Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757734Ab0FFLP7 (ORCPT ); Sun, 6 Jun 2010 07:15:59 -0400 Received: from mail.lang.hm ([64.81.33.126]:59550 "EHLO bifrost.lang.hm" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755438Ab0FFLP5 (ORCPT ); Sun, 6 Jun 2010 07:15:57 -0400 Date: Sun, 6 Jun 2010 04:14:09 -0700 (PDT) From: david@lang.hm X-X-Sender: dlang@asgard.lang.hm To: Florian Mickler cc: Vitaly Wool , Brian Swetland , =?ISO-8859-15?Q?Arve_Hj=F8nnev=E5g?= , Arjan van de Ven , tytso@mit.edu, Peter Zijlstra , "H. Peter Anvin" , LKML , Neil Brown , James Bottomley , Alan Cox , Linux PM , Ingo Molnar , Linux OMAP Mailing List , Linus Torvalds , Thomas Gleixner , Felipe Balbi Subject: Re: [linux-pm] suspend blockers & Android integration In-Reply-To: <20100606124949.539fa636@schatten.dmk.lab> Message-ID: References: <20100603193045.GA7188@elte.hu> <20100604071354.GA14451@elte.hu> <20100604083423.GD15181@elte.hu> <1275653210.27810.39762.camel@twins> <1275731653.27810.41078.camel@twins> <20100605092851.6ee15f13@infradead.org> <20100606124949.539fa636@schatten.dmk.lab> User-Agent: Alpine 2.01 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2079 Lines: 52 On Sun, 6 Jun 2010, Florian Mickler wrote: > On Sun, 6 Jun 2010 12:19:08 +0200 > Vitaly Wool wrote: > >> 2010/6/6 : >> >>> as an example (taken from this thread). >>> >>> system A needs to wake up to get a battery reading, store it and go back to >>> sleep, It does so every 10 seconds. But when it does so it only runs the one >>> process and then goes back to sleep. >>> >>> system B has the same need, but wakes up every 10 minutes. but when it does >>> so it fully wakes up and this allows the mail app to power up the radio, >>> connect to the Internet and start checking for new mail before oppurtunistic >>> sleep shuts things down (causing the mail check to fail) >>> >>> System A will last considerably longer on a battery than System B. >> >> Exactly, thanks for pointing out the specific example :) >> >> ~Vitaly > > This does not affect suspend_blockers nor does suspend_blockers > interfere with that. > > Suspend_blockers allow the system to suspend ("mem">/sys/power/state > suspend), when the userspace decides that the device is not in use. > > So implementing suspend_blockers support does not impact any > optimizations done to either system A nor system B. Actually, it does. system A is what's being proposed by kernel developers, where the untrusted stuff is in a different cgroup and what puts the system to sleep is 'normal' power management. It doesn't sleep as long, but when it wakes up the untrusted stuff is still frozen, so it doesn't stay awake long, or do very much. System B is suspend blockers where you are either awake or asleep, and when you wake up you wake up fully, but oppertunistic sleep can interrupt untrusted processes at any time. The system sleeps longer (as fewer things can wake it), but when it wakes up it's fully awake. David Lang -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/