From a6d4f25888b83b8300aef28d9ee22765c1cc9b34 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 19 Aug 2025 17:40:30 +0000 Subject: net: set net.core.rmem_max and net.core.wmem_max to 4 MB SO_RCVBUF and SO_SNDBUF have limited range today, unless distros or system admins change rmem_max and wmem_max. Even iproute2 uses 1 MB SO_RCVBUF which is capped by the kernel. Decouple [rw]mem_max and [rw]mem_default and increase [rw]mem_max to 4 MB. Before: $ sysctl net.core.rmem_default net.core.rmem_max net.core.wmem_default net.core.wmem_max net.core.rmem_default = 212992 net.core.rmem_max = 212992 net.core.wmem_default = 212992 net.core.wmem_max = 212992 After: $ sysctl net.core.rmem_default net.core.rmem_max net.core.wmem_default net.core.wmem_max net.core.rmem_default = 212992 net.core.rmem_max = 4194304 net.core.wmem_default = 212992 net.core.wmem_max = 4194304 Signed-off-by: Eric Dumazet Reviewed-by: Neal Cardwell Link: https://patch.msgid.link/20250819174030.1986278-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- Documentation/admin-guide/sysctl/net.rst | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation/admin-guide/sysctl') diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst index 7b0c4291c686..2ef50828aff1 100644 --- a/Documentation/admin-guide/sysctl/net.rst +++ b/Documentation/admin-guide/sysctl/net.rst @@ -222,6 +222,8 @@ rmem_max The maximum receive socket buffer size in bytes. +Default: 4194304 + rps_default_mask ---------------- @@ -247,6 +249,8 @@ wmem_max The maximum send socket buffer size in bytes. +Default: 4194304 + message_burst and message_cost ------------------------------ -- cgit v1.2.3