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
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
22 * bind Only allocate memory on a specific set of nodes,
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 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
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.
57 fix mmap readahead to honour policy and enable policy for any page cache
59 statistics for bigpages
60 global policy for page cache? currently it uses process policy. Requires
62 handle mremap for shared memory (currently ignored for the policy)
64 make bind policy root only? It can trigger oom much faster and the
65 kernel is not always grateful with that.
68 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
70 #include <linux/mempolicy.h>
72 #include <linux/highmem.h>
73 #include <linux/hugetlb.h>
74 #include <linux/kernel.h>
75 #include <linux/sched.h>
76 #include <linux/nodemask.h>
77 #include <linux/cpuset.h>
78 #include <linux/slab.h>
79 #include <linux/string.h>
80 #include <linux/export.h>
81 #include <linux/nsproxy.h>
82 #include <linux/interrupt.h>
83 #include <linux/init.h>
84 #include <linux/compat.h>
85 #include <linux/swap.h>
86 #include <linux/seq_file.h>
87 #include <linux/proc_fs.h>
88 #include <linux/migrate.h>
89 #include <linux/ksm.h>
90 #include <linux/rmap.h>
91 #include <linux/security.h>
92 #include <linux/syscalls.h>
93 #include <linux/ctype.h>
94 #include <linux/mm_inline.h>
95 #include <linux/mmu_notifier.h>
96 #include <linux/printk.h>
98 #include <asm/tlbflush.h>
99 #include <asm/uaccess.h>
100 #include <linux/random.h>
102 #include "internal.h"
105 #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
106 #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
108 static struct kmem_cache *policy_cache;
109 static struct kmem_cache *sn_cache;
111 /* Highest zone. An specific allocation for a zone below that is not
113 enum zone_type policy_zone = 0;
116 * run-time system-wide default policy => local allocation
118 static struct mempolicy default_policy = {
119 .refcnt = ATOMIC_INIT(1), /* never free it */
120 .mode = MPOL_PREFERRED,
121 .flags = MPOL_F_LOCAL,
124 static struct mempolicy preferred_node_policy[MAX_NUMNODES];
126 struct mempolicy *get_task_policy(struct task_struct *p)
128 struct mempolicy *pol = p->mempolicy;
134 node = numa_node_id();
135 if (node != NUMA_NO_NODE) {
136 pol = &preferred_node_policy[node];
137 /* preferred_node_policy is not initialised early in boot */
142 return &default_policy;
145 static const struct mempolicy_operations {
146 int (*create)(struct mempolicy *pol, const nodemask_t *nodes);
148 * If read-side task has no lock to protect task->mempolicy, write-side
149 * task will rebind the task->mempolicy by two step. The first step is
150 * setting all the newly nodes, and the second step is cleaning all the
151 * disallowed nodes. In this way, we can avoid finding no node to alloc
153 * If we have a lock to protect task->mempolicy in read-side, we do
157 * MPOL_REBIND_ONCE - do rebind work at once
158 * MPOL_REBIND_STEP1 - set all the newly nodes
159 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
161 void (*rebind)(struct mempolicy *pol, const nodemask_t *nodes,
162 enum mpol_rebind_step step);
163 } mpol_ops[MPOL_MAX];
165 static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
167 return pol->flags & MPOL_MODE_FLAGS;
170 static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
171 const nodemask_t *rel)
174 nodes_fold(tmp, *orig, nodes_weight(*rel));
175 nodes_onto(*ret, tmp, *rel);
178 static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
180 if (nodes_empty(*nodes))
182 pol->v.nodes = *nodes;
186 static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
189 pol->flags |= MPOL_F_LOCAL; /* local allocation */
190 else if (nodes_empty(*nodes))
191 return -EINVAL; /* no allowed nodes */
193 pol->v.preferred_node = first_node(*nodes);
197 static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
199 if (nodes_empty(*nodes))
201 pol->v.nodes = *nodes;
206 * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
207 * any, for the new policy. mpol_new() has already validated the nodes
208 * parameter with respect to the policy mode and flags. But, we need to
209 * handle an empty nodemask with MPOL_PREFERRED here.
211 * Must be called holding task's alloc_lock to protect task's mems_allowed
212 * and mempolicy. May also be called holding the mmap_semaphore for write.
214 static int mpol_set_nodemask(struct mempolicy *pol,
215 const nodemask_t *nodes, struct nodemask_scratch *nsc)
219 /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
223 nodes_and(nsc->mask1,
224 cpuset_current_mems_allowed, node_states[N_MEMORY]);
227 if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
228 nodes = NULL; /* explicit local allocation */
230 if (pol->flags & MPOL_F_RELATIVE_NODES)
231 mpol_relative_nodemask(&nsc->mask2, nodes, &nsc->mask1);
233 nodes_and(nsc->mask2, *nodes, nsc->mask1);
235 if (mpol_store_user_nodemask(pol))
236 pol->w.user_nodemask = *nodes;
238 pol->w.cpuset_mems_allowed =
239 cpuset_current_mems_allowed;
243 ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
245 ret = mpol_ops[pol->mode].create(pol, NULL);
250 * This function just creates a new policy, does some check and simple
251 * initialization. You must invoke mpol_set_nodemask() to set nodes.
253 static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
256 struct mempolicy *policy;
258 pr_debug("setting mode %d flags %d nodes[0] %lx\n",
259 mode, flags, nodes ? nodes_addr(*nodes)[0] : NUMA_NO_NODE);
261 if (mode == MPOL_DEFAULT) {
262 if (nodes && !nodes_empty(*nodes))
263 return ERR_PTR(-EINVAL);
269 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
270 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
271 * All other modes require a valid pointer to a non-empty nodemask.
273 if (mode == MPOL_PREFERRED) {
274 if (nodes_empty(*nodes)) {
275 if (((flags & MPOL_F_STATIC_NODES) ||
276 (flags & MPOL_F_RELATIVE_NODES)))
277 return ERR_PTR(-EINVAL);
279 } else if (mode == MPOL_LOCAL) {
280 if (!nodes_empty(*nodes))
281 return ERR_PTR(-EINVAL);
282 mode = MPOL_PREFERRED;
283 } else if (nodes_empty(*nodes))
284 return ERR_PTR(-EINVAL);
285 policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
287 return ERR_PTR(-ENOMEM);
288 atomic_set(&policy->refcnt, 1);
290 policy->flags = flags;
295 /* Slow path of a mpol destructor. */
296 void __mpol_put(struct mempolicy *p)
298 if (!atomic_dec_and_test(&p->refcnt))
300 kmem_cache_free(policy_cache, p);
303 static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes,
304 enum mpol_rebind_step step)
310 * MPOL_REBIND_ONCE - do rebind work at once
311 * MPOL_REBIND_STEP1 - set all the newly nodes
312 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
314 static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes,
315 enum mpol_rebind_step step)
319 if (pol->flags & MPOL_F_STATIC_NODES)
320 nodes_and(tmp, pol->w.user_nodemask, *nodes);
321 else if (pol->flags & MPOL_F_RELATIVE_NODES)
322 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
325 * if step == 1, we use ->w.cpuset_mems_allowed to cache the
328 if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP1) {
329 nodes_remap(tmp, pol->v.nodes,
330 pol->w.cpuset_mems_allowed, *nodes);
331 pol->w.cpuset_mems_allowed = step ? tmp : *nodes;
332 } else if (step == MPOL_REBIND_STEP2) {
333 tmp = pol->w.cpuset_mems_allowed;
334 pol->w.cpuset_mems_allowed = *nodes;
339 if (nodes_empty(tmp))
342 if (step == MPOL_REBIND_STEP1)
343 nodes_or(pol->v.nodes, pol->v.nodes, tmp);
344 else if (step == MPOL_REBIND_ONCE || step == MPOL_REBIND_STEP2)
349 if (!node_isset(current->il_next, tmp)) {
350 current->il_next = next_node(current->il_next, tmp);
351 if (current->il_next >= MAX_NUMNODES)
352 current->il_next = first_node(tmp);
353 if (current->il_next >= MAX_NUMNODES)
354 current->il_next = numa_node_id();
358 static void mpol_rebind_preferred(struct mempolicy *pol,
359 const nodemask_t *nodes,
360 enum mpol_rebind_step step)
364 if (pol->flags & MPOL_F_STATIC_NODES) {
365 int node = first_node(pol->w.user_nodemask);
367 if (node_isset(node, *nodes)) {
368 pol->v.preferred_node = node;
369 pol->flags &= ~MPOL_F_LOCAL;
371 pol->flags |= MPOL_F_LOCAL;
372 } else if (pol->flags & MPOL_F_RELATIVE_NODES) {
373 mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
374 pol->v.preferred_node = first_node(tmp);
375 } else if (!(pol->flags & MPOL_F_LOCAL)) {
376 pol->v.preferred_node = node_remap(pol->v.preferred_node,
377 pol->w.cpuset_mems_allowed,
379 pol->w.cpuset_mems_allowed = *nodes;
384 * mpol_rebind_policy - Migrate a policy to a different set of nodes
386 * If read-side task has no lock to protect task->mempolicy, write-side
387 * task will rebind the task->mempolicy by two step. The first step is
388 * setting all the newly nodes, and the second step is cleaning all the
389 * disallowed nodes. In this way, we can avoid finding no node to alloc
391 * If we have a lock to protect task->mempolicy in read-side, we do
395 * MPOL_REBIND_ONCE - do rebind work at once
396 * MPOL_REBIND_STEP1 - set all the newly nodes
397 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
399 static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask,
400 enum mpol_rebind_step step)
404 if (!mpol_store_user_nodemask(pol) && step == MPOL_REBIND_ONCE &&
405 nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
408 if (step == MPOL_REBIND_STEP1 && (pol->flags & MPOL_F_REBINDING))
411 if (step == MPOL_REBIND_STEP2 && !(pol->flags & MPOL_F_REBINDING))
414 if (step == MPOL_REBIND_STEP1)
415 pol->flags |= MPOL_F_REBINDING;
416 else if (step == MPOL_REBIND_STEP2)
417 pol->flags &= ~MPOL_F_REBINDING;
418 else if (step >= MPOL_REBIND_NSTEP)
421 mpol_ops[pol->mode].rebind(pol, newmask, step);
425 * Wrapper for mpol_rebind_policy() that just requires task
426 * pointer, and updates task mempolicy.
