813262 - Cost control widget process stays "foreground" as long as phone screen is turned on

Status: RESOLVED DUPLICATE of bug 810453

(Firefox OS Graveyard :: Gaia::Cost Control, defect, P3)

Description

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

cjones@beast:~[]$ adb reboot
cjones@beast:~[]$ adb shell b2g-ps | grep Cost
Cost Control     app_0     359   106   63084  22568 ffffffff 400e2330 S /system/b2g/plugin-container

1. Turn on phone screen, so that we're at the lock screen:

cjones@beast:~[]$ adb shell cat /proc/359/oom_adj
1

2. Unlock lock screen:

cjones@beast:~[]$ adb shell cat /proc/359/oom_adj
1

3. Pull down system tray:

cjones@beast:~[]$ adb shell cat /proc/359/oom_adj
1

4. Close system tray:

cjones@beast:~[]$ adb shell cat /proc/359/oom_adj
1

5. Turn off screen:

cjones@beast:~[]$ adb shell cat /proc/359/oom_adj
6

6. Turn screen back on (go to lock screen):

cjones@beast:~[]$ adb shell cat /proc/359/oom_adj
1

Expected results are that cost control's oom_adj values are

 1. 6 (background) [buggy]
 2. 6              [buggy]
 3. 1 (foreground) [correct]
 4. 6              [buggy]
 5. 6              [correct]
 6. 6              [buggy]

This is a very bad bug because it will essentially lock all the cost control memory in RAM; cost control won't be able to be killed on memory pressure.

Comment 1

[Justin Lebar (not reading bugmail)]

> This is a very bad bug because it will essentially lock all the cost control memory in RAM; cost 
> control won't be able to be killed on memory pressure.

I've been ignoring all bugs related to the cost-control process because I was under the impression that we were removing the cost-control process altogether.

Is that still the plan?

Comment 2

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

I had hoped this was related to bug 813243 but it appears like it's not.

(In reply to Justin Lebar [:jlebar] from comment #1)
> > This is a very bad bug because it will essentially lock all the cost control memory in RAM; cost 
> > control won't be able to be killed on memory pressure.
> 
> I've been ignoring all bugs related to the cost-control process because I
> was under the impression that we were removing the cost-control process
> altogether.
> 
> Is that still the plan?

The cost control *service* is no longer needed and should (already?) be dead.

This is the cost control *widget*, the UI part.  This isn't going anywhere.

Comment 3

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

I had hoped this bug was related to bug 813243, but it appears not.

Comment 4

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Re-testing with bug 810453 applied

1. Turn on phone screen, so that we're at the lock screen:

cjones@beast:~[]$ adb shell cat /proc/`adb shell b2g-ps | grep 'Cost Control' | awk '{print $3}'`/oom_adj
/proc//oom_adj: No such file or directory

2. Unlock lock screen:

cjones@beast:~[]$ adb shell cat /proc/`adb shell b2g-ps | grep 'Cost Control' | awk '{print $3}'`/oom_adj
/proc//oom_adj: No such file or directory

3. Pull down system tray:

cjones@beast:~[]$ adb shell cat /proc/`adb shell b2g-ps | grep 'Cost Control' | awk '{print $4}'`/oom_adj
1

4. Close system tray:

cjones@beast:~[]$ adb shell cat /proc/`adb shell b2g-ps | grep 'Cost Control' | awk '{print $4}'`/oom_adj
1

5. Turn off screen:

cjones@beast:~[]$ adb shell cat /proc/`adb shell b2g-ps | grep 'Cost Control' | awk '{print $4}'`/oom_adj
6

6. Turn screen back on (go to lock screen):

cjones@beast:~[]$ adb shell cat /proc/`adb shell b2g-ps | grep 'Cost Control' | awk '{print $4}'`/oom_adj
1

Expected results are that cost control's oom_adj values are

 1. 6 (background) [OK]
 2. 6              [OK]
 3. 1 (foreground) [OK]
 4. 6              [buggy]
 5. 6              [OK]
 6. 6              [buggy]

So looks like we still have some work to do here that doesn't have to do with background services.

Comment 5

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

More specifically, since IIRC cost control is managed as a special case, we'll probably need a patch like the one in bug 810453 for that special-case code.

Comment 6

[Salvador de la Puente González [:salva]]

(In reply to Chris Jones [:cjones] [:warhammer] from comment #5)
> More specifically, since IIRC cost control is managed as a special case,
> we'll probably need a patch like the one in bug 810453 for that special-case
> code.

The code for controlling visibility of Cost Control is here:
https://github.com/mozilla-b2g/gaia/blob/master/apps/system/js/cost_control.js#L54

What could it be?

Comment 7

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

I confirmed that these show/hide statements are successfully being hit.

As I recall, cost control does a window.open().  I suspect that that window is not being set to background.  Checking.  (I have no idea which embedder will end up handling that call ...)

Comment 8

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

We're reaching the code added in bug 810453, but then

I/GeckoDump( 1848): COST CONTROL: could not hide: TypeError: frame.setVisible is not a function

jlebar, halp?  Popups of mozbrowser frames aren't also mozbrowser?

Comment 9

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

http://mxr.mozilla.org/mozilla-central/source/dom/browser-element/BrowserElementParent.cpp#48 says that they are ...

Comment 10

[Justin Lebar (not reading bugmail)]

> jlebar, halp?  Popups of mozbrowser frames aren't also mozbrowser?

Bug 810431.  And, sorry about that.

Comment 11

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Some code has a bug?  Perish the thought! ;)

The suggested workaround should suffice here.

Comment 12

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Works like a charm.

Nothing more to do here.