Re: [PATCH RFC] irq_work: Flush work on CPU_DYING (was: Re: [PATCH7/7] printk: Wake up klogd using irq_work)

From: Steven Rostedt
Date: Thu Nov 15 2012 - 13:16:10 EST


On Thu, 2012-11-15 at 13:13 -0500, Steven Rostedt wrote:

> > +
> > +/*
> > + * Run the irq_work entries on this cpu. Requires to be ran from hardirq
> > + * context with local IRQs disabled.
> > + */
> > +void irq_work_run(void)
> > +{
> > + BUG_ON(!in_irq());
> > + __irq_work_run();
> > +}
> > EXPORT_SYMBOL_GPL(irq_work_run);
>
> #ifdef CONFIG_HOTPLUG_CPU
> >
> > +static void irq_work_run_cpu_down(void)
> > +{
> > + __irq_work_run();
> > +}
> #endif
>
> Or just move the function into the #ifdef that is below.

Or even, just call __irq_work_run() directly.

>
> -- Steve
>
> > +
> > /*
> > * Synchronize against the irq_work @entry, ensures the entry is not
> > * currently in use.
> > @@ -169,3 +180,35 @@ void irq_work_sync(struct irq_work *work
> > cpu_relax();
> > }
> > EXPORT_SYMBOL_GPL(irq_work_sync);
> > +
> > +#ifdef CONFIG_HOTPLUG_CPU
> > +static int irq_work_cpu_notify(struct notifier_block *self,
> > + unsigned long action, void *hcpu)
> > +{
> > + long cpu = (long)hcpu;
> > +
> > + switch (action) {
> > + case CPU_DYING:
> > + /* Called from stop_machine */
> > + if (WARN_ON_ONCE(cpu != smp_processor_id()))
> > + break;
> > + irq_work_run_cpu_down();

__irq_work_run();

-- Steve

> > + break;
> > + default:
> > + break;
> > + }
> > + return NOTIFY_OK;
> > +}
> > +
> > +static struct notifier_block cpu_notify;
> > +
> > +static __init int irq_work_init_cpu_notifier(void)
> > +{
> > + cpu_notify.notifier_call = irq_work_cpu_notify;
> > + cpu_notify.priority = 0;
> > + register_cpu_notifier(&cpu_notify);
> > + return 0;
> > +}
> > +device_initcall(irq_work_init_cpu_notifier);
> > +
> > +#endif /* CONFIG_HOTPLUG_CPU */
> >
>


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