Messages in this thread | | | From | Valentin Schneider <> | Subject | Re: [PATCH 2/4] sched/deadline: Improve admission control for asymmetric CPU capacities | Date | Wed, 08 Apr 2020 11:42:14 +0100 |
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On 08/04/20 10:50, Dietmar Eggemann wrote: > +++ b/kernel/sched/sched.h > @@ -304,11 +304,14 @@ void __dl_add(struct dl_bw *dl_b, u64 tsk_bw, int cpus) > __dl_update(dl_b, -((s32)tsk_bw / cpus)); > } > > +static inline unsigned long rd_capacity(int cpu); > + > static inline > -bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw) > +bool __dl_overflow(struct dl_bw *dl_b, int cpu, u64 old_bw, u64 new_bw) > { > return dl_b->bw != -1 && > - dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw; > + cap_scale(dl_b->bw, rd_capacity(cpu)) < > + dl_b->total_bw - old_bw + new_bw; > } >
I don't think this is strictly equivalent to what we have now for the SMP case. 'cpus' used to come from dl_bw_cpus(), which is an ugly way of writing
cpumask_weight(rd->span AND cpu_active_mask);
The rd->cpu_capacity_orig field you added gets set once per domain rebuild, so it also happens in sched_cpu_(de)activate() but is separate from touching cpu_active_mask. AFAICT this mean we can observe a CPU as !active but still see its capacity_orig accounted in a root_domain.
> extern void init_dl_bw(struct dl_bw *dl_b);
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