From 90b14889d2f9b29d7e5b4b2d36251c13ce3dd13f Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 3 Nov 2016 15:49:58 +0100 Subject: [PATCH] kernel/printk: Convert to hotplug state machine Install the callbacks via the state machine. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Cc: Andrew Morton Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161103145021.28528-3-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner --- include/linux/cpuhotplug.h | 1 + kernel/printk/printk.c | 29 +++++++++++++---------------- 2 files changed, 14 insertions(+), 16 deletions(-) diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 69b74fa..4174083 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -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, diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index de08fc9..4487ffc 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -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) -{ - switch (action) { - case CPU_ONLINE: - case CPU_DEAD: - case CPU_DOWN_FAILED: - case CPU_UP_CANCELED: - console_lock(); - console_unlock(); - } - return NOTIFY_OK; +static int console_cpu_notify(unsigned int cpu) +{ + 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); -- 2.7.4