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1 | /* | |
2 | * Simple NUMA memory policy for the Linux kernel. | |
3 | * | |
4 | * Copyright 2003,2004 Andi Kleen, SuSE Labs. | |
5 | * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc. | |
6 | * Subject to the GNU Public License, version 2. | |
7 | * | |
8 | * NUMA policy allows the user to give hints in which node(s) memory should | |
9 | * be allocated. | |
10 | * | |
11 | * Support four policies per VMA and per process: | |
12 | * | |
13 | * The VMA policy has priority over the process policy for a page fault. | |
14 | * | |
15 | * interleave Allocate memory interleaved over a set of nodes, | |
16 | * with normal fallback if it fails. | |
17 | * For VMA based allocations this interleaves based on the | |
18 | * offset into the backing object or offset into the mapping | |
19 | * for anonymous memory. For process policy an process counter | |
20 | * is used. | |
21 | * | |
22 | * bind Only allocate memory on a specific set of nodes, | |
23 | * no fallback. | |
24 | * FIXME: memory is allocated starting with the first node | |
25 | * to the last. It would be better if bind would truly restrict | |
26 | * the allocation to memory nodes instead | |
27 | * | |
28 | * preferred Try a specific node first before normal fallback. | |
29 | * As a special case node -1 here means do the allocation | |
30 | * on the local CPU. This is normally identical to default, | |
31 | * but useful to set in a VMA when you have a non default | |
32 | * process policy. | |
33 | * | |
34 | * default Allocate on the local node first, or when on a VMA | |
35 | * use the process policy. This is what Linux always did | |
36 | * in a NUMA aware kernel and still does by, ahem, default. | |
37 | * | |
38 | * The process policy is applied for most non interrupt memory allocations | |
39 | * in that process' context. Interrupts ignore the policies and always | |
40 | * try to allocate on the local CPU. The VMA policy is only applied for memory | |
41 | * allocations for a VMA in the VM. | |
42 | * | |
43 | * Currently there are a few corner cases in swapping where the policy | |
44 | * is not applied, but the majority should be handled. When process policy | |
45 | * is used it is not remembered over swap outs/swap ins. | |
46 | * | |
47 | * Only the highest zone in the zone hierarchy gets policied. Allocations | |
48 | * requesting a lower zone just use default policy. This implies that | |
49 | * on systems with highmem kernel lowmem allocation don't get policied. | |
50 | * Same with GFP_DMA allocations. | |
51 | * | |
52 | * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between | |
53 | * all users and remembered even when nobody has memory mapped. | |
54 | */ | |
55 | ||
56 | /* Notebook: | |
57 | fix mmap readahead to honour policy and enable policy for any page cache | |
58 | object | |
59 | statistics for bigpages | |
60 | global policy for page cache? currently it uses process policy. Requires | |
61 | first item above. | |
62 | handle mremap for shared memory (currently ignored for the policy) | |
63 | grows down? | |
64 | make bind policy root only? It can trigger oom much faster and the | |
65 | kernel is not always grateful with that. | |
66 | */ | |
67 | ||
68 | #include <linux/mempolicy.h> | |
69 | #include <linux/mm.h> | |
70 | #include <linux/highmem.h> | |
71 | #include <linux/hugetlb.h> | |
72 | #include <linux/kernel.h> | |
73 | #include <linux/sched.h> | |
74 | #include <linux/nodemask.h> | |
75 | #include <linux/cpuset.h> | |
76 | #include <linux/gfp.h> | |
77 | #include <linux/slab.h> | |
78 | #include <linux/string.h> | |
79 | #include <linux/module.h> | |
80 | #include <linux/nsproxy.h> | |
81 | #include <linux/interrupt.h> | |
82 | #include <linux/init.h> | |
83 | #include <linux/compat.h> | |
84 | #include <linux/swap.h> | |
85 | #include <linux/seq_file.h> | |
86 | #include <linux/proc_fs.h> | |
87 | #include <linux/migrate.h> | |
88 | #include <linux/ksm.h> | |
89 | #include <linux/rmap.h> | |
90 | #include <linux/security.h> | |
91 | #include <linux/syscalls.h> | |
92 | #include <linux/ctype.h> | |
93 | #include <linux/mm_inline.h> | |
94 | ||
95 | #include <asm/tlbflush.h> | |
96 | #include <asm/uaccess.h> | |
97 | ||
98 | #include "internal.h" | |
99 | ||
100 | /* Internal flags */ | |
101 | #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */ | |
102 | #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */ | |
103 | #define MPOL_MF_STATS (MPOL_MF_INTERNAL << 2) /* Gather statistics */ | |
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 | 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 const struct mempolicy_operations { | |
122 | int (*create)(struct mempolicy *pol, const nodemask_t *nodes); | |
123 | void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes); | |
124 | } mpol_ops[MPOL_MAX]; | |
125 | ||
126 | /* Check that the nodemask contains at least one populated zone */ | |
127 | static int is_valid_nodemask(const nodemask_t *nodemask) | |
128 | { | |
129 | int nd, k; | |
130 | ||
131 | /* Check that there is something useful in this mask */ | |
132 | k = policy_zone; | |
133 | ||
134 | for_each_node_mask(nd, *nodemask) { | |
135 | struct zone *z; | |
136 | ||
137 | for (k = 0; k <= policy_zone; k++) { | |
138 | z = &NODE_DATA(nd)->node_zones[k]; | |
139 | if (z->present_pages > 0) | |
140 | return 1; | |
141 | } | |
142 | } | |
143 | ||
144 | return 0; | |
145 | } | |
146 | ||
147 | static inline int mpol_store_user_nodemask(const struct mempolicy *pol) | |
148 | { | |
149 | return pol->flags & (MPOL_F_STATIC_NODES | MPOL_F_RELATIVE_NODES); | |
150 | } | |
151 | ||
152 | static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig, | |
153 | const nodemask_t *rel) | |
154 | { | |
155 | nodemask_t tmp; | |
156 | nodes_fold(tmp, *orig, nodes_weight(*rel)); | |
157 | nodes_onto(*ret, tmp, *rel); | |
158 | } | |
159 | ||
160 | static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes) | |
161 | { | |
162 | if (nodes_empty(*nodes)) | |
163 | return -EINVAL; | |
164 | pol->v.nodes = *nodes; | |
165 | return 0; | |
166 | } | |
167 | ||
168 | static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes) | |
169 | { | |
170 | if (!nodes) | |
171 | pol->flags |= MPOL_F_LOCAL; /* local allocation */ | |
172 | else if (nodes_empty(*nodes)) | |
173 | return -EINVAL; /* no allowed nodes */ | |
174 | else | |
175 | pol->v.preferred_node = first_node(*nodes); | |
176 | return 0; | |
177 | } | |
178 | ||
179 | static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes) | |
180 | { | |
181 | if (!is_valid_nodemask(nodes)) | |
182 | return -EINVAL; | |
183 | pol->v.nodes = *nodes; | |
184 | return 0; | |
185 | } | |
186 | ||
187 | /* | |
188 | * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if | |
189 | * any, for the new policy. mpol_new() has already validated the nodes | |
190 | * parameter with respect to the policy mode and flags. But, we need to | |
191 | * handle an empty nodemask with MPOL_PREFERRED here. | |
192 | * | |
193 | * Must be called holding task's alloc_lock to protect task's mems_allowed | |
194 | * and mempolicy. May also be called holding the mmap_semaphore for write. | |
195 | */ | |
196 | static int mpol_set_nodemask(struct mempolicy *pol, | |
197 | const nodemask_t *nodes, struct nodemask_scratch *nsc) | |
198 | { | |
199 | int ret; | |
200 | ||
201 | /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */ | |
202 | if (pol == NULL) | |
203 | return 0; | |
204 | /* Check N_HIGH_MEMORY */ | |
205 | nodes_and(nsc->mask1, | |
206 | cpuset_current_mems_allowed, node_states[N_HIGH_MEMORY]); | |
207 | ||
208 | VM_BUG_ON(!nodes); | |
209 | if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes)) | |
210 | nodes = NULL; /* explicit local allocation */ | |
211 | else { | |
212 | if (pol->flags & MPOL_F_RELATIVE_NODES) | |
213 | mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1); | |
214 | else | |
215 | nodes_and(nsc->mask2, *nodes, nsc->mask1); | |
216 | ||
217 | if (mpol_store_user_nodemask(pol)) | |
218 | pol->w.user_nodemask = *nodes; | |
219 | else | |
220 | pol->w.cpuset_mems_allowed = | |
221 | cpuset_current_mems_allowed; | |
222 | } | |
223 | ||
224 | if (nodes) | |
225 | ret = mpol_ops[pol->mode].create(pol, &nsc->mask2); | |
226 | else | |
227 | ret = mpol_ops[pol->mode].create(pol, NULL); | |
228 | return ret; | |
229 | } | |
230 | ||
231 | /* | |
232 | * This function just creates a new policy, does some check and simple | |
233 | * initialization. You must invoke mpol_set_nodemask() to set nodes. | |
234 | */ | |
235 | static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, | |
236 | nodemask_t *nodes) | |
237 | { | |
238 | struct mempolicy *policy; | |
239 | ||
240 | pr_debug("setting mode %d flags %d nodes[0] %lx\n", | |
241 | mode, flags, nodes ? nodes_addr(*nodes)[0] : -1); | |
242 | ||
243 | if (mode == MPOL_DEFAULT) { | |
244 | if (nodes && !nodes_empty(*nodes)) | |
245 | return ERR_PTR(-EINVAL); | |
246 | return NULL; /* simply delete any existing policy */ | |
247 | } | |
248 | VM_BUG_ON(!nodes); | |
249 | ||
250 | /* | |
251 | * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or | |
252 | * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation). | |
253 | * All other modes require a valid pointer to a non-empty nodemask. | |
254 | */ | |
255 | if (mode == MPOL_PREFERRED) { | |
256 | if (nodes_empty(*nodes)) { | |
257 | if (((flags & MPOL_F_STATIC_NODES) || | |
258 | (flags & MPOL_F_RELATIVE_NODES))) | |
259 | return ERR_PTR(-EINVAL); | |
260 | } | |
261 | } else if (nodes_empty(*nodes)) | |
262 | return ERR_PTR(-EINVAL); | |
263 | policy = kmem_cache_alloc(policy_cache, GFP_KERNEL); | |
264 | if (!policy) | |
265 | return ERR_PTR(-ENOMEM); | |
266 | atomic_set(&policy->refcnt, 1); | |
267 | policy->mode = mode; | |
268 | policy->flags = flags; | |
269 | ||
270 | return policy; | |
271 | } | |
272 | ||
273 | /* Slow path of a mpol destructor. */ | |
274 | void __mpol_put(struct mempolicy *p) | |
275 | { | |
276 | if (!atomic_dec_and_test(&p->refcnt)) | |
277 | return; | |
278 | kmem_cache_free(policy_cache, p); | |
279 | } | |
280 | ||
281 | static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes) | |
282 | { | |
283 | } | |
284 | ||
285 | static void mpol_rebind_nodemask(struct mempolicy *pol, | |
286 | const nodemask_t *nodes) | |
287 | { | |
288 | nodemask_t tmp; | |
289 | ||
290 | if (pol->flags & MPOL_F_STATIC_NODES) | |
291 | nodes_and(tmp, pol->w.user_nodemask, *nodes); | |
292 | else if (pol->flags & MPOL_F_RELATIVE_NODES) | |
293 | mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); | |
294 | else { | |
295 | nodes_remap(tmp, pol->v.nodes, pol->w.cpuset_mems_allowed, | |
