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
next reply other threads:[~2019-01-30 21:40 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-30 21:40 Ladislav Michl [this message]
2019-02-06 10:34 ` [PATCH] PM/runtime: Optimize pm_runtime_autosuspend_expiration() 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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).