Re: Big git diff speedup by avoiding x86 "fast string" memcmp

[AmÃrico Wang]

On Mon, Dec 13, 2010 at 07:25:05PM +1100, Nick Piggin wrote:
>On Mon, Dec 13, 2010 at 6:29 PM, J. R. Okajima <hooanon05@xxxxxxxxxxx> wrote:
>> But is the "rep cmp has quite a long latency" issue generic for all x86
>> architecture, or Westmere system specific?
>
>I don't believe it is Westmere specific. Intel and AMD have
>been improving these instructions in the past few years, so
>Westmere is probably as good or better than any.
>
>That said, rep cmp may not be as heavily optimized as the
>set and copy string instructions.
>
>In short, I think the change should be suitable for all x86 CPUs,
>but I would like to hear more opinions or see numbers for other
>cores.
>

How about other arch? If this is only for x86, shouldn't it be
protected by CONFIG_X86?

Thanks.
--
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/