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From: Keith Owens <kaos@ocs.com.au>
To: devnetfs <devnetfs@yahoo.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: compiling kernel with debug and optimization 
In-reply-to: Your message of "Mon, 10 Feb 2003 03:11:51 -0800."
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Date: Mon, 10 Feb 2003 22:32:37 +1100
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On Mon, 10 Feb 2003 03:11:51 -0800 (PST), 
devnetfs <devnetfs@yahoo.com> wrote:
>Does compiling with -g option degrade performance? IMO it should NOT.

Compiling with -g slows down compilation and link, mainly because of
the extra debugging data that has to be copied around.  -g
significantly increases disk usage.

>If that's true, then why dont we compile kernels with both -g and -O2
>always? Also does using -g AND -O2 cause some optimizations to be 
>missed out?

With gcc, compiling with -g should have no effect on the kernel.  One
of my occasional tests is to build vmlinux with and without -g, run
both through strip -g and compare the results.  They should be
identical except for the build timestamp.

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