net: Add sendmmsg socket system call
This patch adds a multiple message send syscall and is the send
version of the existing recvmmsg syscall. This is heavily
based on the patch by Arnaldo that added recvmmsg.
I wrote a microbenchmark to test the performance gains of using
this new syscall:
http://ozlabs.org/~anton/junkcode/sendmmsg_test.c
The test was run on a ppc64 box with a 10 Gbit network card. The
benchmark can send both UDP and RAW ethernet packets.
64B UDP
batch pkts/sec
1 804570
2 872800 (+ 8 %)
4 916556 (+14 %)
8 939712 (+17 %)
16 952688 (+18 %)
32 956448 (+19 %)
64 964800 (+20 %)
64B raw socket
batch pkts/sec
1 1201449
2 1350028 (+12 %)
4 1461416 (+22 %)
8 1513080 (+26 %)
16 1541216 (+28 %)
32 1553440 (+29 %)
64 1557888 (+30 %)
We see a 20% improvement in throughput on UDP send and 30%
on raw socket send.
[ Add sparc syscall entries. -DaveM ]
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/compat.c b/net/compat.c
index 3649d58..c578d93 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -722,11 +722,11 @@
/* Argument list sizes for compat_sys_socketcall */
#define AL(x) ((x) * sizeof(u32))
-static unsigned char nas[20] = {
+static unsigned char nas[21] = {
AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
- AL(4), AL(5)
+ AL(4), AL(5), AL(4)
};
#undef AL
@@ -735,6 +735,13 @@
return sys_sendmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
}
+asmlinkage long compat_sys_sendmmsg(int fd, struct compat_mmsghdr __user *mmsg,
+ unsigned vlen, unsigned int flags)
+{
+ return __sys_sendmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
+ flags | MSG_CMSG_COMPAT);
+}
+
asmlinkage long compat_sys_recvmsg(int fd, struct compat_msghdr __user *msg, unsigned int flags)
{
return sys_recvmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
@@ -780,7 +787,7 @@
u32 a[6];
u32 a0, a1;
- if (call < SYS_SOCKET || call > SYS_RECVMMSG)
+ if (call < SYS_SOCKET || call > SYS_SENDMMSG)
return -EINVAL;
if (copy_from_user(a, args, nas[call]))
return -EFAULT;
@@ -839,6 +846,9 @@
case SYS_SENDMSG:
ret = compat_sys_sendmsg(a0, compat_ptr(a1), a[2]);
break;
+ case SYS_SENDMMSG:
+ ret = compat_sys_sendmmsg(a0, compat_ptr(a1), a[2], a[3]);
+ break;
case SYS_RECVMSG:
ret = compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
break;
