Well I can tell you that if it didn’t make it upstream Fedora didn’t ship it.
It looks there was a copr for a custom kernel-fsync and projects like Bazzite or Nobara are adding patches.
From my understanding the fsync patches were never upstreamed.
It looks there was a copr for a custom kernel-fsync and projects like Bazzite or Nobara are adding patches.
From my understanding the fsync patches were never upstreamed.
The point being that these massive speed gains will probably not be seen by most people as you suggest, because most Linux gamers already have access to either esync or fsync.
The Proton build is Valve's build. It supports both fsync and esync, the latter of which does not require a kernel patch. If you're gaming on Linux with Steam, you're probably already using it.
https://github.com/ValveSoftware/Proton/?tab=readme-ov-file#...