From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ladislav Michl Subject: [PATCH] PM/runtime: Optimize pm_runtime_autosuspend_expiration() Date: Wed, 30 Jan 2019 22:40:17 +0100 Message-ID: <20190130214017.GA5038@lenoch> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: "Rafael J. Wysocki" Cc: Ulf Hansson , Vincent Guittot , Linux PM , Linux Kernel Mailing List , Biju Das , Linux-Renesas , Geert Uytterhoeven , Linux OMAP Mailing List , Linux ARM List-Id: linux-pm@vger.kernel.org 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 Acked-by: Tony Lindgren Acked-by: Vincent Guittot --- 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