From 4e637c70b503b686aae45716a25a94dc3a434f3a Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 25 May 2020 23:41:13 +0200 Subject: mptcp: attempt coalescing when moving skbs to mptcp rx queue We can try to coalesce skbs we take from the subflows rx queue with the tail of the mptcp rx queue. If successful, the skb head can be discarded early. We can also free the skb extensions, we do not access them after this. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller --- net/mptcp/protocol.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index ba9d3d5c625f..b2c8b57e7942 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -144,12 +144,29 @@ static void __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk, unsigned int offset, size_t copy_len) { struct sock *sk = (struct sock *)msk; + struct sk_buff *tail; __skb_unlink(skb, &ssk->sk_receive_queue); - skb_set_owner_r(skb, sk); - __skb_queue_tail(&sk->sk_receive_queue, skb); + skb_ext_reset(skb); + skb_orphan(skb); msk->ack_seq += copy_len; + + tail = skb_peek_tail(&sk->sk_receive_queue); + if (offset == 0 && tail) { + bool fragstolen; + int delta; + + if (skb_try_coalesce(tail, skb, &fragstolen, &delta)) { + kfree_skb_partial(skb, fragstolen); + atomic_add(delta, &sk->sk_rmem_alloc); + sk_mem_charge(sk, delta); + return; + } + } + + skb_set_owner_r(skb, sk); + __skb_queue_tail(&sk->sk_receive_queue, skb); MPTCP_SKB_CB(skb)->offset = offset; } -- cgit v1.2.3