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

DRM Base PRIME Support Part Of VGEM Work

X.Org

Published on 23 February 2012 07:44 AM EST
Written by Michael Larabel in X.Org
1 Comment

Remember the proof of concept PRIME multi-GPU rendering / GPU offloading work that was being hacked on two years ago? Work on it has been resurrected and could make it into the kernel when the VGEM driver is ready.

David Airlie was the one that began work on PRIME in 2010 and in H2'2011 he restarted work on PRIME after re-basing it on the new DMA-BUF infrastructure. The kernel PRIME implementation shares a DRI2 front pixmap between devices/drivers and also sharing a pixmap that the rendering GPU copies dirty updates to and the "GPU output slaves" use that as their scan-out pixmap.

Dave's latest use-case for PRIME has been GPU hot-plugging support, such as when using the interesting USB-based DisplayLink devices.

Hitting the dri-devel mailing list yesterday was an updated patch-set for VGEM, the Virtual GEM Provider for the Linux kernel DRM, as VGEM Prime (dma-buf) . This is the new fake DRM driver to do some "fake" GEM memory management within the kernel. It's quite interesting and could be used by the Gallium3D LLVMpipe driver (among other clients) for potentially enhancing its software-accelerated performance. From my earlier article, "This VGEM driver would then just allocate a shadow frame-buffer while in certain cases like dealing with virtualization the front-buffer could be bound directly to a GEM object, which would eliminate a memory copy and slightly better the performance."

As part of this third revision to the VGEM patch-set is patch one, which is titled "drm: base prime support." Ben Widawsky is the one that's been working on VGEM lately while Adam Jackson (the original VGEM author) has been busy with other Red Hat chores. The base PRIME support patch is David Airlie's code that lays the foundation for PRIME in the Linux kernel.

Besides adding the base PRIME support with its new ioctls and other changes, the VGEM driver hooks into it with import and export support. This would allow for the "fake" driver to then play with other PRIME-enabled drivers/hardware. Ben Widawsky also has plans for checking out the Intel PRIME support work too. From Ben, "After getting feedback on what I have now, I will incorporate Dave's earlier work on i915 prime, and get some better test cases going."

Ben Widawsky has been working on the VGEM driver as a way to further the DMA-BUF happenings. "In addition's to Adam's requirements below, I would like to use VGEM to help support dma-buf development. VGEM is without quirks and makes both development and debug of other importers and exporters substantially easier."

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. AMD FX-8320E Performance On Linux
  2. Linux Compiler Benchmarks Of LLVM Clang 3.5 vs. LLVM Clang 3.6-rc1
  3. Intel Broadwell HD Graphics 5500: Windows 8.1 vs. Linux
  4. Linux Benchmarks Of NVIDIA's Early 2015 GeForce Line-Up
  5. NVIDIA GeForce GTX 960: A Great $200 GPU For Linux Gamers
  6. Disk Encryption Tests On Fedora 21
Latest Linux News
  1. Wine Staging Update Has Better CUDA Support, Driver Testing Framework
  2. Nouveau In Linux 3.20 Will Have A Lot Of Code Cleaning
  3. Compare Your Linux System To The i7-5600U Broadwell X1 Carbon ThinkPad
  4. Debian 8.0 "Jessie" Installer RC1 Released
  5. Chromebook "Rush" With 64-bit Tegra SoC Support Lands In Coreboot
  6. 2015 X.Org Elections Get Underway For Board Members, SPI Merger
  7. Linux 3.19-rc6 Kernel Released: LInux 3.19 Final In Two Weeks
  8. Ubuntu's Mir Gains Server-Side Platform Probing
  9. Broadwell Linux Ultrabook Running MUCH Cooler Than Haswell
  10. LZHAM 1.0 Lossless Data Compression Codec Released
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. Interstellar Marines On Linux With Catalyst: Bull S*#@