zIIP dispatching is the same as GP dispatching. ZIIPAWMT has analogous parameters for GP (CCCAWMT) and zAAP (ZAAPAWMT). Alternate wait management was created long before there were specialty engines.
Jim Mulder z/OS Diagnosis, Design, Development, Test IBM Corp. Poughkeepsie NY "IBM Mainframe Discussion List" <IBM-MAIN@LISTSERV.UA.EDU> wrote on 06/09/2018 10:58:25 AM: > From: "Christopher Y. Blaicher" <cblaic...@syncsort.com> > To: IBM-MAIN@LISTSERV.UA.EDU > Date: 06/09/2018 12:46 PM > Subject: Re: Why are highly busy zIIPs worse than highly busy CPs? > Sent by: "IBM Mainframe Discussion List" <IBM-MAIN@LISTSERV.UA.EDU> > > Peter, > I started off as saying, a lot of the descriptions are based on > assumptions, as IBM has let out little on how the zIIP dispatcher works. > > Also, I was only talking about SRBs on zIIPs, so non-enclave SRBs > were not part of the discussion. > > I believe hyper dispatch is very different from zIIP dispatch. I > stand by my assumption that GP dispatch is very different from zIIP > dispatch, or why would there be the ZIIPAWMT parameter and have the > comment about waking up after that interval to see if there is work. > When non-zIIP work comes ready and a processor is free, the work is > dispatched. No waiting. The comments in the parameter description > for ZIIPAWMT is describing a polling environment, at least to me. > > I have looked through the internet, OK not the be-all and end-all > but a reasonable place to start, and there is a lot on what can get > dispatched on a zIIP, but no detail on how. > > As I said, I wish someone from IBM would at least chime in with some > level of description as to how zIIP dispatch works and why high zIIP > utilization rates are, shall we say, not good. Then maybe we can > stop guessing. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
