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From: Vincent Guittot <vincent.guittot@linaro.org>
To: Ladislav Michl <ladis@linux-mips.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
	Linux PM <linux-pm@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Tony Lindgren <tony@atomide.com>
Subject: Re: [PATCH] PM/runtime: Do not needlessly call ktime_get
Date: Thu, 10 Jan 2019 19:56:19 +0100	[thread overview]
Message-ID: <CAKfTPtCV=PYAqG=LavafTpMxvXdr7W-bfsOkpP+04EtOaicjyg@mail.gmail.com> (raw)
In-Reply-To: <20190110095125.GA4491@lenoch>

On Thu, 10 Jan 2019 at 10:51, Ladislav Michl <ladis@linux-mips.org> wrote:
>
> pm_runtime_autosuspend_expiration calls ktime_get even when
> its returned value may be unused. Therefore get current time
> later and remove gotos while there.
>
> Signed-off-by: Ladislav Michl <ladis@linux-mips.org>

Acked-by: Vincent Guittot <vincent.guittot@linaro.org>

> ---
>  NOTE: Depends on Vincent's "[PATCH v2] PM/runtime: Fix autosuspend_delay
>        on 32bits arch"!
>
>  drivers/base/power/runtime.c | 19 ++++++++-----------
>  1 file changed, 8 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
> index 457be03b744d..836b1b8784eb 100644
> --- a/drivers/base/power/runtime.c
> +++ b/drivers/base/power/runtime.c
> @@ -129,24 +129,21 @@ static void pm_runtime_cancel_pending(struct device *dev)
>  u64 pm_runtime_autosuspend_expiration(struct device *dev)
>  {
>         int autosuspend_delay;
> -       u64 last_busy, expires = 0;
> -       u64 now = ktime_to_ns(ktime_get());
> +       u64 expires;
>
>         if (!dev->power.use_autosuspend)
> -               goto out;
> +               return 0;
>
>         autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay);
>         if (autosuspend_delay < 0)
> -               goto out;
> -
> -       last_busy = READ_ONCE(dev->power.last_busy);
> +               return 0;
>
> -       expires = last_busy + (u64)autosuspend_delay * NSEC_PER_MSEC;
> -       if (expires <= now)
> -               expires = 0;    /* Already expired. */
> +       expires  = READ_ONCE(dev->power.last_busy);
> +       expires += (u64)autosuspend_delay * NSEC_PER_MSEC;
> +       if (expires > ktime_to_ns(ktime_get()))
> +               return expires; /* Expires in the future */
>
> - out:
> -       return expires;
> +       return 0;
>  }
>  EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration);
>
> --
> 2.20.1
>

WARNING: multiple messages have this Message-ID (diff)
From: Vincent Guittot <vincent.guittot@linaro.org>
To: Ladislav Michl <ladis@linux-mips.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
	Linux PM <linux-pm@vger.kernel.org>,
	Tony Lindgren <tony@atomide.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] PM/runtime: Do not needlessly call ktime_get
Date: Thu, 10 Jan 2019 19:56:19 +0100	[thread overview]
Message-ID: <CAKfTPtCV=PYAqG=LavafTpMxvXdr7W-bfsOkpP+04EtOaicjyg@mail.gmail.com> (raw)
In-Reply-To: <20190110095125.GA4491@lenoch>

On Thu, 10 Jan 2019 at 10:51, Ladislav Michl <ladis@linux-mips.org> wrote:
>
> pm_runtime_autosuspend_expiration calls ktime_get even when
> its returned value may be unused. Therefore get current time
> later and remove gotos while there.
>
> Signed-off-by: Ladislav Michl <ladis@linux-mips.org>

Acked-by: Vincent Guittot <vincent.guittot@linaro.org>

> ---
>  NOTE: Depends on Vincent's "[PATCH v2] PM/runtime: Fix autosuspend_delay
>        on 32bits arch"!
>
>  drivers/base/power/runtime.c | 19 ++++++++-----------
>  1 file changed, 8 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
> index 457be03b744d..836b1b8784eb 100644
> --- a/drivers/base/power/runtime.c
> +++ b/drivers/base/power/runtime.c
> @@ -129,24 +129,21 @@ static void pm_runtime_cancel_pending(struct device *dev)
>  u64 pm_runtime_autosuspend_expiration(struct device *dev)
>  {
>         int autosuspend_delay;
> -       u64 last_busy, expires = 0;
> -       u64 now = ktime_to_ns(ktime_get());
> +       u64 expires;
>
>         if (!dev->power.use_autosuspend)
> -               goto out;
> +               return 0;
>
>         autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay);
>         if (autosuspend_delay < 0)
> -               goto out;
> -
> -       last_busy = READ_ONCE(dev->power.last_busy);
> +               return 0;
>
> -       expires = last_busy + (u64)autosuspend_delay * NSEC_PER_MSEC;
> -       if (expires <= now)
> -               expires = 0;    /* Already expired. */
> +       expires  = READ_ONCE(dev->power.last_busy);
> +       expires += (u64)autosuspend_delay * NSEC_PER_MSEC;
> +       if (expires > ktime_to_ns(ktime_get()))
> +               return expires; /* Expires in the future */
>
> - out:
> -       return expires;
> +       return 0;
>  }
>  EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration);
>
> --
> 2.20.1
>

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  parent reply	other threads:[~2019-01-10 18:56 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-10  9:51 [PATCH] PM/runtime: Do not needlessly call ktime_get Ladislav Michl
2019-01-10  9:51 ` Ladislav Michl
2019-01-10 16:44 ` Tony Lindgren
2019-01-10 16:44   ` Tony Lindgren
2019-01-10 18:56 ` Vincent Guittot [this message]
2019-01-10 18:56   ` Vincent Guittot
2019-01-16 11:57   ` Rafael J. Wysocki
2019-01-16 11:57     ` Rafael J. Wysocki

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