tcp: adjust rcv_ssthresh according to sk_reserved_mem
When user sets SO_RESERVE_MEM socket option, in order to utilize the
reserved memory when in memory pressure state, we adjust rcv_ssthresh
according to the available reserved memory for the socket, instead of
using 4 * advmss always.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 32cf6c0..4c2898a 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1421,6 +1421,17 @@ static inline int tcp_full_space(const struct sock *sk)
return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf));
}
+static inline void tcp_adjust_rcv_ssthresh(struct sock *sk)
+{
+ int unused_mem = sk_unused_reserved_mem(sk);
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss);
+ if (unused_mem)
+ tp->rcv_ssthresh = max_t(u32, tp->rcv_ssthresh,
+ tcp_win_from_space(sk, unused_mem));
+}
+
void tcp_cleanup_rbuf(struct sock *sk, int copied);
/* We provision sk_rcvbuf around 200% of sk_rcvlowat.