I havenât benchmarked to be able to provide factual data,
but Iâve done a lot of optimization and tweaking of lwIP to improve
bandwidth and my study of pbufs and memory pools did not show the need for improvement
considering all of the other things required to handle a TCP connection.
I saw the patch not as speed optimization but as a way to simplify the netif driver: to provide a robust implementation, a netif driver would have to ensure it retries if pbuf_alloc fails because the pool is empty (to prevent a deadlock). This patch prevents a netif driver having to implement some sort of timer because it just gets notified when pbufs are available again.