stress_mem.rb

@retained = []

MAX_STRING_SIZE = 100

def stress(allocate_count, retain_count, chunk_size)
  chunk = []
  while retain_count > 0 || allocate_count > 0
    if retain_count == 0 || (Random.rand < 0.5 && allocate_count > 0)
      chunk << " " * (Random.rand * MAX_STRING_SIZE).to_i
      allocate_count -= 1
      if chunk.length > chunk_size
        chunk = []
      end
    else
      @retained << " " * (Random.rand * MAX_STRING_SIZE).to_i
      retain_count -= 1
    end
  end
end

start = Time.now
stress(10_000_000, 600_000, 200_000)

duration = (Time.now - start).to_f

_, size = `ps ax -o pid,rss | grep -E "^[[:space:]]*#{$$}"`.strip.split.map(&:to_i)
puts "#{size},#{duration}"