[mpich-discuss] Clarification needed on runningprocessesonMPICH2

Sat Nov 29 23:31:47 CST 2008

no only 4

2008/11/30 Rajeev Thakur <thakur at mcs.anl.gov>

>  But you don't have 6 cores, do you?
>
>  ------------------------------
> *From:* mpich-discuss-bounces at mcs.anl.gov [mailto:
> mpich-discuss-bounces at mcs.anl.gov] *On Behalf Of *Waruna Ranasinghe
> *Sent:* Saturday, November 29, 2008 11:03 PM
>
> *To:* mpich-discuss at mcs.anl.gov
> *Subject:* Re: [mpich-discuss] Clarification needed on
> runningprocessesonMPICH2
>
> Yes, I'm sorry if you were miss led by my wordings.
> I meant running two instances.
>
> 2008/11/30 Rajeev Thakur <thakur at mcs.anl.gov>
>
>>  If you run two instances of mpiexec -n 3 tst, you are running a total of
>> 6 processes, not 2 or 3.
>>
>> Rajeev
>>
>>  ------------------------------
>>  *From:* mpich-discuss-bounces at mcs.anl.gov [mailto:
>> mpich-discuss-bounces at mcs.anl.gov] *On Behalf Of *Waruna Ranasinghe
>> *Sent:* Saturday, November 29, 2008 5:38 AM
>>
>> *To:* mpich-discuss at mcs.anl.gov
>> *Subject:* Re: [mpich-discuss] Clarification needed on
>> runningprocessesonMPICH2
>>
>>   >What do you mean by "one process" when it is clearly 3
>> >processes are running ?  When you say 2 processes of tst,
>> >do you mean you launched two instances of
>> >"mpiexec -n 3 ./tst" simultaneously.
>>
>> Yes, I meant of launching two instances of "mpiexec -n 3 ./tst"
>> simultaneously.
>>
>> I could not reach the MPICH cluster until monday, so that I'll send the
>> modified programme on Monday.
>>
>> Thank You,
>> Waruna
>>
>> 2008/11/29 Anthony Chan <chan at mcs.anl.gov>
>>
>>> >From your Readme file:
>>>
>>> > mpiexec -n 3 <path>
>>> >
>>> > output:
>>> > when only one process runs
>>> >
>>> > 0:Total: 499999999500000000 : Time: 9.272023
>>> > 2:Total: 499999999500000000 : Time: 10.722239
>>> > 1:Total: 499999999500000000 : Time: 11.324907
>>> >
>>> > When two processes of 'tst' runs in the same time
>>> >
>>> > 0:Total: 499999999500000000 : Time: 9.538206
>>> > 2:Total: 499999999500000000 : Time: 16.045104
>>> > 1:Total: 499999999500000000 : Time: 22.400754
>>>
>>> What do you mean by "one process" when it is clearly 3
>>> processes are running ?  When you say 2 processes of tst,
>>> do you mean you launched two instances of
>>> "mpiexec -n 3 ./tst" simultaneously.
>>>
>>> Could you add the following lines to your tst.cpp
>>>
>>>         char host_name[ MPI_MAX_PROCESSOR_NAME ];
>>>         int  namelen;
>>>         MPI_Get_processor_name( host_name, &namelen );
>>>         printf("rank %d running on %s\n", rank, host_name);
>>>
>>> before first fflush(stdout) to show the location of each process.
>>> Rerun your experiments and let us know the result.
>>>
>>> Also, you can use MPI_Wtime() instead of Duration.cpp that may
>>> simplify your test program.
>>>
>>> A.Chan
>>>
>>> ----- "Waruna Ranasinghe" <warunapww at gmail.com> wrote:
>>>
>>> > Hi Rajeev,
>>> > Here's test programme. It's just for testing. The results I got, are
>>> > in the
>>> > read me file in the attachment
>>> >
>>> > Thank You
>>> > Waruna
>>> >
>>> > 2008/11/27 Rajeev Thakur <thakur at mcs.anl.gov>
>>> >
>>> > >  In that case, what kind of program are you running? Can you send us
>>> > a
>>> > > small test program.
>>> > >
>>> > > 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 9:05 PM
>>> > >
>>> > > *To:* mpich-discuss at mcs.anl.gov
>>> > > *Subject:* Re: [mpich-discuss] Clarification needed on
>>> > > runningprocessesonMPICH2
>>> > >
>>> > > Hi Rajeev,
>>> > > There's no doubt that process runs on all 3 machines.
>>> > > I have tried cpi example and it prints the hostnames of 3 machines
>>> > >
>>> > > mpiexec -l -n 3 <path to process>
>>> > > (the same path is available in all 3 machines)
>>> > >
>>> > > Thank you
>>> > > Waruna
>>> > >
>>> > >
>>> > > 2008/11/26 Rajeev Thakur <thakur at mcs.anl.gov>
>>> > >
>>> > >>  Make sure the processes are actually running on the 3 machines.
>>> > Try the
>>> > >> cpi example in the examples directory. It prints out the hostname.
>>> > How are
>>> > >> you running the job?
>>> > >>
>>> > >> 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 11:07 AM
>>> > >>
>>> > >> *To:* mpich-discuss at mcs.anl.gov
>>> > >> *Subject:* Re: [mpich-discuss] Clarification needed on running
>>> > >> processesonMPICH2
>>> > >>
>>> > >>   Fedora 8 - MPICH2 one 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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