Go Profiling - Wrong file

Question

I'm doing profiling in Go using github.com/pkg/profile and it's creating the file when I run my code, but the return comes from the example page code, how would it be to run through my code? thanks in advance

Code:

package main

import (
    "fmt"
    "github.com/pkg/profile"
    "time"
)

func main() {

    defer profile.Start(profile.MemProfile).Stop()

    var inicio = time.Now().UnixNano()

    var text = "Olá Mundo!"

    fmt.Println(text)

    var fim = time.Now().UnixNano()

    fmt.Println(fim - inicio)

}

Return:

you need to do something, where in you need to do something much more practical, profiler is not getting enough samples(enough time) to acquire any data. — nilsocket, Oct 19 '18 at 05:21
@nilsocket but even in the most complex examples the result is this — Henrique Buzin, Oct 19 '18 at 11:44
`pkg/profile` outputs the profiling file to `/tmp` directory, are you opening that file? If so then may be you are not allocating enough memory to actually look at something. — nilsocket, Oct 19 '18 at 11:48

nilsocket · Accepted Answer · 2018-10-20T03:36:57.573

You can change your profile output path to to your current working directory,

profile.ProfilePath(path)

If you are unable to make retrieve any samples, it either means your MemProfileRate is not small enough to actually capture small changes.

If you are allocation less amount of memory, then set the MemProfileRate to lesser value, If you are allocating large amount of memory, just keep to default. If you think you capturing minor memory changes, then increase the MemProfileRate.

profile.MemProfileRate(100)

and one thing you shouldn't forget when you are using profile package is your call should be deferred.

defer profile.Start(xxx).Stop()

Here is the complete program.

package main

import (
    "os"

    "github.com/pkg/profile"
)

func main() {
    dir, _ := os.Getwd()
    defer profile.Start(profile.MemProfile, profile.MemProfileRate(100), profile.ProfilePath(dir)).Stop()
    //decrease mem profile rate for capturing more samples
    for i := 0; i < 10000; i++ {
        tmp := make([]byte, 100000)
        tmp[0] = tmp[1] << 0 //fake workload
    }
}

you can also set profile path for having the profile output in your current workign directory.

Go Profiling - Wrong file

1 Answers1