Commit a8cfdc68 authored by Olof Johansson's avatar Olof Johansson Committed by Linus Torvalds
Browse files

printk: add Kconfig option to set default console loglevel 

Add a configuration option to set the default console loglevel.  This
is, as before, still possible to override at runtime through bootargs
(loglevel=<x>), sysrq and /proc/printk.

There are cases where adding additional arguments on the commandline is
impractical, and changing the default for the kernel when being built
makes more sense.  Provide such a method here, for those who choose to
do so.

Also, while touching this code, clarify the difference between
MESSAGE_LOGLEVEL_DEFAULT and CONSOLE_LOGLEVEL_DEFAULT.

Link: http://lkml.kernel.org/r/1479676829-30031-1-git-send-email-olof@lixom.net


Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0a4824bf

include/linux/printk.h

+6 −1
Original line number Diff line number Diff line
@@ -50,10 +50,15 @@ static inline const char *printk_skip_headers(const char *buffer) 
#define CONSOLE_LOGLEVEL_SILENT  0 /* Mum's the word */

#define CONSOLE_LOGLEVEL_MIN	 1 /* Minimum loglevel we let people use */

#define CONSOLE_LOGLEVEL_QUIET	 4 /* Shhh ..., when booted with "quiet" */

#define CONSOLE_LOGLEVEL_DEFAULT 7 /* anything MORE serious than KERN_DEBUG */

#define CONSOLE_LOGLEVEL_DEBUG	10 /* issue debug messages */

#define CONSOLE_LOGLEVEL_MOTORMOUTH 15	/* You can't shut this one up */



/*

 * Default used to be hard-coded at 7, we're now allowing it to be set from

 * kernel config.

 */

#define CONSOLE_LOGLEVEL_DEFAULT CONFIG_CONSOLE_LOGLEVEL_DEFAULT



extern int console_printk[];



#define console_loglevel (console_printk[0])

lib/Kconfig.debug

+19 −0
Original line number Diff line number Diff line
@@ -15,6 +15,21 @@ config PRINTK_TIME 
	  The behavior is also controlled by the kernel command line

	  parameter printk.time=1. See Documentation/kernel-parameters.txt



config CONSOLE_LOGLEVEL_DEFAULT

	int "Default console loglevel (1-15)"

	range 1 15

	default "7"

	help

	  Default loglevel to determine what will be printed on the console.



	  Setting a default here is equivalent to passing in loglevel=<x> in

	  the kernel bootargs. loglevel=<x> continues to override whatever

	  value is specified here as well.



	  Note: This does not affect the log level of un-prefixed prink()

	  usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT

	  option.



config MESSAGE_LOGLEVEL_DEFAULT

	int "Default message log level (1-7)"

	range 1 7
@@ -26,6 +41,10 @@ config MESSAGE_LOGLEVEL_DEFAULT 
	  that are auditing their logs closely may want to set it to a lower

	  priority.



	  Note: This does not affect what message level gets printed on the console

	  by default. To change that, use loglevel=<x> in the kernel bootargs,

	  or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.



config BOOT_PRINTK_DELAY

	bool "Delay each boot printk message by N milliseconds"

	depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY

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