slub: Disable NUMA remote node defragmentation by default
Switch remote node defragmentation off by default. The current settings can
cause excessive node local allocations with hackbench:
SLAB:
% cat /proc/meminfo
MemTotal: 7701760 kB
MemFree: 5940096 kB
Slab: 123840 kB
SLUB:
% cat /proc/meminfo
MemTotal: 7701376 kB
MemFree: 4740928 kB
Slab: 1591680 kB
[Note: this feature is not related to slab defragmentation.]
You can find the original discussion here:
http://lkml.org/lkml/2008/8/4/308
Reported-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
diff --git a/mm/slub.c b/mm/slub.c
index 4f5b961..fb486d5 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2312,7 +2312,7 @@
s->refcount = 1;
#ifdef CONFIG_NUMA
- s->remote_node_defrag_ratio = 100;
+ s->remote_node_defrag_ratio = 1000;
#endif
if (!init_kmem_cache_nodes(s, gfpflags & ~SLUB_DMA))
goto error;
@@ -4058,7 +4058,7 @@
if (err)
return err;
- if (ratio < 100)
+ if (ratio <= 100)
s->remote_node_defrag_ratio = ratio * 10;
return length;