itaps-parallel removal of

[Vitus Leung]

On Wed, 2008-03-19 at 10:24 -0600, Onkar Sahni wrote:
> >
> > In the specific case of repartitioning, it knows because every entity
> > comes to it with a part handle attached.
> 
>   every local entity comes with local part-handle(s) (may be neighbors
> touching each other for graph-edges crossing inter-part/process bdry.)
> and how can a partitioning service then get local part-handle(s)
> transported to remote parts/processes. This is exactly the point I was
> trying to make during boot-camp.

I too have been concerned about this, but had reached a conclusion
similar to Carl's that non-iMeshP communications would be necessary to
obtain remote part handles.  An iMeshP solution that removes that would
be fine with me.

Vitus

> During file I/O (parallel read) I think (as of now) we will have to talk
> in terms of integers for part IDs (or may be pair of integers) and map
> these to processes/ranks (this map could default to something but can be
> provided by application).
> 
> - Onkar
> 
> >
> > I'll admit I hadn't thought about (one of?) the bootstrap problem: how
> > does a parallel read manage to work out which part handle for some
> > remote part goes with however the part is identified in the file?  I can
> > imagine any number of really bad, expensive ways to do that, but having
> > a mapping from part number to part ID would be cleaner, more accurate,
> > and faster.
> >
> > So in the end, I think Mark's got me convinced of the need for a
> > function to do this mapping.  I think it's possible to implement this in
> > a way that requires no communication (and not too much storage, at least
> > in common cases), although obviously this mapping will have to be one of
> > the things that updatePartitionAll updates.
> 
>   If we reserve bits (fixed m and n across processes), then I think
> updatePartitionAll do not necessarily need to do anything extra for part
> IDS (and their mapping).
> 
> - Onkar
> 
> >
> > Carl
> >
> > --
> > ------------------------------------------------------------------------
> > Dr. Carl Ollivier-Gooch, P.Eng.                   Voice: +1-604-822-1854
> > Associate Professor                                 Fax: +1-604-822-2403
> > Department of Mechanical Engineering             email: cfog at mech.ubc.ca
> > University of British Columbia              http://www.mech.ubc.ca/~cfog
> > Vancouver, BC  V6T 1Z4                  http://tetra.mech.ubc.ca/ANSLab/
> > ------------------------------------------------------------------------
> >
> 
> 
>