1371240 - 2.27 - 2.4% kraken (linux64) regression on push 514cd61f92a0970ba495ffe39f0252b50bd8d4ea (Wed Jun 7 2017)

Status: RESOLVED WONTFIX

(Core :: JavaScript Engine, defect)

Description

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

Talos has detected a Firefox performance regression from push:

https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?changeset=514cd61f92a0970ba495ffe39f0252b50bd8d4ea

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

Regressions:

  2%  kraken summary linux64 pgo e10s     1,478.16 -> 1,513.61
  2%  kraken summary linux64 opt e10s     1,530.01 -> 1,564.81


You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=7117

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)]

:jandem, I see you are the patch author of bug 1370823 which is looking like the patch which caused this regression.  Can you take a look at this and help determine if this is expected or if not expected propose a fix or recommend accepting the regression?

Comment 2

[Jan de Mooij [:jandem]]

What's happening is probably that we no longer evict the nursery in NukeCrossCompartmentWrappers when we reload the test iframe, but we now happen to do it during one of the tests. There's not much we can do about it - in general not evicting the nursery is a good thing - so I think we should WONTFIX this...

FWIW I don't see a (clear) Kraken regression on the Windows machines on AWFY.

Comment 3

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

yeah, this looks to be linux only, lets wontfix.