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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 NUMA_NO_NODE 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 | #include <linux/mmu_notifier.h> | |
94 | ||
95 | #include <asm/tlbflush.h> | |
96 | #include <asm/uaccess.h> | |
97 | #include <linux/random.h> | |
98 | ||
99 | #include "internal.h" | |
100 | ||
101 | /* Internal flags */ | |
102 | #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */ | |
103 | #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */ | |
104 | ||
105 | static struct kmem_cache *policy_cache; | |
106 | static struct kmem_cache *sn_cache; | |
107 | ||
108 | /* Highest zone. An specific allocation for a zone below that is not | |
109 | policied. */ | |
110 | enum zone_type policy_zone = 0; | |
111 | ||
112 | /* | |
113 | * run-time system-wide default policy => local allocation | |
114 | */ | |
115 | static struct mempolicy default_policy = { | |
116 | .refcnt = ATOMIC_INIT(1), /* never free it */ | |
117 | .mode = MPOL_PREFERRED, | |
118 | .flags = MPOL_F_LOCAL, | |
119 | }; | |
120 | ||
121 | static struct mempolicy preferred_node_policy[MAX_NUMNODES]; | |
122 | ||
123 | static struct mempolicy *get_task_policy(struct task_struct *p) | |
124 | { | |
125 | struct mempolicy *pol = p->mempolicy; | |
126 | int node; | |
127 | ||
128 | if (!pol) { | |
129 | node = numa_node_id(); | |
130 | if (node != NUMA_NO_NODE) | |
131 | pol = &preferred_node_policy[node]; | |
132 | ||
133 | /* preferred_node_policy is not initialised early in boot */ | |
134 | if (!pol->mode) | |
135 | pol = NULL; | |
136 | } | |
137 | ||
138 | return pol; | |
139 | } | |
140 | ||
141 | static const struct mempolicy_operations { | |
142 | int (*create)(struct mempolicy *pol, const nodemask_t *nodes); | |
143 | /* | |
144 | * If read-side task has no lock to protect task->mempolicy, write-side | |
145 | * task will rebind the task->mempolicy by two step. The first step is | |
146 | * setting all the newly nodes, and the second step is cleaning all the | |
147 | * disallowed nodes. In this way, we can avoid finding no node to alloc | |
148 | * page. | |
149 | * If we have a lock to protect task->mempolicy in read-side, we do | |
150 | * rebind directly. | |
151 | * | |
152 | * step: | |
153 | * MPOL_REBIND_ONCE - do rebind work at once | |
154 | * MPOL_REBIND_STEP1 - set all the newly nodes | |
155 | * MPOL_REBIND_STEP2 - clean all the disallowed nodes | |
156 | */ | |
157 | void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes, | |
158 | enum mpol_rebind_step step); | |
159 | } mpol_ops[MPOL_MAX]; | |
160 | ||
161 | /* Check that the nodemask contains at least one populated zone */ | |
162 | static int is_valid_nodemask(const nodemask_t *nodemask) | |
163 | { | |
164 | return nodes_intersects(*nodemask, node_states[N_MEMORY]); | |
165 | } | |
166 | ||
167 | static inline int mpol_store_user_nodemask(const struct mempolicy *pol) | |
168 | { | |
169 | return pol->flags & MPOL_MODE_FLAGS; | |
170 | } | |
171 | ||
172 | static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig, | |
173 | const nodemask_t *rel) | |
174 | { | |
175 | nodemask_t tmp; | |
176 | nodes_fold(tmp, *orig, nodes_weight(*rel)); | |
177 | nodes_onto(*ret, tmp, *rel); | |
178 | } | |
179 | ||
180 | static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes) | |
181 | { | |
182 | if (nodes_empty(*nodes)) | |
183 | return -EINVAL; | |
184 | pol->v.nodes = *nodes; | |
185 | return 0; | |
186 | } | |
187 | ||
188 | static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes) | |
189 | { | |
190 | if (!nodes) | |
191 | pol->flags |= MPOL_F_LOCAL; /* local allocation */ | |
192 | else if (nodes_empty(*nodes)) | |
193 | return -EINVAL; /* no allowed nodes */ | |
194 | else | |
195 | pol->v.preferred_node = first_node(*nodes); | |
196 | return 0; | |
197 | } | |
198 | ||
199 | static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes) | |
200 | { | |
201 | if (!is_valid_nodemask(nodes)) | |
202 | return -EINVAL; | |
203 | pol->v.nodes = *nodes; | |
204 | return 0; | |
205 | } | |
206 | ||
207 | /* | |
208 | * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if | |
209 | * any, for the new policy. mpol_new() has already validated the nodes | |
210 | * parameter with respect to the policy mode and flags. But, we need to | |
211 | * handle an empty nodemask with MPOL_PREFERRED here. | |
212 | * | |
213 | * Must be called holding task's alloc_lock to protect task's mems_allowed | |
214 | * and mempolicy. May also be called holding the mmap_semaphore for write. | |
215 | */ | |
216 | static int mpol_set_nodemask(struct mempolicy *pol, | |
217 | const nodemask_t *nodes, struct nodemask_scratch *nsc) | |
218 | { | |
219 | int ret; | |
220 | ||
221 | /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */ | |
222 | if (pol == NULL) | |
223 | return 0; | |
224 | /* Check N_MEMORY */ | |
225 | nodes_and(nsc->mask1, | |
226 | cpuset_current_mems_allowed, node_states[N_MEMORY]); | |
227 | ||
228 | VM_BUG_ON(!nodes); | |
229 | if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes)) | |
230 | nodes = NULL; /* explicit local allocation */ | |
231 | else { | |
232 | if (pol->flags & MPOL_F_RELATIVE_NODES) | |
233 | mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1); | |
234 | else | |
235 | nodes_and(nsc->mask2, *nodes, nsc->mask1); | |
236 | ||
237 | if (mpol_store_user_nodemask(pol)) | |
238 | pol->w.user_nodemask = *nodes; | |
239 | else | |
240 | pol->w.cpuset_mems_allowed = | |
241 | cpuset_current_mems_allowed; | |
242 | } | |
243 | ||
244 | if (nodes) | |
245 | ret = mpol_ops[pol->mode].create(pol, &nsc->mask2); | |
246 | else | |
247 | ret = mpol_ops[pol->mode].create(pol, NULL); | |
248 | return ret; | |
249 | } | |
250 | ||
251 | /* | |
252 | * This function just creates a new policy, does some check and simple | |
253 | * initialization. You must invoke mpol_set_nodemask() to set nodes. | |
254 | */ | |
255 | static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, | |
256 | nodemask_t *nodes) | |
257 | { | |
258 | struct mempolicy *policy; | |
259 | ||
260 | pr_debug("setting mode %d flags %d nodes[0] %lx\n", | |
261 | mode, flags, nodes ? nodes_addr(*nodes)[0] : NUMA_NO_NODE); | |
262 | ||
263 | if (mode == MPOL_DEFAULT) { | |
264 | if (nodes && !nodes_empty(*nodes)) | |
265 | return ERR_PTR(-EINVAL); | |
266 | return NULL; | |
267 | } | |
268 | VM_BUG_ON(!nodes); | |
269 | ||
270 | /* | |
271 | * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or | |
272 | * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation). | |
273 | * All other modes require a valid pointer to a non-empty nodemask. | |
274 | */ | |
275 | if (mode == MPOL_PREFERRED) { | |
276 | if (nodes_empty(*nodes)) { | |
277 | if (((flags & MPOL_F_STATIC_NODES) || | |
278 | (flags & MPOL_F_RELATIVE_NODES))) | |
279 | return ERR_PTR(-EINVAL); | |
280 | } | |
281 | } else if (mode == MPOL_LOCAL) { | |
282 | if (!nodes_empty(*nodes)) | |
283 | return ERR_PTR(-EINVAL); | |
284 | mode = MPOL_PREFERRED; | |
285 | } else if (nodes_empty(*nodes)) | |
286 | return ERR_PTR(-EINVAL); | |
287 | policy = kmem_cache_alloc(policy_cache, GFP_KERNEL); | |
288 | if (!policy) | |
289 | return ERR_PTR(-ENOMEM); | |
290 | atomic_set(&policy->refcnt, 1); | |
291 | policy->mode = mode; | |
292 | policy->flags = flags; | |
293 | ||
294 | return policy; | |
295 | } | |
296 | ||
297 | /* Slow path of a mpol destructor. */ | |
298 | void __mpol_put(struct mempolicy *p) | |
299 | { | |
300 | if (!atomic_dec_and_test(&p->refcnt)) | |
301 | return; | |
302 | kmem_cache_free(policy_cache, p); | |
303 | } | |
304 | ||
305 | static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes, | |
306 | enum mpol_rebind_step step) | |
307 | { | |
308 | } | |
309 | ||
310 | /* | |
311 | * step: | |
312 | * MPOL_REBIND_ONCE - do rebind work at once | |
313 | * MPOL_REBIND_STEP1 - set all the newly nodes | |
314 | * MPOL_REBIND_STEP2 - clean all the disallowed nodes | |
315 | */ | |
316 | static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes, | |
317 | enum mpol_rebind_step step) | |
318 | { | |
319 | nodemask_t tmp; | |
320 | ||
321 | if (pol->flags & MPOL_F_STATIC_NODES) | |
322 | nodes_and(tmp, pol->w.user_nodemask, *nodes); | |
323 | else if (pol->flags & MPOL_F_RELATIVE_NODES) | |
324 | mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); | |
325 | else { | |
326 | /* | |
327 | * if step == 1, we use ->w.cpuset_mems_allowed to cache the | |
328 | * result | |
329 | */ | |
330 | if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP1) { | |
331 | nodes_remap(tmp, pol->v.nodes, | |
332 | pol->w.cpuset_mems_allowed, *nodes); | |
333 | pol->w.cpuset_mems_allowed = step ? tmp : *nodes; | |
334 | } else if (step == MPOL_REBIND_STEP2) { | |
335 | tmp = pol->w.cpuset_mems_allowed; | |
336 | pol->w.cpuset_mems_allowed = *nodes; | |
337 | } else | |
338 | BUG(); | |
339 | } | |
340 | ||
341 | if (nodes_empty(tmp)) | |
342 | tmp = *nodes; | |
343 | ||
344 | if (step == MPOL_REBIND_STEP1) | |
345 | nodes_or(pol->v.nodes, pol->v.nodes, tmp); | |
346 | else if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP2) | |
347 | pol->v.nodes = tmp; | |
348 | else | |
349 | BUG(); | |
350 | ||
351 | if (!node_isset(current->il_next, tmp)) { | |
352 | current->il_next = next_node(current->il_next, tmp); | |
353 | if (current->il_next >= MAX_NUMNODES) | |
354 | current->il_next = first_node(tmp); | |
355 | if (current->il_next >= MAX_NUMNODES) | |
356 | current->il_next = numa_node_id(); | |
357 | } | |
358 | } | |
359 | ||
360 | static void mpol_rebind_preferred(struct mempolicy *pol, | |
361 | const nodemask_t *nodes, | |
362 | enum mpol_rebind_step step) | |
363 | { | |
364 | nodemask_t tmp; | |
365 | ||
366 | if (pol->flags & MPOL_F_STATIC_NODES) { | |
367 | int node = first_node(pol->w.user_nodemask); | |
368 | ||
369 | if (node_isset(node, *nodes)) { | |
370 | pol->v.preferred_node = node; | |
371 | pol->flags &= ~MPOL_F_LOCAL; | |
372 | } else | |
373 | pol->flags |= MPOL_F_LOCAL; | |
374 | } else if (pol->flags & MPOL_F_RELATIVE_NODES) { | |
375 | mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); | |
376 | pol->v.preferred_node = first_node(tmp); | |
377 | } else if (!(pol->flags & MPOL_F_LOCAL)) { | |
378 | pol->v.preferred_node = node_remap(pol->v.preferred_node, | |
379 | pol->w.cpuset_mems_allowed, | |
380 | *nodes); | |
381 | pol->w.cpuset_mems_allowed = *nodes; | |
382 | } | |
383 | } | |
384 | ||
385 | /* | |
386 | * mpol_rebind_policy - Migrate a policy to a different set of nodes | |
387 | * | |
388 | * If read-side task has no lock to protect task->mempolicy, write-side | |
389 | * task will rebind the task->mempolicy by two step. The first step is | |
390 | * setting all the newly nodes, and the second step is cleaning all the | |
391 | * disallowed nodes. In this way, we can avoid finding no node to alloc | |
392 | * page. | |
393 | * If we have a lock to protect task->mempolicy in read-side, we do | |
394 | * rebind directly. | |
395 | * | |
396 | * step: | |
397 | * MPOL_REBIND_ONCE - do rebind work at once | |
398 | * MPOL_REBIND_STEP1 - set all the newly nodes | |
399 | * MPOL_REBIND_STEP2 - clean all the disallowed nodes | |
400 | */ | |
401 | static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask, | |
402 | enum mpol_rebind_step step) | |
403 | { | |
404 | if (!pol) | |
405 | return; | |
406 | if (!mpol_store_user_nodemask(pol) && step == MPOL_REBIND_ONCE && | |
407 | nodes_equal(pol->w.cpuset_mems_allowed, *newmask)) | |
408 | return; | |
409 | ||
410 | if (step == MPOL_REBIND_STEP1 && (pol->flags & MPOL_F_REBINDING)) | |
411 | return; | |
412 | ||
413 | if (step == MPOL_REBIND_STEP2 && !(pol->flags & MPOL_F_REBINDING)) | |
