From b1f712b308dcdb1af73e5fcf3d8bf8eb44b36600 Mon Sep 17 00:00:00 2001
From: fuyuanli <fuyuanli@didiglobal.com>
Date: Wed, 1 Feb 2023 21:54:33 +0800
Subject: [PATCH] hung_task: print message when hung_task_warnings gets down to
 zero.

It's useful to report it when hung_task_warnings gets down to zero, so
that we can know if kernel log was lost or there is no hung task was
detected.

Link: https://lkml.kernel.org/r/20230201135416.GA6560@didi-ThinkCentre-M920t-N000
Signed-off-by: fuyuanli <fuyuanli@didiglobal.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 kernel/hung_task.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index c71889f3f3fc..322813366c6c 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -142,6 +142,8 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
 
 		if (sysctl_hung_task_all_cpu_backtrace)
 			hung_task_show_all_bt = true;
+		if (!sysctl_hung_task_warnings)
+			pr_info("Future hung task reports are suppressed, see sysctl kernel.hung_task_warnings\n");
 	}
 
 	touch_nmi_watchdog();