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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 | */ | |
67 | ||
68 | #include <linux/mempolicy.h> | |
69 | #include <linux/mm.h> | |
70 | #include <linux/highmem.h> | |
71 | #include <linux/hugetlb.h> | |
72 | #include <linux/kernel.h> | |
73 | #include <linux/sched.h> | |
74 | #include <linux/nodemask.h> | |
75 | #include <linux/cpuset.h> | |
76 | #include <linux/slab.h> | |
77 | #include <linux/string.h> | |
78 | #include <linux/export.h> | |
79 | #include <linux/nsproxy.h> | |
80 | #include <linux/interrupt.h> | |
81 | #include <linux/init.h> | |
82 | #include <linux/compat.h> | |
83 | #include <linux/swap.h> | |
84 | #include <linux/seq_file.h> | |
85 | #include <linux/proc_fs.h> | |
86 | #include <linux/migrate.h> | |
87 | #include <linux/ksm.h> | |
88 | #include <linux/rmap.h> | |
89 | #include <linux/security.h> | |
90 | #include <linux/syscalls.h> | |
91 | #include <linux/ctype.h> | |
92 | #include <linux/mm_inline.h> | |
93 | ||
94 | #include <asm/tlbflush.h> | |
95 | #include <asm/uaccess.h> | |
96 | #include <linux/random.h> | |
97 | ||
98 | #include "internal.h" | |
99 | ||
100 | /* Internal flags */ | |
101 | #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */ | |
102 | #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */ | |
103 | ||
104 | static struct kmem_cache *policy_cache; | |
105 | static struct kmem_cache *sn_cache; | |
106 | ||
107 | /* Highest zone. An specific allocation for a zone below that is not | |
108 | policied. */ | |
109 | enum zone_type policy_zone = 0; | |
110 | ||
111 | /* | |
112 | * run-time system-wide default policy => local allocation | |
113 | */ | |
114 | static struct mempolicy default_policy = { | |
115 | .refcnt = ATOMIC_INIT(1), /* never free it */ | |
116 | .mode = MPOL_PREFERRED, | |
117 | .flags = MPOL_F_LOCAL, | |
118 | }; | |
119 | ||
120 | static const struct mempolicy_operations { | |
121 | int (*create)(struct mempolicy *pol, const nodemask_t *nodes); | |
122 | /* | |
123 | * If read-side task has no lock to protect task->mempolicy, write-side | |
124 | * task will rebind the task->mempolicy by two step. The first step is | |
125 | * setting all the newly nodes, and the second step is cleaning all the | |
126 | * disallowed nodes. In this way, we can avoid finding no node to alloc | |
127 | * page. | |
128 | * If we have a lock to protect task->mempolicy in read-side, we do | |
129 | * rebind directly. | |
130 | * | |
131 | * step: | |
132 | * MPOL_REBIND_ONCE - do rebind work at once | |
133 | * MPOL_REBIND_STEP1 - set all the newly nodes | |
134 | * MPOL_REBIND_STEP2 - clean all the disallowed nodes | |
135 | */ | |
136 | void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes, | |
137 | enum mpol_rebind_step step); | |
138 | } mpol_ops[MPOL_MAX]; | |
139 | ||
140 | /* Check that the nodemask contains at least one populated zone */ | |
141 | static int is_valid_nodemask(const nodemask_t *nodemask) | |
142 | { | |
143 | int nd, k; | |
144 | ||
145 | for_each_node_mask(nd, *nodemask) { | |
146 | struct zone *z; | |
147 | ||
148 | for (k = 0; k <= policy_zone; k++) { | |
149 | z = &NODE_DATA(nd)->node_zones[k]; | |
150 | if (z->present_pages > 0) | |
151 | return 1; | |
152 | } | |
153 | } | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
158 | static inline int mpol_store_user_nodemask(const struct mempolicy *pol) | |
159 | { | |
160 | return pol->flags & MPOL_MODE_FLAGS; | |
161 | } | |
162 | ||
163 | static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig, | |
164 | const nodemask_t *rel) | |
165 | { | |
166 | nodemask_t tmp; | |
167 | nodes_fold(tmp, *orig, nodes_weight(*rel)); | |
168 | nodes_onto(*ret, tmp, *rel); | |
169 | } | |
170 | ||
171 | static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes) | |
172 | { | |
173 | if (nodes_empty(*nodes)) | |
174 | return -EINVAL; | |
175 | pol->v.nodes = *nodes; | |
176 | return 0; | |
177 | } | |
178 | ||
179 | static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes) | |
180 | { | |
181 | if (!nodes) | |
182 | pol->flags |= MPOL_F_LOCAL; /* local allocation */ | |
183 | else if (nodes_empty(*nodes)) | |
184 | return -EINVAL; /* no allowed nodes */ | |
185 | else | |
186 | pol->v.preferred_node = first_node(*nodes); | |
187 | return 0; | |
188 | } | |
189 | ||
190 | static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes) | |
191 | { | |
192 | if (!is_valid_nodemask(nodes)) | |
193 | return -EINVAL; | |
194 | pol->v.nodes = *nodes; | |
195 | return 0; | |
196 | } | |
197 | ||
198 | /* | |
199 | * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if | |
200 | * any, for the new policy. mpol_new() has already validated the nodes | |
201 | * parameter with respect to the policy mode and flags. But, we need to | |
202 | * handle an empty nodemask with MPOL_PREFERRED here. | |
203 | * | |
204 | * Must be called holding task's alloc_lock to protect task's mems_allowed | |
205 | * and mempolicy. May also be called holding the mmap_semaphore for write. | |
206 | */ | |
207 | static int mpol_set_nodemask(struct mempolicy *pol, | |
208 | const nodemask_t *nodes, struct nodemask_scratch *nsc) | |
209 | { | |
210 | int ret; | |
211 | ||
212 | /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */ | |
213 | if (pol == NULL) | |
214 | return 0; | |
215 | /* Check N_HIGH_MEMORY */ | |
216 | nodes_and(nsc->mask1, | |
217 | cpuset_current_mems_allowed, node_states[N_HIGH_MEMORY]); | |
218 | ||
219 | VM_BUG_ON(!nodes); | |
220 | if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes)) | |
221 | nodes = NULL; /* explicit local allocation */ | |
222 | else { | |
223 | if (pol->flags & MPOL_F_RELATIVE_NODES) | |
224 | mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1); | |
225 | else | |
226 | nodes_and(nsc->mask2, *nodes, nsc->mask1); | |
227 | ||
228 | if (mpol_store_user_nodemask(pol)) | |
229 | pol->w.user_nodemask = *nodes; | |
230 | else | |
231 | pol->w.cpuset_mems_allowed = | |
232 | cpuset_current_mems_allowed; | |
233 | } | |
234 | ||
235 | if (nodes) | |
236 | ret = mpol_ops[pol->mode].create(pol, &nsc->mask2); | |
237 | else | |
238 | ret = mpol_ops[pol->mode].create(pol, NULL); | |
239 | return ret; | |
240 | } | |
241 | ||
242 | /* | |
243 | * This function just creates a new policy, does some check and simple | |
244 | * initialization. You must invoke mpol_set_nodemask() to set nodes. | |
245 | */ | |
246 | static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, | |
247 | nodemask_t *nodes) | |
248 | { | |
249 | struct mempolicy *policy; | |
250 | ||
251 | pr_debug("setting mode %d flags %d nodes[0] %lx\n", | |
252 | mode, flags, nodes ? nodes_addr(*nodes)[0] : -1); | |
253 | ||
254 | if (mode == MPOL_DEFAULT) { | |
255 | if (nodes && !nodes_empty(*nodes)) | |
256 | return ERR_PTR(-EINVAL); | |
257 | return NULL; /* simply delete any existing policy */ | |
258 | } | |
259 | VM_BUG_ON(!nodes); | |
260 | ||
261 | /* | |
262 | * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or | |
263 | * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation). | |
264 | * All other modes require a valid pointer to a non-empty nodemask. | |
265 | */ | |
266 | if (mode == MPOL_PREFERRED) { | |
267 | if (nodes_empty(*nodes)) { | |
268 | if (((flags & MPOL_F_STATIC_NODES) || | |
269 | (flags & MPOL_F_RELATIVE_NODES))) | |
270 | return ERR_PTR(-EINVAL); | |
271 | } | |
272 | } else if (nodes_empty(*nodes)) | |
273 | return ERR_PTR(-EINVAL); | |
274 | policy = kmem_cache_alloc(policy_cache, GFP_KERNEL); | |
275 | if (!policy) | |
276 | return ERR_PTR(-ENOMEM); | |
277 | atomic_set(&policy->refcnt, 1); | |
278 | policy->mode = mode; | |
279 | policy->flags = flags; | |
280 | ||
281 | return policy; | |
282 | } | |
283 | ||
284 | /* Slow path of a mpol destructor. */ | |
285 | void __mpol_put(struct mempolicy *p) | |
286 | { | |
287 | if (!atomic_dec_and_test(&p->refcnt)) | |
288 | return; | |
289 | kmem_cache_free(policy_cache, p); | |
290 | } | |
291 | ||
292 | static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes, | |
293 | enum mpol_rebind_step step) | |
294 | { | |
295 | } | |
296 | ||
297 | /* | |
298 | * step: | |
299 | * MPOL_REBIND_ONCE - do rebind work at once | |
300 | * MPOL_REBIND_STEP1 - set all the newly nodes | |
301 | * MPOL_REBIND_STEP2 - clean all the disallowed nodes | |
302 | */ | |
303 | static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes, | |
304 | enum mpol_rebind_step step) | |
305 | { | |
306 | nodemask_t tmp; | |
307 | ||
308 | if (pol->flags & MPOL_F_STATIC_NODES) | |
309 | nodes_and(tmp, pol->w.user_nodemask, *nodes); | |
310 | else if (pol->flags & MPOL_F_RELATIVE_NODES) | |
311 | mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); | |
312 | else { | |
313 | /* | |
314 | * if step == 1, we use ->w.cpuset_mems_allowed to cache the | |
315 | * result | |
316 | */ | |
317 | if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP1) { | |
318 | nodes_remap(tmp, pol->v.nodes, | |
319 | pol->w.cpuset_mems_allowed, *nodes); | |
320 | pol->w.cpuset_mems_allowed = step ? tmp : *nodes; | |
321 | } else if (step == MPOL_REBIND_STEP2) { | |
322 | tmp = pol->w.cpuset_mems_allowed; | |
323 | pol->w.cpuset_mems_allowed = *nodes; | |
324 | } else | |
325 | BUG(); | |
326 | } | |
327 | ||
328 | if (nodes_empty(tmp)) | |
329 | tmp = *nodes; | |
330 | ||
331 | if (step == MPOL_REBIND_STEP1) | |
332 | nodes_or(pol->v.nodes, pol->v.nodes, tmp); | |
333 | else if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP2) | |
334 | pol->v.nodes = tmp; | |
335 | else | |
336 | BUG(); | |
337 | ||
338 | if (!node_isset(current->il_next, tmp)) { | |
339 | current->il_next = next_node(current->il_next, tmp); | |
340 | if (current->il_next >= MAX_NUMNODES) | |
341 | current->il_next = first_node(tmp); | |
342 | if (current->il_next >= MAX_NUMNODES) | |
343 | current->il_next = numa_node_id(); | |
344 | } | |
345 | } | |
346 | ||
347 | static void mpol_rebind_preferred(struct mempolicy *pol, | |
348 | const nodemask_t *nodes, | |
349 | enum mpol_rebind_step step) | |
350 | { | |
351 | nodemask_t tmp; | |
352 | ||
353 | if (pol->flags & MPOL_F_STATIC_NODES) { | |
354 | int node = first_node(pol->w.user_nodemask); | |
355 | ||
356 | if (node_isset(node, *nodes)) { | |
357 | pol->v.preferred_node = node; | |
358 | pol->flags &= ~MPOL_F_LOCAL; | |
359 | } else | |
360 | pol->flags |= MPOL_F_LOCAL; | |
361 | } else if (pol->flags & MPOL_F_RELATIVE_NODES) { | |
362 | mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); | |
363 | pol->v.preferred_node = first_node(tmp); | |
364 | } else if (!(pol->flags & MPOL_F_LOCAL)) { | |
365 | pol->v.preferred_node = node_remap(pol->v.preferred_node, | |
366 | pol->w.cpuset_mems_allowed, | |
367 | *nodes); | |
368 | pol->w.cpuset_mems_allowed = *nodes; | |
369 | } | |
370 | } | |
371 | ||
372 | /* | |
373 | * mpol_rebind_policy - Migrate a policy to a different set of nodes | |
