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From:   Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
To:     Johannes Berg <johannes@sipsolutions.net>,
        Kan Yan <kyan@google.com>
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        make-wifi-fast@lists.bufferbloat.net, nbd@nbd.name,
        yiboz@codeaurora.org, john@phrozen.org, lorenzo@kernel.org,
        rmanohar@codeaurora.org, kevinhayes@google.com
Subject: Re: [PATCH v11 2/4] mac80211: Import airtime calculation code from mt76
In-Reply-To: <994e486e8e82c01e70150eacf59dedf61b80fc65.camel@sipsolutions.net>
References: <20191119060610.76681-1-kyan@google.com> <20191119060610.76681-3-kyan@google.com> <3e7bea0cc643714ec90978a7999022544a39b118.camel@sipsolutions.net> <87tv6w3w92.fsf@toke.dk> <dea9da1dd31900306c886c308c555691552290f5.camel@sipsolutions.net> <87imnc3vk9.fsf@toke.dk> <994e486e8e82c01e70150eacf59dedf61b80fc65.camel@sipsolutions.net>
Date:   Fri, 22 Nov 2019 15:41:38 +0100
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Johannes Berg <johannes@sipsolutions.net> writes:

> On Fri, 2019-11-22 at 14:11 +0100, Toke H=C3=B8iland-J=C3=B8rgensen wrote=
:
>>=20
>> as in bitrate =3D 1/airtime? Dunno, maybe? How important is precision to
>> the bitrate calculations?
>
> Not *that* important, it's just sort of advisory for userspace.
>
> Though I think there's at least one place in mac80211 related to
> radiotap that actually does use it for airtime calculation, which should
> probably be changed to the new code now ...

Yeah, I guess so. The ath9k driver is also doing software calculations
for RX, so that could also be converted; and mt76 should be, of course...

>> > Or maybe we should keep both and use them as a sanity check for each
>> > other :P
>>=20
>> Hmm, yeah, it should be possible to write a selftest to iterate through
>> all rates and compare the output of each calculation, shouldn't it?
>> Where would be a good place to put that?
>
> No idea ... make a new kselftest thing for wireless?

Right; was just wondering if there was something like that already which
I didn't know about :)

-Toke