100% CPU load on client in Show event window

A requestAnimationFrame Promise Callback from popper.min.js (what is some tooltip and positioning JS library) takes about 60ms to execute and is called repeatedly, leading to 100% CPU load and very low client responsiveness (I get 0.2 FPS on Firefox 68.5 ESR on i7-6500U) making the UI unusable.
A complication is that this does not happen all the time, but frequently enough to be super annoying. It does not seem to be related to specific events.
Sometimes the Promise Callback takes much less time, but triggers several Style Recalculations for many elements. All the time it seems to be called in loop, so load is extreme and usability abysmal.

assigned to @Jan_Mach

By Radko Krkoš on 2024-12-26T14:06:58

added C-Dev-GUI Done 0% P4 S-New T-Bug labels

changed milestone to %Backlog

Thank you for reporting, I have identified the root of the problem. Popovers are created on hover, but not destroyed on cursor leaving the element. New popover is created on next hover, so...yeah, bad (because positions for popovers are calculated for all popovers, even those invisible, hence the 100% load). I will schedule it for next release.

By Jan Mach on 2020-03-05T18:51:11

added P3 label and removed P4 label

changed milestone to %2.7

Attached patch should resolve the issue. Deploying to mentat-alt.

By Jan Mach on 2020-03-08T11:21:33

added Done 100% S-Resolved labels and removed Done 0% S-New labels

Issue seems to be resolved on mentat-alt. It is just necessary to make sure /mentat/static/design/js/hawat-jquery.js is not cached in the browser.

By Jan Mach on 2020-03-08T18:23:53

assigned to @radko_krkos and unassigned @Jan_Mach

By Jan Mach on 2024-12-26T14:21:03

Use CTRL+SHIFT+R to refresh everything including scripts in Chrome (i did not know that before).

By Jan Mach on 2020-03-08T18:25:32

I am not able to reproduce the issue on mentat-alt now, while easily reproducing it on mentat-hub.
There is still a lot of JavaScript calculations going on, but my client seems capable of handling it at 50 FPS+.
Closing. Thanks, this was a nasty one.

By Radko Krkoš on 2020-03-09T07:56:12

added S-Closed label and removed S-Resolved label

closed