | 2202 | spin_unlock(&mm->page_table_lock); |
508034a3 | 2203 | flush_tlb_range(vma, start, end); |
cddb8a5c | 2204 | mmu_notifier_invalidate_range_end(mm, start, end); |
fe1668ae KC |
2205 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
2206 | list_del(&page->lru); | |
2207 | put_page(page); | |
2208 | } | |
1da177e4 | 2209 | } |
63551ae0 | 2210 | |
502717f4 | 2211 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 2212 | unsigned long end, struct page *ref_page) |
502717f4 | 2213 | { |
a137e1cc AK |
2214 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
2215 | __unmap_hugepage_range(vma, start, end, ref_page); | |
2216 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); | |
502717f4 KC |
2217 | } |
2218 | ||
04f2cbe3 MG |
2219 | /* |
2220 | * This is called when the original mapper is failing to COW a MAP_PRIVATE | |
2221 | * mappping it owns the reserve page for. The intention is to unmap the page | |
2222 | * from other VMAs and let the children be SIGKILLed if they are faulting the | |
2223 | * same region. | |
2224 | */ | |
2a4b3ded HH |
2225 | static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, |
2226 | struct page *page, unsigned long address) | |
04f2cbe3 | 2227 | { |
7526674d | 2228 | struct hstate *h = hstate_vma(vma); |
04f2cbe3 MG |
2229 | struct vm_area_struct *iter_vma; |
2230 | struct address_space *mapping; | |
2231 | struct prio_tree_iter iter; | |
2232 | pgoff_t pgoff; | |
2233 | ||
2234 | /* | |
2235 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation | |
2236 | * from page cache lookup which is in HPAGE_SIZE units. | |
2237 | */ | |
7526674d | 2238 | address = address & huge_page_mask(h); |
04f2cbe3 MG |
2239 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) |
2240 | + (vma->vm_pgoff >> PAGE_SHIFT); | |
2241 | mapping = (struct address_space *)page_private(page); | |
2242 | ||
4eb2b1dc MG |
2243 | /* |
2244 | * Take the mapping lock for the duration of the table walk. As | |
2245 | * this mapping should be shared between all the VMAs, | |
2246 | * __unmap_hugepage_range() is called as the lock is already held | |
2247 | */ | |
2248 | spin_lock(&mapping->i_mmap_lock); | |
04f2cbe3 MG |
2249 | vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { |
2250 | /* Do not unmap the current VMA */ | |
2251 | if (iter_vma == vma) | |
2252 | continue; | |
2253 | ||
2254 | /* | |
2255 | * Unmap the page from other VMAs without their own reserves. | |
2256 | * They get marked to be SIGKILLed if they fault in these | |
2257 | * areas. This is because a future no-page fault on this VMA | |
2258 | * could insert a zeroed page instead of the data existing | |
2259 | * from the time of fork. This would look like data corruption | |
2260 | */ | |
2261 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) | |
4eb2b1dc | 2262 | __unmap_hugepage_range(iter_vma, |
7526674d | 2263 | address, address + huge_page_size(h), |
04f2cbe3 MG |
2264 | page); |
2265 | } | |
4eb2b1dc | 2266 | spin_unlock(&mapping->i_mmap_lock); |
04f2cbe3 MG |
2267 | |
2268 | return 1; | |
2269 | } | |
2270 | ||
1e8f889b | 2271 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
04f2cbe3 MG |
2272 | unsigned long address, pte_t *ptep, pte_t pte, |
2273 | struct page *pagecache_page) | |
1e8f889b | 2274 | { |
a5516438 | 2275 | struct hstate *h = hstate_vma(vma); |
1e8f889b | 2276 | struct page *old_page, *new_page; |
79ac6ba4 | 2277 | int avoidcopy; |
04f2cbe3 | 2278 | int outside_reserve = 0; |
