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 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
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 #include <linux/mempolicy.h>
70 #include <linux/highmem.h>
71 #include <linux/hugetlb.h>
72 #include <linux/kernel.h>
73 #include <linux/sched.h>
74 #include <linux/nodemask.h>
75 #include <linux/cpuset.h>
76 #include <linux/gfp.h>
77 #include <linux/slab.h>
78 #include <linux/string.h>
79 #include <linux/module.h>
80 #include <linux/nsproxy.h>
81 #include <linux/interrupt.h>
82 #include <linux/init.h>
83 #include <linux/compat.h>
84 #include <linux/swap.h>
85 #include <linux/seq_file.h>
86 #include <linux/proc_fs.h>
87 #include <linux/migrate.h>
88 #include <linux/rmap.h>
89 #include <linux/security.h>
90 #include <linux/syscalls.h>
91 #include <linux/ctype.h>
93 #include <asm/tlbflush.h>
94 #include <asm/uaccess.h>
99 #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
100 #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
101 #define MPOL_MF_STATS (MPOL_MF_INTERNAL << 2) /* Gather statistics */
103 static struct kmem_cache
*policy_cache
;
104 static struct kmem_cache
*sn_cache
;
106 /* Highest zone. An specific allocation for a zone below that is not
108 enum zone_type policy_zone
= 0;
111 * run-time system-wide default policy => local allocation
113 struct mempolicy default_policy
= {
114 .refcnt
= ATOMIC_INIT(1), /* never free it */
115 .mode
= MPOL_PREFERRED
,
116 .flags
= MPOL_F_LOCAL
,
119 static const struct mempolicy_operations
{
120 int (*create
)(struct mempolicy
*pol
, const nodemask_t
*nodes
);
121 void (*rebind
)(struct mempolicy
*pol
, const nodemask_t
*nodes
);
122 } mpol_ops
[MPOL_MAX
];
124 /* Check that the nodemask contains at least one populated zone */
125 static int is_valid_nodemask(const nodemask_t
*nodemask
)
129 /* Check that there is something useful in this mask */
132 for_each_node_mask(nd
, *nodemask
) {
135 for (k
= 0; k
<= policy_zone
; k
++) {
136 z
= &NODE_DATA(nd
)->node_zones
[k
];
137 if (z
->present_pages
> 0)
145 static inline int mpol_store_user_nodemask(const struct mempolicy
*pol
)
147 return pol
->flags
& (MPOL_F_STATIC_NODES
| MPOL_F_RELATIVE_NODES
);
150 static void mpol_relative_nodemask(nodemask_t
*ret
, const nodemask_t
*orig
,
151 const nodemask_t
*rel
)
154 nodes_fold(tmp
, *orig
, nodes_weight(*rel
));
155 nodes_onto(*ret
, tmp
, *rel
);
158 static int mpol_new_interleave(struct mempolicy
*pol
, const nodemask_t
*nodes
)
160 if (nodes_empty(*nodes
))
162 pol
->v
.nodes
= *nodes
;
166 static int mpol_new_preferred(struct mempolicy
*pol
, const nodemask_t
*nodes
)
169 pol
->flags
|= MPOL_F_LOCAL
; /* local allocation */
170 else if (nodes_empty(*nodes
))
171 return -EINVAL
; /* no allowed nodes */
173 pol
->v
.preferred_node
= first_node(*nodes
);
177 static int mpol_new_bind(struct mempolicy
*pol
, const nodemask_t
*nodes
)
179 if (!is_valid_nodemask(nodes
))
181 pol
->v
.nodes
= *nodes
;
185 /* Create a new policy */
186 static struct mempolicy
*mpol_new(unsigned short mode
, unsigned short flags
,
189 struct mempolicy
*policy
;
190 nodemask_t cpuset_context_nmask
;
193 pr_debug("setting mode %d flags %d nodes[0] %lx\n",
194 mode
, flags
, nodes
? nodes_addr(*nodes
)[0] : -1);
196 if (mode
== MPOL_DEFAULT
) {
197 if (nodes
&& !nodes_empty(*nodes
))
198 return ERR_PTR(-EINVAL
);
199 return NULL
; /* simply delete any existing policy */
204 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
205 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
206 * All other modes require a valid pointer to a non-empty nodemask.
208 if (mode
== MPOL_PREFERRED
) {
209 if (nodes_empty(*nodes
)) {
210 if (((flags
& MPOL_F_STATIC_NODES
) ||
211 (flags
& MPOL_F_RELATIVE_NODES
)))
212 return ERR_PTR(-EINVAL
);
213 nodes
= NULL
; /* flag local alloc */
215 } else if (nodes_empty(*nodes
))
216 return ERR_PTR(-EINVAL
);
217 policy
= kmem_cache_alloc(policy_cache
, GFP_KERNEL
);
219 return ERR_PTR(-ENOMEM
);
220 atomic_set(&policy
->refcnt
, 1);
222 policy
->flags
= flags
;
226 * cpuset related setup doesn't apply to local allocation
228 cpuset_update_task_memory_state();
229 if (flags
& MPOL_F_RELATIVE_NODES
)
230 mpol_relative_nodemask(&cpuset_context_nmask
, nodes
,
231 &cpuset_current_mems_allowed
);
233 nodes_and(cpuset_context_nmask
, *nodes
,
234 cpuset_current_mems_allowed
);
235 if (mpol_store_user_nodemask(policy
))
236 policy
->w
.user_nodemask
= *nodes
;
238 policy
->w
.cpuset_mems_allowed
=
239 cpuset_mems_allowed(current
);
242 ret
= mpol_ops
[mode
].create(policy
,
243 nodes
? &cpuset_context_nmask
: NULL
);
245 kmem_cache_free(policy_cache
, policy
);
251 /* Slow path of a mpol destructor. */
252 void __mpol_put(struct mempolicy
*p
)
254 if (!atomic_dec_and_test(&p
->refcnt
))
256 kmem_cache_free(policy_cache
, p
);
259 static void mpol_rebind_default(struct mempolicy
*pol
, const nodemask_t
*nodes
)
263 static void mpol_rebind_nodemask(struct mempolicy
*pol
,
264 const nodemask_t
*nodes
)
268 if (pol
->flags
& MPOL_F_STATIC_NODES
)
269 nodes_and(tmp
, pol
->w
.user_nodemask
, *nodes
);
270 else if (pol
->flags
& MPOL_F_RELATIVE_NODES
)
271 mpol_relative_nodemask(&tmp
, &pol
->w
.user_nodemask
, nodes
);
273 nodes_remap(tmp
, pol
->v
.nodes
, pol
->w
.cpuset_mems_allowed
,
275 pol
->w
.cpuset_mems_allowed
= *nodes
;
279 if (!node_isset(current
->il_next
, tmp
)) {
280 current
->il_next
= next_node(current
->il_next
, tmp
);
281 if (current
->il_next
>= MAX_NUMNODES
)
282 current
->il_next
= first_node(tmp
);
283 if (current
->il_next
>= MAX_NUMNODES
)
284 current
->il_next
= numa_node_id();
288 static void mpol_rebind_preferred(struct mempolicy
*pol
,
289 const nodemask_t
*nodes
)
293 if (pol
->flags
& MPOL_F_STATIC_NODES
) {
294 int node
= first_node(pol
->w
.user_nodemask
);
296 if (node_isset(node
, *nodes
)) {
297 pol
->v
.preferred_node
= node
;
298 pol
->flags
&= ~MPOL_F_LOCAL
;
300 pol
->flags
|= MPOL_F_LOCAL
;
301 } else if (pol
->flags
& MPOL_F_RELATIVE_NODES
) {
302 mpol_relative_nodemask(&tmp
, &pol
->w
.user_nodemask
, nodes
);
303 pol
->v
.preferred_node
= first_node(tmp
);
304 } else if (!(pol
->flags
& MPOL_F_LOCAL
)) {
305 pol
->v
.preferred_node
= node_remap(pol
->v
.preferred_node
,
306 pol
->w
.cpuset_mems_allowed
,
308 pol
->w
.cpuset_mems_allowed
= *nodes
;
312 /* Migrate a policy to a different set of nodes */
313 static void mpol_rebind_policy(struct mempolicy
*pol
,
314 const nodemask_t
*newmask
)
318 if (!mpol_store_user_nodemask(pol
) &&
319 nodes_equal(pol
->w
.cpuset_mems_allowed
, *newmask
))
321 mpol_ops
[pol
->mode
].rebind(pol
, newmask
);
325 * Wrapper for mpol_rebind_policy() that just requires task
326 * pointer, and updates task mempolicy.
