Re: [PATCH v6 3/4] mac80211: Implement Airtime-based Queue Limit (AQL)

Johannes Berg
2019-11-08T11:17:29Z

On Fri, 2019-11-08 at 12:10 +0100, Toke Høiland-Jørgensen wrote:

> Right, bugger. I was thinking maybe there's a case where skbs can be
> cloned (and retain the tx_time_est field) and then released twice?

They could be cloned, but I don't see how that'd be while *inside* the
stack and then they get reported twice - unless the driver did something
like that?

I mean, TCP surely does that for example, but it's before we even get to
mac80211.

> Or
> maybe somewhere that steps on the skb->cb field in some other way?
> Couldn't find anything obvious on a first perusal of the TX path code,
> but maybe you could think of something?

No, sorry. But I also didn't actually look at the driver at all.

> Otherwise I guess we'll be forced to go and do some actual,
> old-fashioned debugging ;)

:)

johannes