From: Andrew Morton Subject: Re: A unresponsive file system can hang all I/O in the system on linux-2.6.23-rc6 (dirty_thresh problem?) Date: Fri, 28 Sep 2007 13:10:12 -0700 Message-ID: <20070928131012.4a03c53e.akpm@linux-foundation.org> References: <92cbf19b0709272332s25684643odaade0e98cb3a1f4@mail.gmail.com> <20070927235034.ae7bd73d.akpm@linux-foundation.org> <1190998853.6702.17.camel@heimdal.trondhjem.org> <20070928114930.2c201324.akpm@linux-foundation.org> <1191006971.6702.25.camel@heimdal.trondhjem.org> <20070928122628.965137f2.akpm@linux-foundation.org> <1191009148.6702.46.camel@heimdal.trondhjem.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: nfs@lists.sourceforge.net, linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl To: Trond Myklebust Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1IbMBg-0003xd-26 for nfs@lists.sourceforge.net; Fri, 28 Sep 2007 13:11:53 -0700 Received: from smtp2.linux-foundation.org ([207.189.120.14]) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1IbMBi-0008F8-Tn for nfs@lists.sourceforge.net; Fri, 28 Sep 2007 13:11:53 -0700 In-Reply-To: <1191009148.6702.46.camel@heimdal.trondhjem.org> List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net On Fri, 28 Sep 2007 15:52:28 -0400 Trond Myklebust wrote: > On Fri, 2007-09-28 at 12:26 -0700, Andrew Morton wrote: > > On Fri, 28 Sep 2007 15:16:11 -0400 Trond Myklebust wrote: > > > Looking back, they were getting caught up in > > > balance_dirty_pages_ratelimited() and friends. See the attached > > > example... > > > > that one is nfs-on-loopback, which is a special case, isn't it? > > I'm not sure that the hang that is illustrated here is so special. It is > an example of a bog-standard ext3 write, that ends up calling the NFS > client, which is hanging. The fact that it happens to be hanging on the > nfsd process is more or less irrelevant here: the same thing could > happen to any other process in the case where we have an NFS server that > is down. hm, so ext3 got stuck in nfs via __alloc_pages direct reclaim? We should be able to fix that by marking the backing device as write-congested. That'll have small race windows, but it should be a 99.9% fix? ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs