Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030204AbWIRWDd (ORCPT ); Mon, 18 Sep 2006 18:03:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030202AbWIRWDd (ORCPT ); Mon, 18 Sep 2006 18:03:33 -0400 Received: from tentacle.snto-msu.net ([194.88.210.4]:43962 "EHLO tentacle.sectorb.msk.ru") by vger.kernel.org with ESMTP id S1030201AbWIRWDc (ORCPT ); Mon, 18 Sep 2006 18:03:32 -0400 Date: Tue, 19 Sep 2006 02:03:31 +0400 From: "Vladimir B. Savkin" To: Alexey Kuznetsov Cc: Andi Kleen , Jesper Dangaard Brouer , Harry Edmon , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: Network performance degradation from 2.6.11.12 to 2.6.16.20 Message-ID: <20060918220331.GB32520@tentacle.sectorb.msk.ru> References: <4492D5D3.4000303@atmos.washington.edu> <200609181754.37623.ak@suse.de> <20060918162847.GA4863@ms2.inr.ac.ru> <200609181850.22851.ak@suse.de> <20060918211759.GB31746@tentacle.sectorb.msk.ru> <20060918220038.GB14322@ms2.inr.ac.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline In-Reply-To: <20060918220038.GB14322@ms2.inr.ac.ru> X-Organization: Moscow State Univ., Institute of Mechanics X-Operating-System: Linux 2.6.17-rc6-64 User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1352 Lines: 39 On Tue, Sep 19, 2006 at 02:00:38AM +0400, Alexey Kuznetsov wrote: > Hello! > > > Please think about it this way: > > suppose you haave a heavily loaded router and some network problem is to > > be diagnosed. You run tcpdump and suddenly router becomes overloaded (by > > switching to timestamp-it-all mode > > I am sorry. I cannot think that way. :-) > > Instead of attempts to scare, better resend original report, > where you said how much performance degraded, I cannot find it. > > * I do see get_offset_pmtmr() in top lines of profile. That's scary enough. I had it at the very top line. > * I do not undestand what the hell dhcp needs timestamps for. > * I do not listen any suggestions to screw up tcpdump with a sysctl. > Kernel already implements much better thing then a sysctl. > Do not want timestamps? Fix tcpdump, add an options, submit the > patch to tcpdump maintainers. Not a big deal. OK, point taken. It's better to patch tcpdump. > > Alexey > ~ :wq With best regards, Vladimir Savkin. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/