Messages in this thread | | | Date | Wed, 7 Dec 2022 18:00:32 +0100 | From | Dietmar Eggemann <> | Subject | Re: [PATCH v2 06/22] sched/fair: Collect load-balancing stats for IPC classes |
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On 28/11/2022 14:20, Ricardo Neri wrote:
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> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 224107278471..3a1d6c50a19b 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -9100,6 +9100,57 @@ group_type group_classify(unsigned int imbalance_pct, > return group_has_spare; > } > > +struct sg_lb_ipcc_stats { > + int min_score; /* Min(score(rq->curr->ipcc)) */ > + int min_ipcc; /* Min(rq->curr->ipcc) */ > + long sum_score; /* Sum(score(rq->curr->ipcc)) */ > +};
Wouldn't it be cleaner to put `min_score`, `min_ipcc` and `sum_score` into `struct sg_lb_stats` next to `ipcc_score_{after, before}` under the same #ifdef CONFIG_IPC_CLASSES?
Looks like those IPCC stats would only be needed in the specific condition under which update_sg_lb_stats_scores() is called?
> +#ifdef CONFIG_IPC_CLASSES > +static void init_rq_ipcc_stats(struct sg_lb_ipcc_stats *sgcs) > +{ > + *sgcs = (struct sg_lb_ipcc_stats) { > + .min_score = INT_MAX, > + }; > +} > + > +/** Called only if cpu_of(@rq) is not idle and has tasks running. */ > +static void update_sg_lb_ipcc_stats(struct sg_lb_ipcc_stats *sgcs, > + struct rq *rq) > +{ > + struct task_struct *curr; > + unsigned short ipcc; > + int score; > + > + if (!sched_ipcc_enabled()) > + return; > + > + curr = rcu_dereference(rq->curr); > + if (!curr || (curr->flags & PF_EXITING) || is_idle_task(curr))
So the Idle task is excluded but RT, DL, (Stopper) tasks are not. Looks weird if non-CFS tasks could influence CFS load-balancing. AFAICS, RT and DL tasks could have p->ipcc != IPC_CLASS_UNCLASSIFIED?
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