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 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
69 | |
70 | #include <linux/mempolicy.h> |
71 | #include <linux/mm.h> |
72 | #include <linux/highmem.h> |
73 | #include <linux/hugetlb.h> |
74 | #include <linux/kernel.h> |
75 | #include <linux/sched.h> |
76 | #include <linux/sched/mm.h> |
77 | #include <linux/sched/numa_balancing.h> |
78 | #include <linux/sched/task.h> |
79 | #include <linux/nodemask.h> |
80 | #include <linux/cpuset.h> |
81 | #include <linux/slab.h> |
82 | #include <linux/string.h> |
83 | #include <linux/export.h> |
84 | #include <linux/nsproxy.h> |
85 | #include <linux/interrupt.h> |
86 | #include <linux/init.h> |
87 | #include <linux/compat.h> |
88 | #include <linux/ptrace.h> |
89 | #include <linux/swap.h> |
90 | #include <linux/seq_file.h> |
91 | #include <linux/proc_fs.h> |
92 | #include <linux/migrate.h> |
93 | #include <linux/ksm.h> |
94 | #include <linux/rmap.h> |
95 | #include <linux/security.h> |
96 | #include <linux/syscalls.h> |
97 | #include <linux/ctype.h> |
98 | #include <linux/mm_inline.h> |
99 | #include <linux/mmu_notifier.h> |
100 | #include <linux/printk.h> |
101 | #include <linux/swapops.h> |
102 | |
103 | #include <asm/tlbflush.h> |
104 | #include <linux/uaccess.h> |
105 | |
106 | #include "internal.h" |
107 | |
108 | /* Internal flags */ |
109 | #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */ |
110 | #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */ |
111 | |
112 | static struct kmem_cache *policy_cache; |
113 | static struct kmem_cache *sn_cache; |
114 | |
115 | /* Highest zone. An specific allocation for a zone below that is not |
116 | policied. */ |
117 | enum zone_type policy_zone = 0; |
118 | |
119 | /* |
120 | * run-time system-wide default policy => local allocation |
121 | */ |
122 | static struct mempolicy default_policy = { |
123 | .refcnt = ATOMIC_INIT(1), /* never free it */ |
124 | .mode = MPOL_PREFERRED, |
125 | .flags = MPOL_F_LOCAL, |
126 | }; |
127 | |
128 | static struct mempolicy preferred_node_policy[MAX_NUMNODES]; |
129 | |
130 | struct mempolicy *get_task_policy(struct task_struct *p) |
131 | { |
132 | struct mempolicy *pol = p->mempolicy; |
133 | int node; |
134 | |
135 | if (pol) |
136 | return pol; |
137 | |
138 | node = numa_node_id(); |
139 | if (node != NUMA_NO_NODE) { |
140 | pol = &preferred_node_policy[node]; |
141 | /* preferred_node_policy is not initialised early in boot */ |
142 | if (pol->mode) |
143 | return pol; |
144 | } |
145 | |
146 | return &default_policy; |
147 | } |
148 | |
149 | static const struct mempolicy_operations { |
150 | int (*create)(struct mempolicy *pol, const nodemask_t *nodes); |
151 | void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes); |
152 | } mpol_ops[MPOL_MAX]; |
153 | |
154 | static inline int mpol_store_user_nodemask(const struct mempolicy *pol) |
155 | { |
156 | return pol->flags & MPOL_MODE_FLAGS; |
157 | } |
158 | |
159 | static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig, |
160 | const nodemask_t *rel) |
161 | { |
162 | nodemask_t tmp; |
163 | nodes_fold(tmp, *orig, nodes_weight(*rel)); |
164 | nodes_onto(*ret, tmp, *rel); |
165 | } |
166 | |
167 | static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes) |
168 | { |
169 | if (nodes_empty(*nodes)) |
170 | return -EINVAL; |
171 | pol->v.nodes = *nodes; |
172 | return 0; |
173 | } |
174 | |
175 | static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes) |
176 | { |
177 | if (!nodes) |
178 | pol->flags |= MPOL_F_LOCAL; /* local allocation */ |
179 | else if (nodes_empty(*nodes)) |
180 | return -EINVAL; /* no allowed nodes */ |
181 | else |
182 | pol->v.preferred_node = first_node(*nodes); |
183 | return 0; |
184 | } |
185 | |
186 | static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes) |
187 | { |
188 | if (nodes_empty(*nodes)) |
189 | return -EINVAL; |
190 | pol->v.nodes = *nodes; |
191 | return 0; |
192 | } |
193 | |
194 | /* |
195 | * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if |
196 | * any, for the new policy. mpol_new() has already validated the nodes |
197 | * parameter with respect to the policy mode and flags. But, we need to |
198 | * handle an empty nodemask with MPOL_PREFERRED here. |
199 | * |
200 | * Must be called holding task's alloc_lock to protect task's mems_allowed |
201 | * and mempolicy. May also be called holding the mmap_semaphore for write. |
202 | */ |
203 | static int mpol_set_nodemask(struct mempolicy *pol, |
204 | const nodemask_t *nodes, struct nodemask_scratch *nsc) |
205 | { |
206 | int ret; |
207 | |
208 | /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */ |
209 | if (pol == NULL) |
210 | return 0; |
211 | /* Check N_MEMORY */ |
212 | nodes_and(nsc->mask1, |
213 | cpuset_current_mems_allowed, node_states[N_MEMORY]); |
214 | |
215 | VM_BUG_ON(!nodes); |
216 | if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes)) |
217 | nodes = NULL; /* explicit local allocation */ |
218 | else { |
219 | if (pol->flags & MPOL_F_RELATIVE_NODES) |
220 | mpol_relative_nodemask(&nsc->mask2, nodes, &nsc->mask1); |
221 | else |
222 | nodes_and(nsc->mask2, *nodes, nsc->mask1); |
223 | |
224 | if (mpol_store_user_nodemask(pol)) |
225 | pol->w.user_nodemask = *nodes; |
226 | else |
227 | pol->w.cpuset_mems_allowed = |
228 | cpuset_current_mems_allowed; |
229 | } |
230 | |
231 | if (nodes) |
232 | ret = mpol_ops[pol->mode].create(pol, &nsc->mask2); |
233 | else |
234 | ret = mpol_ops[pol->mode].create(pol, NULL); |
235 | return ret; |
236 | } |
237 | |
238 | /* |
239 | * This function just creates a new policy, does some check and simple |
240 | * initialization. You must invoke mpol_set_nodemask() to set nodes. |
241 | */ |
242 | static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, |
243 | nodemask_t *nodes) |
244 | { |
245 | struct mempolicy *policy; |
246 | |
247 | pr_debug("setting mode %d flags %d nodes[0] %lx\n" , |
248 | mode, flags, nodes ? nodes_addr(*nodes)[0] : NUMA_NO_NODE); |
249 | |
250 | if (mode == MPOL_DEFAULT) { |
251 | if (nodes && !nodes_empty(*nodes)) |
252 | return ERR_PTR(-EINVAL); |
253 | return NULL; |
254 | } |
255 | VM_BUG_ON(!nodes); |
256 | |
257 | /* |
258 | * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or |
259 | * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation). |
260 | * All other modes require a valid pointer to a non-empty nodemask. |
261 | */ |
262 | if (mode == MPOL_PREFERRED) { |
263 | if (nodes_empty(*nodes)) { |
264 | if (((flags & MPOL_F_STATIC_NODES) || |
265 | (flags & MPOL_F_RELATIVE_NODES))) |
266 | return ERR_PTR(-EINVAL); |
267 | } |
268 | } else if (mode == MPOL_LOCAL) { |
269 | if (!nodes_empty(*nodes) || |
270 | (flags & MPOL_F_STATIC_NODES) || |
271 | (flags & MPOL_F_RELATIVE_NODES)) |
272 | return ERR_PTR(-EINVAL); |
273 | mode = MPOL_PREFERRED; |
274 | } else if (nodes_empty(*nodes)) |
275 | return ERR_PTR(-EINVAL); |
276 | policy = kmem_cache_alloc(policy_cache, GFP_KERNEL); |
277 | if (!policy) |
278 | return ERR_PTR(-ENOMEM); |
279 | atomic_set(&policy->refcnt, 1); |
280 | policy->mode = mode; |
281 | policy->flags = flags; |
282 | |
283 | return policy; |
284 | } |
285 | |
286 | /* Slow path of a mpol destructor. */ |
287 | void __mpol_put(struct mempolicy *p) |
288 | { |
289 | if (!atomic_dec_and_test(&p->refcnt)) |
290 | return; |
291 | kmem_cache_free(policy_cache, p); |
292 | } |
293 | |
294 | static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes) |
295 | { |
296 | } |
297 | |
298 | static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes) |
299 | { |
300 | nodemask_t tmp; |
301 | |
302 | if (pol->flags & MPOL_F_STATIC_NODES) |
303 | nodes_and(tmp, pol->w.user_nodemask, *nodes); |
304 | else if (pol->flags & MPOL_F_RELATIVE_NODES) |
305 | mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); |
306 | else { |
307 | nodes_remap(tmp, pol->v.nodes,pol->w.cpuset_mems_allowed, |
308 | *nodes); |
309 | pol->w.cpuset_mems_allowed = tmp; |
310 | } |
311 | |
312 | if (nodes_empty(tmp)) |
313 | tmp = *nodes; |
314 | |
315 | pol->v.nodes = tmp; |
316 | } |
317 | |
318 | static void mpol_rebind_preferred(struct mempolicy *pol, |
319 | const nodemask_t *nodes) |
320 | { |
321 | nodemask_t tmp; |
322 | |
323 | if (pol->flags & MPOL_F_STATIC_NODES) { |
324 | int node = first_node(pol->w.user_nodemask); |
325 | |
326 | if (node_isset(node, *nodes)) { |
327 | pol->v.preferred_node = node; |
328 | pol->flags &= ~MPOL_F_LOCAL; |
329 | } else |
330 | pol->flags |= MPOL_F_LOCAL; |
331 | } else if (pol->flags & MPOL_F_RELATIVE_NODES) { |
332 | mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); |
333 | pol->v.preferred_node = first_node(tmp); |
334 | } else if (!(pol->flags & MPOL_F_LOCAL)) { |
335 | pol->v.preferred_node = node_remap(pol->v.preferred_node, |
336 | pol->w.cpuset_mems_allowed, |
337 | *nodes); |
338 | pol->w.cpuset_mems_allowed = *nodes; |
339 | } |
340 | } |
341 | |
342 | /* |
343 | * mpol_rebind_policy - Migrate a policy to a different set of nodes |
344 | * |
345 | * Per-vma policies are protected by mmap_sem. Allocations using per-task |
346 | * policies are protected by task->mems_allowed_seq to prevent a premature |
347 | * OOM/allocation failure due to parallel nodemask modification. |
348 | */ |
349 | static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask) |
350 | { |
351 | if (!pol) |
352 | return; |
353 | if (!mpol_store_user_nodemask(pol) && !(pol->flags & MPOL_F_LOCAL) && |
354 | nodes_equal(pol->w.cpuset_mems_allowed, *newmask)) |
355 | return; |
356 | |
357 | mpol_ops[pol->mode].rebind(pol, newmask); |
358 | } |
359 | |
360 | /* |
361 | * Wrapper for mpol_rebind_policy() that just requires task |
362 | * pointer, and updates task mempolicy. |
363 | * |
364 | * Called with task's alloc_lock held. |
365 | */ |
366 | |
367 | void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new) |
368 | { |
369 | mpol_rebind_policy(tsk->mempolicy, new); |
370 | } |
371 | |
372 | /* |
373 | * Rebind each vma in mm to new nodemask. |
374 | * |
375 | * Call holding a reference to mm. Takes mm->mmap_sem during call. |
376 | */ |
377 | |
378 | void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new) |
379 | { |
380 | struct vm_area_struct *vma; |
381 | |
382 | down_write(&mm->mmap_sem); |
383 | for (vma = mm->mmap; vma; vma = vma->vm_next) |
384 | mpol_rebind_policy(vma->vm_policy, new); |
385 | up_write(&mm->mmap_sem); |
386 | } |
387 | |
388 | static const struct mempolicy_operations mpol_ops[MPOL_MAX] = { |
389 | [MPOL_DEFAULT] = { |
390 | .rebind = mpol_rebind_default, |
391 | }, |
392 | [MPOL_INTERLEAVE] = { |
393 | .create = mpol_new_interleave, |
394 | .rebind = mpol_rebind_nodemask, |
395 | }, |
396 | [MPOL_PREFERRED] = { |
397 | .create = mpol_new_preferred, |
398 | .rebind = mpol_rebind_preferred, |
399 | }, |
400 | [MPOL_BIND] = { |
401 | .create = mpol_new_bind, |
402 | .rebind = mpol_rebind_nodemask, |
403 | }, |
404 | }; |
405 | |
406 | static void migrate_page_add(struct page *page, struct list_head *pagelist, |
407 | unsigned long flags); |
408 | |
409 | struct queue_pages { |
410 | struct list_head *pagelist; |
411 | unsigned long flags; |
412 | nodemask_t *nmask; |
413 | struct vm_area_struct *prev; |
414 | }; |
