This patch adds support to enable/disable IOAPIC NMI watchdog in runtime via
procfs.
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
---
arch/x86/kernel/nmi.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
--- linus-2.6.orig/arch/x86/kernel/nmi.c 2008-10-27 11:31:56.000000000 -0400
+++ linus-2.6/arch/x86/kernel/nmi.c 2008-10-27 11:43:49.000000000 -0400
@@ -340,6 +340,8 @@ void stop_apic_nmi_watchdog(void *unused
return;
if (nmi_watchdog == NMI_LOCAL_APIC)
lapic_watchdog_stop();
+ else
+ __acpi_nmi_disable(NULL);
__get_cpu_var(wd_enabled) = 0;
atomic_dec(&nmi_active);
}
@@ -465,6 +467,24 @@ nmi_watchdog_tick(struct pt_regs *regs,
#ifdef CONFIG_SYSCTL
+static void enable_ioapic_nmi_watchdog_single(void *unused)
+{
+ __get_cpu_var(wd_enabled) = 1;
+ atomic_inc(&nmi_active);
+ __acpi_nmi_enable(NULL);
+}
+
+static void enable_ioapic_nmi_watchdog(void)
+{
+ on_each_cpu(enable_ioapic_nmi_watchdog_single, NULL, 1);
+ touch_nmi_watchdog();
+}
+
+static void disable_ioapic_nmi_watchdog(void)
+{
+ on_each_cpu(stop_apic_nmi_watchdog, NULL, 1);
+}
+
static int __init setup_unknown_nmi_panic(char *str)
{
unknown_nmi_panic = 1;
@@ -507,6 +527,11 @@ int proc_nmi_enabled(struct ctl_table *t
enable_lapic_nmi_watchdog();
else
disable_lapic_nmi_watchdog();
+ } else if (nmi_watchdog == NMI_IO_APIC) {
+ if (nmi_watchdog_enabled)
+ enable_ioapic_nmi_watchdog();
+ else
+ disable_ioapic_nmi_watchdog();
} else {
printk(KERN_WARNING
"NMI watchdog doesn't know what hardware to touch\n");
--
Aristeu
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