[KLUG Members] SMP and ACPI in 2.6.12

[Bruce Smith]

Did it break SMP or hyper-threading?

Was the old kernel compiled with ACPI as modules, if loaded in the
initrd would fix the problem?

 - BS


> I recently upgraded some dual Xeon machines from the 2.6.3 kernel to 
> 2.6.12 and it appeared to break SMP.  When I would cat /proc/cpuinfo or 
> ran top I would only see 2 processors rather than the previous 4 
> processors.  After some head scratching and google searches I tried 
> enabling ACPI support for Processor and Thermal Zone and recompiled and 
> I had my 4 processors again.  It appears that there has been some change 
> in the kernel between 2.6.3 and 2.6.12 that makes this necessary.  Does 
> anyone know if this is intentional?  Has anyone else ran into such a 
> thing?