drm/i915: kill ring->setup_status_page
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / mm / mempolicy.c
blobf969da5dd8a2136b92aab7e7c1a6ecc9083d6cb9
1 /*
2 * Simple NUMA memory policy for the Linux kernel.
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.
8 * NUMA policy allows the user to give hints in which node(s) memory should
9 * be allocated.
11 * Support four policies per VMA and per process:
13 * The VMA policy has priority over the process policy for a page fault.
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.
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
28 * preferred Try a specific node first before normal fallback.
29 * As a special case node -1 here means do the allocation
30 * on the local CPU. This is normally identical to default,
31 * but useful to set in a VMA when you have a non default
32 * process policy.
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.
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.
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.
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.
52 * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between
53 * all users and remembered even when nobody has memory mapped.
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.
68 #include <linux/mempolicy.h>
69 #include <linux/mm.h>
70 #include <linux/highmem.h>
71 #include <linux/hugetlb.h>
72 #include <linux/kernel.h>
73 #include <linux/sched.h>
74 #include <linux/nodemask.h>
75 #include <linux/cpuset.h>
76 #include <linux/slab.h>
77 #include <linux/string.h>
78 #include <linux/module.h>
79 #include <linux/nsproxy.h>
80 #include <linux/interrupt.h>
81 #include <linux/init.h>
82 #include <linux/compat.h>
83 #include <linux/swap.h>
84 #include <linux/seq_file.h>
85 #include <linux/proc_fs.h>
86 #include <linux/migrate.h>
87 #include <linux/ksm.h>
88 #include <linux/rmap.h>
89 #include <linux/security.h>
90 #include <linux/syscalls.h>
91 #include <linux/ctype.h>
92 #include <linux/mm_inline.h>
94 #include <asm/tlbflush.h>
95 #include <asm/uaccess.h>
97 #include "internal.h"
99 /* Internal flags */
100 #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
101 #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
102 #define MPOL_MF_STATS (MPOL_MF_INTERNAL << 2) /* Gather statistics */
104 static struct kmem_cache *policy_cache;
105 static struct kmem_cache *sn_cache;
107 /* Highest zone. An specific allocation for a zone below that is not
108 policied. */
109 enum zone_type policy_zone = 0;
112 * run-time system-wide default policy => local allocation
114 struct mempolicy default_policy = {
115 .refcnt = ATOMIC_INIT(1), /* never free it */
116 .mode = MPOL_PREFERRED,
117 .flags = MPOL_F_LOCAL,
120 static const struct mempolicy_operations {
121 int (*create)(struct mempolicy *pol, const nodemask_t *nodes);
123 * If read-side task has no lock to protect task->mempolicy, write-side
124 * task will rebind the task->mempolicy by two step. The first step is
125 * setting all the newly nodes, and the second step is cleaning all the
126 * disallowed nodes. In this way, we can avoid finding no node to alloc
127 * page.
128 * If we have a lock to protect task->mempolicy in read-side, we do
129 * rebind directly.
131 * step:
132 * MPOL_REBIND_ONCE - do rebind work at once
133 * MPOL_REBIND_STEP1 - set all the newly nodes
134 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
136 void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes,
137 enum mpol_rebind_step step);
138 } mpol_ops[MPOL_MAX];
140 /* Check that the nodemask contains at least one populated zone */
141 static int is_valid_nodemask(const nodemask_t *nodemask)
143 int nd, k;
145 for_each_node_mask(nd, *nodemask) {
146 struct zone *z;
148 for (k = 0; k <= policy_zone; k++) {
149 z = &NODE_DATA(nd)->node_zones[k];
150 if (z->present_pages > 0)
151 return 1;
155 return 0;
158 static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
160 return pol->flags & MPOL_MODE_FLAGS;
163 static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
164 const nodemask_t *rel)
166 nodemask_t tmp;
167 nodes_fold(tmp, *orig, nodes_weight(*rel));
168 nodes_onto(*ret, tmp, *rel);
171 static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
173 if (nodes_empty(*nodes))
174 return -EINVAL;
175 pol->v.nodes = *nodes;
176 return 0;
179 static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
181 if (!nodes)
182 pol->flags |= MPOL_F_LOCAL; /* local allocation */
183 else if (nodes_empty(*nodes))
184 return -EINVAL; /* no allowed nodes */
185 else
186 pol->v.preferred_node = first_node(*nodes);
187 return 0;
190 static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
192 if (!is_valid_nodemask(nodes))
193 return -EINVAL;
194 pol->v.nodes = *nodes;
195 return 0;
199 * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
200 * any, for the new policy. mpol_new() has already validated the nodes
201 * parameter with respect to the policy mode and flags. But, we need to
202 * handle an empty nodemask with MPOL_PREFERRED here.
204 * Must be called holding task's alloc_lock to protect task's mems_allowed
205 * and mempolicy. May also be called holding the mmap_semaphore for write.
207 static int mpol_set_nodemask(struct mempolicy *pol,
208 const nodemask_t *nodes, struct nodemask_scratch *nsc)
210 int ret;
212 /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
213 if (pol == NULL)
214 return 0;
215 /* Check N_HIGH_MEMORY */
216 nodes_and(nsc->mask1,
217 cpuset_current_mems_allowed, node_states[N_HIGH_MEMORY]);
219 VM_BUG_ON(!nodes);
220 if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
221 nodes = NULL; /* explicit local allocation */
222 else {
223 if (pol->flags & MPOL_F_RELATIVE_NODES)
224 mpol_relative_nodemask(&nsc->mask2, nodes,&nsc->mask1);
225 else
226 nodes_and(nsc->mask2, *nodes, nsc->mask1);
228 if (mpol_store_user_nodemask(pol))
229 pol->w.user_nodemask = *nodes;
230 else
231 pol->w.cpuset_mems_allowed =
232 cpuset_current_mems_allowed;
235 if (nodes)
236 ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
237 else
238 ret = mpol_ops[pol->mode].create(pol, NULL);
239 return ret;
243 * This function just creates a new policy, does some check and simple
244 * initialization. You must invoke mpol_set_nodemask() to set nodes.
246 static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
247 nodemask_t *nodes)
249 struct mempolicy *policy;
251 pr_debug("setting mode %d flags %d nodes[0] %lx\n",
252 mode, flags, nodes ? nodes_addr(*nodes)[0] : -1);
254 if (mode == MPOL_DEFAULT) {
255 if (nodes && !nodes_empty(*nodes))
256 return ERR_PTR(-EINVAL);
257 return NULL; /* simply delete any existing policy */
259 VM_BUG_ON(!nodes);
262 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
263 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
264 * All other modes require a valid pointer to a non-empty nodemask.
266 if (mode == MPOL_PREFERRED) {
267 if (nodes_empty(*nodes)) {
268 if (((flags & MPOL_F_STATIC_NODES) ||
269 (flags & MPOL_F_RELATIVE_NODES)))
270 return ERR_PTR(-EINVAL);
272 } else if (nodes_empty(*nodes))
273 return ERR_PTR(-EINVAL);
274 policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
275 if (!policy)
276 return ERR_PTR(-ENOMEM);
277 atomic_set(&policy->refcnt, 1);
278 policy->mode = mode;
279 policy->flags = flags;
281 return policy;
284 /* Slow path of a mpol destructor. */
285 void __mpol_put(struct mempolicy *p)
287 if (!atomic_dec_and_test(&p->refcnt))
288 return;
289 kmem_cache_free(policy_cache, p);
292 static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes,
293 enum mpol_rebind_step step)
298 * step:
299 * MPOL_REBIND_ONCE - do rebind work at once
300 * MPOL_REBIND_STEP1 - set all the newly nodes
301 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
303 static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes,
304 enum mpol_rebind_step step)
306 nodemask_t tmp;
308 if (pol->flags & MPOL_F_STATIC_NODES)
309 nodes_and(tmp, pol->w.user_nodemask, *nodes);
310 else if (pol->flags & MPOL_F_RELATIVE_NODES)
311 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
312 else {
314 * if step == 1, we use ->w.cpuset_mems_allowed to cache the
315 * result
317 if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP1) {
318 nodes_remap(tmp, pol->v.nodes,
319 pol->w.cpuset_mems_allowed, *nodes);
320 pol->w.cpuset_mems_allowed = step ? tmp : *nodes;
321 } else if (step == MPOL_REBIND_STEP2) {
322 tmp = pol->w.cpuset_mems_allowed;
323 pol->w.cpuset_mems_allowed = *nodes;
324 } else
325 BUG();
328 if (nodes_empty(tmp))
329 tmp = *nodes;
331 if (step == MPOL_REBIND_STEP1)
332 nodes_or(pol->v.nodes, pol->v.nodes, tmp);
333 else if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP2)
334 pol->v.nodes = tmp;
335 else
336 BUG();
338 if (!node_isset(current->il_next, tmp)) {
339 current->il_next = next_node(current->il_next, tmp);
340 if (current->il_next >= MAX_NUMNODES)
341 current->il_next = first_node(tmp);
342 if (current->il_next >= MAX_NUMNODES)
343 current->il_next = numa_node_id();
347 static void mpol_rebind_preferred(struct mempolicy *pol,
348 const nodemask_t *nodes,
349 enum mpol_rebind_step step)
351 nodemask_t tmp;
353 if (pol->flags & MPOL_F_STATIC_NODES) {
354 int node = first_node(pol->w.user_nodemask);
356 if (node_isset(node, *nodes)) {
357 pol->v.preferred_node = node;
358 pol->flags &= ~MPOL_F_LOCAL;
359 } else
360 pol->flags |= MPOL_F_LOCAL;
361 } else if (pol->flags & MPOL_F_RELATIVE_NODES) {
362 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
363 pol->v.preferred_node = first_node(tmp);
364 } else if (!(pol->flags & MPOL_F_LOCAL)) {
365 pol->v.preferred_node = node_remap(pol->v.preferred_node,
366 pol->w.cpuset_mems_allowed,
367 *nodes);
368 pol->w.cpuset_mems_allowed = *nodes;
373 * mpol_rebind_policy - Migrate a policy to a different set of nodes
375 * If read-side task has no lock to protect task->mempolicy, write-side
376 * task will rebind the task->mempolicy by two step. The first step is
377 * setting all the newly nodes, and the second step is cleaning all the
378 * disallowed nodes. In this way, we can avoid finding no node to alloc
379 * page.
