2023004 - Make Gecko child process preallocation happen serially and delay it if we're just showing the homescreen

Status: RESOLVED FIXED

(Firefox for Android :: Performance, task)

Description

[Markus Stange [:mstange]]

I'm filing this bug so that I can land the first two patches from bug 1960752 separately, since they make sense on their own.

Comment 1

[Markus Stange [:mstange]]

Attachment: Bug 2023004 - Change how we do child process preallocation. r=jalmeida

In the past, we were allocating a content process unconditionally
during GeckoThread initialization. This means that we would spend
CPU time starting up a tab process very early during startup even
when we were only going to show the home screen. It also means that
we can't add more processes here without affecting home screen startup
negatively.

This patch does the following:

• Do the preallocation during GeckoEngine.warmUp(). We had an existing
  warmUp method but it was just there to trigger the instance creation
  on a lazy property. Now it has an actual purpose.
• Replace the call to warmUp() in FenixApplication.onCreate with a simple
  property access, so that Engine instance creation is still triggered in
  the same place as before.
• Add a call to warmUp() to the visual completeness queue.
  This means that during home view startup, we will delay the child
  process preallocation until the home view is visible.
• Additionally, to keep preallocation happening early during applink
  startup, create a speculative Gecko session if the IntentReceiverActivity
  notices that we're about to load a page. And call warmUp() from the
  speculative Gecko session method.
• Call setIsolatedProcessEnabled and setAppZygoteEnabled earlier so that
  warmUp creates the right content process types.

As a result, we'll still allocate a tab process early during applink startup,
but we'll delay it during homeview startup.

Comment 2

[Markus Stange [:mstange]]

Attachment: Bug 2023004 - Preload processes sequentially. r=#geckoview-reviewers

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/41b6fda87e88
https://hg.mozilla.org/integration/autoland/rev/979858ece73c
Change how we do child process preallocation. r=tcampbell,geckoview-reviewers,android-reviewers,geckoview-api-reviewers,jonalmeida
https://github.com/mozilla-firefox/firefox/commit/d4a82e3f9bde
https://hg.mozilla.org/integration/autoland/rev/e7d57519f52e
Preload processes sequentially. r=geckoview-reviewers,tcampbell

Comment 4

[rperta]

https://hg.mozilla.org/mozilla-central/rev/979858ece73c
https://hg.mozilla.org/mozilla-central/rev/e7d57519f52e