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

From: William Lee Irwin III (
Date: Tue Jun 03 2003 - 08:09:12 EST

On Tue, 3 Jun 2003 18:00, Giuliano Pochini wrote:
>> Is there any problem using a frequency other than 100 and 1000Hz ?

On Tue, Jun 03, 2003 at 08:36:49PM +1000, Con Kolivas wrote:
> 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?

You could try profiling cache misses etc.

I blame count_active_tasks(). =)

-- wli
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