mingo@elte.hu said:
>On Mon, 10 Jul 2000, Keith Owens wrote:
>
>> NR_CPUS is not the number of processors. It is the highest processor
>> number+1; processor numbers do not have to be contiguous. On a
>> machine that has 2 processors numbered 1 and 4, NR_CPUS must be 5.
>
>on x86 this is not true anymore, CPU numbers are contiguous since
around
>2.3.40. There are some arrays in the lowlevel x86 SMP code that should
be
>MAX_APIC_ID indexed instead of NR_CPUS, but the main kernel should be
>safe.
>
> Ingo
I thought the reason processors might not be contiguous was due to
future hotplug considerations: if the second overheats or something you
disable it but still have the first and third running. (Or
plugging/pulling physical processor cards on a large hot-swappable box.)
I take it this is way off base?
Rob
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This archive was generated by hypermail 2b29 : Sat Jul 15 2000 - 21:00:11 EST