[PATCH 00/51] Remove the outstanding_lazy_request

John.C.Harrison
2015-02-13T11:49:10Z

From: John Harrison <John.C.Harrison@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:40112. 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.

[Patches against drm-intel-nightly tree fetched 03/02/2015]

John Harrison (51):
drm/i915: Rename 'flags' to 'dispatch_flags' for better code reading
drm/i915: Add missing trace point to LRC execbuff code path
drm/i915: Cache ringbuf pointer in request structure
drm/i915: Merged the many do_execbuf() parameters into a structure
drm/i915: Add return code check to i915_gem_execbuffer_retire_commands()
drm/i915: Wrap request allocation with a function pointer
drm/i915: Early alloc request in execbuff
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 pin_to_display_plane() to do explicit request management
drm/i915: Update i915_gem_object_sync() to take a request structure
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: Add explicit request management to i915_gem_init_hw()
drm/i915: Update ppgtt_init_ring() & context_enable() to take requests
drm/i915: Set context in request from creation even in legacy mode
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 overlay code to do explicit request management
drm/i915: Update queue_flip() to do explicit request management
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 heplers 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 ironlake_enable_rc6() to do explicit request management
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: Remove the now obsolete intel_ring_get_request()
drm/i915: Remove the now obsolete 'outstanding_lazy_request'

drivers/gpu/drm/i915/i915_drv.h | 68 +++---
drivers/gpu/drm/i915/i915_gem.c | 207 +++++++++++--------
drivers/gpu/drm/i915/i915_gem_context.c | 76 +++----
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 138 ++++++++-----
drivers/gpu/drm/i915/i915_gem_gtt.c | 55 ++---
drivers/gpu/drm/i915/i915_gem_gtt.h | 3 +-
drivers/gpu/drm/i915/i915_gem_render_state.c | 16 +-
drivers/gpu/drm/i915/i915_gem_render_state.h | 2 +-
drivers/gpu/drm/i915/intel_display.c | 61 +++---
drivers/gpu/drm/i915/intel_lrc.c | 186 +++++++++--------
drivers/gpu/drm/i915/intel_lrc.h | 20 +-
drivers/gpu/drm/i915/intel_overlay.c | 64 ++++--
drivers/gpu/drm/i915/intel_pm.c | 33 ++-
drivers/gpu/drm/i915/intel_ringbuffer.c | 287 ++++++++++++++------------
drivers/gpu/drm/i915/intel_ringbuffer.h | 51 ++---
15 files changed, 697 insertions(+), 570 deletions(-)

--
1.7.9.5