[patch 03/10] Fix MPOL_INTERLEAVE behavior for memoryless nodes

[clameter@sgi.com]

[-- Attachment #1: memless_fix_interleave --]
[-- Type: text/plain, Size: 1353 bytes --]

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.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>

Index: linux-2.6.22-rc4-mm2/mm/mempolicy.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/mm/mempolicy.c	2007-06-13 23:06:14.000000000 -0700
+++ linux-2.6.22-rc4-mm2/mm/mempolicy.c	2007-06-14 00:49:43.000000000 -0700
@@ -185,7 +185,8 @@ static struct mempolicy *mpol_new(int mo
 	switch (mode) {
 	case MPOL_INTERLEAVE:
 		policy->v.nodes = *nodes;
-		if (nodes_weight(*nodes) == 0) {
+		nodes_and(policy->v.nodes, policy->v.nodes, node_memory_map);
+		if (nodes_weight(policy->v.nodes) == 0) {
 			kmem_cache_free(policy_cache, policy);
 			return ERR_PTR(-EINVAL);
 		}

-- 

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>