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Diffstat (limited to 'net/ipv4/tcp.c')
-rw-r--r--net/ipv4/tcp.c26
1 files changed, 18 insertions, 8 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 450f44b..987b944 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);
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