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>
97 #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
98 #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
99 #define MPOL_MF_STATS (MPOL_MF_INTERNAL << 2) /* Gather statistics */
101 static struct kmem_cache
*policy_cache
;
102 static struct kmem_cache
*sn_cache
;
104 /* Highest zone. An specific allocation for a zone below that is not
106 enum zone_type policy_zone
= 0;
109 * run-time system-wide default policy => local allocation
111 struct mempolicy default_policy
= {
112 .refcnt
= ATOMIC_INIT(1), /* never free it */
113 .mode
= MPOL_PREFERRED
,
114 .flags
= MPOL_F_LOCAL
,
117 static const struct mempolicy_operations
{
118 int (*create
)(struct mempolicy
*pol
, const nodemask_t
*nodes
);
119 void (*rebind
)(struct mempolicy
*pol
, const nodemask_t
*nodes
);
120 } mpol_ops
[MPOL_MAX
];
122 /* Check that the nodemask contains at least one populated zone */
123 static int is_valid_nodemask(const nodemask_t
*nodemask
)
127 /* Check that there is something useful in this mask */
130 for_each_node_mask(nd
, *nodemask
) {
133 for (k
= 0; k
<= policy_zone
; k
++) {
134 z
= &NODE_DATA(nd
)->node_zones
[k
];
135 if (z
->present_pages
> 0)
143 static inline int mpol_store_user_nodemask(const struct mempolicy
*pol
)
145 return pol
->flags
& (MPOL_F_STATIC_NODES
| MPOL_F_RELATIVE_NODES
);
148 static void mpol_relative_nodemask(nodemask_t
*ret
, const nodemask_t
*orig
,
149 const nodemask_t
*rel
)
152 nodes_fold(tmp
, *orig
, nodes_weight(*rel
));
153 nodes_onto(*ret
, tmp
, *rel
);
156 static int mpol_new_interleave(struct mempolicy
*pol
, const nodemask_t
*nodes
)
158 if (nodes_empty(*nodes
))
160 pol
->v
.nodes
= *nodes
;
164 static int mpol_new_preferred(struct mempolicy
*pol
, const nodemask_t
*nodes
)
167 pol
->flags
|= MPOL_F_LOCAL
; /* local allocation */
168 else if (nodes_empty(*nodes
))
169 return -EINVAL
; /* no allowed nodes */
171 pol
->v
.preferred_node
= first_node(*nodes
);
175 static int mpol_new_bind(struct mempolicy
*pol
, const nodemask_t
*nodes
)
177 if (!is_valid_nodemask(nodes
))
179 pol
->v
.nodes
= *nodes
;
183 /* Create a new policy */
184 static struct mempolicy
*mpol_new(unsigned short mode
, unsigned short flags
,
187 struct mempolicy
*policy
;
188 nodemask_t cpuset_context_nmask
;
191 pr_debug("setting mode %d flags %d nodes[0] %lx\n",
192 mode
, flags
, nodes
? nodes_addr(*nodes
)[0] : -1);
194 if (mode
== MPOL_DEFAULT
) {
195 if (nodes
&& !nodes_empty(*nodes
))
196 return ERR_PTR(-EINVAL
);
197 return NULL
; /* simply delete any existing policy */
202 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
203 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
204 * All other modes require a valid pointer to a non-empty nodemask.
206 if (mode
== MPOL_PREFERRED
) {
207 if (nodes_empty(*nodes
)) {
208 if (((flags
& MPOL_F_STATIC_NODES
) ||
209 (flags
& MPOL_F_RELATIVE_NODES
)))
210 return ERR_PTR(-EINVAL
);
211 nodes
= NULL
; /* flag local alloc */
213 } else if (nodes_empty(*nodes
))
214 return ERR_PTR(-EINVAL
);
215 policy
= kmem_cache_alloc(policy_cache
, GFP_KERNEL
);
217 return ERR_PTR(-ENOMEM
);
218 atomic_set(&policy
->refcnt
, 1);
220 policy
->flags
= flags
;
224 * cpuset related setup doesn't apply to local allocation
226 cpuset_update_task_memory_state();
227 if (flags
& MPOL_F_RELATIVE_NODES
)
228 mpol_relative_nodemask(&cpuset_context_nmask
, nodes
,
229 &cpuset_current_mems_allowed
);
231 nodes_and(cpuset_context_nmask
, *nodes
,
232 cpuset_current_mems_allowed
);
233 if (mpol_store_user_nodemask(policy
))
234 policy
->w
.user_nodemask
= *nodes
;
236 policy
->w
.cpuset_mems_allowed
=
237 cpuset_mems_allowed(current
);
240 ret
= mpol_ops
[mode
].create(policy
,
241 nodes
? &cpuset_context_nmask
: NULL
);
243 kmem_cache_free(policy_cache
, policy
);
249 /* Slow path of a mpol destructor. */
250 void __mpol_put(struct mempolicy
*p
)
252 if (!atomic_dec_and_test(&p
->refcnt
))
254 kmem_cache_free(policy_cache
, p
);
257 static void mpol_rebind_default(struct mempolicy
*pol
, const nodemask_t
*nodes
)
261 static void mpol_rebind_nodemask(struct mempolicy
*pol
,
262 const nodemask_t
*nodes
)
266 if (pol
->flags
& MPOL_F_STATIC_NODES
)
267 nodes_and(tmp
, pol
->w
.user_nodemask
, *nodes
);
268 else if (pol
->flags
& MPOL_F_RELATIVE_NODES
)
269 mpol_relative_nodemask(&tmp
, &pol
->w
.user_nodemask
, nodes
);
271 nodes_remap(tmp
, pol
->v
.nodes
, pol
->w
.cpuset_mems_allowed
,
273 pol
->w
.cpuset_mems_allowed
= *nodes
;
277 if (!node_isset(current
->il_next
, tmp
)) {
278 current
->il_next
= next_node(current
->il_next
, tmp
);
279 if (current
->il_next
>= MAX_NUMNODES
)
280 current
->il_next
= first_node(tmp
);
281 if (current
->il_next
>= MAX_NUMNODES
)
282 current
->il_next
= numa_node_id();
286 static void mpol_rebind_preferred(struct mempolicy
*pol
,
287 const nodemask_t
*nodes
)
291 if (pol
->flags
& MPOL_F_STATIC_NODES
) {
292 int node
= first_node(pol
->w
.user_nodemask
);
294 if (node_isset(node
, *nodes
)) {
295 pol
->v
.preferred_node
= node
;
296 pol
->flags
&= ~MPOL_F_LOCAL
;
298 pol
->flags
|= MPOL_F_LOCAL
;
299 } else if (pol
->flags
& MPOL_F_RELATIVE_NODES
) {
300 mpol_relative_nodemask(&tmp
, &pol
->w
.user_nodemask
, nodes
);
301 pol
->v
.preferred_node
= first_node(tmp
);
302 } else if (!(pol
->flags
& MPOL_F_LOCAL
)) {
303 pol
->v
.preferred_node
= node_remap(pol
->v
.preferred_node
,
304 pol
->w
.cpuset_mems_allowed
,
306 pol
->w
.cpuset_mems_allowed
= *nodes
;
310 /* Migrate a policy to a different set of nodes */
311 static void mpol_rebind_policy(struct mempolicy
*pol
,
312 const nodemask_t
*newmask
)
316 if (!mpol_store_user_nodemask(pol
) &&
317 nodes_equal(pol
->w
.cpuset_mems_allowed
, *newmask
))
319 mpol_ops
[pol
->mode
].rebind(pol
, newmask
);
323 * Wrapper for mpol_rebind_policy() that just requires task
324 * pointer, and updates task mempolicy.
327 void mpol_rebind_task(struct task_struct
*tsk
, const nodemask_t
*new)
329 mpol_rebind_policy(tsk
->mempolicy
, new);
333 * Rebind each vma in mm to new nodemask.
335 * Call holding a reference to mm. Takes mm->mmap_sem during call.
