Go version

go 1.22.3

Output of go env in your module/workspace:

GO111MODULE=''
GOARCH='amd64'
GOBIN=''
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/home/<username>/go/pkg/mod'
GONOPROXY='none'
GOOS='linux'
GOPATH='/home/<username>/go'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.22.3'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build3021393819=/tmp/go-build -gno-record-gcc-switches'

What did you do?

1. write a programme to allocate 1MB memory each second
2. don't release the memory
3. watch the GC output, the GC start, the GC end, the heapAlive, the heapGoal size

What did you see happen?

GOGC=100 GODEBUG=gctrace=1 ./test_examples
allocate: 1 MB
allocate: 2 MB
allocate: 3 MB
allocate: 4 MB
gc 1 @3.003s 0%: 0.012+0.15+0.003 ms clock, 0.29+0/0.16/0+0.074 ms cpu, 4->4->4 MB, 4 MB goal, 0 MB stacks, 0 MB globals, 24 P
allocate: 5 MB
allocate: 6 MB
allocate: 7 MB
allocate: 8 MB
allocate: 9 MB
gc 2 @8.004s 0%: 0.16+0.72+0.011 ms clock, 3.9+0/0.73/0+0.28 ms cpu, 9->9->9 MB, 9 MB goal, 0 MB stacks, 0 MB globals, 24 P
allocate: 10 MB
allocate: 11 MB
allocate: 12 MB
allocate: 13 MB
allocate: 14 MB
allocate: 15 MB
allocate: 16 MB
allocate: 17 MB
allocate: 18 MB
allocate: 19 MB
gc 3 @18.008s 0%: 0.087+0.23+0.006 ms clock, 2.0+0/0.23/0+0.14 ms cpu, 19->19->19 MB, 19 MB goal, 0 MB stacks, 0 MB globals, 24 P
allocate: 20 MB
allocate: 21 MB
allocate: 22 MB
allocate: 23 MB
allocate: 24 MB
allocate: 25 MB
allocate: 26 MB
allocate: 27 MB
allocate: 28 MB
allocate: 29 MB
allocate: 30 MB
allocate: 31 MB
allocate: 32 MB
allocate: 33 MB
allocate: 34 MB
allocate: 35 MB
allocate: 36 MB
allocate: 37 MB
allocate: 38 MB

What did you expect to see?

want to see the correct size of heapGoal, it looks like incorrect.