Subject: Re: [PATCH net-next,v2 01/18] net/sched: sch_api: add helper for tc qdisc walker stats dump

From: Toke Høiland-Jørgensen <[email-masked]>
Date: Tue, 20 Sep 2022 15:45:25 +0200

Zhengchao Shao <[email-masked]> writes:

> The walk implementation of most qdisc class modules is basically the
> same. That is, the values of count and skip are checked first. If
> count is greater than or equal to skip, the registered fn function is
> executed. Otherwise, increase the value of count. So we can reconstruct
> them.
>
> Signed-off-by: Zhengchao Shao <[email-masked]>
> ---
>  include/net/pkt_sched.h | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
> index 29f65632ebc5..243e8b0cb7ea 100644
> --- a/include/net/pkt_sched.h
> +++ b/include/net/pkt_sched.h
> @@ -222,4 +222,17 @@ static inline struct tc_skb_cb *tc_skb_cb(const struct sk_buff *skb)
>  	return cb;
>  }
>  
> +static inline bool tc_qdisc_stats_dump(struct Qdisc *sch,
> +				       struct qdisc_walker *arg,
> +				       unsigned long cl)
> +{
> +	if (arg->count >= arg->skip && arg->fn(sch, cl, arg) < 0) {

Seems a bit confusing that tc_qdisc_stats_dump() reverses the order of
the 'cl' and 'arg' parameters relative to the callback?

-Toke