<div>Here's what I get with this simple example (source and makefile also attached):</div><div><div><br></div><div><br></div><div>#include <petscksp.h></div><div><br></div><div>#undef __FUNCT__</div><div>#define __FUNCT__ "main"</div>
<div>int main(int argc,char **args)</div><div>{</div><div> KSP ksp;</div><div> PetscErrorCode ierr;</div><div> PetscInitialize(&argc,&args,(char*)0,(char*)0);</div><div> ierr = KSPCreate(PETSC_COMM_WORLD, &ksp);CHKERRQ(ierr);</div>
<div> ierr = KSPSetPCSide(ksp, PC_RIGHT);CHKERRQ(ierr);</div><div> ierr = KSPSetFromOptions(ksp);CHKERRQ(ierr);</div><div> ierr = KSPDestroy(&ksp);CHKERRQ(ierr);</div><div> PetscFinalize();</div><div>}</div><div>
<br>
</div><div><br></div><div>Then</div><div><div><br></div><div>[hal3 Tue Feb 26 09:34 PM] ~/petsc/dev/c/src/ksp/ksp/examples/tutorials/tmp >./ex -ksp_type preonly -ksp_pc_side left</div><div>[0]PETSC ERROR: --------------------- Error Message ------------------------------------</div>
<div>[0]PETSC ERROR: No support for this operation for this object type!</div><div>[0]PETSC ERROR: KSP preonly does not support RIGHT!</div><div>[0]PETSC ERROR: ------------------------------------------------------------------------</div>
<div>[0]PETSC ERROR: Petsc Development HG revision: 55699a42ce9360fb4641931ab7ec242cba302c58 HG Date: Mon Feb 25 22:15:44 2013 -0500</div><div>[0]PETSC ERROR: See docs/changes/index.html for recent updates.</div><div>[0]PETSC ERROR: See docs/faq.html for hints about trouble shooting.</div>
<div>[0]PETSC ERROR: See docs/index.html for manual pages.</div><div>[0]PETSC ERROR: ------------------------------------------------------------------------</div><div>[0]PETSC ERROR: ./ex on a arch-gxx-real named hal3 by karpeev Tue Feb 26 21:37:13 2013</div>
<div>[0]PETSC ERROR: Libraries linked from /home/karpeev/petsc/dev/c/arch-gxx-real/lib</div><div>[0]PETSC ERROR: Configure run at Tue Feb 26 17:50:35 2013</div><div>[0]PETSC ERROR: Configure options --PETSC_ARCH=arch-gxx-real --download-f-blas-lapack=1 --download-mpich=1 --with-cc=gcc --with-clanguage=C++ --with-cxx=g++ --with-dynamic-loading=1 --with-python=1 --with-scalar-type=real --with-shared-libraries=1</div>
<div>[0]PETSC ERROR: ------------------------------------------------------------------------</div><div>[0]PETSC ERROR: KSPSetUpNorms_Private() line 385 in /home/karpeev/petsc/dev/c/src/ksp/ksp/interface/itcreate.c</div>
<div>
[0]PETSC ERROR: KSPSetFromOptions() line 409 in /home/karpeev/petsc/dev/c/src/ksp/ksp/interface/itcl.c</div><div>[0]PETSC ERROR: main() line 13 in ex.c</div><div>application called MPI_Abort(MPI_COMM_WORLD, 56) - process 0</div>
<div>[unset]: aborting job:</div><div>application called MPI_Abort(MPI_COMM_WORLD, 56) - process 0</div><div>[hal3 Tue Feb 26 09:37 PM] ~/petsc/dev/c/src/ksp/ksp/examples/tutorials/tmp ></div></div><div><br></div><div>
The problem seems to be this clause in KSPSetUpNorms_Private():</div><div><div><br></div><div><br></div><div> if (ksp->normtype == KSP_NORM_DEFAULT && i == KSP_NORM_NONE && ksp->normsupporttable[i][j] <= 1) {</div>
<div> continue; /* Skip because we don't want to default to no norms unless set by the KSP (preonly). */</div></div><div><br></div><div><br></div><div>It is hit because of the code in KSPCreate_PREONLY() you quoted:</div>