415 | |
416 | /* |
417 | * Check if the page's nid is in qp->nmask. |
418 | * |
419 | * If MPOL_MF_INVERT is set in qp->flags, check if the nid is |
420 | * in the invert of qp->nmask. |
421 | */ |
422 | static inline bool queue_pages_required(struct page *page, |
423 | struct queue_pages *qp) |
424 | { |
425 | int nid = page_to_nid(page); |
426 | unsigned long flags = qp->flags; |
427 | |
428 | return node_isset(nid, *qp->nmask) == !(flags & MPOL_MF_INVERT); |
429 | } |
430 | |
431 | static int queue_pages_pmd(pmd_t *pmd, spinlock_t *ptl, unsigned long addr, |
432 | unsigned long end, struct mm_walk *walk) |
433 | { |
434 | int ret = 0; |
435 | struct page *page; |
436 | struct queue_pages *qp = walk->private; |
437 | unsigned long flags; |
438 | |
439 | if (unlikely(is_pmd_migration_entry(*pmd))) { |
440 | ret = 1; |
441 | goto unlock; |
442 | } |
443 | page = pmd_page(*pmd); |
444 | if (is_huge_zero_page(page)) { |
445 | spin_unlock(ptl); |
446 | __split_huge_pmd(walk->vma, pmd, addr, false, NULL); |
447 | goto out; |
448 | } |
449 | if (!queue_pages_required(page, qp)) { |
450 | ret = 1; |
451 | goto unlock; |
452 | } |
453 | |
454 | ret = 1; |
455 | flags = qp->flags; |
456 | /* go to thp migration */ |
457 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) |
458 | migrate_page_add(page, qp->pagelist, flags); |
459 | unlock: |
460 | spin_unlock(ptl); |
461 | out: |
462 | return ret; |
463 | } |
464 | |
465 | /* |
466 | * Scan through pages checking if pages follow certain conditions, |
467 | * and move them to the pagelist if they do. |
468 | */ |
469 | static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr, |
470 | unsigned long end, struct mm_walk *walk) |
471 | { |
472 | struct vm_area_struct *vma = walk->vma; |
473 | struct page *page; |
474 | struct queue_pages *qp = walk->private; |
475 | unsigned long flags = qp->flags; |
476 | int ret; |
477 | pte_t *pte; |
478 | spinlock_t *ptl; |
479 | |
480 | ptl = pmd_trans_huge_lock(pmd, vma); |
481 | if (ptl) { |
482 | ret = queue_pages_pmd(pmd, ptl, addr, end, walk); |
483 | if (ret) |
484 | return 0; |
485 | } |
486 | |
487 | if (pmd_trans_unstable(pmd)) |
488 | return 0; |
489 | |
490 | pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); |
491 | for (; addr != end; pte++, addr += PAGE_SIZE) { |
492 | if (!pte_present(*pte)) |
493 | continue; |
494 | page = vm_normal_page(vma, addr, *pte); |
495 | if (!page) |
496 | continue; |
497 | /* |
498 | * vm_normal_page() filters out zero pages, but there might |
499 | * still be PageReserved pages to skip, perhaps in a VDSO. |
500 | */ |
501 | if (PageReserved(page)) |
502 | continue; |
503 | if (!queue_pages_required(page, qp)) |
504 | continue; |
505 | migrate_page_add(page, qp->pagelist, flags); |
506 | } |
507 | pte_unmap_unlock(pte - 1, ptl); |
508 | cond_resched(); |
509 | return 0; |
510 | } |
511 | |
512 | static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask, |
513 | unsigned long addr, unsigned long end, |
514 | struct mm_walk *walk) |
515 | { |
516 | #ifdef CONFIG_HUGETLB_PAGE |
517 | struct queue_pages *qp = walk->private; |
518 | unsigned long flags = qp->flags; |
519 | struct page *page; |
520 | spinlock_t *ptl; |
521 | pte_t entry; |
522 | |
523 | ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte); |
524 | entry = huge_ptep_get(pte); |
525 | if (!pte_present(entry)) |
526 | goto unlock; |
527 | page = pte_page(entry); |
528 | if (!queue_pages_required(page, qp)) |
529 | goto unlock; |
530 | /* With MPOL_MF_MOVE, we migrate only unshared hugepage. */ |
531 | if (flags & (MPOL_MF_MOVE_ALL) || |
532 | (flags & MPOL_MF_MOVE && page_mapcount(page) == 1)) |
533 | isolate_huge_page(page, qp->pagelist); |
534 | unlock: |
535 | spin_unlock(ptl); |
536 | #else |
537 | BUG(); |
538 | #endif |
539 | return 0; |
540 | } |
541 | |
542 | #ifdef CONFIG_NUMA_BALANCING |
543 | /* |
544 | * This is used to mark a range of virtual addresses to be inaccessible. |
545 | * These are later cleared by a NUMA hinting fault. Depending on these |
546 | * faults, pages may be migrated for better NUMA placement. |
547 | * |
548 | * This is assuming that NUMA faults are handled using PROT_NONE. If |
549 | * an architecture makes a different choice, it will need further |
550 | * changes to the core. |
551 | */ |
552 | unsigned long change_prot_numa(struct vm_area_struct *vma, |
553 | unsigned long addr, unsigned long end) |
554 | { |
555 | int nr_updated; |
556 | |
557 | nr_updated = change_protection(vma, addr, end, PAGE_NONE, 0, 1); |
558 | if (nr_updated) |
559 | count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated); |
560 | |
561 | return nr_updated; |
562 | } |
563 | #else |
564 | static unsigned long change_prot_numa(struct vm_area_struct *vma, |
565 | unsigned long addr, unsigned long end) |
566 | { |
567 | return 0; |
568 | } |
569 | #endif /* CONFIG_NUMA_BALANCING */ |
570 | |
571 | static int queue_pages_test_walk(unsigned long start, unsigned long end, |
572 | struct mm_walk *walk) |
573 | { |
574 | struct vm_area_struct *vma = walk->vma; |
575 | struct queue_pages *qp = walk->private; |
576 | unsigned long endvma = vma->vm_end; |
577 | unsigned long flags = qp->flags; |
578 | |
579 | if (!vma_migratable(vma)) |
580 | return 1; |
581 | |
582 | if (endvma > end) |
583 | endvma = end; |
584 | if (vma->vm_start > start) |
585 | start = vma->vm_start; |
586 | |
587 | if (!(flags & MPOL_MF_DISCONTIG_OK)) { |
588 | if (!vma->vm_next && vma->vm_end < end) |
589 | return -EFAULT; |
590 | if (qp->prev && qp->prev->vm_end < vma->vm_start) |
591 | return -EFAULT; |
592 | } |
593 | |
594 | qp->prev = vma; |
595 | |
596 | if (flags & MPOL_MF_LAZY) { |
597 | /* Similar to task_numa_work, skip inaccessible VMAs */ |
598 | if (!is_vm_hugetlb_page(vma) && |
599 | (vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)) && |
600 | !(vma->vm_flags & VM_MIXEDMAP)) |
601 | change_prot_numa(vma, start, endvma); |
602 | return 1; |
603 | } |
604 | |
605 | /* queue pages from current vma */ |
606 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) |
607 | return 0; |
608 | return 1; |
609 | } |
610 | |
611 | /* |
612 | * Walk through page tables and collect pages to be migrated. |
613 | * |
614 | * If pages found in a given range are on a set of nodes (determined by |
615 | * @nodes and @flags,) it's isolated and queued to the pagelist which is |
616 | * passed via @private.) |
617 | */ |
618 | static int |
619 | queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end, |
620 | nodemask_t *nodes, unsigned long flags, |
621 | struct list_head *pagelist) |
622 | { |
623 | struct queue_pages qp = { |
624 | .pagelist = pagelist, |
625 | .flags = flags, |
626 | .nmask = nodes, |
627 | .prev = NULL, |
628 | }; |
629 | struct mm_walk queue_pages_walk = { |
630 | .hugetlb_entry = queue_pages_hugetlb, |
631 | .pmd_entry = queue_pages_pte_range, |
632 | .test_walk = queue_pages_test_walk, |
633 | .mm = mm, |
634 | .private = &qp, |
635 | }; |
636 | |
637 | return walk_page_range(start, end, &queue_pages_walk); |
638 | } |
639 | |
640 | /* |
641 | * Apply policy to a single VMA |
642 | * This must be called with the mmap_sem held for writing. |
643 | */ |
644 | static int vma_replace_policy(struct vm_area_struct *vma, |
645 | struct mempolicy *pol) |
646 | { |
647 | int err; |
648 | struct mempolicy *old; |
649 | struct mempolicy *new; |
650 | |
651 | pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n" , |
652 | vma->vm_start, vma->vm_end, vma->vm_pgoff, |
653 | vma->vm_ops, vma->vm_file, |
654 | vma->vm_ops ? vma->vm_ops->set_policy : NULL); |
655 | |
656 | new = mpol_dup(pol); |
657 | if (IS_ERR(new)) |
658 | return PTR_ERR(new); |
659 | |
660 | if (vma->vm_ops && vma->vm_ops->set_policy) { |
661 | err = vma->vm_ops->set_policy(vma, new); |
662 | if (err) |
663 | goto err_out; |
664 | } |
665 | |
666 | old = vma->vm_policy; |
667 | vma->vm_policy = new; /* protected by mmap_sem */ |
668 | mpol_put(old); |
669 | |
670 | return 0; |
671 | err_out: |
672 | mpol_put(new); |
673 | return err; |
674 | } |
675 | |
676 | /* Step 2: apply policy to a range and do splits. */ |
677 | static int mbind_range(struct mm_struct *mm, unsigned long start, |
678 | unsigned long end, struct mempolicy *new_pol) |
679 | { |
680 | struct vm_area_struct *next; |
681 | struct vm_area_struct *prev; |
682 | struct vm_area_struct *vma; |
683 | int err = 0; |
684 | pgoff_t pgoff; |
685 | unsigned long vmstart; |
686 | unsigned long vmend; |
687 | |
688 | vma = find_vma(mm, start); |
689 | if (!vma || vma->vm_start > start) |
690 | return -EFAULT; |
691 | |
692 | prev = vma->vm_prev; |
693 | if (start > vma->vm_start) |
694 | prev = vma; |
695 | |
696 | for (; vma && vma->vm_start < end; prev = vma, vma = next) { |
697 | next = vma->vm_next; |
698 | vmstart = max(start, vma->vm_start); |
699 | vmend = min(end, vma->vm_end); |
700 | |
701 | if (mpol_equal(vma_policy(vma), new_pol)) |
702 | continue; |
703 | |
704 | pgoff = vma->vm_pgoff + |
705 | ((vmstart - vma->vm_start) >> PAGE_SHIFT); |
706 | prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags, |
707 | vma->anon_vma, vma->vm_file, pgoff, |
708 | new_pol, vma->vm_userfaultfd_ctx); |
709 | if (prev) { |
710 | vma = prev; |
711 | next = vma->vm_next; |
712 | if (mpol_equal(vma_policy(vma), new_pol)) |
713 | continue; |
714 | /* vma_merge() joined vma && vma->next, case 8 */ |
715 | goto replace; |
716 | } |
717 | if (vma->vm_start != vmstart) { |
718 | err = split_vma(vma->vm_mm, vma, vmstart, 1); |
719 | if (err) |
720 | goto out; |
721 | } |
722 | if (vma->vm_end != vmend) { |
723 | err = split_vma(vma->vm_mm, vma, vmend, 0); |
724 | if (err) |
725 | goto out; |
726 | } |
727 | replace: |
728 | err = vma_replace_policy(vma, new_pol); |
729 | if (err) |
730 | goto out; |
731 | } |
732 | |
733 | out: |
734 | return err; |
735 | } |
736 | |
737 | /* Set the process memory policy */ |
738 | static long do_set_mempolicy(unsigned short mode, unsigned short flags, |
739 | nodemask_t *nodes) |
740 | { |
741 | struct mempolicy *new, *old; |
742 | NODEMASK_SCRATCH(scratch); |
743 | int ret; |
744 | |
745 | if (!scratch) |
746 | return -ENOMEM; |
747 | |
748 | new = mpol_new(mode, flags, nodes); |
749 | if (IS_ERR(new)) { |
750 | ret = PTR_ERR(new); |
751 | goto out; |
752 | } |
753 | |
754 | task_lock(current); |
755 | ret = mpol_set_nodemask(new, nodes, scratch); |
756 | if (ret) { |
757 | task_unlock(current); |
758 | mpol_put(new); |
759 | goto out; |
760 | } |
761 | old = current->mempolicy; |
762 | current->mempolicy = new; |
763 | if (new && new->mode == MPOL_INTERLEAVE) |
764 | current->il_prev = MAX_NUMNODES-1; |
765 | task_unlock(current); |
766 | mpol_put(old); |
767 | ret = 0; |
768 | out: |
769 | NODEMASK_SCRATCH_FREE(scratch); |
770 | return ret; |
771 | } |
772 | |
773 | /* |
774 | * Return nodemask for policy for get_mempolicy() query |
775 | * |
776 | * Called with task's alloc_lock held |
777 | */ |
778 | static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes) |
779 | { |
780 | nodes_clear(*nodes); |
781 | if (p == &default_policy) |
782 | return; |
783 | |
784 | switch (p->mode) { |
785 | case MPOL_BIND: |
786 | /* Fall through */ |
787 | case MPOL_INTERLEAVE: |
788 | *nodes = p->v.nodes; |
