diff options
| author | Rik van Riel <riel@redhat.com> | 2017-06-23 12:55:27 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-12 16:55:25 +0200 |
| commit | 6cd951eefda55cbbd4f638ec0f0cb173e4d3e4b9 (patch) | |
| tree | 7980c512e0590781eb6f4bfceede285d19c5953c /kernel | |
| parent | 7084a918af5c4e934e2993c24b479673c54b31a8 (diff) | |
sched/numa: Override part of migrate_degrades_locality() when idle balancing
commit 739294fb03f590401bbd7faa6d31a507e3ffada5 upstream.
Several tests in the NAS benchmark seem to run a lot slower with
NUMA balancing enabled, than with NUMA balancing disabled. The
slower run time corresponds with increased idle time.
Overriding the final test of migrate_degrades_locality (but still
doing the other NUMA tests first) seems to improve performance
of those benchmarks.
Reported-by: Jirka Hladky <jhladky@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20170623165530.22514-2-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/fair.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 2c89ad8a3eba..58f2228f4820 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6661,6 +6661,10 @@ static int migrate_degrades_locality(struct task_struct *p, struct lb_env *env) if (dst_nid == p->numa_preferred_nid) return 0; + /* Leaving a core idle is often worse than degrading locality. */ + if (env->idle != CPU_NOT_IDLE) + return -1; + if (numa_group) { src_faults = group_faults(p, src_nid); dst_faults = group_faults(p, dst_nid); |