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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Ed W <lists@wildgooses.com>
Cc: Linux Networking Developer Mailing List <netdev@vger.kernel.org>
Subject: Re: Modifying the exponential backoff on new connection SYN packets
Date: Tue, 09 Apr 2013 09:03:38 -0700	[thread overview]
Message-ID: <1365523418.3887.149.camel@edumazet-glaptop> (raw)
In-Reply-To: <51643935.6070201@wildgooses.com>

On Tue, 2013-04-09 at 16:52 +0100, Ed W wrote:
> On 09/04/2013 16:12, Eric Dumazet wrote:
> > On Tue, 2013-04-09 at 06:48 -0700, Eric Dumazet wrote:
> >
> >> You'll have to change inet_csk_reqsk_queue_prune() in
> >> net/ipv4/inet_connection_sock.c
> >>
> >> timeo = min(timeout << req->num_timeout, max_rto);
> >> req->expires = now + timeo;
> >>
> >> Good luck !
> > Oh well, this code is for SYNACK retransmits...
> >
> > For other retransmits, you'll have to take a look in
> > net/ipv4/tcp_timer.c, around lines 475
> >
> > icsk->icsk_rto = min(icsk->icsk_rto << 1, TCP_RTO_MAX);
> >
> >
> 
> Hmm, I don't necessarily want to change the normal data timeouts, just 
> the initial SYN timeouts. How might I make detect that I'm in SYN state 
> and cap the timer appropriately? Apologies for beginner questions...

You'll have to add a test on :

if (sk->sk_state == TCP_SYN_SENT)

should be pretty easy.

      reply	other threads:[~2013-04-09 16:03 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-09  9:06 Modifying the exponential backoff on new connection SYN packets Ed W
2013-04-09 13:48 ` Eric Dumazet
2013-04-09 15:12   ` Eric Dumazet
2013-04-09 15:52     ` Ed W
2013-04-09 16:03       ` Eric Dumazet [this message]

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