<div><br></div><div> ierr = KSPSetSupportedNorm(ksp,KSP_NORM_NONE,PC_LEFT,2);CHKERRQ(ierr); /* LEFT/RIGHT is arbitrary, so "support" both */<br> ierr = KSPSetSupportedNorm(ksp,KSP_NORM_NONE,PC_RIGHT,1);CHKERRQ(ierr);<br>
</div><div><br></div><div>The problem is that PC_RIGHT is preferred by KSP_NORM only with priority 1, which is too weak to overcome</div><div>that "continue" clause above.</div><div><br></div><div>One way to fix it is to jack up the priority of PC_RIGHT, but I still don't understand why this combination</div>
<div>of norms and pc sides is being figured out in KSPSetFromOptions() (twice) with only partial KSP data.</div><div>And then again, this time "for real", in KSPSetUp().</div><div><br></div><div>Dmitry.</div><div>
<br><div class="gmail_quote">On Wed, Feb 27, 2013 at 2:52 AM, Barry Smith <span dir="ltr"><<a href="mailto:bsmith@mcs.anl.gov" target="_blank">bsmith@mcs.anl.gov</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="im"><br>
On Feb 26, 2013, at 4:44 PM, Dmitry Karpeev <<a href="mailto:karpeev@mcs.anl.gov">karpeev@mcs.anl.gov</a>> wrote:<br>
<br>
> These calls compute default values for normtype and pcside based on partial KSP options,<br>
> which can cause an unwarranted error to be thrown.<br>
> For example, in code there may be<br>
><br>
> KSPSetPCSide(ksp, PC_RIGHT); /* hardwired default, e.g., in Moose. */<br>
><br>
> Now, when I'm using command-line arguments<br>
> -ksp_type preonly<br>
> an error is thrown, since KSPPREONLY doesn't work with PC_RIGHT.<br>
<br>
</div> Huh?<br>
<br>
EXTERN_C_BEGIN<br>
#undef __FUNCT__<br>
#define __FUNCT__ "KSPCreate_PREONLY"<br>
PetscErrorCode KSPCreate_PREONLY(KSP ksp)<br>
{<br>
PetscErrorCode ierr;<br>
<br>
PetscFunctionBegin;<br>
ierr = KSPSetSupportedNorm(ksp,KSP_NORM_NONE,PC_LEFT,2);CHKERRQ(ierr); /* LEFT/RIGHT is arbitrary, so "support" both */<br>
ierr = KSPSetSupportedNorm(ksp,KSP_NORM_NONE,PC_RIGHT,1);CHKERRQ(ierr);<br>
<br>
Is it because MOOSE also hardwires the norm type and preonly doesn't support it? What is the full and complete error message.<br>
<div class="im"><br>
> Fine, I try<br>
> -ksp_type preonly -ksp_pc_side left<br>
> but still get the same error, since KSPSetUpNorms_Private() is called after KSP type has been set to KSPPREONLY,<br>
> but BEFORE there was a chance to set the PC side!<br>
><br>
> Is there any reason to keep these calls to KSPSetUpNorms_Private() in KSPSetFromOptions()?<br>
<br>
</div> I think they are there so that users can overwrite them in the rest of KSPSetFromOptions(). If you move them to KSPSetUp() then the user cannot reset them.<br>
<span class="HOEnZb"><font color="#888888"><br>
Barry<br>
</font></span><div class="HOEnZb"><div class="h5"><br>
<br>
> KSPSetUpNorms_Private() will be just about the first thing called in KSPSetUp() and will compute the appropriate normtype and pcside,<br>
> but now based on complete KSP options.<br>
><br>
> Not to mention that calling XXXSetUp_YYY() XXXSetFromOptions() seems generally contrary to PETSc's design<br>
> philosophy.<br>
><br>
> Dmitry.<br>
><br>
><br>
<br>
</div></div></blockquote></div><br><br clear="all"><div><br></div>
</div></div>