Constraining CPU usage

Nash Nipples trashy_bumper at
Sat Dec 3 07:18:40 PST 2005

Arne Woerner <arne_woerner at> wrote:  --- Shane Ambler  wrote:
> On 3/12/2005 3:14, "Arne Woerner"
>  wrote:
> > Why should somebody want to keep CPU usage of a
> > process below a certain value (e. g. 20%)?
> Well if your machine isn't smp enabled (specifically
> pre-HTT) then one process can slow the server down
> to a point where your web/databse server can't get
> processor time to give a response - effectively making
> it non existent for the duration.

Isn't that problem solved already by nice'ing a process?
I think that problem is completely solved by idprio'ing a

When the NIC gets a packet for a database server, the kernel
interrupts the executing of a potential idprio'ed process and
starts the DB process... Or am I wrong?


Looks pretty simple and clear. Thank you Arne.
  In respect to what Mike said i must admit: "its all about high utilization numbers fear"
  If the machine was smp enabled i think the number would be around 50% or so.. thank you Shane.
  Reasoning the topic i believe i should do a little research on:
  Understanding units and measurements used in FreeBSD performance representation.
  Calculating a machine's available resources and estimating its possible  low/average/peak load when performing user/system tasks during a  specific amount of time (24 hours). E.g: 1 user will read $File of  $Size Mb from $Storage_media using $Transfer_media. The operation will  last $time and consume $CPU CPU time, $Storage_media_capacity  $Transfer_media_bandwith, $RAM, $Other shared resources.
  So eventually, one can build an operations chart/table, estimate  timings and balance a target machine's load among the processes that  are a subject to order/priority.
  Gather and analyze collected in a real-time situation statistics.
  I'm planning to google that for a while.
  Thank you everyone once again.

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