380 * If we have a lock to protect task->mempolicy in read-side, we do
381 * rebind directly.
383 * step:
384 * MPOL_REBIND_ONCE - do rebind work at once
385 * MPOL_REBIND_STEP1 - set all the newly nodes
386 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
388 static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask,
389 enum mpol_rebind_step step)
391 if (!pol)
392 return;
393 if (!mpol_store_user_nodemask(pol) && step == 0 &&
394 nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
395 return;
397 if (step == MPOL_REBIND_STEP1 && (pol->flags & MPOL_F_REBINDING))
398 return;
400 if (step == MPOL_REBIND_STEP2 && !(pol->flags & MPOL_F_REBINDING))
401 BUG();
403 if (step == MPOL_REBIND_STEP1)
404 pol->flags |= MPOL_F_REBINDING;
405 else if (step == MPOL_REBIND_STEP2)
406 pol->flags &= ~MPOL_F_REBINDING;
407 else if (step >= MPOL_REBIND_NSTEP)
408 BUG();
410 mpol_ops[pol->mode].rebind(pol, newmask, step);
414 * Wrapper for mpol_rebind_policy() that just requires task
415 * pointer, and updates task mempolicy.
417 * Called with task's alloc_lock held.
420 void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new,
421 enum mpol_rebind_step step)
423 mpol_rebind_policy(tsk->mempolicy, new, step);
427 * Rebind each vma in mm to new nodemask.
429 * Call holding a reference to mm. Takes mm->mmap_sem during call.
432 void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
434 struct vm_area_struct *vma;
436 down_write(&mm->mmap_sem);
437 for (vma = mm->mmap; vma; vma = vma->vm_next)
438 mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE);
439 up_write(&mm->mmap_sem);
442 static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
443 [MPOL_DEFAULT] = {
444 .rebind = mpol_rebind_default,
446 [MPOL_INTERLEAVE] = {
447 .create = mpol_new_interleave,
448 .rebind = mpol_rebind_nodemask,
450 [MPOL_PREFERRED] = {
451 .create = mpol_new_preferred,
452 .rebind = mpol_rebind_preferred,
454 [MPOL_BIND] = {
455 .create = mpol_new_bind,
456 .rebind = mpol_rebind_nodemask,
460 static void gather_stats(struct page *, void *, int pte_dirty);
461 static void migrate_page_add(struct page *page, struct list_head *pagelist,
462 unsigned long flags);
464 /* Scan through pages checking if pages follow certain conditions. */
465 static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
466 unsigned long addr, unsigned long end,
467 const nodemask_t *nodes, unsigned long flags,
468 void *private)
470 pte_t *orig_pte;
471 pte_t *pte;
472 spinlock_t *ptl;
474 orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
475 do {
476 struct page *page;
477 int nid;
479 if (!pte_present(*pte))
480 continue;
481 page = vm_normal_page(vma, addr, *pte);
482 if (!page)
483 continue;
485 * vm_normal_page() filters out zero pages, but there might
486 * still be PageReserved pages to skip, perhaps in a VDSO.
487 * And we cannot move PageKsm pages sensibly or safely yet.
489 if (PageReserved(page) || PageKsm(page))
490 continue;
491 nid = page_to_nid(page);
492 if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
493 continue;
495 if (flags & MPOL_MF_STATS)
496 gather_stats(page, private, pte_dirty(*pte));
497 else if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
498 migrate_page_add(page, private, flags);
499 else
500 break;
501 } while (pte++, addr += PAGE_SIZE, addr != end);
502 pte_unmap_unlock(orig_pte, ptl);
503 return addr != end;
506 static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
507 unsigned long addr, unsigned long end,
508 const nodemask_t *nodes, unsigned long flags,
509 void *private)
511 pmd_t *pmd;
512 unsigned long next;
514 pmd = pmd_offset(pud, addr);
515 do {
516 next = pmd_addr_end(addr, end);
517 if (pmd_none_or_clear_bad(pmd))
518 continue;
519 if (check_pte_range(vma, pmd, addr, next, nodes,
520 flags, private))
521 return -EIO;
522 } while (pmd++, addr = next, addr != end);
523 return 0;
526 static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
527 unsigned long addr, unsigned long end,
528 const nodemask_t *nodes, unsigned long flags,
529 void *private)
531 pud_t *pud;
532 unsigned long next;
534 pud = pud_offset(pgd, addr);
535 do {
536 next = pud_addr_end(addr, end);
537 if (pud_none_or_clear_bad(pud))
538 continue;
539 if (check_pmd_range(vma, pud, addr, next, nodes,
540 flags, private))
541 return -EIO;
542 } while (pud++, addr = next, addr != end);
543 return 0;
546 static inline int check_pgd_range(struct vm_area_struct *vma,
547 unsigned long addr, unsigned long end,
548 const nodemask_t *nodes, unsigned long flags,
549 void *private)
551 pgd_t *pgd;
552 unsigned long next;
554 pgd = pgd_offset(vma->vm_mm, addr);
555 do {
556 next = pgd_addr_end(addr, end);
557 if (pgd_none_or_clear_bad(pgd))
558 continue;
559 if (check_pud_range(vma, pgd, addr, next, nodes,
560 flags, private))
561 return -EIO;
562 } while (pgd++, addr = next, addr != end);
563 return 0;
567 * Check if all pages in a range are on a set of nodes.
568 * If pagelist != NULL then isolate pages from the LRU and
569 * put them on the pagelist.
571 static struct vm_area_struct *
572 check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
573 const nodemask_t *nodes, unsigned long flags, void *private)
575 int err;
576 struct vm_area_struct *first, *vma, *prev;
579 first = find_vma(mm, start);
580 if (!first)
581 return ERR_PTR(-EFAULT);
582 prev = NULL;
583 for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) {
584 if (!(flags & MPOL_MF_DISCONTIG_OK)) {
585 if (!vma->vm_next && vma->vm_end < end)
586 return ERR_PTR(-EFAULT);
587 if (prev && prev->vm_end < vma->vm_start)
588 return ERR_PTR(-EFAULT);
590 if (!is_vm_hugetlb_page(vma) &&
591 ((flags & MPOL_MF_STRICT) ||
592 ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) &&
593 vma_migratable(vma)))) {
594 unsigned long endvma = vma->vm_end;
596 if (endvma > end)
597 endvma = end;
598 if (vma->vm_start > start)
599 start = vma->vm_start;
600 err = check_pgd_range(vma, start, endvma, nodes,
601 flags, private);
602 if (err) {
603 first = ERR_PTR(err);
604 break;
607 prev = vma;
609 return first;
612 /* Apply policy to a single VMA */
613 static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new)
615 int err = 0;
616 struct mempolicy *old = vma->vm_policy;
618 pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
619 vma->vm_start, vma->vm_end, vma->vm_pgoff,
620 vma->vm_ops, vma->vm_file,
621 vma->vm_ops ? vma->vm_ops->set_policy : NULL);
623 if (vma->vm_ops && vma->vm_ops->set_policy)
624 err = vma->vm_ops->set_policy(vma, new);
625 if (!err) {
626 mpol_get(new);
627 vma->vm_policy = new;
628 mpol_put(old);
630 return err;
633 /* Step 2: apply policy to a range and do splits. */
634 static int mbind_range(struct mm_struct *mm, unsigned long start,
635 unsigned long end, struct mempolicy *new_pol)
637 struct vm_area_struct *next;
638 struct vm_area_struct *prev;
639 struct vm_area_struct *vma;
640 int err = 0;
641 pgoff_t pgoff;
642 unsigned long vmstart;
643 unsigned long vmend;
645 vma = find_vma_prev(mm, start, &prev);
646 if (!vma || vma->vm_start > start)
647 return -EFAULT;
649 for (; vma && vma->vm_start < end; prev = vma, vma = next) {
650 next = vma->vm_next;
651 vmstart = max(start, vma->vm_start);
652 vmend = min(end, vma->vm_end);
654 pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
655 prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
656 vma->anon_vma, vma->vm_file, pgoff, new_pol);
657 if (prev) {
658 vma = prev;
659 next = vma->vm_next;
660 continue;
662 if (vma->vm_start != vmstart) {
663 err = split_vma(vma->vm_mm, vma, vmstart, 1);
664 if (err)
665 goto out;
667 if (vma->vm_end != vmend) {
668 err = split_vma(vma->vm_mm, vma, vmend, 0);
669 if (err)
670 goto out;
672 err = policy_vma(vma, new_pol);
673 if (err)
674 goto out;
677 out:
678 return err;
682 * Update task->flags PF_MEMPOLICY bit: set iff non-default
683 * mempolicy. Allows more rapid checking of this (combined perhaps
684 * with other PF_* flag bits) on memory allocation hot code paths.
686 * If called from outside this file, the task 'p' should -only- be
687 * a newly forked child not yet visible on the task list, because
688 * manipulating the task flags of a visible task is not safe.
690 * The above limitation is why this routine has the funny name
691 * mpol_fix_fork_child_flag().
693 * It is also safe to call this with a task pointer of current,
694 * which the static wrapper mpol_set_task_struct_flag() does,
695 * for use within this file.
