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Constant CPU usage even while firefox is "idle" #59

xapaho opened this Issue · 9 comments

4 participants


Constant CPU usage even while firefox is "idle"

Looking at top while firefox is running, but not being used :

  • If YSlow! is installed and enabled, usage is constantly around 4 to 5% minimum, typically 4.3%.
  • If YSlow! is not installed, or installed but disabled, typical cpu usage is 0.3% -- as expected

YSlow 3.1.4


NB. reproduced with a fresh profile and any system plugin disabled just in case, "of course" :s


Having the same isssue with Firefox 21.0 and YSlow 3.1.4.

I tried open only one empty tab in Firefox and with only one extension YSlow, top shows Firefox is using about 10% of cpu, after disable YSlow and cpu usage of Firefox is dropped blow 3%.


@marcelduran No, I have Firebug 1.11.3 installed, idle Firefox cpu usage is below 3%.

BTW: I'm using Mac OS X 10.7.5


Just install FireFinder, FireQuery and CSS Usage and cpu usage no noticeable change after restart Firefox.

And I enabled YSlow once again, and cpu usage is back to 10% again after restart Firefox.


The CPU usage I'm talking about is stablized CPU usage, not the CPU usage right after Firefox restarted or Firebug enabled or new page opened.


Same for me, using latest YSlow, Firebug and Firefox 25 on Ubuntu (13.10).
This happens even if YSlow is the only enabled extension (Firebug disabled)!

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