From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: new ipdelay= option for faster netboot Date: Mon, 17 Aug 2009 18:03:23 -0700 (PDT) Message-ID: <20090817.180323.253692704.davem@davemloft.net> References: <20090814204305.GA31727@pengutronix.de> <4A89AC40.2040109@am.sony.com> <4A89DB15.6060101@am.sony.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4A89DB15.6060101@am.sony.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: Text/Plain; charset="us-ascii" 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 From: Tim Bird 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: