From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758376AbZHRBDN (ORCPT ); Mon, 17 Aug 2009 21:03:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752335AbZHRBDN (ORCPT ); Mon, 17 Aug 2009 21:03:13 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:36501 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752223AbZHRBDM (ORCPT ); Mon, 17 Aug 2009 21:03:12 -0400 Date: Mon, 17 Aug 2009 18:03:23 -0700 (PDT) Message-Id: <20090817.180323.253692704.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 From: David Miller In-Reply-To: <4A89DB15.6060101@am.sony.com> References: <20090814204305.GA31727@pengutronix.de> <4A89AC40.2040109@am.sony.com> <4A89DB15.6060101@am.sony.com> X-Mailer: Mew version 6.2.51 on Emacs 22.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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: