From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: limited network bandwidth with 3.2.x kernels Date: Mon, 13 Feb 2012 21:18:13 +0100 Message-ID: <1329164293.2523.0.camel@edumazet-laptop> References: <8633039.fHPLx6GNq3@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev@vger.kernel.org To: alekcejk@googlemail.com Return-path: Received: from mail-we0-f174.google.com ([74.125.82.174]:43185 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755937Ab2BMUSR (ORCPT ); Mon, 13 Feb 2012 15:18:17 -0500 Received: by werb13 with SMTP id b13so3727162wer.19 for ; Mon, 13 Feb 2012 12:18:16 -0800 (PST) In-Reply-To: <8633039.fHPLx6GNq3@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-ID: Le lundi 13 f=C3=A9vrier 2012 =C3=A0 22:04 +0200, alekcejk@googlemail.c= om a =C3=A9crit : > Hi, >=20 > I noticed that with 3.2.x kernels download speed from some internet r= esources > became about half of speed that was with previous kernels (3.1 and ol= der). > I tested Fedora 15 kernels 2.6.41.10 =3D 3.1.10 and 2.6.42.3 =3D 3.2.= 3 > (many times rebooted for testing with first and second kernels). > See bug https://bugzilla.redhat.com/show_bug.cgi?id=3D789659 >=20 > lsmod: > Module Size Used by > nvidia 10778232 40 > i2c_core 28123 1 nvidia > 8139too 32490 0 > mii 13311 1 8139too >=20 > dmesg: > 8139too: 8139too Fast Ethernet driver 0.9.28 > 8139too 0000:01:02.0: PCI INT A -> GSI 22 (level, low) -> IRQ 22 > 8139too 0000:01:02.0: eth0: RealTek RTL8139 at , IRQ 22 > 8139too 0000:01:02.0: eth0: link up, 100Mbps, full-duplex, lpa 0x41E1 >=20 > For testing I selected fastest for me download mirrors of FreeBSD and= Ubuntu, > also I tested download speed from site speedtest.tele2.net. >=20 > For these sites download speed with 3.1 kernels (and older) is about = 11 MB/s > but with 3.2.x kernels - limited 5.5 MB/s and for some sites still ap= proximately > the same as with 3.1 kernels (see bug mentioned above). >=20 MB/s means MBytes or Mbits ? > Also I want to pay attention that limited speed stays constant - alwa= ys > 5.5 MB/s with straight line on traffic plotter as if was network band= width shaping. > With 3.1 kernels this never happens - speed can vary in some ranges > but at maximum it is about 11 MB/s, no limitations such as 5.5 MB/s. >=20 Could you post "netstat -s" result ?