698 void mpol_fix_fork_child_flag(struct task_struct *p)
700 if (p->mempolicy)
701 p->flags |= PF_MEMPOLICY;
702 else
703 p->flags &= ~PF_MEMPOLICY;
706 static void mpol_set_task_struct_flag(void)
708 mpol_fix_fork_child_flag(current);
711 /* Set the process memory policy */
712 static long do_set_mempolicy(unsigned short mode, unsigned short flags,
713 nodemask_t *nodes)
715 struct mempolicy *new, *old;
716 struct mm_struct *mm = current->mm;
717 NODEMASK_SCRATCH(scratch);
718 int ret;
720 if (!scratch)
721 return -ENOMEM;
723 new = mpol_new(mode, flags, nodes);
724 if (IS_ERR(new)) {
725 ret = PTR_ERR(new);
726 goto out;
729 * prevent changing our mempolicy while show_numa_maps()
730 * is using it.
731 * Note: do_set_mempolicy() can be called at init time
732 * with no 'mm'.
734 if (mm)
735 down_write(&mm->mmap_sem);
736 task_lock(current);
737 ret = mpol_set_nodemask(new, nodes, scratch);
738 if (ret) {
739 task_unlock(current);
740 if (mm)
741 up_write(&mm->mmap_sem);
742 mpol_put(new);
743 goto out;
745 old = current->mempolicy;
746 current->mempolicy = new;
747 mpol_set_task_struct_flag();
748 if (new && new->mode == MPOL_INTERLEAVE &&
749 nodes_weight(new->v.nodes))
750 current->il_next = first_node(new->v.nodes);
751 task_unlock(current);
752 if (mm)
753 up_write(&mm->mmap_sem);
755 mpol_put(old);
756 ret = 0;
757 out:
758 NODEMASK_SCRATCH_FREE(scratch);
759 return ret;
763 * Return nodemask for policy for get_mempolicy() query
765 * Called with task's alloc_lock held
767 static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
769 nodes_clear(*nodes);
770 if (p == &default_policy)
771 return;
773 switch (p->mode) {
774 case MPOL_BIND:
775 /* Fall through */
776 case MPOL_INTERLEAVE:
777 *nodes = p->v.nodes;
778 break;
779 case MPOL_PREFERRED:
780 if (!(p->flags & MPOL_F_LOCAL))
781 node_set(p->v.preferred_node, *nodes);
782 /* else return empty node mask for local allocation */
783 break;
784 default:
785 BUG();
789 static int lookup_node(struct mm_struct *mm, unsigned long addr)
791 struct page *p;
792 int err;
794 err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL);
795 if (err >= 0) {
796 err = page_to_nid(p);
797 put_page(p);
799 return err;
802 /* Retrieve NUMA policy */
803 static long do_get_mempolicy(int *policy, nodemask_t *nmask,
804 unsigned long addr, unsigned long flags)
806 int err;
807 struct mm_struct *mm = current->mm;
808 struct vm_area_struct *vma = NULL;
809 struct mempolicy *pol = current->mempolicy;
811 if (flags &
812 ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
813 return -EINVAL;
815 if (flags & MPOL_F_MEMS_ALLOWED) {
816 if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
817 return -EINVAL;
818 *policy = 0; /* just so it's initialized */
819 task_lock(current);
820 *nmask = cpuset_current_mems_allowed;
821 task_unlock(current);
822 return 0;
825 if (flags & MPOL_F_ADDR) {
827 * Do NOT fall back to task policy if the
828 * vma/shared policy at addr is NULL. We
829 * want to return MPOL_DEFAULT in this case.
831 down_read(&mm->mmap_sem);
832 vma = find_vma_intersection(mm, addr, addr+1);
833 if (!vma) {
834 up_read(&mm->mmap_sem);
835 return -EFAULT;
837 if (vma->vm_ops && vma->vm_ops->get_policy)
838 pol = vma->vm_ops->get_policy(vma, addr);
839 else
840 pol = vma->vm_policy;
841 } else if (addr)
842 return -EINVAL;
844 if (!pol)
845 pol = &default_policy; /* indicates default behavior */
847 if (flags & MPOL_F_NODE) {
848 if (flags & MPOL_F_ADDR) {
849 err = lookup_node(mm, addr);
850 if (err < 0)
851 goto out;
852 *policy = err;
853 } else if (pol == current->mempolicy &&
854 pol->mode == MPOL_INTERLEAVE) {
855 *policy = current->il_next;
856 } else {
857 err = -EINVAL;
858 goto out;
860 } else {
861 *policy = pol == &default_policy ? MPOL_DEFAULT :
862 pol->mode;
864 * Internal mempolicy flags must be masked off before exposing
865 * the policy to userspace.
867 *policy |= (pol->flags & MPOL_MODE_FLAGS);
870 if (vma) {
871 up_read(&current->mm->mmap_sem);
872 vma = NULL;
875 err = 0;
876 if (nmask) {
877 if (mpol_store_user_nodemask(pol)) {
878 *nmask = pol->w.user_nodemask;
879 } else {
880 task_lock(current);
881 get_policy_nodemask(pol, nmask);
882 task_unlock(current);
886 out:
887 mpol_cond_put(pol);
888 if (vma)
889 up_read(&current->mm->mmap_sem);
890 return err;
893 #ifdef CONFIG_MIGRATION
895 * page migration
897 static void migrate_page_add(struct page *page, struct list_head *pagelist,
898 unsigned long flags)
901 * Avoid migrating a page that is shared with others.
903 if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
904 if (!isolate_lru_page(page)) {
905 list_add_tail(&page->lru, pagelist);
906 inc_zone_page_state(page, NR_ISOLATED_ANON +
907 page_is_file_cache(page));
912 static struct page *new_node_page(struct page *page, unsigned long node, int **x)
914 return alloc_pages_exact_node(node, GFP_HIGHUSER_MOVABLE, 0);
918 * Migrate pages from one node to a target node.
919 * Returns error or the number of pages not migrated.
921 static int migrate_to_node(struct mm_struct *mm, int source, int dest,
922 int flags)
924 nodemask_t nmask;
925 LIST_HEAD(pagelist);
926 int err = 0;
928 nodes_clear(nmask);
929 node_set(source, nmask);
931 check_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
932 flags | MPOL_MF_DISCONTIG_OK, &pagelist);
934 if (!list_empty(&pagelist))
935 err = migrate_pages(&pagelist, new_node_page, dest, 0);
937 return err;
941 * Move pages between the two nodesets so as to preserve the physical
942 * layout as much as possible.
944 * Returns the number of page that could not be moved.
946 int do_migrate_pages(struct mm_struct *mm,
947 const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
949 int busy = 0;
950 int err;
951 nodemask_t tmp;
953 err = migrate_prep();
954 if (err)
955 return err;
957 down_read(&mm->mmap_sem);
959 err = migrate_vmas(mm, from_nodes, to_nodes, flags);
960 if (err)
961 goto out;
964 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
965 * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
966 * bit in 'tmp', and return that <source, dest> pair for migration.
967 * The pair of nodemasks 'to' and 'from' define the map.
969 * If no pair of bits is found that way, fallback to picking some
970 * pair of 'source' and 'dest' bits that are not the same. If the
971 * 'source' and 'dest' bits are the same, this represents a node
972 * that will be migrating to itself, so no pages need move.
974 * If no bits are left in 'tmp', or if all remaining bits left
975 * in 'tmp' correspond to the same bit in 'to', return false
976 * (nothing left to migrate).
978 * This lets us pick a pair of nodes to migrate between, such that
979 * if possible the dest node is not already occupied by some other
980 * source node, minimizing the risk of overloading the memory on a
981 * node that would happen if we migrated incoming memory to a node
982 * before migrating outgoing memory source that same node.
984 * A single scan of tmp is sufficient. As we go, we remember the
985 * most recent <s, d> pair that moved (s != d). If we find a pair
986 * that not only moved, but what's better, moved to an empty slot
987 * (d is not set in tmp), then we break out then, with that pair.
988 * Otherwise when we finish scannng from_tmp, we at least have the
989 * most recent <s, d> pair that moved. If we get all the way through
990 * the scan of tmp without finding any node that moved, much less
991 * moved to an empty node, then there is nothing left worth migrating.
994 tmp = *from_nodes;
995 while (!nodes_empty(tmp)) {
996 int s,d;
997 int source = -1;
998 int dest = 0;
1000 for_each_node_mask(s, tmp) {
1001 d = node_remap(s, *from_nodes, *to_nodes);
1002 if (s == d)
1003 continue;
1005 source = s; /* Node moved. Memorize */
1006 dest = d;
1008 /* dest not in remaining from nodes? */
1009 if (!node_isset(dest, tmp))
1010 break;
1012 if (source == -1)
1013 break;
1015 node_clear(source, tmp);
1016 err = migrate_to_node(mm, source, dest, flags);
1017 if (err > 0)
1018 busy += err;
1019 if (err < 0)
1020 break;
1022 out:
1023 up_read(&mm->mmap_sem);
1024 if (err < 0)
1025 return err;
1026 return busy;
1031 * Allocate a new page for page migration based on vma policy.
1032 * Start assuming that page is mapped by vma pointed to by @private.
1033 * Search forward from there, if not. N.B., this assumes that the
1034 * list of pages handed to migrate_pages()--which is how we get here--
1035 * is in virtual address order.
