From mboxrd@z Thu Jan  1 00:00:00 1970
Return-path: <linux-wireless-owner@vger.kernel.org>
Received: from smtp.codeaurora.org ([198.145.29.96]:52042 "EHLO
        smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1751226AbdBLQ2v (ORCPT
        <rfc822;linux-wireless@vger.kernel.org>);
        Sun, 12 Feb 2017 11:28:51 -0500
From: Kalle Valo <kvalo@codeaurora.org>
To: Felix Fietkau <nbd@nbd.name>
Cc: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@toke.dk>,
        linux-wireless@vger.kernel.org
Subject: Re: [PATCH] ath9k: clean up and fix ath_tx_count_airtime
References: <20170212132931.43510-1-nbd@nbd.name>
        <87lgtb5t9h.fsf@alrua-karlstad>
        <fbda67b4-7db6-984a-af50-610ec25d2fe0@nbd.name>
Date: Sun, 12 Feb 2017 18:28:43 +0200
In-Reply-To: <fbda67b4-7db6-984a-af50-610ec25d2fe0@nbd.name> (Felix Fietkau's
        message of "Sun, 12 Feb 2017 16:54:17 +0100")
Message-ID: <87d1entltw.fsf@kamboji.qca.qualcomm.com> (sfid-20170212_172901_649596_B54BA98D)
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Sender: linux-wireless-owner@vger.kernel.org
List-ID: <linux-wireless.vger.kernel.org>

Felix Fietkau <nbd@nbd.name> writes:

> On 2017-02-12 16:22, Toke H=C3=B8iland-J=C3=B8rgensen wrote:
>> Felix Fietkau <nbd@nbd.name> writes:
>>=20
>>> ath_tx_count_airtime is doing a lot of unnecessary work:
>>>
>>> - Redundant station lookup
>>> - Redundant rcu_read_lock/unlock
>>> - Useless memcpy of bf->rates
>>> - Useless NULL check of bf->bf_mpdu
>>> - Redundant lookup of the skb tid
>>>
>>> Additionally, it tries to look up the mac80211 queue index from the txq,
>>> which fails if the frame was delivered via the power save queue.

What does this mean in practise, what's the user level impact?

>>> This patch fixes all of these issues by passing down the right set of
>>> pointers instead of doing extra work
>>>
>>> Cc: stable@vger.kernel.org
>>> Fixes: 63fefa050477 ("ath9k: Introduce airtime fairness scheduling
>>> between stations")
>>> Signed-off-by: Felix Fietkau <nbd@nbd.name>
>>=20
>> Not sure if there's anything for stable to do with this; don't think the
>> airtime fairness code has gone into a release yet? Otherwise:
>>=20
>> Acked-by: Toke H=C3=B8iland-J=C3=B8rgensen <toke@toke.dk>
>
> I added this, because I'm not sure this patch will make it to 4.10 in
> time, since we're really close to a release. I assume this patch will
> probably go into 4.11.

Yeah, to try to get a patch to 4.10 at this point needs to be a really
high profile regression. That is if Linus doesn't release 4.10 today, of
course.

--=20
Kalle Valo