measuring Ruby GC

test_gc.rb

require 'benchmark'

def show_memory_consumption
	puts `pmap #{Process.pid} | tail -n 1`
end

#GC.disable
result = Benchmark.measure do 
	200.times { |i|
		"a"*100_000_000 
		#GC.start if i%20 == 0
	}
end
puts result

show_memory_consumption
GC.start
show_memory_consumption

pp GC.stat

# Run once, notice execution time, memory consumption and count of GC calls.
# Uncomment lines 7 and 11, run again, notice differences.