414 | BUG(); | |
415 | ||
416 | if (step == MPOL_REBIND_STEP1) | |
417 | pol->flags |= MPOL_F_REBINDING; | |
418 | else if (step == MPOL_REBIND_STEP2) | |
419 | pol->flags &= ~MPOL_F_REBINDING; | |
420 | else if (step >= MPOL_REBIND_NSTEP) | |
421 | BUG(); | |
422 | ||
423 | mpol_ops[pol->mode].rebind(pol, newmask, step); | |
424 | } | |
425 | ||
426 | /* | |
427 | * Wrapper for mpol_rebind_policy() that just requires task | |
428 | * pointer, and updates task mempolicy. | |
429 | * | |
430 | * Called with task's alloc_lock held. | |
431 | */ | |
432 | ||
433 | void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new, | |
434 | enum mpol_rebind_step step) | |
435 | { | |
436 | mpol_rebind_policy(tsk->mempolicy, new, step); | |
437 | } | |
438 | ||
439 | /* | |
440 | * Rebind each vma in mm to new nodemask. | |
441 | * | |
442 | * Call holding a reference to mm. Takes mm->mmap_sem during call. | |
443 | */ | |
444 | ||
445 | void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new) | |
446 | { | |
447 | struct vm_area_struct *vma; | |
448 | ||
449 | down_write(&mm->mmap_sem); | |
450 | for (vma = mm->mmap; vma; vma = vma->vm_next) | |
451 | mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE); | |
452 | up_write(&mm->mmap_sem); | |
453 | } | |
454 | ||
455 | static const struct mempolicy_operations mpol_ops[MPOL_MAX] = { | |
456 | [MPOL_DEFAULT] = { | |
457 | .rebind = mpol_rebind_default, | |
458 | }, | |
459 | [MPOL_INTERLEAVE] = { | |
460 | .create = mpol_new_interleave, | |
461 | .rebind = mpol_rebind_nodemask, | |
462 | }, | |
463 | [MPOL_PREFERRED] = { | |
464 | .create = mpol_new_preferred, | |
465 | .rebind = mpol_rebind_preferred, | |
466 | }, | |
467 | [MPOL_BIND] = { | |
468 | .create = mpol_new_bind, | |
469 | .rebind = mpol_rebind_nodemask, | |
470 | }, | |
471 | }; | |
472 | ||
473 | static void migrate_page_add(struct page *page, struct list_head *pagelist, | |
474 | unsigned long flags); | |
475 | ||
476 | /* Scan through pages checking if pages follow certain conditions. */ | |
477 | static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd, | |
478 | unsigned long addr, unsigned long end, | |
479 | const nodemask_t *nodes, unsigned long flags, | |
480 | void *private) | |
481 | { | |
482 | pte_t *orig_pte; | |
483 | pte_t *pte; | |
484 | spinlock_t *ptl; | |
485 | ||
486 | orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
487 | do { | |
488 | struct page *page; | |
489 | int nid; | |
490 | ||
491 | if (!pte_present(*pte)) | |
492 | continue; | |
493 | page = vm_normal_page(vma, addr, *pte); | |
494 | if (!page) | |
495 | continue; | |
496 | /* | |
497 | * vm_normal_page() filters out zero pages, but there might | |
498 | * still be PageReserved pages to skip, perhaps in a VDSO. | |
499 | */ | |
500 | if (PageReserved(page)) | |
501 | continue; | |
502 | nid = page_to_nid(page); | |
503 | if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT)) | |
504 | continue; | |
505 | ||
506 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) | |
507 | migrate_page_add(page, private, flags); | |
508 | else | |
509 | break; | |
510 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
511 | pte_unmap_unlock(orig_pte, ptl); | |
512 | return addr != end; | |
513 | } | |
514 | ||
515 | static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud, | |
516 | unsigned long addr, unsigned long end, | |
517 | const nodemask_t *nodes, unsigned long flags, | |
518 | void *private) | |
519 | { | |
520 | pmd_t *pmd; | |
521 | unsigned long next; | |
522 | ||
523 | pmd = pmd_offset(pud, addr); | |
524 | do { | |
525 | next = pmd_addr_end(addr, end); | |
526 | split_huge_page_pmd(vma, addr, pmd); | |
527 | if (pmd_none_or_trans_huge_or_clear_bad(pmd)) | |
528 | continue; | |
529 | if (check_pte_range(vma, pmd, addr, next, nodes, | |
530 | flags, private)) | |
531 | return -EIO; | |
532 | } while (pmd++, addr = next, addr != end); | |
533 | return 0; | |
534 | } | |
535 | ||
536 | static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd, | |
537 | unsigned long addr, unsigned long end, | |
538 | const nodemask_t *nodes, unsigned long flags, | |
539 | void *private) | |
540 | { | |
541 | pud_t *pud; | |
542 | unsigned long next; | |
543 | ||
544 | pud = pud_offset(pgd, addr); | |
545 | do { | |
546 | next = pud_addr_end(addr, end); | |
547 | if (pud_none_or_clear_bad(pud)) | |
548 | continue; | |
549 | if (check_pmd_range(vma, pud, addr, next, nodes, | |
550 | flags, private)) | |
551 | return -EIO; | |
552 | } while (pud++, addr = next, addr != end); | |
553 | return 0; | |
554 | } | |
555 | ||
556 | static inline int check_pgd_range(struct vm_area_struct *vma, | |
557 | unsigned long addr, unsigned long end, | |
558 | const nodemask_t *nodes, unsigned long flags, | |
559 | void *private) | |
560 | { | |
561 | pgd_t *pgd; | |
562 | unsigned long next; | |
563 | ||
564 | pgd = pgd_offset(vma->vm_mm, addr); | |
565 | do { | |
566 | next = pgd_addr_end(addr, end); | |
567 | if (pgd_none_or_clear_bad(pgd)) | |
568 | continue; | |
569 | if (check_pud_range(vma, pgd, addr, next, nodes, | |
570 | flags, private)) | |
571 | return -EIO; | |
572 | } while (pgd++, addr = next, addr != end); | |
573 | return 0; | |
574 | } | |
575 | ||
576 | #ifdef CONFIG_ARCH_USES_NUMA_PROT_NONE | |
577 | /* | |
578 | * This is used to mark a range of virtual addresses to be inaccessible. | |
579 | * These are later cleared by a NUMA hinting fault. Depending on these | |
580 | * faults, pages may be migrated for better NUMA placement. | |
581 | * | |
582 | * This is assuming that NUMA faults are handled using PROT_NONE. If | |
583 | * an architecture makes a different choice, it will need further | |
584 | * changes to the core. | |
585 | */ | |
586 | unsigned long change_prot_numa(struct vm_area_struct *vma, | |
587 | unsigned long addr, unsigned long end) | |
588 | { | |
589 | int nr_updated; | |
590 | BUILD_BUG_ON(_PAGE_NUMA != _PAGE_PROTNONE); | |
591 | ||
592 | nr_updated = change_protection(vma, addr, end, vma->vm_page_prot, 0, 1); | |
593 | if (nr_updated) | |
594 | count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated); | |
595 | ||
596 | return nr_updated; | |
597 | } | |
598 | #else | |
599 | static unsigned long change_prot_numa(struct vm_area_struct *vma, | |
600 | unsigned long addr, unsigned long end) | |
601 | { | |
602 | return 0; | |
603 | } | |
604 | #endif /* CONFIG_ARCH_USES_NUMA_PROT_NONE */ | |
605 | ||
606 | /* | |
607 | * Check if all pages in a range are on a set of nodes. | |
608 | * If pagelist != NULL then isolate pages from the LRU and | |
609 | * put them on the pagelist. | |
610 | */ | |
611 | static struct vm_area_struct * | |
612 | check_range(struct mm_struct *mm, unsigned long start, unsigned long end, | |
613 | const nodemask_t *nodes, unsigned long flags, void *private) | |
614 | { | |
615 | int err; | |
616 | struct vm_area_struct *first, *vma, *prev; | |
617 | ||
618 | ||
619 | first = find_vma(mm, start); | |
620 | if (!first) | |
621 | return ERR_PTR(-EFAULT); | |
622 | prev = NULL; | |
623 | for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) { | |
624 | unsigned long endvma = vma->vm_end; | |
625 | ||
626 | if (endvma > end) | |
627 | endvma = end; | |
628 | if (vma->vm_start > start) | |
629 | start = vma->vm_start; | |
630 | ||
631 | if (!(flags & MPOL_MF_DISCONTIG_OK)) { | |
632 | if (!vma->vm_next && vma->vm_end < end) | |
633 | return ERR_PTR(-EFAULT); | |
634 | if (prev && prev->vm_end < vma->vm_start) | |
635 | return ERR_PTR(-EFAULT); | |
636 | } | |
637 | ||
638 | if (is_vm_hugetlb_page(vma)) | |
639 | goto next; | |
640 | ||
641 | if (flags & MPOL_MF_LAZY) { | |
642 | change_prot_numa(vma, start, endvma); | |
643 | goto next; | |
644 | } | |
645 | ||
646 | if ((flags & MPOL_MF_STRICT) || | |
647 | ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) && | |
648 | vma_migratable(vma))) { | |
649 | ||
650 | err = check_pgd_range(vma, start, endvma, nodes, | |
651 | flags, private); | |
652 | if (err) { | |
653 | first = ERR_PTR(err); | |
654 | break; | |
655 | } | |
656 | } | |
657 | next: | |
658 | prev = vma; | |
659 | } | |
660 | return first; | |
661 | } | |
662 | ||
663 | /* | |
664 | * Apply policy to a single VMA | |
665 | * This must be called with the mmap_sem held for writing. | |
666 | */ | |
667 | static int vma_replace_policy(struct vm_area_struct *vma, | |
668 | struct mempolicy *pol) | |
669 | { | |
670 | int err; | |
671 | struct mempolicy *old; | |
672 | struct mempolicy *new; | |
673 | ||
674 | pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n", | |
675 | vma->vm_start, vma->vm_end, vma->vm_pgoff, | |
676 | vma->vm_ops, vma->vm_file, | |
677 | vma->vm_ops ? vma->vm_ops->set_policy : NULL); | |
678 | ||
679 | new = mpol_dup(pol); | |
680 | if (IS_ERR(new)) | |
681 | return PTR_ERR(new); | |
682 | ||
683 | if (vma->vm_ops && vma->vm_ops->set_policy) { | |
684 | err = vma->vm_ops->set_policy(vma, new); | |
685 | if (err) | |
686 | goto err_out; | |
687 | } | |
688 | ||
689 | old = vma->vm_policy; | |
690 | vma->vm_policy = new; /* protected by mmap_sem */ | |
691 | mpol_put(old); | |
692 | ||
693 | return 0; | |
694 | err_out: | |
695 | mpol_put(new); | |
696 | return err; | |
697 | } | |
698 | ||
699 | /* Step 2: apply policy to a range and do splits. */ | |
700 | static int mbind_range(struct mm_struct *mm, unsigned long start, | |
701 | unsigned long end, struct mempolicy *new_pol) | |
702 | { | |
703 | struct vm_area_struct *next; | |
704 | struct vm_area_struct *prev; | |
705 | struct vm_area_struct *vma; | |
706 | int err = 0; | |
707 | pgoff_t pgoff; | |
708 | unsigned long vmstart; | |
709 | unsigned long vmend; | |
710 | ||
711 | vma = find_vma(mm, start); | |
712 | if (!vma || vma->vm_start > start) | |
713 | return -EFAULT; | |
714 | ||
715 | prev = vma->vm_prev; | |
716 | if (start > vma->vm_start) | |
717 | prev = vma; | |
718 | ||
719 | for (; vma && vma->vm_start < end; prev = vma, vma = next) { | |
720 | next = vma->vm_next; | |
721 | vmstart = max(start, vma->vm_start); | |
722 | vmend = min(end, vma->vm_end); | |
723 | ||
724 | if (mpol_equal(vma_policy(vma), new_pol)) | |
725 | continue; | |
726 | ||
727 | pgoff = vma->vm_pgoff + | |
728 | ((vmstart - vma->vm_start) >> PAGE_SHIFT); | |
729 | prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags, | |
730 | vma->anon_vma, vma->vm_file, pgoff, | |
731 | new_pol); | |
732 | if (prev) { | |
733 | vma = prev; | |
734 | next = vma->vm_next; | |
735 | if (mpol_equal(vma_policy(vma), new_pol)) | |
736 | continue; | |
737 | /* vma_merge() joined vma && vma->next, case 8 */ | |
738 | goto replace; | |
739 | } | |
740 | if (vma->vm_start != vmstart) { | |
741 | err = split_vma(vma->vm_mm, vma, vmstart, 1); | |
742 | if (err) | |
743 | goto out; | |
744 | } | |
745 | if (vma->vm_end != vmend) { | |
746 | err = split_vma(vma->vm_mm, vma, vmend, 0); | |
747 | if (err) | |
748 | goto out; | |
749 | } | |
750 | replace: | |
751 | err = vma_replace_policy(vma, new_pol); | |
752 | if (err) | |
753 | goto out; | |
754 | } | |
755 | ||
756 | out: | |
757 | return err; | |
758 | } | |
759 | ||
760 | /* | |
761 | * Update task->flags PF_MEMPOLICY bit: set iff non-default | |
762 | * mempolicy. Allows more rapid checking of this (combined perhaps | |
763 | * with other PF_* flag bits) on memory allocation hot code paths. | |
764 | * | |
765 | * If called from outside this file, the task 'p' should -only- be | |
766 | * a newly forked child not yet visible on the task list, because | |
767 | * manipulating the task flags of a visible task is not safe. | |
768 | * | |
769 | * The above limitation is why this routine has the funny name | |
770 | * mpol_fix_fork_child_flag(). | |
