[PATCH] docs: netlink: Correct buffer sizing info

[PATCH] docs: netlink: Correct buffer sizing info

[Konstantin Shabanov]

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 <mail@etehtsea.me>
---
 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