01 July 2008

Serious Problems with XulRunner 1.9

With more and more distributions upgrading to the new XulRunner version 1.9 more and more users send bug reports of Liferea becoming unusable because of constant 100% CPU usage.

Right now I'm sorry to say that I have no clue what causes this, debugging is still going one. Hopefully we will find the problem.

Affected versions: There seems to be no limit to the affected versions. I got reports from 1.4.12 up to 1.4.16b all affected. The common symptom was all setups are using a recent XulRunner 1.9. Until now there were no reports about setups with XulRunner 1.8 having the problem.

If someone reading this with insight in XulRunner/Gecko/Mozilla has any idea please post a comment or send a mail!


thomas said...

probably the debugging in https://bugs.launchpad.net/ubuntu/+source/liferea/+bug/203157 may help

Adrian Bunk said...

Not sure whether it's related, but I made the following observations on a Debian unstable:

Usually I do not have the flashplugin-nonfree package that contains the flash plugin installed.

After the switch to XulRunner 1.9 I'm getting "This page contains information of a type (application/x-shockwave-flash) ... Click OK to download Plugin.OK/Cancel" windows each time I view a webpage containing some flash stuff.

And once I was running Liferea with the flashplugin-nonfree package installed, and I got tho only 100% CPU issue I've seen with XulRunner 1.9.

Lars said...

@thomas: Thanks for the link. I'm aware of the report and in contact with the maintainer of the Ubuntu package.

@adrian: Thanks for this info. It seems like any possibly blocking action (e.g. Flash) in the XulRunner 1.9 HTML widget might cause the livelock.

Anonymous said...

Maybe the following bug:


I see that with FF3 and lots of live bookmarks. I switched to liferea(on xulrunner, imported my feed list, and saw similar problems(eg 30 second lockups and extremely heavy disk usage).

Lars said...

The FF3 bug sounds similar, but isn't it a "Places" only thing? And does XulRunner contain "Places"?

Anonymous said...

FWIW, SVN revision 4031 (Fixes broken single item removal.) fixed the 100% CPU issue that I was seeing, though it obviously wasn't related to xulrunner 1.9.

My DB had accumulated a ton of items and liferea would use a LOT of CPU uselessly trying to remove them every time the corresponding feed was updated.

After running this SVN version and forcefully updating all feeds, the itemsets table went from 21924 to 6797 items. After a vacuum, the DB file went from ~32MB to ~13MB.

This doesn't explain the problems with xulrunner 1.9, but it might account for part of the reports about liferea using 100% CPU.

I wish I had tried the SVN version before starting to hunt this bug earlier today. :-/

Lars said...

@anonymous: Thanks for this valuable feedback. This helps a lot! I'll create another release 1.4.18 today to allow everyone to upgrade as this problem is affecting many users.

BTW this fix was a check in I made today so following SVN ealier wouldn't have helped.