2 * Simple NUMA memory policy for the Linux kernel.
4 * Copyright 2003,2004 Andi Kleen, SuSE Labs.
5 * (C) Copyright 2005 Christoph Lameter, Silicon Graphics, Inc.
6 * Subject to the GNU Public License, version 2.
8 * NUMA policy allows the user to give hints in which node(s) memory should
11 * Support four policies per VMA and per process:
13 * The VMA policy has priority over the process policy for a page fault.
15 * interleave Allocate memory interleaved over a set of nodes,
16 * with normal fallback if it fails.
17 * For VMA based allocations this interleaves based on the
18 * offset into the backing object or offset into the mapping
19 * for anonymous memory. For process policy an process counter
22 * bind Only allocate memory on a specific set of nodes,
24 * FIXME: memory is allocated starting with the first node
25 * to the last. It would be better if bind would truly restrict
26 * the allocation to memory nodes instead
28 * preferred Try a specific node first before normal fallback.
29 * As a special case NUMA_NO_NODE here means do the allocation
30 * on the local CPU. This is normally identical to default,
31 * but useful to set in a VMA when you have a non default
34 * default Allocate on the local node first, or when on a VMA
35 * use the process policy. This is what Linux always did
36 * in a NUMA aware kernel and still does by, ahem, default.
38 * The process policy is applied for most non interrupt memory allocations
39 * in that process' context. Interrupts ignore the policies and always
40 * try to allocate on the local CPU. The VMA policy is only applied for memory
41 * allocations for a VMA in the VM.
43 * Currently there are a few corner cases in swapping where the policy
44 * is not applied, but the majority should be handled. When process policy
45 * is used it is not remembered over swap outs/swap ins.
47 * Only the highest zone in the zone hierarchy gets policied. Allocations
48 * requesting a lower zone just use default policy. This implies that
49 * on systems with highmem kernel lowmem allocation don't get policied.
50 * Same with GFP_DMA allocations.
52 * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between
53 * all users and remembered even when nobody has memory mapped.
57 fix mmap readahead to honour policy and enable policy for any page cache
59 statistics for bigpages
60 global policy for page cache? currently it uses process policy. Requires
62 handle mremap for shared memory (currently ignored for the policy)
64 make bind policy root only? It can trigger oom much faster and the
65 kernel is not always grateful with that.
68 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
70 #include <linux/mempolicy.h>
72 #include <linux/highmem.h>
73 #include <linux/hugetlb.h>
74 #include <linux/kernel.h>
75 #include <linux/sched.h>
76 #include <linux/nodemask.h>
77 #include <linux/cpuset.h>
78 #include <linux/slab.h>
79 #include <linux/string.h>
80 #include <linux/export.h>
81 #include <linux/nsproxy.h>
82 #include <linux/interrupt.h>
83 #include <linux/init.h>
84 #include <linux/compat.h>
85 #include <linux/swap.h>
86 #include <linux/seq_file.h>
87 #include <linux/proc_fs.h>
88 #include <linux/migrate.h>
89 #include <linux/ksm.h>
90 #include <linux/rmap.h>
91 #include <linux/security.h>
92 #include <linux/syscalls.h>
93 #include <linux/ctype.h>
94 #include <linux/mm_inline.h>
95 #include <linux/mmu_notifier.h>
96 #include <linux/printk.h>
98 #include <asm/tlbflush.h>
99 #include <asm/uaccess.h>
100 #include <linux/random.h>
102 #include "internal.h"
105 #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
106 #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
108 static struct kmem_cache
*policy_cache
;
109 static struct kmem_cache
*sn_cache
;
111 /* Highest zone. An specific allocation for a zone below that is not
113 enum zone_type policy_zone
= 0;
116 * run-time system-wide default policy => local allocation
118 static struct mempolicy default_policy
= {
119 .refcnt
= ATOMIC_INIT(1), /* never free it */
120 .mode
= MPOL_PREFERRED
,
121 .flags
= MPOL_F_LOCAL
,
124 static struct mempolicy preferred_node_policy
[MAX_NUMNODES
];
126 static struct mempolicy
*get_task_policy(struct task_struct
*p
)
128 struct mempolicy
*pol
= p
->mempolicy
;
134 node
= numa_node_id();
135 if (node
!= NUMA_NO_NODE
) {
136 pol
= &preferred_node_policy
[node
];
137 /* preferred_node_policy is not initialised early in boot */
142 return &default_policy
;
145 static const struct mempolicy_operations
{
146 int (*create
)(struct mempolicy
*pol
, const nodemask_t
*nodes
);
148 * If read-side task has no lock to protect task->mempolicy, write-side
149 * task will rebind the task->mempolicy by two step. The first step is
150 * setting all the newly nodes, and the second step is cleaning all the
151 * disallowed nodes. In this way, we can avoid finding no node to alloc
153 * If we have a lock to protect task->mempolicy in read-side, we do
157 * MPOL_REBIND_ONCE - do rebind work at once
158 * MPOL_REBIND_STEP1 - set all the newly nodes
159 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
161 void (*rebind
)(struct mempolicy
*pol
, const nodemask_t
*nodes
,
162 enum mpol_rebind_step step
);
163 } mpol_ops
[MPOL_MAX
];
165 /* Check that the nodemask contains at least one populated zone */
166 static int is_valid_nodemask(const nodemask_t
*nodemask
)
168 return nodes_intersects(*nodemask
, node_states
[N_MEMORY
]);
171 static inline int mpol_store_user_nodemask(const struct mempolicy
*pol
)
173 return pol
->flags
& MPOL_MODE_FLAGS
;
176 static void mpol_relative_nodemask(nodemask_t
*ret
, const nodemask_t
*orig
,
177 const nodemask_t
*rel
)
180 nodes_fold(tmp
, *orig
, nodes_weight(*rel
));
181 nodes_onto(*ret
, tmp
, *rel
);
184 static int mpol_new_interleave(struct mempolicy
*pol
, const nodemask_t
*nodes
)
186 if (nodes_empty(*nodes
))
188 pol
->v
.nodes
= *nodes
;
192 static int mpol_new_preferred(struct mempolicy
*pol
, const nodemask_t
*nodes
)
195 pol
->flags
|= MPOL_F_LOCAL
; /* local allocation */
196 else if (nodes_empty(*nodes
))
197 return -EINVAL
; /* no allowed nodes */
199 pol
->v
.preferred_node
= first_node(*nodes
);
203 static int mpol_new_bind(struct mempolicy
*pol
, const nodemask_t
*nodes
)
205 if (!is_valid_nodemask(nodes
))
207 pol
->v
.nodes
= *nodes
;
212 * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
213 * any, for the new policy. mpol_new() has already validated the nodes
214 * parameter with respect to the policy mode and flags. But, we need to
215 * handle an empty nodemask with MPOL_PREFERRED here.
217 * Must be called holding task's alloc_lock to protect task's mems_allowed
218 * and mempolicy. May also be called holding the mmap_semaphore for write.
220 static int mpol_set_nodemask(struct mempolicy
*pol
,
221 const nodemask_t
*nodes
, struct nodemask_scratch
*nsc
)
225 /* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
229 nodes_and(nsc
->mask1
,
230 cpuset_current_mems_allowed
, node_states
[N_MEMORY
]);
233 if (pol
->mode
== MPOL_PREFERRED
&& nodes_empty(*nodes
))
234 nodes
= NULL
; /* explicit local allocation */
236 if (pol
->flags
& MPOL_F_RELATIVE_NODES
)
237 mpol_relative_nodemask(&nsc
->mask2
, nodes
,&nsc
->mask1
);
239 nodes_and(nsc
->mask2
, *nodes
, nsc
->mask1
);
241 if (mpol_store_user_nodemask(pol
))
242 pol
->w
.user_nodemask
= *nodes
;
244 pol
->w
.cpuset_mems_allowed
=
245 cpuset_current_mems_allowed
;
249 ret
= mpol_ops
[pol
->mode
].create(pol
, &nsc
->mask2
);
251 ret
= mpol_ops
[pol
->mode
].create(pol
, NULL
);
256 * This function just creates a new policy, does some check and simple
257 * initialization. You must invoke mpol_set_nodemask() to set nodes.
259 static struct mempolicy
*mpol_new(unsigned short mode
, unsigned short flags
,
262 struct mempolicy
*policy
;
264 pr_debug("setting mode %d flags %d nodes[0] %lx\n",
265 mode
, flags
, nodes
? nodes_addr(*nodes
)[0] : NUMA_NO_NODE
);
267 if (mode
== MPOL_DEFAULT
) {
268 if (nodes
&& !nodes_empty(*nodes
))
269 return ERR_PTR(-EINVAL
);
275 * MPOL_PREFERRED cannot be used with MPOL_F_STATIC_NODES or
276 * MPOL_F_RELATIVE_NODES if the nodemask is empty (local allocation).
277 * All other modes require a valid pointer to a non-empty nodemask.
