Re: This kernel requires the following features not present on theCPU... (on a VIA C7 CPU)

[H. Peter Anvin]

Simon Arlott wrote:
> On 17/05/07 21:15, H. Peter Anvin wrote:
>> Simon Arlott wrote:
>>> Is it automatic? I have CONFIG_X86_CMPXCHG=y without cx8 showing in
>>> cpuinfo, and it appears to work fine.
>>>
>>> Will your changes needlessly prevent the kernel running? Would I be
>>> right in thinking that the kernel is successfully using cmpxchg even
>>> though it's considered disabled? I realise people compile kernels for
>>> the wrong CPU but preventing them working when it's been chosen
>>> correctly seems wrong.
>>>
>>
>> CX8 isn't cmpxchg; it's cmpxchg8b.
> 
> Ok, but I have CONFIG_X86_CMPXCHG64=y too.
> 

OK then, then VIA just masks the CPUID bit as opposed to the
instruction.  Point still holds.

	-hpa
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/