Messages in this thread | | | Date | Wed, 3 Feb 2021 15:15:46 +0000 | From | Qais Yousef <> | Subject | Re: [PATCH 5/8] sched/fair: Make check_misfit_status() only compare dynamic capacities |
| |
On 01/28/21 18:31, Valentin Schneider wrote: > check_misfit_status() checks for both capacity pressure & available CPUs > with higher capacity. Now that we have a sane(ish) capacity comparison > margin which is used throughout load-balance, this can be condensed into a > single check: > > capacity_greater(<root_domain max capacity>, <misfit task CPU's capacity>); > > This has the added benefit of returning false if the misfit task CPU's is > heavily pressured, but there are no better candidates for migration. > > Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> > ---
check_cpu_capacity() call looks redundant now, yes.
Reviewed-by: Qais Yousef <qais.yousef@arm.com>
Thanks
-- Qais Yousef
> kernel/sched/fair.c | 10 ++++------ > 1 file changed, 4 insertions(+), 6 deletions(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 0959a770ecc0..ef44474b8fbf 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -8254,14 +8254,12 @@ check_cpu_capacity(struct rq *rq, struct sched_domain *sd) > > /* > * Check whether a rq has a misfit task and if it looks like we can actually > - * help that task: we can migrate the task to a CPU of higher capacity, or > - * the task's current CPU is heavily pressured. > + * help that task: we can migrate the task to a CPU of higher capacity. > */ > -static inline int check_misfit_status(struct rq *rq, struct sched_domain *sd) > +static inline int check_misfit_status(struct rq *rq) > { > return rq->misfit_task_load && > - (capacity_greater(rq->rd->max_cpu_capacity, rq->cpu_capacity_orig) || > - check_cpu_capacity(rq, sd)); > + capacity_greater(rq->rd->max_cpu_capacity, rq->cpu_capacity); > } > > /* > @@ -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)) { > flags = NOHZ_KICK_MASK; > goto unlock; > } > -- > 2.27.0 >
| |