What version of Go are you using (go version)?

$ go version
go version go1.15.5 linux/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/brent/.cache/go-build"
GOENV="/home/brent/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/brent/Projects/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/brent/Projects/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/lib/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/lib/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build211847425=/tmp/go-build -gno-record-gcc-switches"

What did you do?

I was trying to check the CPU time used by my program using syscall.Getrusage() and syscall.Rusage.Timeval.Nano().
Example code:

func GetCPU() int64 {
	use := new(syscall.Rusage)
	syscall.Getrusage(syscall.RUSAGE_SELF, use)
	return use.Utime.Nano() + use.Stime.Nano()
}

Link to playground: https://play.golang.org/p/-HYHrxvlzwv

What did you expect to see?

I expected the output of use.Utime.Nano() and use.Stime.Nano() to be in units of "nanoseconds elapsed since the Unix epoch" as the documentation states.

What did you see instead?

Instead, I think the results are just the nanoseconds of CPU time used, not nanoseconds since the Unix epoch. That seems to be how the underlying system calls work anyway, so I think the documentation just needs to be updated.