mptcp: add receive queue awareness in tcp_rcv_space_adjust()

This is the MPTCP counter-part of commit ea33537d8292 ("tcp: add receive
queue awareness in tcp_rcv_space_adjust()").

Prior to this commit:

  ESTAB 33165568 0      192.168.255.2:5201 192.168.255.1:53380 \
        skmem:(r33076416,rb33554432,t0,tb91136,f448,w0,o0,bl0,d0)

After:

  ESTAB 3279168 0      192.168.255.2:5201 192.168.255.1]:53042 \
        skmem:(r3190912,rb3719956,t0,tb91136,f1536,w0,o0,bl0,d0)

Same throughput.

Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260407-net-next-mptcp-reduce-rbuf-v2-2-0d1d135bf6f6@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 70a090a952996abefdf47cc69fa231fda66ef1bc..cf5747595259340dbb3f9806c7146af61215329b 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2159,11 +2159,13 @@ static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied)
        if (rtt_us == U32_MAX || time < (rtt_us >> 3))
                return;
 
-       if (msk->rcvq_space.copied <= msk->rcvq_space.space)
+       copied = msk->rcvq_space.copied;
+       copied -= mptcp_inq_hint(sk);
+       if (copied <= msk->rcvq_space.space)
                goto new_measure;
 
        trace_mptcp_rcvbuf_grow(sk, time);
-       if (mptcp_rcvbuf_grow(sk, msk->rcvq_space.copied)) {
+       if (mptcp_rcvbuf_grow(sk, copied)) {
                /* Make subflows follow along.  If we do not do this, we
                 * get drops at subflow level if skbs can't be moved to
                 * the mptcp rx queue fast enough (announced rcv_win can
@@ -2177,7 +2179,7 @@ static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied)
                        slow = lock_sock_fast(ssk);
                        /* subflows can be added before tcp_init_transfer() */
                        if (tcp_sk(ssk)->rcvq_space.space)
-                               tcp_rcvbuf_grow(ssk, msk->rcvq_space.copied);
+                               tcp_rcvbuf_grow(ssk, copied);
                        unlock_sock_fast(ssk, slow);
                }
        }