Merge tag 'wq-for-6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue updates from Tejun Heo:

 - Rework the rescuer to process work items one-by-one instead of
   slurping all pending work items in a single pass.

   As there is only one rescuer per workqueue, a single long-blocking
   work item could cause high latency for all tasks queued behind it,
   even after memory pressure is relieved and regular kworkers become
   available to service them.

 - Add CONFIG_BOOTPARAM_WQ_STALL_PANIC build-time option and
   workqueue.panic_on_stall_time parameter for time-based stall panic,
   giving systems more control over workqueue stall handling.

 - Replace BUG_ON() with panic() in the stall panic path for clearer
   intent and more informative output.

* tag 'wq-for-6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: replace BUG_ON with panic in panic_on_wq_watchdog
  workqueue: add time-based panic for stalls
  workqueue: add CONFIG_BOOTPARAM_WQ_STALL_PANIC option
  workqueue: Process extra works in rescuer on memory pressure
  workqueue: Process rescuer work items one-by-one using a cursor
  workqueue: Make send_mayday() take a PWQ argument directly

Documentation/admin-guide/kernel-parameters.txt

@@ -8376,7 +8376,16 @@ Kernel parameters
 			CONFIG_WQ_WATCHDOG. It sets the number times of the
 			stall to trigger panic.
 
-			The default is 0, which disables the panic on stall.
+			The default is set by CONFIG_BOOTPARAM_WQ_STALL_PANIC,
+			which is 0 (disabled) if not configured.
+
+	workqueue.panic_on_stall_time=<uint>
+			Panic when a workqueue stall has been continuous for
+			the specified number of seconds. Unlike panic_on_stall
+			which counts accumulated stall events, this triggers
+			based on the duration of a single continuous stall.
+
+			The default is 0, which disables the time-based panic.
 
 	workqueue.cpu_intensive_thresh_us=
 			Per-cpu work items which run for longer than this