1e8f889b DG |
2279 | |
2280 | old_page = pte_page(pte); | |
2281 | ||
04f2cbe3 | 2282 | retry_avoidcopy: |
1e8f889b DG |
2283 | /* If no-one else is actually using this page, avoid the copy |
2284 | * and just make the page writable */ | |
2285 | avoidcopy = (page_count(old_page) == 1); | |
2286 | if (avoidcopy) { | |
2287 | set_huge_ptep_writable(vma, address, ptep); | |
83c54070 | 2288 | return 0; |
1e8f889b DG |
2289 | } |
2290 | ||
04f2cbe3 MG |
2291 | /* |
2292 | * If the process that created a MAP_PRIVATE mapping is about to | |
2293 | * perform a COW due to a shared page count, attempt to satisfy | |
2294 | * the allocation without using the existing reserves. The pagecache | |
2295 | * page is used to determine if the reserve at this address was | |
2296 | * consumed or not. If reserves were used, a partial faulted mapping | |
2297 | * at the time of fork() could consume its reserves on COW instead | |
2298 | * of the full address range. | |
2299 | */ | |
f83a275d | 2300 | if (!(vma->vm_flags & VM_MAYSHARE) && |
04f2cbe3 MG |
2301 | is_vma_resv_set(vma, HPAGE_RESV_OWNER) && |
2302 | old_page != pagecache_page) | |
2303 | outside_reserve = 1; | |
2304 | ||
1e8f889b | 2305 | page_cache_get(old_page); |
b76c8cfb LW |
2306 | |
2307 | /* Drop page_table_lock as buddy allocator may be called */ | |
2308 | spin_unlock(&mm->page_table_lock); | |
04f2cbe3 | 2309 | new_page = alloc_huge_page(vma, address, outside_reserve); |
1e8f889b | 2310 | |
2fc39cec | 2311 | if (IS_ERR(new_page)) { |
1e8f889b | 2312 | page_cache_release(old_page); |
04f2cbe3 MG |
2313 | |
2314 | /* | |
2315 | * If a process owning a MAP_PRIVATE mapping fails to COW, | |
2316 | * it is due to references held by a child and an insufficient | |
2317 | * huge page pool. To guarantee the original mappers | |
2318 | * reliability, unmap the page from child processes. The child | |
2319 | * may get SIGKILLed if it later faults. | |
2320 | */ | |
2321 | if (outside_reserve) { | |
2322 | BUG_ON(huge_pte_none(pte)); | |
2323 | if (unmap_ref_private(mm, vma, old_page, address)) { | |
2324 | BUG_ON(page_count(old_page) != 1); | |
2325 | BUG_ON(huge_pte_none(pte)); | |
b76c8cfb | 2326 | spin_lock(&mm->page_table_lock); |
04f2cbe3 MG |
2327 | goto retry_avoidcopy; |
2328 | } | |
2329 | WARN_ON_ONCE(1); | |
2330 | } | |
2331 | ||
b76c8cfb LW |
2332 | /* Caller expects lock to be held */ |
2333 | spin_lock(&mm->page_table_lock); | |
2fc39cec | 2334 | return -PTR_ERR(new_page); |
1e8f889b DG |
2335 | } |
2336 | ||
9de455b2 | 2337 | copy_huge_page(new_page, old_page, address, vma); |
0ed361de | 2338 | __SetPageUptodate(new_page); |
1e8f889b | 2339 | |
b76c8cfb LW |
2340 | /* |
2341 | * Retake the page_table_lock to check for racing updates | |
2342 | * before the page tables are altered | |
2343 | */ | |
2344 | spin_lock(&mm->page_table_lock); | |
a5516438 | 2345 | ptep = huge_pte_offset(mm, address & huge_page_mask(h)); |
7f2e9525 | 2346 | if (likely(pte_same(huge_ptep_get(ptep), pte))) { |
1e8f889b | 2347 | /* Break COW */ |
8fe627ec | 2348 | huge_ptep_clear_flush(vma, address, ptep); |
1e8f889b DG |
2349 | set_huge_pte_at(mm, address, ptep, |
2350 | make_huge_pte(vma, new_page, 1)); | |
2351 | /* Make the old page be freed below */ | |
2352 | new_page = old_page; | |
2353 | } | |
2354 | page_cache_release(new_page); | |
2355 | page_cache_release(old_page); | |
83c54070 | 2356 | return 0; |
1e8f889b DG |
2357 | } |
2358 | ||
