Hi Sam, On Tue, Oct 12, 2004 at 01:20:07PM -0700, Sam Leffler wrote: > >>This pessimizes normal traffic. > > > >m_tag_locate() doesn't look like a very expensive function. And > >with the "normal traffic", I don't expect to be more than one tag, > >no? Also, if if_nvlans > 0, this is already "pessimized". > > > > > >>We should look for a solution in the > >>driver(s) to avoid sending packets up with tags when no vlans are > >>configured. > >> > > > >I'd be opposed to such a change in behavior. The VLAN consumer can > >be not only vlan(4), it can equally be the ng_vlan(4) node, etc. > > I'm not sure what you are opposed to or why. The issue I have is that > m_tag_locate can be expensive if many packets have tags. The check for > the existence of vlans configured on the interface short-circuits this > work. That vlan-tagged packets may be generated when no vlans are > configured seems wrong to me and breaks the assumption used to write the > code. Changing the driver to drop the frame if ifp->if_nvlans is zero > seems straightforward and could probably be hidden in the existing macro. > Please take a moment and re-read what I've already said: vlan(4) is not the only consumer of VLAN frames: ng_vlan(4) is another such one, and I have a proprietary Netgraph node here that demultiplexes VLANs. If you start dropping VLAN frames in drivers when if_nvlans == 0, this will be a problem for me. Is that clear now? Cheers, -- Ruslan Ermilov ru_at_FreeBSD.org FreeBSD committer
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