374 | * | |
375 | * If read-side task has no lock to protect task->mempolicy, write-side | |
376 | * task will rebind the task->mempolicy by two step. The first step is | |
377 | * setting all the newly nodes, and the second step is cleaning all the | |
378 | * disallowed nodes. In this way, we can avoid finding no node to alloc | |
379 | * page. | |
380 | * If we have a lock to protect task->mempolicy in read-side, we do | |
381 | * rebind directly. | |
382 | * | |
383 | * step: | |
384 | * MPOL_REBIND_ONCE - do rebind work at once | |
385 | * MPOL_REBIND_STEP1 - set all the newly nodes | |
386 | * MPOL_REBIND_STEP2 - clean all the disallowed nodes | |
387 | */ | |
388 | static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask, | |
389 | enum mpol_rebind_step step) | |
390 | { | |
391 | if (!pol) | |
392 | return; | |
393 | if (!mpol_store_user_nodemask(pol) && step == MPOL_REBIND_ONCE && | |
394 | nodes_equal(pol->w.cpuset_mems_allowed, *newmask)) | |
395 | return; | |
396 | ||
397 | if (step == MPOL_REBIND_STEP1 && (pol->flags & MPOL_F_REBINDING)) | |
398 | return; | |
399 | ||
400 | if (step == MPOL_REBIND_STEP2 && !(pol->flags & MPOL_F_REBINDING)) | |
401 | BUG(); | |
402 | ||
403 | if (step == MPOL_REBIND_STEP1) | |
404 | pol->flags |= MPOL_F_REBINDING; | |
405 | else if (step == MPOL_REBIND_STEP2) | |
406 | pol->flags &= ~MPOL_F_REBINDING; | |
407 | else if (step >= MPOL_REBIND_NSTEP) | |
408 | BUG(); | |
409 | ||
410 | mpol_ops[pol->mode].rebind(pol, newmask, step); | |
411 | } | |
412 | ||
413 | /* | |
414 | * Wrapper for mpol_rebind_policy() that just requires task | |
415 | * pointer, and updates task mempolicy. | |
416 | * | |
417 | * Called with task's alloc_lock held. | |
418 | */ | |
419 | ||
420 | void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new, | |
421 | enum mpol_rebind_step step) | |
422 | { | |
423 | mpol_rebind_policy(tsk->mempolicy, new, step); | |
424 | } | |
425 | ||
426 | /* | |
427 | * Rebind each vma in mm to new nodemask. | |
428 | * | |
429 | * Call holding a reference to mm. Takes mm->mmap_sem during call. | |
430 | */ | |
431 | ||
432 | void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new) | |
433 | { | |
434 | struct vm_area_struct *vma; | |
435 | ||
436 | down_write(&mm->mmap_sem); | |
437 | for (vma = mm->mmap; vma; vma = vma->vm_next) | |
438 | mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE); | |
439 | up_write(&mm->mmap_sem); | |
440 | } | |
441 | ||
442 | static const struct mempolicy_operations mpol_ops[MPOL_MAX] = { | |
443 | [MPOL_DEFAULT] = { | |
444 | .rebind = mpol_rebind_default, | |
445 | }, | |
446 | [MPOL_INTERLEAVE] = { | |
447 | .create = mpol_new_interleave, | |
448 | .rebind = mpol_rebind_nodemask, | |
449 | }, | |
450 | [MPOL_PREFERRED] = { | |
451 | .create = mpol_new_preferred, | |
452 | .rebind = mpol_rebind_preferred, | |
453 | }, | |
454 | [MPOL_BIND] = { | |
455 | .create = mpol_new_bind, | |
456 | .rebind = mpol_rebind_nodemask, | |
457 | }, | |
458 | }; | |
459 | ||
460 | static void migrate_page_add(struct page *page, struct list_head *pagelist, | |
461 | unsigned long flags); | |
462 | ||
463 | /* Scan through pages checking if pages follow certain conditions. */ | |
464 | static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd, | |
465 | unsigned long addr, unsigned long end, | |
466 | const nodemask_t *nodes, unsigned long flags, | |
467 | void *private) | |
468 | { | |
469 | pte_t *orig_pte; | |
470 | pte_t *pte; | |
471 | spinlock_t *ptl; | |
472 | ||
473 | orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
474 | do { | |
475 | struct page *page; | |
476 | int nid; | |
477 | ||
478 | if (!pte_present(*pte)) | |
479 | continue; | |
480 | page = vm_normal_page(vma, addr, *pte); | |
481 | if (!page) | |
482 | continue; | |
483 | /* | |
484 | * vm_normal_page() filters out zero pages, but there might | |
485 | * still be PageReserved pages to skip, perhaps in a VDSO. | |
486 | * And we cannot move PageKsm pages sensibly or safely yet. | |
487 | */ | |
488 | if (PageReserved(page) || PageKsm(page)) | |
489 | continue; | |
490 | nid = page_to_nid(page); | |
491 | if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT)) | |
492 | continue; | |
493 | ||
494 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) | |
495 | migrate_page_add(page, private, flags); | |
496 | else | |
497 | break; | |
498 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
499 | pte_unmap_unlock(orig_pte, ptl); | |
500 | return addr != end; | |
501 | } | |
502 | ||
503 | static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud, | |
504 | unsigned long addr, unsigned long end, | |
505 | const nodemask_t *nodes, unsigned long flags, | |
506 | void *private) | |
507 | { | |
508 | pmd_t *pmd; | |
509 | unsigned long next; | |
510 | ||
511 | pmd = pmd_offset(pud, addr); | |
512 | do { | |
513 | next = pmd_addr_end(addr, end); | |
514 | split_huge_page_pmd(vma->vm_mm, pmd); | |
515 | if (pmd_none_or_trans_huge_or_clear_bad(pmd)) | |
516 | continue; | |
517 | if (check_pte_range(vma, pmd, addr, next, nodes, | |
518 | flags, private)) | |
519 | return -EIO; | |
520 | } while (pmd++, addr = next, addr != end); | |
521 | return 0; | |
522 | } | |
523 | ||
524 | static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd, | |
525 | unsigned long addr, unsigned long end, | |
526 | const nodemask_t *nodes, unsigned long flags, | |
527 | void *private) | |
528 | { | |
529 | pud_t *pud; | |
530 | unsigned long next; | |
531 | ||
532 | pud = pud_offset(pgd, addr); | |
533 | do { | |
534 | next = pud_addr_end(addr, end); | |
535 | if (pud_none_or_clear_bad(pud)) | |
536 | continue; | |
537 | if (check_pmd_range(vma, pud, addr, next, nodes, | |
538 | flags, private)) | |
539 | return -EIO; | |
540 | } while (pud++, addr = next, addr != end); | |
541 | return 0; | |
542 | } | |
543 | ||
544 | static inline int check_pgd_range(struct vm_area_struct *vma, | |
545 | unsigned long addr, unsigned long end, | |
546 | const nodemask_t *nodes, unsigned long flags, | |
547 | void *private) | |
548 | { | |
549 | pgd_t *pgd; | |
550 | unsigned long next; | |
551 | ||
552 | pgd = pgd_offset(vma->vm_mm, addr); | |
553 | do { | |
554 | next = pgd_addr_end(addr, end); | |
555 | if (pgd_none_or_clear_bad(pgd)) | |
556 | continue; | |
557 | if (check_pud_range(vma, pgd, addr, next, nodes, | |
558 | flags, private)) | |
559 | return -EIO; | |
560 | } while (pgd++, addr = next, addr != end); | |
561 | return 0; | |
562 | } | |
563 | ||
564 | /* | |
565 | * Check if all pages in a range are on a set of nodes. | |
566 | * If pagelist != NULL then isolate pages from the LRU and | |
567 | * put them on the pagelist. | |
568 | */ | |
569 | static struct vm_area_struct * | |
570 | check_range(struct mm_struct *mm, unsigned long start, unsigned long end, | |
571 | const nodemask_t *nodes, unsigned long flags, void *private) | |
572 | { | |
573 | int err; | |
574 | struct vm_area_struct *first, *vma, *prev; | |
575 | ||
576 | ||
577 | first = find_vma(mm, start); | |
578 | if (!first) | |
579 | return ERR_PTR(-EFAULT); | |
580 | prev = NULL; | |
581 | for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) { | |
582 | if (!(flags & MPOL_MF_DISCONTIG_OK)) { | |
583 | if (!vma->vm_next && vma->vm_end < end) | |
584 | return ERR_PTR(-EFAULT); | |
585 | if (prev && prev->vm_end < vma->vm_start) | |
586 | return ERR_PTR(-EFAULT); | |
587 | } | |
588 | if (!is_vm_hugetlb_page(vma) && | |
589 | ((flags & MPOL_MF_STRICT) || | |
590 | ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) && | |
591 | vma_migratable(vma)))) { | |
592 | unsigned long endvma = vma->vm_end; | |
593 | ||
594 | if (endvma > end) | |
595 | endvma = end; | |
596 | if (vma->vm_start > start) | |
597 | start = vma->vm_start; | |
598 | err = check_pgd_range(vma, start, endvma, nodes, | |
599 | flags, private); | |
600 | if (err) { | |
601 | first = ERR_PTR(err); | |
602 | break; | |
603 | } | |
604 | } | |
605 | prev = vma; | |
606 | } | |
607 | return first; | |
608 | } | |
609 | ||
610 | /* | |
611 | * Apply policy to a single VMA | |
612 | * This must be called with the mmap_sem held for writing. | |
613 | */ | |
614 | static int vma_replace_policy(struct vm_area_struct *vma, | |
615 | struct mempolicy *pol) | |
616 | { | |
617 | int err; | |
618 | struct mempolicy *old; | |
619 | struct mempolicy *new; | |
620 | ||
621 | pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n", | |
622 | vma->vm_start, vma->vm_end, vma->vm_pgoff, | |
623 | vma->vm_ops, vma->vm_file, | |
624 | vma->vm_ops ? vma->vm_ops->set_policy : NULL); | |
625 | ||
626 | new = mpol_dup(pol); | |
627 | if (IS_ERR(new)) | |
628 | return PTR_ERR(new); | |
629 | ||
630 | if (vma->vm_ops && vma->vm_ops->set_policy) { | |
631 | err = vma->vm_ops->set_policy(vma, new); | |
632 | if (err) | |
633 | goto err_out; | |
634 | } | |
635 | ||
636 | old = vma->vm_policy; | |
637 | vma->vm_policy = new; /* protected by mmap_sem */ | |
638 | mpol_put(old); | |
639 | ||
640 | return 0; | |
641 | err_out: | |
642 | mpol_put(new); | |
643 | return err; | |
644 | } | |
645 | ||
646 | /* Step 2: apply policy to a range and do splits. */ | |
647 | static int mbind_range(struct mm_struct *mm, unsigned long start, | |
648 | unsigned long end, struct mempolicy *new_pol) | |
649 | { | |
650 | struct vm_area_struct *next; | |
651 | struct vm_area_struct *prev; | |
652 | struct vm_area_struct *vma; | |
653 | int err = 0; | |
654 | pgoff_t pgoff; | |
655 | unsigned long vmstart; | |
656 | unsigned long vmend; | |
657 | ||
658 | vma = find_vma(mm, start); | |
659 | if (!vma || vma->vm_start > start) | |
660 | return -EFAULT; | |
661 | ||
662 | prev = vma->vm_prev; | |
663 | if (start > vma->vm_start) | |
664 | prev = vma; | |
665 | ||
666 | for (; vma && vma->vm_start < end; prev = vma, vma = next) { | |
667 | next = vma->vm_next; | |
668 | vmstart = max(start, vma->vm_start); | |
669 | vmend = min(end, vma->vm_end); | |
670 | ||
671 | if (mpol_equal(vma_policy(vma), new_pol)) | |
672 | continue; | |
673 | ||
674 | pgoff = vma->vm_pgoff + | |
675 | ((vmstart - vma->vm_start) >> PAGE_SHIFT); | |
676 | prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags, | |
677 | vma->anon_vma, vma->vm_file, pgoff, | |
678 | new_pol); | |
679 | if (prev) { | |
680 | vma = prev; | |
681 | next = vma->vm_next; | |
682 | continue; | |
683 | } | |
684 | if (vma->vm_start != vmstart) { | |
685 | err = split_vma(vma->vm_mm, vma, vmstart, 1); | |
686 | if (err) | |
687 | goto out; | |
688 | } | |
689 | if (vma->vm_end != vmend) { | |
690 | err = split_vma(vma->vm_mm, vma, vmend, 0); | |
691 | if (err) | |
692 | goto out; | |
693 | } | |
694 | err = vma_replace_policy(vma, new_pol); | |
695 | if (err) | |
696 | goto out; | |
697 | } | |
698 | ||
699 | out: | |
700 | return err; | |
701 | } | |
702 | ||
703 | /* | |
