From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753290Ab2HEIPK (ORCPT ); Sun, 5 Aug 2012 04:15:10 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:10195 "EHLO mailhub1.si.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751347Ab2HEIPH (ORCPT ); Sun, 5 Aug 2012 04:15:07 -0400 Message-ID: <501E2BC5.5020709@c-s.fr> Date: Sun, 05 Aug 2012 10:16:05 +0200 From: LEROY christophe User-Agent: Mozilla/5.0 (Windows NT 6.0; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Eric Dumazet CC: linux-kernel@vger.kernel.org Subject: Re: Huge performance degradation for UDP between 2.4.17 and 2.6 References: <501A722D.1070900@c-s.fr> <1343916836.9299.189.camel@edumazet-glaptop> In-Reply-To: <1343916836.9299.189.camel@edumazet-glaptop> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Antivirus: avast! (VPS 120805-0, 05/08/2012), Outbound message X-Antivirus-Status: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 02/08/2012 16:13, Eric Dumazet a écrit : > On Thu, 2012-08-02 at 14:27 +0200, leroy christophe wrote: >> Hi >> >> I'm having a big issue with UDP. Using a powerpc board (MPC860). >> >> With our board running kernel 2.4.17, I'm able to send 160000 voice >> packets (UDP, 96 bytes per packet) in 11 seconds. >> With the same board running either Kernel 2.6.35.14 or Kernel 3.4.7, I >> need 55 seconds to send the same amount of packets. >> >> >> Is there anything to tune in order to get same output rate as with >> Kernel 2.4 ? > kernel size is probably too big for your old / slow cpu. > > Maybe you added too many features on your 3.4.7 kernel. (netfilter ? > SLUB debugging ...) > > Its hard to say, 2.4.17 had less features and was faster. > Thanks for your answer. Yes I have netfilter as I need it. However, I tried without it and still need about 37 seconds to send the 160000 packets I was sending in 11 seconds with 2.4.17 I don't think there is any problem with size of the kernel. I still have plenty of memory available. All debugging is turned off, and I'm not using SLUB but SLOB. I have 32Mbytes of RAM. Would SLUB be more performant than SLOB ? Christophe