Date: Sun, 18 Jan 2009 10:37:22 +1100 (EST)
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Kyle McMartin <kyle@infradead.org>
cc: "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>,
       Mikael Pettersson <mikpe@it.uu.se>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: "eliminate warn_on_slowpath()" change causes many gcc-3.2.3
 warnings
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References: <200901171519.n0HFJZuf028704@harpo.it.uu.se> <20090117161817.GA10825@elte.hu> <49723912.6020108@zytor.com> <20090117204421.GA1700@bombadil.infradead.org>
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On Sat, 17 Jan 2009, Kyle McMartin wrote:
> 
> How about something utterly evil? (Since you can't pass a zero-length
> string to a printf attributed function either...)

Don't do this. That just forces a load off a complex pointer instead, with 
no upsides. At least if it was

	extern const char warn_slowpath_nofmt[];

it would only load the pointer itself, which is still a fairly  expensive 
op, but at least doesn't require the extra memory load.

But you'd be better off jusst making it something like

	#define NO_FMT ((const char *)(-1))

instead, which is really much more obvious, and doesn't need any of that 
"get a pointer" overhead.

		Linus
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