stable/10: high load average when box is idle

[Tom Evans]

On Tue, Nov 3, 2015 at 5:47 PM, Ian Smith <smithi at nimnet.asn.au> wrote:
> Like yourself, I think this is far from 'cosmetic' as is oft suggested,
> especially in some fairly ill-informed forum posts but also various list
> posts.  I've been watching load averages since OS/2 through FreeBSD 2.2
> till present and some Linux systems, and have never before seen anything
> like this, especially on virtually entirely idle systems.  While the LAs
> reported during (say) make -j4 buildworld appear more same, who knows?
>
> I'm not suggesting that I think there's any sort of performance hit from
> this; so far I don't, but 'cosmetic' suggests that it doesn't matter ..
>

Have you read mav's explanation on the PR? It certainly seems a valid
explanation of why it is probably a cosmetic issue - that is, we could
wake up more to get a truly perfect load average, but why bother?

ISTM, the problem reports are of the form "My server is idle and it is
reporting a non-idle load average below 1", and not "My server is
supposedly idle, but is doing actual work causing the load average to
be higher than it should be". Is there any evidence that we have the
latter and not the former?

Cheers

Tom