K 10
svn:author
V 3
mjg
K 8
svn:date
V 27
2020-01-31T08:38:38.628451Z
K 7
svn:log
V 320
zfs: convert z_teardown_inactive_lock to sleepable read-mostly lock

This eliminates a global serialisation point. It only gets write locked
on unmount.

Sample result doing an incremental -j 40 build:
before: 173.30s user 458.97s system 2595% cpu 24.358 total
after:  168.58s user 254.92s system 2211% cpu 19.147 total

END