Record a time-consuming and unstable interface in the Go language: ioutil.ReadAll()

This interface is time-consuming and unstable, at least 1ms, up to 120ms or even longer .
Possible reason: The bottom layer of the interface needs to apply for memory, which may be time-consuming for this part.

Interface address: https://golang.org/pkg/io/ioutil/#ReadAll
Reference link: https://blog.csdn.net/xuefeng1207/article/details/87939737