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authorMiao Xie <miaox@cn.fujitsu.com>2010-05-25 01:32:08 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-25 19:06:57 +0400
commitc0ff7453bb5c7c98e0885fb94279f2571946f280 (patch)
tree8bb2b169a5145f0496575dbd2f48bb4b1c83f819 /mm/slub.c
parent708c1bbc9d0c3e57f40501794d9b0eed29d10fce (diff)
downloadlinux-c0ff7453bb5c7c98e0885fb94279f2571946f280.tar.xz
cpuset,mm: fix no node to alloc memory when changing cpuset's mems
Before applying this patch, cpuset updates task->mems_allowed and mempolicy by setting all new bits in the nodemask first, and clearing all old unallowed bits later. But in the way, the allocator may find that there is no node to alloc memory. The reason is that cpuset rebinds the task's mempolicy, it cleans the nodes which the allocater can alloc pages on, for example: (mpol: mempolicy) task1 task1's mpol task2 alloc page 1 alloc on node0? NO 1 1 change mems from 1 to 0 1 rebind task1's mpol 0-1 set new bits 0 clear disallowed bits alloc on node1? NO 0 ... can't alloc page goto oom This patch fixes this problem by expanding the nodes range first(set newly allowed bits) and shrink it lazily(clear newly disallowed bits). So we use a variable to tell the write-side task that read-side task is reading nodemask, and the write-side task clears newly disallowed nodes after read-side task ends the current memory allocation. [akpm@linux-foundation.org: fix spello] Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Paul Menage <menage@google.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slub.c')
-rw-r--r--mm/slub.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/mm/slub.c b/mm/slub.c
index e46e3129697d..26f0cb9cc584 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1360,6 +1360,7 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
get_cycles() % 1024 > s->remote_node_defrag_ratio)
return NULL;
+ get_mems_allowed();
zonelist = node_zonelist(slab_node(current->mempolicy), flags);
for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
struct kmem_cache_node *n;
@@ -1369,10 +1370,13 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
n->nr_partial > s->min_partial) {
page = get_partial_node(n);
- if (page)
+ if (page) {
+ put_mems_allowed();
return page;
+ }
}
}
+ put_mems_allowed();
#endif
return NULL;
}