On Thu, 4 Sep 2025 19:07:17 +0200 Petr Machata wrote: > Yet another option might be to use in-kernel FDB filtering, and to filter > the local entries when dumping. Unfortunately, this does not help all that > much either, because the linked-list walk still needs to happen. Also, with > the obvious filtering interface built around ndm_flags / ndm_state > filtering, one can't just exclude pure local entries in one query. One > needs to dump all non-local entries first, and then to get permanent > entries in another run filter local & added_by_user. I.e. one needs to pay > the iteration overhead twice, and then integrate the result in userspace. > To get significant savings, one would need a very specific knob like "dump, > but skip/only include local entries". But if we are adding a local-specific > knobs, maybe let's have an option to just not duplicate them in the first > place. Local-specific knob for dump seems like the most direct way to address your concern, if I'm reading the cover letter right. Also, is it normal to special case vlan 0 the way this series does? Wouldn't it be cleaner to store local entries in a separate hash table? Perhaps if they lived in a separate hash table it'd be odd to dump them for VLAN 0 (so the series also conflates the kernel internals and control path/dump output) Given that Nik has authored the previous version a third opinion would be great... adding a handful of people to CC.
