When I find rust is slow

It's crazy, I found a case where Rust is slower than Python! But, really?

Setup

Reproduce the same result requires:

• Rust Development Tools (cargo, rustc, ..)
• Python Development Tools (python3, venv)
• hyperfine (benchmark runner)
• CPU (one of AMD Ryzen 9 5950X, AMD R7 5700X, AMD Ryzen 9 5900X)

Quick Start

./bench python-fs-read rust-std-fs-read

For example:

:) `./bench python-fs-read rust-std-fs-read`
    Finished release [optimized] target(s) in 0.00s
Benchmark 1: python-fs-read/test.py
  Time (mean ± σ):      22.6 ms ±   1.5 ms    [User: 8.0 ms, System: 14.4 ms]
  Range (min … max):    21.1 ms …  30.1 ms    115 runs
 
Benchmark 2: rust-std-fs-read/target/release/test
  Time (mean ± σ):      26.2 ms ±   1.4 ms    [User: 0.3 ms, System: 26.1 ms]
  Range (min … max):    25.4 ms …  36.2 ms    107 runs

If python has lower System time than rust, you reproduce the same result.