On Wed, Feb 18, 2009 at 7:41 AM, Mark Perry <[email protected]> wrote:
>> Why would idle virtual processors be in the dispatch list? >> > > Spin locks ;-) I can see your smiley, so I take it you don't really think that an idle processor would cause lock contention looking for work (though this situation is not uncommon in an office environment...). My main concern for spreading ones small amount of work over multiple virtual CPUs is z/VM memory management. It is already hard enough on a virtual one-way to have long enough periods of silence that the virtual machine can drop from queue. When you spread it over multiple virtual CPUs, times are very rare that CP will find all CPUs idle long enough at the same time. So even when individual virtual CPUs drop from queue, CP does not find a chance to do memory management. 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
