From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932533AbWG0HiS (ORCPT ); Thu, 27 Jul 2006 03:38:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932538AbWG0HiS (ORCPT ); Thu, 27 Jul 2006 03:38:18 -0400 Received: from smtp.osdl.org ([65.172.181.4]:43498 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S932533AbWG0HiR (ORCPT ); Thu, 27 Jul 2006 03:38:17 -0400 Date: Thu, 27 Jul 2006 00:38:06 -0700 From: Andrew Morton To: Anton Altaparmakov Cc: nickpiggin@yahoo.com.au, eike-kernel@sf-tec.de, linux-kernel@vger.kernel.org, aia21@cantab.net Subject: Re: [BUG?] possible recursive locking detected Message-Id: <20060727003806.def43f26.akpm@osdl.org> In-Reply-To: <1153984527.21849.2.camel@imp.csi.cam.ac.uk> References: <200607261805.26711.eike-kernel@sf-tec.de> <20060726225311.f51cee6d.akpm@osdl.org> <44C86271.9030603@yahoo.com.au> <1153984527.21849.2.camel@imp.csi.cam.ac.uk> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.17; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 27 Jul 2006 08:15:27 +0100 Anton Altaparmakov wrote: > > I'm surprised ext2 is allocating with __GFP_FS set, though. Would that > > cause any problem? > > That is an ext2 bug IMO. There is no bug. What there is is an ill-defined set of rules. If we want to tighten these rules we have a choice between a) Never enter page reclaim while holding i_mutex or b) never take i_mutex on the page reclaim path. Implementing a) would be a disaster. It means that our main write() implementation in mm/filemap.c (which holds i_mutex) wouldn't be able to reclaim pages to satisfy the write. And generally, we do want to use the strongest memory allocation mode at all times. So we'll have a better kernel if we implement b).