Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 07/10] dynamic debug: resurrect old pr_debug() semantics as pr_devel() | Date | Fri, 17 Apr 2009 12:04:31 -0700 |
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From: Michael Ellerman <michael@ellerman.id.au>
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> --- 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 d9e75ec..883cd44 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, ...) \ -- 1.6.2
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