ZFS and sh(1) panic: spin lock [lock addr] (smp rendezvous) held by [sh(1) proc tid] too long

[John Baldwin]

On Saturday 20 February 2010 5:19:39 pm Attilio Rao wrote:
> 2010/1/27 Brandon Gooch <jamesbrandongooch at gmail.com>:
> > The machine, a Dell Optiplex 755, has been locking up recently. The
> > situation usually occurs while using VirtualBox (running a 64-bit
> > Windows 7 instance) and doing anything else in another xterm (such as
> > rebuilding a port).  I've been unable to reliably reproduce it (I'm in
> > an X session and the machine will not panic "properly").
> >
> > However, while rebuilding Xorg today at ttyv0 and runnning
> > VBoxHeadless on ttyv1, I managed to trigger what I believe is the
> > lockup.
> >
> > I've attached a textdump in hopes that someone may be able to take a
> > look and provide clues or instruction on debugging this.
> 
> I think that jhb@ saw a similar problem while working on nVidia driver
> or the like.
> Not sure if he made any progress to debug this.

That was due to a weird bug where I was accidentally zero'ing the local APIC 
due to a then-bug in sg_pager.c (it was forcing the VM system to clear the 
pages it mapped by accident).  That should not be the explanation for this.

-- 
John Baldwin