PMU provides two counters (engine-active-ticks, engine-total-ticks)
to calculate engine activity. When querying engine activity,
user must group these 2 counters using the perf_event
group mechanism to ensure both counters are sampled together.
To list the events
./perf list
xe_0000_03_00.0/engine-active-ticks/ [Kernel PMU event]
xe_0000_03_00.0/engine-total-ticks/ [Kernel PMU event]
The formats to be used with the above are
engine_instance - config:12-19
engine_class - config:20-27
gt - config:60-63
The events can then be read using perf tool
./perf stat -e xe_0000_03_00.0/engine-active-ticks,gt=0,
engine_class=0,engine_instance=0/,
xe_0000_03_00.0/engine-total-ticks,gt=0,
engine_class=0,engine_instance=0/ -I 1000
Engine activity can then be calculated as below
engine activity % = (engine active ticks/engine total ticks) * 100
v2: validate gt
rename total-ticks to engine-total-ticks
add helper to get hwe (Umesh)
v3: fix checkpatch warning
add details to documentation (Umesh)
remove ascii formats from documentation (Lucas)
v4: remove unnecessary warn within raw_spinlock (Lucas)
Signed-off-by: Riana Tauro <riana.tauro@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250224053903.2253539-5-riana.tauro@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
6978c5f5a6