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| author | Pengcheng Yang <yangpc@wangsu.com> | 2022-04-20 05:34:41 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-09 10:03:24 +0300 |
| commit | 2cba635570d817a012dac45eda032e4bbf60930b (patch) | |
| tree | 5d2fa21fe8c0ce84ccd4d7821a9f8bdf8c649728 /include/net | |
| parent | 3ea6190be92f1ee1a41b8111a0c19ab77532a458 (diff) | |
| download | linux-2cba635570d817a012dac45eda032e4bbf60930b.tar.xz | |
tcp: ensure to use the most recently sent skb when filling the rate sample
[ Upstream commit b253a0680ceadc5d7b4acca7aa2d870326cad8ad ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include/net')
| -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 b914959cd2c6..b686a21a8593 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1030,6 +1030,7 @@ 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? */ @@ -1139,6 +1140,11 @@ 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. |