drm: Document fdinfo format specification
authorTvrtko Ursulin <tvrtko.ursulin@intel.com>
Fri, 1 Apr 2022 14:22:03 +0000 (15:22 +0100)
committerTvrtko Ursulin <tvrtko.ursulin@intel.com>
Tue, 5 Apr 2022 07:39:15 +0000 (08:39 +0100)
commit2d12d3da5374433d44692a8681417bc7c424439b
tree317c772318a14fdea553788f4954927b94074cb6
parentbb6287cb18866e49501da5c92a130830db6f5a18
drm: Document fdinfo format specification

Proposal to standardise the fdinfo text format as optionally output by DRM
drivers.

Idea is that a simple but, well defined, spec will enable generic
userspace tools to be written while at the same time avoiding a more heavy
handed approach of adding a mid-layer to DRM.

i915 implements a subset of the spec, everything apart from the memory
stats currently, and a matching intel_gpu_top tool exists.

Open is to see if AMD can migrate to using the proposed GPU utilisation
key-value pairs, or if they are not workable to see whether to go
vendor specific, or if a standardised  alternative can be found which is
workable for both drivers.

Same for the memory utilisation key-value pairs proposal.

v2:
 * Update for removal of name and pid.

v3:
 * 'Drm-driver' tag will be obtained from struct drm_driver.name. (Daniel)

v4:
 * Added drm-engine-capacity- tag.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: David M Nieto <David.Nieto@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Daniel Stone <daniel@fooishbar.org>
Cc: Chris Healy <cphealy@gmail.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220401142205.3123159-7-tvrtko.ursulin@linux.intel.com
Documentation/gpu/drm-usage-stats.rst [new file with mode: 0644]
Documentation/gpu/index.rst