991339 - [Tarako] [B2G][General] Unable to open more than two apps at a time

Status: RESOLVED INVALID

(Firefox OS Graveyard :: Performance, defect, P3)

Description

[Brogan Zumwalt [Inactive]]

Attachment: Logcat

Description:
User is unable to have more than two apps open at a time on Tarako device. Long pressing home button shows two or less apps in card view. Returning to homescreen from open app frequently results in "No Recent Apps" message when looking at card view. 

Repro Steps:
1) Update a Tarako to BuildID: 20140402094402
2) Launch Dialer app from home screen
3) Press home button and launch Messages app
4) Press home button and launch Contacts app
5) Press home button
6) Long press home button

Actual:
Two or less apps visible in card view task manager

Expected:
All three apps visible in card view

1.3T Environmental Variables:
Device: Tarako 1.3T MOZ
BuildID: 20140402094402
Gaia: 578fdccea89a88b417d296f8cf20b39099d44be4
Gecko: 34ed4cbc5a59
Version: 28.1
Firmware Version: sp8810

Notes:
Repro frequency: 3/3, 100%
See attached: logcat, dmesg log, & Youtube video

Comment 1

[Brogan Zumwalt [Inactive]]

Attachment: dmesg dump

Unable to get about memory report from Firewatch, will attach when possible at later time

Comment 2

[Brogan Zumwalt [Inactive]]

Youtube video link: http://youtu.be/pjDG7gmiIDI

Comment 3

[John Hammink]

The requirements are unclear on this as yet, but it may be eventually the case on tarako that we only keep two apps open at a time, due to memory limitations of the device.

NI-ing myself to get clarification here.

Comment 4

[John Hammink]

Ravi - do we have final requirements on how many apps we support at a time.

Comment 5

[bhavana bajaj [:bajaj]]

Marvin, can you confirm if comment #3 holds true or give your input here ? I've seen a lot of card view issues on Tarako and this does not sound like a blocker to me. 

:gwagner, have we determined the minimum number of apps that card view could support on tarako ?

Comment 6

[Jason Smith [:jsmith]]

Pulling smoketest keyword as this feels like something that might be expected for a low memory device.

Comment 7

[Gabriele Svelto [:gsvelto]]

This is actually more brutal than the original STR describes: once you send the first application in the background it gets killed pretty much right away - even before launching the second one. This is a side-effect of a number of changes made on tarako with the most prominent ones being that we almost never kill the preallocated process (which seems to consume ~5 MiB now) and we've set the LMK levels pretty high (background applications get killed as soon as we have less than 24 MiB of free memory).

The rationale behind those changes is that on Tarako it's faster to re-launch an app than to have it partially swapped off to zRAM and then swap it in again when it has to go into the foreground. A lot of these changes were specifically made for resolving issues like incoming calls not being picked as swapping out an app slowed out the dialer so much it wouldn't respond fast enough. The net effect of this however is that it's practically impossible to have more than the homescreen + one app open, unless the app has a higher priority than background. For example I can keep alive the music player on my Tarako while having it play music in the background (which pushes it's oom_adj/min_free thresholds higher) though others are seeing it being killed too, see bug 989710.

Comment 8

[Gregor Wagner [:gwagner]]

(In reply to bhavana bajaj [:bajaj] from comment #5)
> 
> :gwagner, have we determined the minimum number of apps that card view could
> support on tarako ?

No I don't think so. We can come up with a target for certified apps (including payload like number of contacts) 
Just to make sure, this is not a cards view bug. We are hitting OOM.

Comment 10

[Ravi Dandu]

This is being discussed actively. Current Proposal is only for Music app to run the background. Everything else will be closed in background.

I propose that we have dialer also be able to continue in the background, when contacts is being used. One common use case in India is user calls another user, and ask for their relatives/friends phone number. Users should be able to check their contact list, while the voice call(dialer app) is on. 

We should check if competitive feature phones (Asha from Nokia) allow dialer and contacts to be operational at the same time. Marvin, you have a Asha phone, can you check that.

Marvin, can you update on the resolution as this is being discussed in Taipei.

Comment 11

[Marvin Khoo [:Marvin_Khoo]]

Ravi, we are still discussing the proposal I mentioned only have Music app to run in background is doable /acceptable here. For Asha, the dialer/call UI has Contact icon where user can navigate to Contact app.

Comment 12

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

Unfortunately the Tarako device has severe memory constraints.  Unless running these three apps at the same time blocks shipping we don't really have the resources to investigate every "this combination of apps does not run simultaneously" bug.  We'll continue to investigate the general overhead of app processes and ways to slim that down, of course.

Comment 13

[Joe Cheng [:jcheng] (please needinfo)]

[triage]: agree with comment 12, let's use this as meta bug

Comment 14

[John Hammink]

This seems like a "works as expected" for me.