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authorThomas Gleixner <tglx@linutronix.de>2007-02-16 01:28:09 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-02-16 08:13:59 -0800
commitf8b5035b9abd01b52ec6416f0c6bade7e603742c (patch)
tree59b35b073cbd75c979aa7ec61a923d60ba4030c4 /arch
parent741673473a5b26497d5390f38d478362e27e22ad (diff)
downloadop-kernel-dev-f8b5035b9abd01b52ec6416f0c6bade7e603742c.zip
op-kernel-dev-f8b5035b9abd01b52ec6416f0c6bade7e603742c.tar.gz
[PATCH] i386 prepare nmi watchdog for dynticks
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> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/i386/kernel/nmi.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
index 5d8a07c..821df34 100644
--- a/arch/i386/kernel/nmi.c
+++ b/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>
@@ -973,9 +974,13 @@ __kprobes int nmi_watchdog_tick(struct pt_regs * regs, unsigned reason)
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 ...
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