Re: [PATCH net-next v11 3/6] net: add a generation counter for dev->mc changes

[Paolo Abeni]

On 10/20/26 12:22, Yuyang Huang wrote:
> > To clarify: every I mentioned in my previous email was about possible
> > follow-ups - not to be included here.
>
> Understood, I will send them as separate patches.
>
> > My understanding is that there is sort of a pending/implicit question
> > from Jakub on v9: why are you doing this? is does it solve some
> > specific scaling problem or is 'nl is nicer" thing?
>
> I think the motivation question was on the v5 thread, and I replied
> there as well.

FTR (and just in case it's not obvious enough :-P) the ML traffic is
quite overwhelming. I unable to read some of the email/patches I
don't end-up processing, and even when I actually processed the
relevant email, I could end-up forgetting a specific contents of one
given email, some 10-100K emails later...

TL;DR: please include the relevant information in later revisions, at
least as a reference link.

> My original motivation is to simplify some userspace hardware offload
> code I am working on, and to finish moving "ip maddr" to netlink.
>
> RTM_GETMULTICAST already reports IPv4 and IPv6 group memberships with
> IFA_MC_USERS. dev->mc is the only part of the multicast state still
> available only from /proc/net/dev_mcast, so every consumer that needs
> the full picture keeps two paths: netlink for L3 and procfs text
> parsing for L2. The offload code above is one such consumer. iproute2
> is another: "ip maddr show" already gets IPv4/IPv6 over netlink but
> still parses procfs for its link-layer entries. The iproute2 change to
> drop that is ready to follow this series.

I agree that the unified interface makes sense.

/P