All, This a great discussion, what about a 64bit program doing dasd I/O for example? I saw a Share.org presentation by the father of HLASM and he had a tri-modal program, it did I/O below the line and moved data to Above the bar ...
Scott On Tue, Mar 28, 2017 at 5:34 AM Martin Packer <[email protected]> wrote: > It's basically "give people what they need, ahead of when they need it". > > > > I'm glad Development take this approach; I'd like them to spend effort / > > time / money where it's really needed. And doing it all in one go, > > whatever "it all" might be, would've taken us longer to get what was > > needed out the door. > > > > To reminisce only a tiny bit, I was involved in several customer > > situations in the late 1990's where 2GB central storage on an LPAR was not > > enough. I'm really glad we fixed THAT bit first. > > > > Cheers, Martin > > > > Martin Packer, > > zChampion, Principal Systems Investigator, > > Worldwide Cloud & Systems Performance, IBM > > > > +44-7802-245-584 > > > > email: [email protected] > > > > Twitter / Facebook IDs: MartinPacker > > > > Blog: > > https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker > > > > Podcast Series (With Marna Walle): https://developer.ibm.com/tv/mpt/ or > > > > > https://itunes.apple.com/gb/podcast/mainframe-performance-topics/id1127943573?mt=2 > > > > > > > > From: "Blaicher, Christopher Y." <[email protected]> > > To: [email protected] > > Date: 28/03/2017 00:01 > > Subject: Re: 64 bit execution above the bar > > Sent by: IBM Mainframe Discussion List <[email protected]> > > > > > > > > It's called z/OS is not the only thing that runs on a 64-bit machine. I > > haven't looked into all the particulars, but I have heard someplace that > > 'C' can run in 64-bit under z/LINUX. > > > > I think this is more a case of not wanting to have to re-write half of the > > operating system and have dual API's for everything when it isn't needed. > > At least not yet. > > > > Because they have done some work in that direction, it seems to me they > > are taking small deliberate steps to get there. > > > > I know nothing as fact, just a lot of looking at the tea leaves. > > > > Chris Blaicher > > Technical Architect > > Mainframe Development > > Syncsort Incorporated > > 2 Blue Hill Plaza #1563, Pearl River, NY 10965 > > > > P: 201-930-8234 | M: 512-627-3803 > > E: [email protected] > > > > www.syncsort.com > > > > CONNECTING BIG IRON TO BIG DATA > > > > > > -----Original Message----- > > From: IBM Mainframe Discussion List [mailto:[email protected]] On > > Behalf Of Charles Mills > > Sent: Monday, March 27, 2017 6:11 PM > > To: [email protected] > > Subject: Re: 64 bit execution above the bar > > > > The fact that the hardware guys and gals made the hardware capable of > > execution above the bar means IBM is giving this some thought. (The > > thought may be "Heck, no!" <g>) > > > > Charles > > > > -----Original Message----- > > From: IBM Mainframe Discussion List [mailto:[email protected]] On > > Behalf Of Paul Gilmartin > > Sent: Monday, March 27, 2017 5:00 PM > > To: [email protected] > > Subject: Re: 64 bit execution above the bar > > > > On Mon, 27 Mar 2017 15:19:31 -0500, Dave Anderson wrote: > > > > >What is IBM's strategy for migrating code execution to be above the bar? > > Has IBM released any documents detailing the next steps, or is this > > confidential? > > > > > It has been discussed here for a while. You could disable interrupts, > > branch to code above the bar, and branch back later. (I suppose the Old > > PSW was unconditionally scrunched.) More recently, interrupts above the > > bar are tolerated, but no system services can be called from above the > > bar. > > > > >Currently data areas above the bar are widely used but program execution > > above the bar is not currently supported. Other posts have suggested that > > Cobol will soon support 64 bit execution but not only for modules loaded > > below the bar and that 64 bit Cobol is unlikely to be widely used as it is > > not compatible with 31 bit Cobol and has performance issues. > > > > > Performance issues have been mentioned here. Are those because of: > > o I-fetch bandwidth? > > o Address calculation/translation overhead? > > o Computation overhead? > > o Some combination? > > > > I'd guess that instructions with 64-bit operands are slower than > > instructions with shorter operands, even in AMODE 24/31. > > > > Is AMODE 31 slower than AMODE 24? (Or even the opposite?) > > > > >Does anybody know if IBM plans to run system modules above the bar? I > > would be interested in hearing any comments/insights on this topic? > > > > > Not I. How close is LPA to encountering a Virtual Address Storage > > Constraint? > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, send email > > to [email protected] with the message: INFO IBM-MAIN > > > > ________________________________ > > > > > > > > ATTENTION: ----- > > > > The information contained in this message (including any files transmitted > > with this message) may contain proprietary, trade secret or other > > confidential and/or legally privileged information. Any pricing > > information contained in this message or in any files transmitted with > > this message is always confidential and cannot be shared with any third > > parties without prior written approval from Syncsort. This message is > > intended to be read only by the individual or entity to whom it is > > addressed or by their designee. 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