From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757221Ab0EZSKF (ORCPT ); Wed, 26 May 2010 14:10:05 -0400 Received: from cantor2.suse.de ([195.135.220.15]:49209 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754081Ab0EZSKB (ORCPT ); Wed, 26 May 2010 14:10:01 -0400 Subject: Re: [PATCH 1/8] PM: Opportunistic suspend support. From: James Bottomley To: Pavel Machek Cc: Peter Zijlstra , Pekka Enberg , Arve Hj?nnev?g , Florian Mickler , "Rafael J. Wysocki" , Alan Stern , Dmitry Torokhov , Linux-pm mailing list , Kernel development list , Len Brown , Randy Dunlap , Andrew Morton , Andi Kleen , Cornelia Huck , Tejun Heo , Jesse Barnes , Nigel Cunningham , Ming Lei , Wu Fengguang , Maxim Levitsky , linux-doc@vger.kernel.org, Matthew Garrett , Greg KH , tytso@mit.edu In-Reply-To: <20100526174258.GF9069@elf.ucw.cz> References: <1274869262.5882.5222.camel@twins> <1274890736.4467.574.camel@mulgrave.site> <1274891308.1674.1766.camel@laptop> <1274892847.4467.674.camel@mulgrave.site> <1274893228.1674.1772.camel@laptop> <1274894042.4467.727.camel@mulgrave.site> <1274894602.1674.1780.camel@laptop> <1274895188.4467.783.camel@mulgrave.site> <20100526174258.GF9069@elf.ucw.cz> Content-Type: text/plain; charset="UTF-8" Date: Wed, 26 May 2010 13:09:48 -0500 Message-ID: <1274897388.4467.888.camel@mulgrave.site> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2010-05-26 at 19:42 +0200, Pavel Machek wrote: > Hi! > > > > > > The main and most important one being that suspend is a global property > > > > > and can/will hurt sensible tasks. It puts the whole task model upside > > > > > down. > > > > > > > > OK, so I believe you have an android phone ... it already implements > > > > this model ... specifically what are the problems on that platform this > > > > causes? > > > > > > I do not have one, nor have I ever written an application for it (nor > > > will I likely ever do that, since I detest Java), but I would expect an > > > application to run when its runnable. > > > > OK, so I've got one ... tell me what I should see and I'll try to > > reproduce. > > Umm... try to boot ordinary distro and see how it copes with > opportunistic suspend? That's not really going to help, is it? The issue I was curious are what are the bad things that result from interfering with the regular scheduling of processes ... because undeniably suspend (whether opportunistic or ordinary) does produce this interference. I could boot debian on an android and have it suspend ... that's still not going to answer my question. > I do have android here, and of course it work well with custom > userland. Question is: can common distro be reasonably modified to > work with suspend blockers, in a way that's backward compatible? You mean how an app could run if it was compiled with suspend blockers but the platform doesn't support it? That's a simple runtime switch in the library surely? James