Hi Aubrey, Li, Aubrey wrote: > The policy seems not to be good. > It prevents the core from going into idle. When the new kthread is idle > thread, > the policy will change the power state to low power state, this calls > speedstep > power interface on IA platform, which is implemented by xcall. the core > may > spend some time to grab highest mutex here. > I'd like to see this done in a way that doesn't require the xcall. Is it possible to do the P-State transition such that one CPU (the current CPU), affects the whole P-state domain, eliminating the need for the xcall?
> P-state policy implemented in cmt thread switch here seems not to be a > good > idea. Are you saying this because a xcall would be needed? > We can't upgrade or downgrade the speed level just by the old > thread or > the new thread is idle thread. That's the implementation of the current (rather naive) policy. It's really about utilization of the P-state domain, and currently that utilization is tracked by looking at transitions between idle and non-idle threads. > We probably still need change it > according to the > system workload. > Why not on a (P-state) domain by domain basis? We're trying to made some headway towards optimizing for larger systems that are only partially utilized....which is difficult to do considering the system wide workload... Thanks, -Eric > Thanks, > -Aubrey > >
