[Intel-gfx] [RFC 00/14] i915 PMU and engine busy stats

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Rough sketch of the idea I mentioned a few times to various people - merging
the engine busyness tracking with Chris i915 PMU RFC.

First patch is the actual PMU RFC by Chris. It is followed by some cleanup
patches, then come a few improvements, cheap execlists engine busyness tracking,
debugfs view for the same, and finally the i915 PMU is extended to use this
instead of timer based mmio sampling.

This makes it cheaper and also more accurate since engine busyness is not
derived via sampling.

But I haven't figure out the perf API yet. For example is it possible to access
our events in an usable fashion via perf top/stat or something? Do we want to
make the events discoverable as I did (patch 8).

I could not find much (any?) kernel API level documentation for perf.

Btw patch series actually works since intel-gpu-overlay can use these events
when they are available.

Chris Wilson (1):
  RFC drm/i915: Expose a PMU interface for perf queries

Tvrtko Ursulin (13):
  drm/i915/pmu: Add VCS2 engine to the PMU uAPI
  drm/i915/pmu: Add queued samplers to the PMU uAPI
  drm/i915/pmu: Decouple uAPI engine ids
  drm/i915/pmu: Helper to extract engine and sampler from PMU config
  drm/i915/pmu: Only sample enabled samplers
  drm/i915/pmu: Add fake regs
  drm/i915/pmu: Expose events in sysfs
  drm/i915/pmu: Suspend sampling when GPU is idle
  drm/i915: Wrap context schedule notification
  drm/i915: Engine busy time tracking
  drm/i915: Interface for controling engine stats collection
  drm/i915: Export engine busy stats in debugfs
  drm/i915/pmu: Wire up engine busy stats to PMU

 drivers/gpu/drm/i915/Makefile           |   1 +
 drivers/gpu/drm/i915/i915_debugfs.c     |  89 ++++
 drivers/gpu/drm/i915/i915_drv.c         |   2 +
 drivers/gpu/drm/i915/i915_drv.h         |  32 ++
 drivers/gpu/drm/i915/i915_gem.c         |   1 +
 drivers/gpu/drm/i915/i915_gem_request.c |   1 +
 drivers/gpu/drm/i915/i915_pmu.c         | 697 ++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_engine_cs.c  |  59 +++
 drivers/gpu/drm/i915/intel_lrc.c        |  19 +-
 drivers/gpu/drm/i915/intel_ringbuffer.h |  46 +++
 include/uapi/drm/i915_drm.h             |  51 +++
 kernel/events/core.c                    |   1 +
 12 files changed, 996 insertions(+), 3 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/i915_pmu.c

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2.9.4