On Wed, 16 Jun 1999 08:05:31 -0700 
 Chuck Silvers <chuq@chuq.com> wrote:

 > actually, this probably belongs in struct pcb, right next to pcb_onfault.
 > it may need to be saved and restored along with pcb_onfault, too.

...and you'd probably need a macro to retrieve it; the PCB is
machine-dependent.

        -- Jason R. Thorpe <thorpej@nas.nasa.gov>