Re: [ckrm-tech] [PATCH] BC: resource beancounters (v4) (added user memory)

[Balbir Singh <balbir@in.ibm.com>]

Rohit Seth wrote:

> If the limits are set appropriately so that containers total memory
> consumption does not exceed the system memory then there shouldn't be
> any QoS issue (to whatever extent it is applicable for specific
> scenario).
> 
> -rohit
> 

What if the guarantee and limits are subject to change? Consider many groups,
with changing limits - how do we provide guarantees then?

Limit is the upper bound on resource utilization and guarantee is the lower
bound. In a dynamic system, how can we provide a lower bound on a resource
for a group by manipulating the upper bounds on the rest of the groups?

Consider a system with 1GB of ram and two groups such that they need a guarantee
of 100MB and 200MB of memory. How would you setup limits to ensure that
the guarantees are met? The remaining groups will be limited to 700MB, but
how do we ensure that these classes get 100MB and 200MB of the remaining 300MB
respectively?

-- 

	Balbir Singh,
	Linux Technology Center,
	IBM Software Labs