Re: PATCH: extra conntrack stats

[Rusty Russell <rusty@rustcorp.com.au>]

In message <20030501060522.GB15143@oknodo.bof.de> you write:
> > 	struct nf_ct_info infos[IP_CT_NUMBER];
> > 7 * 4 bytes.  We could eliminate this by adding an skb field to hold
> > the state.
> 
> Given a guaranteed cacheline alignment of our 'struct ip_conntrack',
> we could make the current pointer on the skbuffs a tagged pointer,
> i.e. stuff our 3 info bits into the low 3 bits, without consuming
> more room in the skbuffs.

That was my original implementation.  It was fairly ugly, but worse, I
can imagine an arch where it would break.  None would at the moment,
though, since kmalloc cacheline aligns (although we'd have to be a
little careful to explicitly align a conntrack if we were to use a
dummy one for a "notrack" target.

> See http://lists.netfilter.org/pipermail/netfilter-devel/2002-July/008703.html

That looks like a good patch anyway...

Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.