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Date: Sat, 6 Jul 2013 00:21:48 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Seiji Aguchi <seiji.aguchi@hds.com>
cc: "H. Peter Anvin" <hpa@zytor.com>, Dave Jones <davej@redhat.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Linux Kernel <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@kernel.org>, Peter Zijlstra <peterz@infradead.org>
Subject: RE: Yet more softlockups.
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On Fri, 5 Jul 2013, Seiji Aguchi wrote:
> > -----Original Message-----
> > Hmmm... this makes me wonder if the interrupt tracepoint stuff is at
> > fault here, as it changes the IDT handling for NMI context.
> 
> This softlockup happens while disabling the interrupt tracepoints,
> Because if it is enabled, "smp_trace_apic_timer_interrupt" is displayed
> instead of "smp_apic_timer_interrupt" in the call trace below.
> 
> But I can't say anything how this issue is related to the tracepoint stuff,

I doubt it is related. I rather suspect that trinity is able to fuzz
perf into a DoS facility.

Dave, can you trace the perf sys calls and dump that data over serial
when the softlockup hits?

Thanks,

	tglx