Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423819AbWJaTci (ORCPT ); Tue, 31 Oct 2006 14:32:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1423820AbWJaTci (ORCPT ); Tue, 31 Oct 2006 14:32:38 -0500 Received: from caramon.arm.linux.org.uk ([217.147.92.249]:25613 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S1423819AbWJaTch (ORCPT ); Tue, 31 Oct 2006 14:32:37 -0500 Date: Tue, 31 Oct 2006 19:32:12 +0000 From: Russell King To: J?rn Engel Cc: Pierre Ossman , Arnd Bergmann , Christoph Hellwig , Jiri Slaby , Linux Kernel Mailing List , Adrian Bunk , Dominik Brodowski , Harald Welte , Arjan van de Ven , Jean Delvare Subject: Re: feature-removal-schedule obsoletes Message-ID: <20061031193212.GC26625@flint.arm.linux.org.uk> Mail-Followup-To: J?rn Engel , Pierre Ossman , Arnd Bergmann , Christoph Hellwig , Jiri Slaby , Linux Kernel Mailing List , Adrian Bunk , Dominik Brodowski , Harald Welte , Arjan van de Ven , Jean Delvare References: <45324658.1000203@gmail.com> <20061016133352.GA23391@lst.de> <200610242124.49911.arnd@arndb.de> <4543162B.7030701@drzeus.cx> <20061031155756.GA23021@wohnheim.fh-wedel.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061031155756.GA23021@wohnheim.fh-wedel.de> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1210 Lines: 28 On Tue, Oct 31, 2006 at 04:57:56PM +0100, J?rn Engel wrote: > On Sat, 28 October 2006 10:34:51 +0200, Pierre Ossman wrote: > > > > What should be used to replace it? The MMC block driver uses it to > > manage the block device queue. I am not that intimate with the block > > layer so I do not know the proper fix. > > Why does the MMC block driver use a thread? Is there a technical > reason for this or could it be done in original process context as > well, removing some code and useless cpu scheduler overhead? As I understand it, there is no guarantee that a block drivers request function will be called in process context - it could be called in interrupt context. The MMC subsystem needs process context to issue commands since the process of issuing commands entails various sleeps. Hence why the MMC block has its own process context. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - 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/