296 | *nodes); | |
297 | pol->w.cpuset_mems_allowed = *nodes; | |
298 | } | |
299 | ||
300 | pol->v.nodes = tmp; | |
301 | if (!node_isset(current->il_next, tmp)) { | |
302 | current->il_next = next_node(current->il_next, tmp); | |
303 | if (current->il_next >= MAX_NUMNODES) | |
304 | current->il_next = first_node(tmp); | |
305 | if (current->il_next >= MAX_NUMNODES) | |
306 | current->il_next = numa_node_id(); | |
307 | } | |
308 | } | |
309 | ||
310 | static void mpol_rebind_preferred(struct mempolicy *pol, | |
311 | const nodemask_t *nodes) | |
312 | { | |
313 | nodemask_t tmp; | |
314 | ||
315 | if (pol->flags & MPOL_F_STATIC_NODES) { | |
316 | int node = first_node(pol->w.user_nodemask); | |
317 | ||
318 | if (node_isset(node, *nodes)) { | |
319 | pol->v.preferred_node = node; | |
320 | pol->flags &= ~MPOL_F_LOCAL; | |
321 | } else | |
322 | pol->flags |= MPOL_F_LOCAL; | |
323 | } else if (pol->flags & MPOL_F_RELATIVE_NODES) { | |
324 | mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); | |
325 | pol->v.preferred_node = first_node(tmp); | |
326 | } else if (!(pol->flags & MPOL_F_LOCAL)) { | |
327 | pol->v.preferred_node = node_remap(pol->v.preferred_node, | |
328 | pol->w.cpuset_mems_allowed, | |
329 | *nodes); | |
330 | pol->w.cpuset_mems_allowed = *nodes; | |
331 | } | |
332 | } | |
333 | ||
334 | /* Migrate a policy to a different set of nodes */ | |
335 | static void mpol_rebind_policy(struct mempolicy *pol, | |
336 | const nodemask_t *newmask) | |
337 | { | |
338 | if (!pol) | |
339 | return; | |
340 | if (!mpol_store_user_nodemask(pol) && | |
341 | nodes_equal(pol->w.cpuset_mems_allowed, *newmask)) | |
342 | return; | |
343 | mpol_ops[pol->mode].rebind(pol, newmask); | |
344 | } | |
345 | ||
346 | /* | |
347 | * Wrapper for mpol_rebind_policy() that just requires task | |
348 | * pointer, and updates task mempolicy. | |
349 | * | |
350 | * Called with task's alloc_lock held. | |
351 | */ | |
352 | ||
353 | void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new) | |
354 | { | |
355 | mpol_rebind_policy(tsk->mempolicy, new); | |
356 | } | |
357 | ||
358 | /* | |
359 | * Rebind each vma in mm to new nodemask. | |
360 | * | |
361 | * Call holding a reference to mm. Takes mm->mmap_sem during call. | |
362 | */ | |
363 | ||
364 | void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new) | |
365 | { | |
366 | struct vm_area_struct *vma; | |
367 | ||
368 | down_write(&mm->mmap_sem); | |
369 | for (vma = mm->mmap; vma; vma = vma->vm_next) | |
370 | mpol_rebind_policy(vma->vm_policy, new); | |
371 | up_write(&mm->mmap_sem); | |
372 | } | |
373 | ||
374 | static const struct mempolicy_operations mpol_ops[MPOL_MAX] = { | |
375 | [MPOL_DEFAULT] = { | |
376 | .rebind = mpol_rebind_default, | |
377 | }, | |
378 | [MPOL_INTERLEAVE] = { | |
379 | .create = mpol_new_interleave, | |
380 | .rebind = mpol_rebind_nodemask, | |
381 | }, | |
382 | [MPOL_PREFERRED] = { | |
383 | .create = mpol_new_preferred, | |
384 | .rebind = mpol_rebind_preferred, | |
385 | }, | |
386 | [MPOL_BIND] = { | |
387 | .create = mpol_new_bind, | |
388 | .rebind = mpol_rebind_nodemask, | |
389 | }, | |
390 | }; | |
391 | ||
392 | static void gather_stats(struct page *, void *, int pte_dirty); | |
393 | static void migrate_page_add(struct page *page, struct list_head *pagelist, | |
394 | unsigned long flags); | |
395 | ||
396 | /* Scan through pages checking if pages follow certain conditions. */ | |
397 | static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd, | |
398 | unsigned long addr, unsigned long end, | |
399 | const nodemask_t *nodes, unsigned long flags, | |
400 | void *private) | |
401 | { | |
402 | pte_t *orig_pte; | |
403 | pte_t *pte; | |
404 | spinlock_t *ptl; | |
405 | ||
406 | orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
407 | do { | |
408 | struct page *page; | |
409 | int nid; | |
410 | ||
411 | if (!pte_present(*pte)) | |
412 | continue; | |
413 | page = vm_normal_page(vma, addr, *pte); | |
414 | if (!page) | |
415 | continue; | |
416 | /* | |
417 | * vm_normal_page() filters out zero pages, but there might | |
418 | * still be PageReserved pages to skip, perhaps in a VDSO. | |
419 | * And we cannot move PageKsm pages sensibly or safely yet. | |
420 | */ | |
421 | if (PageReserved(page) || PageKsm(page)) | |
422 | continue; | |
423 | nid = page_to_nid(page); | |
424 | if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT)) | |
425 | continue; | |
426 | ||
427 | if (flags & MPOL_MF_STATS) | |
428 | gather_stats(page, private, pte_dirty(*pte)); | |
429 | else if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) | |
430 | migrate_page_add(page, private, flags); | |
431 | else | |
432 | break; | |
433 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
434 | pte_unmap_unlock(orig_pte, ptl); | |
435 | return addr != end; | |
436 | } | |
437 | ||
438 | static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud, | |
439 | unsigned long addr, unsigned long end, | |
440 | const nodemask_t *nodes, unsigned long flags, | |
441 | void *private) | |
442 | { | |
443 | pmd_t *pmd; | |
444 | unsigned long next; | |
445 | ||
446 | pmd = pmd_offset(pud, addr); | |
447 | do { | |
448 | next = pmd_addr_end(addr, end); | |
449 | if (pmd_none_or_clear_bad(pmd)) | |
450 | continue; | |
451 | if (check_pte_range(vma, pmd, addr, next, nodes, | |
452 | flags, private)) | |
453 | return -EIO; | |
454 | } while (pmd++, addr = next, addr != end); | |
455 | return 0; | |
456 | } | |
457 | ||
458 | static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd, | |
459 | unsigned long addr, unsigned long end, | |
460 | const nodemask_t *nodes, unsigned long flags, | |
461 | void *private) | |
462 | { | |
463 | pud_t *pud; | |
464 | unsigned long next; | |
465 | ||
466 | pud = pud_offset(pgd, addr); | |
467 | do { | |
468 | next = pud_addr_end(addr, end); | |
469 | if (pud_none_or_clear_bad(pud)) | |
470 | continue; | |
471 | if (check_pmd_range(vma, pud, addr, next, nodes, | |
472 | flags, private)) | |
473 | return -EIO; | |
474 | } while (pud++, addr = next, addr != end); | |
475 | return 0; | |
476 | } | |
477 | ||
478 | static inline int check_pgd_range(struct vm_area_struct *vma, | |
479 | unsigned long addr, unsigned long end, | |
480 | const nodemask_t *nodes, unsigned long flags, | |
481 | void *private) | |
482 | { | |
483 | pgd_t *pgd; | |
484 | unsigned long next; | |
485 | ||
486 | pgd = pgd_offset(vma->vm_mm, addr); | |
487 | do { | |
488 | next = pgd_addr_end(addr, end); | |
489 | if (pgd_none_or_clear_bad(pgd)) | |
490 | continue; | |
491 | if (check_pud_range(vma, pgd, addr, next, nodes, | |
492 | flags, private)) | |
493 | return -EIO; | |
494 | } while (pgd++, addr = next, addr != end); | |
495 | return 0; | |
496 | } | |
497 | ||
498 | /* | |
499 | * Check if all pages in a range are on a set of nodes. | |
500 | * If pagelist != NULL then isolate pages from the LRU and | |
501 | * put them on the pagelist. | |
502 | */ | |
503 | static struct vm_area_struct * | |
504 | check_range(struct mm_struct *mm, unsigned long start, unsigned long end, | |
505 | const nodemask_t *nodes, unsigned long flags, void *private) | |
506 | { | |
507 | int err; | |
508 | struct vm_area_struct *first, *vma, *prev; | |
509 | ||
510 | ||
511 | first = find_vma(mm, start); | |
512 | if (!first) | |
513 | return ERR_PTR(-EFAULT); | |
514 | prev = NULL; | |
515 | for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) { | |
516 | if (!(flags & MPOL_MF_DISCONTIG_OK)) { | |
517 | if (!vma->vm_next && vma->vm_end < end) | |
518 | return ERR_PTR(-EFAULT); | |
519 | if (prev && prev->vm_end < vma->vm_start) | |
520 | return ERR_PTR(-EFAULT); | |
521 | } | |
522 | if (!is_vm_hugetlb_page(vma) && | |
523 | ((flags & MPOL_MF_STRICT) || | |
524 | ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) && | |
525 | vma_migratable(vma)))) { | |
526 | unsigned long endvma = vma->vm_end; | |
527 | ||
528 | if (endvma > end) | |
529 | endvma = end; | |
530 | if (vma->vm_start > start) | |
531 | start = vma->vm_start; | |
532 | err = check_pgd_range(vma, start, endvma, nodes, | |
533 | flags, private); | |
534 | if (err) { | |
535 | first = ERR_PTR(err); | |
536 | break; | |
537 | } | |
538 | } | |
539 | prev = vma; | |
540 | } | |
541 | return first; | |
542 | } | |
543 | ||
544 | /* Apply policy to a single VMA */ | |
545 | static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new) | |
546 | { | |
547 | int err = 0; | |
548 | struct mempolicy *old = vma->vm_policy; | |
549 | ||
550 | pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n", | |
551 | vma->vm_start, vma->vm_end, vma->vm_pgoff, | |
552 | vma->vm_ops, vma->vm_file, | |
553 | vma->vm_ops ? vma->vm_ops->set_policy : NULL); | |
554 | ||
555 | if (vma->vm_ops && vma->vm_ops->set_policy) | |
556 | err = vma->vm_ops->set_policy(vma, new); | |
557 | if (!err) { | |
558 | mpol_get(new); | |
559 | vma->vm_policy = new; | |
560 | mpol_put(old); | |
561 | } | |
562 | return err; | |
563 | } | |
564 | ||
565 | /* Step 2: apply policy to a range and do splits. */ | |
566 | static int mbind_range(struct mm_struct *mm, unsigned long start, | |
567 | unsigned long end, struct mempolicy *new_pol) | |
568 | { | |
569 | struct vm_area_struct *next; | |
570 | struct vm_area_struct *prev; | |
571 | struct vm_area_struct *vma; | |
572 | int err = 0; | |
573 | pgoff_t pgoff; | |
574 | unsigned long vmstart; | |
575 | unsigned long vmend; | |
576 | ||
577 | vma = find_vma_prev(mm, start, &prev); | |
578 | if (!vma || vma->vm_start > start) | |
579 | return -EFAULT; | |
580 | ||
581 | for (; vma && vma->vm_start < end; prev = vma, vma = next) { | |
582 | next = vma->vm_next; | |
583 | vmstart = max(start, vma->vm_start); | |
584 | vmend = min(end, vma->vm_end); | |
585 | ||
586 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); | |
587 | prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags, | |
588 | vma->anon_vma, vma->vm_file, pgoff, new_pol); | |
589 | if (prev) { | |
590 | vma = prev; | |
591 | next = vma->vm_next; | |
592 | continue; | |
593 | } | |
594 | if (vma->vm_start != vmstart) { | |
595 | err = split_vma(vma->vm_mm, vma, vmstart, 1); | |
596 | if (err) | |
597 | goto out; | |
598 | } | |
599 | if (vma->vm_end != vmend) { | |
600 | err = split_vma(vma->vm_mm, vma, vmend, 0); | |
601 | if (err) | |
602 | goto out; | |
603 | } | |
604 | err = policy_vma(vma, new_pol); | |
605 | if (err) | |
606 | goto out; | |
607 | } | |
608 | ||
609 | out: | |
610 | return err; | |
611 | } | |
612 | ||
613 | /* | |
614 | * Update task->flags PF_MEMPOLICY bit: set iff non-default | |
615 | * mempolicy. Allows more rapid checking of this (combined perhaps | |
616 | * with other PF_* flag bits) on memory allocation hot code paths. | |
