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I'll try to do it in maint. Hong</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Jose E. Roman <jroman@dsic.upv.es><br>
<b>Sent:</b> Thursday, April 23, 2020 2:36 AM<br>
<b>To:</b> Pierre Jolivet <pierre.jolivet@enseeiht.fr><br>
<b>Cc:</b> Zhang, Hong <hzhang@mcs.anl.gov>; Stefano Zampini <stefano.zampini@gmail.com>; petsc-dev <petsc-dev@mcs.anl.gov>; Smith, Barry F. <bsmith@mcs.anl.gov><br>
<b>Subject:</b> Re: [petsc-dev] MATOP_MAT_MULT</font>
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<div class="PlainText">I agree with Pierre. However, if the fix involves an API change then I could understand it goes to master.<br>
<br>
<br>
> El 23 abr 2020, a las 7:43, Pierre Jolivet <pierre.jolivet@enseeiht.fr> escribió:<br>
> <br>
> I don’t know if you really meant to ask for José's opinion here, but I personally think that releasing all 3.13.X version with a broken MatMatMult and no deprecation warning concerning MATOP_MAT_MULT is not the best.<br>
> Thanks,<br>
> Pierre<br>
> <br>
>> On 23 Apr 2020, at 4:03 AM, Zhang, Hong <hzhang@mcs.anl.gov> wrote:<br>
>> <br>
>> Jose,<br>
>> I'll check and fix them. I have to do it in master, is ok?<br>
>> Hong<br>
>> <br>
>> From: Pierre Jolivet <pierre.jolivet@enseeiht.fr><br>
>> Sent: Wednesday, April 22, 2020 3:08 PM<br>
>> To: Zhang, Hong <hzhang@mcs.anl.gov><br>
>> Cc: Jose E. Roman <jroman@dsic.upv.es>; Stefano Zampini <stefano.zampini@gmail.com>; petsc-dev <petsc-dev@mcs.anl.gov>; Smith, Barry F. <bsmith@mcs.anl.gov><br>
>> Subject: Re: [petsc-dev] MATOP_MAT_MULT<br>
>> <br>
>> Hong,<br>
>> I also now just tested some previously PETSC_VERSION_LT(3,13,0) running code with C=A*B, Dense=Nest*Dense, all previously allocated prior to a call to MatMatMult and scall = MAT_REUSE_MATRIX.<br>
>> Sadly, it’s now broken. It is my fault for not having a test for this in <a href="https://gitlab.com/petsc/petsc/-/merge_requests/2069">
https://gitlab.com/petsc/petsc/-/merge_requests/2069</a>, sorry about that.<br>
>> [0]PETSC ERROR: Call MatProductSymbolic() first<br>
>> [0]PETSC ERROR: #1 MatProductNumeric() line 730 in /ccc/work/cont003/rndm/rndm/petsc/src/mat/interface/matproduct.c<br>
>> [0]PETSC ERROR: #2 MatMatMult() line 9335 in /ccc/work/cont003/rndm/rndm/petsc/src/mat/interface/matrix.c<br>
>> <br>
>> Here is a reproducer (that will work OK with 3.12.4).<br>
>> diff --git a/src/mat/tests/ex195.c b/src/mat/tests/ex195.c<br>
>> index c72662bc3c..811de669c5 100644<br>
>> --- a/src/mat/tests/ex195.c<br>
>> +++ b/src/mat/tests/ex195.c<br>
>> @@ -73,2 +73,3 @@ int main(int argc,char **args)<br>
>> ierr = MatMatMult(nest,B,MAT_REUSE_MATRIX,PETSC_DEFAULT,&C);CHKERRQ(ierr);<br>
>> + ierr = MatMatMult(nest,C,MAT_REUSE_MATRIX,PETSC_DEFAULT,&B);CHKERRQ(ierr);<br>
>> ierr = MatMatMultEqual(nest,B,C,10,&equal);CHKERRQ(ierr);<br>
>> <br>
>> $ make -f gmakefile test searchin=mat_tests-ex195<br>
>> <br>
>> I believe this is very close to the topic at hand and issue #608, so maybe you could fix this as well in the same upcoming MR? Just let me know, I can have a crack it otherwise.<br>
>> Thanks,<br>
>> Pierre<br>
>> <br>
>>> On 22 Apr 2020, at 5:38 PM, Zhang, Hong <hzhang@mcs.anl.gov> wrote:<br>
>>> <br>
>>> Jose, Pierre and Stefano,<br>
>>> Now I understand the issue that Stefano raised. I plan to add<br>
>>> MatProductIsSupported(Wmat,&supported,&matproductsetfromoptions)<br>
>>> the flag 'supported' tells if the product is supported/implemented or not,<br>
