1757184 - 26.75 - 14.99% Heap Unclassified / Heap Unclassified + 1 more (OSX, Windows) regression on Wed February 23 2022

Status: RESOLVED FIXED

(Core :: Web Painting, defect)

Description

[Acasandrei Beatrice (needinfo me)]

Perfherder has detected a awsy performance regression from push 0f95a5563c86d7151795f02fc491707bca2f15d9. As author of one of the patches included in that push, we need your help to address this regression.

Regressions:

Ratio	Test	Platform	Options	Absolute values (old vs new)
27%	Heap Unclassified	windows10-64-2004-shippable-qr	tp6	74,973,544.52 -> 95,027,839.49
17%	Heap Unclassified	macosx1015-64-shippable-qr	tp6	125,762,248.40 -> 146,615,124.31
15%	Heap Unclassified	macosx1015-64-shippable-qr	tp6	129,622,352.97 -> 149,049,564.36

Details of the alert can be found in the alert summary, including links to graphs and comparisons for each of the affected tests. Please follow our guide to handling regression bugs and let us know your plans within 3 business days, or the offending patch(es) will be backed out in accordance with our regression policy.

For more information on performance sheriffing please see our FAQ.

Comment 1

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

Set release status flags based on info from the regressing bug 1714584

Comment 2

[tgn-ff]

I'm seeing this in some popular sites, notably youtube. At some point I had 1GiB under heap-unclassified in its content process.

Comment 3

[Miko Mynttinen]

This is most likely is caused by memory allocated by the arena allocator not getting released after display lists are destroyed. This is not a memory leak, but allocations can slowly build up when the same website is active for long periods of time (because the same nsDisplayListBuilder is used).

Currently it is difficult to control when the arena should be destroyed, because nsIFrames hold pointers to nsDisplayItems, that might contain nsDisplayLists that are allocated from the arena. I have a plan to improve this, but for now I think the fastest way to fix this is to use nsPresArena instead. I will write a patch tomorrow.

Comment 4

[Miko Mynttinen]

Attachment: Bug 1757184 - Allocate display list nodes from nsPresArena instead of ArenaAllocator r=emilio

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5e1fbc34be86
Allocate display list nodes from nsPresArena instead of ArenaAllocator r=emilio

Comment 6

[Marian-Vasile Laza]

https://hg.mozilla.org/mozilla-central/rev/5e1fbc34be86

Comment 7

[Andrej (:aglavic)]

== Change summary for alert #33430 (as of Wed, 02 Mar 2022 08:49:06 GMT) ==

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
21%	Heap Unclassified	windows10-64-2004-shippable-qr	tp6	94,685,045.72 -> 74,826,471.30
13%	Heap Unclassified	macosx1015-64-shippable-qr	tp6	147,703,945.36 -> 128,107,435.06

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=33430

Comment 8

[Alexandru Ionescu (needinfo me) [:alexandrui]]

== Change summary for alert #33434 (as of Wed, 02 Mar 2022 07:50:46 GMT) ==

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
3%	netflix fnbpaint	windows10-64-shippable-qr	fission warm webrender	174.29 -> 168.29
3%	netflix fnbpaint	linux1804-64-shippable-qr	fission warm webrender	203.06 -> 197.42

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=33434