Partial views are small but there can be many of them, and since the sg
list space for them is allocated pessimistically, we can save some slab by
trimming the unused tail entries.
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180926080353.20867-1-tvrtko.ursulin@linux.intel.com