Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758411Ab0FOTOZ (ORCPT ); Tue, 15 Jun 2010 15:14:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41245 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754736Ab0FOTOY (ORCPT ); Tue, 15 Jun 2010 15:14:24 -0400 Message-ID: <4C17D0C5.9030203@redhat.com> Date: Tue, 15 Jun 2010 15:13:09 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100430 Fedora/3.0.4-2.fc12 Lightning/1.0b2pre Thunderbird/3.0.4 MIME-Version: 1.0 To: Christoph Hellwig CC: Andrea Arcangeli , Mel Gorman , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Dave Chinner , Chris Mason , Nick Piggin Subject: Re: [RFC PATCH 0/6] Do not call ->writepage[s] from direct reclaim and use a_ops->writepages() where possible References: <1275987745-21708-1-git-send-email-mel@csn.ul.ie> <20100615140011.GD28052@random.random> <20100615141122.GA27893@infradead.org> <20100615142219.GE28052@random.random> <20100615144342.GA3339@infradead.org> <20100615150850.GF28052@random.random> <20100615152526.GA3468@infradead.org> <20100615154516.GG28052@random.random> <20100615162600.GA9910@infradead.org> <4C17AF2D.2060904@redhat.com> <20100615165423.GA16868@infradead.org> In-Reply-To: <20100615165423.GA16868@infradead.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 990 Lines: 25 On 06/15/2010 12:54 PM, Christoph Hellwig wrote: > On Tue, Jun 15, 2010 at 12:49:49PM -0400, Rik van Riel wrote: >> This is already in a filesystem. Why does ->writepage get >> called a second time? Shouldn't this have a gfp_mask >> without __GFP_FS set? > > Why would it? GFP_NOFS is not for all filesystem code, but only for > code where we can't re-enter the filesystem due to deadlock potential. Why? How about because you know the stack is not big enough to have the XFS call path on it twice? :) Isn't the whole purpose of this patch series to prevent writepage from being called by the VM, when invoked from a deep callstack like xfs writepage? That sounds a lot like simply wanting to not have GFP_FS... -- All rights reversed -- 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/