linux-kernel - Re: [PATCH 02/10] x86: Convert BUG() to use unreachable()

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Date:	Sun, 13 Sep 2009 13:12:03 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	David Daney <ddaney@...iumnetworks.com>
CC:	Ingo Molnar <mingo@...e.hu>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	akpm@...ux-foundation.org, linux-kernel@...r.kernel.org,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>, x86@...nel.org,
	Roland McGrath <roland@...hat.com>
Subject: Re: [PATCH 02/10] x86: Convert BUG() to use unreachable()

On 09/11/2009 08:55 AM, David Daney wrote:
> 
> Perhaps, although with a pre-GCC-4.5 compiler, it would end up adding
> the endless loop code to BUG() sites for configurations where the user
> has explicitly stated their preference for the code to be as small as
> possible (by turning off CONFIG_BUG).
> 
> If that is acceptable, I will prepare another revision of the patch set.
> 

The thing is that without the loop, the compiler will generate the
fall-through case code, which may add more code than the loop removes.

	-hpa

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

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