I have observed a similar issue. Upon returning from a 1 day trip, I noticed unresponsiveness when trying to login to my locked screen. I was able to log in, but the system was too unresponsive to continue use. I noticed that I had left three Firefox tabs upon.
Because the system was so unresponsive, I changed to a text terminal. Upon running top, I noticed that plugin-container was using 78% CPU usage and 75% memory usage (of 4 GB total). This is a regression IMHO because prior to upgrade (I had 10.04 and 11.04 systems on similar builds) no such lockup was ever observed. It is still possible that this is an issue with Flash and a specific web page. However, in my experience, Flash issues did not previous cause a system-wide lockup. -- 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/987550 Title: plugin-the container process resource usage is too high Status in “firefox” package in Ubuntu: Incomplete Bug description: plugin-container process resource consumption is too high, the system is often suspended animation ProblemType: BugDistroRelease: Ubuntu 12.04 Package: firefox 11.0+build1-0ubuntu4 ProcVersionSignature: Ubuntu 3.2.0-23.36-generic 3.2.14 Uname: Linux 3.2.0-23-generic x86_64 NonfreeKernelModules: wl fglrx AddonCompatCheckDisabled: False AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24. ApportVersion: 2.0.1-0ubuntu5 Architecture: amd64 ArecordDevices: **** List of CAPTURE Hardware Devices **** card 0: SB [HDA ATI SB], device 0: STAC92xx Analog [STAC92xx Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: gm 2776 F.... pulseaudio /dev/snd/controlC0: gm 2776 F.... pulseaudio /dev/snd/pcmC0D0p: gm 2776 F...m pulseaudio BuildID: 20120410121533 CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found. Card0.Amixer.info: Card hw:0 'SB'/'HDA ATI SB at 0xf7ffc000 irq 16' Mixer name : 'IDT 92HD73C1X5' Components : 'HDA:111d7675,10280255,00100202' Controls : 17 Simple ctrls : 10 Card1.Amixer.info: Card hw:1 'HDMI'/'HDA ATI HDMI at 0xf7dec000 irq 44' Mixer name : 'ATI R6xx HDMI' Components : 'HDA:1002aa01,00aa0100,00100000' Controls : 6 Simple ctrls : 1 Card1.Amixer.values: Simple mixer control 'IEC958',0 Capabilities: pswitch pswitch-joined penum Playback channels: Mono Mono: Playback [on] Channel: release Date: Tue Apr 24 06:12:19 2012 ForcedLayersAccel: False IfupdownConfig: auto lo iface lo inet loopback InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta amd64 (20120328) IpRoute: default via 192.168.1.1 dev eth0 proto static 169.254.0.0/16 dev eth0 scope link metric 1000 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.2 metric 1 Profiles: Profile0 (Default) - LastVersion=11.0/20120410121533 (Running) RunningIncompatibleAddons: FalseSourcePackage: firefox UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 01/11/2010 dmi.bios.vendor: Dell Inc. dmi.bios.version: A06 dmi.board.name: 0M208C dmi.board.vendor: Dell Inc. dmi.chassis.type: 8 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvrA06:bd01/11/2010:svnDellInc.:pnStudio1536:pvr:rvnDellInc.:rn0M208C:rvr:cvnDellInc.:ct8:cvr: dmi.product.name: Studio 1536 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/987550/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp

