linux-kernel - [tip:sched/core] watchdog: Reduce message verbosity

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Message-ID: <tip-1b6266ebe3da8198e9a02fbad77bbb56e2f7ce2e@git.kernel.org>
Date:   Fri, 3 Aug 2018 03:24:50 -0700
From:   tip-bot for Sinan Kaya <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     colin.king@...onical.com, mingo@...nel.org,
        kstewart@...uxfoundation.org, gregkh@...uxfoundation.org,
        dzickus@...hat.com, linux-kernel@...r.kernel.org, hpa@...or.com,
        tglx@...utronix.de, peterz@...radead.org, okaya@...nel.org
Subject: [tip:sched/core] watchdog: Reduce message verbosity

Commit-ID:  1b6266ebe3da8198e9a02fbad77bbb56e2f7ce2e
Gitweb:     https://git.kernel.org/tip/1b6266ebe3da8198e9a02fbad77bbb56e2f7ce2e
Author:     Sinan Kaya <okaya@...nel.org>
AuthorDate: Thu, 2 Aug 2018 23:09:41 -0700
Committer:  Thomas Gleixner <tglx@...utronix.de>
CommitDate: Fri, 3 Aug 2018 12:19:08 +0200

watchdog: Reduce message verbosity

Code is emitting the following error message during boot on systems
without PMU hardware support while probing NMI capability.

 NMI watchdog: Perf event create on CPU 0 failed with -2

This error is emitted as the perf subsystem returns -ENOENT due to lack of
PMUs in the system.

It is followed by the warning that NMI watchdog is disabled:

  NMI watchdog: Perf NMI watchdog permanently disabled

While NMI disabled information is useful for ordinary users, seeing a PERF
event create failed with error code -2 is not.

Reduce the message severity to debug so that if debugging is still possible
in case the error code returned by perf is required for analysis.

Signed-off-by: Sinan Kaya <okaya@...nel.org>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Acked-by: Don Zickus <dzickus@...hat.com>
Cc: Kate Stewart <kstewart@...uxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Colin Ian King <colin.king@...onical.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=599368
Link: https://lkml.kernel.org/r/20180803060943.2643-1-okaya@kernel.org

---
 kernel/watchdog_hld.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c
index e449a23e9d59..1f7020d65d0a 100644
--- a/kernel/watchdog_hld.c
+++ b/kernel/watchdog_hld.c
@@ -175,8 +175,8 @@ static int hardlockup_detector_event_create(void)
 	evt = perf_event_create_kernel_counter(wd_attr, cpu, NULL,
 					       watchdog_overflow_callback, NULL);
 	if (IS_ERR(evt)) {
-		pr_info("Perf event create on CPU %d failed with %ld\n", cpu,
-			PTR_ERR(evt));
+		pr_debug("Perf event create on CPU %d failed with %ld\n", cpu,
+			 PTR_ERR(evt));
 		return PTR_ERR(evt);
 	}
 	this_cpu_write(watchdog_ev, evt);