unregister_netdevice: waiting for ppp0 to become free

unregister_netdevice: waiting for ppp0 to become free

[Martin Petrak]

Hi all,

I am using kernel 2.6.14.6-grsec (x86_64 on AMD Sempron 64) with QoS (HTB)

Occasionally, when pppd drops a connection I see this in syslog :


Mar 25 13:40:17 myserver pppd[1300]: No response to 3 echo-requests
Mar 25 13:40:17 myserver pppd[1300]: Serial link appears to be disconnected.
Mar 25 13:40:17 myserver pppd[1300]: Connect time 1250.6 minutes.
Mar 25 13:40:17 myserver pppd[1300]: Sent 971616622 bytes, received 
1884313787 bytes.
Mar 25 13:40:20 myserver pppd[1300]: Connection terminated.
Mar 25 13:40:30 myserver kernel: unregister_netdevice: waiting for ppp0 
to become free. Usage count = 358

Then only force reboot of the machine solves the problem.

I found very similar problem with same symptoms :
http://groups.google.com/group/linux.debian.kernel/browse_thread/thread/dcb36b5fe827fad6/05445a30be147608

Do you have any ideas how I can debug why dev->refcnt did not reach zero?

regards,

Martin

unregister_netdevice: waiting for ppp0 to become free

[Nicolas George]

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Hi.

I recently upgraded to 2.6.29.1, and since then I get the following message
when my DSL ISP disconnects me (which he does weekly):

unregister_netdevice: waiting for ppp0 to become free. Usage count = 7

I did not manage to get the network up again without rebooting.

PPP is working with kernel-level PPPoE. The only slightly unusual thing in
my configuration is a few QoS rules. The same configuration worked fine with
kernel 2.6.24.2. I do not see anything relevant in the ChangeLog for
2.6.29.2 and 2.6.29.3.

Killing pppd does not seem to trigger the problem. I did not try to unplug
the DSL modem yet.

I attach the SysRq-t log.

I hope someone can help me find the problem.

Regards,

-- 
  Nicolas George

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