338 void mpol_rebind_mm(struct mm_struct
*mm
, nodemask_t
*new)
340 struct vm_area_struct
*vma
;
342 down_write(&mm
->mmap_sem
);
343 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
)
344 mpol_rebind_policy(vma
->vm_policy
, new);
345 up_write(&mm
->mmap_sem
);
348 static const struct mempolicy_operations mpol_ops
[MPOL_MAX
] = {
350 .rebind
= mpol_rebind_default
,
352 [MPOL_INTERLEAVE
] = {
353 .create
= mpol_new_interleave
,
354 .rebind
= mpol_rebind_nodemask
,
357 .create
= mpol_new_preferred
,
358 .rebind
= mpol_rebind_preferred
,
361 .create
= mpol_new_bind
,
362 .rebind
= mpol_rebind_nodemask
,
366 static void gather_stats(struct page
*, void *, int pte_dirty
);
367 static void migrate_page_add(struct page
*page
, struct list_head
*pagelist
,
368 unsigned long flags
);
370 /* Scan through pages checking if pages follow certain conditions. */
371 static int check_pte_range(struct vm_area_struct
*vma
, pmd_t
*pmd
,
372 unsigned long addr
, unsigned long end
,
373 const nodemask_t
*nodes
, unsigned long flags
,
380 orig_pte
= pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
385 if (!pte_present(*pte
))
387 page
= vm_normal_page(vma
, addr
, *pte
);
391 * The check for PageReserved here is important to avoid
392 * handling zero pages and other pages that may have been
393 * marked special by the system.
395 * If the PageReserved would not be checked here then f.e.
396 * the location of the zero page could have an influence
397 * on MPOL_MF_STRICT, zero pages would be counted for
398 * the per node stats, and there would be useless attempts
399 * to put zero pages on the migration list.
401 if (PageReserved(page
))
403 nid
= page_to_nid(page
);
404 if (node_isset(nid
, *nodes
) == !!(flags
& MPOL_MF_INVERT
))
407 if (flags
& MPOL_MF_STATS
)
408 gather_stats(page
, private, pte_dirty(*pte
));
409 else if (flags
& (MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
))
410 migrate_page_add(page
, private, flags
);
413 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
414 pte_unmap_unlock(orig_pte
, ptl
);
418 static inline int check_pmd_range(struct vm_area_struct
*vma
, pud_t
*pud
,
419 unsigned long addr
, unsigned long end
,
420 const nodemask_t
*nodes
, unsigned long flags
,
426 pmd
= pmd_offset(pud
, addr
);
428 next
= pmd_addr_end(addr
, end
);
429 if (pmd_none_or_clear_bad(pmd
))
431 if (check_pte_range(vma
, pmd
, addr
, next
, nodes
,
434 } while (pmd
++, addr
= next
, addr
!= end
);
438 static inline int check_pud_range(struct vm_area_struct
*vma
, pgd_t
*pgd
,
439 unsigned long addr
, unsigned long end
,
440 const nodemask_t
*nodes
, unsigned long flags
,
446 pud
= pud_offset(pgd
, addr
);
448 next
= pud_addr_end(addr
, end
);
449 if (pud_none_or_clear_bad(pud
))
451 if (check_pmd_range(vma
, pud
, addr
, next
, nodes
,
454 } while (pud
++, addr
= next
, addr
!= end
);
458 static inline int check_pgd_range(struct vm_area_struct
*vma
,
459 unsigned long addr
, unsigned long end
,
460 const nodemask_t
*nodes
, unsigned long flags
,
466 pgd
= pgd_offset(vma
->vm_mm
, addr
);
468 next
= pgd_addr_end(addr
, end
);
469 if (pgd_none_or_clear_bad(pgd
))
471 if (check_pud_range(vma
, pgd
, addr
, next
, nodes
,
474 } while (pgd
++, addr
= next
, addr
!= end
);
479 * Check if all pages in a range are on a set of nodes.
480 * If pagelist != NULL then isolate pages from the LRU and
481 * put them on the pagelist.
483 static struct vm_area_struct
*
484 check_range(struct mm_struct
*mm
, unsigned long start
, unsigned long end
,
485 const nodemask_t
*nodes
, unsigned long flags
, void *private)
488 struct vm_area_struct
*first
, *vma
, *prev
;
490 if (flags
& (MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
)) {
492 err
= migrate_prep();
497 first
= find_vma(mm
, start
);
499 return ERR_PTR(-EFAULT
);
501 for (vma
= first
; vma
&& vma
->vm_start
< end
; vma
= vma
->vm_next
) {
502 if (!(flags
& MPOL_MF_DISCONTIG_OK
)) {
503 if (!vma
->vm_next
&& vma
->vm_end
< end
)
504 return ERR_PTR(-EFAULT
);
505 if (prev
&& prev
->vm_end
< vma
->vm_start
)
506 return ERR_PTR(-EFAULT
);
508 if (!is_vm_hugetlb_page(vma
) &&
509 ((flags
& MPOL_MF_STRICT
) ||
510 ((flags
& (MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
)) &&
511 vma_migratable(vma
)))) {
512 unsigned long endvma
= vma
->vm_end
;
516 if (vma
->vm_start
> start
)
517 start
= vma
->vm_start
;
518 err
= check_pgd_range(vma
, start
, endvma
, nodes
,
521 first
= ERR_PTR(err
);
530 /* Apply policy to a single VMA */
531 static int policy_vma(struct vm_area_struct
*vma
, struct mempolicy
*new)
534 struct mempolicy
*old
= vma
->vm_policy
;
536 pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
537 vma
->vm_start
, vma
->vm_end
, vma
->vm_pgoff
,
538 vma
->vm_ops
, vma
->vm_file
,
539 vma
->vm_ops
? vma
->vm_ops
->set_policy
: NULL
);
541 if (vma
->vm_ops
&& vma
->vm_ops
->set_policy
)
542 err
= vma
->vm_ops
->set_policy(vma
, new);
545 vma
->vm_policy
= new;
551 /* Step 2: apply policy to a range and do splits. */
552 static int mbind_range(struct vm_area_struct
*vma
, unsigned long start
,
553 unsigned long end
, struct mempolicy
*new)
555 struct vm_area_struct
*next
;
559 for (; vma
&& vma
->vm_start
< end
; vma
= next
) {
561 if (vma
->vm_start
< start
)
562 err
= split_vma(vma
->vm_mm
, vma
, start
, 1);
563 if (!err
&& vma
->vm_end
> end
)
564 err
= split_vma(vma
->vm_mm
, vma
, end
, 0);
566 err
= policy_vma(vma
, new);
574 * Update task->flags PF_MEMPOLICY bit: set iff non-default
575 * mempolicy. Allows more rapid checking of this (combined perhaps
576 * with other PF_* flag bits) on memory allocation hot code paths.
578 * If called from outside this file, the task 'p' should -only- be
579 * a newly forked child not yet visible on the task list, because
580 * manipulating the task flags of a visible task is not safe.
582 * The above limitation is why this routine has the funny name
583 * mpol_fix_fork_child_flag().
585 * It is also safe to call this with a task pointer of current,
586 * which the static wrapper mpol_set_task_struct_flag() does,
587 * for use within this file.