617 | * | |
618 | * If called from outside this file, the task 'p' should -only- be | |
619 | * a newly forked child not yet visible on the task list, because | |
620 | * manipulating the task flags of a visible task is not safe. | |
621 | * | |
622 | * The above limitation is why this routine has the funny name | |
623 | * mpol_fix_fork_child_flag(). | |
624 | * | |
625 | * It is also safe to call this with a task pointer of current, | |
626 | * which the static wrapper mpol_set_task_struct_flag() does, | |
627 | * for use within this file. | |
628 | */ | |
629 | ||
630 | void mpol_fix_fork_child_flag(struct task_struct *p) | |
631 | { | |
632 | if (p->mempolicy) | |
633 | p->flags |= PF_MEMPOLICY; | |
634 | else | |
635 | p->flags &= ~PF_MEMPOLICY; | |
636 | } | |
637 | ||
638 | static void mpol_set_task_struct_flag(void) | |
639 | { | |
640 | mpol_fix_fork_child_flag(current); | |
641 | } | |
642 | ||
643 | /* Set the process memory policy */ | |
644 | static long do_set_mempolicy(unsigned short mode, unsigned short flags, | |
645 | nodemask_t *nodes) | |
646 | { | |
647 | struct mempolicy *new, *old; | |
648 | struct mm_struct *mm = current->mm; | |
649 | NODEMASK_SCRATCH(scratch); | |
650 | int ret; | |
651 | ||
652 | if (!scratch) | |
653 | return -ENOMEM; | |
654 | ||
655 | new = mpol_new(mode, flags, nodes); | |
656 | if (IS_ERR(new)) { | |
657 | ret = PTR_ERR(new); | |
658 | goto out; | |
659 | } | |
660 | /* | |
661 | * prevent changing our mempolicy while show_numa_maps() | |
662 | * is using it. | |
663 | * Note: do_set_mempolicy() can be called at init time | |
664 | * with no 'mm'. | |
665 | */ | |
666 | if (mm) | |
667 | down_write(&mm->mmap_sem); | |
668 | task_lock(current); | |
669 | ret = mpol_set_nodemask(new, nodes, scratch); | |
670 | if (ret) { | |
671 | task_unlock(current); | |
672 | if (mm) | |
673 | up_write(&mm->mmap_sem); | |
674 | mpol_put(new); | |
675 | goto out; | |
676 | } | |
677 | old = current->mempolicy; | |
678 | current->mempolicy = new; | |
679 | mpol_set_task_struct_flag(); | |
680 | if (new && new->mode == MPOL_INTERLEAVE && | |
681 | nodes_weight(new->v.nodes)) | |
682 | current->il_next = first_node(new->v.nodes); | |
683 | task_unlock(current); | |
684 | if (mm) | |
685 | up_write(&mm->mmap_sem); | |
686 | ||
687 | mpol_put(old); | |
688 | ret = 0; | |
689 | out: | |
690 | NODEMASK_SCRATCH_FREE(scratch); | |
691 | return ret; | |
692 | } | |
693 | ||
694 | /* | |
695 | * Return nodemask for policy for get_mempolicy() query | |
696 | * | |
697 | * Called with task's alloc_lock held | |
698 | */ | |
699 | static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes) | |
700 | { | |
701 | nodes_clear(*nodes); | |
702 | if (p == &default_policy) | |
703 | return; | |
704 | ||
705 | switch (p->mode) { | |
706 | case MPOL_BIND: | |
707 | /* Fall through */ | |
708 | case MPOL_INTERLEAVE: | |
709 | *nodes = p->v.nodes; | |
710 | break; | |
711 | case MPOL_PREFERRED: | |
712 | if (!(p->flags & MPOL_F_LOCAL)) | |
713 | node_set(p->v.preferred_node, *nodes); | |
714 | /* else return empty node mask for local allocation */ | |
715 | break; | |
716 | default: | |
717 | BUG(); | |
718 | } | |
719 | } | |
720 | ||
721 | static int lookup_node(struct mm_struct *mm, unsigned long addr) | |
722 | { | |
723 | struct page *p; | |
724 | int err; | |
725 | ||
726 | err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL); | |
727 | if (err >= 0) { | |
728 | err = page_to_nid(p); | |
729 | put_page(p); | |
730 | } | |
731 | return err; | |
732 | } | |
733 | ||
734 | /* Retrieve NUMA policy */ | |
735 | static long do_get_mempolicy(int *policy, nodemask_t *nmask, | |
736 | unsigned long addr, unsigned long flags) | |
737 | { | |
738 | int err; | |
739 | struct mm_struct *mm = current->mm; | |
740 | struct vm_area_struct *vma = NULL; | |
741 | struct mempolicy *pol = current->mempolicy; | |
742 | ||
743 | if (flags & | |
744 | ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED)) | |
745 | return -EINVAL; | |
746 | ||
747 | if (flags & MPOL_F_MEMS_ALLOWED) { | |
748 | if (flags & (MPOL_F_NODE|MPOL_F_ADDR)) | |
749 | return -EINVAL; | |
750 | *policy = 0; /* just so it's initialized */ | |
751 | task_lock(current); | |
752 | *nmask = cpuset_current_mems_allowed; | |
753 | task_unlock(current); | |
754 | return 0; | |
755 | } | |
756 | ||
757 | if (flags & MPOL_F_ADDR) { | |
758 | /* | |
759 | * Do NOT fall back to task policy if the | |
760 | * vma/shared policy at addr is NULL. We | |
761 | * want to return MPOL_DEFAULT in this case. | |
762 | */ | |
763 | down_read(&mm->mmap_sem); | |
764 | vma = find_vma_intersection(mm, addr, addr+1); | |
765 | if (!vma) { | |
766 | up_read(&mm->mmap_sem); | |
767 | return -EFAULT; | |
768 | } | |
769 | if (vma->vm_ops && vma->vm_ops->get_policy) | |
770 | pol = vma->vm_ops->get_policy(vma, addr); | |
771 | else | |
772 | pol = vma->vm_policy; | |
773 | } else if (addr) | |
774 | return -EINVAL; | |
775 | ||
776 | if (!pol) | |
777 | pol = &default_policy; /* indicates default behavior */ | |
778 | ||
779 | if (flags & MPOL_F_NODE) { | |
780 | if (flags & MPOL_F_ADDR) { | |
781 | err = lookup_node(mm, addr); | |
782 | if (err < 0) | |
783 | goto out; | |
784 | *policy = err; | |
785 | } else if (pol == current->mempolicy && | |
786 | pol->mode == MPOL_INTERLEAVE) { | |
787 | *policy = current->il_next; | |
788 | } else { | |
789 | err = -EINVAL; | |
790 | goto out; | |
791 | } | |
792 | } else { | |
793 | *policy = pol == &default_policy ? MPOL_DEFAULT : | |
794 | pol->mode; | |
795 | /* | |
796 | * Internal mempolicy flags must be masked off before exposing | |
797 | * the policy to userspace. | |
798 | */ | |
799 | *policy |= (pol->flags & MPOL_MODE_FLAGS); | |
800 | } | |
801 | ||
802 | if (vma) { | |
803 | up_read(¤t->mm->mmap_sem); | |
804 | vma = NULL; | |
805 | } | |
806 | ||
807 | err = 0; | |
808 | if (nmask) { | |
809 | task_lock(current); | |
810 | get_policy_nodemask(pol, nmask); | |
811 | task_unlock(current); | |
812 | } | |
813 | ||
814 | out: | |
815 | mpol_cond_put(pol); | |
816 | if (vma) | |
817 | up_read(¤t->mm->mmap_sem); | |
818 | return err; | |
819 | } | |
820 | ||
821 | #ifdef CONFIG_MIGRATION | |
822 | /* | |
823 | * page migration | |
824 | */ | |
825 | static void migrate_page_add(struct page *page, struct list_head *pagelist, | |
826 | unsigned long flags) | |
827 | { | |
828 | /* | |
829 | * Avoid migrating a page that is shared with others. | |
830 | */ | |
831 | if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) { | |
832 | if (!isolate_lru_page(page)) { | |
833 | list_add_tail(&page->lru, pagelist); | |
834 | inc_zone_page_state(page, NR_ISOLATED_ANON + | |
835 | page_is_file_cache(page)); | |
836 | } | |
837 | } | |
838 | } | |
839 | ||
840 | static struct page *new_node_page(struct page *page, unsigned long node, int **x) | |
841 | { | |
842 | return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0); | |
843 | } | |
844 | ||
845 | /* | |
846 | * Migrate pages from one node to a target node. | |
847 | * Returns error or the number of pages not migrated. | |
848 | */ | |
849 | static int migrate_to_node(struct mm_struct *mm, int source, int dest, | |
850 | int flags) | |
851 | { | |
852 | nodemask_t nmask; | |
853 | LIST_HEAD(pagelist); | |
854 | int err = 0; | |
855 | ||
856 | nodes_clear(nmask); | |
857 | node_set(source, nmask); | |
858 | ||
859 | check_range(mm, mm->mmap->vm_start, TASK_SIZE, &nmask, | |
860 | flags | MPOL_MF_DISCONTIG_OK, &pagelist); | |
861 | ||
862 | if (!list_empty(&pagelist)) | |
863 | err = migrate_pages(&pagelist, new_node_page, dest, 0); | |
864 | ||
865 | return err; | |
866 | } | |
867 | ||
868 | /* | |
869 | * Move pages between the two nodesets so as to preserve the physical | |
870 | * layout as much as possible. | |
871 | * | |
872 | * Returns the number of page that could not be moved. | |
873 | */ | |
874 | int do_migrate_pages(struct mm_struct *mm, | |
875 | const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags) | |
876 | { | |
877 | int busy = 0; | |
878 | int err; | |
879 | nodemask_t tmp; | |
880 | ||
881 | err = migrate_prep(); | |
882 | if (err) | |
883 | return err; | |
884 | ||
885 | down_read(&mm->mmap_sem); | |
886 | ||
887 | err = migrate_vmas(mm, from_nodes, to_nodes, flags); | |
888 | if (err) | |
889 | goto out; | |
890 | ||
891 | /* | |
892 | * Find a 'source' bit set in 'tmp' whose corresponding 'dest' | |
893 | * bit in 'to' is not also set in 'tmp'. Clear the found 'source' | |
894 | * bit in 'tmp', and return that <source, dest> pair for migration. | |
895 | * The pair of nodemasks 'to' and 'from' define the map. | |
896 | * | |
897 | * If no pair of bits is found that way, fallback to picking some | |
898 | * pair of 'source' and 'dest' bits that are not the same. If the | |
899 | * 'source' and 'dest' bits are the same, this represents a node | |
900 | * that will be migrating to itself, so no pages need move. | |
901 | * | |
902 | * If no bits are left in 'tmp', or if all remaining bits left | |
903 | * in 'tmp' correspond to the same bit in 'to', return false | |
904 | * (nothing left to migrate). | |
905 | * | |
906 | * This lets us pick a pair of nodes to migrate between, such that | |
907 | * if possible the dest node is not already occupied by some other | |
908 | * source node, minimizing the risk of overloading the memory on a | |
909 | * node that would happen if we migrated incoming memory to a node | |
910 | * before migrating outgoing memory source that same node. | |
911 | * | |
912 | * A single scan of tmp is sufficient. As we go, we remember the | |
913 | * most recent <s, d> pair that moved (s != d). If we find a pair | |
914 | * that not only moved, but what's better, moved to an empty slot | |
915 | * (d is not set in tmp), then we break out then, with that pair. | |
916 | * Otherwise when we finish scannng from_tmp, we at least have the | |
917 | * most recent <s, d> pair that moved. If we get all the way through | |
918 | * the scan of tmp without finding any node that moved, much less | |
919 | * moved to an empty node, then there is nothing left worth migrating. | |
920 | */ | |
921 | ||
922 | tmp = *from_nodes; | |
923 | while (!nodes_empty(tmp)) { | |
924 | int s,d; | |
925 | int source = -1; | |
926 | int dest = 0; | |
927 | ||
928 | for_each_node_mask(s, tmp) { | |
929 | d = node_remap(s, *from_nodes, *to_nodes); | |
930 | if (s == d) | |
931 | continue; | |
932 | ||
933 | source = s; /* Node moved. Memorize */ | |
934 | dest = d; | |
935 | ||
936 | /* dest not in remaining from nodes? */ | |
937 | if (!node_isset(dest, tmp)) | |
938 | break; | |
939 | } | |
940 | if (source == -1) | |
941 | break; | |
942 | ||
943 | node_clear(source, tmp); | |
