Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue update from Tejun Heo:
 "Workqueue changes for v4.5.  One cleanup patch and three to improve
  the debuggability.

  Workqueue now has a stall detector which dumps workqueue state if any
  worker pool hasn't made forward progress over a certain amount of time
  (30s by default) and also triggers a warning if a workqueue which can
  be used in memory reclaim path tries to wait on something which can't
  be.

  These should make workqueue hangs a lot easier to debug."

* 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: simplify the apply_workqueue_attrs_locked()
  workqueue: implement lockup detector
  watchdog: introduce touch_softlockup_watchdog_sched()
  workqueue: warn if memory reclaim tries to flush !WQ_MEM_RECLAIM workqueue

1 files changed, 11 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 8c15b29d5adc..3048bf5b729a 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -812,6 +812,17 @@ config BOOTPARAM_HUNG_TASK_PANIC_VALUE
 	default 0 if !BOOTPARAM_HUNG_TASK_PANIC
 	default 1 if BOOTPARAM_HUNG_TASK_PANIC
 
+config WQ_WATCHDOG
+	bool "Detect Workqueue Stalls"
+	depends on DEBUG_KERNEL
+	help
+	  Say Y here to enable stall detection on workqueues.  If a
+	  worker pool doesn't make forward progress on a pending work
+	  item for over a given amount of time, 30s by default, a
+	  warning message is printed along with dump of workqueue
+	  state.  This can be configured through kernel parameter
+	  "workqueue.watchdog_thresh" and its sysfs counterpart.
+
 endmenu # "Debug lockups and hangs"
 
 config PANIC_ON_OOPS