Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755197Ab0HITc2 (ORCPT ); Mon, 9 Aug 2010 15:32:28 -0400 Received: from smtp-out.google.com ([74.125.121.35]:37938 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754982Ab0HITc1 convert rfc822-to-8bit (ORCPT ); Mon, 9 Aug 2010 15:32:27 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:in-reply-to:references:date:message-id:subject:from:to: cc:content-type:content-transfer-encoding:x-system-of-record; b=tlqK9iXedf8xo0DYARodo/Hx7juM+LgOg4+1uOLtOFVEstj4glHaqdzeR+UHXOB7g DaTvg+kXFJfN2tWRA6Zyw== MIME-Version: 1.0 In-Reply-To: <20100809201822.441905f7@lxorguk.ukuu.org.uk> References: <20100806225453.GA3947@linux.vnet.ibm.com> <20100807061558.GA28087@thunk.org> <20100808155719.GB3635@thunk.org> <20100808213821.GD3635@thunk.org> <20100809112453.77210acc@lxorguk.ukuu.org.uk> <20100809181638.GI3026@linux.vnet.ibm.com> <20100809201822.441905f7@lxorguk.ukuu.org.uk> Date: Mon, 9 Aug 2010 12:32:21 -0700 Message-ID: Subject: Re: Attempted summary of suspend-blockers LKML thread, take three From: Brian Swetland To: Alan Cox Cc: paulmck@linux.vnet.ibm.com, "Ted Ts'o" , Felipe Contreras , david@lang.hm, linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, arve@android.com, mjg59@srcf.ucam.org, pavel@ucw.cz, florian@mickler.org, rjw@sisk.pl, stern@rowland.harvard.edu, peterz@infradead.org, tglx@linutronix.de, menage@google.com, david-b@pacbell.net, James.Bottomley@suse.de, arjan@infradead.org, swmike@swm.pp.se, galibert@pobox.com, dipankar@in.ibm.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2235 Lines: 42 On Mon, Aug 9, 2010 at 12:18 PM, Alan Cox wrote: >> But wouldn't an office suite run as a power-oblivious application on an >> Android device?  After all, office applications do not need to run when > > I was waiting for soemone to leap down the pit I dug  Office suites have > some quite important background activities. Consider the case of a power > oblivious Open Office. You type a critical document, you suspend, your > phone battery dies a bit later, you lost your document. Office suites do > timed backing up as one simple obvious example. That could become a power > aware behaviour but the truely power oblivious office suite is a myth. > >> the screen is turned off, so these the applications do not need to use >> suspend blockers.  That said, I could easily imagine that significant >> work would be required to make OpenOffice run on Android, not due to >> suspend blockers, but rather due to Android's unusual user space. > > You are tightly linking suspend blockers with Android. If they were a > sensible general solution they would be generic not tied closely to > Android Doesn't the same problem exist on my linux laptop? I write out my manifesto in open office, close the lid of my laptop, the system suspends before my huge document finishes writing out, later my battery dies or I foolishly remove it or whatnot... the main difference seems to be that laptops, with their big 'ol batteries, are less aggressive about power management and the result is wider windows before and less frequent wakeups from suspend and thus better odds at missing the race condition. As Arve has pointed out previously, there are a number of uses for suspend blockers, even on plugged-into-the-wall systems -- take his example of wanting his mythtv backend to power down when not busy, but never power down when he happens to be using it on console, or issues with multiple services that want to wake up and keep the device awake while working. Brian -- 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/