On Fri, Oct 20, 2017 at 01:18:18AM +0000, Yongseok Koh wrote: > Hi, > > In some rx_burst functions, especially for vectorized ones (e.g. > i40e_rxtx_vec* > or mlx5_rxtx_vec*), there's actually a requirement of min burst size. > > As it manipulates 4 packets simultaneously in a loop, if nb_pkts of > rte_eth_rx_burst() is less than 4, it just returns without sending a packet. > > One way to handle it could be falling back to regular rx_burst in such cases > but > the burst size isn't a fixed/static parameter but applications can dynamically > change it when it polls a device. So, it might not be a good option. > > Therefore, how about adding min_rx/tx_burst_sz in struct rte_eth_dev_info and > have PMDs fill it in on dev_ops->dev_infos_get() so as to make apps comply > with > it. > > Because the max size of a burst can be handled well by PMD, it may not be > necessary. > > Thoughts? > For a short term fix, having the min burst size in the device info is a good enough fix, I think. Medium to long term, we need to remove this limitation in the vector drivers.
/Bruce
