AMDGPU Submits LRU Bulk Moves Support As A Linux 5.4 "Fix" For Better Performance

While initially queued as a work-in-progress feature for Linux 5.5, AMD has now submitted a batch of "fixes" to the current Linux 5.4 cycle that include enabling of the LRU bulk moves performance-boosting functionality.

Just last week that revert / enabling of LRU bulk moves for AMDGPU was queued in the 5.5 "WIP" branch while on Wednesday it was mailed in as part of the "fixes" targeting the current Linux 5.4 cycle now past its merge window. LRU bulk moves can yield some measurable performance wins for multiple types of workloads but was disabled previously over bugs that were corrected back in Linux 5.0 but then seemingly lost track of with the feature only coming up for re-enabling as of this summer.

There was talk in September of re-enabling LRU bulk moves now that those fixes have settled. A Valve developer also chimed in with how great LRU bulk moves are for demanding Linux games.

So to much excitement, it's great seeing this enablement sent in as a "fix" for Linux 5.4 to help with demanding Linux games as well as OpenCL on Radeon GPUs.

Besides enabling bulk moves, the pull also re-enables stutter mode support for Renoir APUs, provides power metric fixes for Navi, addresses an S4 regression, and has other genuine fixes.

Once this pull lands, Linux 5.4 + Mesa 19.3 Radeon benchmarks are certainly in order.