704 | * Update task->flags PF_MEMPOLICY bit: set iff non-default | |
705 | * mempolicy. Allows more rapid checking of this (combined perhaps | |
706 | * with other PF_* flag bits) on memory allocation hot code paths. | |
707 | * | |
708 | * If called from outside this file, the task 'p' should -only- be | |
709 | * a newly forked child not yet visible on the task list, because | |
710 | * manipulating the task flags of a visible task is not safe. | |
711 | * | |
712 | * The above limitation is why this routine has the funny name | |
713 | * mpol_fix_fork_child_flag(). | |
714 | * | |
715 | * It is also safe to call this with a task pointer of current, | |
716 | * which the static wrapper mpol_set_task_struct_flag() does, | |
717 | * for use within this file. | |
718 | */ | |
719 | ||
720 | void mpol_fix_fork_child_flag(struct task_struct *p) | |
721 | { | |
722 | if (p->mempolicy) | |
723 | p->flags |= PF_MEMPOLICY; | |
724 | else | |
725 | p->flags &= ~PF_MEMPOLICY; | |
726 | } | |
727 | ||
728 | static void mpol_set_task_struct_flag(void) | |
729 | { | |
730 | mpol_fix_fork_child_flag(current); | |
731 | } | |
732 | ||
733 | /* Set the process memory policy */ | |
734 | static long do_set_mempolicy(unsigned short mode, unsigned short flags, | |
735 | nodemask_t *nodes) | |
736 | { | |
737 | struct mempolicy *new, *old; | |
738 | struct mm_struct *mm = current->mm; | |
739 | NODEMASK_SCRATCH(scratch); | |
740 | int ret; | |
741 | ||
742 | if (!scratch) | |
743 | return -ENOMEM; | |
744 | ||
745 | new = mpol_new(mode, flags, nodes); | |
746 | if (IS_ERR(new)) { | |
747 | ret = PTR_ERR(new); | |
748 | goto out; | |
749 | } | |
750 | /* | |
751 | * prevent changing our mempolicy while show_numa_maps() | |
752 | * is using it. | |
753 | * Note: do_set_mempolicy() can be called at init time | |
754 | * with no 'mm'. | |
755 | */ | |
756 | if (mm) | |
757 | down_write(&mm->mmap_sem); | |
758 | task_lock(current); | |
759 | ret = mpol_set_nodemask(new, nodes, scratch); | |
760 | if (ret) { | |
761 | task_unlock(current); | |
762 | if (mm) | |
763 | up_write(&mm->mmap_sem); | |
764 | mpol_put(new); | |
765 | goto out; | |
766 | } | |
767 | old = current->mempolicy; | |
768 | current->mempolicy = new; | |
769 | mpol_set_task_struct_flag(); | |
770 | if (new && new->mode == MPOL_INTERLEAVE && | |
771 | nodes_weight(new->v.nodes)) | |
772 | current->il_next = first_node(new->v.nodes); | |
773 | task_unlock(current); | |
774 | if (mm) | |
775 | up_write(&mm->mmap_sem); | |
776 | ||
777 | mpol_put(old); | |
778 | ret = 0; | |
779 | out: | |
780 | NODEMASK_SCRATCH_FREE(scratch); | |
781 | return ret; | |
782 | } | |
783 | ||
784 | /* | |
785 | * Return nodemask for policy for get_mempolicy() query | |
786 | * | |
787 | * Called with task's alloc_lock held | |
788 | */ | |
789 | static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes) | |
790 | { | |
791 | nodes_clear(*nodes); | |
792 | if (p == &default_policy) | |
793 | return; | |
794 | ||
795 | switch (p->mode) { | |
796 | case MPOL_BIND: | |
797 | /* Fall through */ | |
798 | case MPOL_INTERLEAVE: | |
799 | *nodes = p->v.nodes; | |
800 | break; | |
801 | case MPOL_PREFERRED: | |
802 | if (!(p->flags & MPOL_F_LOCAL)) | |
803 | node_set(p->v.preferred_node, *nodes); | |
804 | /* else return empty node mask for local allocation */ | |
805 | break; | |
806 | default: | |
807 | BUG(); | |
808 | } | |
809 | } | |
810 | ||
811 | static int lookup_node(struct mm_struct *mm, unsigned long addr) | |
812 | { | |
813 | struct page *p; | |
814 | int err; | |
815 | ||
816 | err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL); | |
817 | if (err >= 0) { | |
818 | err = page_to_nid(p); | |
819 | put_page(p); | |
820 | } | |
821 | return err; | |
822 | } | |
823 | ||
824 | /* Retrieve NUMA policy */ | |
825 | static long do_get_mempolicy(int *policy, nodemask_t *nmask, | |
826 | unsigned long addr, unsigned long flags) | |
827 | { | |
828 | int err; | |
829 | struct mm_struct *mm = current->mm; | |
830 | struct vm_area_struct *vma = NULL; | |
831 | struct mempolicy *pol = current->mempolicy; | |
832 | ||
833 | if (flags & | |
834 | ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED)) | |
835 | return -EINVAL; | |
836 | ||
837 | if (flags & MPOL_F_MEMS_ALLOWED) { | |
838 | if (flags & (MPOL_F_NODE|MPOL_F_ADDR)) | |
839 | return -EINVAL; | |
840 | *policy = 0; /* just so it's initialized */ | |
841 | task_lock(current); | |
842 | *nmask = cpuset_current_mems_allowed; | |
843 | task_unlock(current); | |
844 | return 0; | |
845 | } | |
846 | ||
847 | if (flags & MPOL_F_ADDR) { | |
848 | /* | |
849 | * Do NOT fall back to task policy if the | |
850 | * vma/shared policy at addr is NULL. We | |
851 | * want to return MPOL_DEFAULT in this case. | |
852 | */ | |
853 | down_read(&mm->mmap_sem); | |
854 | vma = find_vma_intersection(mm, addr, addr+1); | |
855 | if (!vma) { | |
856 | up_read(&mm->mmap_sem); | |
857 | return -EFAULT; | |
858 | } | |
859 | if (vma->vm_ops && vma->vm_ops->get_policy) | |
860 | pol = vma->vm_ops->get_policy(vma, addr); | |
861 | else | |
862 | pol = vma->vm_policy; | |
863 | } else if (addr) | |
864 | return -EINVAL; | |
865 | ||
866 | if (!pol) | |
867 | pol = &default_policy; /* indicates default behavior */ | |
868 | ||
869 | if (flags & MPOL_F_NODE) { | |
870 | if (flags & MPOL_F_ADDR) { | |
871 | err = lookup_node(mm, addr); | |
872 | if (err < 0) | |
873 | goto out; | |
874 | *policy = err; | |
875 | } else if (pol == current->mempolicy && | |
876 | pol->mode == MPOL_INTERLEAVE) { | |
877 | *policy = current->il_next; | |
878 | } else { | |
879 | err = -EINVAL; | |
880 | goto out; | |
881 | } | |
882 | } else { | |
883 | *policy = pol == &default_policy ? MPOL_DEFAULT : | |
884 | pol->mode; | |
885 | /* | |
886 | * Internal mempolicy flags must be masked off before exposing | |
887 | * the policy to userspace. | |
888 | */ | |
889 | *policy |= (pol->flags & MPOL_MODE_FLAGS); | |
890 | } | |
891 | ||
892 | if (vma) { | |
893 | up_read(¤t->mm->mmap_sem); | |
894 | vma = NULL; | |
895 | } | |
896 | ||
897 | err = 0; | |
898 | if (nmask) { | |
899 | if (mpol_store_user_nodemask(pol)) { | |
900 | *nmask = pol->w.user_nodemask; | |
901 | } else { | |
902 | task_lock(current); | |
903 | get_policy_nodemask(pol, nmask); | |
904 | task_unlock(current); | |
905 | } | |
906 | } | |
907 | ||
908 | out: | |
909 | mpol_cond_put(pol); | |
910 | if (vma) | |
911 | up_read(¤t->mm->mmap_sem); | |
912 | return err; | |
913 | } | |
914 | ||
915 | #ifdef CONFIG_MIGRATION | |
916 | /* | |
917 | * page migration | |
918 | */ | |
919 | static void migrate_page_add(struct page *page, struct list_head *pagelist, | |
920 | unsigned long flags) | |
921 | { | |
922 | /* | |
923 | * Avoid migrating a page that is shared with others. | |
924 | */ | |
925 | if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) { | |
926 | if (!isolate_lru_page(page)) { | |
927 | list_add_tail(&page->lru, pagelist); | |
928 | inc_zone_page_state(page, NR_ISOLATED_ANON + | |
929 | page_is_file_cache(page)); | |
930 | } | |
931 | } | |
932 | } | |
933 | ||
934 | static struct page *new_node_page(struct page *page, unsigned long node, int **x) | |
935 | { | |
936 | return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0); | |
937 | } | |
938 | ||
939 | /* | |
940 | * Migrate pages from one node to a target node. | |
941 | * Returns error or the number of pages not migrated. | |
942 | */ | |
943 | static int migrate_to_node(struct mm_struct *mm, int source, int dest, | |
944 | int flags) | |
945 | { | |
946 | nodemask_t nmask; | |
947 | LIST_HEAD(pagelist); | |
948 | int err = 0; | |
949 | struct vm_area_struct *vma; | |
950 | ||
951 | nodes_clear(nmask); | |
952 | node_set(source, nmask); | |
953 | ||
954 | vma = check_range(mm, mm->mmap->vm_start, mm->task_size, &nmask, | |
955 | flags | MPOL_MF_DISCONTIG_OK, &pagelist); | |
956 | if (IS_ERR(vma)) | |
957 | return PTR_ERR(vma); | |
958 | ||
959 | if (!list_empty(&pagelist)) { | |
960 | err = migrate_pages(&pagelist, new_node_page, dest, | |
961 | false, MIGRATE_SYNC); | |
962 | if (err) | |
963 | putback_lru_pages(&pagelist); | |
964 | } | |
965 | ||
966 | return err; | |
967 | } | |
968 | ||
969 | /* | |
970 | * Move pages between the two nodesets so as to preserve the physical | |
971 | * layout as much as possible. | |
972 | * | |
973 | * Returns the number of page that could not be moved. | |
974 | */ | |
975 | int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, | |
976 | const nodemask_t *to, int flags) | |
977 | { | |
978 | int busy = 0; | |
979 | int err; | |
980 | nodemask_t tmp; | |
981 | ||
982 | err = migrate_prep(); | |
983 | if (err) | |
984 | return err; | |
985 | ||
986 | down_read(&mm->mmap_sem); | |
987 | ||
988 | err = migrate_vmas(mm, from, to, flags); | |
989 | if (err) | |
990 | goto out; | |
991 | ||
992 | /* | |
993 | * Find a 'source' bit set in 'tmp' whose corresponding 'dest' | |
994 | * bit in 'to' is not also set in 'tmp'. Clear the found 'source' | |
995 | * bit in 'tmp', and return that <source, dest> pair for migration. | |
996 | * The pair of nodemasks 'to' and 'from' define the map. | |
997 | * | |
998 | * If no pair of bits is found that way, fallback to picking some | |
999 | * pair of 'source' and 'dest' bits that are not the same. If the | |
1000 | * 'source' and 'dest' bits are the same, this represents a node | |
1001 | * that will be migrating to itself, so no pages need move. | |
1002 | * | |
1003 | * If no bits are left in 'tmp', or if all remaining bits left | |
1004 | * in 'tmp' correspond to the same bit in 'to', return false | |
1005 | * (nothing left to migrate). | |
1006 | * | |
1007 | * This lets us pick a pair of nodes to migrate between, such that | |
1008 | * if possible the dest node is not already occupied by some other | |
1009 | * source node, minimizing the risk of overloading the memory on a | |
1010 | * node that would happen if we migrated incoming memory to a node | |
1011 | * before migrating outgoing memory source that same node. | |
1012 | * | |
1013 | * A single scan of tmp is sufficient. As we go, we remember the | |
1014 | * most recent <s, d> pair that moved (s != d). If we find a pair | |
1015 | * that not only moved, but what's better, moved to an empty slot | |
1016 | * (d is not set in tmp), then we break out then, with that pair. | |
1017 | * Otherwise when we finish scanning from_tmp, we at least have the | |
1018 | * most recent <s, d> pair that moved. If we get all the way through | |
1019 | * the scan of tmp without finding any node that moved, much less | |
1020 | * moved to an empty node, then there is nothing left worth migrating. | |
1021 | */ | |
1022 | ||
1023 | tmp = *from; | |
1024 | while (!nodes_empty(tmp)) { | |
1025 | int s,d; | |
1026 | int source = -1; | |
1027 | int dest = 0; | |
1028 | ||
1029 | for_each_node_mask(s, tmp) { | |
1030 | ||
1031 | /* | |
