Fedora 27 stuck when memory ends

Fedora 27 on my laptop (8GB RAM, SSD) is stuck after aggressive usage (1 VM, a lot of chrome tabs). When it was happened I couldn't switch to another virtual terminal or doing anything to analyze problem. Whole system completely stuck (mouse, keyboard, vty).

I installed memory monitoring to system tray and understood that it happen when memory ends and then OS take 100% of IO. I don't understood what actually OS doing, but after 40 minutes I could find that SWAP is not used more than 10%.

I changed vm.swappiness=100 from default value. Nothing changed.

Then I changed:
vm.dirty_background_ratio = 10
vm.dirty_ratio = 15

It decrease time of stuck but don't solve my problem.

Then I changed:
vm.min_free_kbytes = 800000
vm.overcommit_memory = 1

And it make my system stable when RAM is over.

I think it's not normal OS behavior, but it's a workaround for my Fedora. Also I read that it happen on Fedora 25+.

=== UPDATE ===

Actually problem is a web-browser which don't swapping tabs. I installed Chrome extension "The Great Suspender" and now memory never ends :)