x86, NMI watchdog: add support to enable and disable IOAPIC NMI
Impact: change/improve the way /proc/sys/kernel/nmi_watchdog works
This patch adds support to enable/disable IOAPIC NMI watchdog in runtime via
procfs.
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 2c97f07..2c005fa 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -340,6 +340,8 @@
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 @@
#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 @@
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");