RFC: Hiding per-CPU kernel output behind bootverbose

[Warner Losh]

On Fri, Apr 20, 2018 at 12:11 AM, Julian Elischer <julian at freebsd.org>
wrote:

> On 20/4/18 4:48 am, Steven Hartland wrote:
>
>> Sounds good to me, I think we could actually benefit from even quieter
>> modes if I’m honest.
>>
>> On Thu, 19 Apr 2018 at 21:09, Colin Percival <cperciva at tarsnap.com>
>> wrote:
>>
>> On large systems (e.g., EC2's x1e.32xlarge instance type, with 128 vCPUs)
>>> the boot time console output contains a large number of lines of the
>>> forms
>>>
>>> SMP: AP CPU #N Launched!
>>> cpuN: <ACPI CPU> on acpi0
>>> estN: <Enhanced SpeedStep Frequency Control> on cpuN
>>>
>>> Having 128 almost-identical lines of output doesn't seem very useful, and
>>> it actually has a nontrivial impact on the time spent booting.
>>>
>>> Does anyone mind if I hide these by default, having them only show up if
>>> boot verbosity is requested?
>>>
>>
https://reviews.freebsd.org/D15153 implements that for everything except
the CPU launched.

Warner