]>
git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - mm/mempolicy.c
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.
66 could replace all the switch()es with a mempolicy_ops structure.
69 #include <linux/mempolicy.h>
71 #include <linux/highmem.h>
72 #include <linux/hugetlb.h>
73 #include <linux/kernel.h>
74 #include <linux/sched.h>
76 #include <linux/nodemask.h>
77 #include <linux/cpuset.h>
78 #include <linux/gfp.h>
79 #include <linux/slab.h>
80 #include <linux/string.h>
81 #include <linux/module.h>
82 #include <linux/interrupt.h>
83 #include <linux/init.h>
84 #include <linux/compat.h>
85 #include <linux/mempolicy.h>
86 #include <linux/swap.h>
88 #include <asm/tlbflush.h>
89 #include <asm/uaccess.h>
91 /* Internal MPOL_MF_xxx flags */
92 #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
94 static kmem_cache_t
*policy_cache
;
95 static kmem_cache_t
*sn_cache
;
97 #define PDprintk(fmt...)
99 /* Highest zone. An specific allocation for a zone below that is not
101 int policy_zone
= ZONE_DMA
;
103 struct mempolicy default_policy
= {
104 .refcnt
= ATOMIC_INIT(1), /* never free it */
105 .policy
= MPOL_DEFAULT
,
108 /* Do sanity checking on a policy */
109 static int mpol_check_policy(int mode
, nodemask_t
*nodes
)
111 int empty
= nodes_empty(*nodes
);
119 case MPOL_INTERLEAVE
:
120 /* Preferred will only use the first bit, but allow
126 return nodes_subset(*nodes
, node_online_map
) ? 0 : -EINVAL
;
128 /* Generate a custom zonelist for the BIND policy. */
129 static struct zonelist
*bind_zonelist(nodemask_t
*nodes
)
134 max
= 1 + MAX_NR_ZONES
* nodes_weight(*nodes
);
135 zl
= kmalloc(sizeof(void *) * max
, GFP_KERNEL
);
139 for_each_node_mask(nd
, *nodes
)
140 zl
->zones
[num
++] = &NODE_DATA(nd
)->node_zones
[policy_zone
];
141 zl
->zones
[num
] = NULL
;
145 /* Create a new policy */
146 static struct mempolicy
*mpol_new(int mode
, nodemask_t
*nodes
)
148 struct mempolicy
*policy
;
150 PDprintk("setting mode %d nodes[0] %lx\n", mode
, nodes_addr(*nodes
)[0]);
151 if (mode
== MPOL_DEFAULT
)
153 policy
= kmem_cache_alloc(policy_cache
, GFP_KERNEL
);
155 return ERR_PTR(-ENOMEM
);
156 atomic_set(&policy
->refcnt
, 1);
158 case MPOL_INTERLEAVE
:
159 policy
->v
.nodes
= *nodes
;
160 if (nodes_weight(*nodes
) == 0) {
161 kmem_cache_free(policy_cache
, policy
);
162 return ERR_PTR(-EINVAL
);
166 policy
->v
.preferred_node
= first_node(*nodes
);
167 if (policy
->v
.preferred_node
>= MAX_NUMNODES
)
168 policy
->v
.preferred_node
= -1;
171 policy
->v
.zonelist
= bind_zonelist(nodes
);
172 if (policy
->v
.zonelist
== NULL
) {
173 kmem_cache_free(policy_cache
, policy
);
174 return ERR_PTR(-ENOMEM
);
178 policy
->policy
= mode
;
182 /* Check if we are the only process mapping the page in question */
183 static inline int single_mm_mapping(struct mm_struct
*mm
,
184 struct address_space
*mapping
)
186 struct vm_area_struct
*vma
;
187 struct prio_tree_iter iter
;
190 spin_lock(&mapping
->i_mmap_lock
);
191 vma_prio_tree_foreach(vma
, &iter
, &mapping
->i_mmap
, 0, ULONG_MAX
)
192 if (mm
!= vma
->vm_mm
) {
196 list_for_each_entry(vma
, &mapping
->i_mmap_nonlinear
, shared
.vm_set
.list
)
197 if (mm
!= vma
->vm_mm
) {
202 spin_unlock(&mapping
->i_mmap_lock
);
207 * Add a page to be migrated to the pagelist
209 static void migrate_page_add(struct vm_area_struct
*vma
,
210 struct page
*page
, struct list_head
*pagelist
, unsigned long flags
)
213 * Avoid migrating a page that is shared by others and not writable.
215 if ((flags
& MPOL_MF_MOVE_ALL
) || !page
->mapping
|| PageAnon(page
) ||
216 mapping_writably_mapped(page
->mapping
) ||
217 single_mm_mapping(vma
->vm_mm
, page
->mapping
)) {
218 int rc
= isolate_lru_page(page
);
221 list_add(&page
->lru
, pagelist
);
223 * If the isolate attempt was not successful then we just
224 * encountered an unswappable page. Something must be wrong.
