page allocator: slab: use nr_online_nodes to check for a NUMA platform
SLAB currently avoids checking a bitmap repeatedly by checking once and
storing a flag. When the addition of nr_online_nodes as a cheaper version
of num_online_nodes(), this check can be replaced by nr_online_nodes.
(Christoph did a patch that this is lifted almost verbatim from)
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/slab.c b/mm/slab.c
index bb3254c..744ab9a 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -898,7 +898,6 @@
*/
static int use_alien_caches __read_mostly = 1;
-static int numa_platform __read_mostly = 1;
static int __init noaliencache_setup(char *s)
{
use_alien_caches = 0;
@@ -1457,10 +1456,8 @@
int order;
int node;
- if (num_possible_nodes() == 1) {
+ if (num_possible_nodes() == 1)
use_alien_caches = 0;
- numa_platform = 0;
- }
for (i = 0; i < NUM_INIT_LISTS; i++) {
kmem_list3_init(&initkmem_list3[i]);
@@ -3590,7 +3587,7 @@
* variable to skip the call, which is mostly likely to be present in
* the cache.
*/
- if (numa_platform && cache_free_alien(cachep, objp))
+ if (nr_online_nodes > 1 && cache_free_alien(cachep, objp))
return;
if (likely(ac->avail < ac->limit)) {