smp_store_cpu_info() sets TAINT_UNSAFE_SMP as soon as it finds an K7 cpu 
that doesn't support SMP, even if only one cpu is present. This is wrong 
- it's ok to run an SMP kernel with a non-MP cpu, as long as only one 
cpu is present.
Unfortunately neither num_online_cpus() nor num_booting_cpu() work when 
smp_store_cpu_info() is called.

The attached patch moves that check into an __initcall.
It's tested on my uniprocessor Duron, but not on real SMP.

Could someone with an Athlon-non-MP SMP setup check that the kernel 
still complains about the non-certified setup?

Thanks,
    Manfred