On Mon, Jan 27, 2025 at 02:24:00PM -0800, Jakub Kicinski wrote: > 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() Right, sorry for the typo/added confusion. > 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. OK, I'll start with that when net-next reopens while waiting on the locking changes to come later and do the actual linking.
