[BUG] CPU usage (FreeBSD kevent/kqueue)

I have a FreeBSD host with many jails. In each jail a salt-minion is installed. Although each minion consumes something like 0.1% CPU it starts to have an impact on the load average.

Running truss -p <pid_of_minion> I noticed the following:

kevent(9,0x0,0,{ },1000,{ 0.640124878 })         = 0 (0x0)
getpid()                                         = 18245 (0x4745)
kevent(9,0x0,0,{ },1000,{ 0.958296299 })         = 0 (0x0)
getpid()                                         = 18245 (0x4745)
kevent(9,0x0,0,{ },1000,{ 0.963230610 })         = 0 (0x0)
getpid()                                         = 18245 (0x4745)
kevent(9,0x0,0,{ },1000,{ 0.973388911 })         = 0 (0x0)
getpid()                                         = 18245 (0x4745)
(...)

It happens every second (kevent followed by a getpid).
I'm wondering if this could be the cause of CPU usage and why should it be run every second? Is it configurable?

This is on FreeBSD 13.0-RELEASE with:

chimay% salt --versions-report
Salt Version:
          Salt: 3004
 
Dependency Versions:
          cffi: 1.14.6
      cherrypy: Not Installed
      dateutil: Not Installed
     docker-py: Not Installed
         gitdb: Not Installed
     gitpython: Not Installed
        Jinja2: 3.0.1
       libgit2: Not Installed
      M2Crypto: Not Installed
          Mako: Not Installed
       msgpack: 1.0.2
  msgpack-pure: Not Installed
  mysql-python: Not Installed
     pycparser: 2.20
      pycrypto: Not Installed
  pycryptodome: 3.10.1
        pygit2: Not Installed
        Python: 3.8.12 (default, Nov 27 2021, 21:04:30)
  python-gnupg: Not Installed
        PyYAML: 5.4.1
         PyZMQ: 22.3.0
         smmap: Not Installed
       timelib: Not Installed
       Tornado: 4.5.3
           ZMQ: 4.3.4
 
System Versions:
          dist: freebsd 13.0 
        locale: utf-8
       machine: amd64
       release: 13.0-RELEASE-p4
        system: FreeBSD
       version: FreeBSD 13.0 

Start by reproducing the behavior on FreeBSD 13.0 with a Salt 3004 minion and inspect the kevent/getpid sequence shown by truss. Trace the minion's event-loop path to determine why it wakes every second and whether an existing configuration controls that interval. Done means identifying the cause and documenting or testing a concrete correction.