04f2cbe3 | 2359 | /* Return the pagecache page at a given address within a VMA */ |
a5516438 AK |
2360 | static struct page *hugetlbfs_pagecache_page(struct hstate *h, |
2361 | struct vm_area_struct *vma, unsigned long address) | |
04f2cbe3 MG |
2362 | { |
2363 | struct address_space *mapping; | |
e7c4b0bf | 2364 | pgoff_t idx; |
04f2cbe3 MG |
2365 | |
2366 | mapping = vma->vm_file->f_mapping; | |
a5516438 | 2367 | idx = vma_hugecache_offset(h, vma, address); |
04f2cbe3 MG |
2368 | |
2369 | return find_lock_page(mapping, idx); | |
2370 | } | |
2371 | ||
3ae77f43 HD |
2372 | /* |
2373 | * Return whether there is a pagecache page to back given address within VMA. | |
2374 | * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. | |
2375 | */ | |
2376 | static bool hugetlbfs_pagecache_present(struct hstate *h, | |
2a15efc9 HD |
2377 | struct vm_area_struct *vma, unsigned long address) |
2378 | { | |
2379 | struct address_space *mapping; | |
2380 | pgoff_t idx; | |
2381 | struct page *page; | |
2382 | ||
2383 | mapping = vma->vm_file->f_mapping; | |
2384 | idx = vma_hugecache_offset(h, vma, address); | |
2385 | ||
2386 | page = find_get_page(mapping, idx); | |
2387 | if (page) | |
2388 | put_page(page); | |
2389 | return page != NULL; | |
2390 | } | |
2391 | ||
a1ed3dda | 2392 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
788c7df4 | 2393 | unsigned long address, pte_t *ptep, unsigned int flags) |
ac9b9c66 | 2394 | { |
a5516438 | 2395 | struct hstate *h = hstate_vma(vma); |
ac9b9c66 | 2396 | int ret = VM_FAULT_SIGBUS; |
e7c4b0bf | 2397 | pgoff_t idx; |
4c887265 | 2398 | unsigned long size; |
4c887265 AL |
2399 | struct page *page; |
2400 | struct address_space *mapping; | |
1e8f889b | 2401 | pte_t new_pte; |
4c887265 | 2402 | |
04f2cbe3 MG |
2403 | /* |
2404 | * Currently, we are forced to kill the process in the event the | |
2405 | * original mapper has unmapped pages from the child due to a failed | |
2406 | * COW. Warn that such a situation has occured as it may not be obvious | |
2407 | */ | |
2408 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { | |
2409 | printk(KERN_WARNING | |
2410 | "PID %d killed due to inadequate hugepage pool\n", | |
2411 | current->pid); | |
2412 | return ret; | |
2413 | } | |
2414 | ||
4c887265 | 2415 | mapping = vma->vm_file->f_mapping; |
a5516438 | 2416 | idx = vma_hugecache_offset(h, vma, address); |
4c887265 AL |
2417 | |
2418 | /* | |
2419 | * Use page lock to guard against racing truncation | |
2420 | * before we get page_table_lock. | |
2421 | */ | |
6bda666a CL |
2422 | retry: |
2423 | page = find_lock_page(mapping, idx); | |
2424 | if (!page) { | |
a5516438 | 2425 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
ebed4bfc HD |
2426 | if (idx >= size) |
2427 | goto out; | |
04f2cbe3 | 2428 | page = alloc_huge_page(vma, address, 0); |
2fc39cec AL |
2429 | if (IS_ERR(page)) { |
2430 | ret = -PTR_ERR(page); | |
6bda666a CL |
2431 | goto out; |
2432 | } | |
a5516438 | 2433 | clear_huge_page(page, address, huge_page_size(h)); |
0ed361de | 2434 | __SetPageUptodate(page); |
ac9b9c66 | 2435 | |
f83a275d | 2436 | if (vma->vm_flags & VM_MAYSHARE) { |
6bda666a | 2437 | int err; |
45c682a6 | 2438 | struct inode *inode = mapping->host; |
6bda666a CL |
2439 | |
2440 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
2441 | if (err) { | |
2442 | put_page(page); | |
6bda666a CL |
2443 | if (err == -EEXIST) |
2444 | goto retry; | |
2445 | goto out; | |
