linux-kernel - Re: [Openipmi-developer] [PATCH 9/12] IPMI: add pigeonpoint poweroff

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Message-Id: <200612041206.kB4C61ia004849@laptop13.inf.utfsm.cl>
Date:	Mon, 04 Dec 2006 09:06:01 -0300
From:	"Horst H. von Brand" <vonbrand@....utfsm.cl>
To:	Randy Dunlap <randy.dunlap@...cle.com>
cc:	Bela Lubkin <blubkin@...are.com>, Andrew Morton <akpm@...l.org>,
	Corey Minyard <minyard@....org>,
	OpenIPMI Developers <openipmi-developer@...ts.sourceforge.net>,
	Linux Kernel <linux-kernel@...r.kernel.org>,
	Joseph Barnett <jbarnett@...orola.com>
Subject: Re: [Openipmi-developer] [PATCH 9/12] IPMI: add pigeonpoint poweroff 

Randy Dunlap <randy.dunlap@...cle.com> wrote:
> Bela Lubkin wrote:
> > Andrew Morton wrote:
> >
> >>> Sometime, please go through the IPMI code looking for all these
> >>> statically-allocated things which are initialised to 0 or NULL and remove
> >>> all those intialisations?  They're unneeded, they increase the vmlinux
> >>> image size and there are quite a number of them.  Thanks.
> > Randy Dunlop replied:
> >
> >> I was just about to send that patch.  Here it is,
> >> on top of the series-of-12.
> > ...
> >> -static int bt_debug = BT_DEBUG_OFF;
> >> +static int bt_debug;
> > Is it wise to significantly degrade code readability to work around
> > a minor
> > compiler / linker bug?
> 
> Is that the only one that is a problem?
> 
> I don't think it's a problem.  We *know* that static data areas
> are init to 0.  Everything depends on that.  If that didn't work
> it would all break.

Right. And we know NULL == 0.

> I could say that it's a nice coincidence that BT_DEBUG_OFF == 0,
> but I think that it's more than coincidence.

I'd have had to look over the code to find out what it was initialized
to. In cases where it is not an explicit 0/NULL, I'd leave it as is. It
could also break if somebody later on changes the value of BT_DEBUG_OFF
(yes, very unlikely, but...).

Bug your friendly GCC guy to loose static initializations to zero
(shouldn't be /that/ hard to do...) instead of obfuscating kernel's code.
-- 
Dr. Horst H. von Brand                   User #22616 counter.li.org
Departamento de Informatica                    Fono: +56 32 2654431
Universidad Tecnica Federico Santa Maria             +56 32 2654239
Casilla 110-V, Valparaiso, Chile               Fax:  +56 32 2797513
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