W dniu 25.10.2010 15:06, Beate Kawelke pisze:
Hi all,
I was pretty sure that the STORAGE macros are "better" than GETMAIN/FREEMAIN,
both in terms of functionality and performance. To back that up, I searched for
documentation.
What I found so far is a fairly recent presentation from SHARE:
http://ew.share.org/client_files/callpapers/attach/SHARE_in_Denver/S1237DB120530.pdf
which says (on page 34) that GETMAIN/FREEMAIN is taking a lot less cycles than
STORAGE OBTAIN/RELEASE (17,000 vs. 20,000). I haven't found any IBM document
saying anything about performance, all I got was that STORAGE is recommended
for some environments (e.g. for AR mode). And then I found a thread on IBM-MAIN
where Peter Relson talked about the relationship between the two:
http://www.mail-archive.com/[email protected]/msg122945.html but
unfortunately not much about the default LINKAGE=SYSTEM of STORAGE.
I always thought that an SVC interrupt (GETMAIN) "costs" more than a PC
(STORAGE with LINKAGE=SYSTEM) - am I wrong?
Anyway: In a "normal" environment (primary mode, key 8), what would you recommend to use
and why? And if you want to "modernize" a module, would you change from one to the other?
You can find some info here:
"10.1.1 Comparison of GETMAIN/FREEMAIN Macros with the STORAGE Macro"
http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/IEA2A890/10.1.1?DT=20080602053331
--
Przemyslaw Kupisz
