From: Eric Sandeen Subject: Re: Overwriting w/ discard-capable drive causes soft-lockup in ext4 journal code, 2.6.28.8 Date: Tue, 17 Mar 2009 13:01:22 -0500 Message-ID: <49BFE572.9020302@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: linux-ext4@vger.kernel.org To: Chris Worley Return-path: Received: from mx1.redhat.com ([66.187.233.31]:46314 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758019AbZCQSB0 (ORCPT ); Tue, 17 Mar 2009 14:01:26 -0400 In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: Chris Worley wrote: > The issue I'm seeing is caused by running this repeatedly on an ext4 > fs (2.6.28.8 kernel) w/ discards enabled (a ram-based MTD device > contains the fs): > > while `true` > do i=0 > while [ $i -lt 100 ] > do dd of=foo"$i" if=/dev/zero bs=1024k oflag=direct & > let i=$i+1 > done > wait > done > > (Note: the loop is intended to fill-up the fs w/ 100 dd threads... > successive re-runs of the loop will rewrite the same files from > scratch.) > > ... It causes "soft-lockup" issues on successive iterations, > immediately as the DD's are launched, as previous foo files get their > blocks discarded. I need to find a machine w/ more memory to test on :) but with a device of half that size, on 2.6.29-rc7 machine w/ 2 cpus and 2G ram, I'm not seeing it... Any chance you can try a 2.6.29-rcX kernel just to double-check? Thanks, -Eric