[TCP]: Increase the max_burst threshold from 3 to tp->reordering. (dd9e0dda) · Commits · 戴 / test

This change is necessary to allow cwnd to grow during persistent reordering. Cwnd moderation is applied when in the disorder state and an ack that fills the hole comes in. If the hole was greater than 3 packets, but less than tp->reordering, cwnd will shrink when it should not have. Signed-off-by:

John Heffner <jheffner@napa.(none)> Signed-off-by:

David S. Miller <davem@davemloft.net>

include/net/tcp.h

+5 −2

Original line number	Diff line number	Diff line
		@@ -787,11 +787,14 @@ extern void tcp_enter_cwr(struct sock *sk, const int set_ssthresh);
		extern __u32 tcp_init_cwnd(struct tcp_sock tp, struct dst_entry dst);

		/* Slow start with delack produces 3 packets of burst, so that
		* it is safe "de facto".
		* it is safe "de facto". This will be the default - same as
		* the default reordering threshold - but if reordering increases,
		* we must be able to allow cwnd to burst at least this much in order
		* to not pull it back when holes are filled.
		*/
		static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp)
		{
		return 3;
		return tp->reordering;
		}

		/* Returns end sequence number of the receiver's advertised window */

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