789 | break; |
790 | case MPOL_PREFERRED: |
791 | if (!(p->flags & MPOL_F_LOCAL)) |
792 | node_set(p->v.preferred_node, *nodes); |
793 | /* else return empty node mask for local allocation */ |
794 | break; |
795 | default: |
796 | BUG(); |
797 | } |
798 | } |
799 | |
800 | static int lookup_node(struct mm_struct *mm, unsigned long addr) |
801 | { |
802 | struct page *p; |
803 | int err; |
804 | |
805 | int locked = 1; |
806 | err = get_user_pages_locked(addr & PAGE_MASK, 1, 0, &p, &locked); |
807 | if (err >= 0) { |
808 | err = page_to_nid(p); |
809 | put_page(p); |
810 | } |
811 | if (locked) |
812 | up_read(&mm->mmap_sem); |
813 | return err; |
814 | } |
815 | |
816 | /* Retrieve NUMA policy */ |
817 | static long do_get_mempolicy(int *policy, nodemask_t *nmask, |
818 | unsigned long addr, unsigned long flags) |
819 | { |
820 | int err; |
821 | struct mm_struct *mm = current->mm; |
822 | struct vm_area_struct *vma = NULL; |
823 | struct mempolicy *pol = current->mempolicy, *pol_refcount = NULL; |
824 | |
825 | if (flags & |
826 | ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED)) |
827 | return -EINVAL; |
828 | |
829 | if (flags & MPOL_F_MEMS_ALLOWED) { |
830 | if (flags & (MPOL_F_NODE|MPOL_F_ADDR)) |
831 | return -EINVAL; |
832 | *policy = 0; /* just so it's initialized */ |
833 | task_lock(current); |
834 | *nmask = cpuset_current_mems_allowed; |
835 | task_unlock(current); |
836 | return 0; |
837 | } |
838 | |
839 | if (flags & MPOL_F_ADDR) { |
840 | /* |
841 | * Do NOT fall back to task policy if the |
842 | * vma/shared policy at addr is NULL. We |
843 | * want to return MPOL_DEFAULT in this case. |
844 | */ |
845 | down_read(&mm->mmap_sem); |
846 | vma = find_vma_intersection(mm, addr, addr+1); |
847 | if (!vma) { |
848 | up_read(&mm->mmap_sem); |
849 | return -EFAULT; |
850 | } |
851 | if (vma->vm_ops && vma->vm_ops->get_policy) |
852 | pol = vma->vm_ops->get_policy(vma, addr); |
853 | else |
854 | pol = vma->vm_policy; |
855 | } else if (addr) |
856 | return -EINVAL; |
857 | |
858 | if (!pol) |
859 | pol = &default_policy; /* indicates default behavior */ |
860 | |
861 | if (flags & MPOL_F_NODE) { |
862 | if (flags & MPOL_F_ADDR) { |
863 | /* |
864 | * Take a refcount on the mpol, lookup_node() |
865 | * wil drop the mmap_sem, so after calling |
866 | * lookup_node() only "pol" remains valid, "vma" |
867 | * is stale. |
868 | */ |
869 | pol_refcount = pol; |
870 | vma = NULL; |
871 | mpol_get(pol); |
872 | err = lookup_node(mm, addr); |
873 | if (err < 0) |
874 | goto out; |
875 | *policy = err; |
876 | } else if (pol == current->mempolicy && |
877 | pol->mode == MPOL_INTERLEAVE) { |
878 | *policy = next_node_in(current->il_prev, pol->v.nodes); |
879 | } else { |
880 | err = -EINVAL; |
881 | goto out; |
882 | } |
883 | } else { |
884 | *policy = pol == &default_policy ? MPOL_DEFAULT : |
885 | pol->mode; |
886 | /* |
887 | * Internal mempolicy flags must be masked off before exposing |
888 | * the policy to userspace. |
889 | */ |
890 | *policy |= (pol->flags & MPOL_MODE_FLAGS); |
891 | } |
892 | |
893 | err = 0; |
894 | if (nmask) { |
895 | if (mpol_store_user_nodemask(pol)) { |
896 | *nmask = pol->w.user_nodemask; |
897 | } else { |
898 | task_lock(current); |
899 | get_policy_nodemask(pol, nmask); |
900 | task_unlock(current); |
901 | } |
902 | } |
903 | |
904 | out: |
905 | mpol_cond_put(pol); |
906 | if (vma) |
907 | up_read(&mm->mmap_sem); |
908 | if (pol_refcount) |
909 | mpol_put(pol_refcount); |
910 | return err; |
911 | } |
912 | |
913 | #ifdef CONFIG_MIGRATION |
914 | /* |
915 | * page migration, thp tail pages can be passed. |
916 | */ |
917 | static void migrate_page_add(struct page *page, struct list_head *pagelist, |
918 | unsigned long flags) |
919 | { |
920 | struct page *head = compound_head(page); |
921 | /* |
922 | * Avoid migrating a page that is shared with others. |
923 | */ |
924 | if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(head) == 1) { |
925 | if (!isolate_lru_page(head)) { |
926 | list_add_tail(&head->lru, pagelist); |
927 | mod_node_page_state(page_pgdat(head), |
928 | NR_ISOLATED_ANON + page_is_file_cache(head), |
929 | hpage_nr_pages(head)); |
930 | } |
931 | } |
932 | } |
933 | |
934 | /* page allocation callback for NUMA node migration */ |
935 | struct page *alloc_new_node_page(struct page *page, unsigned long node) |
936 | { |
937 | if (PageHuge(page)) |
938 | return alloc_huge_page_node(page_hstate(compound_head(page)), |
939 | node); |
940 | else if (PageTransHuge(page)) { |
941 | struct page *thp; |
942 | |
943 | thp = alloc_pages_node(node, |
944 | (GFP_TRANSHUGE | __GFP_THISNODE), |
945 | HPAGE_PMD_ORDER); |
946 | if (!thp) |
947 | return NULL; |
948 | prep_transhuge_page(thp); |
949 | return thp; |
950 | } else |
951 | return __alloc_pages_node(node, GFP_HIGHUSER_MOVABLE | |
952 | __GFP_THISNODE, 0); |
953 | } |
954 | |
955 | /* |
956 | * Migrate pages from one node to a target node. |
957 | * Returns error or the number of pages not migrated. |
958 | */ |
959 | static int migrate_to_node(struct mm_struct *mm, int source, int dest, |
960 | int flags) |
961 | { |
962 | nodemask_t nmask; |
963 | LIST_HEAD(pagelist); |
964 | int err = 0; |
965 | |
966 | nodes_clear(nmask); |
967 | node_set(source, nmask); |
968 | |
969 | /* |
970 | * This does not "check" the range but isolates all pages that |
971 | * need migration. Between passing in the full user address |
972 | * space range and MPOL_MF_DISCONTIG_OK, this call can not fail. |
973 | */ |
974 | VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))); |
975 | queue_pages_range(mm, mm->mmap->vm_start, mm->task_size, &nmask, |
976 | flags | MPOL_MF_DISCONTIG_OK, &pagelist); |
977 | |
978 | if (!list_empty(&pagelist)) { |
979 | err = migrate_pages(&pagelist, alloc_new_node_page, NULL, dest, |
980 | MIGRATE_SYNC, MR_SYSCALL); |
981 | if (err) |
982 | putback_movable_pages(&pagelist); |
983 | } |
984 | |
985 | return err; |
986 | } |
987 | |
988 | /* |
989 | * Move pages between the two nodesets so as to preserve the physical |
990 | * layout as much as possible. |
991 | * |
992 | * Returns the number of page that could not be moved. |
993 | */ |
994 | int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, |
995 | const nodemask_t *to, int flags) |
996 | { |
997 | int busy = 0; |
998 | int err; |
999 | nodemask_t tmp; |
1000 | |
1001 | err = migrate_prep(); |
1002 | if (err) |
1003 | return err; |
1004 | |
1005 | down_read(&mm->mmap_sem); |
1006 | |
1007 | /* |
1008 | * Find a 'source' bit set in 'tmp' whose corresponding 'dest' |
1009 | * bit in 'to' is not also set in 'tmp'. Clear the found 'source' |
1010 | * bit in 'tmp', and return that <source, dest> pair for migration. |
1011 | * The pair of nodemasks 'to' and 'from' define the map. |
1012 | * |
1013 | * If no pair of bits is found that way, fallback to picking some |
1014 | * pair of 'source' and 'dest' bits that are not the same. If the |
1015 | * 'source' and 'dest' bits are the same, this represents a node |
1016 | * that will be migrating to itself, so no pages need move. |
1017 | * |
1018 | * If no bits are left in 'tmp', or if all remaining bits left |
1019 | * in 'tmp' correspond to the same bit in 'to', return false |
1020 | * (nothing left to migrate). |
1021 | * |
1022 | * This lets us pick a pair of nodes to migrate between, such that |
1023 | * if possible the dest node is not already occupied by some other |
1024 | * source node, minimizing the risk of overloading the memory on a |
1025 | * node that would happen if we migrated incoming memory to a node |
1026 | * before migrating outgoing memory source that same node. |
1027 | * |
1028 | * A single scan of tmp is sufficient. As we go, we remember the |
1029 | * most recent <s, d> pair that moved (s != d). If we find a pair |
1030 | * that not only moved, but what's better, moved to an empty slot |
1031 | * (d is not set in tmp), then we break out then, with that pair. |
1032 | * Otherwise when we finish scanning from_tmp, we at least have the |
1033 | * most recent <s, d> pair that moved. If we get all the way through |
1034 | * the scan of tmp without finding any node that moved, much less |
1035 | * moved to an empty node, then there is nothing left worth migrating. |
1036 | */ |
1037 | |
1038 | tmp = *from; |
1039 | while (!nodes_empty(tmp)) { |
1040 | int s,d; |
1041 | int source = NUMA_NO_NODE; |
1042 | int dest = 0; |
1043 | |
1044 | for_each_node_mask(s, tmp) { |
1045 | |
1046 | /* |
1047 | * do_migrate_pages() tries to maintain the relative |
1048 | * node relationship of the pages established between |
1049 | * threads and memory areas. |
1050 | * |
1051 | * However if the number of source nodes is not equal to |
1052 | * the number of destination nodes we can not preserve |
1053 | * this node relative relationship. In that case, skip |
1054 | * copying memory from a node that is in the destination |
1055 | * mask. |
1056 | * |
1057 | * Example: [2,3,4] -> [3,4,5] moves everything. |
1058 | * [0-7] - > [3,4,5] moves only 0,1,2,6,7. |
1059 | */ |
1060 | |
1061 | if ((nodes_weight(*from) != nodes_weight(*to)) && |
1062 | (node_isset(s, *to))) |
1063 | continue; |
1064 | |
1065 | d = node_remap(s, *from, *to); |
1066 | if (s == d) |
1067 | continue; |
1068 | |
1069 | source = s; /* Node moved. Memorize */ |
1070 | dest = d; |
1071 | |
1072 | /* dest not in remaining from nodes? */ |
1073 | if (!node_isset(dest, tmp)) |
1074 | break; |
1075 | } |
1076 | if (source == NUMA_NO_NODE) |
1077 | break; |
1078 | |
1079 | node_clear(source, tmp); |
1080 | err = migrate_to_node(mm, source, dest, flags); |
1081 | if (err > 0) |
1082 | busy += err; |
1083 | if (err < 0) |
1084 | break; |
1085 | } |
1086 | up_read(&mm->mmap_sem); |
1087 | if (err < 0) |
1088 | return err; |
1089 | return busy; |
1090 | |
1091 | } |
1092 | |
1093 | /* |
1094 | * Allocate a new page for page migration based on vma policy. |
1095 | * Start by assuming the page is mapped by the same vma as contains @start. |
1096 | * Search forward from there, if not. N.B., this assumes that the |
1097 | * list of pages handed to migrate_pages()--which is how we get here-- |
1098 | * is in virtual address order. |
1099 | */ |
1100 | static struct page *new_page(struct page *page, unsigned long start) |
1101 | { |
1102 | struct vm_area_struct *vma; |
1103 | unsigned long uninitialized_var(address); |
1104 | |
1105 | vma = find_vma(current->mm, start); |
1106 | while (vma) { |
1107 | address = page_address_in_vma(page, vma); |
1108 | if (address != -EFAULT) |
1109 | break; |
1110 | vma = vma->vm_next; |
1111 | } |
1112 | |
1113 | if (PageHuge(page)) { |
1114 | return alloc_huge_page_vma(page_hstate(compound_head(page)), |
1115 | vma, address); |
1116 | } else if (PageTransHuge(page)) { |
1117 | struct page *thp; |
1118 | |
1119 | thp = alloc_hugepage_vma(GFP_TRANSHUGE, vma, address, |
1120 | HPAGE_PMD_ORDER); |
1121 | if (!thp) |
1122 | return NULL; |
1123 | prep_transhuge_page(thp); |
1124 | return thp; |
1125 | } |
1126 | /* |
1127 | * if !vma, alloc_page_vma() will use task or system default policy |
1128 | */ |
1129 | return alloc_page_vma(GFP_HIGHUSER_MOVABLE | __GFP_RETRY_MAYFAIL, |
1130 | vma, address); |
1131 | } |
1132 | #else |
