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-rw-r--r--kernel/watchdog.c89
1 files changed, 45 insertions, 44 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 6e7b575ac33..18bb15776c5 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -27,7 +27,7 @@
#include <asm/irq_regs.h>
#include <linux/perf_event.h>
-int watchdog_enabled;
+int watchdog_enabled = 1;
int __read_mostly softlockup_thresh = 60;
static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts);
@@ -43,9 +43,6 @@ static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
#endif
-static int no_watchdog;
-
-
/* boot commands */
/*
* Should we panic when a soft-lockup or hard-lockup occurs:
@@ -58,7 +55,7 @@ static int __init hardlockup_panic_setup(char *str)
if (!strncmp(str, "panic", 5))
hardlockup_panic = 1;
else if (!strncmp(str, "0", 1))
- no_watchdog = 1;
+ watchdog_enabled = 0;
return 1;
}
__setup("nmi_watchdog=", hardlockup_panic_setup);
@@ -77,7 +74,7 @@ __setup("softlockup_panic=", softlockup_panic_setup);
static int __init nowatchdog_setup(char *str)
{
- no_watchdog = 1;
+ watchdog_enabled = 0;
return 1;
}
__setup("nowatchdog", nowatchdog_setup);
@@ -85,7 +82,7 @@ __setup("nowatchdog", nowatchdog_setup);
/* deprecated */
static int __init nosoftlockup_setup(char *str)
{
- no_watchdog = 1;
+ watchdog_enabled = 0;
return 1;
}
__setup("nosoftlockup", nosoftlockup_setup);
@@ -118,12 +115,12 @@ static void __touch_watchdog(void)
{
int this_cpu = smp_processor_id();
- __get_cpu_var(watchdog_touch_ts) = get_timestamp(this_cpu);
+ __this_cpu_write(watchdog_touch_ts, get_timestamp(this_cpu));
}
void touch_softlockup_watchdog(void)
{
- __raw_get_cpu_var(watchdog_touch_ts) = 0;
+ __this_cpu_write(watchdog_touch_ts, 0);
}
EXPORT_SYMBOL(touch_softlockup_watchdog);
@@ -167,12 +164,12 @@ void touch_softlockup_watchdog_sync(void)
/* watchdog detector functions */
static int is_hardlockup(void)
{
- unsigned long hrint = __get_cpu_var(hrtimer_interrupts);
+ unsigned long hrint = __this_cpu_read(hrtimer_interrupts);
- if (__get_cpu_var(hrtimer_interrupts_saved) == hrint)
+ if (__this_cpu_read(hrtimer_interrupts_saved) == hrint)
return 1;
- __get_cpu_var(hrtimer_interrupts_saved) = hrint;
+ __this_cpu_write(hrtimer_interrupts_saved, hrint);
return 0;
}
#endif
@@ -205,8 +202,8 @@ static void watchdog_overflow_callback(struct perf_event *event, int nmi,
/* Ensure the watchdog never gets throttled */
event->hw.interrupts = 0;
- if (__get_cpu_var(watchdog_nmi_touch) == true) {
- __get_cpu_var(watchdog_nmi_touch) = false;
+ if (__this_cpu_read(watchdog_nmi_touch) == true) {
+ __this_cpu_write(watchdog_nmi_touch, false);
return;
}
@@ -220,7 +217,7 @@ static void watchdog_overflow_callback(struct perf_event *event, int nmi,
int this_cpu = smp_processor_id();
/* only print hardlockups once */
- if (__get_cpu_var(hard_watchdog_warn) == true)
+ if (__this_cpu_read(hard_watchdog_warn) == true)
return;
if (hardlockup_panic)
@@ -228,16 +225,16 @@ static void watchdog_overflow_callback(struct perf_event *event, int nmi,
else
WARN(1, "Watchdog detected hard LOCKUP on cpu %d", this_cpu);
- __get_cpu_var(hard_watchdog_warn) = true;
+ __this_cpu_write(hard_watchdog_warn, true);
return;
}
- __get_cpu_var(hard_watchdog_warn) = false;
+ __this_cpu_write(hard_watchdog_warn, false);
return;
}
static void watchdog_interrupt_count(void)
{
- __get_cpu_var(hrtimer_interrupts)++;
+ __this_cpu_inc(hrtimer_interrupts);
}
#else
static inline void watchdog_interrupt_count(void) { return; }
@@ -246,7 +243,7 @@ static inline void watchdog_interrupt_count(void) { return; }
/* watchdog kicker functions */
static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
{
- unsigned long touch_ts = __get_cpu_var(watchdog_touch_ts);
+ unsigned long touch_ts = __this_cpu_read(watchdog_touch_ts);
struct pt_regs *regs = get_irq_regs();
int duration;
@@ -254,18 +251,18 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
watchdog_interrupt_count();
/* kick the softlockup detector */
- wake_up_process(__get_cpu_var(softlockup_watchdog));
+ wake_up_process(__this_cpu_read(softlockup_watchdog));
/* .. and repeat */
hrtimer_forward_now(hrtimer, ns_to_ktime(get_sample_period()));
if (touch_ts == 0) {
- if (unlikely(__get_cpu_var(softlockup_touch_sync))) {
+ if (unlikely(__this_cpu_read(softlockup_touch_sync))) {
/*
* If the time stamp was touched atomically
* make sure the scheduler tick is up to date.
