2 files changed, 8 insertions, 84 deletions

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index fd8a998eb197..5eb11960e4a2 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -107,6 +107,7 @@ __setup("hardlockup_all_cpu_backtrace=", hardlockup_all_cpu_backtrace_setup);
  */
 int __weak watchdog_nmi_enable(unsigned int cpu)
 {
+        hardlockup_detector_perf_enable();
         return 0;
 }
 
@@ -465,7 +466,8 @@ static void watchdog_enable(unsigned int cpu)
         /* Initialize timestamp */
         __touch_watchdog();
         /* Enable the perf event */
-        watchdog_nmi_enable(cpu);
+        if (watchdog_enabled & NMI_WATCHDOG_ENABLED)
+                watchdog_nmi_enable(cpu);
 
         watchdog_set_prio(SCHED_FIFO, MAX_RT_PRIO - 1);
 }
diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c
index 99a3f22e48cc..509bb6b59c41 100644
--- a/kernel/watchdog_hld.c
+++ b/kernel/watchdog_hld.c
@@ -25,7 +25,7 @@ static DEFINE_PER_CPU(struct perf_event *, dead_event);
 static struct cpumask dead_events_mask;
 
 static unsigned long hardlockup_allcpu_dumped;
-static bool hardlockup_detector_disabled;
+static unsigned int watchdog_cpus;
 
 void arch_touch_nmi_watchdog(void)
 {
@@ -160,84 +160,6 @@ static void watchdog_overflow_callback(struct perf_event *event,
         return;
 }
 
-/*
- * People like the simple clean cpu node info on boot.
- * Reduce the watchdog noise by only printing messages
- * that are different from what cpu0 displayed.
- */
-static unsigned long firstcpu_err;
-static atomic_t watchdog_cpus;
-
-int watchdog_nmi_enable(unsigned int cpu)
-{
-        struct perf_event_attr *wd_attr;
-        struct perf_event *event = per_cpu(watchdog_ev, cpu);
-        int firstcpu = 0;
-
-        /* nothing to do if the hard lockup detector is disabled */
-        if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
-                goto out;
-
-        /* A failure disabled the hardlockup detector permanently */
-        if (hardlockup_detector_disabled)
-                return -ENODEV;
-
-        /* is it already setup and enabled? */
-        if (event && event->state > PERF_EVENT_STATE_OFF)
-                goto out;
-
-        /* it is setup but not enabled */
-        if (event != NULL)
-                goto out_enable;
-
-        if (atomic_inc_return(&watchdog_cpus) == 1)
-                firstcpu = 1;
-
-        wd_attr = &wd_hw_attr;
-        wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh);
-
-        /* Try to register using hardware perf events */
-        event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
-
-        /* save the first cpu's error for future comparision */
-        if (firstcpu && IS_ERR(event))
-                firstcpu_err = PTR_ERR(event);
-
-        if (!IS_ERR(event)) {
-                /* only print for the first cpu initialized */
-                if (firstcpu || firstcpu_err)
-                        pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n");
-                goto out_save;
-        }
-
-        /* skip displaying the same error again */
-        if (!firstcpu && (PTR_ERR(event) == firstcpu_err))
-                return PTR_ERR(event);
-
-        /* vary the KERN level based on the returned errno */
-        if (PTR_ERR(event) == -EOPNOTSUPP)
-                pr_info("disabled (cpu%i): not supported (no LAPIC?)\n", cpu);
-        else if (PTR_ERR(event) == -ENOENT)
-                pr_warn("disabled (cpu%i): hardware events not enabled\n",
-                         cpu);
-        else
-                pr_err("disabled (cpu%i): unable to create perf event: %ld\n",
-                        cpu, PTR_ERR(event));
-
-        pr_info("Disabling hard lockup detector permanently\n");
-        hardlockup_detector_disabled = true;
-
-        return PTR_ERR(event);
-
-        /* success path */
-out_save:
-        per_cpu(watchdog_ev, cpu) = event;
-out_enable:
-        perf_event_enable(per_cpu(watchdog_ev, cpu));
-out:
-        return 0;
-}
-
 static int hardlockup_detector_event_create(void)
 {
         unsigned int cpu = smp_processor_id();
@@ -267,6 +189,9 @@ void hardlockup_detector_perf_enable(void)
         if (hardlockup_detector_event_create())
                 return;
 
+        if (!watchdog_cpus++)
+                pr_info("Enabled. Permanently consumes one hw-PMU counter.\n");
+
         perf_event_enable(this_cpu_read(watchdog_ev));
 }
 
@@ -282,10 +207,7 @@ void hardlockup_detector_perf_disable(void)
                 this_cpu_write(watchdog_ev, NULL);
                 this_cpu_write(dead_event, event);
                 cpumask_set_cpu(smp_processor_id(), &dead_events_mask);
-
-                /* watchdog_nmi_enable() expects this to be zero initially. */
-                if (atomic_dec_and_test(&watchdog_cpus))
-                        firstcpu_err = 0;
+                watchdog_cpus--;
         }
 }