On Mon, Mar 14, 2011 at 09:40:36PM -0700, Vijay Singh wrote: > > As you know, BCM5714, BCM5715 and BCM5780 use unique jumbo frame > > scheme that is not compatible with other controllers. All other > > Broadcom controllers have better jumbo frame scheme. These > > controllers have one send ring, one standard receive producer ring > > and one receive return ring. In order to receive jumbo frames on > > these controllers you have to increase Rx buffer size to hold 9k > > sized jumbo frame. Two Rx modes(standard Rx BDs and extended Rx > > BDs) are supported for these controllers. Using extended Rx BDs on > > BCM5714/BCM5715/BCM5780 reduces the number of Rx BDs to 256 entries > > which shall reduce the performance. I would use standard Rx BDs to > > hold 512 entries for RX buffers. > > > > I think I received jumbo frame support request for these > > controllers in past. At that time I had no interests on > > implementing it due to severe implementation differences. What is > > your main reason to use jumbo frame on this controller? What is > > your expectation on performance numbers? I guess no other OSes > > support jumbo frame on this controller. > > Hi Pyun, I am stuck with this NIC due to it being the one present in > the HW platform that I have to support. The performance is expectation > is mainly for apps that use large payloads (where something TSO would > have helped). >
Here is experimental patch which I tried not to penalize other controllers. I don't have BCM5714 controllers so I don't know whether it works or not. The patch was generated against HEAD and it would be cleanly applied to 8.2R/7.4R. Due to large bge(4) changes I guess it wouldn't be applied to 7.2R. But I guess you can install 8.2R/7.4R to one of your box and experiment this patch for a while then you can backport this to 7.2R. You can find the patch at the following URL. http://people.freebsd.org/~yongari/bge/bge.5714.jumbo.diff > -vijay _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
