You can force DYNALLOC to allocate the DSN to a given DDNAME. This would allow you to reuse the same DDNAME (or a handful of DD names used in a round-robin fashion) and greatly reduce shutdown time and reduce the working set size... see the DALDDNAM keyword in the doc. Don't know how you do this from C but it must be possible.
Eric Spencer Neon Enterprise Software LLC -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Staller, Allan Sent: Tuesday, October 13, 2009 8:28 AM To: [email protected] Subject: Re: Does a DD-Statement "waste memory" after dealloc? This may be SMF keeping the "pieces" it needs to build the SMF records at task termination. A key symptom would be a long shutdown time for the task and an apparent CPU loop in the task after a "xxx is shutting down" message. If this is the case, reference the DDCONS parameter of SMFPRMxx. What is the working set for the application? Unless you have done some things unlikely to have been done for a "application program", I can almost guarantee the working set is not 17,000 pages. HTH, <snip> I currently try to find a obscure memory leak in one of our applications. After some days our appl occupies ~17.000 pages of real memory (needs just ~1.500 after startup). As we track all malloc(), calloc(), realloc() and free() function calls, I can say that there is no obvious memory leak.... Now... after I've looked at the JESYSMSG I've noticed that we've done approx 17.000 DYNALLOCs, everyone with a different DD-Name (we let the z/OS generate a unique one, like "SYS00001", "SYS00002", "SYS00003" and so on)..... to be clear: *NOT* ~17.000 at the same time. mostly only one at the same time... </snip> ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- 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
