Bug 23448

Summary:	Load average goes over 3.0 without any load.
Product:	Base System	Reporter:	htoshi <htoshi>
Component:	kern	Assignee:	freebsd-bugs (Nobody) <bugs>
Status:	Closed FIXED
Severity:	Affects Only Me
Priority:	Normal
Version:	4.2-RELEASE
Hardware:	Any
OS:	Any

Description htoshi 2000-12-10 22:30:01 UTC

Load average periodically goes over 3.0 though there is no
program running. The period is about 40 minutes, and high
load state keeps about 10 minutes. CPU status is nearly
100% idle, and no process has high cpu percentages.

For example
% uptime
7:09AM up 4 days, 11:40, 6 users, load averages: 3.30, 2.52, 1.40

Here is the hardware environment.

PC/AT compatible Motherboard Rioworks PDVIA
CPU: Pentium III 600MHz x 2
Mem: 128MB x 2 DIMM
atapci1: Promise ATA66 controller Fasttrak66 (RAID-1)
ahc0: Adaptec 2940A Ultra SCSI adapter
vr0: VIA VT3043 Rhine I 10/100BaseTX
SVGA: chipset: RIVA 128

I have experienced similar things when I used 3.4-RELEASE,
and 3.5-RELEASE. In case of 3.4-RELEASE, the load average
kept around 1.0 and never fall down unless reboot.
In 3.5-RELEASE, once the load average goes up(not the
cause of user or system program), dropped down after a few
minutes but it was not periodic. This is similar case to
the "Problem report kern/21155 (5.0-current)".

Comment 1 iedowse freebsd_committer

2001-11-15 01:19:29 UTC

State Changed
From-To: open->closed


This is believed to be caused by synchronisation between some system 
processes and the samples that are used to compute the load avarage. 
Revision 1.87.2.4 of kern_synch.c and assiciated changes should  
fix this; please let us know if the problem continues to occur so 
that the PR can be re-opened if necessary.