ring-buffer: reset timestamps when ring buffer is reset

[safe/jmp/linux-2.6] / kernel / softlockup.c

diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 7bd8d1a..d9188c6 100644 (file)
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -164,7 +164,7 @@ unsigned long __read_mostly sysctl_hung_task_check_count = 1024;
 /*
  * Zero means infinite timeout - no checking done:
  */
-unsigned long __read_mostly sysctl_hung_task_timeout_secs = 120;
+unsigned long __read_mostly sysctl_hung_task_timeout_secs = 480;
 
 unsigned long __read_mostly sysctl_hung_task_warnings = 10;
 
@@ -188,7 +188,7 @@ static void check_hung_task(struct task_struct *t, unsigned long now)
        if ((long)(now - t->last_switch_timestamp) <
                                        sysctl_hung_task_timeout_secs)
                return;
-       if (sysctl_hung_task_warnings < 0)
+       if (!sysctl_hung_task_warnings)
                return;
        sysctl_hung_task_warnings--;
 
@@ -226,14 +226,15 @@ static void check_hung_uninterruptible_tasks(int this_cpu)
         * If the system crashed already then all bets are off,
         * do not report extra hung tasks:
         */
-       if ((tainted & TAINT_DIE) || did_panic)
+       if (test_taint(TAINT_DIE) || did_panic)
                return;
 
        read_lock(&tasklist_lock);
        do_each_thread(g, t) {
                if (!--max_count)
                        goto unlock;
-               if (t->state & TASK_UNINTERRUPTIBLE)
+               /* use "==" to skip the TASK_KILLABLE tasks waiting on NFS */
+               if (t->state == TASK_UNINTERRUPTIBLE)
                        check_hung_task(t, now);
        } while_each_thread(g, t);
  unlock:
@@ -302,17 +303,15 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
                break;
        case CPU_ONLINE:
        case CPU_ONLINE_FROZEN:
-               check_cpu = any_online_cpu(cpu_online_map);
+               check_cpu = cpumask_any(cpu_online_mask);
                wake_up_process(per_cpu(watchdog_task, hotcpu));
                break;
 #ifdef CONFIG_HOTPLUG_CPU
        case CPU_DOWN_PREPARE:
        case CPU_DOWN_PREPARE_FROZEN:
                if (hotcpu == check_cpu) {
-                       cpumask_t temp_cpu_online_map = cpu_online_map;
-
-                       cpu_clear(hotcpu, temp_cpu_online_map);
-                       check_cpu = any_online_cpu(temp_cpu_online_map);
+                       /* Pick any other online cpu. */
+                       check_cpu = cpumask_any_but(cpu_online_mask, hotcpu);
                }
                break;
 
@@ -322,7 +321,7 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
                        break;
                /* Unbind so it can run.  Fall thru. */
                kthread_bind(per_cpu(watchdog_task, hotcpu),
-                            any_online_cpu(cpu_online_map));
+                            cpumask_any(cpu_online_mask));
        case CPU_DEAD:
        case CPU_DEAD_FROZEN:
                p = per_cpu(watchdog_task, hotcpu);
@@ -338,14 +337,33 @@ static struct notifier_block __cpuinitdata cpu_nfb = {
        .notifier_call = cpu_callback
 };
 
-__init void spawn_softlockup_task(void)
+static int __initdata nosoftlockup;
+
+static int __init nosoftlockup_setup(char *str)
+{
+       nosoftlockup = 1;
+       return 1;
+}
+__setup("nosoftlockup", nosoftlockup_setup);
+
+static int __init spawn_softlockup_task(void)
 {
        void *cpu = (void *)(long)smp_processor_id();
-       int err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu);
+       int err;
+
+       if (nosoftlockup)
+               return 0;
 
-       BUG_ON(err == NOTIFY_BAD);
+       err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu);
+       if (err == NOTIFY_BAD) {
+               BUG();
+               return 1;
+       }
        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_softlockup_task);