1037 static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
1039 struct vm_area_struct *vma = (struct vm_area_struct *)private;
1040 unsigned long uninitialized_var(address);
1042 while (vma) {
1043 address = page_address_in_vma(page, vma);
1044 if (address != -EFAULT)
1045 break;
1046 vma = vma->vm_next;
1050 * if !vma, alloc_page_vma() will use task or system default policy
1052 return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
1054 #else
1056 static void migrate_page_add(struct page *page, struct list_head *pagelist,
1057 unsigned long flags)
1061 int do_migrate_pages(struct mm_struct *mm,
1062 const nodemask_t *from_nodes, const nodemask_t *to_nodes, int flags)
1064 return -ENOSYS;
1067 static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
1069 return NULL;
1071 #endif
1073 static long do_mbind(unsigned long start, unsigned long len,
1074 unsigned short mode, unsigned short mode_flags,
1075 nodemask_t *nmask, unsigned long flags)
1077 struct vm_area_struct *vma;
1078 struct mm_struct *mm = current->mm;
1079 struct mempolicy *new;
1080 unsigned long end;
1081 int err;
1082 LIST_HEAD(pagelist);
1084 if (flags & ~(unsigned long)(MPOL_MF_STRICT |
1085 MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
1086 return -EINVAL;
1087 if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
1088 return -EPERM;
1090 if (start & ~PAGE_MASK)
1091 return -EINVAL;
1093 if (mode == MPOL_DEFAULT)
1094 flags &= ~MPOL_MF_STRICT;
1096 len = (len + PAGE_SIZE - 1) & PAGE_MASK;
1097 end = start + len;
1099 if (end < start)
1100 return -EINVAL;
1101 if (end == start)
1102 return 0;
1104 new = mpol_new(mode, mode_flags, nmask);
1105 if (IS_ERR(new))
1106 return PTR_ERR(new);
1109 * If we are using the default policy then operation
1110 * on discontinuous address spaces is okay after all
1112 if (!new)
1113 flags |= MPOL_MF_DISCONTIG_OK;
1115 pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
1116 start, start + len, mode, mode_flags,
1117 nmask ? nodes_addr(*nmask)[0] : -1);
1119 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
1121 err = migrate_prep();
1122 if (err)
1123 goto mpol_out;
1126 NODEMASK_SCRATCH(scratch);
1127 if (scratch) {
1128 down_write(&mm->mmap_sem);
1129 task_lock(current);
1130 err = mpol_set_nodemask(new, nmask, scratch);
1131 task_unlock(current);
1132 if (err)
1133 up_write(&mm->mmap_sem);
1134 } else
1135 err = -ENOMEM;
1136 NODEMASK_SCRATCH_FREE(scratch);
1138 if (err)
1139 goto mpol_out;
1141 vma = check_range(mm, start, end, nmask,
1142 flags | MPOL_MF_INVERT, &pagelist);
1144 err = PTR_ERR(vma);
1145 if (!IS_ERR(vma)) {
1146 int nr_failed = 0;
1148 err = mbind_range(mm, start, end, new);
1150 if (!list_empty(&pagelist))
1151 nr_failed = migrate_pages(&pagelist, new_vma_page,
1152 (unsigned long)vma, 0);
1154 if (!err && nr_failed && (flags & MPOL_MF_STRICT))
1155 err = -EIO;
1156 } else
1157 putback_lru_pages(&pagelist);
1159 up_write(&mm->mmap_sem);
1160 mpol_out:
1161 mpol_put(new);
1162 return err;
1166 * User space interface with variable sized bitmaps for nodelists.
1169 /* Copy a node mask from user space. */
1170 static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
1171 unsigned long maxnode)
1173 unsigned long k;
1174 unsigned long nlongs;
1175 unsigned long endmask;
1177 --maxnode;
1178 nodes_clear(*nodes);
1179 if (maxnode == 0 || !nmask)
1180 return 0;
1181 if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
1182 return -EINVAL;
1184 nlongs = BITS_TO_LONGS(maxnode);
1185 if ((maxnode % BITS_PER_LONG) == 0)
1186 endmask = ~0UL;
1187 else
1188 endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;
1190 /* When the user specified more nodes than supported just check
1191 if the non supported part is all zero. */
1192 if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
1193 if (nlongs > PAGE_SIZE/sizeof(long))
1194 return -EINVAL;
1195 for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
1196 unsigned long t;
1197 if (get_user(t, nmask + k))
1198 return -EFAULT;
1199 if (k == nlongs - 1) {
1200 if (t & endmask)
1201 return -EINVAL;
1202 } else if (t)
1203 return -EINVAL;
1205 nlongs = BITS_TO_LONGS(MAX_NUMNODES);
1206 endmask = ~0UL;
1209 if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
1210 return -EFAULT;
1211 nodes_addr(*nodes)[nlongs-1] &= endmask;
1212 return 0;
1215 /* Copy a kernel node mask to user space */
1216 static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
1217 nodemask_t *nodes)
1219 unsigned long copy = ALIGN(maxnode-1, 64) / 8;
1220 const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long);
1222 if (copy > nbytes) {
1223 if (copy > PAGE_SIZE)
1224 return -EINVAL;
1225 if (clear_user((char __user *)mask + nbytes, copy - nbytes))
1226 return -EFAULT;
1227 copy = nbytes;
1229 return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
1232 SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
1233 unsigned long, mode, unsigned long __user *, nmask,
1234 unsigned long, maxnode, unsigned, flags)
1236 nodemask_t nodes;
1237 int err;
1238 unsigned short mode_flags;
1240 mode_flags = mode & MPOL_MODE_FLAGS;
1241 mode &= ~MPOL_MODE_FLAGS;
1242 if (mode >= MPOL_MAX)
1243 return -EINVAL;
1244 if ((mode_flags & MPOL_F_STATIC_NODES) &&
1245 (mode_flags & MPOL_F_RELATIVE_NODES))
1246 return -EINVAL;
1247 err = get_nodes(&nodes, nmask, maxnode);
1248 if (err)
1249 return err;
1250 return do_mbind(start, len, mode, mode_flags, &nodes, flags);
1253 /* Set the process memory policy */
1254 SYSCALL_DEFINE3(set_mempolicy, int, mode, unsigned long __user *, nmask,
1255 unsigned long, maxnode)
1257 int err;
1258 nodemask_t nodes;
1259 unsigned short flags;
1261 flags = mode & MPOL_MODE_FLAGS;
1262 mode &= ~MPOL_MODE_FLAGS;
1263 if ((unsigned int)mode >= MPOL_MAX)
1264 return -EINVAL;
1265 if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
1266 return -EINVAL;
1267 err = get_nodes(&nodes, nmask, maxnode);
1268 if (err)
1269 return err;
1270 return do_set_mempolicy(mode, flags, &nodes);
1273 SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
1274 const unsigned long __user *, old_nodes,
1275 const unsigned long __user *, new_nodes)
1277 const struct cred *cred = current_cred(), *tcred;
1278 struct mm_struct *mm = NULL;
1279 struct task_struct *task;
1280 nodemask_t task_nodes;
1281 int err;
1282 nodemask_t *old;
1283 nodemask_t *new;
1284 NODEMASK_SCRATCH(scratch);
1286 if (!scratch)
1287 return -ENOMEM;
1289 old = &scratch->mask1;
1290 new = &scratch->mask2;
1292 err = get_nodes(old, old_nodes, maxnode);
1293 if (err)
1294 goto out;
1296 err = get_nodes(new, new_nodes, maxnode);
1297 if (err)
1298 goto out;
1300 /* Find the mm_struct */
1301 read_lock(&tasklist_lock);
1302 task = pid ? find_task_by_vpid(pid) : current;
1303 if (!task) {
1304 read_unlock(&tasklist_lock);
1305 err = -ESRCH;
1306 goto out;
1308 mm = get_task_mm(task);
1309 read_unlock(&tasklist_lock);
1311 err = -EINVAL;
1312 if (!mm)
1313 goto out;
1316 * Check if this process has the right to modify the specified
1317 * process. The right exists if the process has administrative
1318 * capabilities, superuser privileges or the same
1319 * userid as the target process.