279 if (mode
== MPOL_PREFERRED
) {
280 if (nodes_empty(*nodes
)) {
281 if (((flags
& MPOL_F_STATIC_NODES
) ||
282 (flags
& MPOL_F_RELATIVE_NODES
)))
283 return ERR_PTR(-EINVAL
);
285 } else if (mode
== MPOL_LOCAL
) {
286 if (!nodes_empty(*nodes
))
287 return ERR_PTR(-EINVAL
);
288 mode
= MPOL_PREFERRED
;
289 } else if (nodes_empty(*nodes
))
290 return ERR_PTR(-EINVAL
);
291 policy
= kmem_cache_alloc(policy_cache
, GFP_KERNEL
);
293 return ERR_PTR(-ENOMEM
);
294 atomic_set(&policy
->refcnt
, 1);
296 policy
->flags
= flags
;
301 /* Slow path of a mpol destructor. */
302 void __mpol_put(struct mempolicy
*p
)
304 if (!atomic_dec_and_test(&p
->refcnt
))
306 kmem_cache_free(policy_cache
, p
);
309 static void mpol_rebind_default(struct mempolicy
*pol
, const nodemask_t
*nodes
,
310 enum mpol_rebind_step step
)
316 * MPOL_REBIND_ONCE - do rebind work at once
317 * MPOL_REBIND_STEP1 - set all the newly nodes
318 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
320 static void mpol_rebind_nodemask(struct mempolicy
*pol
, const nodemask_t
*nodes
,
321 enum mpol_rebind_step step
)
325 if (pol
->flags
& MPOL_F_STATIC_NODES
)
326 nodes_and(tmp
, pol
->w
.user_nodemask
, *nodes
);
327 else if (pol
->flags
& MPOL_F_RELATIVE_NODES
)
328 mpol_relative_nodemask(&tmp
, &pol
->w
.user_nodemask
, nodes
);
331 * if step == 1, we use ->w.cpuset_mems_allowed to cache the
334 if (step
== MPOL_REBIND_ONCE
|| step
== MPOL_REBIND_STEP1
) {
335 nodes_remap(tmp
, pol
->v
.nodes
,
336 pol
->w
.cpuset_mems_allowed
, *nodes
);
337 pol
->w
.cpuset_mems_allowed
= step
? tmp
: *nodes
;
338 } else if (step
== MPOL_REBIND_STEP2
) {
339 tmp
= pol
->w
.cpuset_mems_allowed
;
340 pol
->w
.cpuset_mems_allowed
= *nodes
;
345 if (nodes_empty(tmp
))
348 if (step
== MPOL_REBIND_STEP1
)
349 nodes_or(pol
->v
.nodes
, pol
->v
.nodes
, tmp
);
350 else if (step
== MPOL_REBIND_ONCE
|| step
== MPOL_REBIND_STEP2
)
355 if (!node_isset(current
->il_next
, tmp
)) {
356 current
->il_next
= next_node(current
->il_next
, tmp
);
357 if (current
->il_next
>= MAX_NUMNODES
)
358 current
->il_next
= first_node(tmp
);
359 if (current
->il_next
>= MAX_NUMNODES
)
360 current
->il_next
= numa_node_id();
364 static void mpol_rebind_preferred(struct mempolicy
*pol
,
365 const nodemask_t
*nodes
,
366 enum mpol_rebind_step step
)
370 if (pol
->flags
& MPOL_F_STATIC_NODES
) {
371 int node
= first_node(pol
->w
.user_nodemask
);
373 if (node_isset(node
, *nodes
)) {
374 pol
->v
.preferred_node
= node
;
375 pol
->flags
&= ~MPOL_F_LOCAL
;
377 pol
->flags
|= MPOL_F_LOCAL
;
378 } else if (pol
->flags
& MPOL_F_RELATIVE_NODES
) {
379 mpol_relative_nodemask(&tmp
, &pol
->w
.user_nodemask
, nodes
);
380 pol
->v
.preferred_node
= first_node(tmp
);
381 } else if (!(pol
->flags
& MPOL_F_LOCAL
)) {
382 pol
->v
.preferred_node
= node_remap(pol
->v
.preferred_node
,
383 pol
->w
.cpuset_mems_allowed
,
385 pol
->w
.cpuset_mems_allowed
= *nodes
;
390 * mpol_rebind_policy - Migrate a policy to a different set of nodes
392 * If read-side task has no lock to protect task->mempolicy, write-side
393 * task will rebind the task->mempolicy by two step. The first step is
394 * setting all the newly nodes, and the second step is cleaning all the
395 * disallowed nodes. In this way, we can avoid finding no node to alloc
397 * If we have a lock to protect task->mempolicy in read-side, we do
401 * MPOL_REBIND_ONCE - do rebind work at once
402 * MPOL_REBIND_STEP1 - set all the newly nodes
403 * MPOL_REBIND_STEP2 - clean all the disallowed nodes
405 static void mpol_rebind_policy(struct mempolicy
*pol
, const nodemask_t
*newmask
,
406 enum mpol_rebind_step step
)
410 if (!mpol_store_user_nodemask(pol
) && step
== MPOL_REBIND_ONCE
&&
411 nodes_equal(pol
->w
.cpuset_mems_allowed
, *newmask
))
414 if (step
== MPOL_REBIND_STEP1
&& (pol
->flags
& MPOL_F_REBINDING
))
417 if (step
== MPOL_REBIND_STEP2
&& !(pol
->flags
& MPOL_F_REBINDING
))
420 if (step
== MPOL_REBIND_STEP1
)
421 pol
->flags
|= MPOL_F_REBINDING
;
422 else if (step
== MPOL_REBIND_STEP2
)
423 pol
->flags
&= ~MPOL_F_REBINDING
;
424 else if (step
>= MPOL_REBIND_NSTEP
)
427 mpol_ops
[pol
->mode
].rebind(pol
, newmask
, step
);
431 * Wrapper for mpol_rebind_policy() that just requires task
432 * pointer, and updates task mempolicy.
434 * Called with task's alloc_lock held.
437 void mpol_rebind_task(struct task_struct
*tsk
, const nodemask_t
*new,
438 enum mpol_rebind_step step
)
440 mpol_rebind_policy(tsk
->mempolicy
, new, step
);
444 * Rebind each vma in mm to new nodemask.
446 * Call holding a reference to mm. Takes mm->mmap_sem during call.
449 void mpol_rebind_mm(struct mm_struct
*mm
, nodemask_t
*new)
451 struct vm_area_struct
*vma
;
453 down_write(&mm
->mmap_sem
);
454 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
)
455 mpol_rebind_policy(vma
->vm_policy
, new, MPOL_REBIND_ONCE
);
456 up_write(&mm
->mmap_sem
);
459 static const struct mempolicy_operations mpol_ops
[MPOL_MAX
] = {
461 .rebind
= mpol_rebind_default
,
463 [MPOL_INTERLEAVE
] = {
464 .create
= mpol_new_interleave
,
465 .rebind
= mpol_rebind_nodemask
,
468 .create
= mpol_new_preferred
,
469 .rebind
= mpol_rebind_preferred
,
472 .create
= mpol_new_bind
,
473 .rebind
= mpol_rebind_nodemask
,
477 static void migrate_page_add(struct page
*page
, struct list_head
*pagelist
,
478 unsigned long flags
);
481 * Scan through pages checking if pages follow certain conditions,
482 * and move them to the pagelist if they do.
484 static int queue_pages_pte_range(struct vm_area_struct
*vma
, pmd_t
*pmd
,
485 unsigned long addr
, unsigned long end
,
486 const nodemask_t
*nodes
, unsigned long flags
,
493 orig_pte
= pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
498 if (!pte_present(*pte
))
500 page
= vm_normal_page(vma
, addr
, *pte
);
504 * vm_normal_page() filters out zero pages, but there might
505 * still be PageReserved pages to skip, perhaps in a VDSO.
507 if (PageReserved(page
))
509 nid
= page_to_nid(page
);
510 if (node_isset(nid
, *nodes
) == !!(flags
& MPOL_MF_INVERT
))
513 if (flags
& (MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
))
514 migrate_page_add(page
, private, flags
);
517 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
518 pte_unmap_unlock(orig_pte
, ptl
);
522 static void queue_pages_hugetlb_pmd_range(struct vm_area_struct
*vma
,
523 pmd_t
*pmd
, const nodemask_t
*nodes
, unsigned long flags
,
526 #ifdef CONFIG_HUGETLB_PAGE
532 ptl
= huge_pte_lock(hstate_vma(vma
), vma
->vm_mm
, (pte_t
*)pmd
);
533 entry
= huge_ptep_get((pte_t
*)pmd
);
534 if (!pte_present(entry
))
536 page
= pte_page(entry
);
537 nid
= page_to_nid(page
);
538 if (node_isset(nid
, *nodes
) == !!(flags
& MPOL_MF_INVERT
))
540 /* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
541 if (flags
& (MPOL_MF_MOVE_ALL
) ||
542 (flags
& MPOL_MF_MOVE
&& page_mapcount(page
) == 1))
543 isolate_huge_page(page
, private);
551 static inline int queue_pages_pmd_range(struct vm_area_struct
*vma
, pud_t
*pud
,
552 unsigned long addr
, unsigned long end
,
553 const nodemask_t
*nodes
, unsigned long flags
,
559 pmd
= pmd_offset(pud
, addr
);
561 next
= pmd_addr_end(addr
, end
);
562 if (!pmd_present(*pmd
))
564 if (pmd_huge(*pmd
) && is_vm_hugetlb_page(vma
)) {
565 queue_pages_hugetlb_pmd_range(vma
, pmd
, nodes
,
569 split_huge_page_pmd(vma
, addr
, pmd
);
570 if (pmd_none_or_trans_huge_or_clear_bad(pmd
))
572 if (queue_pages_pte_range(vma
, pmd
, addr
, next
, nodes
,
575 } while (pmd
++, addr
= next
, addr
!= end
);
579 static inline int queue_pages_pud_range(struct vm_area_struct
*vma
, pgd_t
*pgd
,
580 unsigned long addr
, unsigned long end
,
581 const nodemask_t
*nodes
, unsigned long flags
,
587 pud
= pud_offset(pgd
, addr
);
589 next
= pud_addr_end(addr
, end
);
590 if (pud_huge(*pud
) && is_vm_hugetlb_page(vma
))
592 if (pud_none_or_clear_bad(pud
))
594 if (queue_pages_pmd_range(vma
, pud
, addr
, next
, nodes
,
597 } while (pud
++, addr
= next
, addr
!= end
);
601 static inline int queue_pages_pgd_range(struct vm_area_struct
*vma
,
602 unsigned long addr
, unsigned long end
,
603 const nodemask_t
*nodes
, unsigned long flags
,
609 pgd
= pgd_offset(vma
->vm_mm
, addr
);
611 next
= pgd_addr_end(addr
, end
);
612 if (pgd_none_or_clear_bad(pgd
))
614 if (queue_pages_pud_range(vma
, pgd
, addr
, next
, nodes
,
617 } while (pgd
++, addr
= next
, addr
!= end
);
621 #ifdef CONFIG_NUMA_BALANCING
623 * This is used to mark a range of virtual addresses to be inaccessible.
624 * These are later cleared by a NUMA hinting fault. Depending on these
625 * faults, pages may be migrated for better NUMA placement.
627 * This is assuming that NUMA faults are handled using PROT_NONE. If
628 * an architecture makes a different choice, it will need further
629 * changes to the core.
631 unsigned long change_prot_numa(struct vm_area_struct
*vma
,
632 unsigned long addr
, unsigned long end
)
636 nr_updated
= change_protection(vma
, addr
, end
, vma
->vm_page_prot
, 0, 1);
638 count_vm_numa_events(NUMA_PTE_UPDATES
, nr_updated
);
643 static unsigned long change_prot_numa(struct vm_area_struct
*vma
,
644 unsigned long addr
, unsigned long end
)
648 #endif /* CONFIG_NUMA_BALANCING */
651 * Walk through page tables and collect pages to be migrated.
