[PATCH] doc: clarification about setting SO_ZEROCOPY
From: Kornilios Kourtis <hidden>
Date: 2018-01-09 08:52:29
Subsystem:
documentation, networking [general], the rest · Maintainers:
Jonathan Corbet, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Signed-off-by: Kornilios Kourtis <redacted> --- Documentation/networking/msg_zerocopy.rst | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/Documentation/networking/msg_zerocopy.rst b/Documentation/networking/msg_zerocopy.rst
index 77f6d7e..c3380f4 100644
--- a/Documentation/networking/msg_zerocopy.rst
+++ b/Documentation/networking/msg_zerocopy.rst@@ -72,6 +72,10 @@ this flag, a process must first signal intent by setting a socket option: if (setsockopt(fd, SOL_SOCKET, SO_ZEROCOPY, &one, sizeof(one))) error(1, errno, "setsockopt zerocopy"); +Setting the socket option only works when the socket is in its initial +(TCP_CLOSED) state. Trying to set the option for a socket returned by accept(), +for example, will lead to an EBUSY error. In this case, the option should be set +to the listening socket and it will be inherited by the accepted sockets. Transmission ------------
--
2.4.3