printk : kernel log 설정

# cat /proc/sys/kernel/printk

6 4 1 7

=> 맨 처음 숫자가 Log Level을 의미함

#define KERN_EMERG "<0>" /* system is unusable */

#define KERN_ALERT "<1>" /* action must be taken immediately */

#define KERN_CRIT "<2>" /* critical conditions */

#define KERN_ERR "<3>" /* error conditions */

#define KERN_WARNING "<4>" /* warning conditions */

#define KERN_NOTICE "<5>" /* normal but significant condition */

#define KERN_INFO "<6>" /* informational */

#define KERN_DEBUG "<7>" /* debug-level messages */

echo 7 4 1 7 > /proc/sys/kernel/printk

로 설정하면 모든 printk 는 출력되며

echo 0 4 1 7 > /proc/sys/kernel/printk

로 설정하면 모든 printk 는 출력되지 않는다

출처 : KELP (Korea Embedded Linux Project)