2446 | } | |
45c682a6 KC |
2447 | |
2448 | spin_lock(&inode->i_lock); | |
a5516438 | 2449 | inode->i_blocks += blocks_per_huge_page(h); |
45c682a6 | 2450 | spin_unlock(&inode->i_lock); |
6bda666a CL |
2451 | } else |
2452 | lock_page(page); | |
2453 | } | |
1e8f889b | 2454 | |
57303d80 AW |
2455 | /* |
2456 | * If we are going to COW a private mapping later, we examine the | |
2457 | * pending reservations for this page now. This will ensure that | |
2458 | * any allocations necessary to record that reservation occur outside | |
2459 | * the spinlock. | |
2460 | */ | |
788c7df4 | 2461 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) |
2b26736c AW |
2462 | if (vma_needs_reservation(h, vma, address) < 0) { |
2463 | ret = VM_FAULT_OOM; | |
2464 | goto backout_unlocked; | |
2465 | } | |
57303d80 | 2466 | |
ac9b9c66 | 2467 | spin_lock(&mm->page_table_lock); |
a5516438 | 2468 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
4c887265 AL |
2469 | if (idx >= size) |
2470 | goto backout; | |
2471 | ||
83c54070 | 2472 | ret = 0; |
7f2e9525 | 2473 | if (!huge_pte_none(huge_ptep_get(ptep))) |
4c887265 AL |
2474 | goto backout; |
2475 | ||
1e8f889b DG |
2476 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
2477 | && (vma->vm_flags & VM_SHARED))); | |
2478 | set_huge_pte_at(mm, address, ptep, new_pte); | |
2479 | ||
788c7df4 | 2480 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { |
1e8f889b | 2481 | /* Optimization, do the COW without a second fault */ |
04f2cbe3 | 2482 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); |
1e8f889b DG |
2483 | } |
2484 | ||
ac9b9c66 | 2485 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
2486 | unlock_page(page); |
2487 | out: | |
ac9b9c66 | 2488 | return ret; |
4c887265 AL |
2489 | |
2490 | backout: | |
2491 | spin_unlock(&mm->page_table_lock); | |
2b26736c | 2492 | backout_unlocked: |
4c887265 AL |
2493 | unlock_page(page); |
2494 | put_page(page); | |
2495 | goto out; | |
ac9b9c66 HD |
2496 | } |
2497 | ||
86e5216f | 2498 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
788c7df4 | 2499 | unsigned long address, unsigned int flags) |
86e5216f AL |
2500 | { |
2501 | pte_t *ptep; | |
2502 | pte_t entry; | |
1e8f889b | 2503 | int ret; |
57303d80 | 2504 | struct page *pagecache_page = NULL; |
3935baa9 | 2505 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
a5516438 | 2506 | struct hstate *h = hstate_vma(vma); |
86e5216f | 2507 | |
a5516438 | 2508 | ptep = huge_pte_alloc(mm, address, huge_page_size(h)); |
86e5216f AL |
2509 | if (!ptep) |
2510 | return VM_FAULT_OOM; | |
2511 | ||
3935baa9 DG |
2512 | /* |
2513 | * Serialize hugepage allocation and instantiation, so that we don't | |
2514 | * get spurious allocation failures if two CPUs race to instantiate | |
2515 | * the same page in the page cache. | |
2516 | */ | |
2517 | mutex_lock(&hugetlb_instantiation_mutex); | |
7f2e9525 GS |
2518 | entry = huge_ptep_get(ptep); |
2519 | if (huge_pte_none(entry)) { | |
788c7df4 | 2520 | ret = hugetlb_no_page(mm, vma, address, ptep, flags); |
b4d1d99f | 2521 | goto out_mutex; |
3935baa9 | 2522 | } |
86e5216f | 2523 | |
83c54070 | 2524 | ret = 0; |
1e8f889b | 2525 | |
57303d80 AW |
2526 | /* |
2527 | * If we are going to COW the mapping later, we examine the pending | |
2528 | * reservations for this page now. This will ensure that any | |
2529 | * allocations necessary to record that reservation occur outside the | |
