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Commit 504d7cf1 authored by Don Zickus's avatar Don Zickus Committed by Ingo Molnar
Browse files

nmi_watchdog: Compile and portability fixes 



The original patch was x86_64 centric.  Changed the code to make
it less so.

ested by building and running on a powerpc.

Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
Cc: peterz@infradead.org
Cc: gorcunov@gmail.com
Cc: aris@redhat.com
LKML-Reference: <1266013161-31197-2-git-send-email-dzickus@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent c3128fb6

arch/x86/include/asm/nmi.h

+2 −0
Original line number Diff line number Diff line
@@ -17,7 +17,9 @@ int do_nmi_callback(struct pt_regs *regs, int cpu); 


extern void die_nmi(char *str, struct pt_regs *regs, int do_panic);

extern int check_nmi_watchdog(void);

#if !defined(CONFIG_NMI_WATCHDOG)

extern int nmi_watchdog_enabled;

#endif

extern int avail_to_resrv_perfctr_nmi_bit(unsigned int);

extern int reserve_perfctr_nmi(unsigned int);

extern void release_perfctr_nmi(unsigned int);

arch/x86/kernel/apic/hw_nmi.c

+16 −5
Original line number Diff line number Diff line
@@ -32,8 +32,13 @@ static DEFINE_PER_CPU(unsigned, last_irq_sum); 
 */

static inline unsigned int get_timer_irqs(int cpu)

{

        return per_cpu(irq_stat, cpu).apic_timer_irqs +

                per_cpu(irq_stat, cpu).irq0_irqs;

	unsigned int irqs = per_cpu(irq_stat, cpu).irq0_irqs;



#if defined(CONFIG_X86_LOCAL_APIC)

	irqs += per_cpu(irq_stat, cpu).apic_timer_irqs;

#endif



        return irqs;

}



static inline int mce_in_progress(void)
@@ -82,6 +87,11 @@ int hw_nmi_is_cpu_stuck(struct pt_regs *regs) 
	}

}



u64 hw_nmi_get_sample_period(void)

{

        return cpu_khz * 1000;

}



void arch_trigger_all_cpu_backtrace(void)

{

	int i;
@@ -100,15 +110,16 @@ void arch_trigger_all_cpu_backtrace(void) 
}



/* STUB calls to mimic old nmi_watchdog behaviour */

#if defined(CONFIG_X86_LOCAL_APIC)

unsigned int nmi_watchdog = NMI_NONE;

EXPORT_SYMBOL(nmi_watchdog);

void acpi_nmi_enable(void) { return; }

void acpi_nmi_disable(void) { return; }

#endif

atomic_t nmi_active = ATOMIC_INIT(0);           /* oprofile uses this */

EXPORT_SYMBOL(nmi_active);

int nmi_watchdog_enabled;

int unknown_nmi_panic;

void cpu_nmi_set_wd_enabled(void) { return; }

void acpi_nmi_enable(void) { return; }

void acpi_nmi_disable(void) { return; }

void stop_apic_nmi_watchdog(void *unused) { return; }

void setup_apic_nmi_watchdog(void *unused) { return; }

int __init check_nmi_watchdog(void) { return 0; }

include/linux/nmi.h

+9 −0
Original line number Diff line number Diff line
@@ -20,10 +20,14 @@ extern void touch_nmi_watchdog(void); 
extern void acpi_nmi_disable(void);

extern void acpi_nmi_enable(void);

#else

#ifndef CONFIG_NMI_WATCHDOG

static inline void touch_nmi_watchdog(void)

{

	touch_softlockup_watchdog();

}

#else

extern void touch_nmi_watchdog(void);

#endif

static inline void acpi_nmi_disable(void) { }

static inline void acpi_nmi_enable(void) { }

#endif
@@ -49,6 +53,11 @@ static inline bool trigger_all_cpu_backtrace(void) 


#ifdef CONFIG_NMI_WATCHDOG

int hw_nmi_is_cpu_stuck(struct pt_regs *);

u64 hw_nmi_get_sample_period(void);

extern int nmi_watchdog_enabled;

struct ctl_table;

extern int proc_nmi_enabled(struct ctl_table *, int ,

                        void __user *, size_t *, loff_t *);

#endif



#endif

kernel/nmi_watchdog.c

+41 −11
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ 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;
@@ -46,19 +48,49 @@ void touch_all_nmi_watchdog(void) 
	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);



#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 (per_cpu(nmi_watchdog_ev, smp_processor_id()) == NULL)

		nmi_watchdog_enabled = 0;

	else

	if (!write) {

		struct perf_event *event;

		for_each_online_cpu(cpu) {

			event = per_cpu(nmi_watchdog_ev, cpu);

			if (event->state > PERF_EVENT_STATE_OFF) {

				nmi_watchdog_enabled = 1;

				break;

			}

		}

		proc_dointvec(table, write, buffer, length, ppos);

		return 0;

	}



	if (per_cpu(nmi_watchdog_ev, smp_processor_id()) == NULL) {

		nmi_watchdog_enabled = 0;

		proc_dointvec(table, write, buffer, length, ppos);

		printk("NMI watchdog failed configuration, can not be enabled\n");

		return 0;

	}



	touch_all_nmi_watchdog();

	proc_dointvec(table, write, buffer, length, ppos);
@@ -81,8 +113,6 @@ struct perf_event_attr wd_attr = { 
	.disabled = 1,

};



static int panic_on_timeout;



void wd_overflow(struct perf_event *event, int nmi,

		 struct perf_sample_data *data,

		 struct pt_regs *regs)
@@ -103,11 +133,11 @@ void wd_overflow(struct perf_event *event, int nmi, 
		 */

		per_cpu(alert_counter,cpu) += 1;

		if (per_cpu(alert_counter,cpu) == 5) {

			/*

			 * die_nmi will return ONLY if NOTIFY_STOP happens..

			 */

			die_nmi("BUG: NMI Watchdog detected LOCKUP",

				regs, panic_on_timeout);

			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;
@@ -133,7 +163,7 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) 
	case CPU_ONLINE:

	case CPU_ONLINE_FROZEN:

		/* originally wanted the below chunk to be in CPU_UP_PREPARE, but caps is unpriv for non-CPU0 */

		wd_attr.sample_period = cpu_khz * 1000;

		wd_attr.sample_period = hw_nmi_get_sample_period();

		event = perf_event_create_kernel_counter(&wd_attr, hotcpu, -1, wd_overflow);

		if (IS_ERR(event)) {

			printk(KERN_ERR "nmi watchdog failed to create perf event on %i: %p\n", hotcpu, event);

kernel/sysctl.c

+14 −1
Original line number Diff line number Diff line
@@ -60,6 +60,10 @@ 
#include <asm/io.h>

#endif



#ifdef CONFIG_NMI_WATCHDOG

#include <linux/nmi.h>

#endif





#if defined(CONFIG_SYSCTL)
@@ -692,7 +696,16 @@ static struct ctl_table kern_table[] = { 
		.mode		= 0444,

		.proc_handler	= proc_dointvec,

	},

#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)

#if defined(CONFIG_NMI_WATCHDOG)

	{

		.procname       = "nmi_watchdog",

		.data           = &nmi_watchdog_enabled,

		.maxlen         = sizeof (int),

		.mode           = 0644,

		.proc_handler   = proc_nmi_enabled,

	},

#endif

#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) && !defined(CONFIG_NMI_WATCHDOG)

	{

		.procname       = "unknown_nmi_panic",

		.data           = &unknown_nmi_panic,