Hi Frank, You mentioned that you got better MDT TCP performance than LSO, so could you share some data you got? What's the performance numbers and CPU utilizations with or without MDT or LSO?
The complexity of MDT is not only for the drivers, but mainly in the stack. Actually, we have a SOFT LSO implementation that simulates hardware LSO inside driver that can contribute at least the same performance gain compared to MDT. And the LSO implementation, both in stack and driver will be much more simpler than MDT. There is also a plan to implement SOFT LSO in GLDv3 so that any non-LSO-capable drivers may take advantage of it without taking care of the interface. That will address your concern with your hardware that doesn't support H/W UDP LSO. Thanks, Roamer Francesco DiMambro wrote: > Hi Eric > Erik Nordmark wrote: >> Francesco DiMambro wrote: >>> <div class="moz-text-flowed" style="font-family: -moz-fixed">Hi Darren >>> That would be UDP LSO right? Solaris 10 update 4 has >>> LSO for TCP, but not UDP. The key point I want to make here >>> is the adapter I'm working with has LSO for TCP also, the UDP >>> part it doesn't, yet, but no big deal because neither does Solaris. >>> I implemented MDT and it works for UDP and TCP and in a side >>> by side comparison of LSO v MDT, for TCP on the same card >>> MDT wins. >>> I want to get the Max performance for my adapter and Solaris >>> and presently MDT is proving the best way to do it. Having come >>> to this conclusion I thought I should share it with the alias, because >>> I need it to be maintained in Solaris, I was not expecting to hear >>> it was being EOL'd that's just premature. >> Frank, >> >> why did you choose MDT over LSO? > When I started the development, there was no LSO on Solaris 10, so I put MDT > into the driver, I got distracted with Windows driver development for 3 > years. Then > when I returned to Solaris LSO had became available so I added LSO as well. >> Did you need to run on Solaris releases that doesn't support LSO but >> supports MDT? > We're aiming to support Solaris 8, 9 and 10 and following activity on > Solaris11, > sparc and x86. >> Or did you benchmark MDT and LSO and found that MDT was more efficient? > I benchmarked MDT v LSO and MDT was better on our card but I attribute > that to limited hardware capability, if the hardware can go up to 1M LSO > them > I'd expect LSO to overtake MDT, we're not there yet hence the need for MDT. > In the case of UDP there's no LSO in Solaris so the benchmark was against > plain old one packet at a time model. With that MDT was twice as fast, but > was limited by the receiver which couldn't deal with the volume of packets. > (Working on that next.) >> There is a fair bit (understatement) of complexity on the MDT >> implementation and that is why I'd like to understand the above. > The complexity in the driver is equal to the complexity of the one packet at > a time model. The difference is familiarity, in other words most people can > write a one packet at a time Tx, and layer on top of that LSO, no > brainer ;-). > But MDT is a new data structure so needs a different way to Tx, once you > know how to do that then you can handle the complexity. It's just like what > M$ did in the transition from NDIS_PACKET to NBL/NB's, everyone who > knew how to write a NDIS_PACKET tx had to re-learn how to do it > for NBL/NB's. I'm not asking you go that far, but just leave the option to > allow MDT, with it's ability to send more than one packet to the driver in > one call. > > thanks > Frank >> Thanks, >> Erik > > _______________________________________________ > networking-discuss mailing list > [email protected] -- # telnet (650)-786-6759 (x86759) Connected to Solaris.Sun.COM. login: Lu, Yunsong Last login: January 2, 2007 from beyond.sfbay [EMAIL PROTECTED] v1.04 Since Mon Dec. 22, 2003 [EMAIL PROTECTED] Networking]# cd .. _______________________________________________ networking-discuss mailing list [email protected]
