On Thu, Jun 04, 2009 at 03:19:22PM +0300, Avi Kivity wrote: > Bharata B Rao wrote: >> 2. Need for hard limiting CPU resource >> -------------------------------------- >> - Pay-per-use: In enterprise systems that cater to multiple clients/customers >> where a customer demands a certain share of CPU resources and pays only >> that, CPU hard limits will be useful to hard limit the customer's job >> to consume only the specified amount of CPU resource. >> - In container based virtualization environments running multiple containers, >> hard limits will be useful to ensure a container doesn't exceed its >> CPU entitlement. >> - Hard limits can be used to provide guarantees. >> > How can hard limits provide guarantees? > > Let's take an example where I have 1 group that I wish to guarantee a > 20% share of the cpu, and anther 8 groups with no limits or guarantees. > > One way to achieve the guarantee is to hard limit each of the 8 other > groups to 10%; the sum total of the limits is 80%, leaving 20% for the > guarantee group. The downside is the arbitrary limit imposed on the > other groups. This method sounds very similar to the openvz method: http://wiki.openvz.org/Containers/Guarantees_for_resources > > Another way is to place the 8 groups in a container group, and limit > that to 80%. But that doesn't work if I want to provide guarantees to > several groups. Hmm why not ? Reduce the guarantee of the container group and provide the same to additional groups ? Regards, Bharata. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
