Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932151AbZFLBVg (ORCPT ); Thu, 11 Jun 2009 21:21:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753327AbZFLBV2 (ORCPT ); Thu, 11 Jun 2009 21:21:28 -0400 Received: from mail-ew0-f210.google.com ([209.85.219.210]:42867 "EHLO mail-ew0-f210.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757212AbZFLBV1 convert rfc822-to-8bit (ORCPT ); Thu, 11 Jun 2009 21:21:27 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=G4Hk11XoTVkLFowCstaukthpz4fpvwROqOa6U3lN12K5tqhKekSaDhoVNyn7gEva1M MEYrtE2R3BsoELwdEzH5ROnL3EJq9TQxDhDeiYO3tspgQFawWhVzJwaMSfVDclQXzSwe 6cKll2CKlX2soZU45hwXTwE9Pe1GAJbExBEXE= MIME-Version: 1.0 In-Reply-To: <20090611144326.GB2572@ucw.cz> References: <20090611144326.GB2572@ucw.cz> Date: Fri, 12 Jun 2009 09:21:29 +0800 Message-ID: Subject: Re: [PATCH] printk: add halt_delay parameter for printk delay in halt phase From: Dave Young To: Pavel Machek Cc: Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1656 Lines: 47 On Thu, Jun 11, 2009 at 10:43 PM, Pavel Machek wrote: > On Tue 2009-06-02 17:54:52, Dave Young wrote: >> Add a halt_delay module parameter in printk.c used to read the printk >> messages in halt/poweroff/restart phase, delay each printk messages >> by halt_delay milliseconds. It is useful for debugging if there's no >> other way to dump kernel messages that time. >> >> halt_delay default value is 0, change it by: >> >> echo xxx > /sys/module/printk/parameters/halt_delay > > Well, stopping oopses from scrolling offscreen was very useful for me > in past. > >> +static inline void halt_delay_msec(void) >> +{ >> +     if (halt_delay == 0 || !(system_state == SYSTEM_HALT >> +                             || system_state == SYSTEM_POWER_OFF >> +                             || system_state == SYSTEM_RESTART)) >> +             return; >> + >> +     mdelay(halt_delay); > > ...but this will not trigger for oops, right? Hi, Pavel, this is for halt phase only. Andrew suggest to make it a general feature, thus we can enable printk delay when we want. I will write a new patch for that. >                                                                Pavel > > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html > -- Regards dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/