kernel/printk: Convert to hotplug state machine

Install the callbacks via the state machine.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161103145021.28528-3-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Sebastian Andrzej Siewior 2016-11-03 15:49:58 +01:00 committed by Thomas Gleixner
parent fc4d24c9b4
commit 90b14889d2
2 changed files with 13 additions and 15 deletions

View file

@ -31,6 +31,7 @@ enum cpuhp_state {
CPUHP_S390_PFAULT_DEAD,
CPUHP_BLK_MQ_DEAD,
CPUHP_FS_BUFF_DEAD,
CPUHP_PRINTK_DEAD,
CPUHP_WORKQUEUE_PREP,
CPUHP_POWER_NUMA_PREPARE,
CPUHP_HRTIMERS_PREPARE,

View file

@ -2185,27 +2185,18 @@ void resume_console(void)
/**
* console_cpu_notify - print deferred console messages after CPU hotplug
* @self: notifier struct
* @action: CPU hotplug event
* @hcpu: unused
* @cpu: unused
*
* If printk() is called from a CPU that is not online yet, the messages
* will be spooled but will not show up on the console. This function is
* called when a new CPU comes online (or fails to come up), and ensures
* that any such output gets printed.
*/
static int console_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
static int console_cpu_notify(unsigned int cpu)
{
switch (action) {
case CPU_ONLINE:
case CPU_DEAD:
case CPU_DOWN_FAILED:
case CPU_UP_CANCELED:
console_lock();
console_unlock();
}
return NOTIFY_OK;
console_lock();
console_unlock();
return 0;
}
/**
@ -2843,6 +2834,7 @@ EXPORT_SYMBOL(unregister_console);
static int __init printk_late_init(void)
{
struct console *con;
int ret;
for_each_console(con) {
if (!keep_bootcon && con->flags & CON_BOOT) {
@ -2857,7 +2849,12 @@ static int __init printk_late_init(void)
unregister_console(con);
}
}
hotcpu_notifier(console_cpu_notify, 0);
ret = cpuhp_setup_state_nocalls(CPUHP_PRINTK_DEAD, "printk:dead", NULL,
console_cpu_notify);
WARN_ON(ret < 0);
ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "printk:online",
console_cpu_notify, NULL);
WARN_ON(ret < 0);
return 0;
}
late_initcall(printk_late_init);