Return-Path: Received: from merit-proxy01.merit.edu ([207.75.116.193]:37019 "EHLO merit-proxy01.merit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754943Ab1HCLtL (ORCPT ); Wed, 3 Aug 2011 07:49:11 -0400 Date: Wed, 3 Aug 2011 07:49:08 -0400 From: Jim Rees To: Peng Tao Cc: "Myklebust, Trond" , "Adamson, Andy" , Christoph Hellwig , linux-nfs@vger.kernel.org, peter honeyman Subject: Re: [PATCH v4 00/27] add block layout driver to pnfs client Message-ID: <20110803114908.GA5453@merit.edu> References: <1312233006.23392.17.camel@lade.trondhjem.org> <1312238117.23392.19.camel@lade.trondhjem.org> <20110802022144.GA18157@merit.edu> <2E1EB2CF9ED1CB4AA966F0EB76EAB4430A778575@SACMVEXC2-PRD.hq.netapp.com> <20110802032320.GA18296@merit.edu> <1312288134.4616.21.camel@lade.trondhjem.org> <20110803014808.GA4692@merit.edu> <2E1EB2CF9ED1CB4AA966F0EB76EAB4430A778AE2@SACMVEXC2-PRD.hq.netapp.com> <20110803023805.GA4863@merit.edu> Content-Type: text/plain; charset=iso-8859-1 In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Peng Tao wrote: On Wed, Aug 3, 2011 at 10:38 AM, Jim Rees wrote: > Myklebust, Trond wrote: > > ?Can you try to turn on the callback debugging ('echo 256 > > ?/proc/sys/sunrpc/nfs_debug')? A wireshark trace of what is going on > ?during the hang itself might also help. > > It doesn't fail with callback debugging turned on. ?I suspect the output to > my slow serial console disrupts the timing. > > The trace is in > http://www.citi.umich.edu/projects/nfsv4/pnfs/block/download/089.pcap In frame 8785, client returned NFS4ERR_DELAY in response to CB_SEQUENCE and the next RPC was 12s later. So it should be the case that Trond mentioned above. Yes, and there's some funny stuff earlier too. In frame 6381 the client returns a delegation, then in 6387 the server tries to recall the same delegation. Which I suppose is legal but I wonder why. This is followed by another 12 sec delay.