netdev - Re: [PATCH net-next 3/3] tcp: get rid of tcp_tso_should

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Message-ID: <CAK6E8=cU5ZrC9WsozDi3QoiGSg2eaFPS4vDq7e=5uC_63cXgQA@mail.gmail.com>
Date:   Mon, 12 Nov 2018 08:52:16 -0800
From:   Yuchung Cheng <ycheng@...gle.com>
To:     Neal Cardwell <ncardwell@...gle.com>
Cc:     Eric Dumazet <edumazet@...gle.com>,
        David Miller <davem@...emloft.net>,
        Netdev <netdev@...r.kernel.org>,
        Soheil Hassas Yeganeh <soheil@...gle.com>,
        Eric Dumazet <eric.dumazet@...il.com>
Subject: Re: [PATCH net-next 3/3] tcp: get rid of tcp_tso_should_defer()
 dependency on HZ/jiffies

On Sun, Nov 11, 2018 at 11:06 AM, Neal Cardwell <ncardwell@...gle.com> wrote:
> On Sun, Nov 11, 2018 at 9:41 AM Eric Dumazet <edumazet@...gle.com> wrote:
>>
>> tcp_tso_should_defer() first heuristic is to not defer
>> if last send is "old enough".
>>
>> Its current implementation uses jiffies and its low granularity.
>>
>> TSO autodefer performance should not rely on kernel HZ :/
>>
>> After EDT conversion, we have state variables in nanoseconds that
>> can allow us to properly implement the heuristic.
>>
>> This patch increases TSO chunk sizes on medium rate flows,
>> especially when receivers do not use GRO or similar aggregation.
>>
>> It also reduces bursts for HZ=100 or HZ=250 kernels, making TCP
>> behavior more uniform.
>>
>> Signed-off-by: Eric Dumazet <edumazet@...gle.com>
>> Acked-by: Soheil Hassas Yeganeh <soheil@...gle.com>
>> ---
>
> Nice. Thanks!
>
> Acked-by: Neal Cardwell <ncardwell@...gle.com>
Acked-by: Yuchung Cheng <ycheng@...gle.com>

Love it
>
> neal