From a74e910618efb154936958cfeb2aab7c234478c5 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 20 Apr 2012 20:04:01 +0200 Subject: [PATCH] net: change big iov allocations 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 Cc: Mike Waychison Signed-off-by: David S. Miller --- net/socket.c | 37 ++++++++++++++++--------------------- 1 file changed, 16 insertions(+), 21 deletions(-) diff --git a/net/socket.c b/net/socket.c index e345109..d3aaa4f 100644 --- a/net/socket.c +++ b/net/socket.c @@ -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; } -- 2.7.4