1133 | |
1134 | static void migrate_page_add(struct page *page, struct list_head *pagelist, |
1135 | unsigned long flags) |
1136 | { |
1137 | } |
1138 | |
1139 | int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, |
1140 | const nodemask_t *to, int flags) |
1141 | { |
1142 | return -ENOSYS; |
1143 | } |
1144 | |
1145 | static struct page *new_page(struct page *page, unsigned long start) |
1146 | { |
1147 | return NULL; |
1148 | } |
1149 | #endif |
1150 | |
1151 | static long do_mbind(unsigned long start, unsigned long len, |
1152 | unsigned short mode, unsigned short mode_flags, |
1153 | nodemask_t *nmask, unsigned long flags) |
1154 | { |
1155 | struct mm_struct *mm = current->mm; |
1156 | struct mempolicy *new; |
1157 | unsigned long end; |
1158 | int err; |
1159 | LIST_HEAD(pagelist); |
1160 | |
1161 | if (flags & ~(unsigned long)MPOL_MF_VALID) |
1162 | return -EINVAL; |
1163 | if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE)) |
1164 | return -EPERM; |
1165 | |
1166 | if (start & ~PAGE_MASK) |
1167 | return -EINVAL; |
1168 | |
1169 | if (mode == MPOL_DEFAULT) |
1170 | flags &= ~MPOL_MF_STRICT; |
1171 | |
1172 | len = (len + PAGE_SIZE - 1) & PAGE_MASK; |
1173 | end = start + len; |
1174 | |
1175 | if (end < start) |
1176 | return -EINVAL; |
1177 | if (end == start) |
1178 | return 0; |
1179 | |
1180 | new = mpol_new(mode, mode_flags, nmask); |
1181 | if (IS_ERR(new)) |
1182 | return PTR_ERR(new); |
1183 | |
1184 | if (flags & MPOL_MF_LAZY) |
1185 | new->flags |= MPOL_F_MOF; |
1186 | |
1187 | /* |
1188 | * If we are using the default policy then operation |
1189 | * on discontinuous address spaces is okay after all |
1190 | */ |
1191 | if (!new) |
1192 | flags |= MPOL_MF_DISCONTIG_OK; |
1193 | |
1194 | pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n" , |
1195 | start, start + len, mode, mode_flags, |
1196 | nmask ? nodes_addr(*nmask)[0] : NUMA_NO_NODE); |
1197 | |
1198 | if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { |
1199 | |
1200 | err = migrate_prep(); |
1201 | if (err) |
1202 | goto mpol_out; |
1203 | } |
1204 | { |
1205 | NODEMASK_SCRATCH(scratch); |
1206 | if (scratch) { |
1207 | down_write(&mm->mmap_sem); |
1208 | task_lock(current); |
1209 | err = mpol_set_nodemask(new, nmask, scratch); |
1210 | task_unlock(current); |
1211 | if (err) |
1212 | up_write(&mm->mmap_sem); |
1213 | } else |
1214 | err = -ENOMEM; |
1215 | NODEMASK_SCRATCH_FREE(scratch); |
1216 | } |
1217 | if (err) |
1218 | goto mpol_out; |
1219 | |
1220 | err = queue_pages_range(mm, start, end, nmask, |
1221 | flags | MPOL_MF_INVERT, &pagelist); |
1222 | if (!err) |
1223 | err = mbind_range(mm, start, end, new); |
1224 | |
1225 | if (!err) { |
1226 | int nr_failed = 0; |
1227 | |
1228 | if (!list_empty(&pagelist)) { |
1229 | WARN_ON_ONCE(flags & MPOL_MF_LAZY); |
1230 | nr_failed = migrate_pages(&pagelist, new_page, NULL, |
1231 | start, MIGRATE_SYNC, MR_MEMPOLICY_MBIND); |
1232 | if (nr_failed) |
1233 | putback_movable_pages(&pagelist); |
1234 | } |
1235 | |
1236 | if (nr_failed && (flags & MPOL_MF_STRICT)) |
1237 | err = -EIO; |
1238 | } else |
1239 | putback_movable_pages(&pagelist); |
1240 | |
1241 | up_write(&mm->mmap_sem); |
1242 | mpol_out: |
1243 | mpol_put(new); |
1244 | return err; |
1245 | } |
1246 | |
1247 | /* |
1248 | * User space interface with variable sized bitmaps for nodelists. |
1249 | */ |
1250 | |
1251 | /* Copy a node mask from user space. */ |
1252 | static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask, |
1253 | unsigned long maxnode) |
1254 | { |
1255 | unsigned long k; |
1256 | unsigned long t; |
1257 | unsigned long nlongs; |
1258 | unsigned long endmask; |
1259 | |
1260 | --maxnode; |
1261 | nodes_clear(*nodes); |
1262 | if (maxnode == 0 || !nmask) |
1263 | return 0; |
1264 | if (maxnode > PAGE_SIZE*BITS_PER_BYTE) |
1265 | return -EINVAL; |
1266 | |
1267 | nlongs = BITS_TO_LONGS(maxnode); |
1268 | if ((maxnode % BITS_PER_LONG) == 0) |
1269 | endmask = ~0UL; |
1270 | else |
1271 | endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1; |
1272 | |
1273 | /* |
1274 | * When the user specified more nodes than supported just check |
1275 | * if the non supported part is all zero. |
1276 | * |
1277 | * If maxnode have more longs than MAX_NUMNODES, check |
1278 | * the bits in that area first. And then go through to |
1279 | * check the rest bits which equal or bigger than MAX_NUMNODES. |
1280 | * Otherwise, just check bits [MAX_NUMNODES, maxnode). |
1281 | */ |
1282 | if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) { |
1283 | for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) { |
1284 | if (get_user(t, nmask + k)) |
1285 | return -EFAULT; |
1286 | if (k == nlongs - 1) { |
1287 | if (t & endmask) |
1288 | return -EINVAL; |
1289 | } else if (t) |
1290 | return -EINVAL; |
1291 | } |
1292 | nlongs = BITS_TO_LONGS(MAX_NUMNODES); |
1293 | endmask = ~0UL; |
1294 | } |
1295 | |
1296 | if (maxnode > MAX_NUMNODES && MAX_NUMNODES % BITS_PER_LONG != 0) { |
1297 | unsigned long valid_mask = endmask; |
1298 | |
1299 | valid_mask &= ~((1UL << (MAX_NUMNODES % BITS_PER_LONG)) - 1); |
1300 | if (get_user(t, nmask + nlongs - 1)) |
1301 | return -EFAULT; |
1302 | if (t & valid_mask) |
1303 | return -EINVAL; |
1304 | } |
1305 | |
1306 | if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long))) |
1307 | return -EFAULT; |
1308 | nodes_addr(*nodes)[nlongs-1] &= endmask; |
1309 | return 0; |
1310 | } |
1311 | |
1312 | /* Copy a kernel node mask to user space */ |
1313 | static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, |
1314 | nodemask_t *nodes) |
1315 | { |
1316 | unsigned long copy = ALIGN(maxnode-1, 64) / 8; |
1317 | unsigned int nbytes = BITS_TO_LONGS(nr_node_ids) * sizeof(long); |
1318 | |
1319 | if (copy > nbytes) { |
1320 | if (copy > PAGE_SIZE) |
1321 | return -EINVAL; |
1322 | if (clear_user((char __user *)mask + nbytes, copy - nbytes)) |
1323 | return -EFAULT; |
1324 | copy = nbytes; |
1325 | } |
1326 | return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0; |
1327 | } |
1328 | |
1329 | static long kernel_mbind(unsigned long start, unsigned long len, |
1330 | unsigned long mode, const unsigned long __user *nmask, |
1331 | unsigned long maxnode, unsigned int flags) |
1332 | { |
1333 | nodemask_t nodes; |
1334 | int err; |
1335 | unsigned short mode_flags; |
1336 | |
1337 | mode_flags = mode & MPOL_MODE_FLAGS; |
1338 | mode &= ~MPOL_MODE_FLAGS; |
1339 | if (mode >= MPOL_MAX) |
1340 | return -EINVAL; |
1341 | if ((mode_flags & MPOL_F_STATIC_NODES) && |
1342 | (mode_flags & MPOL_F_RELATIVE_NODES)) |
1343 | return -EINVAL; |
1344 | err = get_nodes(&nodes, nmask, maxnode); |
1345 | if (err) |
1346 | return err; |
1347 | return do_mbind(start, len, mode, mode_flags, &nodes, flags); |
1348 | } |
1349 | |
1350 | SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len, |
1351 | unsigned long, mode, const unsigned long __user *, nmask, |
1352 | unsigned long, maxnode, unsigned int, flags) |
1353 | { |
1354 | return kernel_mbind(start, len, mode, nmask, maxnode, flags); |
1355 | } |
1356 | |
1357 | /* Set the process memory policy */ |
1358 | static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask, |
1359 | unsigned long maxnode) |
1360 | { |
1361 | int err; |
1362 | nodemask_t nodes; |
1363 | unsigned short flags; |
1364 | |
1365 | flags = mode & MPOL_MODE_FLAGS; |
1366 | mode &= ~MPOL_MODE_FLAGS; |
1367 | if ((unsigned int)mode >= MPOL_MAX) |
1368 | return -EINVAL; |
1369 | if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES)) |
1370 | return -EINVAL; |
1371 | err = get_nodes(&nodes, nmask, maxnode); |
1372 | if (err) |
1373 | return err; |
1374 | return do_set_mempolicy(mode, flags, &nodes); |
1375 | } |
1376 | |
1377 | SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask, |
1378 | unsigned long, maxnode) |
1379 | { |
1380 | return kernel_set_mempolicy(mode, nmask, maxnode); |
1381 | } |
1382 | |
1383 | static int kernel_migrate_pages(pid_t pid, unsigned long maxnode, |
1384 | const unsigned long __user *old_nodes, |
1385 | const unsigned long __user *new_nodes) |
1386 | { |
1387 | struct mm_struct *mm = NULL; |
1388 | struct task_struct *task; |
1389 | nodemask_t task_nodes; |
1390 | int err; |
1391 | nodemask_t *old; |
1392 | nodemask_t *new; |
1393 | NODEMASK_SCRATCH(scratch); |
1394 | |
1395 | if (!scratch) |
1396 | return -ENOMEM; |
1397 | |
1398 | old = &scratch->mask1; |
1399 | new = &scratch->mask2; |
1400 | |
1401 | err = get_nodes(old, old_nodes, maxnode); |
1402 | if (err) |
1403 | goto out; |
1404 | |
1405 | err = get_nodes(new, new_nodes, maxnode); |
1406 | if (err) |
1407 | goto out; |
1408 | |
1409 | /* Find the mm_struct */ |
1410 | rcu_read_lock(); |
1411 | task = pid ? find_task_by_vpid(pid) : current; |
1412 | if (!task) { |
1413 | rcu_read_unlock(); |
1414 | err = -ESRCH; |
1415 | goto out; |
1416 | } |
1417 | get_task_struct(task); |
1418 | |
1419 | err = -EINVAL; |
1420 | |
1421 | /* |
1422 | * Check if this process has the right to modify the specified process. |
1423 | * Use the regular "ptrace_may_access()" checks. |
1424 | */ |
1425 | if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) { |
1426 | rcu_read_unlock(); |
1427 | err = -EPERM; |
1428 | goto out_put; |
1429 | } |
1430 | rcu_read_unlock(); |
1431 | |
1432 | task_nodes = cpuset_mems_allowed(task); |
1433 | /* Is the user allowed to access the target nodes? */ |
1434 | if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) { |
1435 | err = -EPERM; |
1436 | goto out_put; |
1437 | } |
1438 | |
1439 | task_nodes = cpuset_mems_allowed(current); |
1440 | nodes_and(*new, *new, task_nodes); |
1441 | if (nodes_empty(*new)) |
1442 | goto out_put; |
1443 | |
1444 | nodes_and(*new, *new, node_states[N_MEMORY]); |
1445 | if (nodes_empty(*new)) |
1446 | goto out_put; |
1447 | |
1448 | err = security_task_movememory(task); |
1449 | if (err) |
1450 | goto out_put; |
1451 | |
1452 | mm = get_task_mm(task); |
1453 | put_task_struct(task); |
1454 | |
1455 | if (!mm) { |
1456 | err = -EINVAL; |
1457 | goto out; |
1458 | } |
1459 | |
1460 | err = do_migrate_pages(mm, old, new, |
1461 | capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE); |
1462 | |
1463 | mmput(mm); |
1464 | out: |
1465 | NODEMASK_SCRATCH_FREE(scratch); |
1466 | |
1467 | return err; |
1468 | |
1469 | out_put: |
1470 | put_task_struct(task); |
1471 | goto out; |
1472 | |
1473 | } |
1474 | |
1475 | SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, |
1476 | const unsigned long __user *, old_nodes, |
1477 | const unsigned long __user *, new_nodes) |
1478 | { |
1479 | return kernel_migrate_pages(pid, maxnode, old_nodes, new_nodes); |
1480 | } |
1481 | |
1482 | |
1483 | /* Retrieve NUMA policy */ |
1484 | static int kernel_get_mempolicy(int __user *policy, |
1485 | unsigned long __user *nmask, |
1486 | unsigned long maxnode, |
1487 | unsigned long addr, |
1488 | unsigned long flags) |
1489 | { |
1490 | int err; |
1491 | int uninitialized_var(pval); |
1492 | nodemask_t nodes; |
1493 | |
1494 | if (nmask != NULL && maxnode < nr_node_ids) |
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 | SYSCALL_DEFINE5(get_mempolicy, int __user *, policy, |
1512 | unsigned long __user *, nmask, unsigned long, maxnode, |
