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From: Eric Dumazet <eric.dumazet@gmail.com>
To: alekcejk@googlemail.com
Cc: netdev@vger.kernel.org
Subject: Re: Re: Re: limited network bandwidth with 3.2.x kernels
Date: Tue, 21 Feb 2012 18:31:24 +0100	[thread overview]
Message-ID: <1329845484.18384.20.camel@edumazet-laptop> (raw)
In-Reply-To: <2604639.CVkfrWv5sk@localhost.localdomain>

Le mardi 21 février 2012 à 19:19 +0200, alekcejk@googlemail.com a
écrit :
> Download speed from ftp3.de.freebsd.org increases from 5 MB/s to 10 MB/s
> after I set "sysctl net.ipv4.tcp_rmem="4096 87380 4127616""" in 3.2.7 kernel.
> 
> --2012-02-21 18:56:36--  ftp://ftp3.de.freebsd.org/pub/FreeBSD/ISO-IMAGES-i386/8.2/FreeBSD-8.2-RELEASE-i386-dvd1.iso.xz
> 100%[======================================>] 2 066 424 512 10,3M/s  in 3m 17s
> 2012-02-21 18:59:56 (9,99 MB/s) - «/dev/null» saved [2066424512]
> 

Yep, this confirms the thing. You were at the limit of optimal receiver
window. Find a more remote server (80ms rtt for example) and you'll see
that your default tcp_rmem[2] was too small, even on 3.1.10 kernel.

> But maximum speed in 3.1.10 kernel (without this sysctl settings) still
> a bit more than in 3.2.7 - 11 MB/s instead of 10.3 MB/s.
> 
> --2012-02-21 18:56:36--  ftp://ftp3.de.freebsd.org/pub/FreeBSD/ISO-IMAGES-i386/8.2/FreeBSD-8.2-RELEASE-i386-dvd1.iso.xz
> 100%[======================================>] 2 066 424 512 11,0M/s   in 3m 30s   
> 2012-02-21 19:13:55 (9,39 MB/s) - «/dev/null» saved [2066424512]

Thats one measure, you'll have to make a lot of different measures to
make this significant, preferably in a lab to rule out different
external network conditions.

  reply	other threads:[~2012-02-21 17:31 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 [this message]
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

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