Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Generic hugetlb support. | |
3 | * (C) William Irwin, April 2004 | |
4 | */ | |
5 | #include <linux/gfp.h> | |
6 | #include <linux/list.h> | |
7 | #include <linux/init.h> | |
8 | #include <linux/module.h> | |
9 | #include <linux/mm.h> | |
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> | |
7835e98b | 27 | #include "internal.h" |
1da177e4 LT |
28 | |
29 | const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; | |
396faf03 MG |
30 | static gfp_t htlb_alloc_mask = GFP_HIGHUSER; |
31 | unsigned long hugepages_treat_as_movable; | |
a5516438 | 32 | |
e5ff2159 AK |
33 | static int max_hstate; |
34 | unsigned int default_hstate_idx; | |
35 | struct hstate hstates[HUGE_MAX_HSTATE]; | |
36 | ||
53ba51d2 JT |
37 | __initdata LIST_HEAD(huge_boot_pages); |
38 | ||
e5ff2159 AK |
39 | /* for command line parsing */ |
40 | static struct hstate * __initdata parsed_hstate; | |
41 | static unsigned long __initdata default_hstate_max_huge_pages; | |
e11bfbfc | 42 | static unsigned long __initdata default_hstate_size; |
e5ff2159 AK |
43 | |
44 | #define for_each_hstate(h) \ | |
45 | for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++) | |
396faf03 | 46 | |
3935baa9 DG |
47 | /* |
48 | * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages | |
49 | */ | |
50 | static DEFINE_SPINLOCK(hugetlb_lock); | |
0bd0f9fb | 51 | |
96822904 AW |
52 | /* |
53 | * Region tracking -- allows tracking of reservations and instantiated pages | |
54 | * across the pages in a mapping. | |
84afd99b AW |
55 | * |
56 | * The region data structures are protected by a combination of the mmap_sem | |
57 | * and the hugetlb_instantion_mutex. To access or modify a region the caller | |
58 | * must either hold the mmap_sem for write, or the mmap_sem for read and | |
59 | * the hugetlb_instantiation mutex: | |
60 | * | |
61 | * down_write(&mm->mmap_sem); | |
62 | * or | |
63 | * down_read(&mm->mmap_sem); | |
64 | * mutex_lock(&hugetlb_instantiation_mutex); | |
96822904 AW |
65 | */ |
66 | struct file_region { | |
67 | struct list_head link; | |
68 | long from; | |
69 | long to; | |
70 | }; | |
71 | ||
72 | static long region_add(struct list_head *head, long f, long t) | |
73 | { | |
74 | struct file_region *rg, *nrg, *trg; | |
75 | ||
76 | /* Locate the region we are either in or before. */ | |
77 | list_for_each_entry(rg, head, link) | |
78 | if (f <= rg->to) | |
79 | break; | |
80 | ||
81 | /* Round our left edge to the current segment if it encloses us. */ | |
82 | if (f > rg->from) | |
83 | f = rg->from; | |
84 | ||
85 | /* Check for and consume any regions we now overlap with. */ | |
86 | nrg = rg; | |
87 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
88 | if (&rg->link == head) | |
89 | break; | |
90 | if (rg->from > t) | |
91 | break; | |
92 | ||
93 | /* If this area reaches higher then extend our area to | |
94 | * include it completely. If this is not the first area | |
95 | * which we intend to reuse, free it. */ | |
96 | if (rg->to > t) | |
97 | t = rg->to; | |
98 | if (rg != nrg) { | |
99 | list_del(&rg->link); | |
100 | kfree(rg); | |
101 | } | |
102 | } | |
103 | nrg->from = f; | |
104 | nrg->to = t; | |
105 | return 0; | |
106 | } | |
107 | ||
108 | static long region_chg(struct list_head *head, long f, long t) | |
109 | { | |
110 | struct file_region *rg, *nrg; | |
111 | long chg = 0; | |
112 | ||
113 | /* Locate the region we are before or in. */ | |
114 | list_for_each_entry(rg, head, link) | |
115 | if (f <= rg->to) | |
116 | break; | |
117 | ||
118 | /* If we are below the current region then a new region is required. | |
119 | * Subtle, allocate a new region at the position but make it zero | |
120 | * size such that we can guarantee to record the reservation. */ | |
121 | if (&rg->link == head || t < rg->from) { | |
122 | nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); | |
123 | if (!nrg) | |
124 | return -ENOMEM; | |
125 | nrg->from = f; | |
126 | nrg->to = f; | |
127 | INIT_LIST_HEAD(&nrg->link); | |
128 | list_add(&nrg->link, rg->link.prev); | |
129 | ||
130 | return t - f; | |
131 | } | |
132 | ||
133 | /* Round our left edge to the current segment if it encloses us. */ | |
134 | if (f > rg->from) | |
135 | f = rg->from; | |
136 | chg = t - f; | |
137 | ||
138 | /* Check for and consume any regions we now overlap with. */ | |
139 | list_for_each_entry(rg, rg->link.prev, link) { | |
140 | if (&rg->link == head) | |
141 | break; | |
142 | if (rg->from > t) | |
143 | return chg; | |
144 | ||
145 | /* We overlap with this area, if it extends futher than | |
146 | * us then we must extend ourselves. Account for its | |
147 | * existing reservation. */ | |
148 | if (rg->to > t) { | |
149 | chg += rg->to - t; | |
150 | t = rg->to; | |
151 | } | |
152 | chg -= rg->to - rg->from; | |
153 | } | |
154 | return chg; | |
155 | } | |
156 | ||
157 | static long region_truncate(struct list_head *head, long end) | |
158 | { | |
159 | struct file_region *rg, *trg; | |
160 | long chg = 0; | |
161 | ||
162 | /* Locate the region we are either in or before. */ | |
163 | list_for_each_entry(rg, head, link) | |
164 | if (end <= rg->to) | |
165 | break; | |
166 | if (&rg->link == head) | |
167 | return 0; | |
168 | ||
169 | /* If we are in the middle of a region then adjust it. */ | |
170 | if (end > rg->from) { | |
171 | chg = rg->to - end; | |
172 | rg->to = end; | |
173 | rg = list_entry(rg->link.next, typeof(*rg), link); | |
174 | } | |
175 | ||
176 | /* Drop any remaining regions. */ | |
177 | list_for_each_entry_safe(rg, trg, rg->link.prev, link) { | |
178 | if (&rg->link == head) | |
179 | break; | |
180 | chg += rg->to - rg->from; | |
181 | list_del(&rg->link); | |
182 | kfree(rg); | |
183 | } | |
184 | return chg; | |
185 | } | |
186 | ||
84afd99b AW |
187 | static long region_count(struct list_head *head, long f, long t) |
188 | { | |
189 | struct file_region *rg; | |
190 | long chg = 0; | |
191 | ||
192 | /* Locate each segment we overlap with, and count that overlap. */ | |
193 | list_for_each_entry(rg, head, link) { | |
194 | int seg_from; | |
195 | int seg_to; | |
196 | ||
197 | if (rg->to <= f) | |
198 | continue; | |
199 | if (rg->from >= t) | |
200 | break; | |
201 | ||
202 | seg_from = max(rg->from, f); | |
203 | seg_to = min(rg->to, t); | |
204 | ||
205 | chg += seg_to - seg_from; | |
206 | } | |
207 | ||
208 | return chg; | |
209 | } | |
210 | ||
e7c4b0bf AW |
211 | /* |
212 | * Convert the address within this vma to the page offset within | |
213 | * the mapping, in pagecache page units; huge pages here. | |
214 | */ | |
a5516438 AK |
215 | static pgoff_t vma_hugecache_offset(struct hstate *h, |
216 | struct vm_area_struct *vma, unsigned long address) | |
e7c4b0bf | 217 | { |
a5516438 AK |
218 | return ((address - vma->vm_start) >> huge_page_shift(h)) + |
219 | (vma->vm_pgoff >> huge_page_order(h)); | |
e7c4b0bf AW |
220 | } |
221 | ||
08fba699 MG |
222 | /* |
223 | * Return the size of the pages allocated when backing a VMA. In the majority | |
224 | * cases this will be same size as used by the page table entries. | |
225 | */ | |
226 | unsigned long vma_kernel_pagesize(struct vm_area_struct *vma) | |
227 | { | |
228 | struct hstate *hstate; | |
229 | ||
230 | if (!is_vm_hugetlb_page(vma)) | |
231 | return PAGE_SIZE; | |
232 | ||
233 | hstate = hstate_vma(vma); | |
234 | ||
235 | return 1UL << (hstate->order + PAGE_SHIFT); | |
236 | } | |
f340ca0f | 237 | EXPORT_SYMBOL_GPL(vma_kernel_pagesize); |
08fba699 | 238 | |
3340289d MG |
239 | /* |
240 | * Return the page size being used by the MMU to back a VMA. In the majority | |
241 | * of cases, the page size used by the kernel matches the MMU size. On | |
242 | * architectures where it differs, an architecture-specific version of this | |
243 | * function is required. | |
244 | */ | |
245 | #ifndef vma_mmu_pagesize | |
246 | unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) | |
247 | { | |
248 | return vma_kernel_pagesize(vma); | |
249 | } | |
250 | #endif | |
251 | ||
84afd99b AW |
252 | /* |
253 | * Flags for MAP_PRIVATE reservations. These are stored in the bottom | |
254 | * bits of the reservation map pointer, which are always clear due to | |
255 | * alignment. | |
256 | */ | |
257 | #define HPAGE_RESV_OWNER (1UL << 0) | |
258 | #define HPAGE_RESV_UNMAPPED (1UL << 1) | |
04f2cbe3 | 259 | #define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED) |
84afd99b | 260 | |
a1e78772 MG |
261 | /* |
262 | * These helpers are used to track how many pages are reserved for | |
263 | * faults in a MAP_PRIVATE mapping. Only the process that called mmap() | |
264 | * is guaranteed to have their future faults succeed. | |
265 | * | |
266 | * With the exception of reset_vma_resv_huge_pages() which is called at fork(), | |
267 | * the reserve counters are updated with the hugetlb_lock held. It is safe | |
268 | * to reset the VMA at fork() time as it is not in use yet and there is no | |
269 | * chance of the global counters getting corrupted as a result of the values. | |
84afd99b AW |
270 | * |
271 | * The private mapping reservation is represented in a subtly different | |
272 | * manner to a shared mapping. A shared mapping has a region map associated | |
273 | * with the underlying file, this region map represents the backing file | |
274 | * pages which have ever had a reservation assigned which this persists even | |
275 | * after the page is instantiated. A private mapping has a region map | |
276 | * associated with the original mmap which is attached to all VMAs which | |
277 | * reference it, this region map represents those offsets which have consumed | |
278 | * reservation ie. where pages have been instantiated. | |
a1e78772 | 279 | */ |
e7c4b0bf AW |
280 | static unsigned long get_vma_private_data(struct vm_area_struct *vma) |
281 | { | |
282 | return (unsigned long)vma->vm_private_data; | |
283 | } | |
284 | ||
285 | static void set_vma_private_data(struct vm_area_struct *vma, | |
286 | unsigned long value) | |
287 | { | |
288 | vma->vm_private_data = (void *)value; | |
289 | } | |
290 | ||
84afd99b AW |
291 | struct resv_map { |
292 | struct kref refs; | |
293 | struct list_head regions; | |
294 | }; | |
295 | ||
2a4b3ded | 296 | static struct resv_map *resv_map_alloc(void) |
84afd99b AW |
297 | { |
298 | struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL); | |
299 | if (!resv_map) | |
300 | return NULL; | |
301 | ||
302 | kref_init(&resv_map->refs); | |
303 | INIT_LIST_HEAD(&resv_map->regions); | |
304 | ||
305 | return resv_map; | |
306 | } | |
307 | ||
2a4b3ded | 308 | static void resv_map_release(struct kref *ref) |
84afd99b AW |
309 | { |
310 | struct resv_map *resv_map = container_of(ref, struct resv_map, refs); | |
311 | ||
312 | /* Clear out any active regions before we release the map. */ | |
313 | region_truncate(&resv_map->regions, 0); | |
314 | kfree(resv_map); | |
315 | } | |
316 | ||
317 | static struct resv_map *vma_resv_map(struct vm_area_struct *vma) | |
a1e78772 MG |
318 | { |
319 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
f83a275d | 320 | if (!(vma->vm_flags & VM_MAYSHARE)) |
84afd99b AW |
321 | return (struct resv_map *)(get_vma_private_data(vma) & |
322 | ~HPAGE_RESV_MASK); | |
2a4b3ded | 323 | return NULL; |
a1e78772 MG |
324 | } |
325 | ||
84afd99b | 326 | static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map) |
a1e78772 MG |
327 | { |
328 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
f83a275d | 329 | VM_BUG_ON(vma->vm_flags & VM_MAYSHARE); |
a1e78772 | 330 | |
84afd99b AW |
331 | set_vma_private_data(vma, (get_vma_private_data(vma) & |
332 | HPAGE_RESV_MASK) | (unsigned long)map); | |
