[mpich-discuss] Clarification needed on running processes onMPICH2

[Waruna Ranasinghe]

Fedora 8 - MPICH2one machine with core-2-duo - master
two machines with one core
all together 3 nodes

2008/11/26 Rajeev Thakur <thakur at mcs.anl.gov>

>  What kind of environment are you running on (how many machines, how many
> cores each)?
>
> Rajeev
>
>  ------------------------------
> *From:* mpich-discuss-bounces at mcs.anl.gov [mailto:
> mpich-discuss-bounces at mcs.anl.gov] *On Behalf Of *Waruna Ranasinghe
> *Sent:* Wednesday, November 26, 2008 2:15 AM
> *To:* mpich-discuss at mcs.anl.gov
> *Subject:* Re: [mpich-discuss] Clarification needed on running processes
> onMPICH2
>
> 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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