[Intel-gfx] [PATCH 00/55] Remove the outstanding_lazy_request

[John.C.Harrison at Intel.com]

From: John Harrison <John.C.Harrison at Intel.com>

The driver tracks GPU work using request structures. Unfortunately, this
tracking is not currently explicit but is done by means of a catch-all request
that floats around in the background hoovering up work until it gets submitted.
This background request (ring->outstanding_lazy_request or OLR) is created at
the point of actually writing to the ring rather than when a particular piece of
GPU work is started. This scheme sort of hangs together but causes a number of
issues. It can mean that multiple pieces of independent work are lumped together
in the same request or that work is not officially submitted until much later
than it was created.

This patch series completely removes the OLR and explicitly tracks each piece of
work with it's own personal request structure from start to submission.

The patch set seems to fix the "'gem_ringfill --r render' + ctrl-c straight
after boot" issue logged as BZ:88865. I haven't done any analysis of that
particular issue but the descriptions I've seen appear to blame an inconsistent
or mangled OLR.

Note also that by the end of this series, a number of differences between the
legacy and execlist code paths have been removed. For example add_request() and
emit_request() now have the same signature thus could be merged back to a single
function pointer. Merging some of these together would also allow the removal of
a bunch of 'if(execlists)' tests where the difference is simply to call the
legacy function or the execlist one.

v2: Rebased to newer nightly tree, fixed up a few minor issues, added two extra
patches - one to move the LRC ring begin around in the vein of other recent
reshuffles, the other to clean up some issues with i915_add_request().

v3: Large re-work due to feedback from code review. Some patches have been
removed, extra ones have been added and others have been changed significantly.
It is recommended that all patches are reviewed from scratch rather than
assuming only certain ones have changed and need re-inspecting. The exceptions
are where the 'reviewed-by' tag has been kept because that patch was not
significantly affected.

v4: Further updates due to review feedback and rebasing on top of significant
changes to the underlying tree.

[Patches against drm-intel-nightly tree fetched 22/05/2015]

John Harrison (55):
  drm/i915: Re-instate request->uniq becuase it is extremely useful
  drm/i915: Reserve ring buffer space for i915_add_request() commands
  drm/i915: i915_add_request must not fail
  drm/i915: Early alloc request in execbuff
  drm/i915: Set context in request from creation even in legacy mode
  drm/i915: Merged the many do_execbuf() parameters into a structure
  drm/i915: Simplify i915_gem_execbuffer_retire_commands() parameters
  drm/i915: Update alloc_request to return the allocated request
  drm/i915: Add request to execbuf params and add explicit cleanup
  drm/i915: Update the dispatch tracepoint to use params->request
  drm/i915: Update move_to_gpu() to take a request structure
  drm/i915: Update execbuffer_move_to_active() to take a request structure
  drm/i915: Add flag to i915_add_request() to skip the cache flush
  drm/i915: Update i915_gpu_idle() to manage its own request
  drm/i915: Split i915_ppgtt_init_hw() in half - generic and per ring
  drm/i915: Moved the for_each_ring loop outside of i915_gem_context_enable()
  drm/i915: Don't tag kernel batches as user batches
  drm/i915: Add explicit request management to i915_gem_init_hw()
  drm/i915: Update ppgtt_init_ring() & context_enable() to take requests
  drm/i915: Update i915_switch_context() to take a request structure
  drm/i915: Update do_switch() to take a request structure
  drm/i915: Update deferred context creation to do explicit request management
  drm/i915: Update init_context() to take a request structure
  drm/i915: Update render_state_init() to take a request structure
  drm/i915: Update i915_gem_object_sync() to take a request structure
  drm/i915: Update overlay code to do explicit request management
  drm/i915: Update queue_flip() to take a request structure
  drm/i915: Update add_request() to take a request structure
  drm/i915: Update [vma|object]_move_to_active() to take request structures
  drm/i915: Update l3_remap to take a request structure
  drm/i915: Update mi_set_context() to take a request structure
  drm/i915: Update a bunch of execbuffer helpers to take request structures
  drm/i915: Update workarounds_emit() to take request structures
  drm/i915: Update flush_all_caches() to take request structures
  drm/i915: Update switch_mm() to take a request structure
  drm/i915: Update ring->flush() to take a requests structure
  drm/i915: Update some flush helpers to take request structures
  drm/i915: Update ring->emit_flush() to take a request structure
  drm/i915: Update ring->add_request() to take a request structure
  drm/i915: Update ring->emit_request() to take a request structure
  drm/i915: Update ring->dispatch_execbuffer() to take a request structure
  drm/i915: Update ring->emit_bb_start() to take a request structure
  drm/i915: Update ring->sync_to() to take a request structure
  drm/i915: Update ring->signal() to take a request structure
  drm/i915: Update cacheline_align() to take a request structure
  drm/i915: Update intel_ring_begin() to take a request structure
  drm/i915: Update intel_logical_ring_begin() to take a request structure
  drm/i915: Add *_ring_begin() to request allocation
  drm/i915: Remove the now obsolete intel_ring_get_request()
  drm/i915: Remove the now obsolete 'outstanding_lazy_request'
  drm/i915: Move the request/file and request/pid association to creation time
  drm/i915: Remove 'faked' request from LRC submission
  drm/i915: Update a bunch of LRC functions to take requests
  drm/i915: Remove the now obsolete 'i915_gem_check_olr()'
  drm/i915: Rename the somewhat reduced i915_gem_object_flush_active()

 drivers/gpu/drm/i915/i915_drv.h              |   77 +++---
 drivers/gpu/drm/i915/i915_gem.c              |  368 ++++++++++++++++----------
 drivers/gpu/drm/i915/i915_gem_context.c      |   78 +++---
 drivers/gpu/drm/i915/i915_gem_execbuffer.c   |  128 +++++----
 drivers/gpu/drm/i915/i915_gem_gtt.c          |   59 +++--
 drivers/gpu/drm/i915/i915_gem_gtt.h          |    3 +-
 drivers/gpu/drm/i915/i915_gem_render_state.c |   15 +-
 drivers/gpu/drm/i915/i915_gem_render_state.h |    2 +-
 drivers/gpu/drm/i915/i915_trace.h            |   41 +--
 drivers/gpu/drm/i915/intel_display.c         |   60 +++--
 drivers/gpu/drm/i915/intel_drv.h             |    3 +-
 drivers/gpu/drm/i915/intel_fbdev.c           |    2 +-
 drivers/gpu/drm/i915/intel_lrc.c             |  265 +++++++++----------
 drivers/gpu/drm/i915/intel_lrc.h             |   16 +-
 drivers/gpu/drm/i915/intel_overlay.c         |   63 +++--
 drivers/gpu/drm/i915/intel_ringbuffer.c      |  303 +++++++++++++--------
 drivers/gpu/drm/i915/intel_ringbuffer.h      |   53 ++--
 17 files changed, 876 insertions(+), 660 deletions(-)

-- 
1.7.9.5