K 10
svn:author
V 3
kib
K 8
svn:date
V 27
2018-06-08T18:32:26.793057Z
K 7
svn:log
V 369
Restore release semantic for the old thread unlock on arm64.

With the introduction of pmap_switch(), the DSB instruction on the
address map switch is not necessary executed, which is fixed by
changing the unlock store to release.  Also remove comment which
documented pre-pmap_switch() code.

Reviewed by:	andrew
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week

END