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Commit 6f290b4e authored by Aristeu Rozanski's avatar Aristeu Rozanski Committed by Ingo Molnar
Browse files

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: default avatarAristeu Rozanski <aris@redhat.com>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent f8d56f17

arch/x86/kernel/nmi.c

+25 −0
Original line number Diff line number Diff line
@@ -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, unsigned reason) 


#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 *table, int write, struct file *file, 
			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");