From owner-freebsd-net@freebsd.org Thu Jul 23 19:26:50 2020 Return-Path: Delivered-To: freebsd-net@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id E3173360FDD; Thu, 23 Jul 2020 19:26:50 +0000 (UTC) (envelope-from bzeeb-lists@lists.zabbadoz.net) Received: from mx1.sbone.de (cross.sbone.de [195.201.62.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mx1.sbone.de", Issuer "SBone.DE" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4BCMlZ0DYFz43Q0; Thu, 23 Jul 2020 19:26:49 +0000 (UTC) (envelope-from bzeeb-lists@lists.zabbadoz.net) Received: from mail.sbone.de (mail.sbone.de [IPv6:fde9:577b:c1a9:31::2013:587]) (using TLSv1 with cipher ADH-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by mx1.sbone.de (Postfix) with ESMTPS id 6F5B48D4A156; Thu, 23 Jul 2020 19:26:42 +0000 (UTC) Received: from content-filter.sbone.de (content-filter.sbone.de [IPv6:fde9:577b:c1a9:31::2013:2742]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.sbone.de (Postfix) with ESMTPS id D9125E708CD; Thu, 23 Jul 2020 19:26:41 +0000 (UTC) X-Virus-Scanned: amavisd-new at sbone.de Received: from mail.sbone.de ([IPv6:fde9:577b:c1a9:31::2013:587]) by content-filter.sbone.de (content-filter.sbone.de [fde9:577b:c1a9:31::2013:2742]) (amavisd-new, port 10024) with ESMTP id M1plGXSJ2cS3; Thu, 23 Jul 2020 19:26:40 +0000 (UTC) Received: from [127.0.0.1] (unknown [IPv6:fde9:577b:c1a9:4902:7c3a:ebfc:75b:b9a6]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.sbone.de (Postfix) with ESMTPSA id C73A4E708CA; Thu, 23 Jul 2020 19:26:38 +0000 (UTC) From: "Bjoern A. Zeeb" To: "Kristof Provost" , "Hans Petter Selasky" Cc: "John-Mark Gurney" , freebsd-net@freebsd.org, freebsd-current@freebsd.org Subject: Re: somewhat reproducable vimage panic Date: Thu, 23 Jul 2020 19:26:38 +0000 X-Mailer: MailMate (2.0BETAr6146) Message-ID: In-Reply-To: References: <20200721091654.GC4213@funkthat.com> <20200721113153.42d83119@x23> <20200721202323.GE4213@funkthat.com> <38F5A3A6-B578-4BA4-8F69-C248163CB6E0@libassi.se> <20200722060514.GF4213@funkthat.com> <20200722193443.GG4213@funkthat.com> <6C149617-55BB-4A87-B993-195E5E133790@lists.zabbadoz.net> <20200722221509.GI4213@funkthat.com> <2FFC49F9-83DE-4FA1-A47F-1D8A7AF4B241@FreeBSD.org> <6847FB6B-0B1A-43C7-B567-15BF21AB5D56@FreeBSD.org> <8B72C0B9-9CF0-4557-81D7-77190775805C@lists.zabbadoz.net> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 4BCMlZ0DYFz43Q0 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of bzeeb-lists@lists.zabbadoz.net designates 195.201.62.131 as permitted sender) smtp.mailfrom=bzeeb-lists@lists.zabbadoz.net X-Spamd-Result: default: False [-2.81 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; RCVD_COUNT_FIVE(0.00)[5]; NEURAL_HAM_MEDIUM(-1.02)[-1.017]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+ip4:195.201.62.131]; NEURAL_HAM_LONG(-1.02)[-1.024]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[zabbadoz.net]; RCPT_COUNT_FIVE(0.00)[5]; TO_MATCH_ENVRCPT_SOME(0.00)[]; NEURAL_HAM_SHORT(-0.47)[-0.469]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:24940, ipnet:195.201.0.0/16, country:DE]; RCVD_TLS_LAST(0.00)[]; MID_RHS_MATCH_FROM(0.00)[] X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Jul 2020 19:26:50 -0000 On 23 Jul 2020, at 9:02, Kristof Provost wrote: > On 23 Jul 2020, at 11:00, Bjoern A. Zeeb wrote: >> On 23 Jul 2020, at 8:09, Kristof Provost wrote: >> >>> On 23 Jul 2020, at 9:19, Kristof Provost wrote: >>>> On 23 Jul 2020, at 0:15, John-Mark Gurney wrote: >>>>> So, it's pretty easy to trigger, just attach a couple USB ethernet >>>>> adapters, in my case, they were ure, but likely any two spare >>>>> ethernet >>>>> interfaces will work, and wire them back to back.. >>>>> >>>> I’ve been able to trigger it using epair as well: >>>> >>>> `sudo sh testinterfaces.txt epair0a epair0b` >>>> >>>> I did have to comment out the waitcarrier() check. >>>> >>> I’ve done a little bit of digging, and I think I’m starting to >>> see how this breaks. >>> >>> This always affects the jailed vlan interfaces. They’re getting >>> deleted, but the ifp doesn’t go away just yet because it’s still >>> in use by the multicast code. >>> The multicast code does its cleanup in task queues, >> >> Wow, did I miss that back then? Did I review a change and not notice? >> Sorry if that was the case. >> >> Vnet teardown is blocking and forceful. >> Doing deferred cleanup work isn’t a good idea at all. >> I think that is the real problem here. >> >> I’d rather have us fix this than putting more bandaids into the >> code. >> > Yeah, agreed. I think hselasky has a better fix: > https://reviews.freebsd.org/D24914 > > I just saw his e-mail in a different thread. That’ll probably work; still, the deferred teardown work seems wrong to me; I haven’t investigated; the patch kind-of says exactly that as well: if “wait until deferred stuff is done” is all we are doing, why can we not do it on the spot then? /bz