From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: BUG: soft lockup detected on CPU#0! (2.6.18.2 plus hacks) Date: Tue, 02 Jan 2007 15:43:47 -0800 Message-ID: <459AEE33.7080702@candelatech.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: jarkao2@o2.pl, NetDev Return-path: Received: from ns2.lanforge.com ([66.165.47.211]:42415 "EHLO ns2.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752710AbXABXn5 (ORCPT ); Tue, 2 Jan 2007 18:43:57 -0500 To: David Stevens In-Reply-To: Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org David Stevens wrote: > I've looked at this a little too -- it'd be nice to know who holds > the write lock. > > I see ip_mc_destroy_dev() is bouncing through the lock for > each multicast address, though it starts at the beginning of > the list each time. I don't see a problem with it, but it'd be > simpler if it acquired the write lock once, grabbed and nulled > the list, released the lock and then called igmp_group_dropped() > & ip_ma_put() on each address from the local list copy. > > Are you destroying/creating interfaces or doing a lot of multicasting at > the time? How many group memberships do you have? Lots and lots of interfaces were being created...at least 200 mac-vlans (out-of tree patch somewhat similar to 802.1q vlans.) The avahi-daemon process was running, and it appears to be adding a multicast to each interface. It was spewing failure messages in /var/log/messages, probably because it can't handle so many interfaces. Other than that, there is no (known) multicast traffic being generated. This bug was reported to me by a user in Australia, and we have not yet attempted to recreate this locally, so I am not certain exactly what it takes to trigger this bug. Thanks, Ben > > +-DLS -- Ben Greear Candela Technologies Inc http://www.candelatech.com