Re: [PATCH v2 mptcp-next 1/8] mptcp: enable busypoll from mptcp receive path

[Florian Westphal <fw@strlen.de>]

Paolo Abeni <pabeni@redhat.com> wrote:
> On Tue, 2021-05-11 at 15:36 +0200, Florian Westphal wrote:
> > The setting is only relevant for the msk socket.
> > While at it, also handle rcvlowat/rcvtimeo this way.
> > 
> > Signed-off-by: Florian Westphal <fw@strlen.de>
> > ---
> >  net/mptcp/protocol.c | 7 +++++++
> >  net/mptcp/sockopt.c  | 8 ++++++++
> >  2 files changed, 15 insertions(+)
> > 
> > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
> > index 652e55a0c6e8..86e599eb4403 100644
> > --- a/net/mptcp/protocol.c
> > +++ b/net/mptcp/protocol.c
> > @@ -12,6 +12,7 @@
> >  #include <linux/sched/signal.h>
> >  #include <linux/atomic.h>
> >  #include <net/sock.h>
> > +#include <net/busy_poll.h>
> >  #include <net/inet_common.h>
> >  #include <net/inet_hashtables.h>
> >  #include <net/protocol.h>
> > @@ -1982,6 +1983,12 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
> >  	if (unlikely(flags & MSG_ERRQUEUE))
> >  		return inet_recv_error(sk, msg, len, addr_len);
> >  
> > +	if (sk_can_busy_loop(sk) &&
> > +	    skb_queue_empty_lockless(&msk->receive_queue) &&
> > +	    skb_queue_empty_lockless(&sk->sk_receive_queue) &&
> > +	    inet_sk_state_load(sk) == TCP_ESTABLISHED)
> > +		sk_busy_loop(sk, nonblock);
> 
> If I understand the code correctly, here we need a valid sk-
> >sk_napi_id. That field is set by the TCP input path
> in tcp_finish_connect()/tcp_v{4,6}_do_rcv()/tcp_child_process() for the
> subflow ssk.

Can this patch just be dropped from the series?