Commit 9ae6c4ef authored May 25, 2020 by Chris Wilson

drm/i915/execlists: Shortcircuit queue_prio() for no internal levels



If there are no internal levels and the user priority-shift is zero, we
can help the compiler eliminate some dead code:

Function                                     old     new   delta
start_timeslice                              169     154     -15
__execlists_submission_tasklet              4696    4659     -37

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200525075347.582-4-chris@chris-wilson.co.uk

parent 7c4541a3

drivers/gpu/drm/i915/gt/intel_lrc.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -446,6 +446,9 @@ static int queue_prio(const struct intel_engine_execlists *execlists)
		* we have to flip the index value to become priority.
		*/
		p = to_priolist(rb);
		if (!I915_USER_PRIORITY_SHIFT)
		return p->priority;

		return ((p->priority + 1) << I915_USER_PRIORITY_SHIFT) - ffs(p->used);
		}

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