K 10
svn:author
V 3
alc
K 8
svn:date
V 27
2018-08-08T02:30:34.760135Z
K 7
svn:log
V 679
Defer and aggregate swap_pager_meta_build frees.

Before swp_pager_meta_build replaces an old swapblk with an new one,
it frees the old one.  To allow such freeing of blocks to be
aggregated, have swp_pager_meta_build return the old swap block, and
make the caller responsible for freeing it.

Define a pair of short static functions, swp_pager_init_freerange and
swp_pager_update_freerange, to do the initialization and updating of
blk addresses and counters used in aggregating blocks to be freed.

Submitted by:	Doug Moore <dougm@rice.edu>
Reviewed by:	kib, markj (an earlier version)
Tested by:	pho
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D13707

END