z/OS supports ZIIPs with SMT-2 as well. -----Original Message----- From: Alan Altmark [mailto:alan_altm...@us.ibm.com] Sent: Wednesday, November 8, 2017 5:52 PM To: LINUX-390@VM.MARIST.EDU Subject: Re: How many Intel cores does an IFL emulate
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 https://urldefense.proofpoint.com/v2/url?u=http-3A__www.marist.edu_htbin_wlvindex-3FLINUX-2D390&d=DwIFaQ&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=MQsKeOxcIGeiq-qoJzO2oVgUmKB65Wchl7khwwU0Ijk&m=5m_HW5HHsJo8keiXUnumfx_YUfZORFV-JdasIbf5_GM&s=X8qOnpZWgREJThx0jDDDZGzTZLB1gjvNVXX4EpQno-k&e= ---------------------------------------------------------------------- For more information on Linux on System z, visit https://urldefense.proofpoint.com/v2/url?u=http-3A__wiki.linuxvm.org_&d=DwIFaQ&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=MQsKeOxcIGeiq-qoJzO2oVgUmKB65Wchl7khwwU0Ijk&m=5m_HW5HHsJo8keiXUnumfx_YUfZORFV-JdasIbf5_GM&s=hllBz-_lnaW_LTBx5hYh_fh78xhVSYhBA5FtUXZD-2c&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/
