From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755433AbXLFXGW (ORCPT ); Thu, 6 Dec 2007 18:06:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753245AbXLFXGO (ORCPT ); Thu, 6 Dec 2007 18:06:14 -0500 Received: from one.firstfloor.org ([213.235.205.2]:40246 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752358AbXLFXGN (ORCPT ); Thu, 6 Dec 2007 18:06:13 -0500 Date: Fri, 7 Dec 2007 00:06:11 +0100 From: Andi Kleen To: Chris Friesen Cc: Andi Kleen , Renzo Davoli , linux-kernel@vger.kernel.org Subject: Re: New Address Family: Inter Process Networking (IPN) Message-ID: <20071206230611.GK20595@one.firstfloor.org> References: <20071205164055.GA2082@cs.unibo.it> <20071206053016.GA1464@cs.unibo.it> <20071206163538.GC20595@one.firstfloor.org> <47585D66.3000404@nortel.com> <20071206212644.GA26725@one.firstfloor.org> <47586E7F.1020903@nortel.com> <20071206220754.GF20595@one.firstfloor.org> <47587F90.8010400@nortel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <47587F90.8010400@nortel.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 06, 2007 at 05:02:40PM -0600, Chris Friesen wrote: > Andi Kleen wrote: > > >>On a 1.4GHz P4 I measured a 44% increase in latency between a unix > >>datagram and a UDP datagram. > > >That's weird. > > I just reran on a 3.2GHZ P4 running 2.6.11 (Fedora Core 4). 42% latency > increase. Sounds like something that should be looked into. I know of no principal reasons for that. > For stream sockets, unix gives approximately a 62% bandwidth increase > over tcp. (Although tcp could probably be tuned to do better than this.) How long a stream did you test? You might be measuring slow start. -Andi