1032 | * do_migrate_pages() tries to maintain the relative | |
1033 | * node relationship of the pages established between | |
1034 | * threads and memory areas. | |
1035 | * | |
1036 | * However if the number of source nodes is not equal to | |
1037 | * the number of destination nodes we can not preserve | |
1038 | * this node relative relationship. In that case, skip | |
1039 | * copying memory from a node that is in the destination | |
1040 | * mask. | |
1041 | * | |
1042 | * Example: [2,3,4] -> [3,4,5] moves everything. | |
1043 | * [0-7] - > [3,4,5] moves only 0,1,2,6,7. | |
1044 | */ | |
1045 | ||
1046 | if ((nodes_weight(*from) != nodes_weight(*to)) && | |
1047 | (node_isset(s, *to))) | |
1048 | continue; | |
1049 | ||
1050 | d = node_remap(s, *from, *to); | |
1051 | if (s == d) | |
1052 | continue; | |
1053 | ||
1054 | source = s; /* Node moved. Memorize */ | |
1055 | dest = d; | |
1056 | ||
1057 | /* dest not in remaining from nodes? */ | |
1058 | if (!node_isset(dest, tmp)) | |
1059 | break; | |
1060 | } | |
1061 | if (source == -1) | |
1062 | break; | |
1063 | ||
1064 | node_clear(source, tmp); | |
1065 | err = migrate_to_node(mm, source, dest, flags); | |
1066 | if (err > 0) | |
1067 | busy += err; | |
1068 | if (err < 0) | |
1069 | break; | |
1070 | } | |
1071 | out: | |
1072 | up_read(&mm->mmap_sem); | |
1073 | if (err < 0) | |
1074 | return err; | |
1075 | return busy; | |
1076 | ||
1077 | } | |
1078 | ||
1079 | /* | |
1080 | * Allocate a new page for page migration based on vma policy. | |
1081 | * Start assuming that page is mapped by vma pointed to by @private. | |
1082 | * Search forward from there, if not. N.B., this assumes that the | |
1083 | * list of pages handed to migrate_pages()--which is how we get here-- | |
1084 | * is in virtual address order. | |
1085 | */ | |
1086 | static struct page *new_vma_page(struct page *page, unsigned long private, int **x) | |
1087 | { | |
1088 | struct vm_area_struct *vma = (struct vm_area_struct *)private; | |
1089 | unsigned long uninitialized_var(address); | |
1090 | ||
1091 | while (vma) { | |
1092 | address = page_address_in_vma(page, vma); | |
1093 | if (address != -EFAULT) | |
1094 | break; | |
1095 | vma = vma->vm_next; | |
1096 | } | |
1097 | ||
1098 | /* | |
1099 | * if !vma, alloc_page_vma() will use task or system default policy | |
1100 | */ | |
1101 | return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); | |
1102 | } | |
1103 | #else | |
1104 | ||
1105 | static void migrate_page_add(struct page *page, struct list_head *pagelist, | |
1106 | unsigned long flags) | |
1107 | { | |
1108 | } | |
1109 | ||
1110 | int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, | |
1111 | const nodemask_t *to, int flags) | |
1112 | { | |
1113 | return -ENOSYS; | |
1114 | } | |
1115 | ||
1116 | static struct page *new_vma_page(struct page *page, unsigned long private, int **x) | |
1117 | { | |
1118 | return NULL; | |
1119 | } | |
1120 | #endif | |
1121 | ||
1122 | static long do_mbind(unsigned long start, unsigned long len, | |
1123 | unsigned short mode, unsigned short mode_flags, | |
1124 | nodemask_t *nmask, unsigned long flags) | |
1125 | { | |
1126 | struct vm_area_struct *vma; | |
1127 | struct mm_struct *mm = current->mm; | |
1128 | struct mempolicy *new; | |
1129 | unsigned long end; | |
1130 | int err; | |
1131 | LIST_HEAD(pagelist); | |
1132 | ||
1133 | if (flags & ~(unsigned long)(MPOL_MF_STRICT | | |
1134 | MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) | |
1135 | return -EINVAL; | |
1136 | if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE)) | |
1137 | return -EPERM; | |
1138 | ||
1139 | if (start & ~PAGE_MASK) | |
1140 | return -EINVAL; | |
1141 | ||
1142 | if (mode == MPOL_DEFAULT) | |
1143 | flags &= ~MPOL_MF_STRICT; | |
1144 | ||
1145 | len = (len + PAGE_SIZE - 1) & PAGE_MASK; | |
1146 | end = start + len; | |
1147 | ||
1148 | if (end < start) | |
1149 | return -EINVAL; | |
1150 | if (end == start) | |
1151 | return 0; | |
1152 | ||
1153 | new = mpol_new(mode, mode_flags, nmask); | |
1154 | if (IS_ERR(new)) | |
1155 | return PTR_ERR(new); | |
1156 | ||
1157 | /* | |
1158 | * If we are using the default policy then operation | |
1159 | * on discontinuous address spaces is okay after all | |
1160 | */ | |
1161 | if (!new) | |
1162 | flags |= MPOL_MF_DISCONTIG_OK; | |
1163 | ||
1164 | pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n", | |
1165 | start, start + len, mode, mode_flags, | |
1166 | nmask ? nodes_addr(*nmask)[0] : -1); | |
1167 | ||
1168 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { | |
1169 | ||
1170 | err = migrate_prep(); | |
1171 | if (err) | |
1172 | goto mpol_out; | |
1173 | } | |
1174 | { | |
1175 | NODEMASK_SCRATCH(scratch); | |
1176 | if (scratch) { | |
1177 | down_write(&mm->mmap_sem); | |
1178 | task_lock(current); | |
1179 | err = mpol_set_nodemask(new, nmask, scratch); | |
1180 | task_unlock(current); | |
1181 | if (err) | |
1182 | up_write(&mm->mmap_sem); | |
1183 | } else | |
1184 | err = -ENOMEM; | |
1185 | NODEMASK_SCRATCH_FREE(scratch); | |
1186 | } | |
1187 | if (err) | |
1188 | goto mpol_out; | |
1189 | ||
1190 | vma = check_range(mm, start, end, nmask, | |
1191 | flags | MPOL_MF_INVERT, &pagelist); | |
1192 | ||
1193 | err = PTR_ERR(vma); | |
1194 | if (!IS_ERR(vma)) { | |
1195 | int nr_failed = 0; | |
1196 | ||
1197 | err = mbind_range(mm, start, end, new); | |
1198 | ||
1199 | if (!list_empty(&pagelist)) { | |
1200 | nr_failed = migrate_pages(&pagelist, new_vma_page, | |
1201 | (unsigned long)vma, | |
1202 | false, MIGRATE_SYNC); | |
1203 | if (nr_failed) | |
1204 | putback_lru_pages(&pagelist); | |
1205 | } | |
1206 | ||
1207 | if (!err && nr_failed && (flags & MPOL_MF_STRICT)) | |
1208 | err = -EIO; | |
1209 | } else | |
1210 | putback_lru_pages(&pagelist); | |
1211 | ||
1212 | up_write(&mm->mmap_sem); | |
1213 | mpol_out: | |
1214 | mpol_put(new); | |
1215 | return err; | |
1216 | } | |
1217 | ||
1218 | /* | |
1219 | * User space interface with variable sized bitmaps for nodelists. | |
1220 | */ | |
1221 | ||
1222 | /* Copy a node mask from user space. */ | |
1223 | static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask, | |
1224 | unsigned long maxnode) | |
1225 | { | |
1226 | unsigned long k; | |
1227 | unsigned long nlongs; | |
1228 | unsigned long endmask; | |
1229 | ||
1230 | --maxnode; | |
1231 | nodes_clear(*nodes); | |
1232 | if (maxnode == 0 || !nmask) | |
1233 | return 0; | |
1234 | if (maxnode > PAGE_SIZE*BITS_PER_BYTE) | |
1235 | return -EINVAL; | |
1236 | ||
1237 | nlongs = BITS_TO_LONGS(maxnode); | |
1238 | if ((maxnode % BITS_PER_LONG) == 0) | |
1239 | endmask = ~0UL; | |
1240 | else | |
1241 | endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1; | |
1242 | ||
1243 | /* When the user specified more nodes than supported just check | |
1244 | if the non supported part is all zero. */ | |
1245 | if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) { | |
1246 | if (nlongs > PAGE_SIZE/sizeof(long)) | |
1247 | return -EINVAL; | |
1248 | for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) { | |
1249 | unsigned long t; | |
1250 | if (get_user(t, nmask + k)) | |
1251 | return -EFAULT; | |
1252 | if (k == nlongs - 1) { | |
1253 | if (t & endmask) | |
1254 | return -EINVAL; | |
1255 | } else if (t) | |
1256 | return -EINVAL; | |
1257 | } | |
1258 | nlongs = BITS_TO_LONGS(MAX_NUMNODES); | |
1259 | endmask = ~0UL; | |
1260 | } | |
1261 | ||
1262 | if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long))) | |
1263 | return -EFAULT; | |
1264 | nodes_addr(*nodes)[nlongs-1] &= endmask; | |
1265 | return 0; | |
1266 | } | |
1267 | ||
1268 | /* Copy a kernel node mask to user space */ | |
1269 | static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, | |
1270 | nodemask_t *nodes) | |
1271 | { | |
1272 | unsigned long copy = ALIGN(maxnode-1, 64) / 8; | |
1273 | const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long); | |
1274 | ||
1275 | if (copy > nbytes) { | |
1276 | if (copy > PAGE_SIZE) | |
1277 | return -EINVAL; | |
1278 | if (clear_user((char __user *)mask + nbytes, copy - nbytes)) | |
1279 | return -EFAULT; | |
1280 | copy = nbytes; | |
1281 | } | |
1282 | return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0; | |
1283 | } | |
1284 | ||
1285 | SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len, | |
1286 | unsigned long, mode, unsigned long __user *, nmask, | |
1287 | unsigned long, maxnode, unsigned, flags) | |
1288 | { | |
1289 | nodemask_t nodes; | |
1290 | int err; | |
1291 | unsigned short mode_flags; | |
1292 | ||
1293 | mode_flags = mode & MPOL_MODE_FLAGS; | |
1294 | mode &= ~MPOL_MODE_FLAGS; | |
1295 | if (mode >= MPOL_MAX) | |
1296 | return -EINVAL; | |
1297 | if ((mode_flags & MPOL_F_STATIC_NODES) && | |
1298 | (mode_flags & MPOL_F_RELATIVE_NODES)) | |
1299 | return -EINVAL; | |
1300 | err = get_nodes(&nodes, nmask, maxnode); | |
1301 | if (err) | |
1302 | return err; | |
1303 | return do_mbind(start, len, mode, mode_flags, &nodes, flags); | |
1304 | } | |
1305 | ||
1306 | /* Set the process memory policy */ | |
1307 | SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask, | |
1308 | unsigned long, maxnode) | |
1309 | { | |
1310 | int err; | |
1311 | nodemask_t nodes; | |
1312 | unsigned short flags; | |
1313 | ||
1314 | flags = mode & MPOL_MODE_FLAGS; | |
1315 | mode &= ~MPOL_MODE_FLAGS; | |
1316 | if ((unsigned int)mode >= MPOL_MAX) | |
1317 | return -EINVAL; | |
1318 | if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES)) | |
1319 | return -EINVAL; | |
1320 | err = get_nodes(&nodes, nmask, maxnode); | |
1321 | if (err) | |
1322 | return err; | |
1323 | return do_set_mempolicy(mode, flags, &nodes); | |
1324 | } | |
1325 | ||
1326 | SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, | |
1327 | const unsigned long __user *, old_nodes, | |
1328 | const unsigned long __user *, new_nodes) | |
1329 | { | |
1330 | const struct cred *cred = current_cred(), *tcred; | |
1331 | struct mm_struct *mm = NULL; | |
1332 | struct task_struct *task; | |
1333 | nodemask_t task_nodes; | |
1334 | int err; | |
1335 | nodemask_t *old; | |
1336 | nodemask_t *new; | |
1337 | NODEMASK_SCRATCH(scratch); | |
1338 | ||
1339 | if (!scratch) | |
1340 | return -ENOMEM; | |
1341 | ||
1342 | old = &scratch->mask1; | |
1343 | new = &scratch->mask2; | |
1344 | ||
1345 | err = get_nodes(old, old_nodes, maxnode); | |
1346 | if (err) | |
1347 | goto out; | |
1348 | ||
1349 | err = get_nodes(new, new_nodes, maxnode); | |
1350 | if (err) | |
1351 | goto out; | |
1352 | ||
1353 | /* Find the mm_struct */ | |
1354 | rcu_read_lock(); | |
1355 | task = pid ? find_task_by_vpid(pid) : current; | |
1356 | if (!task) { | |
1357 | rcu_read_unlock(); | |
1358 | err = -ESRCH; | |
1359 | goto out; | |
1360 | } | |
1361 | get_task_struct(task); | |
1362 | ||
1363 | err = -EINVAL; | |
1364 | ||
1365 | /* | |
