On Fri, Jun 22, 2001 at 12:47:11AM +0100, Chris Gilbert wrote:

 > Any advice or hints on the above would be gratefully received :)

Another thing you should do is deferred i-cache invalidation.  This
is something I implemented on Alpha, and it sped things up quite a
bit.

Basically, any time where I previously did an I-stream sync (Alpha
terminology roughly analogous to "invalidate I-cache" :-), I marked
the pmap as "needs I-stream sync on this processor".  Then in the
return-to-userspace path, if the pmap belonging to the process is
so marked, I sync the I-stream.

Assuming you have an easy way to hit the entire I-cache at once,
then this could save you a lot of work.

-- 
        -- Jason R. Thorpe <thorpej@zembu.com>