lockup_detector: Remove nmi_watchdog.c file

This file migrated to kernel/watchdog.c and then combined with
kernel/softlockup.c.  As a result kernel/nmi_watchdog.c is no longer
needed.  Just remove it.
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
LKML-Reference: <1273266711-18706-5-git-send-email-dzickus@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

kernel/nmi_watchdog.c

-/*
- * Detect Hard Lockups using the NMI
- *
- * started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
- *
- * this code detects hard lockups: incidents in where on a CPU
- * the kernel does not respond to anything except NMI.
- *
- * Note: Most of this code is borrowed heavily from softlockup.c,
- * so thanks to Ingo for the initial implementation.
- * Some chunks also taken from arch/x86/kernel/apic/nmi.c, thanks
- * to those contributors as well.
- */
-
-#include <linux/mm.h>
-#include <linux/cpu.h>
-#include <linux/nmi.h>
-#include <linux/init.h>
-#include <linux/delay.h>
-#include <linux/freezer.h>
-#include <linux/lockdep.h>
-#include <linux/notifier.h>
-#include <linux/module.h>
-#include <linux/sysctl.h>
-
-#include <asm/irq_regs.h>
-#include <linux/perf_event.h>
-
-static DEFINE_PER_CPU(struct perf_event *, nmi_watchdog_ev);
-static DEFINE_PER_CPU(int, nmi_watchdog_touch);
-static DEFINE_PER_CPU(long, alert_counter);
-
-static int panic_on_timeout;
-
-void touch_nmi_watchdog(void)
-{
-	__raw_get_cpu_var(nmi_watchdog_touch) = 1;
-	touch_softlockup_watchdog();
-}
-EXPORT_SYMBOL(touch_nmi_watchdog);
-
-void touch_all_nmi_watchdog(void)
-{
-	int cpu;
-
-	for_each_online_cpu(cpu)
-		per_cpu(nmi_watchdog_touch, cpu) = 1;
-	touch_softlockup_watchdog();
-}
-
-static int __init setup_nmi_watchdog(char *str)
-{
-	if (!strncmp(str, "panic", 5)) {
-		panic_on_timeout = 1;
-		str = strchr(str, ',');
-		if (!str)
-			return 1;
-		++str;
-	}
-	return 1;
-}
-__setup("nmi_watchdog=", setup_nmi_watchdog);
-
-struct perf_event_attr wd_hw_attr = {
-	.type		= PERF_TYPE_HARDWARE,
-	.config		= PERF_COUNT_HW_CPU_CYCLES,
-	.size		= sizeof(struct perf_event_attr),
-	.pinned		= 1,
-	.disabled	= 1,
-};
-
-struct perf_event_attr wd_sw_attr = {
-	.type		= PERF_TYPE_SOFTWARE,
-	.config		= PERF_COUNT_SW_CPU_CLOCK,
-	.size		= sizeof(struct perf_event_attr),
-	.pinned		= 1,
-	.disabled	= 1,
-};
-
-void wd_overflow(struct perf_event *event, int nmi,
-		 struct perf_sample_data *data,
-		 struct pt_regs *regs)
-{
-	int cpu = smp_processor_id();
-	int touched = 0;
-
-	if (__get_cpu_var(nmi_watchdog_touch)) {
-		per_cpu(nmi_watchdog_touch, cpu) = 0;
-		touched = 1;
-	}
-
-	/* check to see if the cpu is doing anything */
-	if (!touched && hw_nmi_is_cpu_stuck(regs)) {
-		/*
-		 * Ayiee, looks like this CPU is stuck ...
-		 * wait a few IRQs (5 seconds) before doing the oops ...
-		 */
-		per_cpu(alert_counter, cpu) += 1;
-		if (per_cpu(alert_counter, cpu) == 5) {
-			if (panic_on_timeout)
-				panic("NMI Watchdog detected LOCKUP on cpu %d", cpu);
-			else
-				WARN(1, "NMI Watchdog detected LOCKUP on cpu %d", cpu);
-		}
-	} else {
-		per_cpu(alert_counter, cpu) = 0;
-	}
-
-	return;
-}
-
-static int enable_nmi_watchdog(int cpu)
-{
-	struct perf_event *event;
-	struct perf_event_attr *wd_attr;
-
-	event = per_cpu(nmi_watchdog_ev, cpu);
-	if (event && event->state > PERF_EVENT_STATE_OFF)
-		return 0;
-
-	if (event == NULL) {
-		/* Try to register using hardware perf events first */
