FWIW I added the exact same workaround in nouveau. I think I even also used 64:
https://cgit.freedesktop.org/mesa/mesa/tree/src/gallium/drivers/nouveau/nouveau_fence.c#n270
Reviewed-by: Ilia Mirkin
On Fri, Jun 30, 2017 at 11:24 PM, Bruce Cherniak
This patch limits the number of items on the fence work queue (the
deferred deletion list) by submitting a sync fence when the queue size
exceeds a threshold. This initiates deferred deletion of all resources
on the list and decreases the total amount of memory held waiting for
"deferred