Date: Tue, 11 Mar 2008 10:59:00 +0100
From: Ingo Molnar <mingo@elte.hu>
To: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: Re: Poor PostgreSQL scaling on Linux 2.6.25-rc5 (vs 2.6.22)
Message-ID: <20080311095900.GU25110@elte.hu>
References: <200803111749.29143.nickpiggin@yahoo.com.au> <20080311075845.GA13758@elte.hu> <200803111928.20043.nickpiggin@yahoo.com.au>
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* Nick Piggin <nickpiggin@yahoo.com.au> wrote:

> > Just a quick suggestion, does a simple runtime tune like this fix 
> > the workload:
> >
> >   for N in /proc/sys/kernel/sched_domain/*/*/flags; do
> >      echo $[`cat $N`|16] > N
> >   done
> >
> > this sets SD_WAKE_IDLE for all the nodes in the scheduler domains 
> > tree. (doing this results in over-agressive idle balancing - but if 
> > this fixes your testcase it shows that we were balancing 
> > under-agressively for this workload.) Thanks,
> 
> It doesn't change anything.
> 
> There is no idle time for this workload, btw.

oh, i thought you said that. Could you try to turn SD_WAKE_AFFINE 
all-off and all-on perhaps, via the same scriptlet?

	Ingo
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