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 tput)

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 net/mptcp/protocol.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 9a0a4bfa25e6..a9dbdb413c7e 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2137,11 +2137,13 @@ 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
@@ -2155,7 +2157,7 @@ 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);
 		}
 	}
-- 
2.51.1

On Wed, 12 Nov 2025, Paolo Abeni wrote:

> 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 tput)
>
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
> net/mptcp/protocol.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)

Reviewed-by: Mat Martineau <martineau@kernel.org>