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authorYuchung Cheng <ycheng@google.com>2021-09-23 23:17:07 +0200
committerDavid S. Miller <davem@davemloft.net>2021-09-24 15:16:40 +0200
commit40bc6063796ec77b6073861f9a1993be20d5befd (patch)
treecc2672d4809c34d3f8318724bb557a9fb641ddca /net/ipv4/tcp_input.c
parentnet: phy: broadcom: Fix PHY_BRCM_IDDQ_SUSPEND definition (diff)
downloadlinux-40bc6063796ec77b6073861f9a1993be20d5befd.tar.xz
linux-40bc6063796ec77b6073861f9a1993be20d5befd.zip
tcp: tracking packets with CE marks in BW rate sample
In order to track CE marks per rate sample (one round trip), TCP needs a per-skb header field to record the tp->delivered_ce count when the skb was sent. To make space, we replace the "last_in_flight" field which is used exclusively for NV congestion control. The stat needed by NV can be alternatively approximated by existing stats tcp_sock delivered and mss_cache. This patch counts the number of packets delivered which have CE marks in the rate sample, using similar approach of delivery accounting. Cc: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Luke Hsiao <lukehsiao@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c11
1 files changed, 5 insertions, 6 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 141e85e6422b..53675e284841 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3221,7 +3221,6 @@ static int tcp_clean_rtx_queue(struct sock *sk, const struct sk_buff *ack_skb,
long seq_rtt_us = -1L;
long ca_rtt_us = -1L;
u32 pkts_acked = 0;
- u32 last_in_flight = 0;
bool rtt_update;
int flag = 0;
@@ -3257,7 +3256,6 @@ static int tcp_clean_rtx_queue(struct sock *sk, const struct sk_buff *ack_skb,
if (!first_ackt)
first_ackt = last_ackt;
- last_in_flight = TCP_SKB_CB(skb)->tx.in_flight;
if (before(start_seq, reord))
reord = start_seq;
if (!after(scb->end_seq, tp->high_seq))
@@ -3323,8 +3321,8 @@ static int tcp_clean_rtx_queue(struct sock *sk, const struct sk_buff *ack_skb,
seq_rtt_us = tcp_stamp_us_delta(tp->tcp_mstamp, first_ackt);
ca_rtt_us = tcp_stamp_us_delta(tp->tcp_mstamp, last_ackt);
- if (pkts_acked == 1 && last_in_flight < tp->mss_cache &&
- last_in_flight && !prior_sacked && fully_acked &&
+ if (pkts_acked == 1 && fully_acked && !prior_sacked &&
+ (tp->snd_una - prior_snd_una) < tp->mss_cache &&
sack->rate->prior_delivered + 1 == tp->delivered &&
!(flag & (FLAG_CA_ALERT | FLAG_SYN_ACKED))) {
/* Conservatively mark a delayed ACK. It's typically
@@ -3381,9 +3379,10 @@ static int tcp_clean_rtx_queue(struct sock *sk, const struct sk_buff *ack_skb,
if (icsk->icsk_ca_ops->pkts_acked) {
struct ack_sample sample = { .pkts_acked = pkts_acked,
- .rtt_us = sack->rate->rtt_us,
- .in_flight = last_in_flight };
+ .rtt_us = sack->rate->rtt_us };
+ sample.in_flight = tp->mss_cache *
+ (tp->delivered - sack->rate->prior_delivered);
icsk->icsk_ca_ops->pkts_acked(sk, &sample);
}