Open
Description
What version of Go are you using (go version
)?
λ go version go version go1.14 windows/amd64 λ go version go version go1.13.8 windows/amd64
Does this issue reproduce with the latest release?
Yes.
What operating system and processor architecture are you using (go env
)?
go env
Output
λ go env set GO111MODULE= set GOARCH=amd64 set GOBIN= set GOCACHE=C:\Users\klaus\AppData\Local\go-build set GOENV=C:\Users\klaus\AppData\Roaming\go\env set GOEXE=.exe set GOFLAGS= set GOHOSTARCH=amd64 set GOHOSTOS=windows set GONOPROXY= set GONOSUMDB= set GOOS=windows set GOPATH=e:\gopath set GOPRIVATE= set GOPROXY=https://goproxy.io set GOROOT=c:\go set GOSUMDB=sum.golang.org set GOTMPDIR= set GOTOOLDIR=c:\go\pkg\tool\windows_amd64 set GCCGO=gccgo set AR=ar set CC=gcc set CXX=g++ set CGO_ENABLED=1 set GOMOD= set CGO_CFLAGS=-g -O2 set CGO_CPPFLAGS= set CGO_CXXFLAGS=-g -O2 set CGO_FFLAGS=-g -O2 set CGO_LDFLAGS=-g -O2 set PKG_CONFIG=pkg-config set GOGCCFLAGS=-m64 -mthreads -fmessage-length=0 -fdebug-prefix-map=d:\temp\wintemp\go-build155272862=/tmp/go-build -gno-record-gcc-switches
What did you do?
Run benchmark: https://play.golang.org/p/WeuJg6yaOuJ
go test -bench=. -test.benchtime=10s
used to test.
What did you expect to see?
Close or similar benchmark speeds.
What did you see instead?
40% performance regression.
λ benchcmp go113.txt go114.txt
benchmark old ns/op new ns/op delta
BenchmarkCompressAllocationsSingle/flate-32 87026 121741 +39.89%
BenchmarkCompressAllocationsSingle/gzip-32 88654 122632 +38.33%
This is not a purely theoretical benchmark. While suboptimal, this is the easiest way to compress a piece of data, so this will be seen in the wild. It could also indicate a general regression for applications allocating a lot.
Edit: This is not related to changes in the referenced packages. Seeing this when using packages outside the stdlib as well.