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

[tip-bot for Kirill Tkhai <tipbot@zytor.com>]

Commit-ID:  99b625670f1447ecf0739161efbe7f2f43c0e0b6
Gitweb:     http://git.kernel.org/tip/99b625670f1447ecf0739161efbe7f2f43c0e0b6
Author:     Kirill Tkhai <ktkhai@parallels.com>
AuthorDate: Wed, 25 Jun 2014 12:19:48 +0400
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Sat, 5 Jul 2014 11:17:44 +0200

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>
---
 kernel/sched/rt.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index a490831..671a8b5 100644
--- 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);
 	}
 }