329 void mpol_rebind_task(struct task_struct
*tsk
, const nodemask_t
*new)
331 mpol_rebind_policy(tsk
->mempolicy
, new);
335 * Rebind each vma in mm to new nodemask.
337 * Call holding a reference to mm. Takes mm->mmap_sem during call.
340 void mpol_rebind_mm(struct mm_struct
*mm
, nodemask_t
*new)
342 struct vm_area_struct
*vma
;
344 down_write(&mm
->mmap_sem
);
345 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
)
346 mpol_rebind_policy(vma
->vm_policy
, new);
347 up_write(&mm
->mmap_sem
);
350 static const struct mempolicy_operations mpol_ops
[MPOL_MAX
] = {
352 .rebind
= mpol_rebind_default
,
354 [MPOL_INTERLEAVE
] = {
355 .create
= mpol_new_interleave
,
356 .rebind
= mpol_rebind_nodemask
,
359 .create
= mpol_new_preferred
,
360 .rebind
= mpol_rebind_preferred
,
363 .create
= mpol_new_bind
,
364 .rebind
= mpol_rebind_nodemask
,
368 static void gather_stats(struct page
*, void *, int pte_dirty
);
369 static void migrate_page_add(struct page
*page
, struct list_head
*pagelist
,
370 unsigned long flags
);
372 /* Scan through pages checking if pages follow certain conditions. */
373 static int check_pte_range(struct vm_area_struct
*vma
, pmd_t
*pmd
,
374 unsigned long addr
, unsigned long end
,
375 const nodemask_t
*nodes
, unsigned long flags
,
382 orig_pte
= pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
387 if (!pte_present(*pte
))
389 page
= vm_normal_page(vma
, addr
, *pte
);
393 * The check for PageReserved here is important to avoid
394 * handling zero pages and other pages that may have been
395 * marked special by the system.
397 * If the PageReserved would not be checked here then f.e.
398 * the location of the zero page could have an influence
399 * on MPOL_MF_STRICT, zero pages would be counted for
400 * the per node stats, and there would be useless attempts
401 * to put zero pages on the migration list.
403 if (PageReserved(page
))
405 nid
= page_to_nid(page
);
406 if (node_isset(nid
, *nodes
) == !!(flags
& MPOL_MF_INVERT
))
409 if (flags
& MPOL_MF_STATS
)
410 gather_stats(page
, private, pte_dirty(*pte
));
411 else if (flags
& (MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
))
412 migrate_page_add(page
, private, flags
);
415 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
416 pte_unmap_unlock(orig_pte
, ptl
);
420 static inline int check_pmd_range(struct vm_area_struct
*vma
, pud_t
*pud
,
421 unsigned long addr
, unsigned long end
,
422 const nodemask_t
*nodes
, unsigned long flags
,
428 pmd
= pmd_offset(pud
, addr
);
430 next
= pmd_addr_end(addr
, end
);
431 if (pmd_none_or_clear_bad(pmd
))
433 if (check_pte_range(vma
, pmd
, addr
, next
, nodes
,
436 } while (pmd
++, addr
= next
, addr
!= end
);
440 static inline int check_pud_range(struct vm_area_struct
*vma
, pgd_t
*pgd
,
441 unsigned long addr
, unsigned long end
,
442 const nodemask_t
*nodes
, unsigned long flags
,
448 pud
= pud_offset(pgd
, addr
);
450 next
= pud_addr_end(addr
, end
);
451 if (pud_none_or_clear_bad(pud
))
453 if (check_pmd_range(vma
, pud
, addr
, next
, nodes
,
456 } while (pud
++, addr
= next
, addr
!= end
);
460 static inline int check_pgd_range(struct vm_area_struct
*vma
,
461 unsigned long addr
, unsigned long end
,
462 const nodemask_t
*nodes
, unsigned long flags
,
468 pgd
= pgd_offset(vma
->vm_mm
, addr
);
470 next
= pgd_addr_end(addr
, end
);
471 if (pgd_none_or_clear_bad(pgd
))
473 if (check_pud_range(vma
, pgd
, addr
, next
, nodes
,
476 } while (pgd
++, addr
= next
, addr
!= end
);
481 * Check if all pages in a range are on a set of nodes.
482 * If pagelist != NULL then isolate pages from the LRU and
483 * put them on the pagelist.
485 static struct vm_area_struct
*
486 check_range(struct mm_struct
*mm
, unsigned long start
, unsigned long end
,
487 const nodemask_t
*nodes
, unsigned long flags
, void *private)
490 struct vm_area_struct
*first
, *vma
, *prev
;
493 first
= find_vma(mm
, start
);
495 return ERR_PTR(-EFAULT
);
497 for (vma
= first
; vma
&& vma
->vm_start
< end
; vma
= vma
->vm_next
) {
498 if (!(flags
& MPOL_MF_DISCONTIG_OK
)) {
499 if (!vma
->vm_next
&& vma
->vm_end
< end
)
500 return ERR_PTR(-EFAULT
);
501 if (prev
&& prev
->vm_end
< vma
->vm_start
)
502 return ERR_PTR(-EFAULT
);
504 if (!is_vm_hugetlb_page(vma
) &&
505 ((flags
& MPOL_MF_STRICT
) ||
506 ((flags
& (MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
)) &&
507 vma_migratable(vma
)))) {
508 unsigned long endvma
= vma
->vm_end
;
512 if (vma
->vm_start
> start
)
513 start
= vma
->vm_start
;
514 err
= check_pgd_range(vma
, start
, endvma
, nodes
,
517 first
= ERR_PTR(err
);
526 /* Apply policy to a single VMA */
527 static int policy_vma(struct vm_area_struct
*vma
, struct mempolicy
*new)
530 struct mempolicy
*old
= vma
->vm_policy
;
532 pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
533 vma
->vm_start
, vma
->vm_end
, vma
->vm_pgoff
,
534 vma
->vm_ops
, vma
->vm_file
,
535 vma
->vm_ops
? vma
->vm_ops
->set_policy
: NULL
);
537 if (vma
->vm_ops
&& vma
->vm_ops
->set_policy
)
538 err
= vma
->vm_ops
->set_policy(vma
, new);
541 vma
->vm_policy
= new;
547 /* Step 2: apply policy to a range and do splits. */
548 static int mbind_range(struct vm_area_struct
*vma
, unsigned long start
,
549 unsigned long end
, struct mempolicy
*new)
551 struct vm_area_struct
*next
;
555 for (; vma
&& vma
->vm_start
< end
; vma
= next
) {
557 if (vma
->vm_start
< start
)
558 err
= split_vma(vma
->vm_mm
, vma
, start
, 1);
559 if (!err
&& vma
->vm_end
> end
)
560 err
= split_vma(vma
->vm_mm
, vma
, end
, 0);
562 err
= policy_vma(vma
, new);
570 * Update task->flags PF_MEMPOLICY bit: set iff non-default
571 * mempolicy. Allows more rapid checking of this (combined perhaps
572 * with other PF_* flag bits) on memory allocation hot code paths.
574 * If called from outside this file, the task 'p' should -only- be
575 * a newly forked child not yet visible on the task list, because
576 * manipulating the task flags of a visible task is not safe.
578 * The above limitation is why this routine has the funny name
579 * mpol_fix_fork_child_flag().
581 * It is also safe to call this with a task pointer of current,
582 * which the static wrapper mpol_set_task_struct_flag() does,
583 * for use within this file.
