From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762098AbXGFAtR (ORCPT ); Thu, 5 Jul 2007 20:49:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759900AbXGFAtH (ORCPT ); Thu, 5 Jul 2007 20:49:07 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:52376 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759710AbXGFAtG (ORCPT ); Thu, 5 Jul 2007 20:49:06 -0400 Message-ID: <468D917F.90204@garzik.org> Date: Thu, 05 Jul 2007 20:49:03 -0400 From: Jeff Garzik User-Agent: Thunderbird 1.5.0.12 (X11/20070530) MIME-Version: 1.0 To: Dave Jones , Linux Kernel , Randy Dunlap Subject: Re: slow down printk during boot. References: <20070705211346.GB17030@redhat.com> In-Reply-To: <20070705211346.GB17030@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.3 (----) X-Spam-Report: SpamAssassin version 3.1.9 on srv5.dvmed.net summary: Content analysis details: (-4.3 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Dave Jones wrote: > This patch from Randy has proven quite useful from time to time, > and has been in Fedora kernels for a while for that reason. > I fixed up some checkpatch warnings, and rediffed it a bunch > of times, Randy did the heavy lifting. > > --- > > This one delays each printk() during boot by a variable time > (from kernel command line), while system_state == SYSTEM_BOOTING. > Caveat: it's not terribly SMP safe or SMP nice. > Any ideas for improvements (esp. in the SMP area) are appreciated. > > --- > > From: Randy Dunlap > > Optionally add a boot delay after each kernel printk() call, > crudely measured in milliseconds, with a maximum delay of > 10 seconds per printk. > > Enable CONFIG_BOOT_DELAY=y and then add (e.g.): > "lpj=loops_per_jiffy boot_delay=100" > to the kernel command line. > > Signed-off-by: Randy Dunlap > Signed-off-by: Dave Jones > > --- > > init/calibrate.c | 2 +- > init/main.c | 25 +++++++++++++++++++++++++ > kernel/printk.c | 33 +++++++++++++++++++++++++++++++++ > lib/Kconfig.debug | 18 ++++++++++++++++++ > 4 files changed, 77 insertions(+), 1 deletion(-) hey, that's pretty neat. I've occasionally hand-hacked something similar, to achieve those effects. Jeff