1105632 - Poor interface performance (perf profiles included)

Status: RESOLVED INVALID

(Firefox :: Tabbed Browser, defect)

Description

[tyaremco]

Attachment: about:support, performance and memory profiles for Test

I've always had poor performance with Firefox on my laptop for some time and I thought I'd try to get to the bottom of it.  I experience interface hangs for most operations, including tab switching. 

Luckily I can reproduce the problems on browser start (the symptoms are much worse after a few days of browsing) Below I'll show my testing method.  Performance profiles are attached.


## Testing Method ##
- load two tabs (chosen at random; symptoms appear regardless of tab url)
"A" http://www.redferret.net/?p=47405
"B" http://themeforest.net/item/university-education-event-and-course-theme/full_screen_preview/8412116
- wait for any large CPU activity to stop
- begin with A focused
- start profiler
- mouseover B, wait for tooltip
- click B, keep mouse on tabbar
- mousover A, wait for tooltip
- click A
- stop profiler


## Machine ##
- Windows 7
- Thinkpad X200s
- Intel Core2 Duo CPU L9400
- 8.00GB RAM
- Mobile Intel(R) 4 Series Express Chipset Family (Driver version 8.15.10.2869)

## Profile at the time of testing ##
(about:support is included in attachment)
- new profile
- I have hardware acceleration disabled as I do not find any performance improvement with it enabled.  I experience the exact same symptoms.

## Machine state before profiler start ##
- 60% free RAM
- CPU 0-7%



## Test ##

- start browser in Safe Mode
- execute Testing Method

Only two tabs were loaded in this test.  No tabs remained in an unloaded state.

# Results
Performance is ~14FPS on click/mouseover.  After further testing, it can go as low as 7FPS.



## Observations ##
Firefox does not run well on my hardware config. That said, 14 FPS seems extremely low for an operation as basic as simply switching tabs.  



## What should happen ##
FPS when switching tabs should remain reasonable on a relatively modern machine (eg. Thinkpad X200s).

Comment 1

[Dão Gottwald [:dao]]

(In reply to tyaremco from comment #0)
> ## Profile at the time of testing ##
> (about:support is included in attachment)
> - new profile

Your about:support data shows a large number of enabled add-ons. Can you reproduce the problem without them?

Comment 2

[tyaremco]

(In reply to Dão Gottwald [:dao] from comment #1)
> (In reply to tyaremco from comment #0)
> > ## Profile at the time of testing ##
> > (about:support is included in attachment)
> > - new profile
> 
> Your about:support data shows a large number of enabled add-ons. Can you
> reproduce the problem without them?

As mentioned, all tests are done in Safe Mode.

Comment 3

[Dão Gottwald [:dao]]

Safe mode isn't a good place to test performance. For instance, it disables all Javascript JIT and hardware acceleration (but you already disabled this yourself).

Comment 4

[tyaremco]

Ah, I didn't know that.  I thought Safe Mode just disabled all extensions and reverted any customizations.  

Is JIT relevant in this case?  Looking at the performance profile, in the time regions where my interface hangs there are no scripts running at all.  I'll make a new perf profile if you still think it's worth it.

Comment 5

[Dão Gottwald [:dao]]

(In reply to tyaremco from comment #4)
> Is JIT relevant in this case?

I'm not sure. I also don't know off-hand if safe mode affects other things that might be relevant here, beyond JS and graphics.