Re: [PATCH v2 1/2] percpu: Add percpu_counter_add_local

From: Shakeel Butt
Date: Mon Sep 05 2022 - 15:32:08 EST


On Tue, Sep 06, 2022 at 03:35:16AM +0800, Jiebin Sun wrote:
> Add percpu_counter_add_local for only updating local counter
> without aggregating to global counter.

Please add why do we need this. Who should use this and who shouldn't.

>
> Signed-off-by: Jiebin Sun <jiebin.sun@xxxxxxxxx>

[...]

> diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c
> index ed610b75dc32..d33cb750962a 100644
> --- a/lib/percpu_counter.c
> +++ b/lib/percpu_counter.c
> @@ -72,6 +72,12 @@ void percpu_counter_set(struct percpu_counter *fbc, s64 amount)
> }
> EXPORT_SYMBOL(percpu_counter_set);
>

Add a doc comment here on why someone want to use this?

> +void percpu_counter_add_local(struct percpu_counter *fbc, s64 amount)
> +{
> + this_cpu_add(*fbc->counters, amount);
> +}
> +EXPORT_SYMBOL(percpu_counter_add_local);
> +
> /*
> * This function is both preempt and irq safe. The former is due to explicit
> * preemption disable. The latter is guaranteed by the fact that the slow path
> --
> 2.31.1
>