Bug#599368: [PATCH v2] 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>
---
Further improved the error message based on Cesare's comments.
Ben.
Documentation/kernel-parameters.txt | 2 +-
kernel/watchdog.c | 3 ++-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 7d0cead..6fc0cf4 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1764,7 +1764,7 @@ 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 d74e866..d7ebdf4 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -366,7 +366,8 @@ 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 */
--
1.7.2.3
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