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Subject[tip:perf/nmi] nmi_watchdog: Compile and portability fixes
Commit-ID:  504d7cf10ee42bb76b9556859f23d4121dee0a77
Gitweb: http://git.kernel.org/tip/504d7cf10ee42bb76b9556859f23d4121dee0a77
Author: Don Zickus <dzickus@redhat.com>
AuthorDate: Fri, 12 Feb 2010 17:19:19 -0500
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Sun, 14 Feb 2010 09:19:43 +0100

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: Don 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: Ingo Molnar <mingo@elte.hu>
---
arch/x86/include/asm/nmi.h | 2 +
arch/x86/kernel/apic/hw_nmi.c | 21 ++++++++++++----
include/linux/nmi.h | 9 +++++++
kernel/nmi_watchdog.c | 52 ++++++++++++++++++++++++++++++++--------
kernel/sysctl.c | 15 +++++++++++-
5 files changed, 82 insertions(+), 17 deletions(-)
diff --git a/arch/x86/include/asm/nmi.h b/arch/x86/include/asm/nmi.h
index 93da9c3..5b41b0f 100644
--- a/arch/x86/include/asm/nmi.h
+++ b/arch/x86/include/asm/nmi.h
@@ -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);
diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
index 8c0e6a4..312d772 100644
--- a/arch/x86/kernel/apic/hw_nmi.c
+++ b/arch/x86/kernel/apic/hw_nmi.c
@@ -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; }
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index a42ff0b..794e735 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -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
diff --git a/kernel/nmi_watchdog.c b/kernel/nmi_watchdog.c
index 36817b2..73c1954 100644
--- a/kernel/nmi_watchdog.c
+++ b/kernel/nmi_watchdog.c
@@ -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)
+ 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;
- else
- nmi_watchdog_enabled = 1;
+ 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);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 8a68b24..ac72c9e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -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,

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