Hi,
I?m trying to define a % of cpu for a process, but i don?t have idea
about how i can do it. For example, i said that my process need 40% of
CPU during its lifetime, how can i do it in kernel 2.6?
Thanks for ideas.
Diego.
Hello Diego,
On Fri 12 Nov 2004 03:47 PM, Diego wrote:
> I'm trying to define a % of cpu for a process, but i don?t have idea
> about how i can do it. For example, i said that my process need 40% of
> CPU during its lifetime, how can i do it in kernel 2.6?
> Thanks for ideas.
Why don't you 'ps' the process and divide the running time through the
starting time?
time
---------------- = average process cpu usage
(now - started))
Yours,
--
Ed Schouten <[email protected]>
Website: http://g-rave.nl/
GPG key: finger [email protected]
On Fri, 12 Nov 2004 19:55:33 +0100, Ed Schouten said:
> On Fri 12 Nov 2004 03:47 PM, Diego wrote:
> > I'm trying to define a % of cpu for a process, but i don?t have idea
> > about how i can do it. For example, i said that my process need 40% of
> > CPU during its lifetime, how can i do it in kernel 2.6?
> > Thanks for ideas.
>
> Why don't you 'ps' the process and divide the running time through the
> starting time?
I think he's trying to make a 40% *allotment* - as in "this number cruncher
is authorized to take 40% of the CPU for the next 6 hours". The devil always
ends up being in the details however - things I've seen scheduling systems
fail with in the past:
1) Process is allowed to take 40% of the CPU, but so overcommits memory that
it can't actually *get* it because 65% of the time, the system is in a page
wait from the swap partition. (iterate across any *other* shared resource
that isn't directly tied to CPU).
2) Process is allowed to take 40% of the CPU, and no more - and somebody gets
torqued off because the system is 60% idle.
3) Process is allowed to take 40% at all times, and more if available - and
somebody gets torqued off because it's slow to notice the system has bogged
down - so it's still getting 60% for another 2-3 minutes when we're loaded
before the scheduler catches up.
4) And you always get the whiner who complains it's getting 39% or 41%. ;)
Saying "40% of the CPU" is easy - the fun is in the corner cases...
Diego wrote:
> Hi,
> I?m trying to define a % of cpu for a process, but i don?t have idea
> about how i can do it. For example, i said that my process need 40% of
> CPU during its lifetime, how can i do it in kernel 2.6?
Take a look at CKRM.
Chris