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Message-ID: <17540.32930.566897.960413@domain.hid>
Date: Mon, 5 Jun 2006 21:06:10 +0200
Subject: Re: [Xenomai-core] nervous nmi-watchdog
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From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
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	discussions\)" <xenomai.xenomai.org>
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To: Philippe Gerum <rpm@xenomai.org>
Cc: Jan Kiszka <jan.kiszka@domain.hid>, xenomai-core <xenomai@xenomai.org>

Philippe Gerum wrote:
 > Jan Kiszka wrote:
 > > Hi,
 > > 
 > > I'm getting nmi alarms about latency being > 100 us on a dual P-III 1GHz
 > > (with and without CONFIG_SMP) once I start the latency test tool. But
 > > the must be false positive. Can someone comment on this trace:
 > > 
 > 
 > Issue confirmed here, on a dual 750 Mhz PIII Celeron. Starting the 
 > latency test, the NMI watchdog pulls the break on cpu #0 after a few us, 
 > albeit rthal_nmi_arm() had been told to trigger the NMI more than a 
 > millisecond in the future (likely the HTICK emulation + 100 us NMI 
 > threshold).
 > 
 > Running a UP + LAPIC enabled kernel on the same hw did not trigger the 
 > spurious NMI, so I'd bet that the issue is SMP related, and not 
 > hw/perfctr related.

I never observe this on my dual PIII whereas I always have the NMI
watchdog option enabled. Are you running with or without the tracer ?

-- 


					    Gilles Chanteperdrix.