1366 | * Check if this process has the right to modify the specified | |
1367 | * process. The right exists if the process has administrative | |
1368 | * capabilities, superuser privileges or the same | |
1369 | * userid as the target process. | |
1370 | */ | |
1371 | tcred = __task_cred(task); | |
1372 | if (!uid_eq(cred->euid, tcred->suid) && !uid_eq(cred->euid, tcred->uid) && | |
1373 | !uid_eq(cred->uid, tcred->suid) && !uid_eq(cred->uid, tcred->uid) && | |
1374 | !capable(CAP_SYS_NICE)) { | |
1375 | rcu_read_unlock(); | |
1376 | err = -EPERM; | |
1377 | goto out_put; | |
1378 | } | |
1379 | rcu_read_unlock(); | |
1380 | ||
1381 | task_nodes = cpuset_mems_allowed(task); | |
1382 | /* Is the user allowed to access the target nodes? */ | |
1383 | if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) { | |
1384 | err = -EPERM; | |
1385 | goto out_put; | |
1386 | } | |
1387 | ||
1388 | if (!nodes_subset(*new, node_states[N_HIGH_MEMORY])) { | |
1389 | err = -EINVAL; | |
1390 | goto out_put; | |
1391 | } | |
1392 | ||
1393 | err = security_task_movememory(task); | |
1394 | if (err) | |
1395 | goto out_put; | |
1396 | ||
1397 | mm = get_task_mm(task); | |
1398 | put_task_struct(task); | |
1399 | ||
1400 | if (!mm) { | |
1401 | err = -EINVAL; | |
1402 | goto out; | |
1403 | } | |
1404 | ||
1405 | err = do_migrate_pages(mm, old, new, | |
1406 | capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE); | |
1407 | ||
1408 | mmput(mm); | |
1409 | out: | |
1410 | NODEMASK_SCRATCH_FREE(scratch); | |
1411 | ||
1412 | return err; | |
1413 | ||
1414 | out_put: | |
1415 | put_task_struct(task); | |
1416 | goto out; | |
1417 | ||
1418 | } | |
1419 | ||
1420 | ||
1421 | /* Retrieve NUMA policy */ | |
1422 | SYSCALL_DEFINE5(get_mempolicy, int __user *, policy, | |
1423 | unsigned long __user *, nmask, unsigned long, maxnode, | |
1424 | unsigned long, addr, unsigned long, flags) | |
1425 | { | |
1426 | int err; | |
1427 | int uninitialized_var(pval); | |
1428 | nodemask_t nodes; | |
1429 | ||
1430 | if (nmask != NULL && maxnode < MAX_NUMNODES) | |
1431 | return -EINVAL; | |
1432 | ||
1433 | err = do_get_mempolicy(&pval, &nodes, addr, flags); | |
1434 | ||
1435 | if (err) | |
1436 | return err; | |
1437 | ||
1438 | if (policy && put_user(pval, policy)) | |
1439 | return -EFAULT; | |
1440 | ||
1441 | if (nmask) | |
1442 | err = copy_nodes_to_user(nmask, maxnode, &nodes); | |
1443 | ||
1444 | return err; | |
1445 | } | |
1446 | ||
1447 | #ifdef CONFIG_COMPAT | |
1448 | ||
1449 | asmlinkage long compat_sys_get_mempolicy(int __user *policy, | |
1450 | compat_ulong_t __user *nmask, | |
1451 | compat_ulong_t maxnode, | |
1452 | compat_ulong_t addr, compat_ulong_t flags) | |
1453 | { | |
1454 | long err; | |
1455 | unsigned long __user *nm = NULL; | |
1456 | unsigned long nr_bits, alloc_size; | |
1457 | DECLARE_BITMAP(bm, MAX_NUMNODES); | |
1458 | ||
1459 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
1460 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
1461 | ||
1462 | if (nmask) | |
1463 | nm = compat_alloc_user_space(alloc_size); | |
1464 | ||
1465 | err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags); | |
1466 | ||
1467 | if (!err && nmask) { | |
1468 | unsigned long copy_size; | |
1469 | copy_size = min_t(unsigned long, sizeof(bm), alloc_size); | |
1470 | err = copy_from_user(bm, nm, copy_size); | |
1471 | /* ensure entire bitmap is zeroed */ | |
1472 | err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8); | |
1473 | err |= compat_put_bitmap(nmask, bm, nr_bits); | |
1474 | } | |
1475 | ||
1476 | return err; | |
1477 | } | |
1478 | ||
1479 | asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask, | |
1480 | compat_ulong_t maxnode) | |
1481 | { | |
1482 | long err = 0; | |
1483 | unsigned long __user *nm = NULL; | |
1484 | unsigned long nr_bits, alloc_size; | |
1485 | DECLARE_BITMAP(bm, MAX_NUMNODES); | |
1486 | ||
1487 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
1488 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
1489 | ||
1490 | if (nmask) { | |
1491 | err = compat_get_bitmap(bm, nmask, nr_bits); | |
1492 | nm = compat_alloc_user_space(alloc_size); | |
1493 | err |= copy_to_user(nm, bm, alloc_size); | |
1494 | } | |
1495 | ||
1496 | if (err) | |
1497 | return -EFAULT; | |
1498 | ||
1499 | return sys_set_mempolicy(mode, nm, nr_bits+1); | |
1500 | } | |
1501 | ||
1502 | asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len, | |
1503 | compat_ulong_t mode, compat_ulong_t __user *nmask, | |
1504 | compat_ulong_t maxnode, compat_ulong_t flags) | |
1505 | { | |
1506 | long err = 0; | |
1507 | unsigned long __user *nm = NULL; | |
1508 | unsigned long nr_bits, alloc_size; | |
1509 | nodemask_t bm; | |
1510 | ||
1511 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
1512 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
1513 | ||
1514 | if (nmask) { | |
1515 | err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits); | |
1516 | nm = compat_alloc_user_space(alloc_size); | |
1517 | err |= copy_to_user(nm, nodes_addr(bm), alloc_size); | |
1518 | } | |
1519 | ||
1520 | if (err) | |
1521 | return -EFAULT; | |
1522 | ||
1523 | return sys_mbind(start, len, mode, nm, nr_bits+1, flags); | |
1524 | } | |
1525 | ||
1526 | #endif | |
1527 | ||
1528 | /* | |
1529 | * get_vma_policy(@task, @vma, @addr) | |
1530 | * @task - task for fallback if vma policy == default | |
1531 | * @vma - virtual memory area whose policy is sought | |
1532 | * @addr - address in @vma for shared policy lookup | |
1533 | * | |
1534 | * Returns effective policy for a VMA at specified address. | |
1535 | * Falls back to @task or system default policy, as necessary. | |
1536 | * Current or other task's task mempolicy and non-shared vma policies | |
1537 | * are protected by the task's mmap_sem, which must be held for read by | |
1538 | * the caller. | |
1539 | * Shared policies [those marked as MPOL_F_SHARED] require an extra reference | |
1540 | * count--added by the get_policy() vm_op, as appropriate--to protect against | |
1541 | * freeing by another task. It is the caller's responsibility to free the | |
1542 | * extra reference for shared policies. | |
1543 | */ | |
1544 | struct mempolicy *get_vma_policy(struct task_struct *task, | |
1545 | struct vm_area_struct *vma, unsigned long addr) | |
1546 | { | |
1547 | struct mempolicy *pol = task->mempolicy; | |
1548 | ||
1549 | if (vma) { | |
1550 | if (vma->vm_ops && vma->vm_ops->get_policy) { | |
1551 | struct mempolicy *vpol = vma->vm_ops->get_policy(vma, | |
1552 | addr); | |
1553 | if (vpol) | |
1554 | pol = vpol; | |
1555 | } else if (vma->vm_policy) { | |
1556 | pol = vma->vm_policy; | |
1557 | ||
1558 | /* | |
1559 | * shmem_alloc_page() passes MPOL_F_SHARED policy with | |
1560 | * a pseudo vma whose vma->vm_ops=NULL. Take a reference | |
1561 | * count on these policies which will be dropped by | |
1562 | * mpol_cond_put() later | |
1563 | */ | |
1564 | if (mpol_needs_cond_ref(pol)) | |
1565 | mpol_get(pol); | |
1566 | } | |
1567 | } | |
1568 | if (!pol) | |
1569 | pol = &default_policy; | |
1570 | return pol; | |
1571 | } | |
1572 | ||
1573 | /* | |
1574 | * Return a nodemask representing a mempolicy for filtering nodes for | |
1575 | * page allocation | |
1576 | */ | |
1577 | static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy) | |
1578 | { | |
1579 | /* Lower zones don't get a nodemask applied for MPOL_BIND */ | |
1580 | if (unlikely(policy->mode == MPOL_BIND) && | |
1581 | gfp_zone(gfp) >= policy_zone && | |
1582 | cpuset_nodemask_valid_mems_allowed(&policy->v.nodes)) | |
1583 | return &policy->v.nodes; | |
1584 | ||
1585 | return NULL; | |
1586 | } | |
1587 | ||
1588 | /* Return a zonelist indicated by gfp for node representing a mempolicy */ | |
1589 | static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy, | |
1590 | int nd) | |
1591 | { | |
1592 | switch (policy->mode) { | |
1593 | case MPOL_PREFERRED: | |
1594 | if (!(policy->flags & MPOL_F_LOCAL)) | |
1595 | nd = policy->v.preferred_node; | |
1596 | break; | |
1597 | case MPOL_BIND: | |
1598 | /* | |
1599 | * Normally, MPOL_BIND allocations are node-local within the | |
1600 | * allowed nodemask. However, if __GFP_THISNODE is set and the | |
1601 | * current node isn't part of the mask, we use the zonelist for | |
1602 | * the first node in the mask instead. | |
1603 | */ | |
1604 | if (unlikely(gfp & __GFP_THISNODE) && | |
1605 | unlikely(!node_isset(nd, policy->v.nodes))) | |
1606 | nd = first_node(policy->v.nodes); | |
1607 | break; | |
1608 | default: | |
1609 | BUG(); | |
1610 | } | |
1611 | return node_zonelist(nd, gfp); | |
1612 | } | |
1613 | ||
1614 | /* Do dynamic interleaving for a process */ | |
1615 | static unsigned interleave_nodes(struct mempolicy *policy) | |
1616 | { | |
1617 | unsigned nid, next; | |
1618 | struct task_struct *me = current; | |
1619 | ||
1620 | nid = me->il_next; | |
1621 | next = next_node(nid, policy->v.nodes); | |
1622 | if (next >= MAX_NUMNODES) | |
1623 | next = first_node(policy->v.nodes); | |
1624 | if (next < MAX_NUMNODES) | |
1625 | me->il_next = next; | |
1626 | return nid; | |
1627 | } | |
1628 | ||
1629 | /* | |
1630 | * Depending on the memory policy provide a node from which to allocate the | |
1631 | * next slab entry. | |
1632 | * @policy must be protected by freeing by the caller. If @policy is | |
1633 | * the current task's mempolicy, this protection is implicit, as only the | |
1634 | * task can change it's policy. The system default policy requires no | |
1635 | * such protection. | |
1636 | */ | |
1637 | unsigned slab_node(void) | |
1638 | { | |
1639 | struct mempolicy *policy; | |
1640 | ||
1641 | if (in_interrupt()) | |
1642 | return numa_node_id(); | |
1643 | ||
1644 | policy = current->mempolicy; | |
1645 | if (!policy || policy->flags & MPOL_F_LOCAL) | |
1646 | return numa_node_id(); | |
1647 | ||
1648 | switch (policy->mode) { | |
1649 | case MPOL_PREFERRED: | |
1650 | /* | |
1651 | * handled MPOL_F_LOCAL above | |
1652 | */ | |
1653 | return policy->v.preferred_node; | |
1654 | ||
1655 | case MPOL_INTERLEAVE: | |
1656 | return interleave_nodes(policy); | |
1657 | ||
1658 | case MPOL_BIND: { | |
1659 | /* | |
1660 | * Follow bind policy behavior and start allocation at the | |
1661 | * first node. | |
1662 | */ | |
1663 | struct zonelist *zonelist; | |
1664 | struct zone *zone; | |
1665 | enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL); | |
1666 | zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0]; | |
1667 | (void)first_zones_zonelist(zonelist, highest_zoneidx, | |
1668 | &policy->v.nodes, | |
1669 | &zone); | |
1670 | return zone ? zone->node : numa_node_id(); | |
1671 | } | |
1672 | ||
1673 | default: | |
1674 | BUG(); | |
1675 | } | |
1676 | } | |
1677 | ||
1678 | /* Do static interleaving for a VMA with known offset. */ | |
1679 | static unsigned offset_il_node(struct mempolicy *pol, | |
