统计几个进程的vruntime

vruntime.rb

def pick_pids(tasks)
  pids = tasks.map do |t|
    pids = `pgrep #{t}`.scan(/\d+/).map(&:to_i)
    pids.sample
  end
  pids
end

def vruntimes(pids)
  results = []
  pids.each_with_index do |pid, i|
    open("/proc/#{pid}/sched") do |f|
      content = f.read
      results[i] = content.scan(/vruntime\D*(\d+\.\d+)/)[0][0].to_f
    end 
  end
  results
end

def min_vruntime
  open('/proc/sched_debug').read.scan(/min_vruntime\D*(\d+\.\d+)/)[0][0].to_f
end

require 'json'
require 'pp'

if $0 == __FILE__
  timestamp_start = Time.now.to_f
  tasks = %w{chromium ksoftirqd gnome-terminal bash dbus-daemon gnome-panel ruby}
  pids = pick_pids(tasks)
  5000.times do
    timestamp_offset = Time.now.to_f - timestamp_start
    break if timestamp_offset > 30.0
    puts [timestamp_offset, *vruntimes(pids), min_vruntime] * "\t"
    sleep 0.005
  end
end