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authorJoerg Roedel <jroedel@suse.de>2023-10-26 17:05:58 +0200
committerJoerg Roedel <jroedel@suse.de>2023-10-26 17:05:58 +0200
commit3613047280ec42a4e1350fdc1a6dd161ff4008cc (patch)
tree6cf2f03f518537f3229e6066a8b2638755f0bb48 /net/ipv4/tcp_input.c
parentbbc70e0aec287e164344b1a071bd46466a4f29b3 (diff)
parent05d3ef8bba77c1b5f98d941d8b2d4aeab8118ef1 (diff)
Merge tag 'v6.6-rc7' into core
Linux 6.6-rc7
Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 06fe1cf645d5..8afb0950a697 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -253,6 +253,19 @@ static void tcp_measure_rcv_mss(struct sock *sk, const struct sk_buff *skb)
if (unlikely(len > icsk->icsk_ack.rcv_mss +
MAX_TCP_OPTION_SPACE))
tcp_gro_dev_warn(sk, skb, len);
+ /* If the skb has a len of exactly 1*MSS and has the PSH bit
+ * set then it is likely the end of an application write. So
+ * more data may not be arriving soon, and yet the data sender
+ * may be waiting for an ACK if cwnd-bound or using TX zero
+ * copy. So we set ICSK_ACK_PUSHED here so that
+ * tcp_cleanup_rbuf() will send an ACK immediately if the app
+ * reads all of the data and is not ping-pong. If len > MSS
+ * then this logic does not matter (and does not hurt) because
+ * tcp_cleanup_rbuf() will always ACK immediately if the app
+ * reads data and there is more than an MSS of unACKed data.
+ */
+ if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_PSH)
+ icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
} else {
/* Otherwise, we make more careful check taking into account,
* that SACKs block is variable.