diff options
| author | Haiyang Zhang <haiyangz@microsoft.com> | 2023-10-11 13:30:44 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-10-16 14:55:32 -0700 |
| commit | 562b1fdf061bff9394ccd884456ed1173c224fdc (patch) | |
| tree | e56864865571c6600af484f5e701ba535e6b8f32 /net/ipv4/tcp_output.c | |
| parent | 39d08b91646d83e87f7cbcd846b3ef33b1a53b79 (diff) | |
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 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index d5961a82a9e8..8e6ebf35ed58 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -170,10 +170,10 @@ static void tcp_event_data_sent(struct tcp_sock *tp, tp->lsndtime = now; /* If it is a reply for ato after last received - * packet, enter pingpong mode. + * packet, increase pingpong count. */ if ((u32)(now - icsk->icsk_ack.lrcvtime) < icsk->icsk_ack.ato) - inet_csk_enter_pingpong_mode(sk); + inet_csk_inc_pingpong_cnt(sk); } /* Account for an ACK we sent. */ |