The four values in printk denote: console_loglevel, default_message_loglevel, minimum_console_loglevel and default_console_loglevel respectively.
These values influence printk() behavior when printing or logging error messages. See ‘man 2 syslog’ for more info on the different loglevels.
======================== =====================================
console_loglevel messages with a higher priority than
this will be printed to the console
default_message_loglevel messages without an explicit priority
will be printed with this priority
minimum_console_loglevel minimum (highest) value to which
console_loglevel can be set
default_console_loglevel default value for console_loglevel
======================== =====================================