Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH 2/3] tcp: Reduce SYN resend delay if a suspicous ACK is received | Date | Mon, 3 Feb 2020 15:40:04 +0000 |
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From: Eric Dumazet > Sent: 31 January 2020 22:54 > On 1/31/20 2:11 PM, Neal Cardwell wrote: > > > I looked into fixing this, but my quick reading of the Linux > > tcp_rcv_state_process() code is that it should behave correctly and > > that a connection in FIN_WAIT_1 that receives a FIN/ACK should move to > > TIME_WAIT. > > > > SeongJae, do you happen to have a tcpdump trace of the problematic > > sequence where the "process A" ends up in FIN_WAIT_2 when it should be > > in TIME_WAIT? > > > > If I have time I will try to construct a packetdrill case to verify > > the behavior in this case. > > Unfortunately you wont be able to reproduce the issue with packetdrill, > since it involved packets being processed at the same time (race window)
You might be able to force the timing race by adding a sleep in one of the code paths.
No good for a regression test, but ok for code testing.
David
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