High CPU usage when simply typing in paragraph block

[emrikol]

Describe the bug
Ever since the latest update to 3.1.0, typing in the Gutenberg editor thrashes my CPU. I've tested this on my local site and also using Frontenberg (just to see if it was my setup). Whenever I stop typing, CPU usage drops dramatically. I don't remember this being an issue with the previous version, but it at least wasn't as bad because I didn't notice. Right now I can't even type without serious lag.

To Reproduce
Steps to reproduce the behavior:

1. Open a new post or edit an old post
2. Type in a Gutenberg text box
3. Watch CPU usage

Expected behavior
I would expect just typing to not use 100% of my CPU and lag so much that I can't see what I'm typing without buffering.

Screenshots

Desktop (please complete the following information):

• OS: Microsoft Windows [Version 10.0.16299.492]
• Browser: Google Chrome
• Version: 67.0.3396.87 (Official Build) (64-bit)

[emrikol]

I just downgraded to 3.0.1 and no longer have this problem, so it definitely was the 3.1.0 version.

With 3.0.1 the highest CPU usage a Gutenberg page uses while typing is ~50% typing as fast as I can.

[danielbachhuber]

Yeah, I notice this too right now.

Related #6466

[notnownikki]

Investigated the issue and found the change here: #7680 (comment)

[brunoc]

This is still a big issue in WP 5.3 making Gutenberg unusable (I have to use the "Disable Gutenberg" plugin in prod). I get the same result as below in https://frontenberg.tomjn.com/

FYI in the example post above, I have about 70-80 blocks (hidden above) with 90% text and titles 10% custom HTML blocks. NO Active Plugins. Using Chrome 78.0.3904.87 (Official Build) (64-bit) MacOS 10.13.6

Let me know if you need more diagnostics.

[tlcd96]

There's a need for this to be viewed again. High CPU usage on a span of 6 processes created by Gutenberg.
Please reopen this issue.