diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2014-02-07 20:58:37 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-02-22 18:07:36 +0100 |
| commit | 77177856e3bf39d435b3ae4bfd164ca3c8cd4577 (patch) | |
| tree | 846164e37a2e848e3192b69422335ec284a21f04 /kernel/sched | |
| parent | dc87734106bb6e97c92d8bd81f261fb71976ec2c (diff) | |
sched: Init idle->on_rq in init_idle()
We stumbled in RT over a SMP bringup issue on ARM where the
idle->on_rq == 0 was causing try_to_wakeup() on the other cpu to run
into nada land.
After adding that idle->on_rq = 1; I was able to find the root cause
of the lockup: the idle task on the newly woken up cpu was fiddling
with a sleeping spinlock, which is a nono.
I kept the init of idle->on_rq to keep the state consistent and to
avoid another long lasting debug session.
As a side note, the whole debug mess could have been avoided if
might_sleep() would have yelled when called from the idle task. That's
fixed with patch 2/6 - and that one actually has a changelog :)
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1391803122-4425-2-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 49db434a35d..06da865043e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4443,6 +4443,7 @@ void init_idle(struct task_struct *idle, int cpu) rcu_read_unlock(); rq->curr = rq->idle = idle; + idle->on_rq = 1; #if defined(CONFIG_SMP) idle->on_cpu = 1; #endif |