Re: [patch] bug in cpuid & msr on nosmp machine

[Andi Kleen]

Andrew Morton <akpm@xxxxxxxx> writes:

> Rusty Russell <rusty@xxxxxxxxxxxxxxx> wrote:
>>
>> On Thu, 2004-05-20 at 17:32, Andrew Morton wrote:
>> > I think what you want here is
>> > 
>> > 	if (!cpu_possible(cpu) || !cpu_online(cpu))
>> > 		return -ENXIO;
>> 
>> It works, but it's not really correct.  cpu_possible() is correct, but
>> cpu_online() might no longer be true by the time do_cpu_read() calls
>> do_cpu_id().
>
> mutter.  Are we likely to see any ia32 or x86_64 hotplug-cpu machines?

Yes. Think vmware and virtualization, where partitions could get CPUs 
added and removed at runtime.

-Andi

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