From: Oleksandr Natalenko <oleksandr@natalenko.name>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>,
Neal Cardwell <ncardwell@google.com>,
"David S. Miller" <davem@davemloft.net>,
Netdev <netdev@vger.kernel.org>,
Yuchung Cheng <ycheng@google.com>,
Soheil Hassas Yeganeh <soheil@google.com>,
Jerry Chu <hkchu@google.com>, Dave Taht <dave.taht@gmail.com>
Subject: Re: TCP and BBR: reproducibly low cwnd and bandwidth
Date: Sat, 17 Feb 2018 00:06:23 +0100 [thread overview]
Message-ID: <2829276.7yTBvbjqgd@natalenko.name> (raw)
In-Reply-To: <1518821435.55655.6.camel@gmail.com>
On pátek 16. února 2018 23:50:35 CET Eric Dumazet wrote:
> /* snip */
> If you use
>
> tcptrace -R test_s2c.pcap
> xplot.org d2c_rtt.xpl
>
> Then you'll see plenty of suspect 40ms rtt samples.
That's odd. Even the way how they look uniformly.
> It looks like receiver misses wakeups for some reason,
> and only the TCP delayed ACK timer is helping.
>
> So it does not look like a sender side issue to me.
To make things even more complicated, I've disabled sg on the server, leaving
it enabled on the client:
client to server flow: 935 Mbits/sec
server to client flow: 72.5 Mbits/sec
So still, to me it looks like a sender issue. No?
next prev parent reply other threads:[~2018-02-16 23:06 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-15 20:42 TCP and BBR: reproducibly low cwnd and bandwidth Oleksandr Natalenko
2018-02-16 15:15 ` Oleksandr Natalenko
2018-02-16 16:25 ` Eric Dumazet
2018-02-16 17:37 ` Oleksandr Natalenko
2018-02-16 16:26 ` Holger Hoffstätte
2018-02-16 16:56 ` Neal Cardwell
2018-02-16 17:13 ` Holger Hoffstätte
2018-02-16 17:35 ` Oleksandr Natalenko
2018-02-16 16:21 ` Eric Dumazet
[not found] ` <CADVnQymiswHBp32dcMvWd1WfYLpFqY4QTas8yABFQE7KKKc5ag@mail.gmail.com>
2018-02-16 16:43 ` Eric Dumazet
2018-02-16 16:45 ` Neal Cardwell
2018-02-16 17:00 ` Oleksandr Natalenko
2018-02-16 17:25 ` Oleksandr Natalenko
2018-02-16 17:56 ` Holger Hoffstätte
2018-02-16 19:54 ` Oleksandr Natalenko
2018-02-16 20:54 ` Eric Dumazet
2018-02-16 22:50 ` Eric Dumazet
2018-02-16 23:06 ` Oleksandr Natalenko [this message]
2018-02-16 22:50 ` Oleksandr Natalenko
2018-02-16 22:59 ` Eric Dumazet
2018-02-17 10:01 ` Oleksandr Natalenko
2018-02-17 18:52 ` Eric Dumazet
2018-02-18 21:04 ` Eric Dumazet
2018-02-18 21:06 ` Eric Dumazet
2018-02-18 21:49 ` Oleksandr Natalenko
2018-02-18 22:24 ` Eric Dumazet
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