SMP support on Pentium D

Howard Coles Jr. dhcolesj at
Mon Oct 30 12:59:11 UTC 2006

On Sunday 29 October 2006 5:45 pm, Gareth Lee wrote:
> I'm trying to get dapper to run on a Pentium D (dual) processor CPU.
> The standard 2.6.15 kernel boots fine, apparently detects all my
> hardware, detects the second CPU but refuses to use it since it was
> compiled with NR_CPUS = 1.  When I boot with the latest Knoppix release
> (2.6.17 kernel) it detects and uses both the CPUs so there is no
> fundamental incompatibility (... but I'd much rather run Kubuntu!)
> I have tried using two alternative kernels from the repository,
> the server kernel and the 686 SMP kernel.  In each case the bootup
> starts fine, the ramdisk (apparently) loads and then the kernel hangs
> with no clear error at the point it first mounts my (SATA?) root
> partition.   There is nothing exotic about my hardware setup as far
> as I can see (Pentium D 915 CPU on a recent Asus motherboard).
> As a third alternative I tried obtaining the kernel source files,
> compiling with the same configuration as the default kernel except
> SMP was enabled and NR_CPUS set to 2.  This appears to build
> and install a valid kernel and a set of modules but does not generate
> a initrd file.  Consequently the boot process hangs since it does
> not find the new modules in the standard initrd (and will not
> apparently boot without a ramdisk).  I've found plenty of documentation
> explaining how initrd works but no clear instructions about how to
> build an initrd file and what I need to include in the initrd file
> for use with Ubuntu (other than the new /lib/modules directory of
> course).  I would expect the step to be automated but there does not
> appear to be a make option for the kernel Makefile or any script to do
> the job.
> Since this is a problem that I would expect to have a relatively
> simple solution I wondered if one of you folks can tell me what
> I'm missing here!

Yes, install the linux-686-smp metapackage for the SMP kernel.  There is one 
in the list in synaptic by that very name.  I ran that for some time on my 
Hyperthreaded processor and it worked rather well.

See Ya'
Howard Coles Jr.
John 3:16! Christian bookstore

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