653 * If pages found in a given range are on a set of nodes (determined by
654 * @nodes and @flags,) it's isolated and queued to the pagelist which is
655 * passed via @private.)
658 queue_pages_range(struct mm_struct
*mm
, unsigned long start
, unsigned long end
,
659 const nodemask_t
*nodes
, unsigned long flags
, void *private)
662 struct vm_area_struct
*vma
, *prev
;
664 vma
= find_vma(mm
, start
);
668 for (; vma
&& vma
->vm_start
< end
; vma
= vma
->vm_next
) {
669 unsigned long endvma
= vma
->vm_end
;
673 if (vma
->vm_start
> start
)
674 start
= vma
->vm_start
;
676 if (!(flags
& MPOL_MF_DISCONTIG_OK
)) {
677 if (!vma
->vm_next
&& vma
->vm_end
< end
)
679 if (prev
&& prev
->vm_end
< vma
->vm_start
)
683 if (flags
& MPOL_MF_LAZY
) {
684 change_prot_numa(vma
, start
, endvma
);
688 if ((flags
& MPOL_MF_STRICT
) ||
689 ((flags
& (MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
)) &&
690 vma_migratable(vma
))) {
692 err
= queue_pages_pgd_range(vma
, start
, endvma
, nodes
,
704 * Apply policy to a single VMA
705 * This must be called with the mmap_sem held for writing.
707 static int vma_replace_policy(struct vm_area_struct
*vma
,
708 struct mempolicy
*pol
)
711 struct mempolicy
*old
;
712 struct mempolicy
*new;
714 pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
715 vma
->vm_start
, vma
->vm_end
, vma
->vm_pgoff
,
716 vma
->vm_ops
, vma
->vm_file
,
717 vma
->vm_ops
? vma
->vm_ops
->set_policy
: NULL
);
723 if (vma
->vm_ops
&& vma
->vm_ops
->set_policy
) {
724 err
= vma
->vm_ops
->set_policy(vma
, new);
729 old
= vma
->vm_policy
;
730 vma
->vm_policy
= new; /* protected by mmap_sem */
739 /* Step 2: apply policy to a range and do splits. */
740 static int mbind_range(struct mm_struct
*mm
, unsigned long start
,
741 unsigned long end
, struct mempolicy
*new_pol
)
743 struct vm_area_struct
*next
;
744 struct vm_area_struct
*prev
;
745 struct vm_area_struct
*vma
;
748 unsigned long vmstart
;
751 vma
= find_vma(mm
, start
);
752 if (!vma
|| vma
->vm_start
> start
)
756 if (start
> vma
->vm_start
)
759 for (; vma
&& vma
->vm_start
< end
; prev
= vma
, vma
= next
) {
761 vmstart
= max(start
, vma
->vm_start
);
762 vmend
= min(end
, vma
->vm_end
);
764 if (mpol_equal(vma_policy(vma
), new_pol
))
767 pgoff
= vma
->vm_pgoff
+
768 ((vmstart
- vma
->vm_start
) >> PAGE_SHIFT
);
769 prev
= vma_merge(mm
, prev
, vmstart
, vmend
, vma
->vm_flags
,
770 vma
->anon_vma
, vma
->vm_file
, pgoff
,
775 if (mpol_equal(vma_policy(vma
), new_pol
))
777 /* vma_merge() joined vma && vma->next, case 8 */
780 if (vma
->vm_start
!= vmstart
) {
781 err
= split_vma(vma
->vm_mm
, vma
, vmstart
, 1);
785 if (vma
->vm_end
!= vmend
) {
786 err
= split_vma(vma
->vm_mm
, vma
, vmend
, 0);
791 err
= vma_replace_policy(vma
, new_pol
);
800 /* Set the process memory policy */
801 static long do_set_mempolicy(unsigned short mode
, unsigned short flags
,
804 struct mempolicy
*new, *old
;
805 struct mm_struct
*mm
= current
->mm
;
806 NODEMASK_SCRATCH(scratch
);
812 new = mpol_new(mode
, flags
, nodes
);
818 * prevent changing our mempolicy while show_numa_maps()
820 * Note: do_set_mempolicy() can be called at init time
824 down_write(&mm
->mmap_sem
);
826 ret
= mpol_set_nodemask(new, nodes
, scratch
);
828 task_unlock(current
);
830 up_write(&mm
->mmap_sem
);
834 old
= current
->mempolicy
;
835 current
->mempolicy
= new;
836 if (new && new->mode
== MPOL_INTERLEAVE
&&
837 nodes_weight(new->v
.nodes
))
838 current
->il_next
= first_node(new->v
.nodes
);
839 task_unlock(current
);
841 up_write(&mm
->mmap_sem
);
846 NODEMASK_SCRATCH_FREE(scratch
);
851 * Return nodemask for policy for get_mempolicy() query
853 * Called with task's alloc_lock held
855 static void get_policy_nodemask(struct mempolicy
*p
, nodemask_t
*nodes
)
858 if (p
== &default_policy
)
864 case MPOL_INTERLEAVE
:
868 if (!(p
->flags
& MPOL_F_LOCAL
))
869 node_set(p
->v
.preferred_node
, *nodes
);
870 /* else return empty node mask for local allocation */
877 static int lookup_node(struct mm_struct
*mm
, unsigned long addr
)
882 err
= get_user_pages(current
, mm
, addr
& PAGE_MASK
, 1, 0, 0, &p
, NULL
);
884 err
= page_to_nid(p
);
890 /* Retrieve NUMA policy */
891 static long do_get_mempolicy(int *policy
, nodemask_t
*nmask
,
892 unsigned long addr
, unsigned long flags
)
895 struct mm_struct
*mm
= current
->mm
;
896 struct vm_area_struct
*vma
= NULL
;
897 struct mempolicy
*pol
= current
->mempolicy
;
900 ~(unsigned long)(MPOL_F_NODE
|MPOL_F_ADDR
|MPOL_F_MEMS_ALLOWED
))
903 if (flags
& MPOL_F_MEMS_ALLOWED
) {
904 if (flags
& (MPOL_F_NODE
|MPOL_F_ADDR
))
906 *policy
= 0; /* just so it's initialized */
908 *nmask
= cpuset_current_mems_allowed
;
909 task_unlock(current
);
913 if (flags
& MPOL_F_ADDR
) {
915 * Do NOT fall back to task policy if the
916 * vma/shared policy at addr is NULL. We
917 * want to return MPOL_DEFAULT in this case.
919 down_read(&mm
->mmap_sem
);
920 vma
= find_vma_intersection(mm
, addr
, addr
+1);
922 up_read(&mm
->mmap_sem
);
925 if (vma
->vm_ops
&& vma
->vm_ops
->get_policy
)
926 pol
= vma
->vm_ops
->get_policy(vma
, addr
);
928 pol
= vma
->vm_policy
;
933 pol
= &default_policy
; /* indicates default behavior */
935 if (flags
& MPOL_F_NODE
) {
936 if (flags
& MPOL_F_ADDR
) {
937 err
= lookup_node(mm
, addr
);
941 } else if (pol
== current
->mempolicy
&&
942 pol
->mode
== MPOL_INTERLEAVE
) {
943 *policy
= current
->il_next
;
949 *policy
= pol
== &default_policy
? MPOL_DEFAULT
:
952 * Internal mempolicy flags must be masked off before exposing
953 * the policy to userspace.
955 *policy
|= (pol
->flags
& MPOL_MODE_FLAGS
);
959 up_read(¤t
->mm
->mmap_sem
);
965 if (mpol_store_user_nodemask(pol
)) {
966 *nmask
= pol
->w
.user_nodemask
;
969 get_policy_nodemask(pol
, nmask
);
970 task_unlock(current
);
977 up_read(¤t
->mm
->mmap_sem
);
981 #ifdef CONFIG_MIGRATION
985 static void migrate_page_add(struct page
*page
, struct list_head
*pagelist
,
989 * Avoid migrating a page that is shared with others.
991 if ((flags
& MPOL_MF_MOVE_ALL
) || page_mapcount(page
) == 1) {
992 if (!isolate_lru_page(page
)) {
993 list_add_tail(&page
->lru
, pagelist
);
994 inc_zone_page_state(page
, NR_ISOLATED_ANON
+
995 page_is_file_cache(page
));
1000 static struct page
*new_node_page(struct page
*page
, unsigned long node
, int **x
)
1003 return alloc_huge_page_node(page_hstate(compound_head(page
)),
1006 return alloc_pages_exact_node(node
, GFP_HIGHUSER_MOVABLE
, 0);
1010 * Migrate pages from one node to a target node.
1011 * Returns error or the number of pages not migrated.
1013 static int migrate_to_node(struct mm_struct
*mm
, int source
, int dest
,
1017 LIST_HEAD(pagelist
);
1021 node_set(source
, nmask
);
1024 * This does not "check" the range but isolates all pages that
1025 * need migration. Between passing in the full user address
1026 * space range and MPOL_MF_DISCONTIG_OK, this call can not fail.
1028 VM_BUG_ON(!(flags
& (MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
)));
1029 queue_pages_range(mm
, mm
->mmap
->vm_start
, mm
->task_size
, &nmask
,
1030 flags
| MPOL_MF_DISCONTIG_OK
, &pagelist
);
1032 if (!list_empty(&pagelist
)) {
1033 err
= migrate_pages(&pagelist
, new_node_page
, NULL
, dest
,
1034 MIGRATE_SYNC
, MR_SYSCALL
);
1036 putback_movable_pages(&pagelist
);
1043 * Move pages between the two nodesets so as to preserve the physical
1044 * layout as much as possible.
1046 * Returns the number of page that could not be moved.
1048 int do_migrate_pages(struct mm_struct
*mm
, const nodemask_t
*from
,
1049 const nodemask_t
*to
, int flags
)
1055 err
= migrate_prep();
1059 down_read(&mm
->mmap_sem
);
1061 err
= migrate_vmas(mm
, from
, to
, flags
);
1066 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
1067 * bit in 'to' is not also set in 'tmp'. Clear the found 'source'
1068 * bit in 'tmp', and return that <source, dest> pair for migration.
1069 * The pair of nodemasks 'to' and 'from' define the map.
