Vulkan overlay layer - async compute not supported, making overlay disappear in Doom
Submitted by tem..@..il.com
Assigned to mes..@..op.org
The Vulkan overlay layer doesn't work with async compute on GCN/RDNA and probably neither Nvidia Turing GPUs, it simply disappears. To reproduce, start Doom on any Radeon (driver shouldn't matter) in Steam Play and set it to Vulkan with Ultra preset and 8xTSSAA: When in the actual game, the Mesa overlay will simply disappear. When changing anti aliasing to FXAA, async compute is turned off and the Mesa overlay gets visible again.
On windows, overlays like that of Steam (the overlay of the Linux version for some reason shares the traits of Mesa overlay) or RTSS disable presenting frames from a compute queue. This makes them work, but degrades performance substantially.
The windows open source tool OCAT supports an overlay for Vulkan that is compatible with async compute and doesn't degrade performance: https://ocat.readthedocs.io/en/latest/index.html
Tested with mesa-git some weeks ago.