771 | * | |
772 | * It is also safe to call this with a task pointer of current, | |
773 | * which the static wrapper mpol_set_task_struct_flag() does, | |
774 | * for use within this file. | |
775 | */ | |
776 | ||
777 | void mpol_fix_fork_child_flag(struct task_struct *p) | |
778 | { | |
779 | if (p->mempolicy) | |
780 | p->flags |= PF_MEMPOLICY; | |
781 | else | |
782 | p->flags &= ~PF_MEMPOLICY; | |
783 | } | |
784 | ||
785 | static void mpol_set_task_struct_flag(void) | |
786 | { | |
787 | mpol_fix_fork_child_flag(current); | |
788 | } | |
789 | ||
790 | /* Set the process memory policy */ | |
791 | static long do_set_mempolicy(unsigned short mode, unsigned short flags, | |
792 | nodemask_t *nodes) | |
793 | { | |
794 | struct mempolicy *new, *old; | |
795 | struct mm_struct *mm = current->mm; | |
796 | NODEMASK_SCRATCH(scratch); | |
797 | int ret; | |
798 | ||
799 | if (!scratch) | |
800 | return -ENOMEM; | |
801 | ||
802 | new = mpol_new(mode, flags, nodes); | |
803 | if (IS_ERR(new)) { | |
804 | ret = PTR_ERR(new); | |
805 | goto out; | |
806 | } | |
807 | /* | |
808 | * prevent changing our mempolicy while show_numa_maps() | |
809 | * is using it. | |
810 | * Note: do_set_mempolicy() can be called at init time | |
811 | * with no 'mm'. | |
812 | */ | |
813 | if (mm) | |
814 | down_write(&mm->mmap_sem); | |
815 | task_lock(current); | |
816 | ret = mpol_set_nodemask(new, nodes, scratch); | |
817 | if (ret) { | |
818 | task_unlock(current); | |
819 | if (mm) | |
820 | up_write(&mm->mmap_sem); | |
821 | mpol_put(new); | |
822 | goto out; | |
823 | } | |
824 | old = current->mempolicy; | |
825 | current->mempolicy = new; | |
826 | mpol_set_task_struct_flag(); | |
827 | if (new && new->mode == MPOL_INTERLEAVE && | |
828 | nodes_weight(new->v.nodes)) | |
829 | current->il_next = first_node(new->v.nodes); | |
830 | task_unlock(current); | |
831 | if (mm) | |
832 | up_write(&mm->mmap_sem); | |
833 | ||
834 | mpol_put(old); | |
835 | ret = 0; | |
836 | out: | |
837 | NODEMASK_SCRATCH_FREE(scratch); | |
838 | return ret; | |
839 | } | |
840 | ||
841 | /* | |
842 | * Return nodemask for policy for get_mempolicy() query | |
843 | * | |
844 | * Called with task's alloc_lock held | |
845 | */ | |
846 | static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes) | |
847 | { | |
848 | nodes_clear(*nodes); | |
849 | if (p == &default_policy) | |
850 | return; | |
851 | ||
852 | switch (p->mode) { | |
853 | case MPOL_BIND: | |
854 | /* Fall through */ | |
855 | case MPOL_INTERLEAVE: | |
856 | *nodes = p->v.nodes; | |
857 | break; | |
858 | case MPOL_PREFERRED: | |
859 | if (!(p->flags & MPOL_F_LOCAL)) | |
860 | node_set(p->v.preferred_node, *nodes); | |
861 | /* else return empty node mask for local allocation */ | |
862 | break; | |
863 | default: | |
864 | BUG(); | |
865 | } | |
866 | } | |
867 | ||
868 | static int lookup_node(struct mm_struct *mm, unsigned long addr) | |
869 | { | |
870 | struct page *p; | |
871 | int err; | |
872 | ||
873 | err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL); | |
874 | if (err >= 0) { | |
875 | err = page_to_nid(p); | |
876 | put_page(p); | |
877 | } | |
878 | return err; | |
879 | } | |
880 | ||
881 | /* Retrieve NUMA policy */ | |
882 | static long do_get_mempolicy(int *policy, nodemask_t *nmask, | |
883 | unsigned long addr, unsigned long flags) | |
884 | { | |
885 | int err; | |
886 | struct mm_struct *mm = current->mm; | |
887 | struct vm_area_struct *vma = NULL; | |
888 | struct mempolicy *pol = current->mempolicy; | |
889 | ||
890 | if (flags & | |
891 | ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED)) | |
892 | return -EINVAL; | |
893 | ||
894 | if (flags & MPOL_F_MEMS_ALLOWED) { | |
895 | if (flags & (MPOL_F_NODE|MPOL_F_ADDR)) | |
896 | return -EINVAL; | |
897 | *policy = 0; /* just so it's initialized */ | |
898 | task_lock(current); | |
899 | *nmask = cpuset_current_mems_allowed; | |
900 | task_unlock(current); | |
901 | return 0; | |
902 | } | |
903 | ||
904 | if (flags & MPOL_F_ADDR) { | |
905 | /* | |
906 | * Do NOT fall back to task policy if the | |
907 | * vma/shared policy at addr is NULL. We | |
908 | * want to return MPOL_DEFAULT in this case. | |
909 | */ | |
910 | down_read(&mm->mmap_sem); | |
911 | vma = find_vma_intersection(mm, addr, addr+1); | |
912 | if (!vma) { | |
913 | up_read(&mm->mmap_sem); | |
914 | return -EFAULT; | |
915 | } | |
916 | if (vma->vm_ops && vma->vm_ops->get_policy) | |
917 | pol = vma->vm_ops->get_policy(vma, addr); | |
918 | else | |
919 | pol = vma->vm_policy; | |
920 | } else if (addr) | |
921 | return -EINVAL; | |
922 | ||
923 | if (!pol) | |
924 | pol = &default_policy; /* indicates default behavior */ | |
925 | ||
926 | if (flags & MPOL_F_NODE) { | |
927 | if (flags & MPOL_F_ADDR) { | |
928 | err = lookup_node(mm, addr); | |
929 | if (err < 0) | |
930 | goto out; | |
931 | *policy = err; | |
932 | } else if (pol == current->mempolicy && | |
933 | pol->mode == MPOL_INTERLEAVE) { | |
934 | *policy = current->il_next; | |
935 | } else { | |
936 | err = -EINVAL; | |
937 | goto out; | |
938 | } | |
939 | } else { | |
940 | *policy = pol == &default_policy ? MPOL_DEFAULT : | |
941 | pol->mode; | |
942 | /* | |
943 | * Internal mempolicy flags must be masked off before exposing | |
944 | * the policy to userspace. | |
945 | */ | |
946 | *policy |= (pol->flags & MPOL_MODE_FLAGS); | |
947 | } | |
948 | ||
949 | if (vma) { | |
950 | up_read(¤t->mm->mmap_sem); | |
951 | vma = NULL; | |
952 | } | |
953 | ||
954 | err = 0; | |
955 | if (nmask) { | |
956 | if (mpol_store_user_nodemask(pol)) { | |
957 | *nmask = pol->w.user_nodemask; | |
958 | } else { | |
959 | task_lock(current); | |
960 | get_policy_nodemask(pol, nmask); | |
961 | task_unlock(current); | |
962 | } | |
963 | } | |
964 | ||
965 | out: | |
966 | mpol_cond_put(pol); | |
967 | if (vma) | |
968 | up_read(¤t->mm->mmap_sem); | |
969 | return err; | |
970 | } | |
971 | ||
972 | #ifdef CONFIG_MIGRATION | |
973 | /* | |
974 | * page migration | |
975 | */ | |
976 | static void migrate_page_add(struct page *page, struct list_head *pagelist, | |
977 | unsigned long flags) | |
978 | { | |
979 | /* | |
980 | * Avoid migrating a page that is shared with others. | |
981 | */ | |
982 | if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) { | |
983 | if (!isolate_lru_page(page)) { | |
984 | list_add_tail(&page->lru, pagelist); | |
985 | inc_zone_page_state(page, NR_ISOLATED_ANON + | |
986 | page_is_file_cache(page)); | |
987 | } | |
988 | } | |
989 | } | |
990 | ||
991 | static struct page *new_node_page(struct page *page, unsigned long node, int **x) | |
992 | { | |
993 | return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0); | |
994 | } | |
995 | ||
996 | /* | |
997 | * Migrate pages from one node to a target node. | |
998 | * Returns error or the number of pages not migrated. | |
999 | */ | |
1000 | static int migrate_to_node(struct mm_struct *mm, int source, int dest, | |
1001 | int flags) | |
1002 | { | |
1003 | nodemask_t nmask; | |
1004 | LIST_HEAD(pagelist); | |
1005 | int err = 0; | |
1006 | ||
1007 | nodes_clear(nmask); | |
1008 | node_set(source, nmask); | |
1009 | ||
1010 | /* | |
1011 | * This does not "check" the range but isolates all pages that | |
1012 | * need migration. Between passing in the full user address | |
1013 | * space range and MPOL_MF_DISCONTIG_OK, this call can not fail. | |
1014 | */ | |
1015 | VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))); | |
1016 | check_range(mm, mm->mmap->vm_start, mm->task_size, &nmask, | |
1017 | flags | MPOL_MF_DISCONTIG_OK, &pagelist); | |
1018 | ||
1019 | if (!list_empty(&pagelist)) { | |
1020 | err = migrate_pages(&pagelist, new_node_page, dest, | |
1021 | MIGRATE_SYNC, MR_SYSCALL); | |
1022 | if (err) | |
1023 | putback_lru_pages(&pagelist); | |
1024 | } | |
1025 | ||
1026 | return err; | |
1027 | } | |
1028 | ||
1029 | /* | |
1030 | * Move pages between the two nodesets so as to preserve the physical | |
1031 | * layout as much as possible. | |
1032 | * | |
1033 | * Returns the number of page that could not be moved. | |
1034 | */ | |
1035 | int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, | |
1036 | const nodemask_t *to, int flags) | |
1037 | { | |
1038 | int busy = 0; | |
1039 | int err; | |
1040 | nodemask_t tmp; | |
1041 | ||
1042 | err = migrate_prep(); | |
1043 | if (err) | |
1044 | return err; | |
1045 | ||
1046 | down_read(&mm->mmap_sem); | |
1047 | ||
1048 | err = migrate_vmas(mm, from, to, flags); | |
1049 | if (err) | |
1050 | goto out; | |
1051 | ||
1052 | /* | |
1053 | * Find a 'source' bit set in 'tmp' whose corresponding 'dest' | |
1054 | * bit in 'to' is not also set in 'tmp'. Clear the found 'source' | |
1055 | * bit in 'tmp', and return that <source, dest> pair for migration. | |
1056 | * The pair of nodemasks 'to' and 'from' define the map. | |
1057 | * | |
1058 | * If no pair of bits is found that way, fallback to picking some | |
1059 | * pair of 'source' and 'dest' bits that are not the same. If the | |
1060 | * 'source' and 'dest' bits are the same, this represents a node | |
1061 | * that will be migrating to itself, so no pages need move. | |
1062 | * | |
1063 | * If no bits are left in 'tmp', or if all remaining bits left | |
1064 | * in 'tmp' correspond to the same bit in 'to', return false | |
1065 | * (nothing left to migrate). | |
1066 | * | |
1067 | * This lets us pick a pair of nodes to migrate between, such that | |
1068 | * if possible the dest node is not already occupied by some other | |
1069 | * source node, minimizing the risk of overloading the memory on a | |
1070 | * node that would happen if we migrated incoming memory to a node | |
1071 | * before migrating outgoing memory source that same node. | |
1072 | * | |
1073 | * A single scan of tmp is sufficient. As we go, we remember the | |
1074 | * most recent <s, d> pair that moved (s != d). If we find a pair | |
1075 | * that not only moved, but what's better, moved to an empty slot | |
1076 | * (d is not set in tmp), then we break out then, with that pair. | |
1077 | * Otherwise when we finish scanning from_tmp, we at least have the | |
1078 | * most recent <s, d> pair that moved. If we get all the way through | |
1079 | * the scan of tmp without finding any node that moved, much less | |
1080 | * moved to an empty node, then there is nothing left worth migrating. | |
1081 | */ | |
1082 | ||
1083 | tmp = *from; | |
1084 | while (!nodes_empty(tmp)) { | |
1085 | int s,d; | |
1086 | int source = -1; | |
1087 | int dest = 0; | |
1088 | ||
1089 | for_each_node_mask(s, tmp) { | |
1090 | ||
1091 | /* | |
1092 | * do_migrate_pages() tries to maintain the relative | |
1093 | * node relationship of the pages established between | |
1094 | * threads and memory areas. | |
1095 | * | |
1096 | * However if the number of source nodes is not equal to | |
1097 | * the number of destination nodes we can not preserve | |
1098 | * this node relative relationship. In that case, skip | |
1099 | * copying memory from a node that is in the destination | |
1100 | * mask. | |
1101 | * | |
1102 | * Example: [2,3,4] -> [3,4,5] moves everything. | |
1103 | * [0-7] - > [3,4,5] moves only 0,1,2,6,7. | |
1104 | */ | |
1105 | ||
1106 | if ((nodes_weight(*from) != nodes_weight(*to)) && | |
1107 | (node_isset(s, *to))) | |
1108 | continue; | |
1109 | ||
1110 | d = node_remap(s, *from, *to); | |
1111 | if (s == d) | |
1112 | continue; | |
1113 | ||
1114 | source = s; /* Node moved. Memorize */ | |
1115 | dest = d; | |
1116 | ||
1117 | /* dest not in remaining from nodes? */ | |
1118 | if (!node_isset(dest, tmp)) | |
1119 | break; | |
1120 | } | |
1121 | if (source == -1) | |
1122 | break; | |
1123 | ||
1124 | node_clear(source, tmp); | |
