I was looking into why tests are failing on beta and I noticed that a number of important prefs are still gated on E10S_TESTING_ONLY, which is disabled on beta: extensions.interposition.enabled extensions.interposition.prefetching dom.compartment_per_addon dom.ipc.plugins.asyncInit.enabled So, on beta, the people with e10s enabled are not getting any add-on shims and they're getting async plugin init (which is still broken in e10s AFAIK).

Actually, it looks like async plugin init is unconditionally disabled on beta.

In the meeting we decided we'll have these prefs ride the trains with 45.

Actually, we decided to get this change into 44 so that we can still get some data out of the next beta.

Comment on attachment 8704371 [details] [diff] [review] fix-shims Review of attachment 8704371 [details] [diff] [review]: ----------------------------------------------------------------- I assume we've evaluated the potential for increased memory usage from the new compartments, as well as increased overhead over the interposition layer, and are okay with it? If so, r=me.

Sorry, Mike. Now they want us to enable this stuff only for people with e10s. It turns out that the compartment_per_addon pref is already enabled if you have e10s: https://dxr.mozilla.org/mozilla-central/source/js/xpconnect/src/XPCWrappedNativeScope.cpp#239 And the prefetching pref can be enabled unconditionally since the prefetcher is only used if shims are already enabled. I change each callsite that uses extensions.interposition.enabled so that it also checks BrowserTabsRemoteAutostart.

By the way, we want to get this into the beta, which builds tomorrow.

Gotcha - reviewing now.

Comment on attachment 8704440 [details] [diff] [review] change-default Review of attachment 8704440 [details] [diff] [review]: ----------------------------------------------------------------- Looks good - let's roll.

Comment on attachment 8704440 [details] [diff] [review] change-default This is the patch we want to take on beta so that the e10s experiment has more validity. It only enables interposition if e10s is enabled already.

Comment on attachment 8704371 [details] [diff] [review] fix-shims I'd like to land this patch on Aurora. It ensures that these prefs will be enabled in the next beta, with or without e10s. These prefs have been tested on Nightly and Aurora for many releases already.

Comment on attachment 8704440 [details] [diff] [review] change-default Taking it because it's needed to get e10s add-on telemetry data for FF45, beta44+

Comment on attachment 8704371 [details] [diff] [review] fix-shims aurora too

Hi Bill, could you please backout the patch we landed in this bug to enable the e10s experiment? We've agreed to postpone this experiment from Fx44 to Fx45 beta cycle. Please see https://bugzilla.mozilla.org/show_bug.cgi?id=1238802#c10. Thanks!

[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