590 void mpol_fix_fork_child_flag(struct task_struct
*p
)
593 p
->flags
|= PF_MEMPOLICY
;
595 p
->flags
&= ~PF_MEMPOLICY
;
598 static void mpol_set_task_struct_flag(void)
600 mpol_fix_fork_child_flag(current
);
603 /* Set the process memory policy */
604 static long do_set_mempolicy(unsigned short mode
, unsigned short flags
,
607 struct mempolicy
*new;
608 struct mm_struct
*mm
= current
->mm
;
610 new = mpol_new(mode
, flags
, nodes
);
615 * prevent changing our mempolicy while show_numa_maps()
617 * Note: do_set_mempolicy() can be called at init time
621 down_write(&mm
->mmap_sem
);
622 mpol_put(current
->mempolicy
);
623 current
->mempolicy
= new;
624 mpol_set_task_struct_flag();
625 if (new && new->mode
== MPOL_INTERLEAVE
&&
626 nodes_weight(new->v
.nodes
))
627 current
->il_next
= first_node(new->v
.nodes
);
629 up_write(&mm
->mmap_sem
);
635 * Return nodemask for policy for get_mempolicy() query
637 static void get_policy_nodemask(struct mempolicy
*p
, nodemask_t
*nodes
)
640 if (p
== &default_policy
)
646 case MPOL_INTERLEAVE
:
650 if (!(p
->flags
& MPOL_F_LOCAL
))
651 node_set(p
->v
.preferred_node
, *nodes
);
652 /* else return empty node mask for local allocation */
659 static int lookup_node(struct mm_struct
*mm
, unsigned long addr
)
664 err
= get_user_pages(current
, mm
, addr
& PAGE_MASK
, 1, 0, 0, &p
, NULL
);
666 err
= page_to_nid(p
);
672 /* Retrieve NUMA policy */
673 static long do_get_mempolicy(int *policy
, nodemask_t
*nmask
,
674 unsigned long addr
, unsigned long flags
)
677 struct mm_struct
*mm
= current
->mm
;
678 struct vm_area_struct
*vma
= NULL
;
679 struct mempolicy
*pol
= current
->mempolicy
;
681 cpuset_update_task_memory_state();
683 ~(unsigned long)(MPOL_F_NODE
|MPOL_F_ADDR
|MPOL_F_MEMS_ALLOWED
))
686 if (flags
& MPOL_F_MEMS_ALLOWED
) {
687 if (flags
& (MPOL_F_NODE
|MPOL_F_ADDR
))
689 *policy
= 0; /* just so it's initialized */
690 *nmask
= cpuset_current_mems_allowed
;
694 if (flags
& MPOL_F_ADDR
) {
696 * Do NOT fall back to task policy if the
697 * vma/shared policy at addr is NULL. We
698 * want to return MPOL_DEFAULT in this case.
700 down_read(&mm
->mmap_sem
);
701 vma
= find_vma_intersection(mm
, addr
, addr
+1);
703 up_read(&mm
->mmap_sem
);
706 if (vma
->vm_ops
&& vma
->vm_ops
->get_policy
)
707 pol
= vma
->vm_ops
->get_policy(vma
, addr
);
709 pol
= vma
->vm_policy
;
714 pol
= &default_policy
; /* indicates default behavior */
716 if (flags
& MPOL_F_NODE
) {
717 if (flags
& MPOL_F_ADDR
) {
718 err
= lookup_node(mm
, addr
);
722 } else if (pol
== current
->mempolicy
&&
723 pol
->mode
== MPOL_INTERLEAVE
) {
724 *policy
= current
->il_next
;
730 *policy
= pol
== &default_policy
? MPOL_DEFAULT
:
733 * Internal mempolicy flags must be masked off before exposing
734 * the policy to userspace.
736 *policy
|= (pol
->flags
& MPOL_MODE_FLAGS
);
740 up_read(¤t
->mm
->mmap_sem
);
746 get_policy_nodemask(pol
, nmask
);
751 up_read(¤t
->mm
->mmap_sem
);
755 #ifdef CONFIG_MIGRATION
759 static void migrate_page_add(struct page
*page
, struct list_head
*pagelist
,
763 * Avoid migrating a page that is shared with others.
765 if ((flags
& MPOL_MF_MOVE_ALL
) || page_mapcount(page
) == 1)
766 isolate_lru_page(page
, pagelist
);
769 static struct page
*new_node_page(struct page
*page
, unsigned long node
, int **x
)
771 return alloc_pages_node(node
, GFP_HIGHUSER_MOVABLE
, 0);
775 * Migrate pages from one node to a target node.
776 * Returns error or the number of pages not migrated.
778 static int migrate_to_node(struct mm_struct
*mm
, int source
, int dest
,
786 node_set(source
, nmask
);
788 check_range(mm
, mm
->mmap
->vm_start
, TASK_SIZE
, &nmask
,
789 flags
| MPOL_MF_DISCONTIG_OK
, &pagelist
);
791 if (!list_empty(&pagelist
))
792 err
= migrate_pages(&pagelist
, new_node_page
, dest
);
798 * Move pages between the two nodesets so as to preserve the physical
799 * layout as much as possible.
801 * Returns the number of page that could not be moved.
803 int do_migrate_pages(struct mm_struct
*mm
,
804 const nodemask_t
*from_nodes
, const nodemask_t
*to_nodes
, int flags
)
811 down_read(&mm
->mmap_sem
);
813 err
= migrate_vmas(mm
, from_nodes
, to_nodes
, flags
);
818 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
819 * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
820 * bit in 'tmp', and return that <source, dest> pair for migration.
821 * The pair of nodemasks 'to' and 'from' define the map.
823 * If no pair of bits is found that way, fallback to picking some
824 * pair of 'source' and 'dest' bits that are not the same. If the
825 * 'source' and 'dest' bits are the same, this represents a node
826 * that will be migrating to itself, so no pages need move.
828 * If no bits are left in 'tmp', or if all remaining bits left
829 * in 'tmp' correspond to the same bit in 'to', return false
830 * (nothing left to migrate).
832 * This lets us pick a pair of nodes to migrate between, such that
833 * if possible the dest node is not already occupied by some other
834 * source node, minimizing the risk of overloading the memory on a
835 * node that would happen if we migrated incoming memory to a node
836 * before migrating outgoing memory source that same node.
838 * A single scan of tmp is sufficient. As we go, we remember the
839 * most recent <s, d> pair that moved (s != d). If we find a pair
840 * that not only moved, but what's better, moved to an empty slot
841 * (d is not set in tmp), then we break out then, with that pair.
842 * Otherwise when we finish scannng from_tmp, we at least have the
843 * most recent <s, d> pair that moved. If we get all the way through
844 * the scan of tmp without finding any node that moved, much less
845 * moved to an empty node, then there is nothing left worth migrating.
849 while (!nodes_empty(tmp
)) {
854 for_each_node_mask(s
, tmp
) {
855 d
= node_remap(s
, *from_nodes
, *to_nodes
);
859 source
= s
; /* Node moved. Memorize */
862 /* dest not in remaining from nodes? */
863 if (!node_isset(dest
, tmp
))
869 node_clear(source
, tmp
);
870 err
= migrate_to_node(mm
, source
, dest
, flags
);
877 up_read(&mm
->mmap_sem
);
885 * Allocate a new page for page migration based on vma policy.
886 * Start assuming that page is mapped by vma pointed to by @private.
887 * Search forward from there, if not. N.B., this assumes that the
888 * list of pages handed to migrate_pages()--which is how we get here--
889 * is in virtual address order.
891 static struct page
*new_vma_page(struct page
*page
, unsigned long private, int **x
)
893 struct vm_area_struct
*vma
= (struct vm_area_struct
*)private;
894 unsigned long uninitialized_var(address
);
897 address
= page_address_in_vma(page
, vma
);
898 if (address
!= -EFAULT
)
904 * if !vma, alloc_page_vma() will use task or system default policy
906 return alloc_page_vma(GFP_HIGHUSER_MOVABLE
, vma
, address
);
910 static void migrate_page_add(struct page
*page
, struct list_head
*pagelist
,
915 int do_migrate_pages(struct mm_struct
*mm
,
916 const nodemask_t
*from_nodes
, const nodemask_t
*to_nodes
, int flags
)
921 static struct page
*new_vma_page(struct page
*page
, unsigned long private, int **x
)
927 static long do_mbind(unsigned long start
, unsigned long len
,
928 unsigned short mode
, unsigned short mode_flags
,
929 nodemask_t
*nmask
, unsigned long flags
)
931 struct vm_area_struct
*vma
;
932 struct mm_struct
*mm
= current
->mm
;
933 struct mempolicy
*new;
938 if (flags
& ~(unsigned long)(MPOL_MF_STRICT
|
939 MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
))
941 if ((flags
& MPOL_MF_MOVE_ALL
) && !capable(CAP_SYS_NICE
))
944 if (start
& ~PAGE_MASK
)
947 if (mode
== MPOL_DEFAULT
)
948 flags
&= ~MPOL_MF_STRICT
;
950 len
= (len
+ PAGE_SIZE
- 1) & PAGE_MASK
;
958 new = mpol_new(mode
, mode_flags
, nmask
);
963 * If we are using the default policy then operation
964 * on discontinuous address spaces is okay after all
967 flags
|= MPOL_MF_DISCONTIG_OK
;
969 pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
970 start
, start
+ len
, mode
, mode_flags
,
971 nmask
? nodes_addr(*nmask
)[0] : -1);
973 down_write(&mm
->mmap_sem
);
974 vma
= check_range(mm
, start
, end
, nmask
,
975 flags
| MPOL_MF_INVERT
, &pagelist
);
981 err
= mbind_range(vma
, start
, end
, new);
983 if (!list_empty(&pagelist
))
984 nr_failed
= migrate_pages(&pagelist
, new_vma_page
,
987 if (!err
&& nr_failed
&& (flags
& MPOL_MF_STRICT
))
991 up_write(&mm
->mmap_sem
);
997 * User space interface with variable sized bitmaps for nodelists.