1071 * If no pair of bits is found that way, fallback to picking some
1072 * pair of 'source' and 'dest' bits that are not the same. If the
1073 * 'source' and 'dest' bits are the same, this represents a node
1074 * that will be migrating to itself, so no pages need move.
1076 * If no bits are left in 'tmp', or if all remaining bits left
1077 * in 'tmp' correspond to the same bit in 'to', return false
1078 * (nothing left to migrate).
1080 * This lets us pick a pair of nodes to migrate between, such that
1081 * if possible the dest node is not already occupied by some other
1082 * source node, minimizing the risk of overloading the memory on a
1083 * node that would happen if we migrated incoming memory to a node
1084 * before migrating outgoing memory source that same node.
1086 * A single scan of tmp is sufficient. As we go, we remember the
1087 * most recent <s, d> pair that moved (s != d). If we find a pair
1088 * that not only moved, but what's better, moved to an empty slot
1089 * (d is not set in tmp), then we break out then, with that pair.
1090 * Otherwise when we finish scanning from_tmp, we at least have the
1091 * most recent <s, d> pair that moved. If we get all the way through
1092 * the scan of tmp without finding any node that moved, much less
1093 * moved to an empty node, then there is nothing left worth migrating.
1097 while (!nodes_empty(tmp
)) {
1099 int source
= NUMA_NO_NODE
;
1102 for_each_node_mask(s
, tmp
) {
1105 * do_migrate_pages() tries to maintain the relative
1106 * node relationship of the pages established between
1107 * threads and memory areas.
1109 * However if the number of source nodes is not equal to
1110 * the number of destination nodes we can not preserve
1111 * this node relative relationship. In that case, skip
1112 * copying memory from a node that is in the destination
1115 * Example: [2,3,4] -> [3,4,5] moves everything.
1116 * [0-7] - > [3,4,5] moves only 0,1,2,6,7.
1119 if ((nodes_weight(*from
) != nodes_weight(*to
)) &&
1120 (node_isset(s
, *to
)))
1123 d
= node_remap(s
, *from
, *to
);
1127 source
= s
; /* Node moved. Memorize */
1130 /* dest not in remaining from nodes? */
1131 if (!node_isset(dest
, tmp
))
1134 if (source
== NUMA_NO_NODE
)
1137 node_clear(source
, tmp
);
1138 err
= migrate_to_node(mm
, source
, dest
, flags
);
1145 up_read(&mm
->mmap_sem
);
1153 * Allocate a new page for page migration based on vma policy.
1154 * Start by assuming the page is mapped by the same vma as contains @start.
1155 * Search forward from there, if not. N.B., this assumes that the
1156 * list of pages handed to migrate_pages()--which is how we get here--
1157 * is in virtual address order.
1159 static struct page
*new_page(struct page
*page
, unsigned long start
, int **x
)
1161 struct vm_area_struct
*vma
;
1162 unsigned long uninitialized_var(address
);
1164 vma
= find_vma(current
->mm
, start
);
1166 address
= page_address_in_vma(page
, vma
);
1167 if (address
!= -EFAULT
)
1172 if (PageHuge(page
)) {
1174 return alloc_huge_page_noerr(vma
, address
, 1);
1177 * if !vma, alloc_page_vma() will use task or system default policy
1179 return alloc_page_vma(GFP_HIGHUSER_MOVABLE
, vma
, address
);
1183 static void migrate_page_add(struct page
*page
, struct list_head
*pagelist
,
1184 unsigned long flags
)
1188 int do_migrate_pages(struct mm_struct
*mm
, const nodemask_t
*from
,
1189 const nodemask_t
*to
, int flags
)
1194 static struct page
*new_page(struct page
*page
, unsigned long start
, int **x
)
1200 static long do_mbind(unsigned long start
, unsigned long len
,
1201 unsigned short mode
, unsigned short mode_flags
,
1202 nodemask_t
*nmask
, unsigned long flags
)
1204 struct mm_struct
*mm
= current
->mm
;
1205 struct mempolicy
*new;
1208 LIST_HEAD(pagelist
);
1210 if (flags
& ~(unsigned long)MPOL_MF_VALID
)
1212 if ((flags
& MPOL_MF_MOVE_ALL
) && !capable(CAP_SYS_NICE
))
1215 if (start
& ~PAGE_MASK
)
1218 if (mode
== MPOL_DEFAULT
)
1219 flags
&= ~MPOL_MF_STRICT
;
1221 len
= (len
+ PAGE_SIZE
- 1) & PAGE_MASK
;
1229 new = mpol_new(mode
, mode_flags
, nmask
);
1231 return PTR_ERR(new);
1233 if (flags
& MPOL_MF_LAZY
)
1234 new->flags
|= MPOL_F_MOF
;
1237 * If we are using the default policy then operation
1238 * on discontinuous address spaces is okay after all
1241 flags
|= MPOL_MF_DISCONTIG_OK
;
1243 pr_debug("mbind %lx-%lx mode:%d flags:%d nodes:%lx\n",
1244 start
, start
+ len
, mode
, mode_flags
,
1245 nmask
? nodes_addr(*nmask
)[0] : NUMA_NO_NODE
);
1247 if (flags
& (MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
)) {
1249 err
= migrate_prep();
1254 NODEMASK_SCRATCH(scratch
);
1256 down_write(&mm
->mmap_sem
);
1258 err
= mpol_set_nodemask(new, nmask
, scratch
);
1259 task_unlock(current
);
1261 up_write(&mm
->mmap_sem
);
1264 NODEMASK_SCRATCH_FREE(scratch
);
1269 err
= queue_pages_range(mm
, start
, end
, nmask
,
1270 flags
| MPOL_MF_INVERT
, &pagelist
);
1272 err
= mbind_range(mm
, start
, end
, new);
1277 if (!list_empty(&pagelist
)) {
1278 WARN_ON_ONCE(flags
& MPOL_MF_LAZY
);
1279 nr_failed
= migrate_pages(&pagelist
, new_page
, NULL
,
1280 start
, MIGRATE_SYNC
, MR_MEMPOLICY_MBIND
);
1282 putback_movable_pages(&pagelist
);
1285 if (nr_failed
&& (flags
& MPOL_MF_STRICT
))
1288 putback_movable_pages(&pagelist
);
1290 up_write(&mm
->mmap_sem
);
1297 * User space interface with variable sized bitmaps for nodelists.
1300 /* Copy a node mask from user space. */
1301 static int get_nodes(nodemask_t
*nodes
, const unsigned long __user
*nmask
,
1302 unsigned long maxnode
)
1305 unsigned long nlongs
;
1306 unsigned long endmask
;
1309 nodes_clear(*nodes
);
1310 if (maxnode
== 0 || !nmask
)
1312 if (maxnode
> PAGE_SIZE
*BITS_PER_BYTE
)
1315 nlongs
= BITS_TO_LONGS(maxnode
);
1316 if ((maxnode
% BITS_PER_LONG
) == 0)
1319 endmask
= (1UL << (maxnode
% BITS_PER_LONG
)) - 1;
1321 /* When the user specified more nodes than supported just check
1322 if the non supported part is all zero. */
1323 if (nlongs
> BITS_TO_LONGS(MAX_NUMNODES
)) {
1324 if (nlongs
> PAGE_SIZE
/sizeof(long))
1326 for (k
= BITS_TO_LONGS(MAX_NUMNODES
); k
< nlongs
; k
++) {
1328 if (get_user(t
, nmask
+ k
))
1330 if (k
== nlongs
- 1) {
1336 nlongs
= BITS_TO_LONGS(MAX_NUMNODES
);
1340 if (copy_from_user(nodes_addr(*nodes
), nmask
, nlongs
*sizeof(unsigned long)))
1342 nodes_addr(*nodes
)[nlongs
-1] &= endmask
;
1346 /* Copy a kernel node mask to user space */
1347 static int copy_nodes_to_user(unsigned long __user
*mask
, unsigned long maxnode
,
1350 unsigned long copy
= ALIGN(maxnode
-1, 64) / 8;
1351 const int nbytes
= BITS_TO_LONGS(MAX_NUMNODES
) * sizeof(long);
1353 if (copy
> nbytes
) {
1354 if (copy
> PAGE_SIZE
)
1356 if (clear_user((char __user
*)mask
+ nbytes
, copy
- nbytes
))
1360 return copy_to_user(mask
, nodes_addr(*nodes
), copy
) ? -EFAULT
: 0;
1363 SYSCALL_DEFINE6(mbind
, unsigned long, start
, unsigned long, len
,
1364 unsigned long, mode
, const unsigned long __user
*, nmask
,
1365 unsigned long, maxnode
, unsigned, flags
)
1369 unsigned short mode_flags
;
1371 mode_flags
= mode
& MPOL_MODE_FLAGS
;
1372 mode
&= ~MPOL_MODE_FLAGS
;
1373 if (mode
>= MPOL_MAX
)
1375 if ((mode_flags
& MPOL_F_STATIC_NODES
) &&
1376 (mode_flags
& MPOL_F_RELATIVE_NODES
))
1378 err
= get_nodes(&nodes
, nmask
, maxnode
);
1381 return do_mbind(start
, len
, mode
, mode_flags
, &nodes
, flags
);
1384 /* Set the process memory policy */
1385 SYSCALL_DEFINE3(set_mempolicy
, int, mode
, const unsigned long __user
*, nmask
,
1386 unsigned long, maxnode
)
1390 unsigned short flags
;
1392 flags
= mode
& MPOL_MODE_FLAGS
;
1393 mode
&= ~MPOL_MODE_FLAGS
;
1394 if ((unsigned int)mode
>= MPOL_MAX
)
1396 if ((flags
& MPOL_F_STATIC_NODES
) && (flags
& MPOL_F_RELATIVE_NODES
))
1398 err
= get_nodes(&nodes
, nmask
, maxnode
);
1401 return do_set_mempolicy(mode
, flags
, &nodes
);
1404 SYSCALL_DEFINE4(migrate_pages
, pid_t
, pid
, unsigned long, maxnode
,
1405 const unsigned long __user
*, old_nodes
,
1406 const unsigned long __user
*, new_nodes
)
1408 const struct cred
*cred
= current_cred(), *tcred
;
1409 struct mm_struct
*mm
= NULL
;
1410 struct task_struct
*task
;
1411 nodemask_t task_nodes
;
1415 NODEMASK_SCRATCH(scratch
);
1420 old
= &scratch
->mask1
;
1421 new = &scratch
->mask2
;
1423 err
= get_nodes(old
, old_nodes
, maxnode
);
1427 err
= get_nodes(new, new_nodes
, maxnode
);
1431 /* Find the mm_struct */
1433 task
= pid
? find_task_by_vpid(pid
) : current
;
1439 get_task_struct(task
);
1444 * Check if this process has the right to modify the specified
1445 * process. The right exists if the process has administrative
1446 * capabilities, superuser privileges or the same
1447 * userid as the target process.
