From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965020AbVHYO0t (ORCPT ); Thu, 25 Aug 2005 10:26:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965021AbVHYO0t (ORCPT ); Thu, 25 Aug 2005 10:26:49 -0400 Received: from web33314.mail.mud.yahoo.com ([68.142.206.129]:43860 "HELO web33314.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S965019AbVHYO0s (ORCPT ); Thu, 25 Aug 2005 10:26:48 -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=TGQw1QYqrz4lyYjNNrjoYKcnlCVvO+OLDD/Ph7Za/P6k8dL8rW0C8qqVUq6LuM9cwHu37FKi410AmBMdu8uQS5JIHgxj/Z79zaFPXcgyrTK7yONRZFJgGiskpsa8LvzY94rutASoc2CgjVzZCBiDpuY7imeqRD11JV0msPDLGhk= ; Message-ID: <20050825142647.70995.qmail@web33314.mail.mud.yahoo.com> Date: Thu, 25 Aug 2005 07:26:47 -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: <430D668A.6030306@candelatech.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 --- 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. > >> > >>I used brctl to create a bridge with the two > >>GigE adapters in it and > >>used pktgen to stream traffic through it > >>(250kpps in one direction, 1kpps in > >>the other.) > >> > >>I see a reasonable amount of drops at 250kpps > >>(60 byte packets): > >>about 60,000,000 packets received, 20,700 > >>dropped. > > I get slightly worse performance on this system > when running RH9 > with kernel 2.4.29 (my hacks, HZ=1000, SMP). > Tried increasing > e1000 descriptors to 2048 tx and rx, but that > didn't help, or at least > not much. > > Will try some other tunings, but I doubt it > will affect performance > enough to come close to the discrepency that > you show between 2.4 > and 2.6 kernels... > > I tried copying a 500MB CDROM to HD on my RH9 > system, and only 6kpps > of the 250kpps get through the bridge...btw. The tests I reported where on UP systems. Perhaps the default settings are better for this in 2.4, since that is what I used, and you used your hacks for both. Are you getting drops or overruns (or both)? I would assume drops is a decision to drop rather than an overrun which is a ring overrun. Overruns would imply more about performance than tuning, I'd think. I wouldn't think that HT would be appropriate for this sort of setup...? You're using a dual PCI-X NIC rather than the onboard ports? Supermicro runs their onboard controllers at 32bit/33mhz for some mindless reason. Danial __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com