1172537 - Make the warning: "Tiled PaintedLayer with no scrollable container ancestor" occur only on actual b2g phones

Status: RESOLVED FIXED

(Core :: Graphics: Layers, defect)

Description

[Paul Rouget [:paul]]

B2G on Desktop, the terminal is spammed with:
[Child 6159] WARNING: Tiled PaintedLayer with no scrollable container ancestor: file /Users/paul/mozilla/src/gfx/layers/client/ClientTiledPaintedLayer.cpp, line 150

It happens when scrolling. Around ~20 warning per scroll.

What does this warning mean? Is it bad? Are we taking a slow path?

The setup:
- B2G desktop (osx). Multi-process enabled. Debug build
- app in an iframe
- app itself includes several remote mozbrowser iframes (it's a browser)
- apzc disabled

Comment 1

[Matt Woodrow (:mattwoodrow)]

This shouldn't matter.

The comment above the warning suggests that android/b2g are guaranteed to have a displayport set, which isn't true if apzc is disabled.

Comment 2

[Mason Chang [Inactive] [:mchang]]

Nical, can you please confirm that this warning is ok? Thanks!

Comment 3

[Paul Rouget [:paul]]

(In reply to Matt Woodrow (:mattwoodrow) from comment #1)
> This shouldn't matter.
> 
> The comment above the warning suggests that android/b2g are guaranteed to
> have a displayport set, which isn't true if apzc is disabled.

So we end up in an unexpected code path?
We are trying to enable apzc on B2G on osx, but in the meantime, should we disable tiles?

Comment 4

[Nicolas Silva [:nical]]

(In reply to Mason Chang [:mchang] from comment #2)
> Nical, can you please confirm that this warning is ok? Thanks!

Yeah, shouldn't be a problem. On b2g we only use tiled layers for scrollable content in order to save memory. On mac we use tiled layers for all painted content scrollable or not. It's a tradeoff because non-tiled painted layers are synchronous, so we trade memory consumption for better scheduling/performance.

b2g desktop is a bit of a Frankenstein configuration and it looks like it uses mac's tiling strategy with this warning that is meant for b2g on actual phones.

No need to disable tiles, we should either make sure the warning is only on actual b2g phones (or have b2g desktop use the same tiling strategy as real-b2g).

Comment 5

[Paul Rouget [:paul]]

Attachment: v1

Comment 6

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/b9702891ab15

Comment 7

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/b9702891ab15