Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932597Ab0HDGuc (ORCPT ); Wed, 4 Aug 2010 02:50:32 -0400 Received: from mail-iw0-f174.google.com ([209.85.214.174]:58029 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756438Ab0HDGua convert rfc822-to-8bit (ORCPT ); Wed, 4 Aug 2010 02:50:30 -0400 MIME-Version: 1.0 In-Reply-To: <20100804062804.GA43413@dspnet.fr> References: <20100804001015.GJ2407@linux.vnet.ibm.com> <20100804045813.GA33951@dspnet.fr> <20100804062804.GA43413@dspnet.fr> Date: Tue, 3 Aug 2010 23:50:29 -0700 Message-ID: Subject: Re: Attempted summary of suspend-blockers LKML thread From: =?ISO-8859-1?Q?Arve_Hj=F8nnev=E5g?= To: Olivier Galibert Cc: david@lang.hm, "Paul E. McKenney" , Arjan van de Ven , "Ted Ts'o" , linux-pm@lists.linux-foundation.org, linux-kernel , mjg59@srcf.ucam.org, pavel@ucw.cz, florian@mickler.org, rjw@sisk.pl, stern@rowland.harvard.edu, swetland@google.com, peterz@infradead.org, tglx@linutronix.de, alan@lxorguk.ukuu.org.uk Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2493 Lines: 56 2010/8/3 Olivier Galibert : > On Tue, Aug 03, 2010 at 11:03:15PM -0700, Arve Hj?nnev?g wrote: >> 2010/8/3 Olivier Galibert : >> > On Tue, Aug 03, 2010 at 08:39:22PM -0700, Arve Hj?nnev?g wrote: >> >> If you just program the alarm you will wake up see that the monotonic >> >> clock has not advanced and set the alarm another n seconds into the >> >> future. Or are proposing that suspend should be changed to keep the >> >> monotonic clock running? >> > >> > You're supposed to fix the clock after you wake up. ?That's part of >> > the cost of going suspend. >> >> I'm not sure what you are referring to. The generic Linux timekeeping >> code makes sure the monotonic clock stops while the system is >> suspended regardless of what values the (hardware specific) >> clocksource returns. > > That just means the android-like suspend should not act in that > specific area the same as the generic suspend to ram. ?Which is not Huh? Android uses the generic suspend code. > entirely surprising. ?In any case, it's not "keep the monotonic clock > running", which would cost power. ?It's fix it up afterwards, using > the same means you already do but perhaps at a higher level currently. > People don't want to see the wrong time of the day just because the > phone went to suspend. ?Laptop STR is different in perception because The monotonic clock is not the same as the realtime clock which is used for time of day. > it shuts down things people don't want to see shutdown just by being > idle, namely wifi connectivity. > > If your next polling timer is in half an hour and the screen/touchpad > are off, you want to go as low in power as possible until then, and > that's the deepest level of idle you can find that responds to alarms > which may happen to be called suspend. ?But from a user point of view, Calling the deepest idle state suspend is just confusing. Linux suspend has a different api than idle. In suspend every driver that has a suspend hook is notified. Also, once cpu can be idle while another cpu is running. Suspend is a system wide. > it's just another idle level. ?And from a power management code/policy > decisions point of view, it should be the same. > -- Arve Hj?nnev?g -- 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/