230 /* Ensure all existing pages follow the policy. */
231 static int check_pte_range(struct vm_area_struct
*vma
, pmd_t
*pmd
,
232 unsigned long addr
, unsigned long end
,
233 const nodemask_t
*nodes
, unsigned long flags
,
234 struct list_head
*pagelist
)
240 orig_pte
= pte
= pte_offset_map_lock(vma
->vm_mm
, pmd
, addr
, &ptl
);
245 if (!pte_present(*pte
))
247 page
= vm_normal_page(vma
, addr
, *pte
);
250 nid
= page_to_nid(page
);
251 if (!node_isset(nid
, *nodes
)) {
253 migrate_page_add(vma
, page
, pagelist
, flags
);
257 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
258 pte_unmap_unlock(orig_pte
, ptl
);
262 static inline int check_pmd_range(struct vm_area_struct
*vma
, pud_t
*pud
,
263 unsigned long addr
, unsigned long end
,
264 const nodemask_t
*nodes
, unsigned long flags
,
265 struct list_head
*pagelist
)
270 pmd
= pmd_offset(pud
, addr
);
272 next
= pmd_addr_end(addr
, end
);
273 if (pmd_none_or_clear_bad(pmd
))
275 if (check_pte_range(vma
, pmd
, addr
, next
, nodes
,
278 } while (pmd
++, addr
= next
, addr
!= end
);
282 static inline int check_pud_range(struct vm_area_struct
*vma
, pgd_t
*pgd
,
283 unsigned long addr
, unsigned long end
,
284 const nodemask_t
*nodes
, unsigned long flags
,
285 struct list_head
*pagelist
)
290 pud
= pud_offset(pgd
, addr
);
292 next
= pud_addr_end(addr
, end
);
293 if (pud_none_or_clear_bad(pud
))
295 if (check_pmd_range(vma
, pud
, addr
, next
, nodes
,
298 } while (pud
++, addr
= next
, addr
!= end
);
302 static inline int check_pgd_range(struct vm_area_struct
*vma
,
303 unsigned long addr
, unsigned long end
,
304 const nodemask_t
*nodes
, unsigned long flags
,
305 struct list_head
*pagelist
)
310 pgd
= pgd_offset(vma
->vm_mm
, addr
);
312 next
= pgd_addr_end(addr
, end
);
313 if (pgd_none_or_clear_bad(pgd
))
315 if (check_pud_range(vma
, pgd
, addr
, next
, nodes
,
318 } while (pgd
++, addr
= next
, addr
!= end
);
322 /* Check if a vma is migratable */
323 static inline int vma_migratable(struct vm_area_struct
*vma
)
325 if (vma
->vm_flags
& (
326 VM_LOCKED
|VM_IO
|VM_HUGETLB
|VM_PFNMAP
))
332 * Check if all pages in a range are on a set of nodes.
333 * If pagelist != NULL then isolate pages from the LRU and
334 * put them on the pagelist.
336 static struct vm_area_struct
*
337 check_range(struct mm_struct
*mm
, unsigned long start
, unsigned long end
,
338 const nodemask_t
*nodes
, unsigned long flags
,
339 struct list_head
*pagelist
)
342 struct vm_area_struct
*first
, *vma
, *prev
;
344 first
= find_vma(mm
, start
);
346 return ERR_PTR(-EFAULT
);
348 for (vma
= first
; vma
&& vma
->vm_start
< end
; vma
= vma
->vm_next
) {
349 if (!(flags
& MPOL_MF_DISCONTIG_OK
)) {
350 if (!vma
->vm_next
&& vma
->vm_end
< end
)
351 return ERR_PTR(-EFAULT
);
352 if (prev
&& prev
->vm_end
< vma
->vm_start
)
353 return ERR_PTR(-EFAULT
);
355 if (!is_vm_hugetlb_page(vma
) &&
356 ((flags
& MPOL_MF_STRICT
) ||
357 ((flags
& (MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
)) &&
358 vma_migratable(vma
)))) {
359 unsigned long endvma
= vma
->vm_end
;
363 if (vma
->vm_start
> start
)
364 start
= vma
->vm_start
;
365 err
= check_pgd_range(vma
, start
, endvma
, nodes
,
368 first
= ERR_PTR(err
);
377 /* Apply policy to a single VMA */
378 static int policy_vma(struct vm_area_struct
*vma
, struct mempolicy
*new)
381 struct mempolicy
*old
= vma
->vm_policy
;
383 PDprintk("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
384 vma
->vm_start
, vma
->vm_end
, vma
->vm_pgoff
,
385 vma
->vm_ops
, vma
->vm_file
,
386 vma
->vm_ops
? vma
->vm_ops
->set_policy
: NULL
);
388 if (vma
->vm_ops
&& vma
->vm_ops
->set_policy
)
389 err
= vma
->vm_ops
->set_policy(vma
, new);
392 vma
->vm_policy
= new;
398 /* Step 2: apply policy to a range and do splits. */
399 static int mbind_range(struct vm_area_struct
*vma
, unsigned long start
,
400 unsigned long end
, struct mempolicy
*new)
402 struct vm_area_struct
*next
;
