Panfrost DRM client usage stats implementation¶

The drm/Panfrost driver implements the DRM client usage stats specification asdocumented inDRM client usage stats.

Example of the output showing the implemented key value pairs and entirety ofthe currently possible format options:

::

pos: 0flags: 02400002mnt_id: 27ino: 531drm-driver: panfrostdrm-client-id: 14drm-engine-fragment: 1846584880 nsdrm-cycles-fragment: 1424359409drm-maxfreq-fragment: 799999987 Hzdrm-curfreq-fragment: 799999987 Hzdrm-engine-vertex-tiler: 71932239 nsdrm-cycles-vertex-tiler: 52617357drm-maxfreq-vertex-tiler: 799999987 Hzdrm-curfreq-vertex-tiler: 799999987 Hzdrm-total-memory: 290 MiBdrm-shared-memory: 0 MiBdrm-active-memory: 226 MiBdrm-resident-memory: 36496 KiBdrm-purgeable-memory: 128 KiB

Possibledrm-engine- key names are:fragment, andvertex-tiler.drm-curfreq- values convey the current operating frequency for that engine.

Users must bear in mind that engine and cycle sampling are disabled by default,because of power saving concerns.fdinfo users and benchmark applications whichquery the fdinfo file must make sure to toggle the job profiling status of thedriver by writing into the appropriate sysfs node:

echo <N> > /sys/bus/platform/drivers/panfrost/[a-f0-9]*.gpu/profiling

WhereN is either0 or1, depending on the desired enablement status.