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I play a few games and watch movies online that use flash (Shockwave Flash 10.3 r183) with Firefox (3.6.22). From time to time, flash gets horribly slow and I have to restart the browser (some time it seems that I actually need to wait a few minutes, for things to go back to normal)

This happens on my laptop (Intel Core 2 Duo 2.0, Intel Graphics Card), it only seems to affect the video portion (sound remains OK). Also, if I'm really patient, it seems to get better after a while. I have a much slower computer (Celeron 2.66Gh, 10 years old Nvidia card on AGP) with the same software, and the video is slower, but doesn't get slower after a while.

I've suspected that it's related to frequency scaling (some time the processor slows to 1.2 GH, so I've tried changing the governor to "performance" but it didn't seem to help.

I've suspected it's related to firefox using plugin-container, so I disabled that, but it didn't help.

I've done a strace of the plugin-container process, but nothing seemed out of place, top indicates that when the performance decreases the CPU jumps over 100%, I've searched for a profiling program but I didn't get very far.

Update I've updated flash to the latest version and the problem persists.

Does anyone have any idea how do I gather more information about this ? Where should I look ?

NOTE: This question is not about trying to solve the issue with the flash player, the question is about how to debug the issue and gather more information !

share|improve this question
Have you tried upgrading flash? The current version on 10.04 is 11.x – Karlson Dec 27 '11 at 21:43
I had the impression that 10.3 r183 is the latest (I've tried to upgrade some time ago). I will try again. – Sorin Dec 27 '11 at 22:01
What's the version of Ubuntu you're running? And what flash do you have installed? – Karlson Dec 27 '11 at 22:02
I've upgraded now, thanks for the tip. I'm now at Shockwave Flash 11.1 r102 – Sorin Dec 27 '11 at 22:05
Have you tried upgrading from Firefox 3? I'd go to at least 8. – BlueMerlin Jan 6 '12 at 21:24
up vote 3 down vote accepted

I experience precisely the same problems with Flash as you describe here.

The reason why your CPU is scaling down (despite the governor being set to "performance") is that the Flash player uses software rendering. This requires a lot of CPU.

Load a YouTube video and have e.g. htop running in a terminal window in the background. The moment you click "Play" the CPU usage goes up. (A tip for YouTube: enable HTML5 support (go to; that helps a bit)

Now to your actual question: Adobe Flash Player is a proprietary piece of software. Thus, there's not much you can do to debug it.

The only solution I found that works is upgrading to the latest version of the software you use (Firefox 3.6 is quite old by now) and restart the browser from time to time.

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Have a look at the article Bypass Flash GPU validation in Linux, which advocates to force the Flash Player to bypass its GPU validity checks via one of the following methods :

sudo mkdir /etc/adobe && echo “OverrideGPUValidation=true”|sudo tee /etc/adobe/mms.cfg
echo OverrideGPUValidation=true >> ~/.adobe/mms.cfg

(the above commands came from one of the comments on the article.)

Take a backup of these files before modifying them.

share|improve this answer
This doesn't solve the issue, and it doesn't really answer my question – Sorin Jan 9 '12 at 11:03
I don't know of any way to debug flash, except using tools such as Adobe Flex with the debug version of flash. But you will need the sources used to create the flash file, or some flash decompiler product (google for this). – harrymc Jan 9 '12 at 11:35

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