1293116 - [E10S] Firefox 48 slow starting in Private Mode

Status: RESOLVED INCOMPLETE

(Firefox :: Extension Compatibility, defect)

Description

[MarcosD2]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:48.0) Gecko/20100101 Firefox/48.0
Build ID: 20160726073904

Steps to reproduce:

Right click in the taskbar icon > Open a new Private Window.


Actual results:

It takes 3 seconds in the white page then 2 seconds to load the "purple Private page" with E10S activated.

Without E10S it opens almost instantly.


Expected results:

Opening "Normal Mode" with E10S activated is as fast as with it not activated. "Private Mode" should behave the same way.

Comment 1

[Tracy Walker [:tracy]]

Marcos, can you reproduce in e10s in safe mode (with all add0ons disabled?)

This WFM on on Mac 10.11 with latest Nightly 51.0a1, 20160811030201 (Multiprocess Windows : 1/1 (Enabled by default))

Comment 2

[MarcosD2]

When I start Firefox in Private Mode + Safe Mode (all addons disabled) the issue DOES NOT occur.

When I create a new clean profile, change ONLY the parameters below of 'about:config' and close/start it in Private Mode the issue OCCURS:
   browser.tabs.remote.autostart=true
   extensions.e10sBlockedByAddons=false
   extensions.e10sBlocksEnabling=false
   browser.tabs.remote.force-enable=true

Comment 3

[Tracy Walker [:tracy]]

Marcos, thanks for checking.  This is likely caused by an add-on, please attach your about:support

Comment 4

[MarcosD2]

Attachment: 2016-08-11_about_config.txt

I uninstalled "Free Memory 2.0" addon and it got 1~2 seconds faster to start, although it's slower than 'Normal Mode' with or without the addon installed.

about:support attachment: 2016-08-11_about_config.txt.

Comment 5

[Andy McKay]

Marcos, is there any chance you could try narrowing it down to one addon?

Comment 6

[MarcosD2]

Uninstalling AdBlock Plus makes it 0.5 ~ 1.0 second faster to start
the browser in Private Mode. I couldn't disable Kaspersky Addon.

With all addons, including Free Memory 2.0, it opens instantly in
'Normal Mode'.

Comment 7

[:shell escalante]

can QA test adblock plus in private browsing mode (latest version).  shouldn't be suspect - but validate.

then kapersky

Comment 8

[Liviu Cirdei]

User Agent 	Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:48.0) Gecko/20100101 Firefox/48.0
Build ID	20160726073904

Hi, 

I tried to reproduce the issue with AdBlock Plus 2.7.3 installed but it worked fine for me. I also installed Free Memory 2.0 add-on but still I could not reproduce the issue. 
I wanted to check Kaspersky too, but I could not find the addon, I guess Kaspersky antivirus has to be installed on the machine previously (privilege that I don't have).

I have tried on Firefox 48 (pt-BR) and Firefox 49.0.1 (en-US) on Windows 7 x64 with the preferences from comment 2.

Comment 9

[Liviu Cirdei]

Marcos, can you still reproduce the issue on latest release (49.0.1) or latest Nightly [1]?
[1] https://nightly.mozilla.org/

Comment 10

[MarcosD2]

Attachment: 2016-08-11_about_support.txt

Firefox 49.0.1:
* Private Mode: takes about 3 seconds to be able to type on address bar;
* Normal Mode: takes almost 2 seconds to be able to type on address bar.

Comment 11

[MarcosD2]

Comment on attachment 8780209 [details]
2016-08-11_about_config.txt

Marked as obsolete because there's a new updated attachment regarded to about:support information.

Comment 12

[Firefox Bug Husbandry Bot]

With Firefox 57 only WebExtensions are permitted and are, by default, e10s compatible.