586 void mpol_fix_fork_child_flag(struct task_struct
*p
)
589 p
->flags
|= PF_MEMPOLICY
;
591 p
->flags
&= ~PF_MEMPOLICY
;
594 static void mpol_set_task_struct_flag(void)
596 mpol_fix_fork_child_flag(current
);
599 /* Set the process memory policy */
600 static long do_set_mempolicy(unsigned short mode
, unsigned short flags
,
603 struct mempolicy
*new;
604 struct mm_struct
*mm
= current
->mm
;
606 new = mpol_new(mode
, flags
, nodes
);
611 * prevent changing our mempolicy while show_numa_maps()
613 * Note: do_set_mempolicy() can be called at init time
617 down_write(&mm
->mmap_sem
);
618 mpol_put(current
->mempolicy
);
619 current
->mempolicy
= new;
620 mpol_set_task_struct_flag();
621 if (new && new->mode
== MPOL_INTERLEAVE
&&
622 nodes_weight(new->v
.nodes
))
623 current
->il_next
= first_node(new->v
.nodes
);
625 up_write(&mm
->mmap_sem
);
631 * Return nodemask for policy for get_mempolicy() query
633 static void get_policy_nodemask(struct mempolicy
*p
, nodemask_t
*nodes
)
636 if (p
== &default_policy
)
642 case MPOL_INTERLEAVE
:
646 if (!(p
->flags
& MPOL_F_LOCAL
))
647 node_set(p
->v
.preferred_node
, *nodes
);
648 /* else return empty node mask for local allocation */
655 static int lookup_node(struct mm_struct
*mm
, unsigned long addr
)
660 err
= get_user_pages(current
, mm
, addr
& PAGE_MASK
, 1, 0, 0, &p
, NULL
);
662 err
= page_to_nid(p
);
668 /* Retrieve NUMA policy */
669 static long do_get_mempolicy(int *policy
, nodemask_t
*nmask
,
670 unsigned long addr
, unsigned long flags
)
673 struct mm_struct
*mm
= current
->mm
;
674 struct vm_area_struct
*vma
= NULL
;
675 struct mempolicy
*pol
= current
->mempolicy
;
677 cpuset_update_task_memory_state();
679 ~(unsigned long)(MPOL_F_NODE
|MPOL_F_ADDR
|MPOL_F_MEMS_ALLOWED
))
682 if (flags
& MPOL_F_MEMS_ALLOWED
) {
683 if (flags
& (MPOL_F_NODE
|MPOL_F_ADDR
))
685 *policy
= 0; /* just so it's initialized */
686 *nmask
= cpuset_current_mems_allowed
;
690 if (flags
& MPOL_F_ADDR
) {
692 * Do NOT fall back to task policy if the
693 * vma/shared policy at addr is NULL. We
694 * want to return MPOL_DEFAULT in this case.
696 down_read(&mm
->mmap_sem
);
697 vma
= find_vma_intersection(mm
, addr
, addr
+1);
699 up_read(&mm
->mmap_sem
);
702 if (vma
->vm_ops
&& vma
->vm_ops
->get_policy
)
703 pol
= vma
->vm_ops
->get_policy(vma
, addr
);
705 pol
= vma
->vm_policy
;
710 pol
= &default_policy
; /* indicates default behavior */
712 if (flags
& MPOL_F_NODE
) {
713 if (flags
& MPOL_F_ADDR
) {
714 err
= lookup_node(mm
, addr
);
718 } else if (pol
== current
->mempolicy
&&
719 pol
->mode
== MPOL_INTERLEAVE
) {
720 *policy
= current
->il_next
;
726 *policy
= pol
== &default_policy
? MPOL_DEFAULT
:
729 * Internal mempolicy flags must be masked off before exposing
730 * the policy to userspace.
732 *policy
|= (pol
->flags
& MPOL_MODE_FLAGS
);
736 up_read(¤t
->mm
->mmap_sem
);
742 get_policy_nodemask(pol
, nmask
);
747 up_read(¤t
->mm
->mmap_sem
);
751 #ifdef CONFIG_MIGRATION
755 static void migrate_page_add(struct page
*page
, struct list_head
*pagelist
,
759 * Avoid migrating a page that is shared with others.
761 if ((flags
& MPOL_MF_MOVE_ALL
) || page_mapcount(page
) == 1) {
762 if (!isolate_lru_page(page
)) {
763 list_add_tail(&page
->lru
, pagelist
);
768 static struct page
*new_node_page(struct page
*page
, unsigned long node
, int **x
)
770 return alloc_pages_node(node
, GFP_HIGHUSER_MOVABLE
, 0);
774 * Migrate pages from one node to a target node.
775 * Returns error or the number of pages not migrated.
777 static int migrate_to_node(struct mm_struct
*mm
, int source
, int dest
,
785 node_set(source
, nmask
);
787 check_range(mm
, mm
->mmap
->vm_start
, TASK_SIZE
, &nmask
,
788 flags
| MPOL_MF_DISCONTIG_OK
, &pagelist
);
790 if (!list_empty(&pagelist
))
791 err
= migrate_pages(&pagelist
, new_node_page
, dest
);
797 * Move pages between the two nodesets so as to preserve the physical
798 * layout as much as possible.
800 * Returns the number of page that could not be moved.
802 int do_migrate_pages(struct mm_struct
*mm
,
803 const nodemask_t
*from_nodes
, const nodemask_t
*to_nodes
, int flags
)
809 err
= migrate_prep();
813 down_read(&mm
->mmap_sem
);
815 err
= migrate_vmas(mm
, from_nodes
, to_nodes
, flags
);
820 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
821 * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
822 * bit in 'tmp', and return that <source, dest> pair for migration.
823 * The pair of nodemasks 'to' and 'from' define the map.
825 * If no pair of bits is found that way, fallback to picking some
826 * pair of 'source' and 'dest' bits that are not the same. If the
827 * 'source' and 'dest' bits are the same, this represents a node
828 * that will be migrating to itself, so no pages need move.
830 * If no bits are left in 'tmp', or if all remaining bits left
831 * in 'tmp' correspond to the same bit in 'to', return false
832 * (nothing left to migrate).
834 * This lets us pick a pair of nodes to migrate between, such that
835 * if possible the dest node is not already occupied by some other
836 * source node, minimizing the risk of overloading the memory on a
837 * node that would happen if we migrated incoming memory to a node
838 * before migrating outgoing memory source that same node.
840 * A single scan of tmp is sufficient. As we go, we remember the
841 * most recent <s, d> pair that moved (s != d). If we find a pair
842 * that not only moved, but what's better, moved to an empty slot
843 * (d is not set in tmp), then we break out then, with that pair.
844 * Otherwise when we finish scannng from_tmp, we at least have the
845 * most recent <s, d> pair that moved. If we get all the way through
846 * the scan of tmp without finding any node that moved, much less
847 * moved to an empty node, then there is nothing left worth migrating.
851 while (!nodes_empty(tmp
)) {
856 for_each_node_mask(s
, tmp
) {
857 d
= node_remap(s
, *from_nodes
, *to_nodes
);
861 source
= s
; /* Node moved. Memorize */
864 /* dest not in remaining from nodes? */
865 if (!node_isset(dest
, tmp
))
871 node_clear(source
, tmp
);
872 err
= migrate_to_node(mm
, source
, dest
, flags
);
879 up_read(&mm
->mmap_sem
);
887 * Allocate a new page for page migration based on vma policy.
888 * Start assuming that page is mapped by vma pointed to by @private.
889 * Search forward from there, if not. N.B., this assumes that the
890 * list of pages handed to migrate_pages()--which is how we get here--
891 * is in virtual address order.
893 static struct page
*new_vma_page(struct page
*page
, unsigned long private, int **x
)
895 struct vm_area_struct
*vma
= (struct vm_area_struct
*)private;
896 unsigned long uninitialized_var(address
);
899 address
= page_address_in_vma(page
, vma
);
900 if (address
!= -EFAULT
)
906 * if !vma, alloc_page_vma() will use task or system default policy
908 return alloc_page_vma(GFP_HIGHUSER_MOVABLE
, vma
, address
);
912 static void migrate_page_add(struct page
*page
, struct list_head
*pagelist
,
917 int do_migrate_pages(struct mm_struct
*mm
,
918 const nodemask_t
*from_nodes
, const nodemask_t
*to_nodes
, int flags
)
923 static struct page
*new_vma_page(struct page
*page
, unsigned long private, int **x
)
929 static long do_mbind(unsigned long start
, unsigned long len
,
930 unsigned short mode
, unsigned short mode_flags
,
931 nodemask_t
*nmask
, unsigned long flags
)
933 struct vm_area_struct
*vma
;
934 struct mm_struct
*mm
= current
->mm
;
935 struct mempolicy
*new;
940 if (flags
& ~(unsigned long)(MPOL_MF_STRICT
|
941 MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
))
943 if ((flags
& MPOL_MF_MOVE_ALL
) && !capable(CAP_SYS_NICE
))
946 if (start
& ~PAGE_MASK
)
949 if (mode
== MPOL_DEFAULT
)
950 flags
&= ~MPOL_MF_STRICT
;
952 len
= (len
+ PAGE_SIZE
- 1) & PAGE_MASK
;
960 new = mpol_new(mode
, mode_flags
, nmask
);
965 * If we are using the default policy then operation
966 * on discontinuous address spaces is okay after all
969 flags
|= MPOL_MF_DISCONTIG_OK
;
971 pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
972 start
, start
+ len
, mode
, mode_flags
,
973 nmask
? nodes_addr(*nmask
)[0] : -1);
975 if (flags
& (MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
)) {
977 err
= migrate_prep();
981 down_write(&mm
->mmap_sem
);
982 vma
= check_range(mm
, start
, end
, nmask
,
983 flags
| MPOL_MF_INVERT
, &pagelist
);
989 err
= mbind_range(vma
, start
, end
, new);
991 if (!list_empty(&pagelist
))
992 nr_failed
= migrate_pages(&pagelist
, new_vma_page
,
995 if (!err
&& nr_failed
&& (flags
& MPOL_MF_STRICT
))
999 up_write(&mm
->mmap_sem
);
1005 * User space interface with variable sized bitmaps for nodelists.
