Open MPI logo

Open MPI Development Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Development mailing list

From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2006-09-11 19:42:46


I just filed it:

http://svn.open-mpi.org/trac/ompi/ticket/363

On 9/11/06 7:31 PM, "Graham E Fagg" <fagg_at_[hidden]> wrote:

> Hi Christian, do you have the ticket #, I just looked and didn't see it
> listed...
>
> G.
>
> On Tue, 12 Sep 2006, Christian Siebert wrote:
>
>> Hi,
>>
>> I stumbled across a serious bug in the tuned component of Open MPI,
>> which crashes for example the well-known HPL benchmark in conjunction
>> with the "native MPI_Bcast() patch" [1].
>>
>> The problem is within the function ompi_coll_tuned_bcast_intra_chain(),
>> which does mainly the following:
>>
>> ompi_ddt_type_size( datatype, &typelng );
>> segcount = segsize / typelng;
>> num_segments = count / segcount;
>>
>> Whenever you have a constructed type with a size larger than 'segsize'
>> (16384), you'll get a 'seqcount' of zero and finally a division by zero.
>>
>> Happy fixing!
>>
>> Christian
>>
>> [1] http://www-user.tu-chemnitz.de/~chsi/hpl/
>>
>>
>> _______________________________________________
>> devel mailing list
>> devel_at_[hidden]
>> http://www.open-mpi.org/mailman/listinfo.cgi/devel
>>
>
>
> Thanks,
> Graham.
> ----------------------------------------------------------------------
> Dr Graham E. Fagg | Distributed, Parallel and Meta-Computing
> Innovative Computing Lab. PVM3.4, HARNESS, FT-MPI, SNIPE & Open MPI
> Computer Science Dept | Suite 203, 1122 Volunteer Blvd,
> University of Tennessee | Knoxville, Tennessee, USA. TN 37996-3450
> Email: fagg_at_[hidden] | Phone:+1(865)974-5790 | Fax:+1(865)974-8296
> Broken complex systems are always derived from working simple systems
> ----------------------------------------------------------------------
> _______________________________________________
> devel mailing list
> devel_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/devel

-- 
Jeff Squyres
Server Virtualization Business Unit
Cisco Systems