On Wed, 2005-07-12 at 14:27 -0500, Jeff Garzik wrote: > John Ronciak wrote: > > As far as copybreak goes, we knew it probably won't help routing type > > test with small packets. Robert's test shows it really only hurts > > where it seems to be CPU bound, which makes sense. This can be > > disable at compile time by setting E1000_CB_LENGHT to 2K which means > > that copybreak won't ever be done. > > So... under load, copybreak causes e1000 to fall over more rapidly than > no-copybreak? > > If so, it sounds like copybreak should be disabled by default, and/or a > runtime switched added for it. >
so thats conclusion one. Copybreak oughta be off by default. People who think it is useful can turn it on. But its a little more complicated than that; if you turn off copybreak, the prefetch numbers go down;-> I just did the following: comment out the copybreak code, leave prefetch on. Add a little while loop that counts till 10 to chew cycles. And hallelujah, lord have mercy, the numbers went up by like 10Kpps. So this validates my views from earlier on why both having prefetch and copybreak on seemed to give better numbers than prefetch by itself. 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
