Hi,

Can I know what determines the mbuf fragmentation for a network packet? I am currently evaluate the driver transmission 
performance. But because of the HW DMA limitation, the mbuf fragments has a negative impact on the performance. 

I doubt the mbuf fragmentation is related to IP fragmentation. But just double check with you. We set the MTU size as 
1500. In the TCP throughput test, we saw almost always, the 1514 bytes ethernet packet is fragmented into 2, 3, or 
4(sometimes) mbufs as a chain, even if the mbuf cluster size is 2048 maximum. For example, a normal 1514 byte packet is 
fragmented as 3 packets, with the segments size as 42, 596 and 876.

Is there any way we can force not having mbuf fragmentation, or we prefer each segment, except the last one, to have 
size of 4bytes? 

Thanks a lot!

Yurong