topic Re: CPU Utilisation in Operating System - HP-UX

CPU Utilisation

Siddhesh — Sat, 21 Feb 2004 04:21:43 GMT

Hi Gurus,

Is there any way by which I can prevent any process from consuming 100% CPU. In other words, I want to run that process, but by consuming lesser CPU %.

Thanks,
Siddhesh.

Re: CPU Utilisation

Paula J Frazer-Campbell — Sat, 21 Feb 2004 06:05:56 GMT

Hi

Nice

Man nice

Paula

Re: CPU Utilisation

john korterman — Sat, 21 Feb 2004 07:09:49 GMT

Hi,
try looking into PRM, e.g.:
http://docs.hp.com/hpux/onlinedocs/B8733-90001/B8733-90001.html

regards,
John K.

Re: CPU Utilisation

Bill Hassell — Sat, 21 Feb 2004 17:04:22 GMT

HP-UX doesn't allow a single process to consume all of the CPU time unless there is nothing else running. If two processes want 100% of the CPU, they will get 50% each over time. HP-UX will switch between the programs ever timeslice interval (typically 100ms), and even a dozen programs that use 100% of the CPU will not slow down interactive programs like vi or a shell prompt. HP-UX will process I/O interrupts without regard to the CPU load. You can force a program to take be scheduled less often by using nice.

Re: CPU Utilisation

nibble — Sat, 21 Feb 2004 17:32:18 GMT

you may use top then adjust the priority with nice

Re: CPU Utilisation

Tim D Fulford — Sun, 22 Feb 2004 06:15:37 GMT

added to the above...PRM.. (process resource management)

If you have a few "types" of application on the computer you can split them into groups and assign resource limits.. (However I think these resource limits are generally whole CPU's etc). But if one application is "hogging" lots of CPU, & interfering with another application on the same computer, then PRM may help...

...I suspect that the problem you facing is process like fc60mon, or cclogd ..etc.. regularly hitting 100%. Generally these are fixed with patches.

Lastly... We run a database, Informix, and even after careful tuning we sometimes see "oninit" processes at 100%. This is not necessarily a problem, provided you are getting 100% work out of it. Infact some people recon you are getting your moneies worth out of it in this case (e.g. you buy an 8 cpu box but only run it at 40%, why not buy a 4 CPU box and run it at 80% & save money...)

good luck

Tim