On Tue, 2007-07-24 at 16:39 -0400, Chris Snook wrote: > Divining the intentions of the administrator is an AI-complete problem and > we're > not going to try to solve that in the kernel. An intelligent administrator > could also allocate 50% of each CPU to a resource group containing all the > *other* processes. Then, when the other processes are scheduled out, your > single task will run on whichever CPU is idle. This will very quickly > equilibrate to the scheduling ping-pong you seem to want. The scheduler > deliberately avoids this kind of migration by default because it hurts cache > and > TLB performance, so if you want to override this very sane default behavior, > you're going to have to explicitly configure it yourself. >
Well, the admin wouldn't specifically ask for 50% of each CPU. He would just allocate 50% of total CPU time---it's up to the scheduler to fulfill that. If a task is entitled to one CPU, then it'll stay there and have no migration. Migration occurs only if there's overload, in which case I think you agree in your last email that the cache and TLB impact is not an issue (at least in SMP). tong - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
