From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bharata B Rao <bharata-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
Subject: Re: [RFC] CPU hard limits
Date: Fri, 5 Jun 2009 13:46:51 +0530
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Cc: Peter Zijlstra <a.p.zijlstra-/NLkJaSkS4VmR6Xm/wNWPw@public.gmane.org>,
        Pavel Emelyanov <xemul-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>,
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        Balbir Singh <balbir-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
To: Avi Kivity <avi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
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On Fri, Jun 05, 2009 at 09:01:50AM +0300, Avi Kivity wrote:
> Bharata B Rao wrote:
>>
>> But could there be client models where you are required to strictly
>> adhere to the limit within the bandwidth and not provide more (by advancing
>> the bandwidth period) in the presence of idle cycles ?
>>   
>
> That's the limit part.  I'd like to be able to specify limits and  
> guarantees on the same host and for the same groups; I don't think that  
> works when you advance the bandwidth period.
>
> I think we need to treat guarantees as first-class goals, not something  
> derived from limits (in fact I think guarantees are more useful as they  
> can be used to provide SLAs).

I agree that guarantees are important, but I am not sure about

1. specifying both limits and guarantees for groups and
2. not deriving guarantees from limits.

Guarantees are met by some form of throttling or limiting and hence I think
limiting should drive the guarantees.

Regards,
Bharata.