[Devel] Re: [ckrm-tech] [RFC] Resource Management - Infrastructure choices

[Chris Friesen]

Srivatsa Vaddagiri wrote:

>>>        - Support limit (soft and/or hard depending on the resource
>>>          type) in controllers. Guarantee feature could be indirectly
>>>          met thr limits.

I just thought I'd weigh in on this.  As far as our usage pattern is 
concerned, guarantees cannot be met via limits.

I want to give "x" cpu to container X, "y" cpu to container Y, and "z" 
cpu to container Z.

If these are percentages, x+y+z must be less than 100.

However, if Y does not use its share of the cpu, I would like the 
leftover cpu time to be made available to X and Z, in a ratio based on 
their allocated weights.

With limits, I don't see how I can get the ability for containers to 
make opportunistic use of cpu that becomes available.

I can see that with things like memory this could become tricky (How do 
you free up memory that was allocated to X when Y decides that it really 
wants it after all?) but for CPU I think it's a valid scenario.

Chris