1445254 - 5.02% tpaint (windows10-64) regression on push e3dae8b7e2f2 (Mon Mar 12 2018)

Status: RESOLVED WONTFIX

(Core :: Widget: Win32, defect)

Description

[Ionuț Goldan [:igoldan]]

Talos has detected a Firefox performance regression from push:

https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=62453a779f13a47cd76eb527bc948e6d42e8f60f&tochange=e3dae8b7e2f2f25cb67c27ea54ddb967b304f58b

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

Regressions:

  5%  tpaint windows10-64 opt e10s stylo     250.58 -> 263.17


You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=12089

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

[Ionuț Goldan [:igoldan]]

:xidorn This regression happens only on Windows 10 OPT build. PGO build is not affected and neither are the other platforms.

Comment 2

[Xidorn Quan [:xidorn] UTC+11]

I guess that happens because the extra resize code path there can occasionally trigger an extra resize somehow in some condition.

I wouldn't worry about that, though, because that patch is a prerequisite for bug 1439875, and that bug should eliminate any extra cost caused by additional resize in the window open path as a whole.

Also, I don't think we really care about regression on windows opt build, do we? We should only be shipping pgo builds I suppose.

Comment 3

[Ionuț Goldan [:igoldan]]

(In reply to Xidorn Quan [:xidorn] UTC+10 from comment #2)
> Also, I don't think we really care about regression on windows opt build, do
> we? We should only be shipping pgo builds I suppose.

No, we're very interested in the PGO builds. OPT based results are just an extra eye on
the perf status.

Comment 4

[Xidorn Quan [:xidorn] UTC+11]

(In reply to Ionuț Goldan [:igoldan], Performance Sheriffing from comment #3)
> (In reply to Xidorn Quan [:xidorn] UTC+10 from comment #2)
> > Also, I don't think we really care about regression on windows opt build, do
> > we? We should only be shipping pgo builds I suppose.
> 
> No, we're very interested in the PGO builds. OPT based results are just an
> extra eye on the perf status.

So, can we just close this bug then?

Comment 5

[Ionuț Goldan [:igoldan]]

(In reply to Xidorn Quan [:xidorn] UTC+10 from comment #4)
> (In reply to Ionuț Goldan [:igoldan], Performance Sheriffing from comment #3)
> > (In reply to Xidorn Quan [:xidorn] UTC+10 from comment #2)
> > > Also, I don't think we really care about regression on windows opt build, do
> > > we? We should only be shipping pgo builds I suppose.
> > 
> > No, we're very interested in the PGO builds. OPT based results are just an
> > extra eye on the perf status.
> 
> So, can we just close this bug then?

Yes, we should.