Subject: Re: Cardbus
To: Ken Hornstein <>
From: Lennart Augustsson <>
List: tech-kern
Date: 12/27/1999 09:56:29
Ken Hornstein wrote:

> >I think it's also worth looking at what BSDI did; I don't think it's
> >completely correct but it had certain useful behaivors..  for
> >instance, popping a card and reinserting it doesn't require you to
> >re-ifconfig the interface.
> Hmmmm .... is this a useful semantic to preserve?  I could see it
> getting rather complicated trying to do this in practice.

It don't care one bit about for that semantics.  It would just be a special
case.  I would assume that any card (or whatever) you plug in will have
to be ifconfiged.  Since it must happen for some of them, I'd rather have it
happen for all of them.

> >You also have to worry about interface pointers in received mbufs.
> >Given how the pool allocator works, it shouldn't be too hard to write
> >a function which scans all the mbufs.
> Ah, I knew that I was forgetting something :-)  Buuuttt .... wouldn't
> it be easier to look at ipintrq and arpintrq?  Hmmm, no, that might
> not catch mbufs that are being processed.  Rather sticky, that
> one.  There _are_ a lot of spots where rcvif is used, but they all
> seem to check to see if it's NULL .... so maybe a scan through all the
> mbufs to NULL out rcvif might be sufficient.

Sounds like a good plan to me.  Since the guy who wrote the OpenBSD code
is often in the office next to mine at work I'll ask him the next time I see him
if he knows about any problems with the code.  I know he said there was
more work to be done on it.


        -- Lennart