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Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c29
1 files changed, 11 insertions, 18 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 701cb87043..df7b13f0e5 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -202,23 +202,17 @@ static void bpf_skops_established(struct sock *sk, int bpf_op,
}
#endif
-static void tcp_gro_dev_warn(struct sock *sk, const struct sk_buff *skb,
- unsigned int len)
+static __cold void tcp_gro_dev_warn(const struct sock *sk, const struct sk_buff *skb,
+ unsigned int len)
{
- static bool __once __read_mostly;
+ struct net_device *dev;
- if (!__once) {
- struct net_device *dev;
-
- __once = true;
-
- rcu_read_lock();
- dev = dev_get_by_index_rcu(sock_net(sk), skb->skb_iif);
- if (!dev || len >= dev->mtu)
- pr_warn("%s: Driver has suspect GRO implementation, TCP performance may be compromised.\n",
- dev ? dev->name : "Unknown driver");
- rcu_read_unlock();
- }
+ rcu_read_lock();
+ dev = dev_get_by_index_rcu(sock_net(sk), skb->skb_iif);
+ if (!dev || len >= READ_ONCE(dev->mtu))
+ pr_warn("%s: Driver has suspect GRO implementation, TCP performance may be compromised.\n",
+ dev ? dev->name : "Unknown driver");
+ rcu_read_unlock();
}
/* Adapt the MSS value used to make delayed ack decision to the
@@ -250,9 +244,8 @@ static void tcp_measure_rcv_mss(struct sock *sk, const struct sk_buff *skb)
icsk->icsk_ack.rcv_mss = min_t(unsigned int, len,
tcp_sk(sk)->advmss);
/* Account for possibly-removed options */
- if (unlikely(len > icsk->icsk_ack.rcv_mss +
- MAX_TCP_OPTION_SPACE))
- tcp_gro_dev_warn(sk, skb, len);
+ DO_ONCE_LITE_IF(len > icsk->icsk_ack.rcv_mss + MAX_TCP_OPTION_SPACE,
+ tcp_gro_dev_warn, sk, skb, len);
/* If the skb has a len of exactly 1*MSS and has the PSH bit
* set then it is likely the end of an application write. So
* more data may not be arriving soon, and yet the data sender