On 03/02/2021 16:15, Qais Yousef wrote:
> On 01/28/21 18:31, Valentin Schneider wrote:
[...]
>> @@ -10238,7 +10236,7 @@ static void nohz_balancer_kick(struct rq *rq)
>> * When ASYM_CPUCAPACITY; see if there's a higher capacity CPU
>> * to run the misfit task on.
>> */
>> - if (check_misfit_status(rq, sd)) {
>> + if (check_misfit_status(rq)) {
Since check_misfit_status() doesn't need sd anymore it looks like that
rcu_dereference(per_cpu(sd_asym_cpucapacity, cpu)) could be replaced by
static_branch_unlikely(&sched_asym_cpucapacity)) in nohz_balancer_kick().
But as you mentioned in an earlier conversation we do need to check sd
because of asymmetric CPU capacity systems w/ exclusive cpusets which
could create symmetric islands (unique capacity_orig among CPUs).
Maybe worth putting a comment here (similar to the one in sis()) so
people don't try to optimize?
