On Wed, Jan 24, 2018 at 09:25:36AM +0100, Vincent Guittot wrote: > @@ -8861,7 +8875,14 @@ static int idle_balance(struct rq *this_rq, struct > rq_flags *rf) > update_next_balance(sd, &next_balance); > rcu_read_unlock(); > > - if (time_after(jiffies, next) && atomic_read(&nohz.stats_state)) > + /* > + * Update blocked idle load if it has not been done for a > + * while. Try to do it locally before entering idle but kick a > + * ilb if it takes too much time and might delay next local > + * wake up > + */ > + if (time_after(jiffies, next) && atomic_read(&nohz.stats_state) > && > + !_nohz_idle_balance(this_rq, NOHZ_STATS_KICK, > CPU_NEWLY_IDLE)) > kick_ilb(NOHZ_STATS_KICK); > > goto out;
This I really dislike. We're here because avg_idle is _really_ low, we really should not then call _nohz_idle_balance().
