Xen Developers Continue Work On CPU Core Scheduling Support

Sent out earlier this month is the second version of the Xen core scheduling patches that allow for CPU core and socket-level scheduling by this virtualization hypervisor.

The focus of this core/socket-level scheduling is to ensure the same VM(s) share the vCPU threads, which is more important these days in light of the various CPU speculative execution vulnerabilities that make Hyper Threading look particularly unsafe.

These patches are still under a "request for comments" flag and let all logical CPUs/threads or socket scheduled together. Besides the security advantage, there are also performance benefits around cache sharing.

The RFC v2 patches from earlier this month can be found on the kernel mailing list.

This weekend I also noticed that one of the developers posted many Xen core scheduling benchmarks via the Phoronix Test Suite and OpenBenchmarking.org. Hit up that link for more details on the performance implications of this new core scheduling code.