From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: 2.6.12 Performance problems Date: Sun, 21 Aug 2005 12:47:46 -0700 Message-ID: <20050821124746.5d57203f.akpm@osdl.org> References: <20050821154654.63788.qmail@web33303.mail.mud.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org Return-path: To: danial_thom@yahoo.com In-Reply-To: <20050821154654.63788.qmail@web33303.mail.mud.yahoo.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Danial Thom wrote: > > I just started fiddling with 2.6.12, and there > seems to be a big drop-off in performance from > 2.4.x in terms of networking on a uniprocessor > system. Just bridging packets through the > machine, 2.6.12 starts dropping packets at > ~100Kpps, whereas 2.4.x doesn't start dropping > until over 350Kpps on the same hardware (2.0Ghz > Opteron with e1000 driver). This is pitiful > prformance for this hardware. I've > increased the rx ring in the e1000 driver to 512 > with little change (interrupt moderation is set > to 8000 Ints/second). Has "tuning" for MP > destroyed UP performance altogether, or is there > some tuning parameter that could make a 4-fold > difference? All debugging is off and there are > no messages on the console or in the error logs. > The kernel is the standard kernel.org dowload > config with SMP turned off and the intel ethernet > card drivers as modules without any other > changes, which is exactly the config for my 2.4 > kernels. > (added netdev to cc)