On Wed, 2017-05-31 at 10:00 -0700, Eric Dumazet wrote:
> On Mon, 2017-05-29 at 17:27 +0200, Paolo Abeni wrote:
> > Since UDP no more uses sk->destructor, we can clear completely
> > the skb head state before enqueuing.
>
> ...
>
> > @@ -1739,6 +1740,9 @@ static int __udp_queue_rcv_skb(struct sock *sk,
> > struct sk_buff *skb)
> > sk_mark_napi_id_once(sk, skb);
> > }
> >
> > + /* drop all pending head states; dst, nf and sk are dropped by caller */
> > + secpath_reset(skb);
> > +
>
> I wonder if using skb_release_head_state() would be more appropriate ?
>
> Surely more descriptive and probably not more expensive since all
> cache lines should be already hot at this point.
Thank you for reviewing this.
I would prefer not adding more code to the core, but I think we would
need something new, like:
skb_reset_head_state()
{
skb_dst_drop(skb);
secpath_reset(skb);
nf_reset(skb);
skb_orphan(skb);
}
because elsewhere the skb could be in inconsistent state: skb->sp !=
NULL but with its refcount is already decremented. WDYT?
Paolo