1008 /* Copy a node mask from user space. */
1009 static int get_nodes(nodemask_t
*nodes
, const unsigned long __user
*nmask
,
1010 unsigned long maxnode
)
1013 unsigned long nlongs
;
1014 unsigned long endmask
;
1017 nodes_clear(*nodes
);
1018 if (maxnode
== 0 || !nmask
)
1020 if (maxnode
> PAGE_SIZE
*BITS_PER_BYTE
)
1023 nlongs
= BITS_TO_LONGS(maxnode
);
1024 if ((maxnode
% BITS_PER_LONG
) == 0)
1027 endmask
= (1UL << (maxnode
% BITS_PER_LONG
)) - 1;
1029 /* When the user specified more nodes than supported just check
1030 if the non supported part is all zero. */
1031 if (nlongs
> BITS_TO_LONGS(MAX_NUMNODES
)) {
1032 if (nlongs
> PAGE_SIZE
/sizeof(long))
1034 for (k
= BITS_TO_LONGS(MAX_NUMNODES
); k
< nlongs
; k
++) {
1036 if (get_user(t
, nmask
+ k
))
1038 if (k
== nlongs
- 1) {
1044 nlongs
= BITS_TO_LONGS(MAX_NUMNODES
);
1048 if (copy_from_user(nodes_addr(*nodes
), nmask
, nlongs
*sizeof(unsigned long)))
1050 nodes_addr(*nodes
)[nlongs
-1] &= endmask
;
1054 /* Copy a kernel node mask to user space */
1055 static int copy_nodes_to_user(unsigned long __user
*mask
, unsigned long maxnode
,
1058 unsigned long copy
= ALIGN(maxnode
-1, 64) / 8;
1059 const int nbytes
= BITS_TO_LONGS(MAX_NUMNODES
) * sizeof(long);
1061 if (copy
> nbytes
) {
1062 if (copy
> PAGE_SIZE
)
1064 if (clear_user((char __user
*)mask
+ nbytes
, copy
- nbytes
))
1068 return copy_to_user(mask
, nodes_addr(*nodes
), copy
) ? -EFAULT
: 0;
1071 SYSCALL_DEFINE6(mbind
, unsigned long, start
, unsigned long, len
,
1072 unsigned long, mode
, unsigned long __user
*, nmask
,
1073 unsigned long, maxnode
, unsigned, flags
)
1077 unsigned short mode_flags
;
1079 mode_flags
= mode
& MPOL_MODE_FLAGS
;
1080 mode
&= ~MPOL_MODE_FLAGS
;
1081 if (mode
>= MPOL_MAX
)
1083 if ((mode_flags
& MPOL_F_STATIC_NODES
) &&
1084 (mode_flags
& MPOL_F_RELATIVE_NODES
))
1086 err
= get_nodes(&nodes
, nmask
, maxnode
);
1089 return do_mbind(start
, len
, mode
, mode_flags
, &nodes
, flags
);
1092 /* Set the process memory policy */
1093 SYSCALL_DEFINE3(set_mempolicy
, int, mode
, unsigned long __user
*, nmask
,
1094 unsigned long, maxnode
)
1098 unsigned short flags
;
1100 flags
= mode
& MPOL_MODE_FLAGS
;
1101 mode
&= ~MPOL_MODE_FLAGS
;
1102 if ((unsigned int)mode
>= MPOL_MAX
)
1104 if ((flags
& MPOL_F_STATIC_NODES
) && (flags
& MPOL_F_RELATIVE_NODES
))
1106 err
= get_nodes(&nodes
, nmask
, maxnode
);
1109 return do_set_mempolicy(mode
, flags
, &nodes
);
1112 SYSCALL_DEFINE4(migrate_pages
, pid_t
, pid
, unsigned long, maxnode
,
1113 const unsigned long __user
*, old_nodes
,
1114 const unsigned long __user
*, new_nodes
)
1116 struct mm_struct
*mm
;
1117 struct task_struct
*task
;
1120 nodemask_t task_nodes
;
1123 err
= get_nodes(&old
, old_nodes
, maxnode
);
1127 err
= get_nodes(&new, new_nodes
, maxnode
);
1131 /* Find the mm_struct */
1132 read_lock(&tasklist_lock
);
1133 task
= pid
? find_task_by_vpid(pid
) : current
;
1135 read_unlock(&tasklist_lock
);
1138 mm
= get_task_mm(task
);
1139 read_unlock(&tasklist_lock
);
1145 * Check if this process has the right to modify the specified
1146 * process. The right exists if the process has administrative
1147 * capabilities, superuser privileges or the same
1148 * userid as the target process.
1150 if ((current
->euid
!= task
->suid
) && (current
->euid
!= task
->uid
) &&
1151 (current
->uid
!= task
->suid
) && (current
->uid
!= task
->uid
) &&
1152 !capable(CAP_SYS_NICE
)) {
1157 task_nodes
= cpuset_mems_allowed(task
);
1158 /* Is the user allowed to access the target nodes? */
1159 if (!nodes_subset(new, task_nodes
) && !capable(CAP_SYS_NICE
)) {
1164 if (!nodes_subset(new, node_states
[N_HIGH_MEMORY
])) {
1169 err
= security_task_movememory(task
);
1173 err
= do_migrate_pages(mm
, &old
, &new,
1174 capable(CAP_SYS_NICE
) ? MPOL_MF_MOVE_ALL
: MPOL_MF_MOVE
);
1181 /* Retrieve NUMA policy */
1182 SYSCALL_DEFINE5(get_mempolicy
, int __user
*, policy
,
1183 unsigned long __user
*, nmask
, unsigned long, maxnode
,
1184 unsigned long, addr
, unsigned long, flags
)
1187 int uninitialized_var(pval
);
1190 if (nmask
!= NULL
&& maxnode
< MAX_NUMNODES
)
1193 err
= do_get_mempolicy(&pval
, &nodes
, addr
, flags
);
1198 if (policy
&& put_user(pval
, policy
))
1202 err
= copy_nodes_to_user(nmask
, maxnode
, &nodes
);
1207 #ifdef CONFIG_COMPAT
1209 asmlinkage
long compat_sys_get_mempolicy(int __user
*policy
,
1210 compat_ulong_t __user
*nmask
,
1211 compat_ulong_t maxnode
,
1212 compat_ulong_t addr
, compat_ulong_t flags
)
1215 unsigned long __user
*nm
= NULL
;
1216 unsigned long nr_bits
, alloc_size
;
1217 DECLARE_BITMAP(bm
, MAX_NUMNODES
);
1219 nr_bits
= min_t(unsigned long, maxnode
-1, MAX_NUMNODES
);
1220 alloc_size
= ALIGN(nr_bits
, BITS_PER_LONG
) / 8;
1223 nm
= compat_alloc_user_space(alloc_size
);
1225 err
= sys_get_mempolicy(policy
, nm
, nr_bits
+1, addr
, flags
);
1227 if (!err
&& nmask
) {
1228 err
= copy_from_user(bm
, nm
, alloc_size
);
1229 /* ensure entire bitmap is zeroed */
1230 err
|= clear_user(nmask
, ALIGN(maxnode
-1, 8) / 8);
1231 err
|= compat_put_bitmap(nmask
, bm
, nr_bits
);
1237 asmlinkage
long compat_sys_set_mempolicy(int mode
, compat_ulong_t __user
*nmask
,
1238 compat_ulong_t maxnode
)
1241 unsigned long __user
*nm
= NULL
;
1242 unsigned long nr_bits
, alloc_size
;
1243 DECLARE_BITMAP(bm
, MAX_NUMNODES
);
1245 nr_bits
= min_t(unsigned long, maxnode
-1, MAX_NUMNODES
);
1246 alloc_size
= ALIGN(nr_bits
, BITS_PER_LONG
) / 8;
1249 err
= compat_get_bitmap(bm
, nmask
, nr_bits
);
1250 nm
= compat_alloc_user_space(alloc_size
);
1251 err
|= copy_to_user(nm
, bm
, alloc_size
);
1257 return sys_set_mempolicy(mode
, nm
, nr_bits
+1);
1260 asmlinkage
long compat_sys_mbind(compat_ulong_t start
, compat_ulong_t len
,
1261 compat_ulong_t mode
, compat_ulong_t __user
*nmask
,
1262 compat_ulong_t maxnode
, compat_ulong_t flags
)
1265 unsigned long __user
*nm
= NULL
;
1266 unsigned long nr_bits
, alloc_size
;
1269 nr_bits
= min_t(unsigned long, maxnode
-1, MAX_NUMNODES
);
1270 alloc_size
= ALIGN(nr_bits
, BITS_PER_LONG
) / 8;
1273 err
= compat_get_bitmap(nodes_addr(bm
), nmask
, nr_bits
);
1274 nm
= compat_alloc_user_space(alloc_size
);
1275 err
|= copy_to_user(nm
, nodes_addr(bm
), alloc_size
);
1281 return sys_mbind(start
, len
, mode
, nm
, nr_bits
+1, flags
);
1287 * get_vma_policy(@task, @vma, @addr)
1288 * @task - task for fallback if vma policy == default
1289 * @vma - virtual memory area whose policy is sought
1290 * @addr - address in @vma for shared policy lookup
1292 * Returns effective policy for a VMA at specified address.
