On Tue, Oct 08, 2024 at 11:58:37AM +0200, Morten Brørup wrote: > > From: Ferruh Yigit [mailto:ferruh.yi...@amd.com] > > Sent: Sunday, 6 October 2024 22.51 > > > > On 10/4/2024 9:40 PM, Stephen Hemminger wrote: > > > ... > > >>>>> The stats queue mapping was a feature that was hinted at being > > removed. > > >>>>> It only exists because of HW limitations on Intel ixgbe NIC and > > SW > > >>>>> limitations from RTE_ETHDEV_QUEUE_STAT_CNTRS. > > >>>>> > > >>>> > > >>>> > > >>>> We have a plan to remove 'RTE_ETHDEV_QUEUE_STAT_CNTRS', by moving > > queue > > >>>> stats to xstats. > > >>>> > > >>>> But ixgbe limitation is there. > > >>>> > > >>>>> Perhaps there should be a generic SW emulation for this the > > mapping? > > >>>>> > > >>>> > > >>>> Ack, cc'ed Bruce. > > >>>> But I am not sure ROI of the effort at this stage. > > >>> > > >>> Not sure what the specific ask for me is here. :-) Overall, I think > > moving > > >>> queue stats to xstats is the best way to go. > > >>> > > >> > > >> cc'ed because of "generic SW emulation" comment. > > >> > > >> I was thinking if this mapping can be done transparent to the user > > by > > >> driver mapping queue <-> stats_register before reading stats, but > > @Bruce > > >> let me know this won't work because the stats tracking only happens > > >> after the mapping. > > >> > > >> @Stephen, do you have something specific in your mind for SW > > emulation > > >> for mapping? > > > > > > Probably not worth doing mapping tables for SW drivers. > > > > > > My preference would be something like: > > > 1. Introduce new API's rte_ethdev_get_queue_stats() and > > rte_ethdev_reset_queue_stats(). > > > with callbacks in ethdev ops. > > > if driver does not support this, then do a shim in ethdev > > that uses old stats fields. > > > 2. Mark the stats mapping API's as deprecated and always > > return error. > > > Making special case for ixgbe at this point really is not > > worth maintaining. > > > 3. After all drivers converted over, drop the fields in > > ethdev stats for queues. > > > And fix the examples, etc. Yes this would be a big API > > change. > > > > > > Would take a year to get done (ie 25.11). > > > > > > > The problem with existing a API, 'rte_eth_stats_get()', is it has queue > > stats fixed sized array which limits us also for some cases causes > > unnecessary memory consumption. > > > > Our solution for now is move queue stats to xstats, as it is flexible > > this solves the problem, but as you said in other thread xstats is free > > form and may be hard for the application to use it. > > > > One option is we can add some more data to the xstats, to help > > application to consume it easier, like number of queues just before the > > queue stats and define queue stats formatting syntax. > > > > But if we will go with API option, instead of adding new queue stats > > ('rte_ethdev_get_queue_stats()'), we can update the existing > > 'rte_eth_stats_get()' to return dynamic number of queue stats. > > Some users might not care about queue stats, so let's remove them entirely > from rte_eth_stats_get(), and put them elsewhere. > +1 for this. I think separate APIs for queue stats would make more sense.
/Bruce
