dynamic debug: resurrect old pr_debug() semantics as pr_devel()

pr_debug() used to produce zero code unless DEBUG was #defined.  This is
now no longer the case in practice[1].

There are places where it's useful to have debugging printks, but we don't
want them to generate any code in production kernels.

So add a new macro, pr_devel(), for _devel_opment, to provide the old
semantics, ie.  if the programmer doesn't explicitly enable debugging, no
code is produced.

[1]: You can turn CONFIG_DYNAMIC_DEBUG off, but it's enabled in at least
     one distro kernel, so it's not really a solution.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Greg Banks <gnb@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Michael Ellerman 2009-04-09 14:48:24 -07:00 committed by Greg Kroah-Hartman
parent 13977091a9
commit 4ccb457966
1 changed files with 9 additions and 0 deletions

View File

@ -377,6 +377,15 @@ static inline char *pack_hex_byte(char *buf, u8 byte)
#define pr_cont(fmt, ...) \
printk(KERN_CONT fmt, ##__VA_ARGS__)
/* pr_devel() should produce zero code unless DEBUG is defined */
#ifdef DEBUG
#define pr_devel(fmt, ...) \
printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#else
#define pr_devel(fmt, ...) \
({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
#endif
/* If you are writing a driver, please use dev_dbg instead */
#if defined(DEBUG)
#define pr_debug(fmt, ...) \