From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757546AbcAMTCZ (ORCPT ); Wed, 13 Jan 2016 14:02:25 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:54747 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755240AbcAMTCW (ORCPT ); Wed, 13 Jan 2016 14:02:22 -0500 Date: Wed, 13 Jan 2016 20:02:20 +0100 From: Pavel Machek To: Lucas Stach Cc: "Rafael J . Wysocki" , Thomas Gleixner , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, patchwork-lst@pengutronix.de Subject: Re: [PATCH 2/2] PM / Runtime: use deferrable timer for autosuspend Message-ID: <20160113190220.GC9821@amd> References: <1452619040-27137-1-git-send-email-l.stach@pengutronix.de> <1452619040-27137-2-git-send-email-l.stach@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1452619040-27137-2-git-send-email-l.stach@pengutronix.de> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 2016-01-12 18:17:20, Lucas Stach wrote: > The timeouts used in PM autosuspend are relatively coarse (the shortest > I could find in a quick search through the kernel is 50ms). As they are > already handled relaxed by saving the overhead of always rearming the > timer by opportunistically suspending a device a bit early, it should > not matter if the the timeout is missed slightly. > > By using a deferrable timer the CPU will not be woken just to handle > the autosuspend timeout, but handling will be batched with other > wakeups in the system. > > Signed-off-by: Lucas Stach Acked-by: Pavel Machek -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html