Re: [PATCH] bpf: Simplify code by using for_each_cpu_wrap()

[Alexei Starovoitov]

On Wed, Aug 17, 2022 at 6:08 AM Punit Agrawal
<punit.agrawal@xxxxxxxxxxxxx> wrote:
>
> No functional change intended.

?

> -       orig_cpu = cpu = raw_smp_processor_id();
> -       while (1) {
> +       for_each_cpu_wrap(cpu, cpu_possible_mask, raw_smp_processor_id()) {
>                 struct pcpu_freelist_head *head;
>
>                 head = per_cpu_ptr(s->freelist, cpu);
> @@ -68,15 +67,10 @@ static inline void ___pcpu_freelist_push_nmi(struct pcpu_freelist *s,
>                         raw_spin_unlock(&head->lock);
>                         return;
>                 }
> -               cpu = cpumask_next(cpu, cpu_possible_mask);
> -               if (cpu >= nr_cpu_ids)
> -                       cpu = 0;
> -
> -               /* cannot lock any per cpu lock, try extralist */
> -               if (cpu == orig_cpu &&
> -                   pcpu_freelist_try_push_extra(s, node))
> -                       return;
>         }
> +
> +       /* cannot lock any per cpu lock, try extralist */
> +       pcpu_freelist_try_push_extra(s, node);

This is obviously not equivalent!