Re: NET_NS: unregister_netdevice: waiting for lo to become free (adding ipv6 address to interface)

[Michael Leun <lkml20100708@newton.leun.net>]

On Thu, 05 Aug 2010 12:57:59 -0700
ebiederm@xmission.com (Eric W. Biederman) wrote:

> What puzzles me is that on a slightly patched 2.6.32 (so sysfs works)
> and I am doing very similar things (openvpn tunnels, ipv6 to the
> network as a whole etc), and I am not seeing the infinite
> unregister_netdevice: messages you are talking about.

Hmmm, I think there are 2 possibilities:

- You send me a patch against plain 2.6.32, so I can check my
  scenarios against that kernel

or 

-  You could try yourself, its really just that few lines against a
  fresh booted system in a clean, easy to reproduce state

(Only, if you think that would yield useful information, of course).

> When a network device is removed most references to it are redirected
> to the loopback device so a normal network device should not see the
> worst of the problems.  That is why lo showed up.
> 
> In that context I'm a bit surprised you managed trigger a problem on
> veth1.

Difference was, when that message showed up with veth1, lo in that
namespace was down while testing. When lo was up it showed up on lo.

-- 
MfG,

Michael Leun