Date: Thu, 28 Oct 2004 15:16:22 +0200
From: Ingo Molnar <mingo@elte.hu>
To: Karim Yaghmour <karim@opersys.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH] Restricted hard realtime
Message-ID: <20041028131622.GA13744@elte.hu>
References: <20041023194721.GB1268@us.ibm.com> <417F12F1.5010804@opersys.com> <20041026212956.4729ce98.akpm@osdl.org> <20041027081044.GA14451@elte.hu> <4180DF18.5060808@opersys.com>
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* Karim Yaghmour <karim@opersys.com> wrote:

> >with -RT-V0.3 i get lower than 20 usec _maximum_ latencies during
> >'./hackbench 20'. (the average latency is 1 usec) So while i'm not yet
> >in the sub-femtosecond category, things are looking pretty good in
> >PREEMPT_REALTIME land :)
> 
> Just curious: what's the setup here? (CPU speed, peripherals, distro,
> applications being run to load the system, etc.) [...]

2 GHz Athlon running stock Fedora Core. './hackbench 20' was the
workload.

> I'm assuming that the timings are measured using the tracing
> functionality currently in the patches.

no, i used a user-space timing app called 'realfeel', but the numbers
were corroborated by the in-kernel tracer too.

but ... the best test would be if you tried the patch, it's not hard ;)
There are newer versions since i did the above measurement and testing
feedback is always welcome.

	Ingo
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