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1 | /* | |
2 | * Simple NUMA memory policy for the Linux kernel. | |
3 | * | |
4 | * Copyright 2003,2004 Andi Kleen, SuSE Labs. | |
5 | * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc. | |
6 | * Subject to the GNU Public License, version 2. | |
7 | * | |
8 | * NUMA policy allows the user to give hints in which node(s) memory should | |
9 | * be allocated. | |
10 | * | |
11 | * Support four policies per VMA and per process: | |
12 | * | |
13 | * The VMA policy has priority over the process policy for a page fault. | |
14 | * | |
15 | * interleave Allocate memory interleaved over a set of nodes, | |
16 | * with normal fallback if it fails. | |
17 | * For VMA based allocations this interleaves based on the | |
18 | * offset into the backing object or offset into the mapping | |
19 | * for anonymous memory. For process policy an process counter | |
20 | * is used. | |
21 | * | |
22 | * bind Only allocate memory on a specific set of nodes, | |
23 | * no fallback. | |
24 | * FIXME: memory is allocated starting with the first node | |
25 | * to the last. It would be better if bind would truly restrict | |
26 | * the allocation to memory nodes instead | |
27 | * | |
28 | * preferred Try a specific node first before normal fallback. | |
29 | * As a special case node -1 here means do the allocation | |
30 | * on the local CPU. This is normally identical to default, | |
31 | * but useful to set in a VMA when you have a non default | |
32 | * process policy. | |
33 | * | |
34 | * default Allocate on the local node first, or when on a VMA | |
35 | * use the process policy. This is what Linux always did | |
36 | * in a NUMA aware kernel and still does by, ahem, default. | |
37 | * | |
38 | * The process policy is applied for most non interrupt memory allocations | |
39 | * in that process' context. Interrupts ignore the policies and always | |
40 | * try to allocate on the local CPU. The VMA policy is only applied for memory | |
41 | * allocations for a VMA in the VM. | |
42 | * | |
43 | * Currently there are a few corner cases in swapping where the policy | |
44 | * is not applied, but the majority should be handled. When process policy | |
45 | * is used it is not remembered over swap outs/swap ins. | |
46 | * | |
47 | * Only the highest zone in the zone hierarchy gets policied. Allocations | |
48 | * requesting a lower zone just use default policy. This implies that | |
49 | * on systems with highmem kernel lowmem allocation don't get policied. | |
50 | * Same with GFP_DMA allocations. | |
51 | * | |
52 | * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between | |
53 | * all users and remembered even when nobody has memory mapped. | |
54 | */ | |
55 | ||
56 | /* Notebook: | |
57 | fix mmap readahead to honour policy and enable policy for any page cache | |
58 | object | |
59 | statistics for bigpages | |
60 | global policy for page cache? currently it uses process policy. Requires | |
61 | first item above. | |
62 | handle mremap for shared memory (currently ignored for the policy) | |
63 | grows down? | |
64 | make bind policy root only? It can trigger oom much faster and the | |
65 | kernel is not always grateful with that. | |
66 | could replace all the switch()es with a mempolicy_ops structure. | |
67 | */ | |
68 | ||
69 | #include <linux/mempolicy.h> | |
70 | #include <linux/mm.h> | |
71 | #include <linux/highmem.h> | |
72 | #include <linux/hugetlb.h> | |
73 | #include <linux/kernel.h> | |
74 | #include <linux/sched.h> | |
75 | #include <linux/mm.h> | |
76 | #include <linux/nodemask.h> | |
77 | #include <linux/cpuset.h> | |
78 | #include <linux/gfp.h> | |
79 | #include <linux/slab.h> | |
80 | #include <linux/string.h> | |
81 | #include <linux/module.h> | |
82 | #include <linux/interrupt.h> | |
83 | #include <linux/init.h> | |
84 | #include <linux/compat.h> | |
85 | #include <linux/mempolicy.h> | |
86 | #include <linux/swap.h> | |
87 | ||
88 | #include <asm/tlbflush.h> | |
89 | #include <asm/uaccess.h> | |
90 | ||
91 | /* Internal MPOL_MF_xxx flags */ | |
92 | #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */ | |
93 | ||
94 | static kmem_cache_t *policy_cache; | |
95 | static kmem_cache_t *sn_cache; | |
96 | ||
97 | #define PDprintk(fmt...) | |
98 | ||
99 | /* Highest zone. An specific allocation for a zone below that is not | |
100 | policied. */ | |
101 | int policy_zone = ZONE_DMA; | |
102 | ||
103 | struct mempolicy default_policy = { | |
104 | .refcnt = ATOMIC_INIT(1), /* never free it */ | |
105 | .policy = MPOL_DEFAULT, | |
106 | }; | |
107 | ||
108 | /* Do sanity checking on a policy */ | |
109 | static int mpol_check_policy(int mode, nodemask_t *nodes) | |
110 | { | |
111 | int empty = nodes_empty(*nodes); | |
112 | ||
113 | switch (mode) { | |
114 | case MPOL_DEFAULT: | |
115 | if (!empty) | |
116 | return -EINVAL; | |
117 | break; | |
118 | case MPOL_BIND: | |
119 | case MPOL_INTERLEAVE: | |
120 | /* Preferred will only use the first bit, but allow | |
121 | more for now. */ | |
122 | if (empty) | |
123 | return -EINVAL; | |
124 | break; | |
125 | } | |
126 | return nodes_subset(*nodes, node_online_map) ? 0 : -EINVAL; | |
127 | } | |
128 | /* Generate a custom zonelist for the BIND policy. */ | |
129 | static struct zonelist *bind_zonelist(nodemask_t *nodes) | |
130 | { | |
131 | struct zonelist *zl; | |
132 | int num, max, nd; | |
133 | ||
134 | max = 1 + MAX_NR_ZONES * nodes_weight(*nodes); | |
135 | zl = kmalloc(sizeof(void *) * max, GFP_KERNEL); | |
136 | if (!zl) | |
137 | return NULL; | |
138 | num = 0; | |
139 | for_each_node_mask(nd, *nodes) | |
140 | zl->zones[num++] = &NODE_DATA(nd)->node_zones[policy_zone]; | |
141 | zl->zones[num] = NULL; | |
