From: Marcelo Ricardo Leitner <mleitner@redhat•com>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: Neal Cardwell <ncardwell@google•com>,
Netdev <netdev@vger•kernel.org>,
Yuchung Cheng <ycheng@google•com>,
Eric Dumazet <edumazet@google•com>
Subject: Re: [PATCH v2 net] tcp: zero retrans_stamp if all retrans were acked
Date: Wed, 05 Nov 2014 13:32:26 -0200 [thread overview]
Message-ID: <545A430A.9000504@redhat.com> (raw)
In-Reply-To: <1415150445.1458.1.camel@edumazet-glaptop2.roam.corp.google.com>
On 04-11-2014 23:20, Eric Dumazet wrote:
> On Tue, 2014-11-04 at 18:51 -0200, Marcelo Ricardo Leitner wrote:
>
>> And thank you guys for all the assistance on it. Btw, would you send me that
>> packetdrill script? I'm curious to see how such corner case could be written
>> on it.
>
> One of the script I saw was :
>
> You might have to adapt preconditions (tcp_rmem[]/tcp_wmem[])
>
> 0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
> // Set a 10s timeout
> +.000 setsockopt(3, SOL_TCP, TCP_USER_TIMEOUT, [10000], 4) = 0
> +.000 bind(3, ..., ...) = 0
> +.000 listen(3, 1) = 0
> +.000 < S 0:0(0) win 32792 <mss 1460,nop,wscale 7>
> +.000 > S. 0:0(0) ack 1 <mss 1460,nop,wscale 6>
> +.010 < . 1:1(0) ack 1 win 257
> +.000 accept(3, ..., ...) = 4
> +.000 write(4, ..., 1000) = 1000
> +.000 > P. 1:1001(1000) ack 1
> +.625 > P. 1:1001(1000) ack 1
> +.020 < . 1:1(0) ack 1001 win 257
> // Purposely write more after the specified timeout for testing
> +11.0 write(4, ..., 1000) = 1000
> +.000 > P. 1001:2001(1000) ack 1
> +1.25 > P. 1001:2001(1000) ack 1
> // socket is killed when the 2nd RTO fires at +2.50 w/o this patch
> // so the next write returns ETIMEOUT
> +2.60 write(4, ..., 1000) = 1000
Cool, thanks!
Marcelo
next prev parent reply other threads:[~2014-11-05 15:32 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-04 14:18 [PATCH net] tcp: zero retrans_stamp if all retrans were acked Marcelo Ricardo Leitner
2014-11-04 18:51 ` Neal Cardwell
2014-11-04 19:03 ` Neal Cardwell
2014-11-04 19:12 ` Marcelo Ricardo Leitner
2014-11-04 19:15 ` [PATCH v2 " Marcelo Ricardo Leitner
2014-11-04 20:10 ` Neal Cardwell
2014-11-04 20:51 ` Marcelo Ricardo Leitner
2014-11-05 1:20 ` Eric Dumazet
2014-11-05 15:32 ` Marcelo Ricardo Leitner [this message]
2014-11-05 22:00 ` David Miller
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