428 * Called with task's alloc_lock held.
431 void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new,
432 enum mpol_rebind_step step)
434 mpol_rebind_policy(tsk->mempolicy, new, step);
438 * Rebind each vma in mm to new nodemask.
440 * Call holding a reference to mm. Takes mm->mmap_sem during call.
443 void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
445 struct vm_area_struct *vma;
447 down_write(&mm->mmap_sem);
448 for (vma = mm->mmap; vma; vma = vma->vm_next)
449 mpol_rebind_policy(vma->vm_policy, new, MPOL_REBIND_ONCE);
450 up_write(&mm->mmap_sem);
453 static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
455 .rebind = mpol_rebind_default,
457 [MPOL_INTERLEAVE] = {
458 .create = mpol_new_interleave,
459 .rebind = mpol_rebind_nodemask,
462 .create = mpol_new_preferred,
463 .rebind = mpol_rebind_preferred,
466 .create = mpol_new_bind,
467 .rebind = mpol_rebind_nodemask,
471 static void migrate_page_add(struct page *page, struct list_head *pagelist,
472 unsigned long flags);
475 struct list_head *pagelist;
478 struct vm_area_struct *prev;
482 * Scan through pages checking if pages follow certain conditions,
483 * and move them to the pagelist if they do.
485 static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
486 unsigned long end, struct mm_walk *walk)
488 struct vm_area_struct *vma = walk->vma;
490 struct queue_pages *qp = walk->private;
491 unsigned long flags = qp->flags;
496 split_huge_page_pmd(vma, addr, pmd);
497 if (pmd_trans_unstable(pmd))
500 pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
501 for (; addr != end; pte++, addr += PAGE_SIZE) {
502 if (!pte_present(*pte))
504 page = vm_normal_page(vma, addr, *pte);
508 * vm_normal_page() filters out zero pages, but there might
509 * still be PageReserved pages to skip, perhaps in a VDSO.
511 if (PageReserved(page))
513 nid = page_to_nid(page);
514 if (node_isset(nid, *qp->nmask) == !!(flags & MPOL_MF_INVERT))
517 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
518 if (!vma_migratable(vma))
520 migrate_page_add(page, qp->pagelist, flags);
524 pte_unmap_unlock(pte - 1, ptl);
526 return addr != end ? -EIO : 0;
529 static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
530 unsigned long addr, unsigned long end,
531 struct mm_walk *walk)
533 #ifdef CONFIG_HUGETLB_PAGE
534 struct queue_pages *qp = walk->private;
535 unsigned long flags = qp->flags;
541 ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte);
542 entry = huge_ptep_get(pte);
543 if (!pte_present(entry))
545 page = pte_page(entry);
546 nid = page_to_nid(page);
547 if (node_isset(nid, *qp->nmask) == !!(flags & MPOL_MF_INVERT))
549 /* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
550 if (flags & (MPOL_MF_MOVE_ALL) ||
551 (flags & MPOL_MF_MOVE && page_mapcount(page) == 1))
552 isolate_huge_page(page, qp->pagelist);
561 #ifdef CONFIG_NUMA_BALANCING
563 * This is used to mark a range of virtual addresses to be inaccessible.
564 * These are later cleared by a NUMA hinting fault. Depending on these
565 * faults, pages may be migrated for better NUMA placement.
567 * This is assuming that NUMA faults are handled using PROT_NONE. If
568 * an architecture makes a different choice, it will need further
569 * changes to the core.
571 unsigned long change_prot_numa(struct vm_area_struct *vma,
572 unsigned long addr, unsigned long end)
576 nr_updated = change_protection(vma, addr, end, PAGE_NONE, 0, 1);
578 count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated);
583 static unsigned long change_prot_numa(struct vm_area_struct *vma,
584 unsigned long addr, unsigned long end)
588 #endif /* CONFIG_NUMA_BALANCING */
590 static int queue_pages_test_walk(unsigned long start, unsigned long end,
591 struct mm_walk *walk)
593 struct vm_area_struct *vma = walk->vma;
594 struct queue_pages *qp = walk->private;
595 unsigned long endvma = vma->vm_end;
596 unsigned long flags = qp->flags;
598 if (vma->vm_flags & VM_PFNMAP)
603 if (vma->vm_start > start)
604 start = vma->vm_start;
606 if (!(flags & MPOL_MF_DISCONTIG_OK)) {
607 if (!vma->vm_next && vma->vm_end < end)
609 if (qp->prev && qp->prev->vm_end < vma->vm_start)
615 if (flags & MPOL_MF_LAZY) {
616 /* Similar to task_numa_work, skip inaccessible VMAs */
617 if (vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))
618 change_prot_numa(vma, start, endvma);
622 if ((flags & MPOL_MF_STRICT) ||
623 ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) &&
624 vma_migratable(vma)))
625 /* queue pages from current vma */
631 * Walk through page tables and collect pages to be migrated.
633 * If pages found in a given range are on a set of nodes (determined by
634 * @nodes and @flags,) it's isolated and queued to the pagelist which is
635 * passed via @private.)
638 queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
639 nodemask_t *nodes, unsigned long flags,
640 struct list_head *pagelist)
642 struct queue_pages qp = {
643 .pagelist = pagelist,
648 struct mm_walk queue_pages_walk = {
649 .hugetlb_entry = queue_pages_hugetlb,
650 .pmd_entry = queue_pages_pte_range,
651 .test_walk = queue_pages_test_walk,
656 return walk_page_range(start, end, &queue_pages_walk);
660 * Apply policy to a single VMA
661 * This must be called with the mmap_sem held for writing.
