Bug 21155

Summary:	Load average (either with uptime both top) go over 1.00 without any load
Product:	Base System	Reporter:	Riccardo Torrini <riccardo>
Component:	kern	Assignee:	freebsd-bugs (Nobody) <bugs>
Status:	Closed FIXED
Severity:	Affects Only Me
Priority:	Normal
Version:	5.0-CURRENT
Hardware:	Any
OS:	Any

Description Riccardo Torrini 2000-09-09 22:40:01 UTC

Load average (either with uptime both top) go over 1.00 without any
program running (I removed also X and tryed on console) but cpu is
really free, as in top, line CPU states:  0.0% user,  0.0% nice,
5.1% system,  0.0% interrupt, 94.9% idle

How-To-Repeat: # uptime
11:30PM  up  2:03, 3 users, load averages: 1.26, 1.14, 1.08

(or see first line of top)

Comment 1 Mike Barcroft freebsd_committer

2001-08-15 17:42:58 UTC

State Changed
From-To: open->closed


I believe this was a problem with the initial SMPng work.  In any 
case, I haven't seen this happen in 5.0-CURRENT in a long time, so 
I'm closing this PR.

Comment 2 Bruce Evans 2001-08-16 12:24:09 UTC

On Wed, 15 Aug 2001 mike@FreeBSD.ORG wrote:

> Synopsis: Load average (either with uptime both top) go over 1.00 without any load
>
> State-Changed-From-To: open->closed
> State-Changed-By: mike
> State-Changed-When: Wed Aug 15 09:42:58 PDT 2001
> State-Changed-Why:
>
> I believe this was a problem with the initial SMPng work.  In any
> case, I haven't seen this happen in 5.0-CURRENT in a long time, so
> I'm closing this PR.

This has been reported again, for 4.3 in PR 27334.  It is believed to
be caused by a process getting in sync with the load average sampler.
If this is the cause, then the problem has very little to do with
SMPng, but later SMPng work may have reduced it by changing the timing
of rescheduling.

Bruce