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 Articles & Reviews
  1. Linux Compiler Benchmarks Of LLVM Clang 3.5 vs. LLVM Clang 3.6-rc1
  2. Intel Broadwell HD Graphics 5500: Windows 8.1 vs. Linux
  3. Linux Benchmarks Of NVIDIA's Early 2015 GeForce Line-Up
  4. NVIDIA GeForce GTX 960: A Great $200 GPU For Linux Gamers
  5. Disk Encryption Tests On Fedora 21
  6. Xonotic 0.8 Performance With The Open-Source AMD/NVIDIA Gallium3D Drivers
Latest Linux News
  1. Chromebook "Rush" With 64-bit Tegra SoC Support Lands In Coreboot
  2. 2015 X.Org Elections Get Underway For Board Members, SPI Merger
  3. Linux 3.19-rc6 Kernel Released: LInux 3.19 Final In Two Weeks
  4. Ubuntu's Mir Gains Server-Side Platform Probing
  5. Broadwell Linux Ultrabook Running MUCH Cooler Than Haswell
  6. LZHAM 1.0 Lossless Data Compression Codec Released
  7. LibreOffice 4.4 Is Coming Soon With New Features
  8. Linux Users Upset By Chromium's Busted HiDPI Support
  9. BPF Backend Merged Into LLVM To Make Use Of New Kernel Functionality
  10. Dying Light Is Headed To Linux, SteamOS
Most Viewed News This Week
  1. Windows 10 To Be A Free Upgrade: What Linux Users Need To Know
  2. Google Admin Encourages Trying Btrfs, Not ZFS On Linux
  3. TraceFS: The Newest Linux File-System
  4. My Initial Intel Broadwell Linux Experience With The ThinkPad X1 Carbon
  5. Mozilla's Servo Still On Track For 2015 Alpha Release
  6. Fedora 23 Likely To Pursue Wayland By Default
  7. Keith Packard Leaves Intel's Linux Graphics Work
  8. A Proposal To Go 64-bit Only With Fedora 23