[CentOS] Load Average ~0.40 when idle

Sat Aug 2 13:19:50 UTC 2008
Johnny Hughes <johnny at centos.org>

listmail wrote:
> On Sat, 19 Jul 2008 13:48:55 -0700, I wrote
>> I am running CentOS 5 on a dual-dual-core Intel machine, and I am seeing
>> a load average of between 0.35 and 0.50 while the machine is idle, i.e.
>> no processes appear to be running.
>>
>> Both top and uptime report the same thing. Looking at top, I cannot 
>> see any processes that are using CPU time except for top and init, 
>> and they are not using enough cycles to push up the load average.
>>
>> According to top, there are occasional tiny (like 0.5%) bumps in the
>> system usage occasionally, and almost no user space usage. Again, not
>> enough to account for the load average I am seeing.
>>
>> I have tried a couple of kernel updates, and upgraded from CentOS 
>> 5.0 to 5.2, none of which make any difference.
>>
>> Has anyone else seen this? And can anyone recommend a way to figure out
>> what is causing the load average to be this high when the machine is 
>> idle?
>>
> A follow-up now that this issue is resolved. Thanks to the help of some
> kind souls on this list, I was able to determine that the problem was only
> manifested when the Ethernet drivers were running. This led me to update
> the drivers, which solved the problem.
> 
> Details for others who will probably encounter this issue:
> 
> 1. The problem occurs with the 2.6.18-92.1.6.el5 kernels that come with
> CentOS 5.2, and the supplied Intel e1000e Ethernet drivers v0.2.0 that
> ship with 5.2.
> 
> 2. The fix is to update the e1000e drivers, which are available from the
> Intel web site. I installed e1000e version 0.4.1.7-NAPI. Instructions
> for installation come with the driver; the package I found was
> e1000e-0.4.1.7.tar.gz
> 
> 3. You have to compile the drivers from source. They require the kernel-devel
> package to be installed in order to compile, of course. But if you are
> running the PAE kernel, you need to install kernel-PAE-devel to compile
> against. News to me, the naming convention makes it hard to figure out
> which name you need until you browse the available kernel packages. Simply
> doing yum install kernel-devel does not get you what you need.
> 
> I hope this saves someone else the time I wasted figuring this out. :-)

I think I am going to file this as a bug on the RH site to inform them 
of this issue so that they can choose to upgrade their driver if they want.

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