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To: Robert Love <rml@tech9.net>
cc: Rick Bressler <rickb@mushroom.ca.boeing.com>, linux-kernel@vger.kernel.org
Reply-To: Gerrit Huizenga <gh@us.ibm.com>
From: Gerrit Huizenga <gh@us.ibm.com>
Subject: Re: [PATCH] scheduler hints 
In-Reply-To: Your message of 05 Jun 2002 18:11:38 PDT.
             <1023325903.912.390.camel@sinai> 
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Date: Wed, 05 Jun 2002 18:19:31 -0700
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In message <1023325903.912.390.camel@sinai>, > : Robert Love writes:
> On Wed, 2002-06-05 at 18:05, Gerrit Huizenga wrote:
> 
> > Actually, process-to-process affinity, which was later generalized
> > as a process gang affinity.
> 
> Oh OK, gang affinity - a bit different and not what we do now :)
> 
> Interesting to look into, although not terribly useful I suspect weighed
> against its implementation...
> 
> 	Robert Love

Our scheduler *was* a long set of conditionals.  However, from the
stock BSD scheduler through the contorted thing that it became, we
saw something like 30-50% increases in some workloads.  I think
the motivator was actually not Oracle originally but something like
SAP.  Specific numbers are hard to extract now since we did so many
SMP & NUMA changes over the years, but I think I remember a slide
showing over 30% increase in SAP for this one additional feature.
I don't know that I ever saw specific Oracle or Oracle Apps numbers
for this although it was viewed as a "large" benefit, especially
in NUMA machines, but even on SMP machines.

gerrit