04f2cbe3 MG |
333 | } |
334 | ||
335 | static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) | |
336 | { | |
04f2cbe3 | 337 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); |
f83a275d | 338 | VM_BUG_ON(vma->vm_flags & VM_MAYSHARE); |
e7c4b0bf AW |
339 | |
340 | set_vma_private_data(vma, get_vma_private_data(vma) | flags); | |
04f2cbe3 MG |
341 | } |
342 | ||
343 | static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) | |
344 | { | |
345 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
e7c4b0bf AW |
346 | |
347 | return (get_vma_private_data(vma) & flag) != 0; | |
a1e78772 MG |
348 | } |
349 | ||
350 | /* Decrement the reserved pages in the hugepage pool by one */ | |
a5516438 AK |
351 | static void decrement_hugepage_resv_vma(struct hstate *h, |
352 | struct vm_area_struct *vma) | |
a1e78772 | 353 | { |
c37f9fb1 AW |
354 | if (vma->vm_flags & VM_NORESERVE) |
355 | return; | |
356 | ||
f83a275d | 357 | if (vma->vm_flags & VM_MAYSHARE) { |
a1e78772 | 358 | /* Shared mappings always use reserves */ |
a5516438 | 359 | h->resv_huge_pages--; |
84afd99b | 360 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
a1e78772 MG |
361 | /* |
362 | * Only the process that called mmap() has reserves for | |
363 | * private mappings. | |
364 | */ | |
a5516438 | 365 | h->resv_huge_pages--; |
a1e78772 MG |
366 | } |
367 | } | |
368 | ||
04f2cbe3 | 369 | /* Reset counters to 0 and clear all HPAGE_RESV_* flags */ |
a1e78772 MG |
370 | void reset_vma_resv_huge_pages(struct vm_area_struct *vma) |
371 | { | |
372 | VM_BUG_ON(!is_vm_hugetlb_page(vma)); | |
f83a275d | 373 | if (!(vma->vm_flags & VM_MAYSHARE)) |
a1e78772 MG |
374 | vma->vm_private_data = (void *)0; |
375 | } | |
376 | ||
377 | /* Returns true if the VMA has associated reserve pages */ | |
7f09ca51 | 378 | static int vma_has_reserves(struct vm_area_struct *vma) |
a1e78772 | 379 | { |
f83a275d | 380 | if (vma->vm_flags & VM_MAYSHARE) |
7f09ca51 MG |
381 | return 1; |
382 | if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) | |
383 | return 1; | |
384 | return 0; | |
a1e78772 MG |
385 | } |
386 | ||
69d177c2 AW |
387 | static void clear_gigantic_page(struct page *page, |
388 | unsigned long addr, unsigned long sz) | |
389 | { | |
390 | int i; | |
391 | struct page *p = page; | |
392 | ||
393 | might_sleep(); | |
394 | for (i = 0; i < sz/PAGE_SIZE; i++, p = mem_map_next(p, page, i)) { | |
395 | cond_resched(); | |
396 | clear_user_highpage(p, addr + i * PAGE_SIZE); | |
397 | } | |
398 | } | |
a5516438 AK |
399 | static void clear_huge_page(struct page *page, |
400 | unsigned long addr, unsigned long sz) | |
79ac6ba4 DG |
401 | { |
402 | int i; | |
403 | ||
ebdd4aea HE |
404 | if (unlikely(sz > MAX_ORDER_NR_PAGES)) { |
405 | clear_gigantic_page(page, addr, sz); | |
406 | return; | |
407 | } | |
69d177c2 | 408 | |
79ac6ba4 | 409 | might_sleep(); |
a5516438 | 410 | for (i = 0; i < sz/PAGE_SIZE; i++) { |
79ac6ba4 | 411 | cond_resched(); |
281e0e3b | 412 | clear_user_highpage(page + i, addr + i * PAGE_SIZE); |
79ac6ba4 DG |
413 | } |
414 | } | |
415 | ||
69d177c2 AW |
416 | static void copy_gigantic_page(struct page *dst, struct page *src, |
417 | unsigned long addr, struct vm_area_struct *vma) | |
418 | { | |
419 | int i; | |
420 | struct hstate *h = hstate_vma(vma); | |
421 | struct page *dst_base = dst; | |
422 | struct page *src_base = src; | |
423 | might_sleep(); | |
424 | for (i = 0; i < pages_per_huge_page(h); ) { | |
425 | cond_resched(); | |
426 | copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma); | |
427 | ||
428 | i++; | |
429 | dst = mem_map_next(dst, dst_base, i); | |
430 | src = mem_map_next(src, src_base, i); | |
431 | } | |
432 | } | |
79ac6ba4 | 433 | static void copy_huge_page(struct page *dst, struct page *src, |
9de455b2 | 434 | unsigned long addr, struct vm_area_struct *vma) |
79ac6ba4 DG |
435 | { |
436 | int i; | |
a5516438 | 437 | struct hstate *h = hstate_vma(vma); |
79ac6ba4 | 438 | |
ebdd4aea HE |
439 | if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) { |
440 | copy_gigantic_page(dst, src, addr, vma); | |
441 | return; | |
442 | } | |
69d177c2 | 443 | |
79ac6ba4 | 444 | might_sleep(); |
a5516438 | 445 | for (i = 0; i < pages_per_huge_page(h); i++) { |
79ac6ba4 | 446 | cond_resched(); |
9de455b2 | 447 | copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); |
79ac6ba4 DG |
448 | } |
449 | } | |
450 | ||
a5516438 | 451 | static void enqueue_huge_page(struct hstate *h, struct page *page) |
1da177e4 LT |
452 | { |
453 | int nid = page_to_nid(page); | |
a5516438 AK |
454 | list_add(&page->lru, &h->hugepage_freelists[nid]); |
455 | h->free_huge_pages++; | |
456 | h->free_huge_pages_node[nid]++; | |
1da177e4 LT |
457 | } |
458 | ||
a5516438 AK |
459 | static struct page *dequeue_huge_page_vma(struct hstate *h, |
460 | struct vm_area_struct *vma, | |
04f2cbe3 | 461 | unsigned long address, int avoid_reserve) |
1da177e4 | 462 | { |
31a5c6e4 | 463 | int nid; |
1da177e4 | 464 | struct page *page = NULL; |
480eccf9 | 465 | struct mempolicy *mpol; |
19770b32 | 466 | nodemask_t *nodemask; |
396faf03 | 467 | struct zonelist *zonelist = huge_zonelist(vma, address, |
19770b32 | 468 | htlb_alloc_mask, &mpol, &nodemask); |
dd1a239f MG |
469 | struct zone *zone; |
470 | struct zoneref *z; | |
1da177e4 | 471 | |
a1e78772 MG |
472 | /* |
473 | * A child process with MAP_PRIVATE mappings created by their parent | |
474 | * have no page reserves. This check ensures that reservations are | |
475 | * not "stolen". The child may still get SIGKILLed | |
476 | */ | |
7f09ca51 | 477 | if (!vma_has_reserves(vma) && |
a5516438 | 478 | h->free_huge_pages - h->resv_huge_pages == 0) |
a1e78772 MG |
479 | return NULL; |
480 | ||
04f2cbe3 | 481 | /* If reserves cannot be used, ensure enough pages are in the pool */ |
a5516438 | 482 | if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0) |
04f2cbe3 MG |
483 | return NULL; |
484 | ||
19770b32 MG |
485 | for_each_zone_zonelist_nodemask(zone, z, zonelist, |
486 | MAX_NR_ZONES - 1, nodemask) { | |
54a6eb5c MG |
487 | nid = zone_to_nid(zone); |
488 | if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) && | |
a5516438 AK |
489 | !list_empty(&h->hugepage_freelists[nid])) { |
490 | page = list_entry(h->hugepage_freelists[nid].next, | |
3abf7afd AM |
491 | struct page, lru); |
492 | list_del(&page->lru); | |
a5516438 AK |
493 | h->free_huge_pages--; |
494 | h->free_huge_pages_node[nid]--; | |
04f2cbe3 MG |
495 | |
496 | if (!avoid_reserve) | |
a5516438 | 497 | decrement_hugepage_resv_vma(h, vma); |
a1e78772 | 498 | |
5ab3ee7b | 499 | break; |
3abf7afd | 500 | } |
1da177e4 | 501 | } |
52cd3b07 | 502 | mpol_cond_put(mpol); |
1da177e4 LT |
503 | return page; |
504 | } | |
505 | ||
a5516438 | 506 | static void update_and_free_page(struct hstate *h, struct page *page) |
6af2acb6 AL |
507 | { |
508 | int i; | |
a5516438 | 509 | |
18229df5 AW |
510 | VM_BUG_ON(h->order >= MAX_ORDER); |
511 | ||
a5516438 AK |
512 | h->nr_huge_pages--; |
513 | h->nr_huge_pages_node[page_to_nid(page)]--; | |
514 | for (i = 0; i < pages_per_huge_page(h); i++) { | |
6af2acb6 AL |
515 | page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | |
516 | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | | |
517 | 1 << PG_private | 1<< PG_writeback); | |
518 | } | |
519 | set_compound_page_dtor(page, NULL); | |
520 | set_page_refcounted(page); | |
7f2e9525 | 521 | arch_release_hugepage(page); |
a5516438 | 522 | __free_pages(page, huge_page_order(h)); |
6af2acb6 AL |
523 | } |
524 | ||
e5ff2159 AK |
525 | struct hstate *size_to_hstate(unsigned long size) |
526 | { | |
527 | struct hstate *h; | |
528 | ||
529 | for_each_hstate(h) { | |
530 | if (huge_page_size(h) == size) | |
531 | return h; | |
532 | } | |
533 | return NULL; | |
534 | } | |
535 | ||
27a85ef1 DG |
536 | static void free_huge_page(struct page *page) |
537 | { | |
a5516438 AK |
538 | /* |
539 | * Can't pass hstate in here because it is called from the | |
540 | * compound page destructor. | |
541 | */ | |
e5ff2159 | 542 | struct hstate *h = page_hstate(page); |
7893d1d5 | 543 | int nid = page_to_nid(page); |
c79fb75e | 544 | struct address_space *mapping; |
27a85ef1 | 545 | |
c79fb75e | 546 | mapping = (struct address_space *) page_private(page); |
e5df70ab | 547 | set_page_private(page, 0); |
7893d1d5 | 548 | BUG_ON(page_count(page)); |
27a85ef1 DG |
549 | INIT_LIST_HEAD(&page->lru); |
550 | ||
551 | spin_lock(&hugetlb_lock); | |
aa888a74 | 552 | if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) { |
a5516438 AK |
553 | update_and_free_page(h, page); |
554 | h->surplus_huge_pages--; | |
555 | h->surplus_huge_pages_node[nid]--; | |
7893d1d5 | 556 | } else { |
a5516438 | 557 | enqueue_huge_page(h, page); |
7893d1d5 | 558 | } |
27a85ef1 | 559 | spin_unlock(&hugetlb_lock); |
c79fb75e | 560 | if (mapping) |
9a119c05 | 561 | hugetlb_put_quota(mapping, 1); |
27a85ef1 DG |
562 | } |
563 | ||
a5516438 | 564 | static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) |
b7ba30c6 AK |
565 | { |
566 | set_compound_page_dtor(page, free_huge_page); | |
567 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
568 | h->nr_huge_pages++; |
569 | h->nr_huge_pages_node[nid]++; | |
b7ba30c6 AK |
570 | spin_unlock(&hugetlb_lock); |
571 | put_page(page); /* free it into the hugepage allocator */ | |
572 | } | |
573 | ||
20a0307c WF |
574 | static void prep_compound_gigantic_page(struct page *page, unsigned long order) |
575 | { | |
576 | int i; | |
577 | int nr_pages = 1 << order; | |
578 | struct page *p = page + 1; | |
579 | ||
580 | /* we rely on prep_new_huge_page to set the destructor */ | |
581 | set_compound_order(page, order); | |
582 | __SetPageHead(page); | |
583 | for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { | |
584 | __SetPageTail(p); | |
585 | p->first_page = page; | |
586 | } | |
587 | } | |
588 | ||
589 | int PageHuge(struct page *page) | |
590 | { | |
591 | compound_page_dtor *dtor; | |
592 | ||
593 | if (!PageCompound(page)) | |
594 | return 0; | |
595 | ||
596 | page = compound_head(page); | |
597 | dtor = get_compound_page_dtor(page); | |
598 | ||
599 | return dtor == free_huge_page; | |
600 | } | |
601 | ||
a5516438 | 602 | static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid) |
1da177e4 | 603 | { |
1da177e4 | 604 | struct page *page; |
f96efd58 | 605 | |
aa888a74 AK |
606 | if (h->order >= MAX_ORDER) |
607 | return NULL; | |
608 | ||
6484eb3e | 609 | page = alloc_pages_exact_node(nid, |
551883ae NA |
610 | htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE| |
611 | __GFP_REPEAT|__GFP_NOWARN, | |
a5516438 | 612 | huge_page_order(h)); |
1da177e4 | 613 | if (page) { |
7f2e9525 | 614 | if (arch_prepare_hugepage(page)) { |
caff3a2c | 615 | __free_pages(page, huge_page_order(h)); |
7b8ee84d | 616 | return NULL; |
7f2e9525 | 617 | } |
a5516438 | 618 | prep_new_huge_page(h, page, nid); |
1da177e4 | 619 | } |
63b4613c NA |
620 | |
621 | return page; | |
622 | } | |
623 | ||
5ced66c9 AK |
624 | /* |
625 | * Use a helper variable to find the next node and then | |
e8c5c824 | 626 | * copy it back to next_nid_to_alloc afterwards: |
5ced66c9 | 627 | * otherwise there's a window in which a racer might |
6484eb3e | 628 | * pass invalid nid MAX_NUMNODES to alloc_pages_exact_node. |
5ced66c9 AK |
629 | * But we don't need to use a spin_lock here: it really |
630 | * doesn't matter if occasionally a racer chooses the | |
631 | * same nid as we do. Move nid forward in the mask even | |
632 | * if we just successfully allocated a hugepage so that | |
633 | * the next caller gets hugepages on the next node. | |
634 | */ | |
e8c5c824 | 635 | static int hstate_next_node_to_alloc(struct hstate *h) |
