Bugzilla – Bug 154073
unregister_netdevice: waiting for modemB to become free. Usage count = 1
Last modified: 2008-06-08 13:59:31 UTC
seife@susi:/tmp> uname -r 2.6.16-rc4-git2-20060222144057-default Following situation: - dialled in via bluetooth-rfcomm-ppp - RAS active - stop the ppp interface, ras gets killed from ip-down.d/ script. - plug the machine into the suse network - try to switch profiles with scpm - network setup hangs, all "ifconfig" or "ip show" hang in state D Log is constantly filled with "unregister_netdevice: waiting for modemB to become free. Usage count = 1" I'll attach sysrq-T and "ps auxwww"
Created attachment 70598 [details] /var/log/messages, including sysrq-t
Created attachment 70599 [details] "ps auxwww" Note that i had to reboot to get the machine running again. And no, i have not seen something like that since ~suse 9.1, so it is probably not easily reproducible :-)
Can you try to reproduce it ? modemB (why modemB ?) is the ppp device I guess, please provide all ifcfg-* files.
(In reply to comment #3) > Can you try to reproduce it ? give me a testcace :-) > modemB (why modemB ?) is the ppp device I guess, please provide all ifcfg-* > files. modemB == bluetooth. Easier to remember "modemB", "modemU" etc instead of modem0, modem1, ... I will attach them all.
Created attachment 70608 [details] ifcfg-modemB
Created attachment 70609 [details] ifcfg-modemK (Kabel)
Created attachment 70610 [details] ifcfg-modemU
Created attachment 70611 [details] wlan
Created attachment 70612 [details] LAN
So "give me a testcace" means, you already tried several times to do the same as you describe in "Following situation" with Beta5 with out hitting this problem ?
yes. I use dialin and RAS every day and i think (from the ps output) that it already hung when killing rasconnect, before plugging into the suse network. And i have not seen those "waiting for ... to become free" for a long time.
It maybe related to this mainline bug report: http://bugzilla.kernel.org/show_bug.cgi?id=6197 The mainline report is about pppoe, but maybe other ppp addons have the same problem. I'll monitor this bug and the ongoing discussion on netdevel.
I did not saw any of these problems with newer version, so I think it was solved. If the problem still exist, please reopen it.
Still happened today. What i did: - At home, i was in the local LAN via interface "cable" (e1000) or "air" (ipw2200) - While in the LAN, i dialled into the 3G network via a option data card (pppd), default route pointed to the dialup - started VPN (rasconnect.pl) - moved from home to office, ppp connection still alive, WLAN probably disconnected - plugged machine into the office LAN - called "scpm switch", to switch the networking setup for the office - scpm switch restarts networking - this includes stopping smpppd, which did not stop the active pppd. (no smpppd enabled in the office profile) - i noticed pppd was still active, so i simply pulled the card out while the scpm switch was running (i thought that the default route pointing to dialup would be a problem, so i wanted to get rid of it). Now i got the infamous "kernel: unregister_netdevice: waiting for modemX to become free. Usage count = 1" message and all i could do was reboot. Everything that was trying to access /proc/net/ was apparently hanging, also "ifconfig" and "ip". I did a sysrq-T trace which i will attach. This is with 10.3RC2
Created attachment 175085 [details] /var/log/messages excerpt, including the events leading up to the problem and a sysrq-t
Newer kernel did resolve some network usage bugs so I hope that this is resolved with 11.0. If you run into this again with 11.0, please open a new bug.