142 | return zl; | |
143 | } | |
144 | ||
145 | /* Create a new policy */ | |
146 | static struct mempolicy *mpol_new(int mode, nodemask_t *nodes) | |
147 | { | |
148 | struct mempolicy *policy; | |
149 | ||
150 | PDprintk("setting mode %d nodes[0] %lx\n", mode, nodes_addr(*nodes)[0]); | |
151 | if (mode == MPOL_DEFAULT) | |
152 | return NULL; | |
153 | policy = kmem_cache_alloc(policy_cache, GFP_KERNEL); | |
154 | if (!policy) | |
155 | return ERR_PTR(-ENOMEM); | |
156 | atomic_set(&policy->refcnt, 1); | |
157 | switch (mode) { | |
158 | case MPOL_INTERLEAVE: | |
159 | policy->v.nodes = *nodes; | |
160 | if (nodes_weight(*nodes) == 0) { | |
161 | kmem_cache_free(policy_cache, policy); | |
162 | return ERR_PTR(-EINVAL); | |
163 | } | |
164 | break; | |
165 | case MPOL_PREFERRED: | |
166 | policy->v.preferred_node = first_node(*nodes); | |
167 | if (policy->v.preferred_node >= MAX_NUMNODES) | |
168 | policy->v.preferred_node = -1; | |
169 | break; | |
170 | case MPOL_BIND: | |
171 | policy->v.zonelist = bind_zonelist(nodes); | |
172 | if (policy->v.zonelist == NULL) { | |
173 | kmem_cache_free(policy_cache, policy); | |
174 | return ERR_PTR(-ENOMEM); | |
175 | } | |
176 | break; | |
177 | } | |
178 | policy->policy = mode; | |
179 | return policy; | |
180 | } | |
181 | ||
182 | /* Check if we are the only process mapping the page in question */ | |
183 | static inline int single_mm_mapping(struct mm_struct *mm, | |
184 | struct address_space *mapping) | |
185 | { | |
186 | struct vm_area_struct *vma; | |
187 | struct prio_tree_iter iter; | |
188 | int rc = 1; | |
189 | ||
190 | spin_lock(&mapping->i_mmap_lock); | |
191 | vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, 0, ULONG_MAX) | |
192 | if (mm != vma->vm_mm) { | |
193 | rc = 0; | |
194 | goto out; | |
195 | } | |
196 | list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list) | |
197 | if (mm != vma->vm_mm) { | |
198 | rc = 0; | |
199 | goto out; | |
200 | } | |
201 | out: | |
202 | spin_unlock(&mapping->i_mmap_lock); | |
203 | return rc; | |
204 | } | |
205 | ||
206 | /* | |
207 | * Add a page to be migrated to the pagelist | |
208 | */ | |
209 | static void migrate_page_add(struct vm_area_struct *vma, | |
210 | struct page *page, struct list_head *pagelist, unsigned long flags) | |
211 | { | |
212 | /* | |
213 | * Avoid migrating a page that is shared by others and not writable. | |
214 | */ | |
215 | if ((flags & MPOL_MF_MOVE_ALL) || !page->mapping || PageAnon(page) || | |
216 | mapping_writably_mapped(page->mapping) || | |
217 | single_mm_mapping(vma->vm_mm, page->mapping)) { | |
218 | int rc = isolate_lru_page(page); | |
219 | ||
220 | if (rc == 1) | |
221 | list_add(&page->lru, pagelist); | |
222 | /* | |
223 | * If the isolate attempt was not successful then we just | |
224 | * encountered an unswappable page. Something must be wrong. | |
225 | */ | |
226 | WARN_ON(rc == 0); | |
227 | } | |
228 | } | |
229 | ||
230 | /* Ensure all existing pages follow the policy. */ | |
231 | static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd, | |
232 | unsigned long addr, unsigned long end, | |
233 | const nodemask_t *nodes, unsigned long flags, | |
234 | struct list_head *pagelist) | |
235 | { | |
236 | pte_t *orig_pte; | |
237 | pte_t *pte; | |
238 | spinlock_t *ptl; | |
239 | ||
240 | orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
241 | do { | |
242 | struct page *page; | |
243 | unsigned int nid; | |
244 | ||
245 | if (!pte_present(*pte)) | |
246 | continue; | |
247 | page = vm_normal_page(vma, addr, *pte); | |
248 | if (!page) | |
249 | continue; | |
250 | nid = page_to_nid(page); | |
251 | if (!node_isset(nid, *nodes)) { | |
252 | if (pagelist) | |
253 | migrate_page_add(vma, page, pagelist, flags); | |
254 | else | |
255 | break; | |
256 | } | |
257 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
258 | pte_unmap_unlock(orig_pte, ptl); | |
259 | return addr != end; | |
260 | } | |
261 | ||
262 | static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud, | |
263 | unsigned long addr, unsigned long end, | |
264 | const nodemask_t *nodes, unsigned long flags, | |
265 | struct list_head *pagelist) | |
266 | { | |
267 | pmd_t *pmd; | |
268 | unsigned long next; | |
269 | ||
270 | pmd = pmd_offset(pud, addr); | |
271 | do { | |
272 | next = pmd_addr_end(addr, end); | |
273 | if (pmd_none_or_clear_bad(pmd)) | |
274 | continue; | |
275 | if (check_pte_range(vma, pmd, addr, next, nodes, | |
276 | flags, pagelist)) | |
277 | return -EIO; | |
278 | } while (pmd++, addr = next, addr != end); | |
279 | return 0; | |
280 | } | |
281 | ||
282 | static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd, | |
283 | unsigned long addr, unsigned long end, | |
284 | const nodemask_t *nodes, unsigned long flags, | |
285 | struct list_head *pagelist) | |
286 | { | |
287 | pud_t *pud; | |
288 | unsigned long next; | |
289 | ||
290 | pud = pud_offset(pgd, addr); | |
291 | do { | |
292 | next = pud_addr_end(addr, end); | |
293 | if (pud_none_or_clear_bad(pud)) | |
294 | continue; | |
295 | if (check_pmd_range(vma, pud, addr, next, nodes, | |
296 | flags, pagelist)) | |
297 | return -EIO; | |
298 | } while (pud++, addr = next, addr != end); | |
299 | return 0; | |
300 | } | |
301 | ||
302 | static inline int check_pgd_range(struct vm_area_struct *vma, | |
303 | unsigned long addr, unsigned long end, | |
304 | const nodemask_t *nodes, unsigned long flags, | |
305 | struct list_head *pagelist) | |
306 | { | |
307 | pgd_t *pgd; | |
308 | unsigned long next; | |
309 | ||
310 | pgd = pgd_offset(vma->vm_mm, addr); | |
311 | do { | |
312 | next = pgd_addr_end(addr, end); | |
313 | if (pgd_none_or_clear_bad(pgd)) | |
314 | continue; | |
