On Fri, 2005-02-12 at 16:53 -0800, Ronciak, John wrote: > > In this combination of hardware and in this forwarding test > > copybreak is bad but prefetching helps. > > > > e1000 vanilla 1150 kpps > > e1000 6.2.15 1084 > > e1000 6.2.15 copybreak disabled 1216 > > e1000 6.2.15 copybreak disabled and no rx prefetch 1097 > > > This is what we are seeing as well. The copybreak performance makes > sense since every packet in this test would be copied increasing the CPU > to probably where it's pegged (that's what we see).
Ok, goody. But copybreak seems to help in some cases? I think Bothe Robert and I at some point gave up on the value of copybreak in our workloads. > The prefetching > does help in almost of cases we've run and we have not seen the prefetch > hurt anywhere. > > So we still need to see a case where performance is hurt by the > prefetching. We have some data coming from another group here at Intel > next week which we'll share once we have it which also shows the > performance gains with prefetching. > you probably wont notice any issues with "newer" hardware - where for example one would put a 10Gige card. Do you guys have access to any hardware that is "older". Pick something ~3 years old with slower RAM and small caches. cheers, jamal - 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
