Commit b6e68bc1 authored Jun 16, 2009 by Mel Gorman Committed by Linus Torvalds Jun 16, 2009

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>

parent 62bc62a8

mm/slab.c

+2 −5

Original line number	Diff line number	Diff line
		@@ -898,7 +898,6 @@ static void __slab_error(const char function, struct kmem_cache cachep,
		*/

		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 @@ void __init kmem_cache_init(void)
		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 @@ static inline void __cache_free(struct kmem_cache cachep, void objp)
		* 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)) {

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