Re: [RFC] CPU hard limits

Bharata B Rao
2009-06-05T08:28:03Z

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.