Re: [PATCH 1/2] sched/topology: build_sched_groups: Skip duplicate group rewrites
From: Qais Yousef
Date: Wed Apr 10 2019 - 06:31:44 EST
On 04/10/19 11:17, Valentin Schneider wrote:
> On 10/04/2019 10:27, Qais Yousef wrote:
> >> @@ -1066,9 +1067,14 @@ static struct sched_group *get_group(int cpu, struct sd_data *sdd)
> >> sg = *per_cpu_ptr(sdd->sg, cpu);
> >> sg->sgc = *per_cpu_ptr(sdd->sgc, cpu);
> >> - /* For claim_allocations: */
> >> - atomic_inc(&sg->ref);
> >> - atomic_inc(&sg->sgc->ref);
> >> + /* Increase refcounts for claim_allocations: */
> >> + already_visited = atomic_inc_return(&sg->ref) > 1;
> >> + /* sgc visits should follow a similar trend as sg */
> >> + WARN_ON(already_visited != (atomic_inc_return(&sg->sgc->ref) > 1));
> > NIT: I think it would be better to not have any side effect of calling
> > WARN_ON(). Ie: do the atomic_inc_return() outside the WARN_ON() condition.
> > Having two bool already_visited_sg and already_visited_sgc will make the code
> > more readable too.
> I agree it's not the nicest reading flow there is. It's already gone in
> tip/sched/core but if needed I can resend with this extra separation.
It was just a nit from my side. So for me it's not worth a resend if it's