cmd/go: go cmd performance degradation on Plan 9 between Go 1.9 and 1.11 #27744
Description
What version of Go are you using (go version)?
go 1.11 plan9/amd64
Does this issue reproduce with the latest release?
Yes
What operating system and processor architecture are you using (go env)?
GOARCH='amd64'
GOBIN=''
GOCACHE='/usr/driusan/lib/cache/go-build'
GOEXE=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='plan9'
GOOS='plan9'
GOPATH='/usr/driusan/go'
GOPROXY=''
GORACE=''
GOROOT='/usr/driusan/go1.11'
GOTMPDIR=''
GOTOOLDIR='/usr/driusan/go1.11/pkg/tool/plan9_amd64'
GCCGO='gccgo'
CC='6c'
CXX='g++'
CGO_ENABLED='0'
GOMOD=''
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 -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build647141787=/tmp/go-build -gno-record-gcc-switches'
What did you do?
Ran go fmt ./... on the package github.com/driusan/dgit. Load spikes to 100% and it takes over 2 minutes, while this wasn't the case with previous versions of Go.
term% time $home/go1.9.2/bin/go fmt ./...
0.05u 0.11s 4.32r /usr/driusan/go1.9.2/bin/go fmt ./...
term% time $home/go1.11/bin/go fmt ./...
39.60u 1.11s 129.93r /usr/driusan/go1.11/bin/go fmt ./...
What did you expect to see?
Similar performance to previous releases in go fmt.
What did you see instead?
A 30x performance degradation.