[mpich-discuss] Threaded Listener

[Jeff Hammond]

How do you create processes on this system?  If you are using an MPI
implementation that has a 1:1 mapping between MPI processes and OS
processes, you've got to be able to create multiple processes somehow.

Do you have any platform details you can share?

Jeff

On Sat, Jan 17, 2015 at 11:46 AM, Eduardo <erocha.ssa at gmail.com> wrote:
> I tried to use a newer MPICH, but, as you said, Hydra forks as part of
> mpiexec. Is it possible to launch a job without mpiexec/mpirun ? That should
> probably work in my environment (assuming that there is no listener as a
> heavy process as it is the case in the default mpich-1.2.7p1).
>
> The problem is not that the fork symbol is missing. The problem is that it
> is been called. My environment actually has a dummy fork, but that only
> causes the program to abort if it is called.
>
> So in summary, the problem is that I cannot use mpiexec to launch a program,
> because it calls fork. In mpich-1.2.7p1 , I can launch myself the program as
> if I was launching a debug (as in section 3.5.6 of the CH_P4 manual). In
> addition, the mpich cannot issue a fork for a listener like task, only
> threads.
>
> Eduardo
>
> On Sat, Jan 17, 2015 at 4:23 PM, Jeff Hammond <jeff.science at gmail.com>
> wrote:
>>
>> MPICH shouldn't fork. Hydra probably uses fork to launch processes as part
>> of mpiexec.
>>
>> Blue Gene doesn't support fork either and MPICH runs there, but the
>> process launcher is not Hydra. Same for Cray last time I checked. So I'm
>> sure that fork isn't required to use MPICH, at least if dynamic processes
>> are not used.
>>
>> Is the issue that you cannot link an MPI program because the fork symbol
>> is missing or that you cannot launch jobs with a Hydra?
>>
>> All mainstream MPI implementations use OS processes to implement MPI
>> processes, but the standard doesn't require this. FG-MPI uses threads to
>> implement MPI processes, but as it still uses Hydra (AFAIK), it may or may
>> not work for you.
>>
>> Can you describe in detail what happens when you try to build and run
>> MPICH-latest on your system?
>>
>> Jeff
>>
>> Sent from my iPhone
>>
>> On Jan 17, 2015, at 9:41 AM, Eduardo <erocha.ssa at gmail.com> wrote:
>>
>> I would use a newer version if I could. However, I cannot issue a fork in
>> my embedded environment. I can create threads though.
>>
>> So, is there any newer versions of mpich that does not create heavy
>> processes? I can live without MPI_Spawn and the like.
>>
>> Regards,
>>
>> Eduardo
>>
>> On Jan 16, 2015 5:42 PM, "Wesley Bland" <wbland at anl.gov> wrote:
>>>
>>> Can you try using a more recent version of MPICH. The version you are
>>> using is years old and we don't support it anymore. Our latest version is
>>> 3.1.3. You might see if the issue is still present there.
>>>
>>> Thanks,
>>> Wesley
>>>
>>> On Fri, Jan 16, 2015 at 10:54 AM, Eduardo <erocha.ssa at gmail.com> wrote:
>>>>
>>>> Hi,
>>>>
>>>> I am trying to compile and use mpich-1.2.7p1 with threaded listener
>>>> (i.e. configured with --enable-threaded-listener). However, I cannot even
>>>> run a simple mpi example with the resulting mpich.
>>>>
>>>> I need to use threaded listener because the environment I am compiling
>>>> for (kind of embedded environment)  does not have fork (no heavy processes).
>>>>
>>>> The error I get with the mpich with threaded listener is:
>>>>
>>>> rm_2889: 1103279872:  p4_error: listener select: -1
>>>>     p4_error: latest msg from perror: Bad file descriptor
>>>> p0_2710: (2.097656) net_recv failed for fd = 5
>>>> p0_2710: 3778266880:  p4_error: net_recv read, errno = : 104
>>>>
>>>> Has anyone experienced a similar problem?
>>>>
>>>> Thanks in advance,
>>>> Eduardo
>>>
>>>
>>>
>>> _______________________________________________
>>> discuss mailing list     discuss at mpich.org
>>> To manage subscription options or unsubscribe:
>>> https://lists.mpich.org/mailman/listinfo/discuss
>>
>> _______________________________________________
>> discuss mailing list     discuss at mpich.org
>> To manage subscription options or unsubscribe:
>> https://lists.mpich.org/mailman/listinfo/discuss
>>
>>
>> _______________________________________________
>> discuss mailing list     discuss at mpich.org
>> To manage subscription options or unsubscribe:
>> https://lists.mpich.org/mailman/listinfo/discuss
>
>
>
> _______________________________________________
> discuss mailing list     discuss at mpich.org
> To manage subscription options or unsubscribe:
> https://lists.mpich.org/mailman/listinfo/discuss



-- 
Jeff Hammond
jeff.science at gmail.com
http://jeffhammond.github.io/
_______________________________________________
discuss mailing list     discuss at mpich.org
To manage subscription options or unsubscribe:
https://lists.mpich.org/mailman/listinfo/discuss