1 files changed, 33 insertions, 21 deletions

diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 708d4882c0c..edeeef3a6a3 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -15,13 +15,16 @@
 #include <linux/notifier.h>
 #include <linux/module.h>
 
+#include <asm/irq_regs.h>
+
 static DEFINE_SPINLOCK(print_lock);
 
 static DEFINE_PER_CPU(unsigned long, touch_timestamp);
 static DEFINE_PER_CPU(unsigned long, print_timestamp);
 static DEFINE_PER_CPU(struct task_struct *, watchdog_task);
 
-static int did_panic = 0;
+static int did_panic;
+int softlockup_thresh = 10;
 
 static int
 softlock_panic(struct notifier_block *this, unsigned long event, void *ptr)
@@ -40,14 +43,16 @@ static struct notifier_block panic_block = {
  * resolution, and we don't need to waste time with a big divide when
  * 2^30ns == 1.074s.
  */
-static unsigned long get_timestamp(void)
+static unsigned long get_timestamp(int this_cpu)
 {
-        return sched_clock() >> 30;  /* 2^30 ~= 10^9 */
+        return cpu_clock(this_cpu) >> 30;  /* 2^30 ~= 10^9 */
 }
 
 void touch_softlockup_watchdog(void)
 {
-        __raw_get_cpu_var(touch_timestamp) = get_timestamp();
+        int this_cpu = raw_smp_processor_id();
+
+        __raw_get_cpu_var(touch_timestamp) = get_timestamp(this_cpu);
 }
 EXPORT_SYMBOL(touch_softlockup_watchdog);
 
@@ -70,6 +75,7 @@ void softlockup_tick(void)
         int this_cpu = smp_processor_id();
         unsigned long touch_timestamp = per_cpu(touch_timestamp, this_cpu);
         unsigned long print_timestamp;
+        struct pt_regs *regs = get_irq_regs();
         unsigned long now;
 
         if (touch_timestamp == 0) {
@@ -80,10 +86,11 @@ void softlockup_tick(void)
         print_timestamp = per_cpu(print_timestamp, this_cpu);
 
         /* report at most once a second */
-        if (print_timestamp < (touch_timestamp + 1) ||
-                did_panic ||
-                        !per_cpu(watchdog_task, this_cpu))
+        if ((print_timestamp >= touch_timestamp &&
+                        print_timestamp < (touch_timestamp + 1)) ||
+                        did_panic || !per_cpu(watchdog_task, this_cpu)) {
                 return;
+        }
 
         /* do not print during early bootup: */
         if (unlikely(system_state != SYSTEM_RUNNING)) {
@@ -91,28 +98,33 @@ void softlockup_tick(void)
                 return;
         }
 
-        now = get_timestamp();
+        now = get_timestamp(this_cpu);
 
         /* Wake up the high-prio watchdog task every second: */
         if (now > (touch_timestamp + 1))
                 wake_up_process(per_cpu(watchdog_task, this_cpu));
 
         /* Warn about unreasonable 10+ seconds delays: */
-        if (now > (touch_timestamp + 10)) {
-                per_cpu(print_timestamp, this_cpu) = touch_timestamp;
+        if (now <= (touch_timestamp + softlockup_thresh))
+                return;
 
-                spin_lock(&print_lock);
-                printk(KERN_ERR "BUG: soft lockup detected on CPU#%d!\n",
-                        this_cpu);
+        per_cpu(print_timestamp, this_cpu) = touch_timestamp;
+
+        spin_lock(&print_lock);
+        printk(KERN_ERR "BUG: soft lockup - CPU#%d stuck for %lus! [%s:%d]\n",
+                        this_cpu, now - touch_timestamp,
+                                current->comm, current->pid);
+        if (regs)
+                show_regs(regs);
+        else
                 dump_stack();
-                spin_unlock(&print_lock);
-        }
+        spin_unlock(&print_lock);
 }
 
 /*
  * The watchdog thread - runs every second and touches the timestamp.
  */
-static int watchdog(void * __bind_cpu)
+static int watchdog(void *__bind_cpu)
 {
         struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
 
@@ -150,13 +162,13 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
                 BUG_ON(per_cpu(watchdog_task, hotcpu));
                 p = kthread_create(watchdog, hcpu, "watchdog/%d", hotcpu);
                 if (IS_ERR(p)) {
-                        printk("watchdog for %i failed\n", hotcpu);
+                        printk(KERN_ERR "watchdog for %i failed\n", hotcpu);
                         return NOTIFY_BAD;
                 }
-                per_cpu(touch_timestamp, hotcpu) = 0;
-                per_cpu(watchdog_task, hotcpu) = p;
+                per_cpu(touch_timestamp, hotcpu) = 0;
+                per_cpu(watchdog_task, hotcpu) = p;
                 kthread_bind(p, hotcpu);
-                break;
+                break;
         case CPU_ONLINE:
         case CPU_ONLINE_FROZEN:
                 wake_up_process(per_cpu(watchdog_task, hotcpu));
@@ -176,7 +188,7 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
                 kthread_stop(p);
                 break;
 #endif /* CONFIG_HOTPLUG_CPU */
-        }
+        }
         return NOTIFY_OK;
 }