diff options
| author | Haiyang Zhang | 2023-10-11 13:30:44 -0700 |
|---|---|---|
| committer | Sasha Levin | 2026-03-04 07:20:22 -0500 |
| commit | 4ec8a98b3dc3cdb0344bcda12847597a141d61d6 (patch) | |
| tree | edaf096147710198e20c142017204cd1d5cd466b /net | |
| parent | b4d5e97679bc786687879710dc2de280c70ca889 (diff) | |
tcp: Set pingpong threshold via sysctl
[ Upstream commit 562b1fdf061bff9394ccd884456ed1173c224fdc ]
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>
Stable-dep-of: 87b08913a9ae ("inet: move icmp_global_{credit,stamp} to a separate cache line")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/sysctl_net_ipv4.c | 8 | ||||
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 2 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 4 |
3 files changed, 12 insertions, 2 deletions
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 18bcbcfee824..96f1b8d39fac 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -1498,6 +1498,14 @@ static struct ctl_table ipv4_net_table[] = { .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_ONE, }, + { + .procname = "tcp_pingpong_thresh", + .data = &init_net.ipv4.sysctl_tcp_pingpong_thresh, + .maxlen = sizeof(u8), + .mode = 0644, + .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ONE, + }, { } }; diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 6cc4cf3ca9f4..ab4be34e58bb 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -3303,6 +3303,8 @@ static int __net_init tcp_sk_init(struct net *net) net->ipv4.sysctl_tcp_syn_linear_timeouts = 4; net->ipv4.sysctl_tcp_shrink_window = 0; + net->ipv4.sysctl_tcp_pingpong_thresh = 1; + return 0; } diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index b82d1c146d3a..db8f2830c67b 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. */ |