663 static int vma_replace_policy(struct vm_area_struct *vma,
664 struct mempolicy *pol)
667 struct mempolicy *old;
668 struct mempolicy *new;
670 pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
671 vma->vm_start, vma->vm_end, vma->vm_pgoff,
672 vma->vm_ops, vma->vm_file,
673 vma->vm_ops ? vma->vm_ops->set_policy : NULL);
679 if (vma->vm_ops && vma->vm_ops->set_policy) {
680 err = vma->vm_ops->set_policy(vma, new);
685 old = vma->vm_policy;
686 vma->vm_policy = new; /* protected by mmap_sem */
695 /* Step 2: apply policy to a range and do splits. */
696 static int mbind_range(struct mm_struct *mm, unsigned long start,
697 unsigned long end, struct mempolicy *new_pol)
699 struct vm_area_struct *next;
700 struct vm_area_struct *prev;
701 struct vm_area_struct *vma;
704 unsigned long vmstart;
707 vma = find_vma(mm, start);
708 if (!vma || vma->vm_start > start)
712 if (start > vma->vm_start)
715 for (; vma && vma->vm_start < end; prev = vma, vma = next) {
717 vmstart = max(start, vma->vm_start);
718 vmend = min(end, vma->vm_end);
720 if (mpol_equal(vma_policy(vma), new_pol))
723 pgoff = vma->vm_pgoff +
724 ((vmstart - vma->vm_start) >> PAGE_SHIFT);
725 prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
726 vma->anon_vma, vma->vm_file, pgoff,
727 new_pol, vma->vm_userfaultfd_ctx,
728 vma_get_anon_name(vma));
732 if (mpol_equal(vma_policy(vma), new_pol))
734 /* vma_merge() joined vma && vma->next, case 8 */
737 if (vma->vm_start != vmstart) {
738 err = split_vma(vma->vm_mm, vma, vmstart, 1);
742 if (vma->vm_end != vmend) {
743 err = split_vma(vma->vm_mm, vma, vmend, 0);
748 err = vma_replace_policy(vma, new_pol);
757 /* Set the process memory policy */
758 static long do_set_mempolicy(unsigned short mode, unsigned short flags,
761 struct mempolicy *new, *old;
762 NODEMASK_SCRATCH(scratch);
768 new = mpol_new(mode, flags, nodes);
775 ret = mpol_set_nodemask(new, nodes, scratch);
777 task_unlock(current);
781 old = current->mempolicy;
782 current->mempolicy = new;
783 if (new && new->mode == MPOL_INTERLEAVE &&
784 nodes_weight(new->v.nodes))
785 current->il_next = first_node(new->v.nodes);
786 task_unlock(current);
790 NODEMASK_SCRATCH_FREE(scratch);
795 * Return nodemask for policy for get_mempolicy() query
797 * Called with task's alloc_lock held
799 static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
802 if (p == &default_policy)
808 case MPOL_INTERLEAVE:
812 if (!(p->flags & MPOL_F_LOCAL))
813 node_set(p->v.preferred_node, *nodes);
814 /* else return empty node mask for local allocation */
821 static int lookup_node(struct mm_struct *mm, unsigned long addr)
826 err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, &p, NULL);
828 err = page_to_nid(p);
834 /* Retrieve NUMA policy */
835 static long do_get_mempolicy(int *policy, nodemask_t *nmask,
836 unsigned long addr, unsigned long flags)
839 struct mm_struct *mm = current->mm;
840 struct vm_area_struct *vma = NULL;
841 struct mempolicy *pol = current->mempolicy;
844 ~(unsigned long)(MPOL_F_NODE|MPOL_F_ADDR|MPOL_F_MEMS_ALLOWED))
847 if (flags & MPOL_F_MEMS_ALLOWED) {
848 if (flags & (MPOL_F_NODE|MPOL_F_ADDR))
850 *policy = 0; /* just so it's initialized */
852 *nmask = cpuset_current_mems_allowed;
853 task_unlock(current);
857 if (flags & MPOL_F_ADDR) {
859 * Do NOT fall back to task policy if the
860 * vma/shared policy at addr is NULL. We
861 * want to return MPOL_DEFAULT in this case.
863 down_read(&mm->mmap_sem);
864 vma = find_vma_intersection(mm, addr, addr+1);
866 up_read(&mm->mmap_sem);
869 if (vma->vm_ops && vma->vm_ops->get_policy)
870 pol = vma->vm_ops->get_policy(vma, addr);
872 pol = vma->vm_policy;
877 pol = &default_policy; /* indicates default behavior */
879 if (flags & MPOL_F_NODE) {
880 if (flags & MPOL_F_ADDR) {
881 err = lookup_node(mm, addr);
885 } else if (pol == current->mempolicy &&
886 pol->mode == MPOL_INTERLEAVE) {
887 *policy = current->il_next;
893 *policy = pol == &default_policy ? MPOL_DEFAULT :
896 * Internal mempolicy flags must be masked off before exposing
897 * the policy to userspace.
899 *policy |= (pol->flags & MPOL_MODE_FLAGS);
904 if (mpol_store_user_nodemask(pol)) {
905 *nmask = pol->w.user_nodemask;
908 get_policy_nodemask(pol, nmask);
909 task_unlock(current);
916 up_read(¤t->mm->mmap_sem);
920 #ifdef CONFIG_MIGRATION
924 static void migrate_page_add(struct page *page, struct list_head *pagelist,
928 * Avoid migrating a page that is shared with others.
930 if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
931 if (!isolate_lru_page(page)) {
932 list_add_tail(&page->lru, pagelist);
933 inc_zone_page_state(page, NR_ISOLATED_ANON +
934 page_is_file_cache(page));
939 static struct page *new_node_page(struct page *page, unsigned long node, int **x)
942 return alloc_huge_page_node(page_hstate(compound_head(page)),
945 return __alloc_pages_node(node, GFP_HIGHUSER_MOVABLE |
950 * Migrate pages from one node to a target node.
951 * Returns error or the number of pages not migrated.
953 static int migrate_to_node(struct mm_struct *mm, int source, int dest,
961 node_set(source, nmask);
964 * This does not "check" the range but isolates all pages that
965 * need migration. Between passing in the full user address
966 * space range and MPOL_MF_DISCONTIG_OK, this call can not fail.
968 VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)));
969 queue_pages_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
970 flags | MPOL_MF_DISCONTIG_OK, &pagelist);
972 if (!list_empty(&pagelist)) {
973 err = migrate_pages(&pagelist, new_node_page, NULL, dest,
974 MIGRATE_SYNC, MR_SYSCALL);
976 putback_movable_pages(&pagelist);
983 * Move pages between the two nodesets so as to preserve the physical
984 * layout as much as possible.
986 * Returns the number of page that could not be moved.
988 int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
989 const nodemask_t *to, int flags)
995 err = migrate_prep();
999 down_read(&mm->mmap_sem);
1002 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
1003 * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
1004 * bit in 'tmp', and return that <source, dest> pair for migration.
1005 * The pair of nodemasks 'to' and 'from' define the map.
1007 * If no pair of bits is found that way, fallback to picking some
1008 * pair of 'source' and 'dest' bits that are not the same. If the
1009 * 'source' and 'dest' bits are the same, this represents a node
1010 * that will be migrating to itself, so no pages need move.
1012 * If no bits are left in 'tmp', or if all remaining bits left
1013 * in 'tmp' correspond to the same bit in 'to', return false
1014 * (nothing left to migrate).
1016 * This lets us pick a pair of nodes to migrate between, such that
1017 * if possible the dest node is not already occupied by some other
1018 * source node, minimizing the risk of overloading the memory on a
1019 * node that would happen if we migrated incoming memory to a node
1020 * before migrating outgoing memory source that same node.
1022 * A single scan of tmp is sufficient. As we go, we remember the
1023 * most recent <s, d> pair that moved (s != d). If we find a pair
1024 * that not only moved, but what's better, moved to an empty slot
1025 * (d is not set in tmp), then we break out then, with that pair.
1026 * Otherwise when we finish scanning from_tmp, we at least have the
1027 * most recent <s, d> pair that moved. If we get all the way through
1028 * the scan of tmp without finding any node that moved, much less
1029 * moved to an empty node, then there is nothing left worth migrating.
1033 while (!nodes_empty(tmp)) {
1035 int source = NUMA_NO_NODE;
1038 for_each_node_mask(s, tmp) {
1041 * do_migrate_pages() tries to maintain the relative
1042 * node relationship of the pages established between
1043 * threads and memory areas.
1045 * However if the number of source nodes is not equal to
1046 * the number of destination nodes we can not preserve
1047 * this node relative relationship. In that case, skip
1048 * copying memory from a node that is in the destination
1051 * Example: [2,3,4] -> [3,4,5] moves everything.
1052 * [0-7] - > [3,4,5] moves only 0,1,2,6,7.
1055 if ((nodes_weight(*from) != nodes_weight(*to)) &&
1056 (node_isset(s, *to)))
1059 d = node_remap(s, *from, *to);
1063 source = s; /* Node moved. Memorize */
1066 /* dest not in remaining from nodes? */
1067 if (!node_isset(dest, tmp))
1070 if (source == NUMA_NO_NODE)
1073 node_clear(source, tmp);
1074 err = migrate_to_node(mm, source, dest, flags);
1080 up_read(&mm->mmap_sem);
1088 * Allocate a new page for page migration based on vma policy.
1089 * Start by assuming the page is mapped by the same vma as contains @start.
1090 * Search forward from there, if not. N.B., this assumes that the
1091 * list of pages handed to migrate_pages()--which is how we get here--
1092 * is in virtual address order.
