On Wed, 31 Aug 2005 19:04:01 -0700 Robert Scott <rbscott@xxxxxxxxxxx> wrote: > Hello, > > I know that this bug has been discussed before at length on this > mailing list, but previous post seemed to indicate that it was fixed > before kernel 2.6.12. I am still seeing this occasionally in kernel > 2.6.12.3. The system is running knoppix, and IPV6 is not compiled > into the kernel(other posts mentioned numerous problems with the IPV6 > code). But every so often, when bringing down the bridge (it doesn't > happen every time), the process hangs, and the following message > appears in dmesg repeatedly: > > 'unregister_netdevice: waiting for br0 to become free. Usage count = 1' > > None of the processes involved can be killed, and an attempt to run > an ifconfig results in a process that is also waiting forever. At > this point the box must be rebooted forcefully. > > Two questions. > 1. In a previous post, someone mentioned one solution was to > commenting out the check that is hanging in the kernel. Does this > check preventing something terrible from happening(i assumed that it > does), or is it safe to remove it Really bad idea, because if the thing that is holding the reference like packets stuck in some dead queue, ever get processed the kernel will die. > 2. Any ideas of something to try in order to make this repeatable? Two other recent reports are: 1. Buggy applications that hold packets in their input queue forever, and/or netfilters. The socket buffer's contain a reference for packets in flight. 2. The VLAN code had a number of reference bugs, if you look through recent netdev mailing list you will see the discussion.
