1. Computers
  2. Display Drivers
  3. Graphics Cards
  4. Memory
  5. Motherboards
  6. Processors
  7. Software
  8. Storage
  9. Operating Systems


Facebook RSS Twitter Twitter Google Plus


Phoronix Test Suite

OpenBenchmarking.org

Awkward Linux Power Management With Xen

Michael Larabel

Published on 21 November 2011
Written by Michael Larabel
Page 1 of 6 - 7 Comments

If you happen to be running a Linux system with Xen support enabled, beware there may be odd behavior with the Linux kernel's power management -- it can easily move in either direction.

Following the publishing of the Xen vs. KVM vs. VirtualBox virtualization benchmarks published last month on Phoronix, a reader had noted something quite interesting within the forums.

"I am currently writing my master's thesis about virtualization and I've been running Xen and KVM tests among other things. I've had similar results with Xen being quite slow - for example, its raw CPU speed in LINPACK test was only 90 % that of HW or KVM (which were very close). I've been using Ubuntu 10.04 and vanilla 3.0.0 kernel in my tests. Just yesterday I did a test with Xen Dom0 kernel 2.6.32.46 and for example the LINPACK result jumped to on par with the hardware. I've measured other quite interesting results also - for example Xen's idle power consumption was like 30 % higher with kernel 3.0.0. It really seems there's something badly wrong in the 3.0.0 kernel with Xen. Next, I'll try running my tests with the 3.2 release candidate kernel to see if things have changed."

In particular, his comment about Xen's power consumption being 30% higher than the normal kernel was found to be quite interesting. Upon running my own set of tests, I too have found that when Xen Dom0 support is present the Linux kernel power management is quite awkward. However, it is not always for the worse.

This testing is looking at the power management between the vanilla Linux kernel and when the Linux kernel is booted with the Xen Hypervisor support enabled, but not looking when running any DomU guests or other changes. It is simply looking at the performance on the host with and without Xen support.

The first Xen 4.1 power usage monitoring tests was done from an Intel Core i5 2520M "Sandy Bridge" Hewlett-Packard notebook.

<< Previous Page
1
Latest Linux Hardware Reviews
  1. AMD Launches New FX CPUs, Cuts Prices On Existing Processors
  2. Preview: AMD's FX-9590 Eight-Core At Up To 5.0GHz On Linux
  3. Intel Launches The Core i7 5960X, Mighty Powerful Haswell-E CPUs
  4. AMD Radeon R9 290: Gallium3D vs. Catalyst Drivers
Latest Linux Articles
  1. Ondemand vs. Performance CPU Governing For AMD FX CPUs On Linux 3.17
  2. How Intel Graphics On Linux Compare To Open-Source AMD/NVIDIA Drivers
  3. The Fastest NVIDIA GPUs For Open-Source Nouveau With Steam Linux Gaming
  4. Testing For The Latest Linux Kernel Power Regression
Latest Linux News
  1. GSoC 2014 Yielded Some Improvements For Mesa/X.Org This Year
  2. webOS Lives On As LuneOS With New Release
  3. Marek Lands Radeon Gallium3D HyperZ Improvements
  4. Mozilla Firefox 32 Surfaces With HTML5, Developer Changes
  5. Nouveau X.Org Driver Released With DRI3+Present, Maxwell, GLAMOR
  6. Microsoft & AMD Release C++ AMP Compiler With Linux Support
  7. AMD, Wine & Valve Dominated August For Linux Users
  8. Linux 3.17-rc3 Kernel Released Back On Schedule
  9. Lennart Poettering Talks Up His New Linux Vision That Involves Btrfs
  10. Mesa 10.3 RC2 Arrives Via Its New Release Manager
Latest Forum Discussions
  1. Lennart Poettering Talks Up His New Linux Vision That Involves Btrfs
  2. AMD graphics doesn't work with AMD Catalyst drivers
  3. Best Radeon for a Power Mac G5?
  4. The dangers of Linux kernel development
  5. Updated and Optimized Ubuntu Free Graphics Drivers
  6. AMD Releases UVD Video Decode Support For R600 GPUs
  7. SSD seems slow
  8. Is laptop with Intel CPU and AMD dGPU worth buying considering especially AMD Enduro?