On Wed, Dec 31, 2008 at 11:38 AM, Harder, Pieter <[email protected]> wrote:
> Just for clarification, you are talking 'other virtual machines', I am > talking 'other VMBKs'. There is a difference there in my opinion. Another > VMBK may very well be your own sibling in a virtual N-way configuration. The > worst case for this would be in the (of course not recommended) situation > when there are more virtual cpu's defined to the vm than there are real cpu's > available. Then steal time basically becomes wait-om-myself time, true? You're correct. A simple way to show CPU contention is to define a virtual 2-way when z/VM has only one logical CPU. With two threads looping, vmstat shows me 49% user and 51% steal. Since CP will try to give both virtual CPUs an equal share of the real resources, Linux will see two CPUs running at half speed effectively. Rob -- Rob van der Heij Velocity Software http://www.velocitysoftware.com/ ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
