Messages in this thread Patch in this message | | | From | Vincent Guittot <> | Subject | [PATCH 1/2] sched/fair: skip newidle update stats | Date | Fri, 12 Nov 2021 10:58:56 +0100 |
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In case we skip the newly idle LB entirely or we abort it because we are going to exceed the avg_idle, we have to make sure to not start an update of the blocked load when entering idle
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> --- kernel/sched/fair.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 13950beb01a2..a162b0ec8963 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -10861,7 +10861,7 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf) int this_cpu = this_rq->cpu; u64 t0, t1, curr_cost = 0; struct sched_domain *sd; - int pulled_task = 0; + int pulled_task = 0, early_stop = 0; update_misfit_status(NULL, this_rq); @@ -10898,8 +10898,16 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf) if (!READ_ONCE(this_rq->rd->overload) || (sd && this_rq->avg_idle < sd->max_newidle_lb_cost)) { - if (sd) + if (sd) { update_next_balance(sd, &next_balance); + + /* + * We skip new idle LB because there is not enough + * time before next wake up. Make sure that we will + * not kick NOHZ_NEWILB_KICK + */ + early_stop = 1; + } rcu_read_unlock(); goto out; @@ -10918,8 +10926,10 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf) update_next_balance(sd, &next_balance); - if (this_rq->avg_idle < curr_cost + sd->max_newidle_lb_cost) + if (this_rq->avg_idle < curr_cost + sd->max_newidle_lb_cost) { + early_stop = 1; break; + } if (sd->flags & SD_BALANCE_NEWIDLE) { @@ -10969,7 +10979,7 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf) if (pulled_task) this_rq->idle_stamp = 0; - else + else if (!early_stop) nohz_newidle_balance(this_rq); rq_repin_lock(this_rq, rf); -- 2.17.1
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