1046158 - [Vertical Homescreen] Use three columns by default everywhere

Status: RESOLVED FIXED

(Firefox OS Graveyard :: Gaia::Homescreen, defect)

Description

[Kevin Grandon :kgrandon]

To solve bug 1029902 we changed the column layout for 256mb devices. Now that we have more information we would like to try to ship three columns everywhere.

We should measure to make sure that this won't impact memory usage.

Comment 1

[Kevin Grandon :kgrandon]

Attachment: Pull request - Update homescreen columns

Comment 2

[Kevin Grandon :kgrandon]

Attachment: Pull request - Revert column settings memory changes

Comment 3

[Kevin Grandon :kgrandon]

Hey Benwa, Kyle - before we try to go to three columns by default everywhere I just wanted to verify that there are no memory problems. I measured using get_about_memory and saw the following results with around 200 icons:

When passing --minimize: both 3 column and 4 column use the same memory.
When not passing --minimize: 3 column seems to use ~20mb of more memory than 4 column.

Does --minimize discard image data, and if so - are we ok landing with the difference in these numbers?

Comment 4

[Benoit Girard (:BenWa)]

I'm going to assume --minimize does mean discarding image data. ~20mb more is big difference. Are you sure you're not seeing a fluctuation? If you don't use minimize try leaving the system idle for 30+ seconds.

Comment 5

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

--minimize does discard image data.

20 MB = 200 * 4 bytes / pixel * (3_column_size^2 - 4_column_size^2)

That number is consistent with moving from 64px icons in the 4 column layout to ~175px icons in the 3 column layout, if we're decoding every icon.  But if the 2.7x number you gave me on Wednesday about the overpainting is accurate we would expect to only have to paint 16 * 2.7 = 43.2 icons at any given time.  So something is going wrong here.

Comment 6

[Kevin Grandon :kgrandon]

Ok, thanks guys. After re-testing without --minimuze and letting both stabilize for ~30s the numbers are much more inline with each other. I think we should be good to get this landed then.

Comment 7

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

I really don't think we can hand wave away the transient spike.  If we need 20 MB more to paint the homescreen every time we do that we're OOM killing 20 MB more of background apps than we were before.

Comment 8

[Kevin Grandon :kgrandon]

(In reply to Kyle Huey [:khuey] ([e-mail]) from comment #7)
> I really don't think we can hand wave away the transient spike.  If we need
> 20 MB more to paint the homescreen every time we do that we're OOM killing
> 20 MB more of background apps than we were before.

Everything is in 'heap-unclassified', I have a small screenshot of the spike, but not the memory report unfortunately. I will try to reproduce the spike on the 4-column to see if it's in the same ballpark.

Comment 9

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

That's interesting.  We should look into that next week.

Comment 10

[:gerard-majax]

Attachment: ion_fromstart_master_20140804_layout_homescreen.png

Measuring ION memory on master with 3 and 4 icons layout, using a userdebug build.

Comment 11

[:gerard-majax]

Attachment: ion_fromstart_master_20140804_apps_layout3_homescreen.png

Measuring ION memory on master with 3 icons layout, using a userdebug build, with 50 or 100 preloaded apps.

Comment 12

[:gerard-majax]

Attachment: ion_fromstart_master_20140804_apps_layout4_homescreen.png

Measuring ION memory on master with 4 icons layout, using a userdebug build, with 50 or 100 preloaded apps.

Comment 13

[Kevin Grandon :kgrandon]

Comment on attachment 8464733 [details] [review]
Pull request - Update homescreen columns

Aus - would you mind throwing a review on this one? Thanks!

Comment 14

[Kevin Grandon :kgrandon]

[Blocking Requested - why for this release]: Shipping three columns by default everywhere is a Product/UX blocker.

Comment 15

[Aus Lacroix [:aus]]

Comment on attachment 8464733 [details] [review]
Pull request - Update homescreen columns

Looks good to me for back-out purposes. Looks like you got a b2g process crash in one of the test runs. It would be nice to re-run it to make sure it's OK (even though the debug b2g process passed the same test suite).

Comment 16

[Kevin Grandon :kgrandon]

Thanks for the review Aus!

Homescreen revert landed: https://github.com/mozilla-b2g/gaia/commit/8355af88970e875cb7e4e9d1852e108dab489829

Settings revert landed: https://github.com/mozilla-b2g/gaia/commit/8001b271c194cf929a42a18cfc061788cf555ed7

Comment 17

[Gregor Wagner [:gwagner]]

Based on email-discussion and product needs.

Comment 18

[Ryan VanderMeulen [:RyanVM]]

v2.0: https://github.com/mozilla-b2g/gaia/commit/5ad694de462c772b63f2ddced283b2d1ccc3b47b
v2.0: https://github.com/mozilla-b2g/gaia/commit/92d2815f3ec3bd9b35c0e2de8dc34cdf5a3bda19