+ dynticks-i386-prepare-nmi-watchdog.patch added to -mm tree

+ dynticks-i386-prepare-nmi-watchdog.patch added to -mm tree

[akpm]

The patch titled
     dynticks: i386, prepare NMI watchdog
has been added to the -mm tree.  Its filename is
     dynticks-i386-prepare-nmi-watchdog.patch

See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this

------------------------------------------------------
Subject: dynticks: i386, prepare NMI watchdog
From: Thomas Gleixner <tglx@linutronix.de>

The NMI watchdog implementation assumes that the local APIC timer
interrupt is happening.  This assumption is not longer true when high
resolution timers and dynamic ticks come into play, as they may switch
off the local APIC timer completely.  Take the PIT/HPET interrupts into
account too, to avoid false positives.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Cc: Zachary Amsden <zach@vmware.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rohit Seth <rohitseth@google.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 arch/i386/kernel/nmi.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff -puN arch/i386/kernel/nmi.c~dynticks-i386-prepare-nmi-watchdog arch/i386/kernel/nmi.c
--- a/arch/i386/kernel/nmi.c~dynticks-i386-prepare-nmi-watchdog
+++ a/arch/i386/kernel/nmi.c
@@ -23,6 +23,7 @@
 #include <linux/dmi.h>
 #include <linux/kprobes.h>
 #include <linux/cpumask.h>
+#include <linux/kernel_stat.h>
 
 #include <asm/smp.h>
 #include <asm/nmi.h>
@@ -950,9 +951,13 @@ __kprobes int nmi_watchdog_tick(struct p
 		cpu_clear(cpu, backtrace_mask);
 	}
 
-	sum = per_cpu(irq_stat, cpu).apic_timer_irqs;
+	/*
+	 * Take the local apic timer and PIT/HPET into account. We don't
+	 * know which one is active, when we have highres/dyntick on
+	 */
+	sum = per_cpu(irq_stat, cpu).apic_timer_irqs + kstat_irqs(0);
 
-	/* if the apic timer isn't firing, this cpu isn't doing much */
+	/* if the none of the timers isn't firing, this cpu isn't doing much */
 	if (!touched && last_irq_sums[cpu] == sum) {
 		/*
 		 * Ayiee, looks like this CPU is stuck ...
_

Patches currently in -mm which might be from tglx@linutronix.de are

origin.patch
git-mtd.patch
gtod-uninline-jiffiesh.patch
gtod-fix-multiple-conversion-bugs-in-msecs_to_jiffies.patch
gtod-fix-timeout-overflow.patch
gtod-persistent-clock-support-core.patch
gtod-persistent-clock-support-i386.patch
dynticks-uninline-irq_enter.patch
dynticks-extend-next_timer_interrupt-to-use-a-reference-jiffie.patch
hrtimers-namespace-and-enum-cleanup.patch
hrtimers-clean-up-locking.patch
hrtimers-add-state-tracking.patch
hrtimers-clean-up-callback-tracking.patch
hrtimers-move-and-add-documentation.patch
acpi-include-fix.patch
acpi-keep-track-of-timer-broadcast.patch
acpi-add-state-propagation-for-dynamic-broadcasting.patch
acpi-cleanups-allow-early-access-to-pmtimer.patch
i386-apic-clean-up-the-apic-code.patch
clockevents-core.patch
clockevents-i386-drivers.patch
clockevents-i386-hpet-driver.patch
i386-apic-rework-and-fix-local-apic-calibration.patch
high-res-timers-core.patch
high-res-timers-core-do-itimer-rearming-in-process-context.patch
high-res-timers-allow-tsc-clocksource-if-pmtimer-present.patch
dynticks-core.patch
dynticks-add-nohz-stats-to-proc-stat.patch
dynticks-i386-support-idle-handler-callbacks.patch
dynticks-i386-prepare-nmi-watchdog.patch
high-res-timers-dynticks-i386-support-enable-in-kconfig.patch
debugging-feature-add-proc-timer_stat.patch