1953172 - 380.08 - 6.02% pdfpaint issue15559.pdf / pdfpaint bug931481.pdf + 271 more (Linux, OSX, Windows) regression on Wed March 5 2025

Status: RESOLVED FIXED

(Firefox :: PDF Viewer, defect)

Description

[Treeherder Bug Filer]

Perfherder has detected a talos performance regression from push 22c9d3c2280fcb14d95687bed93333f355d0b1ce. 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)
380%	pdfpaint issue15559.pdf	windows11-64-24h2-shippable	e10s fission stylo webrender	468.93 -> 2,251.24
360%	pdfpaint issue12306.pdf	macosx1470-64-shippable	e10s fission stylo webrender	284.29 -> 1,308.74
360%	pdfpaint issue15559.pdf	windows11-64-shippable-qr	e10s fission stylo webrender	466.50 -> 2,146.37
356%	pdfpaint issue15559.pdf	macosx1470-64-shippable	e10s fission stylo webrender-sw	995.55 -> 4,537.32
346%	pdfpaint issue15559.pdf	macosx1470-64-shippable	e10s fission stylo webrender	1,000.74 -> 4,467.44
334%	pdfpaint issue12306.pdf	macosx1470-64-shippable	e10s fission stylo webrender-sw	291.29 -> 1,264.02
300%	pdfpaint issue12306.pdf	windows11-64-shippable-qr	e10s fission stylo webrender	172.12 -> 688.42
299%	pdfpaint issue12306.pdf	linux1804-64-shippable-qr	e10s fission stylo webrender-sw	329.46 -> 1,314.29
296%	pdfpaint issue12306.pdf	linux1804-64-shippable-qr	e10s fission stylo webrender	337.71 -> 1,337.96
293%	pdfpaint issue15559.pdf	windows11-64-shippable-qr	e10s fission stylo webrender-sw	539.84 -> 2,123.42
...	...	...	...	...
6%	pdfpaint bug1123803.pdf	windows11-64-24h2-shippable	e10s fission stylo webrender-sw	233.08 -> 247.31
6%	pdfpaint issue15629.pdf	windows11-64-24h2-shippable	e10s fission stylo webrender-sw	149.14 -> 158.26
6%	pdfpaint issue11330.pdf	macosx1470-64-shippable	e10s fission stylo webrender	291.81 -> 309.58
6%	pdfpaint ocs.pdf	windows11-64-24h2-shippable	e10s fission stylo webrender	158.18 -> 167.75
6%	pdfpaint bug931481.pdf	macosx1470-64-shippable	e10s fission stylo webrender-sw	213.55 -> 226.40

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
7%	pdfpaint issue11306.pdf	macosx1470-64-shippable	e10s fission stylo webrender	645.72 -> 598.66
6%	pdfpaint issue12716.pdf	linux1804-64-shippable-qr	e10s fission stylo webrender	393.43 -> 369.01

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 patch(es) may be backed out in accordance with our regression policy.

If you need the profiling jobs you can trigger them yourself from treeherder job view or ask a sheriff to do that for you.

You can run all of these tests on try with ./mach try perf --alert 44232

The following documentation link provides more information about this command.

For more information on performance sheriffing please see our FAQ.

If you have any questions, please do not hesitate to reach out to [e-mail].

Comment 1

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

Set release status flags based on info from the regressing bug 1951955

Comment 2

[Calixte Denizet (:calixte)]

Impressive regression... :(

This due to the patch for https://bugzilla.mozilla.org/show_bug.cgi?id=860023.
We added a wasm binding of qcms in order to be able to apply an ICC profile embedded in the pdf to an image.
For example, in issue15559.pdf there is an image 4961×7016 and an ICC profile and the fallback colorspace is RGB which means that before this patch we just did nothing on the image pixels. So we were expecting this perf regression.

In looking in the profiler, we spend around 1.3s in qcms_convert_array which is a way to much.
But it'll be improved in the next days thanks to an update of the code using qcms: calling precache_output_transform makes qcms_convert_array almost 3x faster.

Comment 3

[Marco Castelluccio [:marco]]

https://github.com/mozilla/pdf.js.qcms/commit/2d7812d166cfd2991be47a252de1e88122aadc77 should help a bit.