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

Shader Optimizations Greatly Speed-Up Wayland

Wayland

Published on 23 August 2012 08:56 AM EDT
Written by Michael Larabel in Wayland
2 Comments

Rob Clark, the Texas Instruments developer known for his work on the OMAP DRM driver, DMA-BUF, and hacking a Qualcomm open-source driver in his spare time, has been dabbling with Wayland. Rob's done some optimizations and simplifications to shaders used by Wayland's Weston reference compositor that greatly improve the performance.

With a patch posted under an "RFC" (Request For Comments) flag on the Wayland development list for Weston, he's optimized and simplified some shaders used by the Wayland compositor. When trying to run Wayland on a small SoC GPU like the TI OMAP4 PandaBoard at 1080p, Rob Clark can now obtain 60 FPS while pushing around windows. When pushing YUV buffers for hardware-accelerated decode of 1080p videos he gets 30 FPS. These numbers are compared to below 30 FPS and about 6 FPS, respectively, before writing these optimized shaders. This work should benefit all Weston users, but especially those on mobile/embedded hardware with less-powerful graphics processors.
Re-work how the shaders and emitted vertices work. Rather than always rendering clip-rect sized quads and doing transformation in tex coords (and requiring the corresponding clipping in frag shader), instead emit transformed vertices, clipped wrt. dirty region, and use simpler frag shaders. Also, split the rendering, so blended surfaces with an opaque region have the opaque region drawn with blend disabled. The result is considerably fewer pixels drawn with blend enabled, and much fewer cycles in the frag shader.

This requires having some more complex logic to figure out the vertices of the shape which forms the intersection of the clip rect and the transformed surface. Which has perhaps got a few bugs or missing cases, still (visual glitches in some cases) but at this point more or less is starting to work. I think it is at least far enough along to get some initial review.

The result, on small SoC GPU (omap4/pandaboard) on 1920x1080 display, for simple stuff like moving windows around, I get 60fps (before 30fps or less), and pushing YUV buffers for hw decoded 1080p video goes from ~6fps to 30fps, with no drop in framerate for transformed/rotated video surface.

TODO: compositor-wayland also needs to be updated..
Rob Clark will be speaking next week in San Diego, which will be covered on Phoronix.

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. 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. New Group Calls For Boycotting Systemd
  2. The Features To Find With The Imminent Release Of LLVM/Clang 3.5
  3. Borderlands 2 Is Coming To Linux
  4. The Witcher 2 Ups The Performance More & Works Around Catalyst Bug
  5. Running Gallium3D's LLVMpipe On The Eight-Core 5GHz CPU
  6. Trying Intel OpenCL On Linux For Video Encoding
  7. GSoC 2014 Yielded Some Improvements For Mesa/X.Org This Year
  8. webOS Lives On As LuneOS With New Release
  9. Marek Lands Radeon Gallium3D HyperZ Improvements
  10. Mozilla Firefox 32 Surfaces With HTML5, Developer Changes
Latest Forum Discussions
  1. Lennart Poettering Talks Up His New Linux Vision That Involves Btrfs
  2. nv and xorg.conf under Debian PPC
  3. AMD graphics doesn't work with AMD Catalyst drivers
  4. Best Radeon for a Power Mac G5?
  5. The dangers of Linux kernel development
  6. Updated and Optimized Ubuntu Free Graphics Drivers
  7. AMD Releases UVD Video Decode Support For R600 GPUs
  8. SSD seems slow