TTM Multihop + Intel Keem Bay Display Support Queued For Linux 5.11

The Translation Table Maps (TTM) video memory management code used within the Linux kernel by DRM drivers such as Nouveau and Radeon/AMDGPU is seeing some improvements with the forthcoming Linux 5.11 kernel cycle.

Covered last week was new TTM allocator code being merged to DRM-Next ahead of December's Linux 5.11 merge window. That new TTM page allocator code can yield 3~5x faster page allocations though it's looking like the real-world impact will be minimal at least from the AMD tests thus far.

The newest TTM improvement now set for DRM-Next by way of DRM-Misc-Next is the TTM Multihop code. TTM Multihop is about improving GPU buffer management when moving between system RAM to/from vRAM. This TTM Multihop work cleans up a lot of driver-specific TTM code and lets the TTM memory management infrastructure handle some of the temporary moves across address spaces. TTM Multihop was led by Red Hat's David Airlie.

Multihop was sent in thus morning as part of the latest drm-misc-next. The other notable feature with this pull is Intel Keem Bay display support.

Since early in the year Intel has been working on Linux support for Keem Bay as the next-gen Movidius VPU. That work includes the "KMB" DRM driver for display support for this SoC with an ARM CPU and Movidius VPU. For Linux 5.11 the Intel Keem Bay display support appears ready to go. KMB provides a basic KMS atomic mode-setting driver for these SoCs -- it's purely display with no 2D/3D graphics support.