From: Kornilios Kourtis Date: Tue, 9 Jan 2018 08:52:22 +0000 (+0100) Subject: doc: clarification about setting SO_ZEROCOPY X-Git-Tag: Ubuntu-5.0.0-8.9~3292^2~8 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=af60d61fa846725566f4a876ae04f891bdff1c7a;p=mirror_ubuntu-disco-kernel.git doc: clarification about setting SO_ZEROCOPY Signed-off-by: Kornilios Kourtis Acked-by: Willem de Bruijn Signed-off-by: David S. Miller --- diff --git a/Documentation/networking/msg_zerocopy.rst b/Documentation/networking/msg_zerocopy.rst index 77f6d7e25cfd..291a01264967 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 ------------