From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> The latest idea on how to load-balance VCS submissions in i915. This time round we have a concept of submission queues implemented as contexts which share PPGTT. Userspace is supposed to create a queue with the virtual flag set to one. Subsequent submissions to this queue will be load-balanced between available VCS engines by the driver. Only new class/instance based execbuf uAPI is supported. Explicit VCS engine selection will be rejected meaning engine instance must be set to zero. Engine capabilities must be used if a submission depends on an non-uniform engine feature like HEVC which is only available on VCS0. This series is just a prototype which illustrates the uAPI proposal. It does not claim to balance well. In fact, it is known to balance poorly - in some cases significantly worse than the same approach implemented in userspace. This potentially stems from the fact it creates a forced dependency when moving between engines (even when there are no data dependencies between batches) in order to simulate a single stream of execution per virtual engine. Series also doesn't implement the virtual engine fully in a way that context state does not move around with the submissions, ie. it is not preserved. I will also post gem_wsim and media-bench.pl IGT patches which allows playing with this easily. Chris Wilson (2): move-timeline-to-ctx drm/i915: Extend CREATE_CONTEXT to allow inheritance ala clone() Tvrtko Ursulin (8): drm/i915: Select engines via class and instance in execbuffer2 drm/i915: Engine capabilities uAPI drm/i915: Re-arrange execbuf so context is known before engine drm/i915: Refactor eb_select_engine to take eb drm/i915: Track latest request per engine class drm/i915: Allow creating virtual contexts drm/i915: Trivial virtual engine implementation drm/i915: Naive engine busyness based load balancing drivers/gpu/drm/i915/i915_drv.h | 11 +- drivers/gpu/drm/i915/i915_gem.c | 9 +- drivers/gpu/drm/i915/i915_gem_context.c | 91 +++++++-- drivers/gpu/drm/i915/i915_gem_context.h | 23 +++ drivers/gpu/drm/i915/i915_gem_execbuffer.c | 223 ++++++++++++++++---- drivers/gpu/drm/i915/i915_gem_gtt.c | 7 +- drivers/gpu/drm/i915/i915_gem_gtt.h | 2 - drivers/gpu/drm/i915/i915_gem_request.c | 15 +- drivers/gpu/drm/i915/i915_gem_request.h | 2 + drivers/gpu/drm/i915/i915_gem_timeline.c | 66 +++++- drivers/gpu/drm/i915/i915_gem_timeline.h | 6 + drivers/gpu/drm/i915/intel_engine_cs.c | 41 +++- drivers/gpu/drm/i915/intel_lrc.c | 2 +- drivers/gpu/drm/i915/intel_ringbuffer.c | 9 +- drivers/gpu/drm/i915/intel_ringbuffer.h | 9 +- drivers/gpu/drm/i915/selftests/huge_pages.c | 1 - drivers/gpu/drm/i915/selftests/i915_gem_context.c | 236 +++++++++++++++++----- drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 1 - drivers/gpu/drm/i915/selftests/mock_context.c | 3 +- drivers/gpu/drm/i915/selftests/mock_engine.c | 3 +- drivers/gpu/drm/i915/selftests/mock_gem_device.c | 4 +- drivers/gpu/drm/i915/selftests/mock_gtt.c | 1 - include/uapi/drm/i915_drm.h | 38 +++- 23 files changed, 660 insertions(+), 143 deletions(-) -- 2.14.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
