Commit-ID: e037fef5fb7d2c887916576c1a288c821b6268f4 Gitweb: http://git.kernel.org/tip/e037fef5fb7d2c887916576c1a288c821b6268f4 Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx> AuthorDate: Fri, 7 Feb 2014 20:58:37 +0100 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitDate: Fri, 21 Feb 2014 21:43:18 +0100 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 :) Cc: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1391803122-4425-2-git-send-email-bigeasy@xxxxxxxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> --- kernel/sched/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 4c8aaf0..86e0558 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4451,6 +4451,7 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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