[petsc-users] MKL Pardiso Solver Execution Step control

[Smith, Barry F.]

> On Jun 4, 2018, at 10:32 PM, Matthew Overholt <overholt at capesim.com> wrote:
> 
> Hello,
> 
> I am using KSP in KSPPREONLY mode to do a direct solve on an A*x = b system, with solver algorithms MUMPS, CPardiso and Pardiso.  For Pardiso, is it possible to control the solver execution step (denoted "phase" in Intel's docs)?  I would like to be able to control when it refactors as one can when calling it directly.

   Matt,

     This is handled automatically by PETSc. If the matrix entries change than PETSc will automatically call the correct code to perform a new numerical factorization; if the matrix entries are not changed then it will not refactor the matrix. I am not sure if it makes sense for a user to be setting different phase values since it is handled automatically. Could you explain your exact use case where you would like to control the phase variable directly?

    Barry

> 
> https://software.intel.com/en-us/mkl-developer-reference-c-pardiso
> 
> If so, please give me the details, since I can't see how to do it from the MATSOLVERMKL_PARDISO docs page (which is clearly listing the iparm[] flags).
> 
> Thank you.
> 
> Matt Overholt
> CapeSym, Inc.
> (508) 653-7100 x204
> overholt at capesim.com
>