From: Ben Hutchings Date: Sun, 2 Jan 2011 23:02:42 +0000 (+0000) Subject: watchdog: Improve initialisation error message and documentation X-Git-Tag: firefly_0821_release~7613^2~3149^2~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=551423748a4eba55f2eb0fc250d757986471f187;p=firefly-linux-kernel-4.4.55.git 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 Signed-off-by: Ben Hutchings Cc: 599368@bugs.debian.org Cc: 608138@bugs.debian.org Cc: Don Zickus Cc: Frederic Weisbecker Cc: # .37.x and later LKML-Reference: <1294009362.3167.126.camel@localhost> Signed-off-by: Ingo Molnar --- diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 8b61c9360999..01ece1b9213e 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1759,7 +1759,7 @@ and is between 256 and 4096 characters. It is defined in the file nousb [USB] Disable the USB subsystem - nowatchdog [KNL] Disable the lockup detector. + nowatchdog [KNL] Disable the lockup detector (NMI watchdog). nowb [ARM] diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 6e3c41a4024c..5b082156cd21 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -364,7 +364,8 @@ 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 PTR_ERR(event); /* success path */