Brian Kuschak wrote: > The performance on 4xx is dependent on how much work > you want to do in the ethernet driver. > > A (nearly) stock kernel will be able to forward 64 > byte packets at around 15,000 pps on 200MHz 405GP. > The interrupts burn alot of CPU cycles. If you > implement a timer-based interrupt mitigation scheme > using the FIT timer interrupt to clean out the RX and > TX rings, you will be able to hit about 35K to 40K > pps.
I definitely agree with Brian's numbers and recommendations :) Just a couple of comments: Starting with 2.4.19 or so, I'd recommend looking at NAPI to do interrupt mitigation instead. Please look at ftp://robur.slu.se/pub/Linux/net-development/NAPI/ > On top of that, you can implement > CONFIG_NET_FASTROUTE in the driver, bypassing most of > the IP stack. But, of course, you'll loose IP tables. Also, CONFIG_NET_FASTROUTE won't help in case you use a DHCP client (or any other app that uses raw sockets). This might not be that important for a router but be warned! Regards, Vladimir ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
