Date: Wed, 4 Aug 2010 09:54:17 -0400
From: Don Zickus <dzickus@redhat.com>
To: Lin Ming <ming.m.lin@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>, Peter Zijlstra <peterz@infradead.org>,
        Cyrill Gorcunov <gorcunov@gmail.com>, robert.richter@amd.com,
        fweisbec@gmail.com, linux-kernel@vger.kernel.org,
        "Huang, Ying" <ying.huang@intel.com>
Subject: Re: A question of perf NMI handler
Message-ID: <20100804135417.GM3353@redhat.com>
References: <1280913670.20797.179.camel@minggr.sh.intel.com>
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On Wed, Aug 04, 2010 at 05:21:10PM +0800, Lin Ming wrote:
> With nmi_watchdog enabled, perf_event_nmi_handler always return
> NOTIFY_STOP(active_events > 0), and the notifier call chain will not
> call further.
> 
> If it was not perf NMI, does the perf nmi handler may stop the real NMI
> handler get called because NOTIFY_STOP is returned??

Yes I sent a cheap and dirty patch to address this a couple of weeks ago

http://lkml.indiana.edu/hypermail//linux/kernel/1007.2/02590.html

Unfortunately, no responded. :-(  Of course, it could have been so gross
no one wanted to comment on it. :-)

Cheers,
Don
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