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-rw-r--r--include/net/tcp.h13
-rw-r--r--net/ipv4/tcp.c14
-rw-r--r--net/ipv4/tcp_input.c3
3 files changed, 26 insertions, 4 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 64f84683feae..6f8e60c6fbc7 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1420,6 +1420,19 @@ static inline int tcp_full_space(const struct sock *sk)
return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf));
}
+/* We provision sk_rcvbuf around 200% of sk_rcvlowat.
+ * If 87.5 % (7/8) of the space has been consumed, we want to override
+ * SO_RCVLOWAT constraint, since we are receiving skbs with too small
+ * len/truesize ratio.
+ */
+static inline bool tcp_rmem_pressure(const struct sock *sk)
+{
+ int rcvbuf = READ_ONCE(sk->sk_rcvbuf);
+ int threshold = rcvbuf - (rcvbuf >> 3);
+
+ return atomic_read(&sk->sk_rmem_alloc) > threshold;
+}
+
extern void tcp_openreq_init_rwin(struct request_sock *req,
const struct sock *sk_listener,
const struct dst_entry *dst);
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index e72bd651d21a..a385fcaaa03b 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -476,9 +476,17 @@ static void tcp_tx_timestamp(struct sock *sk, u16 tsflags)
static inline bool tcp_stream_is_readable(const struct tcp_sock *tp,
int target, struct sock *sk)
{
- return (READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq) >= target) ||
- (sk->sk_prot->stream_memory_read ?
- sk->sk_prot->stream_memory_read(sk) : false);
+ int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq);
+
+ if (avail > 0) {
+ if (avail >= target)
+ return true;
+ if (tcp_rmem_pressure(sk))
+ return true;
+ }
+ if (sk->sk_prot->stream_memory_read)
+ return sk->sk_prot->stream_memory_read(sk);
+ return false;
}
/*
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b996dc1069c5..29c6fc8c7716 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4757,7 +4757,8 @@ void tcp_data_ready(struct sock *sk)
const struct tcp_sock *tp = tcp_sk(sk);
int avail = tp->rcv_nxt - tp->copied_seq;
- if (avail < sk->sk_rcvlowat && !sock_flag(sk, SOCK_DONE))
+ if (avail < sk->sk_rcvlowat && !tcp_rmem_pressure(sk) &&
+ !sock_flag(sk, SOCK_DONE))
return;
sk->sk_data_ready(sk);