Fri, May 13, 2016 at 08:47:48PM CEST, ro...@cumulusnetworks.com wrote: >On 5/12/16, 11:03 PM, Jiri Pirko wrote: >> Thu, May 12, 2016 at 11:10:08PM CEST, ro...@cumulusnetworks.com wrote: >>> On 5/12/16, 4:48 AM, Jiri Pirko wrote: >>>> From: Nogah Frankel <nog...@mellanox.com> >>>> >>>> Till now we had a ndo statistics function that returned SW statistics. >>>> We want to change the "basic" statistics to return HW statistics if >>>> available. >>>> In this case we need to expose a new ndo to return the SW statistics. >>>> Add a new ndo declaration to get SW statistics >>>> Add a function that gets SW statistics if a competible ndo exist >>>> >>>> Signed-off-by: Nogah Frankel <nog...@mellanox.com> >>>> Reviewed-by: Ido Schimmel <ido...@mellanox.com> >>>> Signed-off-by: Jiri Pirko <j...@mellanox.com> >>>> --- >>>> >>> To me netdev stats is combined 'SW + HW' stats for that netdev. >>> ndo_get_stats64 callback into the drivers does the magic of adding HW stats >>> to SW (netdev) stats and returning (see enic_get_stats). HW stats is >>> available for netdevs >>> that are offloaded or are backed by hardware. SW stats is the stats that >>> the driver maintains >>> (logical or physical). HW stats is queried and added to the SW stats. >> I'm not sure I follow. HW stats already contain SW stats. Because on >> slow path every packet that is not offloaded and goes through kernel is >> counted into HW stats as well (because it goes through HW port). >yes, correct... we don't want to double count those. But since these stats are >generally queried from hw, I am calling them HW stats. >you will not really maintain a software counter for this. But, the driver can >maintain its own > counters for rx and tx errors etc and I call these SW stats. They are counted > at the driver. > >> If you >> do HW stats + SW stats, what you get makes no sense. Am I missing something? >If you go by my definition of HW and SW stats above, on a ndo_get_stats64() >call, >you will add the SW counters + HW counters and return. In my definition, the >pkts >that was rx'ed or tx'ed successfully are always in the HW count. > >> Btw, looking at enic_get_stats, looks exactly what we introduce for >> mlxsw in this patchset. > >In enic_get_stats, the ones counted in software are the ones taken from >'enic->' > net_stats->rx_over_errors = enic->rq_truncated_pkts; > net_stats->rx_crc_errors = enic->rq_bad_fcs; > >> >> With this patchset, we only allow user to se the actual stats for >> slow-path aka SW stats. >hmm...ok. But i am not sure how many will use this new attribute. >When you do 'ip -s link show' you really want all counters on that port >hardware or software does not matter at that point. > >My suggestion to move this to ethtool like attribute is because that is an >existing > way to break down your stats which ever way you want. And the best part is it > can be >customized (say rx_pkts_cpu_saw)
I bevieve that ethtool is really not a place to expose sw stats. Does not make sense.