315 | if (check_pud_range(vma, pgd, addr, next, nodes, | |
316 | flags, pagelist)) | |
317 | return -EIO; | |
318 | } while (pgd++, addr = next, addr != end); | |
319 | return 0; | |
320 | } | |
321 | ||
322 | /* Check if a vma is migratable */ | |
323 | static inline int vma_migratable(struct vm_area_struct *vma) | |
324 | { | |
325 | if (vma->vm_flags & ( | |
326 | VM_LOCKED|VM_IO|VM_HUGETLB|VM_PFNMAP)) | |
327 | return 0; | |
328 | return 1; | |
329 | } | |
330 | ||
331 | /* | |
332 | * Check if all pages in a range are on a set of nodes. | |
333 | * If pagelist != NULL then isolate pages from the LRU and | |
334 | * put them on the pagelist. | |
335 | */ | |
336 | static struct vm_area_struct * | |
337 | check_range(struct mm_struct *mm, unsigned long start, unsigned long end, | |
338 | const nodemask_t *nodes, unsigned long flags, | |
339 | struct list_head *pagelist) | |
340 | { | |
341 | int err; | |
342 | struct vm_area_struct *first, *vma, *prev; | |
343 | ||
344 | first = find_vma(mm, start); | |
345 | if (!first) | |
346 | return ERR_PTR(-EFAULT); | |
347 | prev = NULL; | |
348 | for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) { | |
349 | if (!(flags & MPOL_MF_DISCONTIG_OK)) { | |
350 | if (!vma->vm_next && vma->vm_end < end) | |
351 | return ERR_PTR(-EFAULT); | |
352 | if (prev && prev->vm_end < vma->vm_start) | |
353 | return ERR_PTR(-EFAULT); | |
354 | } | |
355 | if (!is_vm_hugetlb_page(vma) && | |
356 | ((flags & MPOL_MF_STRICT) || | |
357 | ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) && | |
358 | vma_migratable(vma)))) { | |
359 | unsigned long endvma = vma->vm_end; | |
360 | ||
361 | if (endvma > end) | |
362 | endvma = end; | |
363 | if (vma->vm_start > start) | |
364 | start = vma->vm_start; | |
365 | err = check_pgd_range(vma, start, endvma, nodes, | |
366 | flags, pagelist); | |
367 | if (err) { | |
368 | first = ERR_PTR(err); | |
369 | break; | |
370 | } | |
371 | } | |
372 | prev = vma; | |
373 | } | |
374 | return first; | |
375 | } | |
376 | ||
377 | /* Apply policy to a single VMA */ | |
378 | static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new) | |
379 | { | |
380 | int err = 0; | |
381 | struct mempolicy *old = vma->vm_policy; | |
382 | ||
383 | PDprintk("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n", | |
384 | vma->vm_start, vma->vm_end, vma->vm_pgoff, | |
385 | vma->vm_ops, vma->vm_file, | |
386 | vma->vm_ops ? vma->vm_ops->set_policy : NULL); | |
387 | ||
388 | if (vma->vm_ops && vma->vm_ops->set_policy) | |
389 | err = vma->vm_ops->set_policy(vma, new); | |
390 | if (!err) { | |
391 | mpol_get(new); | |
392 | vma->vm_policy = new; | |
393 | mpol_free(old); | |
394 | } | |
395 | return err; | |
396 | } | |
397 | ||
398 | /* Step 2: apply policy to a range and do splits. */ | |
399 | static int mbind_range(struct vm_area_struct *vma, unsigned long start, | |
400 | unsigned long end, struct mempolicy *new) | |
401 | { | |
402 | struct vm_area_struct *next; | |
403 | int err; | |
404 | ||
405 | err = 0; | |
406 | for (; vma && vma->vm_start < end; vma = next) { | |
407 | next = vma->vm_next; | |
408 | if (vma->vm_start < start) | |
409 | err = split_vma(vma->vm_mm, vma, start, 1); | |
410 | if (!err && vma->vm_end > end) | |
411 | err = split_vma(vma->vm_mm, vma, end, 0); | |
412 | if (!err) | |
413 | err = policy_vma(vma, new); | |
414 | if (err) | |
415 | break; | |
416 | } | |
417 | return err; | |
418 | } | |
419 | ||
420 | static int contextualize_policy(int mode, nodemask_t *nodes) | |
421 | { | |
422 | if (!nodes) | |
423 | return 0; | |
424 | ||
425 | /* Update current mems_allowed */ | |
426 | cpuset_update_current_mems_allowed(); | |
427 | /* Ignore nodes not set in current->mems_allowed */ | |
428 | cpuset_restrict_to_mems_allowed(nodes->bits); | |
429 | return mpol_check_policy(mode, nodes); | |
430 | } | |
431 | ||
432 | long do_mbind(unsigned long start, unsigned long len, | |
433 | unsigned long mode, nodemask_t *nmask, unsigned long flags) | |
434 | { | |
435 | struct vm_area_struct *vma; | |
436 | struct mm_struct *mm = current->mm; | |
437 | struct mempolicy *new; | |
438 | unsigned long end; | |
439 | int err; | |
440 | LIST_HEAD(pagelist); | |
441 | ||
442 | if ((flags & ~(unsigned long)(MPOL_MF_STRICT|MPOL_MF_MOVE|MPOL_MF_MOVE_ALL)) | |
443 | || mode > MPOL_MAX) | |
444 | return -EINVAL; | |
445 | if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_RESOURCE)) | |
446 | return -EPERM; | |
447 | ||
448 | if (start & ~PAGE_MASK) | |
449 | return -EINVAL; | |
450 | ||
451 | if (mode == MPOL_DEFAULT) | |
452 | flags &= ~MPOL_MF_STRICT; | |
453 | ||
454 | len = (len + PAGE_SIZE - 1) & PAGE_MASK; | |
455 | end = start + len; | |
456 | ||
457 | if (end < start) | |
458 | return -EINVAL; | |
459 | if (end == start) | |
460 | return 0; | |
461 | ||
462 | if (mpol_check_policy(mode, nmask)) | |
463 | return -EINVAL; | |
464 | ||
465 | new = mpol_new(mode, nmask); | |
466 | if (IS_ERR(new)) | |
467 | return PTR_ERR(new); | |
468 | ||
469 | /* | |
470 | * If we are using the default policy then operation | |
471 | * on discontinuous address spaces is okay after all | |
472 | */ | |
473 | if (!new) | |
474 | flags |= MPOL_MF_DISCONTIG_OK; | |
475 | ||
476 | PDprintk("mbind %lx-%lx mode:%ld nodes:%lx\n",start,start+len, | |
477 | mode,nodes_addr(nodes)[0]); | |
478 | ||
479 | down_write(&mm->mmap_sem); | |
480 | vma = check_range(mm, start, end, nmask, flags, | |
481 | (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) ? &pagelist : NULL); | |
482 | err = PTR_ERR(vma); | |
483 | if (!IS_ERR(vma)) { | |
484 | err = mbind_range(vma, start, end, new); | |
485 | if (!list_empty(&pagelist)) | |
486 | migrate_pages(&pagelist, NULL); | |
