* [PATCH] watchdog: Reduce message verbosity
@ 2018-07-30 19:09 Sinan Kaya
2018-07-30 19:28 ` Don Zickus
2018-08-02 12:18 ` Thomas Gleixner
0 siblings, 2 replies; 6+ messages in thread
From: Sinan Kaya @ 2018-07-30 19:09 UTC (permalink / raw)
To: linux-kernel
Cc: Sinan Kaya, Thomas Gleixner, Don Zickus, Ingo Molnar,
Philippe Ombredanne, Greg Kroah-Hartman, Colin Ian King,
Peter Zijlstra
Reducing the verbosity level to debug for people that are interested in
debugging watchdog issues.
[ 0.152492] NMI watchdog: Perf event create on CPU 0 failed with -2
[ 0.156002] NMI watchdog: Perf NMI watchdog permanently disabled
Signed-off-by: Sinan Kaya <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);
--
2.17.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] watchdog: Reduce message verbosity
2018-07-30 19:09 [PATCH] watchdog: Reduce message verbosity Sinan Kaya
@ 2018-07-30 19:28 ` Don Zickus
2018-07-30 19:43 ` Sinan Kaya
2018-08-02 12:18 ` Thomas Gleixner
1 sibling, 1 reply; 6+ messages in thread
From: Don Zickus @ 2018-07-30 19:28 UTC (permalink / raw)
To: Sinan Kaya
Cc: linux-kernel, Thomas Gleixner, Ingo Molnar, Philippe Ombredanne,
Greg Kroah-Hartman, Colin Ian King, Peter Zijlstra
On Mon, Jul 30, 2018 at 12:09:47PM -0700, Sinan Kaya wrote:
> Reducing the verbosity level to debug for people that are interested in
> debugging watchdog issues.
>
> [ 0.152492] NMI watchdog: Perf event create on CPU 0 failed with -2
> [ 0.156002] NMI watchdog: Perf NMI watchdog permanently disabled
Hi Sinan,
Any reason why? Usually when the 'perf event' fails, that indicates a
system problem. And most folks don't boot with the 'debug' option. This
means these unusual failures are hidden and become difficult to debug later
when it propagates.
Or are you running the watchdog in a different configuration such that this
is a common nuisance that you are trying to suppress?
Cheers,
Don
>
> Signed-off-by: Sinan Kaya <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);
> --
> 2.17.1
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] watchdog: Reduce message verbosity
2018-07-30 19:28 ` Don Zickus
@ 2018-07-30 19:43 ` Sinan Kaya
2018-08-01 15:59 ` Don Zickus
0 siblings, 1 reply; 6+ messages in thread
From: Sinan Kaya @ 2018-07-30 19:43 UTC (permalink / raw)
To: Don Zickus
Cc: linux-kernel, Thomas Gleixner, Ingo Molnar, Philippe Ombredanne,
Greg Kroah-Hartman, Colin Ian King, Peter Zijlstra
Hi Don,
On 7/30/2018 12:28 PM, Don Zickus wrote:
>> [ 0.152492] NMI watchdog: Perf event create on CPU 0 failed with -2
>> [ 0.156002] NMI watchdog: Perf NMI watchdog permanently disabled
> Hi Sinan,
>
> Any reason why? Usually when the 'perf event' fails, that indicates a
> system problem. And most folks don't boot with the 'debug' option. This
> means these unusual failures are hidden and become difficult to debug later
> when it propagates.
Sorry, I should have been more clear. I'm only suppressing the first
error message.
[ 0.152492] NMI watchdog: Perf event create on CPU 0 failed with -2
Second message is still visible during boot. User knows that NMI
watchdog is disabled.
[ 0.156002] NMI watchdog: Perf NMI watchdog permanently disabled
Code is trying to probe the platform capabilities and is failing
because of missing PMU in the system. If someone is interested in
finding out why watchdog was disabled, they can turn on the debug
message level.
>
> Or are you running the watchdog in a different configuration such that this
> is a common nuisance that you are trying to suppress?
Yup, system doesn't support PMU.
