java为什么JMHSample_12_Forking fork0比fork1更胖？

Question

我正在读JMH的样本

为什么measure_1_c1()更快 比measure_4_forked_c1()或measure_5_forked_c2()

Find code here

    @Benchmark
    @Fork(0)
    public int measure_1_c1() {
        return measure(c1);
    }


    @Benchmark
    @Fork(1)
    public int measure_4_forked_c1() {
        return measure(c1);
    }

日志Result here

Benchmark                                 Mode  Cnt   Score   Error  Units
JMHSample_12_Forking.measure_1_c1         avgt    5   3.940 ± 0.097  ns/op
JMHSample_12_Forking.measure_2_c2         avgt    5  28.298 ± 0.253  ns/op
JMHSample_12_Forking.measure_3_c1_again   avgt    5  27.643 ± 0.702  ns/op
JMHSample_12_Forking.measure_4_forked_c1  avgt    5   5.974 ± 0.618  ns/op
JMHSample_12_Forking.measure_5_forked_c2  avgt    5   5.734 ± 0.838  ns/op