890780 - Launching Poppit occasionally after previously being launched will show a very delayed app loading transition

Status: RESOLVED WONTFIX

(Firefox OS Graveyard :: Gaia::System::Window Mgmt, defect, P2)

Description

[Jason Smith [:jsmith]]

Attachment: Slow Opening Transition

Build: B2G 18 7/7/2013
Device: Unagi

STR

1. Install Poppit from Marketplace
2. Launch Poppit
3. After a few seconds, hit the home button
4. Try launching Poppit again

Expected

A smooth app transition should be present to load Poppit again.

Actual

See screenshot. Occasionally, a delayed transition is present where half the transition is seen in the screenshot for a few seconds, followed by the app loading. Looks like a performance regression.

Comment 1

[(inactive after 6/18) Alive Kuo [:alive]]

Yes I see this also.
The grey-ed app is stopped at middle of screen for a while before transitioning.

I'd think this is because the heavy loading of the app but I'm not sure. Also I don't see this performance lost on master.

Comment 2

[(inactive after 6/18) Alive Kuo [:alive]]

Try to revert 5d7a0da528dce626b563abafc135eb828599d3c0 on v1-train,
but seems it doesn't offer great help.

It's still very slow to start the open transition.
The different is with the patch we have a grey one in middle of screen but both are very slow to react.

Comment 3

[Jason Smith [:jsmith]]

Hmm...a b2g18-specific performance regression. Do we want this fixed on b2g18? leo noming to find out. If not, then we probably should just wont fix this if this works on master.

Note that the app in question here does do heavy loading during startup, so that's probably why we can easily see this with Poppit. But I'd imagine this bug could happen with any app that does heavy activity during startup.

Comment 4

[Lukas Blakk [:lsblakk] use ?needinfo]

Can you expand on the potential regression here? Comparison to v1.0.1 as well as master?

Comment 5

[Jason Smith [:jsmith]]

(In reply to [e-mail] [:lsblakk] from comment #4)
> Can you expand on the potential regression here? Comparison to v1.0.1 as
> well as master?

On 1.01 - This issue doesn't reproduce. The transition is a smooth opening and closing transition and does not showed the long delay block-like behavior seen in this bug.

On Master - comment 1 indicates this doesn't reproduce on master. I'll double check for my own point of comparison though.

Comment 6

[Jason Smith [:jsmith]]

Actually, this does appear to be reproducible for me on master.

Comment 7

[Alex Keybl [:akeybl]]

We're concerned that this perf regression will impact other applications, so this is definitely worth investigating.

Alive, do you have the time to take a look?

Comment 8

[(inactive after 6/18) Alive Kuo [:alive]]

Hey Jason,
Do you still think this is regression per https://bugzilla.mozilla.org/show_bug.cgi?id=890779#c5  ?

Comment 9

[Jason Smith [:jsmith]]

(In reply to Alive Kuo [:alive] from comment #8)
> Hey Jason,
> Do you still think this is regression per
> https://bugzilla.mozilla.org/show_bug.cgi?id=890779#c5  ?

Yes. The issue cited in bug 870779 I reproduced on 1.01. However, I couldn't reproduce this bug on 1.01, only on 1.1 or later.

Comment 10

[(inactive after 6/18) Alive Kuo [:alive]]

What I see on master: The transition is always smooth during poppit app is loading. But very slow on v1-train. Strange..

Comment 11

[(inactive after 6/18) Alive Kuo [:alive]]

I have two thoughts now:
(1) Do not request next paint while app is still loading before opening transition.
(2) Use animation instead of transition.

However what I really wonder is the big code difference between master and v1-train..

Comment 12

[(inactive after 6/18) Alive Kuo [:alive]]

Rex would track this bug since this is a regression from bug 840147/bug 877903.
I would offer help if necessary.

Comment 13

[Jason Smith [:jsmith]]

requesting to punt - won't block unless we get noise during IOT about this.

Comment 14

[Ben Kelly [:bkelly, not reviewing]]

Just retested this on v1.3 and I get no transition at all when launching poppit after it first fully loads.  It doesn't matter if I am launching a fresh process or bringing an existing process from the background.

Seems like this is still an issue.  Could it be due to extreme memory pressure?  Poppit takes about 70MB.

Comment 15

[Bobby Chien]

suggest WONTFIX per no further feedback on issue. 

As test on sony z3c, it's not affected on master.