5ced66c9 AK |
636 | { |
637 | int next_nid; | |
e8c5c824 | 638 | next_nid = next_node(h->next_nid_to_alloc, node_online_map); |
5ced66c9 AK |
639 | if (next_nid == MAX_NUMNODES) |
640 | next_nid = first_node(node_online_map); | |
e8c5c824 | 641 | h->next_nid_to_alloc = next_nid; |
5ced66c9 AK |
642 | return next_nid; |
643 | } | |
644 | ||
a5516438 | 645 | static int alloc_fresh_huge_page(struct hstate *h) |
63b4613c NA |
646 | { |
647 | struct page *page; | |
648 | int start_nid; | |
649 | int next_nid; | |
650 | int ret = 0; | |
651 | ||
e8c5c824 LS |
652 | start_nid = h->next_nid_to_alloc; |
653 | next_nid = start_nid; | |
63b4613c NA |
654 | |
655 | do { | |
e8c5c824 | 656 | page = alloc_fresh_huge_page_node(h, next_nid); |
63b4613c NA |
657 | if (page) |
658 | ret = 1; | |
e8c5c824 LS |
659 | next_nid = hstate_next_node_to_alloc(h); |
660 | } while (!page && next_nid != start_nid); | |
63b4613c | 661 | |
3b116300 AL |
662 | if (ret) |
663 | count_vm_event(HTLB_BUDDY_PGALLOC); | |
664 | else | |
665 | count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); | |
666 | ||
63b4613c | 667 | return ret; |
1da177e4 LT |
668 | } |
669 | ||
e8c5c824 LS |
670 | /* |
671 | * helper for free_pool_huge_page() - find next node | |
672 | * from which to free a huge page | |
673 | */ | |
674 | static int hstate_next_node_to_free(struct hstate *h) | |
675 | { | |
676 | int next_nid; | |
677 | next_nid = next_node(h->next_nid_to_free, node_online_map); | |
678 | if (next_nid == MAX_NUMNODES) | |
679 | next_nid = first_node(node_online_map); | |
680 | h->next_nid_to_free = next_nid; | |
681 | return next_nid; | |
682 | } | |
683 | ||
684 | /* | |
685 | * Free huge page from pool from next node to free. | |
686 | * Attempt to keep persistent huge pages more or less | |
687 | * balanced over allowed nodes. | |
688 | * Called with hugetlb_lock locked. | |
689 | */ | |
690 | static int free_pool_huge_page(struct hstate *h) | |
691 | { | |
692 | int start_nid; | |
693 | int next_nid; | |
694 | int ret = 0; | |
695 | ||
696 | start_nid = h->next_nid_to_free; | |
697 | next_nid = start_nid; | |
698 | ||
699 | do { | |
700 | if (!list_empty(&h->hugepage_freelists[next_nid])) { | |
701 | struct page *page = | |
702 | list_entry(h->hugepage_freelists[next_nid].next, | |
703 | struct page, lru); | |
704 | list_del(&page->lru); | |
705 | h->free_huge_pages--; | |
706 | h->free_huge_pages_node[next_nid]--; | |
707 | update_and_free_page(h, page); | |
708 | ret = 1; | |
709 | } | |
710 | next_nid = hstate_next_node_to_free(h); | |
711 | } while (!ret && next_nid != start_nid); | |
712 | ||
713 | return ret; | |
714 | } | |
715 | ||
a5516438 AK |
716 | static struct page *alloc_buddy_huge_page(struct hstate *h, |
717 | struct vm_area_struct *vma, unsigned long address) | |
7893d1d5 AL |
718 | { |
719 | struct page *page; | |
d1c3fb1f | 720 | unsigned int nid; |
7893d1d5 | 721 | |
aa888a74 AK |
722 | if (h->order >= MAX_ORDER) |
723 | return NULL; | |
724 | ||
d1c3fb1f NA |
725 | /* |
726 | * Assume we will successfully allocate the surplus page to | |
727 | * prevent racing processes from causing the surplus to exceed | |
728 | * overcommit | |
729 | * | |
730 | * This however introduces a different race, where a process B | |
731 | * tries to grow the static hugepage pool while alloc_pages() is | |
732 | * called by process A. B will only examine the per-node | |
733 | * counters in determining if surplus huge pages can be | |
734 | * converted to normal huge pages in adjust_pool_surplus(). A | |
735 | * won't be able to increment the per-node counter, until the | |
736 | * lock is dropped by B, but B doesn't drop hugetlb_lock until | |
737 | * no more huge pages can be converted from surplus to normal | |
738 | * state (and doesn't try to convert again). Thus, we have a | |
739 | * case where a surplus huge page exists, the pool is grown, and | |
740 | * the surplus huge page still exists after, even though it | |
741 | * should just have been converted to a normal huge page. This | |
742 | * does not leak memory, though, as the hugepage will be freed | |
743 | * once it is out of use. It also does not allow the counters to | |
744 | * go out of whack in adjust_pool_surplus() as we don't modify | |
745 | * the node values until we've gotten the hugepage and only the | |
746 | * per-node value is checked there. | |
747 | */ | |
748 | spin_lock(&hugetlb_lock); | |
a5516438 | 749 | if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { |
d1c3fb1f NA |
750 | spin_unlock(&hugetlb_lock); |
751 | return NULL; | |
752 | } else { | |
a5516438 AK |
753 | h->nr_huge_pages++; |
754 | h->surplus_huge_pages++; | |
d1c3fb1f NA |
755 | } |
756 | spin_unlock(&hugetlb_lock); | |
757 | ||
551883ae NA |
758 | page = alloc_pages(htlb_alloc_mask|__GFP_COMP| |
759 | __GFP_REPEAT|__GFP_NOWARN, | |
a5516438 | 760 | huge_page_order(h)); |
d1c3fb1f | 761 | |
caff3a2c GS |
762 | if (page && arch_prepare_hugepage(page)) { |
763 | __free_pages(page, huge_page_order(h)); | |
764 | return NULL; | |
765 | } | |
766 | ||
d1c3fb1f | 767 | spin_lock(&hugetlb_lock); |
7893d1d5 | 768 | if (page) { |
2668db91 AL |
769 | /* |
770 | * This page is now managed by the hugetlb allocator and has | |
771 | * no users -- drop the buddy allocator's reference. | |
772 | */ | |
773 | put_page_testzero(page); | |
774 | VM_BUG_ON(page_count(page)); | |
d1c3fb1f | 775 | nid = page_to_nid(page); |
7893d1d5 | 776 | set_compound_page_dtor(page, free_huge_page); |
d1c3fb1f NA |
777 | /* |
778 | * We incremented the global counters already | |
779 | */ | |
a5516438 AK |
780 | h->nr_huge_pages_node[nid]++; |
781 | h->surplus_huge_pages_node[nid]++; | |
3b116300 | 782 | __count_vm_event(HTLB_BUDDY_PGALLOC); |
d1c3fb1f | 783 | } else { |
a5516438 AK |
784 | h->nr_huge_pages--; |
785 | h->surplus_huge_pages--; | |
3b116300 | 786 | __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL); |
7893d1d5 | 787 | } |
d1c3fb1f | 788 | spin_unlock(&hugetlb_lock); |
7893d1d5 AL |
789 | |
790 | return page; | |
791 | } | |
792 | ||
e4e574b7 AL |
793 | /* |
794 | * Increase the hugetlb pool such that it can accomodate a reservation | |
795 | * of size 'delta'. | |
796 | */ | |
a5516438 | 797 | static int gather_surplus_pages(struct hstate *h, int delta) |
e4e574b7 AL |
798 | { |
799 | struct list_head surplus_list; | |
800 | struct page *page, *tmp; | |
801 | int ret, i; | |
802 | int needed, allocated; | |
803 | ||
a5516438 | 804 | needed = (h->resv_huge_pages + delta) - h->free_huge_pages; |
ac09b3a1 | 805 | if (needed <= 0) { |
a5516438 | 806 | h->resv_huge_pages += delta; |
e4e574b7 | 807 | return 0; |
ac09b3a1 | 808 | } |
e4e574b7 AL |
809 | |
810 | allocated = 0; | |
811 | INIT_LIST_HEAD(&surplus_list); | |
812 | ||
813 | ret = -ENOMEM; | |
814 | retry: | |
815 | spin_unlock(&hugetlb_lock); | |
816 | for (i = 0; i < needed; i++) { | |
a5516438 | 817 | page = alloc_buddy_huge_page(h, NULL, 0); |
e4e574b7 AL |
818 | if (!page) { |
819 | /* | |
820 | * We were not able to allocate enough pages to | |
821 | * satisfy the entire reservation so we free what | |
822 | * we've allocated so far. | |
823 | */ | |
824 | spin_lock(&hugetlb_lock); | |
825 | needed = 0; | |
826 | goto free; | |
827 | } | |
828 | ||
829 | list_add(&page->lru, &surplus_list); | |
830 | } | |
831 | allocated += needed; | |
832 | ||
833 | /* | |
834 | * After retaking hugetlb_lock, we need to recalculate 'needed' | |
835 | * because either resv_huge_pages or free_huge_pages may have changed. | |
836 | */ | |
837 | spin_lock(&hugetlb_lock); | |
a5516438 AK |
838 | needed = (h->resv_huge_pages + delta) - |
839 | (h->free_huge_pages + allocated); | |
e4e574b7 AL |
840 | if (needed > 0) |
841 | goto retry; | |
842 | ||
843 | /* | |
844 | * The surplus_list now contains _at_least_ the number of extra pages | |
845 | * needed to accomodate the reservation. Add the appropriate number | |
846 | * of pages to the hugetlb pool and free the extras back to the buddy | |
ac09b3a1 AL |
847 | * allocator. Commit the entire reservation here to prevent another |
848 | * process from stealing the pages as they are added to the pool but | |
849 | * before they are reserved. | |
e4e574b7 AL |
850 | */ |
851 | needed += allocated; | |
a5516438 | 852 | h->resv_huge_pages += delta; |
e4e574b7 AL |
853 | ret = 0; |
854 | free: | |
19fc3f0a | 855 | /* Free the needed pages to the hugetlb pool */ |
e4e574b7 | 856 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { |
19fc3f0a AL |
857 | if ((--needed) < 0) |
858 | break; | |
e4e574b7 | 859 | list_del(&page->lru); |
a5516438 | 860 | enqueue_huge_page(h, page); |
19fc3f0a AL |
861 | } |
862 | ||
863 | /* Free unnecessary surplus pages to the buddy allocator */ | |
864 | if (!list_empty(&surplus_list)) { | |
865 | spin_unlock(&hugetlb_lock); | |
866 | list_for_each_entry_safe(page, tmp, &surplus_list, lru) { | |
867 | list_del(&page->lru); | |
af767cbd | 868 | /* |
2668db91 AL |
869 | * The page has a reference count of zero already, so |
870 | * call free_huge_page directly instead of using | |
871 | * put_page. This must be done with hugetlb_lock | |
af767cbd AL |
872 | * unlocked which is safe because free_huge_page takes |
873 | * hugetlb_lock before deciding how to free the page. | |
874 | */ | |
2668db91 | 875 | free_huge_page(page); |
af767cbd | 876 | } |
19fc3f0a | 877 | spin_lock(&hugetlb_lock); |
e4e574b7 AL |
878 | } |
879 | ||
880 | return ret; | |
881 | } | |
882 | ||
883 | /* | |
884 | * When releasing a hugetlb pool reservation, any surplus pages that were | |
885 | * allocated to satisfy the reservation must be explicitly freed if they were | |
886 | * never used. | |
887 | */ | |
a5516438 AK |
888 | static void return_unused_surplus_pages(struct hstate *h, |
889 | unsigned long unused_resv_pages) | |
e4e574b7 AL |
890 | { |
891 | static int nid = -1; | |
892 | struct page *page; | |
893 | unsigned long nr_pages; | |
894 | ||
11320d17 NA |
895 | /* |
896 | * We want to release as many surplus pages as possible, spread | |
897 | * evenly across all nodes. Iterate across all nodes until we | |
898 | * can no longer free unreserved surplus pages. This occurs when | |
899 | * the nodes with surplus pages have no free pages. | |
900 | */ | |
62bc62a8 | 901 | unsigned long remaining_iterations = nr_online_nodes; |
11320d17 | 902 | |
ac09b3a1 | 903 | /* Uncommit the reservation */ |
a5516438 | 904 | h->resv_huge_pages -= unused_resv_pages; |
ac09b3a1 | 905 | |
aa888a74 AK |
906 | /* Cannot return gigantic pages currently */ |
907 | if (h->order >= MAX_ORDER) | |
908 | return; | |
909 | ||
a5516438 | 910 | nr_pages = min(unused_resv_pages, h->surplus_huge_pages); |
e4e574b7 | 911 | |
11320d17 | 912 | while (remaining_iterations-- && nr_pages) { |
e4e574b7 AL |
913 | nid = next_node(nid, node_online_map); |
914 | if (nid == MAX_NUMNODES) | |
915 | nid = first_node(node_online_map); | |
916 | ||
a5516438 | 917 | if (!h->surplus_huge_pages_node[nid]) |
e4e574b7 AL |
918 | continue; |
919 | ||
a5516438 AK |
920 | if (!list_empty(&h->hugepage_freelists[nid])) { |
921 | page = list_entry(h->hugepage_freelists[nid].next, | |
e4e574b7 AL |
922 | struct page, lru); |
923 | list_del(&page->lru); | |
a5516438 AK |
924 | update_and_free_page(h, page); |
925 | h->free_huge_pages--; | |
926 | h->free_huge_pages_node[nid]--; | |
927 | h->surplus_huge_pages--; | |
928 | h->surplus_huge_pages_node[nid]--; | |
e4e574b7 | 929 | nr_pages--; |
62bc62a8 | 930 | remaining_iterations = nr_online_nodes; |
e4e574b7 AL |
931 | } |
932 | } | |
933 | } | |
934 | ||
c37f9fb1 AW |
935 | /* |
936 | * Determine if the huge page at addr within the vma has an associated | |
