From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932399AbWGRUyY (ORCPT ); Tue, 18 Jul 2006 16:54:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932401AbWGRUyY (ORCPT ); Tue, 18 Jul 2006 16:54:24 -0400 Received: from liaag2ad.mx.compuserve.com ([149.174.40.155]:63393 "EHLO liaag2ad.mx.compuserve.com") by vger.kernel.org with ESMTP id S932399AbWGRUyX (ORCPT ); Tue, 18 Jul 2006 16:54:23 -0400 Date: Tue, 18 Jul 2006 16:46:51 -0400 From: Chuck Ebbert <76306.1226@compuserve.com> Subject: Re: CPU numbering & hyperthreading To: Andrew Athan Cc: linux-kernel Message-ID: <200607181649_MC3-1-C55F-72EE@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org In-Reply-To: <44BC4200.90308@cloakmail.com> On Mon, 17 Jul 2006 22:05:52 -0400, Andrew Athan wrote: > > I have two highly CPU/memory/network intensive processes with 3-5 > threads each. I am using sched_setaffinity calls to make sure these two > processes never compete for the same physical CPU. Am I right to assume > that CPU #0 and #1 vs CPU #2 and #3 are separate physical CPUs on a > 2-CPU w/ hyperthreading box? > > I've spent some time looking, but I did not find documentation on > exactly how CPUs are numbered in a hyperthreaded box. There's no fixed numbering. If you want to know the die/core/thread layout, check out Documentation/cputopology.txt. -- Chuck And did we tell you the name of the game, boy, we call it Riding the Gravy Train.