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

From: Keith Owens
Date: Wed May 31 2006 - 00:34:21 EST


Ingo Molnar (on Tue, 30 May 2006 14:29:50 +0200) wrote:
>
>* Mike Galbraith <efault@xxxxxx> wrote:
>
>> > > BUG: warning at kernel/lockdep.c:2398/check_flags()
>> >
>> > this one could be related to NMI. We are already disabling NMI on
>> > x86_64, but i thought i had it fixed up for i386 - apparently not.
>>
>> Booted with nmi_watchdog=0, no warning and no deadlock.
>
>ok, great. The patch below turns off NMI on i386 automatically.
>
>-------------------
>Subject: lock validator: disable NMI watchdog if CONFIG_LOCKDEP, i386
>From: Ingo Molnar <mingo@xxxxxxx>
>
>The NMI watchdog uses spinlocks (notifier chains, etc.),
>so it's not lockdep-safe at the moment.

Where? Since 2.6.17-rc1 the notify_die() callback uses RCU, not
spinlocks.

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