finding child cpu usage of a running child

[Paddy]

On Jan 26, 5:43 am, Karthik Gurusamy <kar1... at gmail.com> wrote:
> Hi,
>
> Wondering if there is a way to measure a child process's cpu usage
> (sys and user) when the child is still running. I see os.times()
> working fine in my system (Linux 2.6.9-42.7.ELsmp), but it gives valid
> data only after the child has exited. When the child is alive,
> os.times() data for child is zero for both child-sys and child-user
> cpu.
>
> My script (process P1) launches child process P2 (using
> popen2.Popen3). P2 is a long running process (big compilation). Every
> minute or so, from P1, I want to measure how much cpu P2 has consumed
> and based on that I can make some estimate on the completion time of
> P2 (I have a rough idea how much total cpu P2 needs to complete).
>
> I understand it may be too expensive to update this information to the
> parent process when any of the child/grand-child completes; but
> wondering if any there is any way to get this info; the expensive
> operations is on-demand only when the request is made.
>
> Thanks,
> Karthik

I had a similar requirement in December and found:
  http://lilypond.org/~janneke/software/

proc-time.c and proc-time.py poll /proc/.... files whilst command
is running to get stats.

Enjoy,  - Paddy.