2530 | * spinlock. For private mappings, we also lookup the pagecache | |
2531 | * page now as it is used to determine if a reservation has been | |
2532 | * consumed. | |
2533 | */ | |
788c7df4 | 2534 | if ((flags & FAULT_FLAG_WRITE) && !pte_write(entry)) { |
2b26736c AW |
2535 | if (vma_needs_reservation(h, vma, address) < 0) { |
2536 | ret = VM_FAULT_OOM; | |
b4d1d99f | 2537 | goto out_mutex; |
2b26736c | 2538 | } |
57303d80 | 2539 | |
f83a275d | 2540 | if (!(vma->vm_flags & VM_MAYSHARE)) |
57303d80 AW |
2541 | pagecache_page = hugetlbfs_pagecache_page(h, |
2542 | vma, address); | |
2543 | } | |
2544 | ||
1e8f889b DG |
2545 | spin_lock(&mm->page_table_lock); |
2546 | /* Check for a racing update before calling hugetlb_cow */ | |
b4d1d99f DG |
2547 | if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) |
2548 | goto out_page_table_lock; | |
2549 | ||
2550 | ||
788c7df4 | 2551 | if (flags & FAULT_FLAG_WRITE) { |
b4d1d99f | 2552 | if (!pte_write(entry)) { |
57303d80 AW |
2553 | ret = hugetlb_cow(mm, vma, address, ptep, entry, |
2554 | pagecache_page); | |
b4d1d99f DG |
2555 | goto out_page_table_lock; |
2556 | } | |
2557 | entry = pte_mkdirty(entry); | |
2558 | } | |
2559 | entry = pte_mkyoung(entry); | |
788c7df4 HD |
2560 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, |
2561 | flags & FAULT_FLAG_WRITE)) | |
b4d1d99f DG |
2562 | update_mmu_cache(vma, address, entry); |
2563 | ||
2564 | out_page_table_lock: | |
1e8f889b | 2565 | spin_unlock(&mm->page_table_lock); |
57303d80 AW |
2566 | |
2567 | if (pagecache_page) { | |
2568 | unlock_page(pagecache_page); | |
2569 | put_page(pagecache_page); | |
2570 | } | |
2571 | ||
b4d1d99f | 2572 | out_mutex: |
3935baa9 | 2573 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
2574 | |
2575 | return ret; | |
86e5216f AL |
2576 | } |
2577 | ||
ceb86879 AK |
2578 | /* Can be overriden by architectures */ |
2579 | __attribute__((weak)) struct page * | |
2580 | follow_huge_pud(struct mm_struct *mm, unsigned long address, | |
2581 | pud_t *pud, int write) | |
2582 | { | |
2583 | BUG(); | |
2584 | return NULL; | |
2585 | } | |
2586 | ||
63551ae0 DG |
2587 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
2588 | struct page **pages, struct vm_area_struct **vmas, | |
5b23dbe8 | 2589 | unsigned long *position, int *length, int i, |
2a15efc9 | 2590 | unsigned int flags) |
63551ae0 | 2591 | { |
d5d4b0aa KC |
2592 | unsigned long pfn_offset; |
2593 | unsigned long vaddr = *position; | |
63551ae0 | 2594 | int remainder = *length; |
a5516438 | 2595 | struct hstate *h = hstate_vma(vma); |
63551ae0 | 2596 | |
1c59827d | 2597 | spin_lock(&mm->page_table_lock); |
63551ae0 | 2598 | while (vaddr < vma->vm_end && remainder) { |
4c887265 | 2599 | pte_t *pte; |
2a15efc9 | 2600 | int absent; |
4c887265 | 2601 | struct page *page; |
63551ae0 | 2602 | |
4c887265 AL |
2603 | /* |
2604 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
2a15efc9 | 2605 | * each hugepage. We have to make sure we get the |
4c887265 AL |
2606 | * first, for the page indexing below to work. |
2607 | */ | |
a5516438 | 2608 | pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); |
2a15efc9 HD |
2609 | absent = !pte || huge_pte_none(huge_ptep_get(pte)); |
2610 | ||
2611 | /* | |
2612 | * When coredumping, it suits get_dump_page if we just return | |
3ae77f43 HD |
2613 | * an error where there's an empty slot with no huge pagecache |
2614 | * to back it. This way, we avoid allocating a hugepage, and | |
