Re: [patch, -rc5-mm1] lock validator: disable NMI watchdog if CONFIG_LOCKDEP, i386

Ingo Molnar
2006-05-30T20:04:50Z

* Ingo Molnar <mingo@elte.hu> wrote:

> yeah, totally agreed, they need to be raw notifiers. Havent had time
> to investigate it in detail yet - i went for the easier hack of
> disabling NMIs while lockdep is enabled.

hm ... atomic_notifier_call_chain ought to be fine - it uses
rcu_read_lock(), which uses preempt_disable(), which is NMI-safe.

so i think this NMI problem might be lockdep-specific. I think it might
be the NMI iret that confuses lockdep. (and irqflags-trace in
particular)

Ingo