K 10
svn:author
V 3
mjg
K 8
svn:date
V 27
2019-12-11T23:11:21.314731Z
K 7
svn:log
V 678
vfs: locking primitives which elide ->v_vnlock and shared locking disablement

Both of these features are not needed by many consumers and result in avoidable
reads which in turn puts them on profiles due to cache-line ping ponging.

On top of that the current lockgmr entry point is slower than necessary
single-threaded. As an attempted clean up preparing for other changes,
provide new routines which don't support any of the aforementioned features.

With these patches in place vop_stdlock and vop_stdunlock disappear from
flamegraphs during -j 104 buildkernel.

Reviewed by:	jeff (previous version)
Tested by:	pho
Differential Revision:	https://reviews.freebsd.org/D22665

END