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I have the linear system Ax=b which solve using mkl pardiso

Number of nonzeros in factors = 697828

Number of factorization MFLOPS = 593

It works well and correct. The system is sparse around main diagonal. But when I add additional subdiagonals far left and ar far right from main diagonal, then I have an error when calling function PARDISO (pt, &maxfct, &mnum, &mtype, &phase,

&n, a, ia, ja, &idum, &nrhs, iparm, &msglvl, &ddum, &ddum, &error);

"Exception at 0x7ffd4633ff10, code: 0xc0000005: write access violation at: 0xf, flags=0x0 (first chance)"

Debug:

1 mkl_pds_lp64_zsytrs_bklbw_pardiso mkl_core_1 0x7ffd4633ff10

2 mkl_pds_lp64_zsytrs_bklbw_pardiso mkl_core_1 0x7ffd45dde773

3 mkl_pds_lp64_zsytrs_bklbw_pardiso mkl_core_1 0x7ffd45ddab62

4 mkl_pds_lp64_metis_mlevelnodebisectionmultiple mkl_core_1 0x7ffd45a5283f

5 mkl_pds_lp64_metis_mlevelnesteddissection_pardiso mkl_sequential_1 0x7ffd602e5767

6 mkl_pds_lp64_metis_mlevelnesteddissection_pardiso mkl_sequential_1 0x7ffd602e5915

7 mkl_pds_lp64_metis_splitgraphorder mkl_core_1 0x7ffd45a53d8b

8 mkl_pds_lp64_zsytrs_bklbw_pardiso mkl_core_1 0x7ffd46372b74

9 mkl_pds_lp64_zsytrs_bklbw_pardiso mkl_core_1 0x7ffd4633df19

10 mkl_pds_lp64_zsytrs_bklbw_pardiso mkl_core_1 0x7ffd45dd52bf

11 mkl_pds_lp64_pardiso mkl_core_1 0x7ffd45a6087b

Iparam:

iparm[0] = 1; /* No solver default */

iparm[1] = 2; /* Fill-in reordering from METIS */

iparm[3] = 0; /* No iterative-direct algorithm */

iparm[4] = 0; /* No user fill-in reducing permutation */

iparm[5] = 0; /* Write solution into x */

iparm[6] = 0; /* Not in use */

iparm[7] = 2; /* Max numbers of iterative refinement steps */

iparm[8] = 0; /* Not in use */

iparm[9] = 13; /* Perturb the pivot elements with 1E-13 */

iparm[10] = 1; /* Use nonsymmetric permutation and scaling MPS */

iparm[11] = 0; /* Conjugate transposed/transpose solve */

iparm[12] = 1; /* Maximum weighted matching algorithm is switched-on (default for non-symmetric) */

iparm[13] = 0; /* Output: Number of perturbed pivots */

iparm[14] = 0; /* Not in use */

iparm[15] = 0; /* Not in use */

iparm[16] = 0; /* Not in use */

iparm[17] = -1; /* Output: Number of nonzeros in the factor LU */

iparm[18] = -1; /* Output: Mflops for LU factorization */

iparm[19] = 0; /* Output: Numbers of CG Iterations */

//iparm[20] = 0;

//iparm[23]=0;

maxfct = 1; /* Maximum number of numerical factorizations. */

mnum = 1; /* Which factorization to use. */

Software: MSVC2019, QT 5.15, win 10 x64, mkl 2021.3.0

Thanks

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Thanks a lot Kirill.

Hi Alexey,

If this resolves your issue, make sure to accept this as a solution. This would help others with similar issue.

Thanks!

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Hi Alexey,

Please turn on matrix checker (iparm[26]=1). It is very likely that something is not right about the matrix pattern (ia, ja). Also check that the indexing and matrix type is set right for the input matrix (e.g., for symmetric matrix types like -2 one needs to pass only the upper triangular part of the matrix).

In case you get no new insight into the problem, please share with us a reproducer.

Best,

Kirill

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Thank you very much. You are absolutely right.

With help of iparm[26]=1 the problem was solved.

Alexey.

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Thanks a lot Kirill.

Hi Alexey,

If this resolves your issue, make sure to accept this as a solution. This would help others with similar issue.

Thanks!

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Hi Alexey,

Thanks for the confirmation and glad to know that your issue is resolved. If you need any additional information, please post a new question as this thread will no longer be monitored by Intel.

Thanks!

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