752029 - Low resolution tiles when panning on photo blog take a while to resolve

Status: RESOLVED DUPLICATE of bug 753028

(Firefox for Android Graveyard :: General, defect)

Description

[Jaclyn Fu]

Attachment: Screenshot

Web page or screen you were on when you saw the issue: nomnompaleo.com

Steps to reproduce:
1. Go to nomnompaleo.com
2. Scroll down quickly

What you expected: Clear photos in the blog posts, but instead they were blurry and distorted for a while before the page finished rendering

Crash report ID (if applicable):

Comment 1

[Aaron Train [:aaronmt]]

This is low-resolution based caching of the page replacing checker-board at work here: bug 746016.

Comment 2

[JP Rosevear [:jpr]]

Adding Jeff, he may be able to profile why the draws are taking so long.

Comment 3

[Jeff Muizelaar [:jrmuizel]]

A couple of things are going on here:
First, the java screen shots take about 1.2 to 1.3 seconds, during which we can't paint the main content.

Screenshot painting time is dominated by bluring and text painting. (about 45.5% of paint time is bluring). The bluring comes from the box-shadow around the photos and around the main area.

Second, during regular paint the time is dominated by a mask operation. I'm not sure what's causing this yet.

During regular drawing, paints take about 200ms which doesn't seem totally unreasonable. The bigger problem here is likely java blocking gecko.

Comment 4

[Jeff Muizelaar [:jrmuizel]]

The java screenshotting code also seems to run every 2.5s

Comment 5

[Aaron Train [:aaronmt]]

I see this pretty bad on the bug URL; Galaxy Nexus (4.0.4), Nightly (05/14).

Comment 6

[Naoki Hirata :nhirata (please use needinfo instead of cc)]

oops.  placed the blocked in the wrong bug.  correcting by removing.

Comment 8

[Chris Lord [:cwiiis]]

(In reply to Jeff Muizelaar [:jrmuizel] from comment #3)
> A couple of things are going on here:
> First, the java screen shots take about 1.2 to 1.3 seconds, during which we
> can't paint the main content.
> 
> Screenshot painting time is dominated by bluring and text painting. (about
> 45.5% of paint time is bluring). The bluring comes from the box-shadow
> around the photos and around the main area.

Perhaps we should be throttling the low-res cache more aggressively? And/or try to cut down on the amount of invalidation that happens to it?