From: Eric Dumazet <eric.dumazet@gmail.com>
To: Neal Cardwell <ncardwell@google.com>
Cc: David Miller <davem@davemloft.net>,
bhutchings@solarflare.com, netdev@vger.kernel.org,
alekcejk@googlemail.com
Subject: Re: limited network bandwidth with 3.2.x kernels
Date: Thu, 16 Feb 2012 20:44:52 +0100 [thread overview]
Message-ID: <1329421492.2645.23.camel@edumazet-laptop> (raw)
In-Reply-To: <1329416523.2645.7.camel@edumazet-laptop>
Le jeudi 16 février 2012 à 19:22 +0100, Eric Dumazet a écrit :
> On sender side, there are also issues, because if I have TSO on or off
> on my 'netem delay 50ms' machine, performance is completely different.
Well, my sender is a 32bit kernel, so tcp_wmem[2] was less than
1Mbytes..
$ cat /proc/sys/net/ipv4/tcp_wmem
4096 16384 903780
Socket cwnd is then capped to ~400 with TSO=off, and ~1500 with TSO=on
TSO off, a 1500 bytes frame now has truesize=2048+192, while in previous
kernel it had truesize=1500+192 before linux 3.2
(903780/2240 = 403)
(TSO permits a better truesize/len ratio, close to 1)
With 50ms RTT, 400 packets in flight means no more than 90Mbit/s
prev parent reply other threads:[~2012-02-16 19:44 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-13 20:04 limited network bandwidth with 3.2.x kernels alekcejk
2012-02-13 20:18 ` Eric Dumazet
2012-02-13 21:13 ` Eric Dumazet
2012-02-13 21:58 ` alekcejk
2012-02-13 22:44 ` Eric Dumazet
2012-02-13 22:51 ` Neal Cardwell
2012-02-13 23:09 ` alekcejk
2012-02-13 23:14 ` Eric Dumazet
2012-02-13 23:24 ` alekcejk
2012-02-13 23:49 ` alekcejk
2012-02-14 3:06 ` Neal Cardwell
2012-02-14 3:26 ` alekcejk
2012-02-14 5:55 ` Eric Dumazet
2012-02-14 14:09 ` alekcejk
2012-02-13 21:16 ` alekcejk
2012-02-21 4:21 ` alekcejk
2012-02-21 16:45 ` Eric Dumazet
2012-02-21 17:19 ` alekcejk
2012-02-21 17:31 ` Eric Dumazet
2012-02-21 18:53 ` alekcejk
2012-02-22 1:26 ` alekcejk
[not found] ` <1920135.kl3o7Tt79c@localhost.localdomain>
[not found] ` <1329228798.4818.0.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC>
2012-02-14 14:28 ` alekcejk
2012-02-14 16:00 ` Eric Dumazet
2012-02-14 16:43 ` alekcejk
2012-02-15 4:43 ` Eric Dumazet
2012-02-15 6:03 ` Neal Cardwell
2012-02-15 6:06 ` Eric Dumazet
2012-02-15 7:52 ` Bill Fink
2012-02-15 8:00 ` Eric Dumazet
2012-02-15 8:18 ` Bill Fink
2012-02-15 8:31 ` Eric Dumazet
2012-02-15 13:44 ` alekcejk
2012-02-15 13:43 ` Re: Re: Re: Re: " alekcejk
2012-02-15 13:44 ` alekcejk
2012-02-15 13:49 ` Eric Dumazet
2012-02-15 13:53 ` Eric Dumazet
2012-02-15 14:11 ` alekcejk
2012-02-15 14:49 ` Neal Cardwell
2012-02-15 14:56 ` Eric Dumazet
2012-02-15 15:05 ` alekcejk
2012-02-15 15:08 ` Eric Dumazet
2012-02-15 19:44 ` Neal Cardwell
2012-02-16 7:29 ` Eric Dumazet
2012-02-16 13:40 ` Eric Dumazet
2012-02-16 13:51 ` Ben Hutchings
2012-02-16 15:09 ` Eric Dumazet
2012-02-16 16:37 ` Ben Hutchings
2012-02-16 17:01 ` David Miller
2012-02-16 17:22 ` Neal Cardwell
2012-02-16 17:54 ` alekcejk
2012-02-16 18:19 ` Neal Cardwell
2012-02-16 21:49 ` alekcejk
2012-02-16 21:59 ` Eric Dumazet
2012-02-16 22:08 ` alekcejk
2012-02-16 22:35 ` Eric Dumazet
2012-02-17 16:41 ` Neal Cardwell
2012-02-21 18:41 ` Eric Dumazet
2012-02-21 19:11 ` David Miller
2012-02-22 5:51 ` Neal Cardwell
2012-02-22 7:36 ` Eric Dumazet
2012-02-23 18:39 ` Neal Cardwell
2012-02-23 18:49 ` Eric Dumazet
2012-02-27 19:39 ` David Miller
2012-02-17 16:55 ` Re: " Neal Cardwell
2012-02-16 18:22 ` Eric Dumazet
2012-02-16 19:44 ` Eric Dumazet [this message]
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