Commit 55142374 authored Jan 02, 2011 by Ben Hutchings Committed by Ingo Molnar Jan 03, 2011

watchdog: Improve initialisation error message and documentation



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>
Cc: <stable@kernel.org> # .37.x and later
LKML-Reference: <1294009362.3167.126.camel@localhost>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent b518a649

Documentation/kernel-parameters.txt

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -1759,7 +1759,7 @@ and is between 256 and 4096 characters. It is defined in the file

	nousb [USB] Disable the USB subsystem		nousb [USB] Disable the USB subsystem

	nowatchdog [KNL] Disable the lockup detector.		nowatchdog [KNL] Disable the lockup detector (NMI watchdog).

	nowb [ARM]		nowb [ARM]

kernel/watchdog.c

+2 −1

Original line number	Original line	Diff line number	Diff line
	@@ -364,7 +364,8 @@ static int watchdog_nmi_enable(int cpu)
	goto out_save;		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 PTR_ERR(event);		return PTR_ERR(event);

	/* success path */		/* success path */