sched: fix rt-bandwidth hotplug race

When we hot-unplug a cpu and rebuild the sched-domain, all cpus will be
detatched. Alex observed the case where a runqueue was stealing bandwidth
from an already disabled runqueue to satisfy its own needs.

Stop this by skipping over already disabled runqueues.

Reported-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2008-08-14 15:49:00 +02:00 committed by Ingo Molnar
parent 09f2724a78
commit f1679d0848

View file

@ -298,7 +298,7 @@ static void __disable_runtime(struct rq *rq)
struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
s64 diff;
if (iter == rt_rq)
if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF)
continue;
spin_lock(&iter->rt_runtime_lock);