It really depends on what you're doing with REXX that's causing it to munch CPU. I associate CPU usage with slow processing, and since I'm not the perf & tune guy, I really only care about how long I have to wait for my code to execute to completion and do so without adversely affecting others.
Recently, I was converting hex IP addresses and running a loop to do NSLOOKUP on all of them to get the DNS. This was slow. So I added an array for the hex IP with the results of the NSLOOKUP, and then checked it for the DNS info instead of calling NSLOOKUP when I already had the DNS. Ultimately, about 90% of the IPs were the same and my stuff ran a whole lot faster. Things I do as a course of habit: -large files, do not read the whole file into an array, read in and write out one record at a time. Normal system i/o and blocking not affected by REXX EXECIO 1 record at a time read/write (which is assumed to be optimized by the JCL/ALLOCATE). -medium large files, after processing a record from the array, set it to null so to keep memory usage from doubling as output records are created. -use DROP to free memory for any array that's no longer needed All I can think of at the moment. In general, don't do or use anymore than is necessary. What does your REXX do? --- On Wed, 3/21/12, Tim Brown <tbr...@cenhud.com> wrote: From: Tim Brown <tbr...@cenhud.com> Subject: rexx cpu intensive To: IBM-MAIN@bama.ua.edu Date: Wednesday, March 21, 2012, 11:38 AM What can be done to prevent REXXX programs from being so CPU intensive Thanks, Tim Brown Systems Specialist - Project Leader Central Hudson Gas & Electric 284 South Ave Poughkeepsie, NY 12601 Email: tbr...@cenhud.com <<mailto:tbr...@cenhud.com>> Phone: 845-486-5643 Fax: 845-486-5921 Cell: 845-235-4255 This message contains confidential information and is only for the intended recipient. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, please notify the sender immediately by replying to this note and deleting all copies and attachments. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
