Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ie0-f175.google.com ([209.85.223.175]:51337 "EHLO mail-ie0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753808Ab3ACW0o (ORCPT ); Thu, 3 Jan 2013 17:26:44 -0500 Date: Thu, 3 Jan 2013 17:26:39 -0500 From: Tejun Heo To: "Myklebust, Trond" Cc: "J. Bruce Fields" , "Adamson, Dros" , Dave Jones , Linux Kernel , "linux-nfs@vger.kernel.org" Subject: Re: nfsd oops on Linus' current tree. Message-ID: <20130103222639.GE2753@mtj.dyndns.org> References: <4FA345DA4F4AE44899BD2B03EEEC2FA91197273D@SACEXCMBX04-PRD.hq.netapp.com> <20121221230849.GB29739@fieldses.org> <4FA345DA4F4AE44899BD2B03EEEC2FA911972C73@SACEXCMBX04-PRD.hq.netapp.com> <20121221232609.GC29739@fieldses.org> <4FA345DA4F4AE44899BD2B03EEEC2FA911972CA1@SACEXCMBX04-PRD.hq.netapp.com> <20121221234530.GA30048@fieldses.org> <0EC8763B847DB24D9ADF5EBD9CD7B4191259E4A2@SACEXCMBX02-PRD.hq.netapp.com> <20130103201120.GA2096@fieldses.org> <20130103220814.GB2753@mtj.dyndns.org> <4FA345DA4F4AE44899BD2B03EEEC2FA9119886EE@SACEXCMBX04-PRD.hq.netapp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <4FA345DA4F4AE44899BD2B03EEEC2FA9119886EE@SACEXCMBX04-PRD.hq.netapp.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Hello, Trond. On Thu, Jan 03, 2013 at 10:12:32PM +0000, Myklebust, Trond wrote: > > The analysis is likely completely wrong, so please don't go off doing > > something unnecessary. Please take look at what's causing the > > deadlocks again. > > The analysis is a no-brainer: > We see a deadlock due to one work item waiting for completion of another > work item that is queued on the same CPU. There is no other dependency > between the two work items. What do you mean "waiting for completion of"? Is one flushing the other? Or is one waiting for the other to take certain action? How are the two work items related? Are they queued on the same workqueue? Can you create a minimal repro case of the observed deadlock? Thanks. -- tejun