From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932109AbZE1Nm3 (ORCPT ); Thu, 28 May 2009 09:42:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761771AbZE1NmI (ORCPT ); Thu, 28 May 2009 09:42:08 -0400 Received: from one.firstfloor.org ([213.235.205.2]:54499 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760571AbZE1NmG (ORCPT ); Thu, 28 May 2009 09:42:06 -0400 Date: Thu, 28 May 2009 15:48:48 +0200 From: Andi Kleen To: Nick Piggin Cc: Andi Kleen , Wu Fengguang , "hugh@veritas.com" , "riel@redhat.com" , "akpm@linux-foundation.org" , "chris.mason@oracle.com" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" Subject: Re: [PATCH] [13/16] HWPOISON: The high level memory error handler in the VM v3 Message-ID: <20090528134848.GI1065@one.firstfloor.org> References: <200905271012.668777061@firstfloor.org> <20090527201239.C2C9C1D0294@basil.firstfloor.org> <20090528082616.GG6920@wotan.suse.de> <20090528095934.GA10678@localhost> <20090528101111.GE1065@one.firstfloor.org> <20090528103300.GA15133@localhost> <20090528105103.GG1065@one.firstfloor.org> <20090528121541.GL6920@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090528121541.GL6920@wotan.suse.de> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 28, 2009 at 02:15:41PM +0200, Nick Piggin wrote: > For correctness for what? You can't remove a page from swapcache or > pagecache under writeback because then the mm thinks that location > is not being used. I'm adding wait_on_page_writeback() to memory_failure(), so it will be out of the picture hopefully > > > > I'm mainly interested in correctness (as in not crashing) of this > > version now. > > > > Also writeback seems to be only used by nfs/afs/nilfs2, not in > > the normal case, unless I'm misreading the code. > > I don't follow. What writeback are you talking about? Sorry I misread the code, it's indeed used more commonly. > > > Then the writeback pages simply won't reach here. And it won't > > > magically go into writeback state, since the page has been locked. > > > > But since we take the page lock they should not be in writeback anyways, > > no? > > No. PG_writeback was introduced so as to reduce page lock hold > times (most of writeback runs without page lock held). Ok. Then the wait_on_page_writeback() will take care of that. Thanks for the feedback, -Andi -- ak@linux.intel.com -- Speaking for myself only.