On 05/02/2021 12:48, Vincent Guittot wrote:
> idle load balance is the only user of update_nohz_stats and doesn't use
> force parameter. Remove it
Wasn't the 'force=true' from ilb eclipsing the jiffy resolution rate
limiting '!time_after(jiffies, rq->last_blocked_load_update_tick)' of
update_blocked_averages()?
So IMHO this has the (maybe intended) side effect that (formerly forced
updates) are now rate limited on one jiffy resolution too.
>
> Signed-off-by: Vincent Guittot <vincent.guit...@linaro.org>
> ---
> kernel/sched/fair.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index bfe1e235fe01..60b8c1c68ab9 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -8352,7 +8352,7 @@ group_type group_classify(unsigned int imbalance_pct,
> return group_has_spare;
> }
>
> -static bool update_nohz_stats(struct rq *rq, bool force)
> +static bool update_nohz_stats(struct rq *rq)
> {
> #ifdef CONFIG_NO_HZ_COMMON
> unsigned int cpu = rq->cpu;
> @@ -8363,7 +8363,7 @@ static bool update_nohz_stats(struct rq *rq, bool force)
> if (!cpumask_test_cpu(cpu, nohz.idle_cpus_mask))
> return false;
>
> - if (!force && !time_after(jiffies, rq->last_blocked_load_update_tick))
> + if (!time_after(jiffies, rq->last_blocked_load_update_tick))
> return true;
>
> update_blocked_averages(cpu);
> @@ -10404,7 +10404,7 @@ static bool _nohz_idle_balance(struct rq *this_rq,
> unsigned int flags,
>
> rq = cpu_rq(balance_cpu);
>
> - has_blocked_load |= update_nohz_stats(rq, true);
> + has_blocked_load |= update_nohz_stats(rq);
>
> /*
> * If time for next balance is due,
>
