Subject: Re: [RFC][PATCH] QoS TBF and latency configuration misbehavior

From: Jarek Poplawski <[email-masked]>
Date: Tue, 31 Aug 2010 21:57:49 +0200

Dan Kruchinin wrote, On 08/31/2010 07:01 PM:

> I'm sorry it seems my email client has broken patch formating.
> Here is properly formated one:
> diff --git a/tc/q_tbf.c b/tc/q_tbf.c
> index dc556fe..850e6db 100644
> --- a/tc/q_tbf.c
> +++ b/tc/q_tbf.c
> @@ -178,7 +178,7 @@ static int tbf_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nl
>  	}
>  
>  	if (opt.limit == 0) {
> -		double lim = opt.rate.rate*(double)latency/TIME_UNITS_PER_SEC + buffer;
> +		double lim = opt.rate.rate*(double)latency/TIME_UNITS_PER_SEC;

The way limit is calculated here from latency suggests some safety defaults
are taken wrt. the implementation, which could be omitted while setting the
limit directly. You try to change/fix this to adhere to the documentation,
but such a change would definitely break many user configs, so I doubt it's
the right solution here. Probably you should rather think about fixing the
manual.

Thanks,
Jarek P.