| From | Mel Gorman <> | Subject | [PATCH 16/20] Do not setup zonelist cache when there is only one node | Date | Sun, 22 Feb 2009 23:17:25 +0000 |
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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 <mel@csn.ul.ie> --- mm/page_alloc.c | 12 +++++++++--- 1 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 9adafba..9e16aec 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1481,9 +1481,15 @@ this_zone_full: 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 */ - allowednodes = zlc_setup(zonelist, alloc_flags); - zlc_active = 1; + /* + * we do zlc_setup after the first zone is tried + * but only if there are multiple nodes to make + * it worthwhile + */ + if (num_online_nodes() > 1) { + allowednodes = zlc_setup(zonelist, alloc_flags); + zlc_active = 1; + } did_zlc_setup = 1; } } -- 1.5.6.5
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