linux-kernel - Re: [PATCH 08/10] x86: Remove __current_clr_polling() from mwait

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Message-ID: <CAJZ5v0gCHcm+BDSK_ih38thw9oim_1qkN5Z2YfUze-1wg6knAg@mail.gmail.com>
Date:   Fri, 11 Aug 2023 19:40:56 +0200
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     Frederic Weisbecker <frederic@...nel.org>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        "Rafael J . Wysocki" <rafael@...nel.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Anna-Maria Behnsen <anna-maria@...utronix.de>
Subject: Re: [PATCH 08/10] x86: Remove __current_clr_polling() from mwait_idle()

On Fri, Aug 11, 2023 at 7:01 PM Frederic Weisbecker <frederic@...nel.org> wrote:
>
> mwait_idle() is only ever called through by cpuidle, either from
> default_idle_call() or from cpuidle_enter(). In any case
> cpuidle_idle_call() sets again TIF_NR_POLLING after calling it so there
> is no point for this atomic operation upon idle exit.
>
> Signed-off-by: Frederic Weisbecker <frederic@...nel.org>

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

> ---
>  arch/x86/kernel/process.c | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
> index 72015dba72ab..f1eb769770b1 100644
> --- a/arch/x86/kernel/process.c
> +++ b/arch/x86/kernel/process.c
> @@ -918,7 +918,6 @@ static __cpuidle void mwait_idle(void)
>                         raw_local_irq_disable();
>                 }
>         }
> -       __current_clr_polling();
>  }
>
>  void select_idle_routine(const struct cpuinfo_x86 *c)
> --
> 2.34.1
>