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charset="utf-8" In sched_balance_newidle(), rq->avg_idle is checked against sd->max_newidle_lb_cost in two places. However these two conditional checks are logically duplicated: sched_balance_newidle() { u64 curr_cost =3D 0; [...] (!get_rd_overloaded(this_rq->rd) || (sd && this_rq->avg_idle < sd->max_newidle_lb_cost)) [1] { [...] goto out; } [...] sched_balance_update_blocked_averages(this_cpu); for_each_domain(this_cpu, sd) { [...] if (this_rq->avg_idle < curr_cost + sd->max_newidle_lb_cost) [2] break; [...] } [...] out: [...] } In the first for_each_domain() loop curr_cost is 0, so conditional check [1] and [2] are same. This patch removed conditional check [1]. After the patch, more cpu cycles might be spent in sched_balance_update_blocked_averages() if [1] is true. However benchmark shows the patch does not change performance. Tested with schbench and Specjbb on AmpereOne CPU. The schbench command is: ./schbench -L -m 4 -M auto -t 256 -n 0 -r 0 -s 0 Signed-off-by: Adam Li --- kernel/sched/fair.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 5b752324270b..bbbe48ae6614 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -12825,8 +12825,7 @@ static int sched_balance_newidle(struct rq *this_rq= , struct rq_flags *rf) rcu_read_lock(); sd =3D rcu_dereference_check_sched_domain(this_rq->sd); =20 - if (!get_rd_overloaded(this_rq->rd) || - (sd && this_rq->avg_idle < sd->max_newidle_lb_cost)) { + if (!get_rd_overloaded(this_rq->rd)) { =20 if (sd) update_next_balance(sd, &next_balance); --=20 2.34.1