937 | * reservation. Where it does not we will need to logically increase | |
938 | * reservation and actually increase quota before an allocation can occur. | |
939 | * Where any new reservation would be required the reservation change is | |
940 | * prepared, but not committed. Once the page has been quota'd allocated | |
941 | * an instantiated the change should be committed via vma_commit_reservation. | |
942 | * No action is required on failure. | |
943 | */ | |
e2f17d94 | 944 | static long vma_needs_reservation(struct hstate *h, |
a5516438 | 945 | struct vm_area_struct *vma, unsigned long addr) |
c37f9fb1 AW |
946 | { |
947 | struct address_space *mapping = vma->vm_file->f_mapping; | |
948 | struct inode *inode = mapping->host; | |
949 | ||
f83a275d | 950 | if (vma->vm_flags & VM_MAYSHARE) { |
a5516438 | 951 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 AW |
952 | return region_chg(&inode->i_mapping->private_list, |
953 | idx, idx + 1); | |
954 | ||
84afd99b AW |
955 | } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { |
956 | return 1; | |
c37f9fb1 | 957 | |
84afd99b | 958 | } else { |
e2f17d94 | 959 | long err; |
a5516438 | 960 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
84afd99b AW |
961 | struct resv_map *reservations = vma_resv_map(vma); |
962 | ||
963 | err = region_chg(&reservations->regions, idx, idx + 1); | |
964 | if (err < 0) | |
965 | return err; | |
966 | return 0; | |
967 | } | |
c37f9fb1 | 968 | } |
a5516438 AK |
969 | static void vma_commit_reservation(struct hstate *h, |
970 | struct vm_area_struct *vma, unsigned long addr) | |
c37f9fb1 AW |
971 | { |
972 | struct address_space *mapping = vma->vm_file->f_mapping; | |
973 | struct inode *inode = mapping->host; | |
974 | ||
f83a275d | 975 | if (vma->vm_flags & VM_MAYSHARE) { |
a5516438 | 976 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
c37f9fb1 | 977 | region_add(&inode->i_mapping->private_list, idx, idx + 1); |
84afd99b AW |
978 | |
979 | } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { | |
a5516438 | 980 | pgoff_t idx = vma_hugecache_offset(h, vma, addr); |
84afd99b AW |
981 | struct resv_map *reservations = vma_resv_map(vma); |
982 | ||
983 | /* Mark this page used in the map. */ | |
984 | region_add(&reservations->regions, idx, idx + 1); | |
c37f9fb1 AW |
985 | } |
986 | } | |
987 | ||
a1e78772 | 988 | static struct page *alloc_huge_page(struct vm_area_struct *vma, |
04f2cbe3 | 989 | unsigned long addr, int avoid_reserve) |
1da177e4 | 990 | { |
a5516438 | 991 | struct hstate *h = hstate_vma(vma); |
348ea204 | 992 | struct page *page; |
a1e78772 MG |
993 | struct address_space *mapping = vma->vm_file->f_mapping; |
994 | struct inode *inode = mapping->host; | |
e2f17d94 | 995 | long chg; |
a1e78772 MG |
996 | |
997 | /* | |
998 | * Processes that did not create the mapping will have no reserves and | |
999 | * will not have accounted against quota. Check that the quota can be | |
1000 | * made before satisfying the allocation | |
c37f9fb1 AW |
1001 | * MAP_NORESERVE mappings may also need pages and quota allocated |
1002 | * if no reserve mapping overlaps. | |
a1e78772 | 1003 | */ |
a5516438 | 1004 | chg = vma_needs_reservation(h, vma, addr); |
c37f9fb1 AW |
1005 | if (chg < 0) |
1006 | return ERR_PTR(chg); | |
1007 | if (chg) | |
a1e78772 MG |
1008 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
1009 | return ERR_PTR(-ENOSPC); | |
1da177e4 LT |
1010 | |
1011 | spin_lock(&hugetlb_lock); | |
a5516438 | 1012 | page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve); |
1da177e4 | 1013 | spin_unlock(&hugetlb_lock); |
b45b5bd6 | 1014 | |
68842c9b | 1015 | if (!page) { |
a5516438 | 1016 | page = alloc_buddy_huge_page(h, vma, addr); |
68842c9b | 1017 | if (!page) { |
a1e78772 | 1018 | hugetlb_put_quota(inode->i_mapping, chg); |
68842c9b KC |
1019 | return ERR_PTR(-VM_FAULT_OOM); |
1020 | } | |
1021 | } | |
348ea204 | 1022 | |
a1e78772 MG |
1023 | set_page_refcounted(page); |
1024 | set_page_private(page, (unsigned long) mapping); | |
90d8b7e6 | 1025 | |
a5516438 | 1026 | vma_commit_reservation(h, vma, addr); |
c37f9fb1 | 1027 | |
90d8b7e6 | 1028 | return page; |
b45b5bd6 DG |
1029 | } |
1030 | ||
91f47662 | 1031 | int __weak alloc_bootmem_huge_page(struct hstate *h) |
aa888a74 AK |
1032 | { |
1033 | struct huge_bootmem_page *m; | |
1034 | int nr_nodes = nodes_weight(node_online_map); | |
1035 | ||
1036 | while (nr_nodes) { | |
1037 | void *addr; | |
1038 | ||
1039 | addr = __alloc_bootmem_node_nopanic( | |
e8c5c824 | 1040 | NODE_DATA(h->next_nid_to_alloc), |
aa888a74 AK |
1041 | huge_page_size(h), huge_page_size(h), 0); |
1042 | ||
1043 | if (addr) { | |
1044 | /* | |
1045 | * Use the beginning of the huge page to store the | |
1046 | * huge_bootmem_page struct (until gather_bootmem | |
1047 | * puts them into the mem_map). | |
1048 | */ | |
1049 | m = addr; | |
91f47662 | 1050 | goto found; |
aa888a74 | 1051 | } |
e8c5c824 | 1052 | hstate_next_node_to_alloc(h); |
aa888a74 AK |
1053 | nr_nodes--; |
1054 | } | |
1055 | return 0; | |
1056 | ||
1057 | found: | |
1058 | BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1)); | |
1059 | /* Put them into a private list first because mem_map is not up yet */ | |
1060 | list_add(&m->list, &huge_boot_pages); | |
1061 | m->hstate = h; | |
1062 | return 1; | |
1063 | } | |
1064 | ||
18229df5 AW |
1065 | static void prep_compound_huge_page(struct page *page, int order) |
1066 | { | |
1067 | if (unlikely(order > (MAX_ORDER - 1))) | |
1068 | prep_compound_gigantic_page(page, order); | |
1069 | else | |
1070 | prep_compound_page(page, order); | |
1071 | } | |
1072 | ||
aa888a74 AK |
1073 | /* Put bootmem huge pages into the standard lists after mem_map is up */ |
1074 | static void __init gather_bootmem_prealloc(void) | |
1075 | { | |
1076 | struct huge_bootmem_page *m; | |
1077 | ||
1078 | list_for_each_entry(m, &huge_boot_pages, list) { | |
1079 | struct page *page = virt_to_page(m); | |
1080 | struct hstate *h = m->hstate; | |
1081 | __ClearPageReserved(page); | |
1082 | WARN_ON(page_count(page) != 1); | |
18229df5 | 1083 | prep_compound_huge_page(page, h->order); |
aa888a74 AK |
1084 | prep_new_huge_page(h, page, page_to_nid(page)); |
1085 | } | |
1086 | } | |
1087 | ||
8faa8b07 | 1088 | static void __init hugetlb_hstate_alloc_pages(struct hstate *h) |
1da177e4 LT |
1089 | { |
1090 | unsigned long i; | |
a5516438 | 1091 | |
e5ff2159 | 1092 | for (i = 0; i < h->max_huge_pages; ++i) { |
aa888a74 AK |
1093 | if (h->order >= MAX_ORDER) { |
1094 | if (!alloc_bootmem_huge_page(h)) | |
1095 | break; | |
1096 | } else if (!alloc_fresh_huge_page(h)) | |
1da177e4 | 1097 | break; |
1da177e4 | 1098 | } |
8faa8b07 | 1099 | h->max_huge_pages = i; |
e5ff2159 AK |
1100 | } |
1101 | ||
1102 | static void __init hugetlb_init_hstates(void) | |
1103 | { | |
1104 | struct hstate *h; | |
1105 | ||
1106 | for_each_hstate(h) { | |
8faa8b07 AK |
1107 | /* oversize hugepages were init'ed in early boot */ |
1108 | if (h->order < MAX_ORDER) | |
1109 | hugetlb_hstate_alloc_pages(h); | |
e5ff2159 AK |
1110 | } |
1111 | } | |
1112 | ||
4abd32db AK |
1113 | static char * __init memfmt(char *buf, unsigned long n) |
1114 | { | |
1115 | if (n >= (1UL << 30)) | |
1116 | sprintf(buf, "%lu GB", n >> 30); | |
1117 | else if (n >= (1UL << 20)) | |
1118 | sprintf(buf, "%lu MB", n >> 20); | |
1119 | else | |
1120 | sprintf(buf, "%lu KB", n >> 10); | |
1121 | return buf; | |
1122 | } | |
1123 | ||
e5ff2159 AK |
1124 | static void __init report_hugepages(void) |
1125 | { | |
1126 | struct hstate *h; | |
1127 | ||
1128 | for_each_hstate(h) { | |
4abd32db AK |
1129 | char buf[32]; |
1130 | printk(KERN_INFO "HugeTLB registered %s page size, " | |
1131 | "pre-allocated %ld pages\n", | |
1132 | memfmt(buf, huge_page_size(h)), | |
1133 | h->free_huge_pages); | |
e5ff2159 AK |
1134 | } |
1135 | } | |
1136 | ||
1da177e4 | 1137 | #ifdef CONFIG_HIGHMEM |
a5516438 | 1138 | static void try_to_free_low(struct hstate *h, unsigned long count) |
1da177e4 | 1139 | { |
4415cc8d CL |
1140 | int i; |
1141 | ||
aa888a74 AK |
1142 | if (h->order >= MAX_ORDER) |
1143 | return; | |
1144 | ||
1da177e4 LT |
1145 | for (i = 0; i < MAX_NUMNODES; ++i) { |
1146 | struct page *page, *next; | |
a5516438 AK |
1147 | struct list_head *freel = &h->hugepage_freelists[i]; |
1148 | list_for_each_entry_safe(page, next, freel, lru) { | |
1149 | if (count >= h->nr_huge_pages) | |
6b0c880d | 1150 | return; |
1da177e4 LT |
1151 | if (PageHighMem(page)) |
1152 | continue; | |
1153 | list_del(&page->lru); | |
e5ff2159 | 1154 | update_and_free_page(h, page); |
a5516438 AK |
1155 | h->free_huge_pages--; |
1156 | h->free_huge_pages_node[page_to_nid(page)]--; | |
1da177e4 LT |
1157 | } |
1158 | } | |
1159 | } | |
1160 | #else | |
a5516438 | 1161 | static inline void try_to_free_low(struct hstate *h, unsigned long count) |
1da177e4 LT |
1162 | { |
1163 | } | |
1164 | #endif | |
1165 | ||
20a0307c WF |
1166 | /* |
1167 | * Increment or decrement surplus_huge_pages. Keep node-specific counters | |
1168 | * balanced by operating on them in a round-robin fashion. | |
1169 | * Returns 1 if an adjustment was made. | |
1170 | */ | |
1171 | static int adjust_pool_surplus(struct hstate *h, int delta) | |
1172 | { | |
e8c5c824 | 1173 | int start_nid, next_nid; |
20a0307c WF |
1174 | int ret = 0; |
1175 | ||
1176 | VM_BUG_ON(delta != -1 && delta != 1); | |
20a0307c | 1177 | |
e8c5c824 LS |
1178 | if (delta < 0) |
1179 | start_nid = h->next_nid_to_alloc; | |
1180 | else | |
1181 | start_nid = h->next_nid_to_free; | |
1182 | next_nid = start_nid; | |
1183 | ||
1184 | do { | |
1185 | int nid = next_nid; | |
1186 | if (delta < 0) { | |
1187 | next_nid = hstate_next_node_to_alloc(h); | |
1188 | /* | |
1189 | * To shrink on this node, there must be a surplus page | |
1190 | */ | |
1191 | if (!h->surplus_huge_pages_node[nid]) | |
1192 | continue; | |
1193 | } | |
1194 | if (delta > 0) { | |
1195 | next_nid = hstate_next_node_to_free(h); | |
1196 | /* | |
1197 | * Surplus cannot exceed the total number of pages | |
1198 | */ | |
1199 | if (h->surplus_huge_pages_node[nid] >= | |
20a0307c | 1200 | h->nr_huge_pages_node[nid]) |
e8c5c824 LS |
1201 | continue; |
1202 | } | |
20a0307c WF |
1203 | |
1204 | h->surplus_huge_pages += delta; | |
1205 | h->surplus_huge_pages_node[nid] += delta; | |
1206 | ret = 1; | |
1207 | break; | |
e8c5c824 | 1208 | } while (next_nid != start_nid); |
20a0307c | 1209 | |
20a0307c WF |
1210 | return ret; |
1211 | } | |
1212 | ||
a5516438 | 1213 | #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) |
e5ff2159 | 1214 | static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count) |
1da177e4 | 1215 | { |
7893d1d5 | 1216 | unsigned long min_count, ret; |
1da177e4 | 1217 | |
aa888a74 AK |
1218 | if (h->order >= MAX_ORDER) |
1219 | return h->max_huge_pages; | |
1220 | ||
7893d1d5 AL |
1221 | /* |
1222 | * Increase the pool size | |
1223 | * First take pages out of surplus state. Then make up the | |
1224 | * remaining difference by allocating fresh huge pages. | |
d1c3fb1f NA |
1225 | * |
1226 | * We might race with alloc_buddy_huge_page() here and be unable | |
1227 | * to convert a surplus huge page to a normal huge page. That is | |
1228 | * not critical, though, it just means the overall size of the | |
1229 | * pool might be one hugepage larger than it needs to be, but | |
1230 | * within all the constraints specified by the sysctls. | |
7893d1d5 | 1231 | */ |
1da177e4 | 1232 | spin_lock(&hugetlb_lock); |
a5516438 AK |
1233 | while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { |
1234 | if (!adjust_pool_surplus(h, -1)) | |
7893d1d5 AL |
1235 | break; |
1236 | } | |
1237 | ||
