x/benchmarks/sweet: support for arm64

[prattmic]

I am testing on a GCE T2A arm64 instance running Debian bullseye. So far I've encountered a few issues:

• fogleman-fauxgl is either extremely slow or completely stuck. Needs more investigation.
• go-build fails due to error creating systemd-run user scope: test.scope: Failed to add PIDs to scope's control group: Permission denied

cc @mknyszek

[prattmic]

(The latter issue in particular may be a general Debian bullseye issue, rather than an arm64 issue)

[gopherbot]

Change https://go.dev/cl/426237 mentions this issue: sweet/benchmarks/go-build: pass through stdout/stderr

[gopherbot]

Change https://go.dev/cl/426238 mentions this issue: sweet/benchmark/internal/cgroups: test system-run functionality

[prattmic]

fogleman-fauxgl is either extremely slow or completely stuck.

It is stuck. We get stuck in this loop because d is +Inf and thus x0 + int(d) overflows and becomes a huge negative number. The immediate cause is division by zero in one of ra12, ra20, or ra01 (which one varies). The reproduction is very consistent, always on the 34641st call to rasterize in go run ./examples/animate.go ./examples/boat.stl from https://github.com/fogleman/fauxgl.

I can't follow this code well enough to tell if this is a legitimate floating point compilation issue on arm64 in the compiler, or this is a bug in the library not handling infinity properly. That said, I suspect the latter given that there is already a special case for spurious d < 0.

[gopherbot]

Change https://go.dev/cl/426714 mentions this issue: sweet/cmd/sweet: disable fogleman-fauxgl on arm64

[zhangfannie]

@prattmic The error message when running system-run is printed in the benchmark result file, which can easily lead users to mistakenly think that the benchmark itself has failed.
Can we not print the error message of running system-run? Or are there other considerations?
Below is the result of the go-build benchmark.

# warning: systemd-run not available: system-run failed: exit status 1

journalctl output: -- No entries --

systemctl cleanup error: exit status 1
output: Failed to reset failed state of unit systemd-run-test-1706769187427737350.scope: Unit systemd-run-test-1706769187427737350.scope not loaded.

# skipping cgroup wrapper...
BenchmarkGoBuildKubelet 1 53021729362 ns/op
BenchmarkGoBuildKubeletLink 1 11654922090 ns/op

Thank you.

[prattmic]

I think it would be nice to print the warning once, but I agree the full output is noisy. Feel free to send a CL simplifying it.

[zhangfannie]

Feel free to send a CL simplifying it.

Thank you for your reply.
Since x/benchmarks is not our internal repo for the time being, considering that this will not affect performance testing, we will put it aside for now.
Thank you.