- * Have a reasonable limit on the number of tasks checked:
- */
-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_warnings = 10;
-
-/*
- * Only do the hung-tasks check on one CPU:
- */
-static int check_cpu __read_mostly = -1;
-
-static void check_hung_task(struct task_struct *t, unsigned long now)
-{
- unsigned long switch_count = t->nvcsw + t->nivcsw;
-
- if (t->flags & PF_FROZEN)
- return;
-
- if (switch_count != t->last_switch_count || !t->last_switch_timestamp) {
- t->last_switch_count = switch_count;
- t->last_switch_timestamp = now;
- return;
- }
- if ((long)(now - t->last_switch_timestamp) <
- sysctl_hung_task_timeout_secs)
- return;
- if (sysctl_hung_task_warnings < 0)
- return;
- sysctl_hung_task_warnings--;
-
- /*
- * Ok, the task did not get scheduled for more than 2 minutes,
- * complain:
- */
- printk(KERN_ERR "INFO: task %s:%d blocked for more than "
- "%ld seconds.\n", t->comm, t->pid,
- sysctl_hung_task_timeout_secs);
- printk(KERN_ERR "\"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\""
- " disables this message.\n");
- sched_show_task(t);
- __debug_show_held_locks(t);
-
- t->last_switch_timestamp = now;
- touch_nmi_watchdog();
-
- if (softlockup_panic)
- panic("softlockup: blocked tasks");
-}
-
-/*
- * Check whether a TASK_UNINTERRUPTIBLE does not get woken up for
- * a really long time (120 seconds). If that happens, print out
- * a warning.
- */
-static void check_hung_uninterruptible_tasks(int this_cpu)
-{
- int max_count = sysctl_hung_task_check_count;
- unsigned long now = get_timestamp(this_cpu);
- struct task_struct *g, *t;
-
- /*
- * If the system crashed already then all bets are off,
- * do not report extra hung tasks:
- */
- if ((tainted & TAINT_DIE) || did_panic)
- return;
-
- read_lock(&tasklist_lock);
- do_each_thread(g, t) {
- if (!--max_count)
- goto unlock;
- if (t->state & TASK_UNINTERRUPTIBLE)
- check_hung_task(t, now);
- } while_each_thread(g, t);
- unlock:
- read_unlock(&tasklist_lock);
-}
-
-/*