406 for (; vma
&& vma
->vm_start
< end
; vma
= next
) {
408 if (vma
->vm_start
< start
)
409 err
= split_vma(vma
->vm_mm
, vma
, start
, 1);
410 if (!err
&& vma
->vm_end
> end
)
411 err
= split_vma(vma
->vm_mm
, vma
, end
, 0);
413 err
= policy_vma(vma
, new);
420 static int contextualize_policy(int mode
, nodemask_t
*nodes
)
425 /* Update current mems_allowed */
426 cpuset_update_current_mems_allowed();
427 /* Ignore nodes not set in current->mems_allowed */
428 cpuset_restrict_to_mems_allowed(nodes
->bits
);
429 return mpol_check_policy(mode
, nodes
);
432 long do_mbind(unsigned long start
, unsigned long len
,
433 unsigned long mode
, nodemask_t
*nmask
, unsigned long flags
)
435 struct vm_area_struct
*vma
;
436 struct mm_struct
*mm
= current
->mm
;
437 struct mempolicy
*new;
442 if ((flags
& ~(unsigned long)(MPOL_MF_STRICT
|MPOL_MF_MOVE
|MPOL_MF_MOVE_ALL
))
445 if ((flags
& MPOL_MF_MOVE_ALL
) && !capable(CAP_SYS_RESOURCE
))
448 if (start
& ~PAGE_MASK
)
451 if (mode
== MPOL_DEFAULT
)
452 flags
&= ~MPOL_MF_STRICT
;
454 len
= (len
+ PAGE_SIZE
- 1) & PAGE_MASK
;
462 if (mpol_check_policy(mode
, nmask
))
465 new = mpol_new(mode
, nmask
);
470 * If we are using the default policy then operation
471 * on discontinuous address spaces is okay after all
474 flags
|= MPOL_MF_DISCONTIG_OK
;
476 PDprintk("mbind %lx-%lx mode:%ld nodes:%lx\n",start
,start
+len
,
477 mode
,nodes_addr(nodes
)[0]);
479 down_write(&mm
->mmap_sem
);
480 vma
= check_range(mm
, start
, end
, nmask
, flags
,
481 (flags
& (MPOL_MF_MOVE
| MPOL_MF_MOVE_ALL
)) ? &pagelist
: NULL
);
484 err
= mbind_range(vma
, start
, end
, new);
485 if (!list_empty(&pagelist
))
486 migrate_pages(&pagelist
, NULL
);
487 if (!err
&& !list_empty(&pagelist
) && (flags
& MPOL_MF_STRICT
))
490 if (!list_empty(&pagelist
))
491 putback_lru_pages(&pagelist
);
493 up_write(&mm
->mmap_sem
);
498 /* Set the process memory policy */
499 long do_set_mempolicy(int mode
, nodemask_t
*nodes
)
501 struct mempolicy
*new;
503 if (contextualize_policy(mode
, nodes
))
505 new = mpol_new(mode
, nodes
);
508 mpol_free(current
->mempolicy
);
509 current
->mempolicy
= new;
510 if (new && new->policy
== MPOL_INTERLEAVE
)
511 current
->il_next
= first_node(new->v
.nodes
);
515 /* Fill a zone bitmap for a policy */
516 static void get_zonemask(struct mempolicy
*p
, nodemask_t
*nodes
)
523 for (i
= 0; p
->v
.zonelist
->zones
[i
]; i
++)
524 node_set(p
->v
.zonelist
->zones
[i
]->zone_pgdat
->node_id
,
529 case MPOL_INTERLEAVE
:
533 /* or use current node instead of online map? */
534 if (p
->v
.preferred_node
< 0)
535 *nodes
= node_online_map
;
537 node_set(p
->v
.preferred_node
, *nodes
);
544 static int lookup_node(struct mm_struct
*mm
, unsigned long addr
)
549 err
= get_user_pages(current
, mm
, addr
& PAGE_MASK
, 1, 0, 0, &p
, NULL
);
551 err
= page_to_nid(p
);
557 /* Retrieve NUMA policy */
558 long do_get_mempolicy(int *policy
, nodemask_t
*nmask
,
559 unsigned long addr
, unsigned long flags
)
562 struct mm_struct
*mm
= current
->mm
;
563 struct vm_area_struct
*vma
= NULL
;
564 struct mempolicy
*pol
= current
->mempolicy
;
566 cpuset_update_current_mems_allowed();
567 if (flags
& ~(unsigned long)(MPOL_F_NODE
|MPOL_F_ADDR
))
569 if (flags
& MPOL_F_ADDR
) {
570 down_read(&mm
->mmap_sem
);
571 vma
= find_vma_intersection(mm
, addr
, addr
+1);
573 up_read(&mm
->mmap_sem
);
576 if (vma
->vm_ops
&& vma
->vm_ops
->get_policy
)
577 pol
= vma
->vm_ops
->get_policy(vma
, addr
);
579 pol
= vma
->vm_policy
;
584 pol
= &default_policy
;
586 if (flags
& MPOL_F_NODE
) {
587 if (flags
& MPOL_F_ADDR
) {
588 err
= lookup_node(mm
, addr
);
592 } else if (pol
== current
->mempolicy
&&
593 pol
->policy
== MPOL_INTERLEAVE
) {
594 *policy
= current
->il_next
;
600 *policy
= pol
->policy
;
603 up_read(¤t
->mm
->mmap_sem
);
609 get_zonemask(pol
, nmask
);
613 up_read(¤t
->mm
->mmap_sem
);
618 * User space interface with variable sized bitmaps for nodelists.
