x/tools/gopls: slow performance

[zhaytee]

What version of Go, VS Code & VS Code Go extension are you using?

go version: go1.14.9 linux/amd64
gopls version: golang.org/x/tools/gopls v0.6.1
vscode version: 1.52.1 (commit ea3859d4ba2f3e577a159bc91e3074c5d85c0523)
vscode-go version: 0.19.1

Checking configured tools....
GOBIN: undefined
toolsGopath: 
gopath: /home/zhaytee/go
GOROOT: /usr/local/go
PATH: /usr/local/go/bin:/home/zhaytee/.vscode-server/bin/ea3859d4ba2f3e577a159bc91e3074c5d85c0523/bin:/home/zhaytee/.nvm/versions/node/v12.18.4/bin:/home/zhaytee/.vscode-server/bin/ea3859d4ba2f3e577a159bc91e3074c5d85c0523/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/home/zhaytee/go/bin:/home/zhaytee/.local/bin

   gocode: gocode not installed
   gopkgs: gopkgs not installed
   go-outline: go-outline not installed
   go-symbols: go-symbols not installed
   guru: guru not installed
   gorename: gorename not installed
   gotests: gotests not installed
   gomodifytags: gomodifytags not installed
   impl: impl not installed
   fillstruct: fillstruct not installed
   goplay: goplay not installed
   godoctor: godoctor not installed
   dlv: dlv not installed
   gocode-gomod: gocode-gomod not installed
   godef: godef not installed
   goreturns: goreturns not installed
   golint: golint not installed
   gopls: /home/zhaytee/go/bin/gopls installed

go env
Workspace Folder (api): /home/zhaytee/Development/platform/api
	GO111MODULE=""
	GOARCH="amd64"
	GOBIN=""
	GOCACHE="/home/zhaytee/.cache/go-build"
	GOENV="/home/zhaytee/.config/go/env"
	GOEXE=""
	GOFLAGS=""
	GOHOSTARCH="amd64"
	GOHOSTOS="linux"
	GOINSECURE=""
	GONOPROXY=""
	GONOSUMDB=""
	GOOS="linux"
	GOPATH="/home/zhaytee/go"
	GOPRIVATE=""
	GOPROXY="https://proxy.golang.org,direct"
	GOROOT="/usr/local/go"
	GOSUMDB="sum.golang.org"
	GOTMPDIR=""
	GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
	GCCGO="gccgo"
	AR="ar"
	CC="gcc"
	CXX="g++"
	CGO_ENABLED="1"
	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 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build361984029=/tmp/go-build -gno-record-gcc-switches"

Share the Go related settings you have added/edited

{
    "go.autocompleteUnimportedPackages": true,
    "gopls": {
        "usePlaceholders": false,
        "staticcheck": false
    },
    "go.languageServerExperimentalFeatures": {
        "diagnostics": true
    },
    "[go.mod]": {
        "editor.formatOnSave": true,
        "editor.codeActionsOnSave": {
            "source.organizeImports": true,
        },
    },
    "[go]": {
        "editor.formatOnSave": true,
        "editor.codeActionsOnSave": {
            "source.organizeImports": true,
        },
        "editor.snippetSuggestions": "none",
    }
}

Describe the bug

VSCode is running on macOS, vscode-go is running on linux/amd64 (I'm using the remote-ssh extension).

Apologies if this is a duplicate, but I couldn't find anything quite similar in the issues log.

Performance is very slow when gopls is performing autocomplete. It takes many seconds (between 3 and 5) to pop up the autocomplete dialog, which is just way too long when I'm trying to move fast.

Please see the linked video for a quick demo: https://www.youtube.com/watch?v=H2aCyG7e_hY

Notice the gopls debugging output. I don't see any one response type standing out as being the slowest; all of the relevant ones seem to be really slow: codeAction, foldingRange, documentLink, codeLens, documentSymbol, completion, etc.

Any help to speed this up would be greatly appreciated! Thank you.

[stamblerre]

Can you please share your gopls logs? See https://github.com/golang/tools/blob/master/gopls/doc/troubleshooting.md#capturing-logs for details on how to capture them. Thanks!

[zhaytee]

Here's a pretty clean trace from the moment I started typing (same as in the video) until the gopls activity stopped.

gopls-trace.txt

[andig]

There are a number of cancelled requests like these:

[Trace - 20:11:36.318 PM] Sending request 'textDocument/completion - (39)'.
Params: {"textDocument":{"uri":"file:///platform/identity/ensure/ensure.go"},"position":{"line":527,"character":23},"context":{"triggerKind":1}}


[Trace - 20:11:36.342 PM] Received notification 'textDocument/publishDiagnostics'.

[stamblerre]

@zhaytee: Above, you mention that your workspace folder is /home/zhaytee/Development/platform/api, but in the logs I see /platform/identity/ensure. Do you have a go.mod file in this workspace? I'm not seeing one in the go env output you shared above.

Also, it looks like you've shared an incomplete log. Can you please include a log that starts from the initialize message at the top? Most of the gopls debugging information is logged early on.

[zhaytee]

Apologies, I haven't had time to update this issue properly. However, I did want to mention that I recently upgraded the version of Go on my dev box from 1.14.9 to 1.15.6, and things seem a LOT faster. I don't know if there's a good reason for that, or if it's just a coincidence.

[stamblerre]

Glad things are working better now. I'll go ahead and close this since the issue's resolved, but feel free to reopen if you run into it again.