Repository: go
Issue: cmd/trace: Mininum mutator utilization plot window durations range is not consistent across Include options
Labels: NeedsInvestigation,compiler/runtime

<!-- Please answer these questions before submitting your issue. Thanks! -->

### What version of Go are you using (`go version`)?

<pre>
$ go version
go version go1.13.4 linux/amd64
</pre>

### Does this issue reproduce with the latest release?

Yes

### What operating system and processor architecture are you using (`go env`)?

<details><summary><code>go env</code> Output</summary><br><pre>
$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/eg/.cache/go-build"
GOENV="/home/eg/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/eg/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="/home/eg/go/src/bitbucket.org/triangleteam/resource-manager/go.mod"
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-build569889623=/tmp/go-build -gno-record-gcc-switches"
</pre></details>

### What did you do?

<details><summary>I wrote a simple code to check built in golang tracing:</summary><br>

```go
package main

import (
	"os"
	"runtime"
	"runtime/trace"
	"sync"
	"time"
)

func main() {
	f, err := os.Create("trace.out")
	if err != nil {
		panic(err)
	}

	trace.Start(f)
	defer func() {
		trace.Stop()
		_ = f.Close()
	}()

	wg := sync.WaitGroup{}

	for g := 0; g < runtime.NumCPU(); g++ {
		wg.Add(1)
		go func() {
			for i := 0; i < 40; i++ {
				bs := make([]byte, 1024*1024)
				for k := range bs {
					bs[k] = byte(k % 8)
				}
				time.Sleep(50 * time.Millisecond)
			}
			wg.Done()
		}()
	}

	wg.Wait()
}
```

</details>

After running this program and getting `trace.out` file as an output I do `$ go tool trace trace.out`, open `http://127.0.0.1:32935/mmu` in the browser and look at the plots with and without **STW** checkbox set.

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### What did you expect to see?

I expect that X-axis range (min and max *Window duration* for which MMU function is evaluated) is the same with **STW** set and not set.

### What did you see instead?
I see that with **STW** checkbox set the window duration range is `[1ms, ~10s]`, and when checkbox is unset range is `[1ns, 1ms]`.

![MMU with STW set](https://i.imgur.com/MMsqrJv.png)
![MMU with STW unset](https://i.imgur.com/s8qfIMi.png)

To conclude: if I get everything correctly, such behavior makes it harder to understand how GC affects the utilization. Should we make the window duration range consistent across any set of checked options? Or maybe we should make it possible for user to configure the range.