What you are wondering about is CPU Affinity. I found that there was a good explanation of CPU affinity on NixCraft. But note that the Linux kernel is indeed, as you say, already making intelligent choices.

Putting Linux processes on certain CPU cores
In our app, when you save/submit a form, two things happen


submit button greys out(becomes disabled)
there's a progress bar running at the top of the page(similar to medium.com), which is an indicator used across the app for an ongoing action(not limited only to saving forms, since it's an SPA app)


Do you think it's clear enough for the user that things are being saved, or it would be better to add a loader directly associated with the form(inside the button for example)?

Here's what it looks like at the moment.
https://youtu.be/xzc7P8R751M
