Re: [PATCH 1/2] x86: Mark __vdso entries as asmlinkage

["H. Peter Anvin" <hpa@zytor.com>]

On 02/26/2014 09:19 PM, Andy Lutomirski wrote:
>>
>> The normal ABI almost certainly makes more sense; as such -mregparm=3 is
>> probably not what we want, and I suspect it makes more sense to just
>> drop that from the CFLAGS line?
> 
> Hmm.  What happens on a native 32-bit build?  IIRC the whole kernel is
> build with regparm(3).
> 

Well, the vdso is still built separately, so we can use different CFLAGS
if we want to.

> If we want to save a cycle or two, then regparm(3) is probably faster.
>  But I think that these functions should either be asmlinkage or (on
> 32 bit builds) explicitly regparm(3) to avoid confusion.

I suggest using the standard ABI, but I suggest doing it via CFLAGS.

It isn't any faster if the C library has to provide a wrapper just to
marshal parameters.

	-hpa