[PATCH 1/5] drm/i915: stop pruning reservation object after wait

[Chris Wilson]

Quoting Christian König (2019-08-05 16:45:50)
> The reservation object should be capable of handling its internal memory
> management itself. And since we search for a free slot to add the fence
> from the beginning this is actually a waste of time and only minimal helpful.

"From the beginning?" Attempting to prune signaled fences on insertion is
quite recent.

However, that doesn't help the cases where reservation_object keeps on
holding a reference to the fences for idle objects. It's an absolute
nightmare of a reference trap.
-Chris