[PATCH 1/1] nmi_watchdog: x86_64 count timer and hpet like i386

["David Bahi" <dbahi@novell.com>]

This modifies nmi_watchdog_tick behavior for x86_64 arch to 
consider both timer and pit/hpet IRQs just as the i386 arch does.

Without this fix a kernel crash occurs very early in the boot 
process if nmi_watchdog is on.

Signed-off-by: David Bahi <dbahi@novell.com>

---
 arch/x86_64/kernel/nmi.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Index: linux-2.6.22.8-rt9_1267/arch/x86_64/kernel/nmi.c
===================================================================
--- linux-2.6.22.8-rt9_1267.orig/arch/x86_64/kernel/nmi.c
+++ linux-2.6.22.8-rt9_1267/arch/x86_64/kernel/nmi.c
@@ -369,8 +369,6 @@ int notrace __kprobes nmi_watchdog_tick(
                touched = 1;
        }
 
-       sum = read_pda(apic_timer_irqs);
-
        if (__get_cpu_var(nmi_touch)) {
                __get_cpu_var(nmi_touch) = 0;
                touched = 1;
@@ -386,6 +384,12 @@ int notrace __kprobes nmi_watchdog_tick(
                cpu_clear(cpu, backtrace_mask);
        }
 
+       /*
+        * 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 = read_pda(apic_timer_irqs) + kstat_cpu(cpu).irqs[0];
+
 #ifdef CONFIG_X86_MCE
        /* Could check oops_in_progress here too, but it's safer
           not too */

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