Mark Johnston 6514b4f061 Add GET_STACK_USAGE() for arm64.
Its absence meant that GEOM direct dispatch was disabled (the service
routines check the current thread's stack usage to determine whether
to hand off the request to a dedicated thread), and this change is
sufficient to enable direct dispatch by default.

Reviewed by:	allanjude
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D15527
2018-05-23 15:43:35 +00:00
..
2018-05-23 15:43:35 +00:00