1094 static struct page *new_page(struct page *page, unsigned long start, int **x)
1096 struct vm_area_struct *vma;
1097 unsigned long uninitialized_var(address);
1099 vma = find_vma(current->mm, start);
1101 address = page_address_in_vma(page, vma);
1102 if (address != -EFAULT)
1107 if (PageHuge(page)) {
1109 return alloc_huge_page_noerr(vma, address, 1);
1112 * if !vma, alloc_page_vma() will use task or system default policy
1114 return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
1118 static void migrate_page_add(struct page *page, struct list_head *pagelist,
1119 unsigned long flags)
1123 int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
1124 const nodemask_t *to, int flags)
1129 static struct page *new_page(struct page *page, unsigned long start, int **x)
1135 static long do_mbind(unsigned long start, unsigned long len,
1136 unsigned short mode, unsigned short mode_flags,
1137 nodemask_t *nmask, unsigned long flags)
1139 struct mm_struct *mm = current->mm;
1140 struct mempolicy *new;
1143 LIST_HEAD(pagelist);
1145 if (flags & ~(unsigned long)MPOL_MF_VALID)
1147 if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
1150 if (start & ~PAGE_MASK)
1153 if (mode == MPOL_DEFAULT)
1154 flags &= ~MPOL_MF_STRICT;
1156 len = (len + PAGE_SIZE - 1) & PAGE_MASK;
1164 new = mpol_new(mode, mode_flags, nmask);
1166 return PTR_ERR(new);
1168 if (flags & MPOL_MF_LAZY)
1169 new->flags |= MPOL_F_MOF;
1172 * If we are using the default policy then operation
1173 * on discontinuous address spaces is okay after all
1176 flags |= MPOL_MF_DISCONTIG_OK;
1178 pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
1179 start, start + len, mode, mode_flags,
1180 nmask ? nodes_addr(*nmask)[0] : NUMA_NO_NODE);
1182 if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
1184 err = migrate_prep();
1189 NODEMASK_SCRATCH(scratch);
1191 down_write(&mm->mmap_sem);
1193 err = mpol_set_nodemask(new, nmask, scratch);
1194 task_unlock(current);
1196 up_write(&mm->mmap_sem);
1199 NODEMASK_SCRATCH_FREE(scratch);
1204 err = queue_pages_range(mm, start, end, nmask,
1205 flags | MPOL_MF_INVERT, &pagelist);
1207 err = mbind_range(mm, start, end, new);
1212 if (!list_empty(&pagelist)) {
1213 WARN_ON_ONCE(flags & MPOL_MF_LAZY);
1214 nr_failed = migrate_pages(&pagelist, new_page, NULL,
1215 start, MIGRATE_SYNC, MR_MEMPOLICY_MBIND);
1217 putback_movable_pages(&pagelist);
1220 if (nr_failed && (flags & MPOL_MF_STRICT))
1223 putback_movable_pages(&pagelist);
1225 up_write(&mm->mmap_sem);
1232 * User space interface with variable sized bitmaps for nodelists.
1235 /* Copy a node mask from user space. */
1236 static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
1237 unsigned long maxnode)
1241 unsigned long nlongs;
1242 unsigned long endmask;
1245 nodes_clear(*nodes);
1246 if (maxnode == 0 || !nmask)
1248 if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
1251 nlongs = BITS_TO_LONGS(maxnode);
1252 if ((maxnode % BITS_PER_LONG) == 0)
1255 endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;
1258 * When the user specified more nodes than supported just check
1259 * if the non supported part is all zero.
1261 * If maxnode have more longs than MAX_NUMNODES, check
1262 * the bits in that area first. And then go through to
1263 * check the rest bits which equal or bigger than MAX_NUMNODES.
1264 * Otherwise, just check bits [MAX_NUMNODES, maxnode).
1266 if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
1267 if (nlongs > PAGE_SIZE/sizeof(long))
1269 for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
1270 if (get_user(t, nmask + k))
1272 if (k == nlongs - 1) {
1278 nlongs = BITS_TO_LONGS(MAX_NUMNODES);
1282 if (maxnode > MAX_NUMNODES && MAX_NUMNODES % BITS_PER_LONG != 0) {
1283 unsigned long valid_mask = endmask;
1285 valid_mask &= ~((1UL << (MAX_NUMNODES % BITS_PER_LONG)) - 1);
1286 if (get_user(t, nmask + nlongs - 1))
1292 if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
1294 nodes_addr(*nodes)[nlongs-1] &= endmask;
1298 /* Copy a kernel node mask to user space */
1299 static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
1302 unsigned long copy = ALIGN(maxnode-1, 64) / 8;
1303 unsigned int nbytes = BITS_TO_LONGS(nr_node_ids) * sizeof(long);
1305 if (copy > nbytes) {
1306 if (copy > PAGE_SIZE)
1308 if (clear_user((char __user *)mask + nbytes, copy - nbytes))
1312 return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
1315 SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
1316 unsigned long, mode, const unsigned long __user *, nmask,
1317 unsigned long, maxnode, unsigned, flags)
1321 unsigned short mode_flags;
1323 mode_flags = mode & MPOL_MODE_FLAGS;
1324 mode &= ~MPOL_MODE_FLAGS;
1325 if (mode >= MPOL_MAX)
1327 if ((mode_flags & MPOL_F_STATIC_NODES) &&
1328 (mode_flags & MPOL_F_RELATIVE_NODES))
1330 err = get_nodes(&nodes, nmask, maxnode);
1333 return do_mbind(start, len, mode, mode_flags, &nodes, flags);
1336 /* Set the process memory policy */
1337 SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask,
1338 unsigned long, maxnode)
1342 unsigned short flags;
1344 flags = mode & MPOL_MODE_FLAGS;
1345 mode &= ~MPOL_MODE_FLAGS;
1346 if ((unsigned int)mode >= MPOL_MAX)
1348 if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
1350 err = get_nodes(&nodes, nmask, maxnode);
1353 return do_set_mempolicy(mode, flags, &nodes);
1356 SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
1357 const unsigned long __user *, old_nodes,
1358 const unsigned long __user *, new_nodes)
1360 const struct cred *cred = current_cred(), *tcred;
1361 struct mm_struct *mm = NULL;
1362 struct task_struct *task;
1363 nodemask_t task_nodes;
1367 NODEMASK_SCRATCH(scratch);
1372 old = &scratch->mask1;
1373 new = &scratch->mask2;
1375 err = get_nodes(old, old_nodes, maxnode);
1379 err = get_nodes(new, new_nodes, maxnode);
1383 /* Find the mm_struct */
1385 task = pid ? find_task_by_vpid(pid) : current;
1391 get_task_struct(task);
1396 * Check if this process has the right to modify the specified
1397 * process. The right exists if the process has administrative
1398 * capabilities, superuser privileges or the same
1399 * userid as the target process.
