Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759245AbYCYRyW (ORCPT ); Tue, 25 Mar 2008 13:54:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756818AbYCYRyH (ORCPT ); Tue, 25 Mar 2008 13:54:07 -0400 Received: from one.firstfloor.org ([213.235.205.2]:46485 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756616AbYCYRyG (ORCPT ); Tue, 25 Mar 2008 13:54:06 -0400 Date: Tue, 25 Mar 2008 18:57:16 +0100 From: Andi Kleen To: Wander Winkelhorst Cc: Michael Meyer , Andi Kleen , linux-kernel@vger.kernel.org Subject: Re: performance differences: "maxcpus=1" vs. "echo 0 > /sys/devices/system/cpu/cpu1/online" Message-ID: <20080325175716.GW2170@one.firstfloor.org> References: <87abkmhgg0.fsf@basil.nowhere.org> <57127.43039.qm@web25812.mail.ukl.yahoo.com> <5699f8f00803251049s1823098u86b5431eadad2917@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5699f8f00803251049s1823098u86b5431eadad2917@mail.gmail.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 Content-Length: 541 Lines: 13 > What kind of CPU are you using? Some Intel CPU's do "funny stuff", > like dynamically overclocking itself when working on a single thread, > or using all of the 2nd level cache instead of sharing it with the > second core. P0 should also work fine with cpu hotplug. At least in theory. -Andi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/