a5516438 | 1238 | while (count > persistent_huge_pages(h)) { |
7893d1d5 AL |
1239 | /* |
1240 | * If this allocation races such that we no longer need the | |
1241 | * page, free_huge_page will handle it by freeing the page | |
1242 | * and reducing the surplus. | |
1243 | */ | |
1244 | spin_unlock(&hugetlb_lock); | |
a5516438 | 1245 | ret = alloc_fresh_huge_page(h); |
7893d1d5 AL |
1246 | spin_lock(&hugetlb_lock); |
1247 | if (!ret) | |
1248 | goto out; | |
1249 | ||
1250 | } | |
7893d1d5 AL |
1251 | |
1252 | /* | |
1253 | * Decrease the pool size | |
1254 | * First return free pages to the buddy allocator (being careful | |
1255 | * to keep enough around to satisfy reservations). Then place | |
1256 | * pages into surplus state as needed so the pool will shrink | |
1257 | * to the desired size as pages become free. | |
d1c3fb1f NA |
1258 | * |
1259 | * By placing pages into the surplus state independent of the | |
1260 | * overcommit value, we are allowing the surplus pool size to | |
1261 | * exceed overcommit. There are few sane options here. Since | |
1262 | * alloc_buddy_huge_page() is checking the global counter, | |
1263 | * though, we'll note that we're not allowed to exceed surplus | |
1264 | * and won't grow the pool anywhere else. Not until one of the | |
1265 | * sysctls are changed, or the surplus pages go out of use. | |
7893d1d5 | 1266 | */ |
a5516438 | 1267 | min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages; |
6b0c880d | 1268 | min_count = max(count, min_count); |
a5516438 AK |
1269 | try_to_free_low(h, min_count); |
1270 | while (min_count < persistent_huge_pages(h)) { | |
e8c5c824 | 1271 | if (!free_pool_huge_page(h)) |
1da177e4 | 1272 | break; |
1da177e4 | 1273 | } |
a5516438 AK |
1274 | while (count < persistent_huge_pages(h)) { |
1275 | if (!adjust_pool_surplus(h, 1)) | |
7893d1d5 AL |
1276 | break; |
1277 | } | |
1278 | out: | |
a5516438 | 1279 | ret = persistent_huge_pages(h); |
1da177e4 | 1280 | spin_unlock(&hugetlb_lock); |
7893d1d5 | 1281 | return ret; |
1da177e4 LT |
1282 | } |
1283 | ||
a3437870 NA |
1284 | #define HSTATE_ATTR_RO(_name) \ |
1285 | static struct kobj_attribute _name##_attr = __ATTR_RO(_name) | |
1286 | ||
1287 | #define HSTATE_ATTR(_name) \ | |
1288 | static struct kobj_attribute _name##_attr = \ | |
1289 | __ATTR(_name, 0644, _name##_show, _name##_store) | |
1290 | ||
1291 | static struct kobject *hugepages_kobj; | |
1292 | static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE]; | |
1293 | ||
1294 | static struct hstate *kobj_to_hstate(struct kobject *kobj) | |
1295 | { | |
1296 | int i; | |
1297 | for (i = 0; i < HUGE_MAX_HSTATE; i++) | |
1298 | if (hstate_kobjs[i] == kobj) | |
1299 | return &hstates[i]; | |
1300 | BUG(); | |
1301 | return NULL; | |
1302 | } | |
1303 | ||
1304 | static ssize_t nr_hugepages_show(struct kobject *kobj, | |
1305 | struct kobj_attribute *attr, char *buf) | |
1306 | { | |
1307 | struct hstate *h = kobj_to_hstate(kobj); | |
1308 | return sprintf(buf, "%lu\n", h->nr_huge_pages); | |
1309 | } | |
1310 | static ssize_t nr_hugepages_store(struct kobject *kobj, | |
1311 | struct kobj_attribute *attr, const char *buf, size_t count) | |
1312 | { | |
1313 | int err; | |
1314 | unsigned long input; | |
1315 | struct hstate *h = kobj_to_hstate(kobj); | |
1316 | ||
1317 | err = strict_strtoul(buf, 10, &input); | |
1318 | if (err) | |
1319 | return 0; | |
1320 | ||
1321 | h->max_huge_pages = set_max_huge_pages(h, input); | |
1322 | ||
1323 | return count; | |
1324 | } | |
1325 | HSTATE_ATTR(nr_hugepages); | |
1326 | ||
1327 | static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj, | |
1328 | struct kobj_attribute *attr, char *buf) | |
1329 | { | |
1330 | struct hstate *h = kobj_to_hstate(kobj); | |
1331 | return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages); | |
1332 | } | |
1333 | static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj, | |
1334 | struct kobj_attribute *attr, const char *buf, size_t count) | |
1335 | { | |
1336 | int err; | |
1337 | unsigned long input; | |
1338 | struct hstate *h = kobj_to_hstate(kobj); | |
1339 | ||
1340 | err = strict_strtoul(buf, 10, &input); | |
1341 | if (err) | |
1342 | return 0; | |
1343 | ||
1344 | spin_lock(&hugetlb_lock); | |
1345 | h->nr_overcommit_huge_pages = input; | |
1346 | spin_unlock(&hugetlb_lock); | |
1347 | ||
1348 | return count; | |
1349 | } | |
1350 | HSTATE_ATTR(nr_overcommit_hugepages); | |
1351 | ||
1352 | static ssize_t free_hugepages_show(struct kobject *kobj, | |
1353 | struct kobj_attribute *attr, char *buf) | |
1354 | { | |
1355 | struct hstate *h = kobj_to_hstate(kobj); | |
1356 | return sprintf(buf, "%lu\n", h->free_huge_pages); | |
1357 | } | |
1358 | HSTATE_ATTR_RO(free_hugepages); | |
1359 | ||
1360 | static ssize_t resv_hugepages_show(struct kobject *kobj, | |
1361 | struct kobj_attribute *attr, char *buf) | |
1362 | { | |
1363 | struct hstate *h = kobj_to_hstate(kobj); | |
1364 | return sprintf(buf, "%lu\n", h->resv_huge_pages); | |
1365 | } | |
1366 | HSTATE_ATTR_RO(resv_hugepages); | |
1367 | ||
1368 | static ssize_t surplus_hugepages_show(struct kobject *kobj, | |
1369 | struct kobj_attribute *attr, char *buf) | |
1370 | { | |
1371 | struct hstate *h = kobj_to_hstate(kobj); | |
1372 | return sprintf(buf, "%lu\n", h->surplus_huge_pages); | |
1373 | } | |
1374 | HSTATE_ATTR_RO(surplus_hugepages); | |
1375 | ||
1376 | static struct attribute *hstate_attrs[] = { | |
1377 | &nr_hugepages_attr.attr, | |
1378 | &nr_overcommit_hugepages_attr.attr, | |
1379 | &free_hugepages_attr.attr, | |
1380 | &resv_hugepages_attr.attr, | |
1381 | &surplus_hugepages_attr.attr, | |
1382 | NULL, | |
1383 | }; | |
1384 | ||
1385 | static struct attribute_group hstate_attr_group = { | |
1386 | .attrs = hstate_attrs, | |
1387 | }; | |
1388 | ||
1389 | static int __init hugetlb_sysfs_add_hstate(struct hstate *h) | |
1390 | { | |
1391 | int retval; | |
1392 | ||
1393 | hstate_kobjs[h - hstates] = kobject_create_and_add(h->name, | |
1394 | hugepages_kobj); | |
1395 | if (!hstate_kobjs[h - hstates]) | |
1396 | return -ENOMEM; | |
1397 | ||
1398 | retval = sysfs_create_group(hstate_kobjs[h - hstates], | |
1399 | &hstate_attr_group); | |
1400 | if (retval) | |
1401 | kobject_put(hstate_kobjs[h - hstates]); | |
1402 | ||
1403 | return retval; | |
1404 | } | |
1405 | ||
1406 | static void __init hugetlb_sysfs_init(void) | |
1407 | { | |
1408 | struct hstate *h; | |
1409 | int err; | |
1410 | ||
1411 | hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj); | |
1412 | if (!hugepages_kobj) | |
1413 | return; | |
1414 | ||
1415 | for_each_hstate(h) { | |
1416 | err = hugetlb_sysfs_add_hstate(h); | |
1417 | if (err) | |
1418 | printk(KERN_ERR "Hugetlb: Unable to add hstate %s", | |
1419 | h->name); | |
1420 | } | |
1421 | } | |
1422 | ||
1423 | static void __exit hugetlb_exit(void) | |
1424 | { | |
1425 | struct hstate *h; | |
1426 | ||
1427 | for_each_hstate(h) { | |
1428 | kobject_put(hstate_kobjs[h - hstates]); | |
1429 | } | |
1430 | ||
1431 | kobject_put(hugepages_kobj); | |
1432 | } | |
1433 | module_exit(hugetlb_exit); | |
1434 | ||
1435 | static int __init hugetlb_init(void) | |
1436 | { | |
0ef89d25 BH |
1437 | /* Some platform decide whether they support huge pages at boot |
1438 | * time. On these, such as powerpc, HPAGE_SHIFT is set to 0 when | |
1439 | * there is no such support | |
1440 | */ | |
1441 | if (HPAGE_SHIFT == 0) | |
1442 | return 0; | |
a3437870 | 1443 | |
e11bfbfc NP |
1444 | if (!size_to_hstate(default_hstate_size)) { |
1445 | default_hstate_size = HPAGE_SIZE; | |
1446 | if (!size_to_hstate(default_hstate_size)) | |
1447 | hugetlb_add_hstate(HUGETLB_PAGE_ORDER); | |
a3437870 | 1448 | } |
e11bfbfc NP |
1449 | default_hstate_idx = size_to_hstate(default_hstate_size) - hstates; |
1450 | if (default_hstate_max_huge_pages) | |
1451 | default_hstate.max_huge_pages = default_hstate_max_huge_pages; | |
a3437870 NA |
1452 | |
1453 | hugetlb_init_hstates(); | |
1454 | ||
aa888a74 AK |
1455 | gather_bootmem_prealloc(); |
1456 | ||
a3437870 NA |
1457 | report_hugepages(); |
1458 | ||
1459 | hugetlb_sysfs_init(); | |
1460 | ||
1461 | return 0; | |
1462 | } | |
1463 | module_init(hugetlb_init); | |
1464 | ||
1465 | /* Should be called on processing a hugepagesz=... option */ | |
1466 | void __init hugetlb_add_hstate(unsigned order) | |
1467 | { | |
1468 | struct hstate *h; | |
8faa8b07 AK |
1469 | unsigned long i; |
1470 | ||
a3437870 NA |
1471 | if (size_to_hstate(PAGE_SIZE << order)) { |
1472 | printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n"); | |
1473 | return; | |
1474 | } | |
1475 | BUG_ON(max_hstate >= HUGE_MAX_HSTATE); | |
1476 | BUG_ON(order == 0); | |
1477 | h = &hstates[max_hstate++]; | |
1478 | h->order = order; | |
1479 | h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1); | |
8faa8b07 AK |
1480 | h->nr_huge_pages = 0; |
1481 | h->free_huge_pages = 0; | |
1482 | for (i = 0; i < MAX_NUMNODES; ++i) | |
1483 | INIT_LIST_HEAD(&h->hugepage_freelists[i]); | |
e8c5c824 LS |
1484 | h->next_nid_to_alloc = first_node(node_online_map); |
1485 | h->next_nid_to_free = first_node(node_online_map); | |
a3437870 NA |
1486 | snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB", |
1487 | huge_page_size(h)/1024); | |
8faa8b07 | 1488 | |
a3437870 NA |
1489 | parsed_hstate = h; |
1490 | } | |
1491 | ||
e11bfbfc | 1492 | static int __init hugetlb_nrpages_setup(char *s) |
a3437870 NA |
1493 | { |
1494 | unsigned long *mhp; | |
8faa8b07 | 1495 | static unsigned long *last_mhp; |
a3437870 NA |
1496 | |
1497 | /* | |
1498 | * !max_hstate means we haven't parsed a hugepagesz= parameter yet, | |
1499 | * so this hugepages= parameter goes to the "default hstate". | |
1500 | */ | |
1501 | if (!max_hstate) | |
1502 | mhp = &default_hstate_max_huge_pages; | |
1503 | else | |
1504 | mhp = &parsed_hstate->max_huge_pages; | |
1505 | ||
8faa8b07 AK |
1506 | if (mhp == last_mhp) { |
1507 | printk(KERN_WARNING "hugepages= specified twice without " | |
1508 | "interleaving hugepagesz=, ignoring\n"); | |
1509 | return 1; | |
1510 | } | |
1511 | ||
a3437870 NA |
1512 | if (sscanf(s, "%lu", mhp) <= 0) |
1513 | *mhp = 0; | |
1514 | ||
8faa8b07 AK |
1515 | /* |
1516 | * Global state is always initialized later in hugetlb_init. | |
1517 | * But we need to allocate >= MAX_ORDER hstates here early to still | |
1518 | * use the bootmem allocator. | |
1519 | */ | |
1520 | if (max_hstate && parsed_hstate->order >= MAX_ORDER) | |
1521 | hugetlb_hstate_alloc_pages(parsed_hstate); | |
1522 | ||
1523 | last_mhp = mhp; | |
1524 | ||
a3437870 NA |
1525 | return 1; |
1526 | } | |
e11bfbfc NP |
1527 | __setup("hugepages=", hugetlb_nrpages_setup); |
1528 | ||
1529 | static int __init hugetlb_default_setup(char *s) | |
1530 | { | |
1531 | default_hstate_size = memparse(s, &s); | |
1532 | return 1; | |
1533 | } | |
1534 | __setup("default_hugepagesz=", hugetlb_default_setup); | |
a3437870 | 1535 | |
8a213460 NA |
1536 | static unsigned int cpuset_mems_nr(unsigned int *array) |
1537 | { | |
1538 | int node; | |
1539 | unsigned int nr = 0; | |
1540 | ||
1541 | for_each_node_mask(node, cpuset_current_mems_allowed) | |
1542 | nr += array[node]; | |
1543 | ||
1544 | return nr; | |
1545 | } | |
1546 | ||
1547 | #ifdef CONFIG_SYSCTL | |
1da177e4 LT |
1548 | int hugetlb_sysctl_handler(struct ctl_table *table, int write, |
1549 | struct file *file, void __user *buffer, | |
1550 | size_t *length, loff_t *ppos) | |
1551 | { | |
e5ff2159 AK |
1552 | struct hstate *h = &default_hstate; |
1553 | unsigned long tmp; | |
1554 | ||
1555 | if (!write) | |
1556 | tmp = h->max_huge_pages; | |
1557 | ||
1558 | table->data = &tmp; | |
1559 | table->maxlen = sizeof(unsigned long); | |
