diff options
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 450f44bb2c8e..987b94403be5 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1116,6 +1116,7 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, long timeo; struct task_struct *user_recv = NULL; int copied_early = 0; + struct sk_buff *skb; lock_sock(sk); @@ -1142,16 +1143,26 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, #ifdef CONFIG_NET_DMA tp->ucopy.dma_chan = NULL; preempt_disable(); - if ((len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && - !sysctl_tcp_low_latency && __get_cpu_var(softnet_data).net_dma) { - preempt_enable_no_resched(); - tp->ucopy.pinned_list = dma_pin_iovec_pages(msg->msg_iov, len); - } else - preempt_enable_no_resched(); + skb = skb_peek_tail(&sk->sk_receive_queue); + { + int available = 0; + + if (skb) + available = TCP_SKB_CB(skb)->seq + skb->len - (*seq); + if ((available < target) && + (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && + !sysctl_tcp_low_latency && + __get_cpu_var(softnet_data).net_dma) { + preempt_enable_no_resched(); + tp->ucopy.pinned_list = + dma_pin_iovec_pages(msg->msg_iov, len); + } else { + preempt_enable_no_resched(); + } + } #endif do { - struct sk_buff *skb; u32 offset; /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */ @@ -1439,7 +1450,6 @@ skip_copy: #ifdef CONFIG_NET_DMA if (tp->ucopy.dma_chan) { - struct sk_buff *skb; dma_cookie_t done, used; dma_async_memcpy_issue_pending(tp->ucopy.dma_chan); |