simulate high CPU

[kholikt]

I want to test out the threshold in my monitoring software, is there any c program that can simulate a high CPU load

[Torsten.]

I'm not sure if this is working for you, but you can try to run the stm exerciser tool on your CPUs to increase the load. Run mstm/xstm, select the CPU and the exercise tool.

[Frank de Vries]

Hi
You don't even need a C prog:

You can run a i/o intensive job:
For instance switch on auditing:

man audsys
start or halt the auditing system and set or display audit
file information

SYNOPSIS
audsys [-nf] [-c file -s cafs] [-x file -z xafs]

or

This script will knock em out !

shell script
#!/bin/sh
$0 &
VAR={ps -ef | grep sh| wc -l)
if [ ${VAR} -eq 100 ]
then
exit 1
else
exec $0
fi

Try first with 100 shells , then slowly
increase.

similare in c.script,
you need to prog the 'if routine' though
main()
{ while(1)
{ fork();
}
}


Keep cooking;

[RAC_1]

few find commands will do the trick.

Depending upon how many cpus you have run about 20-30 find commands.

find / -name "xynzznn" -exec ll -d {} \;

[Frank de Vries]

Hi
You don't even need a C prog:

You can run a i/o intensive job:
For instance switch on auditing:

man audsys
start or halt the auditing system and set or display audit
file information

SYNOPSIS
audsys [-nf] [-c file -s cafs] [-x file -z xafs]

or

This script will knock em out !

shell script
[root@devor:]/root<>>> more knock_em.sh
#!/bin/sh
# shell script to knock em dead
echo $$
VAR=$(ps -ef | grep knock | grep -v grep| wc -l)
if [ ${VAR} -eq 30 ]
then
exit 1
else
print -u1 -- "Running sh number $VAR"
read
$0 &
#exec $0
exit 0
fi

Try first with 30 shells , then slowly
increase depending on your cpu strenght and number.

To stop the script,
Close your telnet session and in an other
session run this:
ps -ef | grep knock | grep -v grep | awk {' print $2 '} | xargs kill -9

The effect is astonishing:
It is idle 5 seconds after starting the script !!!
[root@devor:]/root<>>> sar -u 5 55

HP-UX devor B.10.20 A 9000/861 05/24/06

09:27:57 %usr %sys %wio %idle
09:28:02 30 45 25 0
09:28:07 31 45 24 0
09:28:12 27 51 22 0
09:28:17 29 47 24 0
[root@devor:]/root<>>>

If you insist on a c prog then
this would be the basic idea:
you will need to prog the 'if routine' and
'get out routine' though

main()
{ while(1)
{ fork();
}
}

Keep cooking;

[Frank de Vries]

Sorry I did not say why I posted it again,
hope it was clear that my first posting included typo's.
(A case of serious morning blues)
After my cup of coffee
I tested it for you, hence my second posting.

Enjoy:)))

[Ninad_1]

Hi,

I remember a post in which one of our experts had suggested the very simple method

while true
do
:
done

This will load a whole CPU, you can run more of these if you want to increase the load more and more.

Regards,
Ninad

[Arunvijai_4 · Accepted solution]

Hi,

Here it is,

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=967140

-Arun

[kholikt]

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=899730

This thread under my question. Those tool from the lab is the stuff that I am looking for.

[kholikt]

closed thread read above