From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758846AbYDOSQT (ORCPT ); Tue, 15 Apr 2008 14:16:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752767AbYDOSQE (ORCPT ); Tue, 15 Apr 2008 14:16:04 -0400 Received: from filter2.host.bg ([87.120.40.156]:39675 "EHLO filter2.host.bg" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752265AbYDOSQB (ORCPT ); Tue, 15 Apr 2008 14:16:01 -0400 X-Greylist: delayed 515 seconds by postgrey-1.27 at vger.kernel.org; Tue, 15 Apr 2008 14:16:01 EDT Subject: Bad network performance over 2Gbps From: Anton Titov To: Linux Kernel Mailing List Content-Type: text/plain Organization: Hosting Ltd. Date: Tue, 15 Apr 2008 21:06:44 +0300 Message-Id: <1208282804.23631.27.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.12.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I use Linux for serving a huge amount of static web on few servers. When network traffic goes above 2Gbit/sec ksoftirqd/5 (not every time 5, but every time just one) starts using exactly 100% CPU time and packet packet loss starts preventing traffic from going up. When the network traffic is lower than 1.9Gbit ksoftirqds use 0% CPU according to top. Uplink is 6 gigabit Intel cards bonded together using 802.3ad algorithm with xmit_hash_policy set to layer3+4. On the other side is Cisco 2960 switch. Machine is with two quad core Intel Xeons @2.33GHz. Here goes a screen snapshot of "top" command. The described behavior have nothing to do with 13% io-wait. It happens even if it is 0% io-wait. http://www.titov.net/misc/top-snap.png kernel configuration: http://www.titov.net/misc/config.gz /proc/interrupts, lspci, dmesg (nothing intresting there), ifconfig, uname -a: http://www.titov.net/misc/misc.txt.gz Is it a Linux bug or some hardware limitation? Regards, Anton Titov