Messages in this thread | | | From | Bartlomiej Zolnierkiewicz <> | Subject | Re: [PATCH] preset loops_per_jiffy for faster booting | Date | Tue, 13 Jul 2004 21:24:47 +0200 |
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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.
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