1321 rcu_read_lock();
1322 tcred = __task_cred(task);
1323 if (cred->euid != tcred->suid && cred->euid != tcred->uid &&
1324 cred->uid != tcred->suid && cred->uid != tcred->uid &&
1325 !capable(CAP_SYS_NICE)) {
1326 rcu_read_unlock();
1327 err = -EPERM;
1328 goto out;
1330 rcu_read_unlock();
1332 task_nodes = cpuset_mems_allowed(task);
1333 /* Is the user allowed to access the target nodes? */
1334 if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
1335 err = -EPERM;
1336 goto out;
1339 if (!nodes_subset(*new, node_states[N_HIGH_MEMORY])) {
1340 err = -EINVAL;
1341 goto out;
1344 err = security_task_movememory(task);
1345 if (err)
1346 goto out;
1348 err = do_migrate_pages(mm, old, new,
1349 capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
1350 out:
1351 if (mm)
1352 mmput(mm);
1353 NODEMASK_SCRATCH_FREE(scratch);
1355 return err;
1359 /* Retrieve NUMA policy */
1360 SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
1361 unsigned long __user *, nmask, unsigned long, maxnode,
1362 unsigned long, addr, unsigned long, flags)
1364 int err;
1365 int uninitialized_var(pval);
1366 nodemask_t nodes;
1368 if (nmask != NULL && maxnode < MAX_NUMNODES)
1369 return -EINVAL;
1371 err = do_get_mempolicy(&pval, &nodes, addr, flags);
1373 if (err)
1374 return err;
1376 if (policy && put_user(pval, policy))
1377 return -EFAULT;
1379 if (nmask)
1380 err = copy_nodes_to_user(nmask, maxnode, &nodes);
1382 return err;
1385 #ifdef CONFIG_COMPAT
1387 asmlinkage long compat_sys_get_mempolicy(int __user *policy,
1388 compat_ulong_t __user *nmask,
1389 compat_ulong_t maxnode,
1390 compat_ulong_t addr, compat_ulong_t flags)
1392 long err;
1393 unsigned long __user *nm = NULL;
1394 unsigned long nr_bits, alloc_size;
1395 DECLARE_BITMAP(bm, MAX_NUMNODES);
1397 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1398 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1400 if (nmask)
1401 nm = compat_alloc_user_space(alloc_size);
1403 err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags);
1405 if (!err && nmask) {
1406 err = copy_from_user(bm, nm, alloc_size);
1407 /* ensure entire bitmap is zeroed */
1408 err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
1409 err |= compat_put_bitmap(nmask, bm, nr_bits);
1412 return err;
1415 asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask,
1416 compat_ulong_t maxnode)
1418 long err = 0;
1419 unsigned long __user *nm = NULL;
1420 unsigned long nr_bits, alloc_size;
1421 DECLARE_BITMAP(bm, MAX_NUMNODES);
1423 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1424 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1426 if (nmask) {
1427 err = compat_get_bitmap(bm, nmask, nr_bits);
1428 nm = compat_alloc_user_space(alloc_size);
1429 err |= copy_to_user(nm, bm, alloc_size);
1432 if (err)
1433 return -EFAULT;
1435 return sys_set_mempolicy(mode, nm, nr_bits+1);
1438 asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len,
1439 compat_ulong_t mode, compat_ulong_t __user *nmask,
1440 compat_ulong_t maxnode, compat_ulong_t flags)
1442 long err = 0;
1443 unsigned long __user *nm = NULL;
1444 unsigned long nr_bits, alloc_size;
1445 nodemask_t bm;
1447 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1448 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1450 if (nmask) {
1451 err = compat_get_bitmap(nodes_addr(bm), nmask, nr_bits);
1452 nm = compat_alloc_user_space(alloc_size);
1453 err |= copy_to_user(nm, nodes_addr(bm), alloc_size);
1456 if (err)
1457 return -EFAULT;
1459 return sys_mbind(start, len, mode, nm, nr_bits+1, flags);
1462 #endif
1465 * get_vma_policy(@task, @vma, @addr)
1466 * @task - task for fallback if vma policy == default
1467 * @vma - virtual memory area whose policy is sought
1468 * @addr - address in @vma for shared policy lookup
1470 * Returns effective policy for a VMA at specified address.
1471 * Falls back to @task or system default policy, as necessary.
1472 * Current or other task's task mempolicy and non-shared vma policies
1473 * are protected by the task's mmap_sem, which must be held for read by
1474 * the caller.
1475 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
1476 * count--added by the get_policy() vm_op, as appropriate--to protect against
1477 * freeing by another task. It is the caller's responsibility to free the
1478 * extra reference for shared policies.
1480 static struct mempolicy *get_vma_policy(struct task_struct *task,
1481 struct vm_area_struct *vma, unsigned long addr)
1483 struct mempolicy *pol = task->mempolicy;
1485 if (vma) {
1486 if (vma->vm_ops && vma->vm_ops->get_policy) {
1487 struct mempolicy *vpol = vma->vm_ops->get_policy(vma,
1488 addr);
1489 if (vpol)
1490 pol = vpol;
1491 } else if (vma->vm_policy)
1492 pol = vma->vm_policy;
1494 if (!pol)
1495 pol = &default_policy;
1496 return pol;
1500 * Return a nodemask representing a mempolicy for filtering nodes for
1501 * page allocation
1503 static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
1505 /* Lower zones don't get a nodemask applied for MPOL_BIND */
1506 if (unlikely(policy->mode == MPOL_BIND) &&
1507 gfp_zone(gfp) >= policy_zone &&
1508 cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
1509 return &policy->v.nodes;
1511 return NULL;
1514 /* Return a zonelist indicated by gfp for node representing a mempolicy */
1515 static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy)
1517 int nd = numa_node_id();
1519 switch (policy->mode) {
1520 case MPOL_PREFERRED:
1521 if (!(policy->flags & MPOL_F_LOCAL))
1522 nd = policy->v.preferred_node;
1523 break;
1524 case MPOL_BIND:
1526 * Normally, MPOL_BIND allocations are node-local within the
1527 * allowed nodemask. However, if __GFP_THISNODE is set and the
1528 * current node isn't part of the mask, we use the zonelist for
1529 * the first node in the mask instead.
1531 if (unlikely(gfp & __GFP_THISNODE) &&
1532 unlikely(!node_isset(nd, policy->v.nodes)))
1533 nd = first_node(policy->v.nodes);
1534 break;
1535 default:
1536 BUG();
1538 return node_zonelist(nd, gfp);
1541 /* Do dynamic interleaving for a process */
1542 static unsigned interleave_nodes(struct mempolicy *policy)
1544 unsigned nid, next;
1545 struct task_struct *me = current;
1547 nid = me->il_next;
1548 next = next_node(nid, policy->v.nodes);
1549 if (next >= MAX_NUMNODES)
1550 next = first_node(policy->v.nodes);
1551 if (next < MAX_NUMNODES)
1552 me->il_next = next;
1553 return nid;
1557 * Depending on the memory policy provide a node from which to allocate the
1558 * next slab entry.
1559 * @policy must be protected by freeing by the caller. If @policy is
1560 * the current task's mempolicy, this protection is implicit, as only the
1561 * task can change it's policy. The system default policy requires no
1562 * such protection.
1564 unsigned slab_node(struct mempolicy *policy)
1566 if (!policy || policy->flags & MPOL_F_LOCAL)
1567 return numa_node_id();
1569 switch (policy->mode) {
1570 case MPOL_PREFERRED:
1572 * handled MPOL_F_LOCAL above
1574 return policy->v.preferred_node;
1576 case MPOL_INTERLEAVE:
1577 return interleave_nodes(policy);
1579 case MPOL_BIND: {
1581 * Follow bind policy behavior and start allocation at the
1582 * first node.
1584 struct zonelist *zonelist;
1585 struct zone *zone;
1586 enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
1587 zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0];
1588 (void)first_zones_zonelist(zonelist, highest_zoneidx,
1589 &policy->v.nodes,
1590 &zone);
1591 return zone->node;
1594 default:
1595 BUG();
1599 /* Do static interleaving for a VMA with known offset. */
1600 static unsigned offset_il_node(struct mempolicy *pol,
1601 struct vm_area_struct *vma, unsigned long off)
1603 unsigned nnodes = nodes_weight(pol->v.nodes);
1604 unsigned target;
1605 int c;
1606 int nid = -1;
1608 if (!nnodes)
1609 return numa_node_id();
1610 target = (unsigned int)off % nnodes;
1611 c = 0;
1612 do {
1613 nid = next_node(nid, pol->v.nodes);
1614 c++;
1615 } while (c <= target);
1616 return nid;
1619 /* Determine a node number for interleave */
1620 static inline unsigned interleave_nid(struct mempolicy *pol,
1621 struct vm_area_struct *vma, unsigned long addr, int shift)
1623 if (vma) {
1624 unsigned long off;
1627 * for small pages, there is no difference between
1628 * shift and PAGE_SHIFT, so the bit-shift is safe.
1629 * for huge pages, since vm_pgoff is in units of small
1630 * pages, we need to shift off the always 0 bits to get
1631 * a useful offset.
1633 BUG_ON(shift < PAGE_SHIFT);
1634 off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
1635 off += (addr - vma->vm_start) >> shift;
1636 return offset_il_node(pol, vma, off);
1637 } else
1638 return interleave_nodes(pol);
1641 #ifdef CONFIG_HUGETLBFS
1643 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
1644 * @vma = virtual memory area whose policy is sought
1645 * @addr = address in @vma for shared policy lookup and interleave policy
1646 * @gfp_flags = for requested zone
1647 * @mpol = pointer to mempolicy pointer for reference counted mempolicy
1648 * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
1650 * Returns a zonelist suitable for a huge page allocation and a pointer
1651 * to the struct mempolicy for conditional unref after allocation.
1652 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
1653 * @nodemask for filtering the zonelist.
1655 * Must be protected by get_mems_allowed()
1657 struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
1658 gfp_t gfp_flags, struct mempolicy **mpol,
1659 nodemask_t **nodemask)
1661 struct zonelist *zl;
1663 *mpol = get_vma_policy(current, vma, addr);
1664 *nodemask = NULL; /* assume !MPOL_BIND */
1666 if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
1667 zl = node_zonelist(interleave_nid(*mpol, vma, addr,
1668 huge_page_shift(hstate_vma(vma))), gfp_flags);
1669 } else {
1670 zl = policy_zonelist(gfp_flags, *mpol);
1671 if ((*mpol)->mode == MPOL_BIND)
1672 *nodemask = &(*mpol)->v.nodes;
1674 return zl;
1678 * init_nodemask_of_mempolicy
1680 * If the current task's mempolicy is "default" [NULL], return 'false'
1681 * to indicate default policy. Otherwise, extract the policy nodemask
1682 * for 'bind' or 'interleave' policy into the argument nodemask, or
1683 * initialize the argument nodemask to contain the single node for
1684 * 'preferred' or 'local' policy and return 'true' to indicate presence
1685 * of non-default mempolicy.
1687 * We don't bother with reference counting the mempolicy [mpol_get/put]
1688 * because the current task is examining it's own mempolicy and a task's
1689 * mempolicy is only ever changed by the task itself.
1691 * N.B., it is the caller's responsibility to free a returned nodemask.
