Bug 247853

Summary:	Web Inspector: Timelines Tab: Poor performance makes it almost unusable when capturing screenshots
Product:	WebKit	Reporter:	Tristan Biesecker <sloths.slushy-0m>
Component:	Web Inspector	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Major	CC:	inspector-bugzilla-changes, webkit-bug-importer
Priority:	P2	Keywords:	InRadar, Performance
Version:	Safari 16
Hardware:	Mac (Apple Silicon)
OS:	macOS 13
URL:	https://www.bieseckerart.com/gallery

Description Tristan Biesecker 2022-11-13 00:04:16 PST

When using the Timelines Tab to monitor website performance, the performance is so poor that it effectively makes the tool unusable.

Steps to reproduce:
1) Navigate to https://www.bieseckerart.com/gallery
2) Start an Events recording
3) Hover over some of the images and click on them to open the image modal
4) Close the modal and repeat

Expected Result:
The timeline view continues to remain responsive and can easily be stopped, started, etc.

Observed Result:
The web inspector, and the rest of the page, becomes extremely unresponsive very quickly.

Comment 1 Tristan Biesecker 2022-11-13 00:06:51 PST

I just noticed that if I turn off capturing screenshots, performance is as expected.

Comment 2 Radar WebKit Bug Importer 2022-11-13 16:36:09 PST

<rdar://problem/102297931>