Re: Firefox 31.8.0: Use of Add-On "HTTPS Everywhere 5.1.2" causes 99% CPU utilization

Dave Yeo wrote:
> On 02/14/16 03:39 AM, Lars Erdmann wrote:
>> Hallo,
>>
>> this issue has been mentioned already quite often:
>> after starting the application Firefox becomes completely unresponsive
>> for timespans of say 10 seconds. Then it continues on until the same
>> happens again. When it becomes unresponsive, one of the CPU cores will
>> show 99% of usage, if you only have/use one core then of course that
>> core will show 99% of usage.
>>
>> As this is really frustrating, I disabled all add-ons and restarted
>> Firefox again and again, each time with one additional add-on reenabled.
>>
>> It now turns out that "HTTPS Everywhere 5.1.2" is the culprit.
>> If I have it disabled, I don't see this issue, if I enable it, I run
>> into the above mentioned problem. This is even true if an "internal"
>> webpage like about:addons is displayed in Firefox.
>
> I've installed HTTPS Everywhere 5.1.2 and so far don't see the 100% CPU
> issue.

I ran HTTPS Everywhere till last night when I disabled it as my browsing 
was slowed down due to less cache use and it was taking up room. No high 
CPU issues.

Afterwards I started getting 100% CPU on one core when just changing 
tabs or displaying certain pages, all with scripting enabled.
Earlier I loaded http://kb.mozillazine.org/About:config_entries, and it 
ran weird. Enabled all scripts and it brought the browser to its knees 
with close to consistent 100% CPU on one core and an hourglass cursor 
over the browser. On a single core machine it probably would have 
blocked everything.
I removed HTTPS Everywhere just now and restarted the browser and the 
problems are gone. The above page loads OK with a one second CPU spike.
HTTPS Everywhere is buggy or triggering a bug in our port.
Dave