diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2014-11-10 10:54:35 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-11-16 10:04:17 +0100 |
| commit | 7af683350cb0ddd0e9d3819b4eb7abe9e2d3e709 (patch) | |
| tree | 1e05f9a67523237c633bf1ec18afd1fd6327e2d7 /kernel/sched | |
| parent | c123588b3b193d06588dfb51f475407f835ebfb2 (diff) | |
sched/numa: Avoid selecting oneself as swap target
Because the whole numa task selection stuff runs with preemption
enabled (its long and expensive) we can end up migrating and selecting
oneself as a swap target. This doesn't really work out well -- we end
up trying to acquire the same lock twice for the swap migrate -- so
avoid this.
Reported-and-Tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20141110100328.GF29390@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/fair.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 34baa60f8a7b..3af3d1e7df9b 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1180,6 +1180,13 @@ static void task_numa_compare(struct task_numa_env *env, raw_spin_unlock_irq(&dst_rq->lock); /* + * Because we have preemption enabled we can get migrated around and + * end try selecting ourselves (current == env->p) as a swap candidate. + */ + if (cur == env->p) + goto unlock; + + /* * "imp" is the fault differential for the source task between the * source and destination node. Calculate the total differential for * the source task and potential destination task. The more negative |