Re: [PATCH] reduce netfilte sk_buff enlargement

["David S. Miller" <davem@davemloft.net>]

From: Harald Welte <laforge@netfilter.org>
Date: Wed, 20 Jul 2005 09:23:05 -0400

> On Mon, Jul 18, 2005 at 08:31:45PM -0700, David S. Miller wrote:
> > From: Harald Welte <laforge@netfilter.org>
> > Date: Mon, 18 Jul 2005 00:04:51 +0200
> > 
> > > The only real in-tree user of nfcache was IPVS, who only needs a single
> > > bit.  Unfortunately I couldn't find some other free bit in sk_buff to
> > > stuff that bit into, so I introduced a separate field for them.  Maybe
> > > the IPVS guys can resolve that to further save space.
> > 
> > I think we must resolve this one before 2.6.14 goes out, which
> > gives us a lot of time, but for now I'll eat that one-bit member.
> 
> Well, I hope IPVS people will take care of this.  I don't really know
> that code too well...

Ok, I might take a look at this myself.

> > > Initially I wanted to shrink pkt_type to three bits (PACKET_HOST and
> > > alike are only 6 values defined), but unfortunately the bluetooth code
> > > overloads pkt_type :(
> > 
> > This also must be cured somehow, that really isn't a clean nor nice
> > usage of this field.
> 
> I just ran into Marcel Holtmann earlier today.  He thinks moving that
> data into the cb is fine, though he has to double-check that.
> 
> He also said that he really only needs 5 bits, so even if the current
> pkt_type overloading would persist, we could probably shrink it to make
> space for the IPVS bit.

Ok, sounds great.