vSphere High Performance Cookbook

CPU scheduler – processor topology/cache aware

ESXi Server has an advanced CPU scheduler geared towards providing high performance, fairness, and isolation of virtual machines running on Intel/AMD x86 architectures.

The ESXi CPU scheduler is designed with the following objectives:

• Performance isolation: Multi-VM fairness.
• Co-scheduling: illusion that all vCPUs are concurrently online.
• Performance: high throughput, low latency, high scalability, and low overhead.
• Power efficiency: saving power without losing performance.
• Wide Adoption: enabling all the optimizations on diverse processor architecture.

There can be only one active process per CPU at any given instant, for example, multiple vCPUs can run on the same pCPU, just not at one instant, but there ...