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net: change big iov allocations

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iov of more than 8 entries are allocated in sendmsg()/recvmsg() through
sock_kmalloc()

As these allocations are temporary only and small enough, it makes sense
to use plain kmalloc() and avoid sk_omem_alloc atomic overhead.

Slightly changed fast path to be even faster.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mike Waychison <mikew@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2012-04-20 20:04:01 +02:00 committed by David S. Miller
parent b139ba4e90
commit a74e910618
1 changed files with 16 additions and 21 deletions
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37
net/socket.c
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@ -1908,7 +1908,7 @@ static int __sys_sendmsg(struct socket *sock, struct msghdr __user *msg,
__attribute__ ((aligned(sizeof(__kernel_size_t))));
/* 20 is size of ipv6_pktinfo */
unsigned char *ctl_buf = ctl;
int err, ctl_len, iov_size, total_len;
int err, ctl_len, total_len;
err = -EFAULT;
if (MSG_CMSG_COMPAT & flags) {
@ -1917,16 +1917,13 @@ static int __sys_sendmsg(struct socket *sock, struct msghdr __user *msg,
} else if (copy_from_user(msg_sys, msg, sizeof(struct msghdr)))
return -EFAULT;
/* do not move before msg_sys is valid */
err = -EMSGSIZE;
if (msg_sys->msg_iovlen > UIO_MAXIOV)
goto out;
/* Check whether to allocate the iovec area */
err = -ENOMEM;
iov_size = msg_sys->msg_iovlen * sizeof(struct iovec);
if (msg_sys->msg_iovlen > UIO_FASTIOV) {
iov = sock_kmalloc(sock->sk, iov_size, GFP_KERNEL);
err = -EMSGSIZE;
if (msg_sys->msg_iovlen > UIO_MAXIOV)
goto out;
err = -ENOMEM;
iov = kmalloc(msg_sys->msg_iovlen * sizeof(struct iovec),
GFP_KERNEL);
if (!iov)
goto out;
}
@ -2005,7 +2002,7 @@ out_freectl:
sock_kfree_s(sock->sk, ctl_buf, ctl_len);
out_freeiov:
if (iov != iovstack)
sock_kfree_s(sock->sk, iov, iov_size);
kfree(iov);
out:
return err;
}
@ -2103,7 +2100,7 @@ static int __sys_recvmsg(struct socket *sock, struct msghdr __user *msg,
struct iovec iovstack[UIO_FASTIOV];
struct iovec *iov = iovstack;
unsigned long cmsg_ptr;
int err, iov_size, total_len, len;
int err, total_len, len;
/* kernel mode address */
struct sockaddr_storage addr;
@ -2118,15 +2115,13 @@ static int __sys_recvmsg(struct socket *sock, struct msghdr __user *msg,
} else if (copy_from_user(msg_sys, msg, sizeof(struct msghdr)))
return -EFAULT;
err = -EMSGSIZE;
if (msg_sys->msg_iovlen > UIO_MAXIOV)
goto out;
/* Check whether to allocate the iovec area */
err = -ENOMEM;
iov_size = msg_sys->msg_iovlen * sizeof(struct iovec);
if (msg_sys->msg_iovlen > UIO_FASTIOV) {
iov = sock_kmalloc(sock->sk, iov_size, GFP_KERNEL);
err = -EMSGSIZE;
if (msg_sys->msg_iovlen > UIO_MAXIOV)
goto out;
err = -ENOMEM;
iov = kmalloc(msg_sys->msg_iovlen * sizeof(struct iovec),
GFP_KERNEL);
if (!iov)
goto out;
}
@ -2180,7 +2175,7 @@ static int __sys_recvmsg(struct socket *sock, struct msghdr __user *msg,
out_freeiov:
if (iov != iovstack)
sock_kfree_s(sock->sk, iov, iov_size);
kfree(iov);
out:
return err;
}