1680 | struct vm_area_struct *vma, unsigned long off) | |
1681 | { | |
1682 | unsigned nnodes = nodes_weight(pol->v.nodes); | |
1683 | unsigned target; | |
1684 | int c; | |
1685 | int nid = -1; | |
1686 | ||
1687 | if (!nnodes) | |
1688 | return numa_node_id(); | |
1689 | target = (unsigned int)off % nnodes; | |
1690 | c = 0; | |
1691 | do { | |
1692 | nid = next_node(nid, pol->v.nodes); | |
1693 | c++; | |
1694 | } while (c <= target); | |
1695 | return nid; | |
1696 | } | |
1697 | ||
1698 | /* Determine a node number for interleave */ | |
1699 | static inline unsigned interleave_nid(struct mempolicy *pol, | |
1700 | struct vm_area_struct *vma, unsigned long addr, int shift) | |
1701 | { | |
1702 | if (vma) { | |
1703 | unsigned long off; | |
1704 | ||
1705 | /* | |
1706 | * for small pages, there is no difference between | |
1707 | * shift and PAGE_SHIFT, so the bit-shift is safe. | |
1708 | * for huge pages, since vm_pgoff is in units of small | |
1709 | * pages, we need to shift off the always 0 bits to get | |
1710 | * a useful offset. | |
1711 | */ | |
1712 | BUG_ON(shift < PAGE_SHIFT); | |
1713 | off = vma->vm_pgoff >> (shift - PAGE_SHIFT); | |
1714 | off += (addr - vma->vm_start) >> shift; | |
1715 | return offset_il_node(pol, vma, off); | |
1716 | } else | |
1717 | return interleave_nodes(pol); | |
1718 | } | |
1719 | ||
1720 | /* | |
1721 | * Return the bit number of a random bit set in the nodemask. | |
1722 | * (returns -1 if nodemask is empty) | |
1723 | */ | |
1724 | int node_random(const nodemask_t *maskp) | |
1725 | { | |
1726 | int w, bit = -1; | |
1727 | ||
1728 | w = nodes_weight(*maskp); | |
1729 | if (w) | |
1730 | bit = bitmap_ord_to_pos(maskp->bits, | |
1731 | get_random_int() % w, MAX_NUMNODES); | |
1732 | return bit; | |
1733 | } | |
1734 | ||
1735 | #ifdef CONFIG_HUGETLBFS | |
1736 | /* | |
1737 | * huge_zonelist(@vma, @addr, @gfp_flags, @mpol) | |
1738 | * @vma = virtual memory area whose policy is sought | |
1739 | * @addr = address in @vma for shared policy lookup and interleave policy | |
1740 | * @gfp_flags = for requested zone | |
1741 | * @mpol = pointer to mempolicy pointer for reference counted mempolicy | |
1742 | * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask | |
1743 | * | |
1744 | * Returns a zonelist suitable for a huge page allocation and a pointer | |
1745 | * to the struct mempolicy for conditional unref after allocation. | |
1746 | * If the effective policy is 'BIND, returns a pointer to the mempolicy's | |
1747 | * @nodemask for filtering the zonelist. | |
1748 | * | |
1749 | * Must be protected by get_mems_allowed() | |
1750 | */ | |
1751 | struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr, | |
1752 | gfp_t gfp_flags, struct mempolicy **mpol, | |
1753 | nodemask_t **nodemask) | |
1754 | { | |
1755 | struct zonelist *zl; | |
1756 | ||
1757 | *mpol = get_vma_policy(current, vma, addr); | |
1758 | *nodemask = NULL; /* assume !MPOL_BIND */ | |
1759 | ||
1760 | if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) { | |
1761 | zl = node_zonelist(interleave_nid(*mpol, vma, addr, | |
1762 | huge_page_shift(hstate_vma(vma))), gfp_flags); | |
1763 | } else { | |
1764 | zl = policy_zonelist(gfp_flags, *mpol, numa_node_id()); | |
1765 | if ((*mpol)->mode == MPOL_BIND) | |
1766 | *nodemask = &(*mpol)->v.nodes; | |
1767 | } | |
1768 | return zl; | |
1769 | } | |
1770 | ||
1771 | /* | |
1772 | * init_nodemask_of_mempolicy | |
1773 | * | |
1774 | * If the current task's mempolicy is "default" [NULL], return 'false' | |
1775 | * to indicate default policy. Otherwise, extract the policy nodemask | |
1776 | * for 'bind' or 'interleave' policy into the argument nodemask, or | |
1777 | * initialize the argument nodemask to contain the single node for | |
1778 | * 'preferred' or 'local' policy and return 'true' to indicate presence | |
1779 | * of non-default mempolicy. | |
1780 | * | |
1781 | * We don't bother with reference counting the mempolicy [mpol_get/put] | |
1782 | * because the current task is examining it's own mempolicy and a task's | |
1783 | * mempolicy is only ever changed by the task itself. | |
1784 | * | |
1785 | * N.B., it is the caller's responsibility to free a returned nodemask. | |
1786 | */ | |
1787 | bool init_nodemask_of_mempolicy(nodemask_t *mask) | |
1788 | { | |
1789 | struct mempolicy *mempolicy; | |
1790 | int nid; | |
1791 | ||
1792 | if (!(mask && current->mempolicy)) | |
1793 | return false; | |
1794 | ||
1795 | task_lock(current); | |
1796 | mempolicy = current->mempolicy; | |
1797 | switch (mempolicy->mode) { | |
1798 | case MPOL_PREFERRED: | |
1799 | if (mempolicy->flags & MPOL_F_LOCAL) | |
1800 | nid = numa_node_id(); | |
1801 | else | |
1802 | nid = mempolicy->v.preferred_node; | |
1803 | init_nodemask_of_node(mask, nid); | |
1804 | break; | |
1805 | ||
1806 | case MPOL_BIND: | |
1807 | /* Fall through */ | |
1808 | case MPOL_INTERLEAVE: | |
1809 | *mask = mempolicy->v.nodes; | |
1810 | break; | |
1811 | ||
1812 | default: | |
1813 | BUG(); | |
1814 | } | |
1815 | task_unlock(current); | |
1816 | ||
1817 | return true; | |
1818 | } | |
1819 | #endif | |
1820 | ||
1821 | /* | |
1822 | * mempolicy_nodemask_intersects | |
1823 | * | |
1824 | * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default | |
1825 | * policy. Otherwise, check for intersection between mask and the policy | |
1826 | * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local' | |
1827 | * policy, always return true since it may allocate elsewhere on fallback. | |
1828 | * | |
1829 | * Takes task_lock(tsk) to prevent freeing of its mempolicy. | |
1830 | */ | |
1831 | bool mempolicy_nodemask_intersects(struct task_struct *tsk, | |
1832 | const nodemask_t *mask) | |
1833 | { | |
1834 | struct mempolicy *mempolicy; | |
1835 | bool ret = true; | |
1836 | ||
1837 | if (!mask) | |
1838 | return ret; | |
1839 | task_lock(tsk); | |
1840 | mempolicy = tsk->mempolicy; | |
1841 | if (!mempolicy) | |
1842 | goto out; | |
1843 | ||
1844 | switch (mempolicy->mode) { | |
1845 | case MPOL_PREFERRED: | |
1846 | /* | |
1847 | * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to | |
1848 | * allocate from, they may fallback to other nodes when oom. | |
1849 | * Thus, it's possible for tsk to have allocated memory from | |
1850 | * nodes in mask. | |
1851 | */ | |
1852 | break; | |
1853 | case MPOL_BIND: | |
1854 | case MPOL_INTERLEAVE: | |
1855 | ret = nodes_intersects(mempolicy->v.nodes, *mask); | |
1856 | break; | |
1857 | default: | |
1858 | BUG(); | |
1859 | } | |
1860 | out: | |
1861 | task_unlock(tsk); | |
1862 | return ret; | |
1863 | } | |
1864 | ||
1865 | /* Allocate a page in interleaved policy. | |
1866 | Own path because it needs to do special accounting. */ | |
1867 | static struct page *alloc_page_interleave(gfp_t gfp, unsigned order, | |
1868 | unsigned nid) | |
1869 | { | |
1870 | struct zonelist *zl; | |
1871 | struct page *page; | |
1872 | ||
1873 | zl = node_zonelist(nid, gfp); | |
1874 | page = __alloc_pages(gfp, order, zl); | |
1875 | if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0])) | |
1876 | inc_zone_page_state(page, NUMA_INTERLEAVE_HIT); | |
1877 | return page; | |
1878 | } | |
1879 | ||
1880 | /** | |
1881 | * alloc_pages_vma - Allocate a page for a VMA. | |
1882 | * | |
1883 | * @gfp: | |
1884 | * %GFP_USER user allocation. | |
1885 | * %GFP_KERNEL kernel allocations, | |
1886 | * %GFP_HIGHMEM highmem/user allocations, | |
1887 | * %GFP_FS allocation should not call back into a file system. | |
1888 | * %GFP_ATOMIC don't sleep. | |
1889 | * | |
1890 | * @order:Order of the GFP allocation. | |
1891 | * @vma: Pointer to VMA or NULL if not available. | |
1892 | * @addr: Virtual Address of the allocation. Must be inside the VMA. | |
1893 | * | |
1894 | * This function allocates a page from the kernel page pool and applies | |
1895 | * a NUMA policy associated with the VMA or the current process. | |
1896 | * When VMA is not NULL caller must hold down_read on the mmap_sem of the | |
1897 | * mm_struct of the VMA to prevent it from going away. Should be used for | |
1898 | * all allocations for pages that will be mapped into | |
1899 | * user space. Returns NULL when no page can be allocated. | |
1900 | * | |
1901 | * Should be called with the mm_sem of the vma hold. | |
1902 | */ | |
1903 | struct page * | |
1904 | alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma, | |
1905 | unsigned long addr, int node) | |
1906 | { | |
1907 | struct mempolicy *pol; | |
1908 | struct zonelist *zl; | |
1909 | struct page *page; | |
1910 | unsigned int cpuset_mems_cookie; | |
1911 | ||
1912 | retry_cpuset: | |
1913 | pol = get_vma_policy(current, vma, addr); | |
1914 | cpuset_mems_cookie = get_mems_allowed(); | |
1915 | ||
1916 | if (unlikely(pol->mode == MPOL_INTERLEAVE)) { | |
1917 | unsigned nid; | |
1918 | ||
1919 | nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order); | |
1920 | mpol_cond_put(pol); | |
1921 | page = alloc_page_interleave(gfp, order, nid); | |
1922 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) | |
1923 | goto retry_cpuset; | |
1924 | ||
1925 | return page; | |
1926 | } | |
1927 | zl = policy_zonelist(gfp, pol, node); | |
1928 | if (unlikely(mpol_needs_cond_ref(pol))) { | |
1929 | /* | |
1930 | * slow path: ref counted shared policy | |
1931 | */ | |
1932 | struct page *page = __alloc_pages_nodemask(gfp, order, | |
1933 | zl, policy_nodemask(gfp, pol)); | |
1934 | __mpol_put(pol); | |
1935 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) | |
1936 | goto retry_cpuset; | |
1937 | return page; | |
1938 | } | |
1939 | /* | |
1940 | * fast path: default or task policy | |
1941 | */ | |
1942 | page = __alloc_pages_nodemask(gfp, order, zl, | |
1943 | policy_nodemask(gfp, pol)); | |
1944 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) | |
1945 | goto retry_cpuset; | |
1946 | return page; | |
1947 | } | |
1948 | ||
1949 | /** | |
1950 | * alloc_pages_current - Allocate pages. | |
1951 | * | |
1952 | * @gfp: | |
1953 | * %GFP_USER user allocation, | |
1954 | * %GFP_KERNEL kernel allocation, | |
1955 | * %GFP_HIGHMEM highmem allocation, | |
1956 | * %GFP_FS don't call back into a file system. | |
1957 | * %GFP_ATOMIC don't sleep. | |
1958 | * @order: Power of two of allocation size in pages. 0 is a single page. | |
1959 | * | |
1960 | * Allocate a page from the kernel page pool. When not in | |
1961 | * interrupt context and apply the current process NUMA policy. | |
1962 | * Returns NULL when no page can be allocated. | |
1963 | * | |
1964 | * Don't call cpuset_update_task_memory_state() unless | |
1965 | * 1) it's ok to take cpuset_sem (can WAIT), and | |
1966 | * 2) allocating for current task (not interrupt). | |
1967 | */ | |
1968 | struct page *alloc_pages_current(gfp_t gfp, unsigned order) | |
1969 | { | |
1970 | struct mempolicy *pol = current->mempolicy; | |
1971 | struct page *page; | |
1972 | unsigned int cpuset_mems_cookie; | |
