[petsc-users] On the edge of 2^31 unknowns

[Eric Chamberland]

Le 2016-06-20 23:37, Barry Smith a écrit :
>> On Jun 20, 2016, at 10:32 PM, Eric Chamberland <Eric.Chamberland at giref.ulaval.ca> wrote:
>>
>> ok, but what about -matmatmult_via scalable?
>    Both should work. It just may be one is faster or slower than the other depending on the problem size.
ok, digging further, I found this into blaming the code:

0fc8cf34 (Hong Zhang       2013-06-27 14:04:58 -0500  696) /* same as 
MatMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable(), except using LLCondensed 
to avoid O(BN) memory requirement */

But the commit comment says:
...
     rename MatMatMultSymbolic_MPIAIJ_MPIAIJ -> 
MatMatMultSymbolic_MPIAIJ_MPIAIJ_nonscalable (non-default)

But it *is* the default...  since another commit:

commit 0d3441ae8a080c728abf17e90308c510e39e951b
Author: Hong Zhang <hzhang at mcs.anl.gov>
Date:   Mon Aug 24 16:40:35 2015 -0500

     add MatPtAPxxx_MPIAIJ_MPIAIJ_new

which changed the behaviour programmed in 0fc8cf34.  Is it normal?

Eric