Performance troubleshooting

VS Code extensions run in the extension host, all sharing a single thread in a process separate from the rest of VS Code. In normal usage, this works great, as extensions cannot block the UI, but VSCodeVim essentially hijacks the UI because it must respond to nearly all keystrokes. This means that while VSCodeVim is active, slow extensions will be much more apparent than when it is not active.

This can be mitigated by adding this to settings.json:

"extensions.experimental.affinity": {
  "vscodevim.vim": 1
}