Le 03/07/2024 à 12:46, Lucas Stach a écrit :
Am Freitag, dem 14.06.2024 um 10:16 +0200 schrieb Pierre-Eric Pelloux-
Prayer:
This commit adds a document section in drm-uapi.rst about tracepoints,
and mark the events gpu_scheduler_trace.h as stable uAPI.
The goal is to explicitly state that tools can rely on the fields,
formats and semantics of these events.
Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@xxxxxxx>
---
Documentation/gpu/drm-uapi.rst | 19 ++++++++++++++++
.../gpu/drm/scheduler/gpu_scheduler_trace.h | 22 +++++++++++++++++++
2 files changed, 41 insertions(+)
diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst
index 370d820be248..78496793a8f0 100644
--- a/Documentation/gpu/drm-uapi.rst
+++ b/Documentation/gpu/drm-uapi.rst
@@ -570,3 +570,22 @@ dma-buf interoperability
Please see Documentation/userspace-api/dma-buf-alloc-exchange.rst for
information on how dma-buf is integrated and exposed within DRM.
+
+
+Trace events
+============
+
+See Documentation/trace/tracepoints.rst for the tracepoints documentation.
+In the drm subsystem, some events are considered stable uAPI to avoid
+breaking tools (eg: gpuvis, umr) relying on them. Stable means that fields
+cannot be removed, nor their formatting updated. Adding new fields is
+possible, under the normal uAPI requirements.
What are those "normal uAPI requirements" in this context? Aside from
not being able to remove or change any fields?
The ones from
https://dri.freedesktop.org/docs/drm/gpu/drm-uapi.html#open-source-userspace-requirements
For the trace events, the sentence "patches must be reviewed and ready
for merging into a suitable and canonical upstream project" could be
read as "gpuvis patches must be reviewed and ready for merging".
Thanks,
Pierre-Eric
Regards,
Lucas
+
+Stable uAPI events
+------------------
+
+From ``drivers/gpu/drm/scheduler/gpu_scheduler_trace.h``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
+ :doc: uAPI trace events
\ No newline at end of file
diff --git a/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h b/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
index 0abcad26839c..63113803cdd5 100644
--- a/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
+++ b/drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
@@ -33,6 +33,28 @@
#define TRACE_SYSTEM gpu_scheduler
#define TRACE_INCLUDE_FILE gpu_scheduler_trace
+
+/**
+ * DOC: uAPI trace events
+ *
+ * ``drm_sched_job``, ``drm_run_job``, ``drm_sched_process_job``,
+ * and ``drm_sched_job_wait_dep`` are considered stable uAPI.
+ *
+ * Common trace events attributes:
+ *
+ * * ``id`` - this is &drm_sched_job->id. It uniquely idenfies a job
+ * inside a &struct drm_gpu_scheduler.
+ *
+ * * ``dev`` - the dev_name() of the device running the job.
+ *
+ * * ``ring`` - the hardware ring running the job. Together with ``dev`` it
+ * uniquely identifies where the job is going to be executed.
+ *
+ * * ``fence`` - the &dma_fence.context and the &dma_fence.seqno of
+ * &drm_sched_fence.finished
+ *
+ */
+
#ifndef __TRACE_EVENT_GPU_SCHEDULER_PRINT_FN
#define __TRACE_EVENT_GPU_SCHEDULER_PRINT_FN
/* Similar to trace_print_array_seq but for fences. */
