On Tue, 31 Jan 2023 22:17:18 +0000 Will Deacon <will@xxxxxxxxxx>
>
> +static const struct cpumask *__cs_cpus_allowed(struct cpuset *cs)
> +{
> + const struct cpumask *cs_mask = cs->cpus_allowed;
> + if (!parent_cs(cs))
> + cs_mask = cpu_possible_mask;
> + return cs_mask;
> +}
> +
> +static void cs_cpus_allowed(struct cpuset *cs, struct cpumask *pmask)
> +{
> + do {
> + cpumask_and(pmask, pmask, __cs_cpus_allowed(cs));
> + cs = parent_cs(cs);
> + } while (cs);
> +}
If it is not typo, why is it needed here to spiral the cs hierarchy up,
given the same spiralup below?
> void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
> {
> unsigned long flags;
> + struct cpuset *cs;
>
> spin_lock_irqsave(&callback_lock, flags);
> - guarantee_online_cpus(tsk, pmask);
> + rcu_read_lock();
> +
> + cs = task_cs(tsk);
> + do {
> + cpumask_copy(pmask, task_cpu_possible_mask(tsk));
> + cs_cpus_allowed(cs, pmask);
> +
> + if (cpumask_intersects(pmask, cpu_online_mask))
> + break;
> +
> + cs = parent_cs(cs);
> + } while (cs);
> +
> + rcu_read_unlock();
> spin_unlock_irqrestore(&callback_lock, flags);
> }
>
> --
> 2.39.1.456.gfc5497dd1b-goog
