From owner-freebsd-net@freebsd.org Mon Aug 10 09:47:23 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 683AD37BF6F; Mon, 10 Aug 2020 09:47:23 +0000 (UTC) (envelope-from hps@selasky.org) Received: from mail.turbocat.net (turbocat.net [88.99.82.50]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4BQB2f3d75z43W9; Mon, 10 Aug 2020 09:47:22 +0000 (UTC) (envelope-from hps@selasky.org) Received: from hps2020.home.selasky.org (unknown [178.17.145.105]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id 1AE6B260287; Mon, 10 Aug 2020 11:47:14 +0200 (CEST) Subject: Re: somewhat reproducable vimage panic To: "Bjoern A. Zeeb" , Kristof Provost Cc: John-Mark Gurney , freebsd-net@freebsd.org, freebsd-current@freebsd.org, Stephen Hurd 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> From: Hans Petter Selasky Message-ID: <826eb82b-c6f9-9ef0-8dda-14ad00ce183e@selasky.org> Date: Mon, 10 Aug 2020 11:46:53 +0200 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 4BQB2f3d75z43W9 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of hps@selasky.org designates 88.99.82.50 as permitted sender) smtp.mailfrom=hps@selasky.org X-Spamd-Result: default: False [-2.92 / 15.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+a:mail.turbocat.net:c]; NEURAL_HAM_LONG(-0.97)[-0.975]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[selasky.org]; NEURAL_HAM_MEDIUM(-1.06)[-1.061]; RCPT_COUNT_FIVE(0.00)[6]; TO_MATCH_ENVRCPT_SOME(0.00)[]; NEURAL_HAM_SHORT(-0.59)[-0.587]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:24940, ipnet:88.99.0.0/16, country:DE]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(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: Mon, 10 Aug 2020 09:47:23 -0000 On 2020-07-23 21:26, Bjoern A. Zeeb wrote: > 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? Hi Bjoern, Trying to move the discussion over to Phabricator at: https://reviews.freebsd.org/D24914 The answer to your question I believe is this commit: https://svnweb.freebsd.org/base/head/sys/netinet/in_mcast.c?revision=333175&view=markup It affects both IPv4 and IPv6. I know that sometimes multicast entries can be freed from timer callbacks. I think having a task, probably one is enough, for network related configuration is acceptable. With D24914 there will be two threads to teardown which is probably overkill, but anyway makes a solid solution for now. I don't know why Stephen didn't think about draining those tasks. I know some people are not actively using VIMAGE and that might be the reason. --HPS