1973 | ||
1974 | if (!pol || in_interrupt() || (gfp & __GFP_THISNODE)) | |
1975 | pol = &default_policy; | |
1976 | ||
1977 | retry_cpuset: | |
1978 | cpuset_mems_cookie = get_mems_allowed(); | |
1979 | ||
1980 | /* | |
1981 | * No reference counting needed for current->mempolicy | |
1982 | * nor system default_policy | |
1983 | */ | |
1984 | if (pol->mode == MPOL_INTERLEAVE) | |
1985 | page = alloc_page_interleave(gfp, order, interleave_nodes(pol)); | |
1986 | else | |
1987 | page = __alloc_pages_nodemask(gfp, order, | |
1988 | policy_zonelist(gfp, pol, numa_node_id()), | |
1989 | policy_nodemask(gfp, pol)); | |
1990 | ||
1991 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) | |
1992 | goto retry_cpuset; | |
1993 | ||
1994 | return page; | |
1995 | } | |
1996 | EXPORT_SYMBOL(alloc_pages_current); | |
1997 | ||
1998 | /* | |
1999 | * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it | |
2000 | * rebinds the mempolicy its copying by calling mpol_rebind_policy() | |
2001 | * with the mems_allowed returned by cpuset_mems_allowed(). This | |
2002 | * keeps mempolicies cpuset relative after its cpuset moves. See | |
2003 | * further kernel/cpuset.c update_nodemask(). | |
2004 | * | |
2005 | * current's mempolicy may be rebinded by the other task(the task that changes | |
2006 | * cpuset's mems), so we needn't do rebind work for current task. | |
2007 | */ | |
2008 | ||
2009 | /* Slow path of a mempolicy duplicate */ | |
2010 | struct mempolicy *__mpol_dup(struct mempolicy *old) | |
2011 | { | |
2012 | struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL); | |
2013 | ||
2014 | if (!new) | |
2015 | return ERR_PTR(-ENOMEM); | |
2016 | ||
2017 | /* task's mempolicy is protected by alloc_lock */ | |
2018 | if (old == current->mempolicy) { | |
2019 | task_lock(current); | |
2020 | *new = *old; | |
2021 | task_unlock(current); | |
2022 | } else | |
2023 | *new = *old; | |
2024 | ||
2025 | rcu_read_lock(); | |
2026 | if (current_cpuset_is_being_rebound()) { | |
2027 | nodemask_t mems = cpuset_mems_allowed(current); | |
2028 | if (new->flags & MPOL_F_REBINDING) | |
2029 | mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2); | |
2030 | else | |
2031 | mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE); | |
2032 | } | |
2033 | rcu_read_unlock(); | |
2034 | atomic_set(&new->refcnt, 1); | |
2035 | return new; | |
2036 | } | |
2037 | ||
2038 | /* | |
2039 | * If *frompol needs [has] an extra ref, copy *frompol to *tompol , | |
2040 | * eliminate the * MPOL_F_* flags that require conditional ref and | |
2041 | * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly | |
2042 | * after return. Use the returned value. | |
2043 | * | |
2044 | * Allows use of a mempolicy for, e.g., multiple allocations with a single | |
2045 | * policy lookup, even if the policy needs/has extra ref on lookup. | |
2046 | * shmem_readahead needs this. | |
2047 | */ | |
2048 | struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol, | |
2049 | struct mempolicy *frompol) | |
2050 | { | |
2051 | if (!mpol_needs_cond_ref(frompol)) | |
2052 | return frompol; | |
2053 | ||
2054 | *tompol = *frompol; | |
2055 | tompol->flags &= ~MPOL_F_SHARED; /* copy doesn't need unref */ | |
2056 | __mpol_put(frompol); | |
2057 | return tompol; | |
2058 | } | |
2059 | ||
2060 | /* Slow path of a mempolicy comparison */ | |
2061 | bool __mpol_equal(struct mempolicy *a, struct mempolicy *b) | |
2062 | { | |
2063 | if (!a || !b) | |
2064 | return false; | |
2065 | if (a->mode != b->mode) | |
2066 | return false; | |
2067 | if (a->flags != b->flags) | |
2068 | return false; | |
2069 | if (mpol_store_user_nodemask(a)) | |
2070 | if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask)) | |
2071 | return false; | |
2072 | ||
2073 | switch (a->mode) { | |
2074 | case MPOL_BIND: | |
2075 | /* Fall through */ | |
2076 | case MPOL_INTERLEAVE: | |
2077 | return !!nodes_equal(a->v.nodes, b->v.nodes); | |
2078 | case MPOL_PREFERRED: | |
2079 | return a->v.preferred_node == b->v.preferred_node; | |
2080 | default: | |
2081 | BUG(); | |
2082 | return false; | |
2083 | } | |
2084 | } | |
2085 | ||
2086 | /* | |
2087 | * Shared memory backing store policy support. | |
2088 | * | |
2089 | * Remember policies even when nobody has shared memory mapped. | |
2090 | * The policies are kept in Red-Black tree linked from the inode. | |
2091 | * They are protected by the sp->lock spinlock, which should be held | |
2092 | * for any accesses to the tree. | |
2093 | */ | |
2094 | ||
2095 | /* lookup first element intersecting start-end */ | |
2096 | /* Caller holds sp->mutex */ | |
2097 | static struct sp_node * | |
2098 | sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end) | |
2099 | { | |
2100 | struct rb_node *n = sp->root.rb_node; | |
2101 | ||
2102 | while (n) { | |
2103 | struct sp_node *p = rb_entry(n, struct sp_node, nd); | |
2104 | ||
2105 | if (start >= p->end) | |
2106 | n = n->rb_right; | |
2107 | else if (end <= p->start) | |
2108 | n = n->rb_left; | |
2109 | else | |
2110 | break; | |
2111 | } | |
2112 | if (!n) | |
2113 | return NULL; | |
2114 | for (;;) { | |
2115 | struct sp_node *w = NULL; | |
2116 | struct rb_node *prev = rb_prev(n); | |
2117 | if (!prev) | |
2118 | break; | |
2119 | w = rb_entry(prev, struct sp_node, nd); | |
2120 | if (w->end <= start) | |
2121 | break; | |
2122 | n = prev; | |
2123 | } | |
2124 | return rb_entry(n, struct sp_node, nd); | |
2125 | } | |
2126 | ||
2127 | /* Insert a new shared policy into the list. */ | |
2128 | /* Caller holds sp->lock */ | |
2129 | static void sp_insert(struct shared_policy *sp, struct sp_node *new) | |
2130 | { | |
2131 | struct rb_node **p = &sp->root.rb_node; | |
2132 | struct rb_node *parent = NULL; | |
2133 | struct sp_node *nd; | |
2134 | ||
2135 | while (*p) { | |
2136 | parent = *p; | |
2137 | nd = rb_entry(parent, struct sp_node, nd); | |
2138 | if (new->start < nd->start) | |
2139 | p = &(*p)->rb_left; | |
2140 | else if (new->end > nd->end) | |
2141 | p = &(*p)->rb_right; | |
2142 | else | |
2143 | BUG(); | |
2144 | } | |
2145 | rb_link_node(&new->nd, parent, p); | |
2146 | rb_insert_color(&new->nd, &sp->root); | |
2147 | pr_debug("inserting %lx-%lx: %d\n", new->start, new->end, | |
2148 | new->policy ? new->policy->mode : 0); | |
2149 | } | |
2150 | ||
2151 | /* Find shared policy intersecting idx */ | |
2152 | struct mempolicy * | |
2153 | mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx) | |
2154 | { | |
2155 | struct mempolicy *pol = NULL; | |
2156 | struct sp_node *sn; | |
2157 | ||
2158 | if (!sp->root.rb_node) | |
2159 | return NULL; | |
2160 | mutex_lock(&sp->mutex); | |
2161 | sn = sp_lookup(sp, idx, idx+1); | |
2162 | if (sn) { | |
2163 | mpol_get(sn->policy); | |
2164 | pol = sn->policy; | |
2165 | } | |
2166 | mutex_unlock(&sp->mutex); | |
2167 | return pol; | |
2168 | } | |
2169 | ||
2170 | static void sp_free(struct sp_node *n) | |
2171 | { | |
2172 | mpol_put(n->policy); | |
2173 | kmem_cache_free(sn_cache, n); | |
2174 | } | |
2175 | ||
2176 | static void sp_delete(struct shared_policy *sp, struct sp_node *n) | |
2177 | { | |
2178 | pr_debug("deleting %lx-l%lx\n", n->start, n->end); | |
2179 | rb_erase(&n->nd, &sp->root); | |
2180 | sp_free(n); | |
2181 | } | |
2182 | ||
2183 | static struct sp_node *sp_alloc(unsigned long start, unsigned long end, | |
2184 | struct mempolicy *pol) | |
2185 | { | |
2186 | struct sp_node *n; | |
2187 | struct mempolicy *newpol; | |
2188 | ||
2189 | n = kmem_cache_alloc(sn_cache, GFP_KERNEL); | |
2190 | if (!n) | |
2191 | return NULL; | |
2192 | ||
2193 | newpol = mpol_dup(pol); | |
2194 | if (IS_ERR(newpol)) { | |
2195 | kmem_cache_free(sn_cache, n); | |
2196 | return NULL; | |
2197 | } | |
2198 | newpol->flags |= MPOL_F_SHARED; | |
2199 | ||
2200 | n->start = start; | |
2201 | n->end = end; | |
2202 | n->policy = newpol; | |
2203 | ||
2204 | return n; | |
2205 | } | |
2206 | ||
2207 | /* Replace a policy range. */ | |
2208 | static int shared_policy_replace(struct shared_policy *sp, unsigned long start, | |
2209 | unsigned long end, struct sp_node *new) | |
2210 | { | |
2211 | struct sp_node *n; | |
2212 | int ret = 0; | |
2213 | ||
2214 | mutex_lock(&sp->mutex); | |
2215 | n = sp_lookup(sp, start, end); | |
2216 | /* Take care of old policies in the same range. */ | |
2217 | while (n && n->start < end) { | |
2218 | struct rb_node *next = rb_next(&n->nd); | |
2219 | if (n->start >= start) { | |
2220 | if (n->end <= end) | |
2221 | sp_delete(sp, n); | |
2222 | else | |
2223 | n->start = end; | |
2224 | } else { | |
2225 | /* Old policy spanning whole new range. */ | |
2226 | if (n->end > end) { | |
2227 | struct sp_node *new2; | |
2228 | new2 = sp_alloc(end, n->end, n->policy); | |
2229 | if (!new2) { | |
2230 | ret = -ENOMEM; | |
2231 | goto out; | |
2232 | } | |
2233 | n->end = start; | |
2234 | sp_insert(sp, new2); | |
2235 | break; | |
2236 | } else | |
2237 | n->end = start; | |
2238 | } | |
2239 | if (!next) | |
2240 | break; | |
2241 | n = rb_entry(next, struct sp_node, nd); | |
2242 | } | |
2243 | if (new) | |
2244 | sp_insert(sp, new); | |
2245 | out: | |
2246 | mutex_unlock(&sp->mutex); | |
2247 | return ret; | |
2248 | } | |
2249 | ||
2250 | /** | |
2251 | * mpol_shared_policy_init - initialize shared policy for inode | |
2252 | * @sp: pointer to inode shared policy | |
2253 | * @mpol: struct mempolicy to install | |
2254 | * | |
2255 | * Install non-NULL @mpol in inode's shared policy rb-tree. | |
2256 | * On entry, the current task has a reference on a non-NULL @mpol. | |
2257 | * This must be released on exit. | |
2258 | * This is called at get_inode() calls and we can use GFP_KERNEL. | |
2259 | */ | |
2260 | void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol) | |
2261 | { | |
2262 | int ret; | |
2263 | ||
2264 | sp->root = RB_ROOT; /* empty tree == default mempolicy */ | |
2265 | mutex_init(&sp->mutex); | |
2266 | ||
2267 | if (mpol) { | |
2268 | struct vm_area_struct pvma; | |
2269 | struct mempolicy *new; | |
2270 | NODEMASK_SCRATCH(scratch); | |
2271 | ||
2272 | if (!scratch) | |
2273 | goto put_mpol; | |
2274 | /* contextualize the tmpfs mount point mempolicy */ | |
2275 | new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask); | |
2276 | if (IS_ERR(new)) | |
2277 | goto free_scratch; /* no valid nodemask intersection */ | |
2278 | ||
2279 | task_lock(current); | |
2280 | ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch); | |
2281 | task_unlock(current); | |
2282 | if (ret) | |
2283 | goto put_new; | |
2284 | ||
2285 | /* Create pseudo-vma that contains just the policy */ | |
2286 | memset(&pvma, 0, sizeof(struct vm_area_struct)); | |
2287 | pvma.vm_end = TASK_SIZE; /* policy covers entire file */ | |
2288 | mpol_set_shared_policy(sp, &pvma, new); /* adds ref */ | |
2289 | ||
2290 | put_new: | |
2291 | mpol_put(new); /* drop initial ref */ | |
2292 | free_scratch: | |
