From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D3BFCA9EB9 for ; Tue, 29 Oct 2019 03:58:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB31120862 for ; Tue, 29 Oct 2019 03:58:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="r2LPFFgR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727107AbfJ2D6o (ORCPT ); Mon, 28 Oct 2019 23:58:44 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:43258 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726025AbfJ2D6o (ORCPT ); Mon, 28 Oct 2019 23:58:44 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x9T3t1nK183128; Tue, 29 Oct 2019 03:58:39 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2019-08-05; bh=UYBvEhM01dE1PYclUWFQKX+8PyG3BmJmPceX/miPf/s=; b=r2LPFFgROn9tRxaWqsZeO/cMq4s0NIFAo5JA4V2m3KH469EA33fMzN6hSlNrCbNrPyAC PIW65a6LbpnbkNfJNXB0aQA+zSVxnOyx4iN6/kr2VWNT5SmQLIduyskik7JtzEv30vug k3/5fr+4/XZnOt7yps04g25+vcd5Mkaf0MhkDsbSw+JTCn12AktusuLqBLjJ+TCoCKWh gyLdFEQDRI8lSFX2kh+S7rOF1v+2uBF2eMX67L5cOuP3GFcwXcKj0W5cyojfeuQ9EPwy hLBwyYgJkbPPaka7aQaoDCqoZ9pE1nvUPU6aIpzMqMDwAfhLQw12XNIHvFXL2XK5cRp6 5Q== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by aserp2120.oracle.com with ESMTP id 2vve3q61uy-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 29 Oct 2019 03:58:39 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x9T3mZmZ141765; Tue, 29 Oct 2019 03:58:39 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3030.oracle.com with ESMTP id 2vwam06hkm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 29 Oct 2019 03:58:38 +0000 Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x9T3wWex022059; Tue, 29 Oct 2019 03:58:32 GMT Received: from localhost (/10.159.156.71) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 28 Oct 2019 20:58:32 -0700 Date: Mon, 28 Oct 2019 20:58:31 -0700 From: "Darrick J. Wong" To: Christoph Hellwig Cc: linux-xfs@vger.kernel.org Subject: Re: softlockup with CONFIG_XFS_ONLINE_SCRUB enabled Message-ID: <20191029035831.GE15221@magnolia> References: <20191025102404.GA12255@lst.de> <20191027183232.GA15221@magnolia> <20191028073003.GA20274@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191028073003.GA20274@lst.de> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9424 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910290040 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9424 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910290041 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Mon, Oct 28, 2019 at 08:30:03AM +0100, Christoph Hellwig wrote: > On Sun, Oct 27, 2019 at 11:32:32AM -0700, Darrick J. Wong wrote: > > On Fri, Oct 25, 2019 at 12:24:04PM +0200, Christoph Hellwig wrote: > > > Hi Darrick, > > > > > > the current xfs tree seems to easily cause sotlockups in generic/175 > > > (and a few other tests, but not as reproducible) for me. This is on > > > 20GB 4k block size images on a VM with 4 CPUs and 4G of RAM. > > > > Hrm. I haven't seen that before... what's your kernel config? > > This looks like some kind of lockup in slub debugging...? > > > > Also, is this a new thing? Or something that used to happen with low > > frequency but has slowly increased to the point that it's annoying? > > > > (Or something else?) > > Seems to happen with 5.3 as well. I only recently turned > CONFIG_XFS_ONLINE_SCRUB back on in my usual test config, that is what > made it show up.. > > .config attached. Aha, you have preempt disabled and slub debugging on by default, which (on the million-extent files produced by generic/175) mean that scrub takes long enough to trip the soft lockup watchdog while checking the bmap. The test eventually finishes, but the obvious(ly stupid) bandaid of calling touch_softlockup_watchdog merely plunged the VM into "rcu_sched self-detected stall on CPU" messages and as it's late I'll set it aside until tomorrow. IOWs I think I know what's going on but don't yet know how to fix it. :/ --D