panic on 5.2 BETA: blockable sleep lock

Stefan Ehmann shoesoft at
Sun Nov 30 01:10:57 PST 2003

On Fri, 2003-11-28 at 01:02, Don Lewis wrote:
> On 27 Nov, Stefan Ehmann wrote:
> > On Wed, 2003-11-26 at 08:33, Don Lewis wrote:
> >> The problem is that selrecord() wants to lock a MTX_DEF mutex, which can
> >> cause a context switch if the mutex is already locked by another thread.
> >> This is contrary to what bktr_poll() wants to accomplish by calling
> >> critical_enter().
> > 
> > Strange enough that does not seem to happen with a kernel built without
> > INVARIANTS and WITNESS. Does this make any sense or is this just by
> > chance?
> You might try the patch below with WITNESS enabled.  I don't have the
> hardware, so I can't test it.  It compiles for me, but for all I know it
> could delete all your files if you run it.

Any chance for getting this committed?

More information about the freebsd-current mailing list