K 10
svn:author
V 6
mjoras
K 8
svn:date
V 27
2017-10-11T21:53:53.767954Z
K 7
svn:log
V 491
When unmounting a tmpfs, do not call free_unr.

tmpfs uses unr(9) to allocate inodes. Previously when unmounting it
would individually free the units when it freed each vnode. This is
unnecessary as we can use the newly-added unrhdr_clear function to clear
out the unr in onde go. This measurably reduces the time to unmount a
tmpfs with many files.

Reviewed by:	cem, lidl
Approved by:	rstone (mentor)
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D12591

END