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Message-ID: <010e01c2757b$920e8ed0$2a060e09@beavis>
From: "Andrew Theurer" <habanero@us.ibm.com>
To: "Michael Hohnbaum" <hohnbaum@us.ibm.com>, <torvalds@transmeta.com>,
       <mingo@elte.hu>, <linux-kernel@vger.kernel.org>
Cc: "Erich Focht" <efocht@ess.nec.de>,
       "Martin J. Bligh" <Martin.Bligh@us.ibm.com>
References: <1034807518.9367.910.camel@dyn9-47-17-164.beaverton.ibm.com>
Subject: Re: [PATCH] NUMA Scheduler - rev 4
Date: Wed, 16 Oct 2002 20:21:40 -0500
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> Linus, Ingo,
>
> Attached is a small patch which provides NUMA awareness to the
> O(1) scheduler.  This patch retains the identical O(1) scheduler
> behavior for SMP systems.  For multi-node systems it favors
> runqueues on the current node when looking for another runqueue
> to pull tasks from.  It also makes a balance decision at exec().
> This patch is against 2.5.43.
>
> On NUMA systems these two changes have shown performance gains
> in the 5 - 10% range depending on tests.  Some micro-benchmarks
> provided by Erich Focht which stress the memory subsystem show
> a doubling in performance.
>
> Please consider applying this patch.

FYI, to make sure there was no degrade for non numa systems, I just benched
a kernel compile on an IBM 8500R, with/without your patch.  Compile times
were 38.880 (vanilla) and 38.818 (numa sched).

Andrew Theurer

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