From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [tbench regression fixes]: digging out smelly deadmen.
Date: Fri, 10 Oct 2008 07:40:05 +0200
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References: <20081009231759.GA8664@tservice.net.ru>
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Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	Ingo Molnar <mingo@elte.hu>, David Miller <davem@davemloft.net>
To: Evgeniy Polyakov <s0mbre@tservice.net.ru>
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On Fri, 2008-10-10 at 03:17 +0400, Evgeniy Polyakov wrote:

> I was so lucky to 'guess' (just after couple of hundreds of compilations),
> that it corresponds to 8f4d37ec073c17e2d4aa8851df5837d798606d6f commit about
> high-resolution timers, attached patch against 2.6.25 brings tbench
> performance for the 2.6.25 kernel tree to 455 MB/s.

can you try

echo NO_HRTICK > /debug/sched_features

on .27 like kernels?

Also, what clocksource do those machines use?

cat /sys/devices/system/clocksource/clocksource0/current_clocksource

As to, a7be37ac8e1565e00880531f4e2aff421a21c803, could you try
tip/master? I reworked some of the wakeup preemption code in there.

Thanks for looking into this issue!