1da177e4 | 1560 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
e5ff2159 AK |
1561 | |
1562 | if (write) | |
1563 | h->max_huge_pages = set_max_huge_pages(h, tmp); | |
1564 | ||
1da177e4 LT |
1565 | return 0; |
1566 | } | |
396faf03 MG |
1567 | |
1568 | int hugetlb_treat_movable_handler(struct ctl_table *table, int write, | |
1569 | struct file *file, void __user *buffer, | |
1570 | size_t *length, loff_t *ppos) | |
1571 | { | |
1572 | proc_dointvec(table, write, file, buffer, length, ppos); | |
1573 | if (hugepages_treat_as_movable) | |
1574 | htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; | |
1575 | else | |
1576 | htlb_alloc_mask = GFP_HIGHUSER; | |
1577 | return 0; | |
1578 | } | |
1579 | ||
a3d0c6aa NA |
1580 | int hugetlb_overcommit_handler(struct ctl_table *table, int write, |
1581 | struct file *file, void __user *buffer, | |
1582 | size_t *length, loff_t *ppos) | |
1583 | { | |
a5516438 | 1584 | struct hstate *h = &default_hstate; |
e5ff2159 AK |
1585 | unsigned long tmp; |
1586 | ||
1587 | if (!write) | |
1588 | tmp = h->nr_overcommit_huge_pages; | |
1589 | ||
1590 | table->data = &tmp; | |
1591 | table->maxlen = sizeof(unsigned long); | |
a3d0c6aa | 1592 | proc_doulongvec_minmax(table, write, file, buffer, length, ppos); |
e5ff2159 AK |
1593 | |
1594 | if (write) { | |
1595 | spin_lock(&hugetlb_lock); | |
1596 | h->nr_overcommit_huge_pages = tmp; | |
1597 | spin_unlock(&hugetlb_lock); | |
1598 | } | |
1599 | ||
a3d0c6aa NA |
1600 | return 0; |
1601 | } | |
1602 | ||
1da177e4 LT |
1603 | #endif /* CONFIG_SYSCTL */ |
1604 | ||
e1759c21 | 1605 | void hugetlb_report_meminfo(struct seq_file *m) |
1da177e4 | 1606 | { |
a5516438 | 1607 | struct hstate *h = &default_hstate; |
e1759c21 | 1608 | seq_printf(m, |
4f98a2fe RR |
1609 | "HugePages_Total: %5lu\n" |
1610 | "HugePages_Free: %5lu\n" | |
1611 | "HugePages_Rsvd: %5lu\n" | |
1612 | "HugePages_Surp: %5lu\n" | |
1613 | "Hugepagesize: %8lu kB\n", | |
a5516438 AK |
1614 | h->nr_huge_pages, |
1615 | h->free_huge_pages, | |
1616 | h->resv_huge_pages, | |
1617 | h->surplus_huge_pages, | |
1618 | 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); | |
1da177e4 LT |
1619 | } |
1620 | ||
1621 | int hugetlb_report_node_meminfo(int nid, char *buf) | |
1622 | { | |
a5516438 | 1623 | struct hstate *h = &default_hstate; |
1da177e4 LT |
1624 | return sprintf(buf, |
1625 | "Node %d HugePages_Total: %5u\n" | |
a1de0919 NA |
1626 | "Node %d HugePages_Free: %5u\n" |
1627 | "Node %d HugePages_Surp: %5u\n", | |
a5516438 AK |
1628 | nid, h->nr_huge_pages_node[nid], |
1629 | nid, h->free_huge_pages_node[nid], | |
1630 | nid, h->surplus_huge_pages_node[nid]); | |
1da177e4 LT |
1631 | } |
1632 | ||
1da177e4 LT |
1633 | /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ |
1634 | unsigned long hugetlb_total_pages(void) | |
1635 | { | |
a5516438 AK |
1636 | struct hstate *h = &default_hstate; |
1637 | return h->nr_huge_pages * pages_per_huge_page(h); | |
1da177e4 | 1638 | } |
1da177e4 | 1639 | |
a5516438 | 1640 | static int hugetlb_acct_memory(struct hstate *h, long delta) |
fc1b8a73 MG |
1641 | { |
1642 | int ret = -ENOMEM; | |
1643 | ||
1644 | spin_lock(&hugetlb_lock); | |
1645 | /* | |
1646 | * When cpuset is configured, it breaks the strict hugetlb page | |
1647 | * reservation as the accounting is done on a global variable. Such | |
1648 | * reservation is completely rubbish in the presence of cpuset because | |
1649 | * the reservation is not checked against page availability for the | |
1650 | * current cpuset. Application can still potentially OOM'ed by kernel | |
1651 | * with lack of free htlb page in cpuset that the task is in. | |
1652 | * Attempt to enforce strict accounting with cpuset is almost | |
1653 | * impossible (or too ugly) because cpuset is too fluid that | |
1654 | * task or memory node can be dynamically moved between cpusets. | |
1655 | * | |
1656 | * The change of semantics for shared hugetlb mapping with cpuset is | |
1657 | * undesirable. However, in order to preserve some of the semantics, | |
1658 | * we fall back to check against current free page availability as | |
1659 | * a best attempt and hopefully to minimize the impact of changing | |
1660 | * semantics that cpuset has. | |
1661 | */ | |
1662 | if (delta > 0) { | |
a5516438 | 1663 | if (gather_surplus_pages(h, delta) < 0) |
fc1b8a73 MG |
1664 | goto out; |
1665 | ||
a5516438 AK |
1666 | if (delta > cpuset_mems_nr(h->free_huge_pages_node)) { |
1667 | return_unused_surplus_pages(h, delta); | |
fc1b8a73 MG |
1668 | goto out; |
1669 | } | |
1670 | } | |
1671 | ||
1672 | ret = 0; | |
1673 | if (delta < 0) | |
a5516438 | 1674 | return_unused_surplus_pages(h, (unsigned long) -delta); |
fc1b8a73 MG |
1675 | |
1676 | out: | |
1677 | spin_unlock(&hugetlb_lock); | |
1678 | return ret; | |
1679 | } | |
1680 | ||
84afd99b AW |
1681 | static void hugetlb_vm_op_open(struct vm_area_struct *vma) |
1682 | { | |
1683 | struct resv_map *reservations = vma_resv_map(vma); | |
1684 | ||
1685 | /* | |
1686 | * This new VMA should share its siblings reservation map if present. | |
1687 | * The VMA will only ever have a valid reservation map pointer where | |
1688 | * it is being copied for another still existing VMA. As that VMA | |
1689 | * has a reference to the reservation map it cannot dissappear until | |
1690 | * after this open call completes. It is therefore safe to take a | |
1691 | * new reference here without additional locking. | |
1692 | */ | |
1693 | if (reservations) | |
1694 | kref_get(&reservations->refs); | |
1695 | } | |
1696 | ||
a1e78772 MG |
1697 | static void hugetlb_vm_op_close(struct vm_area_struct *vma) |
1698 | { | |
a5516438 | 1699 | struct hstate *h = hstate_vma(vma); |
84afd99b AW |
1700 | struct resv_map *reservations = vma_resv_map(vma); |
1701 | unsigned long reserve; | |
1702 | unsigned long start; | |
1703 | unsigned long end; | |
1704 | ||
1705 | if (reservations) { | |
a5516438 AK |
1706 | start = vma_hugecache_offset(h, vma, vma->vm_start); |
1707 | end = vma_hugecache_offset(h, vma, vma->vm_end); | |
84afd99b AW |
1708 | |
1709 | reserve = (end - start) - | |
1710 | region_count(&reservations->regions, start, end); | |
1711 | ||
1712 | kref_put(&reservations->refs, resv_map_release); | |
1713 | ||
7251ff78 | 1714 | if (reserve) { |
a5516438 | 1715 | hugetlb_acct_memory(h, -reserve); |
7251ff78 AL |
1716 | hugetlb_put_quota(vma->vm_file->f_mapping, reserve); |
1717 | } | |
84afd99b | 1718 | } |
a1e78772 MG |
1719 | } |
1720 | ||
1da177e4 LT |
1721 | /* |
1722 | * We cannot handle pagefaults against hugetlb pages at all. They cause | |
1723 | * handle_mm_fault() to try to instantiate regular-sized pages in the | |
1724 | * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get | |
1725 | * this far. | |
1726 | */ | |
d0217ac0 | 1727 | static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
1da177e4 LT |
1728 | { |
1729 | BUG(); | |
d0217ac0 | 1730 | return 0; |
1da177e4 LT |
1731 | } |
1732 | ||
1733 | struct vm_operations_struct hugetlb_vm_ops = { | |
d0217ac0 | 1734 | .fault = hugetlb_vm_op_fault, |
84afd99b | 1735 | .open = hugetlb_vm_op_open, |
a1e78772 | 1736 | .close = hugetlb_vm_op_close, |
1da177e4 LT |
1737 | }; |
1738 | ||
1e8f889b DG |
1739 | static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page, |
1740 | int writable) | |
63551ae0 DG |
1741 | { |
1742 | pte_t entry; | |
1743 | ||
1e8f889b | 1744 | if (writable) { |
63551ae0 DG |
1745 | entry = |
1746 | pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); | |
1747 | } else { | |
7f2e9525 | 1748 | entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot)); |
63551ae0 DG |
1749 | } |
1750 | entry = pte_mkyoung(entry); | |
1751 | entry = pte_mkhuge(entry); | |
1752 | ||
1753 | return entry; | |
1754 | } | |
1755 | ||
1e8f889b DG |
1756 | static void set_huge_ptep_writable(struct vm_area_struct *vma, |
1757 | unsigned long address, pte_t *ptep) | |
1758 | { | |
1759 | pte_t entry; | |
1760 | ||
7f2e9525 GS |
1761 | entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep))); |
1762 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) { | |
8dab5241 | 1763 | update_mmu_cache(vma, address, entry); |
8dab5241 | 1764 | } |
1e8f889b DG |
1765 | } |
1766 | ||
1767 | ||
63551ae0 DG |
1768 | int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, |
1769 | struct vm_area_struct *vma) | |
1770 | { | |
1771 | pte_t *src_pte, *dst_pte, entry; | |
1772 | struct page *ptepage; | |
1c59827d | 1773 | unsigned long addr; |
1e8f889b | 1774 | int cow; |
a5516438 AK |
1775 | struct hstate *h = hstate_vma(vma); |
1776 | unsigned long sz = huge_page_size(h); | |
1e8f889b DG |
1777 | |
1778 | cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; | |
63551ae0 | 1779 | |
a5516438 | 1780 | for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) { |
c74df32c HD |
1781 | src_pte = huge_pte_offset(src, addr); |
1782 | if (!src_pte) | |
1783 | continue; | |
a5516438 | 1784 | dst_pte = huge_pte_alloc(dst, addr, sz); |
63551ae0 DG |
1785 | if (!dst_pte) |
1786 | goto nomem; | |
c5c99429 LW |
1787 | |
1788 | /* If the pagetables are shared don't copy or take references */ | |
1789 | if (dst_pte == src_pte) | |
1790 | continue; | |
1791 | ||
c74df32c | 1792 | spin_lock(&dst->page_table_lock); |
46478758 | 1793 | spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING); |
7f2e9525 | 1794 | if (!huge_pte_none(huge_ptep_get(src_pte))) { |
1e8f889b | 1795 | if (cow) |
7f2e9525 GS |
1796 | huge_ptep_set_wrprotect(src, addr, src_pte); |
1797 | entry = huge_ptep_get(src_pte); | |
1c59827d HD |
1798 | ptepage = pte_page(entry); |
1799 | get_page(ptepage); | |
1c59827d HD |
1800 | set_huge_pte_at(dst, addr, dst_pte, entry); |
1801 | } | |
1802 | spin_unlock(&src->page_table_lock); | |
c74df32c | 1803 | spin_unlock(&dst->page_table_lock); |
63551ae0 DG |
1804 | } |
1805 | return 0; | |
1806 | ||
1807 | nomem: | |
1808 | return -ENOMEM; | |
1809 | } | |
1810 | ||
502717f4 | 1811 | void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1812 | unsigned long end, struct page *ref_page) |
63551ae0 DG |
1813 | { |
1814 | struct mm_struct *mm = vma->vm_mm; | |
1815 | unsigned long address; | |
c7546f8f | 1816 | pte_t *ptep; |
63551ae0 DG |
1817 | pte_t pte; |
1818 | struct page *page; | |
fe1668ae | 1819 | struct page *tmp; |
a5516438 AK |
1820 | struct hstate *h = hstate_vma(vma); |
1821 | unsigned long sz = huge_page_size(h); | |
1822 | ||
c0a499c2 CK |
1823 | /* |
1824 | * A page gathering list, protected by per file i_mmap_lock. The | |
1825 | * lock is used to avoid list corruption from multiple unmapping | |
1826 | * of the same page since we are using page->lru. | |
1827 | */ | |
fe1668ae | 1828 | LIST_HEAD(page_list); |
63551ae0 DG |
1829 | |
1830 | WARN_ON(!is_vm_hugetlb_page(vma)); | |
a5516438 AK |
1831 | BUG_ON(start & ~huge_page_mask(h)); |
1832 | BUG_ON(end & ~huge_page_mask(h)); | |
63551ae0 | 1833 | |
cddb8a5c | 1834 | mmu_notifier_invalidate_range_start(mm, start, end); |
508034a3 | 1835 | spin_lock(&mm->page_table_lock); |
a5516438 | 1836 | for (address = start; address < end; address += sz) { |
c7546f8f | 1837 | ptep = huge_pte_offset(mm, address); |
4c887265 | 1838 | if (!ptep) |
c7546f8f DG |
1839 | continue; |
1840 | ||
39dde65c CK |
1841 | if (huge_pmd_unshare(mm, &address, ptep)) |
1842 | continue; | |
1843 | ||
04f2cbe3 MG |
1844 | /* |
1845 | * If a reference page is supplied, it is because a specific | |
1846 | * page is being unmapped, not a range. Ensure the page we | |
1847 | * are about to unmap is the actual page of interest. | |
1848 | */ | |
1849 | if (ref_page) { | |
1850 | pte = huge_ptep_get(ptep); | |
1851 | if (huge_pte_none(pte)) | |
