On Wed, Mar 01, 2017 at 06:19:06PM +0100, Olivier Matz wrote: > This patchset introduces a new ethdev API: > - rte_eth_rx_descriptor_status() > - rte_eth_tx_descriptor_status() > > The Rx API is aims to replace rte_eth_rx_descriptor_done() which > does almost the same, but does not differentiate the case of a > descriptor used by the driver (not returned to the hw). > > The usage of these functions can be: > - on Rx, anticipate that the cpu is not fast enough to process > all incoming packets, and take dispositions to solve the > problem (add more cpus, drop specific packets, ...) > - on Tx, detect that the link is overloaded, and take dispositions > to solve the problem (notify flow control, drop specific > packets) > Looking at it from a slightly higher level, are these APIs really going to help in these situations? If something is overloaded, doing more work by querying the ring status only makes things worse. I suspect that in most cases better results can be got by just looking at the results of RX and TX burst functions. For example, if RX burst is always returning a full set of packets, chances are you are overloaded, or at least have no scope for an unexpected burst or event.
Are these really needed for real applications? I suspect our trivial l3fwd power example can be made to work ok without them. Regards, /Bruce
