From e0799082691eabd3b804103348011ea774802f1b Mon Sep 17 00:00:00 2001 From: David Morley Date: Thu, 19 Jan 2023 19:00:28 +0000 Subject: [PATCH] tcp: fix rate_app_limited to default to 1 stable inclusion from stable-v5.10.166 commit d79e700680f9407abc8aa43e7bb758f94ccfecbf category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7TH9O Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d79e700680f9407abc8aa43e7bb758f94ccfecbf -------------------------------- [ Upstream commit 300b655db1b5152d6101bcb6801d50899b20c2d6 ] The initial default value of 0 for tp->rate_app_limited was incorrect, since a flow is indeed application-limited until it first sends data. Fixing the default to be 1 is generally correct but also specifically will help user-space applications avoid using the initial tcpi_delivery_rate value of 0 that persists until the connection has some non-zero bandwidth sample. Fixes: eb8329e0a04d ("tcp: export data delivery rate") Suggested-by: Yuchung Cheng Signed-off-by: David Morley Signed-off-by: Neal Cardwell Tested-by: David Morley Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: sanglipeng --- net/ipv4/tcp.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index d88de88bbe27..b288dd5a7919 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -436,6 +436,7 @@ void tcp_init_sock(struct sock *sk) /* There's a bubble in the pipe until at least the first ACK. */ tp->app_limited = ~0U; + tp->rate_app_limited = 1; /* See draft-stevens-tcpca-spec-01 for discussion of the * initialization of these values. @@ -2842,6 +2843,7 @@ int tcp_disconnect(struct sock *sk, int flags) tp->last_oow_ack_time = 0; /* There's a bubble in the pipe until at least the first ACK. */ tp->app_limited = ~0U; + tp->rate_app_limited = 1; tp->rack.mstamp = 0; tp->rack.advanced = 0; tp->rack.reo_wnd_steps = 1; -- GitLab