py-spy> Sampling process 500 times a second for 14 seconds. Press Control-C to exit.

py-spy> Wrote raw flamegraph data to 'bench/profiles/python-only-round3-before-workers/stacks.txt'. Samples: 5543 Errors: 0
py-spy> You can use the flamegraph.pl script from https://github.com/brendangregg/flamegraph to generate a SVG