From 6eaf806a223e61dc5f2de4ab591f11beb97a8f3b Mon Sep 17 00:00:00 2001
From: Christoph Lameter <clameter@sgi.com>
Date: Tue, 16 Oct 2007 01:25:30 -0700
Subject: [PATCH] Memoryless nodes: Fix interleave behavior for memoryless
nodes
MPOL_INTERLEAVE currently simply loops over all nodes. Allocations on
memoryless nodes will be redirected to nodes with memory. This results in an
imbalance because the neighboring nodes to memoryless nodes will get
significantly more interleave hits that the rest of the nodes on the system.
We can avoid this imbalance by clearing the nodes in the interleave node set
that have no memory. If we use the node map of the memory nodes instead of
the online nodes then we have only the nodes we want.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Tested-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Bob Picco <bob.picco@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@skynet.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/mempolicy.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index ccbdb22147bb9..5daf63bd97e7f 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -183,7 +183,9 @@ static struct mempolicy *mpol_new(int mode, nodemask_t *nodes)
switch (mode) {
case MPOL_INTERLEAVE:
policy->v.nodes = *nodes;
- if (nodes_weight(*nodes) == 0) {
+ nodes_and(policy->v.nodes, policy->v.nodes,
+ node_states[N_HIGH_MEMORY]);
+ if (nodes_weight(policy->v.nodes) == 0) {
kmem_cache_free(policy_cache, policy);
return ERR_PTR(-EINVAL);
}
--
2.30.2