1293 * Falls back to @task or system default policy, as necessary.
1294 * Current or other task's task mempolicy and non-shared vma policies
1295 * are protected by the task's mmap_sem, which must be held for read by
1297 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
1298 * count--added by the get_policy() vm_op, as appropriate--to protect against
1299 * freeing by another task. It is the caller's responsibility to free the
1300 * extra reference for shared policies.
1302 static struct mempolicy
*get_vma_policy(struct task_struct
*task
,
1303 struct vm_area_struct
*vma
, unsigned long addr
)
1305 struct mempolicy
*pol
= task
->mempolicy
;
1308 if (vma
->vm_ops
&& vma
->vm_ops
->get_policy
) {
1309 struct mempolicy
*vpol
= vma
->vm_ops
->get_policy(vma
,
1313 } else if (vma
->vm_policy
)
1314 pol
= vma
->vm_policy
;
1317 pol
= &default_policy
;
1322 * Return a nodemask representing a mempolicy for filtering nodes for
1325 static nodemask_t
*policy_nodemask(gfp_t gfp
, struct mempolicy
*policy
)
1327 /* Lower zones don't get a nodemask applied for MPOL_BIND */
1328 if (unlikely(policy
->mode
== MPOL_BIND
) &&
1329 gfp_zone(gfp
) >= policy_zone
&&
1330 cpuset_nodemask_valid_mems_allowed(&policy
->v
.nodes
))
1331 return &policy
->v
.nodes
;
1336 /* Return a zonelist indicated by gfp for node representing a mempolicy */
1337 static struct zonelist
*policy_zonelist(gfp_t gfp
, struct mempolicy
*policy
)
1339 int nd
= numa_node_id();
1341 switch (policy
->mode
) {
1342 case MPOL_PREFERRED
:
1343 if (!(policy
->flags
& MPOL_F_LOCAL
))
1344 nd
= policy
->v
.preferred_node
;
1348 * Normally, MPOL_BIND allocations are node-local within the
1349 * allowed nodemask. However, if __GFP_THISNODE is set and the
1350 * current node is part of the mask, we use the zonelist for
1351 * the first node in the mask instead.
1353 if (unlikely(gfp
& __GFP_THISNODE
) &&
1354 unlikely(!node_isset(nd
, policy
->v
.nodes
)))
1355 nd
= first_node(policy
->v
.nodes
);
1357 case MPOL_INTERLEAVE
: /* should not happen */
1362 return node_zonelist(nd
, gfp
);
1365 /* Do dynamic interleaving for a process */
1366 static unsigned interleave_nodes(struct mempolicy
*policy
)
1369 struct task_struct
*me
= current
;
1372 next
= next_node(nid
, policy
->v
.nodes
);
1373 if (next
>= MAX_NUMNODES
)
1374 next
= first_node(policy
->v
.nodes
);
1375 if (next
< MAX_NUMNODES
)
1381 * Depending on the memory policy provide a node from which to allocate the
1383 * @policy must be protected by freeing by the caller. If @policy is
1384 * the current task's mempolicy, this protection is implicit, as only the
1385 * task can change it's policy. The system default policy requires no
1388 unsigned slab_node(struct mempolicy
*policy
)
1390 if (!policy
|| policy
->flags
& MPOL_F_LOCAL
)
1391 return numa_node_id();
1393 switch (policy
->mode
) {
1394 case MPOL_PREFERRED
:
1396 * handled MPOL_F_LOCAL above
1398 return policy
->v
.preferred_node
;
1400 case MPOL_INTERLEAVE
:
1401 return interleave_nodes(policy
);
1405 * Follow bind policy behavior and start allocation at the
1408 struct zonelist
*zonelist
;
1410 enum zone_type highest_zoneidx
= gfp_zone(GFP_KERNEL
);
1411 zonelist
= &NODE_DATA(numa_node_id())->node_zonelists
[0];
1412 (void)first_zones_zonelist(zonelist
, highest_zoneidx
,
1423 /* Do static interleaving for a VMA with known offset. */
1424 static unsigned offset_il_node(struct mempolicy
*pol
,
1425 struct vm_area_struct
*vma
, unsigned long off
)
1427 unsigned nnodes
= nodes_weight(pol
->v
.nodes
);
1433 return numa_node_id();
1434 target
= (unsigned int)off
% nnodes
;
1437 nid
= next_node(nid
, pol
->v
.nodes
);
1439 } while (c
<= target
);
1443 /* Determine a node number for interleave */
1444 static inline unsigned interleave_nid(struct mempolicy
*pol
,
1445 struct vm_area_struct
*vma
, unsigned long addr
, int shift
)
1451 * for small pages, there is no difference between
1452 * shift and PAGE_SHIFT, so the bit-shift is safe.
1453 * for huge pages, since vm_pgoff is in units of small
1454 * pages, we need to shift off the always 0 bits to get
1457 BUG_ON(shift
< PAGE_SHIFT
);
1458 off
= vma
->vm_pgoff
>> (shift
- PAGE_SHIFT
);
1459 off
+= (addr
- vma
->vm_start
) >> shift
;
1460 return offset_il_node(pol
, vma
, off
);
1462 return interleave_nodes(pol
);
1465 #ifdef CONFIG_HUGETLBFS
1467 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
1468 * @vma = virtual memory area whose policy is sought
1469 * @addr = address in @vma for shared policy lookup and interleave policy
1470 * @gfp_flags = for requested zone
1471 * @mpol = pointer to mempolicy pointer for reference counted mempolicy
1472 * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
1474 * Returns a zonelist suitable for a huge page allocation and a pointer
1475 * to the struct mempolicy for conditional unref after allocation.
1476 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
1477 * @nodemask for filtering the zonelist.