1693 bool init_nodemask_of_mempolicy(nodemask_t *mask)
1695 struct mempolicy *mempolicy;
1696 int nid;
1698 if (!(mask && current->mempolicy))
1699 return false;
1701 task_lock(current);
1702 mempolicy = current->mempolicy;
1703 switch (mempolicy->mode) {
1704 case MPOL_PREFERRED:
1705 if (mempolicy->flags & MPOL_F_LOCAL)
1706 nid = numa_node_id();
1707 else
1708 nid = mempolicy->v.preferred_node;
1709 init_nodemask_of_node(mask, nid);
1710 break;
1712 case MPOL_BIND:
1713 /* Fall through */
1714 case MPOL_INTERLEAVE:
1715 *mask = mempolicy->v.nodes;
1716 break;
1718 default:
1719 BUG();
1721 task_unlock(current);
1723 return true;
1725 #endif
1728 * mempolicy_nodemask_intersects
1730 * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
1731 * policy. Otherwise, check for intersection between mask and the policy
1732 * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local'
1733 * policy, always return true since it may allocate elsewhere on fallback.
1735 * Takes task_lock(tsk) to prevent freeing of its mempolicy.
1737 bool mempolicy_nodemask_intersects(struct task_struct *tsk,
1738 const nodemask_t *mask)
1740 struct mempolicy *mempolicy;
1741 bool ret = true;
1743 if (!mask)
1744 return ret;
1745 task_lock(tsk);
1746 mempolicy = tsk->mempolicy;
1747 if (!mempolicy)
1748 goto out;
1750 switch (mempolicy->mode) {
1751 case MPOL_PREFERRED:
1753 * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
1754 * allocate from, they may fallback to other nodes when oom.
1755 * Thus, it's possible for tsk to have allocated memory from
1756 * nodes in mask.
1758 break;
1759 case MPOL_BIND:
1760 case MPOL_INTERLEAVE:
1761 ret = nodes_intersects(mempolicy->v.nodes, *mask);
1762 break;
1763 default:
1764 BUG();
1766 out:
1767 task_unlock(tsk);
1768 return ret;
1771 /* Allocate a page in interleaved policy.
1772 Own path because it needs to do special accounting. */
1773 static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
1774 unsigned nid)
1776 struct zonelist *zl;
1777 struct page *page;
1779 zl = node_zonelist(nid, gfp);
1780 page = __alloc_pages(gfp, order, zl);
1781 if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0]))
1782 inc_zone_page_state(page, NUMA_INTERLEAVE_HIT);
1783 return page;
1787 * alloc_page_vma - Allocate a page for a VMA.
1789 * @gfp:
1790 * %GFP_USER user allocation.
1791 * %GFP_KERNEL kernel allocations,
1792 * %GFP_HIGHMEM highmem/user allocations,
1793 * %GFP_FS allocation should not call back into a file system.
1794 * %GFP_ATOMIC don't sleep.
1796 * @vma: Pointer to VMA or NULL if not available.
1797 * @addr: Virtual Address of the allocation. Must be inside the VMA.
1799 * This function allocates a page from the kernel page pool and applies
1800 * a NUMA policy associated with the VMA or the current process.
1801 * When VMA is not NULL caller must hold down_read on the mmap_sem of the
1802 * mm_struct of the VMA to prevent it from going away. Should be used for
1803 * all allocations for pages that will be mapped into
1804 * user space. Returns NULL when no page can be allocated.
1806 * Should be called with the mm_sem of the vma hold.
1808 struct page *
1809 alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
1811 struct mempolicy *pol = get_vma_policy(current, vma, addr);
1812 struct zonelist *zl;
1813 struct page *page;
1815 get_mems_allowed();
1816 if (unlikely(pol->mode == MPOL_INTERLEAVE)) {
1817 unsigned nid;
1819 nid = interleave_nid(pol, vma, addr, PAGE_SHIFT);
1820 mpol_cond_put(pol);
1821 page = alloc_page_interleave(gfp, 0, nid);
1822 put_mems_allowed();
1823 return page;
1825 zl = policy_zonelist(gfp, pol);
1826 if (unlikely(mpol_needs_cond_ref(pol))) {
1828 * slow path: ref counted shared policy
1830 struct page *page = __alloc_pages_nodemask(gfp, 0,
1831 zl, policy_nodemask(gfp, pol));
1832 __mpol_put(pol);
1833 put_mems_allowed();
1834 return page;
1837 * fast path: default or task policy
1839 page = __alloc_pages_nodemask(gfp, 0, zl, policy_nodemask(gfp, pol));
1840 put_mems_allowed();
1841 return page;
1845 * alloc_pages_current - Allocate pages.
1847 * @gfp:
1848 * %GFP_USER user allocation,
1849 * %GFP_KERNEL kernel allocation,
1850 * %GFP_HIGHMEM highmem allocation,
1851 * %GFP_FS don't call back into a file system.
1852 * %GFP_ATOMIC don't sleep.
1853 * @order: Power of two of allocation size in pages. 0 is a single page.
1855 * Allocate a page from the kernel page pool. When not in
1856 * interrupt context and apply the current process NUMA policy.
1857 * Returns NULL when no page can be allocated.
1859 * Don't call cpuset_update_task_memory_state() unless
1860 * 1) it's ok to take cpuset_sem (can WAIT), and
1861 * 2) allocating for current task (not interrupt).
1863 struct page *alloc_pages_current(gfp_t gfp, unsigned order)
1865 struct mempolicy *pol = current->mempolicy;
1866 struct page *page;
1868 if (!pol || in_interrupt() || (gfp & __GFP_THISNODE))
1869 pol = &default_policy;
1871 get_mems_allowed();
1873 * No reference counting needed for current->mempolicy
1874 * nor system default_policy
1876 if (pol->mode == MPOL_INTERLEAVE)
1877 page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
1878 else
1879 page = __alloc_pages_nodemask(gfp, order,
1880 policy_zonelist(gfp, pol), policy_nodemask(gfp, pol));
1881 put_mems_allowed();
1882 return page;
1884 EXPORT_SYMBOL(alloc_pages_current);
1887 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
1888 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
1889 * with the mems_allowed returned by cpuset_mems_allowed(). This
1890 * keeps mempolicies cpuset relative after its cpuset moves. See
1891 * further kernel/cpuset.c update_nodemask().
1893 * current's mempolicy may be rebinded by the other task(the task that changes
1894 * cpuset's mems), so we needn't do rebind work for current task.
1897 /* Slow path of a mempolicy duplicate */
1898 struct mempolicy *__mpol_dup(struct mempolicy *old)
1900 struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
1902 if (!new)
1903 return ERR_PTR(-ENOMEM);
1905 /* task's mempolicy is protected by alloc_lock */
1906 if (old == current->mempolicy) {
1907 task_lock(current);
1908 *new = *old;
1909 task_unlock(current);
1910 } else
1911 *new = *old;
1913 rcu_read_lock();
1914 if (current_cpuset_is_being_rebound()) {
1915 nodemask_t mems = cpuset_mems_allowed(current);
1916 if (new->flags & MPOL_F_REBINDING)
1917 mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2);
1918 else
1919 mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE);
1921 rcu_read_unlock();
1922 atomic_set(&new->refcnt, 1);
1923 return new;
1927 * If *frompol needs [has] an extra ref, copy *frompol to *tompol ,
1928 * eliminate the * MPOL_F_* flags that require conditional ref and
1929 * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly
1930 * after return. Use the returned value.
1932 * Allows use of a mempolicy for, e.g., multiple allocations with a single
1933 * policy lookup, even if the policy needs/has extra ref on lookup.
1934 * shmem_readahead needs this.
1936 struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol,
1937 struct mempolicy *frompol)
1939 if (!mpol_needs_cond_ref(frompol))
1940 return frompol;
1942 *tompol = *frompol;
1943 tompol->flags &= ~MPOL_F_SHARED; /* copy doesn't need unref */
1944 __mpol_put(frompol);
1945 return tompol;
1948 /* Slow path of a mempolicy comparison */
1949 int __mpol_equal(struct mempolicy *a, struct mempolicy *b)
1951 if (!a || !b)
1952 return 0;
1953 if (a->mode != b->mode)
1954 return 0;
1955 if (a->flags != b->flags)
1956 return 0;
1957 if (mpol_store_user_nodemask(a))
1958 if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask))
1959 return 0;
1961 switch (a->mode) {
1962 case MPOL_BIND:
1963 /* Fall through */
1964 case MPOL_INTERLEAVE:
1965 return nodes_equal(a->v.nodes, b->v.nodes);
1966 case MPOL_PREFERRED:
1967 return a->v.preferred_node == b->v.preferred_node &&
1968 a->flags == b->flags;
1969 default:
1970 BUG();
1971 return 0;
1976 * Shared memory backing store policy support.
1978 * Remember policies even when nobody has shared memory mapped.
1979 * The policies are kept in Red-Black tree linked from the inode.
1980 * They are protected by the sp->lock spinlock, which should be held
1981 * for any accesses to the tree.
