* Re: + nmi-watchdog-quiet-down-the-boot-messages.patch added to -mm tree
[not found] <20120608213709.B320BA022F@akpm.mtv.corp.google.com>
@ 2012-06-11 8:47 ` Ingo Molnar
2012-06-11 13:18 ` Don Zickus
0 siblings, 1 reply; 2+ messages in thread
From: Ingo Molnar @ 2012-06-11 8:47 UTC (permalink / raw)
To: akpm, dzickus
Cc: mm-commits, dzickus, joe, mingo, nzimmer, linux-kernel,
Peter Zijlstra
* akpm@linux-foundation.org <akpm@linux-foundation.org> wrote:
> From: Don Zickus <dzickus@redhat.com>
> Subject: nmi watchdog: quiet down the boot messages
>
> A bunch of bugzillas have complained how noisy the nmi_watchdog is during
> boot-up especially with its expected failure cases (like virt and bios
> resource contention).
>
> This is my attempt to quiet them down and keep it less confusing for the
> end user. What I did is print the message for cpu0 and save it for future
> comparisons. If future cpus have an identical message as cpu0, then don't
> print the redundant info. However, if a future cpu has a different
> message, happily print that loudly.
>
> Before the change, you would see something like:
>
> ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
> CPU0: Intel(R) Core(TM)2 Quad CPU Q9550 @ 2.83GHz stepping 0a
> Performance Events: PEBS fmt0+, Core2 events, Intel PMU driver.
> ... version: 2
> ... bit width: 40
> ... generic registers: 2
> ... value mask: 000000ffffffffff
> ... max period: 000000007fffffff
> ... fixed-purpose events: 3
> ... event mask: 0000000700000003
> NMI watchdog enabled, takes one hw-pmu counter.
> Booting Node 0, Processors #1
> NMI watchdog enabled, takes one hw-pmu counter.
> #2
> NMI watchdog enabled, takes one hw-pmu counter.
> #3 Ok.
> NMI watchdog enabled, takes one hw-pmu counter.
> Brought up 4 CPUs
> Total of 4 processors activated (22607.24 BogoMIPS).
the problem really was that it didn't print which CPU it
referred to - it just repeated the same message over and over
again.
If it said:
NMI watchdog enabled on CPU#0, takes one hw-pmu counter.
it would be far less confusing.
This:
> After the change, it is simplified to:
>
> ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
> CPU0: Intel(R) Core(TM)2 Quad CPU Q9550 @ 2.83GHz stepping 0a
> Performance Events: PEBS fmt0+, Core2 events, Intel PMU driver.
> ... version: 2
> ... bit width: 40
> ... generic registers: 2
> ... value mask: 000000ffffffffff
> ... max period: 000000007fffffff
> ... fixed-purpose events: 3
> ... event mask: 0000000700000003
> NMI watchdog enabled, takes one hw-pmu counter.
> Booting Node 0, Processors #1 #2 #3 Ok.
> Brought up 4 CPUs
Is fine too but should be clarified to something like:
NMI watchdog enabled on all CPUs, permanently consumes one hw-PMU counter
(Please note the capitalization of 'PMU' as well.)
Thanks,
Ingo
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