main.go is a simple go binary that sometimes leaves a hanging process that takes 100% CPU on MacOS M1 machines.
forkexec.c is a C program that forks a process in a new thread and then exits.
This seems to be a bug in the macOS kernel, not Go after all.
Unsure whether this is limited to MacOS M1; I've replicated on the following platforms so far:
- Replicated: go version go1.18.1 darwin/arm64
- Could not replicate: amd64 running under rosetta
Run ./test_race_c or ./test_race_go to create a binary with a random name, run the binary a bunch of times, and check for a process
created by that binary. It often takes several attemtpts to get a reproduction.
Run kill_repros to kill all of the hanging processes, which each take 90-100% CPU.
Related github issue: golang/go#53863