How WQE and DoorBell are handled

[lijh5]

For example: use the rc_verbs interface to transmit 11600 bytes of data, use the bcopy protocol at this time, and then am_bcopy<=8254, the data needs to be segmented.
I looked at the code, and each segment of data will call ibv_post_send once, that is to say wr->next=NULL, why not choose to add it to the postlist and send it once?
This means that every segmented message will ring the doorbell once, is there any advantage to doing this?