From a2e2725541fad72416326798c2d7fa4dafb7d337 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 12 Oct 2009 23:40:10 -0700 Subject: net: Introduce recvmmsg socket syscall MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Meaning receive multiple messages, reducing the number of syscalls and net stack entry/exit operations. Next patches will introduce mechanisms where protocols that want to optimize this operation will provide an unlocked_recvmsg operation. This takes into account comments made by: . Paul Moore: sock_recvmsg is called only for the first datagram, sock_recvmsg_nosec is used for the rest. . Caitlin Bestler: recvmmsg now has a struct timespec timeout, that works in the same fashion as the ppoll one. If the underlying protocol returns a datagram with MSG_OOB set, this will make recvmmsg return right away with as many datagrams (+ the OOB one) it has received so far. . Rémi Denis-Courmont & Steven Whitehouse: If we receive N < vlen datagrams and then recvmsg returns an error, recvmmsg will return the successfully received datagrams, store the error and return it in the next call. This paves the way for a subsequent optimization, sk_prot->unlocked_recvmsg, where we will be able to acquire the lock only at batch start and end, not at every underlying recvmsg call. Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- include/linux/socket.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include/linux/socket.h') diff --git a/include/linux/socket.h b/include/linux/socket.h index 3273a0c5043..59966f12990 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -65,6 +65,12 @@ struct msghdr { unsigned msg_flags; }; +/* For recvmmsg/sendmmsg */ +struct mmsghdr { + struct msghdr msg_hdr; + unsigned msg_len; +}; + /* * POSIX 1003.1g - ancillary data object information * Ancillary data consits of a sequence of pairs of @@ -312,6 +318,10 @@ extern int move_addr_to_user(struct sockaddr *kaddr, int klen, void __user *uadd extern int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr *kaddr); extern int put_cmsg(struct msghdr*, int level, int type, int len, void *data); +struct timespec; + +extern int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen, + unsigned int flags, struct timespec *timeout); #endif #endif /* not kernel and not glibc */ #endif /* _LINUX_SOCKET_H */ -- cgit v1.2.3