Re: [PATCH RFC net-next 4/4] net: allow busy connected flows to switch tx queues

[Eric Dumazet <edumazet@google.com>]

On Wed, Oct 8, 2025 at 8:30 AM Paolo Abeni <pabeni@redhat.com> wrote:
>
> On 10/8/25 12:46 PM, Eric Dumazet wrote:
> > This is a followup of commit 726e9e8b94b9 ("tcp: refine
> > skb->ooo_okay setting") and to the prior commit in this series
> > ("net: control skb->ooo_okay from skb_set_owner_w()")
> >
> > skb->ooo_okay might never be set for bulk flows that always
> > have at least one skb in a qdisc queue of NIC queue,
> > especially if TX completion is delayed because of a stressed cpu.
> >
> > The so-called "strange attractors" has caused many performance
> > issues, we need to do better.
>
> I must admit my ignorance about the topic, do you have any reference handy?
>
> > @@ -1984,6 +1985,14 @@ static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
> >       return __sk_receive_skb(sk, skb, nested, 1, true);
> >  }
> >
> > +/* This helper checks if a socket is a full socket,
> > + * ie _not_ a timewait or request socket.
> > + */
> > +static inline bool sk_fullsock(const struct sock *sk)
> > +{
> > +     return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
> > +}
> > +
>
> I'm possibly low on coffee, but it looks like it's not needed to move
> around sk_fullsock() ?!? possibly sk_tx_queue_get() remained inline in a
> previous version of the patch?

Yes, I was using it in sk_tx_queue_set(), then realized all callers
were already doing it.

Thanks.