From cbce1a686700595de65ee363b9b3283ae85d8fc5 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 11 Jun 2015 14:46:54 +0200 Subject: 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) 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 --- kernel/sched/rt.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'kernel/sched/rt.c') 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 -- cgit v1.2.3