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From: David Miller <davem@davemloft.net>
To: tim.bird@am.sony.com
Cc: r.schwebel@pengutronix.de, vda.linux@googlemail.com,
	linux-kernel@vger.kernel.org, linux-embedded@vger.kernel.org,
	arjan@linux.intel.com, kernel@pengutronix.de,
	netdev@vger.kernel.org
Subject: Re: new ipdelay= option for faster netboot
Date: Mon, 17 Aug 2009 18:03:23 -0700 (PDT)	[thread overview]
Message-ID: <20090817.180323.253692704.davem@davemloft.net> (raw)
In-Reply-To: <4A89DB15.6060101@am.sony.com>

From: Tim Bird <tim.bird@am.sony.com>
Date: Mon, 17 Aug 2009 15:35:01 -0700

> Tim Bird wrote:
>> See the definitions of CONF_PRE_OPEN and CON_POST_OPEN
>> in net/ipv4/ipconfig.c
>> 
>> They are set to ridiculously long values.  In my experience,
>> you can cut them down considerably with no dangerous side
>> effects (but I haven't asked the network guys about the
>> possible downsides).
> 
> It turns out that others have seen this delay.  Simon
> Arlott recently posted a patch to make the delay avoidable
> at boot time from the kernel command line.
> 
> See http://patchwork.kernel.org/patch/31678/

"Rediculiously long" is a relative term.

I have card/switch combinations that take up to 10 seconds to
negotiate a proper link.

So what's there now is actually a quite agressive setting.

And BTW, discussions about stuff like this belong on
netdev@vger.kernel.org, which has been added to the CC:

  reply	other threads:[~2009-08-18  1:03 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-08-14 17:02 New fast(?)-boot results on ARM Robert Schwebel
2009-08-14 18:19 ` Zan Lynx
2009-08-14 18:46   ` Jamie Lokier
2009-08-14 18:58     ` Robert Schwebel
2009-08-14 18:57   ` Robert Schwebel
2009-08-14 21:01     ` Linus Walleij
2009-08-14 21:15       ` Robert Schwebel
2009-08-14 21:35       ` Zan Lynx
2009-08-15  6:21         ` Artem Bityutskiy
2009-08-14 20:04 ` Denys Vlasenko
2009-08-14 20:43   ` Robert Schwebel
2009-08-15  5:59     ` Dirk Behme
2009-08-15 10:35     ` Johannes Stezenbach
2009-08-18 10:06       ` Marco Stornelli
2009-08-18 10:21         ` Robert Schwebel
2009-08-18 10:34           ` Alex Riesen
2009-08-18 10:44             ` Robert Schwebel
2009-08-18 10:48               ` Alex Riesen
2009-08-18 10:53                 ` Robert Schwebel
2009-09-04 16:16       ` Wolfram Sang
2009-09-09 14:33         ` Johannes Stezenbach
2009-09-10  0:03           ` Denys Vlasenko
2009-08-17 19:15     ` Tim Bird
2009-08-17 22:35       ` new ipdelay= option for faster netboot (was Re: New fast(?)-boot results on ARM) Tim Bird
2009-08-18  1:03         ` David Miller [this message]
2009-08-18  1:24           ` new ipdelay= option for faster netboot Tim Bird
2009-08-18  1:27             ` David Miller
2009-08-18  1:40               ` Tim Bird
2009-08-18  1:56                 ` David Miller
2009-08-19 11:57                 ` Jamie Lokier
2009-08-18  4:56               ` Denys Vlasenko
2009-08-18  5:00                 ` David Miller
2009-08-18  1:31           ` Rick Jones
2009-08-18  2:45             ` david
2009-08-18  4:56               ` Willy Tarreau
2009-08-15  6:14   ` New fast(?)-boot results on ARM Artem Bityutskiy
2009-08-18 14:06 ` Sascha Hauer
2009-08-18 15:31   ` Dirk Behme
2009-08-18 16:34     ` Marco Stornelli
2009-08-18 18:23     ` Tim Bird
2009-08-19  7:21     ` Sascha Hauer
2009-08-19 16:20       ` Dirk Behme
2009-08-20  8:57         ` Sascha Hauer

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