1554417 - Firefox main process uses 100%+ CPU after waking MacBook from sleep

Status: RESOLVED DUPLICATE of bug 1551990

(Core :: Performance, defect)

Description

[brymaster]

Attachment: FF High CPU use.zip

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:67.0) Gecko/20100101 Firefox/67.0

Steps to reproduce:

Firefox 67.0
macOS 10.14.5
MacBookPro11,5

Put my MacBook Pro to sleep for about 8 hours, lid closed.

Actual results:

After a long period of sleep, about 8 hours with the lid closed, the main Firefox process gets in a strange state that uses 100% CPU immediately after waking my MacBook. Before entering sleep, Firefox was not using high CPU or doing much of anything, such as computation or intensive graphics. I believe I've experienced this since Firefox 65 or 66 and as this happens and I close the browser, it will hang for a long period of time and then crash. No added bookmarks during this high CPU state will be saved.

I am including the following in the attachment zip to help diagnose:

1. A Time Profiler .trace file saved from Xcode's Instruments, plain text also viewable here: https://pastebin.com/wxRP3Fvm (opening the .trace in Time Profiler is recommended for ease of navigating)

2. A sample of the process from Activity Monitor, plain text also viewable here: https://pastebin.com/pkNkdV7x

3. Some traces from the Firefox/Gecko Profiler extension:
   https://perfht.ml/2XeQNGk

https://perfht.ml/2XeR1gE

https://perfht.ml/2X5qi6o

4. The resulting crash log, also viewable here: https://pastebin.com/E6yfTxvC

Expected results:

Should not resume with Firefox using 100% CPU.

Comment 1

[Mayank Bansal]

Honza, is this a dupe of bug 1551990 ?

Comment 2

[brymaster]

Just to note: after 24 hours and a long laptop sleep, I have Firefox in this state again. Happy to profile or collect whatever info possible.

Comment 3

[Honza Bambas (:mayhemer)]

(In reply to Mayank Bansal from comment #1)

Honza, is this a dupe of bug 1551990 ?

Regarding the description (did look deeply) - YES!