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authorEric Dumazet <edumazet@google.com>2016-02-11 19:58:18 +0300
committerDavid S. Miller <davem@davemloft.net>2016-02-17 00:07:13 +0300
commit372022830b06d9980c7e8b41fa0a4081cff883b0 (patch)
treef3b5d5280ef7720ab66f8d9b015cf8fe7e0ef8a8 /net
parent6c5d89a34a486ad782dfb5b6b3b8fb4976ae7619 (diff)
downloadlinux-372022830b06d9980c7e8b41fa0a4081cff883b0.tar.xz
tcp: do not set rtt_min to 1
There are some cases where rtt_us derives from deltas of jiffies, instead of using usec timestamps. Since we want to track minimal rtt, better to assume a delta of 0 jiffie might be in fact be very close to 1 jiffie. It is kind of sad jiffies_to_usecs(1) calls a function instead of simply using a constant. Fixes: f672258391b42 ("tcp: track min RTT using windowed min-filter") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp_input.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 1c2a73406261..3b2c8e90a475 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2896,7 +2896,10 @@ static void tcp_update_rtt_min(struct sock *sk, u32 rtt_us)
{
const u32 now = tcp_time_stamp, wlen = sysctl_tcp_min_rtt_wlen * HZ;
struct rtt_meas *m = tcp_sk(sk)->rtt_min;
- struct rtt_meas rttm = { .rtt = (rtt_us ? : 1), .ts = now };
+ struct rtt_meas rttm = {
+ .rtt = likely(rtt_us) ? rtt_us : jiffies_to_usecs(1),
+ .ts = now,
+ };
u32 elapsed;
/* Check if the new measurement updates the 1st, 2nd, or 3rd choices */