[PATCH net-next 1/3] net: tcp: add sysctl for controling tcp window shrink
From: <hidden>
Date: 2023-05-17 12:42:23
Also in:
lkml
Subsystem:
networking [general], networking [tcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds
From: Menglong Dong <redacted> Introduce the sysctl 'tcp_wnd_shrink', which will be used in the following patches. Signed-off-by: Menglong Dong <redacted> --- include/net/tcp.h | 1 + net/ipv4/sysctl_net_ipv4.c | 9 +++++++++ net/ipv4/tcp.c | 3 +++ 3 files changed, 13 insertions(+)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index a0a91a988272..a6cf6d823e34 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h@@ -247,6 +247,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo); /* sysctl variables for tcp */ extern int sysctl_tcp_max_orphans; extern long sysctl_tcp_mem[3]; +extern int sysctl_tcp_wnd_shrink; #define TCP_RACK_LOSS_DETECTION 0x1 /* Use RACK to detect losses */ #define TCP_RACK_STATIC_REO_WND 0x2 /* Use static RACK reo wnd */
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 0d0cc4ef2b85..fd6cb5a5c2b9 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c@@ -577,6 +577,15 @@ static struct ctl_table ipv4_table[] = { .extra1 = &sysctl_fib_sync_mem_min, .extra2 = &sysctl_fib_sync_mem_max, }, + { + .procname = "tcp_wnd_shrink", + .data = &sysctl_tcp_wnd_shrink, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE + }, { } };
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index fd68d49490f2..db0483b2159f 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c@@ -297,6 +297,9 @@ EXPORT_SYMBOL(tcp_memory_allocated); DEFINE_PER_CPU(int, tcp_memory_per_cpu_fw_alloc); EXPORT_PER_CPU_SYMBOL_GPL(tcp_memory_per_cpu_fw_alloc); +int sysctl_tcp_wnd_shrink __read_mostly; +EXPORT_SYMBOL(sysctl_tcp_wnd_shrink); + #if IS_ENABLED(CONFIG_SMC) DEFINE_STATIC_KEY_FALSE(tcp_have_smc); EXPORT_SYMBOL(tcp_have_smc);
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2.40.1