[Intel-gfx] [PATCH 1/2] drm/i915/breadcrumbs: Reduce signaler rbtree to a sorted list

[Chris Wilson]

Quoting Joonas Lahtinen (2018-03-05 14:25:07)
> As a pre-existing condition it's bit surprising that intel_breadcrumbs_busy()
> kicks the signaler as a side-effect.

Since we explicitly cancel the signaling on retire now (to prevent the
accumulation of references), we can actually say that we don't need to
check the signaler for busy any more. We still need to spin over kicking
the waiters though... Hmm, though we can just walk the tree and mark
them as complete now.
-Chris