diff options
| author | Pengcheng Yang <yangpc@wangsu.com> | 2022-04-20 05:34:41 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-04-23 01:20:47 +0300 |
| commit | b253a0680ceadc5d7b4acca7aa2d870326cad8ad (patch) | |
| tree | e0c18c5a0aa7e21620282dab9406132d7afd95cc /include | |
| parent | b107a6392b4bdd0e10e155e6b66d75af9e44d85a (diff) | |
| download | linux-b253a0680ceadc5d7b4acca7aa2d870326cad8ad.tar.xz | |
tcp: ensure to use the most recently sent skb when filling the rate sample
If an ACK (s)acks multiple skbs, we favor the information
from the most recently sent skb by choosing the skb with
the highest prior_delivered count. But in the interval
between receiving ACKs, we send multiple skbs with the same
prior_delivered, because the tp->delivered only changes
when we receive an ACK.
We used RACK's solution, copying tcp_rack_sent_after() as
tcp_skb_sent_after() helper to determine "which packet was
sent last?". Later, we will use tcp_skb_sent_after() instead
in RACK.
Fixes: b9f64820fb22 ("tcp: track data delivery rate for a TCP connection")
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Tested-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/1650422081-22153-1-git-send-email-yangpc@wangsu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/tcp.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index 70ca4a5e330a..be712fb9ddd7 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1042,6 +1042,7 @@ struct rate_sample { int losses; /* number of packets marked lost upon ACK */ u32 acked_sacked; /* number of packets newly (S)ACKed upon ACK */ u32 prior_in_flight; /* in flight before this ACK */ + u32 last_end_seq; /* end_seq of most recently ACKed packet */ bool is_app_limited; /* is sample from packet with bubble in pipe? */ bool is_retrans; /* is sample from retransmission? */ bool is_ack_delayed; /* is this (likely) a delayed ACK? */ @@ -1164,6 +1165,11 @@ void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost, bool is_sack_reneg, struct rate_sample *rs); void tcp_rate_check_app_limited(struct sock *sk); +static inline bool tcp_skb_sent_after(u64 t1, u64 t2, u32 seq1, u32 seq2) +{ + return t1 > t2 || (t1 == t2 && after(seq1, seq2)); +} + /* These functions determine how the current flow behaves in respect of SACK * handling. SACK is negotiated with the peer, and therefore it can vary * between different flows. |