Bug#599368: [124/152] watchdog: Improve initialisation error message and documentation
- To: linux-kernel@vger.kernel.org, stable@kernel.org
- Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ben Hutchings <ben@decadent.org.uk>, 599368@bugs.debian.org, 608138@bugs.debian.org, Don Zickus <dzickus@redhat.com>, Frederic Weisbecker <fweisbec@gmail.com>, Ingo Molnar <mingo@elte.hu>
- Subject: Bug#599368: [124/152] watchdog: Improve initialisation error message and documentation
- From: Greg KH <gregkh@suse.de>
- Date: Wed, 05 Jan 2011 16:23:43 -0800
- Message-id: <[🔎] 20110106002308.434740955@clark.site>
- Reply-to: Greg KH <gregkh@suse.de>, 599368@bugs.debian.org
- In-reply-to: <20110106002500.GA3172@kroah.com>
2.6.36-stable review patch. If anyone has any objections, please let us know.
------------------
From: Ben Hutchings <ben@decadent.org.uk>
commit 551423748a4eba55f2eb0fc250d757986471f187 upstream.
The error message 'NMI watchdog failed to create perf event...'
does not make it clear that this is a fatal error for the
watchdog. It also currently prints the error value as a
pointer, rather than extracting the error code with PTR_ERR().
Fix that.
Add a note to the description of the 'nowatchdog' kernel
parameter to associate it with this message.
Reported-by: Cesare Leonardi <celeonar@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: 599368@bugs.debian.org
Cc: 608138@bugs.debian.org
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <[🔎] 1294009362.3167.126.camel@localhost>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
Documentation/kernel-parameters.txt | 2 +-
kernel/watchdog.c | 3 ++-
2 files changed, 3 insertions(+), 2 deletions(-)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1745,7 +1745,7 @@ and is between 256 and 4096 characters.
nousb [USB] Disable the USB subsystem
- nowatchdog [KNL] Disable the lockup detector.
+ nowatchdog [KNL] Disable the lockup detector (NMI watchdog).
nowb [ARM]
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -377,7 +377,8 @@ static int watchdog_nmi_enable(int cpu)
goto out_save;
}
- printk(KERN_ERR "NMI watchdog failed to create perf event on cpu%i: %p\n", cpu, event);
+ printk(KERN_ERR "NMI watchdog disabled for cpu%i: unable to create perf event: %ld\n",
+ cpu, PTR_ERR(event));
return -1;
/* success path */
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