This param permits user-space to forcibly on/off printk emergency mode via /sys/module/printk/parameters/enforce_emergency node.
Signed-off-by: Sergey Senozhatsky <sergey.senozhat...@gmail.com> --- kernel/printk/printk.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index a113f684066c..ba640fbcee7c 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -455,9 +455,15 @@ static struct task_struct *printk_kthread __read_mostly; static atomic_t printk_emergency __read_mostly; /* * Disable printk_kthread permanently. Unlike `oops_in_progress' - * it doesn't go back to 0. + * it doesn't go back to 0 (unless set by user-space). */ static bool printk_enforce_emergency __read_mostly; + +module_param_named(enforce_emergency, printk_enforce_emergency, + bool, 0644); +MODULE_PARM_DESC(printk_enforce_emergency, + "don't offload message printing to printk kthread"); + /* * The number of lines a task can print before offloading printing * job to printk_kthread. 0 indicates 'no limit'. -- 2.12.2
