From: Bo Liu Date: Tue, 18 Aug 2009 21:11:19 +0000 (-0700) Subject: mm: build_zonelists(): move clear node_load[] to __build_all_zonelists() X-Git-Tag: v2.6.31-rc7~17 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7f9cfb31030737a7fc9a1cbca3fd01bec184c849;p=karo-tx-linux.git mm: build_zonelists(): move clear node_load[] to __build_all_zonelists() If node_load[] is cleared everytime build_zonelists() is called,node_load[] will have no help to find the next node that should appear in the given node's fallback list. Because of the bug, zonelist's node_order is not calculated as expected. This bug affects on big machine, which has asynmetric node distance. [synmetric NUMA's node distance] 0 1 2 0 10 12 12 1 12 10 12 2 12 12 10 [asynmetric NUMA's node distance] 0 1 2 0 10 12 20 1 12 10 14 2 20 14 10 This (my bug) is very old but no one has reported this for a long time. Maybe because the number of asynmetric NUMA is very small and they use cpuset for customizing node memory allocation fallback. [akpm@linux-foundation.org: fix CONFIG_NUMA=n build] Signed-off-by: Bo Liu Reviewed-by: KAMEZAWA Hiroyuki Cc: Mel Gorman Cc: Christoph Lameter Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d052abbe3063..5cc986eb9f6f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2544,7 +2544,6 @@ static void build_zonelists(pg_data_t *pgdat) prev_node = local_node; nodes_clear(used_mask); - memset(node_load, 0, sizeof(node_load)); memset(node_order, 0, sizeof(node_order)); j = 0; @@ -2653,6 +2652,9 @@ static int __build_all_zonelists(void *dummy) { int nid; +#ifdef CONFIG_NUMA + memset(node_load, 0, sizeof(node_load)); +#endif for_each_online_node(nid) { pg_data_t *pgdat = NODE_DATA(nid);