Re: [PATCH 06/10] cpuidle: Remove unnecessary current_clr_polling_and_test() from haltpoll

[Rafael J. Wysocki]

On Fri, Aug 11, 2023 at 7:01 PM Frederic Weisbecker <frederic@xxxxxxxxxx> wrote:
>
> When cpuidle drivers ->enter() callback are called, the TIF_NR_POLLING
> flag is cleared already and TIF_NEED_RESCHED checked by call_cpuidle().
>
> Therefore calling current_clr_polling_and_test() is redundant here and
> further setting of TIF_NEED_RESCHED will result in an IPI and thus an
> idle loop exit. This call can be safely removed.
>
> Cc: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
> Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>

Acked-by: Rafael J. Wysocki <rafael@xxxxxxxxxx>

> ---
>  drivers/cpuidle/cpuidle-haltpoll.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/cpuidle/cpuidle-haltpoll.c b/drivers/cpuidle/cpuidle-haltpoll.c
> index e66df22f9695..b641bc535102 100644
> --- a/drivers/cpuidle/cpuidle-haltpoll.c
> +++ b/drivers/cpuidle/cpuidle-haltpoll.c
> @@ -28,11 +28,8 @@ static enum cpuhp_state haltpoll_hp_state;
>  static int default_enter_idle(struct cpuidle_device *dev,
>                               struct cpuidle_driver *drv, int index)
>  {
> -       if (current_clr_polling_and_test()) {
> -               local_irq_enable();
> -               return index;
> -       }
>         arch_cpu_idle();
> +
>         return index;
>  }
>
> --
> 2.34.1
>