On Thu, 2006-06-29 at 13:19 -0700, David Miller wrote: > From: Tom Tucker <[EMAIL PROTECTED]> > Date: Thu, 29 Jun 2006 15:11:06 -0500 > > > Doesn't this position force vendors to build deeper adapters, not > > shallower adapters? Isn't this exactly the opposite of what is intended? > > Nope. > > Look at what the networking developers give a lot of attention and > effort to, things like TCP Large Receive Offload, and Van Jacobson net > channels, both of which are fully stack integrated receive performance > enhancements. They do not bypass netfilter, they do not bypass > packet scheduling, and yet they provide a hardware assist performance > improvement for receive.
These technologies are integrated because someone chose to and was allowed to integrate them. I contend that iWARP could be equally well integrated if the decision was made to do so. It would, however, require cooperation from both the hardware vendors and the netdev maintainers. > > This has been stated over and over again. For TOE, you are correct, however, for iWARP, you can't do RDMA (direct placement into application buffers) without state in the adapter. I personally tried very hard to build an adapter without doing so, but alas, I failed ;-) > > If companies keep designing undesirable hardware that unnecessarily > takes features away from the user, that really is not our problem. I concede that features have been lost, but some applications benefit greatly from RDMA. For these applications and these customers, the hardware is not undesirable and the fact that netfilter won't work on their sub 5us latency adapter is not perceived to be a big issue. The mention of packet scheduling would cause an apoplectic seizure...unless it were in the hardware... All that verbiage aside, I believe that it is not a matter of whether it is possible to integrate iWARP it is question of whether it is permissible. - 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
