From: Chris Worley Subject: Re: Overwriting w/ discard-capable drive causes soft-lockup in ext4 journal code, 2.6.28.8 Date: Tue, 17 Mar 2009 13:19:33 -0600 Message-ID: References: <49BFE572.9020302@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-ext4@vger.kernel.org To: Eric Sandeen Return-path: Received: from wf-out-1314.google.com ([209.85.200.168]:3800 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751981AbZCQTTf convert rfc822-to-8bit (ORCPT ); Tue, 17 Mar 2009 15:19:35 -0400 Received: by wf-out-1314.google.com with SMTP id 29so144467wff.4 for ; Tue, 17 Mar 2009 12:19:33 -0700 (PDT) In-Reply-To: <49BFE572.9020302@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Mar 17, 2009 at 12:01 PM, Eric Sandeen wro= te: > 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 =A0i=3D0 >> =A0 =A0 =A0while [ $i -lt 100 ] >> =A0 =A0 =A0do dd of=3Dfoo"$i" if=3D/dev/zero bs=3D1024k oflag=3Ddire= ct & >> =A0 =A0 =A0 =A0 =A0 let i=3D$i+1 >> =A0 =A0 =A0done >> =A0 =A0 =A0wait >> 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 thei= r >> blocks discarded. > > I need to find a machine w/ more memory to test on :) =A0but with a d= evice > of half that size, on 2.6.29-rc7 machine w/ 2 cpus and 2G ram, I'm no= t > seeing it... > > Any chance you can try a 2.6.29-rcX kernel just to double-check? I'm not able to repeat w/ 2.6.29-rc8. The system just limps-along, though; SATA doesn't work, Ethernet doesn't work, and system response is slow... but disk speed is as expected, and no soft-lockup issues. Chris -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html