If the reentrant program must acquire and release storage (via GETMAIN/FREMAIN or STORAGE ACQUIRE/RELEASE) during each invocation, I can not see how the operation of the internal cache is going to make a difference of sufficient significance to support the performance assertion.
If the reentrant program does not have to invoke these or other system services, it may be a different matter. In fact, I would expect the performance characteristics to be quite different. My experience is that the assertion that reentrant programs ALWAYS perform better than non-reentrant programs can not be justified. There are simply too many variables involved. John P Baker Software Engineer -----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Rick Fochtman Sent: Saturday, October 21, 2006 12:02 To: [email protected] Subject: Re: Is the teaching of non-reentrant HLASM coding practices ever defensible? John, it's a function of the internal cache usage; z900 and later processors have a separate caches for instruction fetch and data fetch; usage DOES have a significant effect on performance. While the factors you cite can have an effect, experimentation has born out the fact that the basic assertion is valid. ---------------------------------------------------------------------- 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
