1837673 - 2.5x slower than Safari in Document.querySelector on TodoMVC-JavaScript-* subtests

Status: VERIFIED FIXED

(Core :: CSS Parsing and Computation, defect)

Description

[Markus Stange [:mstange]]

In the attached testcase, I get the following numbers:

Firefox Nightly: 480ms
Chrome Canary: 373ms
Safari Technology Preview: 190ms

Matching Safari's performance would improve our score by 1% on these three Speedometer3 subtests: TodoMVC-JavaScript-ES5, TodoMVC-JavaScript-ES6, TodoMVC-JavaScript-ES6-Webpack

Another issue in the benchmark (which is not reproduced by this testcase) is the fact that our selector parsing cache doesn't seem to persist across iframe reloads, whereas Safari's does.

Comment 1

[Markus Stange [:mstange]]

Attachment: queryselector-microbenchmark.html

Comment 2

[Emilio Cobos Álvarez (:emilio)]

Here's an attempt at improving this a bit: https://treeherder.mozilla.org/perfherder/compare?originalProject=try&originalRevision=4546bf49916667685fc48bb3cbadfff9c1490de8&newProject=try&newRevision=ecb7c143abdc5b1422c3b0a41ca2e6682249f4c3

Comment 3

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1837673 - Make selector cache not tied to a document. r=#style,#layout

It doesn't really need to.

Comment 4

[Phabricator Automation]

Comment on attachment 9338489 [details]
Bug 1837673 - Make selector cache not tied to a document. r=#style,#layout

Revision D180591 was moved to bug 1837816. Setting attachment 9338489 [details] to obsolete.

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:jwatt, could you have a look please?

For more information, please visit BugBot documentation.

Comment 6

[Markus Stange [:mstange]]

After bug 1839082 we now match or even exceed Safari's performance on this testcase. This is now fixed.

Comment 7

[Daniel Bodea [:danibodea]]

I've tested in MacOS 11: Nightly v118.0a1 and Beta v117.0b7 show relatively constant results of 400ms and above while Safari shows a relatively constant result of 400ms and below. Compared to the considerable difference originally reported, this is a huge improvement. Improvements are also seen in Windows 10, directly proportional to the ones on MacOS. An improvement in branch 116, then another considerable improvement in branch 117. This fix is confirmed.