Thank you for clarifying the threadability of an IFL CP. I worked w/ a fellow who went to work in one of the labs in Vermont working on "hyperthreading" for the pSeries CPUs... I seem to recall him talking about efforts for the zSeries CPs but that seemed a long ask.
-soup On Wed, Nov 8, 2017 at 8:52 PM, Alan Altmark <alan_altm...@us.ibm.com> wrote: > Thanks for advertising, Soup! :-) > > In fact, IFLs are the only engines on Z that have SMT-2, where each core > in the LPAR splits in two, appearing to the host as twice the number of > CPUs. > Alan > > Sent from my iPhone using IBM Verse > > On Nov 8, 2017, 8:36:39 PM, soup...@gmail.com wrote: > > From: soup...@gmail.com > To: LINUX-390@VM.MARIST.EDU > Cc: > Date: Nov 8, 2017, 8:36:39 PM > Subject: Re: [LINUX-390] How many Intel cores does an IFL emulate > > > Come to think of it, I think an IFL is a single zSeries core. z/VM can > fake it, though that's "overcommitting" the CPU resource. > Despite my NOT looking at the zSeries Principles of Operation I somehow > doubt the zSeries has hyperthreading... as the z/VM OS would be dispatch > threads. On the Intel CPUs, Linux is pretty smart in making a > hyperthreaded CPU "double" the number of dispatchable resources... for > each "core" built into the die. > So I'm going to boast about my ignorance; I don't think an IFL CP > implies > multiple "cores" handling the zSeries instruction set. > -soup > On Wed, Nov 8, 2017 at 7:35 PM, Alan Altmark > wrote: > > On Wednesday, 11/08/2017 at 09:55 GMT, Philipp Kern > > wrote: > > > I thought unused CP capacity was literally costing OpEx whereas IFLs > > > would be CapEx? If it's both OpEx, then yes, agreed. (And I suppose > > > originally there might have been deals about giving some IFLs with > > > upgrades? ;-) > > > > Eh? Processors are processors: CP, IFL, zIIP, CF, whatever. > > > > - Processor purchase: CapEx > > - Processor rental: OpEx > > - Processor recurring maintenance: OpEx > > - Software one-time-charge (z/VM): CapEx > > - OTC software recurring maintenance: OpEx > > - Monthly software charges (z/OS): OpEx > > > > This is why z/OS usage is so carefully monitored and controlled. You > can > > budget a large spike for a capital purchase, but uncontrolled monthly > > software charges create monthly budget crises. > > > > By adding capacity, you increase the software costs. > > > > If your software is priced per CPU (z/VM, Linux), then you will know > that > > when you add a CPU, you also need to add money for licenses, and you > know > > exactly what your maintenance bill will be. Over-configured machines > > typically mean over-paying for your software and wasting money on > > maintenance charges on something you're not using. > > > > If your software is priced based on capacity rather than the number of > > CPUs, as z/OS is, then you typically look at subcapacity billing models > > that let you configure your hardware for spikes, but hold the rolling > > 4-hour average to a lower level. There are mechanisms in z/OS that > can be > > configured to thwart it's natural tendency (common to all OSes) to run > as > > much as it can as fast as it using all the resources at its disposal. > > > > No rule applies 100% of the time (except this one), so there can be > > variations and combinations. > > > > Alan Altmark > > > > Senior Managing z/VM and Linux Consultant > > IBM Systems Lab Services > > IBM Z Delivery Practice > > ibm.com/systems/services/labservices > > office: 607.429.3323 > > mobile; 607.321.7556 > > alan_altm...@us.ibm.com > > IBM Endicott > > > > ---------------------------------------------------------------------- > > For LINUX-390 subscribe / signoff / archive access instructions, > > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 > or > > visit > > https://urldefense.proofpoint.com/v2/url?u=http-3A__www. > marist.edu_htbin_wlvindex-3FLINUX-2D390&d=DwIBaQ&c=jf_ > iaSHvJObTbx-siA1ZOg&r=XX3LPhXj6Fv4hkzdpbonTd1gcy88ea-vqLQGEWWoD4M&m= > eYU776321iiJg2XjRTylqK4_Sz9wjs0WKrKDOmwzhb8&s= > VcV1mJ2gCYKMenPFgZ5fOGyenJ87wpav1R-3MTMwkRA&e= > > ---------------------------------------------------------------------- > > For more information on Linux on System z, visit > > https://urldefense.proofpoint.com/v2/url?u=http-3A__wiki. > linuxvm.org_&d=DwIBaQ&c=jf_iaSHvJObTbx-siA1ZOg&r= > XX3LPhXj6Fv4hkzdpbonTd1gcy88ea-vqLQGEWWoD4M&m=eYU776321iiJg2XjRTylqK4_ > Sz9wjs0WKrKDOmwzhb8&s=l6b7c2i0QG7nmc3lYnkNPEDNmbRK5ZGaZAhI7gGU5OY&e= > > > -- > John R. Campbell Speaker to Machines souperb at gmail > dot > com > MacOS X proved it was easier to make Unix user-friendly than to fix > Windows > "It doesn't matter how well-crafted a system is to eliminate errors; > Regardless > of any and all checks and balances in place, all systems will fail > because, > somewhere, there is meat in the loop." - me > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 > or visit > https://urldefense.proofpoint.com/v2/url?u=http-3A__www. > marist.edu_htbin_wlvindex-3FLINUX-2D390&d=DwIBaQ&c=jf_ > iaSHvJObTbx-siA1ZOg&r=XX3LPhXj6Fv4hkzdpbonTd1gcy88ea-vqLQGEWWoD4M&m= > eYU776321iiJg2XjRTylqK4_Sz9wjs0WKrKDOmwzhb8&s= > VcV1mJ2gCYKMenPFgZ5fOGyenJ87wpav1R-3MTMwkRA&e= > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > https://urldefense.proofpoint.com/v2/url?u=http-3A__wiki. > linuxvm.org_&d=DwIBaQ&c=jf_iaSHvJObTbx-siA1ZOg&r= > XX3LPhXj6Fv4hkzdpbonTd1gcy88ea-vqLQGEWWoD4M&m=eYU776321iiJg2XjRTylqK4_ > Sz9wjs0WKrKDOmwzhb8&s=l6b7c2i0QG7nmc3lYnkNPEDNmbRK5ZGaZAhI7gGU5OY&e= > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > -- John R. Campbell Speaker to Machines souperb at gmail dot com MacOS X proved it was easier to make Unix user-friendly than to fix Windows "It doesn't matter how well-crafted a system is to eliminate errors; Regardless of any and all checks and balances in place, all systems will fail because, somewhere, there is meat in the loop." - me ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
