On Tuesday, 08/21/2012 at 11:08 EDT, Lu GL Gao <lu...@cn.ibm.com> wrote: > Based on my understanding, machine guests such as linux on z/VM can get cpu > resource by their SHARE value. > For example, LINUXA system has SHARE RELATIVE 100. LINUXB system also has > SHARE RELATIVE 100. So LINUXA and LINUXB both has 50% of real physical > processor resource. > If LINUXA has 2 virtual processors defined in DIRECTORY, and LINUXB has > only 1 virtual processor. What difference between LINUXA and LINUXB? > > Question1: my understanding is following, is it correct? > LINUXA and LINUXB both has 50% of real cpu resource. Because LINUXA has 2 > virtual processors, every virtual processor of it has 25% of real cpu > resource. > > Question2: As far as cpu resource is concerned, what difference between > LINUXA and LINUXB?
For the answer to these two questions, please see the responses to your same questions vis a vis z/OS over on IBMVM. > Question3: usually what factor determines defining multiple virtual > processor for linux guest? Application determines? Yes, it is the application. If it doesn't have highly parallel multi-threading such that it can keep two CPUs working, then the guest ends up doing extra work to deal with two processors without any benefit. Alan Altmark Senior Managing z/VM and Linux Consultant IBM System Lab Services and Training 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 http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
