1 files changed, 13 insertions, 6 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index f4aa4109334a..5474c9854f25 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -985,7 +985,8 @@ static void tcp_internal_pacing(struct sock *sk)
         sock_hold(sk);
 }
 
-static void tcp_update_skb_after_send(struct sock *sk, struct sk_buff *skb)
+static void tcp_update_skb_after_send(struct sock *sk, struct sk_buff *skb,
+                                      u64 prior_wstamp)
 {
         struct tcp_sock *tp = tcp_sk(sk);
 
@@ -998,7 +999,12 @@ static void tcp_update_skb_after_send(struct sock *sk, struct sk_buff *skb)
                  * this is a minor annoyance.
                  */
                 if (rate != ~0UL && rate && tp->data_segs_out >= 10) {
-                        tp->tcp_wstamp_ns += div64_ul((u64)skb->len * NSEC_PER_SEC, rate);
+                        u64 len_ns = div64_ul((u64)skb->len * NSEC_PER_SEC, rate);
+                        u64 credit = tp->tcp_wstamp_ns - prior_wstamp;
+
+                        /* take into account OS jitter */
+                        len_ns -= min_t(u64, len_ns / 2, credit);
+                        tp->tcp_wstamp_ns += len_ns;
 
                         tcp_internal_pacing(sk);
                 }
@@ -1029,6 +1035,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
         struct sk_buff *oskb = NULL;
         struct tcp_md5sig_key *md5;
         struct tcphdr *th;
+        u64 prior_wstamp;
         int err;
 
         BUG_ON(!skb || !tcp_skb_pcount(skb));
@@ -1050,7 +1057,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
                         return -ENOBUFS;
         }
 
-        /* TODO: might take care of jitter here */
+        prior_wstamp = tp->tcp_wstamp_ns;
         tp->tcp_wstamp_ns = max(tp->tcp_wstamp_ns, tp->tcp_clock_cache);
 
         skb->skb_mstamp_ns = tp->tcp_wstamp_ns;
@@ -1169,7 +1176,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
                 err = net_xmit_eval(err);
         }
         if (!err && oskb) {
-                tcp_update_skb_after_send(sk, oskb);
+                tcp_update_skb_after_send(sk, oskb, prior_wstamp);
                 tcp_rate_skb_sent(sk, oskb);
         }
         return err;
@@ -2321,7 +2328,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 
                 if (unlikely(tp->repair) && tp->repair_queue == TCP_SEND_QUEUE) {
                         /* "skb_mstamp" is used as a start point for the retransmit timer */
-                        tcp_update_skb_after_send(sk, skb);
+                        tcp_update_skb_after_send(sk, skb, tp->tcp_wstamp_ns);
                         goto repair; /* Skip network transmission */
                 }
 
@@ -2896,7 +2903,7 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs)
                 } tcp_skb_tsorted_restore(skb);
 
                 if (!err) {
-                        tcp_update_skb_after_send(sk, skb);
+                        tcp_update_skb_after_send(sk, skb, tp->tcp_wstamp_ns);
                         tcp_rate_skb_sent(sk, skb);
                 }
         } else {