itaps-parallel Part handles

[Tim Tautges]

Vitus Leung wrote:
> In the draft interface, there are functions that take part handles that
> may be local or remote (without rank) and functions that return remote
> part handles (again without rank).  It seems to me that these would
> require globally unique part handles.  

If the application relies on iMesh for getting its part handles, then 
this only requires the implementation to be able to return the rank of 
that remote part handle.  That leaves the implementation to choose how 
it's done.

- tim


Also, there is an open item on
> iMeshP_syncPartitionAll computing a mapping from part handles to
> integers 0,...,k-1.  If that is done, Zoltan could make use of that
> information.  Zoltan takes as input the existing partition.  After
> Zoltan computes new assignments, iMeshP_exchEntArrToPartsAll will
> migrate the entities to their assigned parts.  I believe the parts have
> to already exist since part handles are used for the migration.
> 
> Vitus
> 
>>    + Part handles are globally unique (so that remote part handles make
>> sense and Zoltan doesn't go insane);
>> - remote part handles won't exist on a processor unless they were
>> communicated there somehow; in that case the implementation will be able
>> to store the proc # with (not in) the handle if it so chooses
>> - didn't I hear you say, Karen, that Zoltan computes its own 0..n-1
>> numbering of parts anyway?  Or, will you eliminate that if we have
>> unique part handles?
>> - are we assuming an application will allocate all the part handles
>> before calling Zoltan for the partitioning case?  Does it actually have
>> to migrate entities to the processor owning a part in order to assign
>> those entities to that part?  Or, can a given processor only assign
>> local entities to local parts?  That seems like a pretty severe
>> limitation (and would only allow you to partition for increasing #'s of
>> processors besides)
> 
> 
> 
> 

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              Tim Tautges            Argonne National Laboratory
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