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-rw-r--r--kernel/watchdog.c87
1 files changed, 47 insertions, 40 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 05039e3..52c9a9b 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -31,7 +31,7 @@
int watchdog_enabled = 1;
int __read_mostly watchdog_thresh = 10;
-static int __read_mostly watchdog_disabled;
+static int __read_mostly watchdog_disabled = 1;
static u64 __read_mostly sample_period;
static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts);
@@ -347,11 +347,6 @@ static void watchdog_enable(unsigned int cpu)
hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer->function = watchdog_timer_fn;
- if (!watchdog_enabled) {
- kthread_park(current);
- return;
- }
-
/* Enable the perf event */
watchdog_nmi_enable(cpu);
@@ -374,6 +369,11 @@ static void watchdog_disable(unsigned int cpu)
watchdog_nmi_disable(cpu);
}
+static void watchdog_cleanup(unsigned int cpu, bool online)
+{
+ watchdog_disable(cpu);
+}
+
static int watchdog_should_run(unsigned int cpu)
{
return __this_cpu_read(hrtimer_interrupts) !=
@@ -475,28 +475,40 @@ static int watchdog_nmi_enable(unsigned int cpu) { return 0; }
static void watchdog_nmi_disable(unsigned int cpu) { return; }
#endif /* CONFIG_HARDLOCKUP_DETECTOR */
-/* prepare/enable/disable routines */
-/* sysctl functions */
-#ifdef CONFIG_SYSCTL
-static void watchdog_enable_all_cpus(void)
+static struct smp_hotplug_thread watchdog_threads = {
+ .store = &softlockup_watchdog,
+ .thread_should_run = watchdog_should_run,
+ .thread_fn = watchdog,
+ .thread_comm = "watchdog/%u",
+ .setup = watchdog_enable,
+ .cleanup = watchdog_cleanup,
+ .park = watchdog_disable,
+ .unpark = watchdog_enable,
+};
+
+static int watchdog_enable_all_cpus(void)
{
- unsigned int cpu;
+ int err = 0;
if (watchdog_disabled) {
- watchdog_disabled = 0;
- for_each_online_cpu(cpu)
- kthread_unpark(per_cpu(softlockup_watchdog, cpu));
+ err = smpboot_register_percpu_thread(&watchdog_threads);
+ if (err)
+ pr_err("Failed to create watchdog threads, disabled\n");
+ else
+ watchdog_disabled = 0;
}
+
+ return err;
}
+/* prepare/enable/disable routines */
+/* sysctl functions */
+#ifdef CONFIG_SYSCTL
static void watchdog_disable_all_cpus(void)
{
- unsigned int cpu;
-
if (!watchdog_disabled) {
watchdog_disabled = 1;
- for_each_online_cpu(cpu)
- kthread_park(per_cpu(softlockup_watchdog, cpu));
+ smpboot_unregister_percpu_thread(&watchdog_threads);
}
}
@@ -507,14 +519,14 @@ static void watchdog_disable_all_cpus(void)
int proc_dowatchdog(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
- int ret;
+ int err, old_thresh, old_enabled;
- if (watchdog_disabled < 0)
- return -ENODEV;
+ old_thresh = ACCESS_ONCE(watchdog_thresh);
+ old_enabled = ACCESS_ONCE(watchdog_enabled);
- ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
- if (ret || !write)
- return ret;
+ err = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+ if (err || !write)
+ return err;
set_sample_period();
/*
@@ -523,29 +535,24 @@ int proc_dowatchdog(struct ctl_table *table, int write,
* watchdog_*_all_cpus() function takes care of this.
*/
if (watchdog_enabled && watchdog_thresh)
- watchdog_enable_all_cpus();
+ err = watchdog_enable_all_cpus();
else
watchdog_disable_all_cpus();
- return ret;
+ /* Restore old values on failure */
+ if (err) {
+ watchdog_thresh = old_thresh;
+ watchdog_enabled = old_enabled;
+ }
+
+ return err;
}
#endif /* CONFIG_SYSCTL */
-static struct smp_hotplug_thread watchdog_threads = {
- .store = &softlockup_watchdog,
- .thread_should_run = watchdog_should_run,
- .thread_fn = watchdog,
- .thread_comm = "watchdog/%u",
- .setup = watchdog_enable,
- .park = watchdog_disable,
- .unpark = watchdog_enable,
-};
-
void __init lockup_detector_init(void)
{
set_sample_period();
- if (smpboot_register_percpu_thread(&watchdog_threads)) {
- pr_err("Failed to create watchdog threads, disabled\n");
- watchdog_disabled = -ENODEV;
- }
+
+ if (watchdog_enabled)
+ watchdog_enable_all_cpus();
}
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