AMD Lands Fiji Support & Initial AMDGPU Scheduler For Linux 4.3
The first change up for the improved AMD open-source graphics driver code in Linux 4.3 is AMD R9 Fury "Fiji" support. AMD just published the initial Fiji GPU support recently and with Linux 4.3 the kernel-side work will land while in user-space you'll need to be riding Mesa 11.0 plus LLVM 3.7/SVN. Like with Tonga, Fiji on the AMDGPU driver right now still doesn't support power management / re-clocking thus the performance will be slower than Catalyst. However, I'll still run some AMD R9 Fury open-source benchmarks on Linux 4.3.
Common Graphics Services for AMDGPU (CGS) is another new improvement with Linux 4.3 as outlined in that earlier article.
The initial GPU scheduler code for the AMDGPU driver but that scheduler is currently disabled by default. That article explains the new scheduler and also from the forum comments there. Bridgman had explained, "This is more for OpenGL workloads (and compute going through kernel graphics driver I guess). The HSA stack uses a hardware-based scheduler, but the primary purpose of that scheduler is to provide support for an arbitrary number of user-space compute rings. The kernel graphics driver doesn't need that because it uses a single kernel ring and allows multiple processes to take turns submitting to it. The GPU scheduler Alex just posted basically maintains a number of kernel rings that are not connected directly to the hardware, and feeds work from those rings into that 'single kernel ring' which the HW pulls from."
Aside from that, there's also various bug-fixes and optimizations. If you're an owner of a non-Carrizo/Tonga/Fiji GPU not on AMDGPU, there doesn't appear to be too much to get excited about for the Linux 4.3 with the primary efforts right now by AMD developers being focused on bringing up to speed the next-gen AMDGPU stack. At least when it comes to user-space that support is shared with RadeonSI Gallium3D in the upcoming Mesa 11.0.
The list of AMD changes for DRM-Next for Linux 4.3 can be found via this Git merge. As always, I'll have benchmarks of this new code in due time plus there's also all of the daily kernel Git benchmarks being done seven days a week at LinuxBenchmarking.com.