Go version

go version go1.22.4 windows/amd64

Output of go env in your module/workspace:

λ go env
set GO111MODULE=
set GOARCH=amd64
set GOBIN=
set GOCACHE=e:\temp\gocache
set GOENV=C:\Users\klaus\AppData\Roaming\go\env
set GOEXE=.exe
set GOEXPERIMENT=
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMODCACHE=e:\gopath\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=e:\gopath
set GOPRIVATE=
set GOPROXY=https://goproxy.io,https://proxy.golang.org,direct
set GOROOT=C:\go
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLCHAIN=auto
set GOTOOLDIR=C:\go\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=go1.22.4
set GCCGO=gccgo
set GOAMD64=v1
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=c:\go\src\cmd\go.mod
set GOWORK=
set CGO_CFLAGS=-O2 -g
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-O2 -g
set CGO_FFLAGS=-O2 -g
set CGO_LDFLAGS=-O2 -g
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=e:\temp\wintemp\go-build3441812285=/tmp/go-build -gno-record-gcc-switches

What did you do?

Using go tool trace profile.trace (this is a v2 profile - the -pprof parameter is ignored)

Using sample profile: https://download.klauspost.com/profile.trace.gz

λ go tool trace profile.trace
2024/07/22 14:14:48 Preparing trace for viewer...
2024/07/22 14:14:53 Splitting trace for viewer...
2024/07/22 14:15:23 Opening browser. Trace viewer is listening on http://127.0.0.1:64503

Click links or download with:

curl http://127.0.0.1:64503/io?raw=1 -o io.pprof
curl http://127.0.0.1:64503/block?raw=1 -o block.pprof
curl http://127.0.0.1:64503/syscall?raw=1 -o syscall.pprof
curl http://127.0.0.1:64503/sched?raw=1 -o sched.pprof

What did you see happen?

Empty profiles:

λ ls -l
total 4
-rw-r--r-- 1 klaus 197121 90 Jul 22 14:19 block.pprof
-rw-r--r-- 1 klaus 197121 90 Jul 22 14:19 io.pprof
-rw-r--r-- 1 klaus 197121 90 Jul 22 14:19 sched.pprof
-rw-r--r-- 1 klaus 197121 90 Jul 22 14:19 syscall.pprof

What did you expect to see?

The advertised profiles.

Comment From: klauspost

Here is the output, just for completeness - output.zip

Comment From: gabyhelp

Related Issues and Documentation

(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)

Comment From: klauspost

It seems like pprofOverlappingDuration always returns 0. That is as far as I can go into debugging and still make sense of what is happening.

Replacing pprofOverlappingDuration with return sample.duration() makes it return something, but I don't know enough about the internals to tell how valid it is.

Comment From: dmitshur

CC @golang/runtime via owners.

Comment From: mknyszek

Hm, I'll look into this. I feel like I may have fixed a bug related to this recently -- I will try to dig it up.

Do you have the same problem with the Go 1.23rc2 toolchain? (Using the trace tool from that toolchain, I mean.)

Comment From: rhysh

This looks like what CL 578356 and CL 578318 fixed, for #66782. Checking that go1.23rc2 works should confirm.

Those CLs should probably get backported.

Comment From: mknyszek

Thanks @rhysh! That's exactly what I had in mind. Agreed on backporting.

Comment From: rhysh

@gopherbot please backport to Go 1.22. The impact is limited to local runs of go tool trace, but there's no workaround. And since the change only affects go tool trace, it's relatively low risk.

Comment From: gopherbot

Backport issue(s) opened: #68546 (for 1.22).

Remember to create the cherry-pick CL(s) as soon as the patch is submitted to master, according to https://go.dev/wiki/MinorReleases.

Comment From: gopherbot

Change https://go.dev/cl/600255 mentions this issue: cmd/trace/v2: handle the -pprof flag

Comment From: gopherbot

Change https://go.dev/cl/600275 mentions this issue: cmd/trace/v2: make the -pprof actually useful

Comment From: dmitshur

Closing in favor of #66782, since this is already fixed in Go 1.23.

(CL 600275 included "Fixes #68542" but cherry-pick CLs only close cherry-pick issues automatically, not regular issues.)