[mpich-discuss] Clarification needed on running processes on MPICH2

[Waruna Ranasinghe]

Hi Anthony,
I'm sorry, in this case I have to disagree with you.
Because it is not max(t1,t2) but t1+t2 (this is the real result I got)
I use fflush(stdout) also

What I think is that, Cluster runs two programmes alternatively.
i.e. Process A runs for a while (say t3 seconds) then process B for sometime
and so on.
Therefore, ultimately both the processes will run for t1+t2

Cluster: MPICH2
Fedora 8

2008/11/26 Anthony Chan <chan at mcs.anl.gov>

>
> If process A and B are launched by mpiexec, the time taken
> by mpiexec should be max(t1,t2) not t1 + t2. As Rajeev said,
> calling fflush(stdout) after each printf() is the fastest way
> to get each process's stdout printed to your console.
>
> A.Chan
> ----- "Waruna Ranasinghe" <warunapww at gmail.com> wrote:
>
> > Hi Rajeev,
> > Actually this is not what I'm talking about.
> > Say there are processes A and B
> > Process A utilize 100% of the cpu while it runs. The answer will
> > appear in
> > t1 seconds
> > Process B also utilize 100% of the cpu while it runs. The answer will
> > appear
> > in t2 seconds
> >
> > When I run both the process A and B at the same time, The both answers
> > will
> > appear in t1 + t2 seconds. where as I want to get the Process A's
> > answer
> > first. (Here Process A is submitted before Process B)
> >
> > Is there anything that I can do to make this happen.
> >
> > Thank You,
> > Waruna
> >
> > 2008/11/26 Rajeev Thakur <thakur at mcs.anl.gov>
> >
> > >  If you are refering to the output of "printf", you can try adding
> > an
> > > fflush(stdout) after the printf. You don't have much control over
> > the order
> > > in which it is printed from different processes.
> > >
> > > Rajeev
> > >
> > >  ------------------------------
> > > *From:* mpich-discuss-bounces at mcs.anl.gov [mailto:
> > > mpich-discuss-bounces at mcs.anl.gov] *On Behalf Of *Waruna Ranasinghe
> > > *Sent:* Tuesday, November 25, 2008 1:35 AM
> > > *To:* mpich-discuss at mcs.anl.gov
> > > *Subject:* [mpich-discuss] Clarification needed on running processes
> > on
> > > MPICH2
> > >
> > > Hi all,
> > > I submitted 3 processes at the same time using mpiexec. the results
> > of each
> > > process appears only after all the processes have finished. (I guess
> > that
> > > the way mpich schedule it).
> > > What if I want to get the result of the process, which was submitted
> > first,
> > > first. (like first in first out).
> > >
> > > I use MPICH2 cluster in Fedora 8 (with mpd)
> > >
> > > Thank you.
> > > Waruna Ranasinghe
> > >
> > >
>
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