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authorHaiyang Zhang <haiyangz@microsoft.com>2023-10-11 23:30:44 +0300
committerJakub Kicinski <kuba@kernel.org>2023-10-17 00:55:32 +0300
commit562b1fdf061bff9394ccd884456ed1173c224fdc (patch)
treee56864865571c6600af484f5e701ba535e6b8f32 /include/net/inet_connection_sock.h
parent39d08b91646d83e87f7cbcd846b3ef33b1a53b79 (diff)
downloadlinux-562b1fdf061bff9394ccd884456ed1173c224fdc.tar.xz
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.h16
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)