[PATCH -rt] printk: 'force_early_printk' boot param to help withdebugging

From: Peter Zijlstra
Date: Fri Sep 02 2011 - 08:41:43 EST


Subject: printk: 'force_early_printk' boot param to help with debugging
From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Date: Fri Sep 02 14:29:33 CEST 2011

Gives me an option to screw printk and actually see what the machine
says.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-ykb97nsfmobq44xketrxs977@xxxxxxxxxxxxxx
---
kernel/printk.c | 7 +++++++
1 file changed, 7 insertions(+)

Index: linux-2.6/kernel/printk.c
===================================================================
--- linux-2.6.orig/kernel/printk.c
+++ linux-2.6/kernel/printk.c
@@ -541,6 +541,13 @@ asmlinkage void early_printk(const char
*/
static int __read_mostly printk_killswitch;

+static int __init force_early_printk_setup(char *str)
+{
+ printk_killswitch = 1;
+ return 0;
+}
+early_param("force_early_printk", force_early_printk_setup);
+
void printk_kill(void)
{
printk_killswitch = 1;

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