AMD Working To Allow Linux To Handle Up To 128 DRM Devices Per System

AMD Linux engineers are working on extending the Direct Rendering Manager (DRM) subsystem used by their GPUs/accelerators to allow up to 128 DRM devices per system.

Currently there ends up being a hard-coded limit of 64 DRM devices per system but AMD has volleyed a patch to double that limit to 128. The patch simply notes, "This makes room for up to 128 DRM devices."

It's not clear of AMD's motivation for making a 128 DRM device limit per system whether it's for some inter-connected supercomputer/cluster type setup via CXL or for sub-partitioning a smaller set of actual GPUs/accelerators for shared/VM type usage scenario or what exactly is leading them to raising this 64 to 128 DRM device limit.

It's been noted though that this may potentially break the ABI / user-space compatibility. In any case we'll see how raising this limit is ultimately carried out and if future discussions reveal any further insight to AMD wanting to double this device limit.