Re: [PATCH v2 2/2] selftests: net: Add FIN_ACK processing order related latency spike test

Eric Dumazet
2020-02-01T18:20:14Z

On 1/31/20 11:18 PM, sj38.park@gmail.com wrote:
> From: SeongJae Park <sjpark@amazon.de>
>
> This commit adds a test for FIN_ACK process races related reconnection
> latency spike issues. The issue has described and solved by the
> previous commit ("tcp: Reduce SYN resend delay if a suspicous ACK is
> received").
>
> The test program is configured with a server and a client process. The
> server creates and binds a socket to a port that dynamically allocated,
> listen on it, and start a infinite loop. Inside the loop, it accepts
> connection, reads 4 bytes from the socket, and closes the connection.
> The client is constructed as an infinite loop. Inside the loop, it
> creates a socket with LINGER and NODELAY option, connect to the server,
> send 4 bytes data, try read some data from server. After the read()
> returns, it measure the latency from the beginning of this loop to this
> point and if the latency is larger than 1 second (spike), print a
> message.
>
> Signed-off-by: SeongJae Park <sjpark@amazon.de>

Reviewed-by: Eric Dumazet <edumazet@google.com>