tcp: extract the function to compute delivery rate

Refactor the code to extract the function to compute delivery rate.
This function will be used in later commit.

Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index e022874d509f5021c8259dc13d294daf6c018e31..acee7acdcba62b5693b3c7d76f22eb959389d3f0 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -388,6 +388,19 @@ static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
        return period;
 }
 
+static u64 tcp_compute_delivery_rate(const struct tcp_sock *tp)
+{
+       u32 rate = READ_ONCE(tp->rate_delivered);
+       u32 intv = READ_ONCE(tp->rate_interval_us);
+       u64 rate64 = 0;
+
+       if (rate && intv) {
+               rate64 = (u64)rate * tp->mss_cache * USEC_PER_SEC;
+               do_div(rate64, intv);
+       }
+       return rate64;
+}
+
 /* Address-family independent initialization for a tcp_sock.
  *
  * NOTE: A lot of things set to zero explicitly by call to
@@ -2716,7 +2729,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
 {
        const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
        const struct inet_connection_sock *icsk = inet_csk(sk);
-       u32 now, intv;
+       u32 now;
        u64 rate64;
        bool slow;
        u32 rate;
@@ -2815,13 +2828,9 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
        info->tcpi_data_segs_out = tp->data_segs_out;
 
        info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0;
-       rate = READ_ONCE(tp->rate_delivered);
-       intv = READ_ONCE(tp->rate_interval_us);
-       if (rate && intv) {
-               rate64 = (u64)rate * tp->mss_cache * USEC_PER_SEC;
-               do_div(rate64, intv);
+       rate64 = tcp_compute_delivery_rate(tp);
+       if (rate64)
                info->tcpi_delivery_rate = rate64;
-       }
        unlock_sock_fast(sk, slow);
 }
 EXPORT_SYMBOL_GPL(tcp_get_info);