linux-kernel - Re: [PATCH v2] x86/kernel: use pr_<level>() and dev

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Date:	Tue, 16 Feb 2016 10:01:38 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	Ingo Molnar <mingo@...nel.org>
Cc:	Chen Yucong <slaoub@...il.com>, tglx@...utronix.de, hpa@...or.com,
	x86@...nel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] x86/kernel: use pr_<level>() and dev_<level>

On Tue, Feb 16, 2016 at 09:24:31AM +0100, Ingo Molnar wrote:
> Hm, so I suspect the other patch I already applied is buggy as well?

Yap.

pr_debug() is ugly to use:

/* If you are writing a driver, please use dev_dbg instead */
#if defined(CONFIG_DYNAMIC_DEBUG)
/* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
#define pr_debug(fmt, ...) \
        dynamic_pr_debug(fmt, ##__VA_ARGS__)
#elif defined(DEBUG)
#define pr_debug(fmt, ...) \
        printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#else
#define pr_debug(fmt, ...) \
        no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#endif

so in the !CONFIG_DYNAMIC_DEBUG case, you want to boot with "ignore_loglevel"
and see all those debug statements but that can't work because you have to
rebuild and slap a

#define DEBUG

somewhere *before* all includes.

Which is clearly dumb.

FWIW, that pr_debug() should have been defined without the
defined(DEBUG) conditional in order to be an equivalent conversion like
the rest of the pr_* gunk.

I propose we add

pr_debug_i_mean_it()

and use *that* instead. :-)

-- 
Regards/Gruss,
    Boris.

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