1 files changed, 32 insertions, 33 deletions

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 613bc1f04610..6e3c41a4024c 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -43,8 +43,7 @@ static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
 static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
 #endif
 
-static int __read_mostly did_panic;
-static int __initdata no_watchdog;
+static int no_watchdog;
 
 
 /* boot commands */
@@ -122,7 +121,7 @@ static void __touch_watchdog(void)
 
 void touch_softlockup_watchdog(void)
 {
-        __get_cpu_var(watchdog_touch_ts) = 0;
+        __raw_get_cpu_var(watchdog_touch_ts) = 0;
 }
 EXPORT_SYMBOL(touch_softlockup_watchdog);
 
@@ -142,7 +141,14 @@ void touch_all_softlockup_watchdogs(void)
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 void touch_nmi_watchdog(void)
 {
-        __get_cpu_var(watchdog_nmi_touch) = true;
+        if (watchdog_enabled) {
+                unsigned cpu;
+
+                for_each_present_cpu(cpu) {
+                        if (per_cpu(watchdog_nmi_touch, cpu) != true)
+                                per_cpu(watchdog_nmi_touch, cpu) = true;
+                }
+        }
         touch_softlockup_watchdog();
 }
 EXPORT_SYMBOL(touch_nmi_watchdog);
@@ -180,18 +186,6 @@ static int is_softlockup(unsigned long touch_ts)
         return 0;
 }
 
-static int
-watchdog_panic(struct notifier_block *this, unsigned long event, void *ptr)
-{
-        did_panic = 1;
-
-        return NOTIFY_DONE;
-}
-
-static struct notifier_block panic_block = {
-        .notifier_call = watchdog_panic,
-};
-
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 static struct perf_event_attr wd_hw_attr = {
         .type           = PERF_TYPE_HARDWARE,
@@ -202,10 +196,13 @@ static struct perf_event_attr wd_hw_attr = {
 };
 
 /* Callback function for perf event subsystem */
-void watchdog_overflow_callback(struct perf_event *event, int nmi,
+static void watchdog_overflow_callback(struct perf_event *event, int nmi,
                  struct perf_sample_data *data,
                  struct pt_regs *regs)
 {
+        /* 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;
                 return;
@@ -361,14 +358,14 @@ static int watchdog_nmi_enable(int cpu)
         /* Try to register using hardware perf events */
         wd_attr = &wd_hw_attr;
         wd_attr->sample_period = hw_nmi_get_sample_period();
-        event = perf_event_create_kernel_counter(wd_attr, cpu, -1, watchdog_overflow_callback);
+        event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback);
         if (!IS_ERR(event)) {
                 printk(KERN_INFO "NMI watchdog enabled, takes one hw-pmu counter.\n");
                 goto out_save;
         }
 
         printk(KERN_ERR "NMI watchdog failed to create perf event on cpu%i: %p\n", cpu, event);
-        return -1;
+        return PTR_ERR(event);
 
         /* success path */
 out_save:
@@ -412,17 +409,19 @@ static int watchdog_prepare_cpu(int cpu)
 static int watchdog_enable(int cpu)
 {
         struct task_struct *p = per_cpu(softlockup_watchdog, cpu);
+        int err;
 
         /* enable the perf event */
-        if (watchdog_nmi_enable(cpu) != 0)
-                return -1;
+        err = watchdog_nmi_enable(cpu);
+        if (err)
+                return err;
 
         /* create the watchdog thread */
         if (!p) {
                 p = kthread_create(watchdog, (void *)(unsigned long)cpu, "watchdog/%d", cpu);
                 if (IS_ERR(p)) {
                         printk(KERN_ERR "softlockup watchdog for %i failed\n", cpu);
-                        return -1;
+                        return PTR_ERR(p);
                 }
                 kthread_bind(p, cpu);
                 per_cpu(watchdog_touch_ts, cpu) = 0;
@@ -430,6 +429,9 @@ 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;
 }
 
@@ -452,9 +454,6 @@ static void watchdog_disable(int cpu)
                 per_cpu(softlockup_watchdog, cpu) = NULL;
                 kthread_stop(p);
         }
-
-        /* if any cpu succeeds, watchdog is considered enabled for the system */
-        watchdog_enabled = 1;
 }
 
 static void watchdog_enable_all_cpus(void)
@@ -474,6 +473,9 @@ static void watchdog_disable_all_cpus(void)
 {
         int cpu;
 
+        if (no_watchdog)
+                return;
+
         for_each_online_cpu(cpu)
                 watchdog_disable(cpu);
 
@@ -516,17 +518,16 @@ static int __cpuinit
 cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
 {
         int hotcpu = (unsigned long)hcpu;
+        int err = 0;
 
         switch (action) {
         case CPU_UP_PREPARE:
         case CPU_UP_PREPARE_FROZEN:
-                if (watchdog_prepare_cpu(hotcpu))
-                        return NOTIFY_BAD;
+                err = watchdog_prepare_cpu(hotcpu);
                 break;
         case CPU_ONLINE:
         case CPU_ONLINE_FROZEN:
-                if (watchdog_enable(hotcpu))
-                        return NOTIFY_BAD;
+                err = watchdog_enable(hotcpu);
                 break;
 #ifdef CONFIG_HOTPLUG_CPU
         case CPU_UP_CANCELED:
@@ -539,7 +540,7 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
                 break;
 #endif /* CONFIG_HOTPLUG_CPU */
         }
-        return NOTIFY_OK;
+        return notifier_from_errno(err);
 }
 
 static struct notifier_block __cpuinitdata cpu_nfb = {
@@ -555,13 +556,11 @@ static int __init spawn_watchdog_task(void)
                 return 0;
 
         err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu);
-        WARN_ON(err == NOTIFY_BAD);
+        WARN_ON(notifier_to_errno(err));
 
         cpu_callback(&cpu_nfb, CPU_ONLINE, cpu);
         register_cpu_notifier(&cpu_nfb);
 
-        atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
-
         return 0;
 }
 early_initcall(spawn_watchdog_task);