I finally managed to catch this bug in debugger. After I closed Firefox window there were two threads consuming CPU so I printed their stacktraces. I won't stop process for one day so someone could gather more information by writing me commands to run. (I'm using Firefox 28)
** Attachment added: "firefox-log.txt" https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1266509/+attachment/4033911/+files/firefox-log.txt -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to firefox in Ubuntu. https://bugs.launchpad.net/bugs/1266509 Title: Firefox takes all available CPU power occasionally, and can't quit Status in “firefox” package in Ubuntu: Confirmed Bug description: When this happens, I have to kill it by signal 1 to quit firefox processes. Closing tabs don't help when this happens. ProblemType: Bug DistroRelease: Ubuntu 13.10 Package: firefox 26.0+build2-0ubuntu0.13.10.2 ProcVersionSignature: Ubuntu 3.11.0-15.23-generic 3.11.10 Uname: Linux 3.11.0-15-generic x86_64 AddonCompatCheckDisabled: False ApportVersion: 2.12.5-0ubuntu2.2 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: jarno 1699 F.... panel-10-mixer BuildID: 20131206145143 CRDA: Error: [Errno 2] No such file or directory: 'iw' Channel: Unavailable Date: Mon Jan 6 18:25:25 2014 EcryptfsInUse: Yes Extensions: extensions.sqlite corrupt or missing ForcedLayersAccel: False IfupdownConfig: # interfaces(5) file used by ifup(8) and ifdown(8) auto lo iface lo inet loopback IncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite) InstallationDate: Installed on 2013-09-20 (108 days ago) InstallationMedia: Lubuntu 13.04 "Raring Ringtail" - Release amd64 (20130423.1) IpRoute: default via 192.168.0.254 dev wlan0 proto static 192.168.0.0/24 dev wlan0 proto kernel scope link src 192.168.0.101 metric 9 Locales: extensions.sqlite corrupt or missing MarkForUpload: True MostRecentCrashID: bp-b022607d-fa4c-4923-a0f0-a0cb42140101 PrefSources: prefs.js [Profile]/extensions/{3d7eb24f-2740-49df-8937-200b1cc08f8a}/defaults/preferences/flashblock.js Profiles: Profile0 (Default) - LastVersion=26.0/20131206145143 PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. RelatedPackageVersions: google-talkplugin 4.9.1.0-1 gecko-mediaplayer 1.0.8-4ubuntu1 RfKill: 0: phy0: Wireless LAN Soft blocked: no Hard blocked: no RunningIncompatibleAddons: False SourcePackage: firefox SubmittedCrashIDs: bp-b022607d-fa4c-4923-a0f0-a0cb42140101 Themes: extensions.sqlite corrupt or missing UpgradeStatus: Upgraded to saucy on 2013-10-18 (80 days ago) dmi.bios.date: 09/13/06 dmi.bios.vendor: LENOVO dmi.bios.version: 63ET13WW dmi.board.name: CAPELL VALLEY(NAPA) CRB dmi.board.vendor: LENOVO dmi.board.version: Not Applicable dmi.chassis.type: 10 dmi.chassis.vendor: No Enclosure dmi.chassis.version: N/A dmi.modalias: dmi:bvnLENOVO:bvr63ET13WW:bd09/13/06:svnLENOVO:pn89224MG:pvr3000C200:rvnLENOVO:rnCAPELLVALLEY(NAPA)CRB:rvrNotApplicable:cvnNoEnclosure:ct10:cvrN/A: dmi.product.name: 89224MG dmi.product.version: 3000 C200 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1266509/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
