Why is vim save so slow?

Question

When I save a file in Vim using :update or :w, Vim's entire UI blocks for about a second while it does something mysterious that (as a side effect) writes the buffer being edited to disk.

This takes way too much time. Sitting there like a chump for 1000ms waiting for Vim to finish the monumental task of flushing the buffer to disk is no fun.

My source file is fairly large (100k), and smaller files don't suffer from this issue, but 100k is really not that large. I consider a ~2,000 line, 100KB source file to be a reasonably sized buffer.

How can I speed this up?

Answer 1

The culprit in this particular situation was the Syntastic plugin.

It's forking eslint.

I load Syntastic on entering insert mode (using a vim-plug function loader).

Vim is plenty snappy on its own.