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>
This commit is contained in:
Sebastian Andrzej Siewior 2016-08-18 14:57:21 +02:00 committed by Thomas Gleixner
parent 1d7ac6aec9
commit c4544dbc7a
2 changed files with 7 additions and 21 deletions

View file

@ -17,6 +17,7 @@ enum cpuhp_state {
CPUHP_VIRT_NET_DEAD,
CPUHP_SLUB_DEAD,
CPUHP_MM_WRITEBACK_DEAD,
CPUHP_SOFTIRQ_DEAD,
CPUHP_WORKQUEUE_PREP,
CPUHP_POWER_NUMA_PREPARE,
CPUHP_HRTIMERS_PREPARE,

View file

@ -700,7 +700,7 @@ void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu)
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 @@ static void takeover_tasklets(unsigned int cpu)
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 struct smp_hotplug_thread softirq_threads = {
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;