1596427 - 125.27% tp5n main_normal_fileio (windows7-32-shippable) regression on push 8436f40e05c0f181da8d3c79ba32adc9f0e0aec3 (Mon November 4 2019)

Status: RESOLVED DUPLICATE of bug 1573126

(Core :: Layout: Text and Fonts, defect, P5)

Description

[Florin Strugariu [:Bebe]]

Talos has detected a Firefox performance regression from push:

https://hg.mozilla.org/releases/mozilla-beta/pushloghtml?changeset=8436f40e05c0f181da8d3c79ba32adc9f0e0aec3

As author of one of the patches included in that push, we need your help to address this regression.

Regressions:

125% tp5n main_normal_fileio windows7-32-shippable opt e10s stylo 963,481.36 -> 2,170,414.25

You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=23759

On the page above you can see an alert for each affected platform as well as a link to a graph showing the history of scores for this test. There is also a link to a treeherder page showing the Talos jobs in a pushlog format.

To learn more about the regressing test(s), please see: https://wiki.mozilla.org/TestEngineering/Performance/Talos

For information on reproducing and debugging the regression, either on try or locally, see: https://wiki.mozilla.org/TestEngineering/Performance/Talos/Running

*** Please let us know your plans within 3 business days, or the offending patch(es) will be backed out! ***

Our wiki page outlines the common responses and expectations: https://wiki.mozilla.org/TestEngineering/Performance/Talos/RegressionBugsHandling

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

This regression range doesn't make sense.

Comment 2

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

The graph makes it look like this test is just very noisy; I don't think this clearly indicates any particular regression point, although if there was a regression I think it was probably earlier.

Comment 3

[Jonathan Kew [:jfkthame]]

This reminds me of bug 1573126; maybe similarly related to CJK font configuration changes. Does the timing approximately correspond to when the EARLY_BETA_OR_EARLIER flag is no longer in effect (see https://searchfox.org/mozilla-central/rev/cac340f10816707e91c46db6d285f80259420f07/modules/libpref/init/all.js#2941-2945)?

Comment 4

[Jonathan Kew [:jfkthame]]

Looks like the EARLY_BETA flag was cleared on Nov 1st: https://hg.mozilla.org/releases/mozilla-beta/pushloghtml?changeset=c131aabbc2dd7135103aae842487050c5d0e7b5a. So I think that's what is showing up here -- basically the same as it did during the latter half of previous beta cycles.