path: root/include/linux/kernel.h
diff options
authorJason Baron <jbaron@redhat.com>2008-08-12 16:46:19 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2008-10-16 09:24:47 -0700
commit346e15beb5343c2eb8216d820f2ed8f150822b08 (patch)
tree6433cf2980bbfbed4a9482c5edb156fc8371e071 /include/linux/kernel.h
parent33376c1c043c05077b4ac79c33804266f6c45e49 (diff)
driver core: basic infrastructure for per-module dynamic debug messages
Base infrastructure to enable per-module debug messages. I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes control of debugging statements on a per-module basis in one /proc file, currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG, is not set, debugging statements can still be enabled as before, often by defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set. The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls can be dynamically enabled/disabled on a per-module basis. Future plans include extending this functionality to subsystems, that define their own debug levels and flags. Usage: Dynamic debugging is controlled by the debugfs file, <debugfs>/dynamic_printk/modules. This file contains a list of the modules that can be enabled. The format of the file is as follows: <module_name> <enabled=0/1> . . . <module_name> : Name of the module in which the debug call resides <enabled=0/1> : whether the messages are enabled or not For example: snd_hda_intel enabled=0 fixup enabled=1 driver enabled=0 Enable a module: $echo "set enabled=1 <module_name>" > dynamic_printk/modules Disable a module: $echo "set enabled=0 <module_name>" > dynamic_printk/modules Enable all modules: $echo "set enabled=1 all" > dynamic_printk/modules Disable all modules: $echo "set enabled=0 all" > dynamic_printk/modules Finally, passing "dynamic_printk" at the command line enables debugging for all modules. This mode can be turned off via the above disable command. [gkh: minor cleanups and tweaks to make the build work quietly] Signed-off-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include/linux/kernel.h')
1 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 75d81f157d2..ededb6e83b4 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -16,6 +16,7 @@
#include <linux/log2.h>
#include <linux/typecheck.h>
#include <linux/ratelimit.h>
+#include <linux/dynamic_printk.h>
#include <asm/byteorder.h>
#include <asm/bug.h>
@@ -303,8 +304,12 @@ static inline char *pack_hex_byte(char *buf, u8 byte)
#define pr_info(fmt, arg...) \
printk(KERN_INFO fmt, ##arg)
-#ifdef DEBUG
/* If you are writing a driver, please use dev_dbg instead */
+#define pr_debug(fmt, ...) do { \
+ dynamic_pr_debug(fmt, ##__VA_ARGS__); \
+ } while (0)
+#elif defined(DEBUG)
#define pr_debug(fmt, arg...) \
printk(KERN_DEBUG fmt, ##arg)