This is a z/OS 2.2 issue only. Does not affect either 2.1 or 2.3.
CMOD exposes the following:
IF PE PTF UA96465 is installed and fixing HIPER APAR OA54570 PTF UA97572 is not
THEN page datasets can be filled and not freed even after the started task is ended.
This is more likely to occur with ODF but can also affect ARSSOCKD.
From OA54570:
ERROR DESCRIPTION:
Freemain processing does not indicate that we should free the
auxiliary storage of any related in-flight IO, so when IO
completes we do not release the backing frame and
instead lose the blockid. Later, SCM evacuation discovers
the bad blockid and issues an ABENDC0D.
Additional problem can also occur, when an application uses
IARVSERV TARGET_VIEW=HIDDEN, this results in storage being paged
to auxiliary slots or SCM block. Should this storage be
freemained while having a status of hidden the aux slot/scm
block can be orphaned. This was introduced by changes made in
APAR OA54820. LE Stack management behaves in this manner.
XPLINK applications that quickly create and destroy pthreads
can observe aux slots orphaned at a high rate.
Ed