1984 /* lookup first element intersecting start-end */
1985 /* Caller holds sp->lock */
1986 static struct sp_node *
1987 sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
1989 struct rb_node *n = sp->root.rb_node;
1991 while (n) {
1992 struct sp_node *p = rb_entry(n, struct sp_node, nd);
1994 if (start >= p->end)
1995 n = n->rb_right;
1996 else if (end <= p->start)
1997 n = n->rb_left;
1998 else
1999 break;
2001 if (!n)
2002 return NULL;
2003 for (;;) {
2004 struct sp_node *w = NULL;
2005 struct rb_node *prev = rb_prev(n);
2006 if (!prev)
2007 break;
2008 w = rb_entry(prev, struct sp_node, nd);
2009 if (w->end <= start)
2010 break;
2011 n = prev;
2013 return rb_entry(n, struct sp_node, nd);
2016 /* Insert a new shared policy into the list. */
2017 /* Caller holds sp->lock */
2018 static void sp_insert(struct shared_policy *sp, struct sp_node *new)
2020 struct rb_node **p = &sp->root.rb_node;
2021 struct rb_node *parent = NULL;
2022 struct sp_node *nd;
2024 while (*p) {
2025 parent = *p;
2026 nd = rb_entry(parent, struct sp_node, nd);
2027 if (new->start < nd->start)
2028 p = &(*p)->rb_left;
2029 else if (new->end > nd->end)
2030 p = &(*p)->rb_right;
2031 else
2032 BUG();
2034 rb_link_node(&new->nd, parent, p);
2035 rb_insert_color(&new->nd, &sp->root);
2036 pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
2037 new->policy ? new->policy->mode : 0);
2040 /* Find shared policy intersecting idx */
2041 struct mempolicy *
2042 mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
2044 struct mempolicy *pol = NULL;
2045 struct sp_node *sn;
2047 if (!sp->root.rb_node)
2048 return NULL;
2049 spin_lock(&sp->lock);
2050 sn = sp_lookup(sp, idx, idx+1);
2051 if (sn) {
2052 mpol_get(sn->policy);
2053 pol = sn->policy;
2055 spin_unlock(&sp->lock);
2056 return pol;
2059 static void sp_delete(struct shared_policy *sp, struct sp_node *n)
2061 pr_debug("deleting %lx-l%lx\n", n->start, n->end);
2062 rb_erase(&n->nd, &sp->root);
2063 mpol_put(n->policy);
2064 kmem_cache_free(sn_cache, n);
2067 static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
2068 struct mempolicy *pol)
2070 struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
2072 if (!n)
2073 return NULL;
2074 n->start = start;
2075 n->end = end;
2076 mpol_get(pol);
2077 pol->flags |= MPOL_F_SHARED; /* for unref */
2078 n->policy = pol;
2079 return n;
2082 /* Replace a policy range. */
2083 static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
2084 unsigned long end, struct sp_node *new)
2086 struct sp_node *n, *new2 = NULL;
2088 restart:
2089 spin_lock(&sp->lock);
2090 n = sp_lookup(sp, start, end);
2091 /* Take care of old policies in the same range. */
2092 while (n && n->start < end) {
2093 struct rb_node *next = rb_next(&n->nd);
2094 if (n->start >= start) {
2095 if (n->end <= end)
2096 sp_delete(sp, n);
2097 else
2098 n->start = end;
2099 } else {
2100 /* Old policy spanning whole new range. */
2101 if (n->end > end) {
2102 if (!new2) {
2103 spin_unlock(&sp->lock);
2104 new2 = sp_alloc(end, n->end, n->policy);
2105 if (!new2)
2106 return -ENOMEM;
2107 goto restart;
2109 n->end = start;
2110 sp_insert(sp, new2);
2111 new2 = NULL;
2112 break;
2113 } else
2114 n->end = start;
2116 if (!next)
2117 break;
2118 n = rb_entry(next, struct sp_node, nd);
2120 if (new)
2121 sp_insert(sp, new);
2122 spin_unlock(&sp->lock);
2123 if (new2) {
2124 mpol_put(new2->policy);
2125 kmem_cache_free(sn_cache, new2);
2127 return 0;
2131 * mpol_shared_policy_init - initialize shared policy for inode
2132 * @sp: pointer to inode shared policy
2133 * @mpol: struct mempolicy to install
2135 * Install non-NULL @mpol in inode's shared policy rb-tree.
2136 * On entry, the current task has a reference on a non-NULL @mpol.
2137 * This must be released on exit.
2138 * This is called at get_inode() calls and we can use GFP_KERNEL.
2140 void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
2142 int ret;
2144 sp->root = RB_ROOT; /* empty tree == default mempolicy */
2145 spin_lock_init(&sp->lock);
2147 if (mpol) {
2148 struct vm_area_struct pvma;
2149 struct mempolicy *new;
2150 NODEMASK_SCRATCH(scratch);
2152 if (!scratch)
2153 goto put_mpol;
2154 /* contextualize the tmpfs mount point mempolicy */
2155 new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
2156 if (IS_ERR(new))
2157 goto free_scratch; /* no valid nodemask intersection */
2159 task_lock(current);
2160 ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
2161 task_unlock(current);
2162 if (ret)
2163 goto put_new;
2165 /* Create pseudo-vma that contains just the policy */
2166 memset(&pvma, 0, sizeof(struct vm_area_struct));
2167 pvma.vm_end = TASK_SIZE; /* policy covers entire file */
2168 mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
2170 put_new:
2171 mpol_put(new); /* drop initial ref */
2172 free_scratch:
2173 NODEMASK_SCRATCH_FREE(scratch);
2174 put_mpol:
2175 mpol_put(mpol); /* drop our incoming ref on sb mpol */
2179 int mpol_set_shared_policy(struct shared_policy *info,
2180 struct vm_area_struct *vma, struct mempolicy *npol)
2182 int err;
2183 struct sp_node *new = NULL;
2184 unsigned long sz = vma_pages(vma);
2186 pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
2187 vma->vm_pgoff,
2188 sz, npol ? npol->mode : -1,
2189 npol ? npol->flags : -1,
2190 npol ? nodes_addr(npol->v.nodes)[0] : -1);
2192 if (npol) {
2193 new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
2194 if (!new)
2195 return -ENOMEM;
2197 err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
2198 if (err && new)
2199 kmem_cache_free(sn_cache, new);
2200 return err;
2203 /* Free a backing policy store on inode delete. */
2204 void mpol_free_shared_policy(struct shared_policy *p)
2206 struct sp_node *n;
2207 struct rb_node *next;
2209 if (!p->root.rb_node)
2210 return;
2211 spin_lock(&p->lock);
2212 next = rb_first(&p->root);
2213 while (next) {
2214 n = rb_entry(next, struct sp_node, nd);
2215 next = rb_next(&n->nd);
2216 rb_erase(&n->nd, &p->root);
2217 mpol_put(n->policy);
2218 kmem_cache_free(sn_cache, n);
2220 spin_unlock(&p->lock);
2223 /* assumes fs == KERNEL_DS */
2224 void __init numa_policy_init(void)
2226 nodemask_t interleave_nodes;
2227 unsigned long largest = 0;
2228 int nid, prefer = 0;
2230 policy_cache = kmem_cache_create("numa_policy",
2231 sizeof(struct mempolicy),
2232 0, SLAB_PANIC, NULL);
2234 sn_cache = kmem_cache_create("shared_policy_node",
2235 sizeof(struct sp_node),
2236 0, SLAB_PANIC, NULL);
2239 * Set interleaving policy for system init. Interleaving is only
2240 * enabled across suitably sized nodes (default is >= 16MB), or
2241 * fall back to the largest node if they're all smaller.
2243 nodes_clear(interleave_nodes);
2244 for_each_node_state(nid, N_HIGH_MEMORY) {
2245 unsigned long total_pages = node_present_pages(nid);
2247 /* Preserve the largest node */
2248 if (largest < total_pages) {
2249 largest = total_pages;
2250 prefer = nid;
2253 /* Interleave this node? */
2254 if ((total_pages << PAGE_SHIFT) >= (16 << 20))
2255 node_set(nid, interleave_nodes);
2258 /* All too small, use the largest */
2259 if (unlikely(nodes_empty(interleave_nodes)))
2260 node_set(prefer, interleave_nodes);
2262 if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
2263 printk("numa_policy_init: interleaving failed\n");
2266 /* Reset policy of current process to default */
2267 void numa_default_policy(void)
2269 do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
2273 * Parse and format mempolicy from/to strings
2277 * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag
2278 * Used only for mpol_parse_str() and mpol_to_str()
2280 #define MPOL_LOCAL MPOL_MAX
2281 static const char * const policy_modes[] =
2283 [MPOL_DEFAULT] = "default",
2284 [MPOL_PREFERRED] = "prefer",
2285 [MPOL_BIND] = "bind",
2286 [MPOL_INTERLEAVE] = "interleave",
2287 [MPOL_LOCAL] = "local"
2291 #ifdef CONFIG_TMPFS
2293 * mpol_parse_str - parse string to mempolicy
2294 * @str: string containing mempolicy to parse
2295 * @mpol: pointer to struct mempolicy pointer, returned on success.
2296 * @no_context: flag whether to "contextualize" the mempolicy
2298 * Format of input:
2299 * <mode>[=<flags>][:<nodelist>]
2301 * if @no_context is true, save the input nodemask in w.user_nodemask in
2302 * the returned mempolicy. This will be used to "clone" the mempolicy in
2303 * a specific context [cpuset] at a later time. Used to parse tmpfs mpol
2304 * mount option. Note that if 'static' or 'relative' mode flags were
2305 * specified, the input nodemask will already have been saved. Saving
2306 * it again is redundant, but safe.
