Subject: Re: 060 problem with NetBSD (1.2 upwards)
To: Ignatios Souvatzis <ignatios@theory.cs.uni-bonn.de>
From: Miloslaw Smyk <thorgal@amiga.com.pl>
List: port-amiga
Date: 01/15/1998 14:47:46
Hello,

On 15-Sty-98, Ignatios Souvatzis wrote:

>Oh no....  How do you know it is CPU exceptions which slow down the
machine?

Because it's the most likely cause of pointer jerkiness and general
slowdown. And I didn't say "I know". I said "I guess".

>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).

And so I did. On a clean system (no X) it reported about 30intemu (peak 50)
and ~80fpuemu (all values per second). Then I started X (without wm, because
I run Enlightement and it is quite heavy by itself). I was getting 50intemu
(peak 80), no change with fpuemu. By just moving the mouse around I could
easily increase intemu to about 250.

Then I started mosaic. For the first few seconds I was getting ~1000 (peak
1600) intemu, with still ~80fpuemu. But when the moment of pointer freeze
came, fpuemu reached over 20000 for as long as four or five seconds. At this
time intemu was around 120.

Now I am not surprised I had the same problems with both 040 and 060.


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

I am pretty sure I can convince SSH to use the C-version of the routines.


Considering the above results and the fact that 060 gets exceptions (albait
not on mosaic's or ssh's scale) from almost every software (yep, even gcc is
a trouble maker) what do you think about providing future distributions
compiled with -m68060? Users of earlier CPUs will barely (if at all) feel
the difference, but it will make NetBSD-Amiga a whole lot more usable on
060.

Greetings,
Milek
-- 
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