Re: [PATCH v4 5/8] drm/xe/guc: Add PMU counter for total active ticks

[Aravind Iddamsetty <aravind.iddamsetty@linux.intel.com>]

On 12/22/23 13:15, Riana Tauro wrote:
> GuC provides engine busyness ticks as a 64 bit counter which count
> as clock ticks. These counters are maintained in a
> shared memory buffer and internally updated on a continuous basis.
>
> GuC also provides a periodically total active ticks that GT has been
> active for (GuC loaded and running).
> This counter is exposed to the user such that busyness can
> be calculated as a percentage using
>
> busyness % = (engine active ticks/total active ticks) * 100.
>
> This patch provides a pmu counter for total active ticks.
>
> This is listed by perf tool as
>
> sudo ./perf list
> 	  xe_0000_03_00.0/total-active-ticks-gt0/            [Kernel PMU event]
>
> and can be read using
>
> sudo ./perf stat -e xe_0000_03_00.0/total-active-ticks-gt0/ -I 1000
>         time 	    counts  unit 	events
>     1.001332764    58942964    xe_0000_03_00.0/total-active-ticks-gt0/
>     2.011421147	   21191869    xe_0000_03_00.0/total-active-ticks-gt0/
>     3.013223865	   19269012    xe_0000_03_00.0/total-active-ticks-gt0/
>
> v2: change commit message and comment for
>     total active ticks (Umesh, Tvrtko)
>
> Co-developed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
> Signed-off-by: Riana Tauro <riana.tauro@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_gt.c                  | 11 +++
>  drivers/gpu/drm/xe/xe_gt.h                  |  2 +-
>  drivers/gpu/drm/xe/xe_guc_engine_busyness.c | 72 ++++++++++++++++----
>  drivers/gpu/drm/xe/xe_guc_engine_busyness.h |  1 +
>  drivers/gpu/drm/xe/xe_pmu.c                 | 74 +++++++++++++++++++--
>  include/uapi/drm/xe_drm.h                   | 23 ++++++-
>  6 files changed, 162 insertions(+), 21 deletions(-)
>
<snip>
> diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
> index f8456cda5cda..3134930b0160 100644
> --- a/include/uapi/drm/xe_drm.h
> +++ b/include/uapi/drm/xe_drm.h
> @@ -1341,12 +1341,29 @@ struct drm_xe_wait_user_fence {
>  };
>  
>  /**
> - * DOC: XE PMU event config IDs
> + * DOC: XE PMU Event Config ID's
>   *
> - * Check 'man perf_event_open' to use the ID's DRM_XE_PMU_XXXX listed in xe_drm.h
the reason for mentioning xe_drm.h is the defines will not be included in the documentation
> + * Check 'man perf_event_open' to use the ID's DRM_XE_PMU_XXXX listed here
>   * in 'struct perf_event_attr' as part of perf_event_open syscall to read a
>   * particular event.
>   *
> + * For example to open the DRM_XE_PMU_TOTAL_ACTIVE_TICKS(0):
> + *
> + * .. code-block:: C
> + *
> + *     struct perf_event_attr attr;
> + *     long long count;
> + *     int cpu = 0;
> + *     int fd;
> + *
> + *     memset(&attr, 0, sizeof(struct perf_event_attr));
> + *     attr.type = type; // eg: /sys/bus/event_source/devices/xe_0000_03_00.0/type
> + *     attr.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED;
> + *     attr.use_clockid = 1;
> + *     attr.clockid = CLOCK_MONOTONIC;
> + *     attr.config = DRM_XE_PMU_TOTAL_ACTIVE_TICKS(0);
> + *
> + *     fd = syscall(__NR_perf_event_open, &attr, -1, cpu, -1, 0);
>   */
>  
>  /**
> @@ -1381,6 +1398,8 @@ enum drm_xe_pmu_engine_sample {
>  	__DRM_XE_PMU_GT_EVENT(gt, __DRM_XE_PMU_ENGINE(class, instance, \
>  						      DRM_XE_PMU_SAMPLE_BUSY_TICKS))
>  
> +#define DRM_XE_PMU_TOTAL_ACTIVE_TICKS(gt)	__DRM_XE_PMU_OTHER(gt, 0)
> +
>  #if defined(__cplusplus)
>  }
>  #endif


Thanks,
Aravind.