1479 struct zonelist
*huge_zonelist(struct vm_area_struct
*vma
, unsigned long addr
,
1480 gfp_t gfp_flags
, struct mempolicy
**mpol
,
1481 nodemask_t
**nodemask
)
1483 struct zonelist
*zl
;
1485 *mpol
= get_vma_policy(current
, vma
, addr
);
1486 *nodemask
= NULL
; /* assume !MPOL_BIND */
1488 if (unlikely((*mpol
)->mode
== MPOL_INTERLEAVE
)) {
1489 zl
= node_zonelist(interleave_nid(*mpol
, vma
, addr
,
1490 huge_page_shift(hstate_vma(vma
))), gfp_flags
);
1492 zl
= policy_zonelist(gfp_flags
, *mpol
);
1493 if ((*mpol
)->mode
== MPOL_BIND
)
1494 *nodemask
= &(*mpol
)->v
.nodes
;
1500 /* Allocate a page in interleaved policy.
1501 Own path because it needs to do special accounting. */
1502 static struct page
*alloc_page_interleave(gfp_t gfp
, unsigned order
,
1505 struct zonelist
*zl
;
1508 zl
= node_zonelist(nid
, gfp
);
1509 page
= __alloc_pages(gfp
, order
, zl
);
1510 if (page
&& page_zone(page
) == zonelist_zone(&zl
->_zonerefs
[0]))
1511 inc_zone_page_state(page
, NUMA_INTERLEAVE_HIT
);
1516 * alloc_page_vma - Allocate a page for a VMA.
1519 * %GFP_USER user allocation.
1520 * %GFP_KERNEL kernel allocations,
1521 * %GFP_HIGHMEM highmem/user allocations,
1522 * %GFP_FS allocation should not call back into a file system.
1523 * %GFP_ATOMIC don't sleep.
1525 * @vma: Pointer to VMA or NULL if not available.
1526 * @addr: Virtual Address of the allocation. Must be inside the VMA.
1528 * This function allocates a page from the kernel page pool and applies
1529 * a NUMA policy associated with the VMA or the current process.
1530 * When VMA is not NULL caller must hold down_read on the mmap_sem of the
1531 * mm_struct of the VMA to prevent it from going away. Should be used for
1532 * all allocations for pages that will be mapped into
1533 * user space. Returns NULL when no page can be allocated.
1535 * Should be called with the mm_sem of the vma hold.
1538 alloc_page_vma(gfp_t gfp
, struct vm_area_struct
*vma
, unsigned long addr
)
1540 struct mempolicy
*pol
= get_vma_policy(current
, vma
, addr
);
1541 struct zonelist
*zl
;
1543 cpuset_update_task_memory_state();
1545 if (unlikely(pol
->mode
== MPOL_INTERLEAVE
)) {
1548 nid
= interleave_nid(pol
, vma
, addr
, PAGE_SHIFT
);
1550 return alloc_page_interleave(gfp
, 0, nid
);
1552 zl
= policy_zonelist(gfp
, pol
);
1553 if (unlikely(mpol_needs_cond_ref(pol
))) {
1555 * slow path: ref counted shared policy
1557 struct page
*page
= __alloc_pages_nodemask(gfp
, 0,
1558 zl
, policy_nodemask(gfp
, pol
));
1563 * fast path: default or task policy
1565 return __alloc_pages_nodemask(gfp
, 0, zl
, policy_nodemask(gfp
, pol
));
1569 * alloc_pages_current - Allocate pages.
1572 * %GFP_USER user allocation,
1573 * %GFP_KERNEL kernel allocation,
1574 * %GFP_HIGHMEM highmem allocation,
1575 * %GFP_FS don't call back into a file system.
1576 * %GFP_ATOMIC don't sleep.
1577 * @order: Power of two of allocation size in pages. 0 is a single page.
1579 * Allocate a page from the kernel page pool. When not in
1580 * interrupt context and apply the current process NUMA policy.
1581 * Returns NULL when no page can be allocated.
1583 * Don't call cpuset_update_task_memory_state() unless
1584 * 1) it's ok to take cpuset_sem (can WAIT), and
1585 * 2) allocating for current task (not interrupt).
1587 struct page
*alloc_pages_current(gfp_t gfp
, unsigned order
)
1589 struct mempolicy
*pol
= current
->mempolicy
;
1591 if ((gfp
& __GFP_WAIT
) && !in_interrupt())
1592 cpuset_update_task_memory_state();
1593 if (!pol
|| in_interrupt() || (gfp
& __GFP_THISNODE
))
1594 pol
= &default_policy
;
1597 * No reference counting needed for current->mempolicy
1598 * nor system default_policy
1600 if (pol
->mode
== MPOL_INTERLEAVE
)
1601 return alloc_page_interleave(gfp
, order
, interleave_nodes(pol
));
1602 return __alloc_pages_nodemask(gfp
, order
,
1603 policy_zonelist(gfp
, pol
), policy_nodemask(gfp
, pol
));
1605 EXPORT_SYMBOL(alloc_pages_current
);
1608 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
1609 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
1610 * with the mems_allowed returned by cpuset_mems_allowed(). This
1611 * keeps mempolicies cpuset relative after its cpuset moves. See
1612 * further kernel/cpuset.c update_nodemask().
1615 /* Slow path of a mempolicy duplicate */
1616 struct mempolicy
*__mpol_dup(struct mempolicy
*old
)
1618 struct mempolicy
*new = kmem_cache_alloc(policy_cache
, GFP_KERNEL
);
1621 return ERR_PTR(-ENOMEM
);
1622 if (current_cpuset_is_being_rebound()) {
1623 nodemask_t mems
= cpuset_mems_allowed(current
);
1624 mpol_rebind_policy(old
, &mems
);
1627 atomic_set(&new->refcnt
, 1);
1632 * If *frompol needs [has] an extra ref, copy *frompol to *tompol ,
1633 * eliminate the * MPOL_F_* flags that require conditional ref and
1634 * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly
1635 * after return. Use the returned value.
1637 * Allows use of a mempolicy for, e.g., multiple allocations with a single
1638 * policy lookup, even if the policy needs/has extra ref on lookup.
1639 * shmem_readahead needs this.
1641 struct mempolicy
*__mpol_cond_copy(struct mempolicy
*tompol
,
1642 struct mempolicy
*frompol
)
1644 if (!mpol_needs_cond_ref(frompol
))
1648 tompol
->flags
&= ~MPOL_F_SHARED
; /* copy doesn't need unref */
1649 __mpol_put(frompol
);
1653 static int mpol_match_intent(const struct mempolicy
*a
,
1654 const struct mempolicy
*b
)
1656 if (a
->flags
!= b
->flags
)
1658 if (!mpol_store_user_nodemask(a
))
1660 return nodes_equal(a
->w
.user_nodemask
, b
->w
.user_nodemask
);
1663 /* Slow path of a mempolicy comparison */
1664 int __mpol_equal(struct mempolicy
*a
, struct mempolicy
*b
)
1668 if (a
->mode
!= b
->mode
)
1670 if (a
->mode
!= MPOL_DEFAULT
&& !mpol_match_intent(a
, b
))
1675 case MPOL_INTERLEAVE
:
1676 return nodes_equal(a
->v
.nodes
, b
->v
.nodes
);
1677 case MPOL_PREFERRED
:
1678 return a
->v
.preferred_node
== b
->v
.preferred_node
&&
1679 a
->flags
== b
->flags
;
1687 * Shared memory backing store policy support.
1689 * Remember policies even when nobody has shared memory mapped.
1690 * The policies are kept in Red-Black tree linked from the inode.
1691 * They are protected by the sp->lock spinlock, which should be held
1692 * for any accesses to the tree.
