4.9.65-rt57-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior The original patch changed betwen its posting and what finally went into Rafael's tree so here is the delta. Signed-off-by: Sebastian Andrzej Siewior --- kernel/cpu_pm.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/cpu_pm.c b/kernel/cpu_pm.c index 10f4640f991e..67b02e138a47 100644 --- a/kernel/cpu_pm.c +++ b/kernel/cpu_pm.c @@ -28,8 +28,15 @@ static int cpu_pm_notify(enum cpu_pm_event event, int nr_to_call, int *nr_calls) { int ret; + /* + * __atomic_notifier_call_chain has a RCU read critical section, which + * could be disfunctional in cpu idle. Copy RCU_NONIDLE code to let + * RCU know this. + */ + rcu_irq_enter_irqson(); ret = __atomic_notifier_call_chain(&cpu_pm_notifier_chain, event, NULL, nr_to_call, nr_calls); + rcu_irq_exit_irqson(); return notifier_to_errno(ret); } -- 2.13.2