Re: boot markers ideas (was RE: [boot-time] jent_mod_init on beagleplay)

On 1/7/25 15:42, Bird, Tim wrote:
> 
> 
>> -----Original Message-----
>> From: Francesco Valla <[email protected]>
> ...
>>> I wanted to provide an update on my recent contributions to the BeaglePlay
>>> project. I have recently started contributing and have been analyzing the
>>> boot time of the init process. Below is the output from the system log:
>>>
>>> debian@BeaglePlay:~$ dmesg | grep "init process"
>>> [    1.480490] Run /init as init process
>>>
> ...
> 
>>
>> I started the same journey around a week ago, and it's proving a valuable
>> experience.
>>
>> After some trimming, I reached a (reported) init startup time of around 0.6s:
>>
>> root@beagleplay-ti:~# dmesg|grep /sbin
>> [    0.630046] Run /sbin/init as init process
> 
> 
> I'm starting to think that we should be using this particular kernel message
> as a consistent "boot marker" for kernel startup time.  It's certainly not the
> end of when the kernel is doing stuff on startup, but I do believe it marks
> one of the important transition points (start of user space activity), and
> it seems to be ubiquitously reported.
> 
> At Plumbers, I had proposed to introduce a set of specific instrumentation
> points in the kernel and use those as key checkpoints.  But IMHO it's good
> to use existing printk messages where possible, since they're already present - no
> additional instrumentation needed.

Is there a place to get this measuring script other than fishing it out 
of a webmail archive?

https://www.spinics.net/lists/linux-embedded/msg04363.html

The most recent wiki mention in the archive subject lines was 
https://www.spinics.net/lists/linux-embedded/msg04336.html and trying to 
find this effort in elinux.org's top right search bar found 
https://elinux.org/Boot-up_Time_Reduction_Howto which "view history" 
says was last touched in 2010...

Rob

P.S. Meanwhile, python 3 goes in quite the opposite direction: 
https://landley.net/notes-2024.html#09-04-2024