From: Christoph Lameter <clameter@engr.sgi.com>
Date: Thu, 19 Jan 2006 01:42:37 +0000 (-0800)
Subject: [PATCH] mm: optimize numa policy handling in slab allocator
X-Git-Tag: v2.6.16-rc2~337
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=86c562a9d6683063e071692fe14e0a18e64ee1be;p=linux-2.6-omap-h63xx.git

[PATCH] mm: optimize numa policy handling in slab allocator

Move the interrupt check from slab_node into ___cache_alloc and adds an
"unlikely()" to avoid pipeline stalls on some architectures.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 71430d44082..73790188b0e 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -982,9 +982,6 @@ static unsigned interleave_nodes(struct mempolicy *policy)
  */
 unsigned slab_node(struct mempolicy *policy)
 {
-	if (in_interrupt())
-		return numa_node_id();
-
 	switch (policy->policy) {
 	case MPOL_INTERLEAVE:
 		return interleave_nodes(policy);
diff --git a/mm/slab.c b/mm/slab.c
index 9025608696e..6f8495e2185 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2574,7 +2574,7 @@ static inline void *____cache_alloc(kmem_cache_t *cachep, gfp_t flags)
 	struct array_cache *ac;
 
 #ifdef CONFIG_NUMA
-	if (current->mempolicy) {
+	if (unlikely(current->mempolicy && !in_interrupt())) {
 		int nid = slab_node(current->mempolicy);
 
 		if (nid != numa_node_id())