Paper: The CPU Scheduler in VMware vSphere 5.1

Posted by Kenneth van Surksum   |   Monday, January 28th, 2013   |  

VMware has released a paper titled: “The CPU Scheduler in VMware vSphere 5.1“. The paper which contains 26 pages provides detailed explanations of ESXi CPU scheduling policies to help vSphere users who want to understand how virtual machines are scheduled.

The CPU scheduler is an essential component of vSphere 5.x. All workloads running in a virtual machine must be scheduled for execution and the CPU scheduler handles this task with policies that maintain fairness, throughput, responsiveness, and scalability of CPU resources.

clip_image001

The paper contains the following sections:

  • Executive Summary
  • Introduction
  • Terminology
  • CPU Scheduler Overview
  • Proportional Share-Based Algorithm
  • Relaxed Co-Scheduling
  • Load Balancing
  • Policy on Hyper-Threading
  • NUMA Scheduling Policy
  • Experiments
  • Conclusion
  • References

The ESXi CPU scheduler achieves fair distribution of compute resources among many virtual machines without compromising system throughput and responsiveness. Relaxed co-scheduling is a salient feature that enables both correct and efficient execution of guest instructions with low overhead. The ESXi CPU scheduler is highly scalable and supports very big systems and wide virtual machine.

vSphere 5.1 optimizes the load-balancing algorithm introduced in 5.0. It results in noticeable reductions in CPU scheduling overhead. A policy change on hyper-threaded systems enables out-of-the-box performance of 5.1 exceeding that of a tuned version of vSphere 4.1. No special tuning is required to achieve the best performance for most common application workloads. The irtual NUMA feature introduced in 5.0 can significantly improve performance of workloads that are optimized for a NUMA environment. With vNUMA, virtual machines of any size can display optimal performance on a NUMA system. The vNUMA feature is shown to significantly improve the performance of SPEC OMP workloads. Such improvement closes the performance gap between the virtual and the native environment for high-performance-computing (HPC) workloads.


Labels: ,

blog comments powered by Disqus


virtualization.info Newest articles
Citrix CEO Mark Templeton plans to retire

July 30th, 2015

On July 28 Citrix disclosed that Mark Templeton, the company CEO, has plans to retire after over 20 years of service, an unexpected news that drew attention on the next…

Citrix announces Q2 2015 results

July 30th, 2015

Citrix announced its financial results for second quarter 2015.
The revenues for the second quarter were $797 million for an increase of 2% compared to Q2 2014.
Net income was $103…

VMware announces results for Q2 2015

July 24th, 2015

VMware released the results about its results for Q2 2015.
VMware, announced a GAAP total revenue growth of $1.52 billion, for an increase of 4 percent compared to Q2 2014. License revenues…

Gartner releases its 2015 Magic Quadrant for x86 Server Virtualization Infrastructure

July 21st, 2015

Gartner released its Magic Quadrant for x86 Server Virtualization Infrastructure for year 2015, once more positioning VMware and Microsoft in the leaders Quadrant.
No surprises in the leaders quadrant, as…

Release: Parallels Mac Management 4.0 for Microsoft SCCM

July 21st, 2015

Parallels announced the availability of Parallels Mac Management 4.0 for Microsoft System Center Configuration Manager (SCCM), extending its range of capabilities to Mac computers.
This new release increases the flexibility…

Avast Software Acquires Remotium

July 10th, 2015

On July 8, Avast Software, a Czech private limited company provider of antivirus and security software products announced to have acquired Silicon Valley based Remotium, a company founded in…

Release: Oracle VM VirtualBox 5.0 Candidate 1 (RC1)

July 8th, 2015

Oracle has announced to have released version 5.0 Candidate 1 (RC1) for its virtualization platform VM VirtualBox. The release brings enhancement and bug fixes to the previous versions, improving stability…

IBM announces Docker Based Container Services

July 1st, 2015

Containers continue to gain traction, IBM announced the release of enterprise class containers based on Docker and built on its Platform as a Service, Bluemix for hybrid environments. It will…

Release: Xen Project Hypervisor 4.5.1

July 1st, 2015

The Xen Project, the community which develops the Xen hypervisor under the GNU General Public License (GPLv2) announced the availability of a new maintenance release, version 4.5.1 of the Xen…

Red Hat Summit 2015 Wrap-up

June 29th, 2015

Last week, Red Hat held its premiere event in Boston, Massachusetts from June 23 to 26, the Red Hat Summit,  where several announcements have been made.
The summit offered over…

Midokura expands OpenStack Team with Takashi Yamamoto

June 29th, 2015

Network virtualization is one of the hot topics within the OpenStack community. Last week japanese startup Midokura focused on network virtualization announced the assignment of Takashi Yamamoto as OpenStack…

Red Hat announces Q1 2015 earnings

June 24th, 2015

On June 18 Red Hat announced its financial results for its fiscal year 2016 and for the first quarter of 2015.
Total revenue for the first quarter ended May 31,…

Rancher Labs raises $10M in Series A funding

June 11th, 2015

Rancher Labs is a startup providing management on top of the Docker containers, today the company has announced that it has raised $10 million in a series A funding…

EMC acquires Virtustream

May 26th, 2015

EMC has acquired Virtustream, a Infrastructure as a Service (IaaS) provider originally funded among the others from SAP for 1.2 billion US dollars. Virtustream also provides a Cloud Management Platform…

 
Monthly Archive