1125 | err = migrate_to_node(mm, source, dest, flags); | |
1126 | if (err > 0) | |
1127 | busy += err; | |
1128 | if (err < 0) | |
1129 | break; | |
1130 | } | |
1131 | out: | |
1132 | up_read(&mm->mmap_sem); | |
1133 | if (err < 0) | |
1134 | return err; | |
1135 | return busy; | |
1136 | ||
1137 | } | |
1138 | ||
1139 | /* | |
1140 | * Allocate a new page for page migration based on vma policy. | |
1141 | * Start assuming that page is mapped by vma pointed to by @private. | |
1142 | * Search forward from there, if not. N.B., this assumes that the | |
1143 | * list of pages handed to migrate_pages()--which is how we get here-- | |
1144 | * is in virtual address order. | |
1145 | */ | |
1146 | static struct page *new_vma_page(struct page *page, unsigned long private, int **x) | |
1147 | { | |
1148 | struct vm_area_struct *vma = (struct vm_area_struct *)private; | |
1149 | unsigned long uninitialized_var(address); | |
1150 | ||
1151 | while (vma) { | |
1152 | address = page_address_in_vma(page, vma); | |
1153 | if (address != -EFAULT) | |
1154 | break; | |
1155 | vma = vma->vm_next; | |
1156 | } | |
1157 | ||
1158 | /* | |
1159 | * if !vma, alloc_page_vma() will use task or system default policy | |
1160 | */ | |
1161 | return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); | |
1162 | } | |
1163 | #else | |
1164 | ||
1165 | static void migrate_page_add(struct page *page, struct list_head *pagelist, | |
1166 | unsigned long flags) | |
1167 | { | |
1168 | } | |
1169 | ||
1170 | int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, | |
1171 | const nodemask_t *to, int flags) | |
1172 | { | |
1173 | return -ENOSYS; | |
1174 | } | |
1175 | ||
1176 | static struct page *new_vma_page(struct page *page, unsigned long private, int **x) | |
1177 | { | |
1178 | return NULL; | |
1179 | } | |
1180 | #endif | |
1181 | ||
1182 | static long do_mbind(unsigned long start, unsigned long len, | |
1183 | unsigned short mode, unsigned short mode_flags, | |
1184 | nodemask_t *nmask, unsigned long flags) | |
1185 | { | |
1186 | struct vm_area_struct *vma; | |
1187 | struct mm_struct *mm = current->mm; | |
1188 | struct mempolicy *new; | |
1189 | unsigned long end; | |
1190 | int err; | |
1191 | LIST_HEAD(pagelist); | |
1192 | ||
1193 | if (flags & ~(unsigned long)MPOL_MF_VALID) | |
1194 | return -EINVAL; | |
1195 | if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE)) | |
1196 | return -EPERM; | |
1197 | ||
1198 | if (start & ~PAGE_MASK) | |
1199 | return -EINVAL; | |
1200 | ||
1201 | if (mode == MPOL_DEFAULT) | |
1202 | flags &= ~MPOL_MF_STRICT; | |
1203 | ||
1204 | len = (len + PAGE_SIZE - 1) & PAGE_MASK; | |
1205 | end = start + len; | |
1206 | ||
1207 | if (end < start) | |
1208 | return -EINVAL; | |
1209 | if (end == start) | |
1210 | return 0; | |
1211 | ||
1212 | new = mpol_new(mode, mode_flags, nmask); | |
1213 | if (IS_ERR(new)) | |
1214 | return PTR_ERR(new); | |
1215 | ||
1216 | if (flags & MPOL_MF_LAZY) | |
1217 | new->flags |= MPOL_F_MOF; | |
1218 | ||
1219 | /* | |
1220 | * If we are using the default policy then operation | |
1221 | * on discontinuous address spaces is okay after all | |
1222 | */ | |
1223 | if (!new) | |
1224 | flags |= MPOL_MF_DISCONTIG_OK; | |
1225 | ||
1226 | pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n", | |
1227 | start, start + len, mode, mode_flags, | |
1228 | nmask ? nodes_addr(*nmask)[0] : NUMA_NO_NODE); | |
1229 | ||
1230 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { | |
1231 | ||
1232 | err = migrate_prep(); | |
1233 | if (err) | |
1234 | goto mpol_out; | |
1235 | } | |
1236 | { | |
1237 | NODEMASK_SCRATCH(scratch); | |
1238 | if (scratch) { | |
1239 | down_write(&mm->mmap_sem); | |
1240 | task_lock(current); | |
1241 | err = mpol_set_nodemask(new, nmask, scratch); | |
1242 | task_unlock(current); | |
1243 | if (err) | |
1244 | up_write(&mm->mmap_sem); | |
1245 | } else | |
1246 | err = -ENOMEM; | |
1247 | NODEMASK_SCRATCH_FREE(scratch); | |
1248 | } | |
1249 | if (err) | |
1250 | goto mpol_out; | |
1251 | ||
1252 | vma = check_range(mm, start, end, nmask, | |
1253 | flags | MPOL_MF_INVERT, &pagelist); | |
1254 | ||
1255 | err = PTR_ERR(vma); /* maybe ... */ | |
1256 | if (!IS_ERR(vma)) | |
1257 | err = mbind_range(mm, start, end, new); | |
1258 | ||
1259 | if (!err) { | |
1260 | int nr_failed = 0; | |
1261 | ||
1262 | if (!list_empty(&pagelist)) { | |
1263 | WARN_ON_ONCE(flags & MPOL_MF_LAZY); | |
1264 | nr_failed = migrate_pages(&pagelist, new_vma_page, | |
1265 | (unsigned long)vma, | |
1266 | MIGRATE_SYNC, MR_MEMPOLICY_MBIND); | |
1267 | if (nr_failed) | |
1268 | putback_lru_pages(&pagelist); | |
1269 | } | |
1270 | ||
1271 | if (nr_failed && (flags & MPOL_MF_STRICT)) | |
1272 | err = -EIO; | |
1273 | } else | |
1274 | putback_lru_pages(&pagelist); | |
1275 | ||
1276 | up_write(&mm->mmap_sem); | |
1277 | mpol_out: | |
1278 | mpol_put(new); | |
1279 | return err; | |
1280 | } | |
1281 | ||
1282 | /* | |
1283 | * User space interface with variable sized bitmaps for nodelists. | |
1284 | */ | |
1285 | ||
1286 | /* Copy a node mask from user space. */ | |
1287 | static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask, | |
1288 | unsigned long maxnode) | |
1289 | { | |
1290 | unsigned long k; | |
1291 | unsigned long nlongs; | |
1292 | unsigned long endmask; | |
1293 | ||
1294 | --maxnode; | |
1295 | nodes_clear(*nodes); | |
1296 | if (maxnode == 0 || !nmask) | |
1297 | return 0; | |
1298 | if (maxnode > PAGE_SIZE*BITS_PER_BYTE) | |
1299 | return -EINVAL; | |
1300 | ||
1301 | nlongs = BITS_TO_LONGS(maxnode); | |
1302 | if ((maxnode % BITS_PER_LONG) == 0) | |
1303 | endmask = ~0UL; | |
1304 | else | |
1305 | endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1; | |
1306 | ||
1307 | /* When the user specified more nodes than supported just check | |
1308 | if the non supported part is all zero. */ | |
1309 | if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) { | |
1310 | if (nlongs > PAGE_SIZE/sizeof(long)) | |
1311 | return -EINVAL; | |
1312 | for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) { | |
1313 | unsigned long t; | |
1314 | if (get_user(t, nmask + k)) | |
1315 | return -EFAULT; | |
1316 | if (k == nlongs - 1) { | |
1317 | if (t & endmask) | |
1318 | return -EINVAL; | |
1319 | } else if (t) | |
1320 | return -EINVAL; | |
1321 | } | |
1322 | nlongs = BITS_TO_LONGS(MAX_NUMNODES); | |
1323 | endmask = ~0UL; | |
1324 | } | |
1325 | ||
1326 | if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long))) | |
1327 | return -EFAULT; | |
1328 | nodes_addr(*nodes)[nlongs-1] &= endmask; | |
1329 | return 0; | |
1330 | } | |
1331 | ||
1332 | /* Copy a kernel node mask to user space */ | |
1333 | static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, | |
1334 | nodemask_t *nodes) | |
1335 | { | |
1336 | unsigned long copy = ALIGN(maxnode-1, 64) / 8; | |
1337 | const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long); | |
1338 | ||
1339 | if (copy > nbytes) { | |
1340 | if (copy > PAGE_SIZE) | |
1341 | return -EINVAL; | |
1342 | if (clear_user((char __user *)mask + nbytes, copy - nbytes)) | |
1343 | return -EFAULT; | |
1344 | copy = nbytes; | |
1345 | } | |
1346 | return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0; | |
1347 | } | |
1348 | ||
1349 | SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len, | |
1350 | unsigned long, mode, unsigned long __user *, nmask, | |
1351 | unsigned long, maxnode, unsigned, flags) | |
1352 | { | |
1353 | nodemask_t nodes; | |
1354 | int err; | |
1355 | unsigned short mode_flags; | |
1356 | ||
1357 | mode_flags = mode & MPOL_MODE_FLAGS; | |
1358 | mode &= ~MPOL_MODE_FLAGS; | |
1359 | if (mode >= MPOL_MAX) | |
1360 | return -EINVAL; | |
1361 | if ((mode_flags & MPOL_F_STATIC_NODES) && | |
1362 | (mode_flags & MPOL_F_RELATIVE_NODES)) | |
1363 | return -EINVAL; | |
1364 | err = get_nodes(&nodes, nmask, maxnode); | |
1365 | if (err) | |
1366 | return err; | |
1367 | return do_mbind(start, len, mode, mode_flags, &nodes, flags); | |
1368 | } | |
1369 | ||
1370 | /* Set the process memory policy */ | |
1371 | SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask, | |
1372 | unsigned long, maxnode) | |
1373 | { | |
1374 | int err; | |
1375 | nodemask_t nodes; | |
1376 | unsigned short flags; | |
1377 | ||
1378 | flags = mode & MPOL_MODE_FLAGS; | |
1379 | mode &= ~MPOL_MODE_FLAGS; | |
1380 | if ((unsigned int)mode >= MPOL_MAX) | |
1381 | return -EINVAL; | |
1382 | if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES)) | |
1383 | return -EINVAL; | |
1384 | err = get_nodes(&nodes, nmask, maxnode); | |
1385 | if (err) | |
1386 | return err; | |
1387 | return do_set_mempolicy(mode, flags, &nodes); | |
1388 | } | |
1389 | ||
1390 | SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, | |
1391 | const unsigned long __user *, old_nodes, | |
1392 | const unsigned long __user *, new_nodes) | |
1393 | { | |
1394 | const struct cred *cred = current_cred(), *tcred; | |
1395 | struct mm_struct *mm = NULL; | |
1396 | struct task_struct *task; | |
1397 | nodemask_t task_nodes; | |
1398 | int err; | |
1399 | nodemask_t *old; | |
1400 | nodemask_t *new; | |
1401 | NODEMASK_SCRATCH(scratch); | |
1402 | ||
1403 | if (!scratch) | |
1404 | return -ENOMEM; | |
1405 | ||
1406 | old = &scratch->mask1; | |
1407 | new = &scratch->mask2; | |
1408 | ||
1409 | err = get_nodes(old, old_nodes, maxnode); | |
1410 | if (err) | |
1411 | goto out; | |
1412 | ||
1413 | err = get_nodes(new, new_nodes, maxnode); | |
1414 | if (err) | |
1415 | goto out; | |
1416 | ||
1417 | /* Find the mm_struct */ | |
1418 | rcu_read_lock(); | |
1419 | task = pid ? find_task_by_vpid(pid) : current; | |
1420 | if (!task) { | |
1421 | rcu_read_unlock(); | |
1422 | err = -ESRCH; | |
1423 | goto out; | |
1424 | } | |
1425 | get_task_struct(task); | |
1426 | ||
1427 | err = -EINVAL; | |
1428 | ||
1429 | /* | |
1430 | * Check if this process has the right to modify the specified | |
1431 | * process. The right exists if the process has administrative | |
1432 | * capabilities, superuser privileges or the same | |
1433 | * userid as the target process. | |
1434 | */ | |
1435 | tcred = __task_cred(task); | |
1436 | if (!uid_eq(cred->euid, tcred->suid) && !uid_eq(cred->euid, tcred->uid) && | |
1437 | !uid_eq(cred->uid, tcred->suid) && !uid_eq(cred->uid, tcred->uid) && | |
1438 | !capable(CAP_SYS_NICE)) { | |
1439 | rcu_read_unlock(); | |
1440 | err = -EPERM; | |
1441 | goto out_put; | |
1442 | } | |
1443 | rcu_read_unlock(); | |
1444 | ||
1445 | task_nodes = cpuset_mems_allowed(task); | |
1446 | /* Is the user allowed to access the target nodes? */ | |
1447 | if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) { | |
1448 | err = -EPERM; | |
1449 | goto out_put; | |
1450 | } | |
1451 | ||
1452 | if (!nodes_subset(*new, node_states[N_MEMORY])) { | |
1453 | err = -EINVAL; | |
1454 | goto out_put; | |
1455 | } | |
1456 | ||
1457 | err = security_task_movememory(task); | |
1458 | if (err) | |
1459 | goto out_put; | |
1460 | ||
1461 | mm = get_task_mm(task); | |
1462 | put_task_struct(task); | |
1463 | ||
1464 | if (!mm) { | |
1465 | err = -EINVAL; | |
1466 | goto out; | |
1467 | } | |
1468 | ||
1469 | err = do_migrate_pages(mm, old, new, | |
1470 | capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE); | |
1471 | ||
1472 | mmput(mm); | |
1473 | out: | |
1474 | NODEMASK_SCRATCH_FREE(scratch); | |
1475 | ||
1476 | return err; | |
1477 | ||
1478 | out_put: | |
1479 | put_task_struct(task); | |
1480 | goto out; | |
1481 | ||
1482 | } | |
1483 | ||
1484 | ||
1485 | /* Retrieve NUMA policy */ | |
1486 | SYSCALL_DEFINE5(get_mempolicy, int __user *, policy, | |
1487 | unsigned long __user *, nmask, unsigned long, maxnode, | |
