1086963 - [meta] Gallery app launch latency is worse than Android on quad core device

Status: RESOLVED WORKSFORME

(Firefox OS Graveyard :: Gaia::Gallery, defect, P1)

Description

[Tapas[:tkundu on #b2g/gaia/memshrink/gfx] (always NI me)]

We are seeing following launch latency numbers for gallery :

FFOS v2.1 : 1117 ms
Android : 669 ms

Device used : msm8926 quadcore
RAM: 1GB

It is showing that 2 cpu cores are mostly idle during app launch.

We are tracking it for v2.2

Comment 1

[Hema Koka [:hema]]

Being tracked as part of multi-core performance improvements: https://bugzilla.mozilla.org/show_bug.cgi?id=1093564

Comment 2

[Kai-Chih Hu [:khu]]

We should divide this topic into 2: Gecko and Gaia. Thinker, can you do that?

Comment 3

[Kai-Chih Hu [:khu]]

Looks like we have these bugs already. Clear ni.

Comment 4

[Thinker Li [:sinker]]

please remove 2.2+ since this bug is not in the scope.

Comment 5

[Bobby Chien]

As discussion with Kevin and Ken, this is in v2.2 feature scope. Marked this for scope tracking.

Comment 6

[Hema Koka [:hema]]

Our understanding is that Thinker's team is working on gecko level changes that may improve the app start-up time on quad core. Any recommendation on the gaia side for gallery? 

Thinker: Do we have launch latency results for gallery with the gecko optimizations on quad core device? Thanks for your help!

Comment 7

[Thinker Li [:sinker]]

QA team has a report for Nexus 5.

Comment 8

[William Hsu [:whsu]]

(In reply to Hema Koka [:hema] from comment #6)
> Our understanding is that Thinker's team is working on gecko level changes
> that may improve the app start-up time on quad core. Any recommendation on
> the gaia side for gallery? 
> 
> Thinker: Do we have launch latency results for gallery with the gecko
> optimizations on quad core device? Thanks for your help!

You may need this data. FYI.
- https://docs.google.com/a/mozilla.com/spreadsheets/d/1Hk9kWld3ZdzFxG3vS5au0sepm7eLv2_7BS2Kn3N8Z-A/edit#gid=9028135

Gallery cold launch time (Visually complete):
@ Workload: 20 gallery images (make reference-workload-light)
 - Flame 2.1 (Dual-Core & 1024 MB): 1019.9 ms
 - Flame 2.1 (Single-Core & 319 MB): 1635.5 ms
 - Nexus 2.2 (Quad-Core & 2048 MB): 721.9 ms
 - Madai 2.0 (Quad-Core & 1536 MB): 1057.8 ms

Comment 9

[David Flanagan [:djf]]

As part of bug 1127078, I landed two gaia changes that gave more than 100ms startup time improvement on both Nexus5-l and Flame.  In my testing, the Gallery app startup time for a Nexus5-l running master is now down to 450ms on average with a median of 448ms over 50 trials. See https://bugzilla.mozilla.org/show_bug.cgi?id=1129584#c13

Bug 1129584 may give an additional 10 to 20ms improvement, but that patch involves completely rearranging the gallery app startup code and may not be suitable for uplift to 2.2

The improvement seemed to be a similar amount on the dual-core Flame and the quad-core Nexus 5. So we're still not really taking advantage of the 4 cores. Perhaps this is just because gallery app startup has a bottleneck that cannot be parallelized, or because gecko or gonk aren't properly utilizing all four cores.

Needinfo Tapas so he knows about these recent changes.  Tapas: the relevant Gallery app bugs are 1129563 and 1129572. Both are on master and I have requested uplift to 2.2 for both of them. I'll be interested to know whether these may a significant difference in testing of your quadcore device.

Comment 10

[David Flanagan [:djf]]

Removing the dependency on bug 1126119 because the Gallery app no longer uses mozHasPendingMessages()

Comment 11

[David Flanagan [:djf]]

Tapas,

In addition to the note in comment #9, here's another question for you: can you think of any power management settings that we might tweak to get the idle cpu cores to wake up more quickly when an app is launched? Does the setInteractive() code you contributed in bug 890541 work on Lollipop or was that JB-specific?

By reading /proc/stat, then lauchning the Gallery a bunch of times, then reading /proc/stat again, I can see that core 3 remains turned off most of the time and really doesn't contribute much to startup. Perhaps that is just because gecko can't parallelize the process of loading a app very well. Or maybe we are being to aggressive about power management and core 3 just doesn't get switched on fast enough to help out?

Comment 12

[Bobby Chien]

Coding effort completed. Require verification.

Comment 13

[Mike Lee [:mlee]]

CAF (Inder) expressed a preference to track performance meta bugs like these instead of their more granular blockers since, in their opinion, the individual blockers tend to change and don't always reflect a direct connection to the primary performance issue. CAF will track and update (close) these bugs when the reported performance issue is resolved.

Comment 14

[Bobby Chien]

Cold launch time (Visually Loaded) on Flame:
Datazilla    Master    v2.2    v2.1
Camera       1375      1383    1634
Clock        1266      1164    1041
Contacts      860       806     883
FM Radio      627       554     542
Gallery      1000       940     969
Messages     1392      1255    1262
Music        1312      1164     929 
Phone         615       554     567
Settings     2537      2573    2586
Video        1054      1022     964

Comment 16

[Bobby Chien]

Last update as followings, and Raptor dashboard [1]. Mark worksforme per no longer 2.2 blocker. Please follow bug 1196586 in v2.5.

-------------------------
appName   master  v2.2
--------  ------  ----
Messages  1700    986
Video     1127    1020
Settings  2682    2437
FM Radio  707     496
Gallery   1076    1046
Music     1085    956
E-Mail    463     1973
Contacts  1118    717
Clock     1202    1206
Calendar  1476    1342
Camera    1668    1297

[1] http://raptor.mozilla.org/#/dashboard/file/raptor.json