1 commit

Author	SHA1	Message	Date
Ian Rogers	28917cb17f	perf drm_pmu: Add a tool like PMU to expose DRM information ... DRM clients expose information through usage stats as documented in Documentation/gpu/drm-usage-stats.rst (available online at https://docs.kernel.org/gpu/drm-usage-stats.html). Add a tool like PMU, similar to the hwmon PMU, that exposes DRM information. For example on a tigerlake laptop: ``` $ perf list drm List of pre-defined events (to be used in -e or -M): drm: drm-active-stolen-system0 [Total memory active in one or more engines. Unit: drm_i915] drm-active-system0 [Total memory active in one or more engines. Unit: drm_i915] drm-engine-capacity-video [Engine capacity. Unit: drm_i915] drm-engine-copy [Utilization in ns. Unit: drm_i915] drm-engine-render [Utilization in ns. Unit: drm_i915] drm-engine-video [Utilization in ns. Unit: drm_i915] drm-engine-video-enhance [Utilization in ns. Unit: drm_i915] drm-purgeable-stolen-system0 [Size of resident and purgeable memory bufers. Unit: drm_i915] drm-purgeable-system0 [Size of resident and purgeable memory bufers. Unit: drm_i915] drm-resident-stolen-system0 [Size of resident memory bufers. Unit: drm_i915] drm-resident-system0 [Size of resident memory bufers. Unit: drm_i915] drm-shared-stolen-system0 [Size of shared memory bufers. Unit: drm_i915] drm-shared-system0 [Size of shared memory bufers. Unit: drm_i915] drm-total-stolen-system0 [Size of shared and private memory. Unit: drm_i915] drm-total-system0 [Size of shared and private memory. Unit: drm_i915] ``` System wide data can be gathered: ``` $ perf stat -x, -I 1000 -e drm-active-stolen-system0,drm-active-system0,drm-engine-capacity-video,drm-engine-copy,drm-engine-render,drm-engine-video,drm-engine-video-enhance,drm-purgeable-stolen-system0,drm-purgeable-system0,drm-resident-stolen-system0,drm-resident-system0,drm-shared-stolen-system0,drm-shared-system0,drm-total-stolen-system0,drm-total-system0 1.000904910,0,bytes,drm-active-stolen-system0,1,100.00,, 1.000904910,0,bytes,drm-active-system0,1,100.00,, 1.000904910,36,capacity,drm-engine-capacity-video,1,100.00,, 1.000904910,0,ns,drm-engine-copy,1,100.00,, 1.000904910,1472970566175,ns,drm-engine-render,1,100.00,, 1.000904910,0,ns,drm-engine-video,1,100.00,, 1.000904910,0,ns,drm-engine-video-enhance,1,100.00,, 1.000904910,0,bytes,drm-purgeable-stolen-system0,1,100.00,, 1.000904910,38199296,bytes,drm-purgeable-system0,1,100.00,, 1.000904910,0,bytes,drm-resident-stolen-system0,1,100.00,, 1.000904910,4643196928,bytes,drm-resident-system0,1,100.00,, 1.000904910,0,bytes,drm-shared-stolen-system0,1,100.00,, 1.000904910,1886871552,bytes,drm-shared-system0,1,100.00,, 1.000904910,0,bytes,drm-total-stolen-system0,1,100.00,, 1.000904910,4643196928,bytes,drm-total-system0,1,100.00,, 2.264426839,0,bytes,drm-active-stolen-system0,1,100.00,, ``` Or for a particular process: ``` $ perf stat -x, -I 1000 -e drm-active-stolen-system0,drm-active-system0,drm-engine-capacity-video,drm-engine-copy,drm-engine-render,drm-engine-video,drm-engine-video-enhance,drm-purgeable-stolen-system0,drm-purgeable-system0,drm-resident-stolen-system0,drm-resident-system0,drm-shared-stolen-system0,drm-shared-system0,drm-total-stolen-system0,drm-total-system0 -p 200027 1.001040274,0,bytes,drm-active-stolen-system0,6,100.00,, 1.001040274,0,bytes,drm-active-system0,6,100.00,, 1.001040274,12,capacity,drm-engine-capacity-video,6,100.00,, 1.001040274,0,ns,drm-engine-copy,6,100.00,, 1.001040274,1542300,ns,drm-engine-render,6,100.00,, 1.001040274,0,ns,drm-engine-video,6,100.00,, 1.001040274,0,ns,drm-engine-video-enhance,6,100.00,, 1.001040274,0,bytes,drm-purgeable-stolen-system0,6,100.00,, 1.001040274,13516800,bytes,drm-purgeable-system0,6,100.00,, 1.001040274,0,bytes,drm-resident-stolen-system0,6,100.00,, 1.001040274,27746304,bytes,drm-resident-system0,6,100.00,, 1.001040274,0,bytes,drm-shared-stolen-system0,6,100.00,, 1.001040274,0,bytes,drm-shared-system0,6,100.00,, 1.001040274,0,bytes,drm-total-stolen-system0,6,100.00,, 1.001040274,27746304,bytes,drm-total-system0,6,100.00,, 2.016629075,0,bytes,drm-active-stolen-system0,6,100.00,, ``` As with the hwmon PMU, high numbered PMU types are used to encode multiple possible "DRM" PMUs. The appropriate fdinfo is found by scanning /proc and filtering which fdinfos to read with stat. To avoid some unneeding scanning, events not starting with "drm-" are ignored. The patch builds on commit 57e13264dc ("perf pmus: Restructure pmu_read_sysfs to scan fewer PMUs") and later so that only if full wild carding is being done, the PMU starts with "drm_" or the event starts with "drm-" will /proc be scanned. That is there should be little to no cost in this PMU unless DRM events are requested. Signed-off-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20250624231837.179536-3-irogers@google.com Signed-off-by: Namhyung Kim <namhyung@kernel.org>	2025-06-25 11:12:35 -07:00