From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8) Date: Thu, 27 May 2010 15:26:44 +0200 (CEST) Message-ID: References: <20100526171106.0e44a736@schatten.dmk.lab> <20100526190204.5efe4d59@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: Received: from www.tglx.de ([62.245.132.106]:47374 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754371Ab0E0N1m (ORCPT ); Thu, 27 May 2010 09:27:42 -0400 In-Reply-To: <20100526190204.5efe4d59@lxorguk.ukuu.org.uk> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Alan Cox Cc: Florian Mickler , Vitaly Wool , Peter Zijlstra , LKML , felipe.balbi@nokia.com, Linux OMAP Mailing List , Linux PM On Wed, 26 May 2010, Alan Cox wrote: > > The power efficiency of a mobile device is depending on a sane overall > > software stack and not on the ability to mitigate crappy software in > > some obscure way which is prone to malfunction and disappoint users. > > Even if you believe the kernel should be containing junk the model that > works and is used for everything else is resource management. Not giving > various tasks the ability to override rules, otherwise you end up needing > suspend blocker blockers next week. We definitely will need them when we want to optimize the kernel resource management on a QoS based scheme, which is the only sensible way to go IMNSHO. > A model based on the idea that a task can set its desired wakeup > behaviour *subject to hard limits* (ie soft/hard process wakeup) works > both for the sane system where its elegantly managing hard RT, and for > the crud where you sandbox it to stop it making a nasty mess. Right, the base system can set sensible defaults for "verified" apps, which will work most of the time except for those which have special requirements and need a skilled coder anyway. And for the sandbox crud the sensible default can be "very long time" and allow the kernel to ignore them at will. > Do we even need a syscall or will adding RLIMIT_WAKEUP or similar do the > trick ? That might be a good starting point. Thanks, tglx