1488 | unsigned long, addr, unsigned long, flags) | |
1489 | { | |
1490 | int err; | |
1491 | int uninitialized_var(pval); | |
1492 | nodemask_t nodes; | |
1493 | ||
1494 | if (nmask != NULL && maxnode < MAX_NUMNODES) | |
1495 | return -EINVAL; | |
1496 | ||
1497 | err = do_get_mempolicy(&pval, &nodes, addr, flags); | |
1498 | ||
1499 | if (err) | |
1500 | return err; | |
1501 | ||
1502 | if (policy && put_user(pval, policy)) | |
1503 | return -EFAULT; | |
1504 | ||
1505 | if (nmask) | |
1506 | err = copy_nodes_to_user(nmask, maxnode, &nodes); | |
1507 | ||
1508 | return err; | |
1509 | } | |
1510 | ||
1511 | #ifdef CONFIG_COMPAT | |
1512 | ||
1513 | asmlinkage long compat_sys_get_mempolicy(int __user *policy, | |
1514 | compat_ulong_t __user *nmask, | |
1515 | compat_ulong_t maxnode, | |
1516 | compat_ulong_t addr, compat_ulong_t flags) | |
1517 | { | |
1518 | long err; | |
1519 | unsigned long __user *nm = NULL; | |
1520 | unsigned long nr_bits, alloc_size; | |
1521 | DECLARE_BITMAP(bm, MAX_NUMNODES); | |
1522 | ||
1523 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
1524 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
1525 | ||
1526 | if (nmask) | |
1527 | nm = compat_alloc_user_space(alloc_size); | |
1528 | ||
1529 | err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags); | |
1530 | ||
1531 | if (!err && nmask) { | |
1532 | unsigned long copy_size; | |
1533 | copy_size = min_t(unsigned long, sizeof(bm), alloc_size); | |
1534 | err = copy_from_user(bm, nm, copy_size); | |
1535 | /* ensure entire bitmap is zeroed */ | |
1536 | err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8); | |
1537 | err |= compat_put_bitmap(nmask, bm, nr_bits); | |
1538 | } | |
1539 | ||
1540 | return err; | |
1541 | } | |
1542 | ||
1543 | asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask, | |
1544 | compat_ulong_t maxnode) | |
1545 | { | |
1546 | long err = 0; | |
1547 | unsigned long __user *nm = NULL; | |
1548 | unsigned long nr_bits, alloc_size; | |
1549 | DECLARE_BITMAP(bm, MAX_NUMNODES); | |
1550 | ||
1551 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
1552 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
1553 | ||
1554 | if (nmask) { | |
1555 | err = compat_get_bitmap(bm, nmask, nr_bits); | |
1556 | nm = compat_alloc_user_space(alloc_size); | |
1557 | err |= copy_to_user(nm, bm, alloc_size); | |
1558 | } | |
1559 | ||
1560 | if (err) | |
1561 | return -EFAULT; | |
1562 | ||
1563 | return sys_set_mempolicy(mode, nm, nr_bits+1); | |
1564 | } | |
1565 | ||
1566 | asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len, | |
1567 | compat_ulong_t mode, compat_ulong_t __user *nmask, | |
1568 | compat_ulong_t maxnode, compat_ulong_t flags) | |
1569 | { | |
1570 | long err = 0; | |
1571 | unsigned long __user *nm = NULL; | |
1572 | unsigned long nr_bits, alloc_size; | |
1573 | nodemask_t bm; | |
1574 | ||
1575 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
1576 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
1577 | ||
1578 | if (nmask) { | |
1579 | err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits); | |
1580 | nm = compat_alloc_user_space(alloc_size); | |
1581 | err |= copy_to_user(nm, nodes_addr(bm), alloc_size); | |
1582 | } | |
1583 | ||
1584 | if (err) | |
1585 | return -EFAULT; | |
1586 | ||
1587 | return sys_mbind(start, len, mode, nm, nr_bits+1, flags); | |
1588 | } | |
1589 | ||
1590 | #endif | |
1591 | ||
1592 | /* | |
1593 | * get_vma_policy(@task, @vma, @addr) | |
1594 | * @task - task for fallback if vma policy == default | |
1595 | * @vma - virtual memory area whose policy is sought | |
1596 | * @addr - address in @vma for shared policy lookup | |
1597 | * | |
1598 | * Returns effective policy for a VMA at specified address. | |
1599 | * Falls back to @task or system default policy, as necessary. | |
1600 | * Current or other task's task mempolicy and non-shared vma policies must be | |
1601 | * protected by task_lock(task) by the caller. | |
1602 | * Shared policies [those marked as MPOL_F_SHARED] require an extra reference | |
1603 | * count--added by the get_policy() vm_op, as appropriate--to protect against | |
1604 | * freeing by another task. It is the caller's responsibility to free the | |
1605 | * extra reference for shared policies. | |
1606 | */ | |
1607 | struct mempolicy *get_vma_policy(struct task_struct *task, | |
1608 | struct vm_area_struct *vma, unsigned long addr) | |
1609 | { | |
1610 | struct mempolicy *pol = get_task_policy(task); | |
1611 | ||
1612 | if (vma) { | |
1613 | if (vma->vm_ops && vma->vm_ops->get_policy) { | |
1614 | struct mempolicy *vpol = vma->vm_ops->get_policy(vma, | |
1615 | addr); | |
1616 | if (vpol) | |
1617 | pol = vpol; | |
1618 | } else if (vma->vm_policy) { | |
1619 | pol = vma->vm_policy; | |
1620 | ||
1621 | /* | |
1622 | * shmem_alloc_page() passes MPOL_F_SHARED policy with | |
1623 | * a pseudo vma whose vma->vm_ops=NULL. Take a reference | |
1624 | * count on these policies which will be dropped by | |
1625 | * mpol_cond_put() later | |
1626 | */ | |
1627 | if (mpol_needs_cond_ref(pol)) | |
1628 | mpol_get(pol); | |
1629 | } | |
1630 | } | |
1631 | if (!pol) | |
1632 | pol = &default_policy; | |
1633 | return pol; | |
1634 | } | |
1635 | ||
1636 | static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone) | |
1637 | { | |
1638 | enum zone_type dynamic_policy_zone = policy_zone; | |
1639 | ||
1640 | BUG_ON(dynamic_policy_zone == ZONE_MOVABLE); | |
1641 | ||
1642 | /* | |
1643 | * if policy->v.nodes has movable memory only, | |
1644 | * we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only. | |
1645 | * | |
1646 | * policy->v.nodes is intersect with node_states[N_MEMORY]. | |
1647 | * so if the following test faile, it implies | |
1648 | * policy->v.nodes has movable memory only. | |
1649 | */ | |
1650 | if (!nodes_intersects(policy->v.nodes, node_states[N_HIGH_MEMORY])) | |
1651 | dynamic_policy_zone = ZONE_MOVABLE; | |
1652 | ||
1653 | return zone >= dynamic_policy_zone; | |
1654 | } | |
1655 | ||
1656 | /* | |
1657 | * Return a nodemask representing a mempolicy for filtering nodes for | |
1658 | * page allocation | |
1659 | */ | |
1660 | static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy) | |
1661 | { | |
1662 | /* Lower zones don't get a nodemask applied for MPOL_BIND */ | |
1663 | if (unlikely(policy->mode == MPOL_BIND) && | |
1664 | apply_policy_zone(policy, gfp_zone(gfp)) && | |
1665 | cpuset_nodemask_valid_mems_allowed(&policy->v.nodes)) | |
1666 | return &policy->v.nodes; | |
1667 | ||
1668 | return NULL; | |
1669 | } | |
1670 | ||
1671 | /* Return a zonelist indicated by gfp for node representing a mempolicy */ | |
1672 | static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy, | |
1673 | int nd) | |
1674 | { | |
1675 | switch (policy->mode) { | |
1676 | case MPOL_PREFERRED: | |
1677 | if (!(policy->flags & MPOL_F_LOCAL)) | |
1678 | nd = policy->v.preferred_node; | |
1679 | break; | |
1680 | case MPOL_BIND: | |
1681 | /* | |
1682 | * Normally, MPOL_BIND allocations are node-local within the | |
1683 | * allowed nodemask. However, if __GFP_THISNODE is set and the | |
1684 | * current node isn't part of the mask, we use the zonelist for | |
1685 | * the first node in the mask instead. | |
1686 | */ | |
1687 | if (unlikely(gfp & __GFP_THISNODE) && | |
1688 | unlikely(!node_isset(nd, policy->v.nodes))) | |
1689 | nd = first_node(policy->v.nodes); | |
1690 | break; | |
1691 | default: | |
1692 | BUG(); | |
1693 | } | |
1694 | return node_zonelist(nd, gfp); | |
1695 | } | |
1696 | ||
1697 | /* Do dynamic interleaving for a process */ | |
1698 | static unsigned interleave_nodes(struct mempolicy *policy) | |
1699 | { | |
1700 | unsigned nid, next; | |
1701 | struct task_struct *me = current; | |
1702 | ||
1703 | nid = me->il_next; | |
1704 | next = next_node(nid, policy->v.nodes); | |
1705 | if (next >= MAX_NUMNODES) | |
1706 | next = first_node(policy->v.nodes); | |
1707 | if (next < MAX_NUMNODES) | |
1708 | me->il_next = next; | |
1709 | return nid; | |
1710 | } | |
1711 | ||
1712 | /* | |
1713 | * Depending on the memory policy provide a node from which to allocate the | |
1714 | * next slab entry. | |
1715 | * @policy must be protected by freeing by the caller. If @policy is | |
1716 | * the current task's mempolicy, this protection is implicit, as only the | |
1717 | * task can change it's policy. The system default policy requires no | |
1718 | * such protection. | |
1719 | */ | |
1720 | unsigned slab_node(void) | |
1721 | { | |
1722 | struct mempolicy *policy; | |
1723 | ||
1724 | if (in_interrupt()) | |
1725 | return numa_node_id(); | |
1726 | ||
1727 | policy = current->mempolicy; | |
1728 | if (!policy || policy->flags & MPOL_F_LOCAL) | |
1729 | return numa_node_id(); | |
1730 | ||
1731 | switch (policy->mode) { | |
1732 | case MPOL_PREFERRED: | |
1733 | /* | |
1734 | * handled MPOL_F_LOCAL above | |
1735 | */ | |
1736 | return policy->v.preferred_node; | |
1737 | ||
1738 | case MPOL_INTERLEAVE: | |
1739 | return interleave_nodes(policy); | |
1740 | ||
1741 | case MPOL_BIND: { | |
1742 | /* | |
1743 | * Follow bind policy behavior and start allocation at the | |
1744 | * first node. | |
1745 | */ | |
1746 | struct zonelist *zonelist; | |
1747 | struct zone *zone; | |
1748 | enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL); | |
1749 | zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0]; | |
1750 | (void)first_zones_zonelist(zonelist, highest_zoneidx, | |
1751 | &policy->v.nodes, | |
1752 | &zone); | |
1753 | return zone ? zone->node : numa_node_id(); | |
1754 | } | |
1755 | ||
1756 | default: | |
1757 | BUG(); | |
1758 | } | |
1759 | } | |
1760 | ||
1761 | /* Do static interleaving for a VMA with known offset. */ | |
1762 | static unsigned offset_il_node(struct mempolicy *pol, | |
1763 | struct vm_area_struct *vma, unsigned long off) | |
1764 | { | |
1765 | unsigned nnodes = nodes_weight(pol->v.nodes); | |
1766 | unsigned target; | |
1767 | int c; | |
1768 | int nid = -1; | |
1769 | ||
1770 | if (!nnodes) | |
1771 | return numa_node_id(); | |
1772 | target = (unsigned int)off % nnodes; | |
1773 | c = 0; | |
1774 | do { | |
1775 | nid = next_node(nid, pol->v.nodes); | |
1776 | c++; | |
1777 | } while (c <= target); | |
1778 | return nid; | |
1779 | } | |
1780 | ||
1781 | /* Determine a node number for interleave */ | |
1782 | static inline unsigned interleave_nid(struct mempolicy *pol, | |
1783 | struct vm_area_struct *vma, unsigned long addr, int shift) | |
1784 | { | |
1785 | if (vma) { | |
1786 | unsigned long off; | |
1787 | ||
1788 | /* | |
1789 | * for small pages, there is no difference between | |
1790 | * shift and PAGE_SHIFT, so the bit-shift is safe. | |
1791 | * for huge pages, since vm_pgoff is in units of small | |
1792 | * pages, we need to shift off the always 0 bits to get | |
1793 | * a useful offset. | |
1794 | */ | |
1795 | BUG_ON(shift < PAGE_SHIFT); | |
1796 | off = vma->vm_pgoff >> (shift - PAGE_SHIFT); | |
1797 | off += (addr - vma->vm_start) >> shift; | |
1798 | return offset_il_node(pol, vma, off); | |
1799 | } else | |
1800 | return interleave_nodes(pol); | |
1801 | } | |
1802 | ||
1803 | /* | |
1804 | * Return the bit number of a random bit set in the nodemask. | |
1805 | * (returns -1 if nodemask is empty) | |
1806 | */ | |
1807 | int node_random(const nodemask_t *maskp) | |
1808 | { | |
1809 | int w, bit = -1; | |
1810 | ||
1811 | w = nodes_weight(*maskp); | |
1812 | if (w) | |
1813 | bit = bitmap_ord_to_pos(maskp->bits, | |
1814 | get_random_int() % w, MAX_NUMNODES); | |
1815 | return bit; | |
1816 | } | |
1817 | ||
1818 | #ifdef CONFIG_HUGETLBFS | |
1819 | /* | |
1820 | * huge_zonelist(@vma, @addr, @gfp_flags, @mpol) | |