1449 tcred
= __task_cred(task
);
1450 if (!uid_eq(cred
->euid
, tcred
->suid
) && !uid_eq(cred
->euid
, tcred
->uid
) &&
1451 !uid_eq(cred
->uid
, tcred
->suid
) && !uid_eq(cred
->uid
, tcred
->uid
) &&
1452 !capable(CAP_SYS_NICE
)) {
1459 task_nodes
= cpuset_mems_allowed(task
);
1460 /* Is the user allowed to access the target nodes? */
1461 if (!nodes_subset(*new, task_nodes
) && !capable(CAP_SYS_NICE
)) {
1466 if (!nodes_subset(*new, node_states
[N_MEMORY
])) {
1471 err
= security_task_movememory(task
);
1475 mm
= get_task_mm(task
);
1476 put_task_struct(task
);
1483 err
= do_migrate_pages(mm
, old
, new,
1484 capable(CAP_SYS_NICE
) ? MPOL_MF_MOVE_ALL
: MPOL_MF_MOVE
);
1488 NODEMASK_SCRATCH_FREE(scratch
);
1493 put_task_struct(task
);
1499 /* Retrieve NUMA policy */
1500 SYSCALL_DEFINE5(get_mempolicy
, int __user
*, policy
,
1501 unsigned long __user
*, nmask
, unsigned long, maxnode
,
1502 unsigned long, addr
, unsigned long, flags
)
1505 int uninitialized_var(pval
);
1508 if (nmask
!= NULL
&& maxnode
< MAX_NUMNODES
)
1511 err
= do_get_mempolicy(&pval
, &nodes
, addr
, flags
);
1516 if (policy
&& put_user(pval
, policy
))
1520 err
= copy_nodes_to_user(nmask
, maxnode
, &nodes
);
1525 #ifdef CONFIG_COMPAT
1527 COMPAT_SYSCALL_DEFINE5(get_mempolicy
, int __user
*, policy
,
1528 compat_ulong_t __user
*, nmask
,
1529 compat_ulong_t
, maxnode
,
1530 compat_ulong_t
, addr
, compat_ulong_t
, flags
)
1533 unsigned long __user
*nm
= NULL
;
1534 unsigned long nr_bits
, alloc_size
;
1535 DECLARE_BITMAP(bm
, MAX_NUMNODES
);
1537 nr_bits
= min_t(unsigned long, maxnode
-1, MAX_NUMNODES
);
1538 alloc_size
= ALIGN(nr_bits
, BITS_PER_LONG
) / 8;
1541 nm
= compat_alloc_user_space(alloc_size
);
1543 err
= sys_get_mempolicy(policy
, nm
, nr_bits
+1, addr
, flags
);
1545 if (!err
&& nmask
) {
1546 unsigned long copy_size
;
1547 copy_size
= min_t(unsigned long, sizeof(bm
), alloc_size
);
1548 err
= copy_from_user(bm
, nm
, copy_size
);
1549 /* ensure entire bitmap is zeroed */
1550 err
|= clear_user(nmask
, ALIGN(maxnode
-1, 8) / 8);
1551 err
|= compat_put_bitmap(nmask
, bm
, nr_bits
);
1557 COMPAT_SYSCALL_DEFINE3(set_mempolicy
, int, mode
, compat_ulong_t __user
*, nmask
,
1558 compat_ulong_t
, maxnode
)
1561 unsigned long __user
*nm
= NULL
;
1562 unsigned long nr_bits
, alloc_size
;
1563 DECLARE_BITMAP(bm
, MAX_NUMNODES
);
1565 nr_bits
= min_t(unsigned long, maxnode
-1, MAX_NUMNODES
);
1566 alloc_size
= ALIGN(nr_bits
, BITS_PER_LONG
) / 8;
1569 err
= compat_get_bitmap(bm
, nmask
, nr_bits
);
1570 nm
= compat_alloc_user_space(alloc_size
);
1571 err
|= copy_to_user(nm
, bm
, alloc_size
);
1577 return sys_set_mempolicy(mode
, nm
, nr_bits
+1);
1580 COMPAT_SYSCALL_DEFINE6(mbind
, compat_ulong_t
, start
, compat_ulong_t
, len
,
1581 compat_ulong_t
, mode
, compat_ulong_t __user
*, nmask
,
1582 compat_ulong_t
, maxnode
, compat_ulong_t
, flags
)
1585 unsigned long __user
*nm
= NULL
;
1586 unsigned long nr_bits
, alloc_size
;
1589 nr_bits
= min_t(unsigned long, maxnode
-1, MAX_NUMNODES
);
1590 alloc_size
= ALIGN(nr_bits
, BITS_PER_LONG
) / 8;
1593 err
= compat_get_bitmap(nodes_addr(bm
), nmask
, nr_bits
);
1594 nm
= compat_alloc_user_space(alloc_size
);
1595 err
|= copy_to_user(nm
, nodes_addr(bm
), alloc_size
);
1601 return sys_mbind(start
, len
, mode
, nm
, nr_bits
+1, flags
);
1607 * get_vma_policy(@task, @vma, @addr)
1608 * @task: task for fallback if vma policy == default
1609 * @vma: virtual memory area whose policy is sought
1610 * @addr: address in @vma for shared policy lookup
1612 * Returns effective policy for a VMA at specified address.
1613 * Falls back to @task or system default policy, as necessary.
1614 * Current or other task's task mempolicy and non-shared vma policies must be
1615 * protected by task_lock(task) by the caller.
1616 * Shared policies [those marked as MPOL_F_SHARED] require an extra reference
1617 * count--added by the get_policy() vm_op, as appropriate--to protect against
1618 * freeing by another task. It is the caller's responsibility to free the
1619 * extra reference for shared policies.
1621 struct mempolicy
*get_vma_policy(struct task_struct
*task
,
1622 struct vm_area_struct
*vma
, unsigned long addr
)
1624 struct mempolicy
*pol
= NULL
;
1627 if (vma
->vm_ops
&& vma
->vm_ops
->get_policy
) {
1628 pol
= vma
->vm_ops
->get_policy(vma
, addr
);
1629 } else if (vma
->vm_policy
) {
1630 pol
= vma
->vm_policy
;
1633 * shmem_alloc_page() passes MPOL_F_SHARED policy with
1634 * a pseudo vma whose vma->vm_ops=NULL. Take a reference
1635 * count on these policies which will be dropped by
1636 * mpol_cond_put() later
1638 if (mpol_needs_cond_ref(pol
))
1644 pol
= get_task_policy(task
);
1649 bool vma_policy_mof(struct task_struct
*task
, struct vm_area_struct
*vma
)
1651 struct mempolicy
*pol
= NULL
;
1654 if (vma
->vm_ops
&& vma
->vm_ops
->get_policy
) {
1657 pol
= vma
->vm_ops
->get_policy(vma
, vma
->vm_start
);
1658 if (pol
&& (pol
->flags
& MPOL_F_MOF
))
1665 pol
= vma
->vm_policy
;
1669 pol
= get_task_policy(task
);
1671 return pol
->flags
& MPOL_F_MOF
;
1674 static int apply_policy_zone(struct mempolicy
*policy
, enum zone_type zone
)
1676 enum zone_type dynamic_policy_zone
= policy_zone
;
1678 BUG_ON(dynamic_policy_zone
== ZONE_MOVABLE
);
1681 * if policy->v.nodes has movable memory only,
1682 * we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only.
1684 * policy->v.nodes is intersect with node_states[N_MEMORY].
1685 * so if the following test faile, it implies
1686 * policy->v.nodes has movable memory only.
1688 if (!nodes_intersects(policy
->v
.nodes
, node_states
[N_HIGH_MEMORY
]))
1689 dynamic_policy_zone
= ZONE_MOVABLE
;
1691 return zone
>= dynamic_policy_zone
;
1695 * Return a nodemask representing a mempolicy for filtering nodes for
1698 static nodemask_t
*policy_nodemask(gfp_t gfp
, struct mempolicy
*policy
)
1700 /* Lower zones don't get a nodemask applied for MPOL_BIND */
1701 if (unlikely(policy
->mode
== MPOL_BIND
) &&
1702 apply_policy_zone(policy
, gfp_zone(gfp
)) &&
1703 cpuset_nodemask_valid_mems_allowed(&policy
->v
.nodes
))
1704 return &policy
->v
.nodes
;
1709 /* Return a zonelist indicated by gfp for node representing a mempolicy */
1710 static struct zonelist
*policy_zonelist(gfp_t gfp
, struct mempolicy
*policy
,
1713 switch (policy
->mode
) {
1714 case MPOL_PREFERRED
:
1715 if (!(policy
->flags
& MPOL_F_LOCAL
))
1716 nd
= policy
->v
.preferred_node
;
1720 * Normally, MPOL_BIND allocations are node-local within the
1721 * allowed nodemask. However, if __GFP_THISNODE is set and the
1722 * current node isn't part of the mask, we use the zonelist for
1723 * the first node in the mask instead.
