[PATCH v11 2/2] hung_task: Log summary line when warning budget is exhausted

[Aaron Tomlin]

Once the warning budget is exhausted, hung_task_info() normally stops
printing per-task details. When panic is triggered, full details are
still printed so diagnostics remain available before panic.

To retain visibility without restoring per-task output after budget
exhaustion, emit a single aggregate summary line at the end of each
watchdog scan that detects hung tasks with an exhausted budget. This
keeps non-panic per-task reports budgeted during system-wide hangs.

Suggested-by: Petr Mladek <pmladek@xxxxxxxx>
Suggested-by: Lance Yang <lance.yang@xxxxxxxxx>
Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>
Reviewed-by: Lance Yang <lance.yang@xxxxxxxxx>
Reviewed-by: Bradley Morgan <brads@xxxxxxxxxxxxxx>
Signed-off-by: Aaron Tomlin <atomlin@xxxxxxxxxxx>
---
 kernel/hung_task.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index a5043188456d..b8554aedc589 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -276,8 +276,8 @@ static void hung_task_info(struct task_struct *t, unsigned long timeout,
 		sched_show_task(t);
 		debug_show_blocker(t, timeout);
 
-		if (!hung_task_warnings_budget)
-			pr_info("Future hung task reports are suppressed, see sysctl kernel.hung_task_warnings\n");
+		if (!hung_task_warnings_budget && !hung_task_call_panic)
+			pr_info("hung_task: further per-task details suppressed until warning budget is reset (see sysctl kernel.hung_task_warnings)\n");
 	}
 
 	touch_nmi_watchdog();
@@ -363,6 +363,10 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout)
 		return;
 	}
 
+	if (!hung_task_warnings_budget && !hung_task_call_panic)
+		pr_info("hung_task: %lu hung tasks detected, warning budget exhausted\n",
+			this_round_count);
+
 	if (need_warning || hung_task_call_panic) {
 		si_mask |= SYS_INFO_LOCKS;
 
-- 
2.55.0