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 <[email protected]>
Reviewed-by: Christoph Lameter <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Nick Piggin <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Lee Schermerhorn <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
1 file changed