Thanks, Jim. That answers my question rather completely.
[:)]
Dave
> (I know what I need to do to "fix" this. I'm just curious about what
> good reason IBM might or might not have for doing this.)
(1) Pageable common storage (pageable CSA and DREF SQA) can exist
in the same segment as fixed common storage (fixed CSA and
non-DREF SQA). Pageable common storage processing in RSM is
serialized by the Common RSMAD lock. Fixed common storage
processing in RSM is serialized by the RSMGL lock. If
these two types of processing could allocate and deallocate
page tables, they would be doing so unserialized against
each other.
(2) It has certainly been this way at least since the beginning of
MVS/XA. I didn't work on RSM much back in MVS/370, so I
would hesitate to speculate on how it worked. However, the
locking was simpler in MVS/370 - all of common storage processing
in both VSM and RSM was serialized by the SALLOC lock. The
The VSMPAG, VSMFIX, RSMAD, RSM, and RSMGL locks were introduced
in MVS/XA (and the SALLOC lock became unused) in order to
reduce SALLOC lock contention.
Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO
Search the archives at http://bama.ua.edu/archives/ibm-main.html
Dave Cole REPLY TO: [EMAIL PROTECTED]
Cole Software WEB PAGE: http://www.colesoft.com
736 Fox Hollow Road VOICE: 540-456-8536
Afton, VA 22920 FAX: 540-456-6658
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO
Search the archives at http://bama.ua.edu/archives/ibm-main.html