1725 if (unlikely(gfp
& __GFP_THISNODE
) &&
1726 unlikely(!node_isset(nd
, policy
->v
.nodes
)))
1727 nd
= first_node(policy
->v
.nodes
);
1732 return node_zonelist(nd
, gfp
);
1735 /* Do dynamic interleaving for a process */
1736 static unsigned interleave_nodes(struct mempolicy
*policy
)
1739 struct task_struct
*me
= current
;
1742 next
= next_node(nid
, policy
->v
.nodes
);
1743 if (next
>= MAX_NUMNODES
)
1744 next
= first_node(policy
->v
.nodes
);
1745 if (next
< MAX_NUMNODES
)
1751 * Depending on the memory policy provide a node from which to allocate the
1754 unsigned int mempolicy_slab_node(void)
1756 struct mempolicy
*policy
;
1757 int node
= numa_mem_id();
1762 policy
= current
->mempolicy
;
1763 if (!policy
|| policy
->flags
& MPOL_F_LOCAL
)
1766 switch (policy
->mode
) {
1767 case MPOL_PREFERRED
:
1769 * handled MPOL_F_LOCAL above
1771 return policy
->v
.preferred_node
;
1773 case MPOL_INTERLEAVE
:
1774 return interleave_nodes(policy
);
1778 * Follow bind policy behavior and start allocation at the
1781 struct zonelist
*zonelist
;
1783 enum zone_type highest_zoneidx
= gfp_zone(GFP_KERNEL
);
1784 zonelist
= &NODE_DATA(node
)->node_zonelists
[0];
1785 (void)first_zones_zonelist(zonelist
, highest_zoneidx
,
1788 return zone
? zone
->node
: node
;
1796 /* Do static interleaving for a VMA with known offset. */
1797 static unsigned offset_il_node(struct mempolicy
*pol
,
1798 struct vm_area_struct
*vma
, unsigned long off
)
1800 unsigned nnodes
= nodes_weight(pol
->v
.nodes
);
1803 int nid
= NUMA_NO_NODE
;
1806 return numa_node_id();
1807 target
= (unsigned int)off
% nnodes
;
1810 nid
= next_node(nid
, pol
->v
.nodes
);
1812 } while (c
<= target
);
1816 /* Determine a node number for interleave */
1817 static inline unsigned interleave_nid(struct mempolicy
*pol
,
1818 struct vm_area_struct
*vma
, unsigned long addr
, int shift
)
1824 * for small pages, there is no difference between
1825 * shift and PAGE_SHIFT, so the bit-shift is safe.
1826 * for huge pages, since vm_pgoff is in units of small
1827 * pages, we need to shift off the always 0 bits to get
1830 BUG_ON(shift
< PAGE_SHIFT
);
1831 off
= vma
->vm_pgoff
>> (shift
- PAGE_SHIFT
);
1832 off
+= (addr
- vma
->vm_start
) >> shift
;
1833 return offset_il_node(pol
, vma
, off
);
1835 return interleave_nodes(pol
);
1839 * Return the bit number of a random bit set in the nodemask.
1840 * (returns NUMA_NO_NODE if nodemask is empty)
1842 int node_random(const nodemask_t
*maskp
)
1844 int w
, bit
= NUMA_NO_NODE
;
1846 w
= nodes_weight(*maskp
);
1848 bit
= bitmap_ord_to_pos(maskp
->bits
,
1849 get_random_int() % w
, MAX_NUMNODES
);
1853 #ifdef CONFIG_HUGETLBFS
1855 * huge_zonelist(@vma, @addr, @gfp_flags, @mpol)
1856 * @vma: virtual memory area whose policy is sought
1857 * @addr: address in @vma for shared policy lookup and interleave policy
1858 * @gfp_flags: for requested zone
1859 * @mpol: pointer to mempolicy pointer for reference counted mempolicy
1860 * @nodemask: pointer to nodemask pointer for MPOL_BIND nodemask
1862 * Returns a zonelist suitable for a huge page allocation and a pointer
1863 * to the struct mempolicy for conditional unref after allocation.
1864 * If the effective policy is 'BIND, returns a pointer to the mempolicy's
1865 * @nodemask for filtering the zonelist.
1867 * Must be protected by read_mems_allowed_begin()
1869 struct zonelist
*huge_zonelist(struct vm_area_struct
*vma
, unsigned long addr
,
1870 gfp_t gfp_flags
, struct mempolicy
**mpol
,
1871 nodemask_t
**nodemask
)
1873 struct zonelist
*zl
;
1875 *mpol
= get_vma_policy(current
, vma
, addr
);
1876 *nodemask
= NULL
; /* assume !MPOL_BIND */
1878 if (unlikely((*mpol
)->mode
== MPOL_INTERLEAVE
)) {
1879 zl
= node_zonelist(interleave_nid(*mpol
, vma
, addr
,
1880 huge_page_shift(hstate_vma(vma
))), gfp_flags
);
1882 zl
= policy_zonelist(gfp_flags
, *mpol
, numa_node_id());
1883 if ((*mpol
)->mode
== MPOL_BIND
)
1884 *nodemask
= &(*mpol
)->v
.nodes
;
1890 * init_nodemask_of_mempolicy
1892 * If the current task's mempolicy is "default" [NULL], return 'false'
1893 * to indicate default policy. Otherwise, extract the policy nodemask
1894 * for 'bind' or 'interleave' policy into the argument nodemask, or
1895 * initialize the argument nodemask to contain the single node for
1896 * 'preferred' or 'local' policy and return 'true' to indicate presence
1897 * of non-default mempolicy.
1899 * We don't bother with reference counting the mempolicy [mpol_get/put]
1900 * because the current task is examining it's own mempolicy and a task's
1901 * mempolicy is only ever changed by the task itself.
1903 * N.B., it is the caller's responsibility to free a returned nodemask.
1905 bool init_nodemask_of_mempolicy(nodemask_t
*mask
)
1907 struct mempolicy
*mempolicy
;
1910 if (!(mask
&& current
->mempolicy
))
1914 mempolicy
= current
->mempolicy
;
1915 switch (mempolicy
->mode
) {
1916 case MPOL_PREFERRED
:
1917 if (mempolicy
->flags
& MPOL_F_LOCAL
)
1918 nid
= numa_node_id();
1920 nid
= mempolicy
->v
.preferred_node
;
1921 init_nodemask_of_node(mask
, nid
);
1926 case MPOL_INTERLEAVE
:
1927 *mask
= mempolicy
->v
.nodes
;
1933 task_unlock(current
);
1940 * mempolicy_nodemask_intersects
1942 * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
1943 * policy. Otherwise, check for intersection between mask and the policy
1944 * nodemask for 'bind' or 'interleave' policy. For 'perferred' or 'local'
1945 * policy, always return true since it may allocate elsewhere on fallback.
1947 * Takes task_lock(tsk) to prevent freeing of its mempolicy.
1949 bool mempolicy_nodemask_intersects(struct task_struct
*tsk
,
1950 const nodemask_t
*mask
)
1952 struct mempolicy
*mempolicy
;
1958 mempolicy
= tsk
->mempolicy
;
1962 switch (mempolicy
->mode
) {
1963 case MPOL_PREFERRED
:
1965 * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
1966 * allocate from, they may fallback to other nodes when oom.
1967 * Thus, it's possible for tsk to have allocated memory from
1972 case MPOL_INTERLEAVE
:
1973 ret
= nodes_intersects(mempolicy
->v
.nodes
, *mask
);
1983 /* Allocate a page in interleaved policy.
1984 Own path because it needs to do special accounting. */
1985 static struct page
*alloc_page_interleave(gfp_t gfp
, unsigned order
,
1988 struct zonelist
*zl
;
1991 zl
= node_zonelist(nid
, gfp
);
1992 page
= __alloc_pages(gfp
, order
, zl
);
1993 if (page
&& page_zone(page
) == zonelist_zone(&zl
->_zonerefs
[0]))
1994 inc_zone_page_state(page
, NUMA_INTERLEAVE_HIT
);
1999 * alloc_pages_vma - Allocate a page for a VMA.
2002 * %GFP_USER user allocation.
2003 * %GFP_KERNEL kernel allocations,
2004 * %GFP_HIGHMEM highmem/user allocations,
2005 * %GFP_FS allocation should not call back into a file system.
2006 * %GFP_ATOMIC don't sleep.
2008 * @order:Order of the GFP allocation.
2009 * @vma: Pointer to VMA or NULL if not available.
2010 * @addr: Virtual Address of the allocation. Must be inside the VMA.
2012 * This function allocates a page from the kernel page pool and applies
2013 * a NUMA policy associated with the VMA or the current process.
2014 * When VMA is not NULL caller must hold down_read on the mmap_sem of the
2015 * mm_struct of the VMA to prevent it from going away. Should be used for
2016 * all allocations for pages that will be mapped into
2017 * user space. Returns NULL when no page can be allocated.
2019 * Should be called with the mm_sem of the vma hold.
2022 alloc_pages_vma(gfp_t gfp
, int order
, struct vm_area_struct
*vma
,
2023 unsigned long addr
, int node
)
2025 struct mempolicy
*pol
;
2027 unsigned int cpuset_mems_cookie
;
2030 pol
= get_vma_policy(current
, vma
, addr
);
2031 cpuset_mems_cookie
= read_mems_allowed_begin();
2033 if (unlikely(pol
->mode
== MPOL_INTERLEAVE
)) {
2036 nid
= interleave_nid(pol
, vma
, addr
, PAGE_SHIFT
+ order
);
2038 page
= alloc_page_interleave(gfp
, order
, nid
);
2039 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
2044 page
= __alloc_pages_nodemask(gfp
, order
,
2045 policy_zonelist(gfp
, pol
, node
),
2046 policy_nodemask(gfp
, pol
));
2048 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
2054 * alloc_pages_current - Allocate pages.
2057 * %GFP_USER user allocation,
2058 * %GFP_KERNEL kernel allocation,
2059 * %GFP_HIGHMEM highmem allocation,
2060 * %GFP_FS don't call back into a file system.
2061 * %GFP_ATOMIC don't sleep.
2062 * @order: Power of two of allocation size in pages. 0 is a single page.
2064 * Allocate a page from the kernel page pool. When not in
2065 * interrupt context and apply the current process NUMA policy.
2066 * Returns NULL when no page can be allocated.
2068 * Don't call cpuset_update_task_memory_state() unless
2069 * 1) it's ok to take cpuset_sem (can WAIT), and
2070 * 2) allocating for current task (not interrupt).
2072 struct page
*alloc_pages_current(gfp_t gfp
, unsigned order
)
2074 struct mempolicy
*pol
= &default_policy
;
2076 unsigned int cpuset_mems_cookie
;
2078 if (!in_interrupt() && !(gfp
& __GFP_THISNODE
))
2079 pol
= get_task_policy(current
);
2082 cpuset_mems_cookie
= read_mems_allowed_begin();
2085 * No reference counting needed for current->mempolicy
2086 * nor system default_policy
2088 if (pol
->mode
== MPOL_INTERLEAVE
)
2089 page
= alloc_page_interleave(gfp
, order
, interleave_nodes(pol
));
2091 page
= __alloc_pages_nodemask(gfp
, order
,
2092 policy_zonelist(gfp
, pol
, numa_node_id()),
2093 policy_nodemask(gfp
, pol
));
2095 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
2100 EXPORT_SYMBOL(alloc_pages_current
);
2102 int vma_dup_policy(struct vm_area_struct
*src
, struct vm_area_struct
*dst
)
2104 struct mempolicy
*pol
= mpol_dup(vma_policy(src
));
2107 return PTR_ERR(pol
);
2108 dst
->vm_policy
= pol
;
2113 * If mpol_dup() sees current->cpuset == cpuset_being_rebound, then it
2114 * rebinds the mempolicy its copying by calling mpol_rebind_policy()
2115 * with the mems_allowed returned by cpuset_mems_allowed(). This
2116 * keeps mempolicies cpuset relative after its cpuset moves. See
2117 * further kernel/cpuset.c update_nodemask().
