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List:       linux-kernel
Subject:    Re: [patch] voluntary-preempt-2.6.8.1-P5
From:       Ingo Molnar <mingo () elte ! hu>
Date:       2004-08-21 9:13:38
Message-ID: 20040821091338.GA25931 () elte ! hu
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* Lee Revell <rlrevell@joe-job.com> wrote:

> On Fri, 2004-08-20 at 09:30, Ingo Molnar wrote:
> 
> >  - reduce ZAP_BLOCK_SIZE to 16 when vp != 0. This pushes the exit
> >    latency down to below 100 usecs on Lee Revell's box.
> > 
> 
> Almost:
> 
> http://krustophenia.net/testresults.php?dataset=2.6.8.1-P6#/var/www/2.6.8.1-P6/trace8.txt

i suspect if you turn off tracing (or disable it in the kernel
completely) then you'd see below-100 usec latencies here. A trace entry
costs ~0.3 usecs on your box, so this 50-entry trace has roughly 15
usecs of tracing overhead :-)

	Ingo
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