From 6f290b4e016d6c61511542cf6d9ebdef1965978e Mon Sep 17 00:00:00 2001 From: Aristeu Rozanski Date: Mon, 27 Oct 2008 12:42:34 -0400 Subject: [PATCH] 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 Cc: "Maciej W. Rozycki" Signed-off-by: Ingo Molnar --- arch/x86/kernel/nmi.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c index 2c97f07f1c2c..2c005fac6171 100644 --- a/arch/x86/kernel/nmi.c +++ b/arch/x86/kernel/nmi.c @@ -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");