944 | err = migrate_to_node(mm, source, dest, flags); | |
945 | if (err > 0) | |
946 | busy += err; | |
947 | if (err < 0) | |
948 | break; | |
949 | } | |
950 | out: | |
951 | up_read(&mm->mmap_sem); | |
952 | if (err < 0) | |
953 | return err; | |
954 | return busy; | |
955 | ||
956 | } | |
957 | ||
958 | /* | |
959 | * Allocate a new page for page migration based on vma policy. | |
960 | * Start assuming that page is mapped by vma pointed to by @private. | |
961 | * Search forward from there, if not. N.B., this assumes that the | |
962 | * list of pages handed to migrate_pages()--which is how we get here-- | |
963 | * is in virtual address order. | |
964 | */ | |
965 | static struct page *new_vma_page(struct page *page, unsigned long private, int **x) | |
966 | { | |
967 | struct vm_area_struct *vma = (struct vm_area_struct *)private; | |
968 | unsigned long uninitialized_var(address); | |
969 | ||
970 | while (vma) { | |
971 | address = page_address_in_vma(page, vma); | |
972 | if (address != -EFAULT) | |
973 | break; | |
974 | vma = vma->vm_next; | |
975 | } | |
976 | ||
977 | /* | |
978 | * if !vma, alloc_page_vma() will use task or system default policy | |
979 | */ | |
980 | return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); | |
981 | } | |
982 | #else | |
983 | ||
984 | static void migrate_page_add(struct page *page, struct list_head *pagelist, | |
985 | unsigned long flags) | |
986 | { | |
987 | } | |
988 | ||
989 | int do_migrate_pages(struct mm_struct *mm, | |
990 | const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags) | |
991 | { | |
992 | return -ENOSYS; | |
993 | } | |
994 | ||
995 | static struct page *new_vma_page(struct page *page, unsigned long private, int **x) | |
996 | { | |
997 | return NULL; | |
998 | } | |
999 | #endif | |
1000 | ||
1001 | static long do_mbind(unsigned long start, unsigned long len, | |
1002 | unsigned short mode, unsigned short mode_flags, | |
1003 | nodemask_t *nmask, unsigned long flags) | |
1004 | { | |
1005 | struct vm_area_struct *vma; | |
1006 | struct mm_struct *mm = current->mm; | |
1007 | struct mempolicy *new; | |
1008 | unsigned long end; | |
1009 | int err; | |
1010 | LIST_HEAD(pagelist); | |
1011 | ||
1012 | if (flags & ~(unsigned long)(MPOL_MF_STRICT | | |
1013 | MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) | |
1014 | return -EINVAL; | |
1015 | if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE)) | |
1016 | return -EPERM; | |
1017 | ||
1018 | if (start & ~PAGE_MASK) | |
1019 | return -EINVAL; | |
1020 | ||
1021 | if (mode == MPOL_DEFAULT) | |
1022 | flags &= ~MPOL_MF_STRICT; | |
1023 | ||
1024 | len = (len + PAGE_SIZE - 1) & PAGE_MASK; | |
1025 | end = start + len; | |
1026 | ||
1027 | if (end < start) | |
1028 | return -EINVAL; | |
1029 | if (end == start) | |
1030 | return 0; | |
1031 | ||
1032 | new = mpol_new(mode, mode_flags, nmask); | |
1033 | if (IS_ERR(new)) | |
1034 | return PTR_ERR(new); | |
1035 | ||
1036 | /* | |
1037 | * If we are using the default policy then operation | |
1038 | * on discontinuous address spaces is okay after all | |
1039 | */ | |
1040 | if (!new) | |
1041 | flags |= MPOL_MF_DISCONTIG_OK; | |
1042 | ||
1043 | pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n", | |
1044 | start, start + len, mode, mode_flags, | |
1045 | nmask ? nodes_addr(*nmask)[0] : -1); | |
1046 | ||
1047 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { | |
1048 | ||
1049 | err = migrate_prep(); | |
1050 | if (err) | |
1051 | goto mpol_out; | |
1052 | } | |
1053 | { | |
1054 | NODEMASK_SCRATCH(scratch); | |
1055 | if (scratch) { | |
1056 | down_write(&mm->mmap_sem); | |
1057 | task_lock(current); | |
1058 | err = mpol_set_nodemask(new, nmask, scratch); | |
1059 | task_unlock(current); | |
1060 | if (err) | |
1061 | up_write(&mm->mmap_sem); | |
1062 | } else | |
1063 | err = -ENOMEM; | |
1064 | NODEMASK_SCRATCH_FREE(scratch); | |
1065 | } | |
1066 | if (err) | |
1067 | goto mpol_out; | |
1068 | ||
1069 | vma = check_range(mm, start, end, nmask, | |
1070 | flags | MPOL_MF_INVERT, &pagelist); | |
1071 | ||
1072 | err = PTR_ERR(vma); | |
1073 | if (!IS_ERR(vma)) { | |
1074 | int nr_failed = 0; | |
1075 | ||
1076 | err = mbind_range(mm, start, end, new); | |
1077 | ||
1078 | if (!list_empty(&pagelist)) | |
1079 | nr_failed = migrate_pages(&pagelist, new_vma_page, | |
1080 | (unsigned long)vma, 0); | |
1081 | ||
1082 | if (!err && nr_failed && (flags & MPOL_MF_STRICT)) | |
1083 | err = -EIO; | |
1084 | } else | |
1085 | putback_lru_pages(&pagelist); | |
1086 | ||
1087 | up_write(&mm->mmap_sem); | |
1088 | mpol_out: | |
1089 | mpol_put(new); | |
1090 | return err; | |
1091 | } | |
1092 | ||
1093 | /* | |
1094 | * User space interface with variable sized bitmaps for nodelists. | |
1095 | */ | |
1096 | ||
1097 | /* Copy a node mask from user space. */ | |
1098 | static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask, | |
1099 | unsigned long maxnode) | |
1100 | { | |
1101 | unsigned long k; | |
1102 | unsigned long nlongs; | |
1103 | unsigned long endmask; | |
1104 | ||
1105 | --maxnode; | |
1106 | nodes_clear(*nodes); | |
1107 | if (maxnode == 0 || !nmask) | |
1108 | return 0; | |
1109 | if (maxnode > PAGE_SIZE*BITS_PER_BYTE) | |
1110 | return -EINVAL; | |
1111 | ||
1112 | nlongs = BITS_TO_LONGS(maxnode); | |
1113 | if ((maxnode % BITS_PER_LONG) == 0) | |
1114 | endmask = ~0UL; | |
1115 | else | |
1116 | endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1; | |
1117 | ||
1118 | /* When the user specified more nodes than supported just check | |
1119 | if the non supported part is all zero. */ | |
1120 | if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) { | |
1121 | if (nlongs > PAGE_SIZE/sizeof(long)) | |
1122 | return -EINVAL; | |
1123 | for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) { | |
1124 | unsigned long t; | |
1125 | if (get_user(t, nmask + k)) | |
1126 | return -EFAULT; | |
1127 | if (k == nlongs - 1) { | |
1128 | if (t & endmask) | |
1129 | return -EINVAL; | |
1130 | } else if (t) | |
1131 | return -EINVAL; | |
1132 | } | |
1133 | nlongs = BITS_TO_LONGS(MAX_NUMNODES); | |
1134 | endmask = ~0UL; | |
1135 | } | |
1136 | ||
1137 | if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long))) | |
1138 | return -EFAULT; | |
1139 | nodes_addr(*nodes)[nlongs-1] &= endmask; | |
1140 | return 0; | |
1141 | } | |
1142 | ||
1143 | /* Copy a kernel node mask to user space */ | |
1144 | static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, | |
1145 | nodemask_t *nodes) | |
1146 | { | |
1147 | unsigned long copy = ALIGN(maxnode-1, 64) / 8; | |
1148 | const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long); | |
1149 | ||
1150 | if (copy > nbytes) { | |
1151 | if (copy > PAGE_SIZE) | |
1152 | return -EINVAL; | |
1153 | if (clear_user((char __user *)mask + nbytes, copy - nbytes)) | |
1154 | return -EFAULT; | |
1155 | copy = nbytes; | |
1156 | } | |
1157 | return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0; | |
1158 | } | |
1159 | ||
1160 | SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len, | |
1161 | unsigned long, mode, unsigned long __user *, nmask, | |
1162 | unsigned long, maxnode, unsigned, flags) | |
1163 | { | |
1164 | nodemask_t nodes; | |
1165 | int err; | |
1166 | unsigned short mode_flags; | |
1167 | ||
1168 | mode_flags = mode & MPOL_MODE_FLAGS; | |
1169 | mode &= ~MPOL_MODE_FLAGS; | |
1170 | if (mode >= MPOL_MAX) | |
1171 | return -EINVAL; | |
1172 | if ((mode_flags & MPOL_F_STATIC_NODES) && | |
1173 | (mode_flags & MPOL_F_RELATIVE_NODES)) | |
1174 | return -EINVAL; | |
1175 | err = get_nodes(&nodes, nmask, maxnode); | |
1176 | if (err) | |
1177 | return err; | |
1178 | return do_mbind(start, len, mode, mode_flags, &nodes, flags); | |
1179 | } | |
1180 | ||
1181 | /* Set the process memory policy */ | |
1182 | SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask, | |
1183 | unsigned long, maxnode) | |
1184 | { | |
1185 | int err; | |
1186 | nodemask_t nodes; | |
1187 | unsigned short flags; | |
1188 | ||
1189 | flags = mode & MPOL_MODE_FLAGS; | |
1190 | mode &= ~MPOL_MODE_FLAGS; | |
1191 | if ((unsigned int)mode >= MPOL_MAX) | |
1192 | return -EINVAL; | |
1193 | if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES)) | |
1194 | return -EINVAL; | |
1195 | err = get_nodes(&nodes, nmask, maxnode); | |
1196 | if (err) | |
1197 | return err; | |
1198 | return do_set_mempolicy(mode, flags, &nodes); | |
1199 | } | |
1200 | ||
1201 | SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, | |
1202 | const unsigned long __user *, old_nodes, | |
1203 | const unsigned long __user *, new_nodes) | |
1204 | { | |
1205 | const struct cred *cred = current_cred(), *tcred; | |
1206 | struct mm_struct *mm; | |
1207 | struct task_struct *task; | |
1208 | nodemask_t old; | |
1209 | nodemask_t new; | |
1210 | nodemask_t task_nodes; | |
1211 | int err; | |
1212 | ||
1213 | err = get_nodes(&old, old_nodes, maxnode); | |
1214 | if (err) | |
1215 | return err; | |
1216 | ||
1217 | err = get_nodes(&new, new_nodes, maxnode); | |
1218 | if (err) | |
1219 | return err; | |
1220 | ||
1221 | /* Find the mm_struct */ | |
1222 | read_lock(&tasklist_lock); | |
1223 | task = pid ? find_task_by_vpid(pid) : current; | |
1224 | if (!task) { | |
1225 | read_unlock(&tasklist_lock); | |
1226 | return -ESRCH; | |
1227 | } | |
1228 | mm = get_task_mm(task); | |
1229 | read_unlock(&tasklist_lock); | |
1230 | ||
1231 | if (!mm) | |
1232 | return -EINVAL; | |
1233 | ||
1234 | /* | |
1235 | * Check if this process has the right to modify the specified | |
1236 | * process. The right exists if the process has administrative | |
1237 | * capabilities, superuser privileges or the same | |
1238 | * userid as the target process. | |
1239 | */ | |
1240 | rcu_read_lock(); | |
1241 | tcred = __task_cred(task); | |
1242 | if (cred->euid != tcred->suid && cred->euid != tcred->uid && | |
1243 | cred->uid != tcred->suid && cred->uid != tcred->uid && | |
1244 | !capable(CAP_SYS_NICE)) { | |
1245 | rcu_read_unlock(); | |
1246 | err = -EPERM; | |
1247 | goto out; | |
1248 | } | |
1249 | rcu_read_unlock(); | |
1250 | ||
1251 | task_nodes = cpuset_mems_allowed(task); | |
1252 | /* Is the user allowed to access the target nodes? */ | |
1253 | if (!nodes_subset(new, task_nodes) && !capable(CAP_SYS_NICE)) { | |
1254 | err = -EPERM; | |
1255 | goto out; | |
1256 | } | |
1257 | ||
1258 | if (!nodes_subset(new, node_states[N_HIGH_MEMORY])) { | |
1259 | err = -EINVAL; | |
1260 | goto out; | |
1261 | } | |
1262 | ||
1263 | err = security_task_movememory(task); | |
1264 | if (err) | |
1265 | goto out; | |
1266 | ||
1267 | err = do_migrate_pages(mm, &old, &new, | |
1268 | capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE); | |
