Ahead of the Linux 7.2 kernel release expected out on Sunday, the Direct Rendering Manager (DRM) subsystem was forced to revert their "fair" scheduler policy default new for this kernel. Due to a last minute user-reported regression, FIFO returns as the default DRM scheduler policy for Linux 7.2. But patches are now available for addressing that regression and thus hopefully for Linux 7.3 there will be the fair scheduler becoming the default.

Igalia engineer Tvrtko Ursulin has been working through the regression reported by Luke Wildhardt over poor performance on the Radeon RX 9070 XT when using the fair scheduler policy with Linux 7.2. With two patches changing less than one hundred lines of code, the current belief is the regression is now resolved.

Ursulin commented today with the patch series fixing the DRM scheduler fair policy:

"Many thanks to Luke for reporting, sharing one AI proposed fix, and the super quick testing turnaround!

After these two we can hopefully work at promoting the "fair" policy back to the default in an upcoming kernel release, followed by removing the FIFO and round-robin, and then re-applying the code base simplifications which we had to temporarily revert."

We'll see if this default change back to DRM fair manages to happen for the imminent Linux 7.3 merge window. In any case great seeing this code fixed with DRM fair showing nice results on the Steam Deck and an overall win for GPU clients.