Messages in this thread Patch in this message | | | From | Valentin Schneider <> | Subject | [PATCH 5/8] sched/fair: Make check_misfit_status() only compare dynamic capacities | Date | Thu, 28 Jan 2021 18:31:38 +0000 |
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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> --- 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
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