Description of problem: With kernel 2.6.40-4.fc15.i686 wireless sometimes stops working at which point kpower (one or two instances of it) are taking almost 100% cpu
Version-Release number of selected component (if applicable):
Happens at random about once a day
Steps to Reproduce:
1. Wireless stops working, so restart NetworkManager
Actual results: Wireless still does not work, kpower takes almost 100% cpu
When wireless stops working nm-applet shows connection to my network with an x on it. Wireless is ipw2200. I believe it is only after I restart NetworkManager that kpower starts taking excess cpu. There are no useful messages in dmesg or messages.
Sorry "kworker" not "kpower"
This seems to be essentially a duplicate of bug https://bugzilla.redhat.com/show_bug.cgi?id=717186 . The kworker problem only arises after the network lockup described in that bug, if NetworkManager is then restarted while the network is stuck. Both issues are new in kernel 2.6.40-4.fc15.i686.
This it is fixed for me in Kernel 188.8.131.52-5.fc15.i686
Sorry -- still a problem in Kernel 184.108.40.206-5.fc15.i686
This is a "me too". I have not correlated this bug with wireless; in fact I had it while connected to my wired port. Kernel is 220.127.116.11-5.fc15.i686.PAE, using gnome 3, recently upgraded to Fedora 15 from Fedora 13.
There are so many bugs to choose from, this being the newest; I had a problem that matches this description.
These might be related:
The following threads threads also helped me narrow down the issue on my system.
http://lkml.indiana.edu/hypermail/linux/kernel/1103.3/index.html#03685 (excessive kworker activity when idle)
While not nearly as useful, just confirmation that other distributions are having similar issues (and this thread was initially helpful to me)
Any more research, here or via google, shows this problem as directly associated with laptops (of all sorts). Most likely acpi related. In many threads I've read, powertop alludes to it being related to the snd_* modules (e.g. RealTek, Intel HD Audio, etc.). Though, blacklisting the entire snd module subsystem has no effect on the kworker usaged (prior to bios upgrades).
On an Acer Aspire One D150, I'm using:
Linux sum1 18.104.22.168-5.fc15.i686 #1 SMP Tue Aug 30 14:54:41 UTC 2011 i686 i686 i386 GNU/Linux
The real indicator for me, besides the obvious top & powertop ident, were massive bursts of these in the work queue (the root cause of the kworker cpu usage):
kworker/0:3-610  764.920835: workqueue_queue_work: work struct=f661ce88 function=acpi_os_execute_deferred workqueue=f4ceb180 req_cpu=0 cpu=0
The final fix was to upgrade my BIOS (from the manufacturer).
I just upgraded from InsydeH2O v1.05 to v1.13 and viola, no more excessive kworker.
Most likely, the real fix, like mine, will be mutual adherence between your hardware vendor and 2.6.36+ ...
On Dell D410 the problem occurs much less frequently since update to 22.214.171.124-5.fc15I. It occurs for me only in connection with network interfaces (both wifi and ethernet).
"Most likely, the real fix, like mine, will be mutual adherence between your
hardware vendor and 2.6.36+ ..."
Dell D410 has a BIOS for which there have been no updates since 2005 and it has worked fine with all kernels up to the 2.6.40 series, so this is NOT a BIOS problem, it is a kernel bug.
2005? Maybe. Or, a clever way to burn out a bunch of old PCs to stimulate a declining market ... LOL. Good luck with yours.
For me, I'd simply overlooked the possibility of a BIOS upgrade. Maybe others will benefit from that part of the advice I've left here.
There is some good information on how to debug this here:
is this still occuring with the current update ?