Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262925AbTI2JNe (ORCPT ); Mon, 29 Sep 2003 05:13:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262922AbTI2JNc (ORCPT ); Mon, 29 Sep 2003 05:13:32 -0400 Received: from meryl.it.uu.se ([130.238.12.42]:16587 "EHLO meryl.it.uu.se") by vger.kernel.org with ESMTP id S262910AbTI2JN1 (ORCPT ); Mon, 29 Sep 2003 05:13:27 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16247.63409.996071.860727@gargle.gargle.HOWL> Date: Mon, 29 Sep 2003 11:13:21 +0200 From: Mikael Pettersson To: "J.A. Magallon" Cc: Frank Cusack , lkml Subject: Re: 2nd proc not seen In-Reply-To: <20030929085807.GA22884@werewolf.able.es> References: <20030904021113.A1810@google.com> <20030904091437.A25107@google.com> <20030928205045.B21288@google.com> <20030929085807.GA22884@werewolf.able.es> X-Mailer: VM 6.90 under Emacs 20.7.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org J.A. Magallon writes: > > On 09.29, Frank Cusack wrote: > > On Thu, Sep 04, 2003 at 09:14:37AM -0700, Frank Cusack wrote: > > > On Thu, Sep 04, 2003 at 02:11:13AM -0700, Frank Cusack wrote: > > > > I think I've seen some recent talk about this problem. I have an HPAQ > > > > xw6000 w/ 2xP4 CPUs. A RH kernel finds both CPUs (4 if I enable HT). A > > > > kernel.org kernel only finds 1 (2 if I enable HT). > > > > This turned out to be a CPU numbering issue. The HPAQ machine numbers > > the cpus #0 and #6. I had NR_CPUS set to 2. That only works if the CPUs > > are physically numbered 0 and 1. > > > > So NR_CPUS is a little misleading. I could suggest a Config.help change > > if you like. > > > > This is a little weird. This forces you to have all the SMP structures sized > 8 just to use 2 members. > > Was not there a physical-logical map ? Or that was in -aa kernel and 2.6 ? Problem #1 is that physical CPU numbering isn't dense. This is not a bug. Problem #2 is that the kernel's internal dense-logical-to-sparse-physical numbering was deleted in 2.5.23 or thereabouts. Hence NR_CPUS is basically impossible to use reliably in 2.6 unless we reintroduce cpu_logical_map[]. /Mikael - 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/