vkernel livelocked and core dumped when killed on -HEAD

[Rumko]

Rumko wrote:

> Matthew Dillon wrote:
> 
>> 
>> :Tried to cvs checkout the pkgsrc tree and managed to get "intr 1 at
>> :40001/40000 hz, livelocked limit engaged!". After kill-ing it, it core
>> :dumped. The backtrace repeats itself over and over, I uploaded kernel and
>> :kernel.core to leaf:~rumko/crash/vkernel/30.04.2008/
>> 
>>     Did the vkernel actually lock-up or was it still responding?  e.g. did
>>     you try ^Z'ing or ^C'ing the checkout?  It is quite possible that
>>     the IO co-thread actually managed to exceed the livelock limit without
>>     it being a bug.
>> 
>>     The crash was due to the IO co-thread crashing.  The IO co-thread took
>>     the shutdown signal from the vkernel when you killed it, but since it
>>     doesn't have a globaldata context that blew it up.
>> 
>>     I will mask the shutdown signal on the co-thread to fix the core
>>     dumping issue but we still need to investigate the livelock.  Have
>>     you been able to reproduce it?
>> 
>> -Matt
> 
> If I remember correctly, it was completely locked-up, but I will retry
> tonight.


Managed to lock up the host machine by dd-ing a large (10GB) file ... but
couldn't get a memory dump (it seems it did not create it) ... I'll continue
with this tomorrow when I'll feel bolder
-- 
Regards,
Rumko