linux-kernel - Re: [PATCH 3/3] x86: OLPC: speed up device tree creation during boot (v2)

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Message-ID: <4CE5670B.1060300@zytor.com>
Date:	Thu, 18 Nov 2010 09:48:59 -0800
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Andres Salomon <dilinger@...ued.net>
CC:	michael@...erman.id.au, Ingo Molnar <mingo@...e.hu>,
	devicetree-discuss@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
	Milton Miller <miltonm@....com>,
	Ingo Molnar <mingo@...hat.com>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH 3/3] x86: OLPC: speed up device tree creation during boot
 (v2)

On 11/18/2010 09:41 AM, Andres Salomon wrote:
>>
>> No, sorry, this sounds like a personal preference that is well out of
>> line with the vast majority of C programmers I've ever come across,
>> not just in the Linux kernel world but outside of it.
> 
> 
> This is actually one of the reasons I specifically like initialized
> static variables (inside of functions).  Take the following code:
> 
> int foo(void)
> {
> 	static char *frob = NULL;
> 	int p;
> 
> 	if (frob) {
> 		...
> 	}
> 
> 
> Upon seeing that and thinking "whoa, how could frob be
> initialized and then checked?", I realize that it's either a bug or I
> look back at the initialization and realize that frob is static.  It's
> less obvious (to me) with non-explicit initialization.

I have to agree with this one.  In general I dislike relying on an
implicit (even well-defined) initialized value; unfortunately we ripped
out explicit initializations across the Linux kernel, not due to
readability but due to the fact that long-since-obsolete versions of gcc
would put explicitly-initialized variables in data rather than bss even
if the initial value is zero.

	-hpa


-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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