1852 | continue; | |
1853 | page = pte_page(pte); | |
1854 | if (page != ref_page) | |
1855 | continue; | |
1856 | ||
1857 | /* | |
1858 | * Mark the VMA as having unmapped its page so that | |
1859 | * future faults in this VMA will fail rather than | |
1860 | * looking like data was lost | |
1861 | */ | |
1862 | set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED); | |
1863 | } | |
1864 | ||
c7546f8f | 1865 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
7f2e9525 | 1866 | if (huge_pte_none(pte)) |
63551ae0 | 1867 | continue; |
c7546f8f | 1868 | |
63551ae0 | 1869 | page = pte_page(pte); |
6649a386 KC |
1870 | if (pte_dirty(pte)) |
1871 | set_page_dirty(page); | |
fe1668ae | 1872 | list_add(&page->lru, &page_list); |
63551ae0 | 1873 | } |
1da177e4 | 1874 | spin_unlock(&mm->page_table_lock); |
508034a3 | 1875 | flush_tlb_range(vma, start, end); |
cddb8a5c | 1876 | mmu_notifier_invalidate_range_end(mm, start, end); |
fe1668ae CK |
1877 | list_for_each_entry_safe(page, tmp, &page_list, lru) { |
1878 | list_del(&page->lru); | |
1879 | put_page(page); | |
1880 | } | |
1da177e4 | 1881 | } |
63551ae0 | 1882 | |
502717f4 | 1883 | void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, |
04f2cbe3 | 1884 | unsigned long end, struct page *ref_page) |
502717f4 | 1885 | { |
a137e1cc AK |
1886 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
1887 | __unmap_hugepage_range(vma, start, end, ref_page); | |
1888 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); | |
502717f4 CK |
1889 | } |
1890 | ||
04f2cbe3 MG |
1891 | /* |
1892 | * This is called when the original mapper is failing to COW a MAP_PRIVATE | |
1893 | * mappping it owns the reserve page for. The intention is to unmap the page | |
1894 | * from other VMAs and let the children be SIGKILLed if they are faulting the | |
1895 | * same region. | |
1896 | */ | |
2a4b3ded HH |
1897 | static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, |
1898 | struct page *page, unsigned long address) | |
04f2cbe3 | 1899 | { |
7526674d | 1900 | struct hstate *h = hstate_vma(vma); |
04f2cbe3 MG |
1901 | struct vm_area_struct *iter_vma; |
1902 | struct address_space *mapping; | |
1903 | struct prio_tree_iter iter; | |
1904 | pgoff_t pgoff; | |
1905 | ||
1906 | /* | |
1907 | * vm_pgoff is in PAGE_SIZE units, hence the different calculation | |
1908 | * from page cache lookup which is in HPAGE_SIZE units. | |
1909 | */ | |
7526674d | 1910 | address = address & huge_page_mask(h); |
04f2cbe3 MG |
1911 | pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) |
1912 | + (vma->vm_pgoff >> PAGE_SHIFT); | |
1913 | mapping = (struct address_space *)page_private(page); | |
1914 | ||
1915 | vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { | |
1916 | /* Do not unmap the current VMA */ | |
1917 | if (iter_vma == vma) | |
1918 | continue; | |
1919 | ||
1920 | /* | |
1921 | * Unmap the page from other VMAs without their own reserves. | |
1922 | * They get marked to be SIGKILLed if they fault in these | |
1923 | * areas. This is because a future no-page fault on this VMA | |
1924 | * could insert a zeroed page instead of the data existing | |
1925 | * from the time of fork. This would look like data corruption | |
1926 | */ | |
1927 | if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) | |
1928 | unmap_hugepage_range(iter_vma, | |
7526674d | 1929 | address, address + huge_page_size(h), |
04f2cbe3 MG |
1930 | page); |
1931 | } | |
1932 | ||
1933 | return 1; | |
1934 | } | |
1935 | ||
1e8f889b | 1936 | static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |
04f2cbe3 MG |
1937 | unsigned long address, pte_t *ptep, pte_t pte, |
1938 | struct page *pagecache_page) | |
1e8f889b | 1939 | { |
a5516438 | 1940 | struct hstate *h = hstate_vma(vma); |
1e8f889b | 1941 | struct page *old_page, *new_page; |
79ac6ba4 | 1942 | int avoidcopy; |
04f2cbe3 | 1943 | int outside_reserve = 0; |
1e8f889b DG |
1944 | |
1945 | old_page = pte_page(pte); | |
1946 | ||
04f2cbe3 | 1947 | retry_avoidcopy: |
1e8f889b DG |
1948 | /* If no-one else is actually using this page, avoid the copy |
1949 | * and just make the page writable */ | |
1950 | avoidcopy = (page_count(old_page) == 1); | |
1951 | if (avoidcopy) { | |
1952 | set_huge_ptep_writable(vma, address, ptep); | |
83c54070 | 1953 | return 0; |
1e8f889b DG |
1954 | } |
1955 | ||
04f2cbe3 MG |
1956 | /* |
1957 | * If the process that created a MAP_PRIVATE mapping is about to | |
1958 | * perform a COW due to a shared page count, attempt to satisfy | |
1959 | * the allocation without using the existing reserves. The pagecache | |
1960 | * page is used to determine if the reserve at this address was | |
1961 | * consumed or not. If reserves were used, a partial faulted mapping | |
1962 | * at the time of fork() could consume its reserves on COW instead | |
1963 | * of the full address range. | |
1964 | */ | |
f83a275d | 1965 | if (!(vma->vm_flags & VM_MAYSHARE) && |
04f2cbe3 MG |
1966 | is_vma_resv_set(vma, HPAGE_RESV_OWNER) && |
1967 | old_page != pagecache_page) | |
1968 | outside_reserve = 1; | |
1969 | ||
1e8f889b | 1970 | page_cache_get(old_page); |
04f2cbe3 | 1971 | new_page = alloc_huge_page(vma, address, outside_reserve); |
1e8f889b | 1972 | |
2fc39cec | 1973 | if (IS_ERR(new_page)) { |
1e8f889b | 1974 | page_cache_release(old_page); |
04f2cbe3 MG |
1975 | |
1976 | /* | |
1977 | * If a process owning a MAP_PRIVATE mapping fails to COW, | |
1978 | * it is due to references held by a child and an insufficient | |
1979 | * huge page pool. To guarantee the original mappers | |
1980 | * reliability, unmap the page from child processes. The child | |
1981 | * may get SIGKILLed if it later faults. | |
1982 | */ | |
1983 | if (outside_reserve) { | |
1984 | BUG_ON(huge_pte_none(pte)); | |
1985 | if (unmap_ref_private(mm, vma, old_page, address)) { | |
1986 | BUG_ON(page_count(old_page) != 1); | |
1987 | BUG_ON(huge_pte_none(pte)); | |
1988 | goto retry_avoidcopy; | |
1989 | } | |
1990 | WARN_ON_ONCE(1); | |
1991 | } | |
1992 | ||
2fc39cec | 1993 | return -PTR_ERR(new_page); |
1e8f889b DG |
1994 | } |
1995 | ||
1996 | spin_unlock(&mm->page_table_lock); | |
9de455b2 | 1997 | copy_huge_page(new_page, old_page, address, vma); |
0ed361de | 1998 | __SetPageUptodate(new_page); |
1e8f889b DG |
1999 | spin_lock(&mm->page_table_lock); |
2000 | ||
a5516438 | 2001 | ptep = huge_pte_offset(mm, address & huge_page_mask(h)); |
7f2e9525 | 2002 | if (likely(pte_same(huge_ptep_get(ptep), pte))) { |
1e8f889b | 2003 | /* Break COW */ |
8fe627ec | 2004 | huge_ptep_clear_flush(vma, address, ptep); |
1e8f889b DG |
2005 | set_huge_pte_at(mm, address, ptep, |
2006 | make_huge_pte(vma, new_page, 1)); | |
2007 | /* Make the old page be freed below */ | |
2008 | new_page = old_page; | |
2009 | } | |
2010 | page_cache_release(new_page); | |
2011 | page_cache_release(old_page); | |
83c54070 | 2012 | return 0; |
1e8f889b DG |
2013 | } |
2014 | ||
04f2cbe3 | 2015 | /* Return the pagecache page at a given address within a VMA */ |
a5516438 AK |
2016 | static struct page *hugetlbfs_pagecache_page(struct hstate *h, |
2017 | struct vm_area_struct *vma, unsigned long address) | |
04f2cbe3 MG |
2018 | { |
2019 | struct address_space *mapping; | |
e7c4b0bf | 2020 | pgoff_t idx; |
04f2cbe3 MG |
2021 | |
2022 | mapping = vma->vm_file->f_mapping; | |
a5516438 | 2023 | idx = vma_hugecache_offset(h, vma, address); |
04f2cbe3 MG |
2024 | |
2025 | return find_lock_page(mapping, idx); | |
2026 | } | |
2027 | ||
a1ed3dda | 2028 | static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, |
788c7df4 | 2029 | unsigned long address, pte_t *ptep, unsigned int flags) |
ac9b9c66 | 2030 | { |
a5516438 | 2031 | struct hstate *h = hstate_vma(vma); |
ac9b9c66 | 2032 | int ret = VM_FAULT_SIGBUS; |
e7c4b0bf | 2033 | pgoff_t idx; |
4c887265 | 2034 | unsigned long size; |
4c887265 AL |
2035 | struct page *page; |
2036 | struct address_space *mapping; | |
1e8f889b | 2037 | pte_t new_pte; |
4c887265 | 2038 | |
04f2cbe3 MG |
2039 | /* |
2040 | * Currently, we are forced to kill the process in the event the | |
2041 | * original mapper has unmapped pages from the child due to a failed | |
2042 | * COW. Warn that such a situation has occured as it may not be obvious | |
2043 | */ | |
2044 | if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) { | |
2045 | printk(KERN_WARNING | |
2046 | "PID %d killed due to inadequate hugepage pool\n", | |
2047 | current->pid); | |
2048 | return ret; | |
2049 | } | |
2050 | ||
4c887265 | 2051 | mapping = vma->vm_file->f_mapping; |
a5516438 | 2052 | idx = vma_hugecache_offset(h, vma, address); |
4c887265 AL |
2053 | |
2054 | /* | |
2055 | * Use page lock to guard against racing truncation | |
2056 | * before we get page_table_lock. | |
2057 | */ | |
6bda666a CL |
2058 | retry: |
2059 | page = find_lock_page(mapping, idx); | |
2060 | if (!page) { | |
a5516438 | 2061 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
ebed4bfc HD |
2062 | if (idx >= size) |
2063 | goto out; | |
04f2cbe3 | 2064 | page = alloc_huge_page(vma, address, 0); |
2fc39cec AL |
2065 | if (IS_ERR(page)) { |
2066 | ret = -PTR_ERR(page); | |
6bda666a CL |
2067 | goto out; |
2068 | } | |
a5516438 | 2069 | clear_huge_page(page, address, huge_page_size(h)); |
0ed361de | 2070 | __SetPageUptodate(page); |
ac9b9c66 | 2071 | |
f83a275d | 2072 | if (vma->vm_flags & VM_MAYSHARE) { |
6bda666a | 2073 | int err; |
45c682a6 | 2074 | struct inode *inode = mapping->host; |
6bda666a CL |
2075 | |
2076 | err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); | |
2077 | if (err) { | |
2078 | put_page(page); | |
6bda666a CL |
2079 | if (err == -EEXIST) |
2080 | goto retry; | |
2081 | goto out; | |
2082 | } | |
45c682a6 KC |
2083 | |
2084 | spin_lock(&inode->i_lock); | |
a5516438 | 2085 | inode->i_blocks += blocks_per_huge_page(h); |
45c682a6 | 2086 | spin_unlock(&inode->i_lock); |
6bda666a CL |
2087 | } else |
2088 | lock_page(page); | |
2089 | } | |
1e8f889b | 2090 | |
57303d80 AW |
2091 | /* |
2092 | * If we are going to COW a private mapping later, we examine the | |
2093 | * pending reservations for this page now. This will ensure that | |
2094 | * any allocations necessary to record that reservation occur outside | |
2095 | * the spinlock. | |
2096 | */ | |
788c7df4 | 2097 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) |
2b26736c AW |
2098 | if (vma_needs_reservation(h, vma, address) < 0) { |
2099 | ret = VM_FAULT_OOM; | |
2100 | goto backout_unlocked; | |
2101 | } | |
57303d80 | 2102 | |
ac9b9c66 | 2103 | spin_lock(&mm->page_table_lock); |
a5516438 | 2104 | size = i_size_read(mapping->host) >> huge_page_shift(h); |
4c887265 AL |
2105 | if (idx >= size) |
2106 | goto backout; | |
2107 | ||
83c54070 | 2108 | ret = 0; |
7f2e9525 | 2109 | if (!huge_pte_none(huge_ptep_get(ptep))) |
4c887265 AL |
2110 | goto backout; |
2111 | ||
1e8f889b DG |
2112 | new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) |
2113 | && (vma->vm_flags & VM_SHARED))); | |
2114 | set_huge_pte_at(mm, address, ptep, new_pte); | |
2115 | ||
788c7df4 | 2116 | if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) { |
1e8f889b | 2117 | /* Optimization, do the COW without a second fault */ |
04f2cbe3 | 2118 | ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page); |
1e8f889b DG |
2119 | } |
2120 | ||
ac9b9c66 | 2121 | spin_unlock(&mm->page_table_lock); |
4c887265 AL |
2122 | unlock_page(page); |
2123 | out: | |
ac9b9c66 | 2124 | return ret; |
4c887265 AL |
2125 | |
2126 | backout: | |
2127 | spin_unlock(&mm->page_table_lock); | |
2b26736c | 2128 | backout_unlocked: |
4c887265 AL |
2129 | unlock_page(page); |
2130 | put_page(page); | |
2131 | goto out; | |