1000 /* Copy a node mask from user space. */
1001 static int get_nodes(nodemask_t
*nodes
, const unsigned long __user
*nmask
,
1002 unsigned long maxnode
)
1005 unsigned long nlongs
;
1006 unsigned long endmask
;
1009 nodes_clear(*nodes
);
1010 if (maxnode
== 0 || !nmask
)
1012 if (maxnode
> PAGE_SIZE
*BITS_PER_BYTE
)
1015 nlongs
= BITS_TO_LONGS(maxnode
);
1016 if ((maxnode
% BITS_PER_LONG
) == 0)
1019 endmask
= (1UL << (maxnode
% BITS_PER_LONG
)) - 1;
1021 /* When the user specified more nodes than supported just check
1022 if the non supported part is all zero. */
1023 if (nlongs
> BITS_TO_LONGS(MAX_NUMNODES
)) {
1024 if (nlongs
> PAGE_SIZE
/sizeof(long))
1026 for (k
= BITS_TO_LONGS(MAX_NUMNODES
); k
< nlongs
; k
++) {
1028 if (get_user(t
, nmask
+ k
))
1030 if (k
== nlongs
- 1) {
1036 nlongs
= BITS_TO_LONGS(MAX_NUMNODES
);
1040 if (copy_from_user(nodes_addr(*nodes
), nmask
, nlongs
*sizeof(unsigned long)))
1042 nodes_addr(*nodes
)[nlongs
-1] &= endmask
;
1046 /* Copy a kernel node mask to user space */
1047 static int copy_nodes_to_user(unsigned long __user
*mask
, unsigned long maxnode
,
1050 unsigned long copy
= ALIGN(maxnode
-1, 64) / 8;
1051 const int nbytes
= BITS_TO_LONGS(MAX_NUMNODES
) * sizeof(long);
1053 if (copy
> nbytes
) {
1054 if (copy
> PAGE_SIZE
)
1056 if (clear_user((char __user
*)mask
+ nbytes
, copy
- nbytes
))
1060 return copy_to_user(mask
, nodes_addr(*nodes
), copy
) ? -EFAULT
: 0;
1063 asmlinkage
long sys_mbind(unsigned long start
, unsigned long len
,
1065 unsigned long __user
*nmask
, unsigned long maxnode
,
1070 unsigned short mode_flags
;
1072 mode_flags
= mode
& MPOL_MODE_FLAGS
;
1073 mode
&= ~MPOL_MODE_FLAGS
;
1074 if (mode
>= MPOL_MAX
)
1076 if ((mode_flags
& MPOL_F_STATIC_NODES
) &&
1077 (mode_flags
& MPOL_F_RELATIVE_NODES
))
1079 err
= get_nodes(&nodes
, nmask
, maxnode
);
1082 return do_mbind(start
, len
, mode
, mode_flags
, &nodes
, flags
);
1085 /* Set the process memory policy */
1086 asmlinkage
long sys_set_mempolicy(int mode
, unsigned long __user
*nmask
,
1087 unsigned long maxnode
)
1091 unsigned short flags
;
1093 flags
= mode
& MPOL_MODE_FLAGS
;
1094 mode
&= ~MPOL_MODE_FLAGS
;
1095 if ((unsigned int)mode
>= MPOL_MAX
)
1097 if ((flags
& MPOL_F_STATIC_NODES
) && (flags
& MPOL_F_RELATIVE_NODES
))
1099 err
= get_nodes(&nodes
, nmask
, maxnode
);
1102 return do_set_mempolicy(mode
, flags
, &nodes
);
1105 asmlinkage
long sys_migrate_pages(pid_t pid
, unsigned long maxnode
,
1106 const unsigned long __user
*old_nodes
,
1107 const unsigned long __user
*new_nodes
)
1109 struct mm_struct
*mm
;
1110 struct task_struct
*task
;
1113 nodemask_t task_nodes
;
1116 err
= get_nodes(&old
, old_nodes
, maxnode
);
1120 err
= get_nodes(&new, new_nodes
, maxnode
);
1124 /* Find the mm_struct */
1125 read_lock(&tasklist_lock
);
1126 task
= pid
? find_task_by_vpid(pid
) : current
;
1128 read_unlock(&tasklist_lock
);
1131 mm
= get_task_mm(task
);
1132 read_unlock(&tasklist_lock
);
1138 * Check if this process has the right to modify the specified
1139 * process. The right exists if the process has administrative
1140 * capabilities, superuser privileges or the same
1141 * userid as the target process.
1143 if ((current
->euid
!= task
->suid
) && (current
->euid
!= task
->uid
) &&
1144 (current
->uid
!= task
->suid
) && (current
->uid
!= task
->uid
) &&
1145 !capable(CAP_SYS_NICE
)) {
1150 task_nodes
= cpuset_mems_allowed(task
);
1151 /* Is the user allowed to access the target nodes? */
1152 if (!nodes_subset(new, task_nodes
) && !capable(CAP_SYS_NICE
)) {
1157 if (!nodes_subset(new, node_states
[N_HIGH_MEMORY
])) {
1162 err
= security_task_movememory(task
);
1166 err
= do_migrate_pages(mm
, &old
, &new,
1167 capable(CAP_SYS_NICE
) ? MPOL_MF_MOVE_ALL
: MPOL_MF_MOVE
);
1174 /* Retrieve NUMA policy */
1175 asmlinkage
long sys_get_mempolicy(int __user
*policy
,
1176 unsigned long __user
*nmask
,
1177 unsigned long maxnode
,
1178 unsigned long addr
, unsigned long flags
)
1181 int uninitialized_var(pval
);
1184 if (nmask
!= NULL
&& maxnode
< MAX_NUMNODES
)
1187 err
= do_get_mempolicy(&pval
, &nodes
, addr
, flags
);
1192 if (policy
&& put_user(pval
, policy
))
1196 err
= copy_nodes_to_user(nmask
, maxnode
, &nodes
);
1201 #ifdef CONFIG_COMPAT
1203 asmlinkage
long compat_sys_get_mempolicy(int __user
*policy
,
1204 compat_ulong_t __user
*nmask
,
1205 compat_ulong_t maxnode
,
1206 compat_ulong_t addr
, compat_ulong_t flags
)
1209 unsigned long __user
*nm
= NULL
;
1210 unsigned long nr_bits
, alloc_size
;
1211 DECLARE_BITMAP(bm
, MAX_NUMNODES
);
1213 nr_bits
= min_t(unsigned long, maxnode
-1, MAX_NUMNODES
);
1214 alloc_size
= ALIGN(nr_bits
, BITS_PER_LONG
) / 8;
1217 nm
= compat_alloc_user_space(alloc_size
);
1219 err
= sys_get_mempolicy(policy
, nm
, nr_bits
+1, addr
, flags
);
1221 if (!err
&& nmask
) {
1222 err
= copy_from_user(bm
, nm
, alloc_size
);
1223 /* ensure entire bitmap is zeroed */
1224 err
|= clear_user(nmask
, ALIGN(maxnode
-1, 8) / 8);
1225 err
|= compat_put_bitmap(nmask
, bm
, nr_bits
);
1231 asmlinkage
long compat_sys_set_mempolicy(int mode
, compat_ulong_t __user
*nmask
,
1232 compat_ulong_t maxnode
)
1235 unsigned long __user
*nm
= NULL
;
1236 unsigned long nr_bits
, alloc_size
;
1237 DECLARE_BITMAP(bm
, MAX_NUMNODES
);
1239 nr_bits
= min_t(unsigned long, maxnode
-1, MAX_NUMNODES
);
1240 alloc_size
= ALIGN(nr_bits
, BITS_PER_LONG
) / 8;
1243 err
= compat_get_bitmap(bm
, nmask
, nr_bits
);
1244 nm
= compat_alloc_user_space(alloc_size
);
1245 err
|= copy_to_user(nm
, bm
, alloc_size
);
1251 return sys_set_mempolicy(mode
, nm
, nr_bits
+1);
1254 asmlinkage
long compat_sys_mbind(compat_ulong_t start
, compat_ulong_t len
,
1255 compat_ulong_t mode
, compat_ulong_t __user
*nmask
,
1256 compat_ulong_t maxnode
, compat_ulong_t flags
)
1259 unsigned long __user
*nm
= NULL
;
1260 unsigned long nr_bits
, alloc_size
;
1263 nr_bits
= min_t(unsigned long, maxnode
-1, MAX_NUMNODES
);
1264 alloc_size
= ALIGN(nr_bits
, BITS_PER_LONG
) / 8;
1267 err
= compat_get_bitmap(nodes_addr(bm
), nmask
, nr_bits
);
1268 nm
= compat_alloc_user_space(alloc_size
);
1269 err
|= copy_to_user(nm
, nodes_addr(bm
), alloc_size
);
1275 return sys_mbind(start
, len
, mode
, nm
, nr_bits
+1, flags
);
1281 * get_vma_policy(@task, @vma, @addr)
1282 * @task - task for fallback if vma policy == default
1283 * @vma - virtual memory area whose policy is sought
1284 * @addr - address in @vma for shared policy lookup
1286 * Returns effective policy for a VMA at specified address.
