All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ladislav Michl <ladis@linux-mips.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: 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>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Biju Das <biju.das@bp.renesas.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
	Vincent Guittot <vincent.guittot@linaro.org>
Subject: [PATCH] PM/runtime: Optimize pm_runtime_autosuspend_expiration()
Date: Wed, 30 Jan 2019 22:40:17 +0100	[thread overview]
Message-ID: <20190130214017.GA5038@lenoch> (raw)

pm_runtime_autosuspend_expiration calls ktime_get_mono_fast_ns
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: Tony Lindgren <tony@atomide.com>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
---
 This patch is based on top of bleeding-edge branch, where
 "[PATCH v2 ] PM-runtime: fix deadlock with ktime" is sitting.
 I expect v3 of that patch, which should not harm this one.
 It is meant to replace "PM/runtime: Do not needlessly call ktime_get"
 sent earlier.

 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 65e2b5f48e0c..7bbe28faca8d 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -145,24 +145,21 @@ 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_get_mono_fast_ns();
+	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_get_mono_fast_ns())
+		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: Ladislav Michl <ladis@linux-mips.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Linux PM <linux-pm@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Biju Das <biju.das@bp.renesas.com>,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: [PATCH] PM/runtime: Optimize pm_runtime_autosuspend_expiration()
Date: Wed, 30 Jan 2019 22:40:17 +0100	[thread overview]
Message-ID: <20190130214017.GA5038@lenoch> (raw)

pm_runtime_autosuspend_expiration calls ktime_get_mono_fast_ns
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: Tony Lindgren <tony@atomide.com>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
---
 This patch is based on top of bleeding-edge branch, where
 "[PATCH v2 ] PM-runtime: fix deadlock with ktime" is sitting.
 I expect v3 of that patch, which should not harm this one.
 It is meant to replace "PM/runtime: Do not needlessly call ktime_get"
 sent earlier.

 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 65e2b5f48e0c..7bbe28faca8d 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -145,24 +145,21 @@ 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_get_mono_fast_ns();
+	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_get_mono_fast_ns())
+		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: Ladislav Michl <ladis@linux-mips.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Linux PM <linux-pm@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Biju Das <biju.das@bp.renesas.com>,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: [PATCH] PM/runtime: Optimize pm_runtime_autosuspend_expiration()
Date: Wed, 30 Jan 2019 22:40:17 +0100	[thread overview]
Message-ID: <20190130214017.GA5038@lenoch> (raw)

pm_runtime_autosuspend_expiration calls ktime_get_mono_fast_ns
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: Tony Lindgren <tony@atomide.com>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
---
 This patch is based on top of bleeding-edge branch, where
 "[PATCH v2 ] PM-runtime: fix deadlock with ktime" is sitting.
 I expect v3 of that patch, which should not harm this one.
 It is meant to replace "PM/runtime: Do not needlessly call ktime_get"
 sent earlier.

 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 65e2b5f48e0c..7bbe28faca8d 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -145,24 +145,21 @@ 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_get_mono_fast_ns();
+	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_get_mono_fast_ns())
+		return expires;	/* Expires in the future */
 
- out:
-	return expires;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration);
 
-- 
2.20.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

             reply	other threads:[~2019-01-30 21:40 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-30 21:40 Ladislav Michl [this message]
2019-01-30 21:40 ` [PATCH] PM/runtime: Optimize pm_runtime_autosuspend_expiration() Ladislav Michl
2019-01-30 21:40 ` Ladislav Michl
2019-02-06 10:34 ` Rafael J. Wysocki
2019-02-06 10:34   ` Rafael J. Wysocki

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190130214017.GA5038@lenoch \
    --to=ladis@linux-mips.org \
    --cc=biju.das@bp.renesas.com \
    --cc=geert@linux-m68k.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-omap@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=linux-renesas-soc@vger.kernel.org \
    --cc=rafael@kernel.org \
    --cc=ulf.hansson@linaro.org \
    --cc=vincent.guittot@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.