Kenneth D. Merry writes: > > As a related question, will this work with the broadcom gigabit (bge) > > driver, which is the Tigon III? If not, what would it take to get > > it working? > > Unfortunately, it won't work with the Tigon III. > > If you can get firmware source for the Tigon III, I can probably get header > splitting working. (The only way it wouldn't work is if they've offloaded > most of the packet processing into the hardware.)
I don't want this to sound too much like an advertisement, but since I now work for Myricom, I feel obligated to point out that the other adapters that this can be made to work with are Myricom Myrinet interfaces (*) Anyway, if this gets committed, I will enhance the Myricom GM-2 firmware to support page-flipping receives. I think my boss will approve the work. With FreeBSD & gm-2, we now see roughly 1.8Gb/sec from iperf, but the receiver's CPU is maxed out. It would be nice to have some room left over to actually do something with the data ;) > The send side code will work on any NIC, and you can kludge up special case > header splitting on the receive side if the NIC allows you to break jumbo > frames into multiple chunks of data. (This is what Drew originally did for > the Tigon II -- you just size the initial chunk of data so that it'll just > hold the ethernet header, IP header, TCP header and TCP options, and the > payload will "magically" end up page aligned. This doesn't work for > protocols other than TCP, and it won't work if your TCP header changes in > length.) This mostly doesn't work for TCP at all. It does work for the client-side zero-copy NFS read-response work I did where I page-flip the received frame into the buffer cache. This was something of a hack, because I don't actually parse the rpcs, I just guess that the data starts at a certain offset into the packet (which it does, 99% of the time). Cheers, Drew (*) 2Gb/sec + 2Gb/sec. See http://www.myri.com/myrinet/product_list.html. Before your jaw hits the floor at the price per adapter, take into account how cheap the switches are when compared to high-density gigabit ethernet switches. To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-net" in the body of the message
