hud-service spins at 100% cpu

[James Hunt]

I've seen this intermittently.

$ top -b -n1|head
#top - 17:32:32 up 8:33, 4 users, load average: 2.04, 2.15, 1.66
Tasks: 353 total, 2 running, 350 sleeping, 1 stopped, 0 zombie
%Cpu(s): 11.4 us, 3.8 sy, 0.0 ni, 84.6 id, 0.2 wa, 0.1 hi, 0.0 si, 0.0 st
KiB Mem: 12182620 total, 11934092 used, 248528 free, 166328 buffers
KiB Swap: 12455932 total, 3412 used, 12452520 free. 5905344 cached Mem

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
 2909 james 20 0 1068520 258608 57852 R 100.6 2.1 9:51.79 hud-service
22497 james 20 0 1683732 926356 67876 S 62.9 7.6 5:19.45 emulator-x86
 1690 root 20 0 550036 186848 157316 S 18.9 1.5 17:05.96 Xorg
$ sudo cat /proc/2909/stack
[<ffffffffffffffff>] 0xffffffffffffffff
$ sudo strace -p 2909 -fFv -s 1024 -o /tmp/hud-service.log
Process 2909 attached with 4 threads
Process 2909 detached
Process 2962 detached
Process 2966 detached
Process 3012 detached
^C

strace attached.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: hud 13.10.1+14.04.20140402-0ubuntu2
ProcVersionSignature: Ubuntu 3.13.0-24.47-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.2-0ubuntu2
Architecture: amd64
CurrentDesktop: Unity
Date: Mon May 12 17:30:45 2014
InstallationDate: Installed on 2014-04-11 (30 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Daily amd64 (20140409)
SourcePackage: hud
UpgradeStatus: Upgraded to utopic on 2014-05-08 (4 days ago)
upstart.window-stack-bridge.log: Could not get window property "_UNITY_OBJECT_PATH" "/org/ayatana/bamf/window/100665112"

[James Hunt (jamesodhunt)]

backtrace from connecting to hud-service with gdb.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.