AMD Makes Progress On Their RDNA3 User-Mode Queues For Linux Driver


Just prior to Christmas there was a «request for comments» (RFC) patch series sent out working on RDNA3 user-mode queue support for their AMDGPU kernel driver. That work has now advanced post-RFC with an updated patch series having been sent out on Friday.

This RDNA3 user-mode queue support for their Linux driver is around allowing the direct workload submission from user-space for processes with an AMDGPU graphics context. This direct workload submission could lead to better performance/throughput especially for cases like exclusive/full-screen games and bypass interactions with the kernel/DRM schedulers. The user-space application with this new code allows creating its own work queue and submitting directly to the graphics hardware.

RX 7900 XT

The patch series depends upon a re-design to the AMDGPU doorbell code that is still pending — though there are some admitted «hack» patches available for easier testing until those other changes land. But in any event given the timing of these patches this work isn’t coming for the v6.3 kernel but will not be ready for mainline until v6.4 or later.

AMDGPU user-mode queue approach

Those interested in this user-mode queue work for the AMDGPU driver can find the new patches on the amd-gfx mailing list.