Re: [PATCH RFC V4 09/10] x86/jump_label: use GENERIC_NOP5_ATOMICinstead of jmp5 +0

From: H. Peter Anvin
Date: Fri Oct 14 2011 - 17:53:00 EST


On 10/13/2011 09:50 AM, Jeremy Fitzhardinge wrote:
> On 10/13/2011 08:40 AM, H. Peter Anvin wrote:
>> On 10/12/2011 05:08 PM, Jeremy Fitzhardinge wrote:
>>> From: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
>>>
>>> GENERIC_NOP5_ATOMIC should make a better nop.
>>>
>> On 32 bits, yes. On 64 bits you should use P6_NOP5_ATOMIC.
>
> So the cleanest way of fixing that is to make the GENERIC_NOP* be
> defined to P6_NOP* on 64-bit then? Assuming I'm correct in guessing
> that the intent of GENERIC_NOP* is "a basically good-enough NOP that
> will work on any x86".
>

No, GENERIC_NOPs are not valid on 64 bits at all.

-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/