K 10
svn:author
V 3
kib
K 8
svn:date
V 27
2019-06-23T21:21:11.174668Z
K 7
svn:log
V 491
amd64 pmap: block on turnstile for lock-less DI.

Port the code to block on turnstile instead of yielding, to lock-less
delayed invalidation. The yield might cause tight loop due to priority
inversion.

Since it is impossible to avoid race between block and wake-up, arm
1-tick callout to wakeup when thread blocks itself.

Reported and tested by:	mjg
Reviewed by:	alc, markj
Sponsored by:	The FreeBSD Foundation
MFC after:	2 months
Differential revision:	https://reviews.freebsd.org/D20636

END