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/net/compat.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/net/compat.h') diff --git a/include/net/compat.h b/include/net/compat.h index 7c3002832d05..9679f05e9896 100644 --- a/include/net/compat.h +++ b/include/net/compat.h @@ -18,6 +18,11 @@ struct compat_msghdr { compat_uint_t msg_flags; }; +struct compat_mmsghdr { + struct compat_msghdr msg_hdr; + compat_uint_t msg_len; +}; + struct compat_cmsghdr { compat_size_t cmsg_len; compat_int_t cmsg_level; @@ -35,6 +40,9 @@ extern int get_compat_msghdr(struct msghdr *, struct compat_msghdr __user *); extern int verify_compat_iovec(struct msghdr *, struct iovec *, struct sockaddr *, int); extern asmlinkage long compat_sys_sendmsg(int,struct compat_msghdr __user *,unsigned); extern asmlinkage long compat_sys_recvmsg(int,struct compat_msghdr __user *,unsigned); +extern asmlinkage long compat_sys_recvmmsg(int, struct compat_mmsghdr __user *, + unsigned, unsigned, + struct timespec __user *); extern asmlinkage long compat_sys_getsockopt(int, int, int, char __user *, int __user *); extern int put_cmsg_compat(struct msghdr*, int, int, int, void *); -- cgit v1.2.3-59-g8ed1b