wiki: allocfreetrace=1 doesn't work & traceallocfree is not documented · golang/go#75183

(8 留言) (0 反應) (1 負責人)Go (133,883 star) (19,008 fork)batch import

DocumentationNeedsFixcompiler/runtimehelp wanted

描述

Go version

go version go1.25.0 darwin/arm64

Output of `go env` in your module/workspace:

AR='ar'
CC='clang'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='clang++'
GCCGO='gccgo'
GO111MODULE=''
GOARCH='arm64'
GOARM64='v8.0'
GOAUTH='netrc'
GOBIN='/Users/glen/.local/share/mise/installs/go/1.25.0/bin'
GOCACHE='/Users/glen/Library/Caches/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/Users/glen/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/0y/vtlpbcf55j1_jvbs92x2fsrh0000gn/T/go-build849456377=/tmp/go-build -gno-record-gcc-switches -fno-common'
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMOD='/Users/glen/Development/Geckoboard/turnstile/go.mod'
GOMODCACHE='/Users/glen/go/pkg/mod'
GONOPROXY='github.com/geckoboard'
GONOSUMDB='github.com/geckoboard'
GOOS='darwin'
GOPATH='/Users/glen/go'
GOPRIVATE='github.com/geckoboard'
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/Users/glen/.local/share/mise/installs/go/1.25.0'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/Users/glen/Library/Application Support/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='local'
GOTOOLDIR='/Users/glen/.local/share/mise/installs/go/1.25.0/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.25.0'
GOWORK=''
PKG_CONFIG='pkg-config'

What did you do?

I am attempting to get a trace of allocations being performed on a small amount of code for optimization purposes

As documented here: https://go.dev/wiki/Performance#memory-allocator-trace

So I ran

GODEBUG=traceallocfree=1 go test .

What did you see happen?

Just the output of my tests running

What did you expect to see?

When running under Go 1.19 the flag produces large amounts of allocation trace information

I was able to find https://github.com/golang/go/issues/68885, which has been closed and locked, and links to https://go-review.googlesource.com/c/go/+/583376 - however that CL does not reference any related Go issue or explanation.

I can see a related CL https://go-review.googlesource.com/c/go/+/583377/4 that refers to a GODEBUG of traceallocfree, but I can find no further reference to this anywhere else, and enabling it when executing a binary does not appear to do anything

What is the current state of allocation tracing?

貢獻者指南

技術棧: go
領域: documentationperformance
議題類型: documentation
難度: 3
預計時間: 1-2 days
活動狀態: needs maintainer response
清晰度: clear
前置要求: Basic Go knowledgeUnderstanding of GODEBUG flagsFamiliarity with Go runtime internals
新手友善度: 40
研究方向: This issue reports that the GODEBUG=traceallocfree=1 flag does not produce any output, and the feature is undocumented. Related CLs are https://go review.googlesource.com/c/go/+/583376 and https://go review.googlesource.com/c/go/+/583377. To resolve, investigate the current implementation of allocation tracing, verify whether the flag is correctly registered, and update the wiki page at https://go.dev/wiki/Performance#memory allocator trace. The issue has one assignee but no linked PR, so coordinate with them or the Go team to clarify the intended behavior and document it.

描述