2615 | * the sparse dumpfile avoids allocating disk blocks, but its | |
2616 | * huge holes still show up with zeroes where they need to be. | |
2a15efc9 | 2617 | */ |
3ae77f43 HD |
2618 | if (absent && (flags & FOLL_DUMP) && |
2619 | !hugetlbfs_pagecache_present(h, vma, vaddr)) { | |
2a15efc9 HD |
2620 | remainder = 0; |
2621 | break; | |
2622 | } | |
63551ae0 | 2623 | |
2a15efc9 HD |
2624 | if (absent || |
2625 | ((flags & FOLL_WRITE) && !pte_write(huge_ptep_get(pte)))) { | |
4c887265 | 2626 | int ret; |
63551ae0 | 2627 | |
4c887265 | 2628 | spin_unlock(&mm->page_table_lock); |
2a15efc9 HD |
2629 | ret = hugetlb_fault(mm, vma, vaddr, |
2630 | (flags & FOLL_WRITE) ? FAULT_FLAG_WRITE : 0); | |
4c887265 | 2631 | spin_lock(&mm->page_table_lock); |
a89182c7 | 2632 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 2633 | continue; |
63551ae0 | 2634 | |
4c887265 | 2635 | remainder = 0; |
4c887265 AL |
2636 | break; |
2637 | } | |
2638 | ||
a5516438 | 2639 | pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; |
7f2e9525 | 2640 | page = pte_page(huge_ptep_get(pte)); |
d5d4b0aa | 2641 | same_page: |
d6692183 | 2642 | if (pages) { |
2a15efc9 | 2643 | pages[i] = mem_map_offset(page, pfn_offset); |
4b2e38ad | 2644 | get_page(pages[i]); |
d6692183 | 2645 | } |
63551ae0 DG |
2646 | |
2647 | if (vmas) | |
2648 | vmas[i] = vma; | |
2649 | ||
2650 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 2651 | ++pfn_offset; |
63551ae0 DG |
2652 | --remainder; |
2653 | ++i; | |
d5d4b0aa | 2654 | if (vaddr < vma->vm_end && remainder && |
a5516438 | 2655 | pfn_offset < pages_per_huge_page(h)) { |
d5d4b0aa KC |
2656 | /* |
2657 | * We use pfn_offset to avoid touching the pageframes | |
2658 | * of this compound page. | |
2659 | */ | |
2660 | goto same_page; | |
2661 | } | |
63551ae0 | 2662 | } |
1c59827d | 2663 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
2664 | *length = remainder; |
2665 | *position = vaddr; | |
2666 | ||
2a15efc9 | 2667 | return i ? i : -EFAULT; |
63551ae0 | 2668 | } |
8f860591 ZY |
2669 | |
2670 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
2671 | unsigned long address, unsigned long end, pgprot_t newprot) | |
2672 | { | |
2673 | struct mm_struct *mm = vma->vm_mm; | |
2674 | unsigned long start = address; | |
2675 | pte_t *ptep; | |
2676 | pte_t pte; | |
a5516438 | 2677 | struct hstate *h = hstate_vma(vma); |
8f860591 ZY |
2678 | |
2679 | BUG_ON(address >= end); | |
2680 | flush_cache_range(vma, address, end); | |
2681 | ||
39dde65c | 2682 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 | 2683 | spin_lock(&mm->page_table_lock); |
a5516438 | 2684 | for (; address < end; address += huge_page_size(h)) { |
8f860591 ZY |
2685 | ptep = huge_pte_offset(mm, address); |
2686 | if (!ptep) | |
2687 | continue; | |
39dde65c KC |
2688 | if (huge_pmd_unshare(mm, &address, ptep)) |
2689 | continue; | |
7f2e9525 | 2690 | if (!huge_pte_none(huge_ptep_get(ptep))) { |
8f860591 ZY |
2691 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
2692 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
2693 | set_huge_pte_at(mm, address, ptep, pte); | |
8f860591 ZY |
2694 | } |
2695 | } | |
2696 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 2697 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
2698 | |
2699 | flush_tlb_range(vma, start, end); | |
2700 | } | |
2701 | ||
a1e78772 MG |
2702 | int hugetlb_reserve_pages(struct inode *inode, |
2703 | long from, long to, | |
5a6fe125 MG |
