diff options
author | Mel Gorman <mgorman@suse.de> | 2015-05-14 15:17:09 -0700 |
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committer | Sasha Levin <sasha.levin@oracle.com> | 2015-06-10 13:42:34 -0400 |
commit | 314b9cf3be0a02e5866f2a45e1d259cbff042dc2 (patch) | |
tree | 9598a38894218b17b98e71ec07a8f37c1e03a6d1 /fs/nfsd/nfs4state.c | |
parent | a821ac4c66382f9d6387c8311608f13c6749fea9 (diff) |
mm, numa: really disable NUMA balancing by default on single node machines
[ Upstream commit b0dc2b9bb4ab782115b964310518ee0b17784277 ]
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 <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: <stable@vger.kernel.org> [3.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'fs/nfsd/nfs4state.c')
0 files changed, 0 insertions, 0 deletions