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| author | Christoph Lameter <cl@linux-foundation.org> | 2010-07-26 10:41:14 -0500 |
|---|---|---|
| committer | Pekka Enberg <penberg@cs.helsinki.fi> | 2010-07-29 12:59:00 +0300 |
| commit | bc6488e91078af0b42ee0d8335e0587f64550d7d (patch) | |
| tree | 9adc2fc7fe0824054679ad273af8fe83be1f8269 /mm/slub.c | |
| parent | 7adde04a2f5a798f04a556dfb3b69bff388e5dc4 (diff) | |
| download | lwn-bc6488e91078af0b42ee0d8335e0587f64550d7d.tar.gz lwn-bc6488e91078af0b42ee0d8335e0587f64550d7d.zip | |
slub numa: Fix rare allocation from unexpected node
The network developers have seen sporadic allocations resulting in objects
coming from unexpected NUMA nodes despite asking for objects from a
specific node.
This is due to get_partial() calling get_any_partial() if partial
slabs are exhausted for a node even if a node was specified and therefore
one would expect allocations only from the specified node.
get_any_partial() sporadically may return a slab from a foreign
node to gradually reduce the size of partial lists on remote nodes
and thereby reduce total memory use for a slab cache.
The behavior is controlled by the remote_defrag_ratio of each cache.
Strictly speaking this is permitted behavior since __GFP_THISNODE was
not specified for the allocation but it is certain surprising.
This patch makes sure that the remote defrag behavior only occurs
if no node was specified.
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/slub.c b/mm/slub.c index 578f68f3c51f..39d39653239b 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1390,7 +1390,7 @@ static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node) int searchnode = (node == -1) ? numa_node_id() : node; page = get_partial_node(get_node(s, searchnode)); - if (page || (flags & __GFP_THISNODE)) + if (page || node != -1) return page; return get_any_partial(s, flags); |