1510321 - Stop creating a list of nodes in the DOM for builtin areas in CustomizableUI

Status: RESOLVED FIXED

(Firefox :: Toolbars and Customization, enhancement, P1)

Description

[:Gijs (he/him)]

After bug 1505734 this was pushed into the CUI code. However, it's quite expensive, and with the demise of XPCOM add-ons the list should be fully predictable, meaning we shouldn't need to check the DOM, which would make this code cheaper. Profiles indicate this loses us a few ms on startup. :bgrins has a profile.

Comment 1

[Brian Grinstead [:bgrins]]

Here's the referenced profile: https://perfht.ml/2EDHOcX. I had consistently seen this as ~15ms on a local build pre Bug 1505734.

I just did a new run and am seeing only 3-4ms on registerToolbarNode. This could be either the move away from XBL somehow made this faster, or just inconsistency in measurements (different hardware, OS version, etc). 

`./mach talos-test -a tpaint --gecko-profile` (new window time only) - 3ms - https://perfht.ml/2DNicIG
`./mach talos-test -a ts_paint --gecko-profile --cycles 2` - 4ms - https://perfht.ml/2DMxVYw

I'll do a talos-other try push with --talos-profile and see what those look like.

Comment 2

[Brian Grinstead [:bgrins]]

Push with a bunch of profiles: https://treeherder.mozilla.org/#/jobs?repo=try&revision=001e2382fd8c55aeb5d68e4c7f1b35210a6682b5&selectedJob=214169015. If I click on "open in perf-html.io" on something like ts_paint and filter on "registertoolbarnode" I see generally 2-4ms there as well.

This is less than I remember, but after re-looking at the referenced profile in Comment 1, registerToolbarNode was only a part of the toolbar_XBL_contructor time (~4ms out of ~12). The rest of the time seemed to be firing other XBL constructors (more toolbars and tabbrowser-tabs).

Even still, this is all happening before first paint so even dropping a few ms would be a win.

Comment 3

[:Gijs (he/him)]

Attachment: Bug 1510321 - avoid calling buildArea for all the builtin toolbars, r?jaws!,bgrins!

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/da642018d1c6
avoid calling buildArea for all the builtin toolbars, r=jaws,bgrins

Comment 5

[Daniel Varga [:dvarga]]

https://hg.mozilla.org/mozilla-central/rev/da642018d1c6