1287 * Falls back to @task or system default policy, as necessary.
1288 * Current or other task's task mempolicy and non-shared vma policies
1289 * are protected by the task's mmap_sem, which must be held for read by
1291 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
1292 * count--added by the get_policy() vm_op, as appropriate--to protect against
1293 * freeing by another task. It is the caller's responsibility to free the
1294 * extra reference for shared policies.
1296 static struct mempolicy
*get_vma_policy(struct task_struct
*task
,
1297 struct vm_area_struct
*vma
, unsigned long addr
)
1299 struct mempolicy
*pol
= task
->mempolicy
;
1302 if (vma
->vm_ops
&& vma
->vm_ops
->get_policy
) {
1303 struct mempolicy
*vpol
= vma
->vm_ops
->get_policy(vma
,
1307 } else if (vma
->vm_policy
)
1308 pol
= vma
->vm_policy
;
1311 pol
= &default_policy
;
1316 * Return a nodemask representing a mempolicy for filtering nodes for
1319 static nodemask_t
*policy_nodemask(gfp_t gfp
, struct mempolicy
*policy
)
1321 /* Lower zones don't get a nodemask applied for MPOL_BIND */
1322 if (unlikely(policy
->mode
== MPOL_BIND
) &&
1323 gfp_zone(gfp
) >= policy_zone
&&
1324 cpuset_nodemask_valid_mems_allowed(&policy
->v
.nodes
))
1325 return &policy
->v
.nodes
;
1330 /* Return a zonelist indicated by gfp for node representing a mempolicy */
1331 static struct zonelist
*policy_zonelist(gfp_t gfp
, struct mempolicy
*policy
)
1333 int nd
= numa_node_id();
1335 switch (policy
->mode
) {
1336 case MPOL_PREFERRED
:
1337 if (!(policy
->flags
& MPOL_F_LOCAL
))
1338 nd
= policy
->v
.preferred_node
;
1342 * Normally, MPOL_BIND allocations are node-local within the
1343 * allowed nodemask. However, if __GFP_THISNODE is set and the
1344 * current node is part of the mask, we use the zonelist for
1345 * the first node in the mask instead.
1347 if (unlikely(gfp
& __GFP_THISNODE
) &&
1348 unlikely(!node_isset(nd
, policy
->v
.nodes
)))
1349 nd
= first_node(policy
->v
.nodes
);
1351 case MPOL_INTERLEAVE
: /* should not happen */
1356 return node_zonelist(nd
, gfp
);
1359 /* Do dynamic interleaving for a process */
1360 static unsigned interleave_nodes(struct mempolicy
*policy
)
1363 struct task_struct
*me
= current
;
1366 next
= next_node(nid
, policy
->v
.nodes
);
1367 if (next
>= MAX_NUMNODES
)
1368 next
= first_node(policy
->v
.nodes
);
1369 if (next
< MAX_NUMNODES
)
1375 * Depending on the memory policy provide a node from which to allocate the
1377 * @policy must be protected by freeing by the caller. If @policy is
1378 * the current task's mempolicy, this protection is implicit, as only the
1379 * task can change it's policy. The system default policy requires no
1382 unsigned slab_node(struct mempolicy
*policy
)
1384 if (!policy
|| policy
->flags
& MPOL_F_LOCAL
)
1385 return numa_node_id();
1387 switch (policy
->mode
) {
1388 case MPOL_PREFERRED
:
1390 * handled MPOL_F_LOCAL above
1392 return policy
->v
.preferred_node
;
1394 case MPOL_INTERLEAVE
:
1395 return interleave_nodes(policy
);
1399 * Follow bind policy behavior and start allocation at the
1402 struct zonelist
*zonelist
;
1404 enum zone_type highest_zoneidx
= gfp_zone(GFP_KERNEL
);
1405 zonelist
= &NODE_DATA(numa_node_id())->node_zonelists
[0];
1406 (void)first_zones_zonelist(zonelist
, highest_zoneidx
,
1417 /* Do static interleaving for a VMA with known offset. */
1418 static unsigned offset_il_node(struct mempolicy
*pol
,
1419 struct vm_area_struct
*vma
, unsigned long off
)
1421 unsigned nnodes
= nodes_weight(pol
->v
.nodes
);
1427 return numa_node_id();
1428 target
= (unsigned int)off
% nnodes
;
1431 nid
= next_node(nid
, pol
->v
.nodes
);
1433 } while (c
<= target
);
1437 /* Determine a node number for interleave */
1438 static inline unsigned interleave_nid(struct mempolicy
*pol
,
1439 struct vm_area_struct
*vma
, unsigned long addr
, int shift
)
1445 * for small pages, there is no difference between
1446 * shift and PAGE_SHIFT, so the bit-shift is safe.
1447 * for huge pages, since vm_pgoff is in units of small
1448 * pages, we need to shift off the always 0 bits to get
1451 BUG_ON(shift
< PAGE_SHIFT
);
1452 off
= vma
->vm_pgoff
>> (shift
- PAGE_SHIFT
);
1453 off
+= (addr
- vma
->vm_start
) >> shift
;
1454 return offset_il_node(pol
, vma
, off
);
1456 return interleave_nodes(pol
);
1459 #ifdef CONFIG_HUGETLBFS
1461 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
1462 * @vma = virtual memory area whose policy is sought
1463 * @addr = address in @vma for shared policy lookup and interleave policy
1464 * @gfp_flags = for requested zone
1465 * @mpol = pointer to mempolicy pointer for reference counted mempolicy
1466 * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
1468 * Returns a zonelist suitable for a huge page allocation and a pointer
1469 * to the struct mempolicy for conditional unref after allocation.
1470 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
1471 * @nodemask for filtering the zonelist.
1473 struct zonelist
*huge_zonelist(struct vm_area_struct
*vma
, unsigned long addr
,
1474 gfp_t gfp_flags
, struct mempolicy
**mpol
,
1475 nodemask_t
**nodemask
)
1477 struct zonelist
*zl
;
1479 *mpol
= get_vma_policy(current
, vma
, addr
);
1480 *nodemask
= NULL
; /* assume !MPOL_BIND */
1482 if (unlikely((*mpol
)->mode
== MPOL_INTERLEAVE
)) {
1483 zl
= node_zonelist(interleave_nid(*mpol
, vma
, addr
,
1484 HPAGE_SHIFT
), gfp_flags
);
1486 zl
= policy_zonelist(gfp_flags
, *mpol
);
1487 if ((*mpol
)->mode
== MPOL_BIND
)
1488 *nodemask
= &(*mpol
)->v
.nodes
;
1494 /* Allocate a page in interleaved policy.
