On 8/30/05, Carsten Otte <[EMAIL PROTECTED]> wrote: > > Maybe it would be nice if CP could put the guest in some "power saving > > mode" where we know that it will only use resources required to avoid > > bigger damage. How about when Linux would run those emergency tasks > > only on a specific virtual CPU so that CP can tell that work is > > important? > By using sched_setaffinity [see man page] you can bind processes to CPUs if > you want to. How would Linux tell what work is "important" for you? Usually > load-balancing over CPUs is what people want.
But the reason you want that 'usually' is because you assume that these CPU's are yours all the time and would be a waste not to use that. Whether it makes sense to balance over the CPU's on a discrete server is probably to increase the likelyhood that you can maintain affinity when the system gets more busy. But I would say a lot depends on the hardware architecture. When virtualization is added, much of the assumptions there will not apply. But with Linux on z/VM we could in theory provide the same amount of CPU cycles in any number of logical CPU's. I could imagine CP to put the machine in reduced service and dispatch only the virtual CPU that has a new PSW that identifies kernel mode work. But to keep the network up we probably need more than that. Rob -- Rob van der Heij rvdheij @ gmail.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
