Closed Bug 1251334 Opened 4 years ago Closed 4 years ago

Create a disposable pref to force-disable e10s in an emergency

Categories

(Firefox :: General, defect)

defect
Not set

Tracking

()

RESOLVED FIXED
Firefox 47
Tracking Status
e10s m9+ ---
firefox46 + fixed
firefox47 + fixed

People

(Reporter: Felipe, Assigned: Felipe)

Details

Attachments

(1 file)

There's no uber pref to force-disable e10s, in case we need to do it via a hotfix. It's already relatively easy to do so by changing other prefs, but any time we mess with a pref with a hotfix, we need to change its name on the next version. The existing prefs are used in a lot of places and changing its name would be painful, so it's easier to create a new one that is not used anywhere to do it cleanly. Also it will help track on telemetry in case that happens.

When we approach the e10s rollout we should also have a hotfix to toggle this pref prepared and signed in advance. I'll take care of that later.
My not very long term plan is to get rid of hotfixes and only use system addons. I'm not sure this needs to be more complicated than turning off the system addon from bug 1249845.
Yeah, first attempt would be to do that, but since quick updates of system addon are still unproven, this is an easy safety measure, since we know pref-toggling hotfixes spread very fast and reliably.
Comment on attachment 8723685 [details]
MozReview Request: Bug 1251334 - Create a disposable pref to force-disable e10s in an emergency. r=jimm

https://reviewboard.mozilla.org/r/36671/#review33247
Attachment #8723685 - Flags: review?(jmathies) → review+
https://reviewboard.mozilla.org/r/36671/#review33249

::: toolkit/xre/nsAppRunner.cpp:4816
(Diff revision 1)
> +    status = kE10sForceDisabled;

I don't think this exists!
https://reviewboard.mozilla.org/r/36671/#review33261

::: toolkit/xre/nsAppRunner.cpp:4816
(Diff revision 1)
> +    status = kE10sForceDisabled;

it was added at the beginning of the patch
(In reply to :Felipe Gomes (needinfo me!) from comment #6)
> https://reviewboard.mozilla.org/r/36671/#review33261
> 
> ::: toolkit/xre/nsAppRunner.cpp:4816
> (Diff revision 1)
> > +    status = kE10sForceDisabled;
> 
> it was added at the beginning of the patch

oh, yes. sorry. missed that enum addition there. thanks!
Comment on attachment 8723685 [details]
MozReview Request: Bug 1251334 - Create a disposable pref to force-disable e10s in an emergency. r=jimm

Approval Request Comment
[Feature/regressing bug #]: e10s rollout
[User impact if declined]: one extra measure to be in control of e10s rollout
[Describe test coverage new/current, TreeHerder]: landed on inbound
[Risks and why]: just a pref to cancel e10s, added to the function that checks the prefs to activate it (overrides all other checks)
[String/UUID change made/needed]: -
Attachment #8723685 - Flags: approval-mozilla-aurora?
[Tracking Requested - why for this release]: useful for e10s rollout
https://hg.mozilla.org/mozilla-central/rev/b1793916c7b8
Status: ASSIGNED → RESOLVED
Closed: 4 years ago
Resolution: --- → FIXED
Target Milestone: --- → Firefox 47
Interesting! Tracking for 46.
Comment on attachment 8723685 [details]
MozReview Request: Bug 1251334 - Create a disposable pref to force-disable e10s in an emergency. r=jimm

Override pref seems potentially useful for e10s launch; let's uplift this to aurora.
Attachment #8723685 - Flags: approval-mozilla-aurora? → approval-mozilla-aurora+
[bugday-20160323]

Status: RESOLVED,FIXED -> UNVERIFIED

Comments:
STR: Not clear.
Developer specific testing

Component: 
Name			Firefox
Version			46.0b9
Build ID		20160322075646
Update Channel          beta
User Agent		Mozilla/5.0 (Windows NT 6.1; WOW64; rv:46.0) Gecko/20100101 Firefox/46.0
OS			Windows 7 SP1 x86_64

Expected Results: 
Developer specific testing

Actual Results: 
As expected
You need to log in before you can comment on or make changes to this bug.