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From:   Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
To:     Johannes Berg <johannes@sipsolutions.net>,
        linux-wireless@vger.kernel.org
Subject: Re: [PATCH] mac80211: don't apply flow control on management frames
In-Reply-To: <e0ca70f2241307c44489653d7074c5017ad93943.camel@sipsolutions.net>
References: <20210319232800.0e876c800866.Id2b66eb5a17f3869b776c39b5ca713272ea09d5d@changeid>
 <87h7l6adht.fsf@toke.dk>
 <e0ca70f2241307c44489653d7074c5017ad93943.camel@sipsolutions.net>
Date:   Mon, 22 Mar 2021 11:37:53 +0100
Message-ID: <87wntz8oe6.fsf@toke.dk>
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Johannes Berg <johannes@sipsolutions.net> writes:

> On Sat, 2021-03-20 at 01:13 +0100, Toke H=C3=B8iland-J=C3=B8rgensen wrote:
>>=20
>> 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).

Ah, right, of course; so not much change at all. Cool.

>> 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.

Yup, that's what I meant with "some other mechanism to prevent abuse".
Great.

Feel free to add my:

Acked-by: Toke H=C3=B8iland-J=C3=B8rgensen <toke@redhat.com>