Hi Roy, 

   At this point, I do not have a need for off-processor element data. So, the 
current status of ParallelMesh could be a good thing. 

   I did give it a go for my application, and so far it seems to be working 
well. The memory footprint of each process has also come down significantly 
(from ~4GB to ~0.8GB), which is great! 

   I noticed that the .xdr restart solutions are now written one per mesh 
block. This seems to suggest that this can be read into a ParallelMesh data 
structure for a restart, and not a SerialMesh.  Is this correct?

Thanks, 
Manav

On Apr 3, 2013, at 2:25 AM, Roy Stogner <[email protected]> wrote:

> 
> 
> On Wed, 3 Apr 2013, Manav Bhatia wrote:
> 
>> As a related question, if my code is running on a multicore machine,
>> then can I use --n-threads to parallelize both the matrix assembly
>> and the Petsc linear solvers? Or do I have to use mpi for Petsc?
> 
> PETSc isn't multithreaded, but I'm told it can be built to use
> third-party preconditioners which are multithreaded, so that you get
> decent scaling out of your solve.  I haven't done this myself.
> 
>> I am running problems with over a million elements, and using mpi on
>> my multicore machine makes each process consume over 1GB of RAM.
> 
> ParallelMesh was invented to get me out of a similar jam.
> 
>> On Apr 3, 2013, at 1:24 AM, Manav Bhatia <[email protected]> wrote:
>> 
>>> I am curious if the parallel mesh is now suitable for general use.
> 
> Unfortunately ParallelMesh may never be suitable for "general" use,
> because the most general SerialMesh-using codes sometimes assume at
> the application level that every process can see every element.  If
> your problem includes contact, integro-differential terms, or any such
> coupling beyond the layer of ghost elements that ParallelMesh exposes,
> then you have to do some very careful manual communications to make
> that work on a distributed mesh.
> 
> ParallelMesh is also still much less tested than SerialMesh - it works
> with all the examples and all the compatible application codes I've
> tried, but I wouldn't be surprised if there are tricky AMR or other
> corner cases where it breaks in nasty ways.
> 
> More testing would certainly be appreciated.
> ---
> Roy


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