From 407984f1af259b31957c7c05075a454a751bb801 Mon Sep 17 00:00:00 2001 From: Don Zickus Date: Tue, 26 Sep 2006 10:52:27 +0200 Subject: [PATCH] x86: Add abilty to enable/disable nmi watchdog with sysctl Adds a new /proc/sys/kernel/nmi call that will enable/disable the nmi watchdog. Signed-off-by: Don Zickus Signed-off-by: Andi Kleen --- arch/i386/kernel/nmi.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) (limited to 'arch/i386/kernel/nmi.c') diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c index acd3fdea2a2..28065d0b71a 100644 --- a/arch/i386/kernel/nmi.c +++ b/arch/i386/kernel/nmi.c @@ -846,6 +846,58 @@ static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu) return 0; } +/* + * proc handler for /proc/sys/kernel/nmi_watchdog + */ +int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file, + void __user *buffer, size_t *length, loff_t *ppos) +{ + int old_state; + + nmi_watchdog_enabled = (atomic_read(&nmi_active) > 0) ? 1 : 0; + old_state = nmi_watchdog_enabled; + proc_dointvec(table, write, file, buffer, length, ppos); + if (!!old_state == !!nmi_watchdog_enabled) + return 0; + + if (atomic_read(&nmi_active) < 0) { + printk(KERN_WARNING "NMI watchdog is permanently disabled\n"); + return -EINVAL; + } + + if (nmi_watchdog == NMI_DEFAULT) { + if (nmi_known_cpu() > 0) + nmi_watchdog = NMI_LOCAL_APIC; + else + nmi_watchdog = NMI_IO_APIC; + } + + if (nmi_watchdog == NMI_LOCAL_APIC) + { + if (nmi_watchdog_enabled) + enable_lapic_nmi_watchdog(); + else + disable_lapic_nmi_watchdog(); + } else if (nmi_watchdog == NMI_IO_APIC) { + /* FIXME + * for some reason these functions don't work + */ + printk("Can not enable/disable NMI on IO APIC\n"); + return -EINVAL; +#if 0 + if (nmi_watchdog_enabled) + enable_timer_nmi_watchdog(); + else + disable_timer_nmi_watchdog(); +#endif + } else { + printk( KERN_WARNING + "NMI watchdog doesn't know what hardware to touch\n"); + return -EIO; + } + return 0; +} + #endif EXPORT_SYMBOL(nmi_active); -- cgit v1.2.3