Public bug reported: I have a clean install of 14.04 on an i7-860 with 16GB RAM.
I'm using NFS to share a home directory. The volume is ~2TB, formatted JFS, and it has a single client. I recently noticed that I had a [kworker] process using 100% CPU: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 9253 root 20 0 0 0 0 R 99.9 0.0 0:30.17 [kworker/3:1] Rebooting didn't help. After some troubleshooting I found that it went away immediately when I stopped the nfs-kernel-server daemon. When I start it, it comes back after a minute or two, still using 99-100% CPU. The load goes away when the client is turned off and the NFS server is restarted, but it comes back as soon as it reconnects. The only line in /etc/exports is: /home 192.168.1.0/24(rw,sync,no_root_squash) version_signature: Ubuntu 3.13.0-24.47-generic 3.13.9 # dpkg -l nfs-kernel-server Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Architecture Description +++-==============-============-============-================================== ii nfs-kernel-ser 1:1.2.8-6ubu amd64 support for NFS kernel server Description: Ubuntu 14.04 LTS Release: 14.04 I don't think this is related to my hardware but I can provide lspci output if necessary. ** Affects: linux (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1318116 Title: kworker uses 100% CPU when nfs-kernel-server is active To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1318116/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs