From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752795Ab0EZMy6 (ORCPT ); Wed, 26 May 2010 08:54:58 -0400 Received: from ist.d-labs.de ([213.239.218.44]:34278 "EHLO mx01.d-labs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754805Ab0EZMy4 (ORCPT ); Wed, 26 May 2010 08:54:56 -0400 Date: Wed, 26 May 2010 14:54:52 +0200 From: Florian Mickler To: felipe.balbi@nokia.com Cc: Vitaly Wool , Peter Zijlstra , LKML , "Paul@smtp1.linux-foundation.org" , Linux OMAP Mailing List , Linux PM Subject: Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8) Message-ID: <20100526145452.685337db@schatten.dmk.lab> In-Reply-To: <20100526123532.GA2629@nokia.com> References: <1274863655.5882.4875.camel@twins> <1274867106.5882.5090.camel@twins> <20100526120242.5c9b73ad@schatten.dmk.lab> <20100526133721.602633b2@schatten.dmk.lab> <20100526142430.327ccbc4@schatten.dmk.lab> <20100526122932.GB1990@nokia.com> <20100526143323.7c6f8705@schatten.dmk.lab> <20100526123532.GA2629@nokia.com> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.18.9; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 26 May 2010 15:35:32 +0300 Felipe Balbi wrote: > Hi, > > On Wed, May 26, 2010 at 02:33:23PM +0200, ext Florian Mickler wrote: > >But then someone at the user side has to know what he is doing. > > > >I fear, if you target mass market without central distribution > >channels, you can not assume that much. > > and that's enough to push hacks into the kernel ? I don't think so. Do > it like apple and prevent multi-tasking for any non-apple applications > :-p > :) It really comes down to a policy decision by the distribution maker. And I don't think kernel upstream should be the one to force one way or the other. So merging this patch set will allow android to continue their work _on mainline_ while everybody else can continue as before. All points about the impact on the kernel have already been raised. So you should be happy there. Nonetheless, I really think the kernel needs to allow for the android way of power saving. It misses out on a big feature and a big user-base if not. Also I expect there to be synergies between android development and mainline kernel development _only_ if android development can use mainline kernel. And as for the quality of the "hack": I think you find this ugly, just because you don't like the concept of degrading user space guaranties on timers and stuff. But look at it this way: Suspend blockers are a way for the kernel to make user space programs accountable for using the resource "power". If a user space program needs the "traditional" guaranties for functioning properly, it needs to take a suspend blocker. But _THEN_ it better be well behaved. This is a kind of contract between userspace and kernelspace. On the other hand, if I don't need these traditional guaranties on timers and stuff, I don't have to know device specific things about power consumption. I can just use whatever facilities the programming language provides without needing to worry about low level details. This is a _big_ plus for attracting 3rd party programs. (And of course the thing you don't like). Cheers, Flo