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From: Oleksandr Natalenko <oleksandr@natalenko.name>
To: "Holger Hoffstätte" <holger@applied-asynchrony.com>
Cc: Neal Cardwell <ncardwell@google.com>,
	Eric Dumazet <eric.dumazet@gmail.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>, Eric Dumazet <edumazet@google.com>,
	Dave Taht <dave.taht@gmail.com>
Subject: Re: TCP and BBR: reproducibly low cwnd and bandwidth
Date: Fri, 16 Feb 2018 20:54:47 +0100	[thread overview]
Message-ID: <7131594.kGYvpCWkcy@natalenko.name> (raw)
In-Reply-To: <4edcb644-4530-e771-eea7-947ce0ef12ed@applied-asynchrony.com>

Hi.

On pátek 16. února 2018 18:56:12 CET Holger Hoffstätte wrote:
> There is simply no reason why you shouldn't get approx. line rate
> (~920+-ish) Mbit over wired 1GBit Ethernet; even my broken 10-year old
> Core2Duo laptop can do that. Can you boot with spectre_v2=off and try "the
> simplest case" with the defaults cubic/pfifo_fast? spectre_v2 has terrible
> performance impact esp. on small/older processors.

Just have tried. No visible difference.

> When I last benchmarked full PREEMPT with 4.9.x it was similarly bad and
> also had a noticeable network throughput impact even on my i7.
> 
> Also congratulations for being the only other person I know who ever tried
> YeAH. :-)

Well, according to the git log on tcp_yeah.c and Reported-by tag, I was not 
the only one there ;).

Regards,
  Oleksandr

  reply	other threads:[~2018-02-16 19:54 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 [this message]
2018-02-16 20:54       ` Eric Dumazet
2018-02-16 22:50         ` Eric Dumazet
2018-02-16 23:06           ` Oleksandr Natalenko
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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