2119 * current's mempolicy may be rebinded by the other task(the task that changes
2120 * cpuset's mems), so we needn't do rebind work for current task.
2123 /* Slow path of a mempolicy duplicate */
2124 struct mempolicy
*__mpol_dup(struct mempolicy
*old
)
2126 struct mempolicy
*new = kmem_cache_alloc(policy_cache
, GFP_KERNEL
);
2129 return ERR_PTR(-ENOMEM
);
2131 /* task's mempolicy is protected by alloc_lock */
2132 if (old
== current
->mempolicy
) {
2135 task_unlock(current
);
2139 if (current_cpuset_is_being_rebound()) {
2140 nodemask_t mems
= cpuset_mems_allowed(current
);
2141 if (new->flags
& MPOL_F_REBINDING
)
2142 mpol_rebind_policy(new, &mems
, MPOL_REBIND_STEP2
);
2144 mpol_rebind_policy(new, &mems
, MPOL_REBIND_ONCE
);
2146 atomic_set(&new->refcnt
, 1);
2150 /* Slow path of a mempolicy comparison */
2151 bool __mpol_equal(struct mempolicy
*a
, struct mempolicy
*b
)
2155 if (a
->mode
!= b
->mode
)
2157 if (a
->flags
!= b
->flags
)
2159 if (mpol_store_user_nodemask(a
))
2160 if (!nodes_equal(a
->w
.user_nodemask
, b
->w
.user_nodemask
))
2166 case MPOL_INTERLEAVE
:
2167 return !!nodes_equal(a
->v
.nodes
, b
->v
.nodes
);
2168 case MPOL_PREFERRED
:
2169 return a
->v
.preferred_node
== b
->v
.preferred_node
;
2177 * Shared memory backing store policy support.
2179 * Remember policies even when nobody has shared memory mapped.
2180 * The policies are kept in Red-Black tree linked from the inode.
2181 * They are protected by the sp->lock spinlock, which should be held
2182 * for any accesses to the tree.
2185 /* lookup first element intersecting start-end */
2186 /* Caller holds sp->lock */
2187 static struct sp_node
*
2188 sp_lookup(struct shared_policy
*sp
, unsigned long start
, unsigned long end
)
2190 struct rb_node
*n
= sp
->root
.rb_node
;
2193 struct sp_node
*p
= rb_entry(n
, struct sp_node
, nd
);
2195 if (start
>= p
->end
)
2197 else if (end
<= p
->start
)
2205 struct sp_node
*w
= NULL
;
2206 struct rb_node
*prev
= rb_prev(n
);
2209 w
= rb_entry(prev
, struct sp_node
, nd
);
2210 if (w
->end
<= start
)
2214 return rb_entry(n
, struct sp_node
, nd
);
2217 /* Insert a new shared policy into the list. */
2218 /* Caller holds sp->lock */
2219 static void sp_insert(struct shared_policy
*sp
, struct sp_node
*new)
2221 struct rb_node
**p
= &sp
->root
.rb_node
;
2222 struct rb_node
*parent
= NULL
;
2227 nd
= rb_entry(parent
, struct sp_node
, nd
);
2228 if (new->start
< nd
->start
)
2230 else if (new->end
> nd
->end
)
2231 p
= &(*p
)->rb_right
;
2235 rb_link_node(&new->nd
, parent
, p
);
2236 rb_insert_color(&new->nd
, &sp
->root
);
2237 pr_debug("inserting %lx-%lx: %d\n", new->start
, new->end
,
2238 new->policy
? new->policy
->mode
: 0);
2241 /* Find shared policy intersecting idx */
2243 mpol_shared_policy_lookup(struct shared_policy
*sp
, unsigned long idx
)
2245 struct mempolicy
*pol
= NULL
;
2248 if (!sp
->root
.rb_node
)
2250 spin_lock(&sp
->lock
);
2251 sn
= sp_lookup(sp
, idx
, idx
+1);
2253 mpol_get(sn
->policy
);
2256 spin_unlock(&sp
->lock
);
2260 static void sp_free(struct sp_node
*n
)
2262 mpol_put(n
->policy
);
2263 kmem_cache_free(sn_cache
, n
);
2267 * mpol_misplaced - check whether current page node is valid in policy
2269 * @page: page to be checked
2270 * @vma: vm area where page mapped
2271 * @addr: virtual address where page mapped
2273 * Lookup current policy node id for vma,addr and "compare to" page's
2277 * -1 - not misplaced, page is in the right node
2278 * node - node id where the page should be
2280 * Policy determination "mimics" alloc_page_vma().
2281 * Called from fault path where we know the vma and faulting address.
2283 int mpol_misplaced(struct page
*page
, struct vm_area_struct
*vma
, unsigned long addr
)
2285 struct mempolicy
*pol
;
2287 int curnid
= page_to_nid(page
);
2288 unsigned long pgoff
;
2289 int thiscpu
= raw_smp_processor_id();
2290 int thisnid
= cpu_to_node(thiscpu
);
2296 pol
= get_vma_policy(current
, vma
, addr
);
2297 if (!(pol
->flags
& MPOL_F_MOF
))
2300 switch (pol
->mode
) {
2301 case MPOL_INTERLEAVE
:
2302 BUG_ON(addr
>= vma
->vm_end
);
2303 BUG_ON(addr
< vma
->vm_start
);
2305 pgoff
= vma
->vm_pgoff
;
2306 pgoff
+= (addr
- vma
->vm_start
) >> PAGE_SHIFT
;
2307 polnid
= offset_il_node(pol
, vma
, pgoff
);
2310 case MPOL_PREFERRED
:
2311 if (pol
->flags
& MPOL_F_LOCAL
)
2312 polnid
= numa_node_id();
2314 polnid
= pol
->v
.preferred_node
;
2319 * allows binding to multiple nodes.
2320 * use current page if in policy nodemask,
2321 * else select nearest allowed node, if any.
2322 * If no allowed nodes, use current [!misplaced].
2324 if (node_isset(curnid
, pol
->v
.nodes
))
2326 (void)first_zones_zonelist(
2327 node_zonelist(numa_node_id(), GFP_HIGHUSER
),
2328 gfp_zone(GFP_HIGHUSER
),
2329 &pol
->v
.nodes
, &zone
);
2330 polnid
= zone
->node
;
2337 /* Migrate the page towards the node whose CPU is referencing it */
2338 if (pol
->flags
& MPOL_F_MORON
) {
2341 if (!should_numa_migrate_memory(current
, page
, curnid
, thiscpu
))
2345 if (curnid
!= polnid
)
2353 static void sp_delete(struct shared_policy
*sp
, struct sp_node
*n
)
2355 pr_debug("deleting %lx-l%lx\n", n
->start
, n
->end
);
2356 rb_erase(&n
->nd
, &sp
->root
);
2360 static void sp_node_init(struct sp_node
*node
, unsigned long start
,
2361 unsigned long end
, struct mempolicy
*pol
)
2363 node
->start
= start
;
2368 static struct sp_node
*sp_alloc(unsigned long start
, unsigned long end
,
2369 struct mempolicy
*pol
)
2372 struct mempolicy
*newpol
;
2374 n
= kmem_cache_alloc(sn_cache
, GFP_KERNEL
);
2378 newpol
= mpol_dup(pol
);
2379 if (IS_ERR(newpol
)) {
2380 kmem_cache_free(sn_cache
, n
);
2383 newpol
->flags
|= MPOL_F_SHARED
;
2384 sp_node_init(n
, start
, end
, newpol
);
2389 /* Replace a policy range. */
2390 static int shared_policy_replace(struct shared_policy
*sp
, unsigned long start
,
2391 unsigned long end
, struct sp_node
*new)
2394 struct sp_node
*n_new
= NULL
;
2395 struct mempolicy
*mpol_new
= NULL
;
2399 spin_lock(&sp
->lock
);
2400 n
= sp_lookup(sp
, start
, end
);
2401 /* Take care of old policies in the same range. */
2402 while (n
&& n
->start
< end
) {
2403 struct rb_node
*next
= rb_next(&n
->nd
);
2404 if (n
->start
>= start
) {
2410 /* Old policy spanning whole new range. */
2415 *mpol_new
= *n
->policy
;
2416 atomic_set(&mpol_new
->refcnt
, 1);
2417 sp_node_init(n_new
, end
, n
->end
, mpol_new
);
2419 sp_insert(sp
, n_new
);
2428 n
= rb_entry(next
, struct sp_node
, nd
);
2432 spin_unlock(&sp
->lock
);
2439 kmem_cache_free(sn_cache
, n_new
);
2444 spin_unlock(&sp
->lock
);
2446 n_new
= kmem_cache_alloc(sn_cache
, GFP_KERNEL
);
2449 mpol_new
= kmem_cache_alloc(policy_cache
, GFP_KERNEL
);
2456 * mpol_shared_policy_init - initialize shared policy for inode
2457 * @sp: pointer to inode shared policy
2458 * @mpol: struct mempolicy to install
2460 * Install non-NULL @mpol in inode's shared policy rb-tree.
2461 * On entry, the current task has a reference on a non-NULL @mpol.
2462 * This must be released on exit.
2463 * This is called at get_inode() calls and we can use GFP_KERNEL.
