From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756302AbaIWOxz (ORCPT ); Tue, 23 Sep 2014 10:53:55 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:51646 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756280AbaIWOxw (ORCPT ); Tue, 23 Sep 2014 10:53:52 -0400 Date: Tue, 23 Sep 2014 15:53:56 +0100 From: Will Deacon To: Weston Andros Adamson Cc: Peng Tao , Trond Myklebust , linux-nfs list , "linux-kernel@vger.kernel.org" Subject: Re: WARNING at fs/nfs/write.c:743 nfs_inode_remove_request with -rc6 Message-ID: <20140923145356.GD28608@arm.com> References: <20140923130352.GK26472@arm.com> <2A327753-3E60-46AC-8220-3FF0FF61F08F@primarydata.com> <20140923135938.GB28608@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20140923135938.GB28608@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 23, 2014 at 02:59:38PM +0100, Will Deacon wrote: > On Tue, Sep 23, 2014 at 02:33:06PM +0100, Weston Andros Adamson wrote: > > Any more info on how to reproduce this would be really great. Unfortunately I don’t > > have access to an arm64 system. > > I've not spotted a pattern other than using 64k pages, yet. If I manage to > get a reproducer, I'll let you know. > > > If it’s possible, could we get a packet trace around when this happens? This is pure > > speculation, but this might have something to do the resend path - a commit fails > > and all the requests on the commit list have to be resent. > > Sure, once I can reproduce it reliably, then I'll try to do that. Right, a bunch of DDing from /dev/zero over an ssh session triggers this very quickly. I've put a binary tcpdump here: http://www.willdeacon.ukfsn.org/bitbucket/oopsen/nfs/tcpdump.bin You may want to filter out the ssh packets. The only `interesting' thing to me is a retransmission about half way through, but I don't know what I'm looking for. The NFS server is 10.1.203.204 and the client is 10.1.203.24. Will