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 Benchmarking Platform
Phoromatic Test Orchestration

Radeon VM, DMA-BUF Will Go Into Linux 3.3 Kernel

Linux Kernel

Published on 06 January 2012 01:05 PM EST
Written by Michael Larabel in Linux Kernel
6 Comments

The Radeon virtual memory (VM) support -- part of the Radeon HD 7000 series upbringing -- is now in the DRM next tree for landing in the Linux 3.3 kernel. Separate from the expected 3.3 graphics pull request, Linaro's "dma-buf" has already been sent to Linus Torvalds for merging into the mainline tree.

As talked about earlier today and mentioned before by AMD's John Bridgman, there's invasive Radeon DRM changes coming as part of the Radeon HD 7000 series support upbringing due to the radically new "Southern Islands" / GCN (Graphics Core Next) architecture. Bridgman noted on the Phoronix Forums that the memory patches might come out in early January and last night the virtual memory patches did, which Bridgman confirmed.

The Radeon GPU virtual memory support is invasive and touches more than one thousand lines of code and has already undergone twenty-two revisions before merging. With this work being invasive and the 3.3 merge window only being open for the next two weeks, the code was quick to land and today can now be found in Airlie's tree so it will be part of the Linux 3.3 kernel. But there's still a lot more work left (and the clearing of legal review) before there is open-source Radeon HD 7000 series support available to Linux desktop users.

What was sent into Linus Torvalds this morning by David as separate from the DRM work is the "dma-buf" work that's been worked on by Linaro developers, DRM developers, and other kernel stakeholders for the past several months. This work provides a buffer sharing mechanism for Linux kernel drivers. The ARM SoC vendors have mostly been after this work to design drivers better fitting their hardware designs and being able to share buffers between various drivers such as for V4L, DRM, and fbdev sub-systems.

There's no major users of dma-buf quite yet, but now that it's mainline, by the Linux 3.4 kernel it's expected that it will be utilized. It's also possible dma-buf may be helpful down the road in multi-GPU Linux driver support for buffer sharing. This buffer sharing mechanism is just for the kernel drivers and doesn't expose any interfaces to user-space.

The dma-buf work amounts to about 700 lines of code. The pull request for this code can be found on the mailing list.

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 News
  1. NVIDIA Tegra X1 Chromebooks Appear Closer, Support Added To Coreboot
  2. Pinos Is For Linux Video What PulseAudio Is For Audio
  3. Crossing 200,000 Benchmark Results Posted On LinuxBenchmarking.com
  4. New Mesa Vec4 Backend For Intel, Supports Their NIR Goals
  5. "PulseVideo" Coming To Complement PulseAudio?
  6. Premium Users Now Can Experience Our New Site
  7. XFS Will Get DAX Support In The Linux 4.2 Kernel
  8. X.Org Server Lands More Mode-Setting/GLAMOR Improvements, But No Sign Of 1.18
  9. Linux Mint 17.2 Officially Released With Cinnamon/MATE Flavors
  10. Fedora For MIPS Is Now Out In Testing, Supports The Creator CI20
Latest Articles & Reviews
  1. How KDE VDG Is Trying To Make Open-Source Software Beautiful
  2. Attempting To Try Out BCache On The Linux 4.1 Kernel
  3. CompuLab's Fitlet Is A Very Tiny, Fanless, Linux PC With AMD A10 Micro
  4. AMD A10-7870K Godavari: RadeonSI Gallium3D vs. Catalyst Linux Drivers
Most Viewed News This Week
  1. Kubuntu 15.10 Could Be The End Of The Road
  2. Linus Is Looking Forward To Merging KDBUS, But Not Convinced By Performance
  3. NVIDIA Starts Supplying Open-Source Hardware Reference Headers
  4. KDBUS Won't Be Pushed Until The Linux 4.3 Kernel
  5. Linux 4.2 Kernel Gets Port To New Processor Architecture
  6. The Staging Pull For Linux 4.2: "Big, Really Big"
  7. The State & Complications Of Porting The Unity Editor To Linux
  8. SteamOS "Brewmaster" Is Valve's New Debian 8.1 Based Version