z/OS DFSMShsm Diagnosis
z/OS DFSMShsm Diagnosis
Previous topic |
Next topic |
Contents |
Contact z/OS |
Library |
PDF
Analyzing the CELL POOL free chain z/OS DFSMShsm Diagnosis GC52-1387-00 |
|
Many of the DFSMShsm internal control blocks use CELL POOL services to obtain and free storage. Unlike a FREEMAIN, CELL POOL services will not notify DFSMShsm if it erroneously returns a cell to the free cell chain. Instead, the return of the cell to the free cell chain is performed, allowing that storage to be erroneously used later by two processes. The following patch enables diagnosis code execution that detects
the return of a cell to the free cell chain. If DFSMShsm detects a
second attempt to return a cell to the free cell chain, it will not
perform the second attempt, and it issues an ARCERP code=8 with a
snap dump. The field name is MCVTF_ZCELL_SNIF, the default is OFF
and it slightly increases CPU utilization.
|
 Copyright IBM Corporation 1990, 2014 |
