如何获得命中率，例如：

(pprof) top
Total: 2525 samples
     298  11.8%  11.8%      345  13.7% runtime.mapaccess1_fast64
     268  10.6%  22.4%     2124  84.1% main.FindLoops

不，持续时间如下：

(pprof) top
2220ms of 3080ms total (72.08%)
Dropped 72 nodes (cum <= 15.40ms)
Showing top 10 nodes out of 111 (cum >= 60ms)
      flat  flat%   sum%        cum   cum%
    1340ms 43.51% 43.51%     1410ms 45.78%  runtime.cgocall_errno

env：我使用golang1.4，添加以下代码。

defer pprof.StopCPUProfile()
f, err := os.Create("innercpu.pprof")
if err != nil {
    fmt.Println("Error: ", err)
}
pprof.StartCPUProfile(f)