1513 | unsigned long, addr, unsigned long, flags) |
1514 | { |
1515 | return kernel_get_mempolicy(policy, nmask, maxnode, addr, flags); |
1516 | } |
1517 | |
1518 | #ifdef CONFIG_COMPAT |
1519 | |
1520 | COMPAT_SYSCALL_DEFINE5(get_mempolicy, int __user *, policy, |
1521 | compat_ulong_t __user *, nmask, |
1522 | compat_ulong_t, maxnode, |
1523 | compat_ulong_t, addr, compat_ulong_t, flags) |
1524 | { |
1525 | long err; |
1526 | unsigned long __user *nm = NULL; |
1527 | unsigned long nr_bits, alloc_size; |
1528 | DECLARE_BITMAP(bm, MAX_NUMNODES); |
1529 | |
1530 | nr_bits = min_t(unsigned long, maxnode-1, nr_node_ids); |
1531 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; |
1532 | |
1533 | if (nmask) |
1534 | nm = compat_alloc_user_space(alloc_size); |
1535 | |
1536 | err = kernel_get_mempolicy(policy, nm, nr_bits+1, addr, flags); |
1537 | |
1538 | if (!err && nmask) { |
1539 | unsigned long copy_size; |
1540 | copy_size = min_t(unsigned long, sizeof(bm), alloc_size); |
1541 | err = copy_from_user(bm, nm, copy_size); |
1542 | /* ensure entire bitmap is zeroed */ |
1543 | err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8); |
1544 | err |= compat_put_bitmap(nmask, bm, nr_bits); |
1545 | } |
1546 | |
1547 | return err; |
1548 | } |
1549 | |
1550 | COMPAT_SYSCALL_DEFINE3(set_mempolicy, int, mode, compat_ulong_t __user *, nmask, |
1551 | compat_ulong_t, maxnode) |
1552 | { |
1553 | unsigned long __user *nm = NULL; |
1554 | unsigned long nr_bits, alloc_size; |
1555 | DECLARE_BITMAP(bm, MAX_NUMNODES); |
1556 | |
1557 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); |
1558 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; |
1559 | |
1560 | if (nmask) { |
1561 | if (compat_get_bitmap(bm, nmask, nr_bits)) |
1562 | return -EFAULT; |
1563 | nm = compat_alloc_user_space(alloc_size); |
1564 | if (copy_to_user(nm, bm, alloc_size)) |
1565 | return -EFAULT; |
1566 | } |
1567 | |
1568 | return kernel_set_mempolicy(mode, nm, nr_bits+1); |
1569 | } |
1570 | |
1571 | COMPAT_SYSCALL_DEFINE6(mbind, compat_ulong_t, start, compat_ulong_t, len, |
1572 | compat_ulong_t, mode, compat_ulong_t __user *, nmask, |
1573 | compat_ulong_t, maxnode, compat_ulong_t, flags) |
1574 | { |
1575 | unsigned long __user *nm = NULL; |
1576 | unsigned long nr_bits, alloc_size; |
1577 | nodemask_t bm; |
1578 | |
1579 | nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); |
1580 | alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; |
1581 | |
1582 | if (nmask) { |
1583 | if (compat_get_bitmap(nodes_addr(bm), nmask, nr_bits)) |
1584 | return -EFAULT; |
1585 | nm = compat_alloc_user_space(alloc_size); |
1586 | if (copy_to_user(nm, nodes_addr(bm), alloc_size)) |
1587 | return -EFAULT; |
1588 | } |
1589 | |
1590 | return kernel_mbind(start, len, mode, nm, nr_bits+1, flags); |
1591 | } |
1592 | |
1593 | COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid, |
1594 | compat_ulong_t, maxnode, |
1595 | const compat_ulong_t __user *, old_nodes, |
1596 | const compat_ulong_t __user *, new_nodes) |
1597 | { |
1598 | unsigned long __user *old = NULL; |
1599 | unsigned long __user *new = NULL; |
1600 | nodemask_t tmp_mask; |
1601 | unsigned long nr_bits; |
1602 | unsigned long size; |
1603 | |
1604 | nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES); |
1605 | size = ALIGN(nr_bits, BITS_PER_LONG) / 8; |
1606 | if (old_nodes) { |
1607 | if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits)) |
1608 | return -EFAULT; |
1609 | old = compat_alloc_user_space(new_nodes ? size * 2 : size); |
1610 | if (new_nodes) |
1611 | new = old + size / sizeof(unsigned long); |
1612 | if (copy_to_user(old, nodes_addr(tmp_mask), size)) |
1613 | return -EFAULT; |
1614 | } |
1615 | if (new_nodes) { |
1616 | if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits)) |
1617 | return -EFAULT; |
1618 | if (new == NULL) |
1619 | new = compat_alloc_user_space(size); |
1620 | if (copy_to_user(new, nodes_addr(tmp_mask), size)) |
1621 | return -EFAULT; |
1622 | } |
1623 | return kernel_migrate_pages(pid, nr_bits + 1, old, new); |
1624 | } |
1625 | |
1626 | #endif /* CONFIG_COMPAT */ |
1627 | |
1628 | struct mempolicy *__get_vma_policy(struct vm_area_struct *vma, |
1629 | unsigned long addr) |
1630 | { |
1631 | struct mempolicy *pol = NULL; |
1632 | |
1633 | if (vma) { |
1634 | if (vma->vm_ops && vma->vm_ops->get_policy) { |
1635 | pol = vma->vm_ops->get_policy(vma, addr); |
1636 | } else if (vma->vm_policy) { |
1637 | pol = vma->vm_policy; |
1638 | |
1639 | /* |
1640 | * shmem_alloc_page() passes MPOL_F_SHARED policy with |
1641 | * a pseudo vma whose vma->vm_ops=NULL. Take a reference |
1642 | * count on these policies which will be dropped by |
1643 | * mpol_cond_put() later |
1644 | */ |
1645 | if (mpol_needs_cond_ref(pol)) |
1646 | mpol_get(pol); |
1647 | } |
1648 | } |
1649 | |
1650 | return pol; |
1651 | } |
1652 | |
1653 | /* |
1654 | * get_vma_policy(@vma, @addr) |
1655 | * @vma: virtual memory area whose policy is sought |
1656 | * @addr: address in @vma for shared policy lookup |
1657 | * |
1658 | * Returns effective policy for a VMA at specified address. |
1659 | * Falls back to current->mempolicy or system default policy, as necessary. |
1660 | * Shared policies [those marked as MPOL_F_SHARED] require an extra reference |
1661 | * count--added by the get_policy() vm_op, as appropriate--to protect against |
1662 | * freeing by another task. It is the caller's responsibility to free the |
1663 | * extra reference for shared policies. |
1664 | */ |
1665 | static struct mempolicy *get_vma_policy(struct vm_area_struct *vma, |
1666 | unsigned long addr) |
1667 | { |
1668 | struct mempolicy *pol = __get_vma_policy(vma, addr); |
1669 | |
1670 | if (!pol) |
1671 | pol = get_task_policy(current); |
1672 | |
1673 | return pol; |
1674 | } |
1675 | |
1676 | bool vma_policy_mof(struct vm_area_struct *vma) |
1677 | { |
1678 | struct mempolicy *pol; |
1679 | |
1680 | if (vma->vm_ops && vma->vm_ops->get_policy) { |
1681 | bool ret = false; |
1682 | |
1683 | pol = vma->vm_ops->get_policy(vma, vma->vm_start); |
1684 | if (pol && (pol->flags & MPOL_F_MOF)) |
1685 | ret = true; |
1686 | mpol_cond_put(pol); |
1687 | |
1688 | return ret; |
1689 | } |
1690 | |
1691 | pol = vma->vm_policy; |
1692 | if (!pol) |
1693 | pol = get_task_policy(current); |
1694 | |
1695 | return pol->flags & MPOL_F_MOF; |
1696 | } |
1697 | |
1698 | static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone) |
1699 | { |
1700 | enum zone_type dynamic_policy_zone = policy_zone; |
1701 | |
1702 | BUG_ON(dynamic_policy_zone == ZONE_MOVABLE); |
1703 | |
1704 | /* |
1705 | * if policy->v.nodes has movable memory only, |
1706 | * we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only. |
1707 | * |
1708 | * policy->v.nodes is intersect with node_states[N_MEMORY]. |
1709 | * so if the following test faile, it implies |
1710 | * policy->v.nodes has movable memory only. |
1711 | */ |
1712 | if (!nodes_intersects(policy->v.nodes, node_states[N_HIGH_MEMORY])) |
1713 | dynamic_policy_zone = ZONE_MOVABLE; |
1714 | |
1715 | return zone >= dynamic_policy_zone; |
1716 | } |
1717 | |
1718 | /* |
1719 | * Return a nodemask representing a mempolicy for filtering nodes for |
1720 | * page allocation |
1721 | */ |
1722 | static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy) |
1723 | { |
1724 | /* Lower zones don't get a nodemask applied for MPOL_BIND */ |
1725 | if (unlikely(policy->mode == MPOL_BIND) && |
1726 | apply_policy_zone(policy, gfp_zone(gfp)) && |
1727 | cpuset_nodemask_valid_mems_allowed(&policy->v.nodes)) |
1728 | return &policy->v.nodes; |
1729 | |
1730 | return NULL; |
1731 | } |
1732 | |
1733 | /* Return the node id preferred by the given mempolicy, or the given id */ |
1734 | static int policy_node(gfp_t gfp, struct mempolicy *policy, |
1735 | int nd) |
1736 | { |
1737 | if (policy->mode == MPOL_PREFERRED && !(policy->flags & MPOL_F_LOCAL)) |
1738 | nd = policy->v.preferred_node; |
1739 | else { |
1740 | /* |
1741 | * __GFP_THISNODE shouldn't even be used with the bind policy |
1742 | * because we might easily break the expectation to stay on the |
1743 | * requested node and not break the policy. |
1744 | */ |
1745 | WARN_ON_ONCE(policy->mode == MPOL_BIND && (gfp & __GFP_THISNODE)); |
1746 | } |
1747 | |
1748 | return nd; |
1749 | } |
1750 | |
1751 | /* Do dynamic interleaving for a process */ |
1752 | static unsigned interleave_nodes(struct mempolicy *policy) |
1753 | { |
1754 | unsigned next; |
1755 | struct task_struct *me = current; |
1756 | |
1757 | next = next_node_in(me->il_prev, policy->v.nodes); |
1758 | if (next < MAX_NUMNODES) |
1759 | me->il_prev = next; |
1760 | return next; |
1761 | } |
1762 | |
1763 | /* |
1764 | * Depending on the memory policy provide a node from which to allocate the |
1765 | * next slab entry. |
1766 | */ |
1767 | unsigned int mempolicy_slab_node(void) |
1768 | { |
1769 | struct mempolicy *policy; |
1770 | int node = numa_mem_id(); |
1771 | |
1772 | if (in_interrupt()) |
1773 | return node; |
1774 | |
1775 | policy = current->mempolicy; |
1776 | if (!policy || policy->flags & MPOL_F_LOCAL) |
1777 | return node; |
1778 | |
1779 | switch (policy->mode) { |
1780 | case MPOL_PREFERRED: |
1781 | /* |
1782 | * handled MPOL_F_LOCAL above |
1783 | */ |
1784 | return policy->v.preferred_node; |
1785 | |
1786 | case MPOL_INTERLEAVE: |
1787 | return interleave_nodes(policy); |
1788 | |
1789 | case MPOL_BIND: { |
1790 | struct zoneref *z; |
1791 | |
1792 | /* |
1793 | * Follow bind policy behavior and start allocation at the |
1794 | * first node. |
1795 | */ |
1796 | struct zonelist *zonelist; |
1797 | enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL); |
1798 | zonelist = &NODE_DATA(node)->node_zonelists[ZONELIST_FALLBACK]; |
1799 | z = first_zones_zonelist(zonelist, highest_zoneidx, |
1800 | &policy->v.nodes); |
1801 | return z->zone ? zone_to_nid(z->zone) : node; |
1802 | } |
1803 | |
1804 | default: |
1805 | BUG(); |
1806 | } |
1807 | } |
1808 | |
1809 | /* |
1810 | * Do static interleaving for a VMA with known offset @n. Returns the n'th |
1811 | * node in pol->v.nodes (starting from n=0), wrapping around if n exceeds the |
1812 | * number of present nodes. |
1813 | */ |
1814 | static unsigned offset_il_node(struct mempolicy *pol, unsigned long n) |
1815 | { |
1816 | unsigned nnodes = nodes_weight(pol->v.nodes); |
1817 | unsigned target; |
1818 | int i; |
1819 | int nid; |
1820 | |
1821 | if (!nnodes) |
1822 | return numa_node_id(); |
1823 | target = (unsigned int)n % nnodes; |
1824 | nid = first_node(pol->v.nodes); |
1825 | for (i = 0; i < target; i++) |
1826 | nid = next_node(nid, pol->v.nodes); |
1827 | return nid; |
1828 | } |
1829 | |
1830 | /* Determine a node number for interleave */ |
1831 | static inline unsigned interleave_nid(struct mempolicy *pol, |
1832 | struct vm_area_struct *vma, unsigned long addr, int shift) |
1833 | { |
1834 | if (vma) { |
1835 | unsigned long off; |
1836 | |
1837 | /* |
1838 | * for small pages, there is no difference between |
1839 | * shift and PAGE_SHIFT, so the bit-shift is safe. |
1840 | * for huge pages, since vm_pgoff is in units of small |
1841 | * pages, we need to shift off the always 0 bits to get |
1842 | * a useful offset. |
