Merge branch 'core/softlockup' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core/softlockup' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  softlockup: make DETECT_HUNG_TASK default depend on DETECT_SOFTLOCKUP
  softlockup: move 'one' to the softlockup section in sysctl.c
  softlockup: ensure the task has been switched out once
  softlockup: remove timestamp checking from hung_task
  softlockup: convert read_lock in hung_task to rcu_read_lock
  softlockup: check all tasks in hung_task
  softlockup: remove unused definition for spawn_softlockup_task
  softlockup: fix potential race in hung_task when resetting timeout
  softlockup: fix to allow compiling with !DETECT_HUNG_TASK
  softlockup: decouple hung tasks check from softlockup detection

1 files changed, 38 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 9638d99644af..c6e854f215fa 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -186,6 +186,44 @@ config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
         default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
         default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
 
+config DETECT_HUNG_TASK
+        bool "Detect Hung Tasks"
+        depends on DEBUG_KERNEL
+        default DETECT_SOFTLOCKUP
+        help
+          Say Y here to enable the kernel to detect "hung tasks",
+          which are bugs that cause the task to be stuck in
+          uninterruptible "D" state indefinitiley.
+
+          When a hung task is detected, the kernel will print the
+          current stack trace (which you should report), but the
+          task will stay in uninterruptible state. If lockdep is
+          enabled then all held locks will also be reported. This
+          feature has negligible overhead.
+
+config BOOTPARAM_HUNG_TASK_PANIC
+        bool "Panic (Reboot) On Hung Tasks"
+        depends on DETECT_HUNG_TASK
+        help
+          Say Y here to enable the kernel to panic on "hung tasks",
+          which are bugs that cause the kernel to leave a task stuck
+          in uninterruptible "D" state.
+
+          The panic can be used in combination with panic_timeout,
+          to cause the system to reboot automatically after a
+          hung task has been detected. This feature is useful for
+          high-availability systems that have uptime guarantees and
+          where a hung tasks must be resolved ASAP.
+
+          Say N if unsure.
+
+config BOOTPARAM_HUNG_TASK_PANIC_VALUE
+        int
+        depends on DETECT_HUNG_TASK
+        range 0 1
+        default 0 if !BOOTPARAM_HUNG_TASK_PANIC
+        default 1 if BOOTPARAM_HUNG_TASK_PANIC
+
 config SCHED_DEBUG
         bool "Collect scheduler debugging info"
         depends on DEBUG_KERNEL && PROC_FS