Re: is it em64t ?
On Saturday 07 January 2006 11:46, Hamish Moffatt wrote:
>
> It does, but what if HyperThreading was present but disabled in the
> BIOS? I don't know how you would tell in that case.
Most of these flags are not set simply because the kernel found a certain type
of processor. They are the result of elaborate startup tests which detect
these capabilities.
If a capability is disabled in the bios, two things can happen
1) the kernel does not detect it at all; in which case the relevant flag is
not set;
2) the kernel detects the capability but switched off; in which case the
kernel will attempt to switch it on (if it can of course). If this succeeds
the flag is set, if not you will often see an error and the flag is not
switched on.
I have been told, however, that a few processor capabilities are so bound to
the a certain type of cpu that their flag is simply set if that cpu is found.
I don't know under which category the hyperthreading flag falls, but knowing
that hyperthreading can be disabled in the bios, I would not expect the
kernel to simply set that flag blindly.
Ernest.
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