621 /* Copy a node mask from user space. */
622 static int get_nodes(nodemask_t
*nodes
, unsigned long __user
*nmask
,
623 unsigned long maxnode
)
626 unsigned long nlongs
;
627 unsigned long endmask
;
631 if (maxnode
== 0 || !nmask
)
634 nlongs
= BITS_TO_LONGS(maxnode
);
635 if ((maxnode
% BITS_PER_LONG
) == 0)
638 endmask
= (1UL << (maxnode
% BITS_PER_LONG
)) - 1;
640 /* When the user specified more nodes than supported just check
641 if the non supported part is all zero. */
642 if (nlongs
> BITS_TO_LONGS(MAX_NUMNODES
)) {
643 if (nlongs
> PAGE_SIZE
/sizeof(long))
645 for (k
= BITS_TO_LONGS(MAX_NUMNODES
); k
< nlongs
; k
++) {
647 if (get_user(t
, nmask
+ k
))
649 if (k
== nlongs
- 1) {
655 nlongs
= BITS_TO_LONGS(MAX_NUMNODES
);
659 if (copy_from_user(nodes_addr(*nodes
), nmask
, nlongs
*sizeof(unsigned long)))
661 nodes_addr(*nodes
)[nlongs
-1] &= endmask
;
665 /* Copy a kernel node mask to user space */
666 static int copy_nodes_to_user(unsigned long __user
*mask
, unsigned long maxnode
,
669 unsigned long copy
= ALIGN(maxnode
-1, 64) / 8;
670 const int nbytes
= BITS_TO_LONGS(MAX_NUMNODES
) * sizeof(long);
673 if (copy
> PAGE_SIZE
)
675 if (clear_user((char __user
*)mask
+ nbytes
, copy
- nbytes
))
679 return copy_to_user(mask
, nodes_addr(*nodes
), copy
) ? -EFAULT
: 0;
682 asmlinkage
long sys_mbind(unsigned long start
, unsigned long len
,
684 unsigned long __user
*nmask
, unsigned long maxnode
,
690 err
= get_nodes(&nodes
, nmask
, maxnode
);
693 return do_mbind(start
, len
, mode
, &nodes
, flags
);
696 /* Set the process memory policy */
697 asmlinkage
long sys_set_mempolicy(int mode
, unsigned long __user
*nmask
,
698 unsigned long maxnode
)
703 if (mode
< 0 || mode
> MPOL_MAX
)
705 err
= get_nodes(&nodes
, nmask
, maxnode
);
708 return do_set_mempolicy(mode
, &nodes
);
711 /* Retrieve NUMA policy */
712 asmlinkage
long sys_get_mempolicy(int __user
*policy
,
713 unsigned long __user
*nmask
,
714 unsigned long maxnode
,
715 unsigned long addr
, unsigned long flags
)
720 if (nmask
!= NULL
&& maxnode
< MAX_NUMNODES
)
723 err
= do_get_mempolicy(&pval
, &nodes
, addr
, flags
);
728 if (policy
&& put_user(pval
, policy
))
732 err
= copy_nodes_to_user(nmask
, maxnode
, &nodes
);
739 asmlinkage
long compat_sys_get_mempolicy(int __user
*policy
,
740 compat_ulong_t __user
*nmask
,
741 compat_ulong_t maxnode
,
742 compat_ulong_t addr
, compat_ulong_t flags
)
745 unsigned long __user
*nm
= NULL
;
746 unsigned long nr_bits
, alloc_size
;
747 DECLARE_BITMAP(bm
, MAX_NUMNODES
);
749 nr_bits
= min_t(unsigned long, maxnode
-1, MAX_NUMNODES
);
750 alloc_size
= ALIGN(nr_bits
, BITS_PER_LONG
) / 8;
753 nm
= compat_alloc_user_space(alloc_size
);
755 err
= sys_get_mempolicy(policy
, nm
, nr_bits
+1, addr
, flags
);
758 err
= copy_from_user(bm
, nm
, alloc_size
);
759 /* ensure entire bitmap is zeroed */
760 err
|= clear_user(nmask
, ALIGN(maxnode
-1, 8) / 8);
761 err
|= compat_put_bitmap(nmask
, bm
, nr_bits
);
767 asmlinkage
long compat_sys_set_mempolicy(int mode
, compat_ulong_t __user
*nmask
,
768 compat_ulong_t maxnode
)
771 unsigned long __user
*nm
= NULL
;
772 unsigned long nr_bits
, alloc_size
;
773 DECLARE_BITMAP(bm
, MAX_NUMNODES
);
775 nr_bits
= min_t(unsigned long, maxnode
-1, MAX_NUMNODES
);
776 alloc_size
