Update the docs to match the code (include/linux/netlink.h): /* * skb should fit one page. This choice is good for headerless malloc. * But we should limit to 8K so that userspace does not have to * use enormous buffer sizes on recvmsg() calls just to avoid * MSG_TRUNC when PAGE_SIZE is very large. */ #if PAGE_SIZE < 8192UL #define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE) #else #define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL) #endif Link: https://lore.kernel.org/all/20220819200221.422801-2-kuba@kernel.org/ Signed-off-by: Konstantin Shabanov --- Documentation/userspace-api/netlink/intro.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/Documentation/userspace-api/netlink/intro.rst b/Documentation/userspace-api/netlink/intro.rst index aacffade8f84..ca60abe94e3d 100644 --- a/Documentation/userspace-api/netlink/intro.rst +++ b/Documentation/userspace-api/netlink/intro.rst @@ -526,8 +526,8 @@ of the recvmsg() system call, *not* a Netlink header). Upon truncation the remaining part of the message is discarded. -Netlink expects that the user buffer will be at least 8kB or a page -size of the CPU architecture, whichever is bigger. Particular Netlink +Netlink expects that the user buffer will be at most 8kB or a page +size of the CPU architecture, whichever is smaller. Particular Netlink families may, however, require a larger buffer. 32kB buffer is recommended for most efficient handling of dumps (larger buffer fits more dumped objects and therefore fewer recvmsg() calls are needed). base-commit: 917719c412c48687d4a176965d1fa35320ec457c -- 2.53.0