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Re: [Xen-devel] Power aware credit scheduler

To: "Tian, Kevin" <kevin.tian@xxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] Power aware credit scheduler
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Thu, 19 Jun 2008 09:09:30 +0100
Cc: ackaouy@xxxxxxxxx, "Wei, Gang" <gang.wei@xxxxxxxxx>, "Yu, Ke" <ke.yu@xxxxxxxxx>
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On 19/6/08 09:03, "Tian, Kevin" <kevin.tian@xxxxxxxxx> wrote:

>> Does it then make sense to have the scheduler react to
>> governor? Sounds like it could be a weird feedback loop.
>> 
> 
> Good suggestion. We're considering adding some more inputs from
> key components into on-demand governor, instead of simply polling
> busy ratio for freq change in a fixed interval. For example, when one
> cpu pulls vcpu from other runqueues, it's the indicator that its current
> freq may not fit and it's better to scale to max immediately instead
> of waiting for next 20ms check timer. Other indicators like interrupt,
> event, etc. You kick a good instance. :-)

I see. This specific example doesn't sound unreasonable. I suppose
experimental data will show what works and what doesn't.

 -- Keir



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