Mesa 23.0 initially integrated Vulkan’s VK_KHR_present_wait extension this week. Hans-Kristian Arntzen of the Valve Linux team and VKD3D-Proton agree that due to current specification constraints it can only be added via DriConf option, while the new extension can be done on a per-game/app basis Processing, so they all think this is a very “practical” extension.
VK_KHR_present_wait was added in Vulkan 1.2.185 last year but dates back to 2019. VK_KHR_present_wait was designed by Keith Packard (Keith Packard). This extension allows applications to use KHR_swapchain while waiting for the current operation to complete.
VK_KHR_present_wait can monitor and control the pacing of the application by the number of images not yet presented. This can greatly improve the frame rate of the game, and Valve may deploy this expansion on Steam Deck in the future.
The problem with the VK_KHR_present_wait specification right now is that it lacks a surface query to check each surface for its support. This extension was hidden behind a DriConf option until there was a present-wait capability to query support on a per-surface-type basis.
