panic: Exit: Single threading fouled up

[Gavin Atkinson]

On Mon, 26 Apr 2004, Dan Nelson wrote:
> In the last episode (Apr 26), Gavin Atkinson said:
> > I've seen this panic twice now, once on a heavily loaded UP machine
> > running gnome at the time, and once on an SMP (hyperthreaded) machine
> > which was mostly idle as it was shutting down. Both running with ULE.
> I've gotten it 6 times while running the pike testsuite, but not
> reliably enough that I can run a WITNESS kernel for a couple hours and
> catch it.  SMP system, 4BSD scheduler, libpthread.  Hangs trying to
> flush buffers so it has never generated a crashdump.  The couple of
> times I was able to break into the debugger before the hang, a ps
> showed most of the processes in the system waiting for the "proctree"
> mutex.

I'll find out what ps says from DDB next time it happens. I am running
with WITNESS enabled, but haven't seen any extra messages or anything
before the hang. I am using a libmap.conf to map everythng to libpthread.

I'm cvsupping to top-of-tree at the moment, but I can't see any changes
that would have fixed this.

Gavin