Re: [BENCHMARK] 100Hz v 1000Hz with contest

[Con Kolivas <kernel@kolivas.org>]

On Tue, 3 Jun 2003 18:00, Giuliano Pochini wrote:
> On 03-Jun-2003 Con Kolivas wrote:
> > I've attempted to answer the question does 1000Hz hurt responsiveness in
> > 2.5 as much as I've found in 2.4; since subjectively the difference
> > wasn't there in 2.5. Using the same config with preempt enabled here are
> > results from 2.5.70-mm3 set at default 1000Hz and at 100Hz (mm31):
>
> Is there any problem using a frequency other than 100 and 1000Hz ?

Not at all. These were chosen because they were the default 2.4 (100) and 2.5 
(1000) frequencies. The large difference in Hz was postulated to increase the 
in-kernel overhead and the amount of time spent tearing down and building up 
the cpu cache again. 2.4 running at 1000Hz shows poor performance at high 
(>4) loads whereas 2.5 doesn't seem to do this. I originally thought it was 
cache thrashing/trashing responsible. However since 2.5 performance is almost 
comparable at 100/1000 it seems to be that the pure interrupt overhead in 2.5 
is lower?

Con