2293 | NODEMASK_SCRATCH_FREE(scratch); | |
2294 | put_mpol: | |
2295 | mpol_put(mpol); /* drop our incoming ref on sb mpol */ | |
2296 | } | |
2297 | } | |
2298 | ||
2299 | int mpol_set_shared_policy(struct shared_policy *info, | |
2300 | struct vm_area_struct *vma, struct mempolicy *npol) | |
2301 | { | |
2302 | int err; | |
2303 | struct sp_node *new = NULL; | |
2304 | unsigned long sz = vma_pages(vma); | |
2305 | ||
2306 | pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n", | |
2307 | vma->vm_pgoff, | |
2308 | sz, npol ? npol->mode : -1, | |
2309 | npol ? npol->flags : -1, | |
2310 | npol ? nodes_addr(npol->v.nodes)[0] : -1); | |
2311 | ||
2312 | if (npol) { | |
2313 | new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol); | |
2314 | if (!new) | |
2315 | return -ENOMEM; | |
2316 | } | |
2317 | err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new); | |
2318 | if (err && new) | |
2319 | sp_free(new); | |
2320 | return err; | |
2321 | } | |
2322 | ||
2323 | /* Free a backing policy store on inode delete. */ | |
2324 | void mpol_free_shared_policy(struct shared_policy *p) | |
2325 | { | |
2326 | struct sp_node *n; | |
2327 | struct rb_node *next; | |
2328 | ||
2329 | if (!p->root.rb_node) | |
2330 | return; | |
2331 | mutex_lock(&p->mutex); | |
2332 | next = rb_first(&p->root); | |
2333 | while (next) { | |
2334 | n = rb_entry(next, struct sp_node, nd); | |
2335 | next = rb_next(&n->nd); | |
2336 | sp_delete(p, n); | |
2337 | } | |
2338 | mutex_unlock(&p->mutex); | |
2339 | } | |
2340 | ||
2341 | /* assumes fs == KERNEL_DS */ | |
2342 | void __init numa_policy_init(void) | |
2343 | { | |
2344 | nodemask_t interleave_nodes; | |
2345 | unsigned long largest = 0; | |
2346 | int nid, prefer = 0; | |
2347 | ||
2348 | policy_cache = kmem_cache_create("numa_policy", | |
2349 | sizeof(struct mempolicy), | |
2350 | 0, SLAB_PANIC, NULL); | |
2351 | ||
2352 | sn_cache = kmem_cache_create("shared_policy_node", | |
2353 | sizeof(struct sp_node), | |
2354 | 0, SLAB_PANIC, NULL); | |
2355 | ||
2356 | /* | |
2357 | * Set interleaving policy for system init. Interleaving is only | |
2358 | * enabled across suitably sized nodes (default is >= 16MB), or | |
2359 | * fall back to the largest node if they're all smaller. | |
2360 | */ | |
2361 | nodes_clear(interleave_nodes); | |
2362 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
2363 | unsigned long total_pages = node_present_pages(nid); | |
2364 | ||
2365 | /* Preserve the largest node */ | |
2366 | if (largest < total_pages) { | |
2367 | largest = total_pages; | |
2368 | prefer = nid; | |
2369 | } | |
2370 | ||
2371 | /* Interleave this node? */ | |
2372 | if ((total_pages << PAGE_SHIFT) >= (16 << 20)) | |
2373 | node_set(nid, interleave_nodes); | |
2374 | } | |
2375 | ||
2376 | /* All too small, use the largest */ | |
2377 | if (unlikely(nodes_empty(interleave_nodes))) | |
2378 | node_set(prefer, interleave_nodes); | |
2379 | ||
2380 | if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes)) | |
2381 | printk("numa_policy_init: interleaving failed\n"); | |
2382 | } | |
2383 | ||
2384 | /* Reset policy of current process to default */ | |
2385 | void numa_default_policy(void) | |
2386 | { | |
2387 | do_set_mempolicy(MPOL_DEFAULT, 0, NULL); | |
2388 | } | |
2389 | ||
2390 | /* | |
2391 | * Parse and format mempolicy from/to strings | |
2392 | */ | |
2393 | ||
2394 | /* | |
2395 | * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag | |
2396 | * Used only for mpol_parse_str() and mpol_to_str() | |
2397 | */ | |
2398 | #define MPOL_LOCAL MPOL_MAX | |
2399 | static const char * const policy_modes[] = | |
2400 | { | |
2401 | [MPOL_DEFAULT] = "default", | |
2402 | [MPOL_PREFERRED] = "prefer", | |
2403 | [MPOL_BIND] = "bind", | |
2404 | [MPOL_INTERLEAVE] = "interleave", | |
2405 | [MPOL_LOCAL] = "local" | |
2406 | }; | |
2407 | ||
2408 | ||
2409 | #ifdef CONFIG_TMPFS | |
2410 | /** | |
2411 | * mpol_parse_str - parse string to mempolicy | |
2412 | * @str: string containing mempolicy to parse | |
2413 | * @mpol: pointer to struct mempolicy pointer, returned on success. | |
2414 | * @no_context: flag whether to "contextualize" the mempolicy | |
2415 | * | |
2416 | * Format of input: | |
2417 | * <mode>[=<flags>][:<nodelist>] | |
2418 | * | |
2419 | * if @no_context is true, save the input nodemask in w.user_nodemask in | |
2420 | * the returned mempolicy. This will be used to "clone" the mempolicy in | |
2421 | * a specific context [cpuset] at a later time. Used to parse tmpfs mpol | |
2422 | * mount option. Note that if 'static' or 'relative' mode flags were | |
2423 | * specified, the input nodemask will already have been saved. Saving | |
2424 | * it again is redundant, but safe. | |
2425 | * | |
2426 | * On success, returns 0, else 1 | |
2427 | */ | |
2428 | int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) | |
2429 | { | |
2430 | struct mempolicy *new = NULL; | |
2431 | unsigned short mode; | |
2432 | unsigned short uninitialized_var(mode_flags); | |
2433 | nodemask_t nodes; | |
2434 | char *nodelist = strchr(str, ':'); | |
2435 | char *flags = strchr(str, '='); | |
2436 | int err = 1; | |
2437 | ||
2438 | if (nodelist) { | |
2439 | /* NUL-terminate mode or flags string */ | |
2440 | *nodelist++ = '\0'; | |
2441 | if (nodelist_parse(nodelist, nodes)) | |
2442 | goto out; | |
2443 | if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY])) | |
2444 | goto out; | |
2445 | } else | |
2446 | nodes_clear(nodes); | |
2447 | ||
2448 | if (flags) | |
2449 | *flags++ = '\0'; /* terminate mode string */ | |
2450 | ||
2451 | for (mode = 0; mode <= MPOL_LOCAL; mode++) { | |
2452 | if (!strcmp(str, policy_modes[mode])) { | |
2453 | break; | |
2454 | } | |
2455 | } | |
2456 | if (mode > MPOL_LOCAL) | |
2457 | goto out; | |
2458 | ||
2459 | switch (mode) { | |
2460 | case MPOL_PREFERRED: | |
2461 | /* | |
2462 | * Insist on a nodelist of one node only | |
2463 | */ | |
2464 | if (nodelist) { | |
2465 | char *rest = nodelist; | |
2466 | while (isdigit(*rest)) | |
2467 | rest++; | |
2468 | if (*rest) | |
2469 | goto out; | |
2470 | } | |
2471 | break; | |
2472 | case MPOL_INTERLEAVE: | |
2473 | /* | |
2474 | * Default to online nodes with memory if no nodelist | |
2475 | */ | |
2476 | if (!nodelist) | |
2477 | nodes = node_states[N_HIGH_MEMORY]; | |
2478 | break; | |
2479 | case MPOL_LOCAL: | |
2480 | /* | |
2481 | * Don't allow a nodelist; mpol_new() checks flags | |
2482 | */ | |
2483 | if (nodelist) | |
2484 | goto out; | |
2485 | mode = MPOL_PREFERRED; | |
2486 | break; | |
2487 | case MPOL_DEFAULT: | |
2488 | /* | |
2489 | * Insist on a empty nodelist | |
2490 | */ | |
2491 | if (!nodelist) | |
2492 | err = 0; | |
2493 | goto out; | |
2494 | case MPOL_BIND: | |
2495 | /* | |
2496 | * Insist on a nodelist | |
2497 | */ | |
2498 | if (!nodelist) | |
2499 | goto out; | |
2500 | } | |
2501 | ||
2502 | mode_flags = 0; | |
2503 | if (flags) { | |
2504 | /* | |
2505 | * Currently, we only support two mutually exclusive | |
2506 | * mode flags. | |
2507 | */ | |
2508 | if (!strcmp(flags, "static")) | |
2509 | mode_flags |= MPOL_F_STATIC_NODES; | |
2510 | else if (!strcmp(flags, "relative")) | |
2511 | mode_flags |= MPOL_F_RELATIVE_NODES; | |
2512 | else | |
2513 | goto out; | |
2514 | } | |
2515 | ||
2516 | new = mpol_new(mode, mode_flags, &nodes); | |
2517 | if (IS_ERR(new)) | |
2518 | goto out; | |
2519 | ||
2520 | if (no_context) { | |
2521 | /* save for contextualization */ | |
2522 | new->w.user_nodemask = nodes; | |
2523 | } else { | |
2524 | int ret; | |
2525 | NODEMASK_SCRATCH(scratch); | |
2526 | if (scratch) { | |
2527 | task_lock(current); | |
2528 | ret = mpol_set_nodemask(new, &nodes, scratch); | |
2529 | task_unlock(current); | |
2530 | } else | |
2531 | ret = -ENOMEM; | |
2532 | NODEMASK_SCRATCH_FREE(scratch); | |
2533 | if (ret) { | |
2534 | mpol_put(new); | |
2535 | goto out; | |
2536 | } | |
2537 | } | |
2538 | err = 0; | |
2539 | ||
2540 | out: | |
2541 | /* Restore string for error message */ | |
2542 | if (nodelist) | |
2543 | *--nodelist = ':'; | |
2544 | if (flags) | |
2545 | *--flags = '='; | |
2546 | if (!err) | |
2547 | *mpol = new; | |
2548 | return err; | |
2549 | } | |
2550 | #endif /* CONFIG_TMPFS */ | |
2551 | ||
2552 | /** | |
2553 | * mpol_to_str - format a mempolicy structure for printing | |
2554 | * @buffer: to contain formatted mempolicy string | |
2555 | * @maxlen: length of @buffer | |
2556 | * @pol: pointer to mempolicy to be formatted | |
2557 | * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask | |
2558 | * | |
2559 | * Convert a mempolicy into a string. | |
2560 | * Returns the number of characters in buffer (if positive) | |
2561 | * or an error (negative) | |
2562 | */ | |
2563 | int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context) | |
2564 | { | |
2565 | char *p = buffer; | |
2566 | int l; | |
2567 | nodemask_t nodes; | |
2568 | unsigned short mode; | |
2569 | unsigned short flags = pol ? pol->flags : 0; | |
2570 | ||
2571 | /* | |
2572 | * Sanity check: room for longest mode, flag and some nodes | |
2573 | */ | |
2574 | VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16); | |
2575 | ||
2576 | if (!pol || pol == &default_policy) | |
2577 | mode = MPOL_DEFAULT; | |
2578 | else | |
2579 | mode = pol->mode; | |
2580 | ||
2581 | switch (mode) { | |
2582 | case MPOL_DEFAULT: | |
2583 | nodes_clear(nodes); | |
2584 | break; | |
2585 | ||
2586 | case MPOL_PREFERRED: | |
2587 | nodes_clear(nodes); | |
2588 | if (flags & MPOL_F_LOCAL) | |
2589 | mode = MPOL_LOCAL; /* pseudo-policy */ | |
2590 | else | |
2591 | node_set(pol->v.preferred_node, nodes); | |
2592 | break; | |
2593 | ||
2594 | case MPOL_BIND: | |
2595 | /* Fall through */ | |
2596 | case MPOL_INTERLEAVE: | |
2597 | if (no_context) | |
2598 | nodes = pol->w.user_nodemask; | |
2599 | else | |
2600 | nodes = pol->v.nodes; | |
2601 | break; | |
2602 | ||
2603 | default: | |
2604 | return -EINVAL; | |
2605 | } | |
2606 | ||
2607 | l = strlen(policy_modes[mode]); | |
2608 | if (buffer + maxlen < p + l + 1) | |
2609 | return -ENOSPC; | |
2610 | ||
2611 | strcpy(p, policy_modes[mode]); | |
2612 | p += l; | |
2613 | ||
2614 | if (flags & MPOL_MODE_FLAGS) { | |
2615 | if (buffer + maxlen < p + 2) | |
2616 | return -ENOSPC; | |
2617 | *p++ = '='; | |
2618 | ||
2619 | /* | |
2620 | * Currently, the only defined flags are mutually exclusive | |
2621 | */ | |
2622 | if (flags & MPOL_F_STATIC_NODES) | |
2623 | p += snprintf(p, buffer + maxlen - p, "static"); | |
2624 | else if (flags & MPOL_F_RELATIVE_NODES) | |
2625 | p += snprintf(p, buffer + maxlen - p, "relative"); | |
2626 | } | |
2627 | ||
2628 | if (!nodes_empty(nodes)) { | |
2629 | if (buffer + maxlen < p + 2) | |
2630 | return -ENOSPC; | |
2631 | *p++ = ':'; | |
2632 | p += nodelist_scnprintf(p, buffer + maxlen - p, nodes); | |
2633 | } | |
2634 | return p - buffer; | |
2635 | } |