= ALIGN(nr_bits
, BITS_PER_LONG
) / 8;
779 err
= compat_get_bitmap(bm
, nmask
, nr_bits
);
780 nm
= compat_alloc_user_space(alloc_size
);
781 err
|= copy_to_user(nm
, bm
, alloc_size
);
787 return sys_set_mempolicy(mode
, nm
, nr_bits
+1);
790 asmlinkage
long compat_sys_mbind(compat_ulong_t start
, compat_ulong_t len
,
791 compat_ulong_t mode
, compat_ulong_t __user
*nmask
,
792 compat_ulong_t maxnode
, compat_ulong_t flags
)
795 unsigned long __user
*nm
= NULL
;
796 unsigned long nr_bits
, alloc_size
;
799 nr_bits
= min_t(unsigned long, maxnode
-1, MAX_NUMNODES
);
800 alloc_size
= ALIGN(nr_bits
, BITS_PER_LONG
) / 8;
803 err
= compat_get_bitmap(nodes_addr(bm
), nmask
, nr_bits
);
804 nm
= compat_alloc_user_space(alloc_size
);
805 err
|= copy_to_user(nm
, nodes_addr(bm
), alloc_size
);
811 return sys_mbind(start
, len
, mode
, nm
, nr_bits
+1, flags
);
816 /* Return effective policy for a VMA */
818 get_vma_policy(struct task_struct
*task
, struct vm_area_struct
*vma
, unsigned long addr
)
820 struct mempolicy
*pol
= task
->mempolicy
;
823 if (vma
->vm_ops
&& vma
->vm_ops
->get_policy
)
824 pol
= vma
->vm_ops
->get_policy(vma
, addr
);
825 else if (vma
->vm_policy
&&
826 vma
->vm_policy
->policy
!= MPOL_DEFAULT
)
827 pol
= vma
->vm_policy
;
830 pol
= &default_policy
;
834 /* Return a zonelist representing a mempolicy */
835 static struct zonelist
*zonelist_policy(gfp_t gfp
, struct mempolicy
*policy
)
839 switch (policy
->policy
) {
841 nd
= policy
->v
.preferred_node
;
846 /* Lower zones don't get a policy applied */
847 /* Careful: current->mems_allowed might have moved */
848 if (gfp_zone(gfp
) >= policy_zone
)
849 if (cpuset_zonelist_valid_mems_allowed(policy
->v
.zonelist
))
850 return policy
->v
.zonelist
;
852 case MPOL_INTERLEAVE
: /* should not happen */
860 return NODE_DATA(nd
)->node_zonelists
+ gfp_zone(gfp
);
863 /* Do dynamic interleaving for a process */
864 static unsigned interleave_nodes(struct mempolicy
*policy
)
867 struct task_struct
*me
= current
;
870 next
= next_node(nid
, policy
->v
.nodes
);
871 if (next
>= MAX_NUMNODES
)
872 next
= first_node(policy
->v
.nodes
);
877 /* Do static interleaving for a VMA with known offset. */
878 static unsigned offset_il_node(struct mempolicy
*pol
,
879 struct vm_area_struct
*vma
, unsigned long off
)
881 unsigned nnodes
= nodes_weight(pol
->v
.nodes
);
882 unsigned target
= (unsigned)off
% nnodes
;
888 nid
= next_node(nid
, pol
->v
.nodes
);
890 } while (c
<= target
);
894 /* Determine a node number for interleave */
895 static inline unsigned interleave_nid(struct mempolicy
*pol
,
896 struct vm_area_struct
*vma
, unsigned long addr
, int shift
)
902 off
+= (addr
- vma
->vm_start
) >> shift
;
903 return offset_il_node(pol
, vma
, off
);
905 return interleave_nodes(pol
);
908 /* Return a zonelist suitable for a huge page allocation. */
909 struct zonelist
*huge_zonelist(struct vm_area_struct
*vma
, unsigned long addr
)
911 struct mempolicy
*pol
= get_vma_policy(current
, vma
, addr
);
913 if (pol
->policy
== MPOL_INTERLEAVE
) {
916 nid
= interleave_nid(pol
, vma
, addr
, HPAGE_SHIFT
);
917 return NODE_DATA(nid
)->node_zonelists
+ gfp_zone(GFP_HIGHUSER
);
919 return zonelist_policy(GFP_HIGHUSER
, pol
);
922 /* Allocate a page in interleaved policy.
