On Tue, Feb 26, 2019 at 11:08 PM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote: > > On Tue, Feb 26, 2019 at 3:54 PM Ulf Hansson <ulf.hansson@xxxxxxxxxx> 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], Or the difference between in and ts->idle_entrytime for that matter, whichever is more useful. > 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.
