The L3 finding on Linux is likely caused by the C3 entry cache flush, which goes away in our upcoming 6.1 kernel. It doesn't affect most game workloads but can be a real performance problem in some specific cases.
For those that don't know (like me, three minutes ago) gamescope [1] is a Wayland compositor custom-written for games (and, I believe, what the Steam Deck uses). it's open source, and under the "BSD 2-clause" license.
It seems to be a conversation where Deepak Sharma talks about needing to resubmit a patch (and a follow up patch), rather than be the submitted patches themselves.
Cool. Can I ask why does valve/steamdeck use Gamescope and not Wayland?
To my very limited understanding they both target to do more or less the same thing, and I think we have enough fragmentation in the Linux ecosystem as it is, so to my uninitiated brain it would have seemed logical to put al that development effort in improving Wayland for the steamdeck instead of building another compositor.
Wayland is just a protocol. GNOME and KDE both use their own Wayland compositors for example. Gamescope as a gaming focused Wayland compositor probably has more emphasis on things like latency than other compositors.
https://lore.kernel.org/lkml/CAJZ5v0jWX=H=aZ25PzHdH05bRJvtYb...
The way the benchmark works likely triggers it consistently.