487 | if (!err && !list_empty(&pagelist) && (flags & MPOL_MF_STRICT)) | |
488 | err = -EIO; | |
489 | } | |
490 | if (!list_empty(&pagelist)) | |
491 | putback_lru_pages(&pagelist); | |
492 | ||
493 | up_write(&mm->mmap_sem); | |
494 | mpol_free(new); | |
495 | return err; | |
496 | } | |
497 | ||
498 | /* Set the process memory policy */ | |
499 | long do_set_mempolicy(int mode, nodemask_t *nodes) | |
500 | { | |
501 | struct mempolicy *new; | |
502 | ||
503 | if (contextualize_policy(mode, nodes)) | |
504 | return -EINVAL; | |
505 | new = mpol_new(mode, nodes); | |
506 | if (IS_ERR(new)) | |
507 | return PTR_ERR(new); | |
508 | mpol_free(current->mempolicy); | |
509 | current->mempolicy = new; | |
510 | if (new && new->policy == MPOL_INTERLEAVE) | |
511 | current->il_next = first_node(new->v.nodes); | |
512 | return 0; | |
513 | } | |
514 | ||
515 | /* Fill a zone bitmap for a policy */ | |
516 | static void get_zonemask(struct mempolicy *p, nodemask_t *nodes) | |
517 | { | |
518 | int i; | |
519 | ||
520 | nodes_clear(*nodes); | |
521 | switch (p->policy) { | |
522 | case MPOL_BIND: | |
523 | for (i = 0; p->v.zonelist->zones[i]; i++) | |
524 | node_set(p->v.zonelist->zones[i]->zone_pgdat->node_id, | |
525 | *nodes); | |
526 | break; | |
527 | case MPOL_DEFAULT: | |
528 | break; | |
529 | case MPOL_INTERLEAVE: | |
530 | *nodes = p->v.nodes; | |
531 | break; | |
532 | case MPOL_PREFERRED: | |
533 | /* or use current node instead of online map? */ | |
534 | if (p->v.preferred_node < 0) | |
535 | *nodes = node_online_map; | |
536 | else | |
537 | node_set(p->v.preferred_node, *nodes); | |
538 | break; | |
539 | default: | |
540 | BUG(); | |
541 | } | |
542 | } | |
543 | ||
544 | static int lookup_node(struct mm_struct *mm, unsigned long addr) | |
545 | { | |
546 | struct page *p; | |
547 | int err; | |
548 | ||
549 | err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL); | |
550 | if (err >= 0) { | |
551 | err = page_to_nid(p); | |
552 | put_page(p); | |
553 | } | |
554 | return err; | |
555 | } | |
556 | ||
557 | /* Retrieve NUMA policy */ | |
558 | long do_get_mempolicy(int *policy, nodemask_t *nmask, | |
559 | unsigned long addr, unsigned long flags) | |
560 | { | |
561 | int err; | |
562 | struct mm_struct *mm = current->mm; | |
563 | struct vm_area_struct *vma = NULL; | |
564 | struct mempolicy *pol = current->mempolicy; | |
565 | ||
566 | cpuset_update_current_mems_allowed(); | |
567 | if (flags & ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR)) | |
568 | return -EINVAL; | |
569 | if (flags & MPOL_F_ADDR) { | |
570 | down_read(&mm->mmap_sem); | |
571 | vma = find_vma_intersection(mm, addr, addr+1); | |
572 | if (!vma) { | |
573 | up_read(&mm->mmap_sem); | |
574 | return -EFAULT; | |
575 | } | |
576 | if (vma->vm_ops && vma->vm_ops->get_policy) | |
577 | pol = vma->vm_ops->get_policy(vma, addr); | |
578 | else | |
579 | pol = vma->vm_policy; | |
580 | } else if (addr) | |
581 | return -EINVAL; | |
582 | ||
583 | if (!pol) | |
584 | pol = &default_policy; | |
585 | ||
586 | if (flags & MPOL_F_NODE) { | |
587 | if (flags & MPOL_F_ADDR) { | |
588 | err = lookup_node(mm, addr); | |
589 | if (err < 0) | |
590 | goto out; | |
591 | *policy = err; | |
592 | } else if (pol == current->mempolicy && | |
593 | pol->policy == MPOL_INTERLEAVE) { | |
594 | *policy = current->il_next; | |
595 | } else { | |
596 | err = -EINVAL; | |
597 | goto out; | |
598 | } | |
599 | } else | |
600 | *policy = pol->policy; | |
601 | ||
602 | if (vma) { | |
603 | up_read(¤t->mm->mmap_sem); | |
604 | vma = NULL; | |
605 | } | |
606 | ||
607 | err = 0; | |
608 | if (nmask) | |
609 | get_zonemask(pol, nmask); | |
610 | ||
611 | out: | |
612 | if (vma) | |
613 | up_read(¤t->mm->mmap_sem); | |
614 | return err; | |
615 | } | |
616 | ||
617 | /* | |
618 | * User space interface with variable sized bitmaps for nodelists. | |
619 | */ | |
620 | ||
621 | /* Copy a node mask from user space. */ | |
622 | static int get_nodes(nodemask_t *nodes, unsigned long __user *nmask, | |
623 | unsigned long maxnode) | |
624 | { | |
625 | unsigned long k; | |
626 | unsigned long nlongs; | |
627 | unsigned long endmask; | |
628 | ||
629 | --maxnode; | |
630 | nodes_clear(*nodes); | |
631 | if (maxnode == 0 || !nmask) | |
632 | return 0; | |
633 | ||
634 | nlongs = BITS_TO_LONGS(maxnode); | |
635 | if ((maxnode % BITS_PER_LONG) == 0) | |
636 | endmask = ~0UL; | |
637 | else | |
638 | endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1; | |
639 | ||
640 | /* When the user specified more nodes than supported just check | |
641 | if the non supported part is all zero. */ | |
642 | if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) { | |
643 | if (nlongs > PAGE_SIZE/sizeof(long)) | |
644 | return -EINVAL; | |
645 | for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) { | |
646 | unsigned long t; | |
647 | if (get_user(t, nmask + k)) | |
648 | return -EFAULT; | |
649 | if (k == nlongs - 1) { | |
650 | if (t & endmask) | |
651 | return -EINVAL; | |
652 | } else if (t) | |
653 | return -EINVAL; | |
654 | } | |
655 | nlongs = BITS_TO_LONGS(MAX_NUMNODES); | |
656 | endmask = ~0UL; | |
657 | } | |
658 | ||
659 | if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long))) | |
660 | return -EFAULT; | |
661 | nodes_addr(*nodes)[nlongs-1] &= endmask; | |
662 | return 0; | |
663 | } | |
664 | ||
665 | /* Copy a kernel node mask to user space */ | |
666 | static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, | |
667 | nodemask_t *nodes) | |
668 | { | |
669 | unsigned long copy = ALIGN(maxnode-1, 64) / 8; | |
670 | const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long); | |
671 | ||
672 | if (copy > nbytes) { | |
673 | if (copy > PAGE_SIZE) | |
