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-rw-r--r--net/ipv4/tcp_bbr.c7
-rw-r--r--net/ipv4/tcp_output.c22
-rw-r--r--net/sched/sch_fq.c21
3 files changed, 33 insertions, 17 deletions
diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c
index 02ff2dde9609..a5786e3e2c16 100644
--- a/net/ipv4/tcp_bbr.c
+++ b/net/ipv4/tcp_bbr.c
@@ -128,6 +128,9 @@ static const u32 bbr_probe_rtt_mode_ms = 200;
/* Skip TSO below the following bandwidth (bits/sec): */
static const int bbr_min_tso_rate = 1200000;
+/* Pace at ~1% below estimated bw, on average, to reduce queue at bottleneck. */
+static const int bbr_pacing_marging_percent = 1;
+
/* We use a high_gain value of 2/ln(2) because it's the smallest pacing gain
* that will allow a smoothly increasing pacing rate that will double each RTT
* and send the same number of packets per RTT that an un-paced, slow-starting
@@ -208,12 +211,10 @@ static u64 bbr_rate_bytes_per_sec(struct sock *sk, u64 rate, int gain)
{
unsigned int mss = tcp_sk(sk)->mss_cache;
- if (!tcp_needs_internal_pacing(sk))
- mss = tcp_mss_to_mtu(sk, mss);
rate *= mss;
rate *= gain;
rate >>= BBR_SCALE;
- rate *= USEC_PER_SEC;
+ rate *= USEC_PER_SEC / 100 * (100 - bbr_pacing_marging_percent);
return rate >> BW_SCALE;
}
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index a87068fa9b1a..2adb719e97b8 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1012,9 +1012,23 @@ static void tcp_internal_pacing(struct sock *sk, const struct sk_buff *skb)
sock_hold(sk);
}
-static void tcp_update_skb_after_send(struct tcp_sock *tp, struct sk_buff *skb)
+static void tcp_update_skb_after_send(struct sock *sk, struct sk_buff *skb)
{
+ struct tcp_sock *tp = tcp_sk(sk);
+
skb->skb_mstamp_ns = tp->tcp_wstamp_ns;
+ if (sk->sk_pacing_status != SK_PACING_NONE) {
+ u32 rate = sk->sk_pacing_rate;
+
+ /* Original sch_fq does not pace first 10 MSS
+ * Note that tp->data_segs_out overflows after 2^32 packets,
+ * this is a minor annoyance.
+ */
+ if (rate != ~0U && rate && tp->data_segs_out >= 10) {
+ tp->tcp_wstamp_ns += div_u64((u64)skb->len * NSEC_PER_SEC, rate);
+ /* TODO: update internal pacing here */
+ }
+ }
list_move_tail(&skb->tcp_tsorted_anchor, &tp->tsorted_sent_queue);
}
@@ -1178,7 +1192,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
err = net_xmit_eval(err);
}
if (!err && oskb) {
- tcp_update_skb_after_send(tp, oskb);
+ tcp_update_skb_after_send(sk, oskb);
tcp_rate_skb_sent(sk, oskb);
}
return err;
@@ -2327,7 +2341,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
if (unlikely(tp->repair) && tp->repair_queue == TCP_SEND_QUEUE) {
/* "skb_mstamp" is used as a start point for the retransmit timer */
- tcp_update_skb_after_send(tp, skb);
+ tcp_update_skb_after_send(sk, skb);
goto repair; /* Skip network transmission */
}
@@ -2902,7 +2916,7 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs)
} tcp_skb_tsorted_restore(skb);
if (!err) {
- tcp_update_skb_after_send(tp, skb);
+ tcp_update_skb_after_send(sk, skb);
tcp_rate_skb_sent(sk, skb);
}
} else {
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index d5185c44e9a5..77692ad6741d 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -491,11 +491,16 @@ begin:
}
skb = f->head;
- if (unlikely(skb && now < f->time_next_packet &&
- !skb_is_tcp_pure_ack(skb))) {
- head->first = f->next;
- fq_flow_set_throttled(q, f);
- goto begin;
+ if (skb && !skb_is_tcp_pure_ack(skb)) {
+ u64 time_next_packet = max_t(u64, ktime_to_ns(skb->tstamp),
+ f->time_next_packet);
+
+ if (now < time_next_packet) {
+ head->first = f->next;
+ f->time_next_packet = time_next_packet;
+ fq_flow_set_throttled(q, f);
+ goto begin;
+ }
}
skb = fq_dequeue_head(sch, f);
@@ -513,11 +518,7 @@ begin:
prefetch(&skb->end);
f->credit -= qdisc_pkt_len(skb);
- if (!q->rate_enable)
- goto out;
-
- /* Do not pace locally generated ack packets */
- if (skb_is_tcp_pure_ack(skb))
+ if (ktime_to_ns(skb->tstamp) || !q->rate_enable)
goto out;
rate = q->flow_max_rate;