Trying to remove netconsole, rmmod goes into a tight loop with
100% CPU usage. It can't be killed with 'kill -9'. Shutdown
works, though. Kernel is 2.6.20 FC6 config, and I'm 99.9%
sure the module signing has nothing to do with this.
On Mon, 26 Feb 2007 15:35:11 -0500
Chuck Ebbert <[email protected]> wrote:
> Trying to remove netconsole, rmmod goes into a tight loop with
> 100% CPU usage. It can't be killed with 'kill -9'. Shutdown
> works, though. Kernel is 2.6.20 FC6 config, and I'm 99.9%
> sure the module signing has nothing to do with this.
>
No it probably has to do with printing a message during module removal.
--
Stephen Hemminger <[email protected]>
Stephen Hemminger wrote:
> On Mon, 26 Feb 2007 15:35:11 -0500
> Chuck Ebbert <[email protected]> wrote:
>
>> Trying to remove netconsole, rmmod goes into a tight loop with
>> 100% CPU usage. It can't be killed with 'kill -9'. Shutdown
>> works, though. Kernel is 2.6.20 FC6 config, and I'm 99.9%
>> sure the module signing has nothing to do with this.
>>
>
> No it probably has to do with printing a message during module removal.
>
Yeah that could explain it.
But when I load it after the network has started I can't get it to
output any kernel messages to the network interface, either. I'll
try to reproduce this on a vanilla kernel next...
On Mon, Feb 26, 2007 at 01:31:56PM -0800, Stephen Hemminger wrote:
> On Mon, 26 Feb 2007 15:35:11 -0500
> Chuck Ebbert <[email protected]> wrote:
>
> > Trying to remove netconsole, rmmod goes into a tight loop with
> > 100% CPU usage. It can't be killed with 'kill -9'. Shutdown
> > works, though. Kernel is 2.6.20 FC6 config, and I'm 99.9%
> > sure the module signing has nothing to do with this.
> >
>
> No it probably has to do with printing a message during module removal.
I just reproduced this, and something really spooky happened.
After echo t > /proc/sysrq-trigger, the 'rmmod' process doesn't
show up in the backtrace. Everything else is there though.
The process shows up in a regular 'ps', but not in the sysrq output.
Most bizarre.
Dave
--
http://www.codemonkey.org.uk
Stephen Hemminger wrote:
> On Mon, 26 Feb 2007 15:35:11 -0500
> Chuck Ebbert <[email protected]> wrote:
>
>> Trying to remove netconsole, rmmod goes into a tight loop with
>> 100% CPU usage. It can't be killed with 'kill -9'. Shutdown
>> works, though. Kernel is 2.6.20 FC6 config, and I'm 99.9%
>> sure the module signing has nothing to do with this.
>>
>
> No it probably has to do with printing a message during module removal.
>
Works fine in 2.6.19.5
Hangs in vanilla 2.6.20 in netpoll_cleanup()
Call trace:
flush_cpu_workqueue
flush_workqueue
cancel_rearming_delayed_workqueue
netpoll_cleanup
sys_delete_module
It varies, but is always in one of the first three functions when you
do alt-sysrq-p.