ac9b9c66 HD |
2132 | } |
2133 | ||
86e5216f | 2134 | int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, |
788c7df4 | 2135 | unsigned long address, unsigned int flags) |
86e5216f AL |
2136 | { |
2137 | pte_t *ptep; | |
2138 | pte_t entry; | |
1e8f889b | 2139 | int ret; |
57303d80 | 2140 | struct page *pagecache_page = NULL; |
3935baa9 | 2141 | static DEFINE_MUTEX(hugetlb_instantiation_mutex); |
a5516438 | 2142 | struct hstate *h = hstate_vma(vma); |
86e5216f | 2143 | |
a5516438 | 2144 | ptep = huge_pte_alloc(mm, address, huge_page_size(h)); |
86e5216f AL |
2145 | if (!ptep) |
2146 | return VM_FAULT_OOM; | |
2147 | ||
3935baa9 DG |
2148 | /* |
2149 | * Serialize hugepage allocation and instantiation, so that we don't | |
2150 | * get spurious allocation failures if two CPUs race to instantiate | |
2151 | * the same page in the page cache. | |
2152 | */ | |
2153 | mutex_lock(&hugetlb_instantiation_mutex); | |
7f2e9525 GS |
2154 | entry = huge_ptep_get(ptep); |
2155 | if (huge_pte_none(entry)) { | |
788c7df4 | 2156 | ret = hugetlb_no_page(mm, vma, address, ptep, flags); |
b4d1d99f | 2157 | goto out_mutex; |
3935baa9 | 2158 | } |
86e5216f | 2159 | |
83c54070 | 2160 | ret = 0; |
1e8f889b | 2161 | |
57303d80 AW |
2162 | /* |
2163 | * If we are going to COW the mapping later, we examine the pending | |
2164 | * reservations for this page now. This will ensure that any | |
2165 | * allocations necessary to record that reservation occur outside the | |
2166 | * spinlock. For private mappings, we also lookup the pagecache | |
2167 | * page now as it is used to determine if a reservation has been | |
2168 | * consumed. | |
2169 | */ | |
788c7df4 | 2170 | if ((flags & FAULT_FLAG_WRITE) && !pte_write(entry)) { |
2b26736c AW |
2171 | if (vma_needs_reservation(h, vma, address) < 0) { |
2172 | ret = VM_FAULT_OOM; | |
b4d1d99f | 2173 | goto out_mutex; |
2b26736c | 2174 | } |
57303d80 | 2175 | |
f83a275d | 2176 | if (!(vma->vm_flags & VM_MAYSHARE)) |
57303d80 AW |
2177 | pagecache_page = hugetlbfs_pagecache_page(h, |
2178 | vma, address); | |
2179 | } | |
2180 | ||
1e8f889b DG |
2181 | spin_lock(&mm->page_table_lock); |
2182 | /* Check for a racing update before calling hugetlb_cow */ | |
b4d1d99f DG |
2183 | if (unlikely(!pte_same(entry, huge_ptep_get(ptep)))) |
2184 | goto out_page_table_lock; | |
2185 | ||
2186 | ||
788c7df4 | 2187 | if (flags & FAULT_FLAG_WRITE) { |
b4d1d99f | 2188 | if (!pte_write(entry)) { |
57303d80 AW |
2189 | ret = hugetlb_cow(mm, vma, address, ptep, entry, |
2190 | pagecache_page); | |
b4d1d99f DG |
2191 | goto out_page_table_lock; |
2192 | } | |
2193 | entry = pte_mkdirty(entry); | |
2194 | } | |
2195 | entry = pte_mkyoung(entry); | |
788c7df4 HD |
2196 | if (huge_ptep_set_access_flags(vma, address, ptep, entry, |
2197 | flags & FAULT_FLAG_WRITE)) | |
b4d1d99f DG |
2198 | update_mmu_cache(vma, address, entry); |
2199 | ||
2200 | out_page_table_lock: | |
1e8f889b | 2201 | spin_unlock(&mm->page_table_lock); |
57303d80 AW |
2202 | |
2203 | if (pagecache_page) { | |
2204 | unlock_page(pagecache_page); | |
2205 | put_page(pagecache_page); | |
2206 | } | |
2207 | ||
b4d1d99f | 2208 | out_mutex: |
3935baa9 | 2209 | mutex_unlock(&hugetlb_instantiation_mutex); |
1e8f889b DG |
2210 | |
2211 | return ret; | |
86e5216f AL |
2212 | } |
2213 | ||
ceb86879 AK |
2214 | /* Can be overriden by architectures */ |
2215 | __attribute__((weak)) struct page * | |
2216 | follow_huge_pud(struct mm_struct *mm, unsigned long address, | |
2217 | pud_t *pud, int write) | |
2218 | { | |
2219 | BUG(); | |
2220 | return NULL; | |
2221 | } | |
2222 | ||
4b2e38ad KM |
2223 | static int huge_zeropage_ok(pte_t *ptep, int write, int shared) |
2224 | { | |
2225 | if (!ptep || write || shared) | |
2226 | return 0; | |
2227 | else | |
2228 | return huge_pte_none(huge_ptep_get(ptep)); | |
2229 | } | |
2230 | ||
63551ae0 DG |
2231 | int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, |
2232 | struct page **pages, struct vm_area_struct **vmas, | |
5b23dbe8 AL |
2233 | unsigned long *position, int *length, int i, |
2234 | int write) | |
63551ae0 | 2235 | { |
d5d4b0aa CK |
2236 | unsigned long pfn_offset; |
2237 | unsigned long vaddr = *position; | |
63551ae0 | 2238 | int remainder = *length; |
a5516438 | 2239 | struct hstate *h = hstate_vma(vma); |
4b2e38ad KM |
2240 | int zeropage_ok = 0; |
2241 | int shared = vma->vm_flags & VM_SHARED; | |
63551ae0 | 2242 | |
1c59827d | 2243 | spin_lock(&mm->page_table_lock); |
63551ae0 | 2244 | while (vaddr < vma->vm_end && remainder) { |
4c887265 AL |
2245 | pte_t *pte; |
2246 | struct page *page; | |
63551ae0 | 2247 | |
4c887265 AL |
2248 | /* |
2249 | * Some archs (sparc64, sh*) have multiple pte_ts to | |
2250 | * each hugepage. We have to make * sure we get the | |
2251 | * first, for the page indexing below to work. | |
2252 | */ | |
a5516438 | 2253 | pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); |
4b2e38ad KM |
2254 | if (huge_zeropage_ok(pte, write, shared)) |
2255 | zeropage_ok = 1; | |
63551ae0 | 2256 | |
4b2e38ad KM |
2257 | if (!pte || |
2258 | (huge_pte_none(huge_ptep_get(pte)) && !zeropage_ok) || | |
7f2e9525 | 2259 | (write && !pte_write(huge_ptep_get(pte)))) { |
4c887265 | 2260 | int ret; |
63551ae0 | 2261 | |
4c887265 | 2262 | spin_unlock(&mm->page_table_lock); |
5b23dbe8 | 2263 | ret = hugetlb_fault(mm, vma, vaddr, write); |
4c887265 | 2264 | spin_lock(&mm->page_table_lock); |
a89182c7 | 2265 | if (!(ret & VM_FAULT_ERROR)) |
4c887265 | 2266 | continue; |
63551ae0 | 2267 | |
4c887265 AL |
2268 | remainder = 0; |
2269 | if (!i) | |
2270 | i = -EFAULT; | |
2271 | break; | |
2272 | } | |
2273 | ||
a5516438 | 2274 | pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT; |
7f2e9525 | 2275 | page = pte_page(huge_ptep_get(pte)); |
d5d4b0aa | 2276 | same_page: |
d6692183 | 2277 | if (pages) { |
4b2e38ad KM |
2278 | if (zeropage_ok) |
2279 | pages[i] = ZERO_PAGE(0); | |
2280 | else | |
69d177c2 | 2281 | pages[i] = mem_map_offset(page, pfn_offset); |
4b2e38ad | 2282 | get_page(pages[i]); |
d6692183 | 2283 | } |
63551ae0 DG |
2284 | |
2285 | if (vmas) | |
2286 | vmas[i] = vma; | |
2287 | ||
2288 | vaddr += PAGE_SIZE; | |
d5d4b0aa | 2289 | ++pfn_offset; |
63551ae0 DG |
2290 | --remainder; |
2291 | ++i; | |
d5d4b0aa | 2292 | if (vaddr < vma->vm_end && remainder && |
a5516438 | 2293 | pfn_offset < pages_per_huge_page(h)) { |
d5d4b0aa CK |
2294 | /* |
2295 | * We use pfn_offset to avoid touching the pageframes | |
2296 | * of this compound page. | |
2297 | */ | |
2298 | goto same_page; | |
2299 | } | |
63551ae0 | 2300 | } |
1c59827d | 2301 | spin_unlock(&mm->page_table_lock); |
63551ae0 DG |
2302 | *length = remainder; |
2303 | *position = vaddr; | |
2304 | ||
2305 | return i; | |
2306 | } | |
8f860591 ZY |
2307 | |
2308 | void hugetlb_change_protection(struct vm_area_struct *vma, | |
2309 | unsigned long address, unsigned long end, pgprot_t newprot) | |
2310 | { | |
2311 | struct mm_struct *mm = vma->vm_mm; | |
2312 | unsigned long start = address; | |
2313 | pte_t *ptep; | |
2314 | pte_t pte; | |
a5516438 | 2315 | struct hstate *h = hstate_vma(vma); |
8f860591 ZY |
2316 | |
2317 | BUG_ON(address >= end); | |
2318 | flush_cache_range(vma, address, end); | |
2319 | ||
39dde65c | 2320 | spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 | 2321 | spin_lock(&mm->page_table_lock); |
a5516438 | 2322 | for (; address < end; address += huge_page_size(h)) { |
8f860591 ZY |
2323 | ptep = huge_pte_offset(mm, address); |
2324 | if (!ptep) | |
2325 | continue; | |
39dde65c CK |
2326 | if (huge_pmd_unshare(mm, &address, ptep)) |
2327 | continue; | |
7f2e9525 | 2328 | if (!huge_pte_none(huge_ptep_get(ptep))) { |
8f860591 ZY |
2329 | pte = huge_ptep_get_and_clear(mm, address, ptep); |
2330 | pte = pte_mkhuge(pte_modify(pte, newprot)); | |
2331 | set_huge_pte_at(mm, address, ptep, pte); | |
8f860591 ZY |
2332 | } |
2333 | } | |
2334 | spin_unlock(&mm->page_table_lock); | |
39dde65c | 2335 | spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); |
8f860591 ZY |
2336 | |
2337 | flush_tlb_range(vma, start, end); | |
2338 | } | |
2339 | ||
a1e78772 MG |
2340 | int hugetlb_reserve_pages(struct inode *inode, |
2341 | long from, long to, | |
5a6fe125 MG |
2342 | struct vm_area_struct *vma, |
2343 | int acctflag) | |
e4e574b7 | 2344 | { |
17c9d12e | 2345 | long ret, chg; |
a5516438 | 2346 | struct hstate *h = hstate_inode(inode); |
e4e574b7 | 2347 | |
17c9d12e MG |
2348 | /* |
2349 | * Only apply hugepage reservation if asked. At fault time, an | |
2350 | * attempt will be made for VM_NORESERVE to allocate a page | |
2351 | * and filesystem quota without using reserves | |
2352 | */ | |
2353 | if (acctflag & VM_NORESERVE) | |
2354 | return 0; | |
2355 | ||
a1e78772 MG |
2356 | /* |
2357 | * Shared mappings base their reservation on the number of pages that | |
2358 | * are already allocated on behalf of the file. Private mappings need | |
2359 | * to reserve the full area even if read-only as mprotect() may be | |
2360 | * called to make the mapping read-write. Assume !vma is a shm mapping | |
2361 | */ | |
f83a275d | 2362 | if (!vma || vma->vm_flags & VM_MAYSHARE) |
a1e78772 | 2363 | chg = region_chg(&inode->i_mapping->private_list, from, to); |
17c9d12e MG |
2364 | else { |
2365 | struct resv_map *resv_map = resv_map_alloc(); | |
2366 | if (!resv_map) | |
2367 | return -ENOMEM; | |
2368 | ||
a1e78772 | 2369 | chg = to - from; |
84afd99b | 2370 | |
17c9d12e MG |
2371 | set_vma_resv_map(vma, resv_map); |
2372 | set_vma_resv_flags(vma, HPAGE_RESV_OWNER); | |
2373 | } | |
2374 | ||
e4e574b7 AL |
2375 | if (chg < 0) |
2376 | return chg; | |
8a630112 | 2377 | |
17c9d12e | 2378 | /* There must be enough filesystem quota for the mapping */ |
90d8b7e6 AL |
2379 | if (hugetlb_get_quota(inode->i_mapping, chg)) |
2380 | return -ENOSPC; | |
5a6fe125 MG |
2381 | |
2382 | /* | |
17c9d12e MG |
2383 | * Check enough hugepages are available for the reservation. |
2384 | * Hand back the quota if there are not | |
5a6fe125 | 2385 | */ |
a5516438 | 2386 | ret = hugetlb_acct_memory(h, chg); |
68842c9b KC |
2387 | if (ret < 0) { |
2388 | hugetlb_put_quota(inode->i_mapping, chg); | |
a43a8c39 | 2389 | return ret; |
68842c9b | 2390 | } |
17c9d12e MG |
2391 | |
2392 | /* | |
2393 | * Account for the reservations made. Shared mappings record regions | |
2394 | * that have reservations as they are shared by multiple VMAs. | |
2395 | * When the last VMA disappears, the region map says how much | |
2396 | * the reservation was and the page cache tells how much of | |
2397 | * the reservation was consumed. Private mappings are per-VMA and | |
2398 | * only the consumed reservations are tracked. When the VMA | |
2399 | * disappears, the original reservation is the VMA size and the | |
2400 | * consumed reservations are stored in the map. Hence, nothing | |
2401 | * else has to be done for private mappings here | |
2402 | */ | |
f83a275d | 2403 | if (!vma || vma->vm_flags & VM_MAYSHARE) |
a1e78772 | 2404 | region_add(&inode->i_mapping->private_list, from, to); |
a43a8c39 CK |
2405 | return 0; |
2406 | } | |
2407 | ||
2408 | void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) | |
2409 | { | |
a5516438 | 2410 | struct hstate *h = hstate_inode(inode); |
a43a8c39 | 2411 | long chg = region_truncate(&inode->i_mapping->private_list, offset); |
45c682a6 KC |
2412 | |
2413 | spin_lock(&inode->i_lock); | |
e4c6f8be | 2414 | inode->i_blocks -= (blocks_per_huge_page(h) * freed); |
45c682a6 KC |
2415 | spin_unlock(&inode->i_lock); |
2416 | ||
90d8b7e6 | 2417 | hugetlb_put_quota(inode->i_mapping, (chg - freed)); |
a5516438 | 2418 | hugetlb_acct_memory(h, -(chg - freed)); |
a43a8c39 | 2419 | } |