On Mon, 27 Jan 2025 17:07:54 -0500 Joe Damato wrote: > > Tx NAPIs are one aspect, whether they have ID or not we may want direct > > access to the struct somewhere in the core, via txq, at some point, and > > then people may forget the linking has an unintended effect of also > > changing the netlink attrs. The other aspect is that driver may link > > queue to a Rx NAPI instance before napi_enable(), so before ID is > > assigned. Again, we don't want to report ID of 0 in that case. > > I'm sorry I'm not sure I'm following what you are saying here; I > think there might be separate threads concurrently and I'm probably > just confused :) > > I think you are saying that netdev_nl_napi_fill_one should not > report 0, which I think is fine but probably a separate patch? > > I think, but am not sure, that Jason was asking for guidance on > TX-only NAPIs and linking them with calls to netif_queue_set_napi. > It seems that Jason may be suggesting that the driver shouldn't have > to know that TX-only NAPIs have a NAPI ID of 0 and thus should call > netif_queue_set_napi for all NAPIs and not have to deal think about > TX-only NAPIs at all. > > From you've written, Jakub, I think you are suggesting you agree > with that, but with the caveat that netdev_nl_napi_fill_one should > not report 0. Right up to this point. > Then, one day in the future, if TX-only NAPIs get an ID they will > magically start to show up. > > Is that right? Sort of. I was trying to point out corner cases which would also benefit from netdev_nl_queue_fill_one() being more careful about the NAPI IDs it reports. But the conclusion is the same. > If so, I'll re-spin the RFC to call netif_queue_set_napi for all > NAPIs in virtio_net, including TX-only NAPIs and see about including > a patch to tweak netdev_nl_napi_fill_one, if necessary. netdev_nl_queue_fill_one(), not netdev_nl_napi_fill_one() Otherwise SG. After net-next reopens I think the patch to netdev_nl_queue_fill_one() could be posted separately. There may be drivers out there which already link Tx NAPIs, we shouldn't delay making the reporting more careful.
