Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261515AbVDTL6b (ORCPT ); Wed, 20 Apr 2005 07:58:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261516AbVDTL6a (ORCPT ); Wed, 20 Apr 2005 07:58:30 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:60849 "EHLO amd.ucw.cz") by vger.kernel.org with ESMTP id S261515AbVDTL6R (ORCPT ); Wed, 20 Apr 2005 07:58:17 -0400 Date: Wed, 20 Apr 2005 13:57:39 +0200 From: Pavel Machek To: Dominik Brodowski , Thomas Renninger , Tony Lindgren , Frank Sorenson , linux-kernel@vger.kernel.org, Benjamin Herrenschmidt , Arjan van de Ven , Martin Schwidefsky , Andrea Arcangeli , George Anzinger , Thomas Gleixner , john stultz , Zwane Mwaikambo , Lee Revell , ML ACPI-devel , Bodo Bauer , Andi Kleen Subject: Re: [PATCH] Updated: Dynamic Tick version 050408-1 - C-state measures Message-ID: <20050420115739.GB16819@elf.ucw.cz> References: <4255B247.4080906@tuxrocks.com> <20050408062537.GB4477@atomide.com> <20050408075001.GC4477@atomide.com> <42564584.4080606@tuxrocks.com> <42566C22.4040509@suse.de> <20050408115535.GI4477@atomide.com> <42651C38.6090807@suse.de> <20050419152723.GA9509@isilmar.linta.de> <42657222.5080601@suse.de> <20050420114433.GA28362@isilmar.linta.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050420114433.GA28362@isilmar.linta.de> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 948 Lines: 23 Hi! > > Because I don't consider whether there was bm_activity the last ms, I only > > consider the average, it seems to happen that I try to trigger > > C3/C4 when there is just something copied and some bm active ?!? > > I don't think that this is perfect behaviour: if the system is idle, and > there is _currently_ bus master activity, the CPU should be put into C1 or > C2 type sleep. If you select C3 and actually enter it, you're risking > DMA issues, AFAICS. What kinds of DMA issues? Waiting 32msec or so is only heuristic; it can go wrong any time. It would be really bad if it corrupted data or something like that. Pavel -- Boycott Kodak -- for their patent abuse against Java. - 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/