858781 - Investigate limited ts improvement with android pgo (library re-ordering)

Status: RESOLVED INCOMPLETE

(Firefox for Android Graveyard :: Testing, defect, P5)

Description

[Geoff Brown [:gbrown]]

We have investigated android pgo in bug 781179, but have not been able to demonstrate as much of an improvement in startup time as had been expected.

Note particularly the latest results, from a pandaboard build, reported at https://bugzilla.mozilla.org/show_bug.cgi?id=781179#c38. The "Loaded libs in" times are reduced from ~1000 ms to ~500 ms, but the improvement in Talos Ts (not reported in that comment) is less than 200 ms. 

We have not tried eideticker lately, but the last test showed virtually no improvement: https://bugzilla.mozilla.org/show_bug.cgi?id=781179#c31.

Can we do better? Are we testing appropriately?

Comment 1

[William Lachance (:wlach)]

(In reply to Geoff Brown [:gbrown] from comment #0)
> We have investigated android pgo in bug 781179, but have not been able to
> demonstrate as much of an improvement in startup time as had been expected.
> 
> Note particularly the latest results, from a pandaboard build, reported at
> https://bugzilla.mozilla.org/show_bug.cgi?id=781179#c38. The "Loaded libs
> in" times are reduced from ~1000 ms to ~500 ms, but the improvement in Talos
> Ts (not reported in that comment) is less than 200 ms. 
> 
> We have not tried eideticker lately, but the last test showed virtually no
> improvement: https://bugzilla.mozilla.org/show_bug.cgi?id=781179#c31.
> 
> Can we do better? Are we testing appropriately?

We have a few more eideticker tests we could try since that bug was filed. In particular, we now have a test that measures the amount of time it takes until a full web page is loaded (nytimes-load). May be interesting to try that as well.

Comment 2

[William Lachance (:wlach)]

Ok, here's the eideticker results for nytimes-load, using the "first stable frames" metric (lower numbers are better):

PGO builds:

  First stable frames:
  [501, 1143, 790, 519, 1157]

Non-PGO builds:

  First stable frames:
  [609, 776, 823, 654, 707]

Comment 3

[Kartikaya Gupta (email:[e-mail])]

Did anything further happen here, or did it just stall out?

Comment 4

[Geoff Brown [:gbrown]]

As far as I recall, there was no further investigation.

Comment 5

[Kartikaya Gupta (email:[e-mail])]

Ok. Nathan, since you're focusing on Android perf, do you have some cycles to look at this (or add it to your queue)? Figuring this bug out should unblock us on bug 781179 and bug 748488. If it turns out that this doesn't actually give us any win we should just WONTFIX these bugs.

Comment 6

[Nathan Froyd [:froydnj]]

(In reply to Kartikaya Gupta (email:[e-mail]) from comment #5)
> Ok. Nathan, since you're focusing on Android perf, do you have some cycles
> to look at this (or add it to your queue)? Figuring this bug out should
> unblock us on bug 781179 and bug 748488. If it turns out that this doesn't
> actually give us any win we should just WONTFIX these bugs.

Taras had actually asked me to look at PGO bits independently, so I can say with confidence that this is in my queue.  I wonder if things like bug 888482 hamstrung any improvement we could have gotten with PGO.  A second look will definitely be a good thing.

Comment 7

[Kartikaya Gupta (email:[e-mail])]

Awesome, thank you!

Comment 8

[Mike Hommey [:glandium]]

I'm on this already.

Comment 9

[Firefox Bug Husbandry Bot]

Re-triaging per https://bugzilla.mozilla.org/show_bug.cgi?id=1473195

Needinfo :susheel if you think this bug should be re-triaged.

Comment 10

[BMO Automation]

We have completed our launch of our new Firefox on Android. The development of the new versions use GitHub for issue tracking. If the bug report still reproduces in a current version of [Firefox on Android nightly](https://play.google.com/store/apps/details?id=org.mozilla.fenix) an issue can be reported at the [Fenix GitHub project](https://github.com/mozilla-mobile/fenix/). If you want to discuss your report please use [Mozilla's chat](https://wiki.mozilla.org/Matrix#Connect_to_Matrix) server https://chat.mozilla.org and join the [#fenix](https://chat.mozilla.org/#/room/#fenix:mozilla.org) channel.