[petsc-users] superlu ILUT preconditioner break

[Gong Ding]

BTW, this problem can be avoided by setting 
-mat_superlu_rowperm to NOROWPERM instead of default value LargeDiag


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> Several months ago, I posted message "superlu ILUT preconditioner break" with following link
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> http://lists.mcs.anl.gov/pipermail/petsc-users/2011-March/008355.html
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> Today I studied this problem carefully to see why it crashes.
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> The segment fault is arising at line 692 of superlu's dgsisx.c, because the array "perm" is 0.
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> This array which contains the permutation calculated from MC64 procedure, can only be initialized when nofact flag is true. However, petsc will call dgsisx twice, with nofact value 1 and 0, respectively.  In the second calling, the perm array is not initialized but be used. That's why the code crash.
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> Hope this bug can be fixed without too many efforts.
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> Gong Ding
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