[Intel-gfx] [PATCH 0/7] drm/i915/perf: add OA interrupt support

[Lionel Landwerlin]

Taking the RFC off this series.

To quite the vTune team that tried the previous version :

    "It reduces data collection overhead in VTune by 11x. It is great!"

The GPA team's report on the previous version was a drop in CPU
consumption from 17~20% down to 2~3%.

This version includes :

   - a fix for an issue reported by Chris on the IMR register access
     on Haswell

   - the ability to completely disable the i915 OA head/tail polling

   - a new ioctl on the perf stream file descript (not the i915 drm
     master/render node) to force i915 to look at the OA head/tail
     register (see explanation in last patch).

Cheers,

Lionel Landwerlin (7):
  drm/i915/perf: rework aging tail workaround
  drm/i915/perf: reset pollin when perf stream is enabled
  drm/i915/perf: only append status when data is available
  drm/i915/perf: add new open param to configure polling of OA buffer
  drm/i915: handle interrupts from the OA unit
  drm/i915/perf: add interrupt enabling parameter
  drm/i915/perf: add flushing ioctl

 drivers/gpu/drm/i915/i915_drv.h         |  59 +++-
 drivers/gpu/drm/i915/i915_irq.c         |  39 ++-
 drivers/gpu/drm/i915/i915_perf.c        | 388 +++++++++++++++---------
 drivers/gpu/drm/i915/i915_reg.h         |   7 +
 drivers/gpu/drm/i915/intel_ringbuffer.c |   2 +
 include/uapi/drm/i915_drm.h             |  35 +++
 6 files changed, 357 insertions(+), 173 deletions(-)

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2.20.1