Hi Helmut, On 12/17/2014 08:17 AM, Helmut Sim wrote: >>>>> While working on TSO based solution I faced the following two questions: >>>>> >>>>> 1. >>>>> is there a maximum pkt_len to be used with TSO?, e.g. let's say if >>>>> seg_sz >>>>> is 1400 can the entire segmented pkt be 256K (higer than 64K) ?, then >>>>> the >>>>> driver gets a list of chanined mbufs while the first mbuf is set to TSO >>>>> offload.
I think the limitations depend on: - the window size advertised by the peer: your stack should handle this and not generate more packets that what the peer can receive - the driver: on ixgbe, the maximum payload length is 2^18. I don't know if there is a limitation on number of chained descriptors. I think we should define a way to know this limitation in the API. Maybe a comment saying that the TSO length should not be higher than 256KB (or fix it to 64KB in case future drivers do not support 256KB) is enough. Regards, Olivier