923 Own path because it needs to do special accounting. */
924 static struct page
*alloc_page_interleave(gfp_t gfp
, unsigned order
,
930 zl
= NODE_DATA(nid
)->node_zonelists
+ gfp_zone(gfp
);
931 page
= __alloc_pages(gfp
, order
, zl
);
932 if (page
&& page_zone(page
) == zl
->zones
[0]) {
933 zone_pcp(zl
->zones
[0],get_cpu())->interleave_hit
++;
940 * alloc_page_vma - Allocate a page for a VMA.
943 * %GFP_USER user allocation.
944 * %GFP_KERNEL kernel allocations,
945 * %GFP_HIGHMEM highmem/user allocations,
946 * %GFP_FS allocation should not call back into a file system.
947 * %GFP_ATOMIC don't sleep.
949 * @vma: Pointer to VMA or NULL if not available.
950 * @addr: Virtual Address of the allocation. Must be inside the VMA.
952 * This function allocates a page from the kernel page pool and applies
953 * a NUMA policy associated with the VMA or the current process.
954 * When VMA is not NULL caller must hold down_read on the mmap_sem of the
955 * mm_struct of the VMA to prevent it from going away. Should be used for
956 * all allocations for pages that will be mapped into
957 * user space. Returns NULL when no page can be allocated.
959 * Should be called with the mm_sem of the vma hold.
962 alloc_page_vma(gfp_t gfp
, struct vm_area_struct
*vma
, unsigned long addr
)
964 struct mempolicy
*pol
= get_vma_policy(current
, vma
, addr
);
966 cpuset_update_current_mems_allowed();
968 if (unlikely(pol
->policy
== MPOL_INTERLEAVE
)) {
971 nid
= interleave_nid(pol
, vma
, addr
, PAGE_SHIFT
);
972 return alloc_page_interleave(gfp
, 0, nid
);
974 return __alloc_pages(gfp
, 0, zonelist_policy(gfp
, pol
));
978 * alloc_pages_current - Allocate pages.
981 * %GFP_USER user allocation,
982 * %GFP_KERNEL kernel allocation,
983 * %GFP_HIGHMEM highmem allocation,
984 * %GFP_FS don't call back into a file system.
985 * %GFP_ATOMIC don't sleep.
986 * @order: Power of two of allocation size in pages. 0 is a single page.
988 * Allocate a page from the kernel page pool. When not in
989 * interrupt context and apply the current process NUMA policy.
990 * Returns NULL when no page can be allocated.
992 * Don't call cpuset_update_current_mems_allowed() unless
993 * 1) it's ok to take cpuset_sem (can WAIT), and
994 * 2) allocating for current task (not interrupt).