1843 | */ |
1844 | BUG_ON(shift < PAGE_SHIFT); |
1845 | off = vma->vm_pgoff >> (shift - PAGE_SHIFT); |
1846 | off += (addr - vma->vm_start) >> shift; |
1847 | return offset_il_node(pol, off); |
1848 | } else |
1849 | return interleave_nodes(pol); |
1850 | } |
1851 | |
1852 | #ifdef CONFIG_HUGETLBFS |
1853 | /* |
1854 | * huge_node(@vma, @addr, @gfp_flags, @mpol) |
1855 | * @vma: virtual memory area whose policy is sought |
1856 | * @addr: address in @vma for shared policy lookup and interleave policy |
1857 | * @gfp_flags: for requested zone |
1858 | * @mpol: pointer to mempolicy pointer for reference counted mempolicy |
1859 | * @nodemask: pointer to nodemask pointer for MPOL_BIND nodemask |
1860 | * |
1861 | * Returns a nid suitable for a huge page allocation and a pointer |
1862 | * to the struct mempolicy for conditional unref after allocation. |
1863 | * If the effective policy is 'BIND, returns a pointer to the mempolicy's |
1864 | * @nodemask for filtering the zonelist. |
1865 | * |
1866 | * Must be protected by read_mems_allowed_begin() |
1867 | */ |
1868 | int huge_node(struct vm_area_struct *vma, unsigned long addr, gfp_t gfp_flags, |
1869 | struct mempolicy **mpol, nodemask_t **nodemask) |
1870 | { |
1871 | int nid; |
1872 | |
1873 | *mpol = get_vma_policy(vma, addr); |
1874 | *nodemask = NULL; /* assume !MPOL_BIND */ |
1875 | |
1876 | if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) { |
1877 | nid = interleave_nid(*mpol, vma, addr, |
1878 | huge_page_shift(hstate_vma(vma))); |
1879 | } else { |
1880 | nid = policy_node(gfp_flags, *mpol, numa_node_id()); |
1881 | if ((*mpol)->mode == MPOL_BIND) |
1882 | *nodemask = &(*mpol)->v.nodes; |
1883 | } |
1884 | return nid; |
1885 | } |
1886 | |
1887 | /* |
1888 | * init_nodemask_of_mempolicy |
1889 | * |
1890 | * If the current task's mempolicy is "default" [NULL], return 'false' |
1891 | * to indicate default policy. Otherwise, extract the policy nodemask |
1892 | * for 'bind' or 'interleave' policy into the argument nodemask, or |
1893 | * initialize the argument nodemask to contain the single node for |
1894 | * 'preferred' or 'local' policy and return 'true' to indicate presence |
1895 | * of non-default mempolicy. |
1896 | * |
1897 | * We don't bother with reference counting the mempolicy [mpol_get/put] |
1898 | * because the current task is examining it's own mempolicy and a task's |
1899 | * mempolicy is only ever changed by the task itself. |
1900 | * |
1901 | * N.B., it is the caller's responsibility to free a returned nodemask. |
1902 | */ |
1903 | bool init_nodemask_of_mempolicy(nodemask_t *mask) |
1904 | { |
1905 | struct mempolicy *mempolicy; |
1906 | int nid; |
1907 | |
1908 | if (!(mask && current->mempolicy)) |
1909 | return false; |
1910 | |
1911 | task_lock(current); |
1912 | mempolicy = current->mempolicy; |
1913 | switch (mempolicy->mode) { |
1914 | case MPOL_PREFERRED: |
1915 | if (mempolicy->flags & MPOL_F_LOCAL) |
1916 | nid = numa_node_id(); |
1917 | else |
1918 | nid = mempolicy->v.preferred_node; |
1919 | init_nodemask_of_node(mask, nid); |
1920 | break; |
1921 | |
1922 | case MPOL_BIND: |
1923 | /* Fall through */ |
1924 | case MPOL_INTERLEAVE: |
1925 | *mask = mempolicy->v.nodes; |
1926 | break; |
1927 | |
1928 | default: |
1929 | BUG(); |
1930 | } |
1931 | task_unlock(current); |
1932 | |
1933 | return true; |
1934 | } |
1935 | #endif |
1936 | |
1937 | /* |
1938 | * mempolicy_nodemask_intersects |
1939 | * |
1940 | * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default |
1941 | * policy. Otherwise, check for intersection between mask and the policy |
1942 | * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local' |
1943 | * policy, always return true since it may allocate elsewhere on fallback. |
1944 | * |
1945 | * Takes task_lock(tsk) to prevent freeing of its mempolicy. |
1946 | */ |
1947 | bool mempolicy_nodemask_intersects(struct task_struct *tsk, |
1948 | const nodemask_t *mask) |
1949 | { |
1950 | struct mempolicy *mempolicy; |
1951 | bool ret = true; |
1952 | |
1953 | if (!mask) |
1954 | return ret; |
1955 | task_lock(tsk); |
1956 | mempolicy = tsk->mempolicy; |
1957 | if (!mempolicy) |
1958 | goto out; |
1959 | |
1960 | switch (mempolicy->mode) { |
1961 | case MPOL_PREFERRED: |
1962 | /* |
1963 | * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to |
1964 | * allocate from, they may fallback to other nodes when oom. |
1965 | * Thus, it's possible for tsk to have allocated memory from |
1966 | * nodes in mask. |
1967 | */ |
1968 | break; |
1969 | case MPOL_BIND: |
1970 | case MPOL_INTERLEAVE: |
1971 | ret = nodes_intersects(mempolicy->v.nodes, *mask); |
1972 | break; |
1973 | default: |
1974 | BUG(); |
1975 | } |
1976 | out: |
1977 | task_unlock(tsk); |
1978 | return ret; |
1979 | } |
1980 | |
1981 | /* Allocate a page in interleaved policy. |
1982 | Own path because it needs to do special accounting. */ |
1983 | static struct page *alloc_page_interleave(gfp_t gfp, unsigned order, |
1984 | unsigned nid) |
1985 | { |
1986 | struct page *page; |
1987 | |
1988 | page = __alloc_pages(gfp, order, nid); |
1989 | /* skip NUMA_INTERLEAVE_HIT counter update if numa stats is disabled */ |
1990 | if (!static_branch_likely(&vm_numa_stat_key)) |
1991 | return page; |
1992 | if (page && page_to_nid(page) == nid) { |
1993 | preempt_disable(); |
1994 | __inc_numa_state(page_zone(page), NUMA_INTERLEAVE_HIT); |
1995 | preempt_enable(); |
1996 | } |
1997 | return page; |
1998 | } |
1999 | |
2000 | /** |
2001 | * alloc_pages_vma - Allocate a page for a VMA. |
2002 | * |
2003 | * @gfp: |
2004 | * %GFP_USER user allocation. |
2005 | * %GFP_KERNEL kernel allocations, |
2006 | * %GFP_HIGHMEM highmem/user allocations, |
2007 | * %GFP_FS allocation should not call back into a file system. |
2008 | * %GFP_ATOMIC don't sleep. |
2009 | * |
2010 | * @order:Order of the GFP allocation. |
2011 | * @vma: Pointer to VMA or NULL if not available. |
2012 | * @addr: Virtual Address of the allocation. Must be inside the VMA. |
2013 | * @node: Which node to prefer for allocation (modulo policy). |
2014 | * @hugepage: for hugepages try only the preferred node if possible |
2015 | * |
2016 | * This function allocates a page from the kernel page pool and applies |
2017 | * a NUMA policy associated with the VMA or the current process. |
2018 | * When VMA is not NULL caller must hold down_read on the mmap_sem of the |
2019 | * mm_struct of the VMA to prevent it from going away. Should be used for |
2020 | * all allocations for pages that will be mapped into user space. Returns |
2021 | * NULL when no page can be allocated. |
2022 | */ |
2023 | struct page * |
2024 | alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma, |
2025 | unsigned long addr, int node, bool hugepage) |
2026 | { |
2027 | struct mempolicy *pol; |
2028 | struct page *page; |
2029 | int preferred_nid; |
2030 | nodemask_t *nmask; |
2031 | |
2032 | pol = get_vma_policy(vma, addr); |
2033 | |
2034 | if (pol->mode == MPOL_INTERLEAVE) { |
2035 | unsigned nid; |
2036 | |
2037 | nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order); |
2038 | mpol_cond_put(pol); |
2039 | page = alloc_page_interleave(gfp, order, nid); |
2040 | goto out; |
2041 | } |
2042 | |
2043 | if (unlikely(IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hugepage)) { |
2044 | int hpage_node = node; |
2045 | |
2046 | /* |
2047 | * For hugepage allocation and non-interleave policy which |
2048 | * allows the current node (or other explicitly preferred |
2049 | * node) we only try to allocate from the current/preferred |
2050 | * node and don't fall back to other nodes, as the cost of |
2051 | * remote accesses would likely offset THP benefits. |
2052 | * |
2053 | * If the policy is interleave, or does not allow the current |
2054 | * node in its nodemask, we allocate the standard way. |
2055 | */ |
2056 | if (pol->mode == MPOL_PREFERRED && !(pol->flags & MPOL_F_LOCAL)) |
2057 | hpage_node = pol->v.preferred_node; |
2058 | |
2059 | nmask = policy_nodemask(gfp, pol); |
2060 | if (!nmask || node_isset(hpage_node, *nmask)) { |
2061 | mpol_cond_put(pol); |
2062 | page = __alloc_pages_node(hpage_node, |
2063 | gfp | __GFP_THISNODE, order); |
2064 | goto out; |
2065 | } |
2066 | } |
2067 | |
2068 | nmask = policy_nodemask(gfp, pol); |
2069 | preferred_nid = policy_node(gfp, pol, node); |
2070 | page = __alloc_pages_nodemask(gfp, order, preferred_nid, nmask); |
2071 | mpol_cond_put(pol); |
2072 | out: |
2073 | return page; |
2074 | } |
2075 | |
2076 | /** |
2077 | * alloc_pages_current - Allocate pages. |
2078 | * |
2079 | * @gfp: |
2080 | * %GFP_USER user allocation, |
2081 | * %GFP_KERNEL kernel allocation, |
2082 | * %GFP_HIGHMEM highmem allocation, |
2083 | * %GFP_FS don't call back into a file system. |
2084 | * %GFP_ATOMIC don't sleep. |
2085 | * @order: Power of two of allocation size in pages. 0 is a single page. |
2086 | * |
2087 | * Allocate a page from the kernel page pool. When not in |
2088 | * interrupt context and apply the current process NUMA policy. |
2089 | * Returns NULL when no page can be allocated. |
2090 | */ |
2091 | struct page *alloc_pages_current(gfp_t gfp, unsigned order) |
2092 | { |
2093 | struct mempolicy *pol = &default_policy; |
2094 | struct page *page; |
2095 | |
2096 | if (!in_interrupt() && !(gfp & __GFP_THISNODE)) |
2097 | pol = get_task_policy(current); |
2098 | |
2099 | /* |
2100 | * No reference counting needed for current->mempolicy |
2101 | * nor system default_policy |
2102 | */ |
2103 | if (pol->mode == MPOL_INTERLEAVE) |
2104 | page = alloc_page_interleave(gfp, order, interleave_nodes(pol)); |
2105 | else |
2106 | page = __alloc_pages_nodemask(gfp, order, |
2107 | policy_node(gfp, pol, numa_node_id()), |
2108 | policy_nodemask(gfp, pol)); |
2109 | |
2110 | return page; |
2111 | } |
2112 | EXPORT_SYMBOL(alloc_pages_current); |
2113 | |
2114 | int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst) |
2115 | { |
2116 | struct mempolicy *pol = mpol_dup(vma_policy(src)); |
2117 | |
2118 | if (IS_ERR(pol)) |
2119 | return PTR_ERR(pol); |
2120 | dst->vm_policy = pol; |
2121 | return 0; |
2122 | } |
2123 | |
2124 | /* |
2125 | * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it |
2126 | * rebinds the mempolicy its copying by calling mpol_rebind_policy() |
2127 | * with the mems_allowed returned by cpuset_mems_allowed(). This |
2128 | * keeps mempolicies cpuset relative after its cpuset moves. See |
2129 | * further kernel/cpuset.c update_nodemask(). |
2130 | * |
2131 | * current's mempolicy may be rebinded by the other task(the task that changes |
2132 | * cpuset's mems), so we needn't do rebind work for current task. |
2133 | */ |
2134 | |
2135 | /* Slow path of a mempolicy duplicate */ |
2136 | struct mempolicy *__mpol_dup(struct mempolicy *old) |
2137 | { |
2138 | struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL); |
2139 | |
2140 | if (!new) |
2141 | return ERR_PTR(-ENOMEM); |
2142 | |
2143 | /* task's mempolicy is protected by alloc_lock */ |
2144 | if (old == current->mempolicy) { |
2145 | task_lock(current); |
2146 | *new = *old; |
2147 | task_unlock(current); |
2148 | } else |
2149 | *new = *old; |
2150 | |
2151 | if (current_cpuset_is_being_rebound()) { |
