sched/rt: Enqueue just unthrottled rt_rq back on the stack in __disable_runtime()

Make rt_rq available for pick_next_task(). Otherwise, their tasks
stay prisoned long time till dead cpu becomes alive again.

Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
CC: Konstantin Khorenko <khorenko@parallels.com>
CC: Ben Segall <bsegall@google.com>
CC: Paul Turner <pjt@google.com>
CC: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1403684388.3462.43.camel@tkhai
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index a49083192c64c306952c752ec6b3a05a0df7205d..671a8b5fdb6f32467ccb4413d6c8283a4d4dfd1a 100644 (file)
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -740,6 +740,9 @@ balanced:
                rt_rq->rt_throttled = 0;
                raw_spin_unlock(&rt_rq->rt_runtime_lock);
                raw_spin_unlock(&rt_b->rt_runtime_lock);
+
+               /* Make rt_rq available for pick_next_task() */
+               sched_rt_rq_enqueue(rt_rq);
        }
 }