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| author |   Michael Ellerman <michael@ellerman.id.au> | 2009-04-09 14:48:24 -0700 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@suse.de> | 2009-04-16 16:17:10 -0700 |
| commit | 4ccb457966391295bd9b3644f6bdc9ddd97b6051 (patch) | |
| tree | 9e69013dcb736c33be6ce6a8facaa606f7016fbf /include | |
| parent | Driver Core: early platform driver (diff) | |
| download | linux-dev-4ccb457966391295bd9b3644f6bdc9ddd97b6051.tar.xz linux-dev-4ccb457966391295bd9b3644f6bdc9ddd97b6051.zip | |
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>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/kernel.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index d9e75ec7def5..883cd44ff765 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -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, ...) \ |