1821 | * @vma = virtual memory area whose policy is sought | |
1822 | * @addr = address in @vma for shared policy lookup and interleave policy | |
1823 | * @gfp_flags = for requested zone | |
1824 | * @mpol = pointer to mempolicy pointer for reference counted mempolicy | |
1825 | * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask | |
1826 | * | |
1827 | * Returns a zonelist suitable for a huge page allocation and a pointer | |
1828 | * to the struct mempolicy for conditional unref after allocation. | |
1829 | * If the effective policy is 'BIND, returns a pointer to the mempolicy's | |
1830 | * @nodemask for filtering the zonelist. | |
1831 | * | |
1832 | * Must be protected by get_mems_allowed() | |
1833 | */ | |
1834 | struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr, | |
1835 | gfp_t gfp_flags, struct mempolicy **mpol, | |
1836 | nodemask_t **nodemask) | |
1837 | { | |
1838 | struct zonelist *zl; | |
1839 | ||
1840 | *mpol = get_vma_policy(current, vma, addr); | |
1841 | *nodemask = NULL; /* assume !MPOL_BIND */ | |
1842 | ||
1843 | if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) { | |
1844 | zl = node_zonelist(interleave_nid(*mpol, vma, addr, | |
1845 | huge_page_shift(hstate_vma(vma))), gfp_flags); | |
1846 | } else { | |
1847 | zl = policy_zonelist(gfp_flags, *mpol, numa_node_id()); | |
1848 | if ((*mpol)->mode == MPOL_BIND) | |
1849 | *nodemask = &(*mpol)->v.nodes; | |
1850 | } | |
1851 | return zl; | |
1852 | } | |
1853 | ||
1854 | /* | |
1855 | * init_nodemask_of_mempolicy | |
1856 | * | |
1857 | * If the current task's mempolicy is "default" [NULL], return 'false' | |
1858 | * to indicate default policy. Otherwise, extract the policy nodemask | |
1859 | * for 'bind' or 'interleave' policy into the argument nodemask, or | |
1860 | * initialize the argument nodemask to contain the single node for | |
1861 | * 'preferred' or 'local' policy and return 'true' to indicate presence | |
1862 | * of non-default mempolicy. | |
1863 | * | |
1864 | * We don't bother with reference counting the mempolicy [mpol_get/put] | |
1865 | * because the current task is examining it's own mempolicy and a task's | |
1866 | * mempolicy is only ever changed by the task itself. | |
1867 | * | |
1868 | * N.B., it is the caller's responsibility to free a returned nodemask. | |
1869 | */ | |
1870 | bool init_nodemask_of_mempolicy(nodemask_t *mask) | |
1871 | { | |
1872 | struct mempolicy *mempolicy; | |
1873 | int nid; | |
1874 | ||
1875 | if (!(mask && current->mempolicy)) | |
1876 | return false; | |
1877 | ||
1878 | task_lock(current); | |
1879 | mempolicy = current->mempolicy; | |
1880 | switch (mempolicy->mode) { | |
1881 | case MPOL_PREFERRED: | |
1882 | if (mempolicy->flags & MPOL_F_LOCAL) | |
1883 | nid = numa_node_id(); | |
1884 | else | |
1885 | nid = mempolicy->v.preferred_node; | |
1886 | init_nodemask_of_node(mask, nid); | |
1887 | break; | |
1888 | ||
1889 | case MPOL_BIND: | |
1890 | /* Fall through */ | |
1891 | case MPOL_INTERLEAVE: | |
1892 | *mask = mempolicy->v.nodes; | |
1893 | break; | |
1894 | ||
1895 | default: | |
1896 | BUG(); | |
1897 | } | |
1898 | task_unlock(current); | |
1899 | ||
1900 | return true; | |
1901 | } | |
1902 | #endif | |
1903 | ||
1904 | /* | |
1905 | * mempolicy_nodemask_intersects | |
1906 | * | |
1907 | * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default | |
1908 | * policy. Otherwise, check for intersection between mask and the policy | |
1909 | * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local' | |
1910 | * policy, always return true since it may allocate elsewhere on fallback. | |
1911 | * | |
1912 | * Takes task_lock(tsk) to prevent freeing of its mempolicy. | |
1913 | */ | |
1914 | bool mempolicy_nodemask_intersects(struct task_struct *tsk, | |
1915 | const nodemask_t *mask) | |
1916 | { | |
1917 | struct mempolicy *mempolicy; | |
1918 | bool ret = true; | |
1919 | ||
1920 | if (!mask) | |
1921 | return ret; | |
1922 | task_lock(tsk); | |
1923 | mempolicy = tsk->mempolicy; | |
1924 | if (!mempolicy) | |
1925 | goto out; | |
1926 | ||
1927 | switch (mempolicy->mode) { | |
1928 | case MPOL_PREFERRED: | |
1929 | /* | |
1930 | * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to | |
1931 | * allocate from, they may fallback to other nodes when oom. | |
1932 | * Thus, it's possible for tsk to have allocated memory from | |
1933 | * nodes in mask. | |
1934 | */ | |
1935 | break; | |
1936 | case MPOL_BIND: | |
1937 | case MPOL_INTERLEAVE: | |
1938 | ret = nodes_intersects(mempolicy->v.nodes, *mask); | |
1939 | break; | |
1940 | default: | |
1941 | BUG(); | |
1942 | } | |
1943 | out: | |
1944 | task_unlock(tsk); | |
1945 | return ret; | |
1946 | } | |
1947 | ||
1948 | /* Allocate a page in interleaved policy. | |
1949 | Own path because it needs to do special accounting. */ | |
1950 | static struct page *alloc_page_interleave(gfp_t gfp, unsigned order, | |
1951 | unsigned nid) | |
1952 | { | |
1953 | struct zonelist *zl; | |
1954 | struct page *page; | |
1955 | ||
1956 | zl = node_zonelist(nid, gfp); | |
1957 | page = __alloc_pages(gfp, order, zl); | |
1958 | if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0])) | |
1959 | inc_zone_page_state(page, NUMA_INTERLEAVE_HIT); | |
1960 | return page; | |
1961 | } | |
1962 | ||
1963 | /** | |
1964 | * alloc_pages_vma - Allocate a page for a VMA. | |
1965 | * | |
1966 | * @gfp: | |
1967 | * %GFP_USER user allocation. | |
1968 | * %GFP_KERNEL kernel allocations, | |
1969 | * %GFP_HIGHMEM highmem/user allocations, | |
1970 | * %GFP_FS allocation should not call back into a file system. | |
1971 | * %GFP_ATOMIC don't sleep. | |
1972 | * | |
1973 | * @order:Order of the GFP allocation. | |
1974 | * @vma: Pointer to VMA or NULL if not available. | |
1975 | * @addr: Virtual Address of the allocation. Must be inside the VMA. | |
1976 | * | |
1977 | * This function allocates a page from the kernel page pool and applies | |
1978 | * a NUMA policy associated with the VMA or the current process. | |
1979 | * When VMA is not NULL caller must hold down_read on the mmap_sem of the | |
1980 | * mm_struct of the VMA to prevent it from going away. Should be used for | |
1981 | * all allocations for pages that will be mapped into | |
1982 | * user space. Returns NULL when no page can be allocated. | |
1983 | * | |
1984 | * Should be called with the mm_sem of the vma hold. | |
1985 | */ | |
1986 | struct page * | |
1987 | alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma, | |
1988 | unsigned long addr, int node) | |
1989 | { | |
1990 | struct mempolicy *pol; | |
1991 | struct page *page; | |
1992 | unsigned int cpuset_mems_cookie; | |
1993 | ||
1994 | retry_cpuset: | |
1995 | pol = get_vma_policy(current, vma, addr); | |
1996 | cpuset_mems_cookie = get_mems_allowed(); | |
1997 | ||
1998 | if (unlikely(pol->mode == MPOL_INTERLEAVE)) { | |
1999 | unsigned nid; | |
2000 | ||
2001 | nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order); | |
2002 | mpol_cond_put(pol); | |
2003 | page = alloc_page_interleave(gfp, order, nid); | |
2004 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) | |
2005 | goto retry_cpuset; | |
2006 | ||
2007 | return page; | |
2008 | } | |
2009 | page = __alloc_pages_nodemask(gfp, order, | |
2010 | policy_zonelist(gfp, pol, node), | |
2011 | policy_nodemask(gfp, pol)); | |
2012 | if (unlikely(mpol_needs_cond_ref(pol))) | |
2013 | __mpol_put(pol); | |
2014 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) | |
2015 | goto retry_cpuset; | |
2016 | return page; | |
2017 | } | |
2018 | ||
2019 | /** | |
2020 | * alloc_pages_current - Allocate pages. | |
2021 | * | |
2022 | * @gfp: | |
2023 | * %GFP_USER user allocation, | |
2024 | * %GFP_KERNEL kernel allocation, | |
2025 | * %GFP_HIGHMEM highmem allocation, | |
2026 | * %GFP_FS don't call back into a file system. | |
2027 | * %GFP_ATOMIC don't sleep. | |
2028 | * @order: Power of two of allocation size in pages. 0 is a single page. | |
2029 | * | |
2030 | * Allocate a page from the kernel page pool. When not in | |
2031 | * interrupt context and apply the current process NUMA policy. | |
2032 | * Returns NULL when no page can be allocated. | |
2033 | * | |
2034 | * Don't call cpuset_update_task_memory_state() unless | |
2035 | * 1) it's ok to take cpuset_sem (can WAIT), and | |
2036 | * 2) allocating for current task (not interrupt). | |
2037 | */ | |
2038 | struct page *alloc_pages_current(gfp_t gfp, unsigned order) | |
2039 | { | |
2040 | struct mempolicy *pol = get_task_policy(current); | |
2041 | struct page *page; | |
2042 | unsigned int cpuset_mems_cookie; | |
2043 | ||
2044 | if (!pol || in_interrupt() || (gfp & __GFP_THISNODE)) | |
2045 | pol = &default_policy; | |
2046 | ||
2047 | retry_cpuset: | |
2048 | cpuset_mems_cookie = get_mems_allowed(); | |
2049 | ||
2050 | /* | |
2051 | * No reference counting needed for current->mempolicy | |
2052 | * nor system default_policy | |
2053 | */ | |
2054 | if (pol->mode == MPOL_INTERLEAVE) | |
2055 | page = alloc_page_interleave(gfp, order, interleave_nodes(pol)); | |
2056 | else | |
2057 | page = __alloc_pages_nodemask(gfp, order, | |
2058 | policy_zonelist(gfp, pol, numa_node_id()), | |
2059 | policy_nodemask(gfp, pol)); | |
2060 | ||
2061 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) | |
2062 | goto retry_cpuset; | |
2063 | ||
2064 | return page; | |
2065 | } | |
2066 | EXPORT_SYMBOL(alloc_pages_current); | |
2067 | ||
2068 | /* | |
2069 | * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it | |
2070 | * rebinds the mempolicy its copying by calling mpol_rebind_policy() | |
2071 | * with the mems_allowed returned by cpuset_mems_allowed(). This | |
2072 | * keeps mempolicies cpuset relative after its cpuset moves. See | |
2073 | * further kernel/cpuset.c update_nodemask(). | |
2074 | * | |
2075 | * current's mempolicy may be rebinded by the other task(the task that changes | |
2076 | * cpuset's mems), so we needn't do rebind work for current task. | |
2077 | */ | |
2078 | ||
2079 | /* Slow path of a mempolicy duplicate */ | |
2080 | struct mempolicy *__mpol_dup(struct mempolicy *old) | |
2081 | { | |
2082 | struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL); | |
2083 | ||
2084 | if (!new) | |
2085 | return ERR_PTR(-ENOMEM); | |
2086 | ||
2087 | /* task's mempolicy is protected by alloc_lock */ | |
2088 | if (old == current->mempolicy) { | |
2089 | task_lock(current); | |
2090 | *new = *old; | |
2091 | task_unlock(current); | |
2092 | } else | |
2093 | *new = *old; | |
2094 | ||
2095 | rcu_read_lock(); | |
2096 | if (current_cpuset_is_being_rebound()) { | |
2097 | nodemask_t mems = cpuset_mems_allowed(current); | |
2098 | if (new->flags & MPOL_F_REBINDING) | |
2099 | mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2); | |
2100 | else | |
2101 | mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE); | |
2102 | } | |
2103 | rcu_read_unlock(); | |
2104 | atomic_set(&new->refcnt, 1); | |
2105 | return new; | |
2106 | } | |
2107 | ||
2108 | /* Slow path of a mempolicy comparison */ | |
2109 | bool __mpol_equal(struct mempolicy *a, struct mempolicy *b) | |
2110 | { | |
2111 | if (!a || !b) | |
2112 | return false; | |
2113 | if (a->mode != b->mode) | |
2114 | return false; | |
2115 | if (a->flags != b->flags) | |
2116 | return false; | |
2117 | if (mpol_store_user_nodemask(a)) | |
2118 | if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask)) | |
2119 | return false; | |
2120 | ||
2121 | switch (a->mode) { | |
2122 | case MPOL_BIND: | |
2123 | /* Fall through */ | |
2124 | case MPOL_INTERLEAVE: | |
2125 | return !!nodes_equal(a->v.nodes, b->v.nodes); | |
2126 | case MPOL_PREFERRED: | |
2127 | return a->v.preferred_node == b->v.preferred_node; | |
2128 | default: | |
2129 | BUG(); | |