1495 Own path because it needs to do special accounting. */
1496 static struct page
*alloc_page_interleave(gfp_t gfp
, unsigned order
,
1499 struct zonelist
*zl
;
1502 zl
= node_zonelist(nid
, gfp
);
1503 page
= __alloc_pages(gfp
, order
, zl
);
1504 if (page
&& page_zone(page
) == zonelist_zone(&zl
->_zonerefs
[0]))
1505 inc_zone_page_state(page
, NUMA_INTERLEAVE_HIT
);
1510 * alloc_page_vma - Allocate a page for a VMA.
1513 * %GFP_USER user allocation.
1514 * %GFP_KERNEL kernel allocations,
1515 * %GFP_HIGHMEM highmem/user allocations,
1516 * %GFP_FS allocation should not call back into a file system.
1517 * %GFP_ATOMIC don't sleep.
1519 * @vma: Pointer to VMA or NULL if not available.
1520 * @addr: Virtual Address of the allocation. Must be inside the VMA.
1522 * This function allocates a page from the kernel page pool and applies
1523 * a NUMA policy associated with the VMA or the current process.
1524 * When VMA is not NULL caller must hold down_read on the mmap_sem of the
1525 * mm_struct of the VMA to prevent it from going away. Should be used for
1526 * all allocations for pages that will be mapped into
1527 * user space. Returns NULL when no page can be allocated.
1529 * Should be called with the mm_sem of the vma hold.
1532 alloc_page_vma(gfp_t gfp
, struct vm_area_struct
*vma
, unsigned long addr
)
1534 struct mempolicy
*pol
= get_vma_policy(current
, vma
, addr
);
1535 struct zonelist
*zl
;
1537 cpuset_update_task_memory_state();
1539 if (unlikely(pol
->mode
== MPOL_INTERLEAVE
)) {
1542 nid
= interleave_nid(pol
, vma
, addr
, PAGE_SHIFT
);
1544 return alloc_page_interleave(gfp
, 0, nid
);
1546 zl
= policy_zonelist(gfp
, pol
);
1547 if (unlikely(mpol_needs_cond_ref(pol
))) {
1549 * slow path: ref counted shared policy
1551 struct page
*page
= __alloc_pages_nodemask(gfp
, 0,
1552 zl
, policy_nodemask(gfp
, pol
));
1557 * fast path: default or task policy
1559 return __alloc_pages_nodemask(gfp
, 0, zl
, policy_nodemask(gfp
, pol
));
1563 * alloc_pages_current - Allocate pages.
1566 * %GFP_USER user allocation,
1567 * %GFP_KERNEL kernel allocation,
1568 * %GFP_HIGHMEM highmem allocation,
1569 * %GFP_FS don't call back into a file system.
1570 * %GFP_ATOMIC don't sleep.
1571 * @order: Power of two of allocation size in pages. 0 is a single page.
1573 * Allocate a page from the kernel page pool. When not in
1574 * interrupt context and apply the current process NUMA policy.
1575 * Returns NULL when no page can be allocated.
1577 * Don't call cpuset_update_task_memory_state() unless
1578 * 1) it's ok to take cpuset_sem (can WAIT), and
1579 * 2) allocating for current task (not interrupt).
1581 struct page
*alloc_pages_current(gfp_t gfp
, unsigned order
)
1583 struct mempolicy
*pol
= current
->mempolicy
;
1585 if ((gfp
& __GFP_WAIT
) && !in_interrupt())
1586 cpuset_update_task_memory_state();
1587 if (!pol
|| in_interrupt() || (gfp
& __GFP_THISNODE
))
1588 pol
= &default_policy
;
1591 * No reference counting needed for current->mempolicy
1592 * nor system default_policy
1594 if (pol
->mode
== MPOL_INTERLEAVE
)
1595 return alloc_page_interleave(gfp
, order
, interleave_nodes(pol
));
1596 return __alloc_pages_nodemask(gfp
, order
,
1597 policy_zonelist(gfp
, pol
), policy_nodemask(gfp
, pol
));
1599 EXPORT_SYMBOL(alloc_pages_current
);
1602 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
1603 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
1604 * with the mems_allowed returned by cpuset_mems_allowed(). This
1605 * keeps mempolicies cpuset relative after its cpuset moves. See
1606 * further kernel/cpuset.c update_nodemask().
1609 /* Slow path of a mempolicy duplicate */
1610 struct mempolicy
*__mpol_dup(struct mempolicy
*old
)
1612 struct mempolicy
*new = kmem_cache_alloc(policy_cache
, GFP_KERNEL
);
1615 return ERR_PTR(-ENOMEM
);
1616 if (current_cpuset_is_being_rebound()) {
1617 nodemask_t mems
= cpuset_mems_allowed(current
);
1618 mpol_rebind_policy(old
, &mems
);
1621 atomic_set(&new->refcnt
, 1);
1626 * If *frompol needs [has] an extra ref, copy *frompol to *tompol ,
1627 * eliminate the * MPOL_F_* flags that require conditional ref and
1628 * [NOTE!!!] drop the extra ref. Not safe to reference *frompol directly
1629 * after return. Use the returned value.
1631 * Allows use of a mempolicy for, e.g., multiple allocations with a single
1632 * policy lookup, even if the policy needs/has extra ref on lookup.
1633 * shmem_readahead needs this.
1635 struct mempolicy
*__mpol_cond_copy(struct mempolicy
*tompol
,
1636 struct mempolicy
*frompol
)
1638 if (!mpol_needs_cond_ref(frompol
))
1642 tompol
->flags
&= ~MPOL_F_SHARED
; /* copy doesn't need unref */
1643 __mpol_put(frompol
);
1647 static int mpol_match_intent(const struct mempolicy
*a
,
1648 const struct mempolicy
*b
)
1650 if (a
->flags
!= b
->flags
)
1652 if (!mpol_store_user_nodemask(a
))
1654 return nodes_equal(a
->w
.user_nodemask
, b
->w
.user_nodemask
);
1657 /* Slow path of a mempolicy comparison */
1658 int __mpol_equal(struct mempolicy
*a
, struct mempolicy
*b
)
1662 if (a
->mode
!= b
->mode
)
1664 if (a
->mode
!= MPOL_DEFAULT
&& !mpol_match_intent(a
, b
))
1669 case MPOL_INTERLEAVE
:
1670 return nodes_equal(a
->v
.nodes
, b
->v
.nodes
);
1671 case MPOL_PREFERRED
:
1672 return a
->v
.preferred_node
== b
->v
.preferred_node
&&
1673 a
->flags
== b
->flags
;
1681 * Shared memory backing store policy support.
1683 * Remember policies even when nobody has shared memory mapped.
1684 * The policies are kept in Red-Black tree linked from the inode.
1685 * They are protected by the sp->lock spinlock, which should be held
1686 * for any accesses to the tree.
