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From:   Guo Ren <guoren@kernel.org>
Date:   Thu, 22 Sep 2022 08:45:37 +0800
Message-ID: <CAJF2gTQxxRQZLV+uJThCZSByUQ0oSoASgwsUggbsR3wHTqrqzg@mail.gmail.com>
Subject: Re: [PATCH v2 07/44] cpuidle,psci: Push RCU-idle into driver
To:     Peter Zijlstra <peterz@infradead.org>
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Reviewed-by: Guo Ren <guoren@kernel.org>

On Mon, Sep 19, 2022 at 6:17 PM Peter Zijlstra <peterz@infradead.org> wrote:
>
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again, at least twice, before going idle is daft.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
>  drivers/cpuidle/cpuidle-psci.c |    9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> --- a/drivers/cpuidle/cpuidle-psci.c
> +++ b/drivers/cpuidle/cpuidle-psci.c
> @@ -69,12 +69,12 @@ static int __psci_enter_domain_idle_stat
>                 return -1;
>
>         /* Do runtime PM to manage a hierarchical CPU toplogy. */
> -       ct_irq_enter_irqson();
>         if (s2idle)
>                 dev_pm_genpd_suspend(pd_dev);
>         else
>                 pm_runtime_put_sync_suspend(pd_dev);
> -       ct_irq_exit_irqson();
> +
> +       ct_idle_enter();
>
>         state = psci_get_domain_state();
>         if (!state)
> @@ -82,12 +82,12 @@ static int __psci_enter_domain_idle_stat
>
>         ret = psci_cpu_suspend_enter(state) ? -1 : idx;
>
> -       ct_irq_enter_irqson();
> +       ct_idle_exit();
> +
>         if (s2idle)
>                 dev_pm_genpd_resume(pd_dev);
>         else
>                 pm_runtime_get_sync(pd_dev);
> -       ct_irq_exit_irqson();
>
>         cpu_pm_exit();
>
> @@ -240,6 +240,7 @@ static int psci_dt_cpu_init_topology(str
>          * of a shared state for the domain, assumes the domain states are all
>          * deeper states.
>          */
> +       drv->states[state_count - 1].flags |= CPUIDLE_FLAG_RCU_IDLE;
>         drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
>         drv->states[state_count - 1].enter_s2idle = psci_enter_s2idle_domain_idle_state;
>         psci_cpuidle_use_cpuhp = true;
>
>


-- 
Best Regards
 Guo Ren