674 | return -EINVAL; | |
675 | if (clear_user((char __user *)mask + nbytes, copy - nbytes)) | |
676 | return -EFAULT; | |
677 | copy = nbytes; | |
678 | } | |
679 | return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0; | |
680 | } | |
681 | ||
682 | asmlinkage long sys_mbind(unsigned long start, unsigned long len, | |
683 | unsigned long mode, | |
684 | unsigned long __user *nmask, unsigned long maxnode, | |
685 | unsigned flags) | |
686 | { | |
687 | nodemask_t nodes; | |
688 | int err; | |
689 | ||
690 | err = get_nodes(&nodes, nmask, maxnode); | |
691 | if (err) | |
692 | return err; | |
693 | return do_mbind(start, len, mode, &nodes, flags); | |
694 | } | |
695 | ||
696 | /* Set the process memory policy */ | |
697 | asmlinkage long sys_set_mempolicy(int mode, unsigned long __user *nmask, | |
698 | unsigned long maxnode) | |
699 | { | |
700 | int err; | |
701 | nodemask_t nodes; | |
702 | ||
703 | if (mode < 0 || mode > MPOL_MAX) | |
704 | return -EINVAL; | |
705 | err = get_nodes(&nodes, nmask, maxnode); | |
706 | if (err) | |
707 | return err; | |
708 | return do_set_mempolicy(mode, &nodes); | |
709 | } | |
710 | ||
711 | /* Retrieve NUMA policy */ | |
712 | asmlinkage long sys_get_mempolicy(int __user *policy, | |
713 | unsigned long __user *nmask, | |
714 | unsigned long maxnode, | |
715 | unsigned long addr, unsigned long flags) | |
716 | { | |
717 | int err, pval; | |
718 | nodemask_t nodes; | |
719 | ||
720 | if (nmask != NULL && maxnode < MAX_NUMNODES) | |
721 | return -EINVAL; | |
722 | ||
723 | err = do_get_mempolicy(&pval, &nodes, addr, flags); | |
724 | ||
725 | if (err) | |
726 | return err; | |
727 | ||
728 | if (policy && put_user(pval, policy)) | |
729 | return -EFAULT; | |
730 | ||
731 | if (nmask) | |
732 | err = copy_nodes_to_user(nmask, maxnode, &nodes); | |
733 | ||
734 | return err; | |
735 | } | |
736 | ||
737 | #ifdef CONFIG_COMPAT | |
738 | ||
739 | asmlinkage long compat_sys_get_mempolicy(int __user *policy, | |
740 | compat_ulong_t __user *nmask, | |
741 | compat_ulong_t maxnode, | |
742 | compat_ulong_t addr, compat_ulong_t flags) | |
743 | { | |
744 | long err; | |
745 | unsigned long __user *nm = NULL; | |
746 | unsigned long nr_bits, alloc_size; | |
747 | DECLARE_BITMAP(bm, MAX_NUMNODES); | |
748 | ||
749 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
750 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
751 | ||
752 | if (nmask) | |
753 | nm = compat_alloc_user_space(alloc_size); | |
754 | ||
755 | err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags); | |
756 | ||
757 | if (!err && nmask) { | |
758 | err = copy_from_user(bm, nm, alloc_size); | |
759 | /* ensure entire bitmap is zeroed */ | |
760 | err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8); | |
761 | err |= compat_put_bitmap(nmask, bm, nr_bits); | |
762 | } | |
763 | ||
764 | return err; | |
765 | } | |
766 | ||
767 | asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask, | |
768 | compat_ulong_t maxnode) | |
769 | { | |
770 | long err = 0; | |
771 | unsigned long __user *nm = NULL; | |
772 | unsigned long nr_bits, alloc_size; | |
773 | DECLARE_BITMAP(bm, MAX_NUMNODES); | |
774 | ||
775 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
776 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
777 | ||
778 | if (nmask) { | |
779 | err = compat_get_bitmap(bm, nmask, nr_bits); | |
780 | nm = compat_alloc_user_space(alloc_size); | |
781 | err |= copy_to_user(nm, bm, alloc_size); | |
782 | } | |
783 | ||
784 | if (err) | |
785 | return -EFAULT; | |
786 | ||
787 | return sys_set_mempolicy(mode, nm, nr_bits+1); | |
788 | } | |
789 | ||
790 | asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len, | |
791 | compat_ulong_t mode, compat_ulong_t __user *nmask, | |
792 | compat_ulong_t maxnode, compat_ulong_t flags) | |
793 | { | |
794 | long err = 0; | |
795 | unsigned long __user *nm = NULL; | |
796 | unsigned long nr_bits, alloc_size; | |
797 | nodemask_t bm; | |
798 | ||
799 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
800 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
801 | ||
802 | if (nmask) { | |
803 | err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits); | |
804 | nm = compat_alloc_user_space(alloc_size); | |
805 | err |= copy_to_user(nm, nodes_addr(bm), alloc_size); | |
806 | } | |
807 | ||
808 | if (err) | |
809 | return -EFAULT; | |
810 | ||
811 | return sys_mbind(start, len, mode, nm, nr_bits+1, flags); | |
812 | } | |
813 | ||
814 | #endif | |
815 | ||
816 | /* Return effective policy for a VMA */ | |
817 | struct mempolicy * | |
818 | get_vma_policy(struct task_struct *task, struct vm_area_struct *vma, unsigned long addr) | |
819 | { | |
820 | struct mempolicy *pol = task->mempolicy; | |
821 | ||
822 | if (vma) { | |
823 | if (vma->vm_ops && vma->vm_ops->get_policy) | |
824 | pol = vma->vm_ops->get_policy(vma, addr); | |
825 | else if (vma->vm_policy && | |
826 | vma->vm_policy->policy != MPOL_DEFAULT) | |
827 | pol = vma->vm_policy; | |
828 | } | |
829 | if (!pol) | |
830 | pol = &default_policy; | |
831 | return pol; | |
832 | } | |
833 | ||
834 | /* Return a zonelist representing a mempolicy */ | |
835 | static struct zonelist *zonelist_policy(gfp_t gfp, struct mempolicy *policy) | |
836 | { | |
837 | int nd; | |
838 | ||
839 | switch (policy->policy) { | |
840 | case MPOL_PREFERRED: | |
841 | nd = policy->v.preferred_node; | |
842 | if (nd < 0) | |
843 | nd = numa_node_id(); | |
844 | break; | |
845 | case MPOL_BIND: | |
846 | /* Lower zones don't get a policy applied */ | |
847 | /* Careful: current->mems_allowed might have moved */ | |
848 | if (gfp_zone(gfp) >= policy_zone) | |
849 | if (cpuset_zonelist_valid_mems_allowed(policy->v.zonelist)) | |