2130 | return false; | |
2131 | } | |
2132 | } | |
2133 | ||
2134 | /* | |
2135 | * Shared memory backing store policy support. | |
2136 | * | |
2137 | * Remember policies even when nobody has shared memory mapped. | |
2138 | * The policies are kept in Red-Black tree linked from the inode. | |
2139 | * They are protected by the sp->lock spinlock, which should be held | |
2140 | * for any accesses to the tree. | |
2141 | */ | |
2142 | ||
2143 | /* lookup first element intersecting start-end */ | |
2144 | /* Caller holds sp->lock */ | |
2145 | static struct sp_node * | |
2146 | sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end) | |
2147 | { | |
2148 | struct rb_node *n = sp->root.rb_node; | |
2149 | ||
2150 | while (n) { | |
2151 | struct sp_node *p = rb_entry(n, struct sp_node, nd); | |
2152 | ||
2153 | if (start >= p->end) | |
2154 | n = n->rb_right; | |
2155 | else if (end <= p->start) | |
2156 | n = n->rb_left; | |
2157 | else | |
2158 | break; | |
2159 | } | |
2160 | if (!n) | |
2161 | return NULL; | |
2162 | for (;;) { | |
2163 | struct sp_node *w = NULL; | |
2164 | struct rb_node *prev = rb_prev(n); | |
2165 | if (!prev) | |
2166 | break; | |
2167 | w = rb_entry(prev, struct sp_node, nd); | |
2168 | if (w->end <= start) | |
2169 | break; | |
2170 | n = prev; | |
2171 | } | |
2172 | return rb_entry(n, struct sp_node, nd); | |
2173 | } | |
2174 | ||
2175 | /* Insert a new shared policy into the list. */ | |
2176 | /* Caller holds sp->lock */ | |
2177 | static void sp_insert(struct shared_policy *sp, struct sp_node *new) | |
2178 | { | |
2179 | struct rb_node **p = &sp->root.rb_node; | |
2180 | struct rb_node *parent = NULL; | |
2181 | struct sp_node *nd; | |
2182 | ||
2183 | while (*p) { | |
2184 | parent = *p; | |
2185 | nd = rb_entry(parent, struct sp_node, nd); | |
2186 | if (new->start < nd->start) | |
2187 | p = &(*p)->rb_left; | |
2188 | else if (new->end > nd->end) | |
2189 | p = &(*p)->rb_right; | |
2190 | else | |
2191 | BUG(); | |
2192 | } | |
2193 | rb_link_node(&new->nd, parent, p); | |
2194 | rb_insert_color(&new->nd, &sp->root); | |
2195 | pr_debug("inserting %lx-%lx: %d\n", new->start, new->end, | |
2196 | new->policy ? new->policy->mode : 0); | |
2197 | } | |
2198 | ||
2199 | /* Find shared policy intersecting idx */ | |
2200 | struct mempolicy * | |
2201 | mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx) | |
2202 | { | |
2203 | struct mempolicy *pol = NULL; | |
2204 | struct sp_node *sn; | |
2205 | ||
2206 | if (!sp->root.rb_node) | |
2207 | return NULL; | |
2208 | spin_lock(&sp->lock); | |
2209 | sn = sp_lookup(sp, idx, idx+1); | |
2210 | if (sn) { | |
2211 | mpol_get(sn->policy); | |
2212 | pol = sn->policy; | |
2213 | } | |
2214 | spin_unlock(&sp->lock); | |
2215 | return pol; | |
2216 | } | |
2217 | ||
2218 | static void sp_free(struct sp_node *n) | |
2219 | { | |
2220 | mpol_put(n->policy); | |
2221 | kmem_cache_free(sn_cache, n); | |
2222 | } | |
2223 | ||
2224 | /** | |
2225 | * mpol_misplaced - check whether current page node is valid in policy | |
2226 | * | |
2227 | * @page - page to be checked | |
2228 | * @vma - vm area where page mapped | |
2229 | * @addr - virtual address where page mapped | |
2230 | * | |
2231 | * Lookup current policy node id for vma,addr and "compare to" page's | |
2232 | * node id. | |
2233 | * | |
2234 | * Returns: | |
2235 | * -1 - not misplaced, page is in the right node | |
2236 | * node - node id where the page should be | |
2237 | * | |
2238 | * Policy determination "mimics" alloc_page_vma(). | |
2239 | * Called from fault path where we know the vma and faulting address. | |
2240 | */ | |
2241 | int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long addr) | |
2242 | { | |
2243 | struct mempolicy *pol; | |
2244 | struct zone *zone; | |
2245 | int curnid = page_to_nid(page); | |
2246 | unsigned long pgoff; | |
2247 | int polnid = -1; | |
2248 | int ret = -1; | |
2249 | ||
2250 | BUG_ON(!vma); | |
2251 | ||
2252 | pol = get_vma_policy(current, vma, addr); | |
2253 | if (!(pol->flags & MPOL_F_MOF)) | |
2254 | goto out; | |
2255 | ||
2256 | switch (pol->mode) { | |
2257 | case MPOL_INTERLEAVE: | |
2258 | BUG_ON(addr >= vma->vm_end); | |
2259 | BUG_ON(addr < vma->vm_start); | |
2260 | ||
2261 | pgoff = vma->vm_pgoff; | |
2262 | pgoff += (addr - vma->vm_start) >> PAGE_SHIFT; | |
2263 | polnid = offset_il_node(pol, vma, pgoff); | |
2264 | break; | |
2265 | ||
2266 | case MPOL_PREFERRED: | |
2267 | if (pol->flags & MPOL_F_LOCAL) | |
2268 | polnid = numa_node_id(); | |
2269 | else | |
2270 | polnid = pol->v.preferred_node; | |
2271 | break; | |
2272 | ||
2273 | case MPOL_BIND: | |
2274 | /* | |
2275 | * allows binding to multiple nodes. | |
2276 | * use current page if in policy nodemask, | |
2277 | * else select nearest allowed node, if any. | |
2278 | * If no allowed nodes, use current [!misplaced]. | |
2279 | */ | |
2280 | if (node_isset(curnid, pol->v.nodes)) | |
2281 | goto out; | |
2282 | (void)first_zones_zonelist( | |
2283 | node_zonelist(numa_node_id(), GFP_HIGHUSER), | |
2284 | gfp_zone(GFP_HIGHUSER), | |
2285 | &pol->v.nodes, &zone); | |
2286 | polnid = zone->node; | |
2287 | break; | |
2288 | ||
2289 | default: | |
2290 | BUG(); | |
2291 | } | |
2292 | ||
2293 | /* Migrate the page towards the node whose CPU is referencing it */ | |
2294 | if (pol->flags & MPOL_F_MORON) { | |
2295 | int last_nid; | |
2296 | ||
2297 | polnid = numa_node_id(); | |
2298 | ||
2299 | /* | |
2300 | * Multi-stage node selection is used in conjunction | |
2301 | * with a periodic migration fault to build a temporal | |
2302 | * task<->page relation. By using a two-stage filter we | |
2303 | * remove short/unlikely relations. | |
2304 | * | |
2305 | * Using P(p) ~ n_p / n_t as per frequentist | |
2306 | * probability, we can equate a task's usage of a | |
2307 | * particular page (n_p) per total usage of this | |
2308 | * page (n_t) (in a given time-span) to a probability. | |
2309 | * | |
2310 | * Our periodic faults will sample this probability and | |
2311 | * getting the same result twice in a row, given these | |
2312 | * samples are fully independent, is then given by | |
2313 | * P(n)^2, provided our sample period is sufficiently | |
2314 | * short compared to the usage pattern. | |
2315 | * | |
2316 | * This quadric squishes small probabilities, making | |
2317 | * it less likely we act on an unlikely task<->page | |
2318 | * relation. | |
2319 | */ | |
2320 | last_nid = page_nid_xchg_last(page, polnid); | |
2321 | if (last_nid != polnid) | |
2322 | goto out; | |
2323 | } | |
2324 | ||
2325 | if (curnid != polnid) | |
2326 | ret = polnid; | |
2327 | out: | |
2328 | mpol_cond_put(pol); | |
2329 | ||
2330 | return ret; | |
2331 | } | |
2332 | ||
2333 | static void sp_delete(struct shared_policy *sp, struct sp_node *n) | |
2334 | { | |
2335 | pr_debug("deleting %lx-l%lx\n", n->start, n->end); | |
2336 | rb_erase(&n->nd, &sp->root); | |
2337 | sp_free(n); | |
2338 | } | |
2339 | ||
2340 | static void sp_node_init(struct sp_node *node, unsigned long start, | |
2341 | unsigned long end, struct mempolicy *pol) | |
2342 | { | |
2343 | node->start = start; | |
2344 | node->end = end; | |
2345 | node->policy = pol; | |
2346 | } | |
2347 | ||
2348 | static struct sp_node *sp_alloc(unsigned long start, unsigned long end, | |
2349 | struct mempolicy *pol) | |
2350 | { | |
2351 | struct sp_node *n; | |
2352 | struct mempolicy *newpol; | |
2353 | ||
2354 | n = kmem_cache_alloc(sn_cache, GFP_KERNEL); | |
2355 | if (!n) | |
2356 | return NULL; | |
2357 | ||
2358 | newpol = mpol_dup(pol); | |
2359 | if (IS_ERR(newpol)) { | |
2360 | kmem_cache_free(sn_cache, n); | |
2361 | return NULL; | |
2362 | } | |
2363 | newpol->flags |= MPOL_F_SHARED; | |
2364 | sp_node_init(n, start, end, newpol); | |
2365 | ||
2366 | return n; | |
2367 | } | |
2368 | ||
2369 | /* Replace a policy range. */ | |
2370 | static int shared_policy_replace(struct shared_policy *sp, unsigned long start, | |
2371 | unsigned long end, struct sp_node *new) | |
2372 | { | |
2373 | struct sp_node *n; | |
2374 | struct sp_node *n_new = NULL; | |
2375 | struct mempolicy *mpol_new = NULL; | |
2376 | int ret = 0; | |
2377 | ||
2378 | restart: | |
2379 | spin_lock(&sp->lock); | |
2380 | n = sp_lookup(sp, start, end); | |
2381 | /* Take care of old policies in the same range. */ | |
2382 | while (n && n->start < end) { | |
2383 | struct rb_node *next = rb_next(&n->nd); | |
2384 | if (n->start >= start) { | |
2385 | if (n->end <= end) | |
2386 | sp_delete(sp, n); | |
2387 | else | |
2388 | n->start = end; | |
2389 | } else { | |
2390 | /* Old policy spanning whole new range. */ | |
2391 | if (n->end > end) { | |
2392 | if (!n_new) | |
2393 | goto alloc_new; | |
2394 | ||
2395 | *mpol_new = *n->policy; | |
2396 | atomic_set(&mpol_new->refcnt, 1); | |
2397 | sp_node_init(n_new, end, n->end, mpol_new); | |
2398 | n->end = start; | |
2399 | sp_insert(sp, n_new); | |
2400 | n_new = NULL; | |
2401 | mpol_new = NULL; | |
2402 | break; | |
2403 | } else | |
2404 | n->end = start; | |
2405 | } | |
2406 | if (!next) | |
2407 | break; | |
2408 | n = rb_entry(next, struct sp_node, nd); | |
2409 | } | |
2410 | if (new) | |
2411 | sp_insert(sp, new); | |
2412 | spin_unlock(&sp->lock); | |
2413 | ret = 0; | |
2414 | ||
2415 | err_out: | |
2416 | if (mpol_new) | |
2417 | mpol_put(mpol_new); | |
2418 | if (n_new) | |
2419 | kmem_cache_free(sn_cache, n_new); | |
2420 | ||
2421 | return ret; | |
2422 | ||
2423 | alloc_new: | |
2424 | spin_unlock(&sp->lock); | |
2425 | ret = -ENOMEM; | |
2426 | n_new = kmem_cache_alloc(sn_cache, GFP_KERNEL); | |
2427 | if (!n_new) | |
2428 | goto err_out; | |
2429 | mpol_new = kmem_cache_alloc(policy_cache, GFP_KERNEL); | |
2430 | if (!mpol_new) | |
2431 | goto err_out; | |
2432 | goto restart; | |
2433 | } | |
2434 | ||
2435 | /** | |
2436 | * mpol_shared_policy_init - initialize shared policy for inode | |
2437 | * @sp: pointer to inode shared policy | |
2438 | * @mpol: struct mempolicy to install | |
2439 | * | |
2440 | * Install non-NULL @mpol in inode's shared policy rb-tree. | |
2441 | * On entry, the current task has a reference on a non-NULL @mpol. | |
2442 | * This must be released on exit. | |
2443 | * This is called at get_inode() calls and we can use GFP_KERNEL. | |
2444 | */ | |
2445 | void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol) | |
2446 | { | |
2447 | int ret; | |
2448 | ||
2449 | sp->root = RB_ROOT; /* empty tree == default mempolicy */ | |
2450 | spin_lock_init(&sp->lock); | |
2451 | ||
2452 | if (mpol) { | |
2453 | struct vm_area_struct pvma; | |
2454 | struct mempolicy *new; | |
2455 | NODEMASK_SCRATCH(scratch); | |
2456 | ||
2457 | if (!scratch) | |
2458 | goto put_mpol; | |
2459 | /* contextualize the tmpfs mount point mempolicy */ | |
2460 | new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask); | |
2461 | if (IS_ERR(new)) | |
2462 | goto free_scratch; /* no valid nodemask intersection */ | |
2463 | ||
2464 | task_lock(current); | |
2465 | ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch); | |
2466 | task_unlock(current); | |
2467 | if (ret) | |
2468 | goto put_new; | |
2469 | ||
2470 | /* Create pseudo-vma that contains just the policy */ | |
2471 | memset(&pvma, 0, sizeof(struct vm_area_struct)); | |
2472 | pvma.vm_end = TASK_SIZE; /* policy covers entire file */ | |
2473 | mpol_set_shared_policy(sp, &pvma, new); /* adds ref */ | |
2474 | ||
2475 | put_new: | |
2476 | mpol_put(new); /* drop initial ref */ | |
2477 | free_scratch: | |
2478 | NODEMASK_SCRATCH_FREE(scratch); | |
2479 | put_mpol: | |
2480 | mpol_put(mpol); /* drop our incoming ref on sb mpol */ | |
2481 | } | |
2482 | } | |
2483 | ||
2484 | int mpol_set_shared_policy(struct shared_policy *info, | |