>>> and the function pointer 'matproductsetfromoptions' gives the name of MatProductSetFromOptions_xxx, (including basic implementation) or NULL.<br>
>>> <br>
>>> Let me know your suggestions. I'll list all of you as reviewer.<br>
>>> Hong<br>
>>> <br>
>>> <br>
>>> From: Jose E. Roman <jroman@dsic.upv.es><br>
>>> Sent: Wednesday, April 22, 2020 9:07 AM<br>
>>> To: Stefano Zampini <stefano.zampini@gmail.com><br>
>>> Cc: Zhang, Hong <hzhang@mcs.anl.gov>; Pierre Jolivet <pierre.jolivet@enseeiht.fr>; petsc-dev <petsc-dev@mcs.anl.gov><br>
>>> Subject: Re: [petsc-dev] MATOP_MAT_MULT<br>
>>> <br>
>>> I agree with Pierre and Stefano.<br>
>>> Hong: your proposed solution would be fine, but MATOP_MATPRODUCT does not exist yet, so I cannot try it.<br>
>>> I would like a solution along the lines of what Stefano suggests. It is not too much trouble if it goes to master instead of maint.<br>
>>> <br>
>>> Thanks.<br>
>>> Jose<br>
>>> <br>
>>> <br>
>>> > El 22 abr 2020, a las 15:26, Stefano Zampini <stefano.zampini@gmail.com> escribió:<br>
>>> > <br>
>>> > <br>
>>> >> <br>
>>> >> MatProductCreateWithMat(A,Vmat,NULL,Wmat);<br>
>>> >> MatProductSetType(Wmat,MATPRODUCT_AB);<br>
>>> >> MatHasOperation(Wmat,MATOP_MATPRODUCT,&flg); //new support, it calls MatProductSetFromOptions(Wmat)<br>
>>> > <br>
>>> > Hong, this would go in the direction I was outlining here <a href="https://gitlab.com/petsc/petsc/-/issues/608">
https://gitlab.com/petsc/petsc/-/issues/608</a><br>
>>> > How about also adding something like<br>
>>> > <br>
>>> > MatProductIsImplemented(Wmat,&flg)<br>
>>> > <br>
>>> > That returns true if a specific implementation is available? This way<br>
>>> > <br>
>>> > This way, if we use both queries, we can assess the presence of the basic fallbacks too, i.e.<br>
>>> > <br>
>>> > MatHasOperation(Wmat,MATOP_MATPRODUCT,&flg1)<br>
>>> > MatProductIsImplemented(Wmat,&flg2)<br>
>>> > <br>
>>> > If flg1 is false, no support at all<br>
>>> > If flg1 is true and flg2 is false -> Basic implementation (i.e, MatShell with products inside)<br>
>>> > If flg1 and flg2 are both true -> Specific implementation available.<br>
>>> > <br>
>>> >> if (V->vmm && flg) {<br>
>>> >> MatProductSymbolic(Wmat);<br>
>>> >> MatProductNumeric(Wmat);<br>
>>> >> } else {<br>
>>> >> MatDestroy(Wmat);<br>
>>> >> ...<br>
>>> >> }<br>
>>> >> Hong<br>
>>> >> <br>
>>> >> <br>
>>> >> From: Jose E. Roman <jroman@dsic.upv.es><br>
>>> >> Sent: Tuesday, April 21, 2020 11:21 AM<br>
>>> >> To: Pierre Jolivet <pierre.jolivet@enseeiht.fr><br>
>>> >> Cc: Zhang, Hong <hzhang@mcs.anl.gov>; petsc-dev <petsc-dev@mcs.anl.gov><br>
>>> >> Subject: Re: [petsc-dev] MATOP_MAT_MULT<br>
>>> >> <br>
>>> >> <br>
>>> >> <br>
>>> >> > El 21 abr 2020, a las 17:53, Pierre Jolivet <pierre.jolivet@enseeiht.fr> escribió:<br>
>>> >> > <br>
>>> >> > <br>
>>> >> > <br>
>>> >> >> On 21 Apr 2020, at 5:22 PM, Zhang, Hong <hzhang@mcs.anl.gov> wrote:<br>
>>> >> >> <br>
>>> >> >> Pierre,<br>
>>> >> >> MatMatMult_xxx() is removed from MatOps table.<br>
>>> >> > <br>
>>> >> > Shouldn’t there be a deprecation notice somewhere?<br>
>>> >> > There is nothing about MATOP_MAT_MULT in the 3.13 changelog <a href="https://www.mcs.anl.gov/petsc/documentation/changes/313.html">
https://www.mcs.anl.gov/petsc/documentation/changes/313.html</a><br>
>>> >> > For example, I see that in SLEPc, José is currently making these checks, which are in practice useless as they always return PETSC_FALSE?https://gitlab.com/slepc/slepc/-/blob/master/src/sys/classes/bv/impls/contiguous/contig.c#L191<br>
