Re: NOHZ: WARNING: at arch/x86/kernel/smp.c:123native_smp_send_reschedule

From: Frederic Weisbecker
Date: Fri May 10 2013 - 11:31:58 EST


On Fri, May 10, 2013 at 11:45:56AM +0200, Borislav Petkov wrote:
> On Fri, May 10, 2013 at 11:37:29AM +0200, Ingo Molnar wrote:
> > The pattern I use in such cases is:
> >
> > if (WARN_ONCE(!cpu_online(cpu))) {
> > printk("%d %d\n", cpu, smp_processor_id());
> > dump_stack();
> > }
>
> Cool, and WARN_ONCE dumps stack already so:
>
> if (WARN_ONCE(!cpu_online(cpu)))
> printk("%d %d\n", cpu, smp_processor_id());

Even better:

if (WARN_ONCE(!cpu_online(cpu)))
printk_once("%d %d\n", cpu, smp_processor_id());

So the printk doesn't flood after the first case.

>
> Nice.
>
> --
> Regards/Gruss,
> Boris.
>
> Sent from a fat crate under my desk. Formatting is fine.
> --
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