2308 * On success, returns 0, else 1
2310 int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
2312 struct mempolicy *new = NULL;
2313 unsigned short mode;
2314 unsigned short uninitialized_var(mode_flags);
2315 nodemask_t nodes;
2316 char *nodelist = strchr(str, ':');
2317 char *flags = strchr(str, '=');
2318 int err = 1;
2320 if (nodelist) {
2321 /* NUL-terminate mode or flags string */
2322 *nodelist++ = '\0';
2323 if (nodelist_parse(nodelist, nodes))
2324 goto out;
2325 if (!nodes_subset(nodes, node_states[N_HIGH_MEMORY]))
2326 goto out;
2327 } else
2328 nodes_clear(nodes);
2330 if (flags)
2331 *flags++ = '\0'; /* terminate mode string */
2333 for (mode = 0; mode <= MPOL_LOCAL; mode++) {
2334 if (!strcmp(str, policy_modes[mode])) {
2335 break;
2338 if (mode > MPOL_LOCAL)
2339 goto out;
2341 switch (mode) {
2342 case MPOL_PREFERRED:
2344 * Insist on a nodelist of one node only
2346 if (nodelist) {
2347 char *rest = nodelist;
2348 while (isdigit(*rest))
2349 rest++;
2350 if (*rest)
2351 goto out;
2353 break;
2354 case MPOL_INTERLEAVE:
2356 * Default to online nodes with memory if no nodelist
2358 if (!nodelist)
2359 nodes = node_states[N_HIGH_MEMORY];
2360 break;
2361 case MPOL_LOCAL:
2363 * Don't allow a nodelist; mpol_new() checks flags
2365 if (nodelist)
2366 goto out;
2367 mode = MPOL_PREFERRED;
2368 break;
2369 case MPOL_DEFAULT:
2371 * Insist on a empty nodelist
2373 if (!nodelist)
2374 err = 0;
2375 goto out;
2376 case MPOL_BIND:
2378 * Insist on a nodelist
2380 if (!nodelist)
2381 goto out;
2384 mode_flags = 0;
2385 if (flags) {
2387 * Currently, we only support two mutually exclusive
2388 * mode flags.
2390 if (!strcmp(flags, "static"))
2391 mode_flags |= MPOL_F_STATIC_NODES;
2392 else if (!strcmp(flags, "relative"))
2393 mode_flags |= MPOL_F_RELATIVE_NODES;
2394 else
2395 goto out;
2398 new = mpol_new(mode, mode_flags, &nodes);
2399 if (IS_ERR(new))
2400 goto out;
2402 if (no_context) {
2403 /* save for contextualization */
2404 new->w.user_nodemask = nodes;
2405 } else {
2406 int ret;
2407 NODEMASK_SCRATCH(scratch);
2408 if (scratch) {
2409 task_lock(current);
2410 ret = mpol_set_nodemask(new, &nodes, scratch);
2411 task_unlock(current);
2412 } else
2413 ret = -ENOMEM;
2414 NODEMASK_SCRATCH_FREE(scratch);
2415 if (ret) {
2416 mpol_put(new);
2417 goto out;
2420 err = 0;
2422 out:
2423 /* Restore string for error message */
2424 if (nodelist)
2425 *--nodelist = ':';
2426 if (flags)
2427 *--flags = '=';
2428 if (!err)
2429 *mpol = new;
2430 return err;
2432 #endif /* CONFIG_TMPFS */
2435 * mpol_to_str - format a mempolicy structure for printing
2436 * @buffer: to contain formatted mempolicy string
2437 * @maxlen: length of @buffer
2438 * @pol: pointer to mempolicy to be formatted
2439 * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask
2441 * Convert a mempolicy into a string.
2442 * Returns the number of characters in buffer (if positive)
2443 * or an error (negative)
2445 int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol, int no_context)
2447 char *p = buffer;
2448 int l;
2449 nodemask_t nodes;
2450 unsigned short mode;
2451 unsigned short flags = pol ? pol->flags : 0;
2454 * Sanity check: room for longest mode, flag and some nodes
2456 VM_BUG_ON(maxlen < strlen("interleave") + strlen("relative") + 16);
2458 if (!pol || pol == &default_policy)
2459 mode = MPOL_DEFAULT;
2460 else
2461 mode = pol->mode;
2463 switch (mode) {
2464 case MPOL_DEFAULT:
2465 nodes_clear(nodes);
2466 break;
2468 case MPOL_PREFERRED:
2469 nodes_clear(nodes);
2470 if (flags & MPOL_F_LOCAL)
2471 mode = MPOL_LOCAL; /* pseudo-policy */
2472 else
2473 node_set(pol->v.preferred_node, nodes);
2474 break;
2476 case MPOL_BIND:
2477 /* Fall through */
2478 case MPOL_INTERLEAVE:
2479 if (no_context)
2480 nodes = pol->w.user_nodemask;
2481 else
2482 nodes = pol->v.nodes;
2483 break;
2485 default:
2486 BUG();
2489 l = strlen(policy_modes[mode]);
2490 if (buffer + maxlen < p + l + 1)
2491 return -ENOSPC;
2493 strcpy(p, policy_modes[mode]);
2494 p += l;
2496 if (flags & MPOL_MODE_FLAGS) {
2497 if (buffer + maxlen < p + 2)
2498 return -ENOSPC;
2499 *p++ = '=';
2502 * Currently, the only defined flags are mutually exclusive
2504 if (flags & MPOL_F_STATIC_NODES)
2505 p += snprintf(p, buffer + maxlen - p, "static");
2506 else if (flags & MPOL_F_RELATIVE_NODES)
2507 p += snprintf(p, buffer + maxlen - p, "relative");
2510 if (!nodes_empty(nodes)) {
2511 if (buffer + maxlen < p + 2)
2512 return -ENOSPC;
2513 *p++ = ':';
2514 p += nodelist_scnprintf(p, buffer + maxlen - p, nodes);
2516 return p - buffer;
2519 struct numa_maps {
2520 unsigned long pages;
2521 unsigned long anon;
2522 unsigned long active;
2523 unsigned long writeback;
2524 unsigned long mapcount_max;
2525 unsigned long dirty;
2526 unsigned long swapcache;
2527 unsigned long node[MAX_NUMNODES];
2530 static void gather_stats(struct page *page, void *private, int pte_dirty)
2532 struct numa_maps *md = private;
2533 int count = page_mapcount(page);
2535 md->pages++;
2536 if (pte_dirty || PageDirty(page))
2537 md->dirty++;
2539 if (PageSwapCache(page))
2540 md->swapcache++;
2542 if (PageActive(page) || PageUnevictable(page))
2543 md->active++;
2545 if (PageWriteback(page))
2546 md->writeback++;
2548 if (PageAnon(page))
2549 md->anon++;
2551 if (count > md->mapcount_max)
2552 md->mapcount_max = count;
2554 md->node[page_to_nid(page)]++;
2557 #ifdef CONFIG_HUGETLB_PAGE
2558 static void check_huge_range(struct vm_area_struct *vma,
2559 unsigned long start, unsigned long end,
2560 struct numa_maps *md)
2562 unsigned long addr;
2563 struct page *page;
2564 struct hstate *h = hstate_vma(vma);
2565 unsigned long sz = huge_page_size(h);
2567 for (addr = start; addr < end; addr += sz) {
2568 pte_t *ptep = huge_pte_offset(vma->vm_mm,
2569 addr & huge_page_mask(h));
2570 pte_t pte;
2572 if (!ptep)
2573 continue;
2575 pte = *ptep;
2576 if (pte_none(pte))
2577 continue;
2579 page = pte_page(pte);
2580 if (!page)
2581 continue;
2583 gather_stats(page, md, pte_dirty(*ptep));
2586 #else
2587 static inline void check_huge_range(struct vm_area_struct *vma,
2588 unsigned long start, unsigned long end,
2589 struct numa_maps *md)
2592 #endif
2595 * Display pages allocated per node and memory policy via /proc.
2597 int show_numa_map(struct seq_file *m, void *v)
2599 struct proc_maps_private *priv = m->private;
2600 struct vm_area_struct *vma = v;
2601 struct numa_maps *md;
2602 struct file *file = vma->vm_file;
2603 struct mm_struct *mm = vma->vm_mm;
2604 struct mempolicy *pol;
2605 int n;
2606 char buffer[50];
2608 if (!mm)
2609 return 0;
2611 md = kzalloc(sizeof(struct numa_maps), GFP_KERNEL);
2612 if (!md)
2613 return 0;
2615 pol = get_vma_policy(priv->task, vma, vma->vm_start);
2616 mpol_to_str(buffer, sizeof(buffer), pol, 0);
2617 mpol_cond_put(pol);
2619 seq_printf(m, "%08lx %s", vma->vm_start, buffer);
2621 if (file) {
2622 seq_printf(m, " file=");
2623 seq_path(m, &file->f_path, "\n\t= ");
2624 } else if (vma->vm_start <= mm->brk && vma->vm_end >= mm->start_brk) {
2625 seq_printf(m, " heap");
2626 } else if (vma->vm_start <= mm->start_stack &&
2627 vma->vm_end >= mm->start_stack) {
2628 seq_printf(m, " stack");
2631 if (is_vm_hugetlb_page(vma)) {
2632 check_huge_range(vma, vma->vm_start, vma->vm_end, md);
2633 seq_printf(m, " huge");
2634 } else {
2635 check_pgd_range(vma, vma->vm_start, vma->vm_end,
2636 &node_states[N_HIGH_MEMORY], MPOL_MF_STATS, md);
2639 if (!md->pages)
2640 goto out;
2642 if (md->anon)
2643 seq_printf(m," anon=%lu",md->anon);
2645 if (md->dirty)
2646 seq_printf(m," dirty=%lu",md->dirty);
2648 if (md->pages != md->anon && md->pages != md->dirty)
2649 seq_printf(m, " mapped=%lu", md->pages);
2651 if (md->mapcount_max > 1)
2652 seq_printf(m, " mapmax=%lu", md->mapcount_max);
2654 if (md->swapcache)
2655 seq_printf(m," swapcache=%lu", md->swapcache);
2657 if (md->active < md->pages && !is_vm_hugetlb_page(vma))
2658 seq_printf(m," active=%lu", md->active);
2660 if (md->writeback)
2661 seq_printf(m," writeback=%lu", md->writeback);
2663 for_each_node_state(n, N_HIGH_MEMORY)
2664 if (md->node[n])
2665 seq_printf(m, " N%d=%lu", n, md->node[n]);
2666 out:
2667 seq_putc(m, '\n');
2668 kfree(md);
2670 if (m->count < m->size)
2671 m->version = (vma != priv->tail_vma) ? vma->vm_start : 0;
2672 return 0;