[PATCH 0/8] drm/xe: GPU frequency tracing support

[Matthew Brost]

On Tue, Aug 19, 2025 at 12:04:09PM +0530, S Sebinraj wrote:
> A periodic GPU frequency monitoring and tracing program for the
> Xe driver. The implementation provides periodic sampling of
> GPU frequency through the Linux ftrace infrastructure.
> 
> Key features:
> - Periodic GPU frequency sampling with configurable intervals
> - Immediate frequency change reporting via tracepoints
> - Integration with Linux ftrace subsystem under 'power' events
> - Per-GT (Graphics Technology) monitoring support
> - Dedicated workqueue for non-blocking frequency sampling
> - Configurable via CONFIG_DRM_XE_GPUFREQTRACER kernel option
> - The monitoring interval can be configured at runtime via the sysfs
>   (default 5sec).
> 
> The module parameter is:
> /sys/module/xe/parameters/gpufreq_monitoring_interval_ms
> 
> The tracepoint is exposed at:
> /sys/kernel/debug/tracing/events/power/gpu_frequency
> 
> Format: {unsigned int state, unsigned int gpu_id}
> - state: GPU frequency in KHz
> - gpu_id: GPU clock domain identifier
> 
> This enables userspace tools and system monitoring applications to track
> GPU frequency changes for power management analysis, performance tuning,
> and debugging purposes.
> 

This doesn’t answer Lucas's question in [1], and I haven’t seen a
response. Why is this feature required when we already have a PMU
interface that appears to provide the same functionality as this series?

Please address this before I look at it again.

Matt

[1] https://patchwork.freedesktop.org/patch/667913/?series=152701&rev=2#comment_1224165

> Signed-off-by: S Sebinraj <s.sebinraj at intel.com>
> 
> S Sebinraj (8):
>   drm/xe: Add Kconfig option for GPU frequency tracing
>   drm/xe: Add module parameter for GPU frequency monitoring
>   drm/xe: Add GPU frequency tracing tracepoint definition
>   drm/xe: Add GPU frequency tracer interface
>   drm/xe: Add basic GPU frequency tracer implementation
>   drm/xe: Add GPU frequency tracer to build system
>   drm/xe: Integrate GPU frequency tracer into device initialization
>   drm/xe: Add core GPU frequency monitoring functionality
> 
>  drivers/gpu/drm/xe/Kconfig                  |  22 ++
>  drivers/gpu/drm/xe/Makefile                 |   3 +
>  drivers/gpu/drm/xe/xe_device.c              |   5 +
>  drivers/gpu/drm/xe/xe_device_types.h        |   4 +
>  drivers/gpu/drm/xe/xe_gpufreqtracer.c       | 336 ++++++++++++++++++++
>  drivers/gpu/drm/xe/xe_gpufreqtracer.h       |  30 ++
>  drivers/gpu/drm/xe/xe_gpufreqtracer_trace.h |  48 +++
>  drivers/gpu/drm/xe/xe_module.c              |  12 +
>  drivers/gpu/drm/xe/xe_module.h              |   3 +
>  9 files changed, 463 insertions(+)
>  create mode 100644 drivers/gpu/drm/xe/xe_gpufreqtracer.c
>  create mode 100644 drivers/gpu/drm/xe/xe_gpufreqtracer.h
>  create mode 100644 drivers/gpu/drm/xe/xe_gpufreqtracer_trace.h
> 
> -- 
> 2.34.1
>