2152 | nodemask_t mems = cpuset_mems_allowed(current); |
2153 | mpol_rebind_policy(new, &mems); |
2154 | } |
2155 | atomic_set(&new->refcnt, 1); |
2156 | return new; |
2157 | } |
2158 | |
2159 | /* Slow path of a mempolicy comparison */ |
2160 | bool __mpol_equal(struct mempolicy *a, struct mempolicy *b) |
2161 | { |
2162 | if (!a || !b) |
2163 | return false; |
2164 | if (a->mode != b->mode) |
2165 | return false; |
2166 | if (a->flags != b->flags) |
2167 | return false; |
2168 | if (mpol_store_user_nodemask(a)) |
2169 | if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask)) |
2170 | return false; |
2171 | |
2172 | switch (a->mode) { |
2173 | case MPOL_BIND: |
2174 | /* Fall through */ |
2175 | case MPOL_INTERLEAVE: |
2176 | return !!nodes_equal(a->v.nodes, b->v.nodes); |
2177 | case MPOL_PREFERRED: |
2178 | /* a's ->flags is the same as b's */ |
2179 | if (a->flags & MPOL_F_LOCAL) |
2180 | return true; |
2181 | return a->v.preferred_node == b->v.preferred_node; |
2182 | default: |
2183 | BUG(); |
2184 | return false; |
2185 | } |
2186 | } |
2187 | |
2188 | /* |
2189 | * Shared memory backing store policy support. |
2190 | * |
2191 | * Remember policies even when nobody has shared memory mapped. |
2192 | * The policies are kept in Red-Black tree linked from the inode. |
2193 | * They are protected by the sp->lock rwlock, which should be held |
2194 | * for any accesses to the tree. |
2195 | */ |
2196 | |
2197 | /* |
2198 | * lookup first element intersecting start-end. Caller holds sp->lock for |
2199 | * reading or for writing |
2200 | */ |
2201 | static struct sp_node * |
2202 | sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end) |
2203 | { |
2204 | struct rb_node *n = sp->root.rb_node; |
2205 | |
2206 | while (n) { |
2207 | struct sp_node *p = rb_entry(n, struct sp_node, nd); |
2208 | |
2209 | if (start >= p->end) |
2210 | n = n->rb_right; |
2211 | else if (end <= p->start) |
2212 | n = n->rb_left; |
2213 | else |
2214 | break; |
2215 | } |
2216 | if (!n) |
2217 | return NULL; |
2218 | for (;;) { |
2219 | struct sp_node *w = NULL; |
2220 | struct rb_node *prev = rb_prev(n); |
2221 | if (!prev) |
2222 | break; |
2223 | w = rb_entry(prev, struct sp_node, nd); |
2224 | if (w->end <= start) |
2225 | break; |
2226 | n = prev; |
2227 | } |
2228 | return rb_entry(n, struct sp_node, nd); |
2229 | } |
2230 | |
2231 | /* |
2232 | * Insert a new shared policy into the list. Caller holds sp->lock for |
2233 | * writing. |
2234 | */ |
2235 | static void sp_insert(struct shared_policy *sp, struct sp_node *new) |
2236 | { |
2237 | struct rb_node **p = &sp->root.rb_node; |
2238 | struct rb_node *parent = NULL; |
2239 | struct sp_node *nd; |
2240 | |
2241 | while (*p) { |
2242 | parent = *p; |
2243 | nd = rb_entry(parent, struct sp_node, nd); |
2244 | if (new->start < nd->start) |
2245 | p = &(*p)->rb_left; |
2246 | else if (new->end > nd->end) |
2247 | p = &(*p)->rb_right; |
2248 | else |
2249 | BUG(); |
2250 | } |
2251 | rb_link_node(&new->nd, parent, p); |
2252 | rb_insert_color(&new->nd, &sp->root); |
2253 | pr_debug("inserting %lx-%lx: %d\n" , new->start, new->end, |
2254 | new->policy ? new->policy->mode : 0); |
2255 | } |
2256 | |
2257 | /* Find shared policy intersecting idx */ |
2258 | struct mempolicy * |
2259 | mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx) |
2260 | { |
2261 | struct mempolicy *pol = NULL; |
2262 | struct sp_node *sn; |
2263 | |
2264 | if (!sp->root.rb_node) |
2265 | return NULL; |
2266 | read_lock(&sp->lock); |
2267 | sn = sp_lookup(sp, idx, idx+1); |
2268 | if (sn) { |
2269 | mpol_get(sn->policy); |
2270 | pol = sn->policy; |
2271 | } |
2272 | read_unlock(&sp->lock); |
2273 | return pol; |
2274 | } |
2275 | |
2276 | static void sp_free(struct sp_node *n) |
2277 | { |
2278 | mpol_put(n->policy); |
2279 | kmem_cache_free(sn_cache, n); |
2280 | } |
2281 | |
2282 | /** |
2283 | * mpol_misplaced - check whether current page node is valid in policy |
2284 | * |
2285 | * @page: page to be checked |
2286 | * @vma: vm area where page mapped |
2287 | * @addr: virtual address where page mapped |
2288 | * |
2289 | * Lookup current policy node id for vma,addr and "compare to" page's |
2290 | * node id. |
2291 | * |
2292 | * Returns: |
2293 | * -1 - not misplaced, page is in the right node |
2294 | * node - node id where the page should be |
2295 | * |
2296 | * Policy determination "mimics" alloc_page_vma(). |
2297 | * Called from fault path where we know the vma and faulting address. |
2298 | */ |
2299 | int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long addr) |
2300 | { |
2301 | struct mempolicy *pol; |
2302 | struct zoneref *z; |
2303 | int curnid = page_to_nid(page); |
2304 | unsigned long pgoff; |
2305 | int thiscpu = raw_smp_processor_id(); |
2306 | int thisnid = cpu_to_node(thiscpu); |
2307 | int polnid = NUMA_NO_NODE; |
2308 | int ret = -1; |
2309 | |
2310 | pol = get_vma_policy(vma, addr); |
2311 | if (!(pol->flags & MPOL_F_MOF)) |
2312 | goto out; |
2313 | |
2314 | switch (pol->mode) { |
2315 | case MPOL_INTERLEAVE: |
2316 | pgoff = vma->vm_pgoff; |
2317 | pgoff += (addr - vma->vm_start) >> PAGE_SHIFT; |
2318 | polnid = offset_il_node(pol, pgoff); |
2319 | break; |
2320 | |
2321 | case MPOL_PREFERRED: |
2322 | if (pol->flags & MPOL_F_LOCAL) |
2323 | polnid = numa_node_id(); |
2324 | else |
2325 | polnid = pol->v.preferred_node; |
2326 | break; |
2327 | |
2328 | case MPOL_BIND: |
2329 | |
2330 | /* |
2331 | * allows binding to multiple nodes. |
2332 | * use current page if in policy nodemask, |
2333 | * else select nearest allowed node, if any. |
2334 | * If no allowed nodes, use current [!misplaced]. |
2335 | */ |
2336 | if (node_isset(curnid, pol->v.nodes)) |
2337 | goto out; |
2338 | z = first_zones_zonelist( |
2339 | node_zonelist(numa_node_id(), GFP_HIGHUSER), |
2340 | gfp_zone(GFP_HIGHUSER), |
2341 | &pol->v.nodes); |
2342 | polnid = zone_to_nid(z->zone); |
2343 | break; |
2344 | |
2345 | default: |
2346 | BUG(); |
2347 | } |
2348 | |
2349 | /* Migrate the page towards the node whose CPU is referencing it */ |
2350 | if (pol->flags & MPOL_F_MORON) { |
2351 | polnid = thisnid; |
2352 | |
2353 | if (!should_numa_migrate_memory(current, page, curnid, thiscpu)) |
2354 | goto out; |
2355 | } |
2356 | |
2357 | if (curnid != polnid) |
2358 | ret = polnid; |
2359 | out: |
2360 | mpol_cond_put(pol); |
2361 | |
2362 | return ret; |
2363 | } |
2364 | |
2365 | /* |
2366 | * Drop the (possibly final) reference to task->mempolicy. It needs to be |
2367 | * dropped after task->mempolicy is set to NULL so that any allocation done as |
2368 | * part of its kmem_cache_free(), such as by KASAN, doesn't reference a freed |
2369 | * policy. |
2370 | */ |
2371 | void mpol_put_task_policy(struct task_struct *task) |
2372 | { |
2373 | struct mempolicy *pol; |
2374 | |
2375 | task_lock(task); |
2376 | pol = task->mempolicy; |
2377 | task->mempolicy = NULL; |
2378 | task_unlock(task); |
2379 | mpol_put(pol); |
2380 | } |
2381 | |
2382 | static void sp_delete(struct shared_policy *sp, struct sp_node *n) |
2383 | { |
2384 | pr_debug("deleting %lx-l%lx\n" , n->start, n->end); |
2385 | rb_erase(&n->nd, &sp->root); |
2386 | sp_free(n); |
2387 | } |
2388 | |
2389 | static void sp_node_init(struct sp_node *node, unsigned long start, |
2390 | unsigned long end, struct mempolicy *pol) |
2391 | { |
2392 | node->start = start; |
2393 | node->end = end; |
2394 | node->policy = pol; |
2395 | } |
2396 | |
2397 | static struct sp_node *sp_alloc(unsigned long start, unsigned long end, |
2398 | struct mempolicy *pol) |
2399 | { |
2400 | struct sp_node *n; |
2401 | struct mempolicy *newpol; |
2402 | |
2403 | n = kmem_cache_alloc(sn_cache, GFP_KERNEL); |
2404 | if (!n) |
2405 | return NULL; |
2406 | |
2407 | newpol = mpol_dup(pol); |
2408 | if (IS_ERR(newpol)) { |
2409 | kmem_cache_free(sn_cache, n); |
2410 | return NULL; |
2411 | } |
2412 | newpol->flags |= MPOL_F_SHARED; |
2413 | sp_node_init(n, start, end, newpol); |
2414 | |
2415 | return n; |
2416 | } |
2417 | |
2418 | /* Replace a policy range. */ |
2419 | static int shared_policy_replace(struct shared_policy *sp, unsigned long start, |
2420 | unsigned long end, struct sp_node *new) |
2421 | { |
2422 | struct sp_node *n; |
2423 | struct sp_node *n_new = NULL; |
2424 | struct mempolicy *mpol_new = NULL; |
2425 | int ret = 0; |
2426 | |
2427 | restart: |
2428 | write_lock(&sp->lock); |
2429 | n = sp_lookup(sp, start, end); |
2430 | /* Take care of old policies in the same range. */ |
2431 | while (n && n->start < end) { |
2432 | struct rb_node *next = rb_next(&n->nd); |
2433 | if (n->start >= start) { |
2434 | if (n->end <= end) |
2435 | sp_delete(sp, n); |
2436 | else |
2437 | n->start = end; |
2438 | } else { |
2439 | /* Old policy spanning whole new range. */ |
2440 | if (n->end > end) { |
2441 | if (!n_new) |
2442 | goto alloc_new; |
2443 | |
2444 | *mpol_new = *n->policy; |
2445 | atomic_set(&mpol_new->refcnt, 1); |
2446 | sp_node_init(n_new, end, n->end, mpol_new); |
2447 | n->end = start; |
2448 | sp_insert(sp, n_new); |
2449 | n_new = NULL; |
2450 | mpol_new = NULL; |
2451 | break; |
2452 | } else |
2453 | n->end = start; |
2454 | } |
2455 | if (!next) |
2456 | break; |
2457 | n = rb_entry(next, struct sp_node, nd); |
2458 | } |
2459 | if (new) |
2460 | sp_insert(sp, new); |
2461 | write_unlock(&sp->lock); |
2462 | ret = 0; |
2463 | |
2464 | err_out: |
2465 | if (mpol_new) |
2466 | mpol_put(mpol_new); |
2467 | if (n_new) |
2468 | kmem_cache_free(sn_cache, n_new); |
2469 | |
2470 | return ret; |
2471 | |
2472 | alloc_new: |
2473 | write_unlock(&sp->lock); |
2474 | ret = -ENOMEM; |
2475 | n_new = kmem_cache_alloc(sn_cache, GFP_KERNEL); |
2476 | if (!n_new) |
2477 | goto err_out; |
2478 | mpol_new = kmem_cache_alloc(policy_cache, GFP_KERNEL); |
2479 | if (!mpol_new) |
2480 | goto err_out; |
2481 | goto restart; |
2482 | } |
2483 | |
2484 | /** |
2485 | * mpol_shared_policy_init - initialize shared policy for inode |
2486 | * @sp: pointer to inode shared policy |
2487 | * @mpol: struct mempolicy to install |
2488 | * |
2489 | * Install non-NULL @mpol in inode's shared policy rb-tree. |
2490 | * On entry, the current task has a reference on a non-NULL @mpol. |
2491 | * This must be released on exit. |
2492 | * This is called at get_inode() calls and we can use GFP_KERNEL. |
2493 | */ |
2494 | void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol) |
2495 | { |
2496 | int ret; |
2497 | |
2498 | sp->root = RB_ROOT; /* empty tree == default mempolicy */ |
2499 | rwlock_init(&sp->lock); |
2500 | |
2501 | if (mpol) { |
2502 | struct vm_area_struct pvma; |
2503 | struct mempolicy *new; |
2504 | NODEMASK_SCRATCH(scratch); |
2505 | |
2506 | if (!scratch) |
2507 | goto put_mpol; |
2508 | /* contextualize the tmpfs mount point mempolicy */ |
2509 | new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask); |
2510 | if (IS_ERR(new)) |
2511 | goto free_scratch; /* no valid nodemask intersection */ |
2512 | |
2513 | task_lock(current); |
2514 | ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch); |
2515 | task_unlock(current); |
2516 | if (ret) |
2517 | goto put_new; |
2518 | |
2519 | /* Create pseudo-vma that contains just the policy */ |
2520 | vma_init(&pvma, NULL); |
