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

VBlank Timestamping Improvements Proposed

Intel

Published on 26 October 2013 05:40 PM EDT
Written by Michael Larabel in Intel
Comment On This Article

A set of Linux kernel patches have been proposed to improve vblank time-stamping by the Linux DRM/KMS drivers. This is able to improve the precision and reliability of the KMS drivers of time-stamps for handing VBlank support.

Mario Kleiner proposed a set of kernel patches that move latency-sensitive code of the VBlank time-stamping from DRM core and into the KMS drivers. Mario has tested this with the Intel and Radeon DRM drivers and for Intel KMS the changes have been of great improvement.

Since the Linux 3.11 kernel, vblank time-stamps for the Intel driver have been "too inaccurate" and also no longer works with a PREEMPT_RT kernel. These patches also restore support for handling DRM drivers with real-time Linux kernels.

The set of four kernel patches for improving vblank timestamps can be found via the dri-devel list. There's been some code review so far on the work but no word whether it will be ready for the Linux 3.13 kernel.

Mario noted that the time-stamp uncertainty for a low-end Atom netbook went from 3-8 micro-seconds with spikes greater than 20 micro-seconds to now typically being just one micro-second and then just occassionally 2 or 3 micro-seconds.

About The Author
Michael Larabel is the principal author of Phoronix.com and founded the web-site in 2004 with a focus on enriching the Linux hardware experience and being the largest web-site devoted to Linux hardware reviews, particularly for products relevant to Linux gamers and enthusiasts but also commonly reviewing servers/workstations and embedded Linux devices. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics hardware drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated testing software. He can be followed via and or contacted via .
Latest Linux Hardware Reviews
  1. Preview: AMD's FX-9590 Eight-Core At Up To 5.0GHz On Linux
  2. Intel Launches The Core i7 5960X, Mighty Powerful Haswell-E CPUs
  3. AMD Radeon R9 290: Gallium3D vs. Catalyst Drivers
  4. AMD Radeon R9 290 Open-Source Driver Works, But Has A Ways To Go
Latest Linux Articles
  1. How Intel Graphics On Linux Compare To Open-Source AMD/NVIDIA Drivers
  2. The Fastest NVIDIA GPUs For Open-Source Nouveau With Steam Linux Gaming
  3. Testing For The Latest Linux Kernel Power Regression
  4. The Most Energy Efficient Radeon GPU For AMD Linux Gaming
Latest Linux News
  1. Nouveau X.Org Driver Released With DRI3+Present, Maxwell, GLAMOR
  2. Microsoft & AMD Release C++ AMP Compiler With Linux Support
  3. AMD, Wine & Valve Dominated August For Linux Users
  4. Linux 3.17-rc3 Kernel Released Back On Schedule
  5. Lennart Poettering Talks Up His New Linux Vision That Involves Btrfs
  6. Mesa 10.3 RC2 Arrives Via Its New Release Manager
  7. Ubuntu 14.10's Lack Of X.Org Server 1.16 Gets Blamed On AMD
  8. MSI Motherboard BIOS Updating Remains A Pain For Linux Users
  9. See How Your Linux System Performs Against The Latest Intel/AMD CPUs
  10. AMD Steppe Eagle Flys To Coreboot
Latest Forum Discussions
  1. Lennart Poettering Talks Up His New Linux Vision That Involves Btrfs
  2. The dangers of Linux kernel development
  3. Updated and Optimized Ubuntu Free Graphics Drivers
  4. AMD Releases UVD Video Decode Support For R600 GPUs
  5. SSD seems slow
  6. Is laptop with Intel CPU and AMD dGPU worth buying considering especially AMD Enduro?
  7. Radeon HD5670 and Ubuntu 14.04
  8. Btrfs Gets Talked Up, Googler Encourages You To Try Btrfs