kworker eating up cpu time when doing dd on 3.2.0 kernels

Fri Jan 27 16:37:15 UTC 2012

Hi all!

I found an issue with kworker on kernel versions: 3.2.0-10-generic, 3.2.0-8-generic and 3.2.0-2-generic.

When I do "dd if=/dev/zero of=/tmp/zero1.tmp bs=1024 count=13000000" kworker threads start eating up my CPU-time as described in: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/887793 posting 22 and 23.

Older kernel versions do not seam to be affected like 3.0.0-13-generic.

Can anyone help me?