Golang pprof完整调用图

I'm kinda new to pprof. I've started CPU profiling, and after a bit of time checked the top25. This is what I got:

Showing top 25 nodes out of 174
      flat  flat%   sum%        cum   cum%
  1.01mins 21.92% 21.92%   1.10mins 23.83%  time.Time.AppendFormat
  0.26mins  5.56% 27.48%   0.26mins  5.56%  type..eq.[65]runtime.sigTabT
  0.23mins  5.07% 32.55%   0.23mins  5.07%  type..hash.[3]runtime.symbol_key
  0.15mins  3.14% 35.69%   0.15mins  3.14%  type..hash.[9]string
  ...

I thought that's all cool, I just need to get rid of that time function. Then realized, I don't even use anything from the time pkg, so it must be either a third party lib, or one of the go internal functions.

So I've generated the graph with the -web flag, so I can see which function calls it, but it doesn't really show directly. Is there any way to track it down where it's coming from?