netdev - Re: PROBLEM: Linux kernel 2.6.31 IPv4 TCP fails to open huge amount of outgoing connections (unable to bind ... )

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Date:	Wed, 21 Apr 2010 20:43:36 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Evgeniy Polyakov <zbr@...emap.net>
Cc:	Ben Greear <greearb@...delatech.com>,
	David Miller <davem@...emloft.net>,
	Gaspar Chilingarov <gasparch@...il.com>,
	netdev <netdev@...r.kernel.org>
Subject: Re: PROBLEM: Linux kernel 2.6.31 IPv4 TCP fails to open huge
 amount of outgoing connections (unable to bind ... )

Le mercredi 21 avril 2010 à 22:27 +0400, Evgeniy Polyakov a écrit :
> On Wed, Apr 21, 2010 at 01:27:33PM +0200, Eric Dumazet (eric.dumazet@...il.com) wrote:
> > Here is the patch I use now and my test application is now able to open
> > and connect 1000000 sockets (ulimit -n 1000000)
> > 
> > Trick is bind_conflict() must refuse a socket to bind to a port on a non
> > null IP if another socket already uses same port on same IP.
> > 
> > Plus the previous patch sent (check a conflict before exiting the search
> > loop)
> > 
> > What do you think ?
> 
> Looks good, but do we want to check only reused socket's address there?
> What if one of the sockets does not have reuse option turned on, will it
> break?
> 

Well, if one socket doesnt have reuse option turned on, the previous
test already works ?

if (!reuse || !sk2->sk_reuse || sk2->sk_state == TCP_LISTEN) {
	if (!sk2_rcv_saddr || !sk_rcv_saddr ||
	    sk2_rcv_saddr == sk_rcv_saddr)
		break;
} else if (reuse && sk2->sk_reuse &&
           sk2_rcv_saddr &&
           sk2_rcv_saddr == sk_rcv_saddr)
	break;

I failed to factorize this complex test :(



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