From d395b73428d9748fb70b33477c9b2acae62f360a Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 16 Jun 2009 15:32:09 -0700 Subject: [PATCH] page allocator: do not setup zonelist cache when there is only one node There is a zonelist cache which is used to track zones that are not in the allowed cpuset or found to be recently full. This is to reduce cache footprint on large machines. On smaller machines, it just incurs cost for no gain. This patch only uses the zonelist cache when there are NUMA nodes. Signed-off-by: Mel Gorman Reviewed-by: Christoph Lameter Cc: KOSAKI Motohiro Cc: Pekka Enberg Cc: Peter Zijlstra Cc: Nick Piggin Cc: Dave Hansen Cc: Lee Schermerhorn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 03a386d24ef2..fd8e3ca0cf3b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1464,8 +1464,11 @@ get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, if (NUMA_BUILD) zlc_mark_zone_full(zonelist, z); try_next_zone: - if (NUMA_BUILD && !did_zlc_setup) { - /* we do zlc_setup after the first zone is tried */ + if (NUMA_BUILD && !did_zlc_setup && num_online_nodes() > 1) { + /* + * we do zlc_setup after the first zone is tried but only + * if there are multiple nodes make it worthwhile + */ allowednodes = zlc_setup(zonelist, alloc_flags); zlc_active = 1; did_zlc_setup = 1; -- GitLab