From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David S. Miller" Subject: Re: unregister_netdevice: waiting for tun6to4 to become free. Date: Wed, 22 Sep 2004 11:15:44 -0700 Sender: netdev-bounce@oss.sgi.com Message-ID: <20040922111544.469dc4c2.davem@davemloft.net> References: <20040920212453.GA15392@ee.oulu.fi> <414F7CD9.3090008@pobox.com> <414FC92F.6090009@tomt.net> <1095854932.17821.1190.camel@hades.cambridge.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: andre@tomt.net, jgarzik@pobox.com, pp@ee.oulu.fi, netdev@oss.sgi.com Return-path: To: David Woodhouse In-Reply-To: <1095854932.17821.1190.camel@hades.cambridge.redhat.com> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Wed, 22 Sep 2004 13:08:52 +0100 David Woodhouse wrote: > On Tue, 2004-09-21 at 08:24 +0200, Andre Tomt wrote: > > Jeff Garzik wrote: > > > I hit this _once_ on my gateway (NAT'ing firewall IPv4, now also IPv6 > > > router). > > > > > > No idea why it went away, I just assumed a more recent kernel fixed > > > something. > > > > We've been seeing this all the time on 2.6.8.1 + "critical fixes". > > Pretty much anytime a router with tunneling interfaces is taken down for > > shutdown or reboot, it hangs spinning waiting for the tunnel devices to > > get freed, as ifdown gets run. > > It's not just tunnel interfaces. It seems to be related to hot-unplug of > interfaces with live IPv6 addresses. I've seen it on my prism54 card too > on many recent kernels. All I have to do is insert it and remove it a > few times. There is code in ipv6 which takes route references to devices and moves that reference over to loopback. There might be bugs in that area, and I would suggest debugging in that area.