-		wd_attr = &wd_hw_attr;
-		wd_attr->sample_period = hw_nmi_get_sample_period();
-		event = perf_event_create_kernel_counter(wd_attr, cpu, -1, wd_overflow);
-		if (IS_ERR(event)) {
-			/* hardware doesn't exist or not supported, fallback to software events */
-			printk(KERN_INFO "nmi_watchdog: hardware not available, trying software events\n");
-			wd_attr = &wd_sw_attr;
-			wd_attr->sample_period = NSEC_PER_SEC;
-			event = perf_event_create_kernel_counter(wd_attr, cpu, -1, wd_overflow);
-			if (IS_ERR(event)) {
-				printk(KERN_ERR "nmi watchdog failed to create perf event on %i: %p\n", cpu, event);
-				return -1;
-			}
-		}
-		per_cpu(nmi_watchdog_ev, cpu) = event;
-	}
-	perf_event_enable(per_cpu(nmi_watchdog_ev, cpu));
-	return 0;
-}
-
-static void disable_nmi_watchdog(int cpu)
-{
-	struct perf_event *event;
-
-	event = per_cpu(nmi_watchdog_ev, cpu);
-	if (event) {
-		perf_event_disable(per_cpu(nmi_watchdog_ev, cpu));
-		per_cpu(nmi_watchdog_ev, cpu) = NULL;
-		perf_event_release_kernel(event);
-	}
-}
-
-#ifdef CONFIG_SYSCTL
-/*
- * proc handler for /proc/sys/kernel/nmi_watchdog
- */
-int nmi_watchdog_enabled;
-
-int proc_nmi_enabled(struct ctl_table *table, int write,
-		     void __user *buffer, size_t *length, loff_t *ppos)
-{
-	int cpu;
-
-	if (!write) {
-		struct perf_event *event;
-		for_each_online_cpu(cpu) {
-			event = per_cpu(nmi_watchdog_ev, cpu);
-			if (event && event->state > PERF_EVENT_STATE_OFF) {
-				nmi_watchdog_enabled = 1;
-				break;
-			}
-		}
-		proc_dointvec(table, write, buffer, length, ppos);
-		return 0;
-	}
-
-	touch_all_nmi_watchdog();
-	proc_dointvec(table, write, buffer, length, ppos);
-	if (nmi_watchdog_enabled) {
-		for_each_online_cpu(cpu)
-			if (enable_nmi_watchdog(cpu)) {
-				printk(KERN_ERR "NMI watchdog failed configuration, "
-					" can not be enabled\n");
-			}
-	} else {
-		for_each_online_cpu(cpu)
-			disable_nmi_watchdog(cpu);
-	}
-	return 0;
-}
-
-#endif /* CONFIG_SYSCTL */
-
-/*
- * Create/destroy watchdog threads as CPUs come and go:
- */
-static int __cpuinit
-cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
-{
-	int hotcpu = (unsigned long)hcpu;
-
-	switch (action) {
-	case CPU_UP_PREPARE:
-	case CPU_UP_PREPARE_FROZEN:
-		per_cpu(nmi_watchdog_touch, hotcpu) = 0;
-		break;
-	case CPU_ONLINE:
-	case CPU_ONLINE_FROZEN:
-		if (enable_nmi_watchdog(hotcpu))
-			return NOTIFY_BAD;
-		break;
-#ifdef CONFIG_HOTPLUG_CPU
-	case CPU_UP_CANCELED:
-	case CPU_UP_CANCELED_FROZEN:
-		disable_nmi_watchdog(hotcpu);
-	case CPU_DEAD:
-	case CPU_DEAD_FROZEN:
-		break;
-#endif /* CONFIG_HOTPLUG_CPU */
-	}
-	return NOTIFY_OK;
-}
-
-static struct notifier_block __cpuinitdata cpu_nfb = {
-	.notifier_call = cpu_callback
-};
-
-static int __initdata nonmi_watchdog;
-
-static int __init nonmi_watchdog_setup(char *str)
-{
-	nonmi_watchdog = 1;
-	return 1;
-}
-__setup("nonmi_watchdog", nonmi_watchdog_setup);
-
-static int __init spawn_nmi_watchdog_task(void)
-{
-	void *cpu = (void *)(long)smp_processor_id();
-	int err;
-
-	if (nonmi_watchdog)
-		return 0;
-
-	printk(KERN_INFO "NMI watchdog enabled, takes one hw-pmu counter.\n");
-
-	err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu);
-	if (err == NOTIFY_BAD) {
-		BUG();
-		return 1;
-	}
-	cpu_callback(&cpu_nfb, CPU_ONLINE, cpu);
-	register_cpu_notifier(&cpu_nfb);
-
-	return 0;
-}
-early_initcall(spawn_nmi_watchdog_task);