Re: 2.6.19-rc2-mm1

Andi Kleen
2006-10-19T12:32:21Z

Andrew Morton <akpm@osdl.org> writes:

> On Wed, 18 Oct 2006 16:01:05 -0700
> Badari Pulavarty <pbadari@us.ibm.com> wrote:
>
> > > Is the NMI watchdog ticking over?
> >
> > I think so.
> >
> > # dmesg | grep NMI
> > ACPI: LAPIC_NMI (acpi_id[0x00] high edge lint[0x1])
> > ACPI: LAPIC_NMI (acpi_id[0x01] high edge lint[0x1])
> > ACPI: LAPIC_NMI (acpi_id[0x02] high edge lint[0x1])
> > ACPI: LAPIC_NMI (acpi_id[0x03] high edge lint[0x1])
> > testing NMI watchdog ... OK.
>
>
> What does it say in /proc/interrupts?
>
> The x86_64 nmi watchdog handling looks rather complex.
>
> <checks a couple of x86-64 machines>
>
> The /proc/interrutps NMI count seems to be going up by about
> one-per-minute. How odd. Maybe you just need to wait longer.

That's consistent with a idle machine. The perfctr used by the nmi
watchdog only increases when the CPU isn't halted and when it's idle
it's not doing very much. When something actually loops it should
increase much faster though.

-Andi