NFS kernel server creates a kworker with 100% CPU usage, then hangs randomly
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Fix Released
|
High
|
Unassigned | ||
Trusty |
Fix Released
|
High
|
Stefan Bader |
Bug Description
This concerns the server edition of 14.04. I have set up a NFS server. Once I attach at least one client, one kworker process starts to use 100% CPU. The runaway kworker returns to idle when I reset the NFS server daemon with "service nfs-kernel-server stop" followed by "service nfs-kernel-server start". With the nfs kernel server stopped, the CPU remains idle. With the nfs kernel server running, as soon as one client requests a connection, the kworker process jumps to 100% CPU again.
After some random time, the nfs kernel server no longer accepts requests from clients. Restarting the service allows clients to reconnect. The syslog shows no relevant information.
This problem has never appeared on a very similar server setup with 12.04.
Configration: The svcgssd is not running. I played with various configurations (enabling/disabling NFSv3 and NFSv4), but it makes no difference.
I tried to enable event debugging:
#> echo workqueue:
#> cat /sys/kernel/
and found the following kernel trace in a tight loop:
[...]
kworker/2:1-86 [002] d... 161940.910668: workqueue_
kworker/2:1-86 [002] d.s. 161940.910674: workqueue_
kworker/2:1-86 [002] d... 161940.910675: workqueue_
kworker/2:1-86 [002] d.s. 161940.910681: workqueue_
kworker/2:1-86 [002] d... 161940.910682: workqueue_
kworker/2:1-86 [002] d.s. 161940.910688: workqueue_
kworker/2:1-86 [002] d... 161940.910689: workqueue_
kworker/2:1-86 [002] d.s. 161940.910695: workqueue_
kworker/2:1-86 [002] d... 161940.910696: workqueue_
kworker/2:1-86 [002] d.s. 161940.910702: workqueue_
[...]
At present, I have to consider NFS fubar.
Thanks,
Mark
ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-
ProcVersionSign
Uname: Linux 3.13.0-24-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version k3.13.0-24-generic.
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.14.1-0ubuntu3.1
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/by-path', '/dev/snd/
CRDA: Error: [Errno 2] No such file or directory: 'iw'
Card0.Amixer.info: Error: [Errno 2] No such file or directory: 'amixer'
Card0.Amixer.
Date: Thu May 22 22:48:48 2014
HibernationDevice: RESUME=
InstallationDate: Installed on 2014-05-12 (10 days ago)
InstallationMedia: Ubuntu-Server 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.2)
IwConfig:
eth0 no wireless extensions.
lo no wireless extensions.
MachineType: Gigabyte Technology Co., Ltd. GA-990XA-UD3
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
XDG_RUNTIME_
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcFB: 0 nouveaufb
ProcKernelCmdLine: BOOT_IMAGE=
RelatedPackageV
linux-
linux-
linux-firmware 1.127.2
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
WifiSyslog:
dmi.bios.date: 10/13/2011
dmi.bios.vendor: Award Software International, Inc.
dmi.bios.version: F9
dmi.board.name: GA-990XA-UD3
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.modalias: dmi:bvnAwardSof
dmi.product.name: GA-990XA-UD3
dmi.sys.vendor: Gigabyte Technology Co., Ltd.
Changed in linux (Ubuntu): | |
importance: | Undecided → High |
tags: | added: kernel-key |
tags: | removed: kernel-key |
This change was made by a bot.