IARV64 pagefix will cause demotion if the area is not 1MB on a 1MB boundary. This was fixed in z/os 2.3 ... what release/ptf level are you running?
On Wed, Jun 2, 2021 at 6:12 AM Crawford, Robert C. < 000001feadb2c2d2-dmarc-requ...@listserv.ua.edu> wrote: > I've been trying to track down what's causing system 1M page demotions on > our test system. The component trace IBM gave me shows, in part: > > SYS5 SGTDEM64 00000063 12:44:53.270019 Demote 1M 64 bit page > FUNC1... COPYSRVH High Virtual Copy Service > JOBN1... ZUMCCMG1 ASID1... 0215 PLOCKS.. 8800C001 CPU..... 0006 > JOBN2... ZUMCCMG3 ASID2... 022D RLOCKS.. 8800C001 RLOCKDET 0800 > KEY..... 0036 ADDR.... 035E1008 ALET.... 00000000 > > The COPYSRVH function isn't well documented but, from I see, UNIX fork > processing invokes it to copy memory to the new process. This makes sense > in that JOBN1 and JOBN3 are both USS processes. > > Both LFAREA and SCM on this system are less than 1% used. Why is z/OS > demoting pages? > > Thanks. > > Robert Crawford > Mainframe Management > United Services Automobile Association > (210) 913-3822 > > « Des clochards comme nous, bébé nous sommes nés pour courir » - Voltaire > Please send requests to mainframe management through our front door at > go/mfmfrontdoor< > https://onc.jira.usaacloud.com/secure/Dashboard.jspa?selectPageId=15466> > > Classification: Internal > > Disclaimer: This email and any attachments are the property of USAA and > may contain confidential and/or privileged material. If you are not the > intended recipient, any use, disclosure or copying of this email or any > attachments is unauthorized. If you received this email in error, please > immediately notify the sender and delete the email and any attachments from > your computer. > > > ---------------------------------------------------------------------- > 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