1401 tcred = __task_cred(task);
1402 if (!uid_eq(cred->euid, tcred->suid) && !uid_eq(cred->euid, tcred->uid) &&
1403 !uid_eq(cred->uid, tcred->suid) && !uid_eq(cred->uid, tcred->uid) &&
1404 !capable(CAP_SYS_NICE)) {
1411 task_nodes = cpuset_mems_allowed(task);
1412 /* Is the user allowed to access the target nodes? */
1413 if (!nodes_subset(*new, task_nodes) && !capable(CAP_SYS_NICE)) {
1418 task_nodes = cpuset_mems_allowed(current);
1419 nodes_and(*new, *new, task_nodes);
1420 if (nodes_empty(*new))
1423 nodes_and(*new, *new, node_states[N_MEMORY]);
1424 if (nodes_empty(*new))
1427 err = security_task_movememory(task);
1431 mm = get_task_mm(task);
1432 put_task_struct(task);
1439 err = do_migrate_pages(mm, old, new,
1440 capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE);
1444 NODEMASK_SCRATCH_FREE(scratch);
1449 put_task_struct(task);
1455 /* Retrieve NUMA policy */
1456 SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
1457 unsigned long __user *, nmask, unsigned long, maxnode,
1458 unsigned long, addr, unsigned long, flags)
1461 int uninitialized_var(pval);
1464 if (nmask != NULL && maxnode < nr_node_ids)
1467 err = do_get_mempolicy(&pval, &nodes, addr, flags);
1472 if (policy && put_user(pval, policy))
1476 err = copy_nodes_to_user(nmask, maxnode, &nodes);
1481 #ifdef CONFIG_COMPAT
1483 COMPAT_SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
1484 compat_ulong_t __user *, nmask,
1485 compat_ulong_t, maxnode,
1486 compat_ulong_t, addr, compat_ulong_t, flags)
1489 unsigned long __user *nm = NULL;
1490 unsigned long nr_bits, alloc_size;
1491 DECLARE_BITMAP(bm, MAX_NUMNODES);
1493 nr_bits = min_t(unsigned long, maxnode-1, nr_node_ids);
1494 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1497 nm = compat_alloc_user_space(alloc_size);
1499 err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags);
1501 if (!err && nmask) {
1502 unsigned long copy_size;
1503 copy_size = min_t(unsigned long, sizeof(bm), alloc_size);
1504 err = copy_from_user(bm, nm, copy_size);
1505 /* ensure entire bitmap is zeroed */
1506 err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
1507 err |= compat_put_bitmap(nmask, bm, nr_bits);
1513 COMPAT_SYSCALL_DEFINE3(set_mempolicy, int, mode, compat_ulong_t __user *, nmask,
1514 compat_ulong_t, maxnode)
1516 unsigned long __user *nm = NULL;
1517 unsigned long nr_bits, alloc_size;
1518 DECLARE_BITMAP(bm, MAX_NUMNODES);
1520 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1521 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1524 if (compat_get_bitmap(bm, nmask, nr_bits))
1526 nm = compat_alloc_user_space(alloc_size);
1527 if (copy_to_user(nm, bm, alloc_size))
1531 return sys_set_mempolicy(mode, nm, nr_bits+1);
1534 COMPAT_SYSCALL_DEFINE6(mbind, compat_ulong_t, start, compat_ulong_t, len,
1535 compat_ulong_t, mode, compat_ulong_t __user *, nmask,
1536 compat_ulong_t, maxnode, compat_ulong_t, flags)
1538 unsigned long __user *nm = NULL;
1539 unsigned long nr_bits, alloc_size;
1542 nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
1543 alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
1546 if (compat_get_bitmap(nodes_addr(bm), nmask, nr_bits))
1548 nm = compat_alloc_user_space(alloc_size);
1549 if (copy_to_user(nm, nodes_addr(bm), alloc_size))
1553 return sys_mbind(start, len, mode, nm, nr_bits+1, flags);
1558 struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
1561 struct mempolicy *pol = NULL;
1564 if (vma->vm_ops && vma->vm_ops->get_policy) {
1565 pol = vma->vm_ops->get_policy(vma, addr);
1566 } else if (vma->vm_policy) {
1567 pol = vma->vm_policy;
1570 * shmem_alloc_page() passes MPOL_F_SHARED policy with
1571 * a pseudo vma whose vma->vm_ops=NULL. Take a reference
1572 * count on these policies which will be dropped by
1573 * mpol_cond_put() later
1575 if (mpol_needs_cond_ref(pol))
1584 * get_vma_policy(@vma, @addr)
1585 * @vma: virtual memory area whose policy is sought
1586 * @addr: address in @vma for shared policy lookup
1588 * Returns effective policy for a VMA at specified address.
1589 * Falls back to current->mempolicy or system default policy, as necessary.
1590 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
1591 * count--added by the get_policy() vm_op, as appropriate--to protect against
1592 * freeing by another task. It is the caller's responsibility to free the
1593 * extra reference for shared policies.
1595 static struct mempolicy *get_vma_policy(struct vm_area_struct *vma,
1598 struct mempolicy *pol = __get_vma_policy(vma, addr);
1601 pol = get_task_policy(current);
1606 bool vma_policy_mof(struct vm_area_struct *vma)
1608 struct mempolicy *pol;
1610 if (vma->vm_ops && vma->vm_ops->get_policy) {
1613 pol = vma->vm_ops->get_policy(vma, vma->vm_start);
1614 if (pol && (pol->flags & MPOL_F_MOF))
1621 pol = vma->vm_policy;
1623 pol = get_task_policy(current);
1625 return pol->flags & MPOL_F_MOF;
1628 static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone)
1630 enum zone_type dynamic_policy_zone = policy_zone;
1632 BUG_ON(dynamic_policy_zone == ZONE_MOVABLE);
1635 * if policy->v.nodes has movable memory only,
1636 * we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only.
1638 * policy->v.nodes is intersect with node_states[N_MEMORY].
1639 * so if the following test faile, it implies
1640 * policy->v.nodes has movable memory only.
1642 if (!nodes_intersects(policy->v.nodes, node_states[N_HIGH_MEMORY]))
1643 dynamic_policy_zone = ZONE_MOVABLE;
1645 return zone >= dynamic_policy_zone;
1649 * Return a nodemask representing a mempolicy for filtering nodes for
1652 static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
1654 /* Lower zones don't get a nodemask applied for MPOL_BIND */
1655 if (unlikely(policy->mode == MPOL_BIND) &&
1656 apply_policy_zone(policy, gfp_zone(gfp)) &&
1657 cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
1658 return &policy->v.nodes;
1663 /* Return a zonelist indicated by gfp for node representing a mempolicy */
1664 static struct zonelist *policy_zonelist(gfp_t gfp, struct mempolicy *policy,
1667 switch (policy->mode) {
1668 case MPOL_PREFERRED:
1669 if (!(policy->flags & MPOL_F_LOCAL))
1670 nd = policy->v.preferred_node;
1674 * Normally, MPOL_BIND allocations are node-local within the
1675 * allowed nodemask. However, if __GFP_THISNODE is set and the
1676 * current node isn't part of the mask, we use the zonelist for
1677 * the first node in the mask instead.
1679 if (unlikely(gfp & __GFP_THISNODE) &&
1680 unlikely(!node_isset(nd, policy->v.nodes)))
1681 nd = first_node(policy->v.nodes);
1686 return node_zonelist(nd, gfp);
1689 /* Do dynamic interleaving for a process */
1690 static unsigned interleave_nodes(struct mempolicy *policy)
1693 struct task_struct *me = current;
1696 next = next_node(nid, policy->v.nodes);
1697 if (next >= MAX_NUMNODES)
1698 next = first_node(policy->v.nodes);
1699 if (next < MAX_NUMNODES)
1705 * Depending on the memory policy provide a node from which to allocate the
1708 unsigned int mempolicy_slab_node(void)
1710 struct mempolicy *policy;
1711 int node = numa_mem_id();
1716 policy = current->mempolicy;
1717 if (!policy || policy->flags & MPOL_F_LOCAL)
1720 switch (policy->mode) {
1721 case MPOL_PREFERRED:
1723 * handled MPOL_F_LOCAL above
1725 return policy->v.preferred_node;
1727 case MPOL_INTERLEAVE:
1728 return interleave_nodes(policy);
1732 * Follow bind policy behavior and start allocation at the
1735 struct zonelist *zonelist;
1737 enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
1738 zonelist = &NODE_DATA(node)->node_zonelists[0];
1739 (void)first_zones_zonelist(zonelist, highest_zoneidx,
1742 return zone ? zone->node : node;
1750 /* Do static interleaving for a VMA with known offset. */
1751 static unsigned offset_il_node(struct mempolicy *pol,
1752 struct vm_area_struct *vma, unsigned long off)
1754 unsigned nnodes = nodes_weight(pol->v.nodes);
1757 int nid = NUMA_NO_NODE;
1760 return numa_node_id();
1761 target = (unsigned int)off % nnodes;
1764 nid = next_node(nid, pol->v.nodes);
1766 } while (c <= target);
1770 /* Determine a node number for interleave */
1771 static inline unsigned interleave_nid(struct mempolicy *pol,
1772 struct vm_area_struct *vma, unsigned long addr, int shift)
1778 * for small pages, there is no difference between
1779 * shift and PAGE_SHIFT, so the bit-shift is safe.
1780 * for huge pages, since vm_pgoff is in units of small
1781 * pages, we need to shift off the always 0 bits to get
1784 BUG_ON(shift < PAGE_SHIFT);
1785 off = vma->vm_pgoff >> (shift - PAGE_SHIFT);
1786 off += (addr - vma->vm_start) >> shift;
1787 return offset_il_node(pol, vma, off);
1789 return interleave_nodes(pol);
1793 * Return the bit number of a random bit set in the nodemask.
1794 * (returns NUMA_NO_NODE if nodemask is empty)
1796 int node_random(const nodemask_t *maskp)
1798 int w, bit = NUMA_NO_NODE;
1800 w = nodes_weight(*maskp);
1802 bit = bitmap_ord_to_pos(maskp->bits,
1803 get_random_int() % w, MAX_NUMNODES);
1807 #ifdef CONFIG_HUGETLBFS
1809 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
1810 * @vma: virtual memory area whose policy is sought
1811 * @addr: address in @vma for shared policy lookup and interleave policy
1812 * @gfp_flags: for requested zone
1813 * @mpol: pointer to mempolicy pointer for reference counted mempolicy
1814 * @nodemask: pointer to nodemask pointer for MPOL_BIND nodemask
1816 * Returns a zonelist suitable for a huge page allocation and a pointer
1817 * to the struct mempolicy for conditional unref after allocation.