996 struct page
*alloc_pages_current(gfp_t gfp
, unsigned order
)
998 struct mempolicy
*pol
= current
->mempolicy
;
1000 if ((gfp
& __GFP_WAIT
) && !in_interrupt())
1001 cpuset_update_current_mems_allowed();
1002 if (!pol
|| in_interrupt())
1003 pol
= &default_policy
;
1004 if (pol
->policy
== MPOL_INTERLEAVE
)
1005 return alloc_page_interleave(gfp
, order
, interleave_nodes(pol
));
1006 return __alloc_pages(gfp
, order
, zonelist_policy(gfp
, pol
));
1008 EXPORT_SYMBOL(alloc_pages_current
);
1010 /* Slow path of a mempolicy copy */
1011 struct mempolicy
*__mpol_copy(struct mempolicy
*old
)
1013 struct mempolicy
*new = kmem_cache_alloc(policy_cache
, GFP_KERNEL
);
1016 return ERR_PTR(-ENOMEM
);
1018 atomic_set(&new->refcnt
, 1);
1019 if (new->policy
== MPOL_BIND
) {
1020 int sz
= ksize(old
->v
.zonelist
);
1021 new->v
.zonelist
= kmalloc(sz
, SLAB_KERNEL
);
1022 if (!new->v
.zonelist
) {
1023 kmem_cache_free(policy_cache
, new);
1024 return ERR_PTR(-ENOMEM
);
1026 memcpy(new->v
.zonelist
, old
->v
.zonelist
, sz
);
1031 /* Slow path of a mempolicy comparison */
1032 int __mpol_equal(struct mempolicy
*a
, struct mempolicy
*b
)
1036 if (a
->policy
!= b
->policy
)
1038 switch (a
->policy
) {
1041 case MPOL_INTERLEAVE
:
1042 return nodes_equal(a
->v
.nodes
, b
->v
.nodes
);
1043 case MPOL_PREFERRED
:
1044 return a
->v
.preferred_node
== b
->v
.preferred_node
;
1047 for (i
= 0; a
->v
.zonelist
->zones
[i
]; i
++)
1048 if (a
->v
.zonelist
->zones
[i
] != b
->v
.zonelist
->zones
[i
])
1050 return b
->v
.zonelist
->zones
[i
] == NULL
;
1058 /* Slow path of a mpol destructor. */
1059 void __mpol_free(struct mempolicy
*p
)
1061 if (!atomic_dec_and_test(&p
->refcnt
))
1063 if (p
->policy
== MPOL_BIND
)
1064 kfree(p
->v
.zonelist
);
1065 p
->policy
= MPOL_DEFAULT
;
1066 kmem_cache_free(policy_cache
, p
);
1070 * Shared memory backing store policy support.
1072 * Remember policies even when nobody has shared memory mapped.
1073 * The policies are kept in Red-Black tree linked from the inode.
1074 * They are protected by the sp->lock spinlock, which should be held
1075 * for any accesses to the tree.
1078 /* lookup first element intersecting start-end */
1079 /* Caller holds sp->lock */
1080 static struct sp_node
*
1081 sp_lookup(struct shared_policy
*sp
, unsigned long start
, unsigned long end
)
1083 struct rb_node
*n
= sp
->root
.rb_node
;
1086 struct sp_node
*p
= rb_entry(n
, struct sp_node
, nd
);
1088 if (start
>= p
->end
)
1090 else if (end
<= p
->start
)
1098 struct sp_node
*w
= NULL
;
1099 struct rb_node
*prev
= rb_prev(n
);
1102 w
= rb_entry(prev
, struct sp_node
, nd
);
1103 if (w
->end
<= start
)
1107 return rb_entry(n
, struct sp_node
, nd
);
1110 /* Insert a new shared policy into the list. */
1111 /* Caller holds sp->lock */
1112 static void sp_insert(struct shared_policy
*sp
, struct sp_node
*new)
1114 struct rb_node
**p
= &sp
->root
.rb_node
;
1115 struct rb_node
*parent
= NULL
;
1120 nd
= rb_entry(parent
, struct sp_node
, nd
);
1121 if (new->start
< nd
->start
)
1123 else if (new->end
> nd
->end
)
1124 p
= &(*p
)->rb_right
;
1128 rb_link_node(&new->nd
, parent
, p
);
1129 rb_insert_color(&new->nd
, &sp
->root
);
1130 PDprintk("inserting %lx-%lx: %d\n", new->start
, new->end
,
1131 new->policy
? new->policy
->policy
: 0);
1134 /* Find shared policy intersecting idx */
1136 mpol_shared_policy_lookup(struct shared_policy
*sp
, unsigned long idx
)
1138 struct mempolicy
*pol
= NULL
;
1141 if (!sp
->root
.rb_node
)
1143 spin_lock(&sp
->lock
);
1144 sn
= sp_lookup(sp
, idx
, idx
+1);
1146 mpol_get(sn
->policy
);
1149 spin_unlock(&sp
->lock
);
1153 static void sp_delete(struct shared_policy
*sp
, struct sp_node
*n
)
1155 PDprintk("deleting %lx-l%x\n", n
->start
, n
->end
);
1156 rb_erase(&n
->nd
, &sp
->root
);
1157 mpol_free(n
->policy
);
1158 kmem_cache_free(sn_cache
, n
);
1162 sp_alloc(unsigned long start
, unsigned long end
