WITNESS bug (Was Re: kern/68442: panic - acquiring duplicate lock of same type: "sleepq chain")

[Brian Fundakowski Feldman]

On Wed, Jul 07, 2004 at 07:13:46PM +0200, Harald Schmalzbauer wrote:
> Am Sonntag, 4. Juli 2004 21:42 schrieb Daniel Lang:
> 
> [...]
> > >
> > > Btw, the addition of WITNESS is indeed something that has
> > > changed since all the trouble started. When the machine was
> > > still running in a stable fashion I did not have WITNESS
> > > enabled. I did it, when I put in more memory and built a PAE
> > > kernel and left it in since.
> >
> > [..]
> >
> > I am now more convinced, that the bug is indeed in WITNESS itself.
> > Without WITNESS the machine is running rock stable again now
> > for three days. With WITNESS enabled it has crashed within minutes,
> > uptime at most a few hours. Also the stack trace I got points
> > into WITNESS code.
> 
> I'd like to contribute a completley unqualifide note:
> When I build a -current kernel with WITNESS and I use the nvidia driver (not 
> the GL-Part, just the kernel module and the x-driver) the system freezes 
> without panic or anything else, only a powercycle helps.
> After removing WITNESS the box is running fine. Now for about 3 Weeks without 
> any problem.....
> 
> If I can do any tests please give me instructions, I'd love to help.

You should never not run with WITNESS_SKIPSPIN if you use modules.  Any
spin mutexes not listed statically in the witness code will cause your
machine to immediately panic.

-- 
Brian Fundakowski Feldman                           \'[ FreeBSD ]''''''''''\
  <> green at FreeBSD.org                               \  The Power to Serve! \
 Opinions expressed are my own.                       \,,,,,,,,,,,,,,,,,,,,,,\