1269 | out: | |
1270 | mmput(mm); | |
1271 | return err; | |
1272 | } | |
1273 | ||
1274 | ||
1275 | /* Retrieve NUMA policy */ | |
1276 | SYSCALL_DEFINE5(get_mempolicy, int __user *, policy, | |
1277 | unsigned long __user *, nmask, unsigned long, maxnode, | |
1278 | unsigned long, addr, unsigned long, flags) | |
1279 | { | |
1280 | int err; | |
1281 | int uninitialized_var(pval); | |
1282 | nodemask_t nodes; | |
1283 | ||
1284 | if (nmask != NULL && maxnode < MAX_NUMNODES) | |
1285 | return -EINVAL; | |
1286 | ||
1287 | err = do_get_mempolicy(&pval, &nodes, addr, flags); | |
1288 | ||
1289 | if (err) | |
1290 | return err; | |
1291 | ||
1292 | if (policy && put_user(pval, policy)) | |
1293 | return -EFAULT; | |
1294 | ||
1295 | if (nmask) | |
1296 | err = copy_nodes_to_user(nmask, maxnode, &nodes); | |
1297 | ||
1298 | return err; | |
1299 | } | |
1300 | ||
1301 | #ifdef CONFIG_COMPAT | |
1302 | ||
1303 | asmlinkage long compat_sys_get_mempolicy(int __user *policy, | |
1304 | compat_ulong_t __user *nmask, | |
1305 | compat_ulong_t maxnode, | |
1306 | compat_ulong_t addr, compat_ulong_t flags) | |
1307 | { | |
1308 | long err; | |
1309 | unsigned long __user *nm = NULL; | |
1310 | unsigned long nr_bits, alloc_size; | |
1311 | DECLARE_BITMAP(bm, MAX_NUMNODES); | |
1312 | ||
1313 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
1314 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
1315 | ||
1316 | if (nmask) | |
1317 | nm = compat_alloc_user_space(alloc_size); | |
1318 | ||
1319 | err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags); | |
1320 | ||
1321 | if (!err && nmask) { | |
1322 | err = copy_from_user(bm, nm, alloc_size); | |
1323 | /* ensure entire bitmap is zeroed */ | |
1324 | err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8); | |
1325 | err |= compat_put_bitmap(nmask, bm, nr_bits); | |
1326 | } | |
1327 | ||
1328 | return err; | |
1329 | } | |
1330 | ||
1331 | asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask, | |
1332 | compat_ulong_t maxnode) | |
1333 | { | |
1334 | long err = 0; | |
1335 | unsigned long __user *nm = NULL; | |
1336 | unsigned long nr_bits, alloc_size; | |
1337 | DECLARE_BITMAP(bm, MAX_NUMNODES); | |
1338 | ||
1339 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
1340 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
1341 | ||
1342 | if (nmask) { | |
1343 | err = compat_get_bitmap(bm, nmask, nr_bits); | |
1344 | nm = compat_alloc_user_space(alloc_size); | |
1345 | err |= copy_to_user(nm, bm, alloc_size); | |
1346 | } | |
1347 | ||
1348 | if (err) | |
1349 | return -EFAULT; | |
1350 | ||
1351 | return sys_set_mempolicy(mode, nm, nr_bits+1); | |
1352 | } | |
1353 | ||
1354 | asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len, | |
1355 | compat_ulong_t mode, compat_ulong_t __user *nmask, | |
1356 | compat_ulong_t maxnode, compat_ulong_t flags) | |
1357 | { | |
1358 | long err = 0; | |
1359 | unsigned long __user *nm = NULL; | |
1360 | unsigned long nr_bits, alloc_size; | |
1361 | nodemask_t bm; | |
1362 | ||
1363 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); | |
1364 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; | |
1365 | ||
1366 | if (nmask) { | |
1367 | err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits); | |
1368 | nm = compat_alloc_user_space(alloc_size); | |
1369 | err |= copy_to_user(nm, nodes_addr(bm), alloc_size); | |
1370 | } | |
1371 | ||
1372 | if (err) | |
1373 | return -EFAULT; | |
1374 | ||
1375 | return sys_mbind(start, len, mode, nm, nr_bits+1, flags); | |
1376 | } | |
1377 | ||
1378 | #endif | |
1379 | ||
1380 | /* | |
1381 | * get_vma_policy(@task, @vma, @addr) | |
1382 | * @task - task for fallback if vma policy == default | |
1383 | * @vma - virtual memory area whose policy is sought | |
1384 | * @addr - address in @vma for shared policy lookup | |
1385 | * | |
1386 | * Returns effective policy for a VMA at specified address. | |
1387 | * Falls back to @task or system default policy, as necessary. | |
1388 | * Current or other task's task mempolicy and non-shared vma policies | |
1389 | * are protected by the task's mmap_sem, which must be held for read by | |
1390 | * the caller. | |
1391 | * Shared policies [those marked as MPOL_F_SHARED] require an extra reference | |
1392 | * count--added by the get_policy() vm_op, as appropriate--to protect against | |
1393 | * freeing by another task. It is the caller's responsibility to free the | |
1394 | * extra reference for shared policies. | |
1395 | */ | |
1396 | static struct mempolicy *get_vma_policy(struct task_struct *task, | |
1397 | struct vm_area_struct *vma, unsigned long addr) | |
1398 | { | |
1399 | struct mempolicy *pol = task->mempolicy; | |
1400 | ||
1401 | if (vma) { | |
1402 | if (vma->vm_ops && vma->vm_ops->get_policy) { | |
1403 | struct mempolicy *vpol = vma->vm_ops->get_policy(vma, | |
1404 | addr); | |
1405 | if (vpol) | |
1406 | pol = vpol; | |
1407 | } else if (vma->vm_policy) | |
1408 | pol = vma->vm_policy; | |
1409 | } | |
1410 | if (!pol) | |
1411 | pol = &default_policy; | |
1412 | return pol; | |
1413 | } | |
1414 | ||
1415 | /* | |
1416 | * Return a nodemask representing a mempolicy for filtering nodes for | |
1417 | * page allocation | |
1418 | */ | |
1419 | static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy) | |
1420 | { | |
1421 | /* Lower zones don't get a nodemask applied for MPOL_BIND */ | |
1422 | if (unlikely(policy->mode == MPOL_BIND) && | |
1423 | gfp_zone(gfp) >= policy_zone && | |
1424 | cpuset_nodemask_valid_mems_allowed(&policy->v.nodes)) | |
1425 | return &policy->v.nodes; | |
1426 | ||
1427 | return NULL; | |
1428 | } | |
1429 | ||
1430 | /* Return a zonelist indicated by gfp for node representing a mempolicy */ | |
1431 | static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy) | |
1432 | { | |
1433 | int nd = numa_node_id(); | |
1434 | ||
1435 | switch (policy->mode) { | |
1436 | case MPOL_PREFERRED: | |
1437 | if (!(policy->flags & MPOL_F_LOCAL)) | |
1438 | nd = policy->v.preferred_node; | |
1439 | break; | |
1440 | case MPOL_BIND: | |
1441 | /* | |
1442 | * Normally, MPOL_BIND allocations are node-local within the | |
1443 | * allowed nodemask. However, if __GFP_THISNODE is set and the | |
1444 | * current node is part of the mask, we use the zonelist for | |
1445 | * the first node in the mask instead. | |
1446 | */ | |
1447 | if (unlikely(gfp & __GFP_THISNODE) && | |
1448 | unlikely(!node_isset(nd, policy->v.nodes))) | |
1449 | nd = first_node(policy->v.nodes); | |
1450 | break; | |
1451 | case MPOL_INTERLEAVE: /* should not happen */ | |
1452 | break; | |
1453 | default: | |
1454 | BUG(); | |
1455 | } | |
1456 | return node_zonelist(nd, gfp); | |
1457 | } | |
1458 | ||
1459 | /* Do dynamic interleaving for a process */ | |
1460 | static unsigned interleave_nodes(struct mempolicy *policy) | |
1461 | { | |
1462 | unsigned nid, next; | |
1463 | struct task_struct *me = current; | |
1464 | ||
1465 | nid = me->il_next; | |
1466 | next = next_node(nid, policy->v.nodes); | |
1467 | if (next >= MAX_NUMNODES) | |
1468 | next = first_node(policy->v.nodes); | |
1469 | if (next < MAX_NUMNODES) | |
1470 | me->il_next = next; | |
1471 | return nid; | |
1472 | } | |
1473 | ||
1474 | /* | |
1475 | * Depending on the memory policy provide a node from which to allocate the | |
1476 | * next slab entry. | |
1477 | * @policy must be protected by freeing by the caller. If @policy is | |
1478 | * the current task's mempolicy, this protection is implicit, as only the | |
1479 | * task can change it's policy. The system default policy requires no | |
1480 | * such protection. | |
1481 | */ | |
1482 | unsigned slab_node(struct mempolicy *policy) | |
1483 | { | |
1484 | if (!policy || policy->flags & MPOL_F_LOCAL) | |
1485 | return numa_node_id(); | |
1486 | ||
1487 | switch (policy->mode) { | |
1488 | case MPOL_PREFERRED: | |
1489 | /* | |
1490 | * handled MPOL_F_LOCAL above | |
1491 | */ | |
1492 | return policy->v.preferred_node; | |
1493 | ||
1494 | case MPOL_INTERLEAVE: | |
1495 | return interleave_nodes(policy); | |
1496 | ||
1497 | case MPOL_BIND: { | |
1498 | /* | |
1499 | * Follow bind policy behavior and start allocation at the | |
1500 | * first node. | |
1501 | */ | |
1502 | struct zonelist *zonelist; | |
1503 | struct zone *zone; | |
1504 | enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL); | |
1505 | zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0]; | |
1506 | (void)first_zones_zonelist(zonelist, highest_zoneidx, | |
1507 | &policy->v.nodes, | |
1508 | &zone); | |
1509 | return zone->node; | |
1510 | } | |
1511 | ||
1512 | default: | |
1513 | BUG(); | |
1514 | } | |
1515 | } | |
1516 | ||
1517 | /* Do static interleaving for a VMA with known offset. */ | |
1518 | static unsigned offset_il_node(struct mempolicy *pol, | |
1519 | struct vm_area_struct *vma, unsigned long off) | |
1520 | { | |
1521 | unsigned nnodes = nodes_weight(pol->v.nodes); | |
1522 | unsigned target; | |
1523 | int c; | |
1524 | int nid = -1; | |
1525 | ||
1526 | if (!nnodes) | |
1527 | return numa_node_id(); | |
1528 | target = (unsigned int)off % nnodes; | |
1529 | c = 0; | |
1530 | do { | |
1531 | nid = next_node(nid, pol->v.nodes); | |
1532 | c++; | |
1533 | } while (c <= target); | |
1534 | return nid; | |
1535 | } | |
1536 | ||
1537 | /* Determine a node number for interleave */ | |
1538 | static inline unsigned interleave_nid(struct mempolicy *pol, | |
1539 | struct vm_area_struct *vma, unsigned long addr, int shift) | |
1540 | { | |
1541 | if (vma) { | |
1542 | unsigned long off; | |
1543 | ||
1544 | /* | |
1545 | * for small pages, there is no difference between | |
1546 | * shift and PAGE_SHIFT, so the bit-shift is safe. | |
1547 | * for huge pages, since vm_pgoff is in units of small | |
1548 | * pages, we need to shift off the always 0 bits to get | |
1549 | * a useful offset. | |
1550 | */ | |
1551 | BUG_ON(shift < PAGE_SHIFT); | |
1552 | off = vma->vm_pgoff >> (shift - PAGE_SHIFT); | |
1553 | off += (addr - vma->vm_start) >> shift; | |
1554 | return offset_il_node(pol, vma, off); | |
1555 | } else | |
1556 | return interleave_nodes(pol); | |
1557 | } | |
1558 | ||
1559 | #ifdef CONFIG_HUGETLBFS | |
1560 | /* | |
1561 | * huge_zonelist(@vma, @addr, @gfp_flags, @mpol) | |
1562 | * @vma = virtual memory area whose policy is sought | |
1563 | * @addr = address in @vma for shared policy lookup and interleave policy | |
1564 | * @gfp_flags = for requested zone | |
1565 | * @mpol = pointer to mempolicy pointer for reference counted mempolicy | |
1566 | * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask | |
1567 | * | |
1568 | * Returns a zonelist suitable for a huge page allocation and a pointer | |
