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Date: Wed, 11 Feb 2015 09:57:33 +0100
Message-ID: <CA+BoTQn=YQQ_yUHvpAG3MMAw+=jxgLDiUMWxiTC3B3vkksTw9g@mail.gmail.com> (sfid-20150211_095742_482114_A655BAEA)
Subject: Re: Throughput regression with `tcp: refine TSO autosizing`
From: Michal Kazior <michal.kazior@tieto.com>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
	Neal Cardwell <ncardwell@google.com>,
	linux-wireless <linux-wireless@vger.kernel.org>,
	Network Development <netdev@vger.kernel.org>,
	Eyal Perry <eyalpe@dev.mellanox.co.il>
Content-Type: text/plain; charset=UTF-8
Sender: linux-wireless-owner@vger.kernel.org

On 10 February 2015 at 15:19, Johannes Berg <johannes@sipsolutions.net> wrote:
> On Tue, 2015-02-10 at 11:33 +0100, Michal Kazior wrote:
>
>> +       if (msdu->sk) {
>> +               ewma_add(&ar->tx_delay_us,
>> +                        ktime_to_ns(ktime_sub(ktime_get(), skb_cb->stamp)) /
>> +                        NSEC_PER_USEC);
>> +
>> +               ACCESS_ONCE(msdu->sk->sk_tx_completion_delay_cushion) =
>> +                               (ewma_read(&ar->tx_delay_us) *
>> +                                msdu->sk->sk_pacing_rate) >> 20;
>> +       }
>
> To some extent, every wifi driver is going to have this problem. Perhaps
> we should do this in mac80211?

Good point. I was actually thinking about it. I can try cooking a
patch unless you want to do it yourself :-)


Michał