>
> Cheers,
> Don
>
Sinan
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] watchdog: Reduce message verbosity
2018-07-30 19:43 ` Sinan Kaya
@ 2018-08-01 15:59 ` Don Zickus
0 siblings, 0 replies; 6+ messages in thread
From: Don Zickus @ 2018-08-01 15:59 UTC (permalink / raw)
To: Sinan Kaya
Cc: linux-kernel, Thomas Gleixner, Ingo Molnar, Philippe Ombredanne,
Greg Kroah-Hartman, Colin Ian King, Peter Zijlstra
On Mon, Jul 30, 2018 at 12:43:34PM -0700, Sinan Kaya wrote:
> Hi Don,
>
> On 7/30/2018 12:28 PM, Don Zickus wrote:
> > > [ 0.152492] NMI watchdog: Perf event create on CPU 0 failed with -2
> > > [ 0.156002] NMI watchdog: Perf NMI watchdog permanently disabled
> > Hi Sinan,
> >
> > Any reason why? Usually when the 'perf event' fails, that indicates a
> > system problem. And most folks don't boot with the 'debug' option. This
> > means these unusual failures are hidden and become difficult to debug later
> > when it propagates.
>
> Sorry, I should have been more clear. I'm only suppressing the first
> error message.
>
> [ 0.152492] NMI watchdog: Perf event create on CPU 0 failed with -2
>
> Second message is still visible during boot. User knows that NMI watchdog is
> disabled.
>
> [ 0.156002] NMI watchdog: Perf NMI watchdog permanently disabled
>
> Code is trying to probe the platform capabilities and is failing
> because of missing PMU in the system. If someone is interested in
> finding out why watchdog was disabled, they can turn on the debug
> message level.
>
> >
> > Or are you running the watchdog in a different configuration such that this
> > is a common nuisance that you are trying to suppress?
>
> Yup, system doesn't support PMU.
Hi Sinan,
Oh, I see. You are just trying to hide the always failing probe. It seems
to make sense.
Acked-by: Don Zickus <dzickus@redhat.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] watchdog: Reduce message verbosity
2018-07-30 19:09 [PATCH] watchdog: Reduce message verbosity Sinan Kaya
2018-07-30 19:28 ` Don Zickus
@ 2018-08-02 12:18 ` Thomas Gleixner
2018-08-02 14:44 ` Sinan Kaya
1 sibling, 1 reply; 6+ messages in thread
From: Thomas Gleixner @ 2018-08-02 12:18 UTC (permalink / raw)
To: Sinan Kaya
Cc: linux-kernel, Don Zickus, Ingo Molnar, Philippe Ombredanne,
Greg Kroah-Hartman, Colin Ian King, Peter Zijlstra
On Mon, 30 Jul 2018, Sinan Kaya wrote:
> Reducing the verbosity level to debug for people that are interested in
> debugging watchdog issues.
>
> [ 0.152492] NMI watchdog: Perf event create on CPU 0 failed with -2
> [ 0.156002] NMI watchdog: Perf NMI watchdog permanently disabled
This changelog is utterly useless.
Thanks,
tglx
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] watchdog: Reduce message verbosity
2018-08-02 12:18 ` Thomas Gleixner
@ 2018-08-02 14:44 ` Sinan Kaya
0 siblings, 0 replies; 6+ messages in thread
From: Sinan Kaya @ 2018-08-02 14:44 UTC (permalink / raw)
To: Thomas Gleixner
Cc: linux-kernel, Don Zickus, Ingo Molnar, Philippe Ombredanne,
Greg Kroah-Hartman, Colin Ian King, Peter Zijlstra
On 8/2/2018 5:18 AM, Thomas Gleixner wrote:
> On Mon, 30 Jul 2018, Sinan Kaya wrote:
>
>> Reducing the verbosity level to debug for people that are interested in
>> debugging watchdog issues.
>>
>> [ 0.152492] NMI watchdog: Perf event create on CPU 0 failed with -2
>> [ 0.156002] NMI watchdog: Perf NMI watchdog permanently disabled
>
> This changelog is utterly useless.
I'll capture my conversation with Don into the commit message and post
post V2.
>
> Thanks,
>
> tglx
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-08-02 14:44 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2018-07-30 19:09 [PATCH] watchdog: Reduce message verbosity Sinan Kaya
2018-07-30 19:28 ` Don Zickus
2018-07-30 19:43 ` Sinan Kaya
2018-08-01 15:59 ` Don Zickus
2018-08-02 12:18 ` Thomas Gleixner
2018-08-02 14:44 ` Sinan Kaya
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