On 11/30/18 1:30 PM, Michael S. Tsirkin wrote: >>>> I would like to see basic packets, bytes, and dropped counters >>>> tracked >>>> for Rx and Tx via the standard netdev counters for all devices. >> >> The problem of reporting XDP_DROP in the netedev drop counter is that >> they don't fit this counter description : "no space in linux buffers" >> and it will be hard for the user to determine whether these drops are >> coming from XDP or because no buffer is available, which will make it >> impossible to estimate packet rate performance without looking at >> ethtool stats. >> And reporting XDP_DROP in the netdev rx packets counter is somehow >> misleading.. since those packets never made it out of this driver.. >> >> >> And reporting XDP_DROP in the netdev rx packets counter is somehow >> misleading.. since those packets never made it out of this driver.. > > I think I agree. XDP needs minimal overhead - if user wants to do > counters then user can via maps. And in a sense XDP dropping packet > is much like e.g. TCP dropping packet - it is not counted > against the driver since it's not driver's fault. >
XDP dropping a packet is completely different. stats are important. packets disappearing with no counters -- standard counters visible by standard tools -- is a user nightmare. If the agreement is for XDP drops to be in driver level (e.g., xdp_drop) that is fine since it is still retrievable by ethtool -S (existing APIs and existing tools).