1695 /* lookup first element intersecting start-end */
1696 /* Caller holds sp->lock */
1697 static struct sp_node
*
1698 sp_lookup(struct shared_policy
*sp
, unsigned long start
, unsigned long end
)
1700 struct rb_node
*n
= sp
->root
.rb_node
;
1703 struct sp_node
*p
= rb_entry(n
, struct sp_node
, nd
);
1705 if (start
>= p
->end
)
1707 else if (end
<= p
->start
)
1715 struct sp_node
*w
= NULL
;
1716 struct rb_node
*prev
= rb_prev(n
);
1719 w
= rb_entry(prev
, struct sp_node
, nd
);
1720 if (w
->end
<= start
)
1724 return rb_entry(n
, struct sp_node
, nd
);
1727 /* Insert a new shared policy into the list. */
1728 /* Caller holds sp->lock */
1729 static void sp_insert(struct shared_policy
*sp
, struct sp_node
*new)
1731 struct rb_node
**p
= &sp
->root
.rb_node
;
1732 struct rb_node
*parent
= NULL
;
1737 nd
= rb_entry(parent
, struct sp_node
, nd
);
1738 if (new->start
< nd
->start
)
1740 else if (new->end
> nd
->end
)
1741 p
= &(*p
)->rb_right
;
1745 rb_link_node(&new->nd
, parent
, p
);
1746 rb_insert_color(&new->nd
, &sp
->root
);
1747 pr_debug("inserting %lx-%lx: %d\n", new->start
, new->end
,
1748 new->policy
? new->policy
->mode
: 0);
1751 /* Find shared policy intersecting idx */
1753 mpol_shared_policy_lookup(struct shared_policy
*sp
, unsigned long idx
)
1755 struct mempolicy
*pol
= NULL
;
1758 if (!sp
->root
.rb_node
)
1760 spin_lock(&sp
->lock
);
1761 sn
= sp_lookup(sp
, idx
, idx
+1);
1763 mpol_get(sn
->policy
);
1766 spin_unlock(&sp
->lock
);
1770 static void sp_delete(struct shared_policy
*sp
, struct sp_node
*n
)
1772 pr_debug("deleting %lx-l%lx\n", n
->start
, n
->end
);
1773 rb_erase(&n
->nd
, &sp
->root
);
1774 mpol_put(n
->policy
);
1775 kmem_cache_free(sn_cache
, n
);
1778 static struct sp_node
*sp_alloc(unsigned long start
, unsigned long end
,
1779 struct mempolicy
*pol
)
1781 struct sp_node
*n
= kmem_cache_alloc(sn_cache
, GFP_KERNEL
);
1788 pol
->flags
|= MPOL_F_SHARED
; /* for unref */
1793 /* Replace a policy range. */
1794 static int shared_policy_replace(struct shared_policy
*sp
, unsigned long start
,
1795 unsigned long end
, struct sp_node
*new)
1797 struct sp_node
*n
, *new2
= NULL
;
1800 spin_lock(&sp
->lock
);
1801 n
= sp_lookup(sp
, start
, end
);
1802 /* Take care of old policies in the same range. */
1803 while (n
&& n
->start
< end
) {
1804 struct rb_node
*next
= rb_next(&n
->nd
);
1805 if (n
->start
>= start
) {
1811 /* Old policy spanning whole new range. */
1814 spin_unlock(&sp
->lock
);
1815 new2
= sp_alloc(end
, n
->end
, n
->policy
);
1821 sp_insert(sp
, new2
);
1829 n
= rb_entry(next
, struct sp_node
, nd
);
1833 spin_unlock(&sp
->lock
);
1835 mpol_put(new2
->policy
);
1836 kmem_cache_free(sn_cache
, new2
);
1842 * mpol_shared_policy_init - initialize shared policy for inode
1843 * @sp: pointer to inode shared policy
1844 * @mpol: struct mempolicy to install
1846 * Install non-NULL @mpol in inode's shared policy rb-tree.
1847 * On entry, the current task has a reference on a non-NULL @mpol.
1848 * This must be released on exit.
1850 void mpol_shared_policy_init(struct shared_policy
*sp
, struct mempolicy
*mpol
)
1852 sp
->root
= RB_ROOT
; /* empty tree == default mempolicy */
1853 spin_lock_init(&sp
->lock
);
1856 struct vm_area_struct pvma
;
1857 struct mempolicy
*new;
1859 /* contextualize the tmpfs mount point mempolicy */
1860 new = mpol_new(mpol
->mode
, mpol
->flags
, &mpol
->w
.user_nodemask
);
1861 mpol_put(mpol
); /* drop our ref on sb mpol */
1863 return; /* no valid nodemask intersection */
1865 /* Create pseudo-vma that contains just the policy */
1866 memset(&pvma
, 0, sizeof(struct vm_area_struct
));
1867 pvma
.vm_end
= TASK_SIZE
; /* policy covers entire file */
1868 mpol_set_shared_policy(sp
, &pvma
, new); /* adds ref */
1869 mpol_put(new); /* drop initial ref */
1873 int mpol_set_shared_policy(struct shared_policy
*info
,
1874 struct vm_area_struct
*vma
, struct mempolicy
*npol
)
1877 struct sp_node
*new = NULL
;
1878 unsigned long sz
= vma_pages(vma
);
1880 pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
1882 sz
, npol
? npol
->mode
: -1,
1883 npol
? npol
->flags
: -1,
1884 npol
? nodes_addr(npol
->v
.nodes
)[0] : -1);
1887 new = sp_alloc(vma
->vm_pgoff
, vma
->vm_pgoff
+ sz
, npol
);
1891 err
= shared_policy_replace(info
, vma
->vm_pgoff
, vma
->vm_pgoff
+sz
, new);
1893 kmem_cache_free(sn_cache
, new);
1897 /* Free a backing policy store on inode delete. */
1898 void mpol_free_shared_policy(struct shared_policy
*p
)
1901 struct rb_node
*next
;
1903 if (!p
->root
.rb_node
)
1905 spin_lock(&p
->lock
);
1906 next
= rb_first(&p
->root
);
1908 n
= rb_entry(next
, struct sp_node
, nd
);
1909 next
= rb_next(&n
->nd
);
1910 rb_erase(&n
->nd
, &p
->root
);
1911 mpol_put(n
->policy
);
1912 kmem_cache_free(sn_cache
, n
);
1914 spin_unlock(&p
->lock
);
1917 /* assumes fs == KERNEL_DS */
1918 void __init
numa_policy_init(void)
1920 nodemask_t interleave_nodes
;
1921 unsigned long largest
= 0;
1922 int nid
, prefer
= 0;
1924 policy_cache
= kmem_cache_create("numa_policy",
1925 sizeof(struct mempolicy
),
1926 0, SLAB_PANIC
, NULL
);
1928 sn_cache
= kmem_cache_create("shared_policy_node",
1929 sizeof(struct sp_node
),
1930 0, SLAB_PANIC
, NULL
);
1933 * Set interleaving policy for system init. Interleaving is only
1934 * enabled across suitably sized nodes (default is >= 16MB), or
1935 * fall back to the largest node if they're all smaller.
1937 nodes_clear(interleave_nodes
);
1938 for_each_node_state(nid
, N_HIGH_MEMORY
) {
1939 unsigned long total_pages
= node_present_pages(nid
);
1941 /* Preserve the largest node */
1942 if (largest
< total_pages
) {
1943 largest
= total_pages
;
1947 /* Interleave this node? */
1948 if ((total_pages
<< PAGE_SHIFT
) >= (16 << 20))
1949 node_set(nid
, interleave_nodes
);
1952 /* All too small, use the largest */
1953 if (unlikely(nodes_empty(interleave_nodes
)))
1954 node_set(prefer
, interleave_nodes
);
1956 if (do_set_mempolicy(MPOL_INTERLEAVE
, 0, &interleave_nodes
))
1957 printk("numa_policy_init: interleaving failed\n");
1960 /* Reset policy of current process to default */
1961 void numa_default_policy(void)
1963 do_set_mempolicy(MPOL_DEFAULT
, 0, NULL
);
1967 * Parse and format mempolicy from/to strings
1971 * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag
1972 * Used only for mpol_parse_str() and mpol_to_str()
1974 #define MPOL_LOCAL (MPOL_INTERLEAVE + 1)
1975 static const char * const policy_types
[] =
1976 { "default", "prefer", "bind", "interleave", "local" };
1981 * mpol_parse_str - parse string to mempolicy
1982 * @str: string containing mempolicy to parse
1983 * @mpol: pointer to struct mempolicy pointer, returned on success.
1984 * @no_context: flag whether to "contextualize" the mempolicy
1987 * <mode>[=<flags>][:<nodelist>]
1989 * if @no_context is true, save the input nodemask in w.user_nodemask in
1990 * the returned mempolicy. This will be used to "clone" the mempolicy in
1991 * a specific context [cpuset] at a later time. Used to parse tmpfs mpol
1992 * mount option. Note that if 'static' or 'relative' mode flags were
1993 * specified, the input nodemask will already have been saved. Saving
1994 * it again is redundant, but safe.
