AFAIK, nothing in current TCP stack absolutely wants BH
being disabled once socket is owned by a thread running in
process context.
As mentioned in my prior patch ("tcp: give prequeue mode some care"),
processing a batch of packets might take time, better not block BH
at all.
Signed-off-by: Eric Dumazet <eduma...@google.com>
---
net/ipv4/tcp.c | 4 ----
net/ipv4/tcp_input.c | 30 ++----------------------------
2 files changed, 2 insertions(+), 32 deletions(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 7f51389814e6..f8856b76f941 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1445,12 +1445,8 @@ static void tcp_prequeue_process(struct sock *sk)
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
- /* RX process wants to run with disabled BHs, though it is not
- * necessary */
- local_bh_disable();
while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
sk_backlog_rcv(sk, skb);
- local_bh_enable();
/* Clear memory counter. */
tp->ucopy.memory = 0;
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 0eb31df8edfa..44e0f9f15f32 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4608,14 +4608,12 @@ static void tcp_data_queue(struct sock *sk, struct
sk_buff *skb)
__set_current_state(TASK_RUNNING);
- local_bh_enable();
if (!skb_copy_datagram_msg(skb, 0, tp->ucopy.msg,
chunk)) {
tp->ucopy.len -= chunk;
tp->copied_seq += chunk;
eaten = (chunk == skb->len);
tcp_rcv_space_adjust(sk);
}
- local_bh_disable();
}
if (eaten <= 0) {
@@ -5131,7 +5129,6 @@ static int tcp_copy_to_iovec(struct sock *sk, struct
sk_buff *skb, int hlen)
int chunk = skb->len - hlen;
int err;
- local_bh_enable();
if (skb_csum_unnecessary(skb))
err = skb_copy_datagram_msg(skb, hlen, tp->ucopy.msg, chunk);
else
@@ -5143,32 +5140,9 @@ static int tcp_copy_to_iovec(struct sock *sk, struct
sk_buff *skb, int hlen)
tcp_rcv_space_adjust(sk);
}
- local_bh_disable();
return err;
}
-static __sum16 __tcp_checksum_complete_user(struct sock *sk,
- struct sk_buff *skb)
-{
- __sum16 result;
-
- if (sock_owned_by_user(sk)) {
- local_bh_enable();
- result = __tcp_checksum_complete(skb);
- local_bh_disable();
- } else {
- result = __tcp_checksum_complete(skb);
- }
- return result;
-}
-
-static inline bool tcp_checksum_complete_user(struct sock *sk,
- struct sk_buff *skb)
-{
- return !skb_csum_unnecessary(skb) &&
- __tcp_checksum_complete_user(sk, skb);
-}
-
/* Does PAWS and seqno based validation of an incoming segment, flags will
* play significant role here.
*/
@@ -5383,7 +5357,7 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff
*skb,
}
}
if (!eaten) {
- if (tcp_checksum_complete_user(sk, skb))
+ if (tcp_checksum_complete(skb))
goto csum_error;
if ((int)skb->truesize > sk->sk_forward_alloc)
@@ -5427,7 +5401,7 @@ no_ack:
}
slow_path:
- if (len < (th->doff << 2) || tcp_checksum_complete_user(sk, skb))
+ if (len < (th->doff << 2) || tcp_checksum_complete(skb))
goto csum_error;
if (!th->ack && !th->rst && !th->syn)
--
2.8.0.rc3.226.g39d4020
