Re: 060 problem with NetBSD (1.2 upwards)

[Ignatios Souvatzis <ignatios%theory.cs.uni-bonn.de@localhost>]

> Hello,
> 
> On my 060 machine I have a problem, which I guess is due to exceptions the
> CPU performs - mouse pointer in X freezes for a few moments or becomes very
> jerky when certain programs are loading/operating. For instance, when mosaic
> is loading there are a few seconds when mouse pointer is is simply frozen
> and I am unable to do anything.
> 
> I remember similar thing from my 040 days, but now (understandably) effect
> is amplifed and even more annoying, especially that exceptions are not only

Oh no....  How do you know it is CPU exceptions which slow down the machine?
This might be the case for the 68060... (much less likely for the 68040; only
slow former FPU operations like FSIN are emulated there) but you'd have to
prove it. (E.g.: run "systat v" in a xterm and watch for 060intemu and 
friends).

> making my machine unfriendly, but also slowing it down quite a bit. For
> example, server key generation in SSH took more time here than on 030/25Mhz
> + FPU in our A3000.

Yes. Problem is, that ssh uses hand-optimized for 68020-40 assembler stuff;
you can't change that with a compiler option.

For X11, using -m68060 will help, probably.

> When I was recompiling kernel recently, I've noticed that gcc had following
> parameteres on its command line: -m68060 -m68030 -msoft-float. Should I
> understand that compiling with these options will make apps run better on

No.

First, it is -m68060 -Wa,-m68030 -msoft-float
-m68060:        C-Compiler avoids 68060-unfriendly opcodes
-Wa,-m68030:    Assembler knows about 68030 specific stuff.
-msoft-float:   Don't create any FPU operations. This is for the kernel,
                which doesn't need FPU, and shouldn't touch it other than
                to save user context on context switches.

Regards,
        -is