1689 /* lookup first element intersecting start-end */
1690 /* Caller holds sp->lock */
1691 static struct sp_node
*
1692 sp_lookup(struct shared_policy
*sp
, unsigned long start
, unsigned long end
)
1694 struct rb_node
*n
= sp
->root
.rb_node
;
1697 struct sp_node
*p
= rb_entry(n
, struct sp_node
, nd
);
1699 if (start
>= p
->end
)
1701 else if (end
<= p
->start
)
1709 struct sp_node
*w
= NULL
;
1710 struct rb_node
*prev
= rb_prev(n
);
1713 w
= rb_entry(prev
, struct sp_node
, nd
);
1714 if (w
->end
<= start
)
1718 return rb_entry(n
, struct sp_node
, nd
);
1721 /* Insert a new shared policy into the list. */
1722 /* Caller holds sp->lock */
1723 static void sp_insert(struct shared_policy
*sp
, struct sp_node
*new)
1725 struct rb_node
**p
= &sp
->root
.rb_node
;
1726 struct rb_node
*parent
= NULL
;
1731 nd
= rb_entry(parent
, struct sp_node
, nd
);
1732 if (new->start
< nd
->start
)
1734 else if (new->end
> nd
->end
)
1735 p
= &(*p
)->rb_right
;
1739 rb_link_node(&new->nd
, parent
, p
);
1740 rb_insert_color(&new->nd
, &sp
->root
);
1741 pr_debug("inserting %lx-%lx: %d\n", new->start
, new->end
,
1742 new->policy
? new->policy
->mode
: 0);
1745 /* Find shared policy intersecting idx */
1747 mpol_shared_policy_lookup(struct shared_policy
*sp
, unsigned long idx
)
1749 struct mempolicy
*pol
= NULL
;
1752 if (!sp
->root
.rb_node
)
1754 spin_lock(&sp
->lock
);
1755 sn
= sp_lookup(sp
, idx
, idx
+1);
1757 mpol_get(sn
->policy
);
1760 spin_unlock(&sp
->lock
);
1764 static void sp_delete(struct shared_policy
*sp
, struct sp_node
*n
)
1766 pr_debug("deleting %lx-l%lx\n", n
->start
, n
->end
);
1767 rb_erase(&n
->nd
, &sp
->root
);
1768 mpol_put(n
->policy
);
1769 kmem_cache_free(sn_cache
, n
);
1772 static struct sp_node
*sp_alloc(unsigned long start
, unsigned long end
,
1773 struct mempolicy
*pol
)
1775 struct sp_node
*n
= kmem_cache_alloc(sn_cache
, GFP_KERNEL
);
1782 pol
->flags
|= MPOL_F_SHARED
; /* for unref */
1787 /* Replace a policy range. */
1788 static int shared_policy_replace(struct shared_policy
*sp
, unsigned long start
,
1789 unsigned long end
, struct sp_node
*new)
1791 struct sp_node
*n
, *new2
= NULL
;
1794 spin_lock(&sp
->lock
);
1795 n
= sp_lookup(sp
, start
, end
);
1796 /* Take care of old policies in the same range. */
1797 while (n
&& n
->start
< end
) {
1798 struct rb_node
*next
= rb_next(&n
->nd
);
1799 if (n
->start
>= start
) {
1805 /* Old policy spanning whole new range. */
1808 spin_unlock(&sp
->lock
);
1809 new2
= sp_alloc(end
, n
->end
, n
->policy
);
1815 sp_insert(sp
, new2
);
1823 n
= rb_entry(next
, struct sp_node
, nd
);
1827 spin_unlock(&sp
->lock
);
1829 mpol_put(new2
->policy
);
1830 kmem_cache_free(sn_cache
, new2
);
1836 * mpol_shared_policy_init - initialize shared policy for inode
1837 * @sp: pointer to inode shared policy
1838 * @mpol: struct mempolicy to install
1840 * Install non-NULL @mpol in inode's shared policy rb-tree.
1841 * On entry, the current task has a reference on a non-NULL @mpol.
1842 * This must be released on exit.
1844 void mpol_shared_policy_init(struct shared_policy
*sp
, struct mempolicy
*mpol
)
1846 sp
->root
= RB_ROOT
; /* empty tree == default mempolicy */
1847 spin_lock_init(&sp
->lock
);
1850 struct vm_area_struct pvma
;
1851 struct mempolicy
*new;
1853 /* contextualize the tmpfs mount point mempolicy */
1854 new = mpol_new(mpol
->mode
, mpol
->flags
, &mpol
->w
.user_nodemask
);
1855 mpol_put(mpol
); /* drop our ref on sb mpol */
1857 return; /* no valid nodemask intersection */
1859 /* Create pseudo-vma that contains just the policy */
1860 memset(&pvma
, 0, sizeof(struct vm_area_struct
));
1861 pvma
.vm_end
= TASK_SIZE
; /* policy covers entire file */
1862 mpol_set_shared_policy(sp
, &pvma
, new); /* adds ref */
1863 mpol_put(new); /* drop initial ref */
1867 int mpol_set_shared_policy(struct shared_policy
*info
,
1868 struct vm_area_struct
*vma
, struct mempolicy
*npol
)
1871 struct sp_node
*new = NULL
;
1872 unsigned long sz
= vma_pages(vma
);
1874 pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
1876 sz
, npol
? npol
->mode
: -1,
1877 npol
? npol
->flags
: -1,
1878 npol
? nodes_addr(npol
->v
.nodes
)[0] : -1);
1881 new = sp_alloc(vma
->vm_pgoff
, vma
->vm_pgoff
+ sz
, npol
);
1885 err
= shared_policy_replace(info
, vma
->vm_pgoff
, vma
->vm_pgoff
+sz
, new);
1887 kmem_cache_free(sn_cache
, new);
1891 /* Free a backing policy store on inode delete. */
1892 void mpol_free_shared_policy(struct shared_policy
*p
)
1895 struct rb_node
*next
;
1897 if (!p
->root
.rb_node
)
1899 spin_lock(&p
->lock
);
1900 next
= rb_first(&p
->root
);
1902 n
= rb_entry(next
, struct sp_node
, nd
);
1903 next
= rb_next(&n
->nd
);
1904 rb_erase(&n
->nd
, &p
->root
);
1905 mpol_put(n
->policy
);
1906 kmem_cache_free(sn_cache
, n
);
1908 spin_unlock(&p
->lock
);
1911 /* assumes fs == KERNEL_DS */
1912 void __init
numa_policy_init(void)
1914 nodemask_t interleave_nodes
;
1915 unsigned long largest
= 0;
1916 int nid
, prefer
= 0;
1918 policy_cache
= kmem_cache_create("numa_policy",
1919 sizeof(struct mempolicy
),
1920 0, SLAB_PANIC
, NULL
);
1922 sn_cache
= kmem_cache_create("shared_policy_node",
1923 sizeof(struct sp_node
),
1924 0, SLAB_PANIC
, NULL
);
1927 * Set interleaving policy for system init. Interleaving is only
1928 * enabled across suitably sized nodes (default is >= 16MB), or
1929 * fall back to the largest node if they're all smaller.
1931 nodes_clear(interleave_nodes
);
1932 for_each_node_state(nid
, N_HIGH_MEMORY
) {
1933 unsigned long total_pages
= node_present_pages(nid
);
1935 /* Preserve the largest node */
1936 if (largest
< total_pages
) {
1937 largest
= total_pages
;
1941 /* Interleave this node? */
1942 if ((total_pages
<< PAGE_SHIFT
) >= (16 << 20))
1943 node_set(nid
, interleave_nodes
);
1946 /* All too small, use the largest */
1947 if (unlikely(nodes_empty(interleave_nodes
)))
1948 node_set(prefer
, interleave_nodes
);
1950 if (do_set_mempolicy(MPOL_INTERLEAVE
, 0, &interleave_nodes
))
1951 printk("numa_policy_init: interleaving failed\n");
1954 /* Reset policy of current process to default */
1955 void numa_default_policy(void)
1957 do_set_mempolicy(MPOL_DEFAULT
, 0, NULL
);
1961 * Parse and format mempolicy from/to strings
1965 * "local" is pseudo-policy: MPOL_PREFERRED with MPOL_F_LOCAL flag
1966 * Used only for mpol_parse_str() and mpol_to_str()
1968 #define MPOL_LOCAL (MPOL_INTERLEAVE + 1)
1969 static const char * const policy_types
[] =
1970 { "default", "prefer", "bind", "interleave", "local" };
1975 * mpol_parse_str - parse string to mempolicy
1976 * @str: string containing mempolicy to parse
1977 * @mpol: pointer to struct mempolicy pointer, returned on success.
1978 * @no_context: flag whether to "contextualize" the mempolicy
1981 * <mode>[=<flags>][:<nodelist>]
1983 * if @no_context is true, save the input nodemask in w.user_nodemask in
1984 * the returned mempolicy. This will be used to "clone" the mempolicy in
1985 * a specific context [cpuset] at a later time. Used to parse tmpfs mpol
1986 * mount option. Note that if 'static' or 'relative' mode flags were
1987 * specified, the input nodemask will already have been saved. Saving
1988 * it again is redundant, but safe.
