K 10
svn:author
V 6
mlaier
K 8
svn:date
V 27
2010-09-01T19:50:03.859837Z
K 7
svn:log
V 466
rmlock(9) two additions and one change/fix:
 - add rm_try_rlock().
 - add RM_SLEEPABLE to use sx(9) as the back-end lock in order to sleep while
   holding the write lock.
 - change rm_noreadtoken to a cpu bitmask to indicate which CPUs need to go
   through the lock/unlock in order to synchronize.  As a side effect, this
   also avoids IPI to CPUs without any readers during rm_wlock.

Discussed with:		ups@, rwatson@ on arch@
Sponsored by:		Isilon Systems, Inc.

END