From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265490AbUGMTS6 (ORCPT ); Tue, 13 Jul 2004 15:18:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265807AbUGMTS6 (ORCPT ); Tue, 13 Jul 2004 15:18:58 -0400 Received: from mion.elka.pw.edu.pl ([194.29.160.35]:34176 "EHLO mion.elka.pw.edu.pl") by vger.kernel.org with ESMTP id S265490AbUGMTSw (ORCPT ); Tue, 13 Jul 2004 15:18:52 -0400 From: Bartlomiej Zolnierkiewicz To: Tim Bird , Adam Kropelin Subject: Re: [PATCH] preset loops_per_jiffy for faster booting Date: Tue, 13 Jul 2004 21:24:47 +0200 User-Agent: KMail/1.5.3 Cc: Andrew Morton , Geert Uytterhoeven , karim@opersys.com, linux-kernel@vger.kernel.org, celinux-dev@tree.celinuxforum.org, tpoynor@mvista.com References: <40EEF10F.1030404@am.sony.com> <20040712153248.A3743@mail.kroptech.com> <40F313A6.909@am.sony.com> In-Reply-To: <40F313A6.909@am.sony.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200407132124.47773.bzolnier@elka.pw.edu.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Tuesday 13 of July 2004 00:41, Tim Bird wrote: > Adam Kropelin wrote: > > On Mon, Jul 12, 2004 at 11:52:44AM -0700, Tim Bird wrote: > >>Adam Kropelin wrote: > >>>Here's a patch. It places the relevant information on the same line as > >>>bogomips and does so without encouraging anyone to fiddle with > >>>loops_per_jiffy and screw up their kernel. > >> > >>The patch is missing the Kconfig piece. Is the wording the > >>same as from your earlier patch? > > > > Andrew requested that the config option be removed, so there are no > > longer any changes to Kconfig. > > Oh - I missed the change where preset_lpj is no longer initialized > from CONFIG_PRESET_LPJ. I see it now. I saw the comment from > Andrew, but thought he was talking about the first version of the > patch that had ifdefs. > > Here's what Andrew Morton said: > > a) I don't see much point in making it configurable. Just add the boot > > option and be done with it. The few hundred bytes of extra code will > > be dropped from core anyway. > > > > The main reason for this is that most people won't turn on the config > > option, so your new code could get accidentally broken quite easily. > > Plus it removes some ifdefs. > > I have one or two arguments in favor of keeping the config option. > First, for embedded systems it is sometimes necessary to compile-in > the value. Unfortunately, not all architectures allow the > kernel command line to be compiled in. (It would be nice if they did, > but that's something to fix separately.) Many do (i.e. arm, h8300, mips, ppc, sh) and IMHO it is better to fix it separately where needed. > The first restructuring of the patch that you did, I think addresses > the issues that Andrew raised. There are now no ifdefs, and since the > core code doesn't drop away (and indeed can be turned on at boot time > if needed), I think the code is not susceptible to accidental breakage > like the first version was. I think Andrew is right that the preset > code path won't get much testing outside of embedded circles, so it is > important that it be as simple as possible. > > The only *code* change from the configurable to the config-less version > of the code is: > > +static unsigned long preset_lpj = CONFIG_PRESET_LPJ; > vs. > +static unsigned long preset_lpj; with the latter statement 'preset_lpj' ends up in BSS instead of data section ;-) > Secondly, I was hoping to get the FASTBOOT menu in the kernel, because > CELF has a few more patches to submit that have the same theme as this > one. (I realize this is not justification for making this option > configurable, per se. If we need to push for this on a subsequent patch, > that's OK.) Separate patch please if/when needed.