1569 | * to the struct mempolicy for conditional unref after allocation. | |
1570 | * If the effective policy is 'BIND, returns a pointer to the mempolicy's | |
1571 | * @nodemask for filtering the zonelist. | |
1572 | */ | |
1573 | struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr, | |
1574 | gfp_t gfp_flags, struct mempolicy **mpol, | |
1575 | nodemask_t **nodemask) | |
1576 | { | |
1577 | struct zonelist *zl; | |
1578 | ||
1579 | *mpol = get_vma_policy(current, vma, addr); | |
1580 | *nodemask = NULL; /* assume !MPOL_BIND */ | |
1581 | ||
1582 | if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) { | |
1583 | zl = node_zonelist(interleave_nid(*mpol, vma, addr, | |
1584 | huge_page_shift(hstate_vma(vma))), gfp_flags); | |
1585 | } else { | |
1586 | zl = policy_zonelist(gfp_flags, *mpol); | |
1587 | if ((*mpol)->mode == MPOL_BIND) | |
1588 | *nodemask = &(*mpol)->v.nodes; | |
1589 | } | |
1590 | return zl; | |
1591 | } | |
1592 | ||
1593 | /* | |
1594 | * init_nodemask_of_mempolicy | |
1595 | * | |
1596 | * If the current task's mempolicy is "default" [NULL], return 'false' | |
1597 | * to indicate default policy. Otherwise, extract the policy nodemask | |
1598 | * for 'bind' or 'interleave' policy into the argument nodemask, or | |
1599 | * initialize the argument nodemask to contain the single node for | |
1600 | * 'preferred' or 'local' policy and return 'true' to indicate presence | |
1601 | * of non-default mempolicy. | |
1602 | * | |
1603 | * We don't bother with reference counting the mempolicy [mpol_get/put] | |
1604 | * because the current task is examining it's own mempolicy and a task's | |
1605 | * mempolicy is only ever changed by the task itself. | |
1606 | * | |
1607 | * N.B., it is the caller's responsibility to free a returned nodemask. | |
1608 | */ | |
1609 | bool init_nodemask_of_mempolicy(nodemask_t *mask) | |
1610 | { | |
1611 | struct mempolicy *mempolicy; | |
1612 | int nid; | |
1613 | ||
1614 | if (!(mask && current->mempolicy)) | |
1615 | return false; | |
1616 | ||
1617 | mempolicy = current->mempolicy; | |
1618 | switch (mempolicy->mode) { | |
1619 | case MPOL_PREFERRED: | |
1620 | if (mempolicy->flags & MPOL_F_LOCAL) | |
1621 | nid = numa_node_id(); | |
1622 | else | |
1623 | nid = mempolicy->v.preferred_node; | |
1624 | init_nodemask_of_node(mask, nid); | |
1625 | break; | |
1626 | ||
1627 | case MPOL_BIND: | |
1628 | /* Fall through */ | |
1629 | case MPOL_INTERLEAVE: | |
1630 | *mask = mempolicy->v.nodes; | |
1631 | break; | |
1632 | ||
1633 | default: | |
1634 | BUG(); | |
1635 | } | |
1636 | ||
1637 | return true; | |
1638 | } | |
1639 | #endif | |
1640 | ||
1641 | /* Allocate a page in interleaved policy. | |
1642 | Own path because it needs to do special accounting. */ | |
1643 | static struct page *alloc_page_interleave(gfp_t gfp, unsigned order, | |
1644 | unsigned nid) | |
1645 | { | |
1646 | struct zonelist *zl; | |
1647 | struct page *page; | |
1648 | ||
1649 | zl = node_zonelist(nid, gfp); | |
1650 | page = __alloc_pages(gfp, order, zl); | |
1651 | if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0])) | |
1652 | inc_zone_page_state(page, NUMA_INTERLEAVE_HIT); | |
1653 | return page; | |
1654 | } | |
1655 | ||
1656 | /** | |
1657 | * alloc_page_vma - Allocate a page for a VMA. | |
1658 | * | |
1659 | * @gfp: | |
1660 | * %GFP_USER user allocation. | |
1661 | * %GFP_KERNEL kernel allocations, | |
1662 | * %GFP_HIGHMEM highmem/user allocations, | |
1663 | * %GFP_FS allocation should not call back into a file system. | |
1664 | * %GFP_ATOMIC don't sleep. | |
1665 | * | |
1666 | * @vma: Pointer to VMA or NULL if not available. | |
1667 | * @addr: Virtual Address of the allocation. Must be inside the VMA. | |
1668 | * | |
1669 | * This function allocates a page from the kernel page pool and applies | |
1670 | * a NUMA policy associated with the VMA or the current process. | |
1671 | * When VMA is not NULL caller must hold down_read on the mmap_sem of the | |
1672 | * mm_struct of the VMA to prevent it from going away. Should be used for | |
1673 | * all allocations for pages that will be mapped into | |
1674 | * user space. Returns NULL when no page can be allocated. | |
1675 | * | |
1676 | * Should be called with the mm_sem of the vma hold. | |
1677 | */ | |
1678 | struct page * | |
1679 | alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr) | |
1680 | { | |
1681 | struct mempolicy *pol = get_vma_policy(current, vma, addr); | |
1682 | struct zonelist *zl; | |
1683 | ||
1684 | if (unlikely(pol->mode == MPOL_INTERLEAVE)) { | |
1685 | unsigned nid; | |
1686 | ||
1687 | nid = interleave_nid(pol, vma, addr, PAGE_SHIFT); | |
1688 | mpol_cond_put(pol); | |
1689 | return alloc_page_interleave(gfp, 0, nid); | |
1690 | } | |
1691 | zl = policy_zonelist(gfp, pol); | |
1692 | if (unlikely(mpol_needs_cond_ref(pol))) { | |
1693 | /* | |
1694 | * slow path: ref counted shared policy | |
1695 | */ | |
1696 | struct page *page = __alloc_pages_nodemask(gfp, 0, | |
1697 | zl, policy_nodemask(gfp, pol)); | |
1698 | __mpol_put(pol); | |
1699 | return page; | |
1700 | } | |
1701 | /* | |
1702 | * fast path: default or task policy | |
1703 | */ | |
1704 | return __alloc_pages_nodemask(gfp, 0, zl, policy_nodemask(gfp, pol)); | |
1705 | } | |
1706 | ||
1707 | /** | |
1708 | * alloc_pages_current - Allocate pages. | |
1709 | * | |
1710 | * @gfp: | |
1711 | * %GFP_USER user allocation, | |
1712 | * %GFP_KERNEL kernel allocation, | |
1713 | * %GFP_HIGHMEM highmem allocation, | |
1714 | * %GFP_FS don't call back into a file system. | |
1715 | * %GFP_ATOMIC don't sleep. | |
1716 | * @order: Power of two of allocation size in pages. 0 is a single page. | |
1717 | * | |
1718 | * Allocate a page from the kernel page pool. When not in | |
1719 | * interrupt context and apply the current process NUMA policy. | |
1720 | * Returns NULL when no page can be allocated. | |
1721 | * | |
1722 | * Don't call cpuset_update_task_memory_state() unless | |
1723 | * 1) it's ok to take cpuset_sem (can WAIT), and | |
1724 | * 2) allocating for current task (not interrupt). | |
1725 | */ | |
1726 | struct page *alloc_pages_current(gfp_t gfp, unsigned order) | |
1727 | { | |
1728 | struct mempolicy *pol = current->mempolicy; | |
1729 | ||
1730 | if (!pol || in_interrupt() || (gfp & __GFP_THISNODE)) | |
1731 | pol = &default_policy; | |
1732 | ||
1733 | /* | |
1734 | * No reference counting needed for current->mempolicy | |
1735 | * nor system default_policy | |
1736 | */ | |
1737 | if (pol->mode == MPOL_INTERLEAVE) | |
1738 | return alloc_page_interleave(gfp, order, interleave_nodes(pol)); | |
1739 | return __alloc_pages_nodemask(gfp, order, | |
1740 | policy_zonelist(gfp, pol), policy_nodemask(gfp, pol)); | |
1741 | } | |
1742 | EXPORT_SYMBOL(alloc_pages_current); | |
1743 | ||
1744 | /* | |
1745 | * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it | |
1746 | * rebinds the mempolicy its copying by calling mpol_rebind_policy() | |
1747 | * with the mems_allowed returned by cpuset_mems_allowed(). This | |
1748 | * keeps mempolicies cpuset relative after its cpuset moves. See | |
1749 | * further kernel/cpuset.c update_nodemask(). | |
1750 | */ | |
1751 | ||
1752 | /* Slow path of a mempolicy duplicate */ | |
1753 | struct mempolicy *__mpol_dup(struct mempolicy *old) | |
1754 | { | |
1755 | struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL); | |
1756 | ||
1757 | if (!new) | |
1758 | return ERR_PTR(-ENOMEM); | |
1759 | rcu_read_lock(); | |
1760 | if (current_cpuset_is_being_rebound()) { | |
1761 | nodemask_t mems = cpuset_mems_allowed(current); | |
1762 | mpol_rebind_policy(old, &mems); | |
1763 | } | |
1764 | rcu_read_unlock(); | |
1765 | *new = *old; | |
1766 | atomic_set(&new->refcnt, 1); | |
1767 | return new; | |
1768 | } | |
1769 | ||
1770 | /* | |
1771 | * If *frompol needs [has] an extra ref, copy *frompol to *tompol , | |
1772 | * eliminate the * MPOL_F_* flags that require conditional ref and | |
1773 | * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly | |
1774 | * after return. Use the returned value. | |
1775 | * | |
1776 | * Allows use of a mempolicy for, e.g., multiple allocations with a single | |
1777 | * policy lookup, even if the policy needs/has extra ref on lookup. | |
1778 | * shmem_readahead needs this. | |
1779 | */ | |
1780 | struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol, | |
1781 | struct mempolicy *frompol) | |
1782 | { | |
1783 | if (!mpol_needs_cond_ref(frompol)) | |
1784 | return frompol; | |
1785 | ||
1786 | *tompol = *frompol; | |
1787 | tompol->flags &= ~MPOL_F_SHARED; /* copy doesn't need unref */ | |
1788 | __mpol_put(frompol); | |
1789 | return tompol; | |
1790 | } | |
1791 | ||
1792 | static int mpol_match_intent(const struct mempolicy *a, | |
1793 | const struct mempolicy *b) | |
1794 | { | |
1795 | if (a->flags != b->flags) | |
1796 | return 0; | |
1797 | if (!mpol_store_user_nodemask(a)) | |
1798 | return 1; | |
1799 | return nodes_equal(a->w.user_nodemask, b->w.user_nodemask); | |
1800 | } | |
1801 | ||
1802 | /* Slow path of a mempolicy comparison */ | |
1803 | int __mpol_equal(struct mempolicy *a, struct mempolicy *b) | |
1804 | { | |
1805 | if (!a || !b) | |
1806 | return 0; | |
1807 | if (a->mode != b->mode) | |
1808 | return 0; | |
1809 | if (a->mode != MPOL_DEFAULT && !mpol_match_intent(a, b)) | |
1810 | return 0; | |
1811 | switch (a->mode) { | |
1812 | case MPOL_BIND: | |
1813 | /* Fall through */ | |
1814 | case MPOL_INTERLEAVE: | |
1815 | return nodes_equal(a->v.nodes, b->v.nodes); | |
1816 | case MPOL_PREFERRED: | |
1817 | return a->v.preferred_node == b->v.preferred_node && | |
1818 | a->flags == b->flags; | |
1819 | default: | |
1820 | BUG(); | |
1821 | return 0; | |
1822 | } | |
1823 | } | |
1824 | ||
1825 | /* | |
1826 | * Shared memory backing store policy support. | |
1827 | * | |
1828 | * Remember policies even when nobody has shared memory mapped. | |
1829 | * The policies are kept in Red-Black tree linked from the inode. | |
1830 | * They are protected by the sp->lock spinlock, which should be held | |
1831 | * for any accesses to the tree. | |
1832 | */ | |
1833 | ||
1834 | /* lookup first element intersecting start-end */ | |
1835 | /* Caller holds sp->lock */ | |
1836 | static struct sp_node * | |
1837 | sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end) | |
1838 | { | |
1839 | struct rb_node *n = sp->root.rb_node; | |
1840 | ||
1841 | while (n) { | |
1842 | struct sp_node *p = rb_entry(n, struct sp_node, nd); | |
1843 | ||
1844 | if (start >= p->end) | |
1845 | n = n->rb_right; | |
1846 | else if (end <= p->start) | |
1847 | n = n->rb_left; | |
1848 | else | |
1849 | break; | |
1850 | } | |
1851 | if (!n) | |
1852 | return NULL; | |
1853 | for (;;) { | |