2704 | struct vm_area_struct *vma, |
2705 | int acctflag) | |
e4e574b7 | 2706 | { |
17c9d12e | 2707 | long ret, chg; |
a5516438 | 2708 | struct hstate *h = hstate_inode(inode); |
e4e574b7 | 2709 | |
17c9d12e MG |
2710 | /* |
2711 | * Only apply hugepage reservation if asked. At fault time, an | |
2712 | * attempt will be made for VM_NORESERVE to allocate a page | |
2713 | * and filesystem quota without using reserves | |
2714 | */ | |
2715 | if (acctflag & VM_NORESERVE) | |
2716 | return 0; | |
2717 | ||
a1e78772 MG |
2718 | /* |
2719 | * Shared mappings base their reservation on the number of pages that | |
2720 | * are already allocated on behalf of the file. Private mappings need | |
2721 | * to reserve the full area even if read-only as mprotect() may be | |
2722 | * called to make the mapping read-write. Assume !vma is a shm mapping | |
2723 | */ | |
f83a275d | 2724 | if (!vma || vma->vm_flags & VM_MAYSHARE) |
a1e78772 | 2725 | chg = region_chg(&inode->i_mapping->private_list, from, to); |
17c9d12e MG |
2726 | else { |
2727 | struct resv_map *resv_map = resv_map_alloc(); | |
2728 | if (!resv_map) | |
2729 | return -ENOMEM; | |
2730 | ||
a1e78772 | 2731 | chg = to - from; |
84afd99b | 2732 | |
17c9d12e MG |
2733 | set_vma_resv_map(vma, resv_map); |
2734 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); | |
2735 | } | |
2736 | ||
e4e574b7 AL |
2737 | if (chg < 0) |
2738 | return chg; | |
8a630112 | 2739 | |
17c9d12e | 2740 | /* There must be enough filesystem quota for the mapping */ |
90d8b7e6 AL |
2741 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
2742 | return -ENOSPC; | |
5a6fe125 MG |
2743 | |
2744 | /* | |
17c9d12e MG |
2745 | * Check enough hugepages are available for the reservation. |
2746 | * Hand back the quota if there are not | |
5a6fe125 | 2747 | */ |
a5516438 | 2748 | ret = hugetlb_acct_memory(h, chg); |
68842c9b KC |
2749 | if (ret < 0) { |
2750 | hugetlb_put_quota(inode->i_mapping, chg); | |
a43a8c39 | 2751 | return ret; |
68842c9b | 2752 | } |
17c9d12e MG |
2753 | |
2754 | /* | |
2755 | * Account for the reservations made. Shared mappings record regions | |
2756 | * that have reservations as they are shared by multiple VMAs. | |
2757 | * When the last VMA disappears, the region map says how much | |
2758 | * the reservation was and the page cache tells how much of | |
2759 | * the reservation was consumed. Private mappings are per-VMA and | |
2760 | * only the consumed reservations are tracked. When the VMA | |
2761 | * disappears, the original reservation is the VMA size and the | |
2762 | * consumed reservations are stored in the map. Hence, nothing | |
2763 | * else has to be done for private mappings here | |
2764 | */ | |
f83a275d | 2765 | if (!vma || vma->vm_flags & VM_MAYSHARE) |
a1e78772 | 2766 | region_add(&inode->i_mapping->private_list, from, to); |
a43a8c39 KC |
2767 | return 0; |
2768 | } | |
2769 | ||
2770 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
2771 | { | |
a5516438 | 2772 | struct hstate *h = hstate_inode(inode); |
a43a8c39 | 2773 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
45c682a6 KC |
2774 | |
2775 | spin_lock(&inode->i_lock); | |
e4c6f8be | 2776 | inode->i_blocks -= (blocks_per_huge_page(h) * freed); |
45c682a6 KC |
2777 | spin_unlock(&inode->i_lock); |
2778 | ||
90d8b7e6 | 2779 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
a5516438 | 2780 | hugetlb_acct_memory(h, -(chg - freed)); |
a43a8c39 | 2781 | } |