Classification: Confidential Agreed!
-----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Anthony Hirst Sent: Tuesday, March 5, 2024 7:18 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: How to reduce the overhead of WLM? [CAUTION: This Email is from outside the Organization. Unless you trust the sender, Don’t click links or open attachments as it may be a Phishing email, which can steal your Information and compromise your Computer.] If you are running a lot of CICS regions, you might want to look at reducing the mastask values, my understanding is that WLM create's PB for every possible active task in CICS and they get scanned every 250 ms too. On Mon, Mar 4, 2024 at 10:15 PM Jim Mulder <d10j...@us.ibm.com> wrote: > The most important thing is RMPTTOM for reducing the SRM timer pop > overhead. > Note that Timer DIE processing is uncaptured time. > > My IEAOPTxx for running under VM has > > RMPTTOM=30000 /*REDUCE SRM INVOKATION FREQUENCY ON VM */ > > And that is a value we set a couple of decades ago, and haven't > thought much about it since. > You might want it even higher for faster machines than we had back then. > > I suggested some years ago that SRM should self-tune the timer pop > interval to be less frequent at low utilization, but I haven't gotten > any traction on that so far.. > > Jim Mulder > > > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On > Behalf Of Wendell Lovewell > Sent: Monday, March 4, 2024 6:08 PM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: How to reduce the overhead of WLM? > > This is probably a strange question, but is there a way to reduce WLM cpu > usage? Here's the situation: > > - The system is a lightly used development system. Unless something > is in a loop (very rare), CPU % probably is usually less than 10%. > And except for system regions & CICS, it's rare to have multiple jobs > running concurrently. > - Only one processor defined to the VM. No ZIIP either. > - We are charged for CPU cycles. > - WLM is the highest consumer of CPU. JES2, TCPIP, ZFS and SDSFAUX > round out the top 5 consumers. > > There is a lot of information about WLM tuning, but as best I can tell > almost none of it relates to reducing WLM usage. > > From reading the Init & Tuning manual, I'm trying these settings: > AIMANAGEMENT=NO > HIPERDISPATCH=NO > CCCAWMT=450000 > RMPTTOM=15000 > > I was thinking that perhaps reducing whatever processing intervals I > could might help. But I can't tell these changes made a difference. > (I don't have a tool to measure WLM usage.) > > Any suggestions would be appreciated. > > TIA, > > Wendell > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send > email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send > email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ::DISCLAIMER:: ________________________________ The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. E-mail transmission is not guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or may contain viruses in transmission. The e mail and its contents (with or without referred errors) shall therefore not attach any liability on the originator or HCL or its affiliates. Views or opinions, if any, presented in this email are solely those of the author and may not necessarily reflect the views or opinions of HCL or its affiliates. Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of this message without the prior written consent of authorized representative of HCL is strictly prohibited. If you have received this email in error please delete it and notify the sender immediately. Before opening any email and/or attachments, please check them for viruses and other defects. ________________________________ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