1854 | struct sp_node *w = NULL; | |
1855 | struct rb_node *prev = rb_prev(n); | |
1856 | if (!prev) | |
1857 | break; | |
1858 | w = rb_entry(prev, struct sp_node, nd); | |
1859 | if (w->end <= start) | |
1860 | break; | |
1861 | n = prev; | |
1862 | } | |
1863 | return rb_entry(n, struct sp_node, nd); | |
1864 | } | |
1865 | ||
1866 | /* Insert a new shared policy into the list. */ | |
1867 | /* Caller holds sp->lock */ | |
1868 | static void sp_insert(struct shared_policy *sp, struct sp_node *new) | |
1869 | { | |
1870 | struct rb_node **p = &sp->root.rb_node; | |
1871 | struct rb_node *parent = NULL; | |
1872 | struct sp_node *nd; | |
1873 | ||
1874 | while (*p) { | |
1875 | parent = *p; | |
1876 | nd = rb_entry(parent, struct sp_node, nd); | |
1877 | if (new->start < nd->start) | |
1878 | p = &(*p)->rb_left; | |
1879 | else if (new->end > nd->end) | |
1880 | p = &(*p)->rb_right; | |
1881 | else | |
1882 | BUG(); | |
1883 | } | |
1884 | rb_link_node(&new->nd, parent, p); | |
1885 | rb_insert_color(&new->nd, &sp->root); | |
1886 | pr_debug("inserting %lx-%lx: %d\n", new->start, new->end, | |
1887 | new->policy ? new->policy->mode : 0); | |
1888 | } | |
1889 | ||
1890 | /* Find shared policy intersecting idx */ | |
1891 | struct mempolicy * | |
1892 | mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx) | |
1893 | { | |
1894 | struct mempolicy *pol = NULL; | |
1895 | struct sp_node *sn; | |
1896 | ||
1897 | if (!sp->root.rb_node) | |
1898 | return NULL; | |
1899 | spin_lock(&sp->lock); | |
1900 | sn = sp_lookup(sp, idx, idx+1); | |
1901 | if (sn) { | |
1902 | mpol_get(sn->policy); | |
1903 | pol = sn->policy; | |
1904 | } | |
1905 | spin_unlock(&sp->lock); | |
1906 | return pol; | |
1907 | } | |
1908 | ||
1909 | static void sp_delete(struct shared_policy *sp, struct sp_node *n) | |
1910 | { | |
1911 | pr_debug("deleting %lx-l%lx\n", n->start, n->end); | |
1912 | rb_erase(&n->nd, &sp->root); | |
1913 | mpol_put(n->policy); | |
1914 | kmem_cache_free(sn_cache, n); | |
1915 | } | |
1916 | ||
1917 | static struct sp_node *sp_alloc(unsigned long start, unsigned long end, | |
1918 | struct mempolicy *pol) | |
1919 | { | |
1920 | struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL); | |
1921 | ||
1922 | if (!n) | |
1923 | return NULL; | |
1924 | n->start = start; | |
1925 | n->end = end; | |
1926 | mpol_get(pol); | |
1927 | pol->flags |= MPOL_F_SHARED; /* for unref */ | |
1928 | n->policy = pol; | |
1929 | return n; | |
1930 | } | |
1931 | ||
1932 | /* Replace a policy range. */ | |
1933 | static int shared_policy_replace(struct shared_policy *sp, unsigned long start, | |
1934 | unsigned long end, struct sp_node *new) | |
1935 | { | |
1936 | struct sp_node *n, *new2 = NULL; | |
1937 | ||
1938 | restart: | |
1939 | spin_lock(&sp->lock); | |
1940 | n = sp_lookup(sp, start, end); | |
1941 | /* Take care of old policies in the same range. */ | |
1942 | while (n && n->start < end) { | |
1943 | struct rb_node *next = rb_next(&n->nd); | |
1944 | if (n->start >= start) { | |
1945 | if (n->end <= end) | |
1946 | sp_delete(sp, n); | |
1947 | else | |
1948 | n->start = end; | |
1949 | } else { | |
1950 | /* Old policy spanning whole new range. */ | |
1951 | if (n->end > end) { | |
1952 | if (!new2) { | |
1953 | spin_unlock(&sp->lock); | |
1954 | new2 = sp_alloc(end, n->end, n->policy); | |
1955 | if (!new2) | |
1956 | return -ENOMEM; | |
1957 | goto restart; | |
1958 | } | |
1959 | n->end = start; | |
1960 | sp_insert(sp, new2); | |
1961 | new2 = NULL; | |
1962 | break; | |
1963 | } else | |
1964 | n->end = start; | |
1965 | } | |
1966 | if (!next) | |
1967 | break; | |
1968 | n = rb_entry(next, struct sp_node, nd); | |
1969 | } | |
1970 | if (new) | |
1971 | sp_insert(sp, new); | |
1972 | spin_unlock(&sp->lock); | |
1973 | if (new2) { | |
1974 | mpol_put(new2->policy); | |
1975 | kmem_cache_free(sn_cache, new2); | |
1976 | } | |
1977 | return 0; | |
1978 | } | |
1979 | ||
1980 | /** | |
1981 | * mpol_shared_policy_init - initialize shared policy for inode | |
1982 | * @sp: pointer to inode shared policy | |
1983 | * @mpol: struct mempolicy to install | |
1984 | * | |
1985 | * Install non-NULL @mpol in inode's shared policy rb-tree. | |
1986 | * On entry, the current task has a reference on a non-NULL @mpol. | |
1987 | * This must be released on exit. | |
1988 | * This is called at get_inode() calls and we can use GFP_KERNEL. | |
1989 | */ | |
1990 | void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol) | |
1991 | { | |
1992 | int ret; | |
1993 | ||
1994 | sp->root = RB_ROOT; /* empty tree == default mempolicy */ | |
1995 | spin_lock_init(&sp->lock); | |
1996 | ||
1997 | if (mpol) { | |
1998 | struct vm_area_struct pvma; | |
1999 | struct mempolicy *new; | |
2000 | NODEMASK_SCRATCH(scratch); | |
2001 | ||
2002 | if (!scratch) | |
2003 | return; | |
2004 | /* contextualize the tmpfs mount point mempolicy */ | |
2005 | new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask); | |
2006 | if (IS_ERR(new)) { | |
2007 | mpol_put(mpol); /* drop our ref on sb mpol */ | |
2008 | NODEMASK_SCRATCH_FREE(scratch); | |
2009 | return; /* no valid nodemask intersection */ | |
2010 | } | |
2011 | ||
2012 | task_lock(current); | |
2013 | ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch); | |
2014 | task_unlock(current); | |
2015 | mpol_put(mpol); /* drop our ref on sb mpol */ | |
2016 | if (ret) { | |
2017 | NODEMASK_SCRATCH_FREE(scratch); | |
2018 | mpol_put(new); | |
2019 | return; | |
2020 | } | |
2021 | ||
2022 | /* Create pseudo-vma that contains just the policy */ | |
2023 | memset(&pvma, 0, sizeof(struct vm_area_struct)); | |
2024 | pvma.vm_end = TASK_SIZE; /* policy covers entire file */ | |
2025 | mpol_set_shared_policy(sp, &pvma, new); /* adds ref */ | |
2026 | mpol_put(new); /* drop initial ref */ | |
2027 | NODEMASK_SCRATCH_FREE(scratch); | |
2028 | } | |
2029 | } | |
2030 | ||
2031 | int mpol_set_shared_policy(struct shared_policy *info, | |
2032 | struct vm_area_struct *vma, struct mempolicy *npol) | |
2033 | { | |
2034 | int err; | |
2035 | struct sp_node *new = NULL; | |
2036 | unsigned long sz = vma_pages(vma); | |
2037 | ||
2038 | pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n", | |
2039 | vma->vm_pgoff, | |
2040 | sz, npol ? npol->mode : -1, | |
2041 | npol ? npol->flags : -1, | |
2042 | npol ? nodes_addr(npol->v.nodes)[0] : -1); | |
2043 | ||
2044 | if (npol) { | |
2045 | new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol); | |
2046 | if (!new) | |
2047 | return -ENOMEM; | |
2048 | } | |
2049 | err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new); | |
2050 | if (err && new) | |
2051 | kmem_cache_free(sn_cache, new); | |
2052 | return err; | |
2053 | } | |
2054 | ||
2055 | /* Free a backing policy store on inode delete. */ | |
2056 | void mpol_free_shared_policy(struct shared_policy *p) | |
2057 | { | |
2058 | struct sp_node *n; | |
2059 | struct rb_node *next; | |
2060 | ||
2061 | if (!p->root.rb_node) | |
2062 | return; | |
2063 | spin_lock(&p->lock); | |
2064 | next = rb_first(&p->root); | |
2065 | while (next) { | |
2066 | n = rb_entry(next, struct sp_node, nd); | |
2067 | next = rb_next(&n->nd); | |
2068 | rb_erase(&n->nd, &p->root); | |
2069 | mpol_put(n->policy); | |
2070 | kmem_cache_free(sn_cache, n); | |
2071 | } | |
2072 | spin_unlock(&p->lock); | |
2073 | } | |
2074 | ||
2075 | /* assumes fs == KERNEL_DS */ | |
2076 | void __init numa_policy_init(void) | |
2077 | { | |
2078 | nodemask_t interleave_nodes; | |
2079 | unsigned long largest = 0; | |
2080 | int nid, prefer = 0; | |
2081 | ||
2082 | policy_cache = kmem_cache_create("numa_policy", | |
2083 | sizeof(struct mempolicy), | |
2084 | 0, SLAB_PANIC, NULL); | |
2085 | ||
2086 | sn_cache = kmem_cache_create("shared_policy_node", | |
2087 | sizeof(struct sp_node), | |
2088 | 0, SLAB_PANIC, NULL); | |
2089 | ||
2090 | /* | |
2091 | * Set interleaving policy for system init. Interleaving is only | |
2092 | * enabled across suitably sized nodes (default is >= 16MB), or | |
2093 | * fall back to the largest node if they're all smaller. | |
2094 | */ | |
2095 | nodes_clear(interleave_nodes); | |
2096 | for_each_node_state(nid, N_HIGH_MEMORY) { | |
2097 | unsigned long total_pages = node_present_pages(nid); | |
2098 | ||
2099 | /* Preserve the largest node */ | |
2100 | if (largest < total_pages) { | |
2101 | largest = total_pages; | |
2102 | prefer = nid; | |
2103 | } | |
2104 | ||
2105 | /* Interleave this node? */ | |
2106 | if ((total_pages << PAGE_SHIFT) >= (16 << 20)) | |
2107 | node_set(nid, interleave_nodes); | |
2108 | } | |
2109 | ||
2110 | /* All too small, use the largest */ | |
2111 | if (unlikely(nodes_empty(interleave_nodes))) | |
2112 | node_set(prefer, interleave_nodes); | |
2113 | ||
2114 | if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes)) | |
2115 | printk("numa_policy_init: interleaving failed\n"); | |
2116 | } | |
2117 | ||
2118 | /* Reset policy of current process to default */ | |
2119 | void numa_default_policy(void) | |
2120 | { | |
2121 | do_set_mempolicy(MPOL_DEFAULT, 0, NULL); | |
2122 | } | |
2123 | ||
2124 | /* | |
2125 | * Parse and format mempolicy from/to strings | |
2126 | */ | |
2127 | ||
2128 | /* | |
2129 | * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag | |
2130 | * Used only for mpol_parse_str() and mpol_to_str() | |
2131 | */ | |
2132 | #define MPOL_LOCAL (MPOL_INTERLEAVE + 1) | |
2133 | static const char * const policy_types[] = | |
2134 | { "default", "prefer", "bind", "interleave", "local" }; | |
2135 | ||
2136 | ||
2137 | #ifdef CONFIG_TMPFS | |
2138 | /** | |
2139 | * mpol_parse_str - parse string to mempolicy | |
2140 | * @str: string containing mempolicy to parse | |
2141 | * @mpol: pointer to struct mempolicy pointer, returned on success. | |
2142 | * @no_context: flag whether to "contextualize" the mempolicy | |
2143 | * | |
2144 | * Format of input: | |
2145 | * <mode>[=<flags>][:<nodelist>] | |
2146 | * | |
2147 | * if @no_context is true, save the input nodemask in w.user_nodemask in | |
2148 | * the returned mempolicy. This will be used to "clone" the mempolicy in | |
2149 | * a specific context [cpuset] at a later time. Used to parse tmpfs mpol | |
2150 | * mount option. Note that if 'static' or 'relative' mode flags were | |
2151 | * specified, the input nodemask will already have been saved. Saving | |
2152 | * it again is redundant, but safe. | |
2153 | * | |
2154 | * On success, returns 0, else 1 | |
2155 | */ | |
2156 | int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) | |
2157 | { | |
2158 | struct mempolicy *new = NULL; | |
2159 | unsigned short uninitialized_var(mode); | |
2160 | unsigned short uninitialized_var(mode_flags); | |
2161 | nodemask_t nodes; | |