>>> >> > (Maybe José is aware of this and this is just for testing)<br>
>>> >> <br>
>>> >> No, I was not aware of this. Thanks for bringing this up. Now in 3.13 we are always doing the slow version (column by column), so yes I am interested in a solution for this.<br>
>>> >> <br>
>>> >> > <br>
>>> >> >> MatMatMult() is replaced by<br>
>>> >> >> MatProductCreate()<br>
>>> >> >> MatProductSetType(,MATPRODUCT_AB)<br>
>>> >> >> MatProductSetFromOptions()<br>
>>> >> >> MatProductSymbolic()<br>
>>> >> >> MatProductNumeric()<br>
>>> >> >> <br>
>>> >> >> Where/when do you need query a single matrix for its product operation?<br>
>>> >> > <br>
>>> >> > I didn’t want to bother at first with the new API, because I’m only interested in C = A*B with C and B being dense.<br>
>>> >> > Of course, I can update my code, but if I understand Stefano’s issue correctly, and let’s say my A is of type SBAIJ, for which there is no MatMatMult, the code will now error out in the MatProduct?<br>
>>> >> > There is no fallback mechanism? Meaning I could in fact _not_ use the new API and will just have to loop on all columns of B, even for AIJ matrices.<br>
>>> >> > <br>
>>> >> > Thanks,<br>
>>> >> > Pierre<br>
>>> >> > <br>
>>> >> >> Hong<br>
>>> >> >> <br>
>>> >> >> From: petsc-dev <petsc-dev-bounces@mcs.anl.gov> on behalf of Pierre Jolivet <pierre.jolivet@enseeiht.fr><br>
>>> >> >> Sent: Tuesday, April 21, 2020 7:50 AM<br>
>>> >> >> To: petsc-dev <petsc-dev@mcs.anl.gov><br>
>>> >> >> Subject: [petsc-dev] MATOP_MAT_MULT<br>
>>> >> >> <br>
>>> >> >> Hello,<br>
>>> >> >> Am I seeing this correctly?<br>
>>> >> >> #include <petsc.h><br>
>>> >> >> <br>
>>> >> >> int main(int argc,char **args)<br>
>>> >> >> {<br>
>>> >> >> Mat A;<br>
>>> >> >> PetscBool hasMatMult;<br>
>>> >> >> PetscErrorCode ierr;<br>
>>> >> >> <br>
>>> >> >> ierr = PetscInitialize(&argc,&args,NULL,NULL);if (ierr) return ierr;<br>
>>> >> >> ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr);<br>
>>> >> >> ierr = MatSetType(A,MATMPIAIJ);CHKERRQ(ierr);<br>
>>> >> >> ierr = MatHasOperation(A,MATOP_MAT_MULT,&hasMatMult);CHKERRQ(ierr);<br>
>>> >> >> printf("%s\n", PetscBools[hasMatMult]);<br>
>>> >> >> ierr = PetscFinalize();<br>
>>> >> >> return ierr;<br>
>>> >> >> }<br>
>>> >> >> <br>
>>> >> >> => FALSE<br>
>>> >> >> <br>
>>> >> >> I believe this is a regression (or at least an undocumented change) introduced here:https://gitlab.com/petsc/petsc/-/merge_requests/2524/<br>
>>> >> >> I also believe Stefano raised a similar point there: <a href="https://gitlab.com/petsc/petsc/-/issues/608">
https://gitlab.com/petsc/petsc/-/issues/608</a><br>
>>> >> >> This is a performance killer in my case because I was previously using this check to know whether I could use MatMatMult or had to loop on all columns and call MatMult on all of them.<br>
>>> >> >> There is also a bunch of (previously functioning but now) broken code, e.g.,https://www.mcs.anl.gov/petsc/petsc-current/src/mat/impls/transpose/transm.c.html#line105or
<a href="https://www.mcs.anl.gov/petsc/petsc-current/src/mat/impls/nest/matnest.c.html#line2105">
https://www.mcs.anl.gov/petsc/petsc-current/src/mat/impls/nest/matnest.c.html#line2105</a><br>
>>> >> >> Is this being addressed/documented?<br>
>>> >> >> <br>
>>> >> >> Thanks,<br>
>>> >> >> Pierre<br>
>>> >> > <br>
>>> ><br>
> <br>
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