Re: [PATCH v2 10/44] cpuidle,armada: Push RCU-idle into driver

Frederic Weisbecker
2022-09-19T14:39:07Z

On Mon, Sep 19, 2022 at 11:59:49AM +0200, Peter Zijlstra wrote:
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again before going idle is daft.

Ah wait, now I see, that's cpu_pm_enter()/cpu_pm_exit() -> cpu_pm_notify*() the culprits.
Might be worth adding a short note about that on your changelogs.

>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> drivers/cpuidle/cpuidle-mvebu-v7.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> --- a/drivers/cpuidle/cpuidle-mvebu-v7.c
> +++ b/drivers/cpuidle/cpuidle-mvebu-v7.c
> @@ -36,7 +36,10 @@ static int mvebu_v7_enter_idle(struct cp
> if (drv->states[index].flags & MVEBU_V7_FLAG_DEEP_IDLE)
> deepidle = true;
>
> + ct_idle_enter();
> ret = mvebu_v7_cpu_suspend(deepidle);
> + ct_idle_exit();

And then yes of course:

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>