Re: 2.6.32.1 kernel configuration only seeing 1 core on Intel E5540 CPU

"S. Kurt Newman" <[email protected]> Thu, 24 Jun 2010 08:39:11 -0500
Newsgroups org.kernel.vger.linux-admin
Message-ID <[email protected]>
Hi Carsten.

Yes, the custom kernel is a 32-bit variant.  However, the Ubuntu and 
CentOS systems I loaded are also 32-bit.  Or so I think they are... I 
don't recall explicitly downloading the 64-bit variations of those OSs.

As far as using .1 instead of .15, I can try using a more recent 
revision to help fix bugs that may exist.. however due to some OS 
constraints I don't think I can go that far.  At least not without using 
custom patches.

For poserity's sake, let's assume all kernels I've used are 32-bit.  How 
would the 2.6.28 (and 2.6.18) kernels support them, but the 2.6.32 that 
I'm using wouldn't?

Thanks,
Kurt

Carsten Aulbert wrote:
> 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 (also .1 is heavily outdated .15 is the 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
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