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From: arjan@fenrus.demon.nl
To: kravetz@us.ibm.com (Mike Kravetz)
Subject: Re: Context switch times
cc: linux-kernel@vger.kernel.org
In-Reply-To: <20011004140417.C1245@w-mikek2.des.beaverton.ibm.com>
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Date: Thu, 04 Oct 2001 22:14:13 +0100
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In article <20011004140417.C1245@w-mikek2.des.beaverton.ibm.com> you wrote:
> 2.4.10 on 8 CPUs:  lat_ctx -s 0 -r 2 results
> "size=0k ovr=2.27
> 2 3.86

> 2.2.16-22 on 8 CPUS:  lat_ctx -s 0 -r 2 results
> "size=0k ovr=1.99
> 2 1.44

> As you can see, the context switch times for 2.4.10 are more
> than double what they were for 2.2.16-22 in this example.  

> Comments?

2.4.x supports SSE on pentium III/athlons, so the SSE registers need to be
saved/restored on a taskswitch as well.... that's not exactly free.

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