Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753335AbYH1JBA (ORCPT ); Thu, 28 Aug 2008 05:01:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751055AbYH1JAu (ORCPT ); Thu, 28 Aug 2008 05:00:50 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:53047 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752704AbYH1JAs (ORCPT ); Thu, 28 Aug 2008 05:00:48 -0400 Date: Thu, 28 Aug 2008 11:00:36 +0200 From: Ingo Molnar To: Joe Korty Cc: Andrew Morton , Linux Kernel Subject: Re: [PATCH] make poll_idle behave more like the other idle methods Message-ID: <20080828090036.GC19422@elte.hu> References: <20080827143506.GA23166@tsunami.ccur.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080827143506.GA23166@tsunami.ccur.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1043 Lines: 26 * Joe Korty wrote: > Make poll_idle() behave more like the other idle methods. > > Currently, poll_idle() returns immediately. The other > idle methods all wait indefinately for some condition > to come true before returning. poll_idle should emulate > these other methods and also wait for a return condition, > in this case, for need_resched() to become 'true'. > > Without this delay the idle loop spends all of its time > in the outer loop that calls poll_idle. This outer loop, > these days, does real work, some of it under rcu locks. > That work should only be done when idle is entered and > when idle exits, not continuously while idle is spinning. i'm wondering, what's the motivation, have you actually seen anything bad/undesired happen due to that? Ingo -- 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/