On Thu, 2011-05-19 at 12:05 -0700, Linus Torvalds wrote: > On Thu, May 19, 2011 at 10:12 AM, Linus Torvalds > <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > Now, notice that right now I'm *only* talking about removing it for > > the "hlist" cases (patch attached). I suspect we should do the same > > thing for all the list helpers. > > Actually, it's the "rcu" versions of the hlist helpers that need this > most, since those are the performance-critical ones and the ones used > in avc traversal. So the previous patch did nothing. > > So here's the actual patch I think I should commit. > > Added davem, benh and rmk explicitly - I think you're on linux-arch, > but still.. You may have machines that like prefetch more, although I > think the "pollute the L1 cache" issue means that even if you don't > have the NULL pointer microtrap issue you'll still find this actually > performs better.. Asked our local performance god: Anton Blanchard: yeah we found this 5 years ago, i thought intel were filtering null prefetches Anton Blanchard: turns out they werent. funny :-) Cheers, Ben. -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
