Re: [Update] Re: [PATCH v3]PM/Sleep: Timer quiesce in freeze state

From: Peter Zijlstra
Date: Fri Feb 06 2015 - 11:15:32 EST


On Fri, Feb 06, 2015 at 02:20:13AM +0100, Rafael J. Wysocki wrote:
> void freeze_wake(void)
> {
> + unsigned long flags;
> +
> + spin_lock_irqsave(&suspend_freeze_lock, flags);
> + if (suspend_freeze_state > FREEZE_STATE_NONE) {
> + suspend_freeze_state = FREEZE_STATE_WAKE;
> + wake_up(&suspend_freeze_wait_head);
> + }
> + spin_unlock_irqrestore(&suspend_freeze_lock, flags);
> }


> +static void enter_freeze_proper(struct cpuidle_driver *drv,
> + struct cpuidle_device *dev, int index)
> +{
> + tick_freeze();
> + drv->states[index].enter_freeze(dev, drv, index);
> + /*
> + * timekeeping_resume() that will be called by tick_unfreeze() for the
> + * last CPU executing it calls functions containing RCU read-side
> + * critical sections, so tell RCU about that.
> + */
> + RCU_NONIDLE(tick_unfreeze());
> +}

So I'm a wee bit confused; if we use an enter_freeze() state that keeps
interrupts disabled; who is going to call the freeze_wake() thing?
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