1818 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
1819 * @nodemask for filtering the zonelist.
1821 * Must be protected by read_mems_allowed_begin()
1823 struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
1824 gfp_t gfp_flags, struct mempolicy **mpol,
1825 nodemask_t **nodemask)
1827 struct zonelist *zl;
1829 *mpol = get_vma_policy(vma, addr);
1830 *nodemask = NULL; /* assume !MPOL_BIND */
1832 if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
1833 zl = node_zonelist(interleave_nid(*mpol, vma, addr,
1834 huge_page_shift(hstate_vma(vma))), gfp_flags);
1836 zl = policy_zonelist(gfp_flags, *mpol, numa_node_id());
1837 if ((*mpol)->mode == MPOL_BIND)
1838 *nodemask = &(*mpol)->v.nodes;
1844 * init_nodemask_of_mempolicy
1846 * If the current task's mempolicy is "default" [NULL], return 'false'
1847 * to indicate default policy. Otherwise, extract the policy nodemask
1848 * for 'bind' or 'interleave' policy into the argument nodemask, or
1849 * initialize the argument nodemask to contain the single node for
1850 * 'preferred' or 'local' policy and return 'true' to indicate presence
1851 * of non-default mempolicy.
1853 * We don't bother with reference counting the mempolicy [mpol_get/put]
1854 * because the current task is examining it's own mempolicy and a task's
1855 * mempolicy is only ever changed by the task itself.
1857 * N.B., it is the caller's responsibility to free a returned nodemask.
1859 bool init_nodemask_of_mempolicy(nodemask_t *mask)
1861 struct mempolicy *mempolicy;
1864 if (!(mask && current->mempolicy))
1868 mempolicy = current->mempolicy;
1869 switch (mempolicy->mode) {
1870 case MPOL_PREFERRED:
1871 if (mempolicy->flags & MPOL_F_LOCAL)
1872 nid = numa_node_id();
1874 nid = mempolicy->v.preferred_node;
1875 init_nodemask_of_node(mask, nid);
1880 case MPOL_INTERLEAVE:
1881 *mask = mempolicy->v.nodes;
1887 task_unlock(current);
1894 * mempolicy_nodemask_intersects
1896 * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
1897 * policy. Otherwise, check for intersection between mask and the policy
1898 * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local'
1899 * policy, always return true since it may allocate elsewhere on fallback.
1901 * Takes task_lock(tsk) to prevent freeing of its mempolicy.
1903 bool mempolicy_nodemask_intersects(struct task_struct *tsk,
1904 const nodemask_t *mask)
1906 struct mempolicy *mempolicy;
1912 mempolicy = tsk->mempolicy;
1916 switch (mempolicy->mode) {
1917 case MPOL_PREFERRED:
1919 * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
1920 * allocate from, they may fallback to other nodes when oom.
1921 * Thus, it's possible for tsk to have allocated memory from
1926 case MPOL_INTERLEAVE:
1927 ret = nodes_intersects(mempolicy->v.nodes, *mask);
1937 /* Allocate a page in interleaved policy.
1938 Own path because it needs to do special accounting. */
1939 static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
1942 struct zonelist *zl;
1945 zl = node_zonelist(nid, gfp);
1946 page = __alloc_pages(gfp, order, zl);
1947 if (page && page_zone(page) == zonelist_zone(&zl->_zonerefs[0]))
1948 inc_zone_page_state(page, NUMA_INTERLEAVE_HIT);
1953 * alloc_pages_vma - Allocate a page for a VMA.
1956 * %GFP_USER user allocation.
1957 * %GFP_KERNEL kernel allocations,
1958 * %GFP_HIGHMEM highmem/user allocations,
1959 * %GFP_FS allocation should not call back into a file system.
1960 * %GFP_ATOMIC don't sleep.
1962 * @order:Order of the GFP allocation.
1963 * @vma: Pointer to VMA or NULL if not available.
1964 * @addr: Virtual Address of the allocation. Must be inside the VMA.
1965 * @node: Which node to prefer for allocation (modulo policy).
1966 * @hugepage: for hugepages try only the preferred node if possible
1968 * This function allocates a page from the kernel page pool and applies
1969 * a NUMA policy associated with the VMA or the current process.
1970 * When VMA is not NULL caller must hold down_read on the mmap_sem of the
1971 * mm_struct of the VMA to prevent it from going away. Should be used for
1972 * all allocations for pages that will be mapped into user space. Returns
1973 * NULL when no page can be allocated.
1976 alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
1977 unsigned long addr, int node, bool hugepage)
1979 struct mempolicy *pol;
1981 unsigned int cpuset_mems_cookie;
1982 struct zonelist *zl;
1986 pol = get_vma_policy(vma, addr);
1987 cpuset_mems_cookie = read_mems_allowed_begin();
1989 if (pol->mode == MPOL_INTERLEAVE) {
1992 nid = interleave_nid(pol, vma, addr, PAGE_SHIFT + order);
1994 page = alloc_page_interleave(gfp, order, nid);
1998 if (unlikely(IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hugepage)) {
1999 int hpage_node = node;
2002 * For hugepage allocation and non-interleave policy which
2003 * allows the current node (or other explicitly preferred
2004 * node) we only try to allocate from the current/preferred
2005 * node and don't fall back to other nodes, as the cost of
2006 * remote accesses would likely offset THP benefits.
2008 * If the policy is interleave, or does not allow the current
2009 * node in its nodemask, we allocate the standard way.
2011 if (pol->mode == MPOL_PREFERRED &&
2012 !(pol->flags & MPOL_F_LOCAL))
2013 hpage_node = pol->v.preferred_node;
2015 nmask = policy_nodemask(gfp, pol);
2016 if (!nmask || node_isset(hpage_node, *nmask)) {
2019 * We cannot invoke reclaim if __GFP_THISNODE
2020 * is set. Invoking reclaim with
2021 * __GFP_THISNODE set, would cause THP
2022 * allocations to trigger heavy swapping
2023 * despite there may be tons of free memory
2024 * (including potentially plenty of THP
2025 * already available in the buddy) on all the
2028 * At most we could invoke compaction when
2029 * __GFP_THISNODE is set (but we would need to
2030 * refrain from invoking reclaim even if
2031 * compaction returned COMPACT_SKIPPED because
2032 * there wasn't not enough memory to succeed
2033 * compaction). For now just avoid
2034 * __GFP_THISNODE instead of limiting the
2035 * allocation path to a strict and single
2036 * compaction invocation.
2038 * Supposedly if direct reclaim was enabled by
2039 * the caller, the app prefers THP regardless
2040 * of the node it comes from so this would be
2041 * more desiderable behavior than only
2042 * providing THP originated from the local
2043 * node in such case.
2045 if (!(gfp & __GFP_DIRECT_RECLAIM))
2046 gfp |= __GFP_THISNODE;
2047 page = __alloc_pages_node(hpage_node, gfp, order);
2052 nmask = policy_nodemask(gfp, pol);
2053 zl = policy_zonelist(gfp, pol, node);
2054 page = __alloc_pages_nodemask(gfp, order, zl, nmask);
2057 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
2063 * alloc_pages_current - Allocate pages.
2066 * %GFP_USER user allocation,
2067 * %GFP_KERNEL kernel allocation,
2068 * %GFP_HIGHMEM highmem allocation,
2069 * %GFP_FS don't call back into a file system.
2070 * %GFP_ATOMIC don't sleep.
2071 * @order: Power of two of allocation size in pages. 0 is a single page.
2073 * Allocate a page from the kernel page pool. When not in
2074 * interrupt context and apply the current process NUMA policy.
2075 * Returns NULL when no page can be allocated.
2077 * Don't call cpuset_update_task_memory_state() unless
2078 * 1) it's ok to take cpuset_sem (can WAIT), and
2079 * 2) allocating for current task (not interrupt).
2081 struct page *alloc_pages_current(gfp_t gfp, unsigned order)
2083 struct mempolicy *pol = &default_policy;
2085 unsigned int cpuset_mems_cookie;
2087 if (!in_interrupt() && !(gfp & __GFP_THISNODE))
2088 pol = get_task_policy(current);
2091 cpuset_mems_cookie = read_mems_allowed_begin();
2094 * No reference counting needed for current->mempolicy
2095 * nor system default_policy
2097 if (pol->mode == MPOL_INTERLEAVE)
2098 page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
2100 page = __alloc_pages_nodemask(gfp, order,
2101 policy_zonelist(gfp, pol, numa_node_id()),
2102 policy_nodemask(gfp, pol));
2104 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
2109 EXPORT_SYMBOL(alloc_pages_current);
2111 int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
2113 struct mempolicy *pol = mpol_dup(vma_policy(src));
2116 return PTR_ERR(pol);
2117 dst->vm_policy = pol;
2122 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
2123 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
2124 * with the mems_allowed returned by cpuset_mems_allowed(). This
2125 * keeps mempolicies cpuset relative after its cpuset moves. See
2126 * further kernel/cpuset.c update_nodemask().
