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author | Neal Cardwell <ncardwell@google.com> | 2013-09-17 01:44:20 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2013-09-17 23:08:08 (GMT) |
commit | 269aa759b474570fa642452742741525cfc226a9 (patch) | |
tree | 00089098af219e1257caaf5c06835d3dbd6d043d | |
parent | 4bdf25976333ba435f7879b4487fe8aca799ac41 (diff) | |
download | linux-269aa759b474570fa642452742741525cfc226a9.tar.xz |
tcp: fix RTO calculated from cached RTT
Commit 1b7fdd2ab5852 ("tcp: do not use cached RTT for RTT estimation")
did not correctly account for the fact that crtt is the RTT shifted
left 3 bits. Fix the calculation to consistently reflect this fact.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-By: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | net/ipv4/tcp_metrics.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c index 4a22f3e..52f3c6b 100644 --- a/net/ipv4/tcp_metrics.c +++ b/net/ipv4/tcp_metrics.c @@ -502,7 +502,9 @@ reset: * ACKs, wait for troubles. */ if (crtt > tp->srtt) { - inet_csk(sk)->icsk_rto = crtt + max(crtt >> 2, tcp_rto_min(sk)); + /* Set RTO like tcp_rtt_estimator(), but from cached RTT. */ + crtt >>= 3; + inet_csk(sk)->icsk_rto = crtt + max(2 * crtt, tcp_rto_min(sk)); } else if (tp->srtt == 0) { /* RFC6298: 5.7 We've failed to get a valid RTT sample from * 3WHS. This is most likely due to retransmission, |