From: Thomas Gleixner 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 Signed-off-by: Ingo Molnar Cc: Andi Kleen Cc: Zachary Amsden Cc: "Eric W. Biederman" Cc: Rohit Seth Signed-off-by: Andrew Morton --- arch/i386/kernel/nmi.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) Index: linux-2.6.20-rc4-mm1-bo/arch/i386/kernel/nmi.c =================================================================== --- linux-2.6.20-rc4-mm1-bo.orig/arch/i386/kernel/nmi.c +++ linux-2.6.20-rc4-mm1-bo/arch/i386/kernel/nmi.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -971,9 +972,13 @@ __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 ... -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/