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 <[email protected]> --- 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 45e585624ced..a1d3a69a023b 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -457,9 +457,15 @@ static DEFINE_PER_CPU(struct task_struct *, printk_kthread); 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'. -- 2.13.0
