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

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  seqlock: Don't smp_rmb in seqlock reader spin loop
  watchdog, hung_task_timeout: Add Kconfig configurable default
  lockdep: Remove cmpxchg to update nr_chain_hlocks
  lockdep: Print a nicer description for simple irq lock inversions
  lockdep: Replace "Bad BFS generated tree" message with something less cryptic
  lockdep: Print a nicer description for irq inversion bugs
  lockdep: Print a nicer description for simple deadlocks
  lockdep: Print a nicer description for normal deadlocks
  lockdep: Print a nicer description for irq lock inversions

1 files changed, 15 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 17ac5f87182d..9b1707b5f646 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -238,6 +238,21 @@ config DETECT_HUNG_TASK
           enabled then all held locks will also be reported. This
           feature has negligible overhead.
 
+config DEFAULT_HUNG_TASK_TIMEOUT
+        int "Default timeout for hung task detection (in seconds)"
+        depends on DETECT_HUNG_TASK
+        default 120
+        help
+          This option controls the default timeout (in seconds) used
+          to determine when a task has become non-responsive and should
+          be considered hung.
+
+          It can be adjusted at runtime via the kernel.hung_task_timeout
+          sysctl or by writing a value to /proc/sys/kernel/hung_task_timeout.
+
+          A timeout of 0 disables the check.  The default is two minutes.
+          Keeping the default should be fine in most cases.
+
 config BOOTPARAM_HUNG_TASK_PANIC
         bool "Panic (Reboot) On Hung Tasks"
         depends on DETECT_HUNG_TASK