On Fri, Mar 22, 2019 at 8:31 AM Abhishek Goel <hunt...@linux.vnet.ibm.com> wrote: > > Currently, the cpuidle governors (menu /ladder) determine what idle state > an idling CPU should enter into based on heuristics that depend on the > idle history on that CPU. Given that no predictive heuristic is perfect, > there are cases where the governor predicts a shallow idle state, hoping > that the CPU will be busy soon. However, if no new workload is scheduled > on that CPU in the near future, the CPU will end up in the shallow state. > > In case of POWER, this is problematic, when the predicted state in the > aforementioned scenario is a lite stop state, as such lite states will > inhibit SMT folding, thereby depriving the other threads in the core from > using the core resources. > > To address this, such lite states need to be autopromoted. The cpuidle- > core can queue timer to correspond with the residency value of the next > available state. Thus leading to auto-promotion to a deeper idle state as > soon as possible.
Isn't the tick stopping avoidance sufficient for that?
