From: Con Kolivas <kernel@kolivas.org>
To: Ingo Molnar <mingo@elte.hu>, Willy Tarreau <willy@w.ods.org>
Subject: Re: Ingo Molnar and Con Kolivas 2.6 scheduler patches
Date: Sun, 27 Jul 2003 21:54:31 +1000
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On Sun, 27 Jul 2003 19:12, Ingo Molnar wrote:
> On Sun, 27 Jul 2003, Willy Tarreau wrote:
> > just a thought : have you tried to set the timer to 100Hz instead of
> > 1kHz to compare with 2.4 ? It might make a difference too.
>
> especially for X, a HZ of 1000 has caused performance problems before -
> short-timeout select()s were looping 10 times faster, which can be
> noticeable.

No doubt X was a bit smoother at 100Hz in 2.5, but not remarkably so. In 2.4 
O(1) there was a slight X flutter (jerkiness) at 1000Hz not evident at 100Hz, 
but very consistent in the frequency/duration of that jerkiness. The 
difference is in 2.5, when X is not smooth it's almost like there's jitter in 
the jerkiness.

Con

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