1037545 - [Settings] - 300ms launch time regression

Status: RESOLVED WONTFIX

(Firefox OS Graveyard :: Performance, defect, P1)

Description

[Jon Hylands [:jhylands]]

On July 11, there was a 300ms regression in Settings launch time.

Comment 1

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

Bug 1024893 landed about then and purports to improve the settings launch time ...

Comment 2

[Jon Hylands [:jhylands]]

So its possible that the changes have a negative affect on this metric, but a net positive gain to the overall startup time. I'll find that out when I do the bisect.

Comment 3

[Jon Hylands [:jhylands]]

The bisect shows what Kyle figured in Comment 1:

1cccdf3b99148ebf1a31697d1cd85d6cc844edac is the first bad commit
commit 1cccdf3b99148ebf1a31697d1cd85d6cc844edac
Author: Sergi Mansilla <[e-mail]>
Date:   Wed Jul 9 18:47:01 2014 +0200

    Bug 1024893 - [dolphin][v1.4]Entering settings app takes more than 2.2s

I suspect that this bug should be marked as invalid, since even though the metric we're measuring regressed, the "proper" metric (apparent launch time to the user) has dramatically improved.

Specifically, looking at the original datazilla report:

https://datazilla.mozilla.org/b2g/?branch=master&device=flame&range=7&test=cold_load_time&app_list=settings&app=settings&gaia_rev=f31f95ec18882dec&gecko_rev=98d3423baef9&plot=avg

you can see the large regression that happened on July 11.

Looking at the new metric that we'll be using soon:

https://datazilla.mozilla.org/b2g/?branch=master&device=flame&range=7&test=startup_%3E_moz-app-visually-complete&app_list=settings&app=settings&gaia_rev=6ecc793750a99c3f&gecko_rev=54fa1568a1af&plot=median

You can clearly see that the overall user experience is greatly improved by this fix.