Eric Saxe wrote: > Bill Holler wrote: > >> Madhavan Venkataraman wrote: >> >> >>> Bill Holler wrote: >>> >>> >>>> How often will callouts cause a cross-call to another cpu? >>>> Will this be eliminated with the new per-cpu callout infrastructure? >>>> >>>> >>>> >>>> >>> Callouts, by themselves, don't use X-calls. However, normal callouts are >>> handled via taskq threads. So, waking up a taskq thread will involve >>> the customary preemption actions which will involve X-calls. >>> Also, realtime callouts are typically used to wake up threads. >>> This wake up can involve the same kind of X-calls. >>> There isn't a whole lot we can do about it. >>> >>> >> Thinking out loud: Callouts will often cause threads to be >> dispatched on cpus other then the one the callout/cyclic >> occurred on. We do not currently know how to account >> for this in idle cpu sleep time prediction.... >> Sounds like a job for the Power Aware Dispatcher. :-b >> >> > Yes, the dispatcher can potentially help here....for example, perhaps > some FIFO behavior where the most recently busy CPUs tend to be used > sooner...in which case those CPUs could know that they are in the > "bullpen" or not. >
Would this information be encapsulated in the power processor groups? The idle cpu will check these when it predicts which c-state to attempt to enter. Bill > -Eric > _______________________________________________ > tesla-dev mailing list > tesla-dev at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/tesla-dev >