2521 | pvma.vm_end = TASK_SIZE; /* policy covers entire file */ |
2522 | mpol_set_shared_policy(sp, &pvma, new); /* adds ref */ |
2523 | |
2524 | put_new: |
2525 | mpol_put(new); /* drop initial ref */ |
2526 | free_scratch: |
2527 | NODEMASK_SCRATCH_FREE(scratch); |
2528 | put_mpol: |
2529 | mpol_put(mpol); /* drop our incoming ref on sb mpol */ |
2530 | } |
2531 | } |
2532 | |
2533 | int mpol_set_shared_policy(struct shared_policy *info, |
2534 | struct vm_area_struct *vma, struct mempolicy *npol) |
2535 | { |
2536 | int err; |
2537 | struct sp_node *new = NULL; |
2538 | unsigned long sz = vma_pages(vma); |
2539 | |
2540 | pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n" , |
2541 | vma->vm_pgoff, |
2542 | sz, npol ? npol->mode : -1, |
2543 | npol ? npol->flags : -1, |
2544 | npol ? nodes_addr(npol->v.nodes)[0] : NUMA_NO_NODE); |
2545 | |
2546 | if (npol) { |
2547 | new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol); |
2548 | if (!new) |
2549 | return -ENOMEM; |
2550 | } |
2551 | err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new); |
2552 | if (err && new) |
2553 | sp_free(new); |
2554 | return err; |
2555 | } |
2556 | |
2557 | /* Free a backing policy store on inode delete. */ |
2558 | void mpol_free_shared_policy(struct shared_policy *p) |
2559 | { |
2560 | struct sp_node *n; |
2561 | struct rb_node *next; |
2562 | |
2563 | if (!p->root.rb_node) |
2564 | return; |
2565 | write_lock(&p->lock); |
2566 | next = rb_first(&p->root); |
2567 | while (next) { |
2568 | n = rb_entry(next, struct sp_node, nd); |
2569 | next = rb_next(&n->nd); |
2570 | sp_delete(p, n); |
2571 | } |
2572 | write_unlock(&p->lock); |
2573 | } |
2574 | |
2575 | #ifdef CONFIG_NUMA_BALANCING |
2576 | static int __initdata numabalancing_override; |
2577 | |
2578 | static void __init check_numabalancing_enable(void) |
2579 | { |
2580 | bool numabalancing_default = false; |
2581 | |
2582 | if (IS_ENABLED(CONFIG_NUMA_BALANCING_DEFAULT_ENABLED)) |
2583 | numabalancing_default = true; |
2584 | |
2585 | /* Parsed by setup_numabalancing. override == 1 enables, -1 disables */ |
2586 | if (numabalancing_override) |
2587 | set_numabalancing_state(numabalancing_override == 1); |
2588 | |
2589 | if (num_online_nodes() > 1 && !numabalancing_override) { |
2590 | pr_info("%s automatic NUMA balancing. Configure with numa_balancing= or the kernel.numa_balancing sysctl\n" , |
2591 | numabalancing_default ? "Enabling" : "Disabling" ); |
2592 | set_numabalancing_state(numabalancing_default); |
2593 | } |
2594 | } |
2595 | |
2596 | static int __init setup_numabalancing(char *str) |
2597 | { |
2598 | int ret = 0; |
2599 | if (!str) |
2600 | goto out; |
2601 | |
2602 | if (!strcmp(str, "enable" )) { |
2603 | numabalancing_override = 1; |
2604 | ret = 1; |
2605 | } else if (!strcmp(str, "disable" )) { |
2606 | numabalancing_override = -1; |
2607 | ret = 1; |
2608 | } |
2609 | out: |
2610 | if (!ret) |
2611 | pr_warn("Unable to parse numa_balancing=\n" ); |
2612 | |
2613 | return ret; |
2614 | } |
2615 | __setup("numa_balancing=" , setup_numabalancing); |
2616 | #else |
2617 | static inline void __init check_numabalancing_enable(void) |
2618 | { |
2619 | } |
2620 | #endif /* CONFIG_NUMA_BALANCING */ |
2621 | |
2622 | /* assumes fs == KERNEL_DS */ |
2623 | void __init numa_policy_init(void) |
2624 | { |
2625 | nodemask_t interleave_nodes; |
2626 | unsigned long largest = 0; |
2627 | int nid, prefer = 0; |
2628 | |
2629 | policy_cache = kmem_cache_create("numa_policy" , |
2630 | sizeof(struct mempolicy), |
2631 | 0, SLAB_PANIC, NULL); |
2632 | |
2633 | sn_cache = kmem_cache_create("shared_policy_node" , |
2634 | sizeof(struct sp_node), |
2635 | 0, SLAB_PANIC, NULL); |
2636 | |
2637 | for_each_node(nid) { |
2638 | preferred_node_policy[nid] = (struct mempolicy) { |
2639 | .refcnt = ATOMIC_INIT(1), |
2640 | .mode = MPOL_PREFERRED, |
2641 | .flags = MPOL_F_MOF | MPOL_F_MORON, |
2642 | .v = { .preferred_node = nid, }, |
2643 | }; |
2644 | } |
2645 | |
2646 | /* |
2647 | * Set interleaving policy for system init. Interleaving is only |
2648 | * enabled across suitably sized nodes (default is >= 16MB), or |
2649 | * fall back to the largest node if they're all smaller. |
2650 | */ |
2651 | nodes_clear(interleave_nodes); |
2652 | for_each_node_state(nid, N_MEMORY) { |
2653 | unsigned long total_pages = node_present_pages(nid); |
2654 | |
2655 | /* Preserve the largest node */ |
2656 | if (largest < total_pages) { |
2657 | largest = total_pages; |
2658 | prefer = nid; |
2659 | } |
2660 | |
2661 | /* Interleave this node? */ |
2662 | if ((total_pages << PAGE_SHIFT) >= (16 << 20)) |
2663 | node_set(nid, interleave_nodes); |
2664 | } |
2665 | |
2666 | /* All too small, use the largest */ |
2667 | if (unlikely(nodes_empty(interleave_nodes))) |
2668 | node_set(prefer, interleave_nodes); |
2669 | |
2670 | if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes)) |
2671 | pr_err("%s: interleaving failed\n" , __func__); |
2672 | |
2673 | check_numabalancing_enable(); |
2674 | } |
2675 | |
2676 | /* Reset policy of current process to default */ |
2677 | void numa_default_policy(void) |
2678 | { |
2679 | do_set_mempolicy(MPOL_DEFAULT, 0, NULL); |
2680 | } |
2681 | |
2682 | /* |
2683 | * Parse and format mempolicy from/to strings |
2684 | */ |
2685 | |
2686 | /* |
2687 | * "local" is implemented internally by MPOL_PREFERRED with MPOL_F_LOCAL flag. |
2688 | */ |
2689 | static const char * const policy_modes[] = |
2690 | { |
2691 | [MPOL_DEFAULT] = "default" , |
2692 | [MPOL_PREFERRED] = "prefer" , |
2693 | [MPOL_BIND] = "bind" , |
2694 | [MPOL_INTERLEAVE] = "interleave" , |
2695 | [MPOL_LOCAL] = "local" , |
2696 | }; |
2697 | |
2698 | |
2699 | #ifdef CONFIG_TMPFS |
2700 | /** |
2701 | * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option. |
2702 | * @str: string containing mempolicy to parse |
2703 | * @mpol: pointer to struct mempolicy pointer, returned on success. |
2704 | * |
2705 | * Format of input: |
2706 | * <mode>[=<flags>][:<nodelist>] |
2707 | * |
2708 | * On success, returns 0, else 1 |
2709 | */ |
2710 | int mpol_parse_str(char *str, struct mempolicy **mpol) |
2711 | { |
2712 | struct mempolicy *new = NULL; |
2713 | unsigned short mode_flags; |
2714 | nodemask_t nodes; |
2715 | char *nodelist = strchr(str, ':'); |
2716 | char *flags = strchr(str, '='); |
2717 | int err = 1, mode; |
2718 | |
2719 | if (nodelist) { |
2720 | /* NUL-terminate mode or flags string */ |
2721 | *nodelist++ = '\0'; |
2722 | if (nodelist_parse(nodelist, nodes)) |
2723 | goto out; |
2724 | if (!nodes_subset(nodes, node_states[N_MEMORY])) |
2725 | goto out; |
2726 | } else |
2727 | nodes_clear(nodes); |
2728 | |
2729 | if (flags) |
2730 | *flags++ = '\0'; /* terminate mode string */ |
2731 | |
2732 | mode = match_string(policy_modes, MPOL_MAX, str); |
2733 | if (mode < 0) |
2734 | goto out; |
2735 | |
2736 | switch (mode) { |
2737 | case MPOL_PREFERRED: |
2738 | /* |
2739 | * Insist on a nodelist of one node only |
2740 | */ |
2741 | if (nodelist) { |
2742 | char *rest = nodelist; |
2743 | while (isdigit(*rest)) |
2744 | rest++; |
2745 | if (*rest) |
2746 | goto out; |
2747 | } |
2748 | break; |
2749 | case MPOL_INTERLEAVE: |
2750 | /* |
2751 | * Default to online nodes with memory if no nodelist |
2752 | */ |
2753 | if (!nodelist) |
2754 | nodes = node_states[N_MEMORY]; |
2755 | break; |
2756 | case MPOL_LOCAL: |
2757 | /* |
2758 | * Don't allow a nodelist; mpol_new() checks flags |
2759 | */ |
2760 | if (nodelist) |
2761 | goto out; |
2762 | mode = MPOL_PREFERRED; |
2763 | break; |
2764 | case MPOL_DEFAULT: |
2765 | /* |
2766 | * Insist on a empty nodelist |
2767 | */ |
2768 | if (!nodelist) |
2769 | err = 0; |
2770 | goto out; |
2771 | case MPOL_BIND: |
2772 | /* |
2773 | * Insist on a nodelist |
2774 | */ |
2775 | if (!nodelist) |
2776 | goto out; |
2777 | } |
2778 | |
2779 | mode_flags = 0; |
2780 | if (flags) { |
2781 | /* |
2782 | * Currently, we only support two mutually exclusive |
2783 | * mode flags. |
2784 | */ |
2785 | if (!strcmp(flags, "static" )) |
2786 | mode_flags |= MPOL_F_STATIC_NODES; |
2787 | else if (!strcmp(flags, "relative" )) |
2788 | mode_flags |= MPOL_F_RELATIVE_NODES; |
2789 | else |
2790 | goto out; |
2791 | } |
2792 | |
2793 | new = mpol_new(mode, mode_flags, &nodes); |
2794 | if (IS_ERR(new)) |
2795 | goto out; |
2796 | |
2797 | /* |
2798 | * Save nodes for mpol_to_str() to show the tmpfs mount options |
2799 | * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo. |
2800 | */ |
2801 | if (mode != MPOL_PREFERRED) |
2802 | new->v.nodes = nodes; |
2803 | else if (nodelist) |
2804 | new->v.preferred_node = first_node(nodes); |
2805 | else |
2806 | new->flags |= MPOL_F_LOCAL; |
2807 | |
2808 | /* |
2809 | * Save nodes for contextualization: this will be used to "clone" |
2810 | * the mempolicy in a specific context [cpuset] at a later time. |
2811 | */ |
2812 | new->w.user_nodemask = nodes; |
2813 | |
2814 | err = 0; |
2815 | |
2816 | out: |
2817 | /* Restore string for error message */ |
2818 | if (nodelist) |
2819 | *--nodelist = ':'; |
2820 | if (flags) |
2821 | *--flags = '='; |
2822 | if (!err) |
2823 | *mpol = new; |
2824 | return err; |
2825 | } |
2826 | #endif /* CONFIG_TMPFS */ |
2827 | |
2828 | /** |
2829 | * mpol_to_str - format a mempolicy structure for printing |
2830 | * @buffer: to contain formatted mempolicy string |
2831 | * @maxlen: length of @buffer |
2832 | * @pol: pointer to mempolicy to be formatted |
2833 | * |
2834 | * Convert @pol into a string. If @buffer is too short, truncate the string. |
2835 | * Recommend a @maxlen of at least 32 for the longest mode, "interleave", the |
2836 | * longest flag, "relative", and to display at least a few node ids. |
2837 | */ |
2838 | void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol) |
2839 | { |
2840 | char *p = buffer; |
2841 | nodemask_t nodes = NODE_MASK_NONE; |
2842 | unsigned short mode = MPOL_DEFAULT; |
2843 | unsigned short flags = 0; |
2844 | |
2845 | if (pol && pol != &default_policy && !(pol->flags & MPOL_F_MORON)) { |
2846 | mode = pol->mode; |
2847 | flags = pol->flags; |
2848 | } |
2849 | |
2850 | switch (mode) { |
2851 | case MPOL_DEFAULT: |
2852 | break; |
2853 | case MPOL_PREFERRED: |
2854 | if (flags & MPOL_F_LOCAL) |
2855 | mode = MPOL_LOCAL; |
2856 | else |
2857 | node_set(pol->v.preferred_node, nodes); |
2858 | break; |
2859 | case MPOL_BIND: |
2860 | case MPOL_INTERLEAVE: |
2861 | nodes = pol->v.nodes; |
2862 | break; |
2863 | default: |
2864 | WARN_ON_ONCE(1); |
2865 | snprintf(p, maxlen, "unknown" ); |
2866 | return; |
2867 | } |
2868 | |
2869 | p += snprintf(p, maxlen, "%s" , policy_modes[mode]); |
2870 | |
2871 | if (flags & MPOL_MODE_FLAGS) { |
2872 | p += snprintf(p, buffer + maxlen - p, "=" ); |
2873 | |
2874 | /* |
2875 | * Currently, the only defined flags are mutually exclusive |
2876 | */ |
2877 | if (flags & MPOL_F_STATIC_NODES) |
2878 | p += snprintf(p, buffer + maxlen - p, "static" ); |
2879 | else if (flags & MPOL_F_RELATIVE_NODES) |
2880 | p += snprintf(p, buffer + maxlen - p, "relative" ); |
2881 | } |
2882 | |
2883 | if (!nodes_empty(nodes)) |
2884 | p += scnprintf(p, buffer + maxlen - p, ":%*pbl" , |
2885 | nodemask_pr_args(&nodes)); |
2886 | } |
2887 | |