Re: [MiNT] Memory protection and speed

[Odd Skancke <oskancke@online.no>]

On Mon, 15 Nov 1999, Frank Naumann wrote:

> Hi!
> 
> > > I noticed it booted alot slower last time I tried it, didn't use
> > > it for long periods of time, but I did notice loading times took
> > > longer.
> > > 
> > Same for my Hades. I couldn't test MP for a long time since the Hades' TOS
> > doesn't set up the MMU. When I used Odd Skankes(?) MMU tool and activated MP
> > I experienced a significant slowdown of the boot process.
> 
> The current 040 MMU code is heavily optimzed from Thomas. On my Milan it's
> now fast as without. I don't feel any difference.

 I have to agree with both Frank and Torsten here. On the Hades, booting
with with mem-prot enabled while using set_mmu is significantly slower
than booting without mem-prot enabled. This is due to the fact that I let
set_mmu setup copyback-caching on all RAM, which makes it impossible to
turn the caches on until booting is done. This is because too many
autofolder progs don't like CB caching. But, as soon as the boot process
is done, I can enable the caches, and then I don't notice any difference
in speed when starting processes, or any other mem-prot related
slow-downs. The only thing I'm waiting for now are a couple of flags in
the program header with which one can set the desired cache-mode ;-)


 Regards,



 Odd Skancke - ozk@atari.org