The Impact Of Switching To Linux 4.3 + Mesa-11.1/LLVM-3.8 On Ubuntu 15.10
The Linux 4.3 kernel was obtained from the Ubuntu Mainline Kernel archive while the new Mesa 11.1-devel and LLVM 3.8 SVN stack is from this Launchpad PPA providing the very latest Mesa/LLVM support. It's sad that with Ubuntu 15.10, their Mesa 11.0 build is against LLVM 3.6 which means there isn't OpenGL 4.0/4.1 support with the AMD RadeonSI Gallium3D driver for all Ubuntu users with a Radeon HD 7000 series graphics card or newer. Fortunately, using the aforementioned PPA makes it easy to tap the latest Mesa code while having a supported AMDGPU LLVM back-end for the necessary GL4 requirements.
Below are some of the results of Ubuntu 15.04 vs. Ubuntu 15.10 vs. Ubuntu 15.10 + Linux 4.3 + Mesa 11.1-dev with LLVM 3.8 SVN.