2128 * current's mempolicy may be rebinded by the other task(the task that changes
2129 * cpuset's mems), so we needn't do rebind work for current task.
2132 /* Slow path of a mempolicy duplicate */
2133 struct mempolicy *__mpol_dup(struct mempolicy *old)
2135 struct mempolicy *new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
2138 return ERR_PTR(-ENOMEM);
2140 /* task's mempolicy is protected by alloc_lock */
2141 if (old == current->mempolicy) {
2144 task_unlock(current);
2148 if (current_cpuset_is_being_rebound()) {
2149 nodemask_t mems = cpuset_mems_allowed(current);
2150 if (new->flags & MPOL_F_REBINDING)
2151 mpol_rebind_policy(new, &mems, MPOL_REBIND_STEP2);
2153 mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE);
2155 atomic_set(&new->refcnt, 1);
2159 /* Slow path of a mempolicy comparison */
2160 bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
2164 if (a->mode != b->mode)
2166 if (a->flags != b->flags)
2168 if (mpol_store_user_nodemask(a))
2169 if (!nodes_equal(a->w.user_nodemask, b->w.user_nodemask))
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)
2181 return a->v.preferred_node == b->v.preferred_node;
2189 * Shared memory backing store policy support.
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 spinlock, which should be held
2194 * for any accesses to the tree.
2197 /* lookup first element intersecting start-end */
2198 /* Caller holds sp->lock */
2199 static struct sp_node *
2200 sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
2202 struct rb_node *n = sp->root.rb_node;
2205 struct sp_node *p = rb_entry(n, struct sp_node, nd);
2207 if (start >= p->end)
2209 else if (end <= p->start)
2217 struct sp_node *w = NULL;
2218 struct rb_node *prev = rb_prev(n);
2221 w = rb_entry(prev, struct sp_node, nd);
2222 if (w->end <= start)
2226 return rb_entry(n, struct sp_node, nd);
2229 /* Insert a new shared policy into the list. */
2230 /* Caller holds sp->lock */
2231 static void sp_insert(struct shared_policy *sp, struct sp_node *new)
2233 struct rb_node **p = &sp->root.rb_node;
2234 struct rb_node *parent = NULL;
2239 nd = rb_entry(parent, struct sp_node, nd);
2240 if (new->start < nd->start)
2242 else if (new->end > nd->end)
2243 p = &(*p)->rb_right;
2247 rb_link_node(&new->nd, parent, p);
2248 rb_insert_color(&new->nd, &sp->root);
2249 pr_debug("inserting %lx-%lx: %d\n", new->start, new->end,
2250 new->policy ? new->policy->mode : 0);
2253 /* Find shared policy intersecting idx */
2255 mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
2257 struct mempolicy *pol = NULL;
2260 if (!sp->root.rb_node)
2262 spin_lock(&sp->lock);
2263 sn = sp_lookup(sp, idx, idx+1);
2265 mpol_get(sn->policy);
2268 spin_unlock(&sp->lock);
2272 static void sp_free(struct sp_node *n)
2274 mpol_put(n->policy);
2275 kmem_cache_free(sn_cache, n);
2279 * mpol_misplaced - check whether current page node is valid in policy
2281 * @page: page to be checked
2282 * @vma: vm area where page mapped
2283 * @addr: virtual address where page mapped
2285 * Lookup current policy node id for vma,addr and "compare to" page's
2289 * -1 - not misplaced, page is in the right node
2290 * node - node id where the page should be
2292 * Policy determination "mimics" alloc_page_vma().
2293 * Called from fault path where we know the vma and faulting address.
2295 int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long addr)
2297 struct mempolicy *pol;
2299 int curnid = page_to_nid(page);
2300 unsigned long pgoff;
2301 int thiscpu = raw_smp_processor_id();
2302 int thisnid = cpu_to_node(thiscpu);
2308 pol = get_vma_policy(vma, addr);
2309 if (!(pol->flags & MPOL_F_MOF))
2312 switch (pol->mode) {
2313 case MPOL_INTERLEAVE:
2314 BUG_ON(addr >= vma->vm_end);
2315 BUG_ON(addr < vma->vm_start);
2317 pgoff = vma->vm_pgoff;
2318 pgoff += (addr - vma->vm_start) >> PAGE_SHIFT;
2319 polnid = offset_il_node(pol, vma, pgoff);
2322 case MPOL_PREFERRED:
2323 if (pol->flags & MPOL_F_LOCAL)
2324 polnid = numa_node_id();
2326 polnid = pol->v.preferred_node;
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].
2336 if (node_isset(curnid, pol->v.nodes))
2338 (void)first_zones_zonelist(
2339 node_zonelist(numa_node_id(), GFP_HIGHUSER),
2340 gfp_zone(GFP_HIGHUSER),
2341 &pol->v.nodes, &zone);
2342 polnid = zone->node;
2349 /* Migrate the page towards the node whose CPU is referencing it */
2350 if (pol->flags & MPOL_F_MORON) {
2353 if (!should_numa_migrate_memory(current, page, curnid, thiscpu))
2357 if (curnid != polnid)
2365 static void sp_delete(struct shared_policy *sp, struct sp_node *n)
2367 pr_debug("deleting %lx-l%lx\n", n->start, n->end);
2368 rb_erase(&n->nd, &sp->root);
2372 static void sp_node_init(struct sp_node *node, unsigned long start,
2373 unsigned long end, struct mempolicy *pol)
2375 node->start = start;
2380 static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
2381 struct mempolicy *pol)
2384 struct mempolicy *newpol;
2386 n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
2390 newpol = mpol_dup(pol);
2391 if (IS_ERR(newpol)) {
2392 kmem_cache_free(sn_cache, n);
2395 newpol->flags |= MPOL_F_SHARED;
2396 sp_node_init(n, start, end, newpol);
2401 /* Replace a policy range. */
2402 static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
2403 unsigned long end, struct sp_node *new)
2406 struct sp_node *n_new = NULL;
2407 struct mempolicy *mpol_new = NULL;
2411 spin_lock(&sp->lock);
2412 n = sp_lookup(sp, start, end);
2413 /* Take care of old policies in the same range. */
2414 while (n && n->start < end) {
2415 struct rb_node *next = rb_next(&n->nd);
2416 if (n->start >= start) {
2422 /* Old policy spanning whole new range. */
2427 *mpol_new = *n->policy;
2428 atomic_set(&mpol_new->refcnt, 1);
2429 sp_node_init(n_new, end, n->end, mpol_new);
2431 sp_insert(sp, n_new);
2440 n = rb_entry(next, struct sp_node, nd);
2444 spin_unlock(&sp->lock);
2451 kmem_cache_free(sn_cache, n_new);
2456 spin_unlock(&sp->lock);
2458 n_new = kmem_cache_alloc(sn_cache, GFP_KERNEL);
2461 mpol_new = kmem_cache_alloc(policy_cache, GFP_KERNEL);
2468 * mpol_shared_policy_init - initialize shared policy for inode
2469 * @sp: pointer to inode shared policy
2470 * @mpol: struct mempolicy to install
2472 * Install non-NULL @mpol in inode's shared policy rb-tree.
2473 * On entry, the current task has a reference on a non-NULL @mpol.
2474 * This must be released on exit.
2475 * This is called at get_inode() calls and we can use GFP_KERNEL.
