[Intel-gfx] [RFC 0/8] Per client engine busyness

[Tvrtko Ursulin]

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

Another re-spin of the per-client engine busyness series. Highlights from this
version:

 * Two patches added on top of the series to provide the data in GuC mode.
   (For warnings and limitations please read the respective commit messages.)
 * Refactor to introduce a notion of i915_drm_client and move to separate source
   file.

Internally we track time spent on engines for each struct intel_context. This
can serve as a building block for several features from the want list:
smarter scheduler decisions, getrusage(2)-like per-GEM-context functionality
wanted by some customers, cgroups controller, dynamic SSEU tuning,...

Externally, in sysfs, we expose time spent on GPU per client and per engine
class.

Sysfs interface enables us to implement a "top-like" tool for GPU tasks. Or with
a "screenshot":
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
intel-gpu-top -  906/ 955 MHz;    0% RC6;  5.30 Watts;      933 irqs/s

      IMC reads:     4414 MiB/s
     IMC writes:     3805 MiB/s

          ENGINE      BUSY                                      MI_SEMA MI_WAIT
     Render/3D/0   93.46% |████████████████████████████████▋  |      0%      0%
       Blitter/0    0.00% |                                   |      0%      0%
         Video/0    0.00% |                                   |      0%      0%
  VideoEnhance/0    0.00% |                                   |      0%      0%

  PID            NAME  Render/3D      Blitter        Video      VideoEnhance
 2733       neverball |██████▌     ||            ||            ||            |
 2047            Xorg |███▊        ||            ||            ||            |
 2737        glxgears |█▍          ||            ||            ||            |
 2128           xfwm4 |            ||            ||            ||            |
 2047            Xorg |            ||            ||            ||            |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Implementation wise we add a a bunch of files in sysfs like:

	# cd /sys/class/drm/card0/clients/
	# tree
	.
	├── 7
	│   ├── busy
	│   │   ├── 0
	│   │   ├── 1
	│   │   ├── 2
	│   │   └── 3
	│   ├── name
	│   └── pid
	├── 8
	│   ├── busy
	│   │   ├── 0
	│   │   ├── 1
	│   │   ├── 2
	│   │   └── 3
	│   ├── name
	│   └── pid
	└── 9
	    ├── busy
	    │   ├── 0
	    │   ├── 1
	    │   ├── 2
	    │   └── 3
	    ├── name
	    └── pid


Files in 'busy' directories are numbered using the engine class ABI values and
they contain accumulated nanoseconds each client spent on engines of a
respective class.

Tvrtko Ursulin (8):
  drm/i915: Expose list of clients in sysfs
  drm/i915: Update client name on context create
  drm/i915: Track per-context engine busyness
  drm/i915: Track all user contexts per client
  drm/i915: Contexts can use struct pid stored in the client
  drm/i915: Expose per-engine client busyness
  drm/i915: Track hw reported context runtime
  drm/i915: Fallback to hw context runtime when sw tracking is not
    available

 drivers/gpu/drm/i915/Makefile                 |   3 +-
 drivers/gpu/drm/i915/gem/i915_gem_context.c   |  60 +++-
 .../gpu/drm/i915/gem/i915_gem_context_types.h |  16 +-
 drivers/gpu/drm/i915/gt/intel_context.c       |  20 ++
 drivers/gpu/drm/i915/gt/intel_context.h       |  18 ++
 drivers/gpu/drm/i915/gt/intel_context_types.h |  14 +
 drivers/gpu/drm/i915/gt/intel_engine_cs.c     |  16 +-
 drivers/gpu/drm/i915/gt/intel_lrc.c           |  55 +++-
 drivers/gpu/drm/i915/i915_debugfs.c           |   7 +-
 drivers/gpu/drm/i915/i915_drm_client.c        | 298 ++++++++++++++++++
 drivers/gpu/drm/i915/i915_drm_client.h        |  83 +++++
 drivers/gpu/drm/i915/i915_drv.h               |   5 +
 drivers/gpu/drm/i915/i915_gem.c               |  35 +-
 drivers/gpu/drm/i915/i915_gpu_error.c         |   8 +-
 drivers/gpu/drm/i915/i915_sysfs.c             |   8 +
 drivers/gpu/drm/i915/intel_device_info.c      |   2 +
 drivers/gpu/drm/i915/intel_device_info.h      |   1 +
 17 files changed, 606 insertions(+), 43 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/i915_drm_client.c
 create mode 100644 drivers/gpu/drm/i915/i915_drm_client.h

-- 
2.20.1