2485 | struct vm_area_struct *vma, struct mempolicy *npol) | |
2486 | { | |
2487 | int err; | |
2488 | struct sp_node *new = NULL; | |
2489 | unsigned long sz = vma_pages(vma); | |
2490 | ||
2491 | pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n", | |
2492 | vma->vm_pgoff, | |
2493 | sz, npol ? npol->mode : -1, | |
2494 | npol ? npol->flags : -1, | |
2495 | npol ? nodes_addr(npol->v.nodes)[0] : NUMA_NO_NODE); | |
2496 | ||
2497 | if (npol) { | |
2498 | new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol); | |
2499 | if (!new) | |
2500 | return -ENOMEM; | |
2501 | } | |
2502 | err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new); | |
2503 | if (err && new) | |
2504 | sp_free(new); | |
2505 | return err; | |
2506 | } | |
2507 | ||
2508 | /* Free a backing policy store on inode delete. */ | |
2509 | void mpol_free_shared_policy(struct shared_policy *p) | |
2510 | { | |
2511 | struct sp_node *n; | |
2512 | struct rb_node *next; | |
2513 | ||
2514 | if (!p->root.rb_node) | |
2515 | return; | |
2516 | spin_lock(&p->lock); | |
2517 | next = rb_first(&p->root); | |
2518 | while (next) { | |
2519 | n = rb_entry(next, struct sp_node, nd); | |
2520 | next = rb_next(&n->nd); | |
2521 | sp_delete(p, n); | |
2522 | } | |
2523 | spin_unlock(&p->lock); | |
2524 | } | |
2525 | ||
2526 | #ifdef CONFIG_NUMA_BALANCING | |
2527 | static bool __initdata numabalancing_override; | |
2528 | ||
2529 | static void __init check_numabalancing_enable(void) | |
2530 | { | |
2531 | bool numabalancing_default = false; | |
2532 | ||
2533 | if (IS_ENABLED(CONFIG_NUMA_BALANCING_DEFAULT_ENABLED)) | |
2534 | numabalancing_default = true; | |
2535 | ||
2536 | if (nr_node_ids > 1 && !numabalancing_override) { | |
2537 | printk(KERN_INFO "Enabling automatic NUMA balancing. " | |
2538 | "Configure with numa_balancing= or sysctl"); | |
2539 | set_numabalancing_state(numabalancing_default); | |
2540 | } | |
2541 | } | |
2542 | ||
2543 | static int __init setup_numabalancing(char *str) | |
2544 | { | |
2545 | int ret = 0; | |
2546 | if (!str) | |
2547 | goto out; | |
2548 | numabalancing_override = true; | |
2549 | ||
2550 | if (!strcmp(str, "enable")) { | |
2551 | set_numabalancing_state(true); | |
2552 | ret = 1; | |
2553 | } else if (!strcmp(str, "disable")) { | |
2554 | set_numabalancing_state(false); | |
2555 | ret = 1; | |
2556 | } | |
2557 | out: | |
2558 | if (!ret) | |
2559 | printk(KERN_WARNING "Unable to parse numa_balancing=\n"); | |
2560 | ||
2561 | return ret; | |
2562 | } | |
2563 | __setup("numa_balancing=", setup_numabalancing); | |
2564 | #else | |
2565 | static inline void __init check_numabalancing_enable(void) | |
2566 | { | |
2567 | } | |
2568 | #endif /* CONFIG_NUMA_BALANCING */ | |
2569 | ||
2570 | /* assumes fs == KERNEL_DS */ | |
2571 | void __init numa_policy_init(void) | |
2572 | { | |
2573 | nodemask_t interleave_nodes; | |
2574 | unsigned long largest = 0; | |
2575 | int nid, prefer = 0; | |
2576 | ||
2577 | policy_cache = kmem_cache_create("numa_policy", | |
2578 | sizeof(struct mempolicy), | |
2579 | 0, SLAB_PANIC, NULL); | |
2580 | ||
2581 | sn_cache = kmem_cache_create("shared_policy_node", | |
2582 | sizeof(struct sp_node), | |
2583 | 0, SLAB_PANIC, NULL); | |
2584 | ||
2585 | for_each_node(nid) { | |
2586 | preferred_node_policy[nid] = (struct mempolicy) { | |
2587 | .refcnt = ATOMIC_INIT(1), | |
2588 | .mode = MPOL_PREFERRED, | |
2589 | .flags = MPOL_F_MOF | MPOL_F_MORON, | |
2590 | .v = { .preferred_node = nid, }, | |
2591 | }; | |
2592 | } | |
2593 | ||
2594 | /* | |
2595 | * Set interleaving policy for system init. Interleaving is only | |
2596 | * enabled across suitably sized nodes (default is >= 16MB), or | |
2597 | * fall back to the largest node if they're all smaller. | |
2598 | */ | |
2599 | nodes_clear(interleave_nodes); | |
2600 | for_each_node_state(nid, N_MEMORY) { | |
2601 | unsigned long total_pages = node_present_pages(nid); | |
2602 | ||
2603 | /* Preserve the largest node */ | |
2604 | if (largest < total_pages) { | |
2605 | largest = total_pages; | |
2606 | prefer = nid; | |
2607 | } | |
2608 | ||
2609 | /* Interleave this node? */ | |
2610 | if ((total_pages << PAGE_SHIFT) >= (16 << 20)) | |
2611 | node_set(nid, interleave_nodes); | |
2612 | } | |
2613 | ||
2614 | /* All too small, use the largest */ | |
2615 | if (unlikely(nodes_empty(interleave_nodes))) | |
2616 | node_set(prefer, interleave_nodes); | |
2617 | ||
2618 | if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes)) | |
2619 | printk("numa_policy_init: interleaving failed\n"); | |
2620 | ||
2621 | check_numabalancing_enable(); | |
2622 | } | |
2623 | ||
2624 | /* Reset policy of current process to default */ | |
2625 | void numa_default_policy(void) | |
2626 | { | |
2627 | do_set_mempolicy(MPOL_DEFAULT, 0, NULL); | |
2628 | } | |
2629 | ||
2630 | /* | |
2631 | * Parse and format mempolicy from/to strings | |
2632 | */ | |
2633 | ||
2634 | /* | |
2635 | * "local" is implemented internally by MPOL_PREFERRED with MPOL_F_LOCAL flag. | |
2636 | */ | |
2637 | static const char * const policy_modes[] = | |
2638 | { | |
2639 | [MPOL_DEFAULT] = "default", | |
2640 | [MPOL_PREFERRED] = "prefer", | |
2641 | [MPOL_BIND] = "bind", | |
2642 | [MPOL_INTERLEAVE] = "interleave", | |
2643 | [MPOL_LOCAL] = "local", | |
2644 | }; | |
2645 | ||
2646 | ||
2647 | #ifdef CONFIG_TMPFS | |
2648 | /** | |
2649 | * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option. | |
2650 | * @str: string containing mempolicy to parse | |
2651 | * @mpol: pointer to struct mempolicy pointer, returned on success. | |
2652 | * | |
2653 | * Format of input: | |
2654 | * <mode>[=<flags>][:<nodelist>] | |
2655 | * | |
2656 | * On success, returns 0, else 1 | |
2657 | */ | |
2658 | int mpol_parse_str(char *str, struct mempolicy **mpol) | |
2659 | { | |
2660 | struct mempolicy *new = NULL; | |
2661 | unsigned short mode; | |
2662 | unsigned short mode_flags; | |
2663 | nodemask_t nodes; | |
2664 | char *nodelist = strchr(str, ':'); | |
2665 | char *flags = strchr(str, '='); | |
2666 | int err = 1; | |
2667 | ||
2668 | if (nodelist) { | |
2669 | /* NUL-terminate mode or flags string */ | |
2670 | *nodelist++ = '\0'; | |
2671 | if (nodelist_parse(nodelist, nodes)) | |
2672 | goto out; | |
2673 | if (!nodes_subset(nodes, node_states[N_MEMORY])) | |
2674 | goto out; | |
2675 | } else | |
2676 | nodes_clear(nodes); | |
2677 | ||
2678 | if (flags) | |
2679 | *flags++ = '\0'; /* terminate mode string */ | |
2680 | ||
2681 | for (mode = 0; mode < MPOL_MAX; mode++) { | |
2682 | if (!strcmp(str, policy_modes[mode])) { | |
2683 | break; | |
2684 | } | |
2685 | } | |
2686 | if (mode >= MPOL_MAX) | |
2687 | goto out; | |
2688 | ||
2689 | switch (mode) { | |
2690 | case MPOL_PREFERRED: | |
2691 | /* | |
2692 | * Insist on a nodelist of one node only | |
2693 | */ | |
2694 | if (nodelist) { | |
2695 | char *rest = nodelist; | |
2696 | while (isdigit(*rest)) | |
2697 | rest++; | |
2698 | if (*rest) | |
2699 | goto out; | |
2700 | } | |
2701 | break; | |
2702 | case MPOL_INTERLEAVE: | |
2703 | /* | |
2704 | * Default to online nodes with memory if no nodelist | |
2705 | */ | |
2706 | if (!nodelist) | |
2707 | nodes = node_states[N_MEMORY]; | |
2708 | break; | |
2709 | case MPOL_LOCAL: | |
2710 | /* | |
2711 | * Don't allow a nodelist; mpol_new() checks flags | |
2712 | */ | |
2713 | if (nodelist) | |
2714 | goto out; | |
2715 | mode = MPOL_PREFERRED; | |
2716 | break; | |
2717 | case MPOL_DEFAULT: | |
2718 | /* | |
2719 | * Insist on a empty nodelist | |
2720 | */ | |
2721 | if (!nodelist) | |
2722 | err = 0; | |
2723 | goto out; | |
2724 | case MPOL_BIND: | |
2725 | /* | |
2726 | * Insist on a nodelist | |
2727 | */ | |
2728 | if (!nodelist) | |
2729 | goto out; | |
2730 | } | |
2731 | ||
2732 | mode_flags = 0; | |
2733 | if (flags) { | |
2734 | /* | |
2735 | * Currently, we only support two mutually exclusive | |
2736 | * mode flags. | |
2737 | */ | |
2738 | if (!strcmp(flags, "static")) | |
2739 | mode_flags |= MPOL_F_STATIC_NODES; | |
2740 | else if (!strcmp(flags, "relative")) | |
2741 | mode_flags |= MPOL_F_RELATIVE_NODES; | |
2742 | else | |
2743 | goto out; | |
2744 | } | |
2745 | ||
2746 | new = mpol_new(mode, mode_flags, &nodes); | |
2747 | if (IS_ERR(new)) | |
2748 | goto out; | |
2749 | ||
2750 | /* | |
2751 | * Save nodes for mpol_to_str() to show the tmpfs mount options | |
2752 | * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo. | |
2753 | */ | |
2754 | if (mode != MPOL_PREFERRED) | |
2755 | new->v.nodes = nodes; | |
2756 | else if (nodelist) | |
2757 | new->v.preferred_node = first_node(nodes); | |
2758 | else | |
2759 | new->flags |= MPOL_F_LOCAL; | |
2760 | ||
2761 | /* | |
2762 | * Save nodes for contextualization: this will be used to "clone" | |
2763 | * the mempolicy in a specific context [cpuset] at a later time. | |
2764 | */ | |
2765 | new->w.user_nodemask = nodes; | |
2766 | ||
2767 | err = 0; | |
2768 | ||
2769 | out: | |
2770 | /* Restore string for error message */ | |
2771 | if (nodelist) | |
2772 | *--nodelist = ':'; | |
2773 | if (flags) | |
2774 | *--flags = '='; | |
2775 | if (!err) | |
2776 | *mpol = new; | |
2777 | return err; | |
2778 | } | |
2779 | #endif /* CONFIG_TMPFS */ | |
2780 | ||
2781 | /** | |
2782 | * mpol_to_str - format a mempolicy structure for printing | |
2783 | * @buffer: to contain formatted mempolicy string | |
2784 | * @maxlen: length of @buffer | |
2785 | * @pol: pointer to mempolicy to be formatted | |
2786 | * | |
2787 | * Convert a mempolicy into a string. | |
2788 | * Returns the number of characters in buffer (if positive) | |
2789 | * or an error (negative) | |
2790 | */ | |
2791 | int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol) | |
2792 | { | |
2793 | char *p = buffer; | |
2794 | int l; | |
2795 | nodemask_t nodes; | |
2796 | unsigned short mode; | |
2797 | unsigned short flags = pol ? pol->flags : 0; | |
2798 | ||
2799 | /* | |
2800 | * Sanity check: room for longest mode, flag and some nodes | |
2801 | */ | |
2802 | VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16); | |
2803 | ||
2804 | if (!pol || pol == &default_policy) | |
2805 | mode = MPOL_DEFAULT; | |
2806 | else | |
2807 | mode = pol->mode; | |
2808 | ||
2809 | switch (mode) { | |
2810 | case MPOL_DEFAULT: | |
2811 | nodes_clear(nodes); | |
2812 | break; | |
2813 | ||
2814 | case MPOL_PREFERRED: | |
2815 | nodes_clear(nodes); | |
2816 | if (flags & MPOL_F_LOCAL) | |
2817 | mode = MPOL_LOCAL; | |
2818 | else | |
2819 | node_set(pol->v.preferred_node, nodes); | |
2820 | break; | |
2821 | ||
2822 | case MPOL_BIND: | |
2823 | /* Fall through */ | |
2824 | case MPOL_INTERLEAVE: | |
2825 | nodes = pol->v.nodes; | |
2826 | break; | |
2827 | ||
2828 | default: | |
2829 | return -EINVAL; | |
2830 | } | |
2831 | ||
2832 | l = strlen(policy_modes[mode]); | |
2833 | if (buffer + maxlen < p + l + 1) | |
2834 | return -ENOSPC; | |
2835 | ||
2836 | strcpy(p, policy_modes[mode]); | |
2837 | p += l; | |
2838 | ||
2839 | if (flags & MPOL_MODE_FLAGS) { | |
2840 | if (buffer + maxlen < p + 2) | |
2841 | return -ENOSPC; | |
2842 | *p++ = '='; | |
2843 | ||
2844 | /* | |
2845 | * Currently, the only defined flags are mutually exclusive | |
2846 | */ | |
2847 | if (flags & MPOL_F_STATIC_NODES) | |
2848 | p += snprintf(p, buffer + maxlen - p, "static"); | |
2849 | else if (flags & MPOL_F_RELATIVE_NODES) | |
2850 | p += snprintf(p, buffer + maxlen - p, "relative"); | |
2851 | } | |
2852 | ||
2853 | if (!nodes_empty(nodes)) { | |
2854 | if (buffer + maxlen < p + 2) | |
2855 | return -ENOSPC; | |
2856 | *p++ = ':'; | |
2857 | p += nodelist_scnprintf(p, buffer + maxlen - p, nodes); | |
2858 | } | |
2859 | return p - buffer; | |
2860 | } |