1415691 - Intermittent CPU spikes in Nightly

Status: RESOLVED DUPLICATE of bug 1415387

(Core :: General, defect)

Description

[Mark]

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:58.0) Gecko/20100101 Firefox/58.0
Build ID: 20171108110838

Steps to reproduce:

I am getting intermittent 2-3 second spikes in CPU in Nightly, starting with the second Nightly update yesterday (2017-11-07) and continuing with this morning's (2017-11-08) update. The spike sits sold at 25% (the equivalent of one core of my 4-core CPU).

Last known trouble-free version appears to have been the first Nightly update yesterday (2017-11-07).

So far I haven't come across a repeatable way of reproducing it, but it has been mentioned by multiple Nightly users, e. g.,

http://forums.mozillazine.org/viewtopic.php?f=23&t=3034937 (starting with 2nd reply, the one by gorhill)

https://www.reddit.com/r/firefox/comments/7bnaor/bug_firefox_nightly_has_cpu_spikes_starting_with/

This was reported by Windows and linux users, Firefox from being idle, to web page load, to playing a YouTube video. When it occurs, it consumes the equivalent of a core (on my machine 25% of the 4-core CPU). gorhill reported the CPU usage is in the main process.

This morning after a CPU spike I ran with the Gecko Profiler running and after a few hours got a CPU spike that I think may be related to this bug:

https://perfht.ml/2ykc8SD

(Look near the end of the capture)

Permalink also showed a second link, but I don't know if it is useful:

https://perfht.ml/2yhYyPE

I am sorry I don't have a run of the Gecko Profiler on a clean profile, nor a way of reliably reproducing the problem

If the reports I have received are for the same problem, then:
- the problem is occurring on multiple platforms: Windows 7 (64-bit), Windows 10 (64-bit), linux.
- Multiple CPU families: AMD, i7
- Different activities: idle (looking at a web page), loading a web page, playing YouTube
- One report identified this as in the Main process.

rhill (aka: gorhill) thinks this may be Bug 1382886 or related to it. If so, then maybe some of the automatic updating of lists, etc., would explain the CPU spikes while Firefox appears to be idle.

Comment 1

[Ekanan Ketunuti]

possible dupe of bug 1415387.

Comment 2

[Ekanan Ketunuti]

I'll mark this as duplicate. Feel free to reopen if you still see this problem.