Mesa 21.0 RadeonSI Will Run Counter-Strike: Global Offensive Faster
Mesa 21.0 with the RadeonSI driver for modern AMD Radeon graphics cards is finally enabling "mesa_glthread" by default for Counter-Strike: GO. This is the opt-in Mesa OpenGL threading behavior that can help increase the performance of various GL games but isn't universally enabled as it has been found to hurt some games or yield no benefits for others.
For the past several Mesa releases that the GL threading has been in good shape, users have found enabling it to boost the frame-rates by 10~20%. Thus Counter-Strike: Global Offensive is now whitelisted so it will happen there by default rather than needing to set the "mesa_glthread=true" environment variable override.
The patch flipping on GL threading for CS:GO also enables the clamp_div_by_zero workaround for the Valve game too. That is needed for fixing up a rendering bug.