, struct mempolicy
*pol
)
1164 struct sp_node
*n
= kmem_cache_alloc(sn_cache
, GFP_KERNEL
);
1175 /* Replace a policy range. */
1176 static int shared_policy_replace(struct shared_policy
*sp
, unsigned long start
,
1177 unsigned long end
, struct sp_node
*new)
1179 struct sp_node
*n
, *new2
= NULL
;
1182 spin_lock(&sp
->lock
);
1183 n
= sp_lookup(sp
, start
, end
);
1184 /* Take care of old policies in the same range. */
1185 while (n
&& n
->start
< end
) {
1186 struct rb_node
*next
= rb_next(&n
->nd
);
1187 if (n
->start
>= start
) {
1193 /* Old policy spanning whole new range. */
1196 spin_unlock(&sp
->lock
);
1197 new2
= sp_alloc(end
, n
->end
, n
->policy
);
1203 sp_insert(sp
, new2
);
1211 n
= rb_entry(next
, struct sp_node
, nd
);
1215 spin_unlock(&sp
->lock
);
1217 mpol_free(new2
->policy
);
1218 kmem_cache_free(sn_cache
, new2
);
1223 int mpol_set_shared_policy(struct shared_policy
*info
,
1224 struct vm_area_struct
*vma
, struct mempolicy
*npol
)
1227 struct sp_node
*new = NULL
;
1228 unsigned long sz
= vma_pages(vma
);
1230 PDprintk("set_shared_policy %lx sz %lu %d %lx\n",
1232 sz
, npol
? npol
->policy
: -1,
1233 npol
? nodes_addr(npol
->v
.nodes
)[0] : -1);
1236 new = sp_alloc(vma
->vm_pgoff
, vma
->vm_pgoff
+ sz
, npol
);
1240 err
= shared_policy_replace(info
, vma
->vm_pgoff
, vma
->vm_pgoff
+sz
, new);
1242 kmem_cache_free(sn_cache
, new);
1246 /* Free a backing policy store on inode delete. */
1247 void mpol_free_shared_policy(struct shared_policy
*p
)
1250 struct rb_node
*next
;
1252 if (!p
->root
.rb_node
)
1254 spin_lock(&p
->lock
);
1255 next
= rb_first(&p
->root
);
1257 n
= rb_entry(next
, struct sp_node
, nd
);
1258 next
= rb_next(&n
->nd
);
1259 rb_erase(&n
->nd
, &p
->root
);
1260 mpol_free(n
->policy
);
1261 kmem_cache_free(sn_cache
, n
);
1263 spin_unlock(&p
->lock
);
1266 /* assumes fs == KERNEL_DS */
1267 void __init
numa_policy_init(void)
1269 policy_cache
= kmem_cache_create("numa_policy",
1270 sizeof(struct mempolicy
),
1271 0, SLAB_PANIC
, NULL
, NULL
);
1273 sn_cache
= kmem_cache_create("shared_policy_node",
1274 sizeof(struct sp_node
),
1275 0, SLAB_PANIC
, NULL
, NULL
);
1277 /* Set interleaving policy for system init. This way not all
1278 the data structures allocated at system boot end up in node zero. */
1280 if (do_set_mempolicy(MPOL_INTERLEAVE
, &node_online_map
))
1281 printk("numa_policy_init: interleaving failed\n");
1284 /* Reset policy of current process to default */
1285 void numa_default_policy(void)
1287 do_set_mempolicy(MPOL_DEFAULT
, NULL
);
1290 /* Migrate a policy to a different set of nodes */
1291 static void rebind_policy(struct mempolicy
*pol
, const nodemask_t
*old
,
1292 const nodemask_t
*new)
1299 switch (pol
->policy
) {
1302 case MPOL_INTERLEAVE
:
1303 nodes_remap(tmp
, pol
->v
.nodes
, *old
, *new);
1305 current
->il_next
= node_remap(current
->il_next
, *old
, *new);
1307 case MPOL_PREFERRED
:
1308 pol
->v
.preferred_node
= node_remap(pol
->v
.preferred_node
,
1314 struct zonelist
*zonelist
;
1317 for (z
= pol
->v
.zonelist
->zones
; *z
; z
++)
1318 node_set((*z
)->zone_pgdat
->node_id
, nodes
);
1319 nodes_remap(tmp
, nodes
, *old
, *new);
1322 zonelist
= bind_zonelist(&nodes
);
1324 /* If no mem, then zonelist is NULL and we keep old zonelist.
1325 * If that old zonelist has no remaining mems_allowed nodes,
1326 * then zonelist_policy() will "FALL THROUGH" to MPOL_DEFAULT.
1330 /* Good - got mem - substitute new zonelist */
1331 kfree(pol
->v
.zonelist
);
1332 pol
->v
.zonelist
= zonelist
;
1343 * Someone moved this task to different nodes. Fixup mempolicies.
1345 * TODO - fixup current->mm->vma and shmfs/tmpfs/hugetlbfs policies as well,
1346 * once we have a cpuset mechanism to mark which cpuset subtree is migrating.
1348 void numa_policy_rebind(const nodemask_t
*old
, const nodemask_t
*new)
1350 rebind_policy(current
->mempolicy
, old
, new);