850 | return policy->v.zonelist; | |
851 | /*FALL THROUGH*/ | |
852 | case MPOL_INTERLEAVE: /* should not happen */ | |
853 | case MPOL_DEFAULT: | |
854 | nd = numa_node_id(); | |
855 | break; | |
856 | default: | |
857 | nd = 0; | |
858 | BUG(); | |
859 | } | |
860 | return NODE_DATA(nd)->node_zonelists + gfp_zone(gfp); | |
861 | } | |
862 | ||
863 | /* Do dynamic interleaving for a process */ | |
864 | static unsigned interleave_nodes(struct mempolicy *policy) | |
865 | { | |
866 | unsigned nid, next; | |
867 | struct task_struct *me = current; | |
868 | ||
869 | nid = me->il_next; | |
870 | next = next_node(nid, policy->v.nodes); | |
871 | if (next >= MAX_NUMNODES) | |
872 | next = first_node(policy->v.nodes); | |
873 | me->il_next = next; | |
874 | return nid; | |
875 | } | |
876 | ||
877 | /* Do static interleaving for a VMA with known offset. */ | |
878 | static unsigned offset_il_node(struct mempolicy *pol, | |
879 | struct vm_area_struct *vma, unsigned long off) | |
880 | { | |
881 | unsigned nnodes = nodes_weight(pol->v.nodes); | |
882 | unsigned target = (unsigned)off % nnodes; | |
883 | int c; | |
884 | int nid = -1; | |
885 | ||
886 | c = 0; | |
887 | do { | |
888 | nid = next_node(nid, pol->v.nodes); | |
889 | c++; | |
890 | } while (c <= target); | |
891 | return nid; | |
892 | } | |
893 | ||
894 | /* Determine a node number for interleave */ | |
895 | static inline unsigned interleave_nid(struct mempolicy *pol, | |
896 | struct vm_area_struct *vma, unsigned long addr, int shift) | |
897 | { | |
898 | if (vma) { | |
899 | unsigned long off; | |
900 | ||
901 | off = vma->vm_pgoff; | |
902 | off += (addr - vma->vm_start) >> shift; | |
903 | return offset_il_node(pol, vma, off); | |
904 | } else | |
905 | return interleave_nodes(pol); | |
906 | } | |
907 | ||
908 | /* Return a zonelist suitable for a huge page allocation. */ | |
909 | struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr) | |
910 | { | |
911 | struct mempolicy *pol = get_vma_policy(current, vma, addr); | |
912 | ||
913 | if (pol->policy == MPOL_INTERLEAVE) { | |
914 | unsigned nid; | |
915 | ||
916 | nid = interleave_nid(pol, vma, addr, HPAGE_SHIFT); | |
917 | return NODE_DATA(nid)->node_zonelists + gfp_zone(GFP_HIGHUSER); | |
918 | } | |
919 | return zonelist_policy(GFP_HIGHUSER, pol); | |
920 | } | |
921 | ||
922 | /* Allocate a page in interleaved policy. | |
923 | Own path because it needs to do special accounting. */ | |
924 | static struct page *alloc_page_interleave(gfp_t gfp, unsigned order, | |
925 | unsigned nid) | |
926 | { | |
927 | struct zonelist *zl; | |
928 | struct page *page; | |
929 | ||
930 | zl = NODE_DATA(nid)->node_zonelists + gfp_zone(gfp); | |
931 | page = __alloc_pages(gfp, order, zl); | |
932 | if (page && page_zone(page) == zl->zones[0]) { | |
933 | zone_pcp(zl->zones[0],get_cpu())->interleave_hit++; | |
934 | put_cpu(); | |
935 | } | |
936 | return page; | |
937 | } | |
938 | ||
939 | /** | |
940 | * alloc_page_vma - Allocate a page for a VMA. | |
941 | * | |
942 | * @gfp: | |
943 | * %GFP_USER user allocation. | |
944 | * %GFP_KERNEL kernel allocations, | |
945 | * %GFP_HIGHMEM highmem/user allocations, | |
946 | * %GFP_FS allocation should not call back into a file system. | |
947 | * %GFP_ATOMIC don't sleep. | |
948 | * | |
949 | * @vma: Pointer to VMA or NULL if not available. | |
950 | * @addr: Virtual Address of the allocation. Must be inside the VMA. | |
951 | * | |
952 | * This function allocates a page from the kernel page pool and applies | |
953 | * a NUMA policy associated with the VMA or the current process. | |
954 | * When VMA is not NULL caller must hold down_read on the mmap_sem of the | |
955 | * mm_struct of the VMA to prevent it from going away. Should be used for | |
956 | * all allocations for pages that will be mapped into | |
957 | * user space. Returns NULL when no page can be allocated. | |
958 | * | |
959 | * Should be called with the mm_sem of the vma hold. | |
960 | */ | |
961 | struct page * | |
962 | alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr) | |
963 | { | |
964 | struct mempolicy *pol = get_vma_policy(current, vma, addr); | |
965 | ||
966 | cpuset_update_current_mems_allowed(); | |
967 | ||
968 | if (unlikely(pol->policy == MPOL_INTERLEAVE)) { | |
969 | unsigned nid; | |
970 | ||
971 | nid = interleave_nid(pol, vma, addr, PAGE_SHIFT); | |
972 | return alloc_page_interleave(gfp, 0, nid); | |
973 | } | |
974 | return __alloc_pages(gfp, 0, zonelist_policy(gfp, pol)); | |
975 | } | |
976 | ||
977 | /** | |
978 | * alloc_pages_current - Allocate pages. | |
979 | * | |
980 | * @gfp: | |
981 | * %GFP_USER user allocation, | |
982 | * %GFP_KERNEL kernel allocation, | |
983 | * %GFP_HIGHMEM highmem allocation, | |
984 | * %GFP_FS don't call back into a file system. | |
985 | * %GFP_ATOMIC don't sleep. | |
986 | * @order: Power of two of allocation size in pages. 0 is a single page. | |
987 | * | |
988 | * Allocate a page from the kernel page pool. When not in | |
989 | * interrupt context and apply the current process NUMA policy. | |
990 | * Returns NULL when no page can be allocated. | |
991 | * | |
992 | * Don't call cpuset_update_current_mems_allowed() unless | |
993 | * 1) it's ok to take cpuset_sem (can WAIT), and | |
994 | * 2) allocating for current task (not interrupt). | |
995 | */ | |
996 | struct page *alloc_pages_current(gfp_t gfp, unsigned order) | |
997 | { | |
998 | struct mempolicy *pol = current->mempolicy; | |
999 | ||
1000 | if ((gfp & __GFP_WAIT) && !in_interrupt()) | |
1001 | cpuset_update_current_mems_allowed(); | |
1002 | if (!pol || in_interrupt()) | |
1003 | pol = &default_policy; | |
1004 | if (pol->policy == MPOL_INTERLEAVE) | |
