On Wed, Dec 15, 2010 at 12:38:40PM +0800, Américo Wang wrote: > 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? That's what I would like to know, but I suspect that for very short strings we are dealing with, the custom loop will be fine for everybody. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