1996 * On success, returns 0, else 1
1998 int mpol_parse_str(char *str
, struct mempolicy
**mpol
, int no_context
)
2000 struct mempolicy
*new = NULL
;
2001 unsigned short uninitialized_var(mode
);
2002 unsigned short uninitialized_var(mode_flags
);
2004 char *nodelist
= strchr(str
, ':');
2005 char *flags
= strchr(str
, '=');
2010 /* NUL-terminate mode or flags string */
2012 if (nodelist_parse(nodelist
, nodes
))
2014 if (!nodes_subset(nodes
, node_states
[N_HIGH_MEMORY
]))
2020 *flags
++ = '\0'; /* terminate mode string */
2022 for (i
= 0; i
<= MPOL_LOCAL
; i
++) {
2023 if (!strcmp(str
, policy_types
[i
])) {
2032 case MPOL_PREFERRED
:
2034 * Insist on a nodelist of one node only
2037 char *rest
= nodelist
;
2038 while (isdigit(*rest
))
2044 case MPOL_INTERLEAVE
:
2046 * Default to online nodes with memory if no nodelist
2049 nodes
= node_states
[N_HIGH_MEMORY
];
2054 * Don't allow a nodelist; mpol_new() checks flags
2058 mode
= MPOL_PREFERRED
;
2062 * case MPOL_BIND: mpol_new() enforces non-empty nodemask.
2063 * case MPOL_DEFAULT: mpol_new() enforces empty nodemask, ignores flags.
2070 * Currently, we only support two mutually exclusive
2073 if (!strcmp(flags
, "static"))
2074 mode_flags
|= MPOL_F_STATIC_NODES
;
2075 else if (!strcmp(flags
, "relative"))
2076 mode_flags
|= MPOL_F_RELATIVE_NODES
;
2081 new = mpol_new(mode
, mode_flags
, &nodes
);
2084 else if (no_context
)
2085 new->w
.user_nodemask
= nodes
; /* save for contextualization */
2088 /* Restore string for error message */
2097 #endif /* CONFIG_TMPFS */
2100 * mpol_to_str - format a mempolicy structure for printing
2101 * @buffer: to contain formatted mempolicy string
2102 * @maxlen: length of @buffer
2103 * @pol: pointer to mempolicy to be formatted
2104 * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask
2106 * Convert a mempolicy into a string.
2107 * Returns the number of characters in buffer (if positive)
2108 * or an error (negative)
2110 int mpol_to_str(char *buffer
, int maxlen
, struct mempolicy
*pol
, int no_context
)
2115 unsigned short mode
;
2116 unsigned short flags
= pol
? pol
->flags
: 0;
2119 * Sanity check: room for longest mode, flag and some nodes
2121 VM_BUG_ON(maxlen
< strlen("interleave") + strlen("relative") + 16);
2123 if (!pol
|| pol
== &default_policy
)
2124 mode
= MPOL_DEFAULT
;
2133 case MPOL_PREFERRED
:
2135 if (flags
& MPOL_F_LOCAL
)
2136 mode
= MPOL_LOCAL
; /* pseudo-policy */
2138 node_set(pol
->v
.preferred_node
, nodes
);
2143 case MPOL_INTERLEAVE
:
2145 nodes
= pol
->w
.user_nodemask
;
2147 nodes
= pol
->v
.nodes
;
2154 l
= strlen(policy_types
[mode
]);
2155 if (buffer
+ maxlen
< p
+ l
+ 1)
2158 strcpy(p
, policy_types
[mode
]);
2161 if (flags
& MPOL_MODE_FLAGS
) {
2162 if (buffer
+ maxlen
< p
+ 2)
2167 * Currently, the only defined flags are mutually exclusive
2169 if (flags
& MPOL_F_STATIC_NODES
)
2170 p
+= snprintf(p
, buffer
+ maxlen
- p
, "static");
2171 else if (flags
& MPOL_F_RELATIVE_NODES
)
2172 p
+= snprintf(p
, buffer
+ maxlen
- p
, "relative");
2175 if (!nodes_empty(nodes
)) {
2176 if (buffer
+ maxlen
< p
+ 2)
2179 p
+= nodelist_scnprintf(p
, buffer
+ maxlen
- p
, nodes
);
2185 unsigned long pages
;
2187 unsigned long active
;
2188 unsigned long writeback
;
2189 unsigned long mapcount_max
;
2190 unsigned long dirty
;
2191 unsigned long swapcache
;
2192 unsigned long node
[MAX_NUMNODES
];
2195 static void gather_stats(struct page
*page
, void *private, int pte_dirty
)
2197 struct numa_maps
*md
= private;
2198 int count
= page_mapcount(page
);
2201 if (pte_dirty
|| PageDirty(page
))
2204 if (PageSwapCache(page
))
2207 if (PageActive(page
) || PageUnevictable(page
))
2210 if (PageWriteback(page
))
2216 if (count
> md
->mapcount_max
)
2217 md
->mapcount_max
= count
;
2219 md
->node
[page_to_nid(page
)]++;
2222 #ifdef CONFIG_HUGETLB_PAGE
2223 static void check_huge_range(struct vm_area_struct
*vma
,
2224 unsigned long start
, unsigned long end
,
2225 struct numa_maps
*md
)
2229 struct hstate
*h
= hstate_vma(vma
);
2230 unsigned long sz
= huge_page_size(h
);
2232 for (addr
= start
; addr
< end
; addr
+= sz
) {
2233 pte_t
*ptep
= huge_pte_offset(vma
->vm_mm
,
2234 addr
& huge_page_mask(h
));
2244 page
= pte_page(pte
);
2248 gather_stats(page
, md
, pte_dirty(*ptep
));
2252 static inline void check_huge_range(struct vm_area_struct
*vma
,
2253 unsigned long start
, unsigned long end
,
2254 struct numa_maps
*md
)
2260 * Display pages allocated per node and memory policy via /proc.
2262 int show_numa_map(struct seq_file
*m
, void *v
)
2264 struct proc_maps_private
*priv
= m
->private;
2265 struct vm_area_struct
*vma
= v
;
2266 struct numa_maps
*md
;
2267 struct file
*file
= vma
->vm_file
;
2268 struct mm_struct
*mm
= vma
->vm_mm
;
2269 struct mempolicy
*pol
;
2276 md
= kzalloc(sizeof(struct numa_maps
), GFP_KERNEL
);
2280 pol
= get_vma_policy(priv
->task
, vma
, vma
->vm_start
);
2281 mpol_to_str(buffer
, sizeof(buffer
), pol
, 0);
2284 seq_printf(m
, "%08lx %s", vma
->vm_start
, buffer
);
2287 seq_printf(m
, " file=");
2288 seq_path(m
, &file
->f_path
, "\n\t= ");
2289 } else if (vma
->vm_start
<= mm
->brk
&& vma
->vm_end
>= mm
->start_brk
) {
2290 seq_printf(m
, " heap");
2291 } else if (vma
->vm_start
<= mm
->start_stack
&&
2292 vma
->vm_end
>= mm
->start_stack
) {
2293 seq_printf(m
, " stack");
2296 if (is_vm_hugetlb_page(vma
)) {
2297 check_huge_range(vma
, vma
->vm_start
, vma
->vm_end
, md
);
2298 seq_printf(m
, " huge");
2300 check_pgd_range(vma
, vma
->vm_start
, vma
->vm_end
,
2301 &node_states
[N_HIGH_MEMORY
], MPOL_MF_STATS
, md
);
2308 seq_printf(m
," anon=%lu",md
->anon
);
2311 seq_printf(m
," dirty=%lu",md
->dirty
);
2313 if (md
->pages
!= md
->anon
&& md
->pages
!= md
->dirty
)
2314 seq_printf(m
, " mapped=%lu", md
->pages
);
2316 if (md
->mapcount_max
> 1)
2317 seq_printf(m
, " mapmax=%lu", md
->mapcount_max
);
2320 seq_printf(m
," swapcache=%lu", md
->swapcache
);
2322 if (md
->active
< md
->pages
&& !is_vm_hugetlb_page(vma
))
2323 seq_printf(m
," active=%lu", md
->active
);
2326 seq_printf(m
," writeback=%lu", md
->writeback
);
2328 for_each_node_state(n
, N_HIGH_MEMORY
)
2330 seq_printf(m
, " N%d=%lu", n
, md
->node
[n
]);
2335 if (m
->count
< m
->size
)
2336 m
->version
= (vma
!= priv
->tail_vma
) ? vma
->vm_start
: 0;