1617300 - First http-on-opening-request observer notification takes longer in Fenix than Fennec, spending time in ExtensionProcessScript.jsm and ExtensionChild.jsm

Status: RESOLVED INVALID

(GeckoView :: Extensions, defect, P2)

Description

[Sean Feng [:sefeng]]

Fennec profile: https://perfht.ml/2Viz8Qh
Fenix profile: https://perfht.ml/32fK3eR

I collected both profile by using browsertime. According to the profiles, Fenix NotifyObserver stuff's took more than than Fennec before the first paint. They are related to some extension related code.

Comment 1

[Markus Stange [:mstange]]

There are two observer notifications in particular that are taking longer:

• The first http-on-opening-request notification (which is sent inside the location.href setter), and
• the initial-document-element-inserted notification.

Both are spending time in code that looks related to extension content script infrastructure.

Comment 2

[Markus Stange [:mstange]]

In this profile, they're taking 74ms and 77ms, so it seems like just the extension content script infrastructure is adding 150ms even if no add-ons actually need to intercept network requests.
This code runs before the first paint.

Comment 3

[Sean Feng [:sefeng]]

here's another profile : https://perfht.ml/2PIeNzY

Comment 4

[Sean Feng [:sefeng]]

Above two were taken by browsertime, and this one https://perfht.ml/38fTJY4 was taken by hand. I typed the url in the url bar manually.
This call delays the time of when the network is being handled in the parent process.

Comment 5

[Markus Stange [:mstange]]

(In reply to Markus Stange [:mstange] from comment #2)

In this profile, they're taking 74ms and 77ms, so it seems like just the extension content script infrastructure is adding 150ms

Much of this extra time is spent in script parsing / emit. So I expect bug 1632682 to help reduce this time.

Comment 6

[Julien Wajsberg [:julienw]]

Hey Sean,
do you think it's still a problem we have? Maybe you could help gather a new profile for this?
Thanks!

Comment 7

[Sean Feng [:sefeng]]

In my newly taken profile. NotifyObserver only took a marginal amount of time. I think this situation has been much improved.

I am going to close this issue as INVALID.