> Re. fatal page faults during panic ... I can't help but wonder of 
> something is trying to operate on curproc while it's NULL.  Note that 
> disk_unbusy() is typically called in an interrupt context.

	/*
	 * The machine independent parts of mi_switch().
	 * Must be called at splstatclock() or higher.
	 */
	void
	mi_switch()
	{
	        register struct proc *p = curproc;      /* XXX */
	        register struct rlimit *rlim;
	        register long s, u;
	        struct timeval tv;
	
	        /*
	         * Compute the amount of time during which the current
	         * process was running, and add that to its total so far.
	         */
	        microtime(&tv);
	        u = p->p_rtime.tv_usec + (tv.tv_usec - runtime.tv_usec);

Thud.  I wonder if there are any non-panic situations when mi_switch() can
be called when curproc is NULL?