1005 | return alloc_page_interleave(gfp, order, interleave_nodes(pol)); | |
1006 | return __alloc_pages(gfp, order, zonelist_policy(gfp, pol)); | |
1007 | } | |
1008 | EXPORT_SYMBOL(alloc_pages_current); | |
1009 | ||
1010 | /* Slow path of a mempolicy copy */ | |
1011 | struct mempolicy *__mpol_copy(struct mempolicy *old) | |
1012 | { | |
1013 | struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL); | |
1014 | ||
1015 | if (!new) | |
1016 | return ERR_PTR(-ENOMEM); | |
1017 | *new = *old; | |
1018 | atomic_set(&new->refcnt, 1); | |
1019 | if (new->policy == MPOL_BIND) { | |
1020 | int sz = ksize(old->v.zonelist); | |
1021 | new->v.zonelist = kmalloc(sz, SLAB_KERNEL); | |
1022 | if (!new->v.zonelist) { | |
1023 | kmem_cache_free(policy_cache, new); | |
1024 | return ERR_PTR(-ENOMEM); | |
1025 | } | |
1026 | memcpy(new->v.zonelist, old->v.zonelist, sz); | |
1027 | } | |
1028 | return new; | |
1029 | } | |
1030 | ||
1031 | /* Slow path of a mempolicy comparison */ | |
1032 | int __mpol_equal(struct mempolicy *a, struct mempolicy *b) | |
1033 | { | |
1034 | if (!a || !b) | |
1035 | return 0; | |
1036 | if (a->policy != b->policy) | |
1037 | return 0; | |
1038 | switch (a->policy) { | |
1039 | case MPOL_DEFAULT: | |
1040 | return 1; | |
1041 | case MPOL_INTERLEAVE: | |
1042 | return nodes_equal(a->v.nodes, b->v.nodes); | |
1043 | case MPOL_PREFERRED: | |
1044 | return a->v.preferred_node == b->v.preferred_node; | |
1045 | case MPOL_BIND: { | |
1046 | int i; | |
1047 | for (i = 0; a->v.zonelist->zones[i]; i++) | |
1048 | if (a->v.zonelist->zones[i] != b->v.zonelist->zones[i]) | |
1049 | return 0; | |
1050 | return b->v.zonelist->zones[i] == NULL; | |
1051 | } | |
1052 | default: | |
1053 | BUG(); | |
1054 | return 0; | |
1055 | } | |
1056 | } | |
1057 | ||
1058 | /* Slow path of a mpol destructor. */ | |
1059 | void __mpol_free(struct mempolicy *p) | |
1060 | { | |
1061 | if (!atomic_dec_and_test(&p->refcnt)) | |
1062 | return; | |
1063 | if (p->policy == MPOL_BIND) | |
1064 | kfree(p->v.zonelist); | |
1065 | p->policy = MPOL_DEFAULT; | |
1066 | kmem_cache_free(policy_cache, p); | |
1067 | } | |
1068 | ||
1069 | /* | |
1070 | * Shared memory backing store policy support. | |
1071 | * | |
1072 | * Remember policies even when nobody has shared memory mapped. | |
1073 | * The policies are kept in Red-Black tree linked from the inode. | |
1074 | * They are protected by the sp->lock spinlock, which should be held | |
1075 | * for any accesses to the tree. | |
1076 | */ | |
1077 | ||
1078 | /* lookup first element intersecting start-end */ | |
1079 | /* Caller holds sp->lock */ | |
1080 | static struct sp_node * | |
1081 | sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end) | |
1082 | { | |
1083 | struct rb_node *n = sp->root.rb_node; | |
1084 | ||
1085 | while (n) { | |
1086 | struct sp_node *p = rb_entry(n, struct sp_node, nd); | |
1087 | ||
1088 | if (start >= p->end) | |
1089 | n = n->rb_right; | |
1090 | else if (end <= p->start) | |
1091 | n = n->rb_left; | |
1092 | else | |
1093 | break; | |
1094 | } | |
1095 | if (!n) | |
1096 | return NULL; | |
1097 | for (;;) { | |
1098 | struct sp_node *w = NULL; | |
1099 | struct rb_node *prev = rb_prev(n); | |
1100 | if (!prev) | |
1101 | break; | |
1102 | w = rb_entry(prev, struct sp_node, nd); | |
1103 | if (w->end <= start) | |
1104 | break; | |
1105 | n = prev; | |
1106 | } | |
1107 | return rb_entry(n, struct sp_node, nd); | |
1108 | } | |
1109 | ||
1110 | /* Insert a new shared policy into the list. */ | |
1111 | /* Caller holds sp->lock */ | |
1112 | static void sp_insert(struct shared_policy *sp, struct sp_node *new) | |
1113 | { | |
1114 | struct rb_node **p = &sp->root.rb_node; | |
1115 | struct rb_node *parent = NULL; | |
1116 | struct sp_node *nd; | |
1117 | ||
1118 | while (*p) { | |
1119 | parent = *p; | |
1120 | nd = rb_entry(parent, struct sp_node, nd); | |
1121 | if (new->start < nd->start) | |
1122 | p = &(*p)->rb_left; | |
1123 | else if (new->end > nd->end) | |
1124 | p = &(*p)->rb_right; | |
1125 | else | |
1126 | BUG(); | |
1127 | } | |
1128 | rb_link_node(&new->nd, parent, p); | |
1129 | rb_insert_color(&new->nd, &sp->root); | |
1130 | PDprintk("inserting %lx-%lx: %d\n", new->start, new->end, | |
1131 | new->policy ? new->policy->policy : 0); | |
1132 | } | |
1133 | ||
1134 | /* Find shared policy intersecting idx */ | |
1135 | struct mempolicy * | |
1136 | mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx) | |
1137 | { | |
1138 | struct mempolicy *pol = NULL; | |
1139 | struct sp_node *sn; | |
1140 | ||
1141 | if (!sp->root.rb_node) | |
1142 | return NULL; | |
1143 | spin_lock(&sp->lock); | |
1144 | sn = sp_lookup(sp, idx, idx+1); | |
1145 | if (sn) { | |
1146 | mpol_get(sn->policy); | |
1147 | pol = sn->policy; | |
1148 | } | |
1149 | spin_unlock(&sp->lock); | |
1150 | return pol; | |
1151 | } | |
1152 | ||
1153 | static void sp_delete(struct shared_policy *sp, struct sp_node *n) | |
1154 | { | |
1155 | PDprintk("deleting %lx-l%x\n", n->start, n->end); | |
1156 | rb_erase(&n->nd, &sp->root); | |
1157 | mpol_free(n->policy); | |
1158 | kmem_cache_free(sn_cache, n); | |
1159 | } | |
1160 | ||
1161 | struct sp_node * | |
1162 | sp_alloc(unsigned long start, unsigned long end, struct mempolicy *pol) | |
1163 | { | |
1164 | struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL); | |
1165 | ||
1166 | if (!n) | |
1167 | return NULL; | |
1168 | n->start = start; | |
1169 | n->end = end; | |
1170 | mpol_get(pol); | |
1171 | n->policy = pol; | |
1172 | return n; | |
1173 | } | |
1174 | ||
1175 | /* Replace a policy range. */ | |
1176 | static int shared_policy_replace(struct shared_policy *sp, unsigned long start, | |
