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Date: Tue, 13 Oct 2009 20:34:11 -0700 (PDT)
From: David Rientjes <rientjes@google.com>
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To: Joe Perches <joe@perches.com>
cc: Andrew Morton <akpm@linux-foundation.org>,
       LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] kernel.h: Add a never optimized away pr_dbg for
 printk(KERN_DEBUG pr_fmt(fmt)...)
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On Tue, 13 Oct 2009, Joe Perches wrote:

> Many developers use a logging message that
> is printed at KERN_DEBUG level that is always
> printed regardless of #define DEBUG levels.
> 
> pr_debug can be optimized away to a null statement.
> 
> Add a pr_dbg message that prints at KERN_DEBUG
> level that uses pr_fmt() that can not be optimized
> to nothing.
> 

pr_dbg() is horribly misnamed, it doesn't indicate why it exists vs. 
pr_debug() at all.  Future users will undoubtedly use it by mistake when 
they only really mean for the message to be emitted on DEBUG because 
they've seen it in other places and haven't checked the implementation.

I'd suggest pr_debug_force(), even though it's much longer (although still 
shorter than printk(KERN_DEBUG)).