1886780 - 5.61 - 5.19% perf_reftest_singletons many-custom-props.html / perf_reftest_singletons many-custom-props.html (OSX) regression on Mon March 11 2024

Status: NEW

(Core :: CSS Parsing and Computation, defect)

Description

[Andrej (:aglavic)]

Perfherder has detected a talos performance regression from one of the two pushes 1f4f2a707dbc968bd8f23c426f0dfab2a37ebbda and/or 7cddfe0bce3ac9a7e96c18e2c2250310e47212fa. As author of these of the patches included in that push, we need your help to address this regression.

The pushes we believe caused the regressions are one of the 5 in: https://treeherder.mozilla.org/jobs?repo=autoland&revision=1f4f2a707dbc968bd8f23c426f0dfab2a37ebbda

Regressions:

Ratio	Test	Platform	Options	Absolute values (old vs new)
6%	perf_reftest_singletons many-custom-props.html	macosx1015-64-shippable-qr	e10s fission stylo webrender	247.07 -> 260.94
5%	perf_reftest_singletons many-custom-props.html	macosx1015-64-shippable-qr	e10s fission stylo webrender	247.52 -> 260.36

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 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 these tests on try with ./mach try perf --alert 41855

For more information on performance sheriffing please see our FAQ.

Comment 1

[Tess Hoffman [:zrhoffman]]

many-custom-props.html does not include registered custom properties, so bug 1877383 is not likely a regressor. Maybe I'm missing something, but I wouldn't have expected a noticeable increase in refcount traffic from this patchset. Emilio, WDYT?

Comment 2

[Emilio Cobos Álvarez [:emilio]]

You're growing the unregistered value and cloning the redundant url data quite a lot, right? I think it's a plausible regressor... It'd be interesting to see which one of the individual patches in the push are really at fault. Should be feasible to push with back outs and figure that out?

Comment 3

[Tess Hoffman [:zrhoffman]]

Sure

Comment 4

[Tess Hoffman [:zrhoffman]]

revision	perf run
Revert "Bug 1877383 - Preserve computed registered custom property types. r=firefox-style-system-reviewers,emilio"	https://treeherder.mozilla.org/jobs?repo=try&revision=3ae4289a9a811e31cf6727ffd2fb2ad8949488b5
Revert "Bug 1864736 - Use ComputedRegisteredValue for custom property maps. r=firefox-style-system-reviewers,emilio"	https://treeherder.mozilla.org/jobs?repo=try&revision=70c595e2b8f6df2366b5325c9b4dbe73b5607a04
Revert "Bug 1864736 - Eliminate redundant URL data. r=zsun"	https://treeherder.mozilla.org/jobs?repo=try&revision=f59d29546692d576dc15bf1a191318b2ac2afcea
Revert "Bug 1864736 - Add URL data to registered custom property struct. r=zsun"	https://treeherder.mozilla.org/jobs?repo=try&revision=c38dbe7d591408a4bf48febea7d222a0098766f7

Comment 5

[Tess Hoffman [:zrhoffman]]

Rerunning with more total runs to confirm, but most of the perf regression seems to come from Bug 1864736 - Use ComputedRegisteredValue for custom property maps. r=firefox-style-system-reviewers,emilio <https://hg.mozilla.org/mozilla-central/rev/63d81375ed6e>. So carrying around the uncomputed value to speed up serialization and reducing cloning of the redundant URL data could help.

revision	comparison
Revert "Bug 1877383 - Preserve computed registered custom property types. r=firefox-style-system-reviewers,emilio"	https://treeherder.mozilla.org/perfherder/compare?originalProject=try&originalRevision=b989e1388877966df27ee9a712d32db5310df6b9&newProject=try&newRevision=19592896094d300c49ea9bb696d7bf78b7075c22
Revert "Bug 1864736 - Use ComputedRegisteredValue for custom property maps. r=firefox-style-system-reviewers,emilio"	https://treeherder.mozilla.org/perfherder/compare?originalProject=try&originalRevision=b989e1388877966df27ee9a712d32db5310df6b9&newProject=try&newRevision=7bf4eb3b1454d8a875a0f63870e56924b05b725c
Revert "Bug 1864736 - Eliminate redundant URL data. r=zsun"	https://treeherder.mozilla.org/perfherder/compare?originalProject=try&originalRevision=b989e1388877966df27ee9a712d32db5310df6b9&newProject=try&newRevision=fdc7d8de9c7da53c98ac9b0d336bb4af8ae95783
Revert "Bug 1864736 - Add URL data to registered custom property struct. r=zsun"	https://treeherder.mozilla.org/perfherder/compare?originalProject=try&originalRevision=b989e1388877966df27ee9a712d32db5310df6b9&newProject=try&newRevision=afac3eff769dbe0093a0453fab00e75cc3dafd89

Comment 6

[BugBot [:suhaib / :marco]]

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

For more information, please visit BugBot documentation.

Comment 7

[Ting-Yu Lin [:TYLin] (PST, UTC-7)]

Set severity as S3. Feel free to bump it higher if the pref regression is more serious than I thought.