769988 - Firefox 13.0.1. consumes huge amounts of CPU (due to leap second ?)

Status: RESOLVED INVALID

(Core :: General, defect)

Description

[Alain Knaff]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:13.0) Gecko/20100101 Firefox/13.0.1
Build ID: 20120615040358

Steps to reproduce:

Start up Firefox, even in safe-mode


Actual results:

Already immediately from the start, CPU consumption jumped at over 50%. If I actually do stuff, it goes over 100%


Expected results:

An idle Firefox, with no tabs should consume next to nothing.
And even with Facebook open, it definitely should consume less than 5% on this 2600 Mhz AMD CPU.
Opera can do it, why not firefox?

Comment 1

[Alain Knaff]

Oddly enough, after restarting my whole system, firefox is fast again.

Just restarting only firefox was not enough to achieve this.

Weird.

Comment 2

[Kai Engert (:KaiE:)]

I got the same behavior. Only reboot helped. Matti thinks related to the kernel leap second issue, which would explain the need to reboot.

Comment 3

[Matthias Versen [:Matti]]

We had a leap second from June 30 to July 1
ftp://hpiers.obspm.fr/iers/bul/bulc/bulletinc.43

That the lap second could be responsible for this is really just a guess from my side.
The guess is based on articles like this http://pedroalves-bi.blogspot.de/2012/07/java-leap-second-bug-how-to-fix-your.html and 2 unique reports from Firefox linux users.

Reproducing and fixing this could be impossible due to rare occurrence of leap seconds.

Comment 4

[Matthias Versen [:Matti]]

This seems to be a bug in the kernel:
http://thread.gmane.org/gmane.linux.kernel/1321255/

Comment 5

[Wayne Mery (:wsmwk)]

(In reply to Matthias Versen (Matti) from comment #4)
> This seems to be a bug in the kernel:
> http://thread.gmane.org/gmane.linux.kernel/1321255/

so not solvable by Firefox?

Comment 6

[Matthias Versen [:Matti]]

Should be solved by bug fixes ion the kernel. Mozilla wasn't the only software affected by this bug