> Quoting Or Gerlitz <[EMAIL PROTECTED]>: > Subject: Re: [PATCH - 11] ipoib - add LSO support > > Eli Cohen wrote: > >On Mon, 2007-08-20 at 18:48 +0300, Or Gerlitz wrote: > > > >>I see that the patch adds the NETIF_F_TSO flag to the device features > >>but not the NETIF_F_UFO flag. Is UDP LSO supported by the connectX HW? > >>if yes, what would it take SW wise to support it? > > > >UDP LSO is not supported by the HW. > > I see. > > > Reading http://en.wikipedia.org/wiki/TCP_segmentation_offload and > thinking about the connectx TCP segmentation offloading a little further > I am somehow confused: > > With the ipoib connected mode a typical MTU exposed to the OS is 64K, > where data goes over IB RC (soon to be UC) transport meaning that the > HCA does the "fragmentation / reassembly" at the QP (IB L4) level > allowing to send one 64K IB packet over a path whose Link layer (IB L2) > MTU is 2k. > > So TCP can use segments size upto 64K and UDP can send datagram's whose > size is upto 64K without IP fragmentation. > > With all this at hand, what does LSO buys you at all?
If you read these patches closely, you'll see that LSO is disabled for connected mode. -- MST _______________________________________________ general mailing list [email protected] http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
