Bug: 6.04 - 4.25% tart icon-open-DPI2.error.TART / tart newtab-open-preload-yes.error.TART + 3 more (Windows) regression on Thu January 16 2025
Status: RESOLVED
Priority: --
Resolution: INVALID
Created: 2025-01-28 14:14:04+00:00
Resolved: 2025-01-29 13:34:04+00:00

Perfherder has detected a talos performance regression from push [2821188eb89d208b750262e5681d9ed6f144097a](https://hg.mozilla.org/integration/autoland/pushloghtml?changeset=2821188eb89d208b750262e5681d9ed6f144097a). 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)** |  
|--|--|--|--|--| 
| [6%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,86465,1,1)  | [tart](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tart) icon-open-DPI2.error.TART | windows11-64-shippable-qr | e10s fission stylo webrender | 10.46 -> 11.09 | 
| [6%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,86453,1,1)  | [tart](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tart) simple-open-DPI1.error.TART | windows11-64-shippable-qr | e10s fission stylo webrender | 9.46 -> 10.02 | 
| [6%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,86459,1,1)  | [tart](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tart) icon-open-DPI1.error.TART | windows11-64-shippable-qr | e10s fission stylo webrender | 10.36 -> 10.95 | 
| [6%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,86477,1,1)  | [tart](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tart) newtab-open-preload-no.error.TART | windows11-64-shippable-qr | e10s fission stylo webrender | 9.54 -> 10.07 | 
| [4%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,86480,1,1)  | [tart](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tart) newtab-open-preload-yes.error.TART | windows11-64-shippable-qr | e10s fission stylo webrender | 16.46 -> 17.16 | 


Details of the alert can be found in the [alert summary](https://treeherder.mozilla.org/perfherder/alerts?id=43530), including links to graphs and comparisons for each of the affected tests. Please follow our [guide to handling regression bugs](https://wiki.mozilla.org/TestEngineering/Performance/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](https://www.mozilla.org/en-US/about/governance/policies/regressions/).

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 43530`

The following [documentation link](https://firefox-source-docs.mozilla.org/testing/perfdocs/mach-try-perf.html#running-alert-tests) provides more information about this command.

For more information on performance sheriffing please see our [FAQ](https://wiki.mozilla.org/TestEngineering/Performance/FAQ).

If you have any questions, please do not hesitate to reach out to bacasandrei@mozilla.com.