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authorPeter Zijlstra <peterz@infradead.org>2015-06-11 14:46:54 +0200
committerThomas Gleixner <tglx@linutronix.de>2015-06-19 00:25:27 +0200
commitcbce1a686700595de65ee363b9b3283ae85d8fc5 (patch)
treef5ab615f38d916532fe96df9914aa2df926ba98a /kernel/sched/rt.c
parenta24fc60d63da2b0b31bf7c876d12a51ed4b778bd (diff)
downloadlinux-cbce1a686700595de65ee363b9b3283ae85d8fc5.tar.gz
sched,lockdep: Employ lock pinning
Employ the new lockdep lock pinning annotation to ensure no
'accidental' lock-breaks happen with rq->lock.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: ktkhai@parallels.com
Cc: rostedt@goodmis.org
Cc: juri.lelli@gmail.com
Cc: pang.xunlei@linaro.org
Cc: oleg@redhat.com
Cc: wanpeng.li@linux.intel.com
Cc: umgwanakikbuti@gmail.com
Link: http://lkml.kernel.org/r/20150611124744.003233193@infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/sched/rt.c')
-rw-r--r--kernel/sched/rt.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 460f85888b74..0d193a243e96 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1478,7 +1478,15 @@ pick_next_task_rt(struct rq *rq, struct task_struct *prev)
 	struct rt_rq *rt_rq = &rq->rt;
 
 	if (need_pull_rt_task(rq, prev)) {
+		/*
+		 * This is OK, because current is on_cpu, which avoids it being
+		 * picked for load-balance and preemption/IRQs are still
+		 * disabled avoiding further scheduler activity on it and we're
+		 * being very careful to re-start the picking loop.
+		 */
+		lockdep_unpin_lock(&rq->lock);
 		pull_rt_task(rq);
+		lockdep_pin_lock(&rq->lock);
 		/*
 		 * pull_rt_task() can drop (and re-acquire) rq->lock; this
 		 * means a dl or stop task can slip in, in which case we need