From: Peter Zijlstra Subject: Re: ext3 lockdep warning in 2.6.25-rc6 Date: Sat, 22 Mar 2008 18:38:47 +0100 Message-ID: <1206207527.6437.83.camel@lappy> References: <200803221437.m2MEbO5H003869@agora.fsl.cs.sunysb.edu> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: sct@redhat.com, akpm@linux-foundation.org, adilger@clusterfs.com, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org To: Erez Zadok Return-path: Received: from bombadil.infradead.org ([18.85.46.34]:46055 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754130AbYCVRjl (ORCPT ); Sat, 22 Mar 2008 13:39:41 -0400 In-Reply-To: <200803221437.m2MEbO5H003869@agora.fsl.cs.sunysb.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sat, 2008-03-22 at 10:37 -0400, Erez Zadok wrote: > I was building a kernel using "make -j 4" inside a unionfs, mounted on top > of ext3. The kernel is vanilla 2.6.25-rc6 plus unionfs patches. At some > point I forced a cache flush using "echo 3 > /proc/sys/vm/drop_caches" and I > got the lockdep warning below. Note that unionfs doesn't appear to be > involved in this lockdep warning at all, so I suspect this is probably an > issue between jbd and ext3 directly. Known issue, drop_caches isn't production quality.