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| author | Haiyang Zhang <haiyangz@microsoft.com> | 2023-10-11 22:30:44 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-10-16 23:55:32 +0200 |
| commit | 562b1fdf061bff9394ccd884456ed1173c224fdc (patch) | |
| tree | e56864865571c6600af484f5e701ba535e6b8f32 /include/net/inet_connection_sock.h | |
| parent | net, sched: Add tcf_set_drop_reason for {__,}tcf_classify (diff) | |
| download | linux-562b1fdf061bff9394ccd884456ed1173c224fdc.tar.xz linux-562b1fdf061bff9394ccd884456ed1173c224fdc.zip | |
tcp: Set pingpong threshold via sysctl
TCP pingpong threshold is 1 by default. But some applications, like SQL DB
may prefer a higher pingpong threshold to activate delayed acks in quick
ack mode for better performance.
The pingpong threshold and related code were changed to 3 in the year
2019 in:
commit 4a41f453bedf ("tcp: change pingpong threshold to 3")
And reverted to 1 in the year 2022 in:
commit 4d8f24eeedc5 ("Revert "tcp: change pingpong threshold to 3"")
There is no single value that fits all applications.
Add net.ipv4.tcp_pingpong_thresh sysctl tunable, so it can be tuned for
optimal performance based on the application needs.
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/1697056244-21888-1-git-send-email-haiyangz@microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/net/inet_connection_sock.h')
| -rw-r--r-- | include/net/inet_connection_sock.h | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index d6d9d1c1985a..086d1193c9ef 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -328,11 +328,10 @@ void inet_csk_update_fastreuse(struct inet_bind_bucket *tb, struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); -#define TCP_PINGPONG_THRESH 1 - static inline void inet_csk_enter_pingpong_mode(struct sock *sk) { - inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH; + inet_csk(sk)->icsk_ack.pingpong = + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_pingpong_thresh); } static inline void inet_csk_exit_pingpong_mode(struct sock *sk) @@ -342,7 +341,16 @@ static inline void inet_csk_exit_pingpong_mode(struct sock *sk) static inline bool inet_csk_in_pingpong_mode(struct sock *sk) { - return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH; + return inet_csk(sk)->icsk_ack.pingpong >= + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_pingpong_thresh); +} + +static inline void inet_csk_inc_pingpong_cnt(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + if (icsk->icsk_ack.pingpong < U8_MAX) + icsk->icsk_ack.pingpong++; } static inline bool inet_csk_has_ulp(const struct sock *sk) |