Panic with vboxnet drivers

[Sean C. Farley]

On Mon, 28 Sep 2009, Fredrik Lindberg wrote:

> Sean C. Farley wrote:
>> I have five witness logs (attached):
>> 1. The first one appeared when I tried to run VirtualBox with
>>    vboxnetadp loaded via loader.conf.  VirtualBox will not be able to
>>    find the VirtualBox network drivers this way, so I unloaded and
>>    loaded vboxnetadp from the command line for the following logs.
>
> Need to look a bit more on this one.

Thank you.

>> 2. The next three logs are LOR's (sleepable after non-sleepable)
>>    concerning VirtualBox's "IPRT Fast Mutex Semaphore" which is an
>>    sx.  I am not sure I am reading the backtrace correctly.  It looks
>>    like the call to RTSemFastMutexRequest(), which calls sx_xlock(),
>>    is the effect.  I just do not know where the cause, i.e.,
>>    RTSemFastMutexRequest(), is being called.
>
> Yeah, this was a real one. The call to RTSemFastMutexRequest is inside 
> the virtual ethernet switch.  I've attached a patch that defers 
> processing to avoid the sleepable after non-sleepable case.  Hopefully 
> this fixes the panic you're seeing as well.

Thank you!  :)  This does fix the panic.

Sean
-- 
scf at FreeBSD.org