If you think a bug might affect users in the 57 release, please set the correct tracking and status flags for Release Management.

6.09 - 32.32% sessionrestore_many_windows (osx-10-10, windows10-64, windows7-32) regression on push 39a94e16a3694c443a985081ac1c6cd761363da2 (Fri Sep 8 2017)

RESOLVED FIXED in Firefox 57



Session Restore
14 days ago
8 days ago


(Reporter: jmaher, Assigned: beekill)


(Blocks: 2 bugs, {perf, regression, talos-regression})

57 Branch
Firefox 57
perf, regression, talos-regression
Dependency tree / graph

Firefox Tracking Flags

(firefox-esr52 unaffected, firefox55 unaffected, firefox56 unaffected, firefox57 fixed)




14 days ago
Talos has detected a Firefox performance regression from push:


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


 32%  sessionrestore_many_windows windows10-64 opt e10s     3,034.50 -> 4,015.33
 31%  sessionrestore_many_windows windows7-32 opt e10s      3,168.58 -> 4,144.17
  6%  sessionrestore_many_windows osx-10-10 opt e10s        2,990.67 -> 3,172.92

You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=9333

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

14 days ago
:beekill, can you look into this large regression in our performance test?
Flags: needinfo?(nnn_bikiu0707)
Resolved by backout of the offending changeset.
Last Resolved: 8 days ago
Flags: needinfo?(nnn_bikiu0707)
Resolution: --- → FIXED
Assignee: nobody → nnn_bikiu0707
status-firefox55: --- → unaffected
status-firefox56: --- → unaffected
status-firefox57: --- → fixed
status-firefox-esr52: --- → unaffected
Target Milestone: --- → Firefox 57
Version: 53 Branch → 57 Branch
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