K 10
svn:author
V 5
markj
K 8
svn:date
V 27
2020-12-01T16:06:31.260852Z
K 7
svn:log
V 624
vmem: Revert r364744

A pair of bugs are believed to have caused the hangs described in the
commit log message for r364744:

1. uma_reclaim() could trigger reclamation of the reserve of boundary
   tags used to avoid deadlock.  This was fixed by r366840.
2. The loop in vmem_xalloc() would in some cases try to allocate more
   boundary tags than the expected upper bound of BT_MAXALLOC.  The
   reserve is sized based on the value BT_MAXMALLOC, so this behaviour
   could deplete the reserve without guaranteeing a successful
   allocation, resulting in a hang.  This was fixed by r366838.

PR:		248008
Tested by:	rmacklem

END