Devconf.cz 2023

In the Kubernetes resource allocation model, abstract concepts like resource request and limits, container QoS, etc are used. These concepts are being converted under the hood to cgroup configs, which have their own resource management model and concepts like CPU shares, CFS quotas, etc.

In the context of Kubevirt, an add-on to Kubernetes to allow running cloud-native VMs, this information is crucial. One especially interesting challenge was to support a true CPU Pinning for VMs running on top of Kubernetes.

This talk will take you through a journey to support true dedicated CPUs for VMs. I hope that the audience will better understand Kubernetes and Cgroup resource allocation models and how they can be further utilized. In addition, I wish that the info presented here will improve the collaboration between different technologies in the ecosystem like Cgroups, KVM, libvirt, Kubevirt and k8s by raising awareness to how they interact together in different and interesting use-cases.