Under Illumos taskq_wait() returns when there are no more tasks
in the queue. This behavior differs from ZoL and FreeBSD where
taskq_wait() returns when all the tasks in the queue at the
beginning of the taskq_wait() call are complete. New tasks
added whilst taskq_wait() is running will be ignored.
This difference in semantics makes it possible that new subtle
issues could be introduced when porting changes from Illumos.
To avoid that possibility the taskq_wait() function is being
updated such that it blocks until the queue in empty.
The previous behavior remains available through the
taskq_wait_outstanding() interface. Note that this function
was previously called taskq_wait_all() but has been renamed
to avoid confusion.
Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#455