[mpich-discuss] MPICH2 and Process Affinity

[Jayesh Krishna]

Hi,
 The MS-MPI developer SDK should be available for free
(http://www.microsoft.com/downloads/details.aspx?familyid=12887DA1-9410-4A
59-B903-693116BFD30E&displaylang=en). 
 MPICH2 will provide this feature (binding MPI processes to cores) in the
1.1 release.

Regards,
Jayesh

-----Original Message-----
From: mpich-discuss-bounces at mcs.anl.gov
[mailto:mpich-discuss-bounces at mcs.anl.gov] On Behalf Of Pavan Balaji
Sent: Tuesday, March 17, 2009 10:14 PM
To: mpich-discuss at mcs.anl.gov
Subject: Re: [mpich-discuss] MPICH2 and Process Affinity


> 1. Is there a similar way in MPICH2 or I have to use
> SetProcessAffinityMask() in Windows to pin all my MPI processes to the 
> specific logical processor/core ?
>     (If a process is pinned to a specific logical processor, the CPU 
> loading histroy from the Windows task manager is smoother rather than 
> lots of zigzags.)

Not right now, but its planned to be added in the mpich2-1.1 release. 
Microsoft's modification to MPICH2 (called MS-MPI) already has this
support, if you want to try it out sooner (http://www.microsoft.com/hpc).
I don't know if it's free though :-).

> 2. Does the process migration cause large penalty in parallel computing
?

I know that Linux gives "preference" to keep processes on the same core
when there are equal number of processes and cores. This is not the same
thing as binding, but it's close to it. Windows probably does something
similar too, but I'm not really sure.

  -- Pavan

--
Pavan Balaji
http://www.mcs.anl.gov/~balaji
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/mpich-discuss/attachments/20090318/4f5b975b/attachment.htm>