1990 * On success, returns 0, else 1
1992 int mpol_parse_str(char *str
, struct mempolicy
**mpol
, int no_context
)
1994 struct mempolicy
*new = NULL
;
1995 unsigned short uninitialized_var(mode
);
1996 unsigned short uninitialized_var(mode_flags
);
1998 char *nodelist
= strchr(str
, ':');
1999 char *flags
= strchr(str
, '=');
2004 /* NUL-terminate mode or flags string */
2006 if (nodelist_parse(nodelist
, nodes
))
2008 if (!nodes_subset(nodes
, node_states
[N_HIGH_MEMORY
]))
2014 *flags
++ = '\0'; /* terminate mode string */
2016 for (i
= 0; i
<= MPOL_LOCAL
; i
++) {
2017 if (!strcmp(str
, policy_types
[i
])) {
2026 case MPOL_PREFERRED
:
2028 * Insist on a nodelist of one node only
2031 char *rest
= nodelist
;
2032 while (isdigit(*rest
))
2038 case MPOL_INTERLEAVE
:
2040 * Default to online nodes with memory if no nodelist
2043 nodes
= node_states
[N_HIGH_MEMORY
];
2048 * Don't allow a nodelist; mpol_new() checks flags
2052 mode
= MPOL_PREFERRED
;
2056 * case MPOL_BIND: mpol_new() enforces non-empty nodemask.
2057 * case MPOL_DEFAULT: mpol_new() enforces empty nodemask, ignores flags.
2064 * Currently, we only support two mutually exclusive
2067 if (!strcmp(flags
, "static"))
2068 mode_flags
|= MPOL_F_STATIC_NODES
;
2069 else if (!strcmp(flags
, "relative"))
2070 mode_flags
|= MPOL_F_RELATIVE_NODES
;
2075 new = mpol_new(mode
, mode_flags
, &nodes
);
2078 else if (no_context
)
2079 new->w
.user_nodemask
= nodes
; /* save for contextualization */
2082 /* Restore string for error message */
2091 #endif /* CONFIG_TMPFS */
2094 * mpol_to_str - format a mempolicy structure for printing
2095 * @buffer: to contain formatted mempolicy string
2096 * @maxlen: length of @buffer
2097 * @pol: pointer to mempolicy to be formatted
2098 * @no_context: "context free" mempolicy - use nodemask in w.user_nodemask
2100 * Convert a mempolicy into a string.
2101 * Returns the number of characters in buffer (if positive)
2102 * or an error (negative)
2104 int mpol_to_str(char *buffer
, int maxlen
, struct mempolicy
*pol
, int no_context
)
2109 unsigned short mode
;
2110 unsigned short flags
= pol
? pol
->flags
: 0;
2113 * Sanity check: room for longest mode, flag and some nodes
2115 VM_BUG_ON(maxlen
< strlen("interleave") + strlen("relative") + 16);
2117 if (!pol
|| pol
== &default_policy
)
2118 mode
= MPOL_DEFAULT
;
2127 case MPOL_PREFERRED
:
2129 if (flags
& MPOL_F_LOCAL
)
2130 mode
= MPOL_LOCAL
; /* pseudo-policy */
2132 node_set(pol
->v
.preferred_node
, nodes
);
2137 case MPOL_INTERLEAVE
:
2139 nodes
= pol
->w
.user_nodemask
;
2141 nodes
= pol
->v
.nodes
;
2148 l
= strlen(policy_types
[mode
]);
2149 if (buffer
+ maxlen
< p
+ l
+ 1)
2152 strcpy(p
, policy_types
[mode
]);
2155 if (flags
& MPOL_MODE_FLAGS
) {
2156 if (buffer
+ maxlen
< p
+ 2)
2161 * Currently, the only defined flags are mutually exclusive
2163 if (flags
& MPOL_F_STATIC_NODES
)
2164 p
+= snprintf(p
, buffer
+ maxlen
- p
, "static");
2165 else if (flags
& MPOL_F_RELATIVE_NODES
)
2166 p
+= snprintf(p
, buffer
+ maxlen
- p
, "relative");
2169 if (!nodes_empty(nodes
)) {
2170 if (buffer
+ maxlen
< p
+ 2)
2173 p
+= nodelist_scnprintf(p
, buffer
+ maxlen
- p
, nodes
);
2179 unsigned long pages
;
2181 unsigned long active
;
2182 unsigned long writeback
;
2183 unsigned long mapcount_max
;
2184 unsigned long dirty
;
2185 unsigned long swapcache
;
2186 unsigned long node
[MAX_NUMNODES
];
2189 static void gather_stats(struct page
*page
, void *private, int pte_dirty
)
2191 struct numa_maps
*md
= private;
2192 int count
= page_mapcount(page
);
2195 if (pte_dirty
|| PageDirty(page
))
2198 if (PageSwapCache(page
))
2201 if (PageActive(page
))
2204 if (PageWriteback(page
))
2210 if (count
> md
->mapcount_max
)
2211 md
->mapcount_max
= count
;
2213 md
->node
[page_to_nid(page
)]++;
2216 #ifdef CONFIG_HUGETLB_PAGE
2217 static void check_huge_range(struct vm_area_struct
*vma
,
2218 unsigned long start
, unsigned long end
,
2219 struct numa_maps
*md
)
2224 for (addr
= start
; addr
< end
; addr
+= HPAGE_SIZE
) {
2225 pte_t
*ptep
= huge_pte_offset(vma
->vm_mm
, addr
& HPAGE_MASK
);
2235 page
= pte_page(pte
);
2239 gather_stats(page
, md
, pte_dirty(*ptep
));
2243 static inline void check_huge_range(struct vm_area_struct
*vma
,
2244 unsigned long start
, unsigned long end
,
2245 struct numa_maps
*md
)
2251 * Display pages allocated per node and memory policy via /proc.
2253 int show_numa_map(struct seq_file
*m
, void *v
)
2255 struct proc_maps_private
*priv
= m
->private;
2256 struct vm_area_struct
*vma
= v
;
2257 struct numa_maps
*md
;
2258 struct file
*file
= vma
->vm_file
;
2259 struct mm_struct
*mm
= vma
->vm_mm
;
2260 struct mempolicy
*pol
;
2267 md
= kzalloc(sizeof(struct numa_maps
), GFP_KERNEL
);
2271 pol
= get_vma_policy(priv
->task
, vma
, vma
->vm_start
);
2272 mpol_to_str(buffer
, sizeof(buffer
), pol
, 0);
2275 seq_printf(m
, "%08lx %s", vma
->vm_start
, buffer
);
2278 seq_printf(m
, " file=");
2279 seq_path(m
, &file
->f_path
, "\n\t= ");
2280 } else if (vma
->vm_start
<= mm
->brk
&& vma
->vm_end
>= mm
->start_brk
) {
2281 seq_printf(m
, " heap");
2282 } else if (vma
->vm_start
<= mm
->start_stack
&&
2283 vma
->vm_end
>= mm
->start_stack
) {
2284 seq_printf(m
, " stack");
2287 if (is_vm_hugetlb_page(vma
)) {
2288 check_huge_range(vma
, vma
->vm_start
, vma
->vm_end
, md
);
2289 seq_printf(m
, " huge");
2291 check_pgd_range(vma
, vma
->vm_start
, vma
->vm_end
,
2292 &node_states
[N_HIGH_MEMORY
], MPOL_MF_STATS
, md
);
2299 seq_printf(m
," anon=%lu",md
->anon
);
2302 seq_printf(m
," dirty=%lu",md
->dirty
);
2304 if (md
->pages
!= md
->anon
&& md
->pages
!= md
->dirty
)
2305 seq_printf(m
, " mapped=%lu", md
->pages
);
2307 if (md
->mapcount_max
> 1)
2308 seq_printf(m
, " mapmax=%lu", md
->mapcount_max
);
2311 seq_printf(m
," swapcache=%lu", md
->swapcache
);
2313 if (md
->active
< md
->pages
&& !is_vm_hugetlb_page(vma
))
2314 seq_printf(m
," active=%lu", md
->active
);
2317 seq_printf(m
," writeback=%lu", md
->writeback
);
2319 for_each_node_state(n
, N_HIGH_MEMORY
)
2321 seq_printf(m
, " N%d=%lu", n
, md
->node
[n
]);
2326 if (m
->count
< m
->size
)
2327 m
->version
= (vma
!= priv
->tail_vma
) ? vma
->vm_start
: 0;