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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=ham 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 3F388C4338F for ; Sun, 15 Aug 2021 12:35:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A37D61103 for ; Sun, 15 Aug 2021 12:35:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231318AbhHOMfk (ORCPT ); Sun, 15 Aug 2021 08:35:40 -0400 Received: from out20-14.mail.aliyun.com ([115.124.20.14]:46034 "EHLO out20-14.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229603AbhHOMfj (ORCPT ); Sun, 15 Aug 2021 08:35:39 -0400 X-Alimail-AntiSpam: AC=CONTINUE;BC=0.08157421|-1;CH=green;DM=|CONTINUE|false|;DS=CONTINUE|ham_regular_dialog|0.0116308-0.00864484-0.979724;FP=0|0|0|0|0|-1|-1|-1;HT=ay29a033018047209;MF=guan@eryu.me;NM=1;PH=DS;RN=7;RT=7;SR=0;TI=SMTPD_---.L.eSNlm_1629030902; Received: from localhost(mailfrom:guan@eryu.me fp:SMTPD_---.L.eSNlm_1629030902) by smtp.aliyun-inc.com(10.147.40.7); Sun, 15 Aug 2021 20:35:03 +0800 Date: Sun, 15 Aug 2021 20:35:02 +0800 From: Eryu Guan To: Luis Chamberlain Cc: fstests@vger.kernel.org, hare@suse.de, dgilbert@interlog.com, jeyu@kernel.org, lucas.demarchi@intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 3/3] common/scsi_debug: use the patient module remover Message-ID: References: <20210811154512.1813622-1-mcgrof@kernel.org> <20210811154512.1813622-4-mcgrof@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210811154512.1813622-4-mcgrof@kernel.org> Precedence: bulk List-ID: X-Mailing-List: fstests@vger.kernel.org On Wed, Aug 11, 2021 at 08:45:12AM -0700, Luis Chamberlain wrote: > If you try to run tests such as generic/108 in a loop > you'll eventually see a failure, but the failure can > be a false positive and the test was just unable to remove > the scsi_debug module. > > We need to give some time for the refcnt to become 0. For > instance for the test generic/108 the refcnt lingers between > 2 and 1. It should be 0 when we're done but a bit of time > seems to be required. The chance of us trying to run rmmod > when the refcnt is 2 or 1 is low, about 1/30 times if you > run the test in a loop on linux-next today. > > Likewise, even when its 0 we just need a tiny breather before > we can remove the module (sleep 10 suffices) but this is > only required on older kernels. Otherwise removing the module > will just fail. > > Some of these races are documented on the korg#212337, and > Doug Gilbert has posted at least one patch attempt to try > to help with this [1]. The patch does not resolve all the > issues though, it helps though. > > [0] https://bugzilla.kernel.org/show_bug.cgi?id=212337 > [1] https://lkml.kernel.org/r/20210508230745.27923-1-dgilbert@interlog.com > Signed-off-by: Luis Chamberlain > --- > common/scsi_debug | 6 ++++-- There're also some "modprobe -r" calls in common/module, should the be replaced with _patient_rmmod as well? > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/common/scsi_debug b/common/scsi_debug > index e7988469..3c9cd820 100644 > --- a/common/scsi_debug > +++ b/common/scsi_debug > @@ -4,11 +4,13 @@ > # > # Functions useful for tests on unique block devices > > +. common/module > + > _require_scsi_debug() > { > # make sure we have the module and it's not already used > modinfo scsi_debug 2>&1 > /dev/null || _notrun "scsi_debug module not found" > - lsmod | grep -wq scsi_debug && (rmmod scsi_debug || _notrun "scsi_debug module in use") > + lsmod | grep -wq scsi_debug && (_patient_rmmod scsi_debug || _notrun "scsi_debug module in use") I don't think we should use _patient_rmmod here, if we set timeout to forever and there's actually some other process using scsi_debug module, we'll loop forever here. And a failure to remove scsi_debug only results in _notrun, and won't cause false test failure. > # make sure it has the features we need > # logical/physical sectors plus unmap support all went in together > modinfo scsi_debug | grep -wq sector_size || _notrun "scsi_debug too old" > @@ -53,5 +55,5 @@ _put_scsi_debug_dev() > $UDEV_SETTLE_PROG > n=$((n-1)) > done I think the above while loop could be removed as well? Thanks, Eryu > - rmmod scsi_debug || _fail "Could not remove scsi_debug module" > + _patient_rmmod scsi_debug || _fail "Could not remove scsi_debug module" > } > -- > 2.30.2