tcp_cubic: remove one conditional from hystart_update() (35821fc2) · Commits · 戴 / test

If we initialize ca->curr_rtt to ~0U, we do not need to test for zero value in hystart_update() We only read ca->curr_rtt if at least HYSTART_MIN_SAMPLES have been processed, and thus ca->curr_rtt will have a sane value. Signed-off-by:

Eric Dumazet <edumazet@google.com> Acked-by:

Neal Cardwell <ncardwell@google.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv4/tcp_cubic.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -133,7 +133,7 @@ static inline void bictcp_hystart_reset(struct sock *sk)

		ca->round_start = ca->last_ack = bictcp_clock();
		ca->end_seq = tp->snd_nxt;
		ca->curr_rtt = 0;
		ca->curr_rtt = ~0U;
		ca->sample_cnt = 0;
		}

		@@ -402,7 +402,7 @@ static void hystart_update(struct sock *sk, u32 delay)
		if (hystart_detect & HYSTART_DELAY) {
		/* obtain the minimum delay of more than sampling packets */
		if (ca->sample_cnt < HYSTART_MIN_SAMPLES) {
		if (ca->curr_rtt == 0 \|\| ca->curr_rtt > delay)
		if (ca->curr_rtt > delay)
		ca->curr_rtt = delay;

		ca->sample_cnt++;

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