Re: PATCH] cpuidle: A new variant of the menu governor to boost IOperformance
From: Jens Axboe
Date: Fri Sep 11 2009 - 12:37:59 EST
On Fri, Sep 11 2009, Arjan van de Ven wrote:
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From: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
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Subject: [PATCH] cpuidle: A new variant of the menu governor
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This patch adds a new idle governor which balances power savings,
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energy efficiency and performance impact.
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The reason for a reworked governor is that there have been
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serious performance issues reported with the existing code
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on Nehalem server systems.
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To show this I'm sure Andrew wants to see benchmark results:
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(benchmark is "fio", "no cstates" is using "idle=poll")
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no cstates current linux new algorithm
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1 disk 107 Mb/s 85 Mb/s 105 Mb/s
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2 disks 215 Mb/s 123 Mb/s 209 Mb/s
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12 disks 590 Mb/s 320 Mb/s 585 Mb/s
Heh that's interesting, I have noticed some oddities that I haven't
pursued further yet. But it was definitely power state related, so I'll
give your patch spin.
--
Jens Axboe
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