[petsc-dev] Lower memory DMDA

[Barry Smith]

On May 8, 2013, at 8:55 AM, Jed Brown <jedbrown at mcs.anl.gov> wrote:

> Barry Smith <bsmith at mcs.anl.gov> writes:
> 
>> On May 8, 2013, at 7:54 AM, Peter Brune <prbrune at gmail.com> wrote:
>> 
>>    You guys are speculating too much. Create a DMDA characteristic
>>    for their code with reasonably large array dimensions and then
>>    -malloc_dump it (or something similar) to find out where the
>>    memory actually is. Then given this table of sizes propose
>>    changes, not before.
> 
> I remember doing this before, maybe last time the issue was discussed
> here.  Flaky internet here is making it hard to find the thread.
> Anyway, they want to have a total of two or three vectors that use all
> available memory, thus they need to eliminate all inessential
> problem-sized data.

   Fine, data is order M*N*P,  but what about order M*N + N*P + M*P data? Some of the scatters are this size and hence ok to keep around?

   Barry