*/
- __get_cpu_var(softlockup_touch_sync) = false;
+ __this_cpu_write(softlockup_touch_sync, false);
sched_clock_tick();
}
__touch_watchdog();
@@ -281,7 +278,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
duration = is_softlockup(touch_ts);
if (unlikely(duration)) {
/* only warn once */
- if (__get_cpu_var(soft_watchdog_warn) == true)
+ if (__this_cpu_read(soft_watchdog_warn) == true)
return HRTIMER_RESTART;
printk(KERN_ERR "BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n",
@@ -296,9 +293,9 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
if (softlockup_panic)
panic("softlockup: hung tasks");
- __get_cpu_var(soft_watchdog_warn) = true;
+ __this_cpu_write(soft_watchdog_warn, true);
} else
- __get_cpu_var(soft_watchdog_warn) = false;
+ __this_cpu_write(soft_watchdog_warn, false);
return HRTIMER_RESTART;
}
@@ -366,8 +363,14 @@ static int watchdog_nmi_enable(int cpu)
goto out_save;
}
- printk(KERN_ERR "NMI watchdog disabled for cpu%i: unable to create perf event: %ld\n",
- cpu, PTR_ERR(event));
+
+ /* vary the KERN level based on the returned errno */
+ if (PTR_ERR(event) == -EOPNOTSUPP)
+ printk(KERN_INFO "NMI watchdog disabled (cpu%i): not supported (no LAPIC?)\n", cpu);
+ else if (PTR_ERR(event) == -ENOENT)
+ printk(KERN_WARNING "NMI watchdog disabled (cpu%i): hardware events not enabled\n", cpu);
+ else
+ printk(KERN_ERR "NMI watchdog disabled (cpu%i): unable to create perf event: %ld\n", cpu, PTR_ERR(event));
return PTR_ERR(event);
/* success path */
@@ -432,9 +435,6 @@ static int watchdog_enable(int cpu)
wake_up_process(p);
}
- /* if any cpu succeeds, watchdog is considered enabled for the system */
- watchdog_enabled = 1;
-
return 0;
}
@@ -462,12 +462,16 @@ static void watchdog_disable(int cpu)
static void watchdog_enable_all_cpus(void)
{
int cpu;
- int result = 0;
+
+ watchdog_enabled = 0;
for_each_online_cpu(cpu)
- result += watchdog_enable(cpu);
+ if (!watchdog_enable(cpu))
+ /* if any cpu succeeds, watchdog is considered
+ enabled for the system */
+ watchdog_enabled = 1;
- if (result)
+ if (!watchdog_enabled)
printk(KERN_ERR "watchdog: failed to be enabled on some cpus\n");
}
@@ -476,9 +480,6 @@ static void watchdog_disable_all_cpus(void)
{
int cpu;
- if (no_watchdog)
- return;
-
for_each_online_cpu(cpu)
watchdog_disable(cpu);
@@ -498,10 +499,12 @@ int proc_dowatchdog_enabled(struct ctl_table *table, int write,
{
proc_dointvec(table, write, buffer, length, ppos);
- if (watchdog_enabled)
- watchdog_enable_all_cpus();
- else
- watchdog_disable_all_cpus();
+ if (write) {
+ if (watchdog_enabled)
+ watchdog_enable_all_cpus();
+ else
+ watchdog_disable_all_cpus();
+ }
return 0;
}
@@ -530,7 +533,8 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
break;
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
- err = watchdog_enable(hotcpu);
+ if (watchdog_enabled)
+ err = watchdog_enable(hotcpu);
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_UP_CANCELED:
@@ -555,9 +559,6 @@ void __init lockup_detector_init(void)
void *cpu = (void *)(long)smp_processor_id();
int err;
- if (no_watchdog)
- return;
-
err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu);
WARN_ON(notifier_to_errno(err));
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-03-28 17:15:15 +0000