From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753926Ab0I3MZU (ORCPT ); Thu, 30 Sep 2010 08:25:20 -0400 Received: from smtp.df.ru ([195.42.160.16]:59719 "EHLO smtp.df.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751159Ab0I3MZS (ORCPT ); Thu, 30 Sep 2010 08:25:18 -0400 Date: Thu, 30 Sep 2010 16:23:21 +0400 From: Alexey Vlasov To: Eric Dumazet Cc: Linux Kernel Mailing List , netdev Subject: Re: Packet time delays on multi-core systems Message-ID: <20100930122321.GA1575@beaver.vrungel.ru> References: <20100929191851.GC86786@beaver.vrungel.ru> <1285796721.5211.156.camel@edumazet-laptop> <20100930062419.GD86786@beaver.vrungel.ru> <1285828432.5211.812.camel@edumazet-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline In-Reply-To: <1285828432.5211.812.camel@edumazet-laptop> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 30, 2010 at 08:33:52AM +0200, Eric Dumazet wrote: > Le jeudi 30 septembre 2010 ?? 10:24 +0400, Alexey Vlasov a ??crit : > > Here I found some dude with the same problem: > > http://lkml.org/lkml/2010/7/9/340 > > > > In your opinion its the same problem. > > But the description you gave is completely different. > > You have time skew only when activating a particular iptables rule. Well I put interrups from NIC, namely tx/rx query, to different processors and got normal pings by adding LOG rule. I also found that overruns is constantly growing, I don't know if these are connected. RX packets:2831439546 errors:0 dropped:134726 overruns:947671733 frame:0 TX packets:2880849825 errors:0 dropped:0 overruns:0 carrier:0 Rather strange that only one processor was involved, even in top was clear that ksoftirqd eats the first processor up to 100%. Here goes the typical distribution of interrups on new servers: CPU0 CPU1 CPU2 CPU3 ... CPU23 752: 11 0 0 0 ... 0 PCI-MSI-edge eth0 753: 2799366721 0 0 0 ... 0 PCI-MSI-edge eth0-rx3 754: 2821840553 0 0 0 ... 0 PCI-MSI-edge eth0-rx2 755: 2786117044 0 0 0 ... 0 PCI-MSI-edge eth0-rx1 756: 2896099336 0 0 0 ... 0 PCI-MSI-edge eth0-rx0 757: 1808404680 0 0 0 ... 0 PCI-MSI-edge eth0-tx3 758: 1797855130 0 0 0 ... 0 PCI-MSI-edge eth0-tx2 759: 1807222032 0 0 0 ... 0 PCI-MSI-edge eth0-tx1 760: 1820309360 0 0 0 ... 0 PCI-MSI-edge eth0-tx0 On the old ones: CPU0 CPU1 CPU2 ... CPU8 502: 522320256 522384039 522327386 ... 522380267 PCI-MSI-edge eth0 -- BRGDS. Alexey Vlasov.