2465 void mpol_shared_policy_init(struct shared_policy
*sp
, struct mempolicy
*mpol
)
2469 sp
->root
= RB_ROOT
; /* empty tree == default mempolicy */
2470 spin_lock_init(&sp
->lock
);
2473 struct vm_area_struct pvma
;
2474 struct mempolicy
*new;
2475 NODEMASK_SCRATCH(scratch
);
2479 /* contextualize the tmpfs mount point mempolicy */
2480 new = mpol_new(mpol
->mode
, mpol
->flags
, &mpol
->w
.user_nodemask
);
2482 goto free_scratch
; /* no valid nodemask intersection */
2485 ret
= mpol_set_nodemask(new, &mpol
->w
.user_nodemask
, scratch
);
2486 task_unlock(current
);
2490 /* Create pseudo-vma that contains just the policy */
2491 memset(&pvma
, 0, sizeof(struct vm_area_struct
));
2492 pvma
.vm_end
= TASK_SIZE
; /* policy covers entire file */
2493 mpol_set_shared_policy(sp
, &pvma
, new); /* adds ref */
2496 mpol_put(new); /* drop initial ref */
2498 NODEMASK_SCRATCH_FREE(scratch
);
2500 mpol_put(mpol
); /* drop our incoming ref on sb mpol */
2504 int mpol_set_shared_policy(struct shared_policy
*info
,
2505 struct vm_area_struct
*vma
, struct mempolicy
*npol
)
2508 struct sp_node
*new = NULL
;
2509 unsigned long sz
= vma_pages(vma
);
2511 pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
2513 sz
, npol
? npol
->mode
: -1,
2514 npol
? npol
->flags
: -1,
2515 npol
? nodes_addr(npol
->v
.nodes
)[0] : NUMA_NO_NODE
);
2518 new = sp_alloc(vma
->vm_pgoff
, vma
->vm_pgoff
+ sz
, npol
);
2522 err
= shared_policy_replace(info
, vma
->vm_pgoff
, vma
->vm_pgoff
+sz
, new);
2528 /* Free a backing policy store on inode delete. */
2529 void mpol_free_shared_policy(struct shared_policy
*p
)
2532 struct rb_node
*next
;
2534 if (!p
->root
.rb_node
)
2536 spin_lock(&p
->lock
);
2537 next
= rb_first(&p
->root
);
2539 n
= rb_entry(next
, struct sp_node
, nd
);
2540 next
= rb_next(&n
->nd
);
2543 spin_unlock(&p
->lock
);
2546 #ifdef CONFIG_NUMA_BALANCING
2547 static int __initdata numabalancing_override
;
2549 static void __init
check_numabalancing_enable(void)
2551 bool numabalancing_default
= false;
2553 if (IS_ENABLED(CONFIG_NUMA_BALANCING_DEFAULT_ENABLED
))
2554 numabalancing_default
= true;
2556 /* Parsed by setup_numabalancing. override == 1 enables, -1 disables */
2557 if (numabalancing_override
)
2558 set_numabalancing_state(numabalancing_override
== 1);
2560 if (nr_node_ids
> 1 && !numabalancing_override
) {
2561 pr_info("%s automatic NUMA balancing. "
2562 "Configure with numa_balancing= or the "
2563 "kernel.numa_balancing sysctl",
2564 numabalancing_default
? "Enabling" : "Disabling");
2565 set_numabalancing_state(numabalancing_default
);
2569 static int __init
setup_numabalancing(char *str
)
2575 if (!strcmp(str
, "enable")) {
2576 numabalancing_override
= 1;
2578 } else if (!strcmp(str
, "disable")) {
2579 numabalancing_override
= -1;
2584 pr_warn("Unable to parse numa_balancing=\n");
2588 __setup("numa_balancing=", setup_numabalancing
);
2590 static inline void __init
check_numabalancing_enable(void)
2593 #endif /* CONFIG_NUMA_BALANCING */
2595 /* assumes fs == KERNEL_DS */
2596 void __init
numa_policy_init(void)
2598 nodemask_t interleave_nodes
;
2599 unsigned long largest
= 0;
2600 int nid
, prefer
= 0;
2602 policy_cache
= kmem_cache_create("numa_policy",
2603 sizeof(struct mempolicy
),
2604 0, SLAB_PANIC
, NULL
);
2606 sn_cache
= kmem_cache_create("shared_policy_node",
2607 sizeof(struct sp_node
),
2608 0, SLAB_PANIC
, NULL
);
2610 for_each_node(nid
) {
2611 preferred_node_policy
[nid
] = (struct mempolicy
) {
2612 .refcnt
= ATOMIC_INIT(1),
2613 .mode
= MPOL_PREFERRED
,
2614 .flags
= MPOL_F_MOF
| MPOL_F_MORON
,
2615 .v
= { .preferred_node
= nid
, },
2620 * Set interleaving policy for system init. Interleaving is only
2621 * enabled across suitably sized nodes (default is >= 16MB), or
2622 * fall back to the largest node if they're all smaller.
2624 nodes_clear(interleave_nodes
);
2625 for_each_node_state(nid
, N_MEMORY
) {
2626 unsigned long total_pages
= node_present_pages(nid
);
2628 /* Preserve the largest node */
2629 if (largest
< total_pages
) {
2630 largest
= total_pages
;
2634 /* Interleave this node? */
2635 if ((total_pages
<< PAGE_SHIFT
) >= (16 << 20))
2636 node_set(nid
, interleave_nodes
);
2639 /* All too small, use the largest */
2640 if (unlikely(nodes_empty(interleave_nodes
)))
2641 node_set(prefer
, interleave_nodes
);
2643 if (do_set_mempolicy(MPOL_INTERLEAVE
, 0, &interleave_nodes
))
2644 pr_err("%s: interleaving failed\n", __func__
);
2646 check_numabalancing_enable();
2649 /* Reset policy of current process to default */
2650 void numa_default_policy(void)
2652 do_set_mempolicy(MPOL_DEFAULT
, 0, NULL
);
2656 * Parse and format mempolicy from/to strings
2660 * "local" is implemented internally by MPOL_PREFERRED with MPOL_F_LOCAL flag.
2662 static const char * const policy_modes
[] =
2664 [MPOL_DEFAULT
] = "default",
2665 [MPOL_PREFERRED
] = "prefer",
2666 [MPOL_BIND
] = "bind",
2667 [MPOL_INTERLEAVE
] = "interleave",
2668 [MPOL_LOCAL
] = "local",
2674 * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option.
2675 * @str: string containing mempolicy to parse
2676 * @mpol: pointer to struct mempolicy pointer, returned on success.
2679 * <mode>[=<flags>][:<nodelist>]
2681 * On success, returns 0, else 1
2683 int mpol_parse_str(char *str
, struct mempolicy
**mpol
)
2685 struct mempolicy
*new = NULL
;
2686 unsigned short mode
;
2687 unsigned short mode_flags
;
2689 char *nodelist
= strchr(str
, ':');
2690 char *flags
= strchr(str
, '=');
2694 /* NUL-terminate mode or flags string */
2696 if (nodelist_parse(nodelist
, nodes
))
2698 if (!nodes_subset(nodes
, node_states
[N_MEMORY
]))
2704 *flags
++ = '\0'; /* terminate mode string */
2706 for (mode
= 0; mode
< MPOL_MAX
; mode
++) {
2707 if (!strcmp(str
, policy_modes
[mode
])) {
2711 if (mode
>= MPOL_MAX
)
2715 case MPOL_PREFERRED
:
2717 * Insist on a nodelist of one node only
2720 char *rest
= nodelist
;
2721 while (isdigit(*rest
))
2727 case MPOL_INTERLEAVE
:
2729 * Default to online nodes with memory if no nodelist
2732 nodes
= node_states
[N_MEMORY
];
2736 * Don't allow a nodelist; mpol_new() checks flags
2740 mode
= MPOL_PREFERRED
;
2744 * Insist on a empty nodelist
2751 * Insist on a nodelist
2760 * Currently, we only support two mutually exclusive
2763 if (!strcmp(flags
, "static"))
2764 mode_flags
|= MPOL_F_STATIC_NODES
;
2765 else if (!strcmp(flags
, "relative"))
2766 mode_flags
|= MPOL_F_RELATIVE_NODES
;
2771 new = mpol_new(mode
, mode_flags
, &nodes
);
2776 * Save nodes for mpol_to_str() to show the tmpfs mount options
2777 * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo.
2779 if (mode
!= MPOL_PREFERRED
)
2780 new->v
.nodes
= nodes
;
2782 new->v
.preferred_node
= first_node(nodes
);
2784 new->flags
|= MPOL_F_LOCAL
;
2787 * Save nodes for contextualization: this will be used to "clone"
2788 * the mempolicy in a specific context [cpuset] at a later time.
2790 new->w
.user_nodemask
= nodes
;
2795 /* Restore string for error message */
2804 #endif /* CONFIG_TMPFS */
2807 * mpol_to_str - format a mempolicy structure for printing
2808 * @buffer: to contain formatted mempolicy string
2809 * @maxlen: length of @buffer
2810 * @pol: pointer to mempolicy to be formatted
2812 * Convert @pol into a string. If @buffer is too short, truncate the string.
2813 * Recommend a @maxlen of at least 32 for the longest mode, "interleave", the
2814 * longest flag, "relative", and to display at least a few node ids.
2816 void mpol_to_str(char *buffer
, int maxlen
, struct mempolicy
*pol
)
2819 nodemask_t nodes
= NODE_MASK_NONE
;
2820 unsigned short mode
= MPOL_DEFAULT
;
2821 unsigned short flags
= 0;
2823 if (pol
&& pol
!= &default_policy
&& !(pol
->flags
& MPOL_F_MORON
)) {
2831 case MPOL_PREFERRED
:
2832 if (flags
& MPOL_F_LOCAL
)
2835 node_set(pol
->v
.preferred_node
, nodes
);
2838 case MPOL_INTERLEAVE
:
2839 nodes
= pol
->v
.nodes
;
2843 snprintf(p
, maxlen
, "unknown");
2847 p
+= snprintf(p
, maxlen
, "%s", policy_modes
[mode
]);
2849 if (flags
& MPOL_MODE_FLAGS
) {
2850 p
+= snprintf(p
, buffer
+ maxlen
- p
, "=");
2853 * Currently, the only defined flags are mutually exclusive
2855 if (flags
& MPOL_F_STATIC_NODES
)
2856 p
+= snprintf(p
, buffer
+ maxlen
- p
, "static");
2857 else if (flags
& MPOL_F_RELATIVE_NODES
)
2858 p
+= snprintf(p
, buffer
+ maxlen
- p
, "relative");
2861 if (!nodes_empty(nodes
)) {
2862 p
+= snprintf(p
, buffer
+ maxlen
- p
, ":");
2863 p
+= nodelist_scnprintf(p
, buffer
+ maxlen
- p
, nodes
);