Bug 264534 – REGRESSION(269859@main): Caused CPU spins in some WebView client applications

• Component: New Bugs
• Status: RESOLVED FIXED

[WebKit Commit Bot]

https://commits.webkit.org/269859@main introduced a regression:
Caused CPU spins in some WebView client applications

This is an automatic bug report generated by webkitbot. If this bug
report was created because of a flaky test, please file a bug for the flaky
test (if we don't already have one on file) and dup this bug against that bug
so that we can track how often these flaky tests fail.

[WebKit Commit Bot]

Created attachment 468546 [details]
REVERT of 269859@main

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[EWS]

Committed 270489@main (927b1ffbab10): <https://commits.webkit.org/270489@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 468546 [details].

[Radar WebKit Bug Importer]

<rdar://problem/118206272>

[Andrey Piskov]

Any chance the fix can be expedited into macOS? Sonoma beta is trashing battery in 1-2 hours because of this.

To make matters worse:

> AppleSeed News Thanksgiving Break
> Please note that our team will not be processing feedback during our Thanksgiving Break, November 18th through November 26th. Please continue to submit your feedback. We will process new feedback and respond to any inquiries when we return to the office on November 27th.

[Simon Fraser (smfr)]

What apps are you seeing this with in Sonoma beta?

[Andrey Piskov]

(In reply to Simon Fraser (smfr) from comment #5)
> What apps are you seeing this with in Sonoma beta?

1. Mail app. Though it’s tricky to reproduce: guess, it’s related to some specific HTML emails. But after a while it most definitely settles with 100% cpu usage — I keep quit the app after reading emails because of this.

2. The best candidate to illustrate this regression is Outline VPN client: just starting the app (without any vpn connection, just opening it is enough) immediately sends it to 99.7% cpu usage.
https://github.com/Jigsaw-Code/outline-client/issues/1786#issuecomment-1820868430

https://itunes.apple.com/us/app/outline-app/id1356178125


(Unfortunately, I don’t remember the dev discussion for some another app that traced the issue right to this specific regression — that’s how I ended on this page).

[Andrey Piskov]

Found it: another app is f.lux. Here’s the discussion that brought me here:
https://forum.justgetflux.com/topic/8491/sonoma-14-2-beta-3-100-cpu/2