top -I and load average from 4.9 into 5.4

Kris Kennaway kris at obsecurity.org
Mon Aug 22 23:09:55 GMT 2005


On Mon, Aug 22, 2005 at 04:36:11PM +0200, pobox at verysmall.org wrote:
> >>We upgraded from 4.9 to 5.4 and the 'top -I' and load average seem to 
> >>behave slightly different. 'top -I' in 5.4 stays empty most of the time 
> >>with processes flashing in and out from time to time. 
> >
> >Well, I'd actually expect them to, as -I filters out any idle 
> >process.  Justed tested on my 6.0B2, major CPU hogs are shown
> >as expected.
> 
> That's clear. Just on the same server under 4.9 somehow the processes 
> tend to 'stay longer' and not just flash for parts of the second. Now 
> under 5.4 the list 'top -I' is most of the time empty while the CPU goes 
> from 0% to 20% and back all the time. And just very seldom a process 
> flashes in the list. 'top' under 5.4 shows all the time 3-5 active 
> processes at the top of the list.

Sampling error.  In order for top to run, nothing else can run on that
CPU at the same time, so you won't get a very meaningful picture of
short-lived processes that are instantaneously 'active'.

Kris
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 187 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-questions/attachments/20050822/05b202c2/attachment.bin


More information about the freebsd-questions mailing list