> Looks like you'll need to do a __get_user() against the page to
> populate the tlb. We're going to need it in the copy_to_user()
> anyway, so the cost is negligible.
Completly puzzled right now. Moving the prefetching to copy_to_user
(and doing the tlb preload & prefetching the whole chunk to be copied
(or cachesize if smaller)) results in a performance drop instead of a win.
My initial guess is that some of the callers of copy_to_user are
doing something that is harmed the prefetching.
(Maybe they are doing additional prefetch() calls)
Dave
-- | Dave Jones. http://www.codemonkey.org.uk | SuSE Labs- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/