From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751593AbVHZWSy (ORCPT ); Fri, 26 Aug 2005 18:18:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751597AbVHZWSy (ORCPT ); Fri, 26 Aug 2005 18:18:54 -0400 Received: from web33314.mail.mud.yahoo.com ([68.142.206.129]:20103 "HELO web33314.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S1751593AbVHZWSx (ORCPT ); Fri, 26 Aug 2005 18:18:53 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Reply-To:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=SO3z1rfLhRdX+7fgczDyW+Gbmtx2bHtwRRRnOJbnKlNBnqzdWHT/GpmhI9rp5aTzWs9B6hheCo9ykcvjzey3RX+DVhVcdyBbtUftWJxPw1QnREmH/kxKEQFMlnkgsOsqfLXGmrRJThsvM+qmasV+Yk6Ap0/P9QJfjXFDJZW6yA0= ; Message-ID: <20050826221852.56495.qmail@web33314.mail.mud.yahoo.com> Date: Fri, 26 Aug 2005 15:18:52 -0700 (PDT) From: Danial Thom Reply-To: danial_thom@yahoo.com Subject: Re: 2.6.12 Performance problems To: Ben Greear Cc: Jesper Juhl , linux-kernel@vger.kernel.org, netdev@vger.kernel.org In-Reply-To: <20050826032938.59796.qmail@web33303.mail.mud.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --- Danial Thom wrote: > > > --- Ben Greear wrote: > > > Danial Thom wrote: > > > > > > --- Ben Greear > > wrote: > > > > > > > > >>Danial Thom wrote: > > >> > > >> > > >>>I think the concensus is that 2.6 has made > > >> > > >>trade > > >> > > >>>offs that lower raw throughput, which is > > what > > >> > > >>a > > >> > > >>>networking device needs. So as a router or > > >>>network appliance, 2.6 seems less > suitable. > > A > > >> > > >>raw > > >> > > >>>bridging test on a 2.0Ghz operton system: > > >>> > > >>>FreeBSD 4.9: Drops no packets at 900K pps > > >>>Linux 2.4.24: Starts dropping packets at > > 350K > > >> > > >>pps > > >> > > >>>Linux 2.6.12: Starts dropping packets at > > 100K > > >> > > >>pps > > >> > > >>I ran some quick tests using kernel 2.6.11, > > 1ms > > >>tick (HZ=1000), SMP kernel. > > >>Hardware is P-IV 3.0Ghz + HT on a new > > >>SuperMicro motherboard with 64/133Mhz > > >>PCI-X bus. NIC is dual Intel pro/1000. > > Kernel > > >>is close to stock 2.6.11. > > > > > What GigE adapters did you use? Clearly > every > > > driver is going to be different. My > > experience is > > > that a 3.4Ghz P4 is about the performance > of > > a > > > 2.0Ghz Opteron. I have to try your tuning > > script > > > tomorrow. > > > > Intel pro/1000, as I mentioned. I haven't > > tried any other > > NIC that comes close in performance to the > > e1000. > > > > > If your test is still set up, try compiling > > > something large while doing the test. The > > drops > > > go through the roof in my tests. > > > > Installing RH9 on the box now to try some > > tests... > > > > Disk access always robs networking, in my > > experience, so > > I am not supprised you see bad ntwk > performance > > while > > compiling. > > > > Ben > > It would be useful if there were some way to > find > out "what" is getting "robbed". If networking > has > priority, then what is keeping it from getting > back to processing the rx interrupts? > > Ah, the e1000 has built-in interrupt > moderation. > I can't get into my lab until tomorrow > afternoon, > but if you get a chance try setting ITR in > e1000_main.c to something larger, like 20K. and > see if it makes a difference. At 200K pps that > would cause an interrupt every 10 packets, > which > may allow the routine to grab back the cpu more > often. > > > Danial > Just FYI, setting interrupt moderation to 20,000 didn't make much difference. ____________________________________________________ Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs