freebsd stable - Apr 2005 - %idle stuck at 33%?

On 5.4-RC3, a Dell 2650 with two processors, and hyperthreading turned
off, a 'make -j4 buildword' never shows idle % less than 33.3, either
in top or systat.  Anybody else see this, or know why it happens?

- Mike H.

On Sun, Apr 17, 2005 at 02:04:28PM -0700, Mike Harding
wrote:
> 
> On 5.4-RC3, a Dell 2650 with two processors, and hyperthreading turned
> off, a 'make -j4 buildword' never shows idle % less than 33.3,
either
> in top or systat.  Anybody else see this, or know why it happens?
Your disks are too slow to keep up?

Kris
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I should be more clear - the idle % never goes below 33.3%, spends
most of its time at 33.3%, and the disks are not even remotely
saturated.  They are 15K SCSI drives and the above is true even when
there is no apparent disk activity.  Seems like the idle % is being
calculated incorrectly.  I am just trying to found out if anyone else
seems anything simlar before I file a PR...

In article <d3ujfu$l9s$1@FreeBSD.csie.NCTU.edu.tw> you
wrote:
> 
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> On Sun, Apr 17, 2005 at 02:04:28PM -0700, Mike Harding wrote:
>>=20
>> On 5.4-RC3, a Dell 2650 with two processors, and hyperthreading turned
>> off, a 'make -j4 buildword' never shows idle % less than 33.3,
either
>> in top or systat.  Anybody else see this, or know why it happens?
> 
> Your disks are too slow to keep up?
> 
> Kris
> 
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In article <d3ulau$o0j$1@FreeBSD.csie.NCTU.edu.tw> you
wrote:
> 
> This kind of thing can happen if your world is out of sync with your
> kernel.
> 
> Kris
> 
The world and kernel are in sync - I used a world/kernel build to
generate the load (several times with the same source).  I don't see
the same behavior on a Dell desktop machine with 2 processors,
hyperthreading disabled, so it must be something specific to the Dell
2650.

- Mike H.