On Tue, Feb 26, 2019 at 3:54 PM Ulf Hansson <[email protected]> wrote: > > A common piece of data used by cpuidle governors, is the information about > when the next timer/tick is going to fire. Rather than having each governor > calling tick_nohz_get_next_timer|hrtimer() separately, let's consolidate > the code by calling these functions before invoking the ->select() callback > of the governor - and store the output data in the struct cpuidle_device.
That misses the point IMO. You don't need to store two values in struct cpuidle_device, but just one, and not before running ->select(), but before invoking the driver's ->enter() callback. At that point, the decision on whether or not to stop the scheduler tick has been made already and it should be sufficient to store the return value of tick_nohz_get_next_hrtimer() introduced by patch [3/8], because that value represents the next timer regardless of what has been decided with respect to the tick. And you won't need the tick_nohz_get_next_timer() any more then.
