Re: NMI watchdog + NOHZ question

From: Andi Kleen
Date: Mon Jun 22 2009 - 04:19:00 EST


David Miller <davem@xxxxxxxxxxxxx> writes:
>
> Is there something fundamental that should be preventing this?

Unless that changed recently when I wasn't looking NOHZ should only
stop timers when the CPU is idle. So when a driver is doing
something and the interrupts are not disabled for too long the timers
should be ticking.

Then when you're idle interrupts should be never off, so the NMI
watchdog cannot fire. On x86 often the NMI watchdog is in fact
stopped on idle.

-Andi
--
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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