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Message-ID: <e0ca70f2241307c44489653d7074c5017ad93943.camel@sipsolutions.net>
Subject: Re: [PATCH] mac80211: don't apply flow control on management frames
From:   Johannes Berg <johannes@sipsolutions.net>
To:     Toke =?ISO-8859-1?Q?H=F8iland-J=F8rgensen?= <toke@redhat.com>,
        linux-wireless@vger.kernel.org
Date:   Sat, 20 Mar 2021 20:58:48 +0100
In-Reply-To: <87h7l6adht.fsf@toke.dk>
References: <20210319232800.0e876c800866.Id2b66eb5a17f3869b776c39b5ca713272ea09d5d@changeid>
         <87h7l6adht.fsf@toke.dk>
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On Sat, 2021-03-20 at 01:13 +0100, Toke Høiland-Jørgensen wrote:
> 
> One consequence of this is that we create a strict priority queue for
> management frames.

Yes, for iwlwifi that's actually a change. For everyone else (not
setting BUFF_MMPDU_TXQ or STA_MMPDU_TXQ) it already is since it goes
directly to ->tx() and from there to the hardware queue(s).

> With all the possibilities for badness (such as the
> ability of starving all other queues) that carries with it. I guess
> that's probably fine for management frames, though, right? As in, there
> is some other mechanism that prevents abuse of this?

Well, there's just not that many management frames to start with? And
only wpa_supplicant (or root in general) can create them. So I don't
think we need to worry about that yet. With QoS-mgmt frames we might
eventually want to think about that, but even there I'd say we never
really want to drop them.

johannes