diff options
| author | Rik van Riel <[email protected]> | 2017-06-23 12:55:27 -0400 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2017-06-24 08:57:46 +0200 |
| commit | 739294fb03f590401bbd7faa6d31a507e3ffada5 (patch) | |
| tree | 90009f4544cfddb9308655a22186890bdae659de | |
| parent | 1bc3cd4dfa9f2f5385ee15de2301d25e51cf43f0 (diff) | |
sched/numa: Override part of migrate_degrades_locality() when idle balancing
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 <[email protected]>
Signed-off-by: Rik van Riel <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
| -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 694c258b8771..6e0c0524131e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6688,6 +6688,10 @@ 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); |