[Intel-gfx] [PATCH 1/2] drm/i915: Introduce execlist_port_* accessors

[Chris Wilson]

Quoting Mika Kuoppala (2017-11-30 09:10:27)
> From: Mika Kuoppala <mika.kuoppala at intel.com>
> 
> Instead of trusting that first available port is at index 0,
> use accessor to hide this. This is a preparation for a
> following patches where head can be at arbitrary location
> in the port array.
> 
> v2: improved commit message, elsp_ready readability (Chris)
> v3: s/execlist_port_index/execlist_port (Chris)
> v4: rebase to new naming
> v5: fix port_next indexing
> v6: adapt to preempt
> v7: improved _port_next (Chris)
> v8: whitespace, for loop (Chris),
>     find_first_unset and GEM_BUG_ON after next_port in guc submission
> 
> Cc: Michał Winiarski <michal.winiarski at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>

I get
add/remove: 0/0 grow/shrink: 4/2 up/down: 380/-2 (378)
function                                     old     new   delta
guc_submission_tasklet                      1488    1660    +172
execlists_submission_tasklet                2129    2245    +116
intel_engine_dump                           2234    2281     +47
execlists_cancel_port_requests               254     299     +45
intel_engine_init_cmd_parser                1134    1133      -1
capture                                     5700    5699      -1

Not the end of the world, just something we may be able to tweak.

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris