First usage golang benchmarks in Ubuntu WSL

Hi there!

Some days ago I first time faces with benchmarks in go and did hands-on for my class. If you use Windows + WSL Ubuntu for Golang, my experience would be useful for you.

I faced couple of problems with components, lets talk about

No Graphvis for pprof

I made my first profile

$ go test -bench=BenchmarkGetDomainStat -cpuprofile=cpu -memprofile=mem
$ go tool pprof -http="localhost:8080" cpu

Serving web UI on http://localhost:8080
Failed to execute dot. Is Graphviz installed?
exec: "dot": executable file not found in $PATH

There is no Graphviz. Google it up, we have to install graphviz:

$ sudo apt install graphviz gv

If you get some fails like I:

E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/g/ghostscript/ghostscript-x_9.26~dfsg+0-0ubuntu0.18.04.15_amd64.deb  404  Not Found [IP: 91.189.91.38 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

just update and repeat:

$ sudo apt-get update
$ sudo apt install graphviz gv

Whoa! You have your graphviz and pprof ready to show you cool graphs.

No benchstat

I installed Go 1.17.1 and forget about anything. But in case of benchmarks i want to compare two results:

$ benchstat benchmarks/00 benchmarks/01
benchstat: command not found

WTF? there is no benchstat installed by default, lets fix it:

$ go get golang.org/x/perf/cmd/benchstat
go: downloading golang.org/x/perf v0.0.0-20220722155240-3d85ee92886d
go get: added golang.org/x/perf v0.0.0-20220722155240-3d85ee92886d

also go get informs me about deprecating and offers to use 'go install'. Good idea for trying next time

Now lets check result:

$ benchstat benchmarks/00 benchmarks/01
name             old time/op  new time/op  delta
GetDomainStat-8   1.15s ±75%   0.36s ±11%  -69.05%  (p=0.000 n=10+10)

Cool, benchstat is avaible and my optimizations work well

I hope my googling is helpful and will save few minutes for you, my dear Windows WSL gophers!