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>