From mboxrd@z Thu Jan  1 00:00:00 1970
From: Carsten Aulbert <carsten.aulbert@aei.mpg.de>
Subject: Re: 2.6.32.1 kernel configuration only seeing 1 core on Intel E5540 CPU
Date: Thu, 24 Jun 2010 09:43:36 +0200
Message-ID: <201006240943.38529.carsten.aulbert@aei.mpg.de>
References: <4C22907A.6020601@globaldataguard.com>
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Return-path: <linux-admin-owner@vger.kernel.org>
In-Reply-To: <4C22907A.6020601@globaldataguard.com>
Sender: linux-admin-owner@vger.kernel.org
List-ID: <linux-admin.vger.kernel.org>
Content-Type: Text/Plain; charset="us-ascii"
To: Kurt Newman <knewman@globaldataguard.com>
Cc: linux-admin@vger.kernel.org

Hi Kurt

On Thursday 24 June 2010 00:53:46 Kurt Newman wrote:
> I've loaded this same i7 Nehalem machine with CentOS 5.3
> (2.6.18-128.el5PAE), Ubuntu 9.04 (2.6.28-11-generic), and a modified
> distro with a custom kernel (2.6.32.1).
> 
> The CentOS and Ubuntu kernels find all 4 cores just fine; however, my
> custom kernel only finds 1.  I've enabled the following:
> 
>  - SMP
>  - X86_BIGSMP (systems with more than 8 cpus)
>  - X86_EXTENDED_PLATFORM (extended x86 platform)
>  - SCHED_SMT (hyper-threading)
>  - SCHED_MC (Multi-core scheduler)
>  - and varied between M686 (Pentium Pro) and MCORE2 (newer Xeon)

Just guessing, but could the CentOS and Ubuntu Kernel be a 64bit variant, 
while your custom one is 32bit? (also .1 is heavily outdated .15 is the 
current which apparently fixes several bugs).

I've not been using 32bit kernel for a couple of years and never with a multi-
core system thus just poking into the dark here.

HTH

Carsten