Re: [PATCH v2 0/8] Engine Busyness

[Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>]

Hi,

On 07/12/2023 12:57, 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. 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.

I think I've asked this before but don't remember it was clarified - 
what are the semantics of "active" with total active ticks? In other 
words considering activity timelines like:

1)
      0          1s
rcs0 |xxxxx-----|
bcs0 |-----xxxxx|

2)
      0          1s
rcs0 |xxxxx-----|
bcs0 |xxxxx-----|

Assuming 1s sampling, would the above formula correctly say 50% for both 
engines in both cases?

I am also curious if there are plans to add support to intel_gpu_top in 
which case please copy me on the required refactorings.

Regards,

Tvrtko

> This can be listed as
> 
> sudo ./perf list
>       xe_0000_03_00.0/total-active-ticks-gt0/            [Kernel PMU event]
>       xe_0000_03_00.0/bcs0-busy-ticks-gt0/               [Kernel PMU event]
>       xe_0000_03_00.0/ccs0-busy-ticks-gt0/               [Kernel PMU event]
>       xe_0000_03_00.0/rcs0-busy-ticks-gt0/               [Kernel PMU event]
>       xe_0000_03_00.0/vcs0-busy-ticks-gt0/               [Kernel PMU event]
>       xe_0000_03_00.0/vecs0-busy-ticks-gt0/              [Kernel PMU event]
> 
> and can be read as
> 
> 	sudo ./perf stat -e xe_0000_03_00.0/bcs0-busy-ticks-gt0/,xe_0000_03_00.0/total-active-ticks-gt0/  -I 1000
> 
> v2: rebase
>      fix review comments
> 
> Riana Tauro (8):
>    RFC drm/xe: Move user engine class mappings to functions
>    RFC drm/xe/guc: Add interface for engine busyness ticks
>    RFC drm/xe/guc: Expose engine busyness only for supported GuC version
>    RFC drm/xe/guc: Add PMU counter for total active ticks
>    RFC drm/xe/uapi: Add configs for Engine busyness
>    RFC drm/xe/pmu: Add PMU counters for engine busy ticks
>    RFC drm/xe/guc: Dynamically enable/disable engine busyness stats
>    RFC drm/xe/guc: Handle runtime suspend issues for engine busyness
> 
>   drivers/gpu/drm/xe/Makefile                 |   1 +
>   drivers/gpu/drm/xe/abi/guc_actions_abi.h    |   1 +
>   drivers/gpu/drm/xe/xe_exec_queue.c          |  19 +-
>   drivers/gpu/drm/xe/xe_gt.c                  |  26 ++
>   drivers/gpu/drm/xe/xe_gt.h                  |   3 +
>   drivers/gpu/drm/xe/xe_guc.c                 |   7 +
>   drivers/gpu/drm/xe/xe_guc_engine_busyness.c | 367 ++++++++++++++++++++
>   drivers/gpu/drm/xe/xe_guc_engine_busyness.h |  21 ++
>   drivers/gpu/drm/xe/xe_guc_fwif.h            |  15 +
>   drivers/gpu/drm/xe/xe_guc_types.h           |  25 ++
>   drivers/gpu/drm/xe/xe_hw_engine.c           |  50 +++
>   drivers/gpu/drm/xe/xe_hw_engine.h           |   3 +
>   drivers/gpu/drm/xe/xe_pmu.c                 | 189 +++++++++-
>   drivers/gpu/drm/xe/xe_pmu.h                 |   2 +
>   drivers/gpu/drm/xe/xe_query.c               |  23 +-
>   include/uapi/drm/xe_drm.h                   |  24 ++
>   16 files changed, 726 insertions(+), 50 deletions(-)
>   create mode 100644 drivers/gpu/drm/xe/xe_guc_engine_busyness.c
>   create mode 100644 drivers/gpu/drm/xe/xe_guc_engine_busyness.h
>