cmd/compile: compiling large packages uses too much memory

[pgimalac]

Go version

1.25.10, devel

Output of go env in your module/workspace:

AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE='auto'
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/home/bits/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/home/bits/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build119335857=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/home/bits/pgimalac/go/src/go.mod'
GOMODCACHE='/home/bits/go/pkg/mod'
GONOPROXY=''
GONOSUMDB='github.com/DataDog,go.ddbuild.io'
GOOS='linux'
GOPATH='/home/bits/go'
GOPRIVATE=''
GOROOT='/home/bits/pgimalac/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/home/bits/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/home/bits/pgimalac/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.27-devel_9df04115d6 Sat May 16 21:31:02 2026 -0700'
GOWORK=''
PKG_CONFIG='pkg-config'

What did you do?

Compile large Go packages (eg. github.com/aws/aws-sdk-go-v2/service/ec2 or github.com/DataDog/datadog-api-client-go/v2/api/datadogV2) on a VM with only 4GB of memory.

What did you see happen?

Big memory usage, go tool compile gets OOM killed.

On a big VM, running go tool compile for github.com/aws/aws-sdk-go-v2/service/ec2 under time -v with a single proc shows around 2.7GB peek memory usage.

Relates to aws/aws-sdk-go-v2#2871.

What did you expect to see?

Lower memory usage, should work properly even on small VMs.

[gopherbot]

Change https://go.dev/cl/778880 mentions this issue: cmd/compile: free IR fields after compiling each function

[gabyhelp]

Related Issues

• cmd/compile: ccxt oom killed on compilation #73365
• cmd/compile: consumes 30GB memory #69054 (closed)
• cmd/compile: Go 1.9 oom killed on compilation #21713 (closed)
• cmd/compile: memory usage above 1.5 GB #33421 (closed)
• cmd/compile: consider speeding up compile of large ast package in microsoft/typescript-go #73044
• cmd/compile: out of memory #72063 (closed)
• cmd/compile: OOM killed on linux/arm64 [1.25 backport] #75844 (closed)
• cmd/compile: cyclic interfaces cause massive memory usage #35146 (closed)
• cmd/compile: 1.12 compiler needs double the memory than 1.11 #32089 (closed)

Related Discussions

• Compiling a really really large package

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

[JunyangShao]

Can you try setting GOMEMLIMIT to be your threshold?

[dr2chase]

Also GOMAXPROCS=1, to suppress parallel build/compilation.

[pgimalac]

Yeah I'm doing both, which helps, but still very much struggling on a small host
This issue is mostly just a front for https://go.dev/cl/778880

EDIT: actually to be precise I'm using GOFLAGS="-p=1", I don't think GOMAXPROCS would really help here