From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751482AbZH1N0q (ORCPT ); Fri, 28 Aug 2009 09:26:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751438AbZH1N0q (ORCPT ); Fri, 28 Aug 2009 09:26:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2820 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751436AbZH1N0p (ORCPT ); Fri, 28 Aug 2009 09:26:45 -0400 Message-ID: <4A97DAE7.40603@redhat.com> Date: Fri, 28 Aug 2009 09:25:59 -0400 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 2.0.0.17 (X11/20080915) MIME-Version: 1.0 To: raz ben yehuda CC: Thomas Gleixner , Chris Friesen , Andrew Morton , mingo@elte.hu, peterz@infradead.org, maximlevitsky@gmail.com, efault@gmx.de, wiseman@macs.biu.ac.il, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org Subject: Re: RFC: THE OFFLINE SCHEDULER References: <1251282598.3514.20.camel@raz> <1251297910.1791.22.camel@maxim-laptop> <1251298443.4791.7.camel@raz> <1251300625.18584.18.camel@twins> <1251302598.18584.31.camel@twins> <20090826180407.GA13632@elte.hu> <20090826193252.GA14721@elte.hu> <20090826135041.e6169d18.akpm@linux-foundation.org> <4A95A5EE.90400@nortel.com> <1251322663.3882.48.camel@raz> <4A96B997.1070001@nortel.com> <1251408785.3700.22.camel@raz> <1251448697.3872.15.camel@raz> In-Reply-To: <1251448697.3872.15.camel@raz> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org raz ben yehuda wrote: > yes. latency is a crucial property. In the case of network packets, wouldn't you get a lower latency by transmitting the packet from the CPU that knows the packet should be transmitted, instead of sending an IPI to another CPU and waiting for that CPU to do the work? Inter-CPU communication has always been the bottleneck when it comes to SMP performance. Why does adding more inter-CPU communication make your system faster, instead of slower like one would expect? -- All rights reversed.