Bug 278299 – cnn.com becomes unresponsive

• Component: New Bugs
• Status: RESOLVED CONFIGURATION CHANGED

[Jeff Johnson]

Created attachment 472210 [details]
Safari spindump

Safari 17.6 (19618.3.11.11.5) and Safari Technology Preview 201 (Safari 18.0, WebKit 19620.1.2) on macOS 14.6.1 (23G93) with no extensions enabled

Steps to reproduce:
1) Open https://www.cnn.com in Safari
2) Scroll down to the Video section a little over halfway down the page.

It doesn't matter whether Auto-Play it set to Always or Never.

The page becomes somewhat unresponsive: for example, hovering over links and/or clicking them does nothing, and Activity Monitor shows the web process using over 100% CPU.

In Safari Technology Preview, it also launches the AuthenticationServicesAgent-STP process, which bounces in the Dock and also uses over 100% CPU.

[Jeff Johnson]

Created attachment 472211 [details]
AuthenticationServicesAgent-STP spindump

[Jeff Johnson]

Google Chrome Helper (Renderer) and FirefoxCP Isolated Web Content are also experiencing high CPU usage and unresponsiveness on the same page.

[Alexey Proskuryakov]

The Safari (WebContent) sample just shows a lot of work being done by JavaScript, including RegEx, no smoking gun that I can see.

AuthenticationServicesAgent-STP popping up is a known issue, the fix has missed version 201. I don't think that it's related.

[Karl Dubost]

When I go to https://www.cnn.com 
I'm redirected to https://edition.cnn.com

Let's see if I can force www.cnn.com
clicking on the 3 stripes menu I can be redirected to https://us.cnn.com/

On both sites (edition. and us.) I do not experience any real spike of activity on Safari Technology Preview 201 on a recent version of the OS. 

I wonder if it happens if certain conditions are met. Could depends on ads being loaded at this moment too? Jeff if you erase everything cnn from the cache does it reproduce?

[Jeff Johnson]

(In reply to Karl Dubost from comment #4)
> When I go to https://www.cnn.com 
> I'm redirected to https://edition.cnn.com

Apparently that happens outside the United States.

> Let's see if I can force www.cnn.com
> clicking on the 3 stripes menu I can be redirected to https://us.cnn.com/
> 
> On both sites (edition. and us.) I do not experience any real spike of
> activity on Safari Technology Preview 201 on a recent version of the OS. 

I don't experience it on edition.cnn.com but do experience it on us.cnn.com.

> I wonder if it happens if certain conditions are met. Could depends on ads
> being loaded at this moment too? 

It happens every time for me.

> Jeff if you erase everything cnn from the
> cache does it reproduce?

Yes, and it reproduces in a private window.

[Alexey Proskuryakov]

Could it be that this only happens with Web Inspector open, as in some other bugs that you reported? Or is this a different case?

[Jeff Johnson]

(In reply to Alexey Proskuryakov from comment #6)
> Could it be that this only happens with Web Inspector open, as in some other
> bugs that you reported? Or is this a different case?

No, it happened with the Web Inspector closed.

However, I haven't been able to reproduce the issue lately.

[Radar WebKit Bug Importer]

<rdar://problem/134666441>

[Karl Dubost]

This can't be reproduced by a couple of people internally too. 
Let's close, maybe it was a temporary issue at CNN. If the bug comes back, we can still reopen a bug.

Thanks a lot.