X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=kernel%2Fsoftlockup.c;h=c67189a25d52efbd2aa6afdf0655cfe860971189;hb=987b0145d94eecf292d8b301228356f44611ab7c;hp=14c7faf02909e8e4879a057406416a43a34b3fdf;hpb=f7ed79d23a47594e7834d66a8f14449796d4f3e6;p=linux-2.6.git

diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 14c7faf02..c67189a25 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -1,11 +1,12 @@
 /*
  * Detect Soft Lockups
  *
- * started by Ingo Molnar, Copyright (C) 2005, 2006 Red Hat, Inc.
+ * started by Ingo Molnar, (C) 2005, Red Hat
  *
  * this code detects soft lockups: incidents in where on a CPU
  * the kernel does not reschedule for 10 seconds or more.
  */
+
 #include <linux/mm.h>
 #include <linux/cpu.h>
 #include <linux/init.h>
@@ -16,14 +17,13 @@
 
 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(unsigned long, timestamp) = 0;
+static DEFINE_PER_CPU(unsigned long, print_timestamp) = 0;
 static DEFINE_PER_CPU(struct task_struct *, watchdog_task);
 
 static int did_panic = 0;
-
-static int
-softlock_panic(struct notifier_block *this, unsigned long event, void *ptr)
+static int softlock_panic(struct notifier_block *this, unsigned long event,
+				void *ptr)
 {
 	did_panic = 1;
 
@@ -36,7 +36,7 @@ static struct notifier_block panic_block = {
 
 void touch_softlockup_watchdog(void)
 {
-	per_cpu(touch_timestamp, raw_smp_processor_id()) = jiffies;
+	per_cpu(timestamp, raw_smp_processor_id()) = jiffies;
 }
 EXPORT_SYMBOL(touch_softlockup_watchdog);
 
@@ -44,35 +44,25 @@ EXPORT_SYMBOL(touch_softlockup_watchdog);
  * This callback runs from the timer interrupt, and checks
  * whether the watchdog thread has hung or not:
  */
-void softlockup_tick(void)
+void softlockup_tick(struct pt_regs *regs)
 {
 	int this_cpu = smp_processor_id();
-	unsigned long touch_timestamp = per_cpu(touch_timestamp, this_cpu);
+	unsigned long timestamp = per_cpu(timestamp, this_cpu);
 
-	/* prevent double reports: */
-	if (per_cpu(print_timestamp, this_cpu) == touch_timestamp ||
-		did_panic ||
-			!per_cpu(watchdog_task, this_cpu))
+	if (per_cpu(print_timestamp, this_cpu) == timestamp)
 		return;
 
-	/* do not print during early bootup: */
-	if (unlikely(system_state != SYSTEM_RUNNING)) {
-		touch_softlockup_watchdog();
+	/* Do not cause a second panic when there already was one */
+	if (did_panic)
 		return;
-	}
 
-	/* Wake up the high-prio watchdog task every second: */
-	if (time_after(jiffies, touch_timestamp + HZ))
-		wake_up_process(per_cpu(watchdog_task, this_cpu));
-
-	/* Warn about unreasonable 10+ seconds delays: */
-	if (time_after(jiffies, touch_timestamp + 10*HZ)) {
-		per_cpu(print_timestamp, this_cpu) = touch_timestamp;
+	if (time_after(jiffies, timestamp + 10*HZ)) {
+		per_cpu(print_timestamp, this_cpu) = timestamp;
 
 		spin_lock(&print_lock);
 		printk(KERN_ERR "BUG: soft lockup detected on CPU#%d!\n",
 			this_cpu);
-		dump_stack();
+		show_regs(regs);
 		spin_unlock(&print_lock);
 	}
 }
@@ -87,16 +77,18 @@ static int watchdog(void * __bind_cpu)
 	sched_setscheduler(current, SCHED_FIFO, &param);
 	current->flags |= PF_NOFREEZE;
 
+	set_current_state(TASK_INTERRUPTIBLE);
+
 	/*
-	 * Run briefly once per second to reset the softlockup timestamp.
-	 * If this gets delayed for more than 10 seconds then the
-	 * debug-printout triggers in softlockup_tick().
+	 * Run briefly once per second - if this gets delayed for
+	 * more than 10 seconds then the debug-printout triggers
+	 * in softlockup_tick():
 	 */
 	while (!kthread_should_stop()) {
-		set_current_state(TASK_INTERRUPTIBLE);
+		msleep_interruptible(1000);
 		touch_softlockup_watchdog();
-		schedule();
 	}
+	__set_current_state(TASK_RUNNING);
 
 	return 0;
 }
@@ -104,7 +96,7 @@ static int watchdog(void * __bind_cpu)
 /*
  * Create/destroy watchdog threads as CPUs come and go:
  */
-static int
+static int __devinit
 cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
 {
 	int hotcpu = (unsigned long)hcpu;
@@ -118,11 +110,11 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
 			printk("watchdog for %i failed\n", hotcpu);
 			return NOTIFY_BAD;
 		}
-  		per_cpu(touch_timestamp, hotcpu) = jiffies;
   		per_cpu(watchdog_task, hotcpu) = p;
 		kthread_bind(p, hotcpu);
  		break;
 	case CPU_ONLINE:
+
 		wake_up_process(per_cpu(watchdog_task, hotcpu));
 		break;
 #ifdef CONFIG_HOTPLUG_CPU
@@ -140,7 +132,7 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
 	return NOTIFY_OK;
 }
 
-static struct notifier_block cpu_nfb = {
+static struct notifier_block __devinitdata cpu_nfb = {
 	.notifier_call = cpu_callback
 };
 
@@ -152,5 +144,6 @@ __init void spawn_softlockup_task(void)
 	cpu_callback(&cpu_nfb, CPU_ONLINE, cpu);
 	register_cpu_notifier(&cpu_nfb);
 
-	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
+	notifier_chain_register(&panic_notifier_list, &panic_block);
 }
+