measure.rb

#!/usr/bin/env ruby

def mem(pid); `ps p #{pid} -o rss`.split.last.to_i; end
def cpu(pid); `ps p #{pid} -o pcpu`.split.last.to_i; end

t = Time.now
pid = Process.spawn(*ARGV.to_a, '1000')
mem_arr = []
cpu_arr = []

Thread.new do
  mem_arr << mem(pid)
  cpu_arr << cpu(pid)
  while true
    sleep 0.1
    m = mem(pid)
    mem_arr << m
    cpu = cpu(pid)
    cpu_arr << cpu
    # mm = m if m > mm
    # mcpu = cpu if cpu > mcpu
  end
end

Process.waitall

min_mem = mem_arr.min
max_mem = mem_arr.max
total_mem = mem_arr.inject(:+)
len_mem = mem_arr.length
avg_mem = total_mem.to_f/len_mem

min_cpu = cpu_arr.min
max_cpu = cpu_arr.max
total_cpu = cpu_arr.inject(:+)
len_cpu = cpu_arr.length
avg_cpu = total_cpu.to_f/len_cpu

STDERR.puts "TIME: %.2fs" % [Time.now - t]
STDERR.puts "MEM: min %fkB, max %fkB, avg %fkB" % [min_mem, max_mem, avg_mem]
STDERR.puts "CPU: min %f, max %f, avg %f" % [min_cpu, max_cpu, avg_cpu]