kernel/softirq: Convert to hotplug state machine
Install the callbacks via the state machine.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160818125731.27256-7-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 17caf4b..c372114 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -700,7 +700,7 @@
BUG();
}
-static void takeover_tasklets(unsigned int cpu)
+static int takeover_tasklets(unsigned int cpu)
{
/* CPU is dead, so no lock needed. */
local_irq_disable();
@@ -723,27 +723,12 @@
raise_softirq_irqoff(HI_SOFTIRQ);
local_irq_enable();
+ return 0;
}
+#else
+#define takeover_tasklets NULL
#endif /* CONFIG_HOTPLUG_CPU */
-static int cpu_callback(struct notifier_block *nfb, unsigned long action,
- void *hcpu)
-{
- switch (action) {
-#ifdef CONFIG_HOTPLUG_CPU
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- takeover_tasklets((unsigned long)hcpu);
- break;
-#endif /* CONFIG_HOTPLUG_CPU */
- }
- return NOTIFY_OK;
-}
-
-static struct notifier_block cpu_nfb = {
- .notifier_call = cpu_callback
-};
-
static struct smp_hotplug_thread softirq_threads = {
.store = &ksoftirqd,
.thread_should_run = ksoftirqd_should_run,
@@ -753,8 +738,8 @@
static __init int spawn_ksoftirqd(void)
{
- register_cpu_notifier(&cpu_nfb);
-
+ cpuhp_setup_state_nocalls(CPUHP_SOFTIRQ_DEAD, "softirq:dead", NULL,
+ takeover_tasklets);
BUG_ON(smpboot_register_percpu_thread(&softirq_threads));
return 0;