1177 | unsigned long end, struct sp_node *new) | |
1178 | { | |
1179 | struct sp_node *n, *new2 = NULL; | |
1180 | ||
1181 | restart: | |
1182 | spin_lock(&sp->lock); | |
1183 | n = sp_lookup(sp, start, end); | |
1184 | /* Take care of old policies in the same range. */ | |
1185 | while (n && n->start < end) { | |
1186 | struct rb_node *next = rb_next(&n->nd); | |
1187 | if (n->start >= start) { | |
1188 | if (n->end <= end) | |
1189 | sp_delete(sp, n); | |
1190 | else | |
1191 | n->start = end; | |
1192 | } else { | |
1193 | /* Old policy spanning whole new range. */ | |
1194 | if (n->end > end) { | |
1195 | if (!new2) { | |
1196 | spin_unlock(&sp->lock); | |
1197 | new2 = sp_alloc(end, n->end, n->policy); | |
1198 | if (!new2) | |
1199 | return -ENOMEM; | |
1200 | goto restart; | |
1201 | } | |
1202 | n->end = start; | |
1203 | sp_insert(sp, new2); | |
1204 | new2 = NULL; | |
1205 | break; | |
1206 | } else | |
1207 | n->end = start; | |
1208 | } | |
1209 | if (!next) | |
1210 | break; | |
1211 | n = rb_entry(next, struct sp_node, nd); | |
1212 | } | |
1213 | if (new) | |
1214 | sp_insert(sp, new); | |
1215 | spin_unlock(&sp->lock); | |
1216 | if (new2) { | |
1217 | mpol_free(new2->policy); | |
1218 | kmem_cache_free(sn_cache, new2); | |
1219 | } | |
1220 | return 0; | |
1221 | } | |
1222 | ||
1223 | int mpol_set_shared_policy(struct shared_policy *info, | |
1224 | struct vm_area_struct *vma, struct mempolicy *npol) | |
1225 | { | |
1226 | int err; | |
1227 | struct sp_node *new = NULL; | |
1228 | unsigned long sz = vma_pages(vma); | |
1229 | ||
1230 | PDprintk("set_shared_policy %lx sz %lu %d %lx\n", | |
1231 | vma->vm_pgoff, | |
1232 | sz, npol? npol->policy : -1, | |
1233 | npol ? nodes_addr(npol->v.nodes)[0] : -1); | |
1234 | ||
1235 | if (npol) { | |
1236 | new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol); | |
1237 | if (!new) | |
1238 | return -ENOMEM; | |
1239 | } | |
1240 | err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new); | |
1241 | if (err && new) | |
1242 | kmem_cache_free(sn_cache, new); | |
1243 | return err; | |
1244 | } | |
1245 | ||
1246 | /* Free a backing policy store on inode delete. */ | |
1247 | void mpol_free_shared_policy(struct shared_policy *p) | |
1248 | { | |
1249 | struct sp_node *n; | |
1250 | struct rb_node *next; | |
1251 | ||
1252 | if (!p->root.rb_node) | |
1253 | return; | |
1254 | spin_lock(&p->lock); | |
1255 | next = rb_first(&p->root); | |
1256 | while (next) { | |
1257 | n = rb_entry(next, struct sp_node, nd); | |
1258 | next = rb_next(&n->nd); | |
1259 | rb_erase(&n->nd, &p->root); | |
1260 | mpol_free(n->policy); | |
1261 | kmem_cache_free(sn_cache, n); | |
1262 | } | |
1263 | spin_unlock(&p->lock); | |
1264 | } | |
1265 | ||
1266 | /* assumes fs == KERNEL_DS */ | |
1267 | void __init numa_policy_init(void) | |
1268 | { | |
1269 | policy_cache = kmem_cache_create("numa_policy", | |
1270 | sizeof(struct mempolicy), | |
1271 | 0, SLAB_PANIC, NULL, NULL); | |
1272 | ||
1273 | sn_cache = kmem_cache_create("shared_policy_node", | |
1274 | sizeof(struct sp_node), | |
1275 | 0, SLAB_PANIC, NULL, NULL); | |
1276 | ||
1277 | /* Set interleaving policy for system init. This way not all | |
1278 | the data structures allocated at system boot end up in node zero. */ | |
1279 | ||
1280 | if (do_set_mempolicy(MPOL_INTERLEAVE, &node_online_map)) | |
1281 | printk("numa_policy_init: interleaving failed\n"); | |
1282 | } | |
1283 | ||
1284 | /* Reset policy of current process to default */ | |
1285 | void numa_default_policy(void) | |
1286 | { | |
1287 | do_set_mempolicy(MPOL_DEFAULT, NULL); | |
1288 | } | |
1289 | ||
1290 | /* Migrate a policy to a different set of nodes */ | |
1291 | static void rebind_policy(struct mempolicy *pol, const nodemask_t *old, | |
1292 | const nodemask_t *new) | |
1293 | { | |
1294 | nodemask_t tmp; | |
1295 | ||
1296 | if (!pol) | |
1297 | return; | |
1298 | ||
1299 | switch (pol->policy) { | |
1300 | case MPOL_DEFAULT: | |
1301 | break; | |
1302 | case MPOL_INTERLEAVE: | |
1303 | nodes_remap(tmp, pol->v.nodes, *old, *new); | |
1304 | pol->v.nodes = tmp; | |
1305 | current->il_next = node_remap(current->il_next, *old, *new); | |
1306 | break; | |
1307 | case MPOL_PREFERRED: | |
1308 | pol->v.preferred_node = node_remap(pol->v.preferred_node, | |
1309 | *old, *new); | |
1310 | break; | |
1311 | case MPOL_BIND: { | |
1312 | nodemask_t nodes; | |
1313 | struct zone **z; | |
1314 | struct zonelist *zonelist; | |
1315 | ||
1316 | nodes_clear(nodes); | |
1317 | for (z = pol->v.zonelist->zones; *z; z++) | |
1318 | node_set((*z)->zone_pgdat->node_id, nodes); | |
1319 | nodes_remap(tmp, nodes, *old, *new); | |
1320 | nodes = tmp; | |
1321 | ||
1322 | zonelist = bind_zonelist(&nodes); | |
1323 | ||
1324 | /* If no mem, then zonelist is NULL and we keep old zonelist. | |
1325 | * If that old zonelist has no remaining mems_allowed nodes, | |
1326 | * then zonelist_policy() will "FALL THROUGH" to MPOL_DEFAULT. | |
1327 | */ | |
1328 | ||
1329 | if (zonelist) { | |
1330 | /* Good - got mem - substitute new zonelist */ | |
1331 | kfree(pol->v.zonelist); | |
1332 | pol->v.zonelist = zonelist; | |
1333 | } | |
1334 | break; | |
1335 | } | |
1336 | default: | |
1337 | BUG(); | |
1338 | break; | |
1339 | } | |
1340 | } | |
1341 | ||
1342 | /* | |
1343 | * Someone moved this task to different nodes. Fixup mempolicies. | |
1344 | * | |
1345 | * TODO - fixup current->mm->vma and shmfs/tmpfs/hugetlbfs policies as well, | |
1346 | * once we have a cpuset mechanism to mark which cpuset subtree is migrating. | |
1347 | */ | |
1348 | void numa_policy_rebind(const nodemask_t *old, const nodemask_t *new) | |
1349 | { | |
1350 | rebind_policy(current->mempolicy, old, new); | |
1351 | } |