Raspberry Pi V3D Driver Gaining Per-Process GPU Usage Stats

Maíra Canal with Igalia has sent out a set of patches for exposing GPU usage statistics for the Broadcom graphics processor found within the Raspberry Pi 4 single board computers.

Last week Igalia sent out the latest patches for exposing GPU usage statistics with the V3D DRM kernel driver both on a global GPU usage basis as well as on a per-file descriptor basis for seeing specific application usage of the GPU. Maíra explained with the patches:

The first patch exposes the accumulated amount of active time per client through the fdinfo infrastructure. The amount of active time is exposed for each V3D queue. Moreover, it exposes the number of jobs submitted to each queue.

The second patch exposes the accumulated amount of active time for each V3D queue, independent of the client. This data is exposed through the sysfs interface.

With these patches, it is possible to calculate the GPU usage percentage per queue globally and per-file descriptor.

The patches are now under review for hopefully merging soon for this useful functionality to expose the GPU usage via sysfs.

This is similar in nature to what Intel has done with their i915 kernel graphics driver for exposing per-client GPU usage statistics.