2162 | char *nodelist = strchr(str, ':'); | |
2163 | char *flags = strchr(str, '='); | |
2164 | int i; | |
2165 | int err = 1; | |
2166 | ||
2167 | if (nodelist) { | |
2168 | /* NUL-terminate mode or flags string */ | |
2169 | *nodelist++ = '\0'; | |
2170 | if (nodelist_parse(nodelist, nodes)) | |
2171 | goto out; | |
2172 | if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY])) | |
2173 | goto out; | |
2174 | } else | |
2175 | nodes_clear(nodes); | |
2176 | ||
2177 | if (flags) | |
2178 | *flags++ = '\0'; /* terminate mode string */ | |
2179 | ||
2180 | for (i = 0; i <= MPOL_LOCAL; i++) { | |
2181 | if (!strcmp(str, policy_types[i])) { | |
2182 | mode = i; | |
2183 | break; | |
2184 | } | |
2185 | } | |
2186 | if (i > MPOL_LOCAL) | |
2187 | goto out; | |
2188 | ||
2189 | switch (mode) { | |
2190 | case MPOL_PREFERRED: | |
2191 | /* | |
2192 | * Insist on a nodelist of one node only | |
2193 | */ | |
2194 | if (nodelist) { | |
2195 | char *rest = nodelist; | |
2196 | while (isdigit(*rest)) | |
2197 | rest++; | |
2198 | if (*rest) | |
2199 | goto out; | |
2200 | } | |
2201 | break; | |
2202 | case MPOL_INTERLEAVE: | |
2203 | /* | |
2204 | * Default to online nodes with memory if no nodelist | |
2205 | */ | |
2206 | if (!nodelist) | |
2207 | nodes = node_states[N_HIGH_MEMORY]; | |
2208 | break; | |
2209 | case MPOL_LOCAL: | |
2210 | /* | |
2211 | * Don't allow a nodelist; mpol_new() checks flags | |
2212 | */ | |
2213 | if (nodelist) | |
2214 | goto out; | |
2215 | mode = MPOL_PREFERRED; | |
2216 | break; | |
2217 | case MPOL_DEFAULT: | |
2218 | /* | |
2219 | * Insist on a empty nodelist | |
2220 | */ | |
2221 | if (!nodelist) | |
2222 | err = 0; | |
2223 | goto out; | |
2224 | case MPOL_BIND: | |
2225 | /* | |
2226 | * Insist on a nodelist | |
2227 | */ | |
2228 | if (!nodelist) | |
2229 | goto out; | |
2230 | } | |
2231 | ||
2232 | mode_flags = 0; | |
2233 | if (flags) { | |
2234 | /* | |
2235 | * Currently, we only support two mutually exclusive | |
2236 | * mode flags. | |
2237 | */ | |
2238 | if (!strcmp(flags, "static")) | |
2239 | mode_flags |= MPOL_F_STATIC_NODES; | |
2240 | else if (!strcmp(flags, "relative")) | |
2241 | mode_flags |= MPOL_F_RELATIVE_NODES; | |
2242 | else | |
2243 | goto out; | |
2244 | } | |
2245 | ||
2246 | new = mpol_new(mode, mode_flags, &nodes); | |
2247 | if (IS_ERR(new)) | |
2248 | goto out; | |
2249 | ||
2250 | { | |
2251 | int ret; | |
2252 | NODEMASK_SCRATCH(scratch); | |
2253 | if (scratch) { | |
2254 | task_lock(current); | |
2255 | ret = mpol_set_nodemask(new, &nodes, scratch); | |
2256 | task_unlock(current); | |
2257 | } else | |
2258 | ret = -ENOMEM; | |
2259 | NODEMASK_SCRATCH_FREE(scratch); | |
2260 | if (ret) { | |
2261 | mpol_put(new); | |
2262 | goto out; | |
2263 | } | |
2264 | } | |
2265 | err = 0; | |
2266 | if (no_context) { | |
2267 | /* save for contextualization */ | |
2268 | new->w.user_nodemask = nodes; | |
2269 | } | |
2270 | ||
2271 | out: | |
2272 | /* Restore string for error message */ | |
2273 | if (nodelist) | |
2274 | *--nodelist = ':'; | |
2275 | if (flags) | |
2276 | *--flags = '='; | |
2277 | if (!err) | |
2278 | *mpol = new; | |
2279 | return err; | |
2280 | } | |
2281 | #endif /* CONFIG_TMPFS */ | |
2282 | ||
2283 | /** | |
2284 | * mpol_to_str - format a mempolicy structure for printing | |
2285 | * @buffer: to contain formatted mempolicy string | |
2286 | * @maxlen: length of @buffer | |
2287 | * @pol: pointer to mempolicy to be formatted | |
2288 | * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask | |
2289 | * | |
2290 | * Convert a mempolicy into a string. | |
2291 | * Returns the number of characters in buffer (if positive) | |
2292 | * or an error (negative) | |
2293 | */ | |
2294 | int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context) | |
2295 | { | |
2296 | char *p = buffer; | |
2297 | int l; | |
2298 | nodemask_t nodes; | |
2299 | unsigned short mode; | |
2300 | unsigned short flags = pol ? pol->flags : 0; | |
2301 | ||
2302 | /* | |
2303 | * Sanity check: room for longest mode, flag and some nodes | |
2304 | */ | |
2305 | VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16); | |
2306 | ||
2307 | if (!pol || pol == &default_policy) | |
2308 | mode = MPOL_DEFAULT; | |
2309 | else | |
2310 | mode = pol->mode; | |
2311 | ||
2312 | switch (mode) { | |
2313 | case MPOL_DEFAULT: | |
2314 | nodes_clear(nodes); | |
2315 | break; | |
2316 | ||
2317 | case MPOL_PREFERRED: | |
2318 | nodes_clear(nodes); | |
2319 | if (flags & MPOL_F_LOCAL) | |
2320 | mode = MPOL_LOCAL; /* pseudo-policy */ | |
2321 | else | |
2322 | node_set(pol->v.preferred_node, nodes); | |
2323 | break; | |
2324 | ||
2325 | case MPOL_BIND: | |
2326 | /* Fall through */ | |
2327 | case MPOL_INTERLEAVE: | |
2328 | if (no_context) | |
2329 | nodes = pol->w.user_nodemask; | |
2330 | else | |
2331 | nodes = pol->v.nodes; | |
2332 | break; | |
2333 | ||
2334 | default: | |
2335 | BUG(); | |
2336 | } | |
2337 | ||
2338 | l = strlen(policy_types[mode]); | |
2339 | if (buffer + maxlen < p + l + 1) | |
2340 | return -ENOSPC; | |
2341 | ||
2342 | strcpy(p, policy_types[mode]); | |
2343 | p += l; | |
2344 | ||
2345 | if (flags & MPOL_MODE_FLAGS) { | |
2346 | if (buffer + maxlen < p + 2) | |
2347 | return -ENOSPC; | |
2348 | *p++ = '='; | |
2349 | ||
2350 | /* | |
2351 | * Currently, the only defined flags are mutually exclusive | |
2352 | */ | |
2353 | if (flags & MPOL_F_STATIC_NODES) | |
2354 | p += snprintf(p, buffer + maxlen - p, "static"); | |
2355 | else if (flags & MPOL_F_RELATIVE_NODES) | |
2356 | p += snprintf(p, buffer + maxlen - p, "relative"); | |
2357 | } | |
2358 | ||
2359 | if (!nodes_empty(nodes)) { | |
2360 | if (buffer + maxlen < p + 2) | |
2361 | return -ENOSPC; | |
2362 | *p++ = ':'; | |
2363 | p += nodelist_scnprintf(p, buffer + maxlen - p, nodes); | |
2364 | } | |
2365 | return p - buffer; | |
2366 | } | |
2367 | ||
2368 | struct numa_maps { | |
2369 | unsigned long pages; | |
2370 | unsigned long anon; | |
2371 | unsigned long active; | |
2372 | unsigned long writeback; | |
2373 | unsigned long mapcount_max; | |
2374 | unsigned long dirty; | |
2375 | unsigned long swapcache; | |
2376 | unsigned long node[MAX_NUMNODES]; | |
2377 | }; | |
2378 | ||
2379 | static void gather_stats(struct page *page, void *private, int pte_dirty) | |
2380 | { | |
2381 | struct numa_maps *md = private; | |
2382 | int count = page_mapcount(page); | |
2383 | ||
2384 | md->pages++; | |
2385 | if (pte_dirty || PageDirty(page)) | |
2386 | md->dirty++; | |
2387 | ||
2388 | if (PageSwapCache(page)) | |
2389 | md->swapcache++; | |
2390 | ||
2391 | if (PageActive(page) || PageUnevictable(page)) | |
2392 | md->active++; | |
2393 | ||
2394 | if (PageWriteback(page)) | |
2395 | md->writeback++; | |
2396 | ||
2397 | if (PageAnon(page)) | |
2398 | md->anon++; | |
2399 | ||
2400 | if (count > md->mapcount_max) | |
2401 | md->mapcount_max = count; | |
2402 | ||
2403 | md->node[page_to_nid(page)]++; | |
2404 | } | |
2405 | ||
2406 | #ifdef CONFIG_HUGETLB_PAGE | |
2407 | static void check_huge_range(struct vm_area_struct *vma, | |
2408 | unsigned long start, unsigned long end, | |
2409 | struct numa_maps *md) | |
2410 | { | |
2411 | unsigned long addr; | |
2412 | struct page *page; | |
2413 | struct hstate *h = hstate_vma(vma); | |
2414 | unsigned long sz = huge_page_size(h); | |
2415 | ||
2416 | for (addr = start; addr < end; addr += sz) { | |
2417 | pte_t *ptep = huge_pte_offset(vma->vm_mm, | |
2418 | addr & huge_page_mask(h)); | |
2419 | pte_t pte; | |
2420 | ||
2421 | if (!ptep) | |
2422 | continue; | |
2423 | ||
2424 | pte = *ptep; | |
2425 | if (pte_none(pte)) | |
2426 | continue; | |
2427 | ||
2428 | page = pte_page(pte); | |
2429 | if (!page) | |
2430 | continue; | |
2431 | ||
2432 | gather_stats(page, md, pte_dirty(*ptep)); | |
2433 | } | |
2434 | } | |
2435 | #else | |
2436 | static inline void check_huge_range(struct vm_area_struct *vma, | |
2437 | unsigned long start, unsigned long end, | |
2438 | struct numa_maps *md) | |
2439 | { | |
2440 | } | |
2441 | #endif | |
2442 | ||
2443 | /* | |
2444 | * Display pages allocated per node and memory policy via /proc. | |
2445 | */ | |
2446 | int show_numa_map(struct seq_file *m, void *v) | |
2447 | { | |
2448 | struct proc_maps_private *priv = m->private; | |
2449 | struct vm_area_struct *vma = v; | |
2450 | struct numa_maps *md; | |
2451 | struct file *file = vma->vm_file; | |
2452 | struct mm_struct *mm = vma->vm_mm; | |
2453 | struct mempolicy *pol; | |
2454 | int n; | |
2455 | char buffer[50]; | |
2456 | ||
2457 | if (!mm) | |
2458 | return 0; | |
2459 | ||
2460 | md = kzalloc(sizeof(struct numa_maps), GFP_KERNEL); | |
2461 | if (!md) | |
2462 | return 0; | |
2463 | ||
2464 | pol = get_vma_policy(priv->task, vma, vma->vm_start); | |
2465 | mpol_to_str(buffer, sizeof(buffer), pol, 0); | |
2466 | mpol_cond_put(pol); | |
2467 | ||
2468 | seq_printf(m, "%08lx %s", vma->vm_start, buffer); | |
2469 | ||
2470 | if (file) { | |
2471 | seq_printf(m, " file="); | |
2472 | seq_path(m, &file->f_path, "\n\t= "); | |
2473 | } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) { | |
2474 | seq_printf(m, " heap"); | |
2475 | } else if (vma->vm_start <= mm->start_stack && | |
2476 | vma->vm_end >= mm->start_stack) { | |
2477 | seq_printf(m, " stack"); | |
2478 | } | |
2479 | ||
2480 | if (is_vm_hugetlb_page(vma)) { | |
2481 | check_huge_range(vma, vma->vm_start, vma->vm_end, md); | |
2482 | seq_printf(m, " huge"); | |
2483 | } else { | |
2484 | check_pgd_range(vma, vma->vm_start, vma->vm_end, | |
2485 | &node_states[N_HIGH_MEMORY], MPOL_MF_STATS, md); | |
2486 | } | |
2487 | ||
2488 | if (!md->pages) | |
2489 | goto out; | |
2490 | ||
2491 | if (md->anon) | |
2492 | seq_printf(m," anon=%lu",md->anon); | |
2493 | ||
2494 | if (md->dirty) | |
2495 | seq_printf(m," dirty=%lu",md->dirty); | |
2496 | ||
2497 | if (md->pages != md->anon && md->pages != md->dirty) | |
2498 | seq_printf(m, " mapped=%lu", md->pages); | |
2499 | ||
2500 | if (md->mapcount_max > 1) | |
2501 | seq_printf(m, " mapmax=%lu", md->mapcount_max); | |
2502 | ||
2503 | if (md->swapcache) | |
2504 | seq_printf(m," swapcache=%lu", md->swapcache); | |
2505 | ||
2506 | if (md->active < md->pages && !is_vm_hugetlb_page(vma)) | |
2507 | seq_printf(m," active=%lu", md->active); | |
2508 | ||
2509 | if (md->writeback) | |
2510 | seq_printf(m," writeback=%lu", md->writeback); | |
2511 | ||
2512 | for_each_node_state(n, N_HIGH_MEMORY) | |
2513 | if (md->node[n]) | |
2514 | seq_printf(m, " N%d=%lu", n, md->node[n]); | |
2515 | out: | |
2516 | seq_putc(m, '\n'); | |
2517 | kfree(md); | |
2518 | ||
2519 | if (m->count < m->size) | |
2520 | m->version = (vma != priv->tail_vma) ? vma->vm_start : 0; | |
2521 | return 0; | |
2522 | } |