[yocto] CPU Load

[Ryan Meulenkamp]

Hi y'all,

I have some questions about CPU load and performance, but first some 
background information.

We have small embedded system running an openembedded classic (Angström) 
distro. Now to get ourselves up-to-date we started working on a new 
iteration of the OS based on openembedded core and Yocto. It is nearly 
finished now, if it weren't for one problem: The CPU load 
(/proc/loadavg) of the core/yocto based OS is more than double that of 
the classic/Angström OS.

So the way I see it this could be caused by a number of factors:

  - loadavg's calculation changed
  - certain newer versions of applications run heavier
  - The kernel itself is heavier (we upgraded from 2.6.35.14+ to 4.9.28+)
   - Possibly caused by some configs
  - ...

My question: is there something that changed since OE-classic that you 
know could be the cause of this? If not, how would I go about finding 
the cause? I don't think the top command is sufficient for this, because 
it's precision is such that many processes' CPU usage just become 0%. 
Also, both top and htop cause huge cpu loads themselves.

Any tips and tricks would be welcome!

Thanks in advance!

Ryan