On 05/13/2015 04:10 AM, Mel Gorman wrote: > NUMA balancing is meant to be disabled by default on UMA machines but > the check is using nr_node_ids (highest node) instead of num_online_nodes > (online nodes). The consequences are that a UMA machine with a node ID of 1 > or higher will enable NUMA balancing. This will incur useless overhead due > to minor faults with the impact depending on the workload. These are the > impact on the stats when running a kernel build on a single node machine > whose node ID happened to be 1; > > vanilla patched > NUMA base PTE updates 5113158 0 > NUMA huge PMD updates 643 0 > NUMA page range updates 5442374 0 > NUMA hint faults 2109622 0 > NUMA hint local faults 2109622 0 > NUMA hint local percent 100 100 > NUMA pages migrated 0 0 > > Signed-off-by: Mel Gorman <mgor...@suse.de> > Cc: <sta...@vger.kernel.org> #v3.8+
Reviewed-by: Rik van Riel <r...@redhat.com> -- All rights reversed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