2477 void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
2481 sp->root = RB_ROOT; /* empty tree == default mempolicy */
2482 spin_lock_init(&sp->lock);
2485 struct vm_area_struct pvma;
2486 struct mempolicy *new;
2487 NODEMASK_SCRATCH(scratch);
2491 /* contextualize the tmpfs mount point mempolicy */
2492 new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
2494 goto free_scratch; /* no valid nodemask intersection */
2497 ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
2498 task_unlock(current);
2502 /* Create pseudo-vma that contains just the policy */
2503 memset(&pvma, 0, sizeof(struct vm_area_struct));
2504 pvma.vm_end = TASK_SIZE; /* policy covers entire file */
2505 mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
2508 mpol_put(new); /* drop initial ref */
2510 NODEMASK_SCRATCH_FREE(scratch);
2512 mpol_put(mpol); /* drop our incoming ref on sb mpol */
2516 int mpol_set_shared_policy(struct shared_policy *info,
2517 struct vm_area_struct *vma, struct mempolicy *npol)
2520 struct sp_node *new = NULL;
2521 unsigned long sz = vma_pages(vma);
2523 pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
2525 sz, npol ? npol->mode : -1,
2526 npol ? npol->flags : -1,
2527 npol ? nodes_addr(npol->v.nodes)[0] : NUMA_NO_NODE);
2530 new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
2534 err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
2540 /* Free a backing policy store on inode delete. */
2541 void mpol_free_shared_policy(struct shared_policy *p)
2544 struct rb_node *next;
2546 if (!p->root.rb_node)
2548 spin_lock(&p->lock);
2549 next = rb_first(&p->root);
2551 n = rb_entry(next, struct sp_node, nd);
2552 next = rb_next(&n->nd);
2555 spin_unlock(&p->lock);
2558 #ifdef CONFIG_NUMA_BALANCING
2559 static int __initdata numabalancing_override;
2561 static void __init check_numabalancing_enable(void)
2563 bool numabalancing_default = false;
2565 if (IS_ENABLED(CONFIG_NUMA_BALANCING_DEFAULT_ENABLED))
2566 numabalancing_default = true;
2568 /* Parsed by setup_numabalancing. override == 1 enables, -1 disables */
2569 if (numabalancing_override)
2570 set_numabalancing_state(numabalancing_override == 1);
2572 if (num_online_nodes() > 1 && !numabalancing_override) {
2573 pr_info("%s automatic NUMA balancing. Configure with numa_balancing= or the kernel.numa_balancing sysctl\n",
2574 numabalancing_default ? "Enabling" : "Disabling");
2575 set_numabalancing_state(numabalancing_default);
2579 static int __init setup_numabalancing(char *str)
2585 if (!strcmp(str, "enable")) {
2586 numabalancing_override = 1;
2588 } else if (!strcmp(str, "disable")) {
2589 numabalancing_override = -1;
2594 pr_warn("Unable to parse numa_balancing=\n");
2598 __setup("numa_balancing=", setup_numabalancing);
2600 static inline void __init check_numabalancing_enable(void)
2603 #endif /* CONFIG_NUMA_BALANCING */
2605 /* assumes fs == KERNEL_DS */
2606 void __init numa_policy_init(void)
2608 nodemask_t interleave_nodes;
2609 unsigned long largest = 0;
2610 int nid, prefer = 0;
2612 policy_cache = kmem_cache_create("numa_policy",
2613 sizeof(struct mempolicy),
2614 0, SLAB_PANIC, NULL);
2616 sn_cache = kmem_cache_create("shared_policy_node",
2617 sizeof(struct sp_node),
2618 0, SLAB_PANIC, NULL);
2620 for_each_node(nid) {
2621 preferred_node_policy[nid] = (struct mempolicy) {
2622 .refcnt = ATOMIC_INIT(1),
2623 .mode = MPOL_PREFERRED,
2624 .flags = MPOL_F_MOF | MPOL_F_MORON,
2625 .v = { .preferred_node = nid, },
2630 * Set interleaving policy for system init. Interleaving is only
2631 * enabled across suitably sized nodes (default is >= 16MB), or
2632 * fall back to the largest node if they're all smaller.
2634 nodes_clear(interleave_nodes);
2635 for_each_node_state(nid, N_MEMORY) {
2636 unsigned long total_pages = node_present_pages(nid);
2638 /* Preserve the largest node */
2639 if (largest < total_pages) {
2640 largest = total_pages;
2644 /* Interleave this node? */
2645 if ((total_pages << PAGE_SHIFT) >= (16 << 20))
2646 node_set(nid, interleave_nodes);
2649 /* All too small, use the largest */
2650 if (unlikely(nodes_empty(interleave_nodes)))
2651 node_set(prefer, interleave_nodes);
2653 if (do_set_mempolicy(MPOL_INTERLEAVE, 0, &interleave_nodes))
2654 pr_err("%s: interleaving failed\n", __func__);
2656 check_numabalancing_enable();
2659 /* Reset policy of current process to default */
2660 void numa_default_policy(void)
2662 do_set_mempolicy(MPOL_DEFAULT, 0, NULL);
2666 * Parse and format mempolicy from/to strings
2670 * "local" is implemented internally by MPOL_PREFERRED with MPOL_F_LOCAL flag.
2672 static const char * const policy_modes[] =
2674 [MPOL_DEFAULT] = "default",
2675 [MPOL_PREFERRED] = "prefer",
2676 [MPOL_BIND] = "bind",
2677 [MPOL_INTERLEAVE] = "interleave",
2678 [MPOL_LOCAL] = "local",
2684 * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option.
2685 * @str: string containing mempolicy to parse
2686 * @mpol: pointer to struct mempolicy pointer, returned on success.
2689 * <mode>[=<flags>][:<nodelist>]
2691 * On success, returns 0, else 1
2693 int mpol_parse_str(char *str, struct mempolicy **mpol)
2695 struct mempolicy *new = NULL;
2696 unsigned short mode;
2697 unsigned short mode_flags;
2699 char *nodelist = strchr(str, ':');
2700 char *flags = strchr(str, '=');
2704 *flags++ = '\0'; /* terminate mode string */
2707 /* NUL-terminate mode or flags string */
2709 if (nodelist_parse(nodelist, nodes))
2711 if (!nodes_subset(nodes, node_states[N_MEMORY]))
2716 for (mode = 0; mode < MPOL_MAX; mode++) {
2717 if (!strcmp(str, policy_modes[mode])) {
2721 if (mode >= MPOL_MAX)
2725 case MPOL_PREFERRED:
2727 * Insist on a nodelist of one node only
2730 char *rest = nodelist;
2731 while (isdigit(*rest))
2737 case MPOL_INTERLEAVE:
2739 * Default to online nodes with memory if no nodelist
2742 nodes = node_states[N_MEMORY];
2746 * Don't allow a nodelist; mpol_new() checks flags
2750 mode = MPOL_PREFERRED;
2754 * Insist on a empty nodelist
2761 * Insist on a nodelist
2770 * Currently, we only support two mutually exclusive
2773 if (!strcmp(flags, "static"))
2774 mode_flags |= MPOL_F_STATIC_NODES;
2775 else if (!strcmp(flags, "relative"))
2776 mode_flags |= MPOL_F_RELATIVE_NODES;
2781 new = mpol_new(mode, mode_flags, &nodes);
2786 * Save nodes for mpol_to_str() to show the tmpfs mount options
2787 * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo.
2789 if (mode != MPOL_PREFERRED)
2790 new->v.nodes = nodes;
2792 new->v.preferred_node = first_node(nodes);
2794 new->flags |= MPOL_F_LOCAL;
2797 * Save nodes for contextualization: this will be used to "clone"
2798 * the mempolicy in a specific context [cpuset] at a later time.
2800 new->w.user_nodemask = nodes;
2805 /* Restore string for error message */
2814 #endif /* CONFIG_TMPFS */
2817 * mpol_to_str - format a mempolicy structure for printing
2818 * @buffer: to contain formatted mempolicy string
2819 * @maxlen: length of @buffer
2820 * @pol: pointer to mempolicy to be formatted
2822 * Convert @pol into a string. If @buffer is too short, truncate the string.
2823 * Recommend a @maxlen of at least 32 for the longest mode, "interleave", the
2824 * longest flag, "relative", and to display at least a few node ids.
2826 void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
2829 nodemask_t nodes = NODE_MASK_NONE;
2830 unsigned short mode = MPOL_DEFAULT;
2831 unsigned short flags = 0;
2833 if (pol && pol != &default_policy && !(pol->flags & MPOL_F_MORON)) {
2841 case MPOL_PREFERRED:
2842 if (flags & MPOL_F_LOCAL)
2845 node_set(pol->v.preferred_node, nodes);
2848 case MPOL_INTERLEAVE:
2849 nodes = pol->v.nodes;
2853 snprintf(p, maxlen, "unknown");
2857 p += snprintf(p, maxlen, "%s", policy_modes[mode]);
2859 if (flags & MPOL_MODE_FLAGS) {
2860 p += snprintf(p, buffer + maxlen - p, "=");
2863 * Currently, the only defined flags are mutually exclusive
2865 if (flags & MPOL_F_STATIC_NODES)
2866 p += snprintf(p, buffer + maxlen - p, "static");
2867 else if (flags & MPOL_F_RELATIVE_NODES)
2868 p += snprintf(p, buffer + maxlen - p, "relative");
2871 if (!nodes_empty(nodes))
2872 p += scnprintf(p, buffer + maxlen - p, ":%*pbl",
2873 nodemask_pr_args(&nodes));