From: Andi Kleen <[EMAIL PROTECTED]> Date: Sat, 3 Dec 2005 03:03:28 +0100
> On Fri, Dec 02, 2005 at 05:01:39PM -0800, John Ronciak wrote: > > On 12/2/05, Grant Grundler <[EMAIL PROTECTED]> wrote: > > > > > Yup. We can tune for workload/load-latency of each architecture. > > > I think tuning for all of them in one source code is the current problem. > > > We have to come up with a way for the compiler to insert (or not) > > > prefetching at different places for different architectures (and maybe > > > even CPU model) in order for this to be acceptable/optimal. > > > > > We could use a macro defined for each arch which would or not do the > > prefetch I guess. I don't they exist today but we could do that. > > If anything then a runtime test - e.g. behaviour could be very different > for different x86 implementation. Let's not create these silly interfaces until we show a performance loss from e1000's new prefetches. We don't even know the _nature_ of the cases where the e1000 prefetches might want to be disabled by a platform. It's therefore impossible for us to design any kind of reasonable interface or runtime test. All evidence shows the prefetches of the first cache line of the packet data helps, always. We need well analyzed exceptions before we can discuss this any further. :-) - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
