class Concurrent::Utility::ProcessorCounter

def compute_cpu_shares
  if RbConfig::CONFIG["target_os"].include?("linux")
    if File.exist?("/sys/fs/cgroup/cpu.weight")
      # cgroups v2: https://docs.kernel.org/admin-guide/cgroup-v2.html#cpu-interface-files
      # Ref: https://github.com/kubernetes/enhancements/tree/master/keps/sig-node/2254-cgroup-v2#phase-1-convert-from-cgroups-v1-settings-to-v2
      weight = File.read("/sys/fs/cgroup/cpu.weight").to_f
      ((((weight - 1) * 262142) / 9999) + 2) / 1024
    elsif File.exist?("/sys/fs/cgroup/cpu/cpu.shares")
      # cgroups v1: https://kernel.googlesource.com/pub/scm/linux/kernel/git/glommer/memcg/+/cpu_stat/Documentation/cgroups/cpu.txt
      File.read("/sys/fs/cgroup/cpu/cpu.shares").to_f / 1024
    end
  end
end