1391741 - 2.95% tcanvasmark (windows7-32) regression on push 397fe94c67f12877fd4b7136388a2708689e2de2 (Wed Aug 16 2017)

Status: RESOLVED WONTFIX

(Firefox :: Pocket, defect)

Description

[Joel Maher ( :jmaher ) (UTC -8)]

Talos has detected a Firefox performance regression from push:

https://hg.mozilla.org/integration/autoland/pushloghtml?changeset=397fe94c67f12877fd4b7136388a2708689e2de2

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

Regressions:

  3%  tcanvasmark summary windows7-32 pgo e10s     9,754.57 -> 9,466.46


You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=8841

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/Buildbot/Talos/Tests

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

Comment 1

[Joel Maher ( :jmaher ) (UTC -8)]

:adw, I see you authored the patch which looks to have caused this regression.  Luckily this looks to be tcanvasmark only and pgo specific (not on opt).  can you take a look at this and see if there is something that might be related to your code that could cause a tcanvasmark regression?

p.s. as a note, if this is pgo only, it could be a side effect of the pgo process.

Comment 2

[Drew Willcoxon :adw]

(In reply to Drew Willcoxon :adw from bug 1385418 comment #23)
> It seems impossible for this bug to have regressed *canvas* performance. 
> This is purely a front-end bug and there's no way it could have impacted any
> part of the core web platform, like canvas.

Comment 3

[Joel Maher ( :jmaher ) (UTC -8)]

thanks :adw, :snorp, you had originally asked for canvasmark to run, do you agree with this?  should we assume this is a pgo side effect?

Comment 4

[James Willcox (:snorp) ([e-mail]) (he/him)]

I'm fine with assuming it's a PGO side effect.