723298 - New Tab Page - animations are not smooth when moving elements

Status: RESOLVED WORKSFORME

(Firefox :: Tabbed Browser, defect)

Description

[Michał]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0a1) Gecko/20120201 Firefox/13.0a1
Build ID: 20120201031146

Steps to reproduce:

When moving elements in New Tab Page quite fast, whole animation becomes laggy and CPU goes up to 100%. This video shows the problem (tested on clean profile):
http://www.screencast.com/t/DtjVrUHJ



Expected results:

Animations should be smooth.

Comment 1

[Leman Bennett [Omega]]

I also see this.

STR:

Hold Click and Drag the thumbnail, and then move it quickly. The faster the movement the jerkier it gets. Eventually smooth movement will stop and painting becomes a slideshow. 

On multicore processors, the movement will max a core completely. This is most likely worse on single core processors.

Comment 2

[Virgil Dicu [:virgil] [QA]]

Mozilla/5.0 (X11; Linux x86_64; rv:13.0a1) Gecko/20120212 Firefox/13.0a1

I can see a slight lag on Ubuntu too when the grid is populated. I can easily replicate this when attempting to move a thumbnail for the first time with 9 thumbnails available.

Comment 3

[ferongr]

I can reproduce this. Moving the mouse slowly results in animation with constantly low FPS. Making (not so) sharp mouse movements results in momentary jank.

Since the SPS profiler extension is the next best thing since sliced bread (or so I'm told when it comes to finding why things are slow) I took the time and uploaded a profile.

http://people.mozilla.com/~bgirard/cleopatra/?report=34ca8ab2570d4989c2f4995873f698d02e22a879

Comment 4

[u279076]

John, are you able to reproduce in the latest Nightly? nightly.mozilla.org

Comment 5

[ferongr]

The profile was from yesterday's Nightly build and I can reproduce the issue even on today's Nightly.

The system I run Nightly on is a reasonable powerful Intel i3-2120 with an AMD HD6850 on Windows 7 64bit, running the 32bit Nightlies with HWA enabled.

Comment 6

[u279076]

What happens if you turn off HWA?

Comment 7

[ferongr]

The experience remains roughly the same as I perceive it. Here's a profile without HWA FWIW.

http://people.mozilla.com/~bgirard/cleopatra/?report=bdf012315290b4a0369c288a137bfd95fe16909e

Comment 8

[ferongr]

FWIW I cannot reproduce anymore with the 2012-08-31 Nightly. The symptoms of the jankiness (with the dragged element not responding at all during fast dragging)are very similar to the symptoms I described in bug 786397. Looks like something landed that improved performance. Maybe something landed that improved performance for drag and drop for both cases?

The dragged thumbnail is not following the mouse perfectly fluidly still, like the movement is calculated at a low framerate so it's not perfect yet.

Comment 9

[u279076]

John, are you able to reproduce with the 2012-08-30 Nightly? If not, would you mind going back through the Nightlies to find out when it was "fixed"? We may be able to find a patch or series of patches that fixed this and uplift it.

Comment 10

[ferongr]

I have found the cause of my problems described both in comment 5 and bug 786397 and it was the Gecko profiler extension regressing performance in many areas after being deactivated from about:addons without first stopping profiling. I've been using the profiler extensively the last few days so that's why the problem persisted across restarts.

Sorry for the misdirection, filed https://github.com/bgirard/Gecko-Profiler-Addon/issues/21

Comment 11

[Virgil Dicu [:virgil] [QA]]

I'll close this for the moment, as I'm not seeing